/* * tty.c - code for handling serial ports in pppd. * * Copyright (C) 2000-2004 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to * endorse or promote products derived from this software without * prior written permission. * * 3. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by Paul Mackerras * ". * * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Portions derived from main.c, which is: * * Copyright (c) 1984-2000 Carnegie Mellon University. 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. The name "Carnegie Mellon University" must not be used to * endorse or promote products derived from this software without * prior written permission. For permission or any legal * details, please contact * Office of Technology Transfer * Carnegie Mellon University * 5000 Forbes Avenue * Pittsburgh, PA 15213-3890 * (412) 268-4387, fax: (412) 268-7395 * tech-transfer@andrew.cmu.edu * * 4. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by Computing Services * at Carnegie Mellon University (http://www.cmu.edu/computing/)." * * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #define RCSID "$Id: tty.c,v 1.22 2004/11/13 12:07:29 paulus Exp $" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pppd.h" #include "fsm.h" #include "lcp.h" void tty_process_extra_options __P((void)); void tty_check_options __P((void)); int connect_tty __P((void)); void disconnect_tty __P((void)); void tty_close_fds __P((void)); void cleanup_tty __P((void)); void tty_do_send_config __P((int, u_int32_t, int, int)); static int setdevname __P((char *, char **, int)); static int setspeed __P((char *, char **, int)); static int setxonxoff __P((char **)); static int setescape __P((char **)); static void printescape __P((option_t *, void (*)(void *, char *,...),void *)); static void finish_tty __P((void)); static int start_charshunt __P((int, int)); static void stop_charshunt __P((void *, int)); static void charshunt_done __P((void *)); static void charshunt __P((int, int, char *)); static int record_write __P((FILE *, int code, u_char *buf, int nb, struct timeval *)); static int open_socket __P((char *)); static void maybe_relock __P((void *, int)); static int pty_master; /* fd for master side of pty */ static int pty_slave; /* fd for slave side of pty */ static int real_ttyfd; /* fd for actual serial port (not pty) */ static int ttyfd; /* Serial port file descriptor */ static char speed_str[16]; /* Serial port speed as string */ mode_t tty_mode = (mode_t)-1; /* Original access permissions to tty */ int baud_rate; /* Actual bits/second for serial device */ char *callback_script; /* script for doing callback */ int charshunt_pid; /* Process ID for charshunt */ int locked; /* lock() has succeeded */ struct stat devstat; /* result of stat() on devnam */ /* option variables */ int crtscts = 0; /* Use hardware flow control */ bool modem = 1; /* Use modem control lines */ int inspeed = 0; /* Input/Output speed requested */ bool lockflag = 0; /* Create lock file to lock the serial dev */ char *initializer = NULL; /* Script to initialize physical link */ char *connect_script = NULL; /* Script to establish physical link */ char *disconnect_script = NULL; /* Script to disestablish physical link */ char *welcomer = NULL; /* Script to run after phys link estab. */ char *ptycommand = NULL; /* Command to run on other side of pty */ bool notty = 0; /* Stdin/out is not a tty */ char *record_file = NULL; /* File to record chars sent/received */ int max_data_rate; /* max bytes/sec through charshunt */ bool sync_serial = 0; /* Device is synchronous serial device */ char *pty_socket = NULL; /* Socket to connect to pty */ int using_pty = 0; /* we're allocating a pty as the device */ extern uid_t uid; extern int kill_link; extern int asked_to_quit; extern int got_sigterm; /* XXX */ extern int privopen; /* don't lock, open device as root */ u_int32_t xmit_accm[8]; /* extended transmit ACCM */ /* option descriptors */ option_t tty_options[] = { /* device name must be first, or change connect_tty() below! */ { "device name", o_wild, (void *) &setdevname, "Serial port device name", OPT_DEVNAM | OPT_PRIVFIX | OPT_NOARG | OPT_A2STRVAL | OPT_STATIC, devnam}, { "tty speed", o_wild, (void *) &setspeed, "Baud rate for serial port", OPT_PRIO | OPT_NOARG | OPT_A2STRVAL | OPT_STATIC, speed_str }, { "lock", o_bool, &lockflag, "Lock serial device with UUCP-style lock file", OPT_PRIO | 1 }, { "nolock", o_bool, &lockflag, "Don't lock serial device", OPT_PRIOSUB | OPT_PRIV }, { "init", o_string, &initializer, "A program to initialize the device", OPT_PRIO | OPT_PRIVFIX }, { "connect", o_string, &connect_script, "A program to set up a connection", OPT_PRIO | OPT_PRIVFIX }, { "disconnect", o_string, &disconnect_script, "Program to disconnect serial device", OPT_PRIO | OPT_PRIVFIX }, { "welcome", o_string, &welcomer, "Script to welcome client", OPT_PRIO | OPT_PRIVFIX }, { "pty", o_string, &ptycommand, "Script to run on pseudo-tty master side", OPT_PRIO | OPT_PRIVFIX | OPT_DEVNAM }, { "notty", o_bool, ¬ty, "Input/output is not a tty", OPT_DEVNAM | 1 }, { "socket", o_string, &pty_socket, "Send and receive over socket, arg is host:port", OPT_PRIO | OPT_DEVNAM }, { "record", o_string, &record_file, "Record characters sent/received to file", OPT_PRIO }, { "crtscts", o_int, &crtscts, "Set hardware (RTS/CTS) flow control", OPT_PRIO | OPT_NOARG | OPT_VAL(1) }, { "cdtrcts", o_int, &crtscts, "Set alternate hardware (DTR/CTS) flow control", OPT_PRIOSUB | OPT_NOARG | OPT_VAL(2) }, { "nocrtscts", o_int, &crtscts, "Disable hardware flow control", OPT_PRIOSUB | OPT_NOARG | OPT_VAL(-1) }, { "-crtscts", o_int, &crtscts, "Disable hardware flow control", OPT_PRIOSUB | OPT_ALIAS | OPT_NOARG | OPT_VAL(-1) }, { "nocdtrcts", o_int, &crtscts, "Disable hardware flow control", OPT_PRIOSUB | OPT_ALIAS | OPT_NOARG | OPT_VAL(-1) }, { "xonxoff", o_special_noarg, (void *)setxonxoff, "Set software (XON/XOFF) flow control", OPT_PRIOSUB }, { "modem", o_bool, &modem, "Use modem control lines", OPT_PRIO | 1 }, { "local", o_bool, &modem, "Don't use modem control lines", OPT_PRIOSUB | 0 }, { "sync", o_bool, &sync_serial, "Use synchronous HDLC serial encoding", 1 }, { "datarate", o_int, &max_data_rate, "Maximum data rate in bytes/sec (with pty, notty or record option)", OPT_PRIO }, { "escape", o_special, (void *)setescape, "List of character codes to escape on transmission", OPT_A2PRINTER, (void *)printescape }, { NULL } }; struct channel tty_channel = { tty_options, &tty_process_extra_options, &tty_check_options, &connect_tty, &disconnect_tty, &tty_establish_ppp, &tty_disestablish_ppp, &tty_do_send_config, &tty_recv_config, &cleanup_tty, &tty_close_fds }; /* * setspeed - Set the serial port baud rate. * If doit is 0, the call is to check whether this option is * potentially a speed value. */ static int setspeed(arg, argv, doit) char *arg; char **argv; int doit; { char *ptr; int spd; spd = strtol(arg, &ptr, 0); if (ptr == arg || *ptr != 0 || spd == 0) return 0; if (doit) { inspeed = spd; slprintf(speed_str, sizeof(speed_str), "%d", spd); } return 1; } /* * setdevname - Set the device name. * If doit is 0, the call is to check whether this option is * potentially a device name. */ static int setdevname(cp, argv, doit) char *cp; char **argv; int doit; { struct stat statbuf; char dev[MAXPATHLEN]; if (*cp == 0) return 0; if (*cp != '/') { strlcpy(dev, "/dev/", sizeof(dev)); strlcat(dev, cp, sizeof(dev)); cp = dev; } /* * Check if there is a character device by this name. */ if (stat(cp, &statbuf) < 0) { if (!doit) return errno != ENOENT; option_error("Couldn't stat %s: %m", cp); return 0; } if (!S_ISCHR(statbuf.st_mode)) { if (doit) option_error("%s is not a character device", cp); return 0; } if (doit) { strlcpy(devnam, cp, sizeof(devnam)); devstat = statbuf; default_device = 0; } return 1; } static int setxonxoff(argv) char **argv; { lcp_wantoptions[0].asyncmap |= 0x000A0000; /* escape ^S and ^Q */ lcp_wantoptions[0].neg_asyncmap = 1; crtscts = -2; return 1; } /* * setescape - add chars to the set we escape on transmission. */ static int setescape(argv) char **argv; { int n, ret; char *p, *endp; p = *argv; ret = 1; while (*p) { n = strtol(p, &endp, 16); if (p == endp) { option_error("escape parameter contains invalid hex number '%s'", p); return 0; } p = endp; if (n < 0 || n == 0x5E || n > 0xFF) { option_error("can't escape character 0x%x", n); ret = 0; } else xmit_accm[n >> 5] |= 1 << (n & 0x1F); while (*p == ',' || *p == ' ') ++p; } lcp_allowoptions[0].asyncmap = xmit_accm[0]; return ret; } static void printescape(opt, printer, arg) option_t *opt; void (*printer) __P((void *, char *, ...)); void *arg; { int n; int first = 1; for (n = 0; n < 256; ++n) { if (n == 0x7d) n += 2; /* skip 7d, 7e */ if (xmit_accm[n >> 5] & (1 << (n & 0x1f))) { if (!first) printer(arg, ","); else first = 0; printer(arg, "%x", n); } } if (first) printer(arg, "oops # nothing escaped"); } /* * tty_init - do various tty-related initializations. */ void tty_init() { add_notifier(&pidchange, maybe_relock, 0); the_channel = &tty_channel; xmit_accm[3] = 0x60000000; } /* * tty_process_extra_options - work out which tty device we are using * and read its options file. */ void tty_process_extra_options() { using_pty = notty || ptycommand != NULL || pty_socket != NULL; if (using_pty) return; if (default_device) { char *p; if (!isatty(0) || (p = ttyname(0)) == NULL) { option_error("no device specified and stdin is not a tty"); exit(EXIT_OPTION_ERROR); } strlcpy(devnam, p, sizeof(devnam)); if (stat(devnam, &devstat) < 0) fatal("Couldn't stat default device %s: %m", devnam); } /* * Parse the tty options file. * The per-tty options file should not change * ptycommand, pty_socket, notty or devnam. * options_for_tty doesn't override options set on the command line, * except for some privileged options. */ if (!options_for_tty()) exit(EXIT_OPTION_ERROR); } /* * tty_check_options - do consistency checks on the options we were given. */ void tty_check_options() { struct stat statbuf; int fdflags; if (demand && notty) { option_error("demand-dialling is incompatible with notty"); exit(EXIT_OPTION_ERROR); } if (demand && connect_script == 0 && ptycommand == NULL && pty_socket == NULL) { option_error("connect script is required for demand-dialling\n"); exit(EXIT_OPTION_ERROR); } /* default holdoff to 0 if no connect script has been given */ if (connect_script == 0 && !holdoff_specified) holdoff = 0; if (using_pty) { if (!default_device) { option_error("%s option precludes specifying device name", pty_socket? "socket": notty? "notty": "pty"); exit(EXIT_OPTION_ERROR); } if (ptycommand != NULL && notty) { option_error("pty option is incompatible with notty option"); exit(EXIT_OPTION_ERROR); } if (pty_socket != NULL && (ptycommand != NULL || notty)) { option_error("socket option is incompatible with pty and notty"); exit(EXIT_OPTION_ERROR); } default_device = notty; lockflag = 0; modem = 0; if (notty && log_to_fd <= 1) log_to_fd = -1; } else { /* * If the user has specified a device which is the same as * the one on stdin, pretend they didn't specify any. * If the device is already open read/write on stdin, * we assume we don't need to lock it, and we can open it * as root. */ if (fstat(0, &statbuf) >= 0 && S_ISCHR(statbuf.st_mode) && statbuf.st_rdev == devstat.st_rdev) { default_device = 1; fdflags = fcntl(0, F_GETFL); if (fdflags != -1 && (fdflags & O_ACCMODE) == O_RDWR) privopen = 1; } } if (default_device) nodetach = 1; /* * Don't send log messages to the serial port, it tends to * confuse the peer. :-) */ if (log_to_fd >= 0 && fstat(log_to_fd, &statbuf) >= 0 && S_ISCHR(statbuf.st_mode) && statbuf.st_rdev == devstat.st_rdev) log_to_fd = -1; } /* * connect_tty - get the serial port ready to start doing PPP. * That is, open the serial port, set its speed and mode, and run * the connector and/or welcomer. */ int connect_tty() { char *connector; int fdflags; #ifndef __linux__ struct stat statbuf; #endif char numbuf[16]; /* * Get a pty master/slave pair if the pty, notty, socket, * or record options were specified. */ strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam)); pty_master = -1; pty_slave = -1; real_ttyfd = -1; if (using_pty || record_file != NULL) { if (!get_pty(&pty_master, &pty_slave, ppp_devnam, uid)) { error("Couldn't allocate pseudo-tty"); status = EXIT_FATAL_ERROR; return -1; } set_up_tty(pty_slave, 1); } /* * Lock the device if we've been asked to. */ status = EXIT_LOCK_FAILED; if (lockflag && !privopen) { if (lock(devnam) < 0) goto errret; locked = 1; } /* * Open the serial device and set it up to be the ppp interface. * First we open it in non-blocking mode so we can set the * various termios flags appropriately. If we aren't dialling * out and we want to use the modem lines, we reopen it later * in order to wait for the carrier detect signal from the modem. */ hungup = 0; got_sigterm = 0; connector = doing_callback? callback_script: connect_script; if (devnam[0] != 0) { for (;;) { /* If the user specified the device name, become the user before opening it. */ int err, prio; prio = privopen? OPRIO_ROOT: tty_options[0].priority; if (prio < OPRIO_ROOT) seteuid(uid); real_ttyfd = open(devnam, O_NONBLOCK | O_RDWR, 0); err = errno; if (prio < OPRIO_ROOT) seteuid(0); if (real_ttyfd >= 0) break; errno = err; if (err != EINTR) { error("Failed to open %s: %m", devnam); status = EXIT_OPEN_FAILED; } if (!persist || err != EINTR) goto errret; } ttyfd = real_ttyfd; if ((fdflags = fcntl(ttyfd, F_GETFL)) == -1 || fcntl(ttyfd, F_SETFL, fdflags & ~O_NONBLOCK) < 0) warn("Couldn't reset non-blocking mode on device: %m"); #ifndef __linux__ /* * Linux 2.4 and above blocks normal writes to the tty * when it is in PPP line discipline, so this isn't needed. */ /* * Do the equivalent of `mesg n' to stop broadcast messages. */ if (fstat(ttyfd, &statbuf) < 0 || fchmod(ttyfd, statbuf.st_mode & ~(S_IWGRP | S_IWOTH)) < 0) { warn("Couldn't restrict write permissions to %s: %m", devnam); } else tty_mode = statbuf.st_mode; #endif /* __linux__ */ /* * Set line speed, flow control, etc. * If we have a non-null connection or initializer script, * on most systems we set CLOCAL for now so that we can talk * to the modem before carrier comes up. But this has the * side effect that we might miss it if CD drops before we * get to clear CLOCAL below. On systems where we can talk * successfully to the modem with CLOCAL clear and CD down, * we could clear CLOCAL at this point. */ set_up_tty(ttyfd, ((connector != NULL && connector[0] != 0) || initializer != NULL)); } /* * If the pty, socket, notty and/or record option was specified, * start up the character shunt now. */ status = EXIT_PTYCMD_FAILED; if (ptycommand != NULL) { if (record_file != NULL) { int ipipe[2], opipe[2], ok; if (pipe(ipipe) < 0 || pipe(opipe) < 0) fatal("Couldn't create pipes for record option: %m"); /* don't leak these to the ptycommand */ (void) fcntl(ipipe[0], F_SETFD, FD_CLOEXEC); (void) fcntl(opipe[1], F_SETFD, FD_CLOEXEC); ok = device_script(ptycommand, opipe[0], ipipe[1], 1) == 0 && start_charshunt(ipipe[0], opipe[1]); close(ipipe[0]); close(ipipe[1]); close(opipe[0]); close(opipe[1]); if (!ok) goto errret; } else { if (device_script(ptycommand, pty_master, pty_master, 1) < 0) goto errret; } } else if (pty_socket != NULL) { int fd = open_socket(pty_socket); if (fd < 0) goto errret; if (!start_charshunt(fd, fd)) goto errret; close(fd); } else if (notty) { if (!start_charshunt(0, 1)) goto errret; dup2(fd_devnull, 0); dup2(fd_devnull, 1); if (log_to_fd == 1) log_to_fd = -1; if (log_to_fd != 2) dup2(fd_devnull, 2); } else if (record_file != NULL) { int fd = dup(ttyfd); if (!start_charshunt(fd, fd)) goto errret; } if (using_pty || record_file != NULL) { ttyfd = pty_slave; close(pty_master); pty_master = -1; } /* run connection script */ if ((connector && connector[0]) || initializer) { if (real_ttyfd != -1) { /* XXX do this if doing_callback == CALLBACK_DIALIN? */ if (!default_device && modem) { setdtr(real_ttyfd, 0); /* in case modem is off hook */ sleep(1); setdtr(real_ttyfd, 1); } } if (initializer && initializer[0]) { if (device_script(initializer, ttyfd, ttyfd, 0) < 0) { error("Initializer script failed"); status = EXIT_INIT_FAILED; goto errret; } if (got_sigterm) { disconnect_tty(); goto errret; } info("Serial port initialized."); } if (connector && connector[0]) { if (device_script(connector, ttyfd, ttyfd, 0) < 0) { error("Connect script failed"); status = EXIT_CONNECT_FAILED; goto errret; } if (got_sigterm) { disconnect_tty(); goto errret; } info("Serial connection established."); } /* set line speed, flow control, etc.; clear CLOCAL if modem option */ if (real_ttyfd != -1) set_up_tty(real_ttyfd, 0); if (doing_callback == CALLBACK_DIALIN) connector = NULL; } /* reopen tty if necessary to wait for carrier */ if (connector == NULL && modem && devnam[0] != 0) { int i; for (;;) { if ((i = open(devnam, O_RDWR)) >= 0) break; if (errno != EINTR) { error("Failed to reopen %s: %m", devnam); status = EXIT_OPEN_FAILED; } if (!persist || errno != EINTR || hungup || got_sigterm) goto errret; } close(i); } slprintf(numbuf, sizeof(numbuf), "%d", baud_rate); script_setenv("SPEED", numbuf, 0); /* run welcome script, if any */ if (welcomer && welcomer[0]) { if (device_script(welcomer, ttyfd, ttyfd, 0) < 0) warn("Welcome script failed"); } /* * If we are initiating this connection, wait for a short * time for something from the peer. This can avoid bouncing * our packets off his tty before he has it set up. */ if (connector != NULL || ptycommand != NULL || pty_socket != NULL) listen_time = connect_delay; return ttyfd; errret: if (pty_master >= 0) { close(pty_master); pty_master = -1; } if (pty_slave >= 0) { close(pty_slave); pty_slave = -1; } if (real_ttyfd >= 0) { close(real_ttyfd); real_ttyfd = -1; } ttyfd = -1; if (got_sigterm) asked_to_quit = 1; return -1; } void disconnect_tty() { if (disconnect_script == NULL || hungup) return; if (real_ttyfd >= 0) set_up_tty(real_ttyfd, 1); if (device_script(disconnect_script, ttyfd, ttyfd, 0) < 0) { warn("disconnect script failed"); } else { info("Serial link disconnected."); } } void tty_close_fds() { if (pty_slave >= 0) close(pty_slave); if (real_ttyfd >= 0) { close(real_ttyfd); real_ttyfd = -1; } /* N.B. ttyfd will == either pty_slave or real_ttyfd */ } void cleanup_tty() { if (real_ttyfd >= 0) finish_tty(); tty_close_fds(); if (locked) { unlock(); locked = 0; } } /* * tty_do_send_config - set transmit-side PPP configuration. * We set the extended transmit ACCM here as well. */ void tty_do_send_config(mtu, accm, pcomp, accomp) int mtu; u_int32_t accm; int pcomp, accomp; { tty_set_xaccm(xmit_accm); tty_send_config(mtu, accm, pcomp, accomp); } /* * finish_tty - restore the terminal device to its original settings */ static void finish_tty() { /* drop dtr to hang up */ if (!default_device && modem) { setdtr(real_ttyfd, 0); /* * This sleep is in case the serial port has CLOCAL set by default, * and consequently will reassert DTR when we close the device. */ sleep(1); } restore_tty(real_ttyfd); #ifndef __linux__ if (tty_mode != (mode_t) -1) { if (fchmod(real_ttyfd, tty_mode) != 0) error("Couldn't restore tty permissions"); } #endif /* __linux__ */ close(real_ttyfd); real_ttyfd = -1; } /* * maybe_relock - our PID has changed, maybe update the lock file. */ static void maybe_relock(arg, pid) void *arg; int pid; { if (locked) relock(pid); } /* * open_socket - establish a stream socket connection to the nominated * host and port. */ static int open_socket(dest) char *dest; { char *sep, *endp = NULL; int sock, port = -1; u_int32_t host; struct hostent *hent; struct sockaddr_in sad; /* parse host:port and resolve host to an IP address */ sep = strchr(dest, ':'); if (sep != NULL) port = strtol(sep+1, &endp, 10); if (port < 0 || endp == sep+1 || sep == dest) { error("Can't parse host:port for socket destination"); return -1; } *sep = 0; host = inet_addr(dest); if (host == (u_int32_t) -1) { hent = gethostbyname(dest); if (hent == NULL) { error("%s: unknown host in socket option", dest); *sep = ':'; return -1; } host = *(u_int32_t *)(hent->h_addr_list[0]); } *sep = ':'; /* get a socket and connect it to the other end */ sock = socket(PF_INET, SOCK_STREAM, 0); if (sock < 0) { error("Can't create socket: %m"); return -1; } memset(&sad, 0, sizeof(sad)); sad.sin_family = AF_INET; sad.sin_port = htons(port); sad.sin_addr.s_addr = host; if (connect(sock, (struct sockaddr *)&sad, sizeof(sad)) < 0) { error("Can't connect to %s: %m", dest); close(sock); return -1; } return sock; } /* * start_charshunt - create a child process to run the character shunt. */ static int start_charshunt(ifd, ofd) int ifd, ofd; { int cpid; cpid = safe_fork(ifd, ofd, (log_to_fd >= 0? log_to_fd: 2)); if (cpid == -1) { error("Can't fork process for character shunt: %m"); return 0; } if (cpid == 0) { /* child */ reopen_log(); if (!nodetach) log_to_fd = -1; else if (log_to_fd >= 0) log_to_fd = 2; setgid(getgid()); setuid(uid); if (getuid() != uid) fatal("setuid failed"); charshunt(0, 1, record_file); exit(0); } charshunt_pid = cpid; add_notifier(&sigreceived, stop_charshunt, 0); record_child(cpid, "pppd (charshunt)", charshunt_done, NULL); return 1; } static void charshunt_done(arg) void *arg; { charshunt_pid = 0; } static void stop_charshunt(arg, sig) void *arg; int sig; { if (charshunt_pid) kill(charshunt_pid, (sig == SIGINT? sig: SIGTERM)); } /* * charshunt - the character shunt, which passes characters between * the pty master side and the serial port (or stdin/stdout). * This runs as the user (not as root). * (We assume ofd >= ifd which is true the way this gets called. :-). */ static void charshunt(ifd, ofd, record_file) int ifd, ofd; char *record_file; { int n, nfds; fd_set ready, writey; u_char *ibufp, *obufp; int nibuf, nobuf; int flags; int pty_readable, stdin_readable; struct timeval lasttime; FILE *recordf = NULL; int ilevel, olevel, max_level; struct timeval levelt, tout, *top; extern u_char inpacket_buf[]; /* * Reset signal handlers. */ signal(SIGHUP, SIG_IGN); /* Hangup */ signal(SIGINT, SIG_DFL); /* Interrupt */ signal(SIGTERM, SIG_DFL); /* Terminate */ signal(SIGCHLD, SIG_DFL); signal(SIGUSR1, SIG_DFL); signal(SIGUSR2, SIG_DFL); signal(SIGABRT, SIG_DFL); signal(SIGALRM, SIG_DFL); signal(SIGFPE, SIG_DFL); signal(SIGILL, SIG_DFL); signal(SIGPIPE, SIG_DFL); signal(SIGQUIT, SIG_DFL); signal(SIGSEGV, SIG_DFL); #ifdef SIGBUS signal(SIGBUS, SIG_DFL); #endif #ifdef SIGEMT signal(SIGEMT, SIG_DFL); #endif #ifdef SIGPOLL signal(SIGPOLL, SIG_DFL); #endif #ifdef SIGPROF signal(SIGPROF, SIG_DFL); #endif #ifdef SIGSYS signal(SIGSYS, SIG_DFL); #endif #ifdef SIGTRAP signal(SIGTRAP, SIG_DFL); #endif #ifdef SIGVTALRM signal(SIGVTALRM, SIG_DFL); #endif #ifdef SIGXCPU signal(SIGXCPU, SIG_DFL); #endif #ifdef SIGXFSZ signal(SIGXFSZ, SIG_DFL); #endif /* * Check that the fds won't overrun the fd_sets */ if (ifd >= FD_SETSIZE || ofd >= FD_SETSIZE || pty_master >= FD_SETSIZE) fatal("internal error: file descriptor too large (%d, %d, %d)", ifd, ofd, pty_master); /* * Open the record file if required. */ if (record_file != NULL) { recordf = fopen(record_file, "a"); if (recordf == NULL) error("Couldn't create record file %s: %m", record_file); } /* set all the fds to non-blocking mode */ flags = fcntl(pty_master, F_GETFL); if (flags == -1 || fcntl(pty_master, F_SETFL, flags | O_NONBLOCK) == -1) warn("couldn't set pty master to nonblock: %m"); flags = fcntl(ifd, F_GETFL); if (flags == -1 || fcntl(ifd, F_SETFL, flags | O_NONBLOCK) == -1) warn("couldn't set %s to nonblock: %m", (ifd==0? "stdin": "tty")); if (ofd != ifd) { flags = fcntl(ofd, F_GETFL); if (flags == -1 || fcntl(ofd, F_SETFL, flags | O_NONBLOCK) == -1) warn("couldn't set stdout to nonblock: %m"); } nibuf = nobuf = 0; ibufp = obufp = NULL; pty_readable = stdin_readable = 1; ilevel = olevel = 0; gettimeofday(&levelt, NULL); if (max_data_rate) { max_level = max_data_rate / 10; if (max_level < 100) max_level = 100; } else max_level = PPP_MRU + PPP_HDRLEN + 1; nfds = (ofd > pty_master? ofd: pty_master) + 1; if (recordf != NULL) { gettimeofday(&lasttime, NULL); putc(7, recordf); /* put start marker */ putc(lasttime.tv_sec >> 24, recordf); putc(lasttime.tv_sec >> 16, recordf); putc(lasttime.tv_sec >> 8, recordf); putc(lasttime.tv_sec, recordf); lasttime.tv_usec = 0; } while (nibuf != 0 || nobuf != 0 || pty_readable || stdin_readable) { top = 0; tout.tv_sec = 0; tout.tv_usec = 10000; FD_ZERO(&ready); FD_ZERO(&writey); if (nibuf != 0) { if (ilevel >= max_level) top = &tout; else FD_SET(pty_master, &writey); } else if (stdin_readable) FD_SET(ifd, &ready); if (nobuf != 0) { if (olevel >= max_level) top = &tout; else FD_SET(ofd, &writey); } else if (pty_readable) FD_SET(pty_master, &ready); if (select(nfds, &ready, &writey, NULL, top) < 0) { if (errno != EINTR) fatal("select"); continue; } if (max_data_rate) { double dt; int nbt; struct timeval now; gettimeofday(&now, NULL); dt = (now.tv_sec - levelt.tv_sec + (now.tv_usec - levelt.tv_usec) / 1e6); nbt = (int)(dt * max_data_rate); ilevel = (nbt < 0 || nbt > ilevel)? 0: ilevel - nbt; olevel = (nbt < 0 || nbt > olevel)? 0: olevel - nbt; levelt = now; } else ilevel = olevel = 0; if (FD_ISSET(ifd, &ready)) { ibufp = inpacket_buf; nibuf = read(ifd, ibufp, PPP_MRU + PPP_HDRLEN); if (nibuf < 0 && errno == EIO) nibuf = 0; if (nibuf < 0) { if (!(errno == EINTR || errno == EAGAIN)) { error("Error reading standard input: %m"); break; } nibuf = 0; } else if (nibuf == 0) { /* end of file from stdin */ stdin_readable = 0; if (recordf) if (!record_write(recordf, 4, NULL, 0, &lasttime)) recordf = NULL; } else { FD_SET(pty_master, &writey); if (recordf) if (!record_write(recordf, 2, ibufp, nibuf, &lasttime)) recordf = NULL; } } if (FD_ISSET(pty_master, &ready)) { obufp = outpacket_buf; nobuf = read(pty_master, obufp, PPP_MRU + PPP_HDRLEN); if (nobuf < 0 && errno == EIO) nobuf = 0; if (nobuf < 0) { if (!(errno == EINTR || errno == EAGAIN)) { error("Error reading pseudo-tty master: %m"); break; } nobuf = 0; } else if (nobuf == 0) { /* end of file from the pty - slave side has closed */ pty_readable = 0; stdin_readable = 0; /* pty is not writable now */ nibuf = 0; close(ofd); if (recordf) if (!record_write(recordf, 3, NULL, 0, &lasttime)) recordf = NULL; } else { FD_SET(ofd, &writey); if (recordf) if (!record_write(recordf, 1, obufp, nobuf, &lasttime)) recordf = NULL; } } else if (!stdin_readable) pty_readable = 0; if (FD_ISSET(ofd, &writey)) { n = nobuf; if (olevel + n > max_level) n = max_level - olevel; n = write(ofd, obufp, n); if (n < 0) { if (errno == EIO) { pty_readable = 0; nobuf = 0; } else if (errno != EAGAIN && errno != EINTR) { error("Error writing standard output: %m"); break; } } else { obufp += n; nobuf -= n; olevel += n; } } if (FD_ISSET(pty_master, &writey)) { n = nibuf; if (ilevel + n > max_level) n = max_level - ilevel; n = write(pty_master, ibufp, n); if (n < 0) { if (errno == EIO) { stdin_readable = 0; nibuf = 0; } else if (errno != EAGAIN && errno != EINTR) { error("Error writing pseudo-tty master: %m"); break; } } else { ibufp += n; nibuf -= n; ilevel += n; } } } exit(0); } static int record_write(f, code, buf, nb, tp) FILE *f; int code; u_char *buf; int nb; struct timeval *tp; { struct timeval now; int diff; gettimeofday(&now, NULL); now.tv_usec /= 100000; /* actually 1/10 s, not usec now */ diff = (now.tv_sec - tp->tv_sec) * 10 + (now.tv_usec - tp->tv_usec); if (diff > 0) { if (diff > 255) { putc(5, f); putc(diff >> 24, f); putc(diff >> 16, f); putc(diff >> 8, f); putc(diff, f); } else { putc(6, f); putc(diff, f); } *tp = now; } putc(code, f); if (buf != NULL) { putc(nb >> 8, f); putc(nb, f); fwrite(buf, nb, 1, f); } fflush(f); if (ferror(f)) { error("Error writing record file: %m"); return 0; } return 1; }