linux/include/net/sctp, branch v3.13

sctp: Remove outqueue empty state

2014-01-02T22:22:48Z

The SCTP outqueue structure maintains a data chunks that are pending transmission, the list of chunks that are pending a retransmission and a length of data in flight. It also tries to keep the emtpy state so that it can performe shutdown sequence or notify user. The problem is that the empy state is inconsistently tracked. It is possible to completely drain the queue without sending anything when using PR-SCTP. In this case, the empty state will not be correctly state as report by Jamal Hadi Salim . This can cause an association to be perminantly stuck in the SHUTDOWN_PENDING state. Additionally, SCTP is incredibly inefficient when setting the empty state. Even though all the data is availaible in the outqueue structure, we ignore it and walk a list of trasnports. In the end, we can completely remove the extra empty state and figure out if the queue is empty by looking at 3 things: length of pending data, length of in-flight data, and exisiting of retransmit data. All of these are already in the strucutre. Reported-by: Jamal Hadi Salim Signed-off-by: Vlad Yasevich Acked-by: Neil Horman Tested-by: Jamal Hadi Salim Signed-off-by: David S. Miller

sctp: properly latch and use autoclose value from sock to association

2013-12-11T03:41:26Z

Currently, sctp associations latch a sockets autoclose value to an association at association init time, subject to capping constraints from the max_autoclose sysctl value. This leads to an odd situation where an application may set a socket level autoclose timeout, but sliently sctp will limit the autoclose timeout to something less than that. Fix this by modifying the autoclose setsockopt function to check the limit, cap it and warn the user via syslog that the timeout is capped. This will allow getsockopt to return valid autoclose timeout values that reflect what subsequent associations actually use. While were at it, also elimintate the assoc->autoclose variable, it duplicates whats in the timeout array, which leads to multiple sources for the same information, that may differ (as the former isn't subject to any capping). This gives us the timeout information in a canonical place and saves some space in the association structure as well. Signed-off-by: Neil Horman Acked-by: Vlad Yasevich CC: Wang Weidong CC: David Miller CC: Vlad Yasevich CC: netdev@vger.kernel.org Signed-off-by: David S. Miller

sctp: Restore 'resent' bit to avoid retransmitted chunks for RTT measurements

2013-11-28T23:29:58Z

Currently retransmitted DATA chunks could also be used for RTT measurements since there are no flag to identify whether the transmitted DATA chunk is a new one or a retransmitted one. This problem is introduced by commit ae19c5486 ("sctp: remove 'resent' bit from the chunk") which inappropriately removed the 'resent' bit completely, instead of doing this, we should set the resent bit only for the retransmitted DATA chunks. Signed-off-by: Xufeng Zhang Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

net: sctp: fix and consolidate SCTP checksumming code

2013-11-04T04:04:57Z

This fixes an outstanding bug found through IPVS, where SCTP packets with skb->data_len > 0 (non-linearized) and empty frag_list, but data accumulated in frags[] member, are forwarded with incorrect checksum letting SCTP initial handshake fail on some systems. Linearizing each SCTP skb in IPVS to prevent that would not be a good solution as this leads to an additional and unnecessary performance penalty on the load-balancer itself for no good reason (as we actually only want to update the checksum, and can do that in a different/better way presented here). The actual problem is elsewhere, namely, that SCTP's checksumming in sctp_compute_cksum() does not take frags[] into account like skb_checksum() does. So while we are fixing this up, we better reuse the existing code that we have anyway in __skb_checksum() and use it for walking through the data doing checksumming. This will not only fix this issue, but also consolidates some SCTP code with core sk_buff code, bringing it closer together and removing respectively avoiding reimplementation of skb_checksum() for no good reason. As crc32c() can use hardware implementation within the crypto layer, we leave that intact (it wraps around / falls back to e.g. slice-by-8 algorithm in __crc32c_le() otherwise); plus use the __crc32c_le_combine() combinator for crc32c blocks. Also, we remove all other SCTP checksumming code, so that we only have to use sctp_compute_cksum() from now on; for doing that, we need to transform SCTP checkumming in output path slightly, and can leave the rest intact. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

sctp: Remove extern from function prototypes

2013-09-23T20:29:42Z

There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

net: sctp: reorder sctp_globals to reduce cacheline usage

2013-08-29T18:55:54Z

Reduce cacheline usage from 2 to 1 cacheline for sctp_globals structure. By reordering elements, we can close gaps and simply achieve the following: Current situation: /* size: 80, cachelines: 2, members: 10 */ /* sum members: 57, holes: 4, sum holes: 16 */ /* padding: 7 */ /* last cacheline: 16 bytes */ Afterwards: /* size: 64, cachelines: 1, members: 10 */ /* padding: 7 */ Signed-off-by: Daniel Borkmann Acked-by: Neil Horman Signed-off-by: David S. Miller

Revert "net: sctp: convert sctp_checksum_disable module param into sctp sysctl"

2013-08-09T20:09:41Z

This reverts commit cda5f98e36576596b9230483ec52bff3cc97eb21. As per Vlad's request. Signed-off-by: David S. Miller

net: sctp: trivial: update bug report in header comment

2013-08-09T18:33:02Z

With the restructuring of the lksctp.org site, we only allow bug reports through the SCTP mailing list linux-sctp@vger.kernel.org, not via SF, as SF is only used for web hosting and nothing more. While at it, also remove the obvious statement that bugs will be fixed and incooperated into the kernel. Signed-off-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller

net: sctp: convert sctp_checksum_disable module param into sctp sysctl

2013-08-09T18:33:02Z

Get rid of the last module parameter for SCTP and make this configurable via sysctl for SCTP like all the rest of SCTP's configuration knobs. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

sctp: Pack dst_cookie into 1st cacheline hole for 64bit host

2013-08-05T19:20:51Z

As dst_cookie is used in fast path sctp_transport_dst_check. Before: struct sctp_transport { struct list_head transports; /* 0 16 */ atomic_t refcnt; /* 16 4 */ __u32 dead:1; /* 20:31 4 */ __u32 rto_pending:1; /* 20:30 4 */ __u32 hb_sent:1; /* 20:29 4 */ __u32 pmtu_pending:1; /* 20:28 4 */ /* XXX 28 bits hole, try to pack */ __u32 sack_generation; /* 24 4 */ /* XXX 4 bytes hole, try to pack */ struct flowi fl; /* 32 64 */ /* --- cacheline 1 boundary (64 bytes) was 32 bytes ago --- */ union sctp_addr ipaddr; /* 96 28 */ After: struct sctp_transport { struct list_head transports; /* 0 16 */ atomic_t refcnt; /* 16 4 */ __u32 dead:1; /* 20:31 4 */ __u32 rto_pending:1; /* 20:30 4 */ __u32 hb_sent:1; /* 20:29 4 */ __u32 pmtu_pending:1; /* 20:28 4 */ /* XXX 28 bits hole, try to pack */ __u32 sack_generation; /* 24 4 */ u32 dst_cookie; /* 28 4 */ struct flowi fl; /* 32 64 */ /* --- cacheline 1 boundary (64 bytes) was 32 bytes ago --- */ union sctp_addr ipaddr; /* 96 28 */ Signed-off-by: Fan Du Acked-by: Neil Horman Signed-off-by: David S. Miller