kernel/linux.git/include/net/tcp.h, branch v4.20.5

tcp: add tcp_reset_xmit_timer() helper

2018-10-24T02:42:44+00:00

With EDT model, SRTT no longer is inflated by pacing delays. This means that RTO and some other xmit timers might be setup incorrectly. This is particularly visible with either : - Very small enforced pacing rates (SO_MAX_PACING_RATE) - Reduced rto (from the default 200 ms) This can lead to TCP flows aborts in the worst case, or spurious retransmits in other cases. For example, this session gets far more throughput than the requested 80kbit : $ netperf -H 127.0.0.2 -l 100 -- -q 10000 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 127.0.0.2 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 540000 262144 262144 104.00 2.66 With the fix : $ netperf -H 127.0.0.2 -l 100 -- -q 10000 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 127.0.0.2 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 540000 262144 262144 104.00 0.12 EDT allows for better control of rtx timers, since TCP has a better idea of the earliest departure time of each skb in the rtx queue. We only have to eventually add to the timer the difference of the EDT time with current time. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ulp: remove uid and user_visible members

2018-10-21T06:13:32+00:00

They are not used anymore and therefore should be removed. Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov

bpf: sockmap, support for msg_peek in sk_msg with redirect ingress

2018-10-17T00:30:32+00:00

This adds support for the MSG_PEEK flag when doing redirect to ingress and receiving on the sk_msg psock queue. Previously the flag was being ignored which could confuse applications if they expected the flag to work as normal. Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann

bpf, sockmap: convert to generic sk_msg interface

2018-10-15T19:23:19+00:00

Add a generic sk_msg layer, and convert current sockmap and later kTLS over to make use of it. While sk_buff handles network packet representation from netdevice up to socket, sk_msg handles data representation from application to socket layer. This means that sk_msg framework spans across ULP users in the kernel, and enables features such as introspection or filtering of data with the help of BPF programs that operate on this data structure. Latter becomes in particular useful for kTLS where data encryption is deferred into the kernel, and as such enabling the kernel to perform L7 introspection and policy based on BPF for TLS connections where the record is being encrypted after BPF has run and came to a verdict. In order to get there, first step is to transform open coding of scatter-gather list handling into a common core framework that subsystems can use. The code itself has been split and refactored into three bigger pieces: i) the generic sk_msg API which deals with managing the scatter gather ring, providing helpers for walking and mangling, transferring application data from user space into it, and preparing it for BPF pre/post-processing, ii) the plain sock map itself where sockets can be attached to or detached from; these bits are independent of i) which can now be used also without sock map, and iii) the integration with plain TCP as one protocol to be used for processing L7 application data (later this could e.g. also be extended to other protocols like UDP). The semantics are the same with the old sock map code and therefore no change of user facing behavior or APIs. While pursuing this work it also helped finding a number of bugs in the old sockmap code that we've fixed already in earlier commits. The test_sockmap kselftest suite passes through fine as well. Joint work with John. Signed-off-by: Daniel Borkmann Signed-off-by: John Fastabend Signed-off-by: Alexei Starovoitov

tcp, ulp: remove ulp bits from sockmap

2018-10-15T19:23:19+00:00

In order to prepare sockmap logic to be used in combination with kTLS we need to detangle it from ULP, and further split it in later commits into a generic API. Joint work with John. Signed-off-by: Daniel Borkmann Signed-off-by: John Fastabend Signed-off-by: Alexei Starovoitov

tcp/fq: move back to CLOCK_MONOTONIC

2018-10-02T06:18:51+00:00

In the recent TCP/EDT patch series, I switched TCP and sch_fq clocks from MONOTONIC to TAI, in order to meet the choice done earlier for sch_etf packet scheduler. But sure enough, this broke some setups were the TAI clock jumps forward (by almost 50 year...), as reported by Leonard Crestez. If we want to converge later, we'll probably need to add an skb field to differentiate the clock bases, or a socket option. In the meantime, an UDP application will need to use CLOCK_MONOTONIC base for its SCM_TXTIME timestamps if using fq packet scheduler. Fixes: 72b0094f9182 ("tcp: switch tcp_clock_ns() to CLOCK_TAI base") Fixes: 142537e41923 ("net_sched: sch_fq: switch to CLOCK_TAI") Fixes: fd2bca2aa789 ("tcp: switch internal pacing timer to CLOCK_TAI") Signed-off-by: Eric Dumazet Reported-by: Leonard Crestez Tested-by: Leonard Crestez Signed-off-by: David S. Miller

tcp: provide earliest departure time in skb->tstamp

2018-09-22T02:37:59+00:00

Switch internal TCP skb->skb_mstamp to skb->skb_mstamp_ns, from usec units to nsec units. Do not clear skb->tstamp before entering IP stacks in TX, so that qdisc or devices can implement pacing based on the earliest departure time instead of socket sk->sk_pacing_rate Packets are fed with tcp_wstamp_ns, and following patch will update tcp_wstamp_ns when both TCP and sch_fq switch to the earliest departure time mechanism. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: add tcp_wstamp_ns socket field

2018-09-22T02:37:59+00:00

TCP will soon provide earliest departure time on TX skbs. It needs to track this in a new variable. tcp_mstamp_refresh() needs to update this variable, and became too big to stay an inline. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: introduce tcp_skb_timestamp_us() helper

2018-09-22T02:37:59+00:00

There are few places where TCP reads skb->skb_mstamp expecting a value in usec unit. skb->tstamp (aka skb->skb_mstamp) will soon store CLOCK_TAI nsec value. Add tcp_skb_timestamp_us() to provide proper conversion when needed. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

tcp: switch tcp_clock_ns() to CLOCK_TAI base

2018-09-22T02:37:59+00:00

TCP pacing is either implemented in sch_fq or internally. We have the goal of being able to offload pacing on the NICS. TCP will soon provide per skb skb->tstamp as early departure time. Like ETF in commit 25db26a91364 ("net/sched: Introduce the ETF Qdisc") we chose CLOCK_T as the clock base, so that TCP and pacers can share a common clock, to get better RTT samples (without pacing artificially inflating these samples). Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller