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* tcp: fastopen: avoid negative sk_forward_allocEric Dumazet2016-09-081-0/+1
| | | | | | | | | | | | | | | | | When DATA and/or FIN are carried in a SYN/ACK message or SYN message, we append an skb in socket receive queue, but we forget to call sk_forced_mem_schedule(). Effect is that the socket has a negative sk->sk_forward_alloc as long as the message is not read by the application. Josh Hunt fixed a similar issue in commit d22e15371811 ("tcp: fix tcp fin memory accounting") Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Josh Hunt <johunt@akamai.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fastopen: fix rcv_wup initialization for TFO server on SYN/dataNeal Cardwell2016-09-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | Yuchung noticed that on the first TFO server data packet sent after the (TFO) handshake, the server echoed the TCP timestamp value in the SYN/data instead of the timestamp value in the final ACK of the handshake. This problem did not happen on regular opens. The tcp_replace_ts_recent() logic that decides whether to remember an incoming TS value needs tp->rcv_wup to hold the latest receive sequence number that we have ACKed (latest tp->rcv_nxt we have ACKed). This commit fixes this issue by ensuring that a TFO server properly updates tp->rcv_wup to match tp->rcv_nxt at the time it sends a SYN/ACK for the SYN/data. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path") Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: do not assume TCP code is non preemptibleEric Dumazet2016-05-021-6/+6
| | | | | | | | | | | | | | | | | We want to to make TCP stack preemptible, as draining prequeue and backlog queues can take lot of time. Many SNMP updates were assuming that BH (and preemption) was disabled. Need to convert some __NET_INC_STATS() calls to NET_INC_STATS() and some __TCP_INC_STATS() to TCP_INC_STATS() Before using this_cpu_ptr(net->ipv4.tcp_sk) in tcp_v4_send_reset() and tcp_v4_send_ack(), we add an explicit preempt disabled section. 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>
* net: rename NET_{ADD|INC}_STATS_BH()Eric Dumazet2016-04-271-7/+7
| | | | | | | | Rename NET_INC_STATS_BH() to __NET_INC_STATS() and NET_ADD_STATS_BH() to __NET_ADD_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds2016-03-191-30/+48
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking updates from David Miller: "Highlights: 1) Support more Realtek wireless chips, from Jes Sorenson. 2) New BPF types for per-cpu hash and arrap maps, from Alexei Starovoitov. 3) Make several TCP sysctls per-namespace, from Nikolay Borisov. 4) Allow the use of SO_REUSEPORT in order to do per-thread processing of incoming TCP/UDP connections. The muxing can be done using a BPF program which hashes the incoming packet. From Craig Gallek. 5) Add a multiplexer for TCP streams, to provide a messaged based interface. BPF programs can be used to determine the message boundaries. From Tom Herbert. 6) Add 802.1AE MACSEC support, from Sabrina Dubroca. 7) Avoid factorial complexity when taking down an inetdev interface with lots of configured addresses. We were doing things like traversing the entire address less for each address removed, and flushing the entire netfilter conntrack table for every address as well. 8) Add and use SKB bulk free infrastructure, from Jesper Brouer. 9) Allow offloading u32 classifiers to hardware, and implement for ixgbe, from John Fastabend. 10) Allow configuring IRQ coalescing parameters on a per-queue basis, from Kan Liang. 11) Extend ethtool so that larger link mode masks can be supported. From David Decotigny. 12) Introduce devlink, which can be used to configure port link types (ethernet vs Infiniband, etc.), port splitting, and switch device level attributes as a whole. From Jiri Pirko. 13) Hardware offload support for flower classifiers, from Amir Vadai. 14) Add "Local Checksum Offload". Basically, for a tunneled packet the checksum of the outer header is 'constant' (because with the checksum field filled into the inner protocol header, the payload of the outer frame checksums to 'zero'), and we can take advantage of that in various ways. From Edward Cree" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits) bonding: fix bond_get_stats() net: bcmgenet: fix dma api length mismatch net/mlx4_core: Fix backward compatibility on VFs phy: mdio-thunder: Fix some Kconfig typos lan78xx: add ndo_get_stats64 lan78xx: handle statistics counter rollover RDS: TCP: Remove unused constant RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket net: smc911x: convert pxa dma to dmaengine team: remove duplicate set of flag IFF_MULTICAST bonding: remove duplicate set of flag IFF_MULTICAST net: fix a comment typo ethernet: micrel: fix some error codes ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it bpf, dst: add and use dst_tclassid helper bpf: make skb->tc_classid also readable net: mvneta: bm: clarify dependencies cls_bpf: reset class and reuse major in da ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c ldmvsw: Add ldmvsw.c driver code ...
| * tcp: Add RFC4898 tcpEStatsPerfDataSegsOut/InMartin KaFai Lau2016-03-141-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Per RFC4898, they count segments sent/received containing a positive length data segment (that includes retransmission segments carrying data). Unlike tcpi_segs_out/in, tcpi_data_segs_out/in excludes segments carrying no data (e.g. pure ack). The patch also updates the segs_in in tcp_fastopen_add_skb() so that segs_in >= data_segs_in property is kept. Together with retransmission data, tcpi_data_segs_out gives a better signal on the rxmit rate. v6: Rebase on the latest net-next v5: Eric pointed out that checking skb->len is still needed in tcp_fastopen_add_skb() because skb can carry a FIN without data. Hence, instead of open coding segs_in and data_segs_in, tcp_segs_in() helper is used. Comment is added to the fastopen case to explain why segs_in has to be reset and tcp_segs_in() has to be called before __skb_pull(). v4: Add comment to the changes in tcp_fastopen_add_skb() and also add remark on this case in the commit message. v3: Add const modifier to the skb parameter in tcp_segs_in() v2: Rework based on recent fix by Eric: commit a9d99ce28ed3 ("tcp: fix tcpi_segs_in after connection establishment") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Chris Rapier <rapier@psc.edu> Cc: Eric Dumazet <edumazet@google.com> Cc: Marcelo Ricardo Leitner <mleitner@redhat.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: fastopen: call tcp_fin() if FIN present in SYNACKEric Dumazet2016-02-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we acknowledge a FIN, it is not enough to ack the sequence number and queue the skb into receive queue. We also have to call tcp_fin() to properly update socket state and send proper poll() notifications. It seems we also had the problem if we received a SYN packet with the FIN flag set, but it does not seem an urgent issue, as no known implementation can do that. Fixes: 61d2bcae99f6 ("tcp: fastopen: accept data/FIN present in SYNACK message") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: do not enqueue skb with SYN flagEric Dumazet2016-02-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we remove the SYN flag from the skbs that tcp_fastopen_add_skb() places in socket receive queue, then we can remove the test that tcp_recvmsg() has to perform in fast path. All we have to do is to adjust SEQ in the slow path. For the moment, we place an unlikely() and output a message if we find an skb having SYN flag set. Goal would be to get rid of the test completely. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * tcp: fastopen: accept data/FIN present in SYNACK messageEric Dumazet2016-02-061-30/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RFC 7413 (TCP Fast Open) 4.2.2 states that the SYNACK message MAY include data and/or FIN This patch adds support for the client side : If we receive a SYNACK with payload or FIN, queue the skb instead of ignoring it. Since we already support the same for SYN, we refactor the existing code and reuse it. Note we need to clone the skb, so this operation might fail under memory pressure. Sara Dickinson pointed out FreeBSD server Fast Open implementation was planned to generate such SYNACK in the future. The server side might be implemented on linux later. Reported-by: Sara Dickinson <sara@sinodun.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: Use ahashHerbert Xu2016-01-271-0/+1
|/ | | | | | | | This patch replaces uses of the long obsolete hash interface with ahash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: David S. Miller <davem@davemloft.net>
* tcp/dccp: fix hashdance race for passive sessionsEric Dumazet2015-10-231-1/+3
| | | | | | | | | | | | | | | | | | | | | | Multiple cpus can process duplicates of incoming ACK messages matching a SYN_RECV request socket. This is a rare event under normal operations, but definitely can happen. Only one must win the race, otherwise corruption would occur. To fix this without adding new atomic ops, we use logic in inet_ehash_nolisten() to detect the request was present in the same ehash bucket where we try to insert the new child. If request socket was not found, we have to undo the child creation. This actually removes a spin_lock()/spin_unlock() pair in reqsk_queue_unlink() for the fast path. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix fastopen races vs lockless listenerEric Dumazet2015-10-051-19/+7
| | | | | | | | | | | | | | | | | | | | | | There are multiple races that need fixes : 1) skb_get() + queue skb + kfree_skb() is racy An accept() can be done on another cpu, data consumed immediately. tcp_recvmsg() uses __kfree_skb() as it is assumed all skb found in socket receive queue are private. Then the kfree_skb() in tcp_rcv_state_process() uses an already freed skb 2) tcp_reqsk_record_syn() needs to be done before tcp_try_fastopen() for the same reasons. 3) We want to send the SYNACK before queueing child into accept queue, otherwise we might reintroduce the ooo issue fixed in commit 7c85af881044 ("tcp: avoid reorders for TFO passive connections") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: attach SYNACK messages to request sockets instead of listenerEric Dumazet2015-10-031-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a listen backlog is very big (to avoid syncookies), then the listener sk->sk_wmem_alloc is the main source of false sharing, as we need to touch it twice per SYNACK re-transmit and TX completion. (One SYN packet takes listener lock once, but up to 6 SYNACK are generated) By attaching the skb to the request socket, we remove this source of contention. Tested: listen(fd, 10485760); // single listener (no SO_REUSEPORT) 16 RX/TX queue NIC Sustain a SYNFLOOD attack of ~320,000 SYN per second, Sending ~1,400,000 SYNACK per second. Perf profiles now show listener spinlock being next bottleneck. 20.29% [kernel] [k] queued_spin_lock_slowpath 10.06% [kernel] [k] __inet_lookup_established 5.12% [kernel] [k] reqsk_timer_handler 3.22% [kernel] [k] get_next_timer_interrupt 3.00% [kernel] [k] tcp_make_synack 2.77% [kernel] [k] ipt_do_table 2.70% [kernel] [k] run_timer_softirq 2.50% [kernel] [k] ip_finish_output 2.04% [kernel] [k] cascade Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: prepare fastopen code for upcoming listener changesEric Dumazet2015-09-291-5/+5
| | | | | | | | | | | | | | | | | | | | | While auditing TCP stack for upcoming 'lockless' listener changes, I found I had to change fastopen_init_queue() to properly init the object before publishing it. Otherwise an other cpu could try to lock the spinlock before it gets properly initialized. Instead of adding appropriate barriers, just remove dynamic memory allocations : - Structure is 28 bytes on 64bit arches. Using additional 8 bytes for holding a pointer seems overkill. - Two listeners can share same cache line and performance would suffer. If we really want to save few bytes, we would instead dynamically allocate whole struct request_sock_queue in the future. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: avoid reorders for TFO passive connectionsEric Dumazet2015-09-281-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We found that a TCP Fast Open passive connection was vulnerable to reorders, as the exchange might look like [1] C -> S S <FO ...> <request> [2] S -> C S. ack request <options> [3] S -> C . <answer> packets [2] and [3] can be generated at almost the same time. If C receives the 3rd packet before the 2nd, it will drop it as the socket is in SYN_SENT state and expects a SYNACK. S will have to retransmit the answer. Current OOO avoidance in linux is defeated because SYNACK packets are attached to the LISTEN socket, while DATA packets are attached to the children. They might be sent by different cpus, and different TX queues might be selected. It turns out that for TFO, we created a child, which is a full blown socket in TCP_SYN_RECV state, and we simply can attach the SYNACK packet to this socket. This means that at the time tcp_sendmsg() pushes DATA packet, skb->ooo_okay will be set iff the SYNACK packet had been sent and TX completed. This removes the reorder source at the host level. We also removed the export of tcp_try_fastopen(), as it is no longer called from IPv6. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Do not call tcp_fastopen_reset_cipher from interrupt contextChristoph Paasch2015-06-231-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tcp_fastopen_reset_cipher really cannot be called from interrupt context. It allocates the tcp_fastopen_context with GFP_KERNEL and calls crypto_alloc_cipher, which allocates all kind of stuff with GFP_KERNEL. Thus, we might sleep when the key-generation is triggered by an incoming TFO cookie-request which would then happen in interrupt- context, as shown by enabling CONFIG_DEBUG_ATOMIC_SLEEP: [ 36.001813] BUG: sleeping function called from invalid context at mm/slub.c:1266 [ 36.003624] in_atomic(): 1, irqs_disabled(): 0, pid: 1016, name: packetdrill [ 36.004859] CPU: 1 PID: 1016 Comm: packetdrill Not tainted 4.1.0-rc7 #14 [ 36.006085] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 36.008250] 00000000000004f2 ffff88007f8838a8 ffffffff8171d53a ffff880075a084a8 [ 36.009630] ffff880075a08000 ffff88007f8838c8 ffffffff810967d3 ffff88007f883928 [ 36.011076] 0000000000000000 ffff88007f8838f8 ffffffff81096892 ffff88007f89be00 [ 36.012494] Call Trace: [ 36.012953] <IRQ> [<ffffffff8171d53a>] dump_stack+0x4f/0x6d [ 36.014085] [<ffffffff810967d3>] ___might_sleep+0x103/0x170 [ 36.015117] [<ffffffff81096892>] __might_sleep+0x52/0x90 [ 36.016117] [<ffffffff8118e887>] kmem_cache_alloc_trace+0x47/0x190 [ 36.017266] [<ffffffff81680d82>] ? tcp_fastopen_reset_cipher+0x42/0x130 [ 36.018485] [<ffffffff81680d82>] tcp_fastopen_reset_cipher+0x42/0x130 [ 36.019679] [<ffffffff81680f01>] tcp_fastopen_init_key_once+0x61/0x70 [ 36.020884] [<ffffffff81680f2c>] __tcp_fastopen_cookie_gen+0x1c/0x60 [ 36.022058] [<ffffffff816814ff>] tcp_try_fastopen+0x58f/0x730 [ 36.023118] [<ffffffff81671788>] tcp_conn_request+0x3e8/0x7b0 [ 36.024185] [<ffffffff810e3872>] ? __module_text_address+0x12/0x60 [ 36.025327] [<ffffffff8167b2e1>] tcp_v4_conn_request+0x51/0x60 [ 36.026410] [<ffffffff816727e0>] tcp_rcv_state_process+0x190/0xda0 [ 36.027556] [<ffffffff81661f97>] ? __inet_lookup_established+0x47/0x170 [ 36.028784] [<ffffffff8167c2ad>] tcp_v4_do_rcv+0x16d/0x3d0 [ 36.029832] [<ffffffff812e6806>] ? security_sock_rcv_skb+0x16/0x20 [ 36.030936] [<ffffffff8167cc8a>] tcp_v4_rcv+0x77a/0x7b0 [ 36.031875] [<ffffffff816af8c3>] ? iptable_filter_hook+0x33/0x70 [ 36.032953] [<ffffffff81657d22>] ip_local_deliver_finish+0x92/0x1f0 [ 36.034065] [<ffffffff81657f1a>] ip_local_deliver+0x9a/0xb0 [ 36.035069] [<ffffffff81657c90>] ? ip_rcv+0x3d0/0x3d0 [ 36.035963] [<ffffffff81657569>] ip_rcv_finish+0x119/0x330 [ 36.036950] [<ffffffff81657ba7>] ip_rcv+0x2e7/0x3d0 [ 36.037847] [<ffffffff81610652>] __netif_receive_skb_core+0x552/0x930 [ 36.038994] [<ffffffff81610a57>] __netif_receive_skb+0x27/0x70 [ 36.040033] [<ffffffff81610b72>] process_backlog+0xd2/0x1f0 [ 36.041025] [<ffffffff81611482>] net_rx_action+0x122/0x310 [ 36.042007] [<ffffffff81076743>] __do_softirq+0x103/0x2f0 [ 36.042978] [<ffffffff81723e3c>] do_softirq_own_stack+0x1c/0x30 This patch moves the call to tcp_fastopen_init_key_once to the places where a listener socket creates its TFO-state, which always happens in user-context (either from the setsockopt, or implicitly during the listen()-call) Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Fixes: 222e83d2e0ae ("tcp: switch tcp_fastopen key generation to net_get_random_once") Signed-off-by: Christoph Paasch <cpaasch@apple.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix a potential deadlock in tcp_get_info()Eric Dumazet2015-05-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Taking socket spinlock in tcp_get_info() can deadlock, as inet_diag_dump_icsk() holds the &hashinfo->ehash_locks[i], while packet processing can use the reverse locking order. We could avoid this locking for TCP_LISTEN states, but lockdep would certainly get confused as all TCP sockets share same lockdep classes. [ 523.722504] ====================================================== [ 523.728706] [ INFO: possible circular locking dependency detected ] [ 523.734990] 4.1.0-dbg-DEV #1676 Not tainted [ 523.739202] ------------------------------------------------------- [ 523.745474] ss/18032 is trying to acquire lock: [ 523.750002] (slock-AF_INET){+.-...}, at: [<ffffffff81669d44>] tcp_get_info+0x2c4/0x360 [ 523.758129] [ 523.758129] but task is already holding lock: [ 523.763968] (&(&hashinfo->ehash_locks[i])->rlock){+.-...}, at: [<ffffffff816bcb75>] inet_diag_dump_icsk+0x1d5/0x6c0 [ 523.774661] [ 523.774661] which lock already depends on the new lock. [ 523.774661] [ 523.782850] [ 523.782850] the existing dependency chain (in reverse order) is: [ 523.790326] -> #1 (&(&hashinfo->ehash_locks[i])->rlock){+.-...}: [ 523.796599] [<ffffffff811126bb>] lock_acquire+0xbb/0x270 [ 523.802565] [<ffffffff816f5868>] _raw_spin_lock+0x38/0x50 [ 523.808628] [<ffffffff81665af8>] __inet_hash_nolisten+0x78/0x110 [ 523.815273] [<ffffffff816819db>] tcp_v4_syn_recv_sock+0x24b/0x350 [ 523.822067] [<ffffffff81684d41>] tcp_check_req+0x3c1/0x500 [ 523.828199] [<ffffffff81682d09>] tcp_v4_do_rcv+0x239/0x3d0 [ 523.834331] [<ffffffff816842fe>] tcp_v4_rcv+0xa8e/0xc10 [ 523.840202] [<ffffffff81658fa3>] ip_local_deliver_finish+0x133/0x3e0 [ 523.847214] [<ffffffff81659a9a>] ip_local_deliver+0xaa/0xc0 [ 523.853440] [<ffffffff816593b8>] ip_rcv_finish+0x168/0x5c0 [ 523.859624] [<ffffffff81659db7>] ip_rcv+0x307/0x420 Lets use u64_sync infrastructure instead. As a bonus, 64bit arches get optimized, as these are nop for them. Fixes: 0df48c26d841 ("tcp: add tcpi_bytes_acked to tcp_info") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: add tcpi_bytes_received to tcp_infoEric Dumazet2015-04-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | This patch tracks total number of payload bytes received on a TCP socket. This is the sum of all changes done to tp->rcv_nxt RFC4898 named this : tcpEStatsAppHCThruOctetsReceived This is a 64bit field, and can be fetched both from TCP_INFO getsockopt() if one has a handle on a TCP socket, or from inet_diag netlink facility (iproute2/ss patch will follow) Note that tp->bytes_received was placed near tp->rcv_nxt for best data locality and minimal performance impact. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Matt Mathis <mattmathis@google.com> Cc: Eric Salo <salo@google.com> Cc: Martin Lau <kafai@fb.com> Cc: Chris Rapier <rapier@psc.edu> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: RFC7413 option support for Fast Open serverDaniel Lee2015-04-071-0/+1
| | | | | | | | | | | | | | | Fast Open has been using the experimental option with a magic number (RFC6994) to request and grant Fast Open cookies. This patch enables the server to support the official IANA option 34 in RFC7413 in addition. The change has passed all existing Fast Open tests with both old and new options at Google. Signed-off-by: Daniel Lee <Longinus00@gmail.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: coding style: comparison for equality with NULLIan Morris2015-04-031-3/+3
| | | | | | | | | | | | The ipv4 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x == NULL and sometimes as !x. !x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris <ipm@chirality.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: get rid of central tcp/dccp listener timerEric Dumazet2015-03-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the major issue for TCP is the SYNACK rtx handling, done by inet_csk_reqsk_queue_prune(), fired by the keepalive timer of a TCP_LISTEN socket. This function runs for awful long times, with socket lock held, meaning that other cpus needing this lock have to spin for hundred of ms. SYNACK are sent in huge bursts, likely to cause severe drops anyway. This model was OK 15 years ago when memory was very tight. We now can afford to have a timer per request sock. Timer invocations no longer need to lock the listener, and can be run from all cpus in parallel. With following patch increasing somaxconn width to 32 bits, I tested a listener with more than 4 million active request sockets, and a steady SYNFLOOD of ~200,000 SYN per second. Host was sending ~830,000 SYNACK per second. This is ~100 times more what we could achieve before this patch. Later, we will get rid of the listener hash and use ehash instead. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: fix request sock refcountingEric Dumazet2015-03-171-0/+1
| | | | | | | | | | | | | | | | | While testing last patch series, I found req sock refcounting was wrong. We must set skc_refcnt to 1 for all request socks added in hashes, but also on request sockets created by FastOpen or syncookies. It is tricky because we need to defer this initialization so that future RCU lookups do not try to take a refcount on a not yet fully initialized request socket. Also get rid of ireq_refcnt alias. Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 13854e5a6046 ("inet: add proper refcounting to request sock") Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: rename struct tcp_request_sock listenerEric Dumazet2015-03-171-6/+1
| | | | | | | | | The listener field in struct tcp_request_sock is a pointer back to the listener. We now have req->rsk_listener, so TCP only needs one boolean and not a full pointer. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet: add proper refcounting to request sockEric Dumazet2015-03-161-1/+1
| | | | | | | | | | | | | | | | reqsk_put() is the generic function that should be used to release a refcount (and automatically call reqsk_free()) reqsk_free() might be called if refcount is known to be 0 or undefined. refcnt is set to one in inet_csk_reqsk_queue_add() As request socks are not yet in global ehash table, I added temporary debugging checks in reqsk_put() and reqsk_free() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: cleanup static functionsEric Dumazet2015-02-281-1/+0
| | | | | | | | | tcp_fastopen_create_child() is static and should not be exported. tcp4_gso_segment() and tcp6_gso_segment() should be static. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: make sure skb is not shared before using skb_get()Eric Dumazet2015-02-131-8/+24
| | | | | | | | | | | | | | | IPv6 can keep a copy of SYN message using skb_get() in tcp_v6_conn_request() so that caller wont free the skb when calling kfree_skb() later. Therefore TCP fast open has to clone the skb it is queuing in child->sk_receive_queue, as all skbs consumed from receive_queue are freed using __kfree_skb() (ie assuming skb->users == 1) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Fixes: 5b7ed0892f2af ("tcp: move fastopen functions to tcp_fastopen.c") Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: don't include Fast Open option in SYN-ACK on pure SYN-dataYuchung Cheng2015-02-091-5/+8
| | | | | | | | | | | | | | | | If a server has enabled Fast Open and it receives a pure SYN-data packet (without a Fast Open option), it won't accept the data but it incorrectly returns a SYN-ACK with a Fast Open cookie and also increments the SNMP stat LINUX_MIB_TCPFASTOPENPASSIVEFAIL. This patch makes the server include a Fast Open cookie in SYN-ACK only if the SYN has some Fast Open option (i.e., when client requests or presents a cookie). Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove unnecessary assignment.Li RongQing2014-09-291-1/+1
| | | | | | | This variable i is overwritten to 0 by following code Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove unnecessary tcp_sk assignment.Dave Jones2014-06-161-1/+1
| | | | | | | | This variable is overwritten by the child socket assignment before it ever gets used. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: IPv6 support for fastopen serverDaniel Lee2014-05-131-14/+43
| | | | | | | | | | | | | | After all the preparatory works, supporting IPv6 in Fast Open is now easy. We pretty much just mirror v4 code. The only difference is how we generate the Fast Open cookie for IPv6 sockets. Since Fast Open cookie is 128 bits and we use AES 128, we use CBC-MAC to encrypt both the source and destination IPv6 addresses since the cookie is a MAC tag. Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Jerry Chu <hkchu@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: use tcp_v4_send_synack on first SYN-ACKYuchung Cheng2014-05-131-36/+31
| | | | | | | | | | | | | | | | | | | | To avoid large code duplication in IPv6, we need to first simplify the complicate SYN-ACK sending code in tcp_v4_conn_request(). To use tcp_v4(6)_send_synack() to send all SYN-ACKs, we need to initialize the mini socket's receive window before trying to create the child socket and/or building the SYN-ACK packet. So we move that initialization from tcp_make_synack() to tcp_v4_conn_request() as a new function tcp_openreq_init_req_rwin(). After this refactoring the SYN-ACK sending code is simpler and easier to implement Fast Open for IPv6. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Jerry Chu <hkchu@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: simplify fast open cookie processingYuchung Cheng2014-05-131-43/+28
| | | | | | | | | | | | | | | | | Consolidate various cookie checking and generation code to simplify the fast open processing. The main goal is to reduce code duplication in tcp_v4_conn_request() for IPv6 support. Removes two experimental sysctl flags TFO_SERVER_ALWAYS and TFO_SERVER_COOKIE_NOT_CHKD used primarily for developmental debugging purposes. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Jerry Chu <hkchu@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: move fastopen functions to tcp_fastopen.cYuchung Cheng2014-05-131-0/+190
| | | | | | | | | | | | Move common TFO functions that will be used by both v4 and v6 to tcp_fastopen.c. Create a helper tcp_fastopen_queue_check(). Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Daniel Lee <longinus00@gmail.com> Signed-off-by: Jerry Chu <hkchu@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: enable sockets to use MSG_FASTOPEN by defaultYuchung Cheng2013-11-041-1/+1
| | | | | | | | | | | | | Applications have started to use Fast Open (e.g., Chrome browser has such an optional flag) and the feature has gone through several generations of kernels since 3.7 with many real network tests. It's time to enable this flag by default for applications to test more conveniently and extensively. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: switch tcp_fastopen key generation to net_get_random_onceHannes Frederic Sowa2013-10-191-11/+16
| | | | | | | | | | | | | | Changed key initialization of tcp_fastopen cookies to net_get_random_once. If the user sets a custom key net_get_random_once must be called at least once to ensure we don't overwrite the user provided key when the first cookie is generated later on. Cc: Yuchung Cheng <ycheng@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: add server ip to encrypt cookie in fast openYuchung Cheng2013-08-101-7/+6
| | | | | | | | | | | | Encrypt the cookie with both server and client IPv4 addresses, such that multi-homed server will grant different cookies based on both the source and destination IPs. No client change is needed since cookie is opaque to the client. Signed-off-by: Yuchung Cheng <ycheng@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: TCP Fast Open Server - header & support functionsJerry Chu2012-08-311-1/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds all the necessary data structure and support functions to implement TFO server side. It also documents a number of flags for the sysctl_tcp_fastopen knob, and adds a few Linux extension MIBs. In addition, it includes the following: 1. a new TCP_FASTOPEN socket option an application must call to supply a max backlog allowed in order to enable TFO on its listener. 2. A number of key data structures: "fastopen_rsk" in tcp_sock - for a big socket to access its request_sock for retransmission and ack processing purpose. It is non-NULL iff 3WHS not completed. "fastopenq" in request_sock_queue - points to a per Fast Open listener data structure "fastopen_queue" to keep track of qlen (# of outstanding Fast Open requests) and max_qlen, among other things. "listener" in tcp_request_sock - to point to the original listener for book-keeping purpose, i.e., to maintain qlen against max_qlen as part of defense against IP spoofing attack. 3. various data structure and functions, many in tcp_fastopen.c, to support server side Fast Open cookie operations, including /proc/sys/net/ipv4/tcp_fastopen_key to allow manual rekeying. Signed-off-by: H.K. Jerry Chu <hkchu@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net-tcp: Fast Open baseYuchung Cheng2012-07-191-0/+11
This patch impelements the common code for both the client and server. 1. TCP Fast Open option processing. Since Fast Open does not have an option number assigned by IANA yet, it shares the experiment option code 254 by implementing draft-ietf-tcpm-experimental-options with a 16 bits magic number 0xF989. This enables global experiments without clashing the scarce(2) experimental options available for TCP. When the draft status becomes standard (maybe), the client should switch to the new option number assigned while the server supports both numbers for transistion. 2. The new sysctl tcp_fastopen 3. A place holder init function Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 04:34:25 +0000