user/sven/linux.git/include/net/tcp.h, branch v3.2.78

tcp: md5: remove spinlock usage in fast path

2015-01-01T01:27:52Z

commit 71cea17ed39fdf1c0634f530ddc6a2c2fc601c2b upstream. TCP md5 code uses per cpu variables but protects access to them with a shared spinlock, which is a contention point. [ tcp_md5sig_pool_lock is locked twice per incoming packet ] Makes things much simpler, by allocating crypto structures once, first time a socket needs md5 keys, and not deallocating them as they are really small. Next step would be to allow crypto allocations being done in a NUMA aware way. Signed-off-by: Eric Dumazet Cc: Herbert Xu Signed-off-by: David S. Miller [bwh: Backported to 3.2: - Adjust context - Conditions for alloc/free are quite different] Signed-off-by: Ben Hutchings

tcp: be more strict before accepting ECN negociation

2014-12-14T16:24:00Z

commit bd14b1b2e29bd6812597f896dde06eaf7c6d2f24 upstream. It appears some networks play bad games with the two bits reserved for ECN. This can trigger false congestion notifications and very slow transferts. Since RFC 3168 (6.1.1) forbids SYN packets to carry CT bits, we can disable TCP ECN negociation if it happens we receive mangled CT bits in the SYN packet. Signed-off-by: Eric Dumazet Cc: Perry Lorier Cc: Matt Mathis Cc: Yuchung Cheng Cc: Neal Cardwell Cc: Wilmer van der Gaast Cc: Ankur Jain Cc: Tom Herbert Cc: Dave Täht Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings Cc: Florian Westphal

tcp: force a dst refcount when prequeue packet

2013-05-30T13:35:11Z

[ Upstream commit 093162553c33e9479283e107b4431378271c735d ] Before escaping RCU protected section and adding packet into prequeue, make sure the dst is refcounted. Reported-by: Mike Galbraith Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

tcp: implement RFC 5961 3.2

2013-01-16T01:13:25Z

[ Upstream commit 282f23c6ee343126156dd41218b22ece96d747e3 ] Implement the RFC 5691 mitigation against Blind Reset attack using RST bit. Idea is to validate incoming RST sequence, to match RCV.NXT value, instead of previouly accepted window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND) If sequence is in window but not an exact match, send a "challenge ACK", so that the other part can resend an RST with the appropriate sequence. Add a new sysctl, tcp_challenge_ack_limit, to limit number of challenge ACK sent per second. Add a new SNMP counter to count number of challenge acks sent. (netstat -s | grep TCPChallengeACK) Signed-off-by: Eric Dumazet Cc: Kiran Kumar Kella Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

net: make the tcp and udp file_operations for the /proc stuff const

2011-11-01T21:56:14Z

the tcp and udp code creates a set of struct file_operations at runtime while it can also be done at compile time, with the added benefit of then having these file operations be const. the trickiest part was to get the "THIS_MODULE" reference right; the naive method of declaring a struct in the place of registration would not work for this reason. Signed-off-by: Arjan van de Ven Signed-off-by: David S. Miller

TCP: remove TCP_DEBUG

2011-10-24T21:36:08Z

It was enabled by default and the messages guarded by the define are useful. Signed-off-by: Flavio Leitner Signed-off-by: David S. Miller

tcp: md5: add more const attributes

2011-10-24T06:46:04Z

Now tcp_md5_hash_header() has a const tcphdr argument, we can add more const attributes to callers. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: md5: dont write skb head in tcp_md5_hash_header()

2011-10-24T05:52:35Z

tcp_md5_hash_header() writes into skb header a temporary zero value, this might confuse other users of this area. Since tcphdr is small (20 bytes), copy it in a temporary variable and make the change in the copy. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: add const qualifiers where possible

2011-10-21T09:22:42Z

Adding const qualifiers to pointers can ease code review, and spot some bugs. It might allow compiler to optimize code further. For example, is it legal to temporary write a null cksum into tcphdr in tcp_md5_hash_header() ? I am afraid a sniffer could catch the temporary null value... Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: rename tcp_skb_cb flags

2011-09-27T17:25:05Z

Rename struct tcp_skb_cb "flags" to "tcp_flags" to ease code review and maintenance. Its content is a combination of FIN/SYN/RST/PSH/ACK/URG/ECE/CWR flags Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller