* Re: [PATCH net] sctp: fix the issue that flags are ignored when using kernel_connect
From: Marcelo Ricardo Leitner @ 2018-05-21 15:52 UTC (permalink / raw)
To: Xin Long; +Cc: network dev, linux-sctp, davem, Neil Horman, mkubecek
In-Reply-To: <4863916c3e574b0d860725466d7d4a2f445fbe5b.1526805550.git.lucien.xin@gmail.com>
On Sun, May 20, 2018 at 04:39:10PM +0800, Xin Long wrote:
> Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags
> param can't be passed into its proto .connect where this flags is really
> needed.
>
> sctp works around it by getting flags from socket file in __sctp_connect.
> It works for connecting from userspace, as inherently the user sock has
> socket file and it passes f_flags as the flags param into the proto_ops
> .connect.
>
> However, the sock created by sock_create_kern doesn't have a socket file,
> and it passes the flags (like O_NONBLOCK) by using the flags param in
> kernel_connect, which calls proto_ops .connect later.
>
> So to fix it, this patch defines a new proto_ops .connect for sctp,
> sctp_inet_connect, which calls __sctp_connect() directly with this
> flags param. After this, the sctp's proto .connect can be removed.
>
> Note that sctp_inet_connect doesn't need to do some checks that are not
> needed for sctp, which makes thing better than with inet_dgram_connect.
>
> Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
> ---
> include/net/sctp/sctp.h | 2 ++
> net/sctp/ipv6.c | 2 +-
> net/sctp/protocol.c | 2 +-
> net/sctp/socket.c | 51 +++++++++++++++++++++++++++++++++----------------
> 4 files changed, 39 insertions(+), 18 deletions(-)
>
> diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> index 28b996d..35498e6 100644
> --- a/include/net/sctp/sctp.h
> +++ b/include/net/sctp/sctp.h
> @@ -103,6 +103,8 @@ void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
> /*
> * sctp/socket.c
> */
> +int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
> + int addr_len, int flags);
> int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
> int sctp_inet_listen(struct socket *sock, int backlog);
> void sctp_write_space(struct sock *sk);
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 4224711..0cd2e76 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -1006,7 +1006,7 @@ static const struct proto_ops inet6_seqpacket_ops = {
> .owner = THIS_MODULE,
> .release = inet6_release,
> .bind = inet6_bind,
> - .connect = inet_dgram_connect,
> + .connect = sctp_inet_connect,
> .socketpair = sock_no_socketpair,
> .accept = inet_accept,
> .getname = sctp_getname,
> diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
> index d685f84..6bf0a99 100644
> --- a/net/sctp/protocol.c
> +++ b/net/sctp/protocol.c
> @@ -1012,7 +1012,7 @@ static const struct proto_ops inet_seqpacket_ops = {
> .owner = THIS_MODULE,
> .release = inet_release, /* Needs to be wrapped... */
> .bind = inet_bind,
> - .connect = inet_dgram_connect,
> + .connect = sctp_inet_connect,
> .socketpair = sock_no_socketpair,
> .accept = inet_accept,
> .getname = inet_getname, /* Semantics are different. */
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index 80835ac..ae7e7c6 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -1086,7 +1086,7 @@ static int sctp_setsockopt_bindx(struct sock *sk,
> */
> static int __sctp_connect(struct sock *sk,
> struct sockaddr *kaddrs,
> - int addrs_size,
> + int addrs_size, int flags,
> sctp_assoc_t *assoc_id)
> {
> struct net *net = sock_net(sk);
> @@ -1104,7 +1104,6 @@ static int __sctp_connect(struct sock *sk,
> union sctp_addr *sa_addr = NULL;
> void *addr_buf;
> unsigned short port;
> - unsigned int f_flags = 0;
>
> sp = sctp_sk(sk);
> ep = sp->ep;
> @@ -1254,13 +1253,7 @@ static int __sctp_connect(struct sock *sk,
> sp->pf->to_sk_daddr(sa_addr, sk);
> sk->sk_err = 0;
>
> - /* in-kernel sockets don't generally have a file allocated to them
> - * if all they do is call sock_create_kern().
> - */
> - if (sk->sk_socket->file)
> - f_flags = sk->sk_socket->file->f_flags;
> -
> - timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
> + timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
>
> if (assoc_id)
> *assoc_id = asoc->assoc_id;
> @@ -1348,7 +1341,7 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
> sctp_assoc_t *assoc_id)
> {
> struct sockaddr *kaddrs;
> - int err = 0;
> + int err = 0, flags = 0;
>
> pr_debug("%s: sk:%p addrs:%p addrs_size:%d\n",
> __func__, sk, addrs, addrs_size);
> @@ -1367,7 +1360,13 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
> if (err)
> goto out_free;
>
> - err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
> + /* in-kernel sockets don't generally have a file allocated to them
> + * if all they do is call sock_create_kern().
> + */
> + if (sk->sk_socket->file)
> + flags = sk->sk_socket->file->f_flags;
> +
> + err = __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id);
>
> out_free:
> kvfree(kaddrs);
> @@ -4397,16 +4396,26 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
> * len: the size of the address.
> */
> static int sctp_connect(struct sock *sk, struct sockaddr *addr,
> - int addr_len)
> + int addr_len, int flags)
> {
> - int err = 0;
> + struct inet_sock *inet = inet_sk(sk);
> struct sctp_af *af;
> + int err = 0;
>
> lock_sock(sk);
>
> pr_debug("%s: sk:%p, sockaddr:%p, addr_len:%d\n", __func__, sk,
> addr, addr_len);
>
> + /* We may need to bind the socket. */
> + if (!inet->inet_num) {
> + if (sk->sk_prot->get_port(sk, 0)) {
> + release_sock(sk);
> + return -EAGAIN;
> + }
> + inet->inet_sport = htons(inet->inet_num);
> + }
> +
> /* Validate addr_len before calling common connect/connectx routine. */
> af = sctp_get_af_specific(addr->sa_family);
> if (!af || addr_len < af->sockaddr_len) {
> @@ -4415,13 +4424,25 @@ static int sctp_connect(struct sock *sk, struct sockaddr *addr,
> /* Pass correct addr len to common routine (so it knows there
> * is only one address being passed.
> */
> - err = __sctp_connect(sk, addr, af->sockaddr_len, NULL);
> + err = __sctp_connect(sk, addr, af->sockaddr_len, flags, NULL);
> }
>
> release_sock(sk);
> return err;
> }
>
> +int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
> + int addr_len, int flags)
> +{
> + if (addr_len < sizeof(uaddr->sa_family))
> + return -EINVAL;
> +
> + if (uaddr->sa_family == AF_UNSPEC)
> + return -EOPNOTSUPP;
> +
> + return sctp_connect(sock->sk, uaddr, addr_len, flags);
> +}
> +
> /* FIXME: Write comments. */
> static int sctp_disconnect(struct sock *sk, int flags)
> {
> @@ -8724,7 +8745,6 @@ struct proto sctp_prot = {
> .name = "SCTP",
> .owner = THIS_MODULE,
> .close = sctp_close,
> - .connect = sctp_connect,
> .disconnect = sctp_disconnect,
> .accept = sctp_accept,
> .ioctl = sctp_ioctl,
> @@ -8767,7 +8787,6 @@ struct proto sctpv6_prot = {
> .name = "SCTPv6",
> .owner = THIS_MODULE,
> .close = sctp_close,
> - .connect = sctp_connect,
> .disconnect = sctp_disconnect,
> .accept = sctp_accept,
> .ioctl = sctp_ioctl,
> --
> 2.1.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-sctp" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
^ permalink raw reply
* [PATCH v2 bpf-next 0/3] bpf: Add MTU check to fib lookup helper
From: dsahern @ 2018-05-21 16:08 UTC (permalink / raw)
To: netdev, borkmann, ast; +Cc: davem, David Ahern
From: David Ahern <dsahern@gmail.com>
Packets that exceed the egress MTU can not be forwarded in the fast path.
Add IPv4 and IPv6 MTU helpers that take a FIB lookup result (versus the
typical dst path) and add the calls to bpf_ipv{4,6}_fib_lookup.
v2
- add ip6_mtu_from_fib6 to ipv6_stub
- only call the new MTU helpers for fib lookups in XDP path; skb
path uses is_skb_forwardable to determine if the packet can be
sent via the egress device from the FIB lookup
David Ahern (3):
net/ipv4: Add helper to return path MTU based on fib result
net/ipv6: Add helper to return path MTU based on fib result
bpf: Add mtu checking to FIB forwarding helper
include/net/addrconf.h | 2 ++
include/net/ip6_fib.h | 6 ++++++
include/net/ip6_route.h | 3 +++
include/net/ip_fib.h | 2 ++
net/core/filter.c | 42 +++++++++++++++++++++++++++++++++++-------
net/ipv4/route.c | 31 +++++++++++++++++++++++++++++++
net/ipv6/addrconf_core.c | 8 ++++++++
net/ipv6/af_inet6.c | 1 +
net/ipv6/route.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
9 files changed, 136 insertions(+), 7 deletions(-)
--
2.11.0
^ permalink raw reply
* [PATCH v2 bpf-next 1/3] net/ipv4: Add helper to return path MTU based on fib result
From: dsahern @ 2018-05-21 16:08 UTC (permalink / raw)
To: netdev, borkmann, ast; +Cc: davem, David Ahern
In-Reply-To: <20180521160816.7060-1-dsahern@kernel.org>
From: David Ahern <dsahern@gmail.com>
Determine path MTU from a FIB lookup result. Logic is a distillation of
ip_dst_mtu_maybe_forward.
Signed-off-by: David Ahern <dsahern@gmail.com>
---
include/net/ip_fib.h | 2 ++
net/ipv4/route.c | 31 +++++++++++++++++++++++++++++++
2 files changed, 33 insertions(+)
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 81d0f2107ff1..69c91d1934c1 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -449,4 +449,6 @@ static inline void fib_proc_exit(struct net *net)
}
#endif
+u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr);
+
#endif /* _NET_FIB_H */
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 29268efad247..ac3b22bc51b2 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1352,6 +1352,37 @@ static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
return NULL;
}
+/* MTU selection:
+ * 1. mtu on route is locked - use it
+ * 2. mtu from nexthop exception
+ * 3. mtu from egress device
+ */
+
+u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr)
+{
+ struct fib_info *fi = res->fi;
+ struct fib_nh *nh = &fi->fib_nh[res->nh_sel];
+ struct net_device *dev = nh->nh_dev;
+ u32 mtu = 0;
+
+ if (dev_net(dev)->ipv4.sysctl_ip_fwd_use_pmtu ||
+ fi->fib_metrics->metrics[RTAX_LOCK - 1] & (1 << RTAX_MTU))
+ mtu = fi->fib_mtu;
+
+ if (likely(!mtu)) {
+ struct fib_nh_exception *fnhe;
+
+ fnhe = find_exception(nh, daddr);
+ if (fnhe && !time_after_eq(jiffies, fnhe->fnhe_expires))
+ mtu = fnhe->fnhe_pmtu;
+ }
+
+ if (likely(!mtu))
+ mtu = min(READ_ONCE(dev->mtu), IP_MAX_MTU);
+
+ return mtu - lwtunnel_headroom(nh->nh_lwtstate, mtu);
+}
+
static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
__be32 daddr, const bool do_cache)
{
--
2.11.0
^ permalink raw reply related
* [PATCH v2 bpf-next 3/3] bpf: Add mtu checking to FIB forwarding helper
From: dsahern @ 2018-05-21 16:08 UTC (permalink / raw)
To: netdev, borkmann, ast; +Cc: davem, David Ahern
In-Reply-To: <20180521160816.7060-1-dsahern@kernel.org>
From: David Ahern <dsahern@gmail.com>
Add check that egress MTU can handle packet to be forwarded. If
the MTU is less than the packet length, return 0 meaning the
packet is expected to continue up the stack for help - eg.,
fragmenting the packet or sending an ICMP.
The XDP path needs to leverage the FIB entry for an MTU on the
route spec or an exception entry for a given destination. The
skb path lets is_skb_forwardable decide if the packet can be
sent.
Signed-off-by: David Ahern <dsahern@gmail.com>
---
net/core/filter.c | 42 +++++++++++++++++++++++++++++++++++-------
1 file changed, 35 insertions(+), 7 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index aec5ebafb262..ba3ff5aa575a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4089,7 +4089,7 @@ static int bpf_fib_set_fwd_params(struct bpf_fib_lookup *params,
#if IS_ENABLED(CONFIG_INET)
static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
- u32 flags)
+ u32 flags, bool check_mtu)
{
struct in_device *in_dev;
struct neighbour *neigh;
@@ -4098,6 +4098,7 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
struct fib_nh *nh;
struct flowi4 fl4;
int err;
+ u32 mtu;
dev = dev_get_by_index_rcu(net, params->ifindex);
if (unlikely(!dev))
@@ -4149,6 +4150,12 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
if (res.fi->fib_nhs > 1)
fib_select_path(net, &res, &fl4, NULL);
+ if (check_mtu) {
+ mtu = ip_mtu_from_fib_result(&res, params->ipv4_dst);
+ if (params->tot_len > mtu)
+ return 0;
+ }
+
nh = &res.fi->fib_nh[res.nh_sel];
/* do not handle lwt encaps right now */
@@ -4177,7 +4184,7 @@ static int bpf_ipv4_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
#if IS_ENABLED(CONFIG_IPV6)
static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
- u32 flags)
+ u32 flags, bool check_mtu)
{
struct in6_addr *src = (struct in6_addr *) params->ipv6_src;
struct in6_addr *dst = (struct in6_addr *) params->ipv6_dst;
@@ -4188,6 +4195,7 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
struct flowi6 fl6;
int strict = 0;
int oif;
+ u32 mtu;
/* link local addresses are never forwarded */
if (rt6_need_strict(dst) || rt6_need_strict(src))
@@ -4250,6 +4258,12 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
fl6.flowi6_oif, NULL,
strict);
+ if (check_mtu) {
+ mtu = ipv6_stub->ip6_mtu_from_fib6(f6i, dst, src);
+ if (params->tot_len > mtu)
+ return 0;
+ }
+
if (f6i->fib6_nh.nh_lwtstate)
return 0;
@@ -4282,12 +4296,12 @@ BPF_CALL_4(bpf_xdp_fib_lookup, struct xdp_buff *, ctx,
#if IS_ENABLED(CONFIG_INET)
case AF_INET:
return bpf_ipv4_fib_lookup(dev_net(ctx->rxq->dev), params,
- flags);
+ flags, true);
#endif
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
return bpf_ipv6_fib_lookup(dev_net(ctx->rxq->dev), params,
- flags);
+ flags, true);
#endif
}
return 0;
@@ -4306,20 +4320,34 @@ static const struct bpf_func_proto bpf_xdp_fib_lookup_proto = {
BPF_CALL_4(bpf_skb_fib_lookup, struct sk_buff *, skb,
struct bpf_fib_lookup *, params, int, plen, u32, flags)
{
+ struct net *net = dev_net(skb->dev);
+ int index = 0;
+
if (plen < sizeof(*params))
return -EINVAL;
switch (params->family) {
#if IS_ENABLED(CONFIG_INET)
case AF_INET:
- return bpf_ipv4_fib_lookup(dev_net(skb->dev), params, flags);
+ index = bpf_ipv4_fib_lookup(net, params, flags, false);
+ break;
#endif
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
- return bpf_ipv6_fib_lookup(dev_net(skb->dev), params, flags);
+ index = bpf_ipv6_fib_lookup(net, params, flags, false);
+ break;
#endif
}
- return -ENOTSUPP;
+
+ if (index > 0) {
+ struct net_device *dev;
+
+ dev = dev_get_by_index_rcu(net, index);
+ if (!is_skb_forwardable(dev, skb))
+ index = 0;
+ }
+
+ return index;
}
static const struct bpf_func_proto bpf_skb_fib_lookup_proto = {
--
2.11.0
^ permalink raw reply related
* [PATCH v2 bpf-next 2/3] net/ipv6: Add helper to return path MTU based on fib result
From: dsahern @ 2018-05-21 16:08 UTC (permalink / raw)
To: netdev, borkmann, ast; +Cc: davem, David Ahern
In-Reply-To: <20180521160816.7060-1-dsahern@kernel.org>
From: David Ahern <dsahern@gmail.com>
Determine path MTU from a FIB lookup result. Logic is based on
ip6_dst_mtu_forward plus lookup of nexthop exception.
Add ip6_dst_mtu_forward to ipv6_stubs to handle access by core
bpf code.
Signed-off-by: David Ahern <dsahern@gmail.com>
---
include/net/addrconf.h | 2 ++
include/net/ip6_fib.h | 6 ++++++
include/net/ip6_route.h | 3 +++
net/ipv6/addrconf_core.c | 8 ++++++++
net/ipv6/af_inet6.c | 1 +
net/ipv6/route.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 68 insertions(+)
diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index ff766ab207e0..c07d4dd09361 100644
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -236,6 +236,8 @@ struct ipv6_stub {
struct flowi6 *fl6, int oif,
const struct sk_buff *skb,
int strict);
+ u32 (*ip6_mtu_from_fib6)(struct fib6_info *f6i, struct in6_addr *daddr,
+ struct in6_addr *saddr);
void (*udpv6_encap_enable)(void);
void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index cc70f6da8462..7897efe80727 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -412,6 +412,12 @@ static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i)
return f6i->fib6_nh.nh_dev;
}
+static inline
+struct lwtunnel_state *fib6_info_nh_lwt(const struct fib6_info *f6i)
+{
+ return f6i->fib6_nh.nh_lwtstate;
+}
+
void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
unsigned int flags);
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 4cf1ef935ed9..7b9c82de11cc 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -300,6 +300,9 @@ static inline unsigned int ip6_dst_mtu_forward(const struct dst_entry *dst)
return mtu;
}
+u32 ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr,
+ struct in6_addr *saddr);
+
struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
struct net_device *dev, struct sk_buff *skb,
const void *daddr);
diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c
index 2fe754fd4f5e..5cd0029d930e 100644
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -161,12 +161,20 @@ eafnosupport_fib6_multipath_select(const struct net *net, struct fib6_info *f6i,
return f6i;
}
+static u32
+eafnosupport_ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr,
+ struct in6_addr *saddr)
+{
+ return 0;
+}
+
const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
.ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup,
.fib6_get_table = eafnosupport_fib6_get_table,
.fib6_table_lookup = eafnosupport_fib6_table_lookup,
.fib6_lookup = eafnosupport_fib6_lookup,
.fib6_multipath_select = eafnosupport_fib6_multipath_select,
+ .ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
};
EXPORT_SYMBOL_GPL(ipv6_stub);
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 50de8b0d4f70..9ed0eae91758 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -894,6 +894,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
.fib6_table_lookup = fib6_table_lookup,
.fib6_lookup = fib6_lookup,
.fib6_multipath_select = fib6_multipath_select,
+ .ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
.udpv6_encap_enable = udpv6_encap_enable,
.ndisc_send_na = ndisc_send_na,
.nd_tbl = &nd_tbl,
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index cc24ed3bc334..dc5d5c84dbef 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2603,6 +2603,54 @@ static unsigned int ip6_mtu(const struct dst_entry *dst)
return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
}
+/* MTU selection:
+ * 1. mtu on route is locked - use it
+ * 2. mtu from nexthop exception
+ * 3. mtu from egress device
+ *
+ * based on ip6_dst_mtu_forward and exception logic of
+ * rt6_find_cached_rt; called with rcu_read_lock
+ */
+u32 ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr,
+ struct in6_addr *saddr)
+{
+ struct rt6_exception_bucket *bucket;
+ struct rt6_exception *rt6_ex;
+ struct in6_addr *src_key;
+ struct inet6_dev *idev;
+ u32 mtu = 0;
+
+ if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
+ mtu = f6i->fib6_pmtu;
+ if (mtu)
+ goto out;
+ }
+
+ src_key = NULL;
+#ifdef CONFIG_IPV6_SUBTREES
+ if (f6i->fib6_src.plen)
+ src_key = saddr;
+#endif
+
+ bucket = rcu_dereference(f6i->rt6i_exception_bucket);
+ rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
+ if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
+ mtu = dst_metric_raw(&rt6_ex->rt6i->dst, RTAX_MTU);
+
+ if (likely(!mtu)) {
+ struct net_device *dev = fib6_info_nh_dev(f6i);
+
+ mtu = IPV6_MIN_MTU;
+ idev = __in6_dev_get(dev);
+ if (idev && idev->cnf.mtu6 > mtu)
+ mtu = idev->cnf.mtu6;
+ }
+
+ mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
+out:
+ return mtu - lwtunnel_headroom(fib6_info_nh_lwt(f6i), mtu);
+}
+
struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
struct flowi6 *fl6)
{
--
2.11.0
^ permalink raw reply related
* Re: [PATCH net-next] net: phy: phylink: Don't release NULL GPIO
From: David Miller @ 2018-05-21 16:14 UTC (permalink / raw)
To: f.fainelli; +Cc: netdev, rmk+kernel, andrew, linux-kernel
In-Reply-To: <20180521034947.469-1-f.fainelli@gmail.com>
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sun, 20 May 2018 20:49:47 -0700
> If CONFIG_GPIOLIB is disabled, gpiod_put() becomes a stub that produces a
> warning, this helped identify that we could be attempting to release a NULL
> pl->link_gpio GPIO descriptor, so guard against that.
>
> Fixes: daab3349ad1a ("net: phy: phylink: Release link GPIO")
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Applied.
^ permalink raw reply
* Re: [PATCH net-next] net: ethernet: Sort Kconfig sourcing alphabetically
From: David Miller @ 2018-05-21 16:15 UTC (permalink / raw)
To: f.fainelli
Cc: netdev, arnd, andrew, aviad.krawczyk, jaswinder.singh,
hayashi.kunihiko, mdf, linus.walleij, alexandre.belloni,
linux-kernel
In-Reply-To: <20180521035830.7897-1-f.fainelli@gmail.com>
From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sun, 20 May 2018 20:58:28 -0700
> A number of entries were not alphabetically sorted, remedy that.
>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Applied.
^ permalink raw reply
* Re: [PACTH net-next] cxgb4: copy the length of cpl_tx_pkt_core to fw_wr
From: David Miller @ 2018-05-21 16:16 UTC (permalink / raw)
To: ganeshgr; +Cc: netdev, nirranjan, indranil, venkatesh
In-Reply-To: <1526885796-13618-1-git-send-email-ganeshgr@chelsio.com>
From: Ganesh Goudar <ganeshgr@chelsio.com>
Date: Mon, 21 May 2018 12:26:36 +0530
> immdlen field of FW_ETH_TX_PKT_WR is filled in a wrong way,
> we must copy the length of all the cpls encapsulated in fw
> work request. In the xmit path we missed adding the length
> of CPL_TX_PKT_CORE but we added the length of WR_HDR and it
> worked because WR_HDR and CPL_TX_PKT_CORE are of same length.
> Add the length of cpl_tx_pkt_core not WR_HDR's. This also
> fixes the lso cpl errors for udp tunnels
>
> Fixes: d0a1299c6bf7 ("cxgb4: add support for vxlan segmentation offload")
> Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Applied.
^ permalink raw reply
* [PATCH net] dccp: don't free ccid2_hc_tx_sock struct in dccp_disconnect()
From: Alexey Kodanev @ 2018-05-21 16:28 UTC (permalink / raw)
To: netdev; +Cc: David Miller, Alexey Kodanev
Syzbot reported the use-after-free in timer_is_static_object() [1].
This can happen because the structure for the rto timer (ccid2_hc_tx_sock)
is removed in dccp_disconnect(), and ccid2_hc_tx_rto_expire() can be
called after that.
The report [1] is similar to the one in commit 120e9dabaf55 ("dccp:
defer ccid_hc_tx_delete() at dismantle time"). And the fix is the same,
delay freeing ccid2_hc_tx_sock structure, so that it is freed in
dccp_sk_destruct().
[1]
==================================================================
BUG: KASAN: use-after-free in timer_is_static_object+0x80/0x90
kernel/time/timer.c:607
Read of size 8 at addr ffff8801bebb5118 by task syz-executor2/25299
CPU: 1 PID: 25299 Comm: syz-executor2 Not tainted 4.17.0-rc5+ #54
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
timer_is_static_object+0x80/0x90 kernel/time/timer.c:607
debug_object_activate+0x2d9/0x670 lib/debugobjects.c:508
debug_timer_activate kernel/time/timer.c:709 [inline]
debug_activate kernel/time/timer.c:764 [inline]
__mod_timer kernel/time/timer.c:1041 [inline]
mod_timer+0x4d3/0x13b0 kernel/time/timer.c:1102
sk_reset_timer+0x22/0x60 net/core/sock.c:2742
ccid2_hc_tx_rto_expire+0x587/0x680 net/dccp/ccids/ccid2.c:147
call_timer_fn+0x230/0x940 kernel/time/timer.c:1326
expire_timers kernel/time/timer.c:1363 [inline]
__run_timers+0x79e/0xc50 kernel/time/timer.c:1666
run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692
__do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
invoke_softirq kernel/softirq.c:365 [inline]
irq_exit+0x1d1/0x200 kernel/softirq.c:405
exiting_irq arch/x86/include/asm/apic.h:525 [inline]
smp_apic_timer_interrupt+0x17e/0x710 arch/x86/kernel/apic/apic.c:1052
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
</IRQ>
...
Allocated by task 25374:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151
dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44
__dccp_feat_activate+0x184/0x270 net/dccp/feat.c:344
dccp_feat_activate_values+0x3a7/0x819 net/dccp/feat.c:1538
dccp_create_openreq_child+0x472/0x610 net/dccp/minisocks.c:128
dccp_v4_request_recv_sock+0x12c/0xca0 net/dccp/ipv4.c:408
dccp_v6_request_recv_sock+0x125d/0x1f10 net/dccp/ipv6.c:415
dccp_check_req+0x455/0x6a0 net/dccp/minisocks.c:197
dccp_v4_rcv+0x7b8/0x1f3f net/dccp/ipv4.c:841
ip_local_deliver_finish+0x2e3/0xd80 net/ipv4/ip_input.c:215
NF_HOOK include/linux/netfilter.h:288 [inline]
ip_local_deliver+0x1e1/0x720 net/ipv4/ip_input.c:256
dst_input include/net/dst.h:450 [inline]
ip_rcv_finish+0x81b/0x2200 net/ipv4/ip_input.c:396
NF_HOOK include/linux/netfilter.h:288 [inline]
ip_rcv+0xb70/0x143d net/ipv4/ip_input.c:492
__netif_receive_skb_core+0x26f5/0x3630 net/core/dev.c:4592
__netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4657
process_backlog+0x219/0x760 net/core/dev.c:5337
napi_poll net/core/dev.c:5735 [inline]
net_rx_action+0x7b7/0x1930 net/core/dev.c:5801
__do_softirq+0x2e0/0xaf5 kernel/softirq.c:285
Freed by task 25374:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190
dccp_disconnect+0x130/0xc66 net/dccp/proto.c:286
dccp_close+0x3bc/0xe60 net/dccp/proto.c:1045
inet_release+0x104/0x1f0 net/ipv4/af_inet.c:427
inet6_release+0x50/0x70 net/ipv6/af_inet6.c:460
sock_release+0x96/0x1b0 net/socket.c:594
sock_close+0x16/0x20 net/socket.c:1149
__fput+0x34d/0x890 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1e4/0x290 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:191 [inline]
exit_to_usermode_loop+0x2bd/0x310 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff8801bebb4cc0
which belongs to the cache ccid2_hc_tx_sock of size 1240
The buggy address is located 1112 bytes inside of
1240-byte region [ffff8801bebb4cc0, ffff8801bebb5198)
The buggy address belongs to the page:
page:ffffea0006faed00 count:1 mapcount:0 mapping:ffff8801bebb41c0
index:0xffff8801bebb5240 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801bebb41c0 ffff8801bebb5240 0000000100000003
raw: ffff8801cdba3138 ffffea0007634120 ffff8801cdbaab40 0000000000000000
page dumped because: kasan: bad access detected
...
==================================================================
Reported-by: syzbot+5d47e9ec91a6f15dbd6f@syzkaller.appspotmail.com
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
---
net/dccp/proto.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 84cd4e3..0d56e36 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -283,9 +283,7 @@ int dccp_disconnect(struct sock *sk, int flags)
dccp_clear_xmit_timers(sk);
ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
- ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
dp->dccps_hc_rx_ccid = NULL;
- dp->dccps_hc_tx_ccid = NULL;
__skb_queue_purge(&sk->sk_receive_queue);
__skb_queue_purge(&sk->sk_write_queue);
--
1.8.3.1
^ permalink raw reply related
* Re: [PATCH net-next] cxgb4: do L1 config when module is inserted
From: David Miller @ 2018-05-21 16:21 UTC (permalink / raw)
To: ganeshgr; +Cc: netdev, nirranjan, indranil, venkatesh, leedom
In-Reply-To: <1526894143-4986-1-git-send-email-ganeshgr@chelsio.com>
From: Ganesh Goudar <ganeshgr@chelsio.com>
Date: Mon, 21 May 2018 14:45:43 +0530
> trigger an L1 configure operation when a transceiver module
> is inserted in order to cause current "sticky" options like
> Requested Forward Error Correction to be reapplied.
>
> Signed-off-by: Casey Leedom <leedom@chelsio.com>
> Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Applied, although:
> @@ -491,6 +491,9 @@ struct link_config {
>
> unsigned char link_ok; /* link up? */
> unsigned char link_down_rc; /* link down reason */
> +
> + unsigned char new_module; /* ->OS Transceiver Module inserted */
> + unsigned char redo_l1cfg; /* ->CC redo current "sticky" L1 CFG */
> };
The various booleans in link_config should be converted to use type 'bool'
and true/false values.
^ permalink raw reply
* Re: [PATCH net-next] cxgb4: do L1 config when module is inserted
From: David Miller @ 2018-05-21 16:23 UTC (permalink / raw)
To: ganeshgr; +Cc: netdev, nirranjan, indranil, venkatesh, leedom
In-Reply-To: <20180521.122104.1660333635075713378.davem@davemloft.net>
From: David Miller <davem@davemloft.net>
Date: Mon, 21 May 2018 12:21:04 -0400 (EDT)
> From: Ganesh Goudar <ganeshgr@chelsio.com>
> Date: Mon, 21 May 2018 14:45:43 +0530
>
>> trigger an L1 configure operation when a transceiver module
>> is inserted in order to cause current "sticky" options like
>> Requested Forward Error Correction to be reapplied.
>>
>> Signed-off-by: Casey Leedom <leedom@chelsio.com>
>> Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
>
> Applied, although:
Actually I had to revert, this doesn't even compile:
drivers/scsi/csiostor/csio_hw.c: In function ‘fwcaps16_to_caps32’:
drivers/scsi/csiostor/csio_hw.c:1490:17: error: ‘FW_PORT_CAP_MDIX’ undeclared (first use in this function); did you mean ‘FW_PORT_CAP_MDI_S’?
if (caps16 & FW_PORT_CAP_##__cap) \
^
^ permalink raw reply
* Re: [PATCH net-next] cxgb4/cxgb4vf: link management changes for new SFP
From: David Miller @ 2018-05-21 16:23 UTC (permalink / raw)
To: ganeshgr; +Cc: netdev, nirranjan, indranil, venkatesh
In-Reply-To: <1526894195-5048-1-git-send-email-ganeshgr@chelsio.com>
From: Ganesh Goudar <ganeshgr@chelsio.com>
Date: Mon, 21 May 2018 14:46:35 +0530
> newer SFPs like SFP28 and QSFP28 Transceiver Modules present
> several new possibilities which we haven't faced before. Fix the
> assumptions in the code reflecting the more limited capabilities
> of previous Transceiver Module systems
>
> Original work by Casey Leedom <leedom@chelsio.com>
>
> Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
This patch doesn't apply to the net-next tree.
^ permalink raw reply
* Re: [RFC PATCH net-next 01/12] vhost_net: introduce helper to initialize tx iov iter
From: Jesse Brandeburg @ 2018-05-21 16:24 UTC (permalink / raw)
To: Jason Wang
Cc: mst, netdev, linux-kernel, kvm, virtualization, jesse.brandeburg
In-Reply-To: <1526893473-20128-2-git-send-email-jasowang@redhat.com>
Hi Jason, a few nits.
On Mon, 21 May 2018 17:04:22 +0800 Jason wrote:
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vhost/net.c | 34 +++++++++++++++++++++++-----------
> 1 file changed, 23 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index c4b49fc..15d191a 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -459,6 +459,26 @@ static bool vhost_exceeds_maxpend(struct vhost_net *net)
> min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2);
> }
>
> +static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
> + size_t hdr_size, int out)
> +{
> + /* Skip header. TODO: support TSO. */
> + size_t len = iov_length(vq->iov, out);
> +
> + iov_iter_init(iter, WRITE, vq->iov, out, len);
> + iov_iter_advance(iter, hdr_size);
> + /* Sanity check */
> + if (!iov_iter_count(iter)) {
> + vq_err(vq, "Unexpected header len for TX: "
> + "%zd expected %zd\n",
> + len, hdr_size);
ok, it was like this before, but please unwrap the string in " ", there
should be no line breaks in string declarations and they are allowed to
go over 80 characters.
> + return -EFAULT;
> + }
> + len = iov_iter_count(iter);
> +
> + return len;
> +}
> +
> /* Expects to be always run from workqueue - which acts as
> * read-size critical section for our kind of RCU. */
> static void handle_tx(struct vhost_net *net)
> @@ -521,18 +541,10 @@ static void handle_tx(struct vhost_net *net)
> "out %d, int %d\n", out, in);
> break;
> }
> - /* Skip header. TODO: support TSO. */
> - len = iov_length(vq->iov, out);
> - iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len);
> - iov_iter_advance(&msg.msg_iter, hdr_size);
> - /* Sanity check */
> - if (!msg_data_left(&msg)) {
> - vq_err(vq, "Unexpected header len for TX: "
> - "%zd expected %zd\n",
> - len, hdr_size);
> +
> + len = init_iov_iter(vq, &msg.msg_iter, hdr_size, out);
> + if (len < 0)
len is declared as size_t, which is unsigned, and can never be
negative. I'm pretty sure this is a bug.
> break;
> - }
> - len = msg_data_left(&msg);
>
> zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
> && !vhost_exceeds_maxpend(net)
^ permalink raw reply
* [PATCH net-next v13 0/7] sched: Add Common Applications Kept Enhanced (cake) qdisc
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
This patch series adds the CAKE qdisc, and has been split up to ease
review.
I have attempted to split out each configurable feature into its own patch.
The first commit adds the base shaper and packet scheduler, while
subsequent commits add the optional features. The full userspace API and
most data structures are included in this commit, but options not
understood in the base version will be ignored.
The result of applying the entire series is identical to the out of tree
version that have seen extensive testing in previous deployments, most
notably as an out of tree patch to OpenWrt. However, note that I have only
compile tested the individual patches; so the whole series should be
considered as a unit.
---
Changelog
v13:
- Avoid ktime_t to scalar compares
- Add class dumping and basic stats
- Fail with ENOTSUPP when requesting NAT mode and conntrack is not
available.
- Parse all TCP options in ACK filter and make sure to only drop safe
ones. Also handle SACK ranges properly.
v12:
- Get rid of custom time typedefs. Use ktime_t for time and u64 for
duration instead.
v11:
- Fix overhead compensation calculation for GSO packets
- Change configured rate to be u64 (I ran out of bits before I ran out
of CPU when testing the effects of the above)
v10:
- Christmas tree gardening (fix variable declarations to be in reverse
line length order)
v9:
- Remove duplicated checks around kvfree() and just call it
unconditionally.
- Don't pass __GFP_NOWARN when allocating memory
- Move options in cake_dump() that are related to optional features to
later patches implementing the features.
- Support attaching filters to the qdisc and use the classification
result to select flow queue.
- Support overriding diffserv priority tin from skb->priority
v8:
- Remove inline keyword from function definitions
- Simplify ACK filter; remove the complex state handling to make the
logic easier to follow. This will potentially be a bit less efficient,
but I have not been able to measure a difference.
v7:
- Split up patch into a series to ease review.
- Constify the ACK filter.
v6:
- Fix 6in4 encapsulation checks in ACK filter code
- Checkpatch fixes
v5:
- Refactor ACK filter code and hopefully fix the safety issues
properly this time.
v4:
- Only split GSO packets if shaping at speeds <= 1Gbps
- Fix overhead calculation code to also work for GSO packets
- Don't re-implement kvzalloc()
- Remove local header include from out-of-tree build (fixes kbuild-bot
complaint).
- Several fixes to the ACK filter:
- Check pskb_may_pull() before deref of transport headers.
- Don't run ACK filter logic on split GSO packets
- Fix TCP sequence number compare to deal with wraparounds
v3:
- Use IS_REACHABLE() macro to fix compilation when sch_cake is
built-in and conntrack is a module.
- Switch the stats output to use nested netlink attributes instead
of a versioned struct.
- Remove GPL boilerplate.
- Fix array initialisation style.
v2:
- Fix kbuild test bot complaint
- Clean up the netlink ABI
- Fix checkpatch complaints
- A few tweaks to the behaviour of cake based on testing carried out
while writing the paper.
---
Toke Høiland-Jørgensen (7):
sched: Add Common Applications Kept Enhanced (cake) qdisc
sch_cake: Add ingress mode
sch_cake: Add optional ACK filter
sch_cake: Add NAT awareness to packet classifier
sch_cake: Add DiffServ handling
sch_cake: Add overhead compensation support to the rate shaper
sch_cake: Conditionally split GSO segments
include/uapi/linux/pkt_sched.h | 113 ++
net/sched/Kconfig | 11
net/sched/Makefile | 1
net/sched/sch_cake.c | 2992 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 3117 insertions(+)
create mode 100644 net/sched/sch_cake.c
^ permalink raw reply
* [PATCH net-next v13 3/7] sch_cake: Add optional ACK filter
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
The ACK filter is an optional feature of CAKE which is designed to improve
performance on links with very asymmetrical rate limits. On such links
(which are unfortunately quite prevalent, especially for DSL and cable
subscribers), the downstream throughput can be limited by the number of
ACKs capable of being transmitted in the *upstream* direction.
Filtering ACKs can, in general, have adverse effects on TCP performance
because it interferes with ACK clocking (especially in slow start), and it
reduces the flow's resiliency to ACKs being dropped further along the path.
To alleviate these drawbacks, the ACK filter in CAKE tries its best to
always keep enough ACKs queued to ensure forward progress in the TCP flow
being filtered. It does this by only filtering redundant ACKs. In its
default 'conservative' mode, the filter will always keep at least two
redundant ACKs in the queue, while in 'aggressive' mode, it will filter
down to a single ACK.
The ACK filter works by inspecting the per-flow queue on every packet
enqueue. Starting at the head of the queue, the filter looks for another
eligible packet to drop (so the ACK being dropped is always closer to the
head of the queue than the packet being enqueued). An ACK is eligible only
if it ACKs *fewer* bytes than the new packet being enqueued, including any
SACK options. This prevents duplicate ACKs from being filtered, to avoid
interfering with retransmission logic. In addition, we check TCP header
options and only drop those that are known to not interfere with sender
state. In particular, packets with unknown option codes are never dropped.
In aggressive mode, an eligible packet is always dropped, while in
conservative mode, at least two ACKs are kept in the queue. Only pure ACKs
(with no data segments) are considered eligible for dropping, but when an
ACK with data segments is enqueued, this can cause another pure ACK to
become eligible for dropping.
The approach described above ensures that this ACK filter avoids most of
the drawbacks of a naive filtering mechanism that only keeps flow state but
does not inspect the queue. This is the rationale for including the ACK
filter in CAKE itself rather than as separate module (as the TC filter, for
instance).
Our performance evaluation has shown that on a 30/1 Mbps link with a
bidirectional traffic test (RRUL), turning on the ACK filter on the
upstream link improves downstream throughput by ~20% (both modes) and
upstream throughput by ~12% in conservative mode and ~40% in aggressive
mode, at the cost of ~5ms of inter-flow latency due to the increased
congestion.
In *really* pathological cases, the effect can be a lot more; for instance,
the ACK filter increases the achievable downstream throughput on a link
with 100 Kbps in the upstream direction by an order of magnitude (from ~2.5
Mbps to ~25 Mbps).
Finally, even though we consider the ACK filter to be safer than most, we
do not recommend turning it on everywhere: on more symmetrical link
bandwidths the effect is negligible at best.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 425 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 423 insertions(+), 2 deletions(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 10e208e4255d..c20f33940a57 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -757,6 +757,404 @@ static void flow_queue_add(struct cake_flow *flow, struct sk_buff *skb)
skb->next = NULL;
}
+static struct iphdr *cake_get_iphdr(const struct sk_buff *skb,
+ struct ipv6hdr *buf)
+{
+ unsigned int offset = skb_network_offset(skb);
+ struct iphdr *iph;
+
+ iph = skb_header_pointer(skb, offset, sizeof(struct iphdr), buf);
+
+ if (!iph)
+ return NULL;
+
+ if (iph->version == 4 && iph->protocol == IPPROTO_IPV6)
+ return skb_header_pointer(skb, offset + iph->ihl * 4,
+ sizeof(struct ipv6hdr), buf);
+
+ else if (iph->version == 4)
+ return iph;
+
+ else if (iph->version == 6)
+ return skb_header_pointer(skb, offset, sizeof(struct ipv6hdr),
+ buf);
+
+ return NULL;
+}
+
+static struct tcphdr *cake_get_tcphdr(const struct sk_buff *skb,
+ void *buf, unsigned int bufsize)
+{
+ unsigned int offset = skb_network_offset(skb);
+ const struct ipv6hdr *ipv6h;
+ const struct tcphdr *tcph;
+ const struct iphdr *iph;
+ struct ipv6hdr _ipv6h;
+ struct tcphdr _tcph;
+
+ ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
+
+ if (!ipv6h)
+ return NULL;
+
+ if (ipv6h->version == 4) {
+ iph = (struct iphdr *)ipv6h;
+ offset += iph->ihl * 4;
+
+ /* special-case 6in4 tunnelling, as that is a common way to get
+ * v6 connectivity in the home
+ */
+ if (iph->protocol == IPPROTO_IPV6) {
+ ipv6h = skb_header_pointer(skb, offset,
+ sizeof(_ipv6h), &_ipv6h);
+
+ if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
+ return NULL;
+
+ offset += sizeof(struct ipv6hdr);
+
+ } else if (iph->protocol != IPPROTO_TCP) {
+ return NULL;
+ }
+
+ } else if (ipv6h->version == 6) {
+ if (ipv6h->nexthdr != IPPROTO_TCP)
+ return NULL;
+
+ offset += sizeof(struct ipv6hdr);
+ } else {
+ return NULL;
+ }
+
+ tcph = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
+ if (!tcph)
+ return NULL;
+
+ return skb_header_pointer(skb, offset,
+ min(__tcp_hdrlen(tcph), bufsize), buf);
+}
+
+static const u8 *cake_get_tcpopt(const struct tcphdr *tcph,
+ int code, int *oplen)
+{
+ /* inspired by tcp_parse_options in tcp_input.c */
+ int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr);
+ const u8 *ptr = (const u8 *)(tcph + 1);
+
+ while (length > 0) {
+ int opcode = *ptr++;
+ int opsize;
+
+ if (opcode == TCPOPT_EOL)
+ break;
+ if (opcode == TCPOPT_NOP) {
+ length--;
+ continue;
+ }
+ opsize = *ptr++;
+ if (opsize < 2 || opsize > length)
+ break;
+
+ if (opcode == code) {
+ *oplen = opsize;
+ return ptr;
+ }
+
+ ptr += opsize - 2;
+ length -= opsize;
+ }
+
+ return NULL;
+}
+
+/* Compare two SACK sequences. A sequence is considered greater if it SACKs more
+ * bytes than the other. In the case where both sequences ACKs bytes that the
+ * other doesn't, A is considered greater.
+ *
+ * @return -1, 0 or 1 as normal compare functions
+ */
+static int cake_tcph_sack_compare(const struct tcphdr *tcph_a,
+ const struct tcphdr *tcph_b)
+{
+ u64 bytes_a = 0, bytes_b = 0;
+ const u8 *sack_a, *sack_b;
+ int oplen_a, oplen_b;
+ bool first = true;
+
+ sack_a = cake_get_tcpopt(tcph_a, TCPOPT_SACK, &oplen_a);
+ sack_b = cake_get_tcpopt(tcph_b, TCPOPT_SACK, &oplen_b);
+
+ if (sack_a && !sack_b)
+ return -1;
+ else if (sack_b && !sack_a)
+ return 1;
+ else if (!sack_a && !sack_b)
+ return 0;
+
+ /* pointer has already advanced past opcode and length bytes */
+ oplen_a -= 2;
+
+ while (oplen_a >= 8) {
+ u32 right_a = get_unaligned_be32(sack_a + 4);
+ u32 left_a = get_unaligned_be32(sack_a);
+ const u8 *sack_tmp = sack_b;
+ int oplen_tmp = oplen_b - 2;
+ bool found = false;
+
+ /* invalid or empty SACK range; ignore */
+ if (left_a >= right_a)
+ continue;
+
+ bytes_a += right_a - left_a;
+
+ while (oplen_tmp >= 8) {
+ u32 right_b = get_unaligned_be32(sack_tmp + 4);
+ u32 left_b = get_unaligned_be32(sack_tmp);
+
+ if (left_b >= right_b)
+ continue;
+
+ if (first)
+ bytes_b += right_b - left_b;
+
+ if (left_b <= left_a && right_a <= right_b) {
+ found = true;
+ if (!first)
+ break;
+ }
+ oplen_tmp -= 8;
+ sack_tmp += 8;
+ }
+
+ first = false;
+
+ if (!found)
+ return -1;
+
+ oplen_a -= 8;
+ sack_a += 8;
+ }
+
+ /* If we made it this far, all ranges SACKed by A are covered by B, so
+ * either the SACKs are equal, or B SACKs more bytes.
+ */
+ return bytes_b > bytes_a ? 1 : 0;
+}
+
+static void cake_tcph_get_tstamp(const struct tcphdr *tcph,
+ u32 *tsval, u32 *tsecr)
+{
+ const u8 *ptr;
+ int opsize;
+
+ ptr = cake_get_tcpopt(tcph, TCPOPT_TIMESTAMP, &opsize);
+
+ if (ptr && opsize == TCPOLEN_TIMESTAMP) {
+ *tsval = get_unaligned_be32(ptr);
+ *tsecr = get_unaligned_be32(ptr + 4);
+ }
+}
+
+static bool cake_tcph_may_drop(const struct tcphdr *tcph,
+ u32 tstamp_new, u32 tsecr_new)
+{
+ /* inspired by tcp_parse_options in tcp_input.c */
+ int length = __tcp_hdrlen(tcph) - sizeof(struct tcphdr);
+ const u8 *ptr = (const u8 *)(tcph + 1);
+ u32 tstamp, tsecr;
+
+ /* 3 reserved flags must be unset to avoid future breakage
+ * ECE/CWR/NS can be safely ignored
+ * ACK must be set
+ * All other flags URG/PSH/RST/SYN/FIN must be unset
+ * 0x0FFF0000 = all TCP flags (confirm ACK=1, others zero)
+ * 0x01C00000 = NS/CWR/ECE (safe to ignore)
+ * 0x0E3F0000 = 0x0FFF0000 & ~0x01C00000
+ */
+ if (((tcp_flag_word(tcph) &
+ cpu_to_be32(0x0E3F0000)) != TCP_FLAG_ACK))
+ return false;
+
+ while (length > 0) {
+ int opcode = *ptr++;
+ int opsize;
+
+ if (opcode == TCPOPT_EOL)
+ break;
+ if (opcode == TCPOPT_NOP) {
+ length--;
+ continue;
+ }
+ opsize = *ptr++;
+ if (opsize < 2 || opsize > length)
+ break;
+
+ switch (opcode) {
+ case TCPOPT_MD5SIG: /* doesn't influence state */
+ break;
+
+ case TCPOPT_SACK: /* stricter checking performed later */
+ if (opsize % 8 != 2)
+ return false;
+ break;
+
+ case TCPOPT_TIMESTAMP:
+ /* only drop timestamps lower than new */
+ if (opsize != TCPOLEN_TIMESTAMP)
+ return false;
+ tstamp = get_unaligned_be32(ptr);
+ tsecr = get_unaligned_be32(ptr + 4);
+ if (tstamp > tstamp_new || tsecr > tsecr_new)
+ return false;
+ break;
+
+ case TCPOPT_MSS: /* these should only be set on SYN */
+ case TCPOPT_WINDOW:
+ case TCPOPT_SACK_PERM:
+ case TCPOPT_FASTOPEN:
+ case TCPOPT_EXP:
+ default: /* don't drop if any unknown options are present */
+ return false;
+ }
+
+ ptr += opsize - 2;
+ length -= opsize;
+ }
+
+ return true;
+}
+
+static struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
+ struct cake_flow *flow)
+{
+ bool aggressive = q->ack_filter == CAKE_ACK_AGGRESSIVE;
+ struct sk_buff *elig_ack = NULL, *elig_ack_prev = NULL;
+ struct sk_buff *skb_check, *skb_prev = NULL;
+ const struct ipv6hdr *ipv6h, *ipv6h_check;
+ unsigned char _tcph[64], _tcph_check[64];
+ const struct tcphdr *tcph, *tcph_check;
+ const struct iphdr *iph, *iph_check;
+ struct ipv6hdr _iph, _iph_check;
+ const struct sk_buff *skb;
+ int seglen, num_found = 0;
+ u32 tstamp = 0, tsecr = 0;
+ int sack_comp;
+
+ /* no other possible ACKs to filter */
+ if (flow->head == flow->tail)
+ return NULL;
+
+ skb = flow->tail;
+ tcph = cake_get_tcphdr(skb, _tcph, sizeof(_tcph));
+ iph = cake_get_iphdr(skb, &_iph);
+ if (!tcph)
+ return NULL;
+
+ cake_tcph_get_tstamp(tcph, &tstamp, &tsecr);
+
+ /* the 'triggering' packet need only have the ACK flag set.
+ * also check that SYN is not set, as there won't be any previous ACKs.
+ */
+ if ((tcp_flag_word(tcph) &
+ (TCP_FLAG_ACK | TCP_FLAG_SYN)) != TCP_FLAG_ACK)
+ return NULL;
+
+ /* the 'triggering' ACK is at the tail of the queue, we have already
+ * returned if it is the only packet in the flow. loop through the rest
+ * of the queue looking for pure ACKs with the same 5-tuple as the
+ * triggering one.
+ */
+ for (skb_check = flow->head;
+ skb_check && skb_check != skb;
+ skb_prev = skb_check, skb_check = skb_check->next) {
+ iph_check = cake_get_iphdr(skb_check, &_iph_check);
+ tcph_check = cake_get_tcphdr(skb_check, &_tcph_check,
+ sizeof(_tcph_check));
+
+ /* only TCP packets with matching 5-tuple are eligible, and only
+ * drop safe headers
+ */
+ if (!tcph_check || iph->version != iph_check->version ||
+ tcph_check->source != tcph->source ||
+ tcph_check->dest != tcph->dest ||
+ !cake_tcph_may_drop(tcph_check, tstamp, tsecr))
+ continue;
+
+ if (iph_check->version == 4) {
+ if (iph_check->saddr != iph->saddr ||
+ iph_check->daddr != iph->daddr)
+ continue;
+
+ seglen = ntohs(iph_check->tot_len) -
+ (4 * iph_check->ihl);
+ } else if (iph_check->version == 6) {
+ ipv6h = (struct ipv6hdr *)iph;
+ ipv6h_check = (struct ipv6hdr *)iph_check;
+
+ if (ipv6_addr_cmp(&ipv6h_check->saddr, &ipv6h->saddr) ||
+ ipv6_addr_cmp(&ipv6h_check->daddr, &ipv6h->daddr))
+ continue;
+
+ seglen = ntohs(ipv6h_check->payload_len);
+ } else {
+ WARN_ON(1); /* shouldn't happen */
+ continue;
+ }
+
+ /* Don't drop ACKs with segment data, and don't drop ACKs higher
+ * cumulative ACK counter than triggering packet. Check ACK
+ * seqno here to avoid parsing SACK options of packets we are
+ * going to exclude anyway.
+ */
+ if ((seglen - __tcp_hdrlen(tcph_check)) != 0 ||
+ (int32_t)(ntohl(tcph_check->ack_seq) -
+ ntohl(tcph->ack_seq)) > 0)
+ continue;
+
+ /* Check SACK options. The triggering packet must SACK more data
+ * than the ACK under consideration, or SACK the same range but
+ * have a larger cumulative ACK counter. The latter is a
+ * pathological case, but is contained in the following check
+ * anyway, just to be safe.
+ */
+ sack_comp = cake_tcph_sack_compare(tcph_check, tcph);
+
+ if (sack_comp < 0 ||
+ (ntohl(tcph_check->ack_seq) == ntohl(tcph->ack_seq) &&
+ sack_comp == 0))
+ continue;
+
+ /* At this point we have found an eligible pure ACK to drop; if
+ * we are in aggressive mode, we are done. Otherwise, keep
+ * searching unless this is the second eligible ACK we
+ * found.
+ *
+ * Since we want to drop ACK closest to the head of the queue,
+ * save the first eligible ACK we find, even if we need to loop
+ * again.
+ */
+ if (!elig_ack) {
+ elig_ack = skb_check;
+ elig_ack_prev = skb_prev;
+ }
+
+ if (num_found++ > 0 || aggressive)
+ goto found;
+ }
+
+ return NULL;
+
+found:
+ if (elig_ack_prev)
+ elig_ack_prev->next = elig_ack->next;
+ else
+ flow->head = elig_ack->next;
+
+ elig_ack->next = NULL;
+
+ return elig_ack;
+}
+
static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
{
avg -= avg >> shift;
@@ -934,6 +1332,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct cake_sched_data *q = qdisc_priv(sch);
int len = qdisc_pkt_len(skb);
int uninitialized_var(ret);
+ struct sk_buff *ack = NULL;
ktime_t now = ktime_get();
struct cake_tin_data *b;
struct cake_flow *flow;
@@ -980,8 +1379,24 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
cobalt_set_enqueue_time(skb, now);
flow_queue_add(flow, skb);
- sch->q.qlen++;
- q->buffer_used += skb->truesize;
+ if (q->ack_filter)
+ ack = cake_ack_filter(q, flow);
+
+ if (ack) {
+ b->ack_drops++;
+ sch->qstats.drops++;
+ b->bytes += qdisc_pkt_len(ack);
+ len -= qdisc_pkt_len(ack);
+ q->buffer_used += skb->truesize - ack->truesize;
+ if (q->rate_flags & CAKE_FLAG_INGRESS)
+ cake_advance_shaper(q, b, ack, now, true);
+
+ qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
+ consume_skb(ack);
+ } else {
+ sch->q.qlen++;
+ q->buffer_used += skb->truesize;
+ }
/* stats */
b->packets++;
@@ -1511,6 +1926,9 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
q->rate_flags &= ~CAKE_FLAG_INGRESS;
}
+ if (tb[TCA_CAKE_ACK_FILTER])
+ q->ack_filter = nla_get_u32(tb[TCA_CAKE_ACK_FILTER]);
+
if (tb[TCA_CAKE_MEMORY])
q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
@@ -1642,6 +2060,9 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
!!(q->rate_flags & CAKE_FLAG_INGRESS)))
goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter))
+ goto nla_put_failure;
+
return nla_nest_end(skb, opts);
nla_put_failure:
^ permalink raw reply related
* [PATCH net-next v13 4/7] sch_cake: Add NAT awareness to packet classifier
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
When CAKE is deployed on a gateway that also performs NAT (which is a
common deployment mode), the host fairness mechanism cannot distinguish
internal hosts from each other, and so fails to work correctly.
To fix this, we add an optional NAT awareness mode, which will query the
kernel conntrack mechanism to obtain the pre-NAT addresses for each packet
and use that in the flow and host hashing.
When the shaper is enabled and the host is already performing NAT, the cost
of this lookup is negligible. However, in unlimited mode with no NAT being
performed, there is a significant CPU cost at higher bandwidths. For this
reason, the feature is turned off by default.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 79 insertions(+)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index c20f33940a57..116c935b2914 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -71,6 +71,12 @@
#include <net/tcp.h>
#include <net/flow_dissector.h>
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
#define CAKE_SET_WAYS (8)
#define CAKE_MAX_TINS (8)
#define CAKE_QUEUES (1024)
@@ -516,6 +522,60 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
return drop;
}
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+
+static void cake_update_flowkeys(struct flow_keys *keys,
+ const struct sk_buff *skb)
+{
+ const struct nf_conntrack_tuple *tuple;
+ enum ip_conntrack_info ctinfo;
+ struct nf_conn *ct;
+ bool rev = false;
+
+ if (tc_skb_protocol(skb) != htons(ETH_P_IP))
+ return;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (ct) {
+ tuple = nf_ct_tuple(ct, CTINFO2DIR(ctinfo));
+ } else {
+ const struct nf_conntrack_tuple_hash *hash;
+ struct nf_conntrack_tuple srctuple;
+
+ if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
+ NFPROTO_IPV4, dev_net(skb->dev),
+ &srctuple))
+ return;
+
+ hash = nf_conntrack_find_get(dev_net(skb->dev),
+ &nf_ct_zone_dflt,
+ &srctuple);
+ if (!hash)
+ return;
+
+ rev = true;
+ ct = nf_ct_tuplehash_to_ctrack(hash);
+ tuple = nf_ct_tuple(ct, !hash->tuple.dst.dir);
+ }
+
+ keys->addrs.v4addrs.src = rev ? tuple->dst.u3.ip : tuple->src.u3.ip;
+ keys->addrs.v4addrs.dst = rev ? tuple->src.u3.ip : tuple->dst.u3.ip;
+
+ if (keys->ports.ports) {
+ keys->ports.src = rev ? tuple->dst.u.all : tuple->src.u.all;
+ keys->ports.dst = rev ? tuple->src.u.all : tuple->dst.u.all;
+ }
+ if (rev)
+ nf_ct_put(ct);
+}
+#else
+static void cake_update_flowkeys(struct flow_keys *keys,
+ const struct sk_buff *skb)
+{
+ /* There is nothing we can do here without CONNTRACK */
+}
+#endif
+
/* Cake has several subtle multiple bit settings. In these cases you
* would be matching triple isolate mode as well.
*/
@@ -543,6 +603,9 @@ static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
skb_flow_dissect_flow_keys(skb, &keys,
FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
+ if (flow_mode & CAKE_FLOW_NAT_FLAG)
+ cake_update_flowkeys(&keys, skb);
+
/* flow_hash_from_keys() sorts the addresses by value, so we have
* to preserve their order in a separate data structure to treat
* src and dst host addresses as independently selectable.
@@ -1891,6 +1954,18 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
if (err < 0)
return err;
+ if (tb[TCA_CAKE_NAT]) {
+#if IS_REACHABLE(CONFIG_NF_CONNTRACK)
+ q->flow_mode &= ~CAKE_FLOW_NAT_FLAG;
+ q->flow_mode |= CAKE_FLOW_NAT_FLAG *
+ !!nla_get_u32(tb[TCA_CAKE_NAT]);
+#else
+ NL_SET_ERR_MSG_ATTR(extack, "No conntrack support in kernel",
+ tb[TCA_CAKE_NAT]);
+ return -EOPNOTSUPP;
+#endif
+ }
+
if (tb[TCA_CAKE_BASE_RATE64])
q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
@@ -2063,6 +2138,10 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
if (nla_put_u32(skb, TCA_CAKE_ACK_FILTER, q->ack_filter))
goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CAKE_NAT,
+ !!(q->flow_mode & CAKE_FLOW_NAT_FLAG)))
+ goto nla_put_failure;
+
return nla_nest_end(skb, opts);
nla_put_failure:
^ permalink raw reply related
* [PATCH net-next v13 5/7] sch_cake: Add DiffServ handling
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
This adds support for DiffServ-based priority queueing to CAKE. If the
shaper is in use, each priority tier gets its own virtual clock, which
limits that tier's rate to a fraction of the overall shaped rate, to
discourage trying to game the priority mechanism.
CAKE defaults to a simple, three-tier mode that interprets most code points
as "best effort", but places CS1 traffic into a low-priority "bulk" tier
which is assigned 1/16 of the total rate, and a few code points indicating
latency-sensitive or control traffic (specifically TOS4, VA, EF, CS6, CS7)
into a "latency sensitive" high-priority tier, which is assigned 1/4 rate.
The other supported DiffServ modes are a 4-tier mode matching the 802.11e
precedence rules, as well as two 8-tier modes, one of which implements
strict precedence of the eight priority levels.
This commit also adds an optional DiffServ 'wash' mode, which will zero out
the DSCP fields of any packet passing through CAKE. While this can
technically be done with other mechanisms in the kernel, having the feature
available in CAKE significantly decreases configuration complexity; and the
implementation cost is low on top of the other DiffServ-handling code.
Filters and applications can set the skb->priority field to override the
DSCP-based classification into tiers. If TC_H_MAJ(skb->priority) matches
CAKE's qdisc handle, the minor number will be interpreted as a priority
tier if it is less than or equal to the number of configured priority
tiers.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 412 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 404 insertions(+), 8 deletions(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 116c935b2914..d025899ef11f 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -298,6 +298,68 @@ static void cobalt_set_enqueue_time(struct sk_buff *skb,
static u16 quantum_div[CAKE_QUEUES + 1] = {0};
+/* Diffserv lookup tables */
+
+static const u8 precedence[] = {
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 1, 1, 1, 1, 1, 1, 1, 1,
+ 2, 2, 2, 2, 2, 2, 2, 2,
+ 3, 3, 3, 3, 3, 3, 3, 3,
+ 4, 4, 4, 4, 4, 4, 4, 4,
+ 5, 5, 5, 5, 5, 5, 5, 5,
+ 6, 6, 6, 6, 6, 6, 6, 6,
+ 7, 7, 7, 7, 7, 7, 7, 7,
+};
+
+static const u8 diffserv8[] = {
+ 2, 5, 1, 2, 4, 2, 2, 2,
+ 0, 2, 1, 2, 1, 2, 1, 2,
+ 5, 2, 4, 2, 4, 2, 4, 2,
+ 3, 2, 3, 2, 3, 2, 3, 2,
+ 6, 2, 3, 2, 3, 2, 3, 2,
+ 6, 2, 2, 2, 6, 2, 6, 2,
+ 7, 2, 2, 2, 2, 2, 2, 2,
+ 7, 2, 2, 2, 2, 2, 2, 2,
+};
+
+static const u8 diffserv4[] = {
+ 0, 2, 0, 0, 2, 0, 0, 0,
+ 1, 0, 0, 0, 0, 0, 0, 0,
+ 2, 0, 2, 0, 2, 0, 2, 0,
+ 2, 0, 2, 0, 2, 0, 2, 0,
+ 3, 0, 2, 0, 2, 0, 2, 0,
+ 3, 0, 0, 0, 3, 0, 3, 0,
+ 3, 0, 0, 0, 0, 0, 0, 0,
+ 3, 0, 0, 0, 0, 0, 0, 0,
+};
+
+static const u8 diffserv3[] = {
+ 0, 0, 0, 0, 2, 0, 0, 0,
+ 1, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 2, 0, 2, 0,
+ 2, 0, 0, 0, 0, 0, 0, 0,
+ 2, 0, 0, 0, 0, 0, 0, 0,
+};
+
+static const u8 besteffort[] = {
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0,
+};
+
+/* tin priority order for stats dumping */
+
+static const u8 normal_order[] = {0, 1, 2, 3, 4, 5, 6, 7};
+static const u8 bulk_order[] = {1, 0, 2, 3};
+
#define REC_INV_SQRT_CACHE (16)
static u32 cobalt_rec_inv_sqrt_cache[REC_INV_SQRT_CACHE] = {0};
@@ -1387,6 +1449,46 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
return idx + (tin << 16);
}
+static void cake_wash_diffserv(struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
+ break;
+ case htons(ETH_P_IPV6):
+ ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
+ break;
+ default:
+ break;
+ }
+}
+
+static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash)
+{
+ u8 dscp;
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ dscp = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
+ if (wash && dscp)
+ ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0);
+ return dscp;
+
+ case htons(ETH_P_IPV6):
+ dscp = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
+ if (wash && dscp)
+ ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0);
+ return dscp;
+
+ case htons(ETH_P_ARP):
+ return 0x38; /* CS7 - Net Control */
+
+ default:
+ /* If there is no Diffserv field, treat as best-effort */
+ return 0;
+ }
+}
+
static void cake_reconfigure(struct Qdisc *sch);
static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
@@ -1401,7 +1503,26 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct cake_flow *flow;
u32 idx, tin;
- tin = 0;
+ if (TC_H_MAJ(skb->priority) == sch->handle &&
+ TC_H_MIN(skb->priority) > 0 &&
+ TC_H_MIN(skb->priority) <= q->tin_cnt) {
+ tin = TC_H_MIN(skb->priority) - 1;
+
+ if (q->rate_flags & CAKE_FLAG_WASH)
+ cake_wash_diffserv(skb);
+ } else if (q->tin_mode != CAKE_DIFFSERV_BESTEFFORT) {
+ /* extract the Diffserv Precedence field, if it exists */
+ /* and clear DSCP bits if washing */
+ tin = q->tin_index[cake_handle_diffserv(skb,
+ q->rate_flags & CAKE_FLAG_WASH)];
+ if (unlikely(tin >= q->tin_cnt))
+ tin = 0;
+ } else {
+ tin = 0;
+ if (q->rate_flags & CAKE_FLAG_WASH)
+ cake_wash_diffserv(skb);
+ }
+
b = &q->tins[tin];
/* choose flow to insert into */
@@ -1902,18 +2023,275 @@ static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
b->cparams.p_dec = 1 << 20; /* 1/4096 */
}
-static void cake_reconfigure(struct Qdisc *sch)
+static int cake_config_besteffort(struct Qdisc *sch)
{
struct cake_sched_data *q = qdisc_priv(sch);
struct cake_tin_data *b = &q->tins[0];
- int c, ft = 0;
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ u64 rate = q->rate_bps;
q->tin_cnt = 1;
- cake_set_rate(b, q->rate_bps, psched_mtu(qdisc_dev(sch)),
+
+ q->tin_index = besteffort;
+ q->tin_order = normal_order;
+
+ cake_set_rate(b, rate, mtu,
us_to_ns(q->target), us_to_ns(q->interval));
b->tin_quantum_band = 65535;
b->tin_quantum_prio = 65535;
+ return 0;
+}
+
+static int cake_config_precedence(struct Qdisc *sch)
+{
+ /* convert high-level (user visible) parameters into internal format */
+ struct cake_sched_data *q = qdisc_priv(sch);
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ u64 rate = q->rate_bps;
+ u32 quantum1 = 256;
+ u32 quantum2 = 256;
+ u32 i;
+
+ q->tin_cnt = 8;
+ q->tin_index = precedence;
+ q->tin_order = normal_order;
+
+ for (i = 0; i < q->tin_cnt; i++) {
+ struct cake_tin_data *b = &q->tins[i];
+
+ cake_set_rate(b, rate, mtu, us_to_ns(q->target),
+ us_to_ns(q->interval));
+
+ b->tin_quantum_prio = max_t(u16, 1U, quantum1);
+ b->tin_quantum_band = max_t(u16, 1U, quantum2);
+
+ /* calculate next class's parameters */
+ rate *= 7;
+ rate >>= 3;
+
+ quantum1 *= 3;
+ quantum1 >>= 1;
+
+ quantum2 *= 7;
+ quantum2 >>= 3;
+ }
+
+ return 0;
+}
+
+/* List of known Diffserv codepoints:
+ *
+ * Least Effort (CS1)
+ * Best Effort (CS0)
+ * Max Reliability & LLT "Lo" (TOS1)
+ * Max Throughput (TOS2)
+ * Min Delay (TOS4)
+ * LLT "La" (TOS5)
+ * Assured Forwarding 1 (AF1x) - x3
+ * Assured Forwarding 2 (AF2x) - x3
+ * Assured Forwarding 3 (AF3x) - x3
+ * Assured Forwarding 4 (AF4x) - x3
+ * Precedence Class 2 (CS2)
+ * Precedence Class 3 (CS3)
+ * Precedence Class 4 (CS4)
+ * Precedence Class 5 (CS5)
+ * Precedence Class 6 (CS6)
+ * Precedence Class 7 (CS7)
+ * Voice Admit (VA)
+ * Expedited Forwarding (EF)
+
+ * Total 25 codepoints.
+ */
+
+/* List of traffic classes in RFC 4594:
+ * (roughly descending order of contended priority)
+ * (roughly ascending order of uncontended throughput)
+ *
+ * Network Control (CS6,CS7) - routing traffic
+ * Telephony (EF,VA) - aka. VoIP streams
+ * Signalling (CS5) - VoIP setup
+ * Multimedia Conferencing (AF4x) - aka. video calls
+ * Realtime Interactive (CS4) - eg. games
+ * Multimedia Streaming (AF3x) - eg. YouTube, NetFlix, Twitch
+ * Broadcast Video (CS3)
+ * Low Latency Data (AF2x,TOS4) - eg. database
+ * Ops, Admin, Management (CS2,TOS1) - eg. ssh
+ * Standard Service (CS0 & unrecognised codepoints)
+ * High Throughput Data (AF1x,TOS2) - eg. web traffic
+ * Low Priority Data (CS1) - eg. BitTorrent
+
+ * Total 12 traffic classes.
+ */
+
+static int cake_config_diffserv8(struct Qdisc *sch)
+{
+/* Pruned list of traffic classes for typical applications:
+ *
+ * Network Control (CS6, CS7)
+ * Minimum Latency (EF, VA, CS5, CS4)
+ * Interactive Shell (CS2, TOS1)
+ * Low Latency Transactions (AF2x, TOS4)
+ * Video Streaming (AF4x, AF3x, CS3)
+ * Bog Standard (CS0 etc.)
+ * High Throughput (AF1x, TOS2)
+ * Background Traffic (CS1)
+ *
+ * Total 8 traffic classes.
+ */
+
+ struct cake_sched_data *q = qdisc_priv(sch);
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ u64 rate = q->rate_bps;
+ u32 quantum1 = 256;
+ u32 quantum2 = 256;
+ u32 i;
+
+ q->tin_cnt = 8;
+
+ /* codepoint to class mapping */
+ q->tin_index = diffserv8;
+ q->tin_order = normal_order;
+
+ /* class characteristics */
+ for (i = 0; i < q->tin_cnt; i++) {
+ struct cake_tin_data *b = &q->tins[i];
+
+ cake_set_rate(b, rate, mtu, us_to_ns(q->target),
+ us_to_ns(q->interval));
+
+ b->tin_quantum_prio = max_t(u16, 1U, quantum1);
+ b->tin_quantum_band = max_t(u16, 1U, quantum2);
+
+ /* calculate next class's parameters */
+ rate *= 7;
+ rate >>= 3;
+
+ quantum1 *= 3;
+ quantum1 >>= 1;
+
+ quantum2 *= 7;
+ quantum2 >>= 3;
+ }
+
+ return 0;
+}
+
+static int cake_config_diffserv4(struct Qdisc *sch)
+{
+/* Further pruned list of traffic classes for four-class system:
+ *
+ * Latency Sensitive (CS7, CS6, EF, VA, CS5, CS4)
+ * Streaming Media (AF4x, AF3x, CS3, AF2x, TOS4, CS2, TOS1)
+ * Best Effort (CS0, AF1x, TOS2, and those not specified)
+ * Background Traffic (CS1)
+ *
+ * Total 4 traffic classes.
+ */
+
+ struct cake_sched_data *q = qdisc_priv(sch);
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ u64 rate = q->rate_bps;
+ u32 quantum = 1024;
+
+ q->tin_cnt = 4;
+
+ /* codepoint to class mapping */
+ q->tin_index = diffserv4;
+ q->tin_order = bulk_order;
+
+ /* class characteristics */
+ cake_set_rate(&q->tins[0], rate, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+ cake_set_rate(&q->tins[1], rate >> 4, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+ cake_set_rate(&q->tins[2], rate >> 1, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+ cake_set_rate(&q->tins[3], rate >> 2, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+
+ /* priority weights */
+ q->tins[0].tin_quantum_prio = quantum;
+ q->tins[1].tin_quantum_prio = quantum >> 4;
+ q->tins[2].tin_quantum_prio = quantum << 2;
+ q->tins[3].tin_quantum_prio = quantum << 4;
+
+ /* bandwidth-sharing weights */
+ q->tins[0].tin_quantum_band = quantum;
+ q->tins[1].tin_quantum_band = quantum >> 4;
+ q->tins[2].tin_quantum_band = quantum >> 1;
+ q->tins[3].tin_quantum_band = quantum >> 2;
+
+ return 0;
+}
+
+static int cake_config_diffserv3(struct Qdisc *sch)
+{
+/* Simplified Diffserv structure with 3 tins.
+ * Low Priority (CS1)
+ * Best Effort
+ * Latency Sensitive (TOS4, VA, EF, CS6, CS7)
+ */
+ struct cake_sched_data *q = qdisc_priv(sch);
+ u32 mtu = psched_mtu(qdisc_dev(sch));
+ u64 rate = q->rate_bps;
+ u32 quantum = 1024;
+
+ q->tin_cnt = 3;
+
+ /* codepoint to class mapping */
+ q->tin_index = diffserv3;
+ q->tin_order = bulk_order;
+
+ /* class characteristics */
+ cake_set_rate(&q->tins[0], rate, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+ cake_set_rate(&q->tins[1], rate >> 4, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+ cake_set_rate(&q->tins[2], rate >> 2, mtu,
+ us_to_ns(q->target), us_to_ns(q->interval));
+
+ /* priority weights */
+ q->tins[0].tin_quantum_prio = quantum;
+ q->tins[1].tin_quantum_prio = quantum >> 4;
+ q->tins[2].tin_quantum_prio = quantum << 4;
+
+ /* bandwidth-sharing weights */
+ q->tins[0].tin_quantum_band = quantum;
+ q->tins[1].tin_quantum_band = quantum >> 4;
+ q->tins[2].tin_quantum_band = quantum >> 2;
+
+ return 0;
+}
+
+static void cake_reconfigure(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ int c, ft;
+
+ switch (q->tin_mode) {
+ case CAKE_DIFFSERV_BESTEFFORT:
+ ft = cake_config_besteffort(sch);
+ break;
+
+ case CAKE_DIFFSERV_PRECEDENCE:
+ ft = cake_config_precedence(sch);
+ break;
+
+ case CAKE_DIFFSERV_DIFFSERV8:
+ ft = cake_config_diffserv8(sch);
+ break;
+
+ case CAKE_DIFFSERV_DIFFSERV4:
+ ft = cake_config_diffserv4(sch);
+ break;
+
+ case CAKE_DIFFSERV_DIFFSERV3:
+ default:
+ ft = cake_config_diffserv3(sch);
+ break;
+ }
+
for (c = q->tin_cnt; c < CAKE_MAX_TINS; c++) {
cake_clear_tin(sch, c);
q->tins[c].cparams.mtu_time = q->tins[ft].cparams.mtu_time;
@@ -1969,6 +2347,16 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
if (tb[TCA_CAKE_BASE_RATE64])
q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
+ if (tb[TCA_CAKE_DIFFSERV_MODE])
+ q->tin_mode = nla_get_u32(tb[TCA_CAKE_DIFFSERV_MODE]);
+
+ if (tb[TCA_CAKE_WASH]) {
+ if (!!nla_get_u32(tb[TCA_CAKE_WASH]))
+ q->rate_flags |= CAKE_FLAG_WASH;
+ else
+ q->rate_flags &= ~CAKE_FLAG_WASH;
+ }
+
if (tb[TCA_CAKE_FLOW_MODE])
q->flow_mode = (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
CAKE_FLOW_MASK);
@@ -2032,7 +2420,7 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt,
int i, j, err;
sch->limit = 10240;
- q->tin_mode = CAKE_DIFFSERV_BESTEFFORT;
+ q->tin_mode = CAKE_DIFFSERV_DIFFSERV3;
q->flow_mode = CAKE_FLOW_TRIPLE;
q->rate_bps = 0; /* unlimited by default */
@@ -2142,6 +2530,13 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
!!(q->flow_mode & CAKE_FLOW_NAT_FLAG)))
goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CAKE_DIFFSERV_MODE, q->tin_mode))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_WASH,
+ !!(q->rate_flags & CAKE_FLAG_WASH)))
+ goto nla_put_failure;
+
return nla_nest_end(skb, opts);
nla_put_failure:
@@ -2195,7 +2590,7 @@ static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
} while (0)
for (i = 0; i < q->tin_cnt; i++) {
- struct cake_tin_data *b = &q->tins[i];
+ struct cake_tin_data *b = &q->tins[q->tin_order[i]];
ts = nla_nest_start(d->skb, i + 1);
if (!ts)
@@ -2294,7 +2689,8 @@ static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
u32 idx = cl - 1;
if (idx < CAKE_QUEUES * q->tin_cnt) {
- const struct cake_tin_data *b = &q->tins[idx / CAKE_QUEUES];
+ const struct cake_tin_data *b = \
+ &q->tins[q->tin_order[idx / CAKE_QUEUES]];
const struct sk_buff *skb;
flow = &b->flows[idx % CAKE_QUEUES];
@@ -2366,7 +2762,7 @@ static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg)
return;
for (i = 0; i < q->tin_cnt; i++) {
- struct cake_tin_data *b = &q->tins[i];
+ struct cake_tin_data *b = &q->tins[q->tin_order[i]];
for (j = 0; j < CAKE_QUEUES; j++) {
if (list_empty(&b->flows[j].flowchain) ||
^ permalink raw reply related
* [PATCH net-next v13 2/7] sch_cake: Add ingress mode
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
The ingress mode is meant to be enabled when CAKE runs downlink of the
actual bottleneck (such as on an IFB device). The mode changes the shaper
to also account dropped packets to the shaped rate, as these have already
traversed the bottleneck.
Enabling ingress mode will also tune the AQM to always keep at least two
packets queued *for each flow*. This is done by scaling the minimum queue
occupancy level that will disable the AQM by the number of active bulk
flows. The rationale for this is that retransmits are more expensive in
ingress mode, since dropped packets have to traverse the bottleneck again
when they are retransmitted; thus, being more lenient and keeping a minimum
number of packets queued will improve throughput in cases where the number
of active flows are so large that they saturate the bottleneck even at
their minimum window size.
This commit also adds a separate switch to enable ingress mode rate
autoscaling. If enabled, the autoscaling code will observe the actual
traffic rate and adjust the shaper rate to match it. This can help avoid
latency increases in the case where the actual bottleneck rate decreases
below the shaped rate. The scaling filters out spikes by an EWMA filter.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 81 insertions(+), 4 deletions(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 7ea4aa261cec..10e208e4255d 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -435,7 +435,8 @@ static bool cobalt_queue_empty(struct cobalt_vars *vars,
static bool cobalt_should_drop(struct cobalt_vars *vars,
struct cobalt_params *p,
ktime_t now,
- struct sk_buff *skb)
+ struct sk_buff *skb,
+ u32 bulk_flows)
{
bool next_due, over_target, drop = false;
ktime_t schedule;
@@ -459,6 +460,7 @@ static bool cobalt_should_drop(struct cobalt_vars *vars,
sojourn = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
schedule = ktime_sub(now, vars->drop_next);
over_target = sojourn > p->target &&
+ sojourn > p->mtu_time * bulk_flows * 2 &&
sojourn > p->mtu_time * 4;
next_due = vars->count && ktime_to_ns(schedule) >= 0;
@@ -913,6 +915,9 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
b->tin_dropped++;
sch->qstats.drops++;
+ if (q->rate_flags & CAKE_FLAG_INGRESS)
+ cake_advance_shaper(q, b, skb, now, true);
+
__qdisc_drop(skb, to_free);
sch->q.qlen--;
@@ -990,8 +995,46 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
cake_heapify_up(q, b->overflow_idx[idx]);
/* incoming bandwidth capacity estimate */
- q->avg_window_bytes = 0;
- q->last_packet_time = now;
+ if (q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS) {
+ u64 packet_interval = \
+ ktime_to_ns(ktime_sub(now, q->last_packet_time));
+
+ if (packet_interval > NSEC_PER_SEC)
+ packet_interval = NSEC_PER_SEC;
+
+ /* filter out short-term bursts, eg. wifi aggregation */
+ q->avg_packet_interval = \
+ cake_ewma(q->avg_packet_interval,
+ packet_interval,
+ (packet_interval > q->avg_packet_interval ?
+ 2 : 8));
+
+ q->last_packet_time = now;
+
+ if (packet_interval > q->avg_packet_interval) {
+ u64 window_interval = \
+ ktime_to_ns(ktime_sub(now,
+ q->avg_window_begin));
+ u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC;
+
+ do_div(b, window_interval);
+ q->avg_peak_bandwidth =
+ cake_ewma(q->avg_peak_bandwidth, b,
+ b > q->avg_peak_bandwidth ? 2 : 8);
+ q->avg_window_bytes = 0;
+ q->avg_window_begin = now;
+
+ if (ktime_after(now,
+ ktime_add_ms(q->last_reconfig_time,
+ 250))) {
+ q->rate_bps = (q->avg_peak_bandwidth * 15) >> 4;
+ cake_reconfigure(sch);
+ }
+ }
+ } else {
+ q->avg_window_bytes = 0;
+ q->last_packet_time = now;
+ }
/* flowchain */
if (!flow->set || flow->set == CAKE_SET_DECAYING) {
@@ -1251,15 +1294,27 @@ static struct sk_buff *cake_dequeue(struct Qdisc *sch)
}
/* Last packet in queue may be marked, shouldn't be dropped */
- if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb) ||
+ if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb,
+ (b->bulk_flow_count *
+ !!(q->rate_flags &
+ CAKE_FLAG_INGRESS))) ||
!flow->head)
break;
+ /* drop this packet, get another one */
+ if (q->rate_flags & CAKE_FLAG_INGRESS) {
+ len = cake_advance_shaper(q, b, skb,
+ now, true);
+ flow->deficit -= len;
+ b->tin_deficit -= len;
+ }
flow->dropped++;
b->tin_dropped++;
qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
qdisc_qstats_drop(sch);
kfree_skb(skb);
+ if (q->rate_flags & CAKE_FLAG_INGRESS)
+ goto retry;
}
b->tin_ecn_mark += !!flow->cvars.ecn_marked;
@@ -1442,6 +1497,20 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
q->target = 1;
}
+ if (tb[TCA_CAKE_AUTORATE]) {
+ if (!!nla_get_u32(tb[TCA_CAKE_AUTORATE]))
+ q->rate_flags |= CAKE_FLAG_AUTORATE_INGRESS;
+ else
+ q->rate_flags &= ~CAKE_FLAG_AUTORATE_INGRESS;
+ }
+
+ if (tb[TCA_CAKE_INGRESS]) {
+ if (!!nla_get_u32(tb[TCA_CAKE_INGRESS]))
+ q->rate_flags |= CAKE_FLAG_INGRESS;
+ else
+ q->rate_flags &= ~CAKE_FLAG_INGRESS;
+ }
+
if (tb[TCA_CAKE_MEMORY])
q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
@@ -1565,6 +1634,14 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
if (nla_put_u32(skb, TCA_CAKE_MEMORY, q->buffer_config_limit))
goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CAKE_AUTORATE,
+ !!(q->rate_flags & CAKE_FLAG_AUTORATE_INGRESS)))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_INGRESS,
+ !!(q->rate_flags & CAKE_FLAG_INGRESS)))
+ goto nla_put_failure;
+
return nla_nest_end(skb, opts);
nla_put_failure:
^ permalink raw reply related
* [PATCH net-next v13 7/7] sch_cake: Conditionally split GSO segments
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
At lower bandwidths, the transmission time of a single GSO segment can add
an unacceptable amount of latency due to HOL blocking. Furthermore, with a
software shaper, any tuning mechanism employed by the kernel to control the
maximum size of GSO segments is thrown off by the artificial limit on
bandwidth. For this reason, we split GSO segments into their individual
packets iff the shaper is active and configured to a bandwidth <= 1 Gbps.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 99 +++++++++++++++++++++++++++++++++++++-------------
1 file changed, 73 insertions(+), 26 deletions(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index 4bccfee714c8..1bf413759bd4 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -82,6 +82,7 @@
#define CAKE_QUEUES (1024)
#define CAKE_FLOW_MASK 63
#define CAKE_FLOW_NAT_FLAG 64
+#define CAKE_SPLIT_GSO_THRESHOLD (125000000) /* 1Gbps */
/* struct cobalt_params - contains codel and blue parameters
* @interval: codel initial drop rate
@@ -1643,36 +1644,73 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
if (unlikely(len > b->max_skblen))
b->max_skblen = len;
- cobalt_set_enqueue_time(skb, now);
- get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
- flow_queue_add(flow, skb);
-
- if (q->ack_filter)
- ack = cake_ack_filter(q, flow);
+ if (skb_is_gso(skb) && q->rate_flags & CAKE_FLAG_SPLIT_GSO) {
+ struct sk_buff *segs, *nskb;
+ netdev_features_t features = netif_skb_features(skb);
+ unsigned int slen = 0;
+
+ segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
+ if (IS_ERR_OR_NULL(segs))
+ return qdisc_drop(skb, sch, to_free);
+
+ while (segs) {
+ nskb = segs->next;
+ segs->next = NULL;
+ qdisc_skb_cb(segs)->pkt_len = segs->len;
+ cobalt_set_enqueue_time(segs, now);
+ get_cobalt_cb(segs)->adjusted_len = cake_overhead(q,
+ segs);
+ flow_queue_add(flow, segs);
+
+ sch->q.qlen++;
+ slen += segs->len;
+ q->buffer_used += segs->truesize;
+ b->packets++;
+ segs = nskb;
+ }
- if (ack) {
- b->ack_drops++;
- sch->qstats.drops++;
- b->bytes += qdisc_pkt_len(ack);
- len -= qdisc_pkt_len(ack);
- q->buffer_used += skb->truesize - ack->truesize;
- if (q->rate_flags & CAKE_FLAG_INGRESS)
- cake_advance_shaper(q, b, ack, now, true);
+ /* stats */
+ b->bytes += slen;
+ b->backlogs[idx] += slen;
+ b->tin_backlog += slen;
+ sch->qstats.backlog += slen;
+ q->avg_window_bytes += slen;
- qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
- consume_skb(ack);
+ qdisc_tree_reduce_backlog(sch, 1, len);
+ consume_skb(skb);
} else {
- sch->q.qlen++;
- q->buffer_used += skb->truesize;
- }
+ /* not splitting */
+ cobalt_set_enqueue_time(skb, now);
+ get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
+ flow_queue_add(flow, skb);
+
+ if (q->ack_filter)
+ ack = cake_ack_filter(q, flow);
+
+ if (ack) {
+ b->ack_drops++;
+ sch->qstats.drops++;
+ b->bytes += qdisc_pkt_len(ack);
+ len -= qdisc_pkt_len(ack);
+ q->buffer_used += skb->truesize - ack->truesize;
+ if (q->rate_flags & CAKE_FLAG_INGRESS)
+ cake_advance_shaper(q, b, ack, now, true);
+
+ qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(ack));
+ consume_skb(ack);
+ } else {
+ sch->q.qlen++;
+ q->buffer_used += skb->truesize;
+ }
- /* stats */
- b->packets++;
- b->bytes += len;
- b->backlogs[idx] += len;
- b->tin_backlog += len;
- sch->qstats.backlog += len;
- q->avg_window_bytes += len;
+ /* stats */
+ b->packets++;
+ b->bytes += len;
+ b->backlogs[idx] += len;
+ b->tin_backlog += len;
+ sch->qstats.backlog += len;
+ q->avg_window_bytes += len;
+ }
if (q->overflow_timeout)
cake_heapify_up(q, b->overflow_idx[idx]);
@@ -2504,6 +2542,11 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
if (tb[TCA_CAKE_MEMORY])
q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
+ if (q->rate_bps && q->rate_bps <= CAKE_SPLIT_GSO_THRESHOLD)
+ q->rate_flags |= CAKE_FLAG_SPLIT_GSO;
+ else
+ q->rate_flags &= ~CAKE_FLAG_SPLIT_GSO;
+
if (q->tins) {
sch_tree_lock(sch);
cake_reconfigure(sch);
@@ -2659,6 +2702,10 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
if (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu))
goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CAKE_SPLIT_GSO,
+ !!(q->rate_flags & CAKE_FLAG_SPLIT_GSO)))
+ goto nla_put_failure;
+
return nla_nest_end(skb, opts);
nla_put_failure:
^ permalink raw reply related
* [PATCH net-next v13 1/7] sched: Add Common Applications Kept Enhanced (cake) qdisc
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
sch_cake targets the home router use case and is intended to squeeze the
most bandwidth and latency out of even the slowest ISP links and routers,
while presenting an API simple enough that even an ISP can configure it.
Example of use on a cable ISP uplink:
tc qdisc add dev eth0 cake bandwidth 20Mbit nat docsis ack-filter
To shape a cable download link (ifb and tc-mirred setup elided)
tc qdisc add dev ifb0 cake bandwidth 200mbit nat docsis ingress wash
CAKE is filled with:
* A hybrid Codel/Blue AQM algorithm, "Cobalt", tied to an FQ_Codel
derived Flow Queuing system, which autoconfigures based on the bandwidth.
* A novel "triple-isolate" mode (the default) which balances per-host
and per-flow FQ even through NAT.
* An deficit based shaper, that can also be used in an unlimited mode.
* 8 way set associative hashing to reduce flow collisions to a minimum.
* A reasonable interpretation of various diffserv latency/loss tradeoffs.
* Support for zeroing diffserv markings for entering and exiting traffic.
* Support for interacting well with Docsis 3.0 shaper framing.
* Extensive support for DSL framing types.
* Support for ack filtering.
* Extensive statistics for measuring, loss, ecn markings, latency
variation.
A paper describing the design of CAKE is available at
https://arxiv.org/abs/1804.07617, and will be published at the 2018 IEEE
International Symposium on Local and Metropolitan Area Networks (LANMAN).
This patch adds the base shaper and packet scheduler, while subsequent
commits add the optional (configurable) features. The full userspace API
and most data structures are included in this commit, but options not
understood in the base version will be ignored.
Various versions baking have been available as an out of tree build for
kernel versions going back to 3.10, as the embedded router world has been
running a few years behind mainline Linux. A stable version has been
generally available on lede-17.01 and later.
sch_cake replaces a combination of iptables, tc filter, htb and fq_codel
in the sqm-scripts, with sane defaults and vastly simpler configuration.
CAKE's principal author is Jonathan Morton, with contributions from
Kevin Darbyshire-Bryant, Toke Høiland-Jørgensen, Sebastian Moeller,
Ryan Mounce, Guido Sarducci, Dean Scarff, Nils Andreas Svee, Dave Täht,
and Loganaden Velvindron.
Testing from Pete Heist, Georgios Amanakis, and the many other members of
the cake@lists.bufferbloat.net mailing list.
tc -s qdisc show dev eth2
qdisc cake 1: root refcnt 2 bandwidth 100Mbit diffserv3 triple-isolate rtt 100.0ms raw overhead 0
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
memory used: 0b of 5000000b
capacity estimate: 100Mbit
min/max network layer size: 65535 / 0
min/max overhead-adjusted size: 65535 / 0
average network hdr offset: 0
Bulk Best Effort Voice
thresh 6250Kbit 100Mbit 25Mbit
target 5.0ms 5.0ms 5.0ms
interval 100.0ms 100.0ms 100.0ms
pk_delay 0us 0us 0us
av_delay 0us 0us 0us
sp_delay 0us 0us 0us
pkts 0 0 0
bytes 0 0 0
way_inds 0 0 0
way_miss 0 0 0
way_cols 0 0 0
drops 0 0 0
marks 0 0 0
ack_drop 0 0 0
sp_flows 0 0 0
bk_flows 0 0 0
un_flows 0 0 0
max_len 0 0 0
quantum 300 1514 762
Tested-by: Pete Heist <peteheist@gmail.com>
Tested-by: Georgios Amanakis <gamanakis@gmail.com>
Signed-off-by: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
include/uapi/linux/pkt_sched.h | 113 ++
net/sched/Kconfig | 11
net/sched/Makefile | 1
net/sched/sch_cake.c | 1850 ++++++++++++++++++++++++++++++++++++++++
4 files changed, 1975 insertions(+)
create mode 100644 net/sched/sch_cake.c
diff --git a/include/uapi/linux/pkt_sched.h b/include/uapi/linux/pkt_sched.h
index 37b5096ae97b..07648e6ea569 100644
--- a/include/uapi/linux/pkt_sched.h
+++ b/include/uapi/linux/pkt_sched.h
@@ -934,4 +934,117 @@ enum {
#define TCA_CBS_MAX (__TCA_CBS_MAX - 1)
+/* CAKE */
+enum {
+ TCA_CAKE_UNSPEC,
+ TCA_CAKE_PAD,
+ TCA_CAKE_BASE_RATE64,
+ TCA_CAKE_DIFFSERV_MODE,
+ TCA_CAKE_ATM,
+ TCA_CAKE_FLOW_MODE,
+ TCA_CAKE_OVERHEAD,
+ TCA_CAKE_RTT,
+ TCA_CAKE_TARGET,
+ TCA_CAKE_AUTORATE,
+ TCA_CAKE_MEMORY,
+ TCA_CAKE_NAT,
+ TCA_CAKE_RAW,
+ TCA_CAKE_WASH,
+ TCA_CAKE_MPU,
+ TCA_CAKE_INGRESS,
+ TCA_CAKE_ACK_FILTER,
+ TCA_CAKE_SPLIT_GSO,
+ __TCA_CAKE_MAX
+};
+#define TCA_CAKE_MAX (__TCA_CAKE_MAX - 1)
+
+enum {
+ __TCA_CAKE_STATS_INVALID,
+ TCA_CAKE_STATS_PAD,
+ TCA_CAKE_STATS_CAPACITY_ESTIMATE64,
+ TCA_CAKE_STATS_MEMORY_LIMIT,
+ TCA_CAKE_STATS_MEMORY_USED,
+ TCA_CAKE_STATS_AVG_NETOFF,
+ TCA_CAKE_STATS_MIN_NETLEN,
+ TCA_CAKE_STATS_MAX_NETLEN,
+ TCA_CAKE_STATS_MIN_ADJLEN,
+ TCA_CAKE_STATS_MAX_ADJLEN,
+ TCA_CAKE_STATS_TIN_STATS,
+ TCA_CAKE_STATS_DEFICIT,
+ TCA_CAKE_STATS_COBALT_COUNT,
+ TCA_CAKE_STATS_DROPPING,
+ TCA_CAKE_STATS_DROP_NEXT_US,
+ TCA_CAKE_STATS_P_DROP,
+ TCA_CAKE_STATS_BLUE_TIMER_US,
+ __TCA_CAKE_STATS_MAX
+};
+#define TCA_CAKE_STATS_MAX (__TCA_CAKE_STATS_MAX - 1)
+
+enum {
+ __TCA_CAKE_TIN_STATS_INVALID,
+ TCA_CAKE_TIN_STATS_PAD,
+ TCA_CAKE_TIN_STATS_SENT_PACKETS,
+ TCA_CAKE_TIN_STATS_SENT_BYTES64,
+ TCA_CAKE_TIN_STATS_DROPPED_PACKETS,
+ TCA_CAKE_TIN_STATS_DROPPED_BYTES64,
+ TCA_CAKE_TIN_STATS_ACKS_DROPPED_PACKETS,
+ TCA_CAKE_TIN_STATS_ACKS_DROPPED_BYTES64,
+ TCA_CAKE_TIN_STATS_ECN_MARKED_PACKETS,
+ TCA_CAKE_TIN_STATS_ECN_MARKED_BYTES64,
+ TCA_CAKE_TIN_STATS_BACKLOG_PACKETS,
+ TCA_CAKE_TIN_STATS_BACKLOG_BYTES,
+ TCA_CAKE_TIN_STATS_THRESHOLD_RATE64,
+ TCA_CAKE_TIN_STATS_TARGET_US,
+ TCA_CAKE_TIN_STATS_INTERVAL_US,
+ TCA_CAKE_TIN_STATS_WAY_INDIRECT_HITS,
+ TCA_CAKE_TIN_STATS_WAY_MISSES,
+ TCA_CAKE_TIN_STATS_WAY_COLLISIONS,
+ TCA_CAKE_TIN_STATS_PEAK_DELAY_US,
+ TCA_CAKE_TIN_STATS_AVG_DELAY_US,
+ TCA_CAKE_TIN_STATS_BASE_DELAY_US,
+ TCA_CAKE_TIN_STATS_SPARSE_FLOWS,
+ TCA_CAKE_TIN_STATS_BULK_FLOWS,
+ TCA_CAKE_TIN_STATS_UNRESPONSIVE_FLOWS,
+ TCA_CAKE_TIN_STATS_MAX_SKBLEN,
+ TCA_CAKE_TIN_STATS_FLOW_QUANTUM,
+ __TCA_CAKE_TIN_STATS_MAX
+};
+#define TCA_CAKE_TIN_STATS_MAX (__TCA_CAKE_TIN_STATS_MAX - 1)
+#define TC_CAKE_MAX_TINS (8)
+
+enum {
+ CAKE_FLOW_NONE = 0,
+ CAKE_FLOW_SRC_IP,
+ CAKE_FLOW_DST_IP,
+ CAKE_FLOW_HOSTS, /* = CAKE_FLOW_SRC_IP | CAKE_FLOW_DST_IP */
+ CAKE_FLOW_FLOWS,
+ CAKE_FLOW_DUAL_SRC, /* = CAKE_FLOW_SRC_IP | CAKE_FLOW_FLOWS */
+ CAKE_FLOW_DUAL_DST, /* = CAKE_FLOW_DST_IP | CAKE_FLOW_FLOWS */
+ CAKE_FLOW_TRIPLE, /* = CAKE_FLOW_HOSTS | CAKE_FLOW_FLOWS */
+ CAKE_FLOW_MAX,
+};
+
+enum {
+ CAKE_DIFFSERV_DIFFSERV3 = 0,
+ CAKE_DIFFSERV_DIFFSERV4,
+ CAKE_DIFFSERV_DIFFSERV8,
+ CAKE_DIFFSERV_BESTEFFORT,
+ CAKE_DIFFSERV_PRECEDENCE,
+ CAKE_DIFFSERV_MAX
+};
+
+enum {
+ CAKE_ACK_NONE = 0,
+ CAKE_ACK_FILTER,
+ CAKE_ACK_AGGRESSIVE,
+ CAKE_ACK_MAX
+};
+
+enum {
+ CAKE_ATM_NONE = 0,
+ CAKE_ATM_ATM,
+ CAKE_ATM_PTM,
+ CAKE_ATM_MAX
+};
+
#endif
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index a01169fb5325..6e7d614b5757 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -284,6 +284,17 @@ config NET_SCH_FQ_CODEL
If unsure, say N.
+config NET_SCH_CAKE
+ tristate "Common Applications Kept Enhanced (CAKE)"
+ help
+ Say Y here if you want to use the Common Applications Kept Enhanced
+ (CAKE) queue management algorithm.
+
+ To compile this driver as a module, choose M here: the module
+ will be called sch_cake.
+
+ If unsure, say N.
+
config NET_SCH_FQ
tristate "Fair Queue"
help
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 8811d3804878..435054cee32c 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_NET_SCH_CHOKE) += sch_choke.o
obj-$(CONFIG_NET_SCH_QFQ) += sch_qfq.o
obj-$(CONFIG_NET_SCH_CODEL) += sch_codel.o
obj-$(CONFIG_NET_SCH_FQ_CODEL) += sch_fq_codel.o
+obj-$(CONFIG_NET_SCH_CAKE) += sch_cake.o
obj-$(CONFIG_NET_SCH_FQ) += sch_fq.o
obj-$(CONFIG_NET_SCH_HHF) += sch_hhf.o
obj-$(CONFIG_NET_SCH_PIE) += sch_pie.o
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
new file mode 100644
index 000000000000..7ea4aa261cec
--- /dev/null
+++ b/net/sched/sch_cake.c
@@ -0,0 +1,1850 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+
+/* COMMON Applications Kept Enhanced (CAKE) discipline
+ *
+ * Copyright (C) 2014-2018 Jonathan Morton <chromatix99@gmail.com>
+ * Copyright (C) 2015-2018 Toke Høiland-Jørgensen <toke@toke.dk>
+ * Copyright (C) 2014-2018 Dave Täht <dave.taht@gmail.com>
+ * Copyright (C) 2015-2018 Sebastian Moeller <moeller0@gmx.de>
+ * (C) 2015-2018 Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
+ * Copyright (C) 2017-2018 Ryan Mounce <ryan@mounce.com.au>
+ *
+ * The CAKE Principles:
+ * (or, how to have your cake and eat it too)
+ *
+ * This is a combination of several shaping, AQM and FQ techniques into one
+ * easy-to-use package:
+ *
+ * - An overall bandwidth shaper, to move the bottleneck away from dumb CPE
+ * equipment and bloated MACs. This operates in deficit mode (as in sch_fq),
+ * eliminating the need for any sort of burst parameter (eg. token bucket
+ * depth). Burst support is limited to that necessary to overcome scheduling
+ * latency.
+ *
+ * - A Diffserv-aware priority queue, giving more priority to certain classes,
+ * up to a specified fraction of bandwidth. Above that bandwidth threshold,
+ * the priority is reduced to avoid starving other tins.
+ *
+ * - Each priority tin has a separate Flow Queue system, to isolate traffic
+ * flows from each other. This prevents a burst on one flow from increasing
+ * the delay to another. Flows are distributed to queues using a
+ * set-associative hash function.
+ *
+ * - Each queue is actively managed by Cobalt, which is a combination of the
+ * Codel and Blue AQM algorithms. This serves flows fairly, and signals
+ * congestion early via ECN (if available) and/or packet drops, to keep
+ * latency low. The codel parameters are auto-tuned based on the bandwidth
+ * setting, as is necessary at low bandwidths.
+ *
+ * The configuration parameters are kept deliberately simple for ease of use.
+ * Everything has sane defaults. Complete generality of configuration is *not*
+ * a goal.
+ *
+ * The priority queue operates according to a weighted DRR scheme, combined with
+ * a bandwidth tracker which reuses the shaper logic to detect which side of the
+ * bandwidth sharing threshold the tin is operating. This determines whether a
+ * priority-based weight (high) or a bandwidth-based weight (low) is used for
+ * that tin in the current pass.
+ *
+ * This qdisc was inspired by Eric Dumazet's fq_codel code, which he kindly
+ * granted us permission to leverage.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/jhash.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/reciprocal_div.h>
+#include <net/netlink.h>
+#include <linux/version.h>
+#include <linux/if_vlan.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/tcp.h>
+#include <net/flow_dissector.h>
+
+#define CAKE_SET_WAYS (8)
+#define CAKE_MAX_TINS (8)
+#define CAKE_QUEUES (1024)
+#define CAKE_FLOW_MASK 63
+#define CAKE_FLOW_NAT_FLAG 64
+
+/* struct cobalt_params - contains codel and blue parameters
+ * @interval: codel initial drop rate
+ * @target: maximum persistent sojourn time & blue update rate
+ * @mtu_time: serialisation delay of maximum-size packet
+ * @p_inc: increment of blue drop probability (0.32 fxp)
+ * @p_dec: decrement of blue drop probability (0.32 fxp)
+ */
+struct cobalt_params {
+ u64 interval;
+ u64 target;
+ u64 mtu_time;
+ u32 p_inc;
+ u32 p_dec;
+};
+
+/* struct cobalt_vars - contains codel and blue variables
+ * @count: codel dropping frequency
+ * @rec_inv_sqrt: reciprocal value of sqrt(count) >> 1
+ * @drop_next: time to drop next packet, or when we dropped last
+ * @blue_timer: Blue time to next drop
+ * @p_drop: BLUE drop probability (0.32 fxp)
+ * @dropping: set if in dropping state
+ * @ecn_marked: set if marked
+ */
+struct cobalt_vars {
+ u32 count;
+ u32 rec_inv_sqrt;
+ ktime_t drop_next;
+ ktime_t blue_timer;
+ u32 p_drop;
+ bool dropping;
+ bool ecn_marked;
+};
+
+enum {
+ CAKE_SET_NONE = 0,
+ CAKE_SET_SPARSE,
+ CAKE_SET_SPARSE_WAIT, /* counted in SPARSE, actually in BULK */
+ CAKE_SET_BULK,
+ CAKE_SET_DECAYING
+};
+
+struct cake_flow {
+ /* this stuff is all needed per-flow at dequeue time */
+ struct sk_buff *head;
+ struct sk_buff *tail;
+ struct list_head flowchain;
+ s32 deficit;
+ u32 dropped;
+ struct cobalt_vars cvars;
+ u16 srchost; /* index into cake_host table */
+ u16 dsthost;
+ u8 set;
+}; /* please try to keep this structure <= 64 bytes */
+
+struct cake_host {
+ u32 srchost_tag;
+ u32 dsthost_tag;
+ u16 srchost_refcnt;
+ u16 dsthost_refcnt;
+};
+
+struct cake_heap_entry {
+ u16 t:3, b:10;
+};
+
+struct cake_tin_data {
+ struct cake_flow flows[CAKE_QUEUES];
+ u32 backlogs[CAKE_QUEUES];
+ u32 tags[CAKE_QUEUES]; /* for set association */
+ u16 overflow_idx[CAKE_QUEUES];
+ struct cake_host hosts[CAKE_QUEUES]; /* for triple isolation */
+ u16 flow_quantum;
+
+ struct cobalt_params cparams;
+ u32 drop_overlimit;
+ u16 bulk_flow_count;
+ u16 sparse_flow_count;
+ u16 decaying_flow_count;
+ u16 unresponsive_flow_count;
+
+ u32 max_skblen;
+
+ struct list_head new_flows;
+ struct list_head old_flows;
+ struct list_head decaying_flows;
+
+ /* time_next = time_this + ((len * rate_ns) >> rate_shft) */
+ ktime_t time_next_packet;
+ u64 tin_rate_ns;
+ u64 tin_rate_bps;
+ u16 tin_rate_shft;
+
+ u16 tin_quantum_prio;
+ u16 tin_quantum_band;
+ s32 tin_deficit;
+ u32 tin_backlog;
+ u32 tin_dropped;
+ u32 tin_ecn_mark;
+
+ u32 packets;
+ u64 bytes;
+
+ u32 ack_drops;
+
+ /* moving averages */
+ u64 avge_delay;
+ u64 peak_delay;
+ u64 base_delay;
+
+ /* hash function stats */
+ u32 way_directs;
+ u32 way_hits;
+ u32 way_misses;
+ u32 way_collisions;
+}; /* number of tins is small, so size of this struct doesn't matter much */
+
+struct cake_sched_data {
+ struct tcf_proto __rcu *filter_list; /* optional external classifier */
+ struct tcf_block *block;
+ struct cake_tin_data *tins;
+
+ struct cake_heap_entry overflow_heap[CAKE_QUEUES * CAKE_MAX_TINS];
+ u16 overflow_timeout;
+
+ u16 tin_cnt;
+ u8 tin_mode;
+ u8 flow_mode;
+ u8 ack_filter;
+ u8 atm_mode;
+
+ /* time_next = time_this + ((len * rate_ns) >> rate_shft) */
+ u16 rate_shft;
+ ktime_t time_next_packet;
+ ktime_t failsafe_next_packet;
+ u64 rate_ns;
+ u64 rate_bps;
+ u16 rate_flags;
+ s16 rate_overhead;
+ u16 rate_mpu;
+ u64 interval;
+ u64 target;
+
+ /* resource tracking */
+ u32 buffer_used;
+ u32 buffer_max_used;
+ u32 buffer_limit;
+ u32 buffer_config_limit;
+
+ /* indices for dequeue */
+ u16 cur_tin;
+ u16 cur_flow;
+
+ struct qdisc_watchdog watchdog;
+ const u8 *tin_index;
+ const u8 *tin_order;
+
+ /* bandwidth capacity estimate */
+ ktime_t last_packet_time;
+ ktime_t avg_window_begin;
+ u64 avg_packet_interval;
+ u64 avg_window_bytes;
+ u64 avg_peak_bandwidth;
+ ktime_t last_reconfig_time;
+
+ /* packet length stats */
+ u32 avg_netoff;
+ u16 max_netlen;
+ u16 max_adjlen;
+ u16 min_netlen;
+ u16 min_adjlen;
+};
+
+enum {
+ CAKE_FLAG_OVERHEAD = BIT(0),
+ CAKE_FLAG_AUTORATE_INGRESS = BIT(1),
+ CAKE_FLAG_INGRESS = BIT(2),
+ CAKE_FLAG_WASH = BIT(3),
+ CAKE_FLAG_SPLIT_GSO = BIT(4)
+};
+
+/* COBALT operates the Codel and BLUE algorithms in parallel, in order to
+ * obtain the best features of each. Codel is excellent on flows which
+ * respond to congestion signals in a TCP-like way. BLUE is more effective on
+ * unresponsive flows.
+ */
+
+struct cobalt_skb_cb {
+ ktime_t enqueue_time;
+};
+
+static u64 us_to_ns(u64 us)
+{
+ return us * NSEC_PER_USEC;
+}
+
+static struct cobalt_skb_cb *get_cobalt_cb(const struct sk_buff *skb)
+{
+ qdisc_cb_private_validate(skb, sizeof(struct cobalt_skb_cb));
+ return (struct cobalt_skb_cb *)qdisc_skb_cb(skb)->data;
+}
+
+static ktime_t cobalt_get_enqueue_time(const struct sk_buff *skb)
+{
+ return get_cobalt_cb(skb)->enqueue_time;
+}
+
+static void cobalt_set_enqueue_time(struct sk_buff *skb,
+ ktime_t now)
+{
+ get_cobalt_cb(skb)->enqueue_time = now;
+}
+
+static u16 quantum_div[CAKE_QUEUES + 1] = {0};
+
+#define REC_INV_SQRT_CACHE (16)
+static u32 cobalt_rec_inv_sqrt_cache[REC_INV_SQRT_CACHE] = {0};
+
+/* http://en.wikipedia.org/wiki/Methods_of_computing_square_roots
+ * new_invsqrt = (invsqrt / 2) * (3 - count * invsqrt^2)
+ *
+ * Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32
+ */
+
+static void cobalt_newton_step(struct cobalt_vars *vars)
+{
+ u32 invsqrt, invsqrt2;
+ u64 val;
+
+ invsqrt = vars->rec_inv_sqrt;
+ invsqrt2 = ((u64)invsqrt * invsqrt) >> 32;
+ val = (3LL << 32) - ((u64)vars->count * invsqrt2);
+
+ val >>= 2; /* avoid overflow in following multiply */
+ val = (val * invsqrt) >> (32 - 2 + 1);
+
+ vars->rec_inv_sqrt = val;
+}
+
+static void cobalt_invsqrt(struct cobalt_vars *vars)
+{
+ if (vars->count < REC_INV_SQRT_CACHE)
+ vars->rec_inv_sqrt = cobalt_rec_inv_sqrt_cache[vars->count];
+ else
+ cobalt_newton_step(vars);
+}
+
+/* There is a big difference in timing between the accurate values placed in
+ * the cache and the approximations given by a single Newton step for small
+ * count values, particularly when stepping from count 1 to 2 or vice versa.
+ * Above 16, a single Newton step gives sufficient accuracy in either
+ * direction, given the precision stored.
+ *
+ * The magnitude of the error when stepping up to count 2 is such as to give
+ * the value that *should* have been produced at count 4.
+ */
+
+static void cobalt_cache_init(void)
+{
+ struct cobalt_vars v;
+
+ memset(&v, 0, sizeof(v));
+ v.rec_inv_sqrt = ~0U;
+ cobalt_rec_inv_sqrt_cache[0] = v.rec_inv_sqrt;
+
+ for (v.count = 1; v.count < REC_INV_SQRT_CACHE; v.count++) {
+ cobalt_newton_step(&v);
+ cobalt_newton_step(&v);
+ cobalt_newton_step(&v);
+ cobalt_newton_step(&v);
+
+ cobalt_rec_inv_sqrt_cache[v.count] = v.rec_inv_sqrt;
+ }
+}
+
+static void cobalt_vars_init(struct cobalt_vars *vars)
+{
+ memset(vars, 0, sizeof(*vars));
+
+ if (!cobalt_rec_inv_sqrt_cache[0]) {
+ cobalt_cache_init();
+ cobalt_rec_inv_sqrt_cache[0] = ~0;
+ }
+}
+
+/* CoDel control_law is t + interval/sqrt(count)
+ * We maintain in rec_inv_sqrt the reciprocal value of sqrt(count) to avoid
+ * both sqrt() and divide operation.
+ */
+static ktime_t cobalt_control(ktime_t t,
+ u64 interval,
+ u32 rec_inv_sqrt)
+{
+ return ktime_add_ns(t, reciprocal_scale(interval,
+ rec_inv_sqrt));
+}
+
+/* Call this when a packet had to be dropped due to queue overflow. Returns
+ * true if the BLUE state was quiescent before but active after this call.
+ */
+static bool cobalt_queue_full(struct cobalt_vars *vars,
+ struct cobalt_params *p,
+ ktime_t now)
+{
+ bool up = false;
+
+ if (ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) {
+ up = !vars->p_drop;
+ vars->p_drop += p->p_inc;
+ if (vars->p_drop < p->p_inc)
+ vars->p_drop = ~0;
+ vars->blue_timer = now;
+ }
+ vars->dropping = true;
+ vars->drop_next = now;
+ if (!vars->count)
+ vars->count = 1;
+
+ return up;
+}
+
+/* Call this when the queue was serviced but turned out to be empty. Returns
+ * true if the BLUE state was active before but quiescent after this call.
+ */
+static bool cobalt_queue_empty(struct cobalt_vars *vars,
+ struct cobalt_params *p,
+ ktime_t now)
+{
+ bool down = false;
+
+ if (vars->p_drop &&
+ ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) {
+ if (vars->p_drop < p->p_dec)
+ vars->p_drop = 0;
+ else
+ vars->p_drop -= p->p_dec;
+ vars->blue_timer = now;
+ down = !vars->p_drop;
+ }
+ vars->dropping = false;
+
+ if (vars->count && ktime_to_ns(ktime_sub(now, vars->drop_next)) >= 0) {
+ vars->count--;
+ cobalt_invsqrt(vars);
+ vars->drop_next = cobalt_control(vars->drop_next,
+ p->interval,
+ vars->rec_inv_sqrt);
+ }
+
+ return down;
+}
+
+/* Call this with a freshly dequeued packet for possible congestion marking.
+ * Returns true as an instruction to drop the packet, false for delivery.
+ */
+static bool cobalt_should_drop(struct cobalt_vars *vars,
+ struct cobalt_params *p,
+ ktime_t now,
+ struct sk_buff *skb)
+{
+ bool next_due, over_target, drop = false;
+ ktime_t schedule;
+ u64 sojourn;
+
+/* The 'schedule' variable records, in its sign, whether 'now' is before or
+ * after 'drop_next'. This allows 'drop_next' to be updated before the next
+ * scheduling decision is actually branched, without destroying that
+ * information. Similarly, the first 'schedule' value calculated is preserved
+ * in the boolean 'next_due'.
+ *
+ * As for 'drop_next', we take advantage of the fact that 'interval' is both
+ * the delay between first exceeding 'target' and the first signalling event,
+ * *and* the scaling factor for the signalling frequency. It's therefore very
+ * natural to use a single mechanism for both purposes, and eliminates a
+ * significant amount of reference Codel's spaghetti code. To help with this,
+ * both the '0' and '1' entries in the invsqrt cache are 0xFFFFFFFF, as close
+ * as possible to 1.0 in fixed-point.
+ */
+
+ sojourn = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
+ schedule = ktime_sub(now, vars->drop_next);
+ over_target = sojourn > p->target &&
+ sojourn > p->mtu_time * 4;
+ next_due = vars->count && ktime_to_ns(schedule) >= 0;
+
+ vars->ecn_marked = false;
+
+ if (over_target) {
+ if (!vars->dropping) {
+ vars->dropping = true;
+ vars->drop_next = cobalt_control(now,
+ p->interval,
+ vars->rec_inv_sqrt);
+ }
+ if (!vars->count)
+ vars->count = 1;
+ } else if (vars->dropping) {
+ vars->dropping = false;
+ }
+
+ if (next_due && vars->dropping) {
+ /* Use ECN mark if possible, otherwise drop */
+ drop = !(vars->ecn_marked = INET_ECN_set_ce(skb));
+
+ vars->count++;
+ if (!vars->count)
+ vars->count--;
+ cobalt_invsqrt(vars);
+ vars->drop_next = cobalt_control(vars->drop_next,
+ p->interval,
+ vars->rec_inv_sqrt);
+ schedule = ktime_sub(now, vars->drop_next);
+ } else {
+ while (next_due) {
+ vars->count--;
+ cobalt_invsqrt(vars);
+ vars->drop_next = cobalt_control(vars->drop_next,
+ p->interval,
+ vars->rec_inv_sqrt);
+ schedule = ktime_sub(now, vars->drop_next);
+ next_due = vars->count && ktime_to_ns(schedule) >= 0;
+ }
+ }
+
+ /* Simple BLUE implementation. Lack of ECN is deliberate. */
+ if (vars->p_drop)
+ drop |= (prandom_u32() < vars->p_drop);
+
+ /* Overload the drop_next field as an activity timeout */
+ if (!vars->count)
+ vars->drop_next = ktime_add_ns(now, p->interval);
+ else if (ktime_to_ns(schedule) > 0 && !drop)
+ vars->drop_next = now;
+
+ return drop;
+}
+
+/* Cake has several subtle multiple bit settings. In these cases you
+ * would be matching triple isolate mode as well.
+ */
+
+static bool cake_dsrc(int flow_mode)
+{
+ return (flow_mode & CAKE_FLOW_DUAL_SRC) == CAKE_FLOW_DUAL_SRC;
+}
+
+static bool cake_ddst(int flow_mode)
+{
+ return (flow_mode & CAKE_FLOW_DUAL_DST) == CAKE_FLOW_DUAL_DST;
+}
+
+static u32 cake_hash(struct cake_tin_data *q, const struct sk_buff *skb,
+ int flow_mode)
+{
+ u32 flow_hash = 0, srchost_hash, dsthost_hash;
+ u16 reduced_hash, srchost_idx, dsthost_idx;
+ struct flow_keys keys, host_keys;
+
+ if (unlikely(flow_mode == CAKE_FLOW_NONE))
+ return 0;
+
+ skb_flow_dissect_flow_keys(skb, &keys,
+ FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
+
+ /* flow_hash_from_keys() sorts the addresses by value, so we have
+ * to preserve their order in a separate data structure to treat
+ * src and dst host addresses as independently selectable.
+ */
+ host_keys = keys;
+ host_keys.ports.ports = 0;
+ host_keys.basic.ip_proto = 0;
+ host_keys.keyid.keyid = 0;
+ host_keys.tags.flow_label = 0;
+
+ switch (host_keys.control.addr_type) {
+ case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
+ host_keys.addrs.v4addrs.src = 0;
+ dsthost_hash = flow_hash_from_keys(&host_keys);
+ host_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
+ host_keys.addrs.v4addrs.dst = 0;
+ srchost_hash = flow_hash_from_keys(&host_keys);
+ break;
+
+ case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
+ memset(&host_keys.addrs.v6addrs.src, 0,
+ sizeof(host_keys.addrs.v6addrs.src));
+ dsthost_hash = flow_hash_from_keys(&host_keys);
+ host_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
+ memset(&host_keys.addrs.v6addrs.dst, 0,
+ sizeof(host_keys.addrs.v6addrs.dst));
+ srchost_hash = flow_hash_from_keys(&host_keys);
+ break;
+
+ default:
+ dsthost_hash = 0;
+ srchost_hash = 0;
+ }
+
+ /* This *must* be after the above switch, since as a
+ * side-effect it sorts the src and dst addresses.
+ */
+ if (flow_mode & CAKE_FLOW_FLOWS)
+ flow_hash = flow_hash_from_keys(&keys);
+
+ if (!(flow_mode & CAKE_FLOW_FLOWS)) {
+ if (flow_mode & CAKE_FLOW_SRC_IP)
+ flow_hash ^= srchost_hash;
+
+ if (flow_mode & CAKE_FLOW_DST_IP)
+ flow_hash ^= dsthost_hash;
+ }
+
+ reduced_hash = flow_hash % CAKE_QUEUES;
+
+ /* set-associative hashing */
+ /* fast path if no hash collision (direct lookup succeeds) */
+ if (likely(q->tags[reduced_hash] == flow_hash &&
+ q->flows[reduced_hash].set)) {
+ q->way_directs++;
+ } else {
+ u32 inner_hash = reduced_hash % CAKE_SET_WAYS;
+ u32 outer_hash = reduced_hash - inner_hash;
+ bool allocate_src = false;
+ bool allocate_dst = false;
+ u32 i, k;
+
+ /* check if any active queue in the set is reserved for
+ * this flow.
+ */
+ for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
+ i++, k = (k + 1) % CAKE_SET_WAYS) {
+ if (q->tags[outer_hash + k] == flow_hash) {
+ if (i)
+ q->way_hits++;
+
+ if (!q->flows[outer_hash + k].set) {
+ /* need to increment host refcnts */
+ allocate_src = cake_dsrc(flow_mode);
+ allocate_dst = cake_ddst(flow_mode);
+ }
+
+ goto found;
+ }
+ }
+
+ /* no queue is reserved for this flow, look for an
+ * empty one.
+ */
+ for (i = 0; i < CAKE_SET_WAYS;
+ i++, k = (k + 1) % CAKE_SET_WAYS) {
+ if (!q->flows[outer_hash + k].set) {
+ q->way_misses++;
+ allocate_src = cake_dsrc(flow_mode);
+ allocate_dst = cake_ddst(flow_mode);
+ goto found;
+ }
+ }
+
+ /* With no empty queues, default to the original
+ * queue, accept the collision, update the host tags.
+ */
+ q->way_collisions++;
+ q->hosts[q->flows[reduced_hash].srchost].srchost_refcnt--;
+ q->hosts[q->flows[reduced_hash].dsthost].dsthost_refcnt--;
+ allocate_src = cake_dsrc(flow_mode);
+ allocate_dst = cake_ddst(flow_mode);
+found:
+ /* reserve queue for future packets in same flow */
+ reduced_hash = outer_hash + k;
+ q->tags[reduced_hash] = flow_hash;
+
+ if (allocate_src) {
+ srchost_idx = srchost_hash % CAKE_QUEUES;
+ inner_hash = srchost_idx % CAKE_SET_WAYS;
+ outer_hash = srchost_idx - inner_hash;
+ for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
+ i++, k = (k + 1) % CAKE_SET_WAYS) {
+ if (q->hosts[outer_hash + k].srchost_tag ==
+ srchost_hash)
+ goto found_src;
+ }
+ for (i = 0; i < CAKE_SET_WAYS;
+ i++, k = (k + 1) % CAKE_SET_WAYS) {
+ if (!q->hosts[outer_hash + k].srchost_refcnt)
+ break;
+ }
+ q->hosts[outer_hash + k].srchost_tag = srchost_hash;
+found_src:
+ srchost_idx = outer_hash + k;
+ q->hosts[srchost_idx].srchost_refcnt++;
+ q->flows[reduced_hash].srchost = srchost_idx;
+ }
+
+ if (allocate_dst) {
+ dsthost_idx = dsthost_hash % CAKE_QUEUES;
+ inner_hash = dsthost_idx % CAKE_SET_WAYS;
+ outer_hash = dsthost_idx - inner_hash;
+ for (i = 0, k = inner_hash; i < CAKE_SET_WAYS;
+ i++, k = (k + 1) % CAKE_SET_WAYS) {
+ if (q->hosts[outer_hash + k].dsthost_tag ==
+ dsthost_hash)
+ goto found_dst;
+ }
+ for (i = 0; i < CAKE_SET_WAYS;
+ i++, k = (k + 1) % CAKE_SET_WAYS) {
+ if (!q->hosts[outer_hash + k].dsthost_refcnt)
+ break;
+ }
+ q->hosts[outer_hash + k].dsthost_tag = dsthost_hash;
+found_dst:
+ dsthost_idx = outer_hash + k;
+ q->hosts[dsthost_idx].dsthost_refcnt++;
+ q->flows[reduced_hash].dsthost = dsthost_idx;
+ }
+ }
+
+ return reduced_hash;
+}
+
+static u32 cake_classify(struct Qdisc *sch, struct cake_tin_data *t,
+ struct sk_buff *skb, int flow_mode, int *qerr)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct tcf_proto *filter;
+ struct tcf_result res;
+ int result;
+
+ filter = rcu_dereference_bh(q->filter_list);
+ if (!filter)
+ return cake_hash(t, skb, flow_mode) + 1;
+
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+ result = tcf_classify(skb, filter, &res, false);
+ if (result >= 0) {
+#ifdef CONFIG_NET_CLS_ACT
+ switch (result) {
+ case TC_ACT_STOLEN:
+ case TC_ACT_QUEUED:
+ case TC_ACT_TRAP:
+ *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+ /* fall through */
+ case TC_ACT_SHOT:
+ return 0;
+ }
+#endif
+ if (TC_H_MIN(res.classid) <= CAKE_QUEUES)
+ return TC_H_MIN(res.classid);
+ }
+ return 0;
+}
+
+/* helper functions : might be changed when/if skb use a standard list_head */
+/* remove one skb from head of slot queue */
+
+static struct sk_buff *dequeue_head(struct cake_flow *flow)
+{
+ struct sk_buff *skb = flow->head;
+
+ if (skb) {
+ flow->head = skb->next;
+ skb->next = NULL;
+ }
+
+ return skb;
+}
+
+/* add skb to flow queue (tail add) */
+
+static void flow_queue_add(struct cake_flow *flow, struct sk_buff *skb)
+{
+ if (!flow->head)
+ flow->head = skb;
+ else
+ flow->tail->next = skb;
+ flow->tail = skb;
+ skb->next = NULL;
+}
+
+static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
+{
+ avg -= avg >> shift;
+ avg += sample >> shift;
+ return avg;
+}
+
+static void cake_heap_swap(struct cake_sched_data *q, u16 i, u16 j)
+{
+ struct cake_heap_entry ii = q->overflow_heap[i];
+ struct cake_heap_entry jj = q->overflow_heap[j];
+
+ q->overflow_heap[i] = jj;
+ q->overflow_heap[j] = ii;
+
+ q->tins[ii.t].overflow_idx[ii.b] = j;
+ q->tins[jj.t].overflow_idx[jj.b] = i;
+}
+
+static u32 cake_heap_get_backlog(const struct cake_sched_data *q, u16 i)
+{
+ struct cake_heap_entry ii = q->overflow_heap[i];
+
+ return q->tins[ii.t].backlogs[ii.b];
+}
+
+static void cake_heapify(struct cake_sched_data *q, u16 i)
+{
+ static const u32 a = CAKE_MAX_TINS * CAKE_QUEUES;
+ u32 mb = cake_heap_get_backlog(q, i);
+ u32 m = i;
+
+ while (m < a) {
+ u32 l = m + m + 1;
+ u32 r = l + 1;
+
+ if (l < a) {
+ u32 lb = cake_heap_get_backlog(q, l);
+
+ if (lb > mb) {
+ m = l;
+ mb = lb;
+ }
+ }
+
+ if (r < a) {
+ u32 rb = cake_heap_get_backlog(q, r);
+
+ if (rb > mb) {
+ m = r;
+ mb = rb;
+ }
+ }
+
+ if (m != i) {
+ cake_heap_swap(q, i, m);
+ i = m;
+ } else {
+ break;
+ }
+ }
+}
+
+static void cake_heapify_up(struct cake_sched_data *q, u16 i)
+{
+ while (i > 0 && i < CAKE_MAX_TINS * CAKE_QUEUES) {
+ u16 p = (i - 1) >> 1;
+ u32 ib = cake_heap_get_backlog(q, i);
+ u32 pb = cake_heap_get_backlog(q, p);
+
+ if (ib > pb) {
+ cake_heap_swap(q, i, p);
+ i = p;
+ } else {
+ break;
+ }
+ }
+}
+
+static int cake_advance_shaper(struct cake_sched_data *q,
+ struct cake_tin_data *b,
+ struct sk_buff *skb,
+ ktime_t now, bool drop)
+{
+ u32 len = qdisc_pkt_len(skb);
+
+ /* charge packet bandwidth to this tin
+ * and to the global shaper.
+ */
+ if (q->rate_ns) {
+ u64 tin_dur = (len * b->tin_rate_ns) >> b->tin_rate_shft;
+ u64 global_dur = (len * q->rate_ns) >> q->rate_shft;
+ u64 failsafe_dur = global_dur + (global_dur >> 1);
+
+ if (ktime_before(b->time_next_packet, now))
+ b->time_next_packet = ktime_add_ns(b->time_next_packet,
+ tin_dur);
+
+ else if (ktime_before(b->time_next_packet,
+ ktime_add_ns(now, tin_dur)))
+ b->time_next_packet = ktime_add_ns(now, tin_dur);
+
+ q->time_next_packet = ktime_add_ns(q->time_next_packet,
+ global_dur);
+ if (!drop)
+ q->failsafe_next_packet = \
+ ktime_add_ns(q->failsafe_next_packet,
+ failsafe_dur);
+ }
+ return len;
+}
+
+static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ ktime_t now = ktime_get();
+ u32 idx = 0, tin = 0, len;
+ struct cake_heap_entry qq;
+ struct cake_tin_data *b;
+ struct cake_flow *flow;
+ struct sk_buff *skb;
+
+ if (!q->overflow_timeout) {
+ int i;
+ /* Build fresh max-heap */
+ for (i = CAKE_MAX_TINS * CAKE_QUEUES / 2; i >= 0; i--)
+ cake_heapify(q, i);
+ }
+ q->overflow_timeout = 65535;
+
+ /* select longest queue for pruning */
+ qq = q->overflow_heap[0];
+ tin = qq.t;
+ idx = qq.b;
+
+ b = &q->tins[tin];
+ flow = &b->flows[idx];
+ skb = dequeue_head(flow);
+ if (unlikely(!skb)) {
+ /* heap has gone wrong, rebuild it next time */
+ q->overflow_timeout = 0;
+ return idx + (tin << 16);
+ }
+
+ if (cobalt_queue_full(&flow->cvars, &b->cparams, now))
+ b->unresponsive_flow_count++;
+
+ len = qdisc_pkt_len(skb);
+ q->buffer_used -= skb->truesize;
+ b->backlogs[idx] -= len;
+ b->tin_backlog -= len;
+ sch->qstats.backlog -= len;
+ qdisc_tree_reduce_backlog(sch, 1, len);
+
+ flow->dropped++;
+ b->tin_dropped++;
+ sch->qstats.drops++;
+
+ __qdisc_drop(skb, to_free);
+ sch->q.qlen--;
+
+ cake_heapify(q, 0);
+
+ return idx + (tin << 16);
+}
+
+static void cake_reconfigure(struct Qdisc *sch);
+
+static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+ struct sk_buff **to_free)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ int len = qdisc_pkt_len(skb);
+ int uninitialized_var(ret);
+ ktime_t now = ktime_get();
+ struct cake_tin_data *b;
+ struct cake_flow *flow;
+ u32 idx, tin;
+
+ tin = 0;
+ b = &q->tins[tin];
+
+ /* choose flow to insert into */
+ idx = cake_classify(sch, b, skb, q->flow_mode, &ret);
+ if (idx == 0) {
+ if (ret & __NET_XMIT_BYPASS)
+ qdisc_qstats_drop(sch);
+ __qdisc_drop(skb, to_free);
+ return ret;
+ }
+ idx--;
+ flow = &b->flows[idx];
+
+ /* ensure shaper state isn't stale */
+ if (!b->tin_backlog) {
+ if (ktime_before(b->time_next_packet, now))
+ b->time_next_packet = now;
+
+ if (!sch->q.qlen) {
+ if (ktime_before(q->time_next_packet, now)) {
+ q->failsafe_next_packet = now;
+ q->time_next_packet = now;
+ } else if (ktime_after(q->time_next_packet, now) &&
+ ktime_after(q->failsafe_next_packet, now)) {
+ u64 next = \
+ min(ktime_to_ns(q->time_next_packet),
+ ktime_to_ns(
+ q->failsafe_next_packet));
+ sch->qstats.overlimits++;
+ qdisc_watchdog_schedule_ns(&q->watchdog, next);
+ }
+ }
+ }
+
+ if (unlikely(len > b->max_skblen))
+ b->max_skblen = len;
+
+ cobalt_set_enqueue_time(skb, now);
+ flow_queue_add(flow, skb);
+
+ sch->q.qlen++;
+ q->buffer_used += skb->truesize;
+
+ /* stats */
+ b->packets++;
+ b->bytes += len;
+ b->backlogs[idx] += len;
+ b->tin_backlog += len;
+ sch->qstats.backlog += len;
+ q->avg_window_bytes += len;
+
+ if (q->overflow_timeout)
+ cake_heapify_up(q, b->overflow_idx[idx]);
+
+ /* incoming bandwidth capacity estimate */
+ q->avg_window_bytes = 0;
+ q->last_packet_time = now;
+
+ /* flowchain */
+ if (!flow->set || flow->set == CAKE_SET_DECAYING) {
+ struct cake_host *srchost = &b->hosts[flow->srchost];
+ struct cake_host *dsthost = &b->hosts[flow->dsthost];
+ u16 host_load = 1;
+
+ if (!flow->set) {
+ list_add_tail(&flow->flowchain, &b->new_flows);
+ } else {
+ b->decaying_flow_count--;
+ list_move_tail(&flow->flowchain, &b->new_flows);
+ }
+ flow->set = CAKE_SET_SPARSE;
+ b->sparse_flow_count++;
+
+ if (cake_dsrc(q->flow_mode))
+ host_load = max(host_load, srchost->srchost_refcnt);
+
+ if (cake_ddst(q->flow_mode))
+ host_load = max(host_load, dsthost->dsthost_refcnt);
+
+ flow->deficit = (b->flow_quantum *
+ quantum_div[host_load]) >> 16;
+ } else if (flow->set == CAKE_SET_SPARSE_WAIT) {
+ /* this flow was empty, accounted as a sparse flow, but actually
+ * in the bulk rotation.
+ */
+ flow->set = CAKE_SET_BULK;
+ b->sparse_flow_count--;
+ b->bulk_flow_count++;
+ }
+
+ if (q->buffer_used > q->buffer_max_used)
+ q->buffer_max_used = q->buffer_used;
+
+ if (q->buffer_used > q->buffer_limit) {
+ u32 dropped = 0;
+
+ while (q->buffer_used > q->buffer_limit) {
+ dropped++;
+ cake_drop(sch, to_free);
+ }
+ b->drop_overlimit += dropped;
+ }
+ return NET_XMIT_SUCCESS;
+}
+
+static struct sk_buff *cake_dequeue_one(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct cake_tin_data *b = &q->tins[q->cur_tin];
+ struct cake_flow *flow = &b->flows[q->cur_flow];
+ struct sk_buff *skb = NULL;
+ u32 len;
+
+ if (flow->head) {
+ skb = dequeue_head(flow);
+ len = qdisc_pkt_len(skb);
+ b->backlogs[q->cur_flow] -= len;
+ b->tin_backlog -= len;
+ sch->qstats.backlog -= len;
+ q->buffer_used -= skb->truesize;
+ sch->q.qlen--;
+
+ if (q->overflow_timeout)
+ cake_heapify(q, b->overflow_idx[q->cur_flow]);
+ }
+ return skb;
+}
+
+/* Discard leftover packets from a tin no longer in use. */
+static void cake_clear_tin(struct Qdisc *sch, u16 tin)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct sk_buff *skb;
+
+ q->cur_tin = tin;
+ for (q->cur_flow = 0; q->cur_flow < CAKE_QUEUES; q->cur_flow++)
+ while (!!(skb = cake_dequeue_one(sch)))
+ kfree_skb(skb);
+}
+
+static struct sk_buff *cake_dequeue(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct cake_tin_data *b = &q->tins[q->cur_tin];
+ struct cake_host *srchost, *dsthost;
+ ktime_t now = ktime_get();
+ struct cake_flow *flow;
+ struct list_head *head;
+ bool first_flow = true;
+ struct sk_buff *skb;
+ u16 host_load;
+ u64 delay;
+ u32 len;
+
+begin:
+ if (!sch->q.qlen)
+ return NULL;
+
+ /* global hard shaper */
+ if (ktime_after(q->time_next_packet, now) &&
+ ktime_after(q->failsafe_next_packet, now)) {
+ u64 next = min(ktime_to_ns(q->time_next_packet),
+ ktime_to_ns(q->failsafe_next_packet));
+
+ sch->qstats.overlimits++;
+ qdisc_watchdog_schedule_ns(&q->watchdog, next);
+ return NULL;
+ }
+
+ /* Choose a class to work on. */
+ if (!q->rate_ns) {
+ /* In unlimited mode, can't rely on shaper timings, just balance
+ * with DRR
+ */
+ while (b->tin_deficit < 0 ||
+ !(b->sparse_flow_count + b->bulk_flow_count)) {
+ if (b->tin_deficit <= 0)
+ b->tin_deficit += b->tin_quantum_band;
+
+ q->cur_tin++;
+ b++;
+ if (q->cur_tin >= q->tin_cnt) {
+ q->cur_tin = 0;
+ b = q->tins;
+ }
+ }
+ } else {
+ /* In shaped mode, choose:
+ * - Highest-priority tin with queue and meeting schedule, or
+ * - The earliest-scheduled tin with queue.
+ */
+ ktime_t best_time = KTIME_MAX;
+ int tin, best_tin = 0;
+
+ for (tin = 0; tin < q->tin_cnt; tin++) {
+ b = q->tins + tin;
+ if ((b->sparse_flow_count + b->bulk_flow_count) > 0) {
+ ktime_t time_to_pkt = \
+ ktime_sub(b->time_next_packet, now);
+
+ if (ktime_to_ns(time_to_pkt) <= 0 ||
+ ktime_compare(time_to_pkt,
+ best_time) <= 0) {
+ best_time = time_to_pkt;
+ best_tin = tin;
+ }
+ }
+ }
+
+ q->cur_tin = best_tin;
+ b = q->tins + best_tin;
+ }
+
+retry:
+ /* service this class */
+ head = &b->decaying_flows;
+ if (!first_flow || list_empty(head)) {
+ head = &b->new_flows;
+ if (list_empty(head)) {
+ head = &b->old_flows;
+ if (unlikely(list_empty(head))) {
+ head = &b->decaying_flows;
+ if (unlikely(list_empty(head)))
+ goto begin;
+ }
+ }
+ }
+ flow = list_first_entry(head, struct cake_flow, flowchain);
+ q->cur_flow = flow - b->flows;
+ first_flow = false;
+
+ /* triple isolation (modified DRR++) */
+ srchost = &b->hosts[flow->srchost];
+ dsthost = &b->hosts[flow->dsthost];
+ host_load = 1;
+
+ if (cake_dsrc(q->flow_mode))
+ host_load = max(host_load, srchost->srchost_refcnt);
+
+ if (cake_ddst(q->flow_mode))
+ host_load = max(host_load, dsthost->dsthost_refcnt);
+
+ WARN_ON(host_load > CAKE_QUEUES);
+
+ /* flow isolation (DRR++) */
+ if (flow->deficit <= 0) {
+ /* The shifted prandom_u32() is a way to apply dithering to
+ * avoid accumulating roundoff errors
+ */
+ flow->deficit += (b->flow_quantum * quantum_div[host_load] +
+ (prandom_u32() >> 16)) >> 16;
+ list_move_tail(&flow->flowchain, &b->old_flows);
+
+ /* Keep all flows with deficits out of the sparse and decaying
+ * rotations. No non-empty flow can go into the decaying
+ * rotation, so they can't get deficits
+ */
+ if (flow->set == CAKE_SET_SPARSE) {
+ if (flow->head) {
+ b->sparse_flow_count--;
+ b->bulk_flow_count++;
+ flow->set = CAKE_SET_BULK;
+ } else {
+ /* we've moved it to the bulk rotation for
+ * correct deficit accounting but we still want
+ * to count it as a sparse flow, not a bulk one.
+ */
+ flow->set = CAKE_SET_SPARSE_WAIT;
+ }
+ }
+ goto retry;
+ }
+
+ /* Retrieve a packet via the AQM */
+ while (1) {
+ skb = cake_dequeue_one(sch);
+ if (!skb) {
+ /* this queue was actually empty */
+ if (cobalt_queue_empty(&flow->cvars, &b->cparams, now))
+ b->unresponsive_flow_count--;
+
+ if (flow->cvars.p_drop || flow->cvars.count ||
+ ktime_before(now, flow->cvars.drop_next)) {
+ /* keep in the flowchain until the state has
+ * decayed to rest
+ */
+ list_move_tail(&flow->flowchain,
+ &b->decaying_flows);
+ if (flow->set == CAKE_SET_BULK) {
+ b->bulk_flow_count--;
+ b->decaying_flow_count++;
+ } else if (flow->set == CAKE_SET_SPARSE ||
+ flow->set == CAKE_SET_SPARSE_WAIT) {
+ b->sparse_flow_count--;
+ b->decaying_flow_count++;
+ }
+ flow->set = CAKE_SET_DECAYING;
+ } else {
+ /* remove empty queue from the flowchain */
+ list_del_init(&flow->flowchain);
+ if (flow->set == CAKE_SET_SPARSE ||
+ flow->set == CAKE_SET_SPARSE_WAIT)
+ b->sparse_flow_count--;
+ else if (flow->set == CAKE_SET_BULK)
+ b->bulk_flow_count--;
+ else
+ b->decaying_flow_count--;
+
+ flow->set = CAKE_SET_NONE;
+ srchost->srchost_refcnt--;
+ dsthost->dsthost_refcnt--;
+ }
+ goto begin;
+ }
+
+ /* Last packet in queue may be marked, shouldn't be dropped */
+ if (!cobalt_should_drop(&flow->cvars, &b->cparams, now, skb) ||
+ !flow->head)
+ break;
+
+ flow->dropped++;
+ b->tin_dropped++;
+ qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
+ qdisc_qstats_drop(sch);
+ kfree_skb(skb);
+ }
+
+ b->tin_ecn_mark += !!flow->cvars.ecn_marked;
+ qdisc_bstats_update(sch, skb);
+
+ /* collect delay stats */
+ delay = ktime_to_ns(ktime_sub(now, cobalt_get_enqueue_time(skb)));
+ b->avge_delay = cake_ewma(b->avge_delay, delay, 8);
+ b->peak_delay = cake_ewma(b->peak_delay, delay,
+ delay > b->peak_delay ? 2 : 8);
+ b->base_delay = cake_ewma(b->base_delay, delay,
+ delay < b->base_delay ? 2 : 8);
+
+ len = cake_advance_shaper(q, b, skb, now, false);
+ flow->deficit -= len;
+ b->tin_deficit -= len;
+
+ if (ktime_after(q->time_next_packet, now) && sch->q.qlen) {
+ u64 next = min(ktime_to_ns(q->time_next_packet),
+ ktime_to_ns(q->failsafe_next_packet));
+
+ qdisc_watchdog_schedule_ns(&q->watchdog, next);
+ } else if (!sch->q.qlen) {
+ int i;
+
+ for (i = 0; i < q->tin_cnt; i++) {
+ if (q->tins[i].decaying_flow_count) {
+ ktime_t next = \
+ ktime_add_ns(now,
+ q->tins[i].cparams.target);
+
+ qdisc_watchdog_schedule_ns(&q->watchdog,
+ ktime_to_ns(next));
+ break;
+ }
+ }
+ }
+
+ if (q->overflow_timeout)
+ q->overflow_timeout--;
+
+ return skb;
+}
+
+static void cake_reset(struct Qdisc *sch)
+{
+ u32 c;
+
+ for (c = 0; c < CAKE_MAX_TINS; c++)
+ cake_clear_tin(sch, c);
+}
+
+static const struct nla_policy cake_policy[TCA_CAKE_MAX + 1] = {
+ [TCA_CAKE_BASE_RATE64] = { .type = NLA_U64 },
+ [TCA_CAKE_DIFFSERV_MODE] = { .type = NLA_U32 },
+ [TCA_CAKE_ATM] = { .type = NLA_U32 },
+ [TCA_CAKE_FLOW_MODE] = { .type = NLA_U32 },
+ [TCA_CAKE_OVERHEAD] = { .type = NLA_S32 },
+ [TCA_CAKE_RTT] = { .type = NLA_U32 },
+ [TCA_CAKE_TARGET] = { .type = NLA_U32 },
+ [TCA_CAKE_AUTORATE] = { .type = NLA_U32 },
+ [TCA_CAKE_MEMORY] = { .type = NLA_U32 },
+ [TCA_CAKE_NAT] = { .type = NLA_U32 },
+ [TCA_CAKE_RAW] = { .type = NLA_U32 },
+ [TCA_CAKE_WASH] = { .type = NLA_U32 },
+ [TCA_CAKE_MPU] = { .type = NLA_U32 },
+ [TCA_CAKE_INGRESS] = { .type = NLA_U32 },
+ [TCA_CAKE_ACK_FILTER] = { .type = NLA_U32 },
+};
+
+static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu,
+ u64 target_ns, u64 rtt_est_ns)
+{
+ /* convert byte-rate into time-per-byte
+ * so it will always unwedge in reasonable time.
+ */
+ static const u64 MIN_RATE = 64;
+ u32 byte_target = mtu;
+ u64 byte_target_ns;
+ u8 rate_shft = 0;
+ u64 rate_ns = 0;
+
+ b->flow_quantum = 1514;
+ if (rate) {
+ b->flow_quantum = max(min(rate >> 12, 1514ULL), 300ULL);
+ rate_shft = 34;
+ rate_ns = ((u64)NSEC_PER_SEC) << rate_shft;
+ rate_ns = div64_u64(rate_ns, max(MIN_RATE, rate));
+ while (!!(rate_ns >> 34)) {
+ rate_ns >>= 1;
+ rate_shft--;
+ }
+ } /* else unlimited, ie. zero delay */
+
+ b->tin_rate_bps = rate;
+ b->tin_rate_ns = rate_ns;
+ b->tin_rate_shft = rate_shft;
+
+ byte_target_ns = (byte_target * rate_ns) >> rate_shft;
+
+ b->cparams.target = max((byte_target_ns * 3) / 2, target_ns);
+ b->cparams.interval = max(rtt_est_ns +
+ b->cparams.target - target_ns,
+ b->cparams.target * 2);
+ b->cparams.mtu_time = byte_target_ns;
+ b->cparams.p_inc = 1 << 24; /* 1/256 */
+ b->cparams.p_dec = 1 << 20; /* 1/4096 */
+}
+
+static void cake_reconfigure(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct cake_tin_data *b = &q->tins[0];
+ int c, ft = 0;
+
+ q->tin_cnt = 1;
+ cake_set_rate(b, q->rate_bps, psched_mtu(qdisc_dev(sch)),
+ us_to_ns(q->target), us_to_ns(q->interval));
+ b->tin_quantum_band = 65535;
+ b->tin_quantum_prio = 65535;
+
+ for (c = q->tin_cnt; c < CAKE_MAX_TINS; c++) {
+ cake_clear_tin(sch, c);
+ q->tins[c].cparams.mtu_time = q->tins[ft].cparams.mtu_time;
+ }
+
+ q->rate_ns = q->tins[ft].tin_rate_ns;
+ q->rate_shft = q->tins[ft].tin_rate_shft;
+
+ if (q->buffer_config_limit) {
+ q->buffer_limit = q->buffer_config_limit;
+ } else if (q->rate_bps) {
+ u64 t = q->rate_bps * q->interval;
+
+ do_div(t, USEC_PER_SEC / 4);
+ q->buffer_limit = max_t(u32, t, 4U << 20);
+ } else {
+ q->buffer_limit = ~0;
+ }
+
+ sch->flags &= ~TCQ_F_CAN_BYPASS;
+
+ q->buffer_limit = min(q->buffer_limit,
+ max(sch->limit * psched_mtu(qdisc_dev(sch)),
+ q->buffer_config_limit));
+}
+
+static int cake_change(struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct nlattr *tb[TCA_CAKE_MAX + 1];
+ int err;
+
+ if (!opt)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_CAKE_MAX, opt, cake_policy, extack);
+ if (err < 0)
+ return err;
+
+ if (tb[TCA_CAKE_BASE_RATE64])
+ q->rate_bps = nla_get_u64(tb[TCA_CAKE_BASE_RATE64]);
+
+ if (tb[TCA_CAKE_FLOW_MODE])
+ q->flow_mode = (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
+ CAKE_FLOW_MASK);
+
+ if (tb[TCA_CAKE_RTT]) {
+ q->interval = nla_get_u32(tb[TCA_CAKE_RTT]);
+
+ if (!q->interval)
+ q->interval = 1;
+ }
+
+ if (tb[TCA_CAKE_TARGET]) {
+ q->target = nla_get_u32(tb[TCA_CAKE_TARGET]);
+
+ if (!q->target)
+ q->target = 1;
+ }
+
+ if (tb[TCA_CAKE_MEMORY])
+ q->buffer_config_limit = nla_get_u32(tb[TCA_CAKE_MEMORY]);
+
+ if (q->tins) {
+ sch_tree_lock(sch);
+ cake_reconfigure(sch);
+ sch_tree_unlock(sch);
+ }
+
+ return 0;
+}
+
+static void cake_destroy(struct Qdisc *sch)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+
+ qdisc_watchdog_cancel(&q->watchdog);
+ tcf_block_put(q->block);
+ kvfree(q->tins);
+}
+
+static int cake_init(struct Qdisc *sch, struct nlattr *opt,
+ struct netlink_ext_ack *extack)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ int i, j, err;
+
+ sch->limit = 10240;
+ q->tin_mode = CAKE_DIFFSERV_BESTEFFORT;
+ q->flow_mode = CAKE_FLOW_TRIPLE;
+
+ q->rate_bps = 0; /* unlimited by default */
+
+ q->interval = 100000; /* 100ms default */
+ q->target = 5000; /* 5ms: codel RFC argues
+ * for 5 to 10% of interval
+ */
+
+ q->cur_tin = 0;
+ q->cur_flow = 0;
+
+ if (opt) {
+ int err = cake_change(sch, opt, extack);
+
+ if (err)
+ return err;
+ }
+
+ err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
+ if (err)
+ return err;
+
+ qdisc_watchdog_init(&q->watchdog, sch);
+
+ quantum_div[0] = ~0;
+ for (i = 1; i <= CAKE_QUEUES; i++)
+ quantum_div[i] = 65535 / i;
+
+ q->tins = kvzalloc(CAKE_MAX_TINS * sizeof(struct cake_tin_data),
+ GFP_KERNEL);
+ if (!q->tins)
+ goto nomem;
+
+ for (i = 0; i < CAKE_MAX_TINS; i++) {
+ struct cake_tin_data *b = q->tins + i;
+
+ INIT_LIST_HEAD(&b->new_flows);
+ INIT_LIST_HEAD(&b->old_flows);
+ INIT_LIST_HEAD(&b->decaying_flows);
+ b->sparse_flow_count = 0;
+ b->bulk_flow_count = 0;
+ b->decaying_flow_count = 0;
+
+ for (j = 0; j < CAKE_QUEUES; j++) {
+ struct cake_flow *flow = b->flows + j;
+ u32 k = j * CAKE_MAX_TINS + i;
+
+ INIT_LIST_HEAD(&flow->flowchain);
+ cobalt_vars_init(&flow->cvars);
+
+ q->overflow_heap[k].t = i;
+ q->overflow_heap[k].b = j;
+ b->overflow_idx[j] = k;
+ }
+ }
+
+ cake_reconfigure(sch);
+ q->avg_peak_bandwidth = q->rate_bps;
+ q->min_netlen = ~0;
+ q->min_adjlen = ~0;
+ return 0;
+
+nomem:
+ cake_destroy(sch);
+ return -ENOMEM;
+}
+
+static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct nlattr *opts;
+
+ opts = nla_nest_start(skb, TCA_OPTIONS);
+ if (!opts)
+ goto nla_put_failure;
+
+ if (nla_put_u64_64bit(skb, TCA_CAKE_BASE_RATE64, q->rate_bps,
+ TCA_CAKE_PAD))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_FLOW_MODE,
+ q->flow_mode & CAKE_FLOW_MASK))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_RTT, q->interval))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_TARGET, q->target))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_MEMORY, q->buffer_config_limit))
+ goto nla_put_failure;
+
+ return nla_nest_end(skb, opts);
+
+nla_put_failure:
+ return -1;
+}
+
+static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
+{
+ struct nlattr *stats = nla_nest_start(d->skb, TCA_STATS_APP);
+ struct cake_sched_data *q = qdisc_priv(sch);
+ struct nlattr *tstats, *ts;
+ int i;
+
+ if (!stats)
+ return -1;
+
+#define PUT_STAT_U32(attr, data) do { \
+ if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
+ goto nla_put_failure; \
+ } while (0)
+#define PUT_STAT_U64(attr, data) do { \
+ if (nla_put_u64_64bit(d->skb, TCA_CAKE_STATS_ ## attr, \
+ data, TCA_CAKE_STATS_PAD)) \
+ goto nla_put_failure; \
+ } while (0)
+
+ PUT_STAT_U64(CAPACITY_ESTIMATE64, q->avg_peak_bandwidth);
+ PUT_STAT_U32(MEMORY_LIMIT, q->buffer_limit);
+ PUT_STAT_U32(MEMORY_USED, q->buffer_max_used);
+ PUT_STAT_U32(AVG_NETOFF, ((q->avg_netoff + 0x8000) >> 16));
+ PUT_STAT_U32(MAX_NETLEN, q->max_netlen);
+ PUT_STAT_U32(MAX_ADJLEN, q->max_adjlen);
+ PUT_STAT_U32(MIN_NETLEN, q->min_netlen);
+ PUT_STAT_U32(MIN_ADJLEN, q->min_adjlen);
+
+#undef PUT_STAT_U32
+#undef PUT_STAT_U64
+
+ tstats = nla_nest_start(d->skb, TCA_CAKE_STATS_TIN_STATS);
+ if (!tstats)
+ goto nla_put_failure;
+
+#define PUT_TSTAT_U32(attr, data) do { \
+ if (nla_put_u32(d->skb, TCA_CAKE_TIN_STATS_ ## attr, data)) \
+ goto nla_put_failure; \
+ } while (0)
+#define PUT_TSTAT_U64(attr, data) do { \
+ if (nla_put_u64_64bit(d->skb, TCA_CAKE_TIN_STATS_ ## attr, \
+ data, TCA_CAKE_TIN_STATS_PAD)) \
+ goto nla_put_failure; \
+ } while (0)
+
+ for (i = 0; i < q->tin_cnt; i++) {
+ struct cake_tin_data *b = &q->tins[i];
+
+ ts = nla_nest_start(d->skb, i + 1);
+ if (!ts)
+ goto nla_put_failure;
+
+ PUT_TSTAT_U64(THRESHOLD_RATE64, b->tin_rate_bps);
+ PUT_TSTAT_U64(SENT_BYTES64, b->bytes);
+ PUT_TSTAT_U32(BACKLOG_BYTES, b->tin_backlog);
+
+ PUT_TSTAT_U32(TARGET_US,
+ ktime_to_us(ns_to_ktime(b->cparams.target)));
+ PUT_TSTAT_U32(INTERVAL_US,
+ ktime_to_us(ns_to_ktime(b->cparams.interval)));
+
+ PUT_TSTAT_U32(SENT_PACKETS, b->packets);
+ PUT_TSTAT_U32(DROPPED_PACKETS, b->tin_dropped);
+ PUT_TSTAT_U32(ECN_MARKED_PACKETS, b->tin_ecn_mark);
+ PUT_TSTAT_U32(ACKS_DROPPED_PACKETS, b->ack_drops);
+
+ PUT_TSTAT_U32(PEAK_DELAY_US,
+ ktime_to_us(ns_to_ktime(b->peak_delay)));
+ PUT_TSTAT_U32(AVG_DELAY_US,
+ ktime_to_us(ns_to_ktime(b->avge_delay)));
+ PUT_TSTAT_U32(BASE_DELAY_US,
+ ktime_to_us(ns_to_ktime(b->base_delay)));
+
+ PUT_TSTAT_U32(WAY_INDIRECT_HITS, b->way_hits);
+ PUT_TSTAT_U32(WAY_MISSES, b->way_misses);
+ PUT_TSTAT_U32(WAY_COLLISIONS, b->way_collisions);
+
+ PUT_TSTAT_U32(SPARSE_FLOWS, b->sparse_flow_count +
+ b->decaying_flow_count);
+ PUT_TSTAT_U32(BULK_FLOWS, b->bulk_flow_count);
+ PUT_TSTAT_U32(UNRESPONSIVE_FLOWS, b->unresponsive_flow_count);
+ PUT_TSTAT_U32(MAX_SKBLEN, b->max_skblen);
+
+ PUT_TSTAT_U32(FLOW_QUANTUM, b->flow_quantum);
+ nla_nest_end(d->skb, ts);
+ }
+
+#undef PUT_TSTAT_U32
+#undef PUT_TSTAT_U64
+
+ nla_nest_end(d->skb, tstats);
+ return nla_nest_end(d->skb, stats);
+
+nla_put_failure:
+ nla_nest_cancel(d->skb, stats);
+ return -1;
+}
+
+static struct Qdisc *cake_leaf(struct Qdisc *sch, unsigned long arg)
+{
+ return NULL;
+}
+
+static unsigned long cake_find(struct Qdisc *sch, u32 classid)
+{
+ return 0;
+}
+
+static unsigned long cake_bind(struct Qdisc *sch, unsigned long parent,
+ u32 classid)
+{
+ return 0;
+}
+
+static void cake_unbind(struct Qdisc *q, unsigned long cl)
+{
+}
+
+static struct tcf_block *cake_tcf_block(struct Qdisc *sch, unsigned long cl,
+ struct netlink_ext_ack *extack)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+
+ if (cl)
+ return NULL;
+ return q->block;
+}
+
+static int cake_dump_class(struct Qdisc *sch, unsigned long cl,
+ struct sk_buff *skb, struct tcmsg *tcm)
+{
+ tcm->tcm_handle |= TC_H_MIN(cl);
+ return 0;
+}
+
+static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
+ struct gnet_dump *d)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ const struct cake_flow *flow = NULL;
+ struct gnet_stats_queue qs = { 0 };
+ struct nlattr *stats;
+ u32 idx = cl - 1;
+
+ if (idx < CAKE_QUEUES * q->tin_cnt) {
+ const struct cake_tin_data *b = &q->tins[idx / CAKE_QUEUES];
+ const struct sk_buff *skb;
+
+ flow = &b->flows[idx % CAKE_QUEUES];
+
+ if (flow->head) {
+ sch_tree_lock(sch);
+ skb = flow->head;
+ while (skb) {
+ qs.qlen++;
+ skb = skb->next;
+ }
+ sch_tree_unlock(sch);
+ }
+ qs.backlog = b->backlogs[idx % CAKE_QUEUES];
+ qs.drops = flow->dropped;
+ }
+ if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0)
+ return -1;
+ if (flow) {
+ ktime_t now = ktime_get();
+
+ stats = nla_nest_start(d->skb, TCA_STATS_APP);
+ if (!stats)
+ return -1;
+
+#define PUT_STAT_U32(attr, data) do { \
+ if (nla_put_u32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
+ goto nla_put_failure; \
+ } while (0)
+#define PUT_STAT_S32(attr, data) do { \
+ if (nla_put_s32(d->skb, TCA_CAKE_STATS_ ## attr, data)) \
+ goto nla_put_failure; \
+ } while (0)
+
+ PUT_STAT_S32(DEFICIT, flow->deficit);
+ PUT_STAT_U32(DROPPING, flow->cvars.dropping);
+ PUT_STAT_U32(COBALT_COUNT, flow->cvars.count);
+ PUT_STAT_U32(P_DROP, flow->cvars.p_drop);
+ if (flow->cvars.p_drop) {
+ PUT_STAT_S32(BLUE_TIMER_US,
+ ktime_to_us(
+ ktime_sub(now,
+ flow->cvars.blue_timer)));
+ }
+ if (flow->cvars.dropping) {
+ PUT_STAT_S32(DROP_NEXT_US,
+ ktime_to_us(
+ ktime_sub(now,
+ flow->cvars.drop_next)));
+ }
+
+ if (nla_nest_end(d->skb, stats) < 0)
+ return -1;
+ }
+
+ return 0;
+
+nla_put_failure:
+ nla_nest_cancel(d->skb, stats);
+ return -1;
+}
+
+static void cake_walk(struct Qdisc *sch, struct qdisc_walker *arg)
+{
+ struct cake_sched_data *q = qdisc_priv(sch);
+ unsigned int i, j;
+
+ if (arg->stop)
+ return;
+
+ for (i = 0; i < q->tin_cnt; i++) {
+ struct cake_tin_data *b = &q->tins[i];
+
+ for (j = 0; j < CAKE_QUEUES; j++) {
+ if (list_empty(&b->flows[j].flowchain) ||
+ arg->count < arg->skip) {
+ arg->count++;
+ continue;
+ }
+ if (arg->fn(sch, i * CAKE_QUEUES + j + 1, arg) < 0) {
+ arg->stop = 1;
+ break;
+ }
+ arg->count++;
+ }
+ }
+}
+
+static const struct Qdisc_class_ops cake_class_ops = {
+ .leaf = cake_leaf,
+ .find = cake_find,
+ .tcf_block = cake_tcf_block,
+ .bind_tcf = cake_bind,
+ .unbind_tcf = cake_unbind,
+ .dump = cake_dump_class,
+ .dump_stats = cake_dump_class_stats,
+ .walk = cake_walk,
+};
+
+static struct Qdisc_ops cake_qdisc_ops __read_mostly = {
+ .cl_ops = &cake_class_ops,
+ .id = "cake",
+ .priv_size = sizeof(struct cake_sched_data),
+ .enqueue = cake_enqueue,
+ .dequeue = cake_dequeue,
+ .peek = qdisc_peek_dequeued,
+ .init = cake_init,
+ .reset = cake_reset,
+ .destroy = cake_destroy,
+ .change = cake_change,
+ .dump = cake_dump,
+ .dump_stats = cake_dump_stats,
+ .owner = THIS_MODULE,
+};
+
+static int __init cake_module_init(void)
+{
+ return register_qdisc(&cake_qdisc_ops);
+}
+
+static void __exit cake_module_exit(void)
+{
+ unregister_qdisc(&cake_qdisc_ops);
+}
+
+module_init(cake_module_init)
+module_exit(cake_module_exit)
+MODULE_AUTHOR("Jonathan Morton");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("The CAKE shaper.");
^ permalink raw reply related
* [PATCH net-next v13 6/7] sch_cake: Add overhead compensation support to the rate shaper
From: Toke Høiland-Jørgensen @ 2018-05-21 16:24 UTC (permalink / raw)
To: netdev, cake
In-Reply-To: <152691970035.4083.3349902669266371765.stgit@alrua-kau>
This commit adds configurable overhead compensation support to the rate
shaper. With this feature, userspace can configure the actual bottleneck
link overhead and encapsulation mode used, which will be used by the shaper
to calculate the precise duration of each packet on the wire.
This feature is needed because CAKE is often deployed one or two hops
upstream of the actual bottleneck (which can be, e.g., inside a DSL or
cable modem). In this case, the link layer characteristics and overhead
reported by the kernel does not match the actual bottleneck. Being able to
set the actual values in use makes it possible to configure the shaper rate
much closer to the actual bottleneck rate (our experience shows it is
possible to get with 0.1% of the actual physical bottleneck rate), thus
keeping latency low without sacrificing bandwidth.
The overhead compensation has three tunables: A fixed per-packet overhead
size (which, if set, will be accounted from the IP packet header), a
minimum packet size (MPU) and a framing mode supporting either ATM or PTM
framing. We include a set of common keywords in TC to help users configure
the right parameters. If no overhead value is set, the value reported by
the kernel is used.
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
---
net/sched/sch_cake.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 123 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index d025899ef11f..4bccfee714c8 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -272,6 +272,7 @@ enum {
struct cobalt_skb_cb {
ktime_t enqueue_time;
+ u32 adjusted_len;
};
static u64 us_to_ns(u64 us)
@@ -1287,6 +1288,88 @@ static u64 cake_ewma(u64 avg, u64 sample, u32 shift)
return avg;
}
+static u32 cake_calc_overhead(struct cake_sched_data *q, u32 len, u32 off)
+{
+ if (q->rate_flags & CAKE_FLAG_OVERHEAD)
+ len -= off;
+
+ if (q->max_netlen < len)
+ q->max_netlen = len;
+ if (q->min_netlen > len)
+ q->min_netlen = len;
+
+ len += q->rate_overhead;
+
+ if (len < q->rate_mpu)
+ len = q->rate_mpu;
+
+ if (q->atm_mode == CAKE_ATM_ATM) {
+ len += 47;
+ len /= 48;
+ len *= 53;
+ } else if (q->atm_mode == CAKE_ATM_PTM) {
+ /* Add one byte per 64 bytes or part thereof.
+ * This is conservative and easier to calculate than the
+ * precise value.
+ */
+ len += (len + 63) / 64;
+ }
+
+ if (q->max_adjlen < len)
+ q->max_adjlen = len;
+ if (q->min_adjlen > len)
+ q->min_adjlen = len;
+
+ return len;
+}
+
+static u32 cake_overhead(struct cake_sched_data *q, const struct sk_buff *skb)
+{
+ const struct skb_shared_info *shinfo = skb_shinfo(skb);
+ unsigned int hdr_len, last_len = 0;
+ u32 off = skb_network_offset(skb);
+ u32 len = qdisc_pkt_len(skb);
+ u16 segs = 1;
+
+ q->avg_netoff = cake_ewma(q->avg_netoff, off << 16, 8);
+
+ if (!shinfo->gso_size)
+ return cake_calc_overhead(q, len, off);
+
+ /* borrowed from qdisc_pkt_len_init() */
+ hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
+
+ /* + transport layer */
+ if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 |
+ SKB_GSO_TCPV6))) {
+ const struct tcphdr *th;
+ struct tcphdr _tcphdr;
+
+ th = skb_header_pointer(skb, skb_transport_offset(skb),
+ sizeof(_tcphdr), &_tcphdr);
+ if (likely(th))
+ hdr_len += __tcp_hdrlen(th);
+ } else {
+ struct udphdr _udphdr;
+
+ if (skb_header_pointer(skb, skb_transport_offset(skb),
+ sizeof(_udphdr), &_udphdr))
+ hdr_len += sizeof(struct udphdr);
+ }
+
+ if (unlikely(shinfo->gso_type & SKB_GSO_DODGY))
+ segs = DIV_ROUND_UP(skb->len - hdr_len,
+ shinfo->gso_size);
+ else
+ segs = shinfo->gso_segs;
+
+ len = shinfo->gso_size + hdr_len;
+ last_len = skb->len - shinfo->gso_size * (segs - 1);
+
+ return (cake_calc_overhead(q, len, off) * (segs - 1) +
+ cake_calc_overhead(q, last_len, off));
+}
+
static void cake_heap_swap(struct cake_sched_data *q, u16 i, u16 j)
{
struct cake_heap_entry ii = q->overflow_heap[i];
@@ -1364,7 +1447,7 @@ static int cake_advance_shaper(struct cake_sched_data *q,
struct sk_buff *skb,
ktime_t now, bool drop)
{
- u32 len = qdisc_pkt_len(skb);
+ u32 len = get_cobalt_cb(skb)->adjusted_len;
/* charge packet bandwidth to this tin
* and to the global shaper.
@@ -1561,6 +1644,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
b->max_skblen = len;
cobalt_set_enqueue_time(skb, now);
+ get_cobalt_cb(skb)->adjusted_len = cake_overhead(q, skb);
flow_queue_add(flow, skb);
if (q->ack_filter)
@@ -2361,6 +2445,31 @@ static int cake_change(struct Qdisc *sch, struct nlattr *opt,
q->flow_mode = (nla_get_u32(tb[TCA_CAKE_FLOW_MODE]) &
CAKE_FLOW_MASK);
+ if (tb[TCA_CAKE_ATM])
+ q->atm_mode = nla_get_u32(tb[TCA_CAKE_ATM]);
+
+ if (tb[TCA_CAKE_OVERHEAD]) {
+ q->rate_overhead = nla_get_s32(tb[TCA_CAKE_OVERHEAD]);
+ q->rate_flags |= CAKE_FLAG_OVERHEAD;
+
+ q->max_netlen = 0;
+ q->max_adjlen = 0;
+ q->min_netlen = ~0;
+ q->min_adjlen = ~0;
+ }
+
+ if (tb[TCA_CAKE_RAW]) {
+ q->rate_flags &= ~CAKE_FLAG_OVERHEAD;
+
+ q->max_netlen = 0;
+ q->max_adjlen = 0;
+ q->min_netlen = ~0;
+ q->min_adjlen = ~0;
+ }
+
+ if (tb[TCA_CAKE_MPU])
+ q->rate_mpu = nla_get_u32(tb[TCA_CAKE_MPU]);
+
if (tb[TCA_CAKE_RTT]) {
q->interval = nla_get_u32(tb[TCA_CAKE_RTT]);
@@ -2537,6 +2646,19 @@ static int cake_dump(struct Qdisc *sch, struct sk_buff *skb)
!!(q->rate_flags & CAKE_FLAG_WASH)))
goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CAKE_OVERHEAD, q->rate_overhead))
+ goto nla_put_failure;
+
+ if (!(q->rate_flags & CAKE_FLAG_OVERHEAD))
+ if (nla_put_u32(skb, TCA_CAKE_RAW, 0))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_ATM, q->atm_mode))
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, TCA_CAKE_MPU, q->rate_mpu))
+ goto nla_put_failure;
+
return nla_nest_end(skb, opts);
nla_put_failure:
^ permalink raw reply related
* Re: [PATCH] [RFC] bpf: tracing: new helper bpf_get_current_cgroup_ino
From: Alexei Starovoitov @ 2018-05-21 16:26 UTC (permalink / raw)
To: Alban Crequy; +Cc: netdev, linux-kernel, containers, cgroups, Alban Crequy, tj
In-Reply-To: <20180513173318.21680-1-alban@kinvolk.io>
On Sun, May 13, 2018 at 07:33:18PM +0200, Alban Crequy wrote:
>
> +BPF_CALL_2(bpf_get_current_cgroup_ino, u32, hierarchy, u64, flags)
> +{
> + // TODO: pick the correct hierarchy instead of the mem controller
> + struct cgroup *cgrp = task_cgroup(current, memory_cgrp_id);
> +
> + if (unlikely(!cgrp))
> + return -EINVAL;
> + if (unlikely(hierarchy))
> + return -EINVAL;
> + if (unlikely(flags))
> + return -EINVAL;
> +
> + return cgrp->kn->id.ino;
ino only is not enough to identify cgroup. It needs generation number too.
I don't quite see how hierarchy and flags can be used in the future.
Also why limit it to memcg?
How about something like this instead:
BPF_CALL_2(bpf_get_current_cgroup_id)
{
struct cgroup *cgrp = task_dfl_cgroup(current);
return cgrp->kn->id.id;
}
The user space can use fhandle api to get the same 64-bit id.
^ permalink raw reply
* Re: [RFC PATCH net-next 02/12] vhost_net: introduce vhost_exceeds_weight()
From: Jesse Brandeburg @ 2018-05-21 16:29 UTC (permalink / raw)
To: Jason Wang
Cc: mst, netdev, linux-kernel, kvm, virtualization, jesse.brandeburg
In-Reply-To: <1526893473-20128-3-git-send-email-jasowang@redhat.com>
On Mon, 21 May 2018 17:04:23 +0800 Jason wrote:
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vhost/net.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 15d191a..de544ee 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -479,6 +479,12 @@ static size_t init_iov_iter(struct vhost_virtqueue *vq, struct iov_iter *iter,
> return len;
> }
>
> +static bool vhost_exceeds_weight(int pkts, int total_len)
> +{
> + return unlikely(total_len >= VHOST_NET_WEIGHT) ||
> + unlikely(pkts >= VHOST_NET_PKT_WEIGHT);
I was going to say just one unlikely, but then the caller of this
function also says unlikely(vhost_exceeds...), so I think you should
just drop the unlikely statements here (both of them)
> +}
> +
> /* Expects to be always run from workqueue - which acts as
> * read-size critical section for our kind of RCU. */
> static void handle_tx(struct vhost_net *net)
> @@ -570,7 +576,6 @@ static void handle_tx(struct vhost_net *net)
> msg.msg_control = NULL;
> ubufs = NULL;
> }
> -
unrelated whitespace changes?
> total_len += len;
> if (total_len < VHOST_NET_WEIGHT &&
> !vhost_vq_avail_empty(&net->dev, vq) &&
> @@ -600,8 +605,7 @@ static void handle_tx(struct vhost_net *net)
> else
> vhost_zerocopy_signal_used(net, vq);
> vhost_net_tx_packet(net);
> - if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
> - unlikely(++sent_pkts >= VHOST_NET_PKT_WEIGHT)) {
> + if (unlikely(vhost_exceeds_weight(++sent_pkts, total_len))) {
> vhost_poll_queue(&vq->poll);
> break;
> }
> @@ -887,8 +891,7 @@ static void handle_rx(struct vhost_net *net)
> if (unlikely(vq_log))
> vhost_log_write(vq, vq_log, log, vhost_len);
> total_len += vhost_len;
> - if (unlikely(total_len >= VHOST_NET_WEIGHT) ||
> - unlikely(++recv_pkts >= VHOST_NET_PKT_WEIGHT)) {
> + if (unlikely(vhost_exceeds_weight(++recv_pkts, total_len))) {
> vhost_poll_queue(&vq->poll);
> goto out;
> }
^ permalink raw reply
* Re: [PATCH net-next 2/8] qed: Add support for tlv request processing.
From: David Miller @ 2018-05-21 16:30 UTC (permalink / raw)
To: sudarsana.kalluru; +Cc: netdev, Ariel.Elior, chad.dupuis, manish.rangankar
In-Reply-To: <20180521104018.5506-3-sudarsana.kalluru@cavium.com>
From: Sudarsana Reddy Kalluru <sudarsana.kalluru@cavium.com>
Date: Mon, 21 May 2018 03:40:12 -0700
> +struct qed_tlv_parsed_buf {
> + /* To be filled with the address to set in Value field */
> + u8 *p_val;
Assignments to this pointer are cast hundreds of times, like:
> + p_buf->p_val = (u8 *)&p_drv_buf->rx_frames;
Over and over again.
Just make p_val a void pointer, and then you don't need any of the
casts at all.
^ permalink raw reply
* Re: [PATCH net-next] vmcore: move get_vmcore_size out of __init
From: David Miller @ 2018-05-21 16:34 UTC (permalink / raw)
To: rahul.lakkireddy
Cc: netdev, kexec, linux-fsdevel, linux-kernel, viro, ebiederm,
stephen, akpm, torvalds, ganeshgr, nirranjan, indranil
In-Reply-To: <1526909870-27630-1-git-send-email-rahul.lakkireddy@chelsio.com>
From: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Date: Mon, 21 May 2018 19:07:50 +0530
> Fix below build warning:
>
> WARNING: vmlinux.o(.text+0x422bb8): Section mismatch in reference from
> the function vmcore_add_device_dump() to the function
> .init.text:get_vmcore_size.constprop.5()
>
> The function vmcore_add_device_dump() references
> the function __init get_vmcore_size.constprop.5().
> This is often because vmcore_add_device_dump lacks a __init
> annotation or the annotation of get_vmcore_size.constprop.5 is wrong.
>
> Fixes: 7efe48df8a3d ("vmcore: append device dumps to vmcore as elf notes")
> Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
> Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Applied, thank you.
^ permalink raw reply
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