diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-09-22 06:42:19 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-10-01 21:39:19 +0300 |
| commit | 959d5c11601b2b337c364b2e3102d392365e3dd3 (patch) | |
| tree | f73ca0bc48ac759666bb259de30bd61bc1c5acfd /net/ipv4/udp.c | |
| parent | 3523bc91e4b4da39ccf18a0252d13108877ece0a (diff) | |
| download | linux-959d5c11601b2b337c364b2e3102d392365e3dd3.tar.xz | |
inet: implement lockless getsockopt(IP_UNICAST_IF)
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>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 731a723dc808..1e0c3aba1e5a 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; } } |