diff options
| author | Eric Dumazet <edumazet@google.com> | 2023-09-22 03:42:14 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-10-01 19:39:18 +0100 |
| commit | c9746e6a19c24b2d9a74d6657daee3b39fdc1bec (patch) | |
| tree | 0c4c1653ac642f05004c576ce39640e3cc055011 | |
| parent | 2be825ebb9d1b17f1a9e46af78d24b76c4ff7a1f (diff) | |
inet: implement lockless IP_MULTICAST_TTL
inet->mc_ttl can be read locklessly.
Implement proper lockless reads and writes to inet->mc_ttl
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/ip_output.c | 2 | ||||
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 31 | ||||
| -rw-r--r-- | net/netfilter/ipvs/ip_vs_sync.c | 2 |
3 files changed, 18 insertions, 17 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 6b14097e80ad..f07ce051760d 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1430,7 +1430,7 @@ struct sk_buff *__ip_make_skb(struct sock *sk, if (cork->ttl != 0) ttl = cork->ttl; else if (rt->rt_type == RTN_MULTICAST) - ttl = inet->mc_ttl; + ttl = READ_ONCE(inet->mc_ttl); else ttl = ip_select_ttl(inet, &rt->dst); diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index cce9cb25f3b3..4ad3003378ae 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -1039,6 +1039,17 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname, WRITE_ONCE(inet->min_ttl, val); return 0; + case IP_MULTICAST_TTL: + if (sk->sk_type == SOCK_STREAM) + return -EINVAL; + if (optlen < 1) + return -EINVAL; + if (val == -1) + val = 1; + if (val < 0 || val > 255) + return -EINVAL; + WRITE_ONCE(inet->mc_ttl, val); + return 0; } err = 0; @@ -1101,17 +1112,6 @@ int do_ip_setsockopt(struct sock *sk, int level, int optname, goto e_inval; inet->pmtudisc = val; break; - case IP_MULTICAST_TTL: - if (sk->sk_type == SOCK_STREAM) - goto e_inval; - if (optlen < 1) - goto e_inval; - if (val == -1) - val = 1; - if (val < 0 || val > 255) - goto e_inval; - inet->mc_ttl = val; - break; case IP_UNICAST_IF: { struct net_device *dev = NULL; @@ -1592,6 +1592,9 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname, case IP_MINTTL: val = READ_ONCE(inet->min_ttl); goto copyval; + case IP_MULTICAST_TTL: + val = READ_ONCE(inet->mc_ttl); + goto copyval; } if (needs_rtnl) @@ -1649,9 +1652,6 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname, } break; } - case IP_MULTICAST_TTL: - val = inet->mc_ttl; - break; case IP_UNICAST_IF: val = (__force int)htonl((__u32) inet->uc_index); break; @@ -1718,7 +1718,8 @@ int do_ip_getsockopt(struct sock *sk, int level, int optname, put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info); } if (inet_test_bit(TTL, sk)) { - int hlim = inet->mc_ttl; + int hlim = READ_ONCE(inet->mc_ttl); + put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim); } if (inet_test_bit(TOS, sk)) { diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c index 5820a8156c47..3eed16702248 100644 --- a/net/netfilter/ipvs/ip_vs_sync.c +++ b/net/netfilter/ipvs/ip_vs_sync.c @@ -1316,7 +1316,7 @@ static void set_mcast_ttl(struct sock *sk, u_char ttl) /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */ lock_sock(sk); - inet->mc_ttl = ttl; + WRITE_ONCE(inet->mc_ttl, ttl); #ifdef CONFIG_IP_VS_IPV6 if (sk->sk_family == AF_INET6) { struct ipv6_pinfo *np = inet6_sk(sk); |