From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: David Ahern <dsahern@kernel.org>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH net-next 6/8] inet: implement lockless getsockopt(IP_UNICAST_IF)
Date: Thu, 21 Sep 2023 13:30:19 +0000 [thread overview]
Message-ID: <20230921133021.1995349-7-edumazet@google.com> (raw)
In-Reply-To: <20230921133021.1995349-1-edumazet@google.com>
Add missing READ_ONCE() annotations when reading inet->uc_index
Implementing getsockopt(IP_UNICAST_IF) locklessly seems possible,
the setsockopt() part might not be possible at the moment.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
net/ipv4/datagram.c | 2 +-
net/ipv4/ip_sockglue.c | 10 +++++-----
net/ipv4/ping.c | 2 +-
net/ipv4/raw.c | 13 +++++++------
net/ipv4/udp.c | 12 +++++++-----
5 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c
index cb5dbee9e018fbba1bc1e5705e8bec6c4203af56..1480e9ebdfef445960e1f70f34f33a0e0c52b65b 100644
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -43,7 +43,7 @@ int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len
if (!saddr)
saddr = inet->mc_addr;
} else if (!oif) {
- oif = inet->uc_index;
+ oif = READ_ONCE(inet->uc_index);
}
fl4 = &inet->cork.fl.u.ip4;
rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif,
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 04579e390ddd4dadb8a107ef0b5da15e7a60f1ff..58995526c6e965d613b8cdea61b84916d608a6fb 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1113,7 +1113,7 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
ifindex = (__force int)ntohl((__force __be32)val);
if (ifindex == 0) {
- inet->uc_index = 0;
+ WRITE_ONCE(inet->uc_index, 0);
err = 0;
break;
}
@@ -1130,7 +1130,7 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname,
if (sk->sk_bound_dev_if && midx != sk->sk_bound_dev_if)
break;
- inet->uc_index = ifindex;
+ WRITE_ONCE(inet->uc_index, ifindex);
err = 0;
break;
}
@@ -1633,6 +1633,9 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
return -ENOTCONN;
goto copyval;
}
+ case IP_UNICAST_IF:
+ val = (__force int)htonl((__u32) READ_ONCE(inet->uc_index));
+ goto copyval;
}
if (needs_rtnl)
@@ -1640,9 +1643,6 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname,
sockopt_lock_sock(sk);
switch (optname) {
- case IP_UNICAST_IF:
- val = (__force int)htonl((__u32) inet->uc_index);
- break;
case IP_MULTICAST_IF:
{
struct in_addr addr;
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 50d12b0c8d46fdcd9b448c3ebc90395ebf426075..66ad1f95af49f222afe0ee75b9163dd0af0a2c49 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -777,7 +777,7 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
if (!saddr)
saddr = inet->mc_addr;
} else if (!ipc.oif)
- ipc.oif = inet->uc_index;
+ ipc.oif = READ_ONCE(inet->uc_index);
flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, scope,
sk->sk_protocol, inet_sk_flowi_flags(sk), faddr,
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index ade1aecd7c71184d753a28a67bc9b30087247db4..e2357d23202e5a39832bb1550c365de9a836c363 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -482,7 +482,7 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
int free = 0;
__be32 daddr;
__be32 saddr;
- int err;
+ int uc_index, err;
struct ip_options_data opt_copy;
struct raw_frag_vec rfv;
int hdrincl;
@@ -576,24 +576,25 @@ static int raw_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
tos = get_rttos(&ipc, inet);
scope = ip_sendmsg_scope(inet, &ipc, msg);
+ uc_index = READ_ONCE(inet->uc_index);
if (ipv4_is_multicast(daddr)) {
if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
ipc.oif = inet->mc_index;
if (!saddr)
saddr = inet->mc_addr;
} else if (!ipc.oif) {
- ipc.oif = inet->uc_index;
- } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
+ ipc.oif = uc_index;
+ } else if (ipv4_is_lbcast(daddr) && uc_index) {
/* oif is set, packet is to local broadcast
* and uc_index is set. oif is most likely set
* by sk_bound_dev_if. If uc_index != oif check if the
* oif is an L3 master and uc_index is an L3 slave.
* If so, we want to allow the send using the uc_index.
*/
- if (ipc.oif != inet->uc_index &&
+ if (ipc.oif != uc_index &&
ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
- inet->uc_index)) {
- ipc.oif = inet->uc_index;
+ uc_index)) {
+ ipc.oif = uc_index;
}
}
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 731a723dc80816f0b5b0803d7397f7e9e8cd8b09..1e0c3aba1e5a88c7ba50a28511412a1710f1bab5 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1055,6 +1055,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
struct sk_buff *skb;
struct ip_options_data opt_copy;
+ int uc_index;
if (len > 0xFFFF)
return -EMSGSIZE;
@@ -1173,6 +1174,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
if (scope == RT_SCOPE_LINK)
connected = 0;
+ uc_index = READ_ONCE(inet->uc_index);
if (ipv4_is_multicast(daddr)) {
if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
ipc.oif = inet->mc_index;
@@ -1180,18 +1182,18 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
saddr = inet->mc_addr;
connected = 0;
} else if (!ipc.oif) {
- ipc.oif = inet->uc_index;
- } else if (ipv4_is_lbcast(daddr) && inet->uc_index) {
+ ipc.oif = uc_index;
+ } else if (ipv4_is_lbcast(daddr) && uc_index) {
/* oif is set, packet is to local broadcast and
* uc_index is set. oif is most likely set
* by sk_bound_dev_if. If uc_index != oif check if the
* oif is an L3 master and uc_index is an L3 slave.
* If so, we want to allow the send using the uc_index.
*/
- if (ipc.oif != inet->uc_index &&
+ if (ipc.oif != uc_index &&
ipc.oif == l3mdev_master_ifindex_by_index(sock_net(sk),
- inet->uc_index)) {
- ipc.oif = inet->uc_index;
+ uc_index)) {
+ ipc.oif = uc_index;
}
}
--
2.42.0.459.ge4e396fd5e-goog
next prev parent reply other threads:[~2023-09-21 17:49 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-21 13:30 [PATCH net-next 0/8] inet: more data-race fixes Eric Dumazet
2023-09-21 13:30 ` [PATCH net-next 1/8] inet: implement lockless IP_MULTICAST_TTL Eric Dumazet
2023-09-21 19:03 ` David Ahern
2023-09-21 13:30 ` [PATCH net-next 2/8] inet: implement lockless IP_MTU_DISCOVER Eric Dumazet
2023-09-21 19:03 ` David Ahern
2023-09-21 13:30 ` [PATCH net-next 3/8] inet: implement lockless IP_TOS Eric Dumazet
2023-09-21 19:10 ` David Ahern
2023-09-21 19:15 ` Eric Dumazet
2023-09-21 13:30 ` [PATCH net-next 4/8] inet: lockless getsockopt(IP_OPTIONS) Eric Dumazet
2023-09-21 19:12 ` David Ahern
2023-09-21 13:30 ` [PATCH net-next 5/8] inet: lockless getsockopt(IP_MTU) Eric Dumazet
2023-09-21 19:13 ` David Ahern
2023-09-21 13:30 ` Eric Dumazet [this message]
2023-09-21 19:19 ` [PATCH net-next 6/8] inet: implement lockless getsockopt(IP_UNICAST_IF) David Ahern
2023-09-21 13:30 ` [PATCH net-next 7/8] inet: lockless IP_PKTOPTIONS implementation Eric Dumazet
2023-09-21 19:23 ` David Ahern
2023-09-21 13:30 ` [PATCH net-next 8/8] inet: implement lockless getsockopt(IP_MULTICAST_IF) Eric Dumazet
2023-09-21 19:24 ` David Ahern
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