[ 72/82] sctp: check cached dst before using it
From: Ben Hutchings <hidden>
Date: 2012-06-08 05:14:49
Also in:
lkml
Subsystem:
networking [general], sctp protocol, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Marcelo Ricardo Leitner, Xin Long, Linus Torvalds
3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Dichtel <redacted> [ Upstream commit e0268868ba064980488fc8c194db3d8e9fb2959c ] dst_check() will take care of SA (and obsolete field), hence IPsec rekeying scenario is taken into account. Signed-off-by: Nicolas Dichtel <redacted> Acked-by: Vlad Yaseivch <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <redacted> --- include/net/sctp/sctp.h | 13 +++++++++++++ net/sctp/output.c | 4 +--- net/sctp/transport.c | 17 ----------------- 3 files changed, 14 insertions(+), 20 deletions(-)
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 6a72a58..ad03988 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h@@ -703,4 +703,17 @@ static inline void sctp_v4_map_v6(union sctp_addr *addr) addr->v6.sin6_addr.s6_addr32[2] = htonl(0x0000ffff); } +/* The cookie is always 0 since this is how it's used in the + * pmtu code. + */ +static inline struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) +{ + if (t->dst && !dst_check(t->dst, 0)) { + dst_release(t->dst); + t->dst = NULL; + } + + return t->dst; +} + #endif /* __net_sctp_h__ */
diff --git a/net/sctp/output.c b/net/sctp/output.c
index 817174e..8fc4dcd 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c@@ -377,9 +377,7 @@ int sctp_packet_transmit(struct sctp_packet *packet) */ skb_set_owner_w(nskb, sk); - /* The 'obsolete' field of dst is set to 2 when a dst is freed. */ - if (!dst || (dst->obsolete > 1)) { - dst_release(dst); + if (!sctp_transport_dst_check(tp)) { sctp_transport_route(tp, NULL, sctp_sk(sk)); if (asoc && (asoc->param_flags & SPP_PMTUD_ENABLE)) { sctp_assoc_sync_pmtu(asoc);
diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 394c57c..8da4481 100644
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c@@ -226,23 +226,6 @@ void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk) transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT; } -/* this is a complete rip-off from __sk_dst_check - * the cookie is always 0 since this is how it's used in the - * pmtu code - */ -static struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t) -{ - struct dst_entry *dst = t->dst; - - if (dst && dst->obsolete && dst->ops->check(dst, 0) == NULL) { - dst_release(t->dst); - t->dst = NULL; - return NULL; - } - - return dst; -} - void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu) { struct dst_entry *dst;