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2021-07-09tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy pathTalal Ahmad
sk_wmem_schedule makes sure that sk_forward_alloc has enough bytes for charging that is going to be done by sk_mem_charge. In the transmit zerocopy path, there is sk_mem_charge but there was no call to sk_wmem_schedule. This change adds that call. Without this call to sk_wmem_schedule, sk_forward_alloc can go negetive which is a bug because sk_forward_alloc is a per-socket space that has been forward charged so this can't be negative. Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY") Signed-off-by: Talal Ahmad <talalahmad@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-30Merge tag 'net-next-5.14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - BPF: - add syscall program type and libbpf support for generating instructions and bindings for in-kernel BPF loaders (BPF loaders for BPF), this is a stepping stone for signed BPF programs - infrastructure to migrate TCP child sockets from one listener to another in the same reuseport group/map to improve flexibility of service hand-off/restart - add broadcast support to XDP redirect - allow bypass of the lockless qdisc to improving performance (for pktgen: +23% with one thread, +44% with 2 threads) - add a simpler version of "DO_ONCE()" which does not require jump labels, intended for slow-path usage - virtio/vsock: introduce SOCK_SEQPACKET support - add getsocketopt to retrieve netns cookie - ip: treat lowest address of a IPv4 subnet as ordinary unicast address allowing reclaiming of precious IPv4 addresses - ipv6: use prandom_u32() for ID generation - ip: add support for more flexible field selection for hashing across multi-path routes (w/ offload to mlxsw) - icmp: add support for extended RFC 8335 PROBE (ping) - seg6: add support for SRv6 End.DT46 behavior - mptcp: - DSS checksum support (RFC 8684) to detect middlebox meddling - support Connection-time 'C' flag - time stamping support - sctp: packetization Layer Path MTU Discovery (RFC 8899) - xfrm: speed up state addition with seq set - WiFi: - hidden AP discovery on 6 GHz and other HE 6 GHz improvements - aggregation handling improvements for some drivers - minstrel improvements for no-ack frames - deferred rate control for TXQs to improve reaction times - switch from round robin to virtual time-based airtime scheduler - add trace points: - tcp checksum errors - openvswitch - action execution, upcalls - socket errors via sk_error_report Device APIs: - devlink: add rate API for hierarchical control of max egress rate of virtual devices (VFs, SFs etc.) - don't require RCU read lock to be held around BPF hooks in NAPI context - page_pool: generic buffer recycling New hardware/drivers: - mobile: - iosm: PCIe Driver for Intel M.2 Modem - support for Qualcomm MSM8998 (ipa) - WiFi: Qualcomm QCN9074 and WCN6855 PCI devices - sparx5: Microchip SparX-5 family of Enterprise Ethernet switches - Mellanox BlueField Gigabit Ethernet (control NIC of the DPU) - NXP SJA1110 Automotive Ethernet 10-port switch - Qualcomm QCA8327 switch support (qca8k) - Mikrotik 10/25G NIC (atl1c) Driver changes: - ACPI support for some MDIO, MAC and PHY devices from Marvell and NXP (our first foray into MAC/PHY description via ACPI) - HW timestamping (PTP) support: bnxt_en, ice, sja1105, hns3, tja11xx - Mellanox/Nvidia NIC (mlx5) - NIC VF offload of L2 bridging - support IRQ distribution to Sub-functions - Marvell (prestera): - add flower and match all - devlink trap - link aggregation - Netronome (nfp): connection tracking offload - Intel 1GE (igc): add AF_XDP support - Marvell DPU (octeontx2): ingress ratelimit offload - Google vNIC (gve): new ring/descriptor format support - Qualcomm mobile (rmnet & ipa): inline checksum offload support - MediaTek WiFi (mt76) - mt7915 MSI support - mt7915 Tx status reporting - mt7915 thermal sensors support - mt7921 decapsulation offload - mt7921 enable runtime pm and deep sleep - Realtek WiFi (rtw88) - beacon filter support - Tx antenna path diversity support - firmware crash information via devcoredump - Qualcomm WiFi (wcn36xx) - Wake-on-WLAN support with magic packets and GTK rekeying - Micrel PHY (ksz886x/ksz8081): add cable test support" * tag 'net-next-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2168 commits) tcp: change ICSK_CA_PRIV_SIZE definition tcp_yeah: check struct yeah size at compile time gve: DQO: Fix off by one in gve_rx_dqo() stmmac: intel: set PCI_D3hot in suspend stmmac: intel: Enable PHY WOL option in EHL net: stmmac: option to enable PHY WOL with PMT enabled net: say "local" instead of "static" addresses in ndo_dflt_fdb_{add,del} net: use netdev_info in ndo_dflt_fdb_{add,del} ptp: Set lookup cookie when creating a PTP PPS source. net: sock: add trace for socket errors net: sock: introduce sk_error_report net: dsa: replay the local bridge FDB entries pointing to the bridge dev too net: dsa: ensure during dsa_fdb_offload_notify that dev_hold and dev_put are on the same dev net: dsa: include fdb entries pointing to bridge in the host fdb list net: dsa: include bridge addresses which are local in the host fdb list net: dsa: sync static FDB entries on foreign interfaces to hardware net: dsa: install the host MDB and FDB entries in the master's RX filter net: dsa: reference count the FDB addresses at the cross-chip notifier level net: dsa: introduce a separate cross-chip notifier type for host FDBs net: dsa: reference count the MDB entries at the cross-chip notifier level ...
2021-06-29net: sock: introduce sk_error_reportAlexander Aring
This patch introduces a function wrapper to call the sk_error_report callback. That will prepare to add additional handling whenever sk_error_report is called, for example to trace socket errors. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29net/ipv5/tcp: use vma_lookup() in tcp_zerocopy_receive()Liam Howlett
Use vma_lookup() to find the VMA at a specific address. As vma_lookup() will return NULL if the address is not within any VMA, the start address no longer needs to be validated. Link: https://lkml.kernel.org/r/20210521174745.2219620-13-Liam.Howlett@Oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-04tcp: export timestamp helpers for mptcpFlorian Westphal
MPTCP is builtin, so no need to add EXPORT_SYMBOL()s. It will be used to support SO_TIMESTAMP(NS) ancillary messages in the mptcp receive path. Acked-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-06tcp: Specify cmsgbuf is user pointer for receive zerocopy.Arjun Roy
A prior change (1f466e1f15cf) introduces separate handling for ->msg_control depending on whether the pointer is a kernel or user pointer. However, while tcp receive zerocopy is using this field, it is not properly annotating that the buffer in this case is a user pointer. This can cause faults when the improper mechanism is used within put_cmsg(). This patch simply annotates tcp receive zerocopy's use as explicitly being a user pointer. Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.") Signed-off-by: Arjun Roy <arjunroy@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20210506223530.2266456-1-arjunroy.kdev@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-09Revert "tcp: Reset tcp connections in SYN-SENT state"Eric Dumazet
This reverts commit e880f8b3a24a73704731a7227ed5fee14bd90192. 1) Patch has not been properly tested, and is wrong [1] 2) Patch submission did not include TCP maintainer (this is me) [1] divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 8426 Comm: syz-executor478 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__tcp_select_window+0x56d/0xad0 net/ipv4/tcp_output.c:3015 Code: 44 89 ff e8 d5 cd f0 f9 45 39 e7 0f 8d 20 ff ff ff e8 f7 c7 f0 f9 44 89 e3 e9 13 ff ff ff e8 ea c7 f0 f9 44 89 e0 44 89 e3 99 <f7> 7c 24 04 29 d3 e9 fc fe ff ff e8 d3 c7 f0 f9 41 f7 dc bf 1f 00 RSP: 0018:ffffc9000184fac0 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff87832e76 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff87832e14 R11: 0000000000000000 R12: 0000000000000000 R13: 1ffff92000309f5c R14: 0000000000000000 R15: 0000000000000000 FS: 00000000023eb300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc2b5f426c0 CR3: 000000001c5cf000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tcp_select_window net/ipv4/tcp_output.c:264 [inline] __tcp_transmit_skb+0xa82/0x38f0 net/ipv4/tcp_output.c:1351 tcp_transmit_skb net/ipv4/tcp_output.c:1423 [inline] tcp_send_active_reset+0x475/0x8e0 net/ipv4/tcp_output.c:3449 tcp_disconnect+0x15a9/0x1e60 net/ipv4/tcp.c:2955 inet_shutdown+0x260/0x430 net/ipv4/af_inet.c:905 __sys_shutdown_sock net/socket.c:2189 [inline] __sys_shutdown_sock net/socket.c:2183 [inline] __sys_shutdown+0xf1/0x1b0 net/socket.c:2201 __do_sys_shutdown net/socket.c:2209 [inline] __se_sys_shutdown net/socket.c:2207 [inline] __x64_sys_shutdown+0x50/0x70 net/socket.c:2207 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Fixes: e880f8b3a24a ("tcp: Reset tcp connections in SYN-SENT state") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Manoj Basapathi <manojbm@codeaurora.org> Cc: Sauvik Saha <ssaha@codeaurora.org> Link: https://lore.kernel.org/r/20210409170237.274904-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-04-06tcp: Reset tcp connections in SYN-SENT stateManoj Basapathi
Userspace sends tcp connection (sock) destroy on network switch i.e switching the default network of the device between multiple networks(Cellular/Wifi/Ethernet). Kernel though doesn't send reset for the connections in SYN-SENT state and these connections continue to remain. Even as per RFC 793, there is no hard rule to not send RST on ABORT in this state. Modify tcp_abort and tcp_disconnect behavior to send RST for connections in syn-sent state to avoid lingering connections on network switch. Signed-off-by: Manoj Basapathi <manojbm@codeaurora.org> Signed-off-by: Sauvik Saha <ssaha@codeaurora.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-17bpf: net: Emit anonymous enum with BPF_TCP_CLOSE value explicitlyYonghong Song
The selftest failed to compile with clang-built bpf-next. Adding LLVM=1 to your vmlinux and selftest build will use clang. The error message is: progs/test_sk_storage_tracing.c:38:18: error: use of undeclared identifier 'BPF_TCP_CLOSE' if (newstate == BPF_TCP_CLOSE) ^ 1 error generated. make: *** [Makefile:423: /bpf-next/tools/testing/selftests/bpf/test_sk_storage_tracing.o] Error 1 The reason for the failure is that BPF_TCP_CLOSE, a value of an anonymous enum defined in uapi bpf.h, is not defined in vmlinux.h. gcc does not have this problem. Since vmlinux.h is derived from BTF which is derived from vmlinux DWARF, that means gcc-produced vmlinux DWARF has BPF_TCP_CLOSE while llvm-produced vmlinux DWARF does not have. BPF_TCP_CLOSE is referenced in net/ipv4/tcp.c as BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE); The following test mimics the above BUILD_BUG_ON, preprocessed with clang compiler, and shows gcc DWARF contains BPF_TCP_CLOSE while llvm DWARF does not. $ cat t.c enum { BPF_TCP_ESTABLISHED = 1, BPF_TCP_CLOSE = 7, }; enum { TCP_ESTABLISHED = 1, TCP_CLOSE = 7, }; int test() { do { extern void __compiletime_assert_767(void) ; if ((int)BPF_TCP_CLOSE != (int)TCP_CLOSE) __compiletime_assert_767(); } while (0); return 0; } $ clang t.c -O2 -c -g && llvm-dwarfdump t.o | grep BPF_TCP_CLOSE $ gcc t.c -O2 -c -g && llvm-dwarfdump t.o | grep BPF_TCP_CLOSE DW_AT_name ("BPF_TCP_CLOSE") Further checking clang code find clang actually tried to evaluate condition at compile time. If it is definitely true/false, it will perform optimization and the whole if condition will be removed before generating IR/debuginfo. This patch explicited add an expression after the above mentioned BUILD_BUG_ON in net/ipv4/tcp.c like (void)BPF_TCP_ESTABLISHED to enable generation of debuginfo for the anonymous enum which also includes BPF_TCP_CLOSE. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210317174132.589276-1-yhs@fb.com
2021-03-01tcp: add sanity tests to TCP_QUEUE_SEQEric Dumazet
Qingyu Li reported a syzkaller bug where the repro changes RCV SEQ _after_ restoring data in the receive queue. mprotect(0x4aa000, 12288, PROT_READ) = 0 mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x1ffff000 mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000 mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x21000000 socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3 setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0 connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0), inet_pton(AF_INET6, "::1", &sin6_addr), sin6_scope_id=0}, 28) = 0 setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0 sendmsg(3, {msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="0x0000000000000003\0\0", iov_len=20}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20 setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0 setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0 recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset by peer) syslog shows: [ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0 [ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343 tcp_recvmsg_locked+0x90e/0x29a0 This should not be allowed. TCP_QUEUE_SEQ should only be used when queues are empty. This patch fixes this case, and the tx path as well. Fixes: ee9952831cfd ("tcp: Initial repair mode") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Link: https://bugzilla.kernel.org/show_bug.cgi?id=212005 Reported-by: Qingyu Li <ieatmuttonchuan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-26tcp: Fix sign comparison bug in getsockopt(TCP_ZEROCOPY_RECEIVE)Arjun Roy
getsockopt(TCP_ZEROCOPY_RECEIVE) has a bug where we read a user-provided "len" field of type signed int, and then compare the value to the result of an "offsetofend" operation, which is unsigned. Negative values provided by the user will be promoted to large positive numbers; thus checking that len < offsetofend() will return false when the intention was that it return true. Note that while len is originally checked for negative values earlier on in do_tcp_getsockopt(), subsequent calls to get_user() re-read the value from userspace which may have changed in the meantime. Therefore, re-add the check for negative values after the call to get_user in the handler code for TCP_ZEROCOPY_RECEIVE. Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Arjun Roy <arjunroy@google.com> Link: https://lore.kernel.org/r/20210225232628.4033281-1-arjunroy.kdev@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
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 <davem@davemloft.net>
2021-02-12tcp: factorize logic into tcp_epollin_ready()Eric Dumazet
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 <edumazet@google.com> Cc: Arjun Roy <arjunroy@google.com> Cc: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-11tcp: Sanitize CMSG flags and reserved args in tcp_zerocopy_receive.Arjun Roy
Explicitly define reserved field and require it and any subsequent fields to be zero-valued for now. Additionally, limit the valid CMSG flags that tcp_zerocopy_receive accepts. Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.") Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Suggested-by: David Ahern <dsahern@gmail.com> Suggested-by: Leon Romanovsky <leon@kernel.org> Suggested-by: Jakub Kicinski <kuba@kernel.org> Acked-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-01-22tcp: Add receive timestamp support for receive zerocopy.Arjun Roy
tcp_recvmsg() uses the CMSG mechanism to receive control information like packet receive timestamps. This patch adds CMSG fields to struct tcp_zerocopy_receive, and provides receive timestamps if available to the user. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-22tcp: Remove CMSG magic numbers for tcp_recvmsg().Arjun Roy
At present, tcp_recvmsg() uses flags to track if any CMSGs are pending and what those CMSGs are. These flags are currently magic numbers, used only within tcp_recvmsg(). To prepare for receive timestamp support in tcp receive zerocopy, gently refactor these magic numbers into enums. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-22tcp: add TTL to SCM_TIMESTAMPING_OPT_STATSYousuk Seung
This patch adds TCP_NLA_TTL to SCM_TIMESTAMPING_OPT_STATS that exports the time-to-live or hop limit of the latest incoming packet with SCM_TSTAMP_ACK. The value exported may not be from the packet that acks the sequence when incoming packets are aggregated. Exporting the time-to-live or hop limit value of incoming packets helps to estimate the hop count of the path of the flow that may change over time. Signed-off-by: Yousuk Seung <ysseung@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Link: https://lore.kernel.org/r/20210120204155.552275-1-ysseung@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-20bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVEStanislav Fomichev
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 <sdf@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com
2021-01-20Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Conflicts: drivers/net/can/dev.c commit 03f16c5075b2 ("can: dev: can_restart: fix use after free bug") commit 3e77f70e7345 ("can: dev: move driver related infrastructure into separate subdir") Code move. drivers/net/dsa/b53/b53_common.c commit 8e4052c32d6b ("net: dsa: b53: fix an off by one in checking "vlan->vid"") commit b7a9e0da2d1c ("net: switchdev: remove vid_begin -> vid_end range from VLAN objects") Field rename. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-18tcp: fix TCP_USER_TIMEOUT with zero windowEnke Chen
The TCP session does not terminate with TCP_USER_TIMEOUT when data remain untransmitted due to zero window. The number of unanswered zero-window probes (tcp_probes_out) is reset to zero with incoming acks irrespective of the window size, as described in tcp_probe_timer(): RFC 1122 4.2.2.17 requires the sender to stay open indefinitely as long as the receiver continues to respond probes. We support this by default and reset icsk_probes_out with incoming ACKs. This counter, however, is the wrong one to be used in calculating the duration that the window remains closed and data remain untransmitted. Thanks to Jonathan Maxwell <jmaxwell37@gmail.com> for diagnosing the actual issue. In this patch a new timestamp is introduced for the socket in order to track the elapsed time for the zero-window probes that have not been answered with any non-zero window ack. Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT") Reported-by: William McCall <william.mccall@gmail.com> Co-developed-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Enke Chen <enchen@paloaltonetworks.com> Reviewed-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20210115223058.GA39267@localhost.localdomain Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07skbuff: Rename skb_zcopy_{get|put} to net_zcopy_{get|put}Jonathan Lemon
Unlike the rest of the skb_zcopy_ functions, these routines operate on a 'struct ubuf', not a skb. Remove the 'skb_' prefix from the naming to make things clearer. Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07net: group skb_shinfo zerocopy related bits together.Jonathan Lemon
In preparation for expanded zerocopy (TX and RX), move the zerocopy related bits out of tx_flags into their own flag word. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07skbuff: rename sock_zerocopy_* to msg_zerocopy_*Jonathan Lemon
At Willem's suggestion, rename the sock_zerocopy_* functions so that they match the MSG_ZEROCOPY flag, which makes it clear they are specific to this zerocopy implementation. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07skbuff: Call sock_zerocopy_put_abort from skb_zcopy_put_abortJonathan Lemon
The sock_zerocopy_put_abort function contains logic which is specific to the current zerocopy implementation. Add a wrapper which checks the callback and dispatches apppropriately. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-01-07skbuff: replace sock_zerocopy_put() with skb_zcopy_put()Jonathan Lemon
Replace sock_zerocopy_put with the generic skb_zcopy_put() function. Pass 'true' as the success argument, as this is identical to no change. Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-10tcp: correctly handle increased zerocopy args struct sizeArjun Roy
A prior patch increased the size of struct tcp_zerocopy_receive but did not update do_tcp_getsockopt() handling to properly account for this. This patch simply reintroduces content erroneously cut from the referenced prior patch that handles the new struct size. Fixes: 18fb76ed5386 ("net-zerocopy: Copy straggler unaligned data for TCP Rx. zerocopy.") Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-04net-zerocopy: Defer vm zap unless actually needed.Arjun Roy
Zapping pages is required only if we are calling vm_insert_page into a region where pages had previously been mapped. Receive zerocopy allows reusing such regions, and hitherto called zap_page_range() before calling vm_insert_page() in that range. zap_page_range() can also be triggered from userspace with madvise(MADV_DONTNEED). If userspace is configured to call this before reusing a segment, or if there was nothing mapped at this virtual address to begin with, we can avoid calling zap_page_range() under the socket lock. That said, if userspace does not do that, then we are still responsible for calling zap_page_range(). This patch adds a flag that the user can use to hint to the kernel that a zap is not required. If the flag is not set, or if an older user application does not have a flags field at all, then the kernel calls zap_page_range as before. Also, if the flag is set but a zap is still required, the kernel performs that zap as necessary. Thus incorrectly indicating that a zap can be avoided does not change the correctness of operation. It also increases the batchsize for vm_insert_pages and prefetches the page struct for the batch since we're about to bump the refcount. An alternative mechanism could be to not have a flag, assume by default a zap is not needed, and fall back to zapping if needed. However, this would harm performance for older applications for which a zap is necessary, and thus we implement it with an explicit flag so newer applications can opt in. When using RPC-style traffic with medium sized (tens of KB) RPCs, this change yields an efficency improvement of about 30% for QPS/CPU usage. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-zerocopy: Set zerocopy hint when data is copiedArjun Roy
Set zerocopy hint, event when falling back to copy, so that the pending data can be efficiently received using zerocopy when possible. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-zerocopy: Introduce short-circuit small reads.Arjun Roy
Sometimes, we may call tcp receive zerocopy when inq is 0, or inq < PAGE_SIZE, or inq is generally small enough that it is cheaper to copy rather than remap pages. In these cases, we may want to either return early (inq=0) or attempt to use the provided copy buffer to simply copy the received data. This allows us to save both system call overhead and the latency of acquiring mmap_sem in read mode for cases where it would be useless to do so. This patchset enables this behaviour by: 1. Returning quickly if inq is 0. 2. Attempting to perform a regular copy if a hybrid copybuffer is provided and it is large enough to absorb all available bytes. 3. Return quickly if no such buffer was provided and there are less than PAGE_SIZE bytes available. For small RPC ping-pong workloads, normally we would have 1 getsockopt(), 1 recvmsg() and 1 sendmsg() call per RPC. With this change, we remove the recvmsg() call entirely, reducing the syscall overhead by about 33%. In testing with small (hundreds of bytes) RPC traffic, this yields a syscall reduction of about 33% and an efficiency gain of about 3-5% when defined as QPS/CPU Util. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-zerocopy: Fast return if inq < PAGE_SIZEArjun Roy
Sometimes, we may call tcp receive zerocopy when inq is 0, or inq < PAGE_SIZE, in which case we cannot remap pages. In this case, simply return the appropriate hint for regular copying without taking mmap_sem. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-zerocopy: Refactor frag-is-remappable test.Arjun Roy
Refactor frag-is-remappable test for tcp receive zerocopy. This is part of a patch set that introduces short-circuited hybrid copies for small receive operations, which results in roughly 33% fewer syscalls for small RPC scenarios. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-zerocopy: Refactor skb frag fast-forward op.Arjun Roy
Refactor skb frag fast-forwarding for tcp receive zerocopy. This is part of a patch set that introduces short-circuited hybrid copies for small receive operations, which results in roughly 33% fewer syscalls for small RPC scenarios. skb_advance_to_frag(), given a skb and an offset into the skb, iterates from the first frag for the skb until we're at the frag specified by the offset. Assuming the offset provided refers to how many bytes in the skb are already read, the returned frag points to the next frag we may read from, while offset_frag is set to the number of bytes from this frag that we have already read. If frag is not null and offset_frag is equal to 0, then we may be able to map this frag's page into the process address space with vm_insert_page(). However, if offset_frag is not equal to 0, then we cannot do so. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-tcp: Introduce tcp_recvmsg_locked().Arjun Roy
Refactor tcp_recvmsg() by splitting it into locked and unlocked portions. Callers already holding the socket lock and not using ERRQUEUE/cmsg/busy polling can simply call tcp_recvmsg_locked(). This is in preparation for a short-circuit copy performed by TCP receive zerocopy for small (< PAGE_SIZE, or otherwise requested by the user) reads. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04net-zerocopy: Copy straggler unaligned data for TCP Rx. zerocopy.Arjun Roy
When TCP receive zerocopy does not successfully map the entire requested space, it outputs a 'hint' that the caller should recvmsg(). Augment zerocopy to accept a user buffer that it tries to copy this hint into - if it is possible to copy the entire hint, it will do so. This elides a recvmsg() call for received traffic that isn't exactly page-aligned in size. This was tested with RPC-style traffic of arbitrary sizes. Normally, each received message required at least one getsockopt() call, and one recvmsg() call for the remaining unaligned data. With this change, almost all of the recvmsg() calls are eliminated, leading to a savings of about 25%-50% in number of system calls for RPC-style workloads. Signed-off-by: Arjun Roy <arjunroy@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski
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 <kuba@kernel.org>
2020-12-03bpf: Adds support for setting window clampPrankur gupta
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 <prankgup@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20201202213152.435886-2-prankgup@fb.com
2020-11-16tcp: factor out __tcp_close() helperPaolo Abeni
unlocked version of protocol level close, will be used by MPTCP to allow decouple orphaning and subflow level close. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-16tcp: factor out tcp_build_frag()Paolo Abeni
Will be needed by the next patch, as MPTCP needs to handle directly the error/memory-allocation-needed path. No functional changes intended. Additionally let MPTCP code access the tcp_remove_empty_skb() helper. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-23tcp: Prevent low rmem stalls with SO_RCVLOWAT.Arjun Roy
With SO_RCVLOWAT, under memory pressure, it is possible to enter a state where: 1. We have not received enough bytes to satisfy SO_RCVLOWAT. 2. We have not entered buffer pressure (see tcp_rmem_pressure()). 3. But, we do not have enough buffer space to accept more packets. In this case, we advertise 0 rwnd (due to #3) but the application does not drain the receive queue (no wakeup because of #1 and #2) so the flow stalls. Modify the heuristic for SO_RCVLOWAT so that, if we are advertising rwnd<=rcv_mss, force a wakeup to prevent a stall. Without this patch, setting tcp_rmem to 6143 and disabling TCP autotune causes a stalled flow. With this patch, no stall occurs. This is with RPC-style traffic with large messages. Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users") Signed-off-by: Arjun Roy <arjunroy@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20201023184709.217614-1-arjunroy.kdev@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Rejecting non-native endian BTF overlapped with the addition of support for it. The rest were more simple overlapping changes, except the renesas ravb binding update, which had to follow a file move as well as a YAML conversion. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02tcp: use sendpage_ok() to detect misused .sendpageColy Li
commit a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab objects") adds the checks for Slab pages, but the pages don't have page_count are still missing from the check. Network layer's sendpage method is not designed to send page_count 0 pages neither, therefore both PageSlab() and page_count() should be both checked for the sending page. This is exactly what sendpage_ok() does. This patch uses sendpage_ok() in do_tcp_sendpages() to detect misused .sendpage, to make the code more robust. Fixes: a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab objects") Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Coly Li <colyli@suse.de> Cc: Vasily Averin <vvs@virtuozzo.com> Cc: David S. Miller <davem@davemloft.net> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-30inet: remove icsk_ack.blockedEric Dumazet
TCP has been using it to work around the possibility of tcp_delack_timer() finding the socket owned by user. After commit 6f458dfb4092 ("tcp: improve latencies of timer triggered events") we added TCP_DELACK_TIMER_DEFERRED atomic bit for more immediate recovery, so we can get rid of icsk_ack.blocked This frees space that following patch will reuse. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-09-23 The following pull-request contains BPF updates for your *net-next* tree. We've added 95 non-merge commits during the last 22 day(s) which contain a total of 124 files changed, 4211 insertions(+), 2040 deletions(-). The main changes are: 1) Full multi function support in libbpf, from Andrii. 2) Refactoring of function argument checks, from Lorenz. 3) Make bpf_tail_call compatible with functions (subprograms), from Maciej. 4) Program metadata support, from YiFei. 5) bpf iterator optimizations, from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14tcp: schedule EPOLLOUT after a partial sendmsgSoheil Hassas Yeganeh
For EPOLLET, applications must call sendmsg until they get EAGAIN. Otherwise, there is no guarantee that EPOLLOUT is sent if there was a failure upon memory allocation. As a result on high-speed NICs, userspace observes multiple small sendmsgs after a partial sendmsg until EAGAIN, since TCP can send 1-2 TSOs in between two sendmsg syscalls: // One large partial send due to memory allocation failure. sendmsg(20MB) = 2MB // Many small sends until EAGAIN. sendmsg(18MB) = 64KB sendmsg(17.9MB) = 128KB sendmsg(17.8MB) = 64KB ... sendmsg(...) = EAGAIN // At this point, userspace can assume an EPOLLOUT. To fix this, set the SOCK_NOSPACE on all partial sendmsg scenarios to guarantee that we send EPOLLOUT after partial sendmsg. After this commit userspace can assume that it will receive an EPOLLOUT after the first partial sendmsg. This EPOLLOUT will benefit from sk_stream_write_space() logic delaying the EPOLLOUT until significant space is available in write queue. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14tcp: return EPOLLOUT from tcp_poll only when notsent_bytes is half the limitSoheil Hassas Yeganeh
If there was any event available on the TCP socket, tcp_poll() will be called to retrieve all the events. In tcp_poll(), we call sk_stream_is_writeable() which returns true as long as we are at least one byte below notsent_lowat. This will result in quite a few spurious EPLLOUT and frequent tiny sendmsg() calls as a result. Similar to sk_stream_write_space(), use __sk_stream_is_writeable with a wake value of 1, so that we set EPOLLOUT only if half the space is available for write. Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14mptcp: call tcp_cleanup_rbuf on subflowsPaolo Abeni
That is needed to let the subflows announce promptly when new space is available in the receive buffer. tcp_cleanup_rbuf() is currently a static function, drop the scope modifier and add a declaration in the TCP header. Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-10tcp: simplify tcp_set_congestion_control(): Always reinitializeNeal Cardwell
Now that the previous patches ensure that all call sites for tcp_set_congestion_control() want to initialize congestion control, we can simplify tcp_set_congestion_control() by removing the reinit argument and the code to support it. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Kevin Yang <yyd@google.com> Cc: Lawrence Brakmo <brakmo@fb.com>
2020-09-10tcp: Only init congestion control if not initialized alreadyNeal Cardwell
Change tcp_init_transfer() to only initialize congestion control if it has not been initialized already. With this new approach, we can arrange things so that if the EBPF code sets the congestion control by calling setsockopt(TCP_CONGESTION) then tcp_init_transfer() will not re-initialize the CC module. This is an approach that has the following beneficial properties: (1) This allows CC module customizations made by the EBPF called in tcp_init_transfer() to persist, and not be wiped out by a later call to tcp_init_congestion_control() in tcp_init_transfer(). (2) Does not flip the order of EBPF and CC init, to avoid causing bugs for existing code upstream that depends on the current order. (3) Does not cause 2 initializations for for CC in the case where the EBPF called in tcp_init_transfer() wants to set the CC to a new CC algorithm. (4) Allows follow-on simplifications to the code in net/core/filter.c and net/ipv4/tcp_cong.c, which currently both have some complexity to special-case CC initialization to avoid double CC initialization if EBPF sets the CC. Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Kevin Yang <yyd@google.com> Cc: Lawrence Brakmo <brakmo@fb.com>
2020-08-24tcp: bpf: Optionally store mac header in TCP_SAVE_SYNMartin KaFai Lau
This patch is adapted from Eric's patch in an earlier discussion [1]. The TCP_SAVE_SYN currently only stores the network header and tcp header. This patch allows it to optionally store the mac header also if the setsockopt's optval is 2. It requires one more bit for the "save_syn" bit field in tcp_sock. This patch achieves this by moving the syn_smc bit next to the is_mptcp. The syn_smc is currently used with the TCP experimental option. Since syn_smc is only used when CONFIG_SMC is enabled, this patch also puts the "IS_ENABLED(CONFIG_SMC)" around it like the is_mptcp did with "IS_ENABLED(CONFIG_MPTCP)". The mac_hdrlen is also stored in the "struct saved_syn" to allow a quick offset from the bpf prog if it chooses to start getting from the network header or the tcp header. [1]: https://lore.kernel.org/netdev/CANn89iLJNWh6bkH7DNhy_kmcAexuUCccqERqe7z2QsvPhGrYPQ@mail.gmail.com/ Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/bpf/20200820190123.2886935-1-kafai@fb.com
2020-08-24tcp: bpf: Add TCP_BPF_RTO_MIN for bpf_setsockoptMartin KaFai Lau
This patch adds bpf_setsockopt(TCP_BPF_RTO_MIN) to allow bpf prog to set the min rto of a connection. It could be used together with the earlier patch which has added bpf_setsockopt(TCP_BPF_DELACK_MAX). A later selftest patch will communicate the max delay ack in a bpf tcp header option and then the receiving side can use bpf_setsockopt(TCP_BPF_RTO_MIN) to set a shorter rto. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200820190027.2884170-1-kafai@fb.com