| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * Implementation of the Transmission Control Protocol(TCP). |
| * |
| * Version: $Id: tcp.c,v 1.216 2002/02/01 22:01:04 davem Exp $ |
| * |
| * Authors: Ross Biro |
| * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| * Mark Evans, <evansmp@uhura.aston.ac.uk> |
| * Corey Minyard <wf-rch!minyard@relay.EU.net> |
| * Florian La Roche, <flla@stud.uni-sb.de> |
| * Charles Hedrick, <hedrick@klinzhai.rutgers.edu> |
| * Linus Torvalds, <torvalds@cs.helsinki.fi> |
| * Alan Cox, <gw4pts@gw4pts.ampr.org> |
| * Matthew Dillon, <dillon@apollo.west.oic.com> |
| * Arnt Gulbrandsen, <agulbra@nvg.unit.no> |
| * Jorge Cwik, <jorge@laser.satlink.net> |
| * |
| * Fixes: |
| * Alan Cox : Numerous verify_area() calls |
| * Alan Cox : Set the ACK bit on a reset |
| * Alan Cox : Stopped it crashing if it closed while |
| * sk->inuse=1 and was trying to connect |
| * (tcp_err()). |
| * Alan Cox : All icmp error handling was broken |
| * pointers passed where wrong and the |
| * socket was looked up backwards. Nobody |
| * tested any icmp error code obviously. |
| * Alan Cox : tcp_err() now handled properly. It |
| * wakes people on errors. poll |
| * behaves and the icmp error race |
| * has gone by moving it into sock.c |
| * Alan Cox : tcp_send_reset() fixed to work for |
| * everything not just packets for |
| * unknown sockets. |
| * Alan Cox : tcp option processing. |
| * Alan Cox : Reset tweaked (still not 100%) [Had |
| * syn rule wrong] |
| * Herp Rosmanith : More reset fixes |
| * Alan Cox : No longer acks invalid rst frames. |
| * Acking any kind of RST is right out. |
| * Alan Cox : Sets an ignore me flag on an rst |
| * receive otherwise odd bits of prattle |
| * escape still |
| * Alan Cox : Fixed another acking RST frame bug. |
| * Should stop LAN workplace lockups. |
| * Alan Cox : Some tidyups using the new skb list |
| * facilities |
| * Alan Cox : sk->keepopen now seems to work |
| * Alan Cox : Pulls options out correctly on accepts |
| * Alan Cox : Fixed assorted sk->rqueue->next errors |
| * Alan Cox : PSH doesn't end a TCP read. Switched a |
| * bit to skb ops. |
| * Alan Cox : Tidied tcp_data to avoid a potential |
| * nasty. |
| * Alan Cox : Added some better commenting, as the |
| * tcp is hard to follow |
| * Alan Cox : Removed incorrect check for 20 * psh |
| * Michael O'Reilly : ack < copied bug fix. |
| * Johannes Stille : Misc tcp fixes (not all in yet). |
| * Alan Cox : FIN with no memory -> CRASH |
| * Alan Cox : Added socket option proto entries. |
| * Also added awareness of them to accept. |
| * Alan Cox : Added TCP options (SOL_TCP) |
| * Alan Cox : Switched wakeup calls to callbacks, |
| * so the kernel can layer network |
| * sockets. |
| * Alan Cox : Use ip_tos/ip_ttl settings. |
| * Alan Cox : Handle FIN (more) properly (we hope). |
| * Alan Cox : RST frames sent on unsynchronised |
| * state ack error. |
| * Alan Cox : Put in missing check for SYN bit. |
| * Alan Cox : Added tcp_select_window() aka NET2E |
| * window non shrink trick. |
| * Alan Cox : Added a couple of small NET2E timer |
| * fixes |
| * Charles Hedrick : TCP fixes |
| * Toomas Tamm : TCP window fixes |
| * Alan Cox : Small URG fix to rlogin ^C ack fight |
| * Charles Hedrick : Rewrote most of it to actually work |
| * Linus : Rewrote tcp_read() and URG handling |
| * completely |
| * Gerhard Koerting: Fixed some missing timer handling |
| * Matthew Dillon : Reworked TCP machine states as per RFC |
| * Gerhard Koerting: PC/TCP workarounds |
| * Adam Caldwell : Assorted timer/timing errors |
| * Matthew Dillon : Fixed another RST bug |
| * Alan Cox : Move to kernel side addressing changes. |
| * Alan Cox : Beginning work on TCP fastpathing |
| * (not yet usable) |
| * Arnt Gulbrandsen: Turbocharged tcp_check() routine. |
| * Alan Cox : TCP fast path debugging |
| * Alan Cox : Window clamping |
| * Michael Riepe : Bug in tcp_check() |
| * Matt Dillon : More TCP improvements and RST bug fixes |
| * Matt Dillon : Yet more small nasties remove from the |
| * TCP code (Be very nice to this man if |
| * tcp finally works 100%) 8) |
| * Alan Cox : BSD accept semantics. |
| * Alan Cox : Reset on closedown bug. |
| * Peter De Schrijver : ENOTCONN check missing in tcp_sendto(). |
| * Michael Pall : Handle poll() after URG properly in |
| * all cases. |
| * Michael Pall : Undo the last fix in tcp_read_urg() |
| * (multi URG PUSH broke rlogin). |
| * Michael Pall : Fix the multi URG PUSH problem in |
| * tcp_readable(), poll() after URG |
| * works now. |
| * Michael Pall : recv(...,MSG_OOB) never blocks in the |
| * BSD api. |
| * Alan Cox : Changed the semantics of sk->socket to |
| * fix a race and a signal problem with |
| * accept() and async I/O. |
| * Alan Cox : Relaxed the rules on tcp_sendto(). |
| * Yury Shevchuk : Really fixed accept() blocking problem. |
| * Craig I. Hagan : Allow for BSD compatible TIME_WAIT for |
| * clients/servers which listen in on |
| * fixed ports. |
| * Alan Cox : Cleaned the above up and shrank it to |
| * a sensible code size. |
| * Alan Cox : Self connect lockup fix. |
| * Alan Cox : No connect to multicast. |
| * Ross Biro : Close unaccepted children on master |
| * socket close. |
| * Alan Cox : Reset tracing code. |
| * Alan Cox : Spurious resets on shutdown. |
| * Alan Cox : Giant 15 minute/60 second timer error |
| * Alan Cox : Small whoops in polling before an |
| * accept. |
| * Alan Cox : Kept the state trace facility since |
| * it's handy for debugging. |
| * Alan Cox : More reset handler fixes. |
| * Alan Cox : Started rewriting the code based on |
| * the RFC's for other useful protocol |
| * references see: Comer, KA9Q NOS, and |
| * for a reference on the difference |
| * between specifications and how BSD |
| * works see the 4.4lite source. |
| * A.N.Kuznetsov : Don't time wait on completion of tidy |
| * close. |
| * Linus Torvalds : Fin/Shutdown & copied_seq changes. |
| * Linus Torvalds : Fixed BSD port reuse to work first syn |
| * Alan Cox : Reimplemented timers as per the RFC |
| * and using multiple timers for sanity. |
| * Alan Cox : Small bug fixes, and a lot of new |
| * comments. |
| * Alan Cox : Fixed dual reader crash by locking |
| * the buffers (much like datagram.c) |
| * Alan Cox : Fixed stuck sockets in probe. A probe |
| * now gets fed up of retrying without |
| * (even a no space) answer. |
| * Alan Cox : Extracted closing code better |
| * Alan Cox : Fixed the closing state machine to |
| * resemble the RFC. |
| * Alan Cox : More 'per spec' fixes. |
| * Jorge Cwik : Even faster checksumming. |
| * Alan Cox : tcp_data() doesn't ack illegal PSH |
| * only frames. At least one pc tcp stack |
| * generates them. |
| * Alan Cox : Cache last socket. |
| * Alan Cox : Per route irtt. |
| * Matt Day : poll()->select() match BSD precisely on error |
| * Alan Cox : New buffers |
| * Marc Tamsky : Various sk->prot->retransmits and |
| * sk->retransmits misupdating fixed. |
| * Fixed tcp_write_timeout: stuck close, |
| * and TCP syn retries gets used now. |
| * Mark Yarvis : In tcp_read_wakeup(), don't send an |
| * ack if state is TCP_CLOSED. |
| * Alan Cox : Look up device on a retransmit - routes may |
| * change. Doesn't yet cope with MSS shrink right |
| * but it's a start! |
| * Marc Tamsky : Closing in closing fixes. |
| * Mike Shaver : RFC1122 verifications. |
| * Alan Cox : rcv_saddr errors. |
| * Alan Cox : Block double connect(). |
| * Alan Cox : Small hooks for enSKIP. |
| * Alexey Kuznetsov: Path MTU discovery. |
| * Alan Cox : Support soft errors. |
| * Alan Cox : Fix MTU discovery pathological case |
| * when the remote claims no mtu! |
| * Marc Tamsky : TCP_CLOSE fix. |
| * Colin (G3TNE) : Send a reset on syn ack replies in |
| * window but wrong (fixes NT lpd problems) |
| * Pedro Roque : Better TCP window handling, delayed ack. |
| * Joerg Reuter : No modification of locked buffers in |
| * tcp_do_retransmit() |
| * Eric Schenk : Changed receiver side silly window |
| * avoidance algorithm to BSD style |
| * algorithm. This doubles throughput |
| * against machines running Solaris, |
| * and seems to result in general |
| * improvement. |
| * Stefan Magdalinski : adjusted tcp_readable() to fix FIONREAD |
| * Willy Konynenberg : Transparent proxying support. |
| * Mike McLagan : Routing by source |
| * Keith Owens : Do proper merging with partial SKB's in |
| * tcp_do_sendmsg to avoid burstiness. |
| * Eric Schenk : Fix fast close down bug with |
| * shutdown() followed by close(). |
| * Andi Kleen : Make poll agree with SIGIO |
| * Salvatore Sanfilippo : Support SO_LINGER with linger == 1 and |
| * lingertime == 0 (RFC 793 ABORT Call) |
| * Hirokazu Takahashi : Use copy_from_user() instead of |
| * csum_and_copy_from_user() if possible. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or(at your option) any later version. |
| * |
| * Description of States: |
| * |
| * TCP_SYN_SENT sent a connection request, waiting for ack |
| * |
| * TCP_SYN_RECV received a connection request, sent ack, |
| * waiting for final ack in three-way handshake. |
| * |
| * TCP_ESTABLISHED connection established |
| * |
| * TCP_FIN_WAIT1 our side has shutdown, waiting to complete |
| * transmission of remaining buffered data |
| * |
| * TCP_FIN_WAIT2 all buffered data sent, waiting for remote |
| * to shutdown |
| * |
| * TCP_CLOSING both sides have shutdown but we still have |
| * data we have to finish sending |
| * |
| * TCP_TIME_WAIT timeout to catch resent junk before entering |
| * closed, can only be entered from FIN_WAIT2 |
| * or CLOSING. Required because the other end |
| * may not have gotten our last ACK causing it |
| * to retransmit the data packet (which we ignore) |
| * |
| * TCP_CLOSE_WAIT remote side has shutdown and is waiting for |
| * us to finish writing our data and to shutdown |
| * (we have to close() to move on to LAST_ACK) |
| * |
| * TCP_LAST_ACK out side has shutdown after remote has |
| * shutdown. There may still be data in our |
| * buffer that we have to finish sending |
| * |
| * TCP_CLOSE socket is finished |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/fcntl.h> |
| #include <linux/poll.h> |
| #include <linux/init.h> |
| #include <linux/smp_lock.h> |
| #include <linux/fs.h> |
| #include <linux/random.h> |
| #include <linux/bootmem.h> |
| #include <linux/cache.h> |
| #include <linux/err.h> |
| #include <linux/crypto.h> |
| |
| #include <net/icmp.h> |
| #include <net/tcp.h> |
| #include <net/xfrm.h> |
| #include <net/ip.h> |
| #include <net/netdma.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/ioctls.h> |
| |
| int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT; |
| |
| DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics) __read_mostly; |
| |
| atomic_t tcp_orphan_count = ATOMIC_INIT(0); |
| |
| EXPORT_SYMBOL_GPL(tcp_orphan_count); |
| |
| int sysctl_tcp_mem[3] __read_mostly; |
| int sysctl_tcp_wmem[3] __read_mostly; |
| int sysctl_tcp_rmem[3] __read_mostly; |
| |
| EXPORT_SYMBOL(sysctl_tcp_mem); |
| EXPORT_SYMBOL(sysctl_tcp_rmem); |
| EXPORT_SYMBOL(sysctl_tcp_wmem); |
| |
| atomic_t tcp_memory_allocated; /* Current allocated memory. */ |
| atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */ |
| |
| EXPORT_SYMBOL(tcp_memory_allocated); |
| EXPORT_SYMBOL(tcp_sockets_allocated); |
| |
| /* |
| * Pressure flag: try to collapse. |
| * Technical note: it is used by multiple contexts non atomically. |
| * All the sk_stream_mem_schedule() is of this nature: accounting |
| * is strict, actions are advisory and have some latency. |
| */ |
| int tcp_memory_pressure __read_mostly; |
| |
| EXPORT_SYMBOL(tcp_memory_pressure); |
| |
| void tcp_enter_memory_pressure(void) |
| { |
| if (!tcp_memory_pressure) { |
| NET_INC_STATS(LINUX_MIB_TCPMEMORYPRESSURES); |
| tcp_memory_pressure = 1; |
| } |
| } |
| |
| EXPORT_SYMBOL(tcp_enter_memory_pressure); |
| |
| /* |
| * Wait for a TCP event. |
| * |
| * Note that we don't need to lock the socket, as the upper poll layers |
| * take care of normal races (between the test and the event) and we don't |
| * go look at any of the socket buffers directly. |
| */ |
| unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait) |
| { |
| unsigned int mask; |
| struct sock *sk = sock->sk; |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| poll_wait(file, sk->sk_sleep, wait); |
| if (sk->sk_state == TCP_LISTEN) |
| return inet_csk_listen_poll(sk); |
| |
| /* Socket is not locked. We are protected from async events |
| by poll logic and correct handling of state changes |
| made by another threads is impossible in any case. |
| */ |
| |
| mask = 0; |
| if (sk->sk_err) |
| mask = POLLERR; |
| |
| /* |
| * POLLHUP is certainly not done right. But poll() doesn't |
| * have a notion of HUP in just one direction, and for a |
| * socket the read side is more interesting. |
| * |
| * Some poll() documentation says that POLLHUP is incompatible |
| * with the POLLOUT/POLLWR flags, so somebody should check this |
| * all. But careful, it tends to be safer to return too many |
| * bits than too few, and you can easily break real applications |
| * if you don't tell them that something has hung up! |
| * |
| * Check-me. |
| * |
| * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and |
| * our fs/select.c). It means that after we received EOF, |
| * poll always returns immediately, making impossible poll() on write() |
| * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP |
| * if and only if shutdown has been made in both directions. |
| * Actually, it is interesting to look how Solaris and DUX |
| * solve this dilemma. I would prefer, if PULLHUP were maskable, |
| * then we could set it on SND_SHUTDOWN. BTW examples given |
| * in Stevens' books assume exactly this behaviour, it explains |
| * why PULLHUP is incompatible with POLLOUT. --ANK |
| * |
| * NOTE. Check for TCP_CLOSE is added. The goal is to prevent |
| * blocking on fresh not-connected or disconnected socket. --ANK |
| */ |
| if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE) |
| mask |= POLLHUP; |
| if (sk->sk_shutdown & RCV_SHUTDOWN) |
| mask |= POLLIN | POLLRDNORM | POLLRDHUP; |
| |
| /* Connected? */ |
| if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) { |
| /* Potential race condition. If read of tp below will |
| * escape above sk->sk_state, we can be illegally awaken |
| * in SYN_* states. */ |
| if ((tp->rcv_nxt != tp->copied_seq) && |
| (tp->urg_seq != tp->copied_seq || |
| tp->rcv_nxt != tp->copied_seq + 1 || |
| sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data)) |
| mask |= POLLIN | POLLRDNORM; |
| |
| if (!(sk->sk_shutdown & SEND_SHUTDOWN)) { |
| if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) { |
| mask |= POLLOUT | POLLWRNORM; |
| } else { /* send SIGIO later */ |
| set_bit(SOCK_ASYNC_NOSPACE, |
| &sk->sk_socket->flags); |
| set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); |
| |
| /* Race breaker. If space is freed after |
| * wspace test but before the flags are set, |
| * IO signal will be lost. |
| */ |
| if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) |
| mask |= POLLOUT | POLLWRNORM; |
| } |
| } |
| |
| if (tp->urg_data & TCP_URG_VALID) |
| mask |= POLLPRI; |
| } |
| return mask; |
| } |
| |
| int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| int answ; |
| |
| switch (cmd) { |
| case SIOCINQ: |
| if (sk->sk_state == TCP_LISTEN) |
| return -EINVAL; |
| |
| lock_sock(sk); |
| if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) |
| answ = 0; |
| else if (sock_flag(sk, SOCK_URGINLINE) || |
| !tp->urg_data || |
| before(tp->urg_seq, tp->copied_seq) || |
| !before(tp->urg_seq, tp->rcv_nxt)) { |
| answ = tp->rcv_nxt - tp->copied_seq; |
| |
| /* Subtract 1, if FIN is in queue. */ |
| if (answ && !skb_queue_empty(&sk->sk_receive_queue)) |
| answ -= |
| tcp_hdr((struct sk_buff *)sk->sk_receive_queue.prev)->fin; |
| } else |
| answ = tp->urg_seq - tp->copied_seq; |
| release_sock(sk); |
| break; |
| case SIOCATMARK: |
| answ = tp->urg_data && tp->urg_seq == tp->copied_seq; |
| break; |
| case SIOCOUTQ: |
| if (sk->sk_state == TCP_LISTEN) |
| return -EINVAL; |
| |
| if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) |
| answ = 0; |
| else |
| answ = tp->write_seq - tp->snd_una; |
| break; |
| default: |
| return -ENOIOCTLCMD; |
| }; |
| |
| 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 tcp_sock *tp, |
| struct sk_buff *skb) |
| { |
| 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_charge_skb(sk, skb); |
| 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->urg_mode = 1; |
| tp->snd_up = tp->write_seq; |
| TCP_SKB_CB(skb)->sacked |= TCPCB_URG; |
| } |
| } |
| |
| static inline void tcp_push(struct sock *sk, struct tcp_sock *tp, int flags, |
| int mss_now, int nonagle) |
| { |
| 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, tp, mss_now, |
| (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle); |
| } |
| } |
| |
| 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_current_mss(sk, !(flags&MSG_OOB)); |
| size_goal = tp->xmit_size_goal; |
| copied = 0; |
| |
| err = -EPIPE; |
| if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) |
| goto do_error; |
| |
| 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_pskb(sk, 0, 0, |
| sk->sk_allocation); |
| if (!skb) |
| goto wait_for_memory; |
| |
| skb_entail(sk, tp, 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_stream_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->sk_forward_alloc -= 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 < mss_now || (flags & MSG_OOB)) |
| continue; |
| |
| if (forced_push(tp)) { |
| tcp_mark_push(tp, skb); |
| __tcp_push_pending_frames(sk, tp, 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, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); |
| |
| if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) |
| goto do_error; |
| |
| mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); |
| size_goal = tp->xmit_size_goal; |
| } |
| |
| out: |
| if (copied) |
| tcp_push(sk, tp, 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) |
| { |
| 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 sock *sk, struct msghdr *msg, |
| size_t size) |
| { |
| 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_current_mss(sk, !(flags&MSG_OOB)); |
| size_goal = tp->xmit_size_goal; |
| |
| /* 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 do_error; |
| |
| 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_pskb(sk, select_size(sk, tp), |
| 0, 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, tp, 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_stream_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 < mss_now || (flags & MSG_OOB)) |
| continue; |
| |
| if (forced_push(tp)) { |
| tcp_mark_push(tp, skb); |
| __tcp_push_pending_frames(sk, tp, 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, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH); |
| |
| if ((err = sk_stream_wait_memory(sk, &timeo)) != 0) |
| goto do_error; |
| |
| mss_now = tcp_current_mss(sk, !(flags&MSG_OOB)); |
| size_goal = tp->xmit_size_goal; |
| } |
| } |
| |
| out: |
| if (copied) |
| tcp_push(sk, tp, 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_stream_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, long timeo, |
| struct msghdr *msg, int len, int flags, |
| int *addr_len) |
| { |
| 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); |
| |
| BUG_TRAP(!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(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->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) { |
| size_t used, 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 <= len) { |
| seq += used; |
| copied += used; |
| offset += used; |
| } |
| if (offset != 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) |
| 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; |
| |
| 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(); |
| if ((len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) && |
| !sysctl_tcp_low_latency && __get_cpu_var(softnet_data).net_dma) { |
| preempt_enable_no_resched(); |
| tp->ucopy.pinned_list = dma_pin_iovec_pages(msg->msg_iov, len); |
| } else |
| preempt_enable_no_resched(); |
| #endif |
| |
| do { |
| struct sk_buff *skb; |
| 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; |
| BUG_TRAP(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) || |
| (flags & MSG_PEEK)) |
| 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; |
| |
| BUG_TRAP(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(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(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, current->pid); |
| 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 = get_softnet_dma(); |
| |
| 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, tp); |
| } |
| 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(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) { |
| struct sk_buff *skb; |
| 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); |
| dma_chan_put(tp->ucopy.dma_chan); |
| 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, timeo, msg, len, flags, addr_len); |
| goto out; |
| } |
| |
| /* |
| * 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 set_sock_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_stream_mem_reclaim(sk); |
| |
| /* As outlined in draft-ietf-tcpimpl-prob-03.txt, section |
| * 3.10, 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(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(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); |
| atomic_inc(sk->sk_prot->orphan_count); |
| |
| /* 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); |
| BUG_TRAP(!sock_owned_by_user(sk)); |
| |
| /* 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(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) { |
| sk_stream_mem_reclaim(sk); |
| if (atomic_read(sk->sk_prot->orphan_count) > sysctl_tcp_max_orphans || |
| (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && |
| atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])) { |
| 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(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); |
| tp->rx_opt.saw_tstamp = 0; |
| tcp_sack_reset(&tp->rx_opt); |
| __sk_dst_reset(sk); |
| |
| BUG_TRAP(!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, tp); |
| } 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, tp); |
| } |
| 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 (tp->rx_opt.sack_ok) |
| 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; |
| |
| 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 len; |
| |
| 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); |
| |
| 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; |
| int mss; |
| |
| 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; |
| |
| mss = skb_shinfo(skb)->gso_size; |
| skb_shinfo(skb)->gso_segs = (skb->len + mss - 1) / mss; |
| |
| segs = NULL; |
| goto out; |
| } |
| |
| segs = skb_segment(skb, features); |
| if (IS_ERR(segs)) |
| goto out; |
| |
| len = skb_shinfo(skb)->gso_size; |
| delta = htonl(oldlen + (thlen + len)); |
| |
| 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 += len; |
| 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); |
| |
| #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); |
| #endif |
| |
| extern void __skb_cb_too_small_for_tcp(int, int); |
| 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 limit; |
| int order, i, max_share; |
| |
| if (sizeof(struct tcp_skb_cb) > sizeof(skb->cb)) |
| __skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb), |
| sizeof(skb->cb)); |
| |
| tcp_hashinfo.bind_bucket_cachep = |
| kmem_cache_create("tcp_bind_bucket", |
| sizeof(struct inet_bind_bucket), 0, |
| SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, 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, |
| 0); |
| tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size; |
| for (i = 0; i < tcp_hashinfo.ehash_size; i++) { |
| rwlock_init(&tcp_hashinfo.ehash[i].lock); |
| INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain); |
| INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain); |
| } |
| |
| 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) { |
| sysctl_local_port_range[0] = 32768; |
| sysctl_local_port_range[1] = 61000; |
| tcp_death_row.sysctl_max_tw_buckets = 180000; |
| sysctl_tcp_max_orphans = 4096 << (order - 4); |
| sysctl_max_syn_backlog = 1024; |
| } else if (order < 3) { |
| sysctl_local_port_range[0] = 1024 * (3 - order); |
| 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. |
| */ |
| limit = min(nr_all_pages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT); |
| limit = (limit * (nr_all_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_STREAM_MEM_QUANTUM; |
| sysctl_tcp_wmem[1] = 16*1024; |
| sysctl_tcp_wmem[2] = max(64*1024, max_share); |
| |
| sysctl_tcp_rmem[0] = SK_STREAM_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_sendpage); |
| EXPORT_SYMBOL(tcp_setsockopt); |
| EXPORT_SYMBOL(tcp_shutdown); |
| EXPORT_SYMBOL(tcp_statistics); |