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authorEric Dumazet <edumazet@google.com>2023-09-22 06:42:14 +0300
committerDavid S. Miller <davem@davemloft.net>2023-10-01 21:39:18 +0300
commitc9746e6a19c24b2d9a74d6657daee3b39fdc1bec (patch)
tree0c4c1653ac642f05004c576ce39640e3cc055011 /net/ipv4/ip_sockglue.c
parent2be825ebb9d1b17f1a9e46af78d24b76c4ff7a1f (diff)
downloadlinux-c9746e6a19c24b2d9a74d6657daee3b39fdc1bec.tar.xz
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>
Diffstat (limited to 'net/ipv4/ip_sockglue.c')
-rw-r--r--net/ipv4/ip_sockglue.c31
1 files changed, 16 insertions, 15 deletions
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)) {