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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | /* * 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. * * TIMER - implementation of software timers for IP. * * Version: @(#)timer.c 1.0.7 05/25/93 * * Authors: Ross Biro, <bir7@leland.Stanford.Edu> * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * Corey Minyard <wf-rch!minyard@relay.EU.net> * Fred Baumgarten, <dc6iq@insu1.etec.uni-karlsruhe.de> * Florian La Roche, <flla@stud.uni-sb.de> * * Fixes: * Alan Cox : To avoid destroying a wait queue as we use it * we defer destruction until the destroy timer goes * off. * Alan Cox : Destroy socket doesn't write a status value to the * socket buffer _AFTER_ freeing it! Also sock ensures * the socket will get removed BEFORE this is called * otherwise if the timer TIME_DESTROY occurs inside * of inet_bh() with this socket being handled it goes * BOOM! Have to stop timer going off if net_bh is * active or the destroy causes crashes. * Alan Cox : Cleaned up unused code. * * 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. */ #include <linux/types.h> #include <linux/errno.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/timer.h> #include <asm/system.h> #include <linux/interrupt.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <net/ip.h> #include <net/protocol.h> #include <net/tcp.h> #include <linux/skbuff.h> #include <net/sock.h> #include <net/arp.h> void delete_timer (struct sock *t) { unsigned long flags; save_flags (flags); cli(); t->timeout = 0; del_timer (&t->timer); restore_flags (flags); } void reset_timer (struct sock *t, int timeout, unsigned long len) { delete_timer (t); t->timeout = timeout; #if 1 /* FIXME: ??? */ if ((int) len < 0) /* prevent close to infinite timers. THEY _DO_ */ len = 3; /* happen (negative values ?) - don't ask me why ! -FB */ #endif t->timer.expires = jiffies+len; add_timer (&t->timer); } /* * Now we will only be called whenever we need to do * something, but we must be sure to process all of the * sockets that need it. */ void net_timer (unsigned long data) { struct sock *sk = (struct sock*)data; int why = sk->timeout; /* * only process if socket is not in use */ if (sk->users) { sk->timer.expires = jiffies+HZ; add_timer(&sk->timer); sti(); return; } /* Always see if we need to send an ack. */ if (sk->ack_backlog && !sk->zapped) { sk->prot->read_wakeup (sk); if (! sk->dead) sk->data_ready(sk,0); } /* Now we need to figure out why the socket was on the timer. */ switch (why) { case TIME_DONE: /* If the socket hasn't been closed off, re-try a bit later */ if (!sk->dead) { reset_timer(sk, TIME_DONE, TCP_DONE_TIME); break; } if (sk->state != TCP_CLOSE) { printk ("non CLOSE socket in time_done\n"); break; } destroy_sock (sk); break; case TIME_DESTROY: /* * We've waited for a while for all the memory associated with * the socket to be freed. */ destroy_sock(sk); break; case TIME_CLOSE: /* We've waited long enough, close the socket. */ tcp_set_state(sk, TCP_CLOSE); if (!sk->dead) sk->state_change(sk); sk->shutdown = SHUTDOWN_MASK; break; default: printk ("net_timer: timer expired - reason %d is unknown\n", why); break; } } |