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path: root/include/net/tcp.h
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2024-04-12tcp: increase the default TCP scaling ratioHechao Li
After commit dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale"), we noticed an application-level timeout due to reduced throughput. Before the commit, for a client that sets SO_RCVBUF to 65k, it takes around 22 seconds to transfer 10M data. After the commit, it takes 40 seconds. Because our application has a 30-second timeout, this regression broke the application. The reason that it takes longer to transfer data is that tp->scaling_ratio is initialized to a value that results in ~0.25 of rcvbuf. In our case, SO_RCVBUF is set to 65536 by the application, which translates to 2 * 65536 = 131,072 bytes in rcvbuf and hence a ~28k initial receive window. Later, even though the scaling_ratio is updated to a more accurate skb->len/skb->truesize, which is ~0.66 in our environment, the window stays at ~0.25 * rcvbuf. This is because tp->window_clamp does not change together with the tp->scaling_ratio update when autotuning is disabled due to SO_RCVBUF. As a result, the window size is capped at the initial window_clamp, which is also ~0.25 * rcvbuf, and never grows bigger. Most modern applications let the kernel do autotuning, and benefit from the increased scaling_ratio. But there are applications such as kafka that has a default setting of SO_RCVBUF=64k. This patch increases the initial scaling_ratio from ~25% to 50% in order to make it backward compatible with the original default sysctl_tcp_adv_win_scale for applications setting SO_RCVBUF. Fixes: dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale") Signed-off-by: Hechao Li <hli@netflix.com> Reviewed-by: Tycho Andersen <tycho@tycho.pizza> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/20240402215405.432863-1-hli@netflix.com/ Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-09tcp: replace TCP_SKB_CB(skb)->tcp_tw_isn with a per-cpu fieldEric Dumazet
TCP can transform a TIMEWAIT socket into a SYN_RECV one from a SYN packet, and the ISN of the SYNACK packet is normally generated using TIMEWAIT tw_snd_nxt : tcp_timewait_state_process() ... u32 isn = tcptw->tw_snd_nxt + 65535 + 2; if (isn == 0) isn++; TCP_SKB_CB(skb)->tcp_tw_isn = isn; return TCP_TW_SYN; This SYN packet also bypasses normal checks against listen queue being full or not. tcp_conn_request() ... __u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn; ... /* TW buckets are converted to open requests without * limitations, they conserve resources and peer is * evidently real one. */ if ((syncookies == 2 || inet_csk_reqsk_queue_is_full(sk)) && !isn) { want_cookie = tcp_syn_flood_action(sk, rsk_ops->slab_name); if (!want_cookie) goto drop; } This was using TCP_SKB_CB(skb)->tcp_tw_isn field in skb. Unfortunately this field has been accidentally cleared after the call to tcp_timewait_state_process() returning TCP_TW_SYN. Using a field in TCP_SKB_CB(skb) for a temporary state is overkill. Switch instead to a per-cpu variable. As a bonus, we do not have to clear tcp_tw_isn in TCP receive fast path. It is temporarily set then cleared only in the TCP_TW_SYN dance. Fixes: 4ad19de8774e ("net: tcp6: fix double call of tcp_v6_fill_cb()") Fixes: eeea10b83a13 ("tcp: add tcp_v4_fill_cb()/tcp_v4_restore_cb()") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-09tcp: propagate tcp_tw_isn via an extra parameter to ->route_req()Eric Dumazet
tcp_v6_init_req() reads TCP_SKB_CB(skb)->tcp_tw_isn to find out if the request socket is created by a SYN hitting a TIMEWAIT socket. This has been buggy for a decade, lets directly pass the information from tcp_conn_request(). This is a preparatory patch to make the following one easier to review. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-04-01tcp/dccp: do not care about families in inet_twsk_purge()Eric Dumazet
We lost ability to unload ipv6 module a long time ago. Instead of calling expensive inet_twsk_purge() twice, we can handle all families in one round. Also remove an extra line added in my prior patch, per Kuniyuki Iwashima feedback. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/20240327192934.6843-1-kuniyu@amazon.com/ Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240329153203.345203-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-01inet: preserve const qualifier in inet_csk()Eric Dumazet
We can change inet_csk() to propagate its argument const qualifier, thanks to container_of_const(). We have to fix few places that had mistakes, like tcp_bound_rto(). Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240329144931.295800-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-28tcp: make the dropreason really work when calling tcp_rcv_state_process()Jason Xing
Update three callers including both ipv4 and ipv6 and let the dropreason mechanism work in reality. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-28tcp: add dropreasons in tcp_rcv_state_process()Jason Xing
In this patch, I equipped this function with more dropreasons, but it still doesn't work yet, which I will do later. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/ipv4/udp.c f796feabb9f5 ("udp: add local "peek offset enabled" flag") 56667da7399e ("net: implement lockless setsockopt(SO_PEEK_OFF)") Adjacent changes: net/unix/garbage.c aa82ac51d633 ("af_unix: Drop oob_skb ref before purging queue in GC.") 11498715f266 ("af_unix: Remove io_uring code for GC.") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-18mptcp: fix lockless access in subflow ULP diagPaolo Abeni
Since the introduction of the subflow ULP diag interface, the dump callback accessed all the subflow data with lockless. We need either to annotate all the read and write operation accordingly, or acquire the subflow socket lock. Let's do latter, even if slower, to avoid a diffstat havoc. Fixes: 5147dfb50832 ("mptcp: allow dumping subflow context to userspace") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <martineau@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-23bpf: Define struct bpf_tcp_req_attrs when CONFIG_SYN_COOKIES=n.Kuniyuki Iwashima
kernel test robot reported the warning below: >> net/core/filter.c:11842:13: warning: declaration of 'struct bpf_tcp_req_attrs' will not be visible outside of this function [-Wvisibility] 11842 | struct bpf_tcp_req_attrs *attrs, int attrs__sz) | ^ 1 warning generated. struct bpf_tcp_req_attrs is defined under CONFIG_SYN_COOKIES but used in kfunc without the config. Let's move struct bpf_tcp_req_attrs definition outside of CONFIG_SYN_COOKIES guard. Fixes: e472f88891ab ("bpf: tcp: Support arbitrary SYN Cookie.") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202401180418.CUVc0hxF-lkp@intel.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240118211751.25790-1-kuniyu@amazon.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-23bpf: tcp: Support arbitrary SYN Cookie.Kuniyuki Iwashima
This patch adds a new kfunc available at TC hook to support arbitrary SYN Cookie. The basic usage is as follows: struct bpf_tcp_req_attrs attrs = { .mss = mss, .wscale_ok = wscale_ok, .rcv_wscale = rcv_wscale, /* Server's WScale < 15 */ .snd_wscale = snd_wscale, /* Client's WScale < 15 */ .tstamp_ok = tstamp_ok, .rcv_tsval = tsval, .rcv_tsecr = tsecr, /* Server's Initial TSval */ .usec_ts_ok = usec_ts_ok, .sack_ok = sack_ok, .ecn_ok = ecn_ok, } skc = bpf_skc_lookup_tcp(...); sk = (struct sock *)bpf_skc_to_tcp_sock(skc); bpf_sk_assign_tcp_reqsk(skb, sk, attrs, sizeof(attrs)); bpf_sk_release(skc); bpf_sk_assign_tcp_reqsk() takes skb, a listener sk, and struct bpf_tcp_req_attrs and allocates reqsk and configures it. Then, bpf_sk_assign_tcp_reqsk() links reqsk with skb and the listener. The notable thing here is that we do not hold refcnt for both reqsk and listener. To differentiate that, we mark reqsk->syncookie, which is only used in TX for now. So, if reqsk->syncookie is 1 in RX, it means that the reqsk is allocated by kfunc. When skb is freed, sock_pfree() checks if reqsk->syncookie is 1, and in that case, we set NULL to reqsk->rsk_listener before calling reqsk_free() as reqsk does not hold a refcnt of the listener. When the TCP stack looks up a socket from the skb, we steal the listener from the reqsk in skb_steal_sock() and create a full sk in cookie_v[46]_check(). The refcnt of reqsk will finally be set to 1 in tcp_get_cookie_sock() after creating a full sk. Note that we can extend struct bpf_tcp_req_attrs in the future when we add a new attribute that is determined in 3WHS. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240115205514.68364-6-kuniyu@amazon.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-23bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check().Kuniyuki Iwashima
We will support arbitrary SYN Cookie with BPF in the following patch. If BPF prog validates ACK and kfunc allocates a reqsk, it will be carried to cookie_[46]_check() as skb->sk. If skb->sk is not NULL, we call cookie_bpf_check(). Then, we clear skb->sk and skb->destructor, which are needed not to hold refcnt for reqsk and the listener. See the following patch for details. After that, we finish initialisation for the remaining fields with cookie_tcp_reqsk_init(). Note that the server side WScale is set only for non-BPF SYN Cookie. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240115205514.68364-5-kuniyu@amazon.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-23tcp: Move tcp_ns_to_ts() to tcp.hKuniyuki Iwashima
We will support arbitrary SYN Cookie with BPF. When BPF prog validates ACK and kfunc allocates a reqsk, we need to call tcp_ns_to_ts() to calculate an offset of TSval for later use: time t0 : Send SYN+ACK -> tsval = Initial TSval (Random Number) t1 : Recv ACK of 3WHS -> tsoff = TSecr - tcp_ns_to_ts(usec_ts_ok, tcp_clock_ns()) = Initial TSval - t1 t2 : Send ACK -> tsval = t2 + tsoff = Initial TSval + (t2 - t1) = Initial TSval + Time Delta (x) (x) Note that the time delta does not include the initial RTT from t0 to t1. Let's move tcp_ns_to_ts() to tcp.h. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240115205514.68364-2-kuniyu@amazon.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/broadcom/bnxt/bnxt.c e009b2efb7a8 ("bnxt_en: Remove mis-applied code from bnxt_cfg_ntp_filters()") 0f2b21477988 ("bnxt_en: Fix compile error without CONFIG_RFS_ACCEL") https://lore.kernel.org/all/20240105115509.225aa8a2@canb.auug.org.au/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-04net/tcp: Only produce AO/MD5 logs if there are any keysDmitry Safonov
User won't care about inproper hash options in the TCP header if they don't use neither TCP-AO nor TCP-MD5. Yet, those logs can add up in syslog, while not being a real concern to the host admin: > kernel: TCP: TCP segment has incorrect auth options set for XX.20.239.12.54681->XX.XX.90.103.80 [S] Keep silent and avoid logging when there aren't any keys in the system. Side-note: I also defined static_branch_tcp_*() helpers to avoid more ifdeffery, going to remove more ifdeffery further with their help. Reported-by: Christian Kujau <lists@nerdbynature.de> Closes: https://lore.kernel.org/all/f6b59324-1417-566f-a976-ff2402718a8d@nerdbynature.de/ Signed-off-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Fixes: 2717b5adea9e ("net/tcp: Add tcp_hash_fail() ratelimited logs") Link: https://lore.kernel.org/r/20240104-tcp_hash_fail-logs-v1-1-ff3e1f6f9e72@arista.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/stmicro/stmmac/dwmac5.c drivers/net/ethernet/stmicro/stmmac/dwmac5.h drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c drivers/net/ethernet/stmicro/stmmac/hwif.h 37e4b8df27bc ("net: stmmac: fix FPE events losing") c3f3b97238f6 ("net: stmmac: Refactor EST implementation") https://lore.kernel.org/all/20231206110306.01e91114@canb.auug.org.au/ Adjacent changes: net/ipv4/tcp_ao.c 9396c4ee93f9 ("net/tcp: Don't store TCP-AO maclen on reqsk") 7b0f570f879a ("tcp: Move TCP-AO bits from cookie_v[46]_check() to tcp_ao_syncookie().") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-05tcp: fix mid stream window clamp.Paolo Abeni
After the blamed commit below, if the user-space application performs window clamping when tp->rcv_wnd is 0, the TCP socket will never be able to announce a non 0 receive window, even after completely emptying the receive buffer and re-setting the window clamp to higher values. Refactor tcp_set_window_clamp() to address the issue: when the user decreases the current clamp value, set rcv_ssthresh according to the same logic used at buffer initialization, but ensuring reserved mem provisioning. To avoid code duplication factor-out the relevant bits from tcp_adjust_rcv_ssthresh() in a new helper and reuse it in the above scenario. When increasing the clamp value, give the rcv_ssthresh a chance to grow according to previously implemented heuristic. Fixes: 3aa7857fe1d7 ("tcp: enable mid stream window clamp") Reported-by: David Gibson <david@gibson.dropbear.id.au> Reported-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/705dad54e6e6e9a010e571bf58e0b35a8ae70503.1701706073.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29tcp: Factorise cookie-dependent fields initialisation in cookie_v[46]_check()Kuniyuki Iwashima
We will support arbitrary SYN Cookie with BPF, and then kfunc at TC will preallocate reqsk and initialise some fields that should not be overwritten later by cookie_v[46]_check(). To simplify the flow in cookie_v[46]_check(), we move such fields' initialisation to cookie_tcp_reqsk_alloc() and factorise non-BPF SYN Cookie handling into cookie_tcp_check(), where we validate the cookie and allocate reqsk, as done by kfunc later. Note that we set ireq->ecn_ok in two steps, the latter of which will be shared by the BPF case. As cookie_ecn_ok() is one-liner, now it's inlined. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20231129022924.96156-9-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29tcp: Move TCP-AO bits from cookie_v[46]_check() to tcp_ao_syncookie().Kuniyuki Iwashima
We initialise treq->af_specific in cookie_tcp_reqsk_alloc() so that we can look up a key later in tcp_create_openreq_child(). Initially, that change was added for MD5 by commit ba5a4fdd63ae ("tcp: make sure treq->af_specific is initialized"), but it has not been used since commit d0f2b7a9ca0a ("tcp: Disable header prediction for MD5 flow."). Now, treq->af_specific is used only by TCP-AO, so, we can move that initialisation into tcp_ao_syncookie(). In addition to that, l3index in cookie_v[46]_check() is only used for tcp_ao_syncookie(), so let's move it as well. While at it, we move down tcp_ao_syncookie() in cookie_v4_check() so that it will be called after security_inet_conn_request() to make functions order consistent with cookie_v6_check(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20231129022924.96156-7-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29tcp: Don't initialise tp->tsoffset in tcp_get_cookie_sock().Kuniyuki Iwashima
When we create a full socket from SYN Cookie, we initialise tcp_sk(sk)->tsoffset redundantly in tcp_get_cookie_sock() as the field is inherited from tcp_rsk(req)->ts_off. cookie_v[46]_check |- treq->ts_off = 0 `- tcp_get_cookie_sock |- tcp_v[46]_syn_recv_sock | `- tcp_create_openreq_child | `- newtp->tsoffset = treq->ts_off `- tcp_sk(child)->tsoffset = tsoff Let's initialise tcp_rsk(req)->ts_off with the correct offset and remove the second initialisation of tcp_sk(sk)->tsoffset. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20231129022924.96156-6-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-29tcp: Don't pass cookie to __cookie_v[46]_check().Kuniyuki Iwashima
tcp_hdr(skb) and SYN Cookie are passed to __cookie_v[46]_check(), but none of the callers passes cookie other than ntohl(th->ack_seq) - 1. Let's fetch it in __cookie_v[46]_check() instead of passing the cookie over and over. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20231129022924.96156-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-27net/tcp: Wire up l3index to TCP-AODmitry Safonov
Similarly how TCP_MD5SIG_FLAG_IFINDEX works for TCP-MD5, TCP_AO_KEYF_IFINDEX is an AO-key flag that binds that MKT to a specified by L3 ifinndex. Similarly, without this flag the key will work in the default VRF l3index = 0 for connections. To prevent AO-keys from overlapping, it's restricted to add key B for a socket that has key A, which have the same sndid/rcvid and one of the following is true: - !(A.keyflags & TCP_AO_KEYF_IFINDEX) or !(B.keyflags & TCP_AO_KEYF_IFINDEX) so that any key is non-bound to a VRF - A.l3index == B.l3index both want to work for the same VRF Additionally, it's restricted to match TCP-MD5 keys for the same peer the following way: |--------------|--------------------|----------------|---------------| | | MD5 key without | MD5 key | MD5 key | | | l3index | l3index=0 | l3index=N | |--------------|--------------------|----------------|---------------| | TCP-AO key | | | | | without | reject | reject | reject | | l3index | | | | |--------------|--------------------|----------------|---------------| | TCP-AO key | | | | | l3index=0 | reject | reject | allow | |--------------|--------------------|----------------|---------------| | TCP-AO key | | | | | l3index=N | reject | allow | reject | |--------------|--------------------|----------------|---------------| This is done with the help of tcp_md5_do_lookup_any_l3index() to reject adding AO key without TCP_AO_KEYF_IFINDEX if there's TCP-MD5 in any VRF. This is important for case where sysctl_tcp_l3mdev_accept = 1 Similarly, for TCP-AO lookups tcp_ao_do_lookup() may be used with l3index < 0, so that __tcp_ao_key_cmp() will match TCP-AO key in any VRF. Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add static_key for TCP-AODmitry Safonov
Similarly to TCP-MD5, add a static key to TCP-AO that is patched out when there are no keys on a machine and dynamically enabled with the first setsockopt(TCP_AO) adds a key on any socket. The static key is as well dynamically disabled later when the socket is destructed. The lifetime of enabled static key here is the same as ao_info: it is enabled on allocation, passed over from full socket to twsk and destructed when ao_info is scheduled for destruction. Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add tcp_hash_fail() ratelimited logsDmitry Safonov
Add a helper for logging connection-detailed messages for failed TCP hash verification (both MD5 and AO). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO segments countersDmitry Safonov
Introduce segment counters that are useful for troubleshooting/debugging as well as for writing tests. Now there are global snmp counters as well as per-socket and per-key. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Verify inbound TCP-AO signed segmentsDmitry Safonov
Now there is a common function to verify signature on TCP segments: tcp_inbound_hash(). It has checks for all possible cross-interactions with MD5 signs as well as with unsigned segments. The rules from RFC5925 are: (1) Any TCP segment can have at max only one signature. (2) TCP connections can't switch between using TCP-MD5 and TCP-AO. (3) TCP-AO connections can't stop using AO, as well as unsigned connections can't suddenly start using AO. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Sign SYN-ACK segments with TCP-AODmitry Safonov
Similarly to RST segments, wire SYN-ACKs to TCP-AO. tcp_rsk_used_ao() is handy here to check if the request socket used AO and needs a signature on the outgoing segments. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Wire TCP-AO to request socketsDmitry Safonov
Now when the new request socket is created from the listening socket, it's recorded what MKT was used by the peer. tcp_rsk_used_ao() is a new helper for checking if TCP-AO option was used to create the request socket. tcp_ao_copy_all_matching() will copy all keys that match the peer on the request socket, as well as preparing them for the usage (creating traffic keys). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add AO sign to RST packetsDmitry Safonov
Wire up sending resets to TCP-AO hashing. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add tcp_parse_auth_options()Dmitry Safonov
Introduce a helper that: (1) shares the common code with TCP-MD5 header options parsing (2) looks for hash signature only once for both TCP-MD5 and TCP-AO (3) fails with -EEXIST if any TCP sign option is present twice, see RFC5925 (2.2): ">> A single TCP segment MUST NOT have more than one TCP-AO in its options sequence. When multiple TCP-AOs appear, TCP MUST discard the segment." Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO sign to outgoing packetsDmitry Safonov
Using precalculated traffic keys, sign TCP segments as prescribed by RFC5925. Per RFC, TCP header options are included in sign calculation: "The TCP header, by default including options, and where the TCP checksum and TCP-AO MAC fields are set to zero, all in network- byte order." (5.1.3) tcp_ao_hash_header() has exclude_options parameter to optionally exclude TCP header from hash calculation, as described in RFC5925 (9.1), this is needed for interaction with middleboxes that may change "some TCP options". This is wired up to AO key flags and setsockopt() later. Similarly to TCP-MD5 hash TCP segment fragments. From this moment a user can start sending TCP-AO signed segments with one of crypto ahash algorithms from supported by Linux kernel. It can have a user-specified MAC length, to either save TCP option header space or provide higher protection using a longer signature. The inbound segments are not yet verified, TCP-AO option is ignored and they are accepted. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Calculate TCP-AO traffic keysDmitry Safonov
Add traffic key calculation the way it's described in RFC5926. Wire it up to tcp_finish_connect() and cache the new keys straight away on already established TCP connections. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Prevent TCP-MD5 with TCP-AO being setDmitry Safonov
Be as conservative as possible: if there is TCP-MD5 key for a given peer regardless of L3 interface - don't allow setting TCP-AO key for the same peer. According to RFC5925, TCP-AO is supposed to replace TCP-MD5 and there can't be any switch between both on any connected tuple. Later it can be relaxed, if there's a use, but in the beginning restrict any intersection. Note: it's still should be possible to set both TCP-MD5 and TCP-AO keys on a listening socket for *different* peers. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Introduce TCP_AO setsockopt()sDmitry Safonov
Add 3 setsockopt()s: 1. TCP_AO_ADD_KEY to add a new Master Key Tuple (MKT) on a socket 2. TCP_AO_DEL_KEY to delete present MKT from a socket 3. TCP_AO_INFO to change flags, Current_key/RNext_key on a TCP-AO sk Userspace has to introduce keys on every socket it wants to use TCP-AO option on, similarly to TCP_MD5SIG/TCP_MD5SIG_EXT. RFC5925 prohibits definition of MKTs that would match the same peer, so do sanity checks on the data provided by userspace. Be as conservative as possible, including refusal of defining MKT on an established connection with no AO, removing the key in-use and etc. (1) and (2) are to be used by userspace key manager to add/remove keys. (3) main purpose is to set RNext_key, which (as prescribed by RFC5925) is the KeyID that will be requested in TCP-AO header from the peer to sign their segments with. At this moment the life of ao_info ends in tcp_v4_destroy_sock(). Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Add TCP-AO config and structuresDmitry Safonov
Introduce new kernel config option and common structures as well as helpers to be used by TCP-AO code. Co-developed-by: Francesco Ruggeri <fruggeri@arista.com> Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Co-developed-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Salam Noureddine <noureddine@arista.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27net/tcp: Prepare tcp_md5sig_pool for TCP-AODmitry Safonov
TCP-AO, similarly to TCP-MD5, needs to allocate tfms on a slow-path, which is setsockopt() and use crypto ahash requests on fast paths, which are RX/TX softirqs. Also, it needs a temporary/scratch buffer for preparing the hash. Rework tcp_md5sig_pool in order to support other hashing algorithms than MD5. It will make it possible to share pre-allocated crypto_ahash descriptors and scratch area between all TCP hash users. Internally tcp_sigpool calls crypto_clone_ahash() API over pre-allocated crypto ahash tfm. Kudos to Herbert, who provided this new crypto API. I was a little concerned over GFP_ATOMIC allocations of ahash and crypto_request in RX/TX (see tcp_sigpool_start()), so I benchmarked both "backends" with different algorithms, using patched version of iperf3[2]. On my laptop with i7-7600U @ 2.80GHz: clone-tfm per-CPU-requests TCP-MD5 2.25 Gbits/sec 2.30 Gbits/sec TCP-AO(hmac(sha1)) 2.53 Gbits/sec 2.54 Gbits/sec TCP-AO(hmac(sha512)) 1.67 Gbits/sec 1.64 Gbits/sec TCP-AO(hmac(sha384)) 1.77 Gbits/sec 1.80 Gbits/sec TCP-AO(hmac(sha224)) 1.29 Gbits/sec 1.30 Gbits/sec TCP-AO(hmac(sha3-512)) 481 Mbits/sec 480 Mbits/sec TCP-AO(hmac(md5)) 2.07 Gbits/sec 2.12 Gbits/sec TCP-AO(hmac(rmd160)) 1.01 Gbits/sec 995 Mbits/sec TCP-AO(cmac(aes128)) [not supporetd yet] 2.11 Gbits/sec So, it seems that my concerns don't have strong grounds and per-CPU crypto_request allocation can be dropped/removed from tcp_sigpool once ciphers get crypto_clone_ahash() support. [1]: https://lore.kernel.org/all/ZDefxOq6Ax0JeTRH@gondor.apana.org.au/T/#u [2]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao Signed-off-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com> Acked-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-25tcp: define initial scaling factor value as a macroPaolo Abeni
So that other users could access it. Notably MPTCP will use it in the next patch. No functional change intended. Acked-by: Matthieu Baerts <matttbe@kernel.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <martineau@kernel.org> Link: https://lore.kernel.org/r/20231023-send-net-next-20231023-2-v1-4-9dc60939d371@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-23tcp: add support for usec resolution in TCP TS valuesEric Dumazet
Back in 2015, Van Jacobson suggested to use usec resolution in TCP TS values. This has been implemented in our private kernels. Goals were : 1) better observability of delays in networking stacks. 2) better disambiguation of events based on TSval/ecr values. 3) building block for congestion control modules needing usec resolution. Back then we implemented a schem based on private SYN options to negotiate the feature. For upstream submission, we chose to use a route attribute, because this feature is probably going to be used in private networks [1] [2]. ip route add 10/8 ... features tcp_usec_ts Note that RFC 7323 recommends a "timestamp clock frequency in the range 1 ms to 1 sec per tick.", but also mentions "the maximum acceptable clock frequency is one tick every 59 ns." [1] Unfortunately RFC 7323 5.5 (Outdated Timestamps) suggests to invalidate TS.Recent values after a flow was idle for more than 24 days. This is the part making usec_ts a problem for peers following this recommendation for long living idle flows. [2] Attempts to standardize usec ts went nowhere: https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf https://datatracker.ietf.org/doc/draft-wang-tcpm-low-latency-opt/ Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: introduce TCP_PAWS_WRAPEric Dumazet
tcp_paws_check() uses TCP_PAWS_24DAYS constant to detect if TCP TS values might have wrapped after a long idle period. This mechanism is described in RFC 7323 5.5 (Outdated Timestamps) TCP_PAWS_24DAYS value was based on the assumption of a clock of 1 Khz. As we want to adopt a 1 Mhz clock in the future, we reduce this constant. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: rename tcp_time_stamp() to tcp_time_stamp_ts()Eric Dumazet
This helper returns a TSval from a TCP socket. It currently calls tcp_time_stamp_ms() but will soon be able to return a usec based TSval, depending on an upcoming tp->tcp_usec_ts field. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: move tcp_ns_to_ts() to net/ipv4/syncookies.cEric Dumazet
tcp_ns_to_ts() is only used once from cookie_init_timestamp(). Also add the 'bool usec_ts' parameter to enable usec TS later. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: rename tcp_skb_timestamp()Eric Dumazet
This helper returns a 32bit TCP TSval from skb->tstamp. As we are going to support usec or ms units soon, rename it to tcp_skb_timestamp_ts() and add a boolean to select the unit. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: replace tcp_time_stamp_raw()Eric Dumazet
In preparation of usec TCP TS support, remove tcp_time_stamp_raw() in favor of tcp_clock_ts() helper. This helper will return a suitable 32bit result to feed TS values, depending on a socket field. Also add tcp_tw_tsval() and tcp_rsk_tsval() helpers to factorize the details. We do not yet support usec timestamps. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: introduce tcp_clock_ms()Eric Dumazet
It delivers current TCP time stamp in ms unit, and is used in place of confusing tcp_time_stamp_raw() It is the same family than tcp_clock_ns() and tcp_clock_ms(). tcp_time_stamp_raw() will be replaced later for TSval contexts with a more descriptive name. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: add tcp_time_stamp_ms() helperEric Dumazet
In preparation of adding usec TCP TS values, add tcp_time_stamp_ms() for contexts needing ms based values. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-23tcp: fix cookie_init_timestamp() overflowsEric Dumazet
cookie_init_timestamp() is supposed to return a 64bit timestamp suitable for both TSval determination and setting of skb->tstamp. Unfortunately it uses 32bit fields and overflows after 2^32 * 10^6 nsec (~49 days) of uptime. Generated TSval are still correct, but skb->tstamp might be set far away in the past, potentially confusing other layers. tcp_ns_to_ts() is changed to return a full 64bit value, ts and ts_now variables are changed to u64 type, and TSMASK is removed in favor of shifts operations. While we are at it, change this sequence: ts >>= TSBITS; ts--; ts <<= TSBITS; ts |= options; to: ts -= (1UL << TSBITS); Fixes: 9a568de4818d ("tcp: switch TCP TS option (RFC 7323) to 1ms clock") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. net/mac80211/key.c 02e0e426a2fb ("wifi: mac80211: fix error path key leak") 2a8b665e6bcc ("wifi: mac80211: remove key_mtx") 7d6904bf26b9 ("Merge wireless into wireless-next") https://lore.kernel.org/all/20231012113648.46eea5ec@canb.auug.org.au/ Adjacent changes: drivers/net/ethernet/ti/Kconfig a602ee3176a8 ("net: ethernet: ti: Fix mixed module-builtin object") 98bdeae9502b ("net: cpmac: remove driver to prepare for platform removal") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-17tcp: fix excessive TLP and RACK timeouts from HZ roundingNeal Cardwell
We discovered from packet traces of slow loss recovery on kernels with the default HZ=250 setting (and min_rtt < 1ms) that after reordering, when receiving a SACKed sequence range, the RACK reordering timer was firing after about 16ms rather than the desired value of roughly min_rtt/4 + 2ms. The problem is largely due to the RACK reorder timer calculation adding in TCP_TIMEOUT_MIN, which is 2 jiffies. On kernels with HZ=250, this is 2*4ms = 8ms. The TLP timer calculation has the exact same issue. This commit fixes the TLP transmit timer and RACK reordering timer floor calculation to more closely match the intended 2ms floor even on kernels with HZ=250. It does this by adding in a new TCP_TIMEOUT_MIN_US floor of 2000 us and then converting to jiffies, instead of the current approach of converting to jiffies and then adding th TCP_TIMEOUT_MIN value of 2 jiffies. Our testing has verified that on kernels with HZ=1000, as expected, this does not produce significant changes in behavior, but on kernels with the default HZ=250 the latency improvement can be large. For example, our tests show that for HZ=250 kernels at low RTTs this fix roughly halves the latency for the RACK reorder timer: instead of mostly firing at 16ms it mostly fires at 8ms. Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Fixes: bb4d991a28cc ("tcp: adjust tail loss probe timeout") Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20231015174700.2206872-1-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-16net: stub tcp_gro_complete if CONFIG_INET=nJacob Keller
A few networking drivers including bnx2x, bnxt, qede, and idpf call tcp_gro_complete as part of offloading TCP GRO. The function is only defined if CONFIG_INET is true, since its TCP specific and is meaningless if the kernel lacks IP networking support. The combination of trying to use the complex network drivers with CONFIG_NET but not CONFIG_INET is rather unlikely in practice: most use cases are going to need IP networking. The tcp_gro_complete function just sets some data in the socket buffer for use in processing the TCP packet in the event that the GRO was offloaded to the device. If the kernel lacks TCP support, such setup will simply go unused. The bnx2x, bnxt, and qede drivers wrap their TCP offload support in CONFIG_INET checks and skip handling on such kernels. The idpf driver did not check CONFIG_INET and thus fails to link if the kernel is configured with CONFIG_NET=y, CONFIG_IDPF=(m|y), and CONFIG_INET=n. While checking CONFIG_INET does allow the driver to bypass significantly more instructions in the event that we know TCP networking isn't supported, the configuration is unlikely to be used widely. Rather than require driver authors to care about this, stub the tcp_gro_complete function when CONFIG_INET=n. This allows drivers to be left as-is. It does mean the idpf driver will perform slightly more work than strictly necessary when CONFIG_INET=n, since it will still execute some of the skb setup in idpf_rx_rsc. However, that work would be performed in the case where CONFIG_INET=y anyways. I did not change the existing drivers, since they appear to wrap a significant portion of code when CONFIG_INET=n. There is little benefit in trashing these drivers just to unwrap and remove the CONFIG_INET check. Using a stub for tcp_gro_complete is still beneficial, as it means future drivers no longer need to worry about this case of CONFIG_NET=y and CONFIG_INET=n, which should reduce noise from buildbots that check such a configuration. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Link: https://lore.kernel.org/r/20231013185502.1473541-1-jacob.e.keller@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-10tcp: record last received ipv6 flowlabelDavid Morley
In order to better estimate whether a data packet has been retransmitted or is the result of a TLP, we save the last received ipv6 flowlabel. To make space for this field we resize the "ato" field in inet_connection_sock as the current value of TCP_DELACK_MAX can be fully contained in 8 bits and add a compile_time_assert ensuring this field is the required size. v2: addressed kernel bot feedback about dccp_delack_timer() v3: addressed build error introduced by commit bbf80d713fe7 ("tcp: derive delack_max from rto_min") Signed-off-by: David Morley <morleyd@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Tested-by: David Morley <morleyd@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>