user/sven/linux.git/include/linux/tcp.h, branch v3.4.67

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2012-03-01T22:57:40Z

Conflicts: drivers/net/ethernet/broadcom/tg3.c Conflicts in the statistics regression bug fix from 'net', but happily Matt Carlson originally posted the fix against 'net-next' so I used that to resolve this. Signed-off-by: David S. Miller

tcp: fix comment for tp->highest_sack

2012-02-28T20:06:33Z

There was an off-by-one error in the comments describing the highest_sack field in struct tcp_sock. The comments previously claimed that it was the "start sequence of the highest skb with SACKed bit". This commit fixes the comments to note that it is the "start sequence of the skb just *after* the highest skb with SACKed bit". Signed-off-by: Neal Cardwell Acked-by: Ilpo Järvinen Signed-off-by: David S. Miller

tcp: md5: protects md5sig_info with RCU

2012-02-01T07:11:47Z

This patch makes sure we use appropriate memory barriers before publishing tp->md5sig_info, allowing tcp_md5_do_lookup() being used from tcp_v4_send_reset() without holding socket lock (upcoming patch from Shawn Lu) Note we also need to respect rcu grace period before its freeing, since we can free socket without this grace period thanks to SLAB_DESTROY_BY_RCU Signed-off-by: Eric Dumazet Cc: Shawn Lu Signed-off-by: David S. Miller

tcp: md5: rcu conversion

2012-01-31T17:14:00Z

In order to be able to support proper RST messages for TCP MD5 flows, we need to allow access to MD5 keys without locking listener socket. This conversion is a nice cleanup, and shrinks size of timewait sockets by 80 bytes. IPv6 code reuses generic code found in IPv4 instead of duplicating it. Control path uses GFP_KERNEL allocations instead of GFP_ATOMIC. Signed-off-by: Eric Dumazet Cc: Shawn Lu Signed-off-by: David S. Miller

tcp: Replace constants with #define macros

2011-12-21T06:03:23Z

to record the state of SACK/FACK and DSACK for better readability and maintenance. Signed-off-by: Vijay Subramanian Signed-off-by: David S. Miller

tcp: report ECN_SEEN in tcp_info

2011-10-03T18:01:21Z

Allows ss command (iproute2) to display "ecnseen" if at least one packet with ECT(0) or ECT(1) or ECN was received by this socket. "ecn" means ECN was negotiated at session establishment (TCP level) "ecnseen" means we received at least one packet with ECT fields set (IP level) ss -i ... ESTAB 0 0 192.168.20.110:22 192.168.20.144:38016 ino:5950 sk:f178e400 mem:(r0,w0,f0,t0) ts sack ecn ecnseen bic wscale:7,8 rto:210 rtt:12.5/7.5 cwnd:10 send 9.3Mbps rcv_space:14480 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Proportional Rate Reduction for TCP.

2011-08-25T02:40:40Z

This patch implements Proportional Rate Reduction (PRR) for TCP. PRR is an algorithm that determines TCP's sending rate in fast recovery. PRR avoids excessive window reductions and aims for the actual congestion window size at the end of recovery to be as close as possible to the window determined by the congestion control algorithm. PRR also improves accuracy of the amount of data sent during loss recovery. The patch implements the recommended flavor of PRR called PRR-SSRB (Proportional rate reduction with slow start reduction bound) and replaces the existing rate halving algorithm. PRR improves upon the existing Linux fast recovery under a number of conditions including: 1) burst losses where the losses implicitly reduce the amount of outstanding data (pipe) below the ssthresh value selected by the congestion control algorithm and, 2) losses near the end of short flows where application runs out of data to send. As an example, with the existing rate halving implementation a single loss event can cause a connection carrying short Web transactions to go into the slow start mode after the recovery. This is because during recovery Linux pulls the congestion window down to packets_in_flight+1 on every ACK. A short Web response often runs out of new data to send and its pipe reduces to zero by the end of recovery when all its packets are drained from the network. Subsequent HTTP responses using the same connection will have to slow start to raise cwnd to ssthresh. PRR on the other hand aims for the cwnd to be as close as possible to ssthresh by the end of recovery. A description of PRR and a discussion of its performance can be found at the following links: - IETF Draft: http://tools.ietf.org/html/draft-mathis-tcpm-proportional-rate-reduction-01 - IETF Slides: http://www.ietf.org/proceedings/80/slides/tcpm-6.pdf http://tools.ietf.org/agenda/81/slides/tcpm-2.pdf - Paper to appear in Internet Measurements Conference (IMC) 2011: Improving TCP Loss Recovery Nandita Dukkipati, Matt Mathis, Yuchung Cheng Signed-off-by: Nandita Dukkipati Signed-off-by: David S. Miller

tcp: RFC2988bis + taking RTT sample from 3WHS for the passive open side

2011-06-09T00:05:30Z

This patch lowers the default initRTO from 3secs to 1sec per RFC2988bis. It falls back to 3secs if the SYN or SYN-ACK packet has been retransmitted, AND the TCP timestamp option is not on. It also adds support to take RTT sample during 3WHS on the passive open side, just like its active open counterpart, and uses it, if valid, to seed the initRTO for the data transmission phase. The patch also resets ssthresh to its initial default at the beginning of the data transmission phase, and reduces cwnd to 1 if there has been MORE THAN ONE retransmission during 3WHS per RFC5681. Signed-off-by: H.K. Jerry Chu Signed-off-by: David S. Miller

tcp: Add TCP_USER_TIMEOUT socket option.

2010-08-30T20:23:33Z

This patch provides a "user timeout" support as described in RFC793. The socket option is also needed for the the local half of RFC5482 "TCP User Timeout Option". TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int, when > 0, to specify the maximum amount of time in ms that transmitted data may remain unacknowledged before TCP will forcefully close the corresponding connection and return ETIMEDOUT to the application. If 0 is given, TCP will continue to use the system default. Increasing the user timeouts allows a TCP connection to survive extended periods without end-to-end connectivity. Decreasing the user timeouts allows applications to "fail fast" if so desired. Otherwise it may take upto 20 minutes with the current system defaults in a normal WAN environment. The socket option can be made during any state of a TCP connection, but is only effective during the synchronized states of a connection (ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, or LAST-ACK). Moreover, when used with the TCP keepalive (SO_KEEPALIVE) option, TCP_USER_TIMEOUT will overtake keepalive to determine when to close a connection due to keepalive failure. The option does not change in anyway when TCP retransmits a packet, nor when a keepalive probe will be sent. This option, like many others, will be inherited by an acceptor from its listener. Signed-off-by: H.K. Jerry Chu Signed-off-by: David S. Miller

net: TCP thin dupack

2010-02-18T23:43:09Z

This patch enables fast retransmissions after one dupACK for TCP if the stream is identified as thin. This will reduce latencies for thin streams that are not able to trigger fast retransmissions due to high packet interarrival time. This mechanism is only active if enabled by iocontrol or syscontrol and the stream is identified as thin. Signed-off-by: Andreas Petlund Signed-off-by: David S. Miller