/* * slattach A program for handling dialup IP connecions. * This program forces a TTY line to go into a special * terminal line discipline, so that it can be used for * network traffic instead of the regular terminal I/O. * * Usage: slattach [-ehlmnqv] [ -k keepalive ] [ -o outfill ] * [-c cmd] [-s speed] [-p protocol] tty | - * * Version: @(#)slattach.c 1.20 1999-05-29 * * Author: Fred N. van Kempen, * Copyright 1988-1993 MicroWalt Corporation * * Modified: * Alan Cox, , July 16 1994 * Miquel van Smoorenburg, , October 1994 * George Shearer, , January 3, 1995 * Yossi Gottlieb, , February 11, 1995 * Peter Tobias, , July 30 1995 * Bernd Eckenfels , May 29, 1999 * added some more printf's for debug and NOBLOCK to open * this should be enough to support 2.2 ttyS-style locks * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(__GLIBC__) #if __GLIBC__ == 2 && __GLIBC_MINOR__ == 0 # include #else # include #endif #endif #include "pathnames.h" #include "net-support.h" #include "version.h" #include "config.h" #include "intl.h" #include "util.h" #ifndef _PATH_LOCKD #define _PATH_LOCKD "/var/lock" /* lock files */ #endif #ifndef _UID_UUCP #define _UID_UUCP "uucp" /* owns locks */ #endif #define DEF_PROTO "cslip" const char *Release = RELEASE, *Version = "$Id: slattach.c,v 1.12 2009/09/06 22:59:43 vapier Exp $", *Signature = "net-tools, Fred N. van Kempen et al."; struct { const char *speed; int code; } tty_speeds[] = { /* table of usable baud rates */ { "50", B50 }, { "75", B75 }, { "110", B110 }, { "300", B300 }, { "600", B600 }, { "1200", B1200 }, { "2400", B2400 }, { "4800", B4800 }, { "9600", B9600 }, #ifdef B14400 { "14400", B14400 }, #endif #ifdef B19200 { "19200", B19200 }, #endif #ifdef B38400 { "38400", B38400 }, #endif #ifdef B57600 { "57600", B57600 }, #endif #ifdef B115200 { "115200", B115200 }, #endif { NULL, 0 } }; struct termios tty_saved, /* saved TTY device state */ tty_current; /* current TTY device state */ int tty_sdisc, /* saved TTY line discipline */ tty_ldisc, /* current TTY line discipline */ tty_fd = -1; /* TTY file descriptor */ int opt_c = 0; /* "command" to run at exit */ int opt_e = 0; /* "activate only" flag */ int opt_h = 0; /* "hangup" on carrier loss */ #ifdef SIOCSKEEPALIVE int opt_k = 0; /* "keepalive" value */ #endif int opt_l = 0; /* "lock it" flag */ int opt_L = 0; /* 3-wire mode flag */ int opt_m = 0; /* "set RAW mode" flag */ int opt_n = 0; /* "set No Mesg" flag */ #ifdef SIOCSOUTFILL int opt_o = 0; /* "outfill" value */ #endif int opt_q = 0; /* "quiet" flag */ int opt_d = 0; /* debug flag */ int opt_v = 0; /* Verbose flag */ /* Disable any messages to the input channel of this process. */ static int tty_nomesg(int fd) { if (opt_n == 0) return(0); return(fchmod(fd, 0600)); } /* Check for an existing lock file on our device */ static int tty_already_locked(char *nam) { int i = 0, pid = 0; FILE *fd = (FILE *)0; /* Does the lock file on our device exist? */ if ((fd = fopen(nam, "r")) == (FILE *)0) return(0); /* No, return perm to continue */ /* Yes, the lock is there. Now let's make sure */ /* at least there's no active process that owns */ /* that lock. */ i = fscanf(fd, "%d", &pid); (void) fclose(fd); if (i != 1) /* Lock file format's wrong! Kill't */ return(0); /* We got the pid, check if the process's alive */ if (kill(pid, 0) == 0) /* it found process */ return(1); /* Yup, it's running... */ /* Dead, we can proceed locking this device... */ return(0); } /* Lock or unlock a terminal line. */ static int tty_lock(char *path, int mode) { static char saved_path[PATH_MAX]; static int saved_lock = 0; struct passwd *pw; int fd; char apid[16]; /* We do not lock standard input. */ if ((opt_l == 0) || ((path == NULL) && (saved_lock == 0))) return(0); if (mode == 1) { /* lock */ sprintf(saved_path, "%s/LCK..%s", _PATH_LOCKD, path); if (tty_already_locked(saved_path)) { fprintf(stderr, _("slattach: /dev/%s already locked!\n"), path); return(-1); } if ((fd = creat(saved_path, 0644)) < 0) { if (errno != EEXIST) if (opt_q == 0) fprintf(stderr, _("slattach: tty_lock: (%s): %s\n"), saved_path, strerror(errno)); return(-1); } sprintf(apid, "%10d\n", getpid()); if (write(fd, apid, strlen(apid)) != strlen(apid)) { fprintf(stderr, _("slattach: cannot write PID file\n")); close(fd); unlink(saved_path); return(-1); } /* Make sure UUCP owns the lockfile. Required by some packages. */ if ((pw = getpwnam(_UID_UUCP)) == NULL) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_lock: UUCP user %s unknown!\n"), _UID_UUCP); (void) close(fd); return(0); /* keep the lock anyway */ } (void) fchown(fd, pw->pw_uid, pw->pw_gid); (void) close(fd); saved_lock = 1; } else { /* unlock */ if (saved_lock != 1) return(0); if (unlink(saved_path) < 0) { if (opt_q == 0) fprintf(stderr, "slattach: tty_unlock: (%s): %s\n", saved_path, strerror(errno)); return(-1); } saved_lock = 0; } return(0); } /* Find a serial speed code in the table. */ static int tty_find_speed(const char *speed) { int i; i = 0; while (tty_speeds[i].speed != NULL) { if (!strcmp(tty_speeds[i].speed, speed)) return(tty_speeds[i].code); i++; } return(-EINVAL); } /* Set the number of stop bits. */ static int tty_set_stopbits(struct termios *tty, char *stopbits) { if (opt_d) printf("slattach: tty_set_stopbits: %c\n", *stopbits); switch(*stopbits) { case '1': tty->c_cflag &= ~CSTOPB; break; case '2': tty->c_cflag |= CSTOPB; break; default: return(-EINVAL); } return(0); } /* Set the number of data bits. */ static int tty_set_databits(struct termios *tty, char *databits) { if (opt_d) printf("slattach: tty_set_databits: %c\n", *databits); tty->c_cflag &= ~CSIZE; switch(*databits) { case '5': tty->c_cflag |= CS5; break; case '6': tty->c_cflag |= CS6; break; case '7': tty->c_cflag |= CS7; break; case '8': tty->c_cflag |= CS8; break; default: return(-EINVAL); } return(0); } /* Set the type of parity encoding. */ static int tty_set_parity(struct termios *tty, char *parity) { if (opt_d) printf("slattach: tty_set_parity: %c\n", *parity); switch(toupper(*parity)) { case 'N': tty->c_cflag &= ~(PARENB | PARODD); break; case 'O': tty->c_cflag &= ~(PARENB | PARODD); tty->c_cflag |= (PARENB | PARODD); break; case 'E': tty->c_cflag &= ~(PARENB | PARODD); tty->c_cflag |= (PARENB); break; default: return(-EINVAL); } return(0); } /* Set the line speed of a terminal line. */ static int tty_set_speed(struct termios *tty, const char *speed) { int code; if (opt_d) printf("slattach: tty_set_speed: %s\n", speed); if ((code = tty_find_speed(speed)) < 0) return(code); tty->c_cflag &= ~CBAUD; tty->c_cflag |= code; return(0); } /* Put a terminal line in a transparent state. */ static int tty_set_raw(struct termios *tty) { int i; int speed; for(i = 0; i < NCCS; i++) tty->c_cc[i] = '\0'; /* no spec chr */ tty->c_cc[VMIN] = 1; tty->c_cc[VTIME] = 0; tty->c_iflag = (IGNBRK | IGNPAR); /* input flags */ tty->c_oflag = (0); /* output flags */ tty->c_lflag = (0); /* local flags */ speed = (tty->c_cflag & CBAUD); /* save current speed */ tty->c_cflag = (HUPCL | CREAD); /* UART flags */ if (opt_L) tty->c_cflag |= CLOCAL; else tty->c_cflag |= CRTSCTS; tty->c_cflag |= speed; /* restore speed */ return(0); } /* Fetch the state of a terminal. */ static int tty_get_state(struct termios *tty) { if (ioctl(tty_fd, TCGETS, tty) < 0) { if (opt_q == 0) fprintf(stderr, "slattach: tty_get_state: %s\n", strerror(errno)); return(-errno); } return(0); } /* Set the state of a terminal. */ static int tty_set_state(struct termios *tty) { if (ioctl(tty_fd, TCSETS, tty) < 0) { if (opt_q == 0) fprintf(stderr, "slattach: tty_set_state: %s\n", strerror(errno)); return(-errno); } return(0); } /* Get the line discipline of a terminal line. */ static int tty_get_disc(int *disc) { if (ioctl(tty_fd, TIOCGETD, disc) < 0) { if (opt_q == 0) fprintf(stderr, "slattach: tty_get_disc: %s\n", strerror(errno)); return(-errno); } return(0); } /* Set the line discipline of a terminal line. */ static int tty_set_disc(int disc) { if (disc == -1) disc = tty_sdisc; if (ioctl(tty_fd, TIOCSETD, &disc) < 0) { if (opt_q == 0) fprintf(stderr, "slattach: tty_set_disc(%d, %d): %s\n", tty_fd, disc, strerror(errno)); return(-errno); } return(0); } /* Fetch the name of the network interface attached to this terminal. */ static int tty_get_name(char *name) { if (ioctl(tty_fd, SIOCGIFNAME, name) < 0) { if (opt_q == 0) perror("tty_get_name"); return(-errno); } return(0); } /* Hangup the line. */ static int tty_hangup(void) { struct termios tty; tty = tty_current; (void) tty_set_speed(&tty, "0"); if (tty_set_state(&tty) < 0) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_hangup(DROP): %s\n"), strerror(errno)); return(-errno); } (void) sleep(1); if (tty_set_state(&tty_current) < 0) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_hangup(RAISE): %s\n"), strerror(errno)); return(-errno); } return(0); } /* Close down a terminal line. */ static int tty_close(void) { (void) tty_set_disc(tty_sdisc); (void) tty_hangup(); (void) tty_lock(NULL, 0); return(0); } /* Open and initialize a terminal line. */ static int tty_open(char *name, const char *speed) { char pathbuf[PATH_MAX]; register char *path_open, *path_lock; int fd; /* Try opening the TTY device. */ if (name != NULL) { if (name[0] != '/') { if (strlen(name + 6) > sizeof(pathbuf)) { if (opt_q == 0) fprintf(stderr, _("slattach: tty name too long\n")); return (-1); } sprintf(pathbuf, "/dev/%s", name); path_open = pathbuf; path_lock = name; } else if (!strncmp(name, "/dev/", 5)) { path_open = name; path_lock = name + 5; } else { path_open = name; path_lock = name; } if (opt_d) printf("slattach: tty_open: looking for lock\n"); if (tty_lock(path_lock, 1)) return(-1); /* can we lock the device? */ if (opt_d) printf("slattach: tty_open: trying to open %s\n", path_open); if ((fd = open(path_open, O_RDWR|O_NDELAY)) < 0) { if (opt_q == 0) fprintf(stderr, "slattach: tty_open(%s, RW): %s\n", path_open, strerror(errno)); return(-errno); } tty_fd = fd; if (opt_d) printf("slattach: tty_open: %s (fd=%d) ", path_open, fd); } else { tty_fd = 0; } /* Fetch the current state of the terminal. */ if (tty_get_state(&tty_saved) < 0) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot get current state!\n")); return(-errno); } tty_current = tty_saved; /* Fetch the current line discipline of this terminal. */ if (tty_get_disc(&tty_sdisc) < 0) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot get current line disc!\n")); return(-errno); } tty_ldisc = tty_sdisc; /* Put this terminal line in a 8-bit transparent mode. */ if (opt_m == 0) { if (tty_set_raw(&tty_current) < 0) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot set RAW mode!\n")); return(-errno); } /* Set the default speed if we need to. */ if (speed != NULL) { if (tty_set_speed(&tty_current, speed) != 0) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot set %s bps!\n"), speed); return(-errno); } } /* Set up a completely 8-bit clean line. */ if (tty_set_databits(&tty_current, "8") || tty_set_stopbits(&tty_current, "1") || tty_set_parity(&tty_current, "N")) { if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot set 8N1 mode!\n")); return(-errno); } /* Set the new line mode. */ if ((fd = tty_set_state(&tty_current)) < 0) return(fd); } /* OK, line is open. Do we need to "silence" it? */ (void) tty_nomesg(tty_fd); return(0); } /* Catch any signals. */ static void sig_catch(int sig) { /* (void) signal(sig, sig_catch); */ tty_close(); exit(0); } static void usage(void) { char *usage_msg = "Usage: slattach [-ehlLmnqv] " #ifdef SIOCSKEEPALIVE "[-k keepalive] " #endif #ifdef SIOCSOUTFILL "[-o outfill] " #endif "[-c cmd] [-s speed] [-p protocol] tty | -\n" " slattach -V | --version\n"; fputs(usage_msg, stderr); exit(1); } static void version(void) { printf("%s\n%s\n%s\n", Release, Version, Signature); exit(E_VERSION); } int main(int argc, char *argv[]) { char path_buf[128]; char *path_dev; char buff[128]; const char *speed = NULL; const char *proto = DEF_PROTO; const char *extcmd = NULL; int s; static struct option longopts[] = { { "version", 0, NULL, 'V' }, { NULL, 0, NULL, 0 } }; strcpy(path_buf, ""); path_dev = path_buf; /* Scan command line for any arguments. */ opterr = 0; while ((s = getopt_long(argc, argv, "c:ehlLmnp:qs:vdVk:o:", longopts, NULL)) != EOF) switch(s) { case 'c': extcmd = optarg; break; case 'e': opt_e = 1 - opt_e; break; case 'h': opt_h = 1 - opt_h; break; #ifdef SIOCSKEEPALIVE case 'k': opt_k = atoi(optarg); break; #endif case 'L': opt_L = 1 - opt_L; break; case 'l': opt_l = 1 - opt_l; break; case 'm': opt_m = 1 - opt_m; break; case 'n': opt_n = 1 - opt_n; break; #ifdef SIOCSOUTFILL case 'o': opt_o = atoi(optarg); break; #endif case 'p': proto = optarg; break; case 'q': opt_q = 1 - opt_q; break; case 's': speed = optarg; break; case 'd': opt_d = 1 - opt_d; break; case 'v': opt_v = 1 - opt_v; break; case 'V': version(); /*NOTREACHED*/ default: usage(); /*NOTREACHED*/ } if (setvbuf(stdout,0,_IOLBF,0)) { if (opt_q == 0) fprintf(stderr, _("slattach: setvbuf(stdout,0,_IOLBF,0) : %s\n"), strerror(errno)); exit(1); } activate_init(); if (!strcmp(proto, "tty")) opt_m++; /* Is a terminal given? */ if (optind != (argc - 1)) usage(); safe_strncpy(path_buf, argv[optind], sizeof(path_buf)); if (!strcmp(path_buf, "-")) { opt_e = 1; path_dev = NULL; if (tty_open(NULL, speed) < 0) { return(3); } } else { path_dev = path_buf; if (tty_open(path_dev, speed) < 0) { return(3); } } /* Start the correct protocol. */ if (!strcmp(proto, "tty")) { tty_sdisc = N_TTY; tty_close(); return(0); } if (activate_ld(proto, tty_fd)) return(1); if ((opt_v == 1) || (opt_d == 1)) { if (tty_get_name(buff)) { return(3); } printf(_("%s started"), proto); if (path_dev != NULL) printf(_(" on %s"), path_dev); printf(_(" interface %s\n"), buff); } /* Configure keepalive and outfill. */ #ifdef SIOCSKEEPALIVE if (opt_k && (ioctl(tty_fd, SIOCSKEEPALIVE, &opt_k) < 0)) fprintf(stderr, "slattach: ioctl(SIOCSKEEPALIVE): %s\n", strerror(errno)); #endif #ifdef SIOCSOUTFILL if (opt_o && (ioctl(tty_fd, SIOCSOUTFILL, &opt_o) < 0)) fprintf(stderr, "slattach: ioctl(SIOCSOUTFILL): %s\n", strerror(errno)); #endif (void) signal(SIGHUP, sig_catch); (void) signal(SIGINT, sig_catch); (void) signal(SIGQUIT, sig_catch); (void) signal(SIGTERM, sig_catch); /* Wait until we get killed if hanging on a terminal. */ if (opt_e == 0) { while(1) { if(opt_h == 1) { /* hangup on carrier loss */ int n = 0; ioctl(tty_fd, TIOCMGET, &n); if(!(n & TIOCM_CAR)) break; sleep(15); } else sleep(60); }; tty_close(); if(extcmd) /* external command on exit */ system(extcmd); } exit(0); }