From 4e54064e0a13b7a7d4a481123c1783f770538e30 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Fri, 18 Jul 2008 23:06:32 -0700 Subject: [PATCH] sctp: Allow only 1 listening socket with SO_REUSEADDR When multiple socket bind to the same port with SO_REUSEADDR, only 1 can be listining. Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- net/sctp/socket.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index fd7ed9d46a48..79bece16aede 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -377,18 +377,19 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len) if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE)) return -EACCES; + /* See if the address matches any of the addresses we may have + * already bound before checking against other endpoints. + */ + if (sctp_bind_addr_match(bp, addr, sp)) + return -EINVAL; + /* Make sure we are allowed to bind here. * The function sctp_get_port_local() does duplicate address * detection. */ addr->v4.sin_port = htons(snum); if ((ret = sctp_get_port_local(sk, addr))) { - if (ret == (long) sk) { - /* This endpoint has a conflicting address. */ - return -EINVAL; - } else { - return -EADDRINUSE; - } + return -EADDRINUSE; } /* Refresh ephemeral port. */ @@ -5584,8 +5585,9 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr) struct sctp_endpoint *ep2; ep2 = sctp_sk(sk2)->ep; - if (reuse && sk2->sk_reuse && - sk2->sk_state != SCTP_SS_LISTENING) + if (sk == sk2 || + (reuse && sk2->sk_reuse && + sk2->sk_state != SCTP_SS_LISTENING)) continue; if (sctp_bind_addr_conflict(&ep2->base.bind_addr, addr, @@ -5702,8 +5704,13 @@ SCTP_STATIC int sctp_seqpacket_listen(struct sock *sk, int backlog) if (!ep->base.bind_addr.port) { if (sctp_autobind(sk)) return -EAGAIN; - } else + } else { + if (sctp_get_port(sk, inet_sk(sk)->num)) { + sk->sk_state = SCTP_SS_CLOSED; + return -EADDRINUSE; + } sctp_sk(sk)->bind_hash->fastreuse = 0; + } sctp_hash_endpoint(ep); return 0; -- GitLab