2939 строки
76 KiB
C
2939 строки
76 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Implementation of the Transmission Control Protocol(TCP).
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*
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* Authors: Ross Biro
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* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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* Mark Evans, <evansmp@uhura.aston.ac.uk>
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* Corey Minyard <wf-rch!minyard@relay.EU.net>
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* Florian La Roche, <flla@stud.uni-sb.de>
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* Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
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* Linus Torvalds, <torvalds@cs.helsinki.fi>
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* Alan Cox, <gw4pts@gw4pts.ampr.org>
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* Matthew Dillon, <dillon@apollo.west.oic.com>
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* Arnt Gulbrandsen, <agulbra@nvg.unit.no>
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* Jorge Cwik, <jorge@laser.satlink.net>
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*
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* Fixes:
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* Alan Cox : Numerous verify_area() calls
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* Alan Cox : Set the ACK bit on a reset
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* Alan Cox : Stopped it crashing if it closed while
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* sk->inuse=1 and was trying to connect
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* (tcp_err()).
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* Alan Cox : All icmp error handling was broken
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* pointers passed where wrong and the
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* socket was looked up backwards. Nobody
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* tested any icmp error code obviously.
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* Alan Cox : tcp_err() now handled properly. It
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* wakes people on errors. poll
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* behaves and the icmp error race
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* has gone by moving it into sock.c
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* Alan Cox : tcp_send_reset() fixed to work for
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* everything not just packets for
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* unknown sockets.
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* Alan Cox : tcp option processing.
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* Alan Cox : Reset tweaked (still not 100%) [Had
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* syn rule wrong]
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* Herp Rosmanith : More reset fixes
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* Alan Cox : No longer acks invalid rst frames.
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* Acking any kind of RST is right out.
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* Alan Cox : Sets an ignore me flag on an rst
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* receive otherwise odd bits of prattle
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* escape still
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* Alan Cox : Fixed another acking RST frame bug.
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* Should stop LAN workplace lockups.
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* Alan Cox : Some tidyups using the new skb list
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* facilities
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* Alan Cox : sk->keepopen now seems to work
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* Alan Cox : Pulls options out correctly on accepts
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* Alan Cox : Fixed assorted sk->rqueue->next errors
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* Alan Cox : PSH doesn't end a TCP read. Switched a
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* bit to skb ops.
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* Alan Cox : Tidied tcp_data to avoid a potential
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* nasty.
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* Alan Cox : Added some better commenting, as the
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* tcp is hard to follow
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* Alan Cox : Removed incorrect check for 20 * psh
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* Michael O'Reilly : ack < copied bug fix.
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* Johannes Stille : Misc tcp fixes (not all in yet).
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* Alan Cox : FIN with no memory -> CRASH
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* Alan Cox : Added socket option proto entries.
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* Also added awareness of them to accept.
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* Alan Cox : Added TCP options (SOL_TCP)
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* Alan Cox : Switched wakeup calls to callbacks,
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* so the kernel can layer network
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* sockets.
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* Alan Cox : Use ip_tos/ip_ttl settings.
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* Alan Cox : Handle FIN (more) properly (we hope).
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* Alan Cox : RST frames sent on unsynchronised
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* state ack error.
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* Alan Cox : Put in missing check for SYN bit.
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* Alan Cox : Added tcp_select_window() aka NET2E
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* window non shrink trick.
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* Alan Cox : Added a couple of small NET2E timer
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* fixes
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* Charles Hedrick : TCP fixes
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* Toomas Tamm : TCP window fixes
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* Alan Cox : Small URG fix to rlogin ^C ack fight
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* Charles Hedrick : Rewrote most of it to actually work
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* Linus : Rewrote tcp_read() and URG handling
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* completely
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* Gerhard Koerting: Fixed some missing timer handling
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* Matthew Dillon : Reworked TCP machine states as per RFC
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* Gerhard Koerting: PC/TCP workarounds
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* Adam Caldwell : Assorted timer/timing errors
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* Matthew Dillon : Fixed another RST bug
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* Alan Cox : Move to kernel side addressing changes.
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* Alan Cox : Beginning work on TCP fastpathing
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* (not yet usable)
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* Arnt Gulbrandsen: Turbocharged tcp_check() routine.
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* Alan Cox : TCP fast path debugging
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* Alan Cox : Window clamping
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* Michael Riepe : Bug in tcp_check()
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* Matt Dillon : More TCP improvements and RST bug fixes
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* Matt Dillon : Yet more small nasties remove from the
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* TCP code (Be very nice to this man if
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* tcp finally works 100%) 8)
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* Alan Cox : BSD accept semantics.
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* Alan Cox : Reset on closedown bug.
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* Peter De Schrijver : ENOTCONN check missing in tcp_sendto().
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* Michael Pall : Handle poll() after URG properly in
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* all cases.
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* Michael Pall : Undo the last fix in tcp_read_urg()
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* (multi URG PUSH broke rlogin).
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* Michael Pall : Fix the multi URG PUSH problem in
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* tcp_readable(), poll() after URG
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* works now.
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* Michael Pall : recv(...,MSG_OOB) never blocks in the
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* BSD api.
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* Alan Cox : Changed the semantics of sk->socket to
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* fix a race and a signal problem with
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* accept() and async I/O.
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* Alan Cox : Relaxed the rules on tcp_sendto().
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* Yury Shevchuk : Really fixed accept() blocking problem.
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* Craig I. Hagan : Allow for BSD compatible TIME_WAIT for
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* clients/servers which listen in on
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* fixed ports.
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* Alan Cox : Cleaned the above up and shrank it to
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* a sensible code size.
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* Alan Cox : Self connect lockup fix.
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* Alan Cox : No connect to multicast.
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* Ross Biro : Close unaccepted children on master
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* socket close.
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* Alan Cox : Reset tracing code.
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* Alan Cox : Spurious resets on shutdown.
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* Alan Cox : Giant 15 minute/60 second timer error
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* Alan Cox : Small whoops in polling before an
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* accept.
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* Alan Cox : Kept the state trace facility since
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* it's handy for debugging.
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* Alan Cox : More reset handler fixes.
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* Alan Cox : Started rewriting the code based on
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* the RFC's for other useful protocol
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* references see: Comer, KA9Q NOS, and
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* for a reference on the difference
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* between specifications and how BSD
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* works see the 4.4lite source.
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* A.N.Kuznetsov : Don't time wait on completion of tidy
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* close.
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* Linus Torvalds : Fin/Shutdown & copied_seq changes.
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* Linus Torvalds : Fixed BSD port reuse to work first syn
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* Alan Cox : Reimplemented timers as per the RFC
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* and using multiple timers for sanity.
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* Alan Cox : Small bug fixes, and a lot of new
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* comments.
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* Alan Cox : Fixed dual reader crash by locking
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* the buffers (much like datagram.c)
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* Alan Cox : Fixed stuck sockets in probe. A probe
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* now gets fed up of retrying without
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* (even a no space) answer.
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* Alan Cox : Extracted closing code better
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* Alan Cox : Fixed the closing state machine to
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* resemble the RFC.
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* Alan Cox : More 'per spec' fixes.
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* Jorge Cwik : Even faster checksumming.
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* Alan Cox : tcp_data() doesn't ack illegal PSH
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* only frames. At least one pc tcp stack
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* generates them.
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* Alan Cox : Cache last socket.
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* Alan Cox : Per route irtt.
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* Matt Day : poll()->select() match BSD precisely on error
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* Alan Cox : New buffers
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* Marc Tamsky : Various sk->prot->retransmits and
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* sk->retransmits misupdating fixed.
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* Fixed tcp_write_timeout: stuck close,
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* and TCP syn retries gets used now.
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* Mark Yarvis : In tcp_read_wakeup(), don't send an
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* ack if state is TCP_CLOSED.
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* Alan Cox : Look up device on a retransmit - routes may
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* change. Doesn't yet cope with MSS shrink right
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* but it's a start!
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* Marc Tamsky : Closing in closing fixes.
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* Mike Shaver : RFC1122 verifications.
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* Alan Cox : rcv_saddr errors.
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* Alan Cox : Block double connect().
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* Alan Cox : Small hooks for enSKIP.
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* Alexey Kuznetsov: Path MTU discovery.
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* Alan Cox : Support soft errors.
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* Alan Cox : Fix MTU discovery pathological case
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* when the remote claims no mtu!
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* Marc Tamsky : TCP_CLOSE fix.
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* Colin (G3TNE) : Send a reset on syn ack replies in
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* window but wrong (fixes NT lpd problems)
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* Pedro Roque : Better TCP window handling, delayed ack.
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* Joerg Reuter : No modification of locked buffers in
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* tcp_do_retransmit()
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* Eric Schenk : Changed receiver side silly window
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* avoidance algorithm to BSD style
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* algorithm. This doubles throughput
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* against machines running Solaris,
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* and seems to result in general
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* improvement.
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* Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD
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* Willy Konynenberg : Transparent proxying support.
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* Mike McLagan : Routing by source
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* Keith Owens : Do proper merging with partial SKB's in
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* tcp_do_sendmsg to avoid burstiness.
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* Eric Schenk : Fix fast close down bug with
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* shutdown() followed by close().
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* Andi Kleen : Make poll agree with SIGIO
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* Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and
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* lingertime == 0 (RFC 793 ABORT Call)
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* Hirokazu Takahashi : Use copy_from_user() instead of
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* csum_and_copy_from_user() if possible.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or(at your option) any later version.
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*
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* Description of States:
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*
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* TCP_SYN_SENT sent a connection request, waiting for ack
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*
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* TCP_SYN_RECV received a connection request, sent ack,
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* waiting for final ack in three-way handshake.
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*
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* TCP_ESTABLISHED connection established
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*
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* TCP_FIN_WAIT1 our side has shutdown, waiting to complete
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* transmission of remaining buffered data
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*
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* TCP_FIN_WAIT2 all buffered data sent, waiting for remote
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* to shutdown
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*
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* TCP_CLOSING both sides have shutdown but we still have
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* data we have to finish sending
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*
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* TCP_TIME_WAIT timeout to catch resent junk before entering
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* closed, can only be entered from FIN_WAIT2
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* or CLOSING. Required because the other end
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* may not have gotten our last ACK causing it
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* to retransmit the data packet (which we ignore)
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*
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* TCP_CLOSE_WAIT remote side has shutdown and is waiting for
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* us to finish writing our data and to shutdown
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* (we have to close() to move on to LAST_ACK)
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*
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* TCP_LAST_ACK out side has shutdown after remote has
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* shutdown. There may still be data in our
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* buffer that we have to finish sending
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*
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* TCP_CLOSE socket is finished
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/fcntl.h>
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#include <linux/poll.h>
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <linux/splice.h>
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#include <linux/net.h>
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#include <linux/socket.h>
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#include <linux/random.h>
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#include <linux/bootmem.h>
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#include <linux/highmem.h>
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#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/crypto.h>
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#include <net/icmp.h>
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#include <net/tcp.h>
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#include <net/xfrm.h>
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#include <net/ip.h>
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#include <net/netdma.h>
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#include <net/sock.h>
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#include <asm/uaccess.h>
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#include <asm/ioctls.h>
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int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
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struct percpu_counter tcp_orphan_count;
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EXPORT_SYMBOL_GPL(tcp_orphan_count);
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int sysctl_tcp_mem[3] __read_mostly;
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int sysctl_tcp_wmem[3] __read_mostly;
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int sysctl_tcp_rmem[3] __read_mostly;
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EXPORT_SYMBOL(sysctl_tcp_mem);
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EXPORT_SYMBOL(sysctl_tcp_rmem);
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EXPORT_SYMBOL(sysctl_tcp_wmem);
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atomic_t tcp_memory_allocated; /* Current allocated memory. */
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EXPORT_SYMBOL(tcp_memory_allocated);
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/*
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* Current number of TCP sockets.
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*/
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struct percpu_counter tcp_sockets_allocated;
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EXPORT_SYMBOL(tcp_sockets_allocated);
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/*
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* TCP splice context
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*/
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struct tcp_splice_state {
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struct pipe_inode_info *pipe;
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size_t len;
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unsigned int flags;
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};
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/*
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* Pressure flag: try to collapse.
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* Technical note: it is used by multiple contexts non atomically.
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* All the __sk_mem_schedule() is of this nature: accounting
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* is strict, actions are advisory and have some latency.
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*/
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int tcp_memory_pressure __read_mostly;
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EXPORT_SYMBOL(tcp_memory_pressure);
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void tcp_enter_memory_pressure(struct sock *sk)
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{
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if (!tcp_memory_pressure) {
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NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
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tcp_memory_pressure = 1;
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}
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}
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EXPORT_SYMBOL(tcp_enter_memory_pressure);
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/*
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* Wait for a TCP event.
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*
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* Note that we don't need to lock the socket, as the upper poll layers
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* take care of normal races (between the test and the event) and we don't
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* go look at any of the socket buffers directly.
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*/
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unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
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{
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unsigned int mask;
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struct sock *sk = sock->sk;
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struct tcp_sock *tp = tcp_sk(sk);
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poll_wait(file, sk->sk_sleep, wait);
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if (sk->sk_state == TCP_LISTEN)
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return inet_csk_listen_poll(sk);
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/* Socket is not locked. We are protected from async events
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* by poll logic and correct handling of state changes
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* made by other threads is impossible in any case.
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*/
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mask = 0;
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if (sk->sk_err)
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mask = POLLERR;
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/*
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* POLLHUP is certainly not done right. But poll() doesn't
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* have a notion of HUP in just one direction, and for a
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* socket the read side is more interesting.
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*
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* Some poll() documentation says that POLLHUP is incompatible
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* with the POLLOUT/POLLWR flags, so somebody should check this
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* all. But careful, it tends to be safer to return too many
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* bits than too few, and you can easily break real applications
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* if you don't tell them that something has hung up!
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*
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* Check-me.
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*
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* Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
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* our fs/select.c). It means that after we received EOF,
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* poll always returns immediately, making impossible poll() on write()
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* in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
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* if and only if shutdown has been made in both directions.
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* Actually, it is interesting to look how Solaris and DUX
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* solve this dilemma. I would prefer, if POLLHUP were maskable,
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* then we could set it on SND_SHUTDOWN. BTW examples given
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* in Stevens' books assume exactly this behaviour, it explains
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* why POLLHUP is incompatible with POLLOUT. --ANK
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*
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* NOTE. Check for TCP_CLOSE is added. The goal is to prevent
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* blocking on fresh not-connected or disconnected socket. --ANK
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*/
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if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
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mask |= POLLHUP;
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if (sk->sk_shutdown & RCV_SHUTDOWN)
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mask |= POLLIN | POLLRDNORM | POLLRDHUP;
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/* Connected? */
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if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
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int target = sock_rcvlowat(sk, 0, INT_MAX);
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if (tp->urg_seq == tp->copied_seq &&
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!sock_flag(sk, SOCK_URGINLINE) &&
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tp->urg_data)
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target--;
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/* Potential race condition. If read of tp below will
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* escape above sk->sk_state, we can be illegally awaken
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* in SYN_* states. */
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if (tp->rcv_nxt - tp->copied_seq >= target)
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mask |= POLLIN | POLLRDNORM;
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if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
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if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
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mask |= POLLOUT | POLLWRNORM;
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} else { /* send SIGIO later */
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set_bit(SOCK_ASYNC_NOSPACE,
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&sk->sk_socket->flags);
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set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
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/* Race breaker. If space is freed after
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* wspace test but before the flags are set,
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* IO signal will be lost.
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*/
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if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
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mask |= POLLOUT | POLLWRNORM;
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}
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}
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if (tp->urg_data & TCP_URG_VALID)
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mask |= POLLPRI;
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}
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return mask;
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}
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int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
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{
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struct tcp_sock *tp = tcp_sk(sk);
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int answ;
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switch (cmd) {
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case SIOCINQ:
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if (sk->sk_state == TCP_LISTEN)
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return -EINVAL;
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lock_sock(sk);
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if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
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answ = 0;
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else if (sock_flag(sk, SOCK_URGINLINE) ||
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!tp->urg_data ||
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before(tp->urg_seq, tp->copied_seq) ||
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!before(tp->urg_seq, tp->rcv_nxt)) {
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answ = tp->rcv_nxt - tp->copied_seq;
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/* Subtract 1, if FIN is in queue. */
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if (answ && !skb_queue_empty(&sk->sk_receive_queue))
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answ -=
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tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin;
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} else
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answ = tp->urg_seq - tp->copied_seq;
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release_sock(sk);
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break;
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case SIOCATMARK:
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answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
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break;
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case SIOCOUTQ:
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if (sk->sk_state == TCP_LISTEN)
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return -EINVAL;
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if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
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answ = 0;
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else
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answ = tp->write_seq - tp->snd_una;
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break;
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default:
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return -ENOIOCTLCMD;
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}
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|
|
return put_user(answ, (int __user *)arg);
|
|
}
|
|
|
|
static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
|
|
{
|
|
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
|
|
tp->pushed_seq = tp->write_seq;
|
|
}
|
|
|
|
static inline int forced_push(struct tcp_sock *tp)
|
|
{
|
|
return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
|
|
}
|
|
|
|
static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
|
|
|
|
skb->csum = 0;
|
|
tcb->seq = tcb->end_seq = tp->write_seq;
|
|
tcb->flags = TCPCB_FLAG_ACK;
|
|
tcb->sacked = 0;
|
|
skb_header_release(skb);
|
|
tcp_add_write_queue_tail(sk, skb);
|
|
sk->sk_wmem_queued += skb->truesize;
|
|
sk_mem_charge(sk, skb->truesize);
|
|
if (tp->nonagle & TCP_NAGLE_PUSH)
|
|
tp->nonagle &= ~TCP_NAGLE_PUSH;
|
|
}
|
|
|
|
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
|
|
struct sk_buff *skb)
|
|
{
|
|
if (flags & MSG_OOB)
|
|
tp->snd_up = tp->write_seq;
|
|
}
|
|
|
|
static inline void tcp_push(struct sock *sk, int flags, int mss_now,
|
|
int nonagle)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
if (tcp_send_head(sk)) {
|
|
struct sk_buff *skb = tcp_write_queue_tail(sk);
|
|
if (!(flags & MSG_MORE) || forced_push(tp))
|
|
tcp_mark_push(tp, skb);
|
|
tcp_mark_urg(tp, flags, skb);
|
|
__tcp_push_pending_frames(sk, mss_now,
|
|
(flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
|
|
}
|
|
}
|
|
|
|
static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
|
|
unsigned int offset, size_t len)
|
|
{
|
|
struct tcp_splice_state *tss = rd_desc->arg.data;
|
|
int ret;
|
|
|
|
ret = skb_splice_bits(skb, offset, tss->pipe, min(rd_desc->count, len),
|
|
tss->flags);
|
|
if (ret > 0)
|
|
rd_desc->count -= ret;
|
|
return ret;
|
|
}
|
|
|
|
static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
|
|
{
|
|
/* Store TCP splice context information in read_descriptor_t. */
|
|
read_descriptor_t rd_desc = {
|
|
.arg.data = tss,
|
|
.count = tss->len,
|
|
};
|
|
|
|
return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
|
|
}
|
|
|
|
/**
|
|
* tcp_splice_read - splice data from TCP socket to a pipe
|
|
* @sock: socket to splice from
|
|
* @ppos: position (not valid)
|
|
* @pipe: pipe to splice to
|
|
* @len: number of bytes to splice
|
|
* @flags: splice modifier flags
|
|
*
|
|
* Description:
|
|
* Will read pages from given socket and fill them into a pipe.
|
|
*
|
|
**/
|
|
ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
|
|
struct pipe_inode_info *pipe, size_t len,
|
|
unsigned int flags)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct tcp_splice_state tss = {
|
|
.pipe = pipe,
|
|
.len = len,
|
|
.flags = flags,
|
|
};
|
|
long timeo;
|
|
ssize_t spliced;
|
|
int ret;
|
|
|
|
/*
|
|
* We can't seek on a socket input
|
|
*/
|
|
if (unlikely(*ppos))
|
|
return -ESPIPE;
|
|
|
|
ret = spliced = 0;
|
|
|
|
lock_sock(sk);
|
|
|
|
timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
|
|
while (tss.len) {
|
|
ret = __tcp_splice_read(sk, &tss);
|
|
if (ret < 0)
|
|
break;
|
|
else if (!ret) {
|
|
if (spliced)
|
|
break;
|
|
if (sock_flag(sk, SOCK_DONE))
|
|
break;
|
|
if (sk->sk_err) {
|
|
ret = sock_error(sk);
|
|
break;
|
|
}
|
|
if (sk->sk_shutdown & RCV_SHUTDOWN)
|
|
break;
|
|
if (sk->sk_state == TCP_CLOSE) {
|
|
/*
|
|
* This occurs when user tries to read
|
|
* from never connected socket.
|
|
*/
|
|
if (!sock_flag(sk, SOCK_DONE))
|
|
ret = -ENOTCONN;
|
|
break;
|
|
}
|
|
if (!timeo) {
|
|
ret = -EAGAIN;
|
|
break;
|
|
}
|
|
sk_wait_data(sk, &timeo);
|
|
if (signal_pending(current)) {
|
|
ret = sock_intr_errno(timeo);
|
|
break;
|
|
}
|
|
continue;
|
|
}
|
|
tss.len -= ret;
|
|
spliced += ret;
|
|
|
|
if (!timeo)
|
|
break;
|
|
release_sock(sk);
|
|
lock_sock(sk);
|
|
|
|
if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
|
|
(sk->sk_shutdown & RCV_SHUTDOWN) ||
|
|
signal_pending(current))
|
|
break;
|
|
}
|
|
|
|
release_sock(sk);
|
|
|
|
if (spliced)
|
|
return spliced;
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
|
|
{
|
|
struct sk_buff *skb;
|
|
|
|
/* The TCP header must be at least 32-bit aligned. */
|
|
size = ALIGN(size, 4);
|
|
|
|
skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
|
|
if (skb) {
|
|
if (sk_wmem_schedule(sk, skb->truesize)) {
|
|
/*
|
|
* Make sure that we have exactly size bytes
|
|
* available to the caller, no more, no less.
|
|
*/
|
|
skb_reserve(skb, skb_tailroom(skb) - size);
|
|
return skb;
|
|
}
|
|
__kfree_skb(skb);
|
|
} else {
|
|
sk->sk_prot->enter_memory_pressure(sk);
|
|
sk_stream_moderate_sndbuf(sk);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
|
|
int large_allowed)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
u32 xmit_size_goal, old_size_goal;
|
|
|
|
xmit_size_goal = mss_now;
|
|
|
|
if (large_allowed && sk_can_gso(sk)) {
|
|
xmit_size_goal = ((sk->sk_gso_max_size - 1) -
|
|
inet_csk(sk)->icsk_af_ops->net_header_len -
|
|
inet_csk(sk)->icsk_ext_hdr_len -
|
|
tp->tcp_header_len);
|
|
|
|
xmit_size_goal = tcp_bound_to_half_wnd(tp, xmit_size_goal);
|
|
|
|
/* We try hard to avoid divides here */
|
|
old_size_goal = tp->xmit_size_goal_segs * mss_now;
|
|
|
|
if (likely(old_size_goal <= xmit_size_goal &&
|
|
old_size_goal + mss_now > xmit_size_goal)) {
|
|
xmit_size_goal = old_size_goal;
|
|
} else {
|
|
tp->xmit_size_goal_segs = xmit_size_goal / mss_now;
|
|
xmit_size_goal = tp->xmit_size_goal_segs * mss_now;
|
|
}
|
|
}
|
|
|
|
return max(xmit_size_goal, mss_now);
|
|
}
|
|
|
|
static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
|
|
{
|
|
int mss_now;
|
|
|
|
mss_now = tcp_current_mss(sk);
|
|
*size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));
|
|
|
|
return mss_now;
|
|
}
|
|
|
|
static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
|
|
size_t psize, int flags)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int mss_now, size_goal;
|
|
int err;
|
|
ssize_t copied;
|
|
long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
|
|
|
|
/* Wait for a connection to finish. */
|
|
if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
|
|
if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
|
|
goto out_err;
|
|
|
|
clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
|
|
|
|
mss_now = tcp_send_mss(sk, &size_goal, flags);
|
|
copied = 0;
|
|
|
|
err = -EPIPE;
|
|
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
|
|
goto out_err;
|
|
|
|
while (psize > 0) {
|
|
struct sk_buff *skb = tcp_write_queue_tail(sk);
|
|
struct page *page = pages[poffset / PAGE_SIZE];
|
|
int copy, i, can_coalesce;
|
|
int offset = poffset % PAGE_SIZE;
|
|
int size = min_t(size_t, psize, PAGE_SIZE - offset);
|
|
|
|
if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0) {
|
|
new_segment:
|
|
if (!sk_stream_memory_free(sk))
|
|
goto wait_for_sndbuf;
|
|
|
|
skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
|
|
if (!skb)
|
|
goto wait_for_memory;
|
|
|
|
skb_entail(sk, skb);
|
|
copy = size_goal;
|
|
}
|
|
|
|
if (copy > size)
|
|
copy = size;
|
|
|
|
i = skb_shinfo(skb)->nr_frags;
|
|
can_coalesce = skb_can_coalesce(skb, i, page, offset);
|
|
if (!can_coalesce && i >= MAX_SKB_FRAGS) {
|
|
tcp_mark_push(tp, skb);
|
|
goto new_segment;
|
|
}
|
|
if (!sk_wmem_schedule(sk, copy))
|
|
goto wait_for_memory;
|
|
|
|
if (can_coalesce) {
|
|
skb_shinfo(skb)->frags[i - 1].size += copy;
|
|
} else {
|
|
get_page(page);
|
|
skb_fill_page_desc(skb, i, page, offset, copy);
|
|
}
|
|
|
|
skb->len += copy;
|
|
skb->data_len += copy;
|
|
skb->truesize += copy;
|
|
sk->sk_wmem_queued += copy;
|
|
sk_mem_charge(sk, copy);
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
tp->write_seq += copy;
|
|
TCP_SKB_CB(skb)->end_seq += copy;
|
|
skb_shinfo(skb)->gso_segs = 0;
|
|
|
|
if (!copied)
|
|
TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
|
|
|
|
copied += copy;
|
|
poffset += copy;
|
|
if (!(psize -= copy))
|
|
goto out;
|
|
|
|
if (skb->len < size_goal || (flags & MSG_OOB))
|
|
continue;
|
|
|
|
if (forced_push(tp)) {
|
|
tcp_mark_push(tp, skb);
|
|
__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
|
|
} else if (skb == tcp_send_head(sk))
|
|
tcp_push_one(sk, mss_now);
|
|
continue;
|
|
|
|
wait_for_sndbuf:
|
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
|
|
wait_for_memory:
|
|
if (copied)
|
|
tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
|
|
|
|
if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
|
|
goto do_error;
|
|
|
|
mss_now = tcp_send_mss(sk, &size_goal, flags);
|
|
}
|
|
|
|
out:
|
|
if (copied)
|
|
tcp_push(sk, flags, mss_now, tp->nonagle);
|
|
return copied;
|
|
|
|
do_error:
|
|
if (copied)
|
|
goto out;
|
|
out_err:
|
|
return sk_stream_error(sk, flags, err);
|
|
}
|
|
|
|
ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
|
|
size_t size, int flags)
|
|
{
|
|
ssize_t res;
|
|
struct sock *sk = sock->sk;
|
|
|
|
if (!(sk->sk_route_caps & NETIF_F_SG) ||
|
|
!(sk->sk_route_caps & NETIF_F_ALL_CSUM))
|
|
return sock_no_sendpage(sock, page, offset, size, flags);
|
|
|
|
lock_sock(sk);
|
|
TCP_CHECK_TIMER(sk);
|
|
res = do_tcp_sendpages(sk, &page, offset, size, flags);
|
|
TCP_CHECK_TIMER(sk);
|
|
release_sock(sk);
|
|
return res;
|
|
}
|
|
|
|
#define TCP_PAGE(sk) (sk->sk_sndmsg_page)
|
|
#define TCP_OFF(sk) (sk->sk_sndmsg_off)
|
|
|
|
static inline int select_size(struct sock *sk)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int tmp = tp->mss_cache;
|
|
|
|
if (sk->sk_route_caps & NETIF_F_SG) {
|
|
if (sk_can_gso(sk))
|
|
tmp = 0;
|
|
else {
|
|
int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
|
|
|
|
if (tmp >= pgbreak &&
|
|
tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
|
|
tmp = pgbreak;
|
|
}
|
|
}
|
|
|
|
return tmp;
|
|
}
|
|
|
|
int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
|
|
size_t size)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct iovec *iov;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct sk_buff *skb;
|
|
int iovlen, flags;
|
|
int mss_now, size_goal;
|
|
int err, copied;
|
|
long timeo;
|
|
|
|
lock_sock(sk);
|
|
TCP_CHECK_TIMER(sk);
|
|
|
|
flags = msg->msg_flags;
|
|
timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
|
|
|
|
/* Wait for a connection to finish. */
|
|
if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
|
|
if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
|
|
goto out_err;
|
|
|
|
/* This should be in poll */
|
|
clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
|
|
|
|
mss_now = tcp_send_mss(sk, &size_goal, flags);
|
|
|
|
/* Ok commence sending. */
|
|
iovlen = msg->msg_iovlen;
|
|
iov = msg->msg_iov;
|
|
copied = 0;
|
|
|
|
err = -EPIPE;
|
|
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
|
|
goto out_err;
|
|
|
|
while (--iovlen >= 0) {
|
|
int seglen = iov->iov_len;
|
|
unsigned char __user *from = iov->iov_base;
|
|
|
|
iov++;
|
|
|
|
while (seglen > 0) {
|
|
int copy;
|
|
|
|
skb = tcp_write_queue_tail(sk);
|
|
|
|
if (!tcp_send_head(sk) ||
|
|
(copy = size_goal - skb->len) <= 0) {
|
|
|
|
new_segment:
|
|
/* Allocate new segment. If the interface is SG,
|
|
* allocate skb fitting to single page.
|
|
*/
|
|
if (!sk_stream_memory_free(sk))
|
|
goto wait_for_sndbuf;
|
|
|
|
skb = sk_stream_alloc_skb(sk, select_size(sk),
|
|
sk->sk_allocation);
|
|
if (!skb)
|
|
goto wait_for_memory;
|
|
|
|
/*
|
|
* Check whether we can use HW checksum.
|
|
*/
|
|
if (sk->sk_route_caps & NETIF_F_ALL_CSUM)
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
|
|
skb_entail(sk, skb);
|
|
copy = size_goal;
|
|
}
|
|
|
|
/* Try to append data to the end of skb. */
|
|
if (copy > seglen)
|
|
copy = seglen;
|
|
|
|
/* Where to copy to? */
|
|
if (skb_tailroom(skb) > 0) {
|
|
/* We have some space in skb head. Superb! */
|
|
if (copy > skb_tailroom(skb))
|
|
copy = skb_tailroom(skb);
|
|
if ((err = skb_add_data(skb, from, copy)) != 0)
|
|
goto do_fault;
|
|
} else {
|
|
int merge = 0;
|
|
int i = skb_shinfo(skb)->nr_frags;
|
|
struct page *page = TCP_PAGE(sk);
|
|
int off = TCP_OFF(sk);
|
|
|
|
if (skb_can_coalesce(skb, i, page, off) &&
|
|
off != PAGE_SIZE) {
|
|
/* We can extend the last page
|
|
* fragment. */
|
|
merge = 1;
|
|
} else if (i == MAX_SKB_FRAGS ||
|
|
(!i &&
|
|
!(sk->sk_route_caps & NETIF_F_SG))) {
|
|
/* Need to add new fragment and cannot
|
|
* do this because interface is non-SG,
|
|
* or because all the page slots are
|
|
* busy. */
|
|
tcp_mark_push(tp, skb);
|
|
goto new_segment;
|
|
} else if (page) {
|
|
if (off == PAGE_SIZE) {
|
|
put_page(page);
|
|
TCP_PAGE(sk) = page = NULL;
|
|
off = 0;
|
|
}
|
|
} else
|
|
off = 0;
|
|
|
|
if (copy > PAGE_SIZE - off)
|
|
copy = PAGE_SIZE - off;
|
|
|
|
if (!sk_wmem_schedule(sk, copy))
|
|
goto wait_for_memory;
|
|
|
|
if (!page) {
|
|
/* Allocate new cache page. */
|
|
if (!(page = sk_stream_alloc_page(sk)))
|
|
goto wait_for_memory;
|
|
}
|
|
|
|
/* Time to copy data. We are close to
|
|
* the end! */
|
|
err = skb_copy_to_page(sk, from, skb, page,
|
|
off, copy);
|
|
if (err) {
|
|
/* If this page was new, give it to the
|
|
* socket so it does not get leaked.
|
|
*/
|
|
if (!TCP_PAGE(sk)) {
|
|
TCP_PAGE(sk) = page;
|
|
TCP_OFF(sk) = 0;
|
|
}
|
|
goto do_error;
|
|
}
|
|
|
|
/* Update the skb. */
|
|
if (merge) {
|
|
skb_shinfo(skb)->frags[i - 1].size +=
|
|
copy;
|
|
} else {
|
|
skb_fill_page_desc(skb, i, page, off, copy);
|
|
if (TCP_PAGE(sk)) {
|
|
get_page(page);
|
|
} else if (off + copy < PAGE_SIZE) {
|
|
get_page(page);
|
|
TCP_PAGE(sk) = page;
|
|
}
|
|
}
|
|
|
|
TCP_OFF(sk) = off + copy;
|
|
}
|
|
|
|
if (!copied)
|
|
TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
|
|
|
|
tp->write_seq += copy;
|
|
TCP_SKB_CB(skb)->end_seq += copy;
|
|
skb_shinfo(skb)->gso_segs = 0;
|
|
|
|
from += copy;
|
|
copied += copy;
|
|
if ((seglen -= copy) == 0 && iovlen == 0)
|
|
goto out;
|
|
|
|
if (skb->len < size_goal || (flags & MSG_OOB))
|
|
continue;
|
|
|
|
if (forced_push(tp)) {
|
|
tcp_mark_push(tp, skb);
|
|
__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
|
|
} else if (skb == tcp_send_head(sk))
|
|
tcp_push_one(sk, mss_now);
|
|
continue;
|
|
|
|
wait_for_sndbuf:
|
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
|
|
wait_for_memory:
|
|
if (copied)
|
|
tcp_push(sk, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
|
|
|
|
if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
|
|
goto do_error;
|
|
|
|
mss_now = tcp_send_mss(sk, &size_goal, flags);
|
|
}
|
|
}
|
|
|
|
out:
|
|
if (copied)
|
|
tcp_push(sk, flags, mss_now, tp->nonagle);
|
|
TCP_CHECK_TIMER(sk);
|
|
release_sock(sk);
|
|
return copied;
|
|
|
|
do_fault:
|
|
if (!skb->len) {
|
|
tcp_unlink_write_queue(skb, sk);
|
|
/* It is the one place in all of TCP, except connection
|
|
* reset, where we can be unlinking the send_head.
|
|
*/
|
|
tcp_check_send_head(sk, skb);
|
|
sk_wmem_free_skb(sk, skb);
|
|
}
|
|
|
|
do_error:
|
|
if (copied)
|
|
goto out;
|
|
out_err:
|
|
err = sk_stream_error(sk, flags, err);
|
|
TCP_CHECK_TIMER(sk);
|
|
release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Handle reading urgent data. BSD has very simple semantics for
|
|
* this, no blocking and very strange errors 8)
|
|
*/
|
|
|
|
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
/* No URG data to read. */
|
|
if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
|
|
tp->urg_data == TCP_URG_READ)
|
|
return -EINVAL; /* Yes this is right ! */
|
|
|
|
if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
|
|
return -ENOTCONN;
|
|
|
|
if (tp->urg_data & TCP_URG_VALID) {
|
|
int err = 0;
|
|
char c = tp->urg_data;
|
|
|
|
if (!(flags & MSG_PEEK))
|
|
tp->urg_data = TCP_URG_READ;
|
|
|
|
/* Read urgent data. */
|
|
msg->msg_flags |= MSG_OOB;
|
|
|
|
if (len > 0) {
|
|
if (!(flags & MSG_TRUNC))
|
|
err = memcpy_toiovec(msg->msg_iov, &c, 1);
|
|
len = 1;
|
|
} else
|
|
msg->msg_flags |= MSG_TRUNC;
|
|
|
|
return err ? -EFAULT : len;
|
|
}
|
|
|
|
if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
|
|
return 0;
|
|
|
|
/* Fixed the recv(..., MSG_OOB) behaviour. BSD docs and
|
|
* the available implementations agree in this case:
|
|
* this call should never block, independent of the
|
|
* blocking state of the socket.
|
|
* Mike <pall@rz.uni-karlsruhe.de>
|
|
*/
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/* Clean up the receive buffer for full frames taken by the user,
|
|
* then send an ACK if necessary. COPIED is the number of bytes
|
|
* tcp_recvmsg has given to the user so far, it speeds up the
|
|
* calculation of whether or not we must ACK for the sake of
|
|
* a window update.
|
|
*/
|
|
void tcp_cleanup_rbuf(struct sock *sk, int copied)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int time_to_ack = 0;
|
|
|
|
#if TCP_DEBUG
|
|
struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
|
|
|
|
WARN_ON(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
|
|
#endif
|
|
|
|
if (inet_csk_ack_scheduled(sk)) {
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
/* Delayed ACKs frequently hit locked sockets during bulk
|
|
* receive. */
|
|
if (icsk->icsk_ack.blocked ||
|
|
/* Once-per-two-segments ACK was not sent by tcp_input.c */
|
|
tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
|
|
/*
|
|
* If this read emptied read buffer, we send ACK, if
|
|
* connection is not bidirectional, user drained
|
|
* receive buffer and there was a small segment
|
|
* in queue.
|
|
*/
|
|
(copied > 0 &&
|
|
((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
|
|
((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
|
|
!icsk->icsk_ack.pingpong)) &&
|
|
!atomic_read(&sk->sk_rmem_alloc)))
|
|
time_to_ack = 1;
|
|
}
|
|
|
|
/* We send an ACK if we can now advertise a non-zero window
|
|
* which has been raised "significantly".
|
|
*
|
|
* Even if window raised up to infinity, do not send window open ACK
|
|
* in states, where we will not receive more. It is useless.
|
|
*/
|
|
if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
|
|
__u32 rcv_window_now = tcp_receive_window(tp);
|
|
|
|
/* Optimize, __tcp_select_window() is not cheap. */
|
|
if (2*rcv_window_now <= tp->window_clamp) {
|
|
__u32 new_window = __tcp_select_window(sk);
|
|
|
|
/* Send ACK now, if this read freed lots of space
|
|
* in our buffer. Certainly, new_window is new window.
|
|
* We can advertise it now, if it is not less than current one.
|
|
* "Lots" means "at least twice" here.
|
|
*/
|
|
if (new_window && new_window >= 2 * rcv_window_now)
|
|
time_to_ack = 1;
|
|
}
|
|
}
|
|
if (time_to_ack)
|
|
tcp_send_ack(sk);
|
|
}
|
|
|
|
static void tcp_prequeue_process(struct sock *sk)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
|
|
|
|
/* RX process wants to run with disabled BHs, though it is not
|
|
* necessary */
|
|
local_bh_disable();
|
|
while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
|
|
sk_backlog_rcv(sk, skb);
|
|
local_bh_enable();
|
|
|
|
/* Clear memory counter. */
|
|
tp->ucopy.memory = 0;
|
|
}
|
|
|
|
static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
|
|
{
|
|
struct sk_buff *skb;
|
|
u32 offset;
|
|
|
|
skb_queue_walk(&sk->sk_receive_queue, skb) {
|
|
offset = seq - TCP_SKB_CB(skb)->seq;
|
|
if (tcp_hdr(skb)->syn)
|
|
offset--;
|
|
if (offset < skb->len || tcp_hdr(skb)->fin) {
|
|
*off = offset;
|
|
return skb;
|
|
}
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* This routine provides an alternative to tcp_recvmsg() for routines
|
|
* that would like to handle copying from skbuffs directly in 'sendfile'
|
|
* fashion.
|
|
* Note:
|
|
* - It is assumed that the socket was locked by the caller.
|
|
* - The routine does not block.
|
|
* - At present, there is no support for reading OOB data
|
|
* or for 'peeking' the socket using this routine
|
|
* (although both would be easy to implement).
|
|
*/
|
|
int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
|
|
sk_read_actor_t recv_actor)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
u32 seq = tp->copied_seq;
|
|
u32 offset;
|
|
int copied = 0;
|
|
|
|
if (sk->sk_state == TCP_LISTEN)
|
|
return -ENOTCONN;
|
|
while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
|
|
if (offset < skb->len) {
|
|
int used;
|
|
size_t len;
|
|
|
|
len = skb->len - offset;
|
|
/* Stop reading if we hit a patch of urgent data */
|
|
if (tp->urg_data) {
|
|
u32 urg_offset = tp->urg_seq - seq;
|
|
if (urg_offset < len)
|
|
len = urg_offset;
|
|
if (!len)
|
|
break;
|
|
}
|
|
used = recv_actor(desc, skb, offset, len);
|
|
if (used < 0) {
|
|
if (!copied)
|
|
copied = used;
|
|
break;
|
|
} else if (used <= len) {
|
|
seq += used;
|
|
copied += used;
|
|
offset += used;
|
|
}
|
|
/*
|
|
* If recv_actor drops the lock (e.g. TCP splice
|
|
* receive) the skb pointer might be invalid when
|
|
* getting here: tcp_collapse might have deleted it
|
|
* while aggregating skbs from the socket queue.
|
|
*/
|
|
skb = tcp_recv_skb(sk, seq-1, &offset);
|
|
if (!skb || (offset+1 != skb->len))
|
|
break;
|
|
}
|
|
if (tcp_hdr(skb)->fin) {
|
|
sk_eat_skb(sk, skb, 0);
|
|
++seq;
|
|
break;
|
|
}
|
|
sk_eat_skb(sk, skb, 0);
|
|
if (!desc->count)
|
|
break;
|
|
}
|
|
tp->copied_seq = seq;
|
|
|
|
tcp_rcv_space_adjust(sk);
|
|
|
|
/* Clean up data we have read: This will do ACK frames. */
|
|
if (copied > 0)
|
|
tcp_cleanup_rbuf(sk, copied);
|
|
return copied;
|
|
}
|
|
|
|
/*
|
|
* This routine copies from a sock struct into the user buffer.
|
|
*
|
|
* Technical note: in 2.3 we work on _locked_ socket, so that
|
|
* tricks with *seq access order and skb->users are not required.
|
|
* Probably, code can be easily improved even more.
|
|
*/
|
|
|
|
int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
|
|
size_t len, int nonblock, int flags, int *addr_len)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int copied = 0;
|
|
u32 peek_seq;
|
|
u32 *seq;
|
|
unsigned long used;
|
|
int err;
|
|
int target; /* Read at least this many bytes */
|
|
long timeo;
|
|
struct task_struct *user_recv = NULL;
|
|
int copied_early = 0;
|
|
struct sk_buff *skb;
|
|
|
|
lock_sock(sk);
|
|
|
|
TCP_CHECK_TIMER(sk);
|
|
|
|
err = -ENOTCONN;
|
|
if (sk->sk_state == TCP_LISTEN)
|
|
goto out;
|
|
|
|
timeo = sock_rcvtimeo(sk, nonblock);
|
|
|
|
/* Urgent data needs to be handled specially. */
|
|
if (flags & MSG_OOB)
|
|
goto recv_urg;
|
|
|
|
seq = &tp->copied_seq;
|
|
if (flags & MSG_PEEK) {
|
|
peek_seq = tp->copied_seq;
|
|
seq = &peek_seq;
|
|
}
|
|
|
|
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
|
|
|
|
#ifdef CONFIG_NET_DMA
|
|
tp->ucopy.dma_chan = NULL;
|
|
preempt_disable();
|
|
skb = skb_peek_tail(&sk->sk_receive_queue);
|
|
{
|
|
int available = 0;
|
|
|
|
if (skb)
|
|
available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
|
|
if ((available < target) &&
|
|
(len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
|
|
!sysctl_tcp_low_latency &&
|
|
dma_find_channel(DMA_MEMCPY)) {
|
|
preempt_enable_no_resched();
|
|
tp->ucopy.pinned_list =
|
|
dma_pin_iovec_pages(msg->msg_iov, len);
|
|
} else {
|
|
preempt_enable_no_resched();
|
|
}
|
|
}
|
|
#endif
|
|
|
|
do {
|
|
u32 offset;
|
|
|
|
/* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
|
|
if (tp->urg_data && tp->urg_seq == *seq) {
|
|
if (copied)
|
|
break;
|
|
if (signal_pending(current)) {
|
|
copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Next get a buffer. */
|
|
|
|
skb = skb_peek(&sk->sk_receive_queue);
|
|
do {
|
|
if (!skb)
|
|
break;
|
|
|
|
/* Now that we have two receive queues this
|
|
* shouldn't happen.
|
|
*/
|
|
if (before(*seq, TCP_SKB_CB(skb)->seq)) {
|
|
printk(KERN_INFO "recvmsg bug: copied %X "
|
|
"seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
|
|
break;
|
|
}
|
|
offset = *seq - TCP_SKB_CB(skb)->seq;
|
|
if (tcp_hdr(skb)->syn)
|
|
offset--;
|
|
if (offset < skb->len)
|
|
goto found_ok_skb;
|
|
if (tcp_hdr(skb)->fin)
|
|
goto found_fin_ok;
|
|
WARN_ON(!(flags & MSG_PEEK));
|
|
skb = skb->next;
|
|
} while (skb != (struct sk_buff *)&sk->sk_receive_queue);
|
|
|
|
/* Well, if we have backlog, try to process it now yet. */
|
|
|
|
if (copied >= target && !sk->sk_backlog.tail)
|
|
break;
|
|
|
|
if (copied) {
|
|
if (sk->sk_err ||
|
|
sk->sk_state == TCP_CLOSE ||
|
|
(sk->sk_shutdown & RCV_SHUTDOWN) ||
|
|
!timeo ||
|
|
signal_pending(current))
|
|
break;
|
|
} else {
|
|
if (sock_flag(sk, SOCK_DONE))
|
|
break;
|
|
|
|
if (sk->sk_err) {
|
|
copied = sock_error(sk);
|
|
break;
|
|
}
|
|
|
|
if (sk->sk_shutdown & RCV_SHUTDOWN)
|
|
break;
|
|
|
|
if (sk->sk_state == TCP_CLOSE) {
|
|
if (!sock_flag(sk, SOCK_DONE)) {
|
|
/* This occurs when user tries to read
|
|
* from never connected socket.
|
|
*/
|
|
copied = -ENOTCONN;
|
|
break;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (!timeo) {
|
|
copied = -EAGAIN;
|
|
break;
|
|
}
|
|
|
|
if (signal_pending(current)) {
|
|
copied = sock_intr_errno(timeo);
|
|
break;
|
|
}
|
|
}
|
|
|
|
tcp_cleanup_rbuf(sk, copied);
|
|
|
|
if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
|
|
/* Install new reader */
|
|
if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
|
|
user_recv = current;
|
|
tp->ucopy.task = user_recv;
|
|
tp->ucopy.iov = msg->msg_iov;
|
|
}
|
|
|
|
tp->ucopy.len = len;
|
|
|
|
WARN_ON(tp->copied_seq != tp->rcv_nxt &&
|
|
!(flags & (MSG_PEEK | MSG_TRUNC)));
|
|
|
|
/* Ugly... If prequeue is not empty, we have to
|
|
* process it before releasing socket, otherwise
|
|
* order will be broken at second iteration.
|
|
* More elegant solution is required!!!
|
|
*
|
|
* Look: we have the following (pseudo)queues:
|
|
*
|
|
* 1. packets in flight
|
|
* 2. backlog
|
|
* 3. prequeue
|
|
* 4. receive_queue
|
|
*
|
|
* Each queue can be processed only if the next ones
|
|
* are empty. At this point we have empty receive_queue.
|
|
* But prequeue _can_ be not empty after 2nd iteration,
|
|
* when we jumped to start of loop because backlog
|
|
* processing added something to receive_queue.
|
|
* We cannot release_sock(), because backlog contains
|
|
* packets arrived _after_ prequeued ones.
|
|
*
|
|
* Shortly, algorithm is clear --- to process all
|
|
* the queues in order. We could make it more directly,
|
|
* requeueing packets from backlog to prequeue, if
|
|
* is not empty. It is more elegant, but eats cycles,
|
|
* unfortunately.
|
|
*/
|
|
if (!skb_queue_empty(&tp->ucopy.prequeue))
|
|
goto do_prequeue;
|
|
|
|
/* __ Set realtime policy in scheduler __ */
|
|
}
|
|
|
|
if (copied >= target) {
|
|
/* Do not sleep, just process backlog. */
|
|
release_sock(sk);
|
|
lock_sock(sk);
|
|
} else
|
|
sk_wait_data(sk, &timeo);
|
|
|
|
#ifdef CONFIG_NET_DMA
|
|
tp->ucopy.wakeup = 0;
|
|
#endif
|
|
|
|
if (user_recv) {
|
|
int chunk;
|
|
|
|
/* __ Restore normal policy in scheduler __ */
|
|
|
|
if ((chunk = len - tp->ucopy.len) != 0) {
|
|
NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
|
|
len -= chunk;
|
|
copied += chunk;
|
|
}
|
|
|
|
if (tp->rcv_nxt == tp->copied_seq &&
|
|
!skb_queue_empty(&tp->ucopy.prequeue)) {
|
|
do_prequeue:
|
|
tcp_prequeue_process(sk);
|
|
|
|
if ((chunk = len - tp->ucopy.len) != 0) {
|
|
NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
|
|
len -= chunk;
|
|
copied += chunk;
|
|
}
|
|
}
|
|
}
|
|
if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
|
|
if (net_ratelimit())
|
|
printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
|
|
current->comm, task_pid_nr(current));
|
|
peek_seq = tp->copied_seq;
|
|
}
|
|
continue;
|
|
|
|
found_ok_skb:
|
|
/* Ok so how much can we use? */
|
|
used = skb->len - offset;
|
|
if (len < used)
|
|
used = len;
|
|
|
|
/* Do we have urgent data here? */
|
|
if (tp->urg_data) {
|
|
u32 urg_offset = tp->urg_seq - *seq;
|
|
if (urg_offset < used) {
|
|
if (!urg_offset) {
|
|
if (!sock_flag(sk, SOCK_URGINLINE)) {
|
|
++*seq;
|
|
offset++;
|
|
used--;
|
|
if (!used)
|
|
goto skip_copy;
|
|
}
|
|
} else
|
|
used = urg_offset;
|
|
}
|
|
}
|
|
|
|
if (!(flags & MSG_TRUNC)) {
|
|
#ifdef CONFIG_NET_DMA
|
|
if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
|
|
tp->ucopy.dma_chan = dma_find_channel(DMA_MEMCPY);
|
|
|
|
if (tp->ucopy.dma_chan) {
|
|
tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
|
|
tp->ucopy.dma_chan, skb, offset,
|
|
msg->msg_iov, used,
|
|
tp->ucopy.pinned_list);
|
|
|
|
if (tp->ucopy.dma_cookie < 0) {
|
|
|
|
printk(KERN_ALERT "dma_cookie < 0\n");
|
|
|
|
/* Exception. Bailout! */
|
|
if (!copied)
|
|
copied = -EFAULT;
|
|
break;
|
|
}
|
|
if ((offset + used) == skb->len)
|
|
copied_early = 1;
|
|
|
|
} else
|
|
#endif
|
|
{
|
|
err = skb_copy_datagram_iovec(skb, offset,
|
|
msg->msg_iov, used);
|
|
if (err) {
|
|
/* Exception. Bailout! */
|
|
if (!copied)
|
|
copied = -EFAULT;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
*seq += used;
|
|
copied += used;
|
|
len -= used;
|
|
|
|
tcp_rcv_space_adjust(sk);
|
|
|
|
skip_copy:
|
|
if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
|
|
tp->urg_data = 0;
|
|
tcp_fast_path_check(sk);
|
|
}
|
|
if (used + offset < skb->len)
|
|
continue;
|
|
|
|
if (tcp_hdr(skb)->fin)
|
|
goto found_fin_ok;
|
|
if (!(flags & MSG_PEEK)) {
|
|
sk_eat_skb(sk, skb, copied_early);
|
|
copied_early = 0;
|
|
}
|
|
continue;
|
|
|
|
found_fin_ok:
|
|
/* Process the FIN. */
|
|
++*seq;
|
|
if (!(flags & MSG_PEEK)) {
|
|
sk_eat_skb(sk, skb, copied_early);
|
|
copied_early = 0;
|
|
}
|
|
break;
|
|
} while (len > 0);
|
|
|
|
if (user_recv) {
|
|
if (!skb_queue_empty(&tp->ucopy.prequeue)) {
|
|
int chunk;
|
|
|
|
tp->ucopy.len = copied > 0 ? len : 0;
|
|
|
|
tcp_prequeue_process(sk);
|
|
|
|
if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
|
|
NET_ADD_STATS_USER(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
|
|
len -= chunk;
|
|
copied += chunk;
|
|
}
|
|
}
|
|
|
|
tp->ucopy.task = NULL;
|
|
tp->ucopy.len = 0;
|
|
}
|
|
|
|
#ifdef CONFIG_NET_DMA
|
|
if (tp->ucopy.dma_chan) {
|
|
dma_cookie_t done, used;
|
|
|
|
dma_async_memcpy_issue_pending(tp->ucopy.dma_chan);
|
|
|
|
while (dma_async_memcpy_complete(tp->ucopy.dma_chan,
|
|
tp->ucopy.dma_cookie, &done,
|
|
&used) == DMA_IN_PROGRESS) {
|
|
/* do partial cleanup of sk_async_wait_queue */
|
|
while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
|
|
(dma_async_is_complete(skb->dma_cookie, done,
|
|
used) == DMA_SUCCESS)) {
|
|
__skb_dequeue(&sk->sk_async_wait_queue);
|
|
kfree_skb(skb);
|
|
}
|
|
}
|
|
|
|
/* Safe to free early-copied skbs now */
|
|
__skb_queue_purge(&sk->sk_async_wait_queue);
|
|
tp->ucopy.dma_chan = NULL;
|
|
}
|
|
if (tp->ucopy.pinned_list) {
|
|
dma_unpin_iovec_pages(tp->ucopy.pinned_list);
|
|
tp->ucopy.pinned_list = NULL;
|
|
}
|
|
#endif
|
|
|
|
/* According to UNIX98, msg_name/msg_namelen are ignored
|
|
* on connected socket. I was just happy when found this 8) --ANK
|
|
*/
|
|
|
|
/* Clean up data we have read: This will do ACK frames. */
|
|
tcp_cleanup_rbuf(sk, copied);
|
|
|
|
TCP_CHECK_TIMER(sk);
|
|
release_sock(sk);
|
|
return copied;
|
|
|
|
out:
|
|
TCP_CHECK_TIMER(sk);
|
|
release_sock(sk);
|
|
return err;
|
|
|
|
recv_urg:
|
|
err = tcp_recv_urg(sk, msg, len, flags);
|
|
goto out;
|
|
}
|
|
|
|
void tcp_set_state(struct sock *sk, int state)
|
|
{
|
|
int oldstate = sk->sk_state;
|
|
|
|
switch (state) {
|
|
case TCP_ESTABLISHED:
|
|
if (oldstate != TCP_ESTABLISHED)
|
|
TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
|
|
break;
|
|
|
|
case TCP_CLOSE:
|
|
if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
|
|
TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
|
|
|
|
sk->sk_prot->unhash(sk);
|
|
if (inet_csk(sk)->icsk_bind_hash &&
|
|
!(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
|
|
inet_put_port(sk);
|
|
/* fall through */
|
|
default:
|
|
if (oldstate == TCP_ESTABLISHED)
|
|
TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
|
|
}
|
|
|
|
/* Change state AFTER socket is unhashed to avoid closed
|
|
* socket sitting in hash tables.
|
|
*/
|
|
sk->sk_state = state;
|
|
|
|
#ifdef STATE_TRACE
|
|
SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
|
|
#endif
|
|
}
|
|
EXPORT_SYMBOL_GPL(tcp_set_state);
|
|
|
|
/*
|
|
* State processing on a close. This implements the state shift for
|
|
* sending our FIN frame. Note that we only send a FIN for some
|
|
* states. A shutdown() may have already sent the FIN, or we may be
|
|
* closed.
|
|
*/
|
|
|
|
static const unsigned char new_state[16] = {
|
|
/* current state: new state: action: */
|
|
/* (Invalid) */ TCP_CLOSE,
|
|
/* TCP_ESTABLISHED */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
|
|
/* TCP_SYN_SENT */ TCP_CLOSE,
|
|
/* TCP_SYN_RECV */ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
|
|
/* TCP_FIN_WAIT1 */ TCP_FIN_WAIT1,
|
|
/* TCP_FIN_WAIT2 */ TCP_FIN_WAIT2,
|
|
/* TCP_TIME_WAIT */ TCP_CLOSE,
|
|
/* TCP_CLOSE */ TCP_CLOSE,
|
|
/* TCP_CLOSE_WAIT */ TCP_LAST_ACK | TCP_ACTION_FIN,
|
|
/* TCP_LAST_ACK */ TCP_LAST_ACK,
|
|
/* TCP_LISTEN */ TCP_CLOSE,
|
|
/* TCP_CLOSING */ TCP_CLOSING,
|
|
};
|
|
|
|
static int tcp_close_state(struct sock *sk)
|
|
{
|
|
int next = (int)new_state[sk->sk_state];
|
|
int ns = next & TCP_STATE_MASK;
|
|
|
|
tcp_set_state(sk, ns);
|
|
|
|
return next & TCP_ACTION_FIN;
|
|
}
|
|
|
|
/*
|
|
* Shutdown the sending side of a connection. Much like close except
|
|
* that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
|
|
*/
|
|
|
|
void tcp_shutdown(struct sock *sk, int how)
|
|
{
|
|
/* We need to grab some memory, and put together a FIN,
|
|
* and then put it into the queue to be sent.
|
|
* Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
|
|
*/
|
|
if (!(how & SEND_SHUTDOWN))
|
|
return;
|
|
|
|
/* If we've already sent a FIN, or it's a closed state, skip this. */
|
|
if ((1 << sk->sk_state) &
|
|
(TCPF_ESTABLISHED | TCPF_SYN_SENT |
|
|
TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
|
|
/* Clear out any half completed packets. FIN if needed. */
|
|
if (tcp_close_state(sk))
|
|
tcp_send_fin(sk);
|
|
}
|
|
}
|
|
|
|
void tcp_close(struct sock *sk, long timeout)
|
|
{
|
|
struct sk_buff *skb;
|
|
int data_was_unread = 0;
|
|
int state;
|
|
|
|
lock_sock(sk);
|
|
sk->sk_shutdown = SHUTDOWN_MASK;
|
|
|
|
if (sk->sk_state == TCP_LISTEN) {
|
|
tcp_set_state(sk, TCP_CLOSE);
|
|
|
|
/* Special case. */
|
|
inet_csk_listen_stop(sk);
|
|
|
|
goto adjudge_to_death;
|
|
}
|
|
|
|
/* We need to flush the recv. buffs. We do this only on the
|
|
* descriptor close, not protocol-sourced closes, because the
|
|
* reader process may not have drained the data yet!
|
|
*/
|
|
while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
|
|
u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
|
|
tcp_hdr(skb)->fin;
|
|
data_was_unread += len;
|
|
__kfree_skb(skb);
|
|
}
|
|
|
|
sk_mem_reclaim(sk);
|
|
|
|
/* As outlined in RFC 2525, section 2.17, we send a RST here because
|
|
* data was lost. To witness the awful effects of the old behavior of
|
|
* always doing a FIN, run an older 2.1.x kernel or 2.0.x, start a bulk
|
|
* GET in an FTP client, suspend the process, wait for the client to
|
|
* advertise a zero window, then kill -9 the FTP client, wheee...
|
|
* Note: timeout is always zero in such a case.
|
|
*/
|
|
if (data_was_unread) {
|
|
/* Unread data was tossed, zap the connection. */
|
|
NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
|
|
tcp_set_state(sk, TCP_CLOSE);
|
|
tcp_send_active_reset(sk, GFP_KERNEL);
|
|
} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
|
|
/* Check zero linger _after_ checking for unread data. */
|
|
sk->sk_prot->disconnect(sk, 0);
|
|
NET_INC_STATS_USER(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
|
|
} else if (tcp_close_state(sk)) {
|
|
/* We FIN if the application ate all the data before
|
|
* zapping the connection.
|
|
*/
|
|
|
|
/* RED-PEN. Formally speaking, we have broken TCP state
|
|
* machine. State transitions:
|
|
*
|
|
* TCP_ESTABLISHED -> TCP_FIN_WAIT1
|
|
* TCP_SYN_RECV -> TCP_FIN_WAIT1 (forget it, it's impossible)
|
|
* TCP_CLOSE_WAIT -> TCP_LAST_ACK
|
|
*
|
|
* are legal only when FIN has been sent (i.e. in window),
|
|
* rather than queued out of window. Purists blame.
|
|
*
|
|
* F.e. "RFC state" is ESTABLISHED,
|
|
* if Linux state is FIN-WAIT-1, but FIN is still not sent.
|
|
*
|
|
* The visible declinations are that sometimes
|
|
* we enter time-wait state, when it is not required really
|
|
* (harmless), do not send active resets, when they are
|
|
* required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
|
|
* they look as CLOSING or LAST_ACK for Linux)
|
|
* Probably, I missed some more holelets.
|
|
* --ANK
|
|
*/
|
|
tcp_send_fin(sk);
|
|
}
|
|
|
|
sk_stream_wait_close(sk, timeout);
|
|
|
|
adjudge_to_death:
|
|
state = sk->sk_state;
|
|
sock_hold(sk);
|
|
sock_orphan(sk);
|
|
|
|
/* It is the last release_sock in its life. It will remove backlog. */
|
|
release_sock(sk);
|
|
|
|
|
|
/* Now socket is owned by kernel and we acquire BH lock
|
|
to finish close. No need to check for user refs.
|
|
*/
|
|
local_bh_disable();
|
|
bh_lock_sock(sk);
|
|
WARN_ON(sock_owned_by_user(sk));
|
|
|
|
percpu_counter_inc(sk->sk_prot->orphan_count);
|
|
|
|
/* Have we already been destroyed by a softirq or backlog? */
|
|
if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
|
|
goto out;
|
|
|
|
/* This is a (useful) BSD violating of the RFC. There is a
|
|
* problem with TCP as specified in that the other end could
|
|
* keep a socket open forever with no application left this end.
|
|
* We use a 3 minute timeout (about the same as BSD) then kill
|
|
* our end. If they send after that then tough - BUT: long enough
|
|
* that we won't make the old 4*rto = almost no time - whoops
|
|
* reset mistake.
|
|
*
|
|
* Nope, it was not mistake. It is really desired behaviour
|
|
* f.e. on http servers, when such sockets are useless, but
|
|
* consume significant resources. Let's do it with special
|
|
* linger2 option. --ANK
|
|
*/
|
|
|
|
if (sk->sk_state == TCP_FIN_WAIT2) {
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
if (tp->linger2 < 0) {
|
|
tcp_set_state(sk, TCP_CLOSE);
|
|
tcp_send_active_reset(sk, GFP_ATOMIC);
|
|
NET_INC_STATS_BH(sock_net(sk),
|
|
LINUX_MIB_TCPABORTONLINGER);
|
|
} else {
|
|
const int tmo = tcp_fin_time(sk);
|
|
|
|
if (tmo > TCP_TIMEWAIT_LEN) {
|
|
inet_csk_reset_keepalive_timer(sk,
|
|
tmo - TCP_TIMEWAIT_LEN);
|
|
} else {
|
|
tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
if (sk->sk_state != TCP_CLOSE) {
|
|
int orphan_count = percpu_counter_read_positive(
|
|
sk->sk_prot->orphan_count);
|
|
|
|
sk_mem_reclaim(sk);
|
|
if (tcp_too_many_orphans(sk, orphan_count)) {
|
|
if (net_ratelimit())
|
|
printk(KERN_INFO "TCP: too many of orphaned "
|
|
"sockets\n");
|
|
tcp_set_state(sk, TCP_CLOSE);
|
|
tcp_send_active_reset(sk, GFP_ATOMIC);
|
|
NET_INC_STATS_BH(sock_net(sk),
|
|
LINUX_MIB_TCPABORTONMEMORY);
|
|
}
|
|
}
|
|
|
|
if (sk->sk_state == TCP_CLOSE)
|
|
inet_csk_destroy_sock(sk);
|
|
/* Otherwise, socket is reprieved until protocol close. */
|
|
|
|
out:
|
|
bh_unlock_sock(sk);
|
|
local_bh_enable();
|
|
sock_put(sk);
|
|
}
|
|
|
|
/* These states need RST on ABORT according to RFC793 */
|
|
|
|
static inline int tcp_need_reset(int state)
|
|
{
|
|
return (1 << state) &
|
|
(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
|
|
TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
|
|
}
|
|
|
|
int tcp_disconnect(struct sock *sk, int flags)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int err = 0;
|
|
int old_state = sk->sk_state;
|
|
|
|
if (old_state != TCP_CLOSE)
|
|
tcp_set_state(sk, TCP_CLOSE);
|
|
|
|
/* ABORT function of RFC793 */
|
|
if (old_state == TCP_LISTEN) {
|
|
inet_csk_listen_stop(sk);
|
|
} else if (tcp_need_reset(old_state) ||
|
|
(tp->snd_nxt != tp->write_seq &&
|
|
(1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
|
|
/* The last check adjusts for discrepancy of Linux wrt. RFC
|
|
* states
|
|
*/
|
|
tcp_send_active_reset(sk, gfp_any());
|
|
sk->sk_err = ECONNRESET;
|
|
} else if (old_state == TCP_SYN_SENT)
|
|
sk->sk_err = ECONNRESET;
|
|
|
|
tcp_clear_xmit_timers(sk);
|
|
__skb_queue_purge(&sk->sk_receive_queue);
|
|
tcp_write_queue_purge(sk);
|
|
__skb_queue_purge(&tp->out_of_order_queue);
|
|
#ifdef CONFIG_NET_DMA
|
|
__skb_queue_purge(&sk->sk_async_wait_queue);
|
|
#endif
|
|
|
|
inet->dport = 0;
|
|
|
|
if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
|
|
inet_reset_saddr(sk);
|
|
|
|
sk->sk_shutdown = 0;
|
|
sock_reset_flag(sk, SOCK_DONE);
|
|
tp->srtt = 0;
|
|
if ((tp->write_seq += tp->max_window + 2) == 0)
|
|
tp->write_seq = 1;
|
|
icsk->icsk_backoff = 0;
|
|
tp->snd_cwnd = 2;
|
|
icsk->icsk_probes_out = 0;
|
|
tp->packets_out = 0;
|
|
tp->snd_ssthresh = 0x7fffffff;
|
|
tp->snd_cwnd_cnt = 0;
|
|
tp->bytes_acked = 0;
|
|
tcp_set_ca_state(sk, TCP_CA_Open);
|
|
tcp_clear_retrans(tp);
|
|
inet_csk_delack_init(sk);
|
|
tcp_init_send_head(sk);
|
|
memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
|
|
__sk_dst_reset(sk);
|
|
|
|
WARN_ON(inet->num && !icsk->icsk_bind_hash);
|
|
|
|
sk->sk_error_report(sk);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Socket option code for TCP.
|
|
*/
|
|
static int do_tcp_setsockopt(struct sock *sk, int level,
|
|
int optname, char __user *optval, int optlen)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
int val;
|
|
int err = 0;
|
|
|
|
/* This is a string value all the others are int's */
|
|
if (optname == TCP_CONGESTION) {
|
|
char name[TCP_CA_NAME_MAX];
|
|
|
|
if (optlen < 1)
|
|
return -EINVAL;
|
|
|
|
val = strncpy_from_user(name, optval,
|
|
min(TCP_CA_NAME_MAX-1, optlen));
|
|
if (val < 0)
|
|
return -EFAULT;
|
|
name[val] = 0;
|
|
|
|
lock_sock(sk);
|
|
err = tcp_set_congestion_control(sk, name);
|
|
release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
if (optlen < sizeof(int))
|
|
return -EINVAL;
|
|
|
|
if (get_user(val, (int __user *)optval))
|
|
return -EFAULT;
|
|
|
|
lock_sock(sk);
|
|
|
|
switch (optname) {
|
|
case TCP_MAXSEG:
|
|
/* Values greater than interface MTU won't take effect. However
|
|
* at the point when this call is done we typically don't yet
|
|
* know which interface is going to be used */
|
|
if (val < 8 || val > MAX_TCP_WINDOW) {
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
tp->rx_opt.user_mss = val;
|
|
break;
|
|
|
|
case TCP_NODELAY:
|
|
if (val) {
|
|
/* TCP_NODELAY is weaker than TCP_CORK, so that
|
|
* this option on corked socket is remembered, but
|
|
* it is not activated until cork is cleared.
|
|
*
|
|
* However, when TCP_NODELAY is set we make
|
|
* an explicit push, which overrides even TCP_CORK
|
|
* for currently queued segments.
|
|
*/
|
|
tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
|
|
tcp_push_pending_frames(sk);
|
|
} else {
|
|
tp->nonagle &= ~TCP_NAGLE_OFF;
|
|
}
|
|
break;
|
|
|
|
case TCP_CORK:
|
|
/* When set indicates to always queue non-full frames.
|
|
* Later the user clears this option and we transmit
|
|
* any pending partial frames in the queue. This is
|
|
* meant to be used alongside sendfile() to get properly
|
|
* filled frames when the user (for example) must write
|
|
* out headers with a write() call first and then use
|
|
* sendfile to send out the data parts.
|
|
*
|
|
* TCP_CORK can be set together with TCP_NODELAY and it is
|
|
* stronger than TCP_NODELAY.
|
|
*/
|
|
if (val) {
|
|
tp->nonagle |= TCP_NAGLE_CORK;
|
|
} else {
|
|
tp->nonagle &= ~TCP_NAGLE_CORK;
|
|
if (tp->nonagle&TCP_NAGLE_OFF)
|
|
tp->nonagle |= TCP_NAGLE_PUSH;
|
|
tcp_push_pending_frames(sk);
|
|
}
|
|
break;
|
|
|
|
case TCP_KEEPIDLE:
|
|
if (val < 1 || val > MAX_TCP_KEEPIDLE)
|
|
err = -EINVAL;
|
|
else {
|
|
tp->keepalive_time = val * HZ;
|
|
if (sock_flag(sk, SOCK_KEEPOPEN) &&
|
|
!((1 << sk->sk_state) &
|
|
(TCPF_CLOSE | TCPF_LISTEN))) {
|
|
__u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
|
|
if (tp->keepalive_time > elapsed)
|
|
elapsed = tp->keepalive_time - elapsed;
|
|
else
|
|
elapsed = 0;
|
|
inet_csk_reset_keepalive_timer(sk, elapsed);
|
|
}
|
|
}
|
|
break;
|
|
case TCP_KEEPINTVL:
|
|
if (val < 1 || val > MAX_TCP_KEEPINTVL)
|
|
err = -EINVAL;
|
|
else
|
|
tp->keepalive_intvl = val * HZ;
|
|
break;
|
|
case TCP_KEEPCNT:
|
|
if (val < 1 || val > MAX_TCP_KEEPCNT)
|
|
err = -EINVAL;
|
|
else
|
|
tp->keepalive_probes = val;
|
|
break;
|
|
case TCP_SYNCNT:
|
|
if (val < 1 || val > MAX_TCP_SYNCNT)
|
|
err = -EINVAL;
|
|
else
|
|
icsk->icsk_syn_retries = val;
|
|
break;
|
|
|
|
case TCP_LINGER2:
|
|
if (val < 0)
|
|
tp->linger2 = -1;
|
|
else if (val > sysctl_tcp_fin_timeout / HZ)
|
|
tp->linger2 = 0;
|
|
else
|
|
tp->linger2 = val * HZ;
|
|
break;
|
|
|
|
case TCP_DEFER_ACCEPT:
|
|
icsk->icsk_accept_queue.rskq_defer_accept = 0;
|
|
if (val > 0) {
|
|
/* Translate value in seconds to number of
|
|
* retransmits */
|
|
while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
|
|
val > ((TCP_TIMEOUT_INIT / HZ) <<
|
|
icsk->icsk_accept_queue.rskq_defer_accept))
|
|
icsk->icsk_accept_queue.rskq_defer_accept++;
|
|
icsk->icsk_accept_queue.rskq_defer_accept++;
|
|
}
|
|
break;
|
|
|
|
case TCP_WINDOW_CLAMP:
|
|
if (!val) {
|
|
if (sk->sk_state != TCP_CLOSE) {
|
|
err = -EINVAL;
|
|
break;
|
|
}
|
|
tp->window_clamp = 0;
|
|
} else
|
|
tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
|
|
SOCK_MIN_RCVBUF / 2 : val;
|
|
break;
|
|
|
|
case TCP_QUICKACK:
|
|
if (!val) {
|
|
icsk->icsk_ack.pingpong = 1;
|
|
} else {
|
|
icsk->icsk_ack.pingpong = 0;
|
|
if ((1 << sk->sk_state) &
|
|
(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
|
|
inet_csk_ack_scheduled(sk)) {
|
|
icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
|
|
tcp_cleanup_rbuf(sk, 1);
|
|
if (!(val & 1))
|
|
icsk->icsk_ack.pingpong = 1;
|
|
}
|
|
}
|
|
break;
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
case TCP_MD5SIG:
|
|
/* Read the IP->Key mappings from userspace */
|
|
err = tp->af_specific->md5_parse(sk, optval, optlen);
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
break;
|
|
}
|
|
|
|
release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
|
|
int optlen)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (level != SOL_TCP)
|
|
return icsk->icsk_af_ops->setsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return do_tcp_setsockopt(sk, level, optname, optval, optlen);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
|
|
char __user *optval, int optlen)
|
|
{
|
|
if (level != SOL_TCP)
|
|
return inet_csk_compat_setsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return do_tcp_setsockopt(sk, level, optname, optval, optlen);
|
|
}
|
|
|
|
EXPORT_SYMBOL(compat_tcp_setsockopt);
|
|
#endif
|
|
|
|
/* Return information about state of tcp endpoint in API format. */
|
|
void tcp_get_info(struct sock *sk, struct tcp_info *info)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
u32 now = tcp_time_stamp;
|
|
|
|
memset(info, 0, sizeof(*info));
|
|
|
|
info->tcpi_state = sk->sk_state;
|
|
info->tcpi_ca_state = icsk->icsk_ca_state;
|
|
info->tcpi_retransmits = icsk->icsk_retransmits;
|
|
info->tcpi_probes = icsk->icsk_probes_out;
|
|
info->tcpi_backoff = icsk->icsk_backoff;
|
|
|
|
if (tp->rx_opt.tstamp_ok)
|
|
info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
|
|
if (tcp_is_sack(tp))
|
|
info->tcpi_options |= TCPI_OPT_SACK;
|
|
if (tp->rx_opt.wscale_ok) {
|
|
info->tcpi_options |= TCPI_OPT_WSCALE;
|
|
info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
|
|
info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
|
|
}
|
|
|
|
if (tp->ecn_flags&TCP_ECN_OK)
|
|
info->tcpi_options |= TCPI_OPT_ECN;
|
|
|
|
info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
|
|
info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
|
|
info->tcpi_snd_mss = tp->mss_cache;
|
|
info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
|
|
|
|
if (sk->sk_state == TCP_LISTEN) {
|
|
info->tcpi_unacked = sk->sk_ack_backlog;
|
|
info->tcpi_sacked = sk->sk_max_ack_backlog;
|
|
} else {
|
|
info->tcpi_unacked = tp->packets_out;
|
|
info->tcpi_sacked = tp->sacked_out;
|
|
}
|
|
info->tcpi_lost = tp->lost_out;
|
|
info->tcpi_retrans = tp->retrans_out;
|
|
info->tcpi_fackets = tp->fackets_out;
|
|
|
|
info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
|
|
info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
|
|
info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
|
|
|
|
info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
|
|
info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
|
|
info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
|
|
info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
|
|
info->tcpi_snd_ssthresh = tp->snd_ssthresh;
|
|
info->tcpi_snd_cwnd = tp->snd_cwnd;
|
|
info->tcpi_advmss = tp->advmss;
|
|
info->tcpi_reordering = tp->reordering;
|
|
|
|
info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
|
|
info->tcpi_rcv_space = tp->rcvq_space.space;
|
|
|
|
info->tcpi_total_retrans = tp->total_retrans;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(tcp_get_info);
|
|
|
|
static int do_tcp_getsockopt(struct sock *sk, int level,
|
|
int optname, char __user *optval, int __user *optlen)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int val, len;
|
|
|
|
if (get_user(len, optlen))
|
|
return -EFAULT;
|
|
|
|
len = min_t(unsigned int, len, sizeof(int));
|
|
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
|
|
switch (optname) {
|
|
case TCP_MAXSEG:
|
|
val = tp->mss_cache;
|
|
if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
|
|
val = tp->rx_opt.user_mss;
|
|
break;
|
|
case TCP_NODELAY:
|
|
val = !!(tp->nonagle&TCP_NAGLE_OFF);
|
|
break;
|
|
case TCP_CORK:
|
|
val = !!(tp->nonagle&TCP_NAGLE_CORK);
|
|
break;
|
|
case TCP_KEEPIDLE:
|
|
val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
|
|
break;
|
|
case TCP_KEEPINTVL:
|
|
val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
|
|
break;
|
|
case TCP_KEEPCNT:
|
|
val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
|
|
break;
|
|
case TCP_SYNCNT:
|
|
val = icsk->icsk_syn_retries ? : sysctl_tcp_syn_retries;
|
|
break;
|
|
case TCP_LINGER2:
|
|
val = tp->linger2;
|
|
if (val >= 0)
|
|
val = (val ? : sysctl_tcp_fin_timeout) / HZ;
|
|
break;
|
|
case TCP_DEFER_ACCEPT:
|
|
val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
|
|
((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
|
|
break;
|
|
case TCP_WINDOW_CLAMP:
|
|
val = tp->window_clamp;
|
|
break;
|
|
case TCP_INFO: {
|
|
struct tcp_info info;
|
|
|
|
if (get_user(len, optlen))
|
|
return -EFAULT;
|
|
|
|
tcp_get_info(sk, &info);
|
|
|
|
len = min_t(unsigned int, len, sizeof(info));
|
|
if (put_user(len, optlen))
|
|
return -EFAULT;
|
|
if (copy_to_user(optval, &info, len))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
case TCP_QUICKACK:
|
|
val = !icsk->icsk_ack.pingpong;
|
|
break;
|
|
|
|
case TCP_CONGESTION:
|
|
if (get_user(len, optlen))
|
|
return -EFAULT;
|
|
len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
|
|
if (put_user(len, optlen))
|
|
return -EFAULT;
|
|
if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
|
|
return -EFAULT;
|
|
return 0;
|
|
default:
|
|
return -ENOPROTOOPT;
|
|
}
|
|
|
|
if (put_user(len, optlen))
|
|
return -EFAULT;
|
|
if (copy_to_user(optval, &val, len))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
|
|
int __user *optlen)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (level != SOL_TCP)
|
|
return icsk->icsk_af_ops->getsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return do_tcp_getsockopt(sk, level, optname, optval, optlen);
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
|
|
char __user *optval, int __user *optlen)
|
|
{
|
|
if (level != SOL_TCP)
|
|
return inet_csk_compat_getsockopt(sk, level, optname,
|
|
optval, optlen);
|
|
return do_tcp_getsockopt(sk, level, optname, optval, optlen);
|
|
}
|
|
|
|
EXPORT_SYMBOL(compat_tcp_getsockopt);
|
|
#endif
|
|
|
|
struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
|
|
{
|
|
struct sk_buff *segs = ERR_PTR(-EINVAL);
|
|
struct tcphdr *th;
|
|
unsigned thlen;
|
|
unsigned int seq;
|
|
__be32 delta;
|
|
unsigned int oldlen;
|
|
unsigned int mss;
|
|
|
|
if (!pskb_may_pull(skb, sizeof(*th)))
|
|
goto out;
|
|
|
|
th = tcp_hdr(skb);
|
|
thlen = th->doff * 4;
|
|
if (thlen < sizeof(*th))
|
|
goto out;
|
|
|
|
if (!pskb_may_pull(skb, thlen))
|
|
goto out;
|
|
|
|
oldlen = (u16)~skb->len;
|
|
__skb_pull(skb, thlen);
|
|
|
|
mss = skb_shinfo(skb)->gso_size;
|
|
if (unlikely(skb->len <= mss))
|
|
goto out;
|
|
|
|
if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
|
|
/* Packet is from an untrusted source, reset gso_segs. */
|
|
int type = skb_shinfo(skb)->gso_type;
|
|
|
|
if (unlikely(type &
|
|
~(SKB_GSO_TCPV4 |
|
|
SKB_GSO_DODGY |
|
|
SKB_GSO_TCP_ECN |
|
|
SKB_GSO_TCPV6 |
|
|
0) ||
|
|
!(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
|
|
goto out;
|
|
|
|
skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
|
|
|
|
segs = NULL;
|
|
goto out;
|
|
}
|
|
|
|
segs = skb_segment(skb, features);
|
|
if (IS_ERR(segs))
|
|
goto out;
|
|
|
|
delta = htonl(oldlen + (thlen + mss));
|
|
|
|
skb = segs;
|
|
th = tcp_hdr(skb);
|
|
seq = ntohl(th->seq);
|
|
|
|
do {
|
|
th->fin = th->psh = 0;
|
|
|
|
th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
|
|
(__force u32)delta));
|
|
if (skb->ip_summed != CHECKSUM_PARTIAL)
|
|
th->check =
|
|
csum_fold(csum_partial(skb_transport_header(skb),
|
|
thlen, skb->csum));
|
|
|
|
seq += mss;
|
|
skb = skb->next;
|
|
th = tcp_hdr(skb);
|
|
|
|
th->seq = htonl(seq);
|
|
th->cwr = 0;
|
|
} while (skb->next);
|
|
|
|
delta = htonl(oldlen + (skb->tail - skb->transport_header) +
|
|
skb->data_len);
|
|
th->check = ~csum_fold((__force __wsum)((__force u32)th->check +
|
|
(__force u32)delta));
|
|
if (skb->ip_summed != CHECKSUM_PARTIAL)
|
|
th->check = csum_fold(csum_partial(skb_transport_header(skb),
|
|
thlen, skb->csum));
|
|
|
|
out:
|
|
return segs;
|
|
}
|
|
EXPORT_SYMBOL(tcp_tso_segment);
|
|
|
|
struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
|
|
{
|
|
struct sk_buff **pp = NULL;
|
|
struct sk_buff *p;
|
|
struct tcphdr *th;
|
|
struct tcphdr *th2;
|
|
unsigned int len;
|
|
unsigned int thlen;
|
|
unsigned int flags;
|
|
unsigned int mss = 1;
|
|
int flush = 1;
|
|
int i;
|
|
|
|
th = skb_gro_header(skb, sizeof(*th));
|
|
if (unlikely(!th))
|
|
goto out;
|
|
|
|
thlen = th->doff * 4;
|
|
if (thlen < sizeof(*th))
|
|
goto out;
|
|
|
|
th = skb_gro_header(skb, thlen);
|
|
if (unlikely(!th))
|
|
goto out;
|
|
|
|
skb_gro_pull(skb, thlen);
|
|
|
|
len = skb_gro_len(skb);
|
|
flags = tcp_flag_word(th);
|
|
|
|
for (; (p = *head); head = &p->next) {
|
|
if (!NAPI_GRO_CB(p)->same_flow)
|
|
continue;
|
|
|
|
th2 = tcp_hdr(p);
|
|
|
|
if ((th->source ^ th2->source) | (th->dest ^ th2->dest)) {
|
|
NAPI_GRO_CB(p)->same_flow = 0;
|
|
continue;
|
|
}
|
|
|
|
goto found;
|
|
}
|
|
|
|
goto out_check_final;
|
|
|
|
found:
|
|
flush = NAPI_GRO_CB(p)->flush;
|
|
flush |= flags & TCP_FLAG_CWR;
|
|
flush |= (flags ^ tcp_flag_word(th2)) &
|
|
~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH);
|
|
flush |= (th->ack_seq ^ th2->ack_seq) | (th->window ^ th2->window);
|
|
for (i = sizeof(*th); !flush && i < thlen; i += 4)
|
|
flush |= *(u32 *)((u8 *)th + i) ^
|
|
*(u32 *)((u8 *)th2 + i);
|
|
|
|
mss = skb_shinfo(p)->gso_size;
|
|
|
|
flush |= (len > mss) | !len;
|
|
flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq);
|
|
|
|
if (flush || skb_gro_receive(head, skb)) {
|
|
mss = 1;
|
|
goto out_check_final;
|
|
}
|
|
|
|
p = *head;
|
|
th2 = tcp_hdr(p);
|
|
tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH);
|
|
|
|
out_check_final:
|
|
flush = len < mss;
|
|
flush |= flags & (TCP_FLAG_URG | TCP_FLAG_PSH | TCP_FLAG_RST |
|
|
TCP_FLAG_SYN | TCP_FLAG_FIN);
|
|
|
|
if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
|
|
pp = head;
|
|
|
|
out:
|
|
NAPI_GRO_CB(skb)->flush |= flush;
|
|
|
|
return pp;
|
|
}
|
|
EXPORT_SYMBOL(tcp_gro_receive);
|
|
|
|
int tcp_gro_complete(struct sk_buff *skb)
|
|
{
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
|
|
skb->csum_start = skb_transport_header(skb) - skb->head;
|
|
skb->csum_offset = offsetof(struct tcphdr, check);
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
|
|
skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
|
|
|
|
if (th->cwr)
|
|
skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(tcp_gro_complete);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
static unsigned long tcp_md5sig_users;
|
|
static struct tcp_md5sig_pool **tcp_md5sig_pool;
|
|
static DEFINE_SPINLOCK(tcp_md5sig_pool_lock);
|
|
|
|
static void __tcp_free_md5sig_pool(struct tcp_md5sig_pool **pool)
|
|
{
|
|
int cpu;
|
|
for_each_possible_cpu(cpu) {
|
|
struct tcp_md5sig_pool *p = *per_cpu_ptr(pool, cpu);
|
|
if (p) {
|
|
if (p->md5_desc.tfm)
|
|
crypto_free_hash(p->md5_desc.tfm);
|
|
kfree(p);
|
|
p = NULL;
|
|
}
|
|
}
|
|
free_percpu(pool);
|
|
}
|
|
|
|
void tcp_free_md5sig_pool(void)
|
|
{
|
|
struct tcp_md5sig_pool **pool = NULL;
|
|
|
|
spin_lock_bh(&tcp_md5sig_pool_lock);
|
|
if (--tcp_md5sig_users == 0) {
|
|
pool = tcp_md5sig_pool;
|
|
tcp_md5sig_pool = NULL;
|
|
}
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
if (pool)
|
|
__tcp_free_md5sig_pool(pool);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_free_md5sig_pool);
|
|
|
|
static struct tcp_md5sig_pool **__tcp_alloc_md5sig_pool(void)
|
|
{
|
|
int cpu;
|
|
struct tcp_md5sig_pool **pool;
|
|
|
|
pool = alloc_percpu(struct tcp_md5sig_pool *);
|
|
if (!pool)
|
|
return NULL;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct tcp_md5sig_pool *p;
|
|
struct crypto_hash *hash;
|
|
|
|
p = kzalloc(sizeof(*p), GFP_KERNEL);
|
|
if (!p)
|
|
goto out_free;
|
|
*per_cpu_ptr(pool, cpu) = p;
|
|
|
|
hash = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC);
|
|
if (!hash || IS_ERR(hash))
|
|
goto out_free;
|
|
|
|
p->md5_desc.tfm = hash;
|
|
}
|
|
return pool;
|
|
out_free:
|
|
__tcp_free_md5sig_pool(pool);
|
|
return NULL;
|
|
}
|
|
|
|
struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(void)
|
|
{
|
|
struct tcp_md5sig_pool **pool;
|
|
int alloc = 0;
|
|
|
|
retry:
|
|
spin_lock_bh(&tcp_md5sig_pool_lock);
|
|
pool = tcp_md5sig_pool;
|
|
if (tcp_md5sig_users++ == 0) {
|
|
alloc = 1;
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
} else if (!pool) {
|
|
tcp_md5sig_users--;
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
cpu_relax();
|
|
goto retry;
|
|
} else
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
|
|
if (alloc) {
|
|
/* we cannot hold spinlock here because this may sleep. */
|
|
struct tcp_md5sig_pool **p = __tcp_alloc_md5sig_pool();
|
|
spin_lock_bh(&tcp_md5sig_pool_lock);
|
|
if (!p) {
|
|
tcp_md5sig_users--;
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
return NULL;
|
|
}
|
|
pool = tcp_md5sig_pool;
|
|
if (pool) {
|
|
/* oops, it has already been assigned. */
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
__tcp_free_md5sig_pool(p);
|
|
} else {
|
|
tcp_md5sig_pool = pool = p;
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
}
|
|
}
|
|
return pool;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);
|
|
|
|
struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu)
|
|
{
|
|
struct tcp_md5sig_pool **p;
|
|
spin_lock_bh(&tcp_md5sig_pool_lock);
|
|
p = tcp_md5sig_pool;
|
|
if (p)
|
|
tcp_md5sig_users++;
|
|
spin_unlock_bh(&tcp_md5sig_pool_lock);
|
|
return (p ? *per_cpu_ptr(p, cpu) : NULL);
|
|
}
|
|
|
|
EXPORT_SYMBOL(__tcp_get_md5sig_pool);
|
|
|
|
void __tcp_put_md5sig_pool(void)
|
|
{
|
|
tcp_free_md5sig_pool();
|
|
}
|
|
|
|
EXPORT_SYMBOL(__tcp_put_md5sig_pool);
|
|
|
|
int tcp_md5_hash_header(struct tcp_md5sig_pool *hp,
|
|
struct tcphdr *th)
|
|
{
|
|
struct scatterlist sg;
|
|
int err;
|
|
|
|
__sum16 old_checksum = th->check;
|
|
th->check = 0;
|
|
/* options aren't included in the hash */
|
|
sg_init_one(&sg, th, sizeof(struct tcphdr));
|
|
err = crypto_hash_update(&hp->md5_desc, &sg, sizeof(struct tcphdr));
|
|
th->check = old_checksum;
|
|
return err;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_md5_hash_header);
|
|
|
|
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
|
|
struct sk_buff *skb, unsigned header_len)
|
|
{
|
|
struct scatterlist sg;
|
|
const struct tcphdr *tp = tcp_hdr(skb);
|
|
struct hash_desc *desc = &hp->md5_desc;
|
|
unsigned i;
|
|
const unsigned head_data_len = skb_headlen(skb) > header_len ?
|
|
skb_headlen(skb) - header_len : 0;
|
|
const struct skb_shared_info *shi = skb_shinfo(skb);
|
|
|
|
sg_init_table(&sg, 1);
|
|
|
|
sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
|
|
if (crypto_hash_update(desc, &sg, head_data_len))
|
|
return 1;
|
|
|
|
for (i = 0; i < shi->nr_frags; ++i) {
|
|
const struct skb_frag_struct *f = &shi->frags[i];
|
|
sg_set_page(&sg, f->page, f->size, f->page_offset);
|
|
if (crypto_hash_update(desc, &sg, f->size))
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_md5_hash_skb_data);
|
|
|
|
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, struct tcp_md5sig_key *key)
|
|
{
|
|
struct scatterlist sg;
|
|
|
|
sg_init_one(&sg, key->key, key->keylen);
|
|
return crypto_hash_update(&hp->md5_desc, &sg, key->keylen);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_md5_hash_key);
|
|
|
|
#endif
|
|
|
|
void tcp_done(struct sock *sk)
|
|
{
|
|
if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
|
|
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
|
|
|
|
tcp_set_state(sk, TCP_CLOSE);
|
|
tcp_clear_xmit_timers(sk);
|
|
|
|
sk->sk_shutdown = SHUTDOWN_MASK;
|
|
|
|
if (!sock_flag(sk, SOCK_DEAD))
|
|
sk->sk_state_change(sk);
|
|
else
|
|
inet_csk_destroy_sock(sk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(tcp_done);
|
|
|
|
extern struct tcp_congestion_ops tcp_reno;
|
|
|
|
static __initdata unsigned long thash_entries;
|
|
static int __init set_thash_entries(char *str)
|
|
{
|
|
if (!str)
|
|
return 0;
|
|
thash_entries = simple_strtoul(str, &str, 0);
|
|
return 1;
|
|
}
|
|
__setup("thash_entries=", set_thash_entries);
|
|
|
|
void __init tcp_init(void)
|
|
{
|
|
struct sk_buff *skb = NULL;
|
|
unsigned long nr_pages, limit;
|
|
int order, i, max_share;
|
|
|
|
BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
|
|
|
|
percpu_counter_init(&tcp_sockets_allocated, 0);
|
|
percpu_counter_init(&tcp_orphan_count, 0);
|
|
tcp_hashinfo.bind_bucket_cachep =
|
|
kmem_cache_create("tcp_bind_bucket",
|
|
sizeof(struct inet_bind_bucket), 0,
|
|
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
|
|
|
|
/* Size and allocate the main established and bind bucket
|
|
* hash tables.
|
|
*
|
|
* The methodology is similar to that of the buffer cache.
|
|
*/
|
|
tcp_hashinfo.ehash =
|
|
alloc_large_system_hash("TCP established",
|
|
sizeof(struct inet_ehash_bucket),
|
|
thash_entries,
|
|
(num_physpages >= 128 * 1024) ?
|
|
13 : 15,
|
|
0,
|
|
&tcp_hashinfo.ehash_size,
|
|
NULL,
|
|
thash_entries ? 0 : 512 * 1024);
|
|
tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
|
|
for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
|
|
INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
|
|
INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
|
|
}
|
|
if (inet_ehash_locks_alloc(&tcp_hashinfo))
|
|
panic("TCP: failed to alloc ehash_locks");
|
|
tcp_hashinfo.bhash =
|
|
alloc_large_system_hash("TCP bind",
|
|
sizeof(struct inet_bind_hashbucket),
|
|
tcp_hashinfo.ehash_size,
|
|
(num_physpages >= 128 * 1024) ?
|
|
13 : 15,
|
|
0,
|
|
&tcp_hashinfo.bhash_size,
|
|
NULL,
|
|
64 * 1024);
|
|
tcp_hashinfo.bhash_size = 1 << tcp_hashinfo.bhash_size;
|
|
for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
|
|
spin_lock_init(&tcp_hashinfo.bhash[i].lock);
|
|
INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
|
|
}
|
|
|
|
/* Try to be a bit smarter and adjust defaults depending
|
|
* on available memory.
|
|
*/
|
|
for (order = 0; ((1 << order) << PAGE_SHIFT) <
|
|
(tcp_hashinfo.bhash_size * sizeof(struct inet_bind_hashbucket));
|
|
order++)
|
|
;
|
|
if (order >= 4) {
|
|
tcp_death_row.sysctl_max_tw_buckets = 180000;
|
|
sysctl_tcp_max_orphans = 4096 << (order - 4);
|
|
sysctl_max_syn_backlog = 1024;
|
|
} else if (order < 3) {
|
|
tcp_death_row.sysctl_max_tw_buckets >>= (3 - order);
|
|
sysctl_tcp_max_orphans >>= (3 - order);
|
|
sysctl_max_syn_backlog = 128;
|
|
}
|
|
|
|
/* Set the pressure threshold to be a fraction of global memory that
|
|
* is up to 1/2 at 256 MB, decreasing toward zero with the amount of
|
|
* memory, with a floor of 128 pages.
|
|
*/
|
|
nr_pages = totalram_pages - totalhigh_pages;
|
|
limit = min(nr_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
|
|
limit = (limit * (nr_pages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
|
|
limit = max(limit, 128UL);
|
|
sysctl_tcp_mem[0] = limit / 4 * 3;
|
|
sysctl_tcp_mem[1] = limit;
|
|
sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;
|
|
|
|
/* Set per-socket limits to no more than 1/128 the pressure threshold */
|
|
limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
|
|
max_share = min(4UL*1024*1024, limit);
|
|
|
|
sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
|
|
sysctl_tcp_wmem[1] = 16*1024;
|
|
sysctl_tcp_wmem[2] = max(64*1024, max_share);
|
|
|
|
sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
|
|
sysctl_tcp_rmem[1] = 87380;
|
|
sysctl_tcp_rmem[2] = max(87380, max_share);
|
|
|
|
printk(KERN_INFO "TCP: Hash tables configured "
|
|
"(established %d bind %d)\n",
|
|
tcp_hashinfo.ehash_size, tcp_hashinfo.bhash_size);
|
|
|
|
tcp_register_congestion_control(&tcp_reno);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_close);
|
|
EXPORT_SYMBOL(tcp_disconnect);
|
|
EXPORT_SYMBOL(tcp_getsockopt);
|
|
EXPORT_SYMBOL(tcp_ioctl);
|
|
EXPORT_SYMBOL(tcp_poll);
|
|
EXPORT_SYMBOL(tcp_read_sock);
|
|
EXPORT_SYMBOL(tcp_recvmsg);
|
|
EXPORT_SYMBOL(tcp_sendmsg);
|
|
EXPORT_SYMBOL(tcp_splice_read);
|
|
EXPORT_SYMBOL(tcp_sendpage);
|
|
EXPORT_SYMBOL(tcp_setsockopt);
|
|
EXPORT_SYMBOL(tcp_shutdown);
|