diff options
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 2386 |
1 files changed, 2386 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c new file mode 100644 index 000000000000..5cff56af7855 --- /dev/null +++ b/net/ipv4/tcp.c @@ -0,0 +1,2386 @@ +/* + * 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, <bir7@leland.Stanford.Edu> + * 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/config.h> +#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 <net/icmp.h> +#include <net/tcp.h> +#include <net/xfrm.h> +#include <net/ip.h> + + +#include <asm/uaccess.h> +#include <asm/ioctls.h> + +int sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT; + +DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics); + +kmem_cache_t *tcp_openreq_cachep; +kmem_cache_t *tcp_bucket_cachep; +kmem_cache_t *tcp_timewait_cachep; + +atomic_t tcp_orphan_count = ATOMIC_INIT(0); + +int sysctl_tcp_mem[3]; +int sysctl_tcp_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 }; +int sysctl_tcp_rmem[3] = { 4 * 1024, 87380, 87380 * 2 }; + +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; + +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); + +/* + * LISTEN is a special case for poll.. + */ +static __inline__ unsigned int tcp_listen_poll(struct sock *sk, + poll_table *wait) +{ + return tcp_sk(sk)->accept_queue ? (POLLIN | POLLRDNORM) : 0; +} + +/* + * 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 tcp_listen_poll(sk, wait); + + /* 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; + + /* 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 -= + ((struct sk_buff *)sk->sk_receive_queue.prev)->h.th->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); +} + + +int tcp_listen_start(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_listen_opt *lopt; + + sk->sk_max_ack_backlog = 0; + sk->sk_ack_backlog = 0; + tp->accept_queue = tp->accept_queue_tail = NULL; + rwlock_init(&tp->syn_wait_lock); + tcp_delack_init(tp); + + lopt = kmalloc(sizeof(struct tcp_listen_opt), GFP_KERNEL); + if (!lopt) + return -ENOMEM; + + memset(lopt, 0, sizeof(struct tcp_listen_opt)); + for (lopt->max_qlen_log = 6; ; lopt->max_qlen_log++) + if ((1 << lopt->max_qlen_log) >= sysctl_max_syn_backlog) + break; + get_random_bytes(&lopt->hash_rnd, 4); + + write_lock_bh(&tp->syn_wait_lock); + tp->listen_opt = lopt; + write_unlock_bh(&tp->syn_wait_lock); + + /* There is race window here: we announce ourselves listening, + * but this transition is still not validated by get_port(). + * It is OK, because this socket enters to hash table only + * after validation is complete. + */ + sk->sk_state = TCP_LISTEN; + if (!sk->sk_prot->get_port(sk, inet->num)) { + inet->sport = htons(inet->num); + + sk_dst_reset(sk); + sk->sk_prot->hash(sk); + + return 0; + } + + sk->sk_state = TCP_CLOSE; + write_lock_bh(&tp->syn_wait_lock); + tp->listen_opt = NULL; + write_unlock_bh(&tp->syn_wait_lock); + kfree(lopt); + return -EADDRINUSE; +} + +/* + * This routine closes sockets which have been at least partially + * opened, but not yet accepted. + */ + +static void tcp_listen_stop (struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_listen_opt *lopt = tp->listen_opt; + struct open_request *acc_req = tp->accept_queue; + struct open_request *req; + int i; + + tcp_delete_keepalive_timer(sk); + + /* make all the listen_opt local to us */ + write_lock_bh(&tp->syn_wait_lock); + tp->listen_opt = NULL; + write_unlock_bh(&tp->syn_wait_lock); + tp->accept_queue = tp->accept_queue_tail = NULL; + + if (lopt->qlen) { + for (i = 0; i < TCP_SYNQ_HSIZE; i++) { + while ((req = lopt->syn_table[i]) != NULL) { + lopt->syn_table[i] = req->dl_next; + lopt->qlen--; + tcp_openreq_free(req); + + /* Following specs, it would be better either to send FIN + * (and enter FIN-WAIT-1, it is normal close) + * or to send active reset (abort). + * Certainly, it is pretty dangerous while synflood, but it is + * bad justification for our negligence 8) + * To be honest, we are not able to make either + * of the variants now. --ANK + */ + } + } + } + BUG_TRAP(!lopt->qlen); + + kfree(lopt); + + while ((req = acc_req) != NULL) { + struct sock *child = req->sk; + + acc_req = req->dl_next; + + local_bh_disable(); + bh_lock_sock(child); + BUG_TRAP(!sock_owned_by_user(child)); + sock_hold(child); + + tcp_disconnect(child, O_NONBLOCK); + + sock_orphan(child); + + atomic_inc(&tcp_orphan_count); + + tcp_destroy_sock(child); + + bh_unlock_sock(child); + local_bh_enable(); + sock_put(child); + + sk_acceptq_removed(sk); + tcp_openreq_fastfree(req); + } + BUG_TRAP(!sk->sk_ack_backlog); +} + +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) +{ + skb->csum = 0; + TCP_SKB_CB(skb)->seq = tp->write_seq; + TCP_SKB_CB(skb)->end_seq = tp->write_seq; + TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK; + TCP_SKB_CB(skb)->sacked = 0; + skb_header_release(skb); + __skb_queue_tail(&sk->sk_write_queue, skb); + sk_charge_skb(sk, skb); + if (!sk->sk_send_head) + sk->sk_send_head = skb; + else 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 (sk->sk_send_head) { + struct sk_buff *skb = sk->sk_write_queue.prev; + 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; + 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)); + copied = 0; + + err = -EPIPE; + if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) + goto do_error; + + while (psize > 0) { + struct sk_buff *skb = sk->sk_write_queue.prev; + 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 (!sk->sk_send_head || (copy = mss_now - 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 = mss_now; + } + + 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->sk_forward_alloc < copy && + !sk_stream_mem_schedule(sk, copy, 0)) + 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_HW; + tp->write_seq += copy; + TCP_SKB_CB(skb)->end_seq += copy; + skb_shinfo(skb)->tso_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 == sk->sk_send_head) + 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)); + } + +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; + +#define TCP_ZC_CSUM_FLAGS (NETIF_F_IP_CSUM | NETIF_F_NO_CSUM | NETIF_F_HW_CSUM) + + if (!(sk->sk_route_caps & NETIF_F_SG) || + !(sk->sk_route_caps & TCP_ZC_CSUM_FLAGS)) + return sock_no_sendpage(sock, page, offset, size, flags); + +#undef TCP_ZC_CSUM_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_std; + + if (sk->sk_route_caps & NETIF_F_SG) { + 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; + 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)); + + /* 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 = sk->sk_write_queue.prev; + + if (!sk->sk_send_head || + (copy = mss_now - 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_IP_CSUM | NETIF_F_NO_CSUM | + NETIF_F_HW_CSUM)) + skb->ip_summed = CHECKSUM_HW; + + skb_entail(sk, tp, skb); + copy = mss_now; + } + + /* 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 page is cached, align + * offset to L1 cache boundary + */ + off = (off + L1_CACHE_BYTES - 1) & + ~(L1_CACHE_BYTES - 1); + if (off == PAGE_SIZE) { + put_page(page); + TCP_PAGE(sk) = page = NULL; + } + } + + if (!page) { + /* Allocate new cache page. */ + if (!(page = sk_stream_alloc_page(sk))) + goto wait_for_memory; + off = 0; + } + + if (copy > PAGE_SIZE - off) + copy = PAGE_SIZE - off; + + /* 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)->tso_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 == sk->sk_send_head) + 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)); + } + } + +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) { + if (sk->sk_send_head == skb) + sk->sk_send_head = NULL; + __skb_unlink(skb, skb->list); + 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. + */ +static void 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 (tcp_ack_scheduled(tp)) { + /* Delayed ACKs frequently hit locked sockets during bulk + * receive. */ + if (tp->ack.blocked || + /* Once-per-two-segments ACK was not sent by tcp_input.c */ + tp->rcv_nxt - tp->rcv_wup > tp->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 && (tp->ack.pending & TCP_ACK_PUSHED) && + !tp->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_ADD_STATS_USER(LINUX_MIB_TCPPREQUEUED, skb_queue_len(&tp->ucopy.prequeue)); + + /* 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 (skb->h.th->syn) + offset--; + if (offset < skb->len || skb->h.th->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 (skb->h.th->fin) { + sk_eat_skb(sk, skb); + ++seq; + break; + } + sk_eat_skb(sk, skb); + 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) + 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; + + 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); + + 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 (skb->h.th->syn) + offset--; + if (offset < skb->len) + goto found_ok_skb; + if (skb->h.th->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; + } + } + + cleanup_rbuf(sk, copied); + + if (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_len(&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); + + 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_len(&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)) { + 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 (skb->h.th->fin) + goto found_fin_ok; + if (!(flags & MSG_PEEK)) + sk_eat_skb(sk, skb); + continue; + + found_fin_ok: + /* Process the FIN. */ + ++*seq; + if (!(flags & MSG_PEEK)) + sk_eat_skb(sk, skb); + break; + } while (len > 0); + + if (user_recv) { + if (skb_queue_len(&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; + } + + /* 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. */ + 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 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); + } +} + +/* + * At this point, there should be no process reference to this + * socket, and thus no user references at all. Therefore we + * can assume the socket waitqueue is inactive and nobody will + * try to jump onto it. + */ +void tcp_destroy_sock(struct sock *sk) +{ + BUG_TRAP(sk->sk_state == TCP_CLOSE); + BUG_TRAP(sock_flag(sk, SOCK_DEAD)); + + /* It cannot be in hash table! */ + BUG_TRAP(sk_unhashed(sk)); + + /* If it has not 0 inet_sk(sk)->num, it must be bound */ + BUG_TRAP(!inet_sk(sk)->num || tcp_sk(sk)->bind_hash); + + sk->sk_prot->destroy(sk); + + sk_stream_kill_queues(sk); + + xfrm_sk_free_policy(sk); + +#ifdef INET_REFCNT_DEBUG + if (atomic_read(&sk->sk_refcnt) != 1) { + printk(KERN_DEBUG "Destruction TCP %p delayed, c=%d\n", + sk, atomic_read(&sk->sk_refcnt)); + } +#endif + + atomic_dec(&tcp_orphan_count); + sock_put(sk); +} + +void tcp_close(struct sock *sk, long timeout) +{ + struct sk_buff *skb; + int data_was_unread = 0; + + lock_sock(sk); + sk->sk_shutdown = SHUTDOWN_MASK; + + if (sk->sk_state == TCP_LISTEN) { + tcp_set_state(sk, TCP_CLOSE); + + /* Special case. */ + tcp_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 - + skb->h.th->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: + /* 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)); + + sock_hold(sk); + sock_orphan(sk); + + /* 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 { + int tmo = tcp_fin_time(tp); + + if (tmo > TCP_TIMEWAIT_LEN) { + tcp_reset_keepalive_timer(sk, tcp_fin_time(tp)); + } else { + atomic_inc(&tcp_orphan_count); + tcp_time_wait(sk, TCP_FIN_WAIT2, tmo); + goto out; + } + } + } + if (sk->sk_state != TCP_CLOSE) { + sk_stream_mem_reclaim(sk); + if (atomic_read(&tcp_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); + } + } + atomic_inc(&tcp_orphan_count); + + if (sk->sk_state == TCP_CLOSE) + tcp_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 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) { + tcp_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 discrepance 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); + sk_stream_writequeue_purge(sk); + __skb_queue_purge(&tp->out_of_order_queue); + + 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; + tp->backoff = 0; + tp->snd_cwnd = 2; + tp->probes_out = 0; + tp->packets_out = 0; + tp->snd_ssthresh = 0x7fffffff; + tp->snd_cwnd_cnt = 0; + tcp_set_ca_state(tp, TCP_CA_Open); + tcp_clear_retrans(tp); + tcp_delack_init(tp); + sk->sk_send_head = NULL; + tp->rx_opt.saw_tstamp = 0; + tcp_sack_reset(&tp->rx_opt); + __sk_dst_reset(sk); + + BUG_TRAP(!inet->num || tp->bind_hash); + + sk->sk_error_report(sk); + return err; +} + +/* + * Wait for an incoming connection, avoid race + * conditions. This must be called with the socket locked. + */ +static int wait_for_connect(struct sock *sk, long timeo) +{ + struct tcp_sock *tp = tcp_sk(sk); + DEFINE_WAIT(wait); + int err; + + /* + * True wake-one mechanism for incoming connections: only + * one process gets woken up, not the 'whole herd'. + * Since we do not 'race & poll' for established sockets + * anymore, the common case will execute the loop only once. + * + * Subtle issue: "add_wait_queue_exclusive()" will be added + * after any current non-exclusive waiters, and we know that + * it will always _stay_ after any new non-exclusive waiters + * because all non-exclusive waiters are added at the + * beginning of the wait-queue. As such, it's ok to "drop" + * our exclusiveness temporarily when we get woken up without + * having to remove and re-insert us on the wait queue. + */ + for (;;) { + prepare_to_wait_exclusive(sk->sk_sleep, &wait, + TASK_INTERRUPTIBLE); + release_sock(sk); + if (!tp->accept_queue) + timeo = schedule_timeout(timeo); + lock_sock(sk); + err = 0; + if (tp->accept_queue) + break; + err = -EINVAL; + if (sk->sk_state != TCP_LISTEN) + break; + err = sock_intr_errno(timeo); + if (signal_pending(current)) + break; + err = -EAGAIN; + if (!timeo) + break; + } + finish_wait(sk->sk_sleep, &wait); + return err; +} + +/* + * This will accept the next outstanding connection. + */ + +struct sock *tcp_accept(struct sock *sk, int flags, int *err) +{ + struct tcp_sock *tp = tcp_sk(sk); + struct open_request *req; + struct sock *newsk; + int error; + + lock_sock(sk); + + /* We need to make sure that this socket is listening, + * and that it has something pending. + */ + error = -EINVAL; + if (sk->sk_state != TCP_LISTEN) + goto out; + + /* Find already established connection */ + if (!tp->accept_queue) { + long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); + + /* If this is a non blocking socket don't sleep */ + error = -EAGAIN; + if (!timeo) + goto out; + + error = wait_for_connect(sk, timeo); + if (error) + goto out; + } + + req = tp->accept_queue; + if ((tp->accept_queue = req->dl_next) == NULL) + tp->accept_queue_tail = NULL; + + newsk = req->sk; + sk_acceptq_removed(sk); + tcp_openreq_fastfree(req); + BUG_TRAP(newsk->sk_state != TCP_SYN_RECV); + release_sock(sk); + return newsk; + +out: + release_sock(sk); + *err = error; + return NULL; +} + +/* + * Socket option code for TCP. + */ +int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, + int optlen) +{ + struct tcp_sock *tp = tcp_sk(sk); + int val; + int err = 0; + + if (level != SOL_TCP) + return tp->af_specific->setsockopt(sk, level, optname, + optval, optlen); + + 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; + tcp_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 + tp->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: + tp->defer_accept = 0; + if (val > 0) { + /* Translate value in seconds to number of + * retransmits */ + while (tp->defer_accept < 32 && + val > ((TCP_TIMEOUT_INIT / HZ) << + tp->defer_accept)) + tp->defer_accept++; + tp->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) { + tp->ack.pingpong = 1; + } else { + tp->ack.pingpong = 0; + if ((1 << sk->sk_state) & + (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) && + tcp_ack_scheduled(tp)) { + tp->ack.pending |= TCP_ACK_PUSHED; + cleanup_rbuf(sk, 1); + if (!(val & 1)) + tp->ack.pingpong = 1; + } + } + break; + + default: + err = -ENOPROTOOPT; + break; + }; + release_sock(sk); + return err; +} + +/* 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); + u32 now = tcp_time_stamp; + + memset(info, 0, sizeof(*info)); + + info->tcpi_state = sk->sk_state; + info->tcpi_ca_state = tp->ca_state; + info->tcpi_retransmits = tp->retransmits; + info->tcpi_probes = tp->probes_out; + info->tcpi_backoff = tp->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(tp->rto); + info->tcpi_ato = jiffies_to_usecs(tp->ack.ato); + info->tcpi_snd_mss = tp->mss_cache_std; + info->tcpi_rcv_mss = tp->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 - tp->ack.lrcvtime); + info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp); + + info->tcpi_pmtu = tp->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); + +int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, + int __user *optlen) +{ + struct tcp_sock *tp = tcp_sk(sk); + int val, len; + + if (level != SOL_TCP) + return tp->af_specific->getsockopt(sk, level, optname, + optval, optlen); + + 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_std; + 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 = tp->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 = !tp->defer_accept ? 0 : ((TCP_TIMEOUT_INIT / HZ) << + (tp->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 = !tp->ack.pingpong; + break; + default: + return -ENOPROTOOPT; + }; + + if (put_user(len, optlen)) + return -EFAULT; + if (copy_to_user(optval, &val, len)) + return -EFAULT; + return 0; +} + + +extern void __skb_cb_too_small_for_tcp(int, int); +extern void tcpdiag_init(void); + +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; + int order, i; + + if (sizeof(struct tcp_skb_cb) > sizeof(skb->cb)) + __skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb), + sizeof(skb->cb)); + + tcp_openreq_cachep = kmem_cache_create("tcp_open_request", + sizeof(struct open_request), + 0, SLAB_HWCACHE_ALIGN, + NULL, NULL); + if (!tcp_openreq_cachep) + panic("tcp_init: Cannot alloc open_request cache."); + + tcp_bucket_cachep = kmem_cache_create("tcp_bind_bucket", + sizeof(struct tcp_bind_bucket), + 0, SLAB_HWCACHE_ALIGN, + NULL, NULL); + if (!tcp_bucket_cachep) + panic("tcp_init: Cannot alloc tcp_bind_bucket cache."); + + tcp_timewait_cachep = kmem_cache_create("tcp_tw_bucket", + sizeof(struct tcp_tw_bucket), + 0, SLAB_HWCACHE_ALIGN, + NULL, NULL); + if (!tcp_timewait_cachep) + panic("tcp_init: Cannot alloc tcp_tw_bucket cache."); + + /* Size and allocate the main established and bind bucket + * hash tables. + * + * The methodology is similar to that of the buffer cache. + */ + tcp_ehash = (struct tcp_ehash_bucket *) + alloc_large_system_hash("TCP established", + sizeof(struct tcp_ehash_bucket), + thash_entries, + (num_physpages >= 128 * 1024) ? + (25 - PAGE_SHIFT) : + (27 - PAGE_SHIFT), + HASH_HIGHMEM, + &tcp_ehash_size, + NULL, + 0); + tcp_ehash_size = (1 << tcp_ehash_size) >> 1; + for (i = 0; i < (tcp_ehash_size << 1); i++) { + rwlock_init(&tcp_ehash[i].lock); + INIT_HLIST_HEAD(&tcp_ehash[i].chain); + } + + tcp_bhash = (struct tcp_bind_hashbucket *) + alloc_large_system_hash("TCP bind", + sizeof(struct tcp_bind_hashbucket), + tcp_ehash_size, + (num_physpages >= 128 * 1024) ? + (25 - PAGE_SHIFT) : + (27 - PAGE_SHIFT), + HASH_HIGHMEM, + &tcp_bhash_size, + NULL, + 64 * 1024); + tcp_bhash_size = 1 << tcp_bhash_size; + for (i = 0; i < tcp_bhash_size; i++) { + spin_lock_init(&tcp_bhash[i].lock); + INIT_HLIST_HEAD(&tcp_bhash[i].chain); + } + + /* Try to be a bit smarter and adjust defaults depending + * on available memory. + */ + for (order = 0; ((1 << order) << PAGE_SHIFT) < + (tcp_bhash_size * sizeof(struct tcp_bind_hashbucket)); + order++) + ; + if (order > 4) { + sysctl_local_port_range[0] = 32768; + sysctl_local_port_range[1] = 61000; + sysctl_tcp_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); + sysctl_tcp_max_tw_buckets >>= (3 - order); + sysctl_tcp_max_orphans >>= (3 - order); + sysctl_max_syn_backlog = 128; + } + tcp_port_rover = sysctl_local_port_range[0] - 1; + + sysctl_tcp_mem[0] = 768 << order; + sysctl_tcp_mem[1] = 1024 << order; + sysctl_tcp_mem[2] = 1536 << order; + + if (order < 3) { + sysctl_tcp_wmem[2] = 64 * 1024; + sysctl_tcp_rmem[0] = PAGE_SIZE; + sysctl_tcp_rmem[1] = 43689; + sysctl_tcp_rmem[2] = 2 * 43689; + } + + printk(KERN_INFO "TCP: Hash tables configured " + "(established %d bind %d)\n", + tcp_ehash_size << 1, tcp_bhash_size); +} + +EXPORT_SYMBOL(tcp_accept); +EXPORT_SYMBOL(tcp_close); +EXPORT_SYMBOL(tcp_destroy_sock); +EXPORT_SYMBOL(tcp_disconnect); +EXPORT_SYMBOL(tcp_getsockopt); +EXPORT_SYMBOL(tcp_ioctl); +EXPORT_SYMBOL(tcp_openreq_cachep); +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); +EXPORT_SYMBOL(tcp_timewait_cachep); |