summaryrefslogtreecommitdiffstats
path: root/include/net/tcp.h
Commit message (Collapse)AuthorAgeFilesLines
* tcp: Revert per-route SACK/DSACK/TIMESTAMP changes.David S. Miller2009-12-151-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It creates a regression, triggering badness for SYN_RECV sockets, for example: [19148.022102] Badness at net/ipv4/inet_connection_sock.c:293 [19148.022570] NIP: c02a0914 LR: c02a0904 CTR: 00000000 [19148.023035] REGS: eeecbd30 TRAP: 0700 Not tainted (2.6.32) [19148.023496] MSR: 00029032 <EE,ME,CE,IR,DR> CR: 24002442 XER: 00000000 [19148.024012] TASK = eee9a820[1756] 'privoxy' THREAD: eeeca000 This is likely caused by the change in the 'estab' parameter passed to tcp_parse_options() when invoked by the functions in net/ipv4/tcp_minisocks.c But even if that is fixed, the ->conn_request() changes made in this patch series is fundamentally wrong. They try to use the listening socket's 'dst' to probe the route settings. The listening socket doesn't even have a route, and you can't get the right route (the child request one) until much later after we setup all of the state, and it must be done by hand. This stuff really isn't ready, so the best thing to do is a full revert. This reverts the following commits: f55017a93f1a74d50244b1254b9a2bd7ac9bbf7d 022c3f7d82f0f1c68018696f2f027b87b9bb45c2 1aba721eba1d84a2defce45b950272cee1e6c72a cda42ebd67ee5fdf09d7057b5a4584d36fe8a335 345cda2fd695534be5a4494f1b59da9daed33663 dc343475ed062e13fc260acccaab91d7d80fd5b2 05eaade2782fb0c90d3034fd7a7d5a16266182bb 6a2a2d6bf8581216e08be15fcb563cfd6c430e1e Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller2009-12-111-1/+0
|\ | | | | | | | | Conflicts: include/net/tcp.h
| * Merge branch 'for-linus' of ↵Linus Torvalds2009-12-091-1/+1
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits) tree-wide: fix misspelling of "definition" in comments reiserfs: fix misspelling of "journaled" doc: Fix a typo in slub.txt. inotify: remove superfluous return code check hdlc: spelling fix in find_pvc() comment doc: fix regulator docs cut-and-pasteism mtd: Fix comment in Kconfig doc: Fix IRQ chip docs tree-wide: fix assorted typos all over the place drivers/ata/libata-sff.c: comment spelling fixes fix typos/grammos in Documentation/edac.txt sysctl: add missing comments fs/debugfs/inode.c: fix comment typos sgivwfb: Make use of ARRAY_SIZE. sky2: fix sky2_link_down copy/paste comment error tree-wide: fix typos "couter" -> "counter" tree-wide: fix typos "offest" -> "offset" fix kerneldoc for set_irq_msi() spidev: fix double "of of" in comment comment typo fix: sybsystem -> subsystem ...
| | * tree-wide: fix assorted typos all over the placeAndré Goddard Rosa2009-12-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | tcp: Stalling connections: Move timeout calculation routineDamian Lukowski2009-12-081-28/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves retransmits_timed_out() from include/net/tcp.h to tcp_timer.c, where it is used. Reported-by: Frederic Leroy <fredo@starox.org> Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | tcp: Stalling connections: Fix timeout calculation routineDamian Lukowski2009-12-081-2/+8
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a problem in the TCP connection timeout calculation. Currently, timeout decisions are made on the basis of the current tcp_time_stamp and retrans_stamp, which is usually set at the first retransmission. However, if the retransmission fails in tcp_retransmit_skb(), retrans_stamp is not updated and remains zero. This leads to wrong decisions in retransmits_timed_out() if tcp_time_stamp is larger than the specified timeout, which is very likely. In this case, the TCP connection dies after the first attempted (and unsuccessful) retransmission. With this patch, tcp_skb_cb->when is used instead, when retrans_stamp is not available. This bug has been introduced together with retransmits_timed_out() in 2.6.32, as the number of retransmissions has been used for timeout decisions before. The corresponding commit was 6fa12c85031485dff38ce550c24f10da23b0adaa (Revert Backoff [v3]: Calculate TCP's connection close threshold as a time value.). Thanks to Ilpo Järvinen for code suggestions and Frederic Leroy for testing. Reported-by: Frederic Leroy <fredo@starox.org> Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: clear hints to avoid a stale one (nfs only affected?)Ilpo Järvinen2009-12-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Eric Dumazet mentioned in a context of another problem: "Well, it seems NFS reuses its socket, so maybe we miss some cleaning as spotted in this old patch" I've not check under which conditions that actually happens but if true, we need to make sure we don't accidently leave stale hints behind when the write queue had to be purged (whether reusing with NFS can actually happen if purging took place is something I'm not sure of). ...At least it compiles. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* | TCPCT part 1g: Responder Cookie => InitiatorWilliam Allen Simpson2009-12-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Parse incoming TCP_COOKIE option(s). Calculate <SYN,ACK> TCP_COOKIE option. Send optional <SYN,ACK> data. This is a significantly revised implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 Requires: TCPCT part 1a: add request_values parameter for sending SYNACK TCPCT part 1b: generate Responder Cookie secret TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS TCPCT part 1d: define TCP cookie option, extend existing struct's TCPCT part 1e: implement socket option TCP_COOKIE_TRANSACTIONS TCPCT part 1f: Initiator Cookie => Responder Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
* | TCPCT part 1d: define TCP cookie option, extend existing struct'sWilliam Allen Simpson2009-12-021-0/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Data structures are carefully composed to require minimal additions. For example, the struct tcp_options_received cookie_plus variable fits between existing 16-bit and 8-bit variables, requiring no additional space (taking alignment into consideration). There are no additions to tcp_request_sock, and only 1 pointer in tcp_sock. This is a significantly revised implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 The principle difference is using a TCP option to carry the cookie nonce, instead of a user configured offset in the data. This is more flexible and less subject to user configuration error. Such a cookie option has been suggested for many years, and is also useful without SYN data, allowing several related concepts to use the same extension option. "Re: SYN floods (was: does history repeat itself?)", September 9, 1996. http://www.merit.net/mail.archives/nanog/1996-09/msg00235.html "Re: what a new TCP header might look like", May 12, 1998. ftp://ftp.isi.edu/end2end/end2end-interest-1998.mail These functions will also be used in subsequent patches that implement additional features. Requires: TCPCT part 1a: add request_values parameter for sending SYNACK TCPCT part 1b: generate Responder Cookie secret TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONS Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
* | TCPCT part 1c: sysctl_tcp_cookie_size, socket option TCP_COOKIE_TRANSACTIONSWilliam Allen Simpson2009-12-021-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define sysctl (tcp_cookie_size) to turn on and off the cookie option default globally, instead of a compiled configuration option. Define per socket option (TCP_COOKIE_TRANSACTIONS) for setting constant data values, retrieving variable cookie values, and other facilities. Move inline tcp_clear_options() unchanged from net/tcp.h to linux/tcp.h, near its corresponding struct tcp_options_received (prior to changes). This is a straightforward re-implementation of an earlier (year-old) patch that no longer applies cleanly, with permission of the original author (Adam Langley): http://thread.gmane.org/gmane.linux.network/102586 These functions will also be used in subsequent patches that implement additional features. Requires: net: TCP_MSS_DEFAULT, TCP_MSS_DESIRED Signed-off-by: William.Allen.Simpson@gmail.com Signed-off-by: David S. Miller <davem@davemloft.net>
* | TCPCT part 1b: generate Responder Cookie secretWilliam Allen Simpson2009-12-021-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define (missing) hash message size for SHA1. Define hashing size constants specific to TCP cookies. Add new function: tcp_cookie_generator(). Maintain global secret values for tcp_cookie_generator(). This is a significantly revised implementation of earlier (15-year-old) Photuris [RFC-2522] code for the KA9Q cooperative multitasking platform. Linux RCU technique appears to be well-suited to this application, though neither of the circular queue items are freed. These functions will also be used in subsequent patches that implement additional features. Signed-off-by: William.Allen.Simpson@gmail.com Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | TCPCT part 1a: add request_values parameter for sending SYNACKWilliam Allen Simpson2009-12-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add optional function parameters associated with sending SYNACK. These parameters are not needed after sending SYNACK, and are not used for retransmission. Avoids extending struct tcp_request_sock, and avoids allocating kernel memory. Also affects DCCP as it uses common struct request_sock_ops, but this parameter is currently reserved for future use. Signed-off-by: William.Allen.Simpson@gmail.com Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: TCP_MSS_DEFAULT, TCP_MSS_DESIREDWilliam Allen Simpson2009-11-131-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Define two symbols needed in both kernel and user space. Remove old (somewhat incorrect) kernel variant that wasn't used in most cases. Default should apply to both RMSS and SMSS (RFC2581). Replace numeric constants with defined symbols. Stand-alone patch, originally developed for TCPCT. Signed-off-by: William.Allen.Simpson@gmail.com Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: cleanup include/netEric Dumazet2009-11-041-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This cleanup patch puts struct/union/enum opening braces, in first line to ease grep games. struct something { becomes : struct something { Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Allow tcp_parse_options to consult dst entryGilad Ben-Yossef2009-10-291-1/+2
|/ | | | | | | | | | We need tcp_parse_options to be aware of dst_entry to take into account per dst_entry TCP options settings Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com> Sigend-off-by: Ori Finkelman <ori@comsleep.com> Sigend-off-by: Yony Amit <yony@comsleep.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Make setsockopt() optlen be unsigned.David S. Miller2009-09-301-2/+2
| | | | | | | | | | | | This provides safety against negative optlen at the type level instead of depending upon (sometimes non-trivial) checks against this sprinkled all over the the place, in each and every implementation. Based upon work done by Arjan van de Ven and feedback from Linus Torvalds. Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: fix ssthresh u16 leftoverIlpo Järvinen2009-09-151-0/+7
| | | | | | | | | | | | | | It was once upon time so that snd_sthresh was a 16-bit quantity. ...That has not been true for long period of time. I run across some ancient compares which still seem to trust such legacy. Put all that magic into a single place, I hopefully found all of them. Compile tested, though linking of allyesconfig is ridiculous nowadays it seems. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: replace hard coded GFP_KERNEL with sk_allocationWu Fengguang2009-09-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This fixed a lockdep warning which appeared when doing stress memory tests over NFS: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. page reclaim => nfs_writepage => tcp_sendmsg => lock sk_lock mount_root => nfs_root_data => tcp_close => lock sk_lock => tcp_send_fin => alloc_skb_fclone => page reclaim David raised a concern that if the allocation fails in tcp_send_fin(), and it's GFP_ATOMIC, we are going to yield() (which sleeps) and loop endlessly waiting for the allocation to succeed. But fact is, the original GFP_KERNEL also sleeps. GFP_ATOMIC+yield() looks weird, but it is no worse the implicit sleep inside GFP_KERNEL. Both could loop endlessly under memory pressure. CC: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> CC: David S. Miller <davem@davemloft.net> CC: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* RTO connection timeout: coding style fixes and commentsDamian Lukowski2009-09-011-7/+12
| | | | | | | | | | | | This patch affects the retransmits_timed_out() function. Changes: 1) Variables have more meaningful names 2) retransmits_timed_out() has an introductionary comment. 3) Small coding style changes. Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* Revert Backoff [v3]: Calculate TCP's connection close threshold as a time value.Damian Lukowski2009-09-011-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RFC 1122 specifies two threshold values R1 and R2 for connection timeouts, which may represent a number of allowed retransmissions or a timeout value. Currently linux uses sysctl_tcp_retries{1,2} to specify the thresholds in number of allowed retransmissions. For any desired threshold R2 (by means of time) one can specify tcp_retries2 (by means of number of retransmissions) such that TCP will not time out earlier than R2. This is the case, because the RTO schedule follows a fixed pattern, namely exponential backoff. However, the RTO behaviour is not predictable any more if RTO backoffs can be reverted, as it is the case in the draft "Make TCP more Robust to Long Connectivity Disruptions" (http://tools.ietf.org/html/draft-zimmermann-tcp-lcd). In the worst case TCP would time out a connection after 3.2 seconds, if the initial RTO equaled MIN_RTO and each backoff has been reverted. This patch introduces a function retransmits_timed_out(N), which calculates the timeout of a TCP connection, assuming an initial RTO of MIN_RTO and N unsuccessful, exponentially backed-off retransmissions. Whenever timeout decisions are made by comparing the retransmission counter to some value N, this function can be used, instead. The meaning of tcp_retries2 will be changed, as many more RTO retransmissions can occur than the value indicates. However, it yields a timeout which is similar to the one of an unpatched, exponentially backing off TCP in the same scenario. As no application could rely on an RTO greater than MIN_RTO, there should be no risk of a regression. Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* Revert Backoff [v3]: Revert RTO on ICMP destination unreachableDamian Lukowski2009-09-011-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | Here, an ICMP host/network unreachable message, whose payload fits to TCP's SND.UNA, is taken as an indication that the RTO retransmission has not been lost due to congestion, but because of a route failure somewhere along the path. With true congestion, a router won't trigger such a message and the patched TCP will operate as standard TCP. This patch reverts one RTO backoff, if an ICMP host/network unreachable message, whose payload fits to TCP's SND.UNA, arrives. Based on the new RTO, the retransmission timer is reset to reflect the remaining time, or - if the revert clocked out the timer - a retransmission is sent out immediately. Backoffs are only reverted, if TCP is in RTO loss recovery, i.e. if there have been retransmissions and reversible backoffs, already. Changes from v2: 1) Renaming of skb in tcp_v4_err() moved to another patch. 2) Reintroduced tcp_bound_rto() and __tcp_set_rto(). 3) Fixed code comments. Signed-off-by: Damian Lukowski <damian@tvk.rwth-aachen.de> Acked-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: keepalive cleanupsEric Dumazet2009-08-281-0/+5
| | | | | | | | Introduce keepalive_probes(tp) helper, and use it, like keepalive_time_when(tp) and keepalive_intvl_when(tp) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Fix MD5 signature checking on IPv4 mapped socketsJohn Dykstra2009-07-201-0/+5
| | | | | | | | | | | Fix MD5 signature checking so that an IPv4 active open to an IPv6 socket can succeed. In particular, use the correct address family's signature generation function for the SYN/ACK. Reported-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: John Dykstra <john.dykstra1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2009-05-081-1/+13
|\ | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: include/net/tcp.h
| * tcp: Fix tcp_prequeue() to get correct rto_min valueSatoru SATOH2009-05-041-1/+13
| | | | | | | | | | | | | | | | | | tcp_prequeue() refers to the constant value (TCP_RTO_MIN) regardless of the actual value might be tuned. The following patches fix this and make tcp_prequeue get the actual value returns from tcp_rto_min(). Signed-off-by: Satoru SATOH <satoru.satoh@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: tcp_prequeue() can use keyed wakeupsEric Dumazet2009-05-071-1/+2
| | | | | | | | | | | | | | | | We can avoid waking up tasks not interested in receive notifications, using wake_up_interruptible_poll() instead of wake_up_interruptible() Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: tcp_prequeue() cleanupEric Dumazet2009-05-071-22/+23
| | | | | | | | | | | | | | | | Small cleanup patch to reduce line lengths, before a change in tcp_prequeue(). Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | syncookies: remove last_synq_overflow from struct tcp_sockFlorian Westphal2009-04-201-0/+13
|/ | | | | | | | | | | | | | | last_synq_overflow eats 4 or 8 bytes in struct tcp_sock, even though it is only used when a listening sockets syn queue is full. We can (ab)use rx_opt.ts_recent_stamp to store the same information; it is not used otherwise as long as a socket is in listen state. Move linger2 around to avoid splitting struct mtu_probe across cacheline boundary on 32 bit arches. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: add helper for counter tweaking due mid-wq changeIlpo Järvinen2009-04-021-15/+0
| | | | | | | | | We need full-scale adjustment to fix a TCP miscount in the next patch, so just move it into a helper and call for that from the other places. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: simplify tcp_current_mssIlpo Järvinen2009-03-151-2/+11
| | | | | | | | | | | | | | | | | | | | There's very little need for most of the callsites to get tp->xmit_goal_size updated. That will cost us divide as is, so slice the function in two. Also, the only users of the tp->xmit_goal_size are directly behind tcp_current_mss(), so there's no need to store that variable into tcp_sock at all! The drop of xmit_goal_size currently leaves 16-bit hole and some reorganization would again be necessary to change that (but I'm aiming to fill that hole with u16 xmit_goal_size_segs to cache the results of the remaining divide to get that tso on regression). Bring xmit_goal_size parts into tcp.c Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: consolidate paws checkIlpo Järvinen2009-03-151-4/+14
| | | | | | | | | | | | | | | | | | | | Wow, it was quite tricky to merge that stream of negations but I think I finally got it right: check & replace_ts_recent: (s32)(rcv_tsval - ts_recent) >= 0 => 0 (s32)(ts_recent - rcv_tsval) <= 0 => 0 discard: (s32)(ts_recent - rcv_tsval) > TCP_PAWS_WINDOW => 1 (s32)(ts_recent - rcv_tsval) <= TCP_PAWS_WINDOW => 0 I toggled the return values of tcp_paws_check around since the old encoding added yet-another negation making tracking of truth-values really complicated. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: tcp_init_wl / tcp_update_wl argument cleanupHantzis Fotis2009-03-021-2/+2
| | | | | | | | | | | The above functions from include/net/tcp.h have been defined with an argument that they never use. The argument is 'u32 ack' which is never used inside the function body, and thus it can be removed. The rest of the patch involves the necessary changes to the function callers of the above two functions. Signed-off-by: Hantzis Fotis <xantzis@ceid.upatras.gr> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: kill eff_sacks "cache", the sole user can calculate itselfIlpo Järvinen2009-03-021-1/+0
| | | | | | | | Also fixes insignificant bug that would cause sending of stale SACK block (would occur in some corner cases). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: add helper for AI algorithmIlpo Järvinen2009-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | It seems that implementation in yeah was inconsistent to what other did as it would increase cwnd one ack earlier than the others do. Size benefits: bictcp_cong_avoid | -36 tcp_cong_avoid_ai | +52 bictcp_cong_avoid | -34 tcp_scalable_cong_avoid | -36 tcp_veno_cong_avoid | -12 tcp_yeah_cong_avoid | -38 = -104 bytes total Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Add GRO supportHerbert Xu2008-12-151-0/+6
| | | | | | | | | | | This patch adds the TCP-specific portion of GRO. The criterion for merging is extremely strict (the TCP header must match exactly apart from the checksum) so as to allow refragmentation. Otherwise this is pretty much identical to LRO, except that we support the merging of ECN packets. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Use a percpu_counter for orphan_countEric Dumazet2008-11-251-1/+1
| | | | | | | | | Instead of using one atomic_t per protocol, use a percpu_counter for "orphan_count", to reduce cache line contention on heavy duty network servers. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Use a percpu_counter for sockets_allocatedEric Dumazet2008-11-251-1/+1
| | | | | | | | | | | | | Instead of using one atomic_t per protocol, use a percpu_counter for "sockets_allocated", to reduce cache line contention on heavy duty network servers. Note : We revert commit (248969ae31e1b3276fc4399d67ce29a5d81e6fd9 net: af_unix can make unix_nr_socks visbile in /proc), since it is not anymore used after sock_prot_inuse_add() addition Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: tcp_limit_reno_sacked can become staticIlpo Järvinen2008-11-251-2/+0
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Try to restore large SKBs while SACK processingIlpo Järvinen2008-11-241-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During SACK processing, most of the benefits of TSO are eaten by the SACK blocks that one-by-one fragment SKBs to MSS sized chunks. Then we're in problems when cleanup work for them has to be done when a large cumulative ACK comes. Try to return back to pre-split state already while more and more SACK info gets discovered by combining newly discovered SACK areas with the previous skb if that's SACKed as well. This approach has a number of benefits: 1) The processing overhead is spread more equally over the RTT 2) Write queue has less skbs to process (affect everything which has to walk in the queue past the sacked areas) 3) Write queue is consistent whole the time, so no other parts of TCP has to be aware of this (this was not the case with some other approach that was, well, quite intrusive all around). 4) Clean_rtx_queue can release most of the pages using single put_page instead of previous PAGE_SIZE/mss+1 calls In case a hole is fully filled by the new SACK block, we attempt to combine the next skb too which allows construction of skbs that are even larger than what tso split them to and it handles hole per on every nth patterns that often occur during slow start overshoot pretty nicely. Though this to be really useful also a retransmission would have to get lost since cumulative ACKs advance one hole at a time in the most typical case. TODO: handle upwards only merging. That should be rather easy when segment is fully sacked but I'm leaving that as future work item (it won't make very large difference anyway since this current approach already covers quite a lot of normal cases). I was earlier thinking of some sophisticated way of tracking timestamps of the first and the last segment but later on realized that it won't be that necessary at all to store the timestamp of the last segment. The cases that can occur are basically either: 1) ambiguous => no sensible measurement can be taken anyway 2) non-ambiguous is due to reordering => having the timestamp of the last segment there is just skewing things more off than does some good since the ack got triggered by one of the holes (besides some substle issues that would make determining right hole/skb even harder problem). Anyway, it has nothing to do with this change then. I choose to route some abnormal looking cases with goto noop, some could be handled differently (eg., by stopping the walking at that skb but again). In general, they either shouldn't happen at all or are rare enough to make no difference in practice. In theory this change (as whole) could cause some macroscale regression (global) because of cache misses that are taken over the round-trip time but it gets very likely better because of much less (local) cache misses per other write queue walkers and the big recovery clearing cumulative ack. Worth to note that these benefits would be very easy to get also without TSO/GSO being on as long as the data is in pages so that we can merge them. Currently I won't let that happen because DSACK splitting at fragment that would mess up pcounts due to sk_can_gso in tcp_set_skb_tso_segs. Once DSACKs fragments gets avoided, we have some conditions that can be made less strict. TODO: I will probably have to convert the excessive pointer passing to struct sacktag_state... :-) My testing revealed that considerable amount of skbs couldn't be shifted because they were cloned (most likely still awaiting tx reclaim)... [The rest is considering future work instead since I got repeatably EFAULT to tcpdump's recvfrom when I added pskb_expand_head to deal with clones, so I separated that into another, later patch] ...To counter that, I gave up on the fifth advantage: 5) When growing previous SACK block, less allocs for new skbs are done, basically a new alloc is needed only when new hole is detected and when the previous skb runs out of frags space ...which now only happens of if reclaim is fast enough to dispose the clone before the SACK block comes in (the window is RTT long), otherwise we'll have to alloc some. With clones being handled I got these numbers (will be somewhat worse without that), taken with fine-grained mibs: TCPSackShifted 398 TCPSackMerged 877 TCPSackShiftFallback 320 TCPSACKCOLLAPSEFALLBACKGSO 0 TCPSACKCOLLAPSEFALLBACKSKBBITS 0 TCPSACKCOLLAPSEFALLBACKSKBDATA 0 TCPSACKCOLLAPSEFALLBACKBELOW 0 TCPSACKCOLLAPSEFALLBACKFIRST 1 TCPSACKCOLLAPSEFALLBACKPREVBITS 318 TCPSACKCOLLAPSEFALLBACKMSS 1 TCPSACKCOLLAPSEFALLBACKNOHEAD 0 TCPSACKCOLLAPSEFALLBACKSHIFT 0 TCPSACKCOLLAPSENOOPSEQ 0 TCPSACKCOLLAPSENOOPSMALLPCOUNT 0 TCPSACKCOLLAPSENOOPSMALLLEN 0 TCPSACKCOLLAPSEHOLE 12 Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: move tcp_simple_retransmit to tcp_inputIlpo Järvinen2008-11-241-2/+0
| | | | | Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: remove an unnecessary field in struct tcp_skb_cbPetr Tesarik2008-11-131-1/+0
| | | | | | | The urg_ptr field is not used anywhere and is merely confusing. Signed-off-by: Petr Tesarik <ptesarik@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: wrap sk->sk_backlog_rcv()Peter Zijlstra2008-10-071-1/+1
| | | | | | | | Wrap calling sk->sk_backlog_rcv() in a function. This will allow extending the generic sk_backlog_rcv behaviour. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Port redirection support for TCPKOVACS Krisztian2008-10-011-0/+1
| | | | | | | | | | | | | | | Current TCP code relies on the local port of the listening socket being the same as the destination address of the incoming connection. Port redirection used by many transparent proxying techniques obviously breaks this, so we have to store the original destination port address. This patch extends struct inet_request_sock and stores the incoming destination port value there. It also modifies the handshake code to use that value as the source port when sending reply packets. Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Use SKB queue handling interfaces instead of by-hand versions.David S. Miller2008-09-231-25/+15
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Use skb_queue_is_last() instead of by-hand version.David S. Miller2008-09-231-3/+3
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Remove __skb_insert() calls outside of skbuff internals.David S. Miller2008-09-211-2/+2
| | | | | | | This minor cleanup simplifies later changes which will convert struct sk_buff and friends over to using struct list_head. Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: don't clear retransmit_skb_hint when not necessaryIlpo Järvinen2008-09-201-1/+6
| | | | | | | | | Most importantly avoid doing it with cumulative ACK. Not clearing means that we no longer need n^2 processing in resolution of each fast recovery. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: reorganize retransmit code loopsIlpo Järvinen2008-09-201-1/+0
| | | | | | | | | Both loops are quite similar, so they can be combined with little effort. As a result, forward_skb_hint becomes obsolete as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: convert retransmit_cnt_hint to seqnoIlpo Järvinen2008-09-201-0/+2
| | | | | | | | | | | | | | | | | | | | | Main benefit in this is that we can then freely point the retransmit_skb_hint to anywhere we want to because there's no longer need to know what would be the count changes involve, and since this is really used only as a terminator, unnecessary work is one time walk at most, and if some retransmissions are necessary after that point later on, the walk is not full waste of time anyway. Since retransmit_high must be kept valid, all lost markers must ensure that. Now I also have learned how those "holes" in the rexmittable skbs can appear, mtu probe does them. So I removed the misleading comment as well. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
* tcp: Partial hint clearing has again become meaninglessIlpo Järvinen2008-09-201-6/+1
| | | | | | | | | Ie., the difference between partial and all clearing doesn't exists anymore since the SACK optimizations got dropped by an sacktag rewrite. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
OpenPOWER on IntegriCloud