473 lines
14 KiB
C
473 lines
14 KiB
C
/*
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* Copyright (c) 1988 Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Rick Adams.
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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. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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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#ifndef lint
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static char copyright[] =
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"@(#) Copyright (c) 1988 Regents of the University of California.\n\
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All rights reserved.\n";
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#endif /* not lint */
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#ifndef lint
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/*static char sccsid[] = "from: @(#)slattach.c 4.6 (Berkeley) 6/1/90";*/
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static char rcsid[] = "$Id";
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#endif /* not lint */
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#include <sys/param.h>
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#include <sys/ioctl.h>
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#include <termios.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <net/if.h>
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#include <net/slip.h>
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#include <net/if_slvar.h>
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#include <netdb.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <paths.h>
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#include <syslog.h>
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#include <signal.h>
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#include <strings.h>
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#define DEFAULT_BAUD 9600
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void sighup_handler(); /* SIGHUP handler */
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void sigint_handler(); /* SIGINT handler */
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void sigterm_handler(); /* SIGTERM handler */
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void exit_handler(int ret); /* run exit_cmd iff specified upon exit. */
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void setup_line(int cflag); /* configure terminal settings */
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void slip_discipline(); /* switch to slip line discipline */
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void configure_network(); /* configure slip interface */
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void acquire_line(); /* get tty device as controling terminal */
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int fd = -1;
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char *dev = (char *)0; /* path name of the tty (e.g. /dev/tty01) */
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int flow_control = 0; /* non-zero to enable hardware flow control. */
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int modem_control = HUPCL; /* !CLOCAL+HUPCL iff we watch carrier. */
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int comstate; /* TIOCMGET current state of serial driver */
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int redial_on_startup = 0; /* iff non-zero execute redial_cmd on startup */
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int speed = DEFAULT_BAUD; /* baud rate of tty */
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int slflags = 0; /* compression flags */
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int unit = -1; /* slip device unit number */
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int foreground = 0; /* act as demon if zero, else don't fork. */
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int exiting = 0; /* allready running exit_handler */
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struct termios tty; /* tty configuration/state */
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char tty_path[32]; /* path name of the tty (e.g. /dev/tty01) */
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char pidfilename[40]; /* e.g. /var/run/slattach.tty01.pid */
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char *redial_cmd = 0; /* command to exec upon shutdown. */
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char *config_cmd = 0; /* command to exec if slip unit changes. */
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char *exit_cmd = 0; /* command to exec before exiting. */
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static char usage_str[] = "\
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usage: %s [-acfhlnz] [-e command] [-r command] [-s speed] [-u command] device\n\
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-a -- autoenable VJ compression\n\
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-c -- enable VJ compression\n\
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-e ECMD -- run ECMD before exiting\n\
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-f -- run in foreground (don't detach from controlling tty)\n\
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-h -- turn on cts/rts style flow control\n\
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-l -- disable modem control (CLOCAL) and ignore carrier detect\n\
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-n -- throw out ICMP packets\n\
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-r RCMD -- run RCMD upon loss of carrier\n\
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-s # -- set baud rate (default 9600)\n\
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-u UCMD -- run 'UCMD <old sl#> <new sl#>' before switch to slip discipline\n\
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-z -- run RCMD upon startup irrespective of carrier\n";
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int main(int argc, char **argv)
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{
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int option;
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extern char *optarg;
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extern int optind;
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char *cp;
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while ((option = getopt(argc, argv, "ace:fhlnr:s:u:z")) != EOF) {
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switch (option) {
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case 'a':
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slflags |= IFF_LINK2;
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slflags &= ~IFF_LINK0;
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break;
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case 'c':
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slflags |= IFF_LINK0;
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slflags &= ~IFF_LINK2;
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break;
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case 'e':
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exit_cmd = (char*) strdup (optarg);
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break;
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case 'f':
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foreground = 1;
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break;
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case 'h':
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flow_control |= CRTSCTS;
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break;
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case 'l':
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modem_control = CLOCAL; /* clear HUPCL too */
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break;
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case 'n':
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slflags |= IFF_LINK1;
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break;
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case 'r':
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redial_cmd = (char*) strdup (optarg);
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break;
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case 's':
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speed = atoi(optarg);
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break;
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case 'u':
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config_cmd = (char*) strdup (optarg);
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break;
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case 'z':
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redial_on_startup = 1;
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break;
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default:
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fprintf(stderr, "%s: Invalid option -- '%c'\n",
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argv[0], option);
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case '?':
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fprintf(stderr, usage_str, argv[0]);
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exit_handler(1);
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}
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}
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if (optind == argc - 1)
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dev = argv[optind];
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if (optind < (argc - 1)) {
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fprintf(stderr, "%s: Too many args, first='%s'\n",
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argv[0], argv[optind]);
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}
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if (optind > (argc - 1)) {
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fprintf(stderr, "%s: Not enough args\n", argv[0]);
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}
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if (dev == (char *)0) {
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fprintf(stderr, usage_str, argv[0]);
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exit_handler(2);
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}
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if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) {
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strcpy(tty_path, _PATH_DEV);
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strcat(tty_path, "/");
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strncat(tty_path, dev, 10);
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dev = tty_path;
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}
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cp = strrchr(dev, '/'); /* always succeeds */
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cp++; /* trailing tty pathname component */
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sprintf(pidfilename, "%sslattach.%s.pid", _PATH_VARRUN, cp);
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printf("%s\n",pidfilename);
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if (!foreground)
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daemon(0,0); /* fork, setsid, chdir /, and close std*. */
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/* daemon() closed stderr, so log errors from here on. */
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openlog("slattach",LOG_CONS|LOG_PID,LOG_DAEMON);
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acquire_line(); /* get tty device as controling terminal */
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setup_line(0); /* configure for slip line discipline */
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slip_discipline(); /* switch to slip line discipline */
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/* upon INT log a timestamp and exit. */
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if ((int)signal(SIGINT,sigint_handler) < 0)
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syslog(LOG_NOTICE,"cannot install SIGINT handler: %m");
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/* upon TERM log a timestamp and exit. */
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if ((int)signal(SIGTERM,sigterm_handler) < 0)
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syslog(LOG_NOTICE,"cannot install SIGTERM handler: %m");
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/* upon HUP redial and reconnect. */
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if ((int)signal(SIGHUP,sighup_handler) < 0)
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syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m");
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if (redial_on_startup)
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sighup_handler();
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else if (!(modem_control & CLOCAL)) {
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if (ioctl(fd, TIOCMGET, &comstate) < 0)
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syslog(LOG_NOTICE,"cannot get carrier state: %m");
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if (!(comstate & TIOCM_CD)) { /* check for carrier */
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/* force a redial if no carrier */
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kill (getpid(), SIGHUP);
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} else
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configure_network();
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}
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else
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configure_network(); /* configure the network if needed. */
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for (;;) {
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sigset_t mask;
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sigemptyset(&mask);
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sigsuspend(&mask);
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}
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}
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/* Close all FDs, fork, reopen tty port as 0-2, and make it the
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controlling terminal for our process group. */
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void acquire_line()
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{
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int ttydisc = TTYDISC;
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FILE *pidfile;
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ioctl(fd, TIOCSETD, &ttydisc); /* reset to tty discipline */
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(void)close(STDIN_FILENO); /* close FDs before forking. */
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(void)close(STDOUT_FILENO);
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(void)close(STDERR_FILENO);
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if (fd > 2)
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(void)close(fd);
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signal(SIGHUP, SIG_IGN); /* ignore HUP signal when parent dies. */
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daemon(0,0); /* fork, setsid, chdir /, and close std*. */
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while (getppid () != 1)
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sleep (1); /* Wait for parent to die. */
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/* create PID file */
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if((pidfile = fopen(pidfilename, "w"))) {
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fprintf(pidfile, "%ld\n", getpid());
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fclose(pidfile);
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}
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if ((int)signal(SIGHUP,sighup_handler) < 0) /* Re-enable HUP signal */
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syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m");
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if ((fd = open(dev, O_RDWR | O_NONBLOCK, 0)) < 0) {
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syslog(LOG_ERR, "open(%s) fd=%d: %m", dev, fd);
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exit_handler(1);
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}
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(void)dup2(fd, STDIN_FILENO);
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(void)dup2(fd, STDOUT_FILENO);
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(void)dup2(fd, STDERR_FILENO);
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if (fd > 2)
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(void)close (fd);
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fd = STDIN_FILENO;
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/* acquire the serial line as a controling terminal. */
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if (ioctl(fd, TIOCSCTTY, 0) < 0)
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syslog(LOG_NOTICE,"ioctl(TIOCSCTTY) failed: %m");
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/* Make us the foreground process group associated with the
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slip line which is our controlling terminal. */
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if (tcsetpgrp(fd, getpid()) < 0)
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syslog(LOG_NOTICE,"tcsetpgrp failed: %m");
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}
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/* Set the tty flags and set DTR. */
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/* Call as setup_line(CLOCAL) to force clocal assertion. */
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void setup_line(int cflag)
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{
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tty.c_lflag = tty.c_iflag = tty.c_oflag = 0;
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tty.c_cflag = CREAD | CS8 | flow_control | modem_control | cflag;
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tty.c_ispeed = tty.c_ospeed = speed;
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/* set the line speed and flow control */
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if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) {
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syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
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exit_handler(1);
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}
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/* set data terminal ready */
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if (ioctl(fd, TIOCSDTR) < 0) {
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syslog(LOG_ERR, "ioctl(TIOCSDTR): %m");
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exit_handler(1);
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}
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}
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/* Put the line in slip discipline. */
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void slip_discipline()
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{
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struct ifreq ifr;
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int slipdisc = SLIPDISC;
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int s, tmp_unit = -1;
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/* Switch to slip line discipline. */
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if (ioctl(fd, TIOCSETD, &slipdisc) < 0) {
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syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
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exit_handler(1);
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}
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/* find out what unit number we were assigned */
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if (ioctl(fd, SLIOCGUNIT, (caddr_t)&tmp_unit) < 0) {
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syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m");
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exit_handler(1);
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}
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if (tmp_unit < 0) {
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syslog(LOG_ERR, "bad unit (%d) from ioctl(SLIOCGUNIT)",tmp_unit);
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exit_handler(1);
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}
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/* open a socket as the handle to the interface */
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s = socket(AF_INET, SOCK_DGRAM, 0);
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if (s < 0) {
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syslog(LOG_ERR, "socket: %m");
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exit_handler(1);
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}
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sprintf(ifr.ifr_name, "sl%d", tmp_unit);
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/* get the flags for the interface */
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if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
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syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
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exit_handler(1);
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}
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/* Assert any compression or no-icmp flags. */
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#define SLMASK (~(IFF_LINK0 | IFF_LINK1 | IFF_LINK2))
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ifr.ifr_flags &= SLMASK;
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ifr.ifr_flags |= slflags;
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if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&ifr) < 0) {
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syslog(LOG_ERR, "ioctl (SIOCSIFFLAGS): %m");
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exit_handler(1);
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}
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close(s);
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}
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/* configure the interface, eg. by passing the unit number to a script. */
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void configure_network()
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{
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int new_unit;
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/* find out what unit number we were assigned */
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if (ioctl(fd, SLIOCGUNIT, (caddr_t)&new_unit) < 0) {
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syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m");
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exit_handler(1);
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}
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/* don't compare unit numbers if this is the first time to attach. */
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if (unit < 0)
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unit = new_unit;
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/* iff the unit number changes either invoke config_cmd or punt. */
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if (config_cmd) {
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char *s;
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s = (char*) malloc(strlen(config_cmd) + 32);
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sprintf (s, "%s %d %d", config_cmd, unit, new_unit);
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syslog(LOG_NOTICE, "Configuring %s (sl%d):", dev, unit);
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syslog(LOG_NOTICE, " '%s'", s);
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system(s);
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free (s);
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unit = new_unit;
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} else {
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if (new_unit != unit) {
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syslog(LOG_ERR, "slip unit changed from sl%d to sl%d, but no -u CMD was specified!");
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exit_handler(1);
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}
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syslog(LOG_NOTICE,"sl%d connected to %s at %d baud",unit,dev,speed);
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}
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}
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/* signup_handler() is invoked when carrier drops, eg. before redial. */
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void sighup_handler()
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{
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if(exiting) return;
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again:
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/* invoke a shell for redial_cmd or punt. */
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if (redial_cmd) {
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acquire_line();
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setup_line(CLOCAL);
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syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); running %s",
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dev,unit,redial_cmd);
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if (system(redial_cmd))
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goto again;
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/* Now check again for carrier (dial command is done): */
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if (!(modem_control & CLOCAL)) {
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tty.c_cflag &= ~CLOCAL;
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if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) {
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syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
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exit_handler(1);
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}
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ioctl(fd, TIOCMGET, &comstate);
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if (!(comstate & TIOCM_CD)) { /* check for carrier */
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/* force a redial if no carrier */
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goto again;
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}
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}
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} else {
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/* If modem control, just wait for carrier before attaching.
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If no modem control, just fall through immediately. */
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if (!(modem_control & CLOCAL)) {
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int carrier = 0;
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syslog(LOG_NOTICE, "Waiting for carrier on %s (sl%d)",
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dev, unit);
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/* Now wait for carrier before attaching line. */
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/* We must poll since CLOCAL prevents signal. */
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while (! carrier) {
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sleep(2);
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ioctl(fd, TIOCMGET, &comstate);
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if (comstate & TIOCM_CD)
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carrier = 1;
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}
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syslog(LOG_NOTICE, "Carrier now present on %s (sl%d)",
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dev, unit);
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}
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}
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setup_line(0);
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slip_discipline();
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configure_network();
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}
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/* Signal handler for SIGINT. We just log and exit. */
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void sigint_handler()
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{
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if(exiting) return;
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syslog(LOG_NOTICE,"SIGINT on %s (sl%d); exiting",dev,unit);
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exit_handler(0);
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}
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/* Signal handler for SIGTERM. We just log and exit. */
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void sigterm_handler()
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{
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if(exiting) return;
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syslog(LOG_NOTICE,"SIGTERM on %s (sl%d); exiting",dev,unit);
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exit_handler(0);
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}
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/* Run config_cmd if specified before exiting. */
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void exit_handler(int ret)
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{
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if(exiting) return;
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exiting = 1;
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/*
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* First close the slip line in case exit_cmd wants it (like to hang
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* up a modem or something).
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*/
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if (fd != -1)
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close(fd);
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/* Remove the PID file */
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(void)unlink(pidfilename);
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/* invoke a shell for exit_cmd. */
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if (exit_cmd) {
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syslog(LOG_NOTICE,"exiting after running %s", exit_cmd);
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system(exit_cmd);
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}
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exit(ret);
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}
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/* local variables: */
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/* c-indent-level: 8 */
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/* c-argdecl-indent: 0 */
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/* c-label-offset: -8 */
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/* c-continued-statement-offset: 8 */
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/* c-brace-offset: 0 */
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/* comment-column: 32 */
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/* end: */
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