ipv6: lockless IPV6_MINHOPCOUNT implementation

Add one missing READ_ONCE() annotation in do_ipv6_getsockopt()
and make IPV6_MINHOPCOUNT 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>
This commit is contained in:
Eric Dumazet 2023-09-12 16:02:03 +00:00 committed by David S. Miller
parent 15f926c445
commit 273784d3c5
1 changed files with 15 additions and 16 deletions

View File

@ -448,6 +448,20 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
return -EINVAL;
WRITE_ONCE(np->frag_size, val);
return 0;
case IPV6_MINHOPCOUNT:
if (optlen < sizeof(int))
return -EINVAL;
if (val < 0 || val > 255)
return -EINVAL;
if (val)
static_branch_enable(&ip6_min_hopcount);
/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
* while we are changing it.
*/
WRITE_ONCE(np->min_hopcount, val);
return 0;
}
if (needs_rtnl)
rtnl_lock();
@ -947,21 +961,6 @@ done:
goto e_inval;
retv = __ip6_sock_set_addr_preferences(sk, val);
break;
case IPV6_MINHOPCOUNT:
if (optlen < sizeof(int))
goto e_inval;
if (val < 0 || val > 255)
goto e_inval;
if (val)
static_branch_enable(&ip6_min_hopcount);
/* tcp_v6_err() and tcp_v6_rcv() might read min_hopcount
* while we are changing it.
*/
WRITE_ONCE(np->min_hopcount, val);
retv = 0;
break;
case IPV6_DONTFRAG:
np->dontfrag = valbool;
retv = 0;
@ -1443,7 +1442,7 @@ int do_ipv6_getsockopt(struct sock *sk, int level, int optname,
break;
case IPV6_MINHOPCOUNT:
val = np->min_hopcount;
val = READ_ONCE(np->min_hopcount);
break;
case IPV6_DONTFRAG: