diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-09-12 16:02:01 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-09-15 10:33:46 +0100 |
| commit | 2da23eb07c91241d962f3ff05565065484cd8929 (patch) | |
| tree | 921417255db7f2389304c5f21aac9c828b58caa8 /net/ipv6/ipv6_sockglue.c | |
| parent | d986f52124e062753e33b6fe303be5904a997eac (diff) | |
ipv6: lockless IPV6_MULTICAST_HOPS implementation
This fixes data-races around np->mcast_hops,
and make IPV6_MULTICAST_HOPS lockless.
Note that np->mcast_hops is never negative,
thus can fit an u8 field instead of s16.
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/ipv6/ipv6_sockglue.c')
| -rw-r--r-- | net/ipv6/ipv6_sockglue.c | 28 |
1 files changed, 15 insertions, 13 deletions
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 755fac85a120..5fff19a87c75 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -431,6 +431,16 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, return -EINVAL; inet6_assign_bit(MC6_LOOP, sk, valbool); return 0; + case IPV6_MULTICAST_HOPS: + if (sk->sk_type == SOCK_STREAM) + return retv; + if (optlen < sizeof(int)) + return -EINVAL; + if (val > 255 || val < -1) + return -EINVAL; + WRITE_ONCE(np->mcast_hops, + val == -1 ? IPV6_DEFAULT_MCASTHOPS : val); + return 0; } if (needs_rtnl) rtnl_lock(); @@ -751,16 +761,6 @@ done: break; } - case IPV6_MULTICAST_HOPS: - if (sk->sk_type == SOCK_STREAM) - break; - if (optlen < sizeof(int)) - goto e_inval; - if (val > 255 || val < -1) - goto e_inval; - np->mcast_hops = (val == -1 ? IPV6_DEFAULT_MCASTHOPS : val); - retv = 0; - break; case IPV6_UNICAST_IF: { @@ -1180,7 +1180,8 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, put_cmsg(&msg, SOL_IPV6, IPV6_PKTINFO, sizeof(src_info), &src_info); } if (np->rxopt.bits.rxhlim) { - int hlim = np->mcast_hops; + int hlim = READ_ONCE(np->mcast_hops); + put_cmsg(&msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim); } if (np->rxopt.bits.rxtclass) { @@ -1197,7 +1198,8 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, put_cmsg(&msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info); } if (np->rxopt.bits.rxohlim) { - int hlim = np->mcast_hops; + int hlim = READ_ONCE(np->mcast_hops); + put_cmsg(&msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim); } if (np->rxopt.bits.rxflow) { @@ -1349,7 +1351,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, if (optname == IPV6_UNICAST_HOPS) val = READ_ONCE(np->hop_limit); else - val = np->mcast_hops; + val = READ_ONCE(np->mcast_hops); if (val < 0) { rcu_read_lock(); |