From 33fce60d6a6e137035f8e23a89d7fd55f3a24cda Mon Sep 17 00:00:00 2001 From: Fan Du Date: Tue, 17 Sep 2013 15:14:13 +0800 Subject: xfrm: Guard IPsec anti replay window against replay bitmap For legacy IPsec anti replay mechanism: bitmap in struct xfrm_replay_state could only provide a 32 bits window size limit in current design, thus user level parameter sadb_sa_replay should honor this limit, otherwise misleading outputs("replay=244") by setkey -D will be: 192.168.25.2 192.168.22.2 esp mode=transport spi=147561170(0x08cb9ad2) reqid=0(0x00000000) E: aes-cbc 9a8d7468 7655cf0b 719d27be b0ddaac2 A: hmac-sha1 2d2115c2 ebf7c126 1c54f186 3b139b58 264a7331 seq=0x00000000 replay=244 flags=0x00000000 state=mature created: Sep 17 14:00:00 2013 current: Sep 17 14:00:22 2013 diff: 22(s) hard: 30(s) soft: 26(s) last: Sep 17 14:00:00 2013 hard: 0(s) soft: 0(s) current: 1408(bytes) hard: 0(bytes) soft: 0(bytes) allocated: 22 hard: 0 soft: 0 sadb_seq=1 pid=4854 refcnt=0 192.168.22.2 192.168.25.2 esp mode=transport spi=255302123(0x0f3799eb) reqid=0(0x00000000) E: aes-cbc 6485d990 f61a6bd5 e5660252 608ad282 A: hmac-sha1 0cca811a eb4fa893 c47ae56c 98f6e413 87379a88 seq=0x00000000 replay=244 flags=0x00000000 state=mature created: Sep 17 14:00:00 2013 current: Sep 17 14:00:22 2013 diff: 22(s) hard: 30(s) soft: 26(s) last: Sep 17 14:00:00 2013 hard: 0(s) soft: 0(s) current: 1408(bytes) hard: 0(bytes) soft: 0(bytes) allocated: 22 hard: 0 soft: 0 sadb_seq=0 pid=4854 refcnt=0 And also, optimizing xfrm_replay_check window checking by setting the desirable x->props.replay_window with only doing the comparison once for all when xfrm_state is first born. Signed-off-by: Fan Du Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_replay.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/xfrm/xfrm_replay.c') diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c index 8dafe6d3c6e..eeca388effc 100644 --- a/net/xfrm/xfrm_replay.c +++ b/net/xfrm/xfrm_replay.c @@ -129,8 +129,7 @@ static int xfrm_replay_check(struct xfrm_state *x, return 0; diff = x->replay.seq - seq; - if (diff >= min_t(unsigned int, x->props.replay_window, - sizeof(x->replay.bitmap) * 8)) { + if (diff >= x->props.replay_window) { x->stats.replay_window++; goto err; } -- cgit v1.2.3-70-g09d2 From cd808fc9a6c7cd3a4311d9d2cffc4adbeaef5f6c Mon Sep 17 00:00:00 2001 From: Thomas Egerer Date: Thu, 19 Sep 2013 13:19:19 +0200 Subject: xfrm: Fix aevent generation for each received packet If asynchronous events are enabled for a particular netlink socket, the notify function is called by the advance function. The notify function creates and dispatches a km_event if a replay timeout occurred, or at least replay_maxdiff packets have been received since the last asynchronous event has been sent. The function is supposed to return if neither of the two events were detected for a state, or replay_maxdiff is equal to zero. Replay_maxdiff is initialized in xfrm_state_construct to the value of the xfrm.sysctl_aevent_rseqth (2 by default), and updated if for a state if the netlink attribute XFRMA_REPLAY_THRESH is set. If, however, replay_maxdiff is set to zero, then all of the three notify implementations perform a break from the switch statement instead of checking whether a timeout occurred, and -- if not -- return. As a result an asynchronous event is generated for every replay update of a state that has a zero replay_maxdiff value. This patch modifies the notify functions such that they immediately return if replay_maxdiff has the value zero, unless a timeout occurred. Signed-off-by: Thomas Egerer Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_replay.c | 51 ++++++++++++++++++++++++++------------------------ 1 file changed, 27 insertions(+), 24 deletions(-) (limited to 'net/xfrm/xfrm_replay.c') diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c index eeca388effc..dab57daae40 100644 --- a/net/xfrm/xfrm_replay.c +++ b/net/xfrm/xfrm_replay.c @@ -61,9 +61,9 @@ static void xfrm_replay_notify(struct xfrm_state *x, int event) switch (event) { case XFRM_REPLAY_UPDATE: - if (x->replay_maxdiff && - (x->replay.seq - x->preplay.seq < x->replay_maxdiff) && - (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff)) { + if (!x->replay_maxdiff || + ((x->replay.seq - x->preplay.seq < x->replay_maxdiff) && + (x->replay.oseq - x->preplay.oseq < x->replay_maxdiff))) { if (x->xflags & XFRM_TIME_DEFER) event = XFRM_REPLAY_TIMEOUT; else @@ -301,9 +301,10 @@ static void xfrm_replay_notify_bmp(struct xfrm_state *x, int event) switch (event) { case XFRM_REPLAY_UPDATE: - if (x->replay_maxdiff && - (replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) && - (replay_esn->oseq - preplay_esn->oseq < x->replay_maxdiff)) { + if (!x->replay_maxdiff || + ((replay_esn->seq - preplay_esn->seq < x->replay_maxdiff) && + (replay_esn->oseq - preplay_esn->oseq + < x->replay_maxdiff))) { if (x->xflags & XFRM_TIME_DEFER) event = XFRM_REPLAY_TIMEOUT; else @@ -352,28 +353,30 @@ static void xfrm_replay_notify_esn(struct xfrm_state *x, int event) switch (event) { case XFRM_REPLAY_UPDATE: - if (!x->replay_maxdiff) - break; - - if (replay_esn->seq_hi == preplay_esn->seq_hi) - seq_diff = replay_esn->seq - preplay_esn->seq; - else - seq_diff = ~preplay_esn->seq + replay_esn->seq + 1; - - if (replay_esn->oseq_hi == preplay_esn->oseq_hi) - oseq_diff = replay_esn->oseq - preplay_esn->oseq; - else - oseq_diff = ~preplay_esn->oseq + replay_esn->oseq + 1; - - if (seq_diff < x->replay_maxdiff && - oseq_diff < x->replay_maxdiff) { + if (x->replay_maxdiff) { + if (replay_esn->seq_hi == preplay_esn->seq_hi) + seq_diff = replay_esn->seq - preplay_esn->seq; + else + seq_diff = ~preplay_esn->seq + replay_esn->seq + + 1; - if (x->xflags & XFRM_TIME_DEFER) - event = XFRM_REPLAY_TIMEOUT; + if (replay_esn->oseq_hi == preplay_esn->oseq_hi) + oseq_diff = replay_esn->oseq + - preplay_esn->oseq; else - return; + oseq_diff = ~preplay_esn->oseq + + replay_esn->oseq + 1; + + if (seq_diff >= x->replay_maxdiff || + oseq_diff >= x->replay_maxdiff) + break; } + if (x->xflags & XFRM_TIME_DEFER) + event = XFRM_REPLAY_TIMEOUT; + else + return; + break; case XFRM_REPLAY_TIMEOUT: -- cgit v1.2.3-70-g09d2