[PATCH 3.12 68/91] sctp: use the same clock as if sock source timestamps were on

From: Jiri Slaby
Date: Tue Jan 05 2016 - 12:56:58 EST


From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

[ Upstream commit cb5e173ed7c03a0d4630ce68a95a186cce3cc872 ]

SCTP echoes a cookie o INIT ACK chunks that contains a timestamp, for
detecting stale cookies. This cookie is echoed back to the server by the
client and then that timestamp is checked.

Thing is, if the listening socket is using packet timestamping, the
cookie is encoded with ktime_get() value and checked against
ktime_get_real(), as done by __net_timestamp().

The fix is to sctp also use ktime_get_real(), so we can compare bananas
with bananas later no matter if packet timestamping was enabled or not.

Fixes: 52db882f3fc2 ("net: sctp: migrate cookie life from timeval to ktime")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Acked-by: Vlad Yasevich <vyasevich@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
net/sctp/sm_make_chunk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index eb5012b03cfb..a15b78de8e7c 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1664,7 +1664,7 @@ static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,

/* Set an expiration time for the cookie. */
cookie->c.expiration = ktime_add(asoc->cookie_life,
- ktime_get());
+ ktime_get_real());

/* Copy the peer's init packet. */
memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
@@ -1792,7 +1792,7 @@ no_hmac:
if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
kt = skb_get_ktime(skb);
else
- kt = ktime_get();
+ kt = ktime_get_real();

if (!asoc && ktime_compare(bear_cookie->expiration, kt) < 0) {
/*
--
2.6.4

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