diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-09-12 16:02:11 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-09-15 10:33:48 +0100 |
| commit | 6b724bc4300b431443f3b99520994a5aece347cd (patch) | |
| tree | 02730c15dc86341705749df48ed87b7ca84688c1 /net/ipv6 | |
| parent | 83cd5eb654b320c1972254f243531f3f3cebcccf (diff) | |
ipv6: lockless IPV6_MTU_DISCOVER implementation
Most np->pmtudisc reads are racy.
Move this 3bit field on a full byte, add annotations
and make IPV6_MTU_DISCOVER setsockopt() lockless.
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')
| -rw-r--r-- | net/ipv6/ip6_output.c | 4 | ||||
| -rw-r--r-- | net/ipv6/ipv6_sockglue.c | 17 | ||||
| -rw-r--r-- | net/ipv6/raw.c | 2 | ||||
| -rw-r--r-- | net/ipv6/udp.c | 2 |
4 files changed, 12 insertions, 13 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index f87d8491d7e2..7e5d9eeb990f 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1436,10 +1436,10 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, v6_cork->hop_limit = ipc6->hlimit; v6_cork->tclass = ipc6->tclass; if (rt->dst.flags & DST_XFRM_TUNNEL) - mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? + mtu = READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE ? READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); else - mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? + mtu = READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE ? READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); frag_size = READ_ONCE(np->frag_size); diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index c22a492e0536..85ea42644dcb 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -493,6 +493,13 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname, return -EINVAL; inet6_assign_bit(RTALERT_ISOLATE, sk, valbool); return 0; + case IPV6_MTU_DISCOVER: + if (optlen < sizeof(int)) + return -EINVAL; + if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT) + return -EINVAL; + WRITE_ONCE(np->pmtudisc, val); + return 0; } if (needs_rtnl) rtnl_lock(); @@ -941,14 +948,6 @@ done: goto e_inval; retv = ip6_ra_control(sk, val); break; - case IPV6_MTU_DISCOVER: - if (optlen < sizeof(int)) - goto e_inval; - if (val < IPV6_PMTUDISC_DONT || val > IPV6_PMTUDISC_OMIT) - goto e_inval; - np->pmtudisc = val; - retv = 0; - break; case IPV6_FLOWINFO_SEND: if (optlen < sizeof(int)) goto e_inval; @@ -1374,7 +1373,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname, break; case IPV6_MTU_DISCOVER: - val = np->pmtudisc; + val = READ_ONCE(np->pmtudisc); break; case IPV6_RECVERR: diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 71f6bdccfa1f..47372cceb98f 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -307,7 +307,7 @@ static void rawv6_err(struct sock *sk, struct sk_buff *skb, harderr = icmpv6_err_convert(type, code, &err); if (type == ICMPV6_PKT_TOOBIG) { ip6_sk_update_pmtu(skb, sk, info); - harderr = (np->pmtudisc == IPV6_PMTUDISC_DO); + harderr = (READ_ONCE(np->pmtudisc) == IPV6_PMTUDISC_DO); } if (type == NDISC_REDIRECT) { ip6_sk_redirect(skb, sk); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 90e873689b88..c17e19fece1b 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -598,7 +598,7 @@ int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, if (!ip6_sk_accept_pmtu(sk)) goto out; ip6_sk_update_pmtu(skb, sk, info); - if (np->pmtudisc != IPV6_PMTUDISC_DONT) + if (READ_ONCE(np->pmtudisc) != IPV6_PMTUDISC_DONT) harderr = 1; } if (type == NDISC_REDIRECT) { |