mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-22 11:17:19 +00:00
258a21fe7a
- simplify by strdup. - set ai_protocol in hints to TCP. - g/c FAITH_NS (no description, not maintained for years) - warn if connection from IPv4 mapped is reached. - IPV6_V6ONLY if possible. - unifdef -UFAITH4. - drop rsh/rlogin support. - deal with negative return value from wait3. Obtained from: KAME
324 lines
8.5 KiB
C
324 lines
8.5 KiB
C
/* $KAME: tcp.c,v 1.13 2003/09/02 22:49:21 itojun Exp $ */
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/*
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* Copyright (C) 1997 and 1998 WIDE Project.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/ioctl.h>
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#include <sys/time.h>
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#include <sys/wait.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <syslog.h>
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include "faithd.h"
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static char tcpbuf[16*1024];
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/* bigger than MSS and may be lesser than window size */
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static int tblen, tboff, oob_exists;
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static fd_set readfds, writefds, exceptfds;
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static char atmark_buf[2];
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static pid_t cpid = (pid_t)0;
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static pid_t ppid = (pid_t)0;
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volatile time_t child_lastactive = (time_t)0;
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static time_t parent_lastactive = (time_t)0;
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static void sig_ctimeout __P((int));
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static void sig_child __P((int));
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static void notify_inactive __P((void));
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static void notify_active __P((void));
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static void send_data __P((int, int, const char *, int));
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static void relay __P((int, int, const char *, int));
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/*
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* Inactivity timer:
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* - child side (ppid != 0) will send SIGUSR1 to parent every (FAITH_TIMEOUT/4)
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* second if traffic is active. if traffic is inactive, don't send SIGUSR1.
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* - parent side (ppid == 0) will check the last SIGUSR1 it have seen.
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*/
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static void
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sig_ctimeout(int sig)
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{
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/* parent side: record notification from the child */
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if (dflag)
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syslog(LOG_DEBUG, "activity timer from child");
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child_lastactive = time(NULL);
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}
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/* parent will terminate if child dies. */
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static void
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sig_child(int sig)
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{
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int status;
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pid_t pid;
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pid = wait3(&status, WNOHANG, (struct rusage *)0);
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if (pid > 0 && WEXITSTATUS(status))
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syslog(LOG_WARNING, "child %ld exit status 0x%x",
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(long)pid, status);
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exit_success("terminate connection due to child termination");
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}
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static void
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notify_inactive()
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{
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time_t t;
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/* only on parent side... */
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if (ppid)
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return;
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/* parent side should check for timeout. */
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t = time(NULL);
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if (dflag) {
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syslog(LOG_DEBUG, "parent side %sactive, child side %sactive",
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(FAITH_TIMEOUT < t - parent_lastactive) ? "in" : "",
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(FAITH_TIMEOUT < t - child_lastactive) ? "in" : "");
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}
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if (FAITH_TIMEOUT < t - child_lastactive
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&& FAITH_TIMEOUT < t - parent_lastactive) {
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/* both side timeouted */
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signal(SIGCHLD, SIG_DFL);
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kill(cpid, SIGTERM);
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wait(NULL);
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exit_failure("connection timeout");
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/* NOTREACHED */
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}
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}
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static void
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notify_active()
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{
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if (ppid) {
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/* child side: notify parent of active traffic */
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time_t t;
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t = time(NULL);
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if (FAITH_TIMEOUT / 4 < t - child_lastactive) {
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if (kill(ppid, SIGUSR1) < 0) {
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exit_failure("terminate connection due to parent termination");
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/* NOTREACHED */
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}
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child_lastactive = t;
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}
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} else {
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/* parent side */
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parent_lastactive = time(NULL);
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}
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}
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static void
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send_data(int s_rcv, int s_snd, const char *service, int direction)
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{
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int cc;
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if (oob_exists) {
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cc = send(s_snd, atmark_buf, 1, MSG_OOB);
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if (cc == -1)
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goto retry_or_err;
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oob_exists = 0;
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if (s_rcv >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_SET(s_rcv, &exceptfds);
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}
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for (; tboff < tblen; tboff += cc) {
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cc = write(s_snd, tcpbuf + tboff, tblen - tboff);
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if (cc < 0)
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goto retry_or_err;
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}
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#ifdef DEBUG
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if (tblen) {
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if (tblen >= sizeof(tcpbuf))
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tblen = sizeof(tcpbuf) - 1;
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tcpbuf[tblen] = '\0';
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syslog(LOG_DEBUG, "from %s (%dbytes): %s",
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direction == 1 ? "client" : "server", tblen, tcpbuf);
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}
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#endif /* DEBUG */
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tblen = 0; tboff = 0;
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if (s_snd >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_CLR(s_snd, &writefds);
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if (s_rcv >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_SET(s_rcv, &readfds);
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return;
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retry_or_err:
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if (errno != EAGAIN)
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exit_failure("writing relay data failed: %s", strerror(errno));
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if (s_snd >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_SET(s_snd, &writefds);
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}
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static void
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relay(int s_rcv, int s_snd, const char *service, int direction)
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{
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int atmark, error, maxfd;
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struct timeval tv;
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fd_set oreadfds, owritefds, oexceptfds;
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FD_ZERO(&readfds);
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FD_ZERO(&writefds);
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FD_ZERO(&exceptfds);
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fcntl(s_snd, F_SETFD, O_NONBLOCK);
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oreadfds = readfds; owritefds = writefds; oexceptfds = exceptfds;
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if (s_rcv >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_SET(s_rcv, &readfds);
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FD_SET(s_rcv, &exceptfds);
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oob_exists = 0;
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maxfd = (s_rcv > s_snd) ? s_rcv : s_snd;
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for (;;) {
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tv.tv_sec = FAITH_TIMEOUT / 4;
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tv.tv_usec = 0;
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oreadfds = readfds;
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owritefds = writefds;
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oexceptfds = exceptfds;
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error = select(maxfd + 1, &readfds, &writefds, &exceptfds, &tv);
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if (error == -1) {
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if (errno == EINTR)
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continue;
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exit_failure("select: %s", strerror(errno));
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} else if (error == 0) {
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readfds = oreadfds;
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writefds = owritefds;
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exceptfds = oexceptfds;
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notify_inactive();
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continue;
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}
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/* activity notification */
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notify_active();
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if (FD_ISSET(s_rcv, &exceptfds)) {
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error = ioctl(s_rcv, SIOCATMARK, &atmark);
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if (error != -1 && atmark == 1) {
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int cc;
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oob_read_retry:
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cc = read(s_rcv, atmark_buf, 1);
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if (cc == 1) {
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if (s_rcv >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_CLR(s_rcv, &exceptfds);
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if (s_snd >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_SET(s_snd, &writefds);
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oob_exists = 1;
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} else if (cc == -1) {
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if (errno == EINTR)
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goto oob_read_retry;
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exit_failure("reading oob data failed"
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": %s",
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strerror(errno));
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}
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}
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}
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if (FD_ISSET(s_rcv, &readfds)) {
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relaydata_read_retry:
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tblen = read(s_rcv, tcpbuf, sizeof(tcpbuf));
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tboff = 0;
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switch (tblen) {
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case -1:
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if (errno == EINTR)
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goto relaydata_read_retry;
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exit_failure("reading relay data failed: %s",
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strerror(errno));
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/* NOTREACHED */
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case 0:
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/* to close opposite-direction relay process */
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shutdown(s_snd, 0);
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close(s_rcv);
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close(s_snd);
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exit_success("terminating %s relay", service);
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/* NOTREACHED */
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default:
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if (s_rcv >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_CLR(s_rcv, &readfds);
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if (s_snd >= FD_SETSIZE)
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exit_failure("descriptor too big");
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FD_SET(s_snd, &writefds);
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break;
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}
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}
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if (FD_ISSET(s_snd, &writefds))
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send_data(s_rcv, s_snd, service, direction);
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}
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}
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void
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tcp_relay(int s_src, int s_dst, const char *service)
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{
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syslog(LOG_INFO, "starting %s relay", service);
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child_lastactive = parent_lastactive = time(NULL);
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cpid = fork();
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switch (cpid) {
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case -1:
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exit_failure("tcp_relay: can't fork grand child: %s",
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strerror(errno));
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/* NOTREACHED */
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case 0:
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/* child process: relay going traffic */
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ppid = getppid();
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/* this is child so reopen log */
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closelog();
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openlog(logname, LOG_PID | LOG_NOWAIT, LOG_DAEMON);
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relay(s_src, s_dst, service, 1);
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/* NOTREACHED */
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default:
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/* parent process: relay coming traffic */
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ppid = (pid_t)0;
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signal(SIGUSR1, sig_ctimeout);
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signal(SIGCHLD, sig_child);
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relay(s_dst, s_src, service, 0);
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/* NOTREACHED */
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}
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}
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