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