kernel.git/net/sctp/output.c, branch linux-4.9.y

sctp: fix the panic caused by route update

2016-10-26T21:32:19Z

Commit 7303a1475008 ("sctp: identify chunks that need to be fragmented at IP level") made the chunk be fragmented at IP level in the next round if it's size exceed PMTU. But there still is another case, PMTU can be updated if transport's dst expires and transport's pmtu_pending is set in sctp_packet_transmit. If the new PMTU is less than the chunk, the same issue with that commit can be triggered. So we should drop this packet and let it retransmit in another round where it would be fragmented at IP level. This patch is to fix it by checking the chunk size after PMTU may be updated and dropping this packet if it's size exceed PMTU. Fixes: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller

sctp: rename WORD_TRUNC/ROUND macros

2016-09-22T07:13:26Z

To something more meaningful these days, specially because this is working on packet headers or lengths and which are not tied to any CPU arch but to the protocol itself. So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4. Reported-by: David Laight Reported-by: David Miller Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: not return ENOMEM err back in sctp_packet_transmit

2016-09-19T02:02:33Z

As David and Marcelo's suggestion, ENOMEM err shouldn't return back to user in transmit path. Instead, sctp's retransmit would take care of the chunks that fail to send because of ENOMEM. This patch is only to do some release job when alloc_skb fails, not to return ENOMEM back any more. Besides, it also cleans up sctp_packet_transmit's err path, and fixes some issues in err path: - It didn't free the head skb in nomem: path. - No need to check nskb in no_route: path. - It should goto err: path if alloc_skb fails for head. - Not all the NOMEMs should free nskb. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: save transmit error to sk_err in sctp_outq_flush

2016-09-19T02:02:32Z

Every time when sctp calls sctp_outq_flush, it sends out the chunks of control queue, retransmit queue and data queue. Even if some trunks are failed to transmit, it still has to flush all the transports, as it's the only chance to clean that transmit_list. So the latest transmit error here should be returned back. This transmit error is an internal error of sctp stack. I checked all the places where it uses the transmit error (the return value of sctp_outq_flush), most of them are actually just save it to sk_err. Except for sctp_assoc/endpoint_bh_rcv, they will drop the chunk if it's failed to send a REPLY, which is actually incorrect, as we can't be sure the error that sctp_outq_flush returns is from sending that REPLY. So it's meaningless for sctp_outq_flush to return error back. This patch is to save transmit error to sk_err in sctp_outq_flush, the new error can update the old value. Eventually, sctp_wait_for_* would check for it. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: identify chunks that need to be fragmented at IP level

2016-09-10T02:18:33Z

Previously, without GSO, it was easy to identify it: if the chunk didn't fit and there was no data chunk in the packet yet, we could fragment at IP level. So if there was an auth chunk and we were bundling a big data chunk, it would fragment regardless of the size of the auth chunk. This also works for the context of PMTU reductions. But with GSO, we cannot distinguish such PMTU events anymore, as the packet is allowed to exceed PMTU. So we need another check: to ensure that the chunk that we are adding, actually fits the current PMTU. If it doesn't, trigger a flush and let it be fragmented at IP level in the next round. Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: fix the issue sctp requeue auth chunk incorrectly

2016-07-31T05:06:22Z

sctp needs to queue auth chunk back when we know that we are going to generate another segment. But commit f1533cce60d1 ("sctp: fix panic when sending auth chunks") requeues the last chunk processed which is probably not the auth chunk. It causes panic when calculating the MAC in sctp_auth_calculate_hmac(), as the incorrect offset of the auth chunk in skb->data. This fix is to requeue it by using packet->auth. Fixes: f1533cce60d1 ("sctp: fix panic when sending auth chunks") Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: implement prsctp TTL policy

2016-07-11T20:25:39Z

prsctp TTL policy is a policy to abandon chunks when they expire at the specific time in local stack. It's similar with expires_at in struct sctp_datamsg. This patch uses sinfo->sinfo_timetolive to set the specific time for TTL policy. sinfo->sinfo_timetolive is also used for msg->expires_at. So if prsctp_enable or TTL policy is not enabled, msg->expires_at still works as before. Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: fix panic when sending auth chunks

2016-07-09T04:08:21Z

When we introduced GSO support, if using auth the auth chunk was being left queued on the packet even after the final segment was generated. Later on sctp_transmit_packet it calls sctp_packet_reset, which zeroed the packet len while not accounting for this left-over. This caused more space to be used the next packet due to the chunk still being queued, but space which wasn't allocated as its size wasn't accounted. The fix is to only queue it back when we know that we are going to generate another segment. Fixes: 90017accff61 ("sctp: Add GSO support") Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: Fix warning in sctp_packet_transmit_chunk()

2016-06-04T05:53:26Z

size_t objects should be printed with %Z printf format. Reported-by: kbuild test robot Signed-off-by: David S. Miller

sctp: improve debug message to also log curr pkt and new chunk size

2016-06-03T23:37:22Z

This is useful for debugging packet sizes. Signed-off-by: Marcelo Ricardo Leitner Tested-by: Xin Long Signed-off-by: David S. Miller