* [PATCH] inet: add RCU protection to inet->opt
2011-04-15 15:39 [RFC] possible bug in inet->opt handling Eric Dumazet
2011-04-15 17:17 ` Herbert Xu
@ 2011-04-21 19:45 ` Eric Dumazet
2011-04-28 20:20 ` David Miller
1 sibling, 1 reply; 8+ messages in thread
From: Eric Dumazet @ 2011-04-21 19:45 UTC (permalink / raw)
To: David Miller; +Cc: Herbert Xu, netdev
Le vendredi 15 avril 2011 à 17:39 +0200, Eric Dumazet a écrit :
> In commit 903ab86d19 (udp: Add lockless transmit path), we added a
> fastpath to avoid taking socket lock if we dont use corking.
>
> Prior work were commit 1c32c5ad6fac8c (inet: Add ip_make_skb and
> ip_finish_skb) and commit 1470ddf7f8cecf776921e5 (inet: Remove explicit
> write references to sk/inet in ip_append_data)
>
> Problem is ip_make_skb() calls ip_setup_cork() and
> ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
> without any protection against another thread manipulating inet->opt.
>
> Another thread can change inet->opt pointer and free old one... kaboom.
>
> This was discovered by code analysis (I am trying to remove the zeroing
> of cork variable in ip_make_skb(), since its a bit expensive and
> probably useless)
>
> Note : race was there before Herbert patches.
>
> My plan is to add RCU protection on inet->opt, unless someone has better
> idea ?
>
>
OK, here is the patch I cooked to address this problem, on top of
net-next-2.6
[PATCH] inet: add RCU protection to inet->opt
We lack proper synchronization to manipulate inet->opt ip_options
Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.
Another thread can change inet->opt pointer and free old one under us.
Use RCU to protect inet->opt (changed to inet->inet_opt).
Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.
We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
---
include/net/inet_sock.h | 14 ++-
include/net/ip.h | 11 +-
net/dccp/ipv4.c | 16 ++--
net/dccp/ipv6.c | 2
net/ipv4/af_inet.c | 17 +++-
net/ipv4/cipso_ipv4.c | 113 ++++++++++++++++--------------
net/ipv4/icmp.c | 23 ++----
net/ipv4/inet_connection_sock.c | 6 -
net/ipv4/ip_options.c | 38 ++++------
net/ipv4/ip_output.c | 44 +++++------
net/ipv4/ip_sockglue.c | 35 ++++++---
net/ipv4/raw.c | 20 ++++-
net/ipv4/syncookies.c | 4 -
net/ipv4/tcp_ipv4.c | 34 +++++----
net/ipv4/udp.c | 22 ++++-
net/ipv6/tcp_ipv6.c | 2
16 files changed, 236 insertions(+), 165 deletions(-)
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 7a37369..ed2ba6e 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -57,7 +57,15 @@ struct ip_options {
unsigned char __data[0];
};
-#define optlength(opt) (sizeof(struct ip_options) + opt->optlen)
+struct ip_options_rcu {
+ struct rcu_head rcu;
+ struct ip_options opt;
+};
+
+struct ip_options_data {
+ struct ip_options_rcu opt;
+ char data[40];
+};
struct inet_request_sock {
struct request_sock req;
@@ -78,7 +86,7 @@ struct inet_request_sock {
acked : 1,
no_srccheck: 1;
kmemcheck_bitfield_end(flags);
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
};
static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
@@ -140,7 +148,7 @@ struct inet_sock {
__be16 inet_sport;
__u16 inet_id;
- struct ip_options *opt;
+ struct ip_options_rcu __rcu *inet_opt;
__u8 tos;
__u8 min_ttl;
__u8 mc_ttl;
diff --git a/include/net/ip.h b/include/net/ip.h
index 7c41658..3a59bf9 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -52,7 +52,7 @@ static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
struct ipcm_cookie {
__be32 addr;
int oif;
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
__u8 tx_flags;
};
@@ -92,7 +92,7 @@ extern int igmp_mc_proc_init(void);
extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
__be32 saddr, __be32 daddr,
- struct ip_options *opt);
+ struct ip_options_rcu *opt);
extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev);
extern int ip_local_deliver(struct sk_buff *skb);
@@ -416,14 +416,15 @@ extern int ip_forward(struct sk_buff *skb);
* Functions provided by ip_options.c
*/
-extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
+extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
+ __be32 daddr, struct rtable *rt, int is_frag);
extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
extern void ip_options_fragment(struct sk_buff *skb);
extern int ip_options_compile(struct net *net,
struct ip_options *opt, struct sk_buff *skb);
-extern int ip_options_get(struct net *net, struct ip_options **optp,
+extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
unsigned char *data, int optlen);
-extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
+extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
unsigned char __user *data, int optlen);
extern void ip_options_undo(struct ip_options * opt);
extern void ip_forward_options(struct sk_buff *skb);
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index ae451c6..1f54ee2 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -47,6 +47,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
struct rtable *rt;
__be32 daddr, nexthop;
int err;
+ struct ip_options_rcu *inet_opt;
dp->dccps_role = DCCP_ROLE_CLIENT;
@@ -57,10 +58,13 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
return -EAFNOSUPPORT;
nexthop = daddr = usin->sin_addr.s_addr;
- if (inet->opt != NULL && inet->opt->srr) {
+
+ inet_opt = rcu_dereference_protected(inet->inet_opt,
+ sock_owned_by_user(sk));
+ if (inet_opt != NULL && inet_opt->opt.srr) {
if (daddr == 0)
return -EINVAL;
- nexthop = inet->opt->faddr;
+ nexthop = inet_opt->opt.faddr;
}
orig_sport = inet->inet_sport;
@@ -77,7 +81,7 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
return -ENETUNREACH;
}
- if (inet->opt == NULL || !inet->opt->srr)
+ if (inet_opt == NULL || !inet_opt->opt.srr)
daddr = rt->rt_dst;
if (inet->inet_saddr == 0)
@@ -88,8 +92,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_daddr = daddr;
inet_csk(sk)->icsk_ext_hdr_len = 0;
- if (inet->opt != NULL)
- inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
+ if (inet_opt)
+ inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
/*
* Socket identity is still unknown (sport may be zero).
* However we set state to DCCP_REQUESTING and not releasing socket
@@ -405,7 +409,7 @@ struct sock *dccp_v4_request_recv_sock(struct sock *sk, struct sk_buff *skb,
newinet->inet_daddr = ireq->rmt_addr;
newinet->inet_rcv_saddr = ireq->loc_addr;
newinet->inet_saddr = ireq->loc_addr;
- newinet->opt = ireq->opt;
+ newinet->inet_opt = ireq->opt;
ireq->opt = NULL;
newinet->mc_index = inet_iif(skb);
newinet->mc_ttl = ip_hdr(skb)->ttl;
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index de1b7e3..43eba99 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -573,7 +573,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
First: no IPv4 options.
*/
- newinet->opt = NULL;
+ newinet->inet_opt = NULL;
/* Clone RX bits */
newnp->rxopt.all = np->rxopt.all;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 807d83c..01ae9b5 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -153,7 +153,7 @@ void inet_sock_destruct(struct sock *sk)
WARN_ON(sk->sk_wmem_queued);
WARN_ON(sk->sk_forward_alloc);
- kfree(inet->opt);
+ kfree(rcu_dereference_protected(inet->inet_opt, 1));
dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
sk_refcnt_debug_dec(sk);
}
@@ -1105,9 +1105,12 @@ static int inet_sk_reselect_saddr(struct sock *sk)
__be32 daddr = inet->inet_daddr;
struct rtable *rt;
__be32 new_saddr;
+ struct ip_options_rcu *inet_opt;
- if (inet->opt && inet->opt->srr)
- daddr = inet->opt->faddr;
+ inet_opt = rcu_dereference_protected(inet->inet_opt,
+ sock_owned_by_user(sk));
+ if (inet_opt && inet_opt->opt.srr)
+ daddr = inet_opt->opt.faddr;
/* Query new route. */
rt = ip_route_connect(daddr, 0, RT_CONN_FLAGS(sk),
@@ -1147,6 +1150,7 @@ int inet_sk_rebuild_header(struct sock *sk)
struct inet_sock *inet = inet_sk(sk);
struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
__be32 daddr;
+ struct ip_options_rcu *inet_opt;
int err;
/* Route is OK, nothing to do. */
@@ -1154,9 +1158,12 @@ int inet_sk_rebuild_header(struct sock *sk)
return 0;
/* Reroute. */
+ rcu_read_lock();
+ inet_opt = rcu_dereference(inet->inet_opt);
daddr = inet->inet_daddr;
- if (inet->opt && inet->opt->srr)
- daddr = inet->opt->faddr;
+ if (inet_opt && inet_opt->opt.srr)
+ daddr = inet_opt->opt.faddr;
+ rcu_read_unlock();
rt = ip_route_output_ports(sock_net(sk), sk, daddr, inet->inet_saddr,
inet->inet_dport, inet->inet_sport,
sk->sk_protocol, RT_CONN_FLAGS(sk),
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index a0af7ea..2b3c23c 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1857,6 +1857,11 @@ static int cipso_v4_genopt(unsigned char *buf, u32 buf_len,
return CIPSO_V4_HDR_LEN + ret_val;
}
+static void opt_kfree_rcu(struct rcu_head *head)
+{
+ kfree(container_of(head, struct ip_options_rcu, rcu));
+}
+
/**
* cipso_v4_sock_setattr - Add a CIPSO option to a socket
* @sk: the socket
@@ -1879,7 +1884,7 @@ int cipso_v4_sock_setattr(struct sock *sk,
unsigned char *buf = NULL;
u32 buf_len;
u32 opt_len;
- struct ip_options *opt = NULL;
+ struct ip_options_rcu *old, *opt = NULL;
struct inet_sock *sk_inet;
struct inet_connection_sock *sk_conn;
@@ -1915,22 +1920,25 @@ int cipso_v4_sock_setattr(struct sock *sk,
ret_val = -ENOMEM;
goto socket_setattr_failure;
}
- memcpy(opt->__data, buf, buf_len);
- opt->optlen = opt_len;
- opt->cipso = sizeof(struct iphdr);
+ memcpy(opt->opt.__data, buf, buf_len);
+ opt->opt.optlen = opt_len;
+ opt->opt.cipso = sizeof(struct iphdr);
kfree(buf);
buf = NULL;
sk_inet = inet_sk(sk);
+
+ old = rcu_dereference_protected(sk_inet->inet_opt, sock_owned_by_user(sk));
if (sk_inet->is_icsk) {
sk_conn = inet_csk(sk);
- if (sk_inet->opt)
- sk_conn->icsk_ext_hdr_len -= sk_inet->opt->optlen;
- sk_conn->icsk_ext_hdr_len += opt->optlen;
+ if (old)
+ sk_conn->icsk_ext_hdr_len -= old->opt.optlen;
+ sk_conn->icsk_ext_hdr_len += opt->opt.optlen;
sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
}
- opt = xchg(&sk_inet->opt, opt);
- kfree(opt);
+ rcu_assign_pointer(sk_inet->inet_opt, opt);
+ if (old)
+ call_rcu(&old->rcu, opt_kfree_rcu);
return 0;
@@ -1960,7 +1968,7 @@ int cipso_v4_req_setattr(struct request_sock *req,
unsigned char *buf = NULL;
u32 buf_len;
u32 opt_len;
- struct ip_options *opt = NULL;
+ struct ip_options_rcu *opt = NULL;
struct inet_request_sock *req_inet;
/* We allocate the maximum CIPSO option size here so we are probably
@@ -1988,15 +1996,16 @@ int cipso_v4_req_setattr(struct request_sock *req,
ret_val = -ENOMEM;
goto req_setattr_failure;
}
- memcpy(opt->__data, buf, buf_len);
- opt->optlen = opt_len;
- opt->cipso = sizeof(struct iphdr);
+ memcpy(opt->opt.__data, buf, buf_len);
+ opt->opt.optlen = opt_len;
+ opt->opt.cipso = sizeof(struct iphdr);
kfree(buf);
buf = NULL;
req_inet = inet_rsk(req);
opt = xchg(&req_inet->opt, opt);
- kfree(opt);
+ if (opt)
+ call_rcu(&opt->rcu, opt_kfree_rcu);
return 0;
@@ -2016,34 +2025,34 @@ req_setattr_failure:
* values on failure.
*
*/
-static int cipso_v4_delopt(struct ip_options **opt_ptr)
+static int cipso_v4_delopt(struct ip_options_rcu **opt_ptr)
{
int hdr_delta = 0;
- struct ip_options *opt = *opt_ptr;
+ struct ip_options_rcu *opt = *opt_ptr;
- if (opt->srr || opt->rr || opt->ts || opt->router_alert) {
+ if (opt->opt.srr || opt->opt.rr || opt->opt.ts || opt->opt.router_alert) {
u8 cipso_len;
u8 cipso_off;
unsigned char *cipso_ptr;
int iter;
int optlen_new;
- cipso_off = opt->cipso - sizeof(struct iphdr);
- cipso_ptr = &opt->__data[cipso_off];
+ cipso_off = opt->opt.cipso - sizeof(struct iphdr);
+ cipso_ptr = &opt->opt.__data[cipso_off];
cipso_len = cipso_ptr[1];
- if (opt->srr > opt->cipso)
- opt->srr -= cipso_len;
- if (opt->rr > opt->cipso)
- opt->rr -= cipso_len;
- if (opt->ts > opt->cipso)
- opt->ts -= cipso_len;
- if (opt->router_alert > opt->cipso)
- opt->router_alert -= cipso_len;
- opt->cipso = 0;
+ if (opt->opt.srr > opt->opt.cipso)
+ opt->opt.srr -= cipso_len;
+ if (opt->opt.rr > opt->opt.cipso)
+ opt->opt.rr -= cipso_len;
+ if (opt->opt.ts > opt->opt.cipso)
+ opt->opt.ts -= cipso_len;
+ if (opt->opt.router_alert > opt->opt.cipso)
+ opt->opt.router_alert -= cipso_len;
+ opt->opt.cipso = 0;
memmove(cipso_ptr, cipso_ptr + cipso_len,
- opt->optlen - cipso_off - cipso_len);
+ opt->opt.optlen - cipso_off - cipso_len);
/* determining the new total option length is tricky because of
* the padding necessary, the only thing i can think to do at
@@ -2052,21 +2061,21 @@ static int cipso_v4_delopt(struct ip_options **opt_ptr)
* from there we can determine the new total option length */
iter = 0;
optlen_new = 0;
- while (iter < opt->optlen)
- if (opt->__data[iter] != IPOPT_NOP) {
- iter += opt->__data[iter + 1];
+ while (iter < opt->opt.optlen)
+ if (opt->opt.__data[iter] != IPOPT_NOP) {
+ iter += opt->opt.__data[iter + 1];
optlen_new = iter;
} else
iter++;
- hdr_delta = opt->optlen;
- opt->optlen = (optlen_new + 3) & ~3;
- hdr_delta -= opt->optlen;
+ hdr_delta = opt->opt.optlen;
+ opt->opt.optlen = (optlen_new + 3) & ~3;
+ hdr_delta -= opt->opt.optlen;
} else {
/* only the cipso option was present on the socket so we can
* remove the entire option struct */
*opt_ptr = NULL;
- hdr_delta = opt->optlen;
- kfree(opt);
+ hdr_delta = opt->opt.optlen;
+ call_rcu(&opt->rcu, opt_kfree_rcu);
}
return hdr_delta;
@@ -2083,15 +2092,15 @@ static int cipso_v4_delopt(struct ip_options **opt_ptr)
void cipso_v4_sock_delattr(struct sock *sk)
{
int hdr_delta;
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
struct inet_sock *sk_inet;
sk_inet = inet_sk(sk);
- opt = sk_inet->opt;
- if (opt == NULL || opt->cipso == 0)
+ opt = rcu_dereference_protected(sk_inet->inet_opt, 1);
+ if (opt == NULL || opt->opt.cipso == 0)
return;
- hdr_delta = cipso_v4_delopt(&sk_inet->opt);
+ hdr_delta = cipso_v4_delopt(&sk_inet->inet_opt);
if (sk_inet->is_icsk && hdr_delta > 0) {
struct inet_connection_sock *sk_conn = inet_csk(sk);
sk_conn->icsk_ext_hdr_len -= hdr_delta;
@@ -2109,12 +2118,12 @@ void cipso_v4_sock_delattr(struct sock *sk)
*/
void cipso_v4_req_delattr(struct request_sock *req)
{
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
struct inet_request_sock *req_inet;
req_inet = inet_rsk(req);
opt = req_inet->opt;
- if (opt == NULL || opt->cipso == 0)
+ if (opt == NULL || opt->opt.cipso == 0)
return;
cipso_v4_delopt(&req_inet->opt);
@@ -2184,14 +2193,18 @@ getattr_return:
*/
int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
{
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
+ int res = -ENOMSG;
- opt = inet_sk(sk)->opt;
- if (opt == NULL || opt->cipso == 0)
- return -ENOMSG;
-
- return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr),
- secattr);
+ rcu_read_lock();
+ opt = rcu_dereference(inet_sk(sk)->inet_opt);
+ if (opt && opt->opt.cipso)
+ res = cipso_v4_getattr(opt->opt.__data +
+ opt->opt.cipso -
+ sizeof(struct iphdr),
+ secattr);
+ rcu_read_unlock();
+ return res;
}
/**
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index e5f8a71..831e7dc 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -108,8 +108,7 @@ struct icmp_bxm {
__be32 times[3];
} data;
int head_len;
- struct ip_options replyopts;
- unsigned char optbuf[40];
+ struct ip_options_data replyopts;
};
/* An array of errno for error messages from dest unreach. */
@@ -333,7 +332,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
struct inet_sock *inet;
__be32 daddr;
- if (ip_options_echo(&icmp_param->replyopts, skb))
+ if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb))
return;
sk = icmp_xmit_lock(net);
@@ -347,10 +346,10 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
daddr = ipc.addr = rt->rt_src;
ipc.opt = NULL;
ipc.tx_flags = 0;
- if (icmp_param->replyopts.optlen) {
- ipc.opt = &icmp_param->replyopts;
- if (ipc.opt->srr)
- daddr = icmp_param->replyopts.faddr;
+ if (icmp_param->replyopts.opt.opt.optlen) {
+ ipc.opt = &icmp_param->replyopts.opt;
+ if (ipc.opt->opt.srr)
+ daddr = icmp_param->replyopts.opt.opt.faddr;
}
{
struct flowi4 fl4 = {
@@ -379,8 +378,8 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
struct icmp_bxm *param)
{
struct flowi4 fl4 = {
- .daddr = (param->replyopts.srr ?
- param->replyopts.faddr : iph->saddr),
+ .daddr = (param->replyopts.opt.opt.srr ?
+ param->replyopts.opt.opt.faddr : iph->saddr),
.saddr = saddr,
.flowi4_tos = RT_TOS(tos),
.flowi4_proto = IPPROTO_ICMP,
@@ -581,7 +580,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
IPTOS_PREC_INTERNETCONTROL) :
iph->tos;
- if (ip_options_echo(&icmp_param.replyopts, skb_in))
+ if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in))
goto out_unlock;
@@ -597,7 +596,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
icmp_param.offset = skb_network_offset(skb_in);
inet_sk(sk)->tos = tos;
ipc.addr = iph->saddr;
- ipc.opt = &icmp_param.replyopts;
+ ipc.opt = &icmp_param.replyopts.opt;
ipc.tx_flags = 0;
rt = icmp_route_lookup(net, skb_in, iph, saddr, tos,
@@ -613,7 +612,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
room = dst_mtu(&rt->dst);
if (room > 576)
room = 576;
- room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
+ room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen;
room -= sizeof(struct icmphdr);
icmp_param.data_len = skb_in->len - icmp_param.offset;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 8514db5..3282cb2 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -354,20 +354,20 @@ struct dst_entry *inet_csk_route_req(struct sock *sk,
{
struct rtable *rt;
const struct inet_request_sock *ireq = inet_rsk(req);
- struct ip_options *opt = inet_rsk(req)->opt;
+ struct ip_options_rcu *opt = inet_rsk(req)->opt;
struct net *net = sock_net(sk);
struct flowi4 fl4;
flowi4_init_output(&fl4, sk->sk_bound_dev_if, sk->sk_mark,
RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE,
sk->sk_protocol, inet_sk_flowi_flags(sk),
- (opt && opt->srr) ? opt->faddr : ireq->rmt_addr,
+ (opt && opt->opt.srr) ? opt->opt.faddr : ireq->rmt_addr,
ireq->loc_addr, ireq->rmt_port, inet_sk(sk)->inet_sport);
security_req_classify_flow(req, flowi4_to_flowi(&fl4));
rt = ip_route_output_flow(net, &fl4, sk);
if (IS_ERR(rt))
goto no_route;
- if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+ if (opt && opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway)
goto route_err;
return &rt->dst;
diff --git a/net/ipv4/ip_options.c b/net/ipv4/ip_options.c
index 2391b24..01fc409 100644
--- a/net/ipv4/ip_options.c
+++ b/net/ipv4/ip_options.c
@@ -36,7 +36,7 @@
* saddr is address of outgoing interface.
*/
-void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
+void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
__be32 daddr, struct rtable *rt, int is_frag)
{
unsigned char *iph = skb_network_header(skb);
@@ -83,9 +83,9 @@ void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
* NOTE: dopt cannot point to skb.
*/
-int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
+int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb)
{
- struct ip_options *sopt;
+ const struct ip_options *sopt;
unsigned char *sptr, *dptr;
int soffset, doffset;
int optlen;
@@ -95,10 +95,8 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
sopt = &(IPCB(skb)->opt);
- if (sopt->optlen == 0) {
- dopt->optlen = 0;
+ if (sopt->optlen == 0)
return 0;
- }
sptr = skb_network_header(skb);
dptr = dopt->__data;
@@ -157,7 +155,7 @@ int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
dopt->optlen += optlen;
}
if (sopt->srr) {
- unsigned char * start = sptr+sopt->srr;
+ unsigned char *start = sptr+sopt->srr;
__be32 faddr;
optlen = start[1];
@@ -499,19 +497,19 @@ void ip_options_undo(struct ip_options * opt)
}
}
-static struct ip_options *ip_options_get_alloc(const int optlen)
+static struct ip_options_rcu *ip_options_get_alloc(const int optlen)
{
- return kzalloc(sizeof(struct ip_options) + ((optlen + 3) & ~3),
+ return kzalloc(sizeof(struct ip_options_rcu) + ((optlen + 3) & ~3),
GFP_KERNEL);
}
-static int ip_options_get_finish(struct net *net, struct ip_options **optp,
- struct ip_options *opt, int optlen)
+static int ip_options_get_finish(struct net *net, struct ip_options_rcu **optp,
+ struct ip_options_rcu *opt, int optlen)
{
while (optlen & 3)
- opt->__data[optlen++] = IPOPT_END;
- opt->optlen = optlen;
- if (optlen && ip_options_compile(net, opt, NULL)) {
+ opt->opt.__data[optlen++] = IPOPT_END;
+ opt->opt.optlen = optlen;
+ if (optlen && ip_options_compile(net, &opt->opt, NULL)) {
kfree(opt);
return -EINVAL;
}
@@ -520,29 +518,29 @@ static int ip_options_get_finish(struct net *net, struct ip_options **optp,
return 0;
}
-int ip_options_get_from_user(struct net *net, struct ip_options **optp,
+int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
unsigned char __user *data, int optlen)
{
- struct ip_options *opt = ip_options_get_alloc(optlen);
+ struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
if (!opt)
return -ENOMEM;
- if (optlen && copy_from_user(opt->__data, data, optlen)) {
+ if (optlen && copy_from_user(opt->opt.__data, data, optlen)) {
kfree(opt);
return -EFAULT;
}
return ip_options_get_finish(net, optp, opt, optlen);
}
-int ip_options_get(struct net *net, struct ip_options **optp,
+int ip_options_get(struct net *net, struct ip_options_rcu **optp,
unsigned char *data, int optlen)
{
- struct ip_options *opt = ip_options_get_alloc(optlen);
+ struct ip_options_rcu *opt = ip_options_get_alloc(optlen);
if (!opt)
return -ENOMEM;
if (optlen)
- memcpy(opt->__data, data, optlen);
+ memcpy(opt->opt.__data, data, optlen);
return ip_options_get_finish(net, optp, opt, optlen);
}
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index bdad3d6..362e66f 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -140,14 +140,14 @@ static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst)
*
*/
int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
- __be32 saddr, __be32 daddr, struct ip_options *opt)
+ __be32 saddr, __be32 daddr, struct ip_options_rcu *opt)
{
struct inet_sock *inet = inet_sk(sk);
struct rtable *rt = skb_rtable(skb);
struct iphdr *iph;
/* Build the IP header. */
- skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+ skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
iph->version = 4;
@@ -163,9 +163,9 @@ int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
iph->protocol = sk->sk_protocol;
ip_select_ident(iph, &rt->dst, sk);
- if (opt && opt->optlen) {
- iph->ihl += opt->optlen>>2;
- ip_options_build(skb, opt, daddr, rt, 0);
+ if (opt && opt->opt.optlen) {
+ iph->ihl += opt->opt.optlen>>2;
+ ip_options_build(skb, &opt->opt, daddr, rt, 0);
}
skb->priority = sk->sk_priority;
@@ -316,7 +316,7 @@ int ip_queue_xmit(struct sk_buff *skb)
{
struct sock *sk = skb->sk;
struct inet_sock *inet = inet_sk(sk);
- struct ip_options *opt = inet->opt;
+ struct ip_options_rcu *inet_opt;
struct rtable *rt;
struct iphdr *iph;
int res;
@@ -325,6 +325,7 @@ int ip_queue_xmit(struct sk_buff *skb)
* f.e. by something like SCTP.
*/
rcu_read_lock();
+ inet_opt = rcu_dereference(inet->inet_opt);
rt = skb_rtable(skb);
if (rt != NULL)
goto packet_routed;
@@ -336,8 +337,8 @@ int ip_queue_xmit(struct sk_buff *skb)
/* Use correct destination address if we have options. */
daddr = inet->inet_daddr;
- if(opt && opt->srr)
- daddr = opt->faddr;
+ if (inet_opt && inet_opt->opt.srr)
+ daddr = inet_opt->opt.faddr;
/* If this fails, retransmit mechanism of transport layer will
* keep trying until route appears or the connection times
@@ -357,11 +358,11 @@ int ip_queue_xmit(struct sk_buff *skb)
skb_dst_set_noref(skb, &rt->dst);
packet_routed:
- if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
+ if (inet_opt && inet_opt->opt.is_strictroute && rt->rt_dst != rt->rt_gateway)
goto no_route;
/* OK, we know where to send it, allocate and build IP header. */
- skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
+ skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
*((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
@@ -375,9 +376,9 @@ packet_routed:
iph->daddr = rt->rt_dst;
/* Transport layer set skb->h.foo itself. */
- if (opt && opt->optlen) {
- iph->ihl += opt->optlen >> 2;
- ip_options_build(skb, opt, inet->inet_daddr, rt, 0);
+ if (inet_opt && inet_opt->opt.optlen) {
+ iph->ihl += inet_opt->opt.optlen >> 2;
+ ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0);
}
ip_select_ident_more(iph, &rt->dst, sk,
@@ -1033,7 +1034,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
struct ipcm_cookie *ipc, struct rtable **rtp)
{
struct inet_sock *inet = inet_sk(sk);
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
struct rtable *rt;
/*
@@ -1047,7 +1048,7 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
if (unlikely(cork->opt == NULL))
return -ENOBUFS;
}
- memcpy(cork->opt, opt, sizeof(struct ip_options) + opt->optlen);
+ memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen);
cork->flags |= IPCORK_OPT;
cork->addr = ipc->addr;
}
@@ -1451,26 +1452,23 @@ void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *ar
unsigned int len)
{
struct inet_sock *inet = inet_sk(sk);
- struct {
- struct ip_options opt;
- char data[40];
- } replyopts;
+ struct ip_options_data replyopts;
struct ipcm_cookie ipc;
__be32 daddr;
struct rtable *rt = skb_rtable(skb);
- if (ip_options_echo(&replyopts.opt, skb))
+ if (ip_options_echo(&replyopts.opt.opt, skb))
return;
daddr = ipc.addr = rt->rt_src;
ipc.opt = NULL;
ipc.tx_flags = 0;
- if (replyopts.opt.optlen) {
+ if (replyopts.opt.opt.optlen) {
ipc.opt = &replyopts.opt;
- if (ipc.opt->srr)
- daddr = replyopts.opt.faddr;
+ if (replyopts.opt.opt.srr)
+ daddr = replyopts.opt.opt.faddr;
}
{
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 3948c86..68cdf2b 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -451,6 +451,11 @@ out:
}
+static void opt_kfree_rcu(struct rcu_head *head)
+{
+ kfree(container_of(head, struct ip_options_rcu, rcu));
+}
+
/*
* Socket option code for IP. This is the end of the line after any
* TCP,UDP etc options on an IP socket.
@@ -497,13 +502,16 @@ static int do_ip_setsockopt(struct sock *sk, int level,
switch (optname) {
case IP_OPTIONS:
{
- struct ip_options *opt = NULL;
+ struct ip_options_rcu *old, *opt = NULL;
+
if (optlen > 40)
goto e_inval;
err = ip_options_get_from_user(sock_net(sk), &opt,
optval, optlen);
if (err)
break;
+ old = rcu_dereference_protected(inet->inet_opt,
+ sock_owned_by_user(sk));
if (inet->is_icsk) {
struct inet_connection_sock *icsk = inet_csk(sk);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -512,17 +520,18 @@ static int do_ip_setsockopt(struct sock *sk, int level,
(TCPF_LISTEN | TCPF_CLOSE)) &&
inet->inet_daddr != LOOPBACK4_IPV6)) {
#endif
- if (inet->opt)
- icsk->icsk_ext_hdr_len -= inet->opt->optlen;
+ if (old)
+ icsk->icsk_ext_hdr_len -= old->opt.optlen;
if (opt)
- icsk->icsk_ext_hdr_len += opt->optlen;
+ icsk->icsk_ext_hdr_len += opt->opt.optlen;
icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
}
#endif
}
- opt = xchg(&inet->opt, opt);
- kfree(opt);
+ rcu_assign_pointer(inet->inet_opt, opt);
+ if (old)
+ call_rcu(&old->rcu, opt_kfree_rcu);
break;
}
case IP_PKTINFO:
@@ -1081,12 +1090,16 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
case IP_OPTIONS:
{
unsigned char optbuf[sizeof(struct ip_options)+40];
- struct ip_options * opt = (struct ip_options *)optbuf;
+ struct ip_options *opt = (struct ip_options *)optbuf;
+ struct ip_options_rcu *inet_opt;
+
+ inet_opt = rcu_dereference_protected(inet->inet_opt,
+ sock_owned_by_user(sk));
opt->optlen = 0;
- if (inet->opt)
- memcpy(optbuf, inet->opt,
- sizeof(struct ip_options)+
- inet->opt->optlen);
+ if (inet_opt)
+ memcpy(optbuf, &inet_opt->opt,
+ sizeof(struct ip_options) +
+ inet_opt->opt.optlen);
release_sock(sk);
if (opt->optlen == 0)
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 2b50cc2..c577d25 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -460,6 +460,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
__be32 saddr;
u8 tos;
int err;
+ struct ip_options_data opt_copy;
err = -EMSGSIZE;
if (len > 0xFFFF)
@@ -520,8 +521,18 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
saddr = ipc.addr;
ipc.addr = daddr;
- if (!ipc.opt)
- ipc.opt = inet->opt;
+ if (!ipc.opt) {
+ struct ip_options_rcu *inet_opt;
+
+ rcu_read_lock();
+ inet_opt = rcu_dereference(inet->inet_opt);
+ if (inet_opt) {
+ memcpy(&opt_copy, inet_opt,
+ sizeof(*inet_opt) + inet_opt->opt.optlen);
+ ipc.opt = &opt_copy.opt;
+ }
+ rcu_read_unlock();
+ }
if (ipc.opt) {
err = -EINVAL;
@@ -530,10 +541,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
*/
if (inet->hdrincl)
goto done;
- if (ipc.opt->srr) {
+ if (ipc.opt->opt.srr) {
if (!daddr)
goto done;
- daddr = ipc.opt->faddr;
+ daddr = ipc.opt->opt.faddr;
}
}
tos = RT_CONN_FLAGS(sk);
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 71e0296..2646149 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -321,10 +321,10 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
* the ACK carries the same options again (see RFC1122 4.2.3.8)
*/
if (opt && opt->optlen) {
- int opt_size = sizeof(struct ip_options) + opt->optlen;
+ int opt_size = sizeof(struct ip_options_rcu) + opt->optlen;
ireq->opt = kmalloc(opt_size, GFP_ATOMIC);
- if (ireq->opt != NULL && ip_options_echo(ireq->opt, skb)) {
+ if (ireq->opt != NULL && ip_options_echo(&ireq->opt->opt, skb)) {
kfree(ireq->opt);
ireq->opt = NULL;
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index f7e6c2c..d120f6f 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -153,6 +153,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
struct rtable *rt;
__be32 daddr, nexthop;
int err;
+ struct ip_options_rcu *inet_opt;
if (addr_len < sizeof(struct sockaddr_in))
return -EINVAL;
@@ -161,10 +162,12 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
return -EAFNOSUPPORT;
nexthop = daddr = usin->sin_addr.s_addr;
- if (inet->opt && inet->opt->srr) {
+ inet_opt = rcu_dereference_protected(inet->inet_opt,
+ sock_owned_by_user(sk));
+ if (inet_opt && inet_opt->opt.srr) {
if (!daddr)
return -EINVAL;
- nexthop = inet->opt->faddr;
+ nexthop = inet_opt->opt.faddr;
}
orig_sport = inet->inet_sport;
@@ -185,7 +188,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
return -ENETUNREACH;
}
- if (!inet->opt || !inet->opt->srr)
+ if (!inet_opt || !inet_opt->opt.srr)
daddr = rt->rt_dst;
if (!inet->inet_saddr)
@@ -221,8 +224,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_daddr = daddr;
inet_csk(sk)->icsk_ext_hdr_len = 0;
- if (inet->opt)
- inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
+ if (inet_opt)
+ inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
@@ -820,17 +823,18 @@ static void syn_flood_warning(const struct sk_buff *skb)
/*
* Save and compile IPv4 options into the request_sock if needed.
*/
-static struct ip_options *tcp_v4_save_options(struct sock *sk,
- struct sk_buff *skb)
+static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk,
+ struct sk_buff *skb)
{
- struct ip_options *opt = &(IPCB(skb)->opt);
- struct ip_options *dopt = NULL;
+ const struct ip_options *opt = &(IPCB(skb)->opt);
+ struct ip_options_rcu *dopt = NULL;
if (opt && opt->optlen) {
- int opt_size = optlength(opt);
+ int opt_size = sizeof(*dopt) + opt->optlen;
+
dopt = kmalloc(opt_size, GFP_ATOMIC);
if (dopt) {
- if (ip_options_echo(dopt, skb)) {
+ if (ip_options_echo(&dopt->opt, skb)) {
kfree(dopt);
dopt = NULL;
}
@@ -1411,6 +1415,7 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
#ifdef CONFIG_TCP_MD5SIG
struct tcp_md5sig_key *key;
#endif
+ struct ip_options_rcu *inet_opt;
if (sk_acceptq_is_full(sk))
goto exit_overflow;
@@ -1431,13 +1436,14 @@ struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
newinet->inet_daddr = ireq->rmt_addr;
newinet->inet_rcv_saddr = ireq->loc_addr;
newinet->inet_saddr = ireq->loc_addr;
- newinet->opt = ireq->opt;
+ inet_opt = ireq->opt;
+ rcu_assign_pointer(newinet->inet_opt, inet_opt);
ireq->opt = NULL;
newinet->mc_index = inet_iif(skb);
newinet->mc_ttl = ip_hdr(skb)->ttl;
inet_csk(newsk)->icsk_ext_hdr_len = 0;
- if (newinet->opt)
- inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
+ if (inet_opt)
+ inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
newinet->inet_id = newtp->write_seq ^ jiffies;
tcp_mtup_init(newsk);
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index a15c8fb..75d24ce 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -804,6 +804,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
struct sk_buff *skb;
+ struct ip_options_data opt_copy;
if (len > 0xFFFF)
return -EMSGSIZE;
@@ -877,22 +878,32 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
free = 1;
connected = 0;
}
- if (!ipc.opt)
- ipc.opt = inet->opt;
+ if (!ipc.opt) {
+ struct ip_options_rcu *inet_opt;
+
+ rcu_read_lock();
+ inet_opt = rcu_dereference(inet->inet_opt);
+ if (inet_opt) {
+ memcpy(&opt_copy, inet_opt,
+ sizeof(*inet_opt) + inet_opt->opt.optlen);
+ ipc.opt = &opt_copy.opt;
+ }
+ rcu_read_unlock();
+ }
saddr = ipc.addr;
ipc.addr = faddr = daddr;
- if (ipc.opt && ipc.opt->srr) {
+ if (ipc.opt && ipc.opt->opt.srr) {
if (!daddr)
return -EINVAL;
- faddr = ipc.opt->faddr;
+ faddr = ipc.opt->opt.faddr;
connected = 0;
}
tos = RT_TOS(inet->tos);
if (sock_flag(sk, SOCK_LOCALROUTE) ||
(msg->msg_flags & MSG_DONTROUTE) ||
- (ipc.opt && ipc.opt->is_strictroute)) {
+ (ipc.opt && ipc.opt->opt.is_strictroute)) {
tos |= RTO_ONLINK;
connected = 0;
}
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 4f49e5d..2c6e606 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1469,7 +1469,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
First: no IPv4 options.
*/
- newinet->opt = NULL;
+ newinet->inet_opt = NULL;
newnp->ipv6_fl_list = NULL;
/* Clone RX bits */
^ permalink raw reply related [flat|nested] 8+ messages in thread