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path: root/net/core/request_sock.c
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2016-12-29ipv4: Namespaceify tcp_max_syn_backlog knobHaishuang Yan
Different namespace application might require different maximal number of remembered connection requests. Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05tcp: restore fastopen operationsEric Dumazet
I accidentally cleared fastopenq.max_qlen in reqsk_queue_alloc() while max_qlen can be set before listen() is called, using TCP_FASTOPEN socket option for example. Fixes: 0536fcc039a8 ("tcp: prepare fastopen code for upcoming listener changes") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03tcp: remove max_qlen_logEric Dumazet
This control variable was set at first listen(fd, backlog) call, but not updated if application tried to increase or decrease backlog. It made sense at the time listener had a non resizeable hash table. Also rounding to powers of two was not very friendly. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03tcp/dccp: remove struct listen_sockEric Dumazet
It is enough to check listener sk_state, no need for an extra condition. max_qlen_log can be moved into struct request_sock_queue We can remove syn_wait_lock and the alignment it enforced. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03tcp/dccp: shrink struct listen_sockEric Dumazet
We no longer use hash_rnd, nr_table_entries and syn_table[] For a listener with a backlog of 10 millions sockets, this saves 80 MBytes of vmalloced memory. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03tcp/dccp: install syn_recv requests into ehash tableEric Dumazet
In this patch, we insert request sockets into TCP/DCCP regular ehash table (where ESTABLISHED and TIMEWAIT sockets are) instead of using the per listener hash table. ACK packets find SYN_RECV pseudo sockets without having to find and lock the listener. In nominal conditions, this halves pressure on listener lock. Note that this will allow for SO_REUSEPORT refinements, so that we can select a listener using cpu/numa affinities instead of the prior 'consistent hash', since only SYN packets will apply this selection logic. We will shrink listen_sock in the following patch to ease code review. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ying Cai <ycai@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03tcp: move qlen/young out of struct listen_sockEric Dumazet
qlen_inc & young_inc were protected by listener lock, while qlen_dec & young_dec were atomic fields. Everything needs to be atomic for upcoming lockless listener. Also move qlen/young in request_sock_queue as we'll get rid of struct listen_sock eventually. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03tcp: add a spinlock to protect struct request_sock_queueEric Dumazet
struct request_sock_queue fields are currently protected by the listener 'lock' (not a real spinlock) We need to add a private spinlock instead, so that softirq handlers creating children do not have to worry with backlog notion that the listener 'lock' carries. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29tcp: prepare fastopen code for upcoming listener changesEric Dumazet
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>
2015-08-10inet: fix races with reqsk timersEric Dumazet
reqsk_queue_destroy() and reqsk_queue_unlink() should use del_timer_sync() instead of del_timer() before calling reqsk_put(), otherwise we could free a req still used by another cpu. But before doing so, reqsk_queue_destroy() must release syn_wait_lock spinlock or risk a dead lock, as reqsk_timer_handler() might need to take this same spinlock from reqsk_queue_unlink() (called from inet_csk_reqsk_queue_drop()) Fixes: fa76ce7328b2 ("inet: get rid of central tcp/dccp listener timer") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23net: convert syn_wait_lock to a spinlockEric Dumazet
This is a low hanging fruit, as we'll get rid of syn_wait_lock eventually. We hold syn_wait_lock for such small sections, that it makes no sense to use a read/write lock. A spin lock is simply faster. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20inet: get rid of central tcp/dccp listener timerEric Dumazet
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>
2015-03-17tcp: rename struct tcp_request_sock listenerEric Dumazet
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>
2015-03-16inet: add proper refcounting to request sockEric Dumazet
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>
2014-06-25inet: reduce TLB pressure for listenersEric Dumazet
It seems overkill to use vmalloc() for typical listeners with less than 2048 hash buckets. Try kmalloc() and fallback to vmalloc() to reduce TLB pressure. Use kvfree() helper as it is now available. Use ilog2() instead of a loop. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-13net: remove unnecessary return'sstephen hemminger
One of my pet coding style peeves is the practice of adding extra return; at the end of function. Kill several instances of this in network code. I suppose some coccinelle wizardy could do this automatically. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-14tcp: fix a panic on UP machines in reqsk_fastopen_removeEric Dumazet
spin_is_locked() on a non !SMP build is kind of useless. BUG_ON(!spin_is_locked(xx)) is guaranteed to crash. Just remove this check in reqsk_fastopen_remove() as the callers do hold the socket lock. Reported-by: Ketan Kulkarni <ketkulka@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jerry Chu <hkchu@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Dave Taht <dave.taht@gmail.com> Acked-by: H.K. Jerry Chu <hkchu@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-31tcp: TCP Fast Open Server - support TFO listenersJerry Chu
This patch builds on top of the previous patch to add the support for TFO listeners. This includes - 1. allocating, properly initializing, and managing the per listener fastopen_queue structure when TFO is enabled 2. changes to the inet_csk_accept code to support TFO. E.g., the request_sock can no longer be freed upon accept(), not until 3WHS finishes 3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg() if it's a TFO socket 4. properly closing a TFO listener, and a TFO socket before 3WHS finishes 5. supporting TCP_FASTOPEN socket option 6. modifying tcp_check_req() to use to check a TFO socket as well as request_sock 7. supporting TCP's TFO cookie option 8. adding a new SYN-ACK retransmit handler to use the timer directly off the TFO socket rather than the listener socket. Note that TFO server side will not retransmit anything other than SYN-ACK until the 3WHS is completed. The patch also contains an important function "reqsk_fastopen_remove()" to manage the somewhat complex relation between a listener, its request_sock, and the corresponding child socket. See the comment above the function for the detail. 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>
2011-12-06ipv4:correct description for tcp_max_syn_backlogPeter Pan(潘卫平)
Since commit c5ed63d66f24(tcp: fix three tcp sysctls tuning), sysctl_max_syn_backlog is determined by tcp_hashinfo->ehash_mask, and the minimal value is 128, and it will increase in proportion to the memory of machine. The original description for tcp_max_syn_backlog and sysctl_max_syn_backlog are out of date. Changelog: V2: update description for sysctl_max_syn_backlog Signed-off-by: Weiping Pan <panweiping3@gmail.com> Reviewed-by: Shan Wei <shanwei88@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-12-08Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/ath/ath9k/ar9003_eeprom.c net/llc/af_llc.c
2010-12-02tcp: Add timewait recycling bits to ipv6 connect code.David S. Miller
This will also improve handling of ipv6 tcp socket request backlog when syncookies are not enabled. When backlog becomes very deep, last quarter of backlog is limited to validated destinations. Previously only ipv4 implemented this logic, but now ipv6 does too. Now we are only one step away from enabling timewait recycling for ipv6, and that step is simply filling in the implementation of tcp_v6_get_peer() and tcp_v6_tw_get_peer(). Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-21net: allow GFP_HIGHMEM in __vmalloc()Eric Dumazet
We forgot to use __GFP_HIGHMEM in several __vmalloc() calls. In ceph, add the missing flag. In fib_trie.c, xfrm_hash.c and request_sock.c, using vzalloc() is cleaner and allows using HIGHMEM pages as well. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-25net: convert BUG_TRAP to generic WARN_ONIlpo Järvinen
Removes legacy reinvent-the-wheel type thing. The generic machinery integrates much better to automated debugging aids such as kerneloops.org (and others), and is unambiguous due to better naming. Non-intuively BUG_TRAP() is actually equal to WARN_ON() rather than BUG_ON() though some might actually be promoted to BUG_ON() but I left that to future. I could make at least one BUILD_BUG_ON conversion. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET] net/core/request_sock.c: Remove unused exports.Adrian Bunk
This patch removes the following unused EXPORT_SYMBOL's: - reqsk_queue_alloc - __reqsk_queue_destroy - reqsk_queue_destroy Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-15[INET]: Fix potential kfree on vmalloc-ed area of request_sock_queuePavel Emelyanov
The request_sock_queue's listen_opt is either vmalloc-ed or kmalloc-ed depending on the number of table entries. Thus it is expected to be handled properly on free, which is done in the reqsk_queue_destroy(). However the error path in inet_csk_listen_start() calls the lite version of reqsk_queue_destroy, called __reqsk_queue_destroy, which calls the kfree unconditionally. Fix this and move the __reqsk_queue_destroy into a .c file as it looks too big to be inline. As David also noticed, this is an error recovery path only, so no locking is required and the lopt is known to be not NULL. reqsk_queue_yank_listen_sk is also now only used in net/core/request_sock.c so we should move it there too. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-02[NET]: Size listen hash tables using backlog hintEric Dumazet
We currently allocate a fixed size (TCP_SYNQ_HSIZE=512) slots hash table for each LISTEN socket, regardless of various parameters (listen backlog for example) On x86_64, this means order-1 allocations (might fail), even for 'small' sockets, expecting few connections. On the contrary, a huge server wanting a backlog of 50000 is slowed down a bit because of this fixed limit. This patch makes the sizing of listen hash table a dynamic parameter, depending of : - net.core.somaxconn tunable (default is 128) - net.ipv4.tcp_max_syn_backlog tunable (default : 256, 1024 or 128) - backlog value given by user application (2nd parameter of listen()) For large allocations (bigger than PAGE_SIZE), we use vmalloc() instead of kmalloc(). We still limit memory allocation with the two existing tunables (somaxconn & tcp_max_syn_backlog). So for standard setups, this patch actually reduce RAM usage. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-04-09[NET]: More kzalloc conversions.Andrew Morton
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-26[NET]: drop duplicate assignment in request_sockNorbert Kiesel
Just noticed that request_sock.[ch] contain a useless assignment of rskq_accept_head to itself. I assume this is a typo and the 2nd one was supposed to be _tail. However, setting _tail to NULL is not needed, so the patch below just drops the 2nd assignment. Signed-off-By: Norbert Kiesel <nkiesel@tbdnetworks.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-27[REQSK]: Don't reset rskq_defer_accept in reqsk_queue_allocArnaldo Carvalho de Melo
In 295f7324ff8d9ea58b4d3ec93b1aaa1d80e048a9 I moved defer_accept from tcp_sock to request_queue and mistakingly reset it at reqsl_queue_alloc, causing calls to setsockopt(TCP_DEFER_ACCEPT ) to be lost after bind, the fix is to remove the zeroing of rskq_defer_accept from reqsl_queue_alloc. Thanks to Alexandra N. Kossovsky <Alexandra.Kossovsky@oktetlabs.ru> for reporting and testing the suggested fix. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[ICSK]: Introduce reqsk_queue_prune from code in tcp_synack_timerArnaldo Carvalho de Melo
With this we're very close to getting all of the current TCP refactorings in my dccp-2.6 tree merged, next changeset will export some functions needed by the current DCCP code and then dccp-2.6.git will be born! Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[IPV4]: possible cleanupsAdrian Bunk
This patch contains the following possible cleanups: - make needlessly global code static - #if 0 the following unused global function: - xfrm4_state.c: xfrm4_state_fini - remove the following unneeded EXPORT_SYMBOL's: - ip_output.c: ip_finish_output - ip_output.c: sysctl_ip_default_ttl - fib_frontend.c: ip_dev_find - inetpeer.c: inet_peer_idlock - ip_options.c: ip_options_compile - ip_options.c: ip_options_undo - net/core/request_sock.c: sysctl_max_syn_backlog Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[REQSK]: Move the syn_table destroy from tcp_listen_stop to reqsk_queue_destroyArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[NET]: Move sysctl_max_syn_backlog into request_sock.cDavid S. Miller
This fixes the CONFIG_INET=n build failure noticed by Andrew Morton. Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[NET] rename struct tcp_listen_opt to struct listen_sockArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18[NET] Generalise tcp_listen_optArnaldo Carvalho de Melo
This chunks out the accept_queue and tcp_listen_opt code and moves them to net/core/request_sock.c and include/net/request_sock.h, to make it useful for other transport protocols, DCCP being the first one to use it. Next patches will rename tcp_listen_opt to accept_sock and remove the inline tcp functions that just call a reqsk_queue_ function. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>