kernel/linux.git/include/net/tcp.h, branch v5.12.1

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2021-02-16T21:14:06+00:00

Daniel Borkmann says: ==================== pull-request: bpf-next 2021-02-16 The following pull-request contains BPF updates for your *net-next* tree. There's a small merge conflict between 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.") from net-next tree and 9cacf81f8161 ("bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE") from bpf-next tree. Resolve as follows: [...] lock_sock(sk); err = tcp_zerocopy_receive(sk, &zc, &tss); err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname, &zc, &len, err); release_sock(sk); [...] We've added 116 non-merge commits during the last 27 day(s) which contain a total of 156 files changed, 5662 insertions(+), 1489 deletions(-). The main changes are: 1) Adds support of pointers to types with known size among global function args to overcome the limit on max # of allowed args, from Dmitrii Banshchikov. 2) Add bpf_iter for task_vma which can be used to generate information similar to /proc/pid/maps, from Song Liu. 3) Enable bpf_{g,s}etsockopt() from all sock_addr related program hooks. Allow rewriting bind user ports from BPF side below the ip_unprivileged_port_start range, both from Stanislav Fomichev. 4) Prevent recursion on fentry/fexit & sleepable programs and allow map-in-map as well as per-cpu maps for the latter, from Alexei Starovoitov. 5) Add selftest script to run BPF CI locally. Also enable BPF ringbuffer for sleepable programs, both from KP Singh. 6) Extend verifier to enable variable offset read/write access to the BPF program stack, from Andrei Matei. 7) Improve tc & XDP MTU handling and add a new bpf_check_mtu() helper to query device MTU from programs, from Jesper Dangaard Brouer. 8) Allow bpf_get_socket_cookie() helper also be called from [sleepable] BPF tracing programs, from Florent Revest. 9) Extend x86 JIT to pad JMPs with NOPs for helping image to converge when otherwise too many passes are required, from Gary Lin. 10) Verifier fixes on atomics with BPF_FETCH as well as function-by-function verification both related to zero-extension handling, from Ilya Leoshkevich. 11) Better kernel build integration of resolve_btfids tool, from Jiri Olsa. 12) Batch of AF_XDP selftest cleanups and small performance improvement for libbpf's xsk map redirect for newer kernels, from Björn Töpel. 13) Follow-up BPF doc and verifier improvements around atomics with BPF_FETCH, from Brendan Jackman. 14) Permit zero-sized data sections e.g. if ELF .rodata section contains read-only data from local variables, from Yonghong Song. 15) veth driver skb bulk-allocation for ndo_xdp_xmit, from Lorenzo Bianconi. ==================== Signed-off-by: David S. Miller

tcp: factorize logic into tcp_epollin_ready()

2021-02-13T01:28:26+00:00

Both tcp_data_ready() and tcp_stream_is_readable() share the same logic. Add tcp_epollin_ready() helper to avoid duplication. Signed-off-by: Eric Dumazet Cc: Arjun Roy Cc: Wei Wang Signed-off-by: David S. Miller

tcp: fix SO_RCVLOWAT related hangs under mem pressure

2021-02-13T01:28:26+00:00

While commit 24adbc1676af ("tcp: fix SO_RCVLOWAT hangs with fat skbs") fixed an issue vs too small sk_rcvbuf for given sk_rcvlowat constraint, it missed to address issue caused by memory pressure. 1) If we are under memory pressure and socket receive queue is empty. First incoming packet is allowed to be queued, after commit 76dfa6082032 ("tcp: allow one skb to be received per socket under memory pressure") But we do not send EPOLLIN yet, in case tcp_data_ready() sees sk_rcvlowat is bigger than skb length. 2) Then, when next packet comes, it is dropped, and we directly call sk->sk_data_ready(). 3) If application is using poll(), tcp_poll() will then use tcp_stream_is_readable() and decide the socket receive queue is not yet filled, so nothing will happen. Even when sender retransmits packets, phases 2) & 3) repeat and flow is effectively frozen, until memory pressure is off. Fix is to consider tcp_under_memory_pressure() to take care of global memory pressure or memcg pressure. Fixes: 24adbc1676af ("tcp: fix SO_RCVLOWAT hangs with fat skbs") Signed-off-by: Eric Dumazet Reported-by: Arjun Roy Suggested-by: Wei Wang Reviewed-by: Wei Wang Signed-off-by: David S. Miller

tcp: fix TLP timer not set when CA_STATE changes from DISORDER to OPEN

2021-01-24T05:33:01+00:00

Upon receiving a cumulative ACK that changes the congestion state from Disorder to Open, the TLP timer is not set. If the sender is app-limited, it can only wait for the RTO timer to expire and retransmit. The reason for this is that the TLP timer is set before the congestion state changes in tcp_ack(), so we delay the time point of calling tcp_set_xmit_timer() until after tcp_fastretrans_alert() returns and remove the FLAG_SET_XMIT_TIMER from ack_flag when the RACK reorder timer is set. This commit has two additional benefits: 1) Make sure to reset RTO according to RFC6298 when receiving ACK, to avoid spurious RTO caused by RTO timer early expires. 2) Reduce the xmit timer reschedule once per ACK when the RACK reorder timer is set. Fixes: df92c8394e6e ("tcp: fix xmit timer to only be reset if data ACKed/SACKed") Link: https://lore.kernel.org/netdev/1611311242-6675-1-git-send-email-yangpc@wangsu.com Signed-off-by: Pengcheng Yang Acked-by: Neal Cardwell Acked-by: Yuchung Cheng Cc: Eric Dumazet Link: https://lore.kernel.org/r/1611464834-23030-1-git-send-email-yangpc@wangsu.com Signed-off-by: Jakub Kicinski

tcp: make TCP_USER_TIMEOUT accurate for zero window probes

2021-01-24T03:32:51+00:00

The TCP_USER_TIMEOUT is checked by the 0-window probe timer. As the timer has backoff with a max interval of about two minutes, the actual timeout for TCP_USER_TIMEOUT can be off by up to two minutes. In this patch the TCP_USER_TIMEOUT is made more accurate by taking it into account when computing the timer value for the 0-window probes. This patch is similar to and builds on top of the one that made TCP_USER_TIMEOUT accurate for RTOs in commit b701a99e431d ("tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy"). Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT") Signed-off-by: Enke Chen Reviewed-by: Neal Cardwell Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20210122191306.GA99540@localhost.localdomain Signed-off-by: Jakub Kicinski

bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE

2021-01-20T22:23:00+00:00

Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE. We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom call in do_tcp_getsockopt using the on-stack data. This removes 3% overhead for locking/unlocking the socket. Without this patch: 3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt | --3.30%--__cgroup_bpf_run_filter_getsockopt | --0.81%--__kmalloc With the patch applied: 0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern Note, exporting uapi/tcp.h requires removing netinet/tcp.h from test_progs.h because those headers have confliciting definitions. Signed-off-by: Stanislav Fomichev Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com

net: Limit logical shift left of TCP probe0 timeout

2020-12-15T01:34:54+00:00

For each TCP zero window probe, the icsk_backoff is increased by one and its max value is tcp_retries2. If tcp_retries2 is greater than 63, the probe0 timeout shift may exceed its max bits. On x86_64/ARMv8/MIPS, the shift count would be masked to range 0 to 63. And on ARMv7 the result is zero. If the shift count is masked, only several probes will be sent with timeout shorter than TCP_RTO_MAX. But if the timeout is zero, it needs tcp_retries2 times probes to end this false timeout. Besides, bitwise shift greater than or equal to the width is an undefined behavior. This patch adds a limit to the backoff. The max value of max_when is TCP_RTO_MAX and the min value of timeout base is TCP_RTO_MIN. The limit is the backoff from TCP_RTO_MIN to TCP_RTO_MAX. Signed-off-by: Cambda Zhu Link: https://lore.kernel.org/r/20201208091910.37618-1-cambda@linux.alibaba.com Signed-off-by: Jakub Kicinski

tcp: parse mptcp options contained in reset packets

2020-12-15T01:30:06+00:00

Because TCP-level resets only affect the subflow, there is a MPTCP option to indicate that the MPTCP-level connection should be closed immediately without a mptcp-level fin exchange. This is the 'MPTCP fast close option'. It can be carried on ack segments or TCP resets. In the latter case, its needed to parse mptcp options also for reset packets so that MPTCP can act accordingly. Next patch will add receive side fastclose support in MPTCP. Acked-by: Matthieu Baerts Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski

Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

2020-12-04T15:48:12+00:00

Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-12-03 The main changes are: 1) Support BTF in kernel modules, from Andrii. 2) Introduce preferred busy-polling, from Björn. 3) bpf_ima_inode_hash() and bpf_bprm_opts_set() helpers, from KP Singh. 4) Memcg-based memory accounting for bpf objects, from Roman. 5) Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks, from Stanislav. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (118 commits) selftests/bpf: Fix invalid use of strncat in test_sockmap libbpf: Use memcpy instead of strncpy to please GCC selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module selftests/bpf: Add tp_btf CO-RE reloc test for modules libbpf: Support attachment of BPF tracing programs to kernel modules libbpf: Factor out low-level BPF program loading helper bpf: Allow to specify kernel module BTFs when attaching BPF programs bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF selftests/bpf: Add support for marking sub-tests as skipped selftests/bpf: Add bpf_testmod kernel module for testing libbpf: Add kernel module BTF support for CO-RE relocations libbpf: Refactor CO-RE relocs to not assume a single BTF object libbpf: Add internal helper to load BTF data by FD bpf: Keep module's btf_data_size intact after load bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address() selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP bpf: Adds support for setting window clamp samples/bpf: Fix spelling mistake "recieving" -> "receiving" bpf: Fix cold build of test_progs-no_alu32 ... ==================== Link: https://lore.kernel.org/r/20201204021936.85653-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski

bpf: Adds support for setting window clamp

2020-12-04T01:23:24+00:00

Adds a new bpf_setsockopt for TCP sockets, TCP_BPF_WINDOW_CLAMP, which sets the maximum receiver window size. It will be useful for limiting receiver window based on RTT. Signed-off-by: Prankur gupta Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201202213152.435886-2-prankgup@fb.com