user/sven/linux.git/include/uapi/linux/snmp.h, branch v4.12.13

net/tcp_fastopen: Add snmp counter for blackhole detection

2017-04-24T18:27:17Z

This counter records the number of times the firewall blackhole issue is detected and active TFO is disabled. Signed-off-by: Wei Wang Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller

tcp: remove tcp_tw_recycle

2017-03-17T03:33:56Z

The tcp_tw_recycle was already broken for connections behind NAT, since the per-destination timestamp is not monotonically increasing for multiple machines behind a single destination address. After the randomization of TCP timestamp offsets in commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets for each connection), the tcp_tw_recycle is broken for all types of connections for the same reason: the timestamps received from a single machine is not monotonically increasing, anymore. Remove tcp_tw_recycle, since it is not functional. Also, remove the PAWSPassive SNMP counter since it is only used for tcp_tw_recycle, and simplify tcp_v4_route_req and tcp_v6_route_req since the strict argument is only set when tcp_tw_recycle is enabled. Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Eric Dumazet Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Cc: Lutz Vieweg Cc: Florian Westphal Signed-off-by: David S. Miller

net: add LINUX_MIB_PFMEMALLOCDROP counter

2017-02-03T04:34:19Z

Debugging issues caused by pfmemalloc is often tedious. Add a new SNMP counter to more easily diagnose these problems. Signed-off-by: Eric Dumazet Cc: Josef Bacik Acked-by: Josef Bacik Signed-off-by: David S. Miller

tcp: md5: add LINUX_MIB_TCPMD5FAILURE counter

2016-08-25T23:43:11Z

Adds SNMP counter for drops caused by MD5 mismatches. The current syslog might help, but a counter is more precise and helps monitoring. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: track success and failure of TCP PMTU probing

2015-07-22T05:36:33Z

Track success and failure of TCP PMTU probing. Signed-off-by: Rick Jones Signed-off-by: David S. Miller

tcp: add TCPWinProbe and TCPKeepAlive SNMP counters

2015-05-09T20:42:32Z

Diagnosing problems related to Window Probes has been hard because we lack a counter. TCPWinProbe counts the number of ACK packets a sender has to send at regular intervals to make sure a reverse ACK packet opening back a window had not been lost. TCPKeepAlive counts the number of ACK packets sent to keep TCP flows alive (SO_KEEPALIVE) Signed-off-by: Eric Dumazet Signed-off-by: Yuchung Cheng Acked-by: Neal Cardwell Acked-by: Nandita Dukkipati Signed-off-by: David S. Miller

tcp: helpers to mitigate ACK loops by rate-limiting out-of-window dupacks

2015-02-08T09:03:12Z

Helpers for mitigating ACK loops by rate-limiting dupacks sent in response to incoming out-of-window packets. This patch includes: - rate-limiting logic - sysctl to control how often we allow dupacks to out-of-window packets - SNMP counter for cases where we rate-limited our dupack sending The rate-limiting logic in this patch decides to not send dupacks in response to out-of-window segments if (a) they are SYNs or pure ACKs and (b) the remote endpoint is sending them faster than the configured rate limit. We rate-limit our responses rather than blocking them entirely or resetting the connection, because legitimate connections can rely on dupacks in response to some out-of-window segments. For example, zero window probes are typically sent with a sequence number that is below the current window, and ZWPs thus expect to thus elicit a dupack in response. We allow dupacks in response to TCP segments with data, because these may be spurious retransmissions for which the remote endpoint wants to receive DSACKs. This is safe because segments with data can't realistically be part of ACK loops, which by their nature consist of each side sending pure/data-less ACKs to each other. The dupack interval is controlled by a new sysctl knob, tcp_invalid_ratelimit, given in milliseconds, in case an administrator needs to dial this upward in the face of a high-rate DoS attack. The name and units are chosen to be analogous to the existing analogous knob for ICMP, icmp_ratelimit. The default value for tcp_invalid_ratelimit is 500ms, which allows at most one such dupack per 500ms. This is chosen to be 2x faster than the 1-second minimum RTO interval allowed by RFC 6298 (section 2, rule 2.4). We allow the extra 2x factor because network delay variations can cause packets sent at 1 second intervals to be compressed and arrive much closer. Reported-by: Avery Fay Signed-off-by: Neal Cardwell Signed-off-by: Yuchung Cheng Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp_cubic: add SNMP counters to track how effective is Hystart

2014-12-09T19:58:23Z

When deploying FQ pacing, one thing we noticed is that CUBIC Hystart triggers too soon. Having SNMP counters to have an idea of how often the various Hystart methods trigger is useful prior to any modifications. This patch adds SNMP counters tracking, how many time "ack train" or "Delay" based Hystart triggers, and cumulative sum of cwnd at the time Hystart decided to end SS (Slow Start) myhost:~# nstat -a | grep Hystart TcpExtTCPHystartTrainDetect 9 0.0 TcpExtTCPHystartTrainCwnd 20650 0.0 TcpExtTCPHystartDelayDetect 10 0.0 TcpExtTCPHystartDelayCwnd 360 0.0 -> Train detection was triggered 9 times, and average cwnd was 20650/9=2294, Delay detection was triggered 10 times and average cwnd was 36 Signed-off-by: Eric Dumazet Acked-by: Neal Cardwell Signed-off-by: David S. Miller

udp: Increment UDP_MIB_IGNOREDMULTI for arriving unmatched multicasts

2014-11-07T20:45:50Z

As NIC multicast filtering isn't perfect, and some platforms are quite content to spew broadcasts, we should not trigger an event for skb:kfree_skb when we do not have a match for such an incoming datagram. We do though want to avoid sweeping the matter under the rug entirely, so increment a suitable statistic. This incorporates feedback from David L. Stevens, Karl Neiss and Eric Dumazet. V3 - use bool per David Miller Signed-off-by: Rick Jones Signed-off-by: David S. Miller

tcp: snmp stats for Fast Open, SYN rtx, and data pkts

2014-03-03T20:58:03Z

Add the following snmp stats: TCPFastOpenActiveFail: Fast Open attempts (SYN/data) failed beacuse the remote does not accept it or the attempts timed out. TCPSynRetrans: number of SYN and SYN/ACK retransmits to break down retransmissions into SYN, fast-retransmits, timeout retransmits, etc. TCPOrigDataSent: number of outgoing packets with original data (excluding retransmission but including data-in-SYN). This counter is different from TcpOutSegs because TcpOutSegs also tracks pure ACKs. TCPOrigDataSent is more useful to track the TCP retransmission rate. Change TCPFastOpenActive to track only successful Fast Opens to be symmetric to TCPFastOpenPassive. Signed-off-by: Yuchung Cheng Signed-off-by: Eric Dumazet Signed-off-by: Nandita Dukkipati Signed-off-by: Lawrence Brakmo Signed-off-by: David S. Miller