diff options
Diffstat (limited to 'usr.sbin/sliplogin/sliplogin.c')
| -rw-r--r-- | usr.sbin/sliplogin/sliplogin.c | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/usr.sbin/sliplogin/sliplogin.c b/usr.sbin/sliplogin/sliplogin.c new file mode 100644 index 0000000..7e52ff7 --- /dev/null +++ b/usr.sbin/sliplogin/sliplogin.c @@ -0,0 +1,381 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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. + */ + +#ifndef lint +static char copyright[] = +"@(#) Copyright (c) 1990, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif /* not lint */ + +#ifndef lint +static char sccsid[] = "@(#)sliplogin.c 8.2 (Berkeley) 2/1/94"; +#endif /* not lint */ + +/* + * sliplogin.c + * [MUST BE RUN SUID, SLOPEN DOES A SUSER()!] + * + * This program initializes its own tty port to be an async TCP/IP interface. + * It sets the line discipline to slip, invokes a shell script to initialize + * the network interface, then pauses forever waiting for hangup. + * + * It is a remote descendant of several similar programs with incestuous ties: + * - Kirk Smith's slipconf, modified by Richard Johnsson @ DEC WRL. + * - slattach, probably by Rick Adams but touched by countless hordes. + * - the original sliplogin for 4.2bsd, Doug Kingston the mover behind it. + * + * There are two forms of usage: + * + * "sliplogin" + * Invoked simply as "sliplogin", the program looks up the username + * in the file /etc/slip.hosts. + * If an entry is found, the line on fd0 is configured for SLIP operation + * as specified in the file. + * + * "sliplogin IPhostlogin </dev/ttyb" + * Invoked by root with a username, the name is looked up in the + * /etc/slip.hosts file and if found fd0 is configured as in case 1. + */ + +#include <sys/param.h> +#include <sys/socket.h> +#include <sys/signal.h> +#include <sys/file.h> +#include <sys/syslog.h> +#include <netdb.h> + +#if BSD >= 199006 +#define POSIX +#endif +#ifdef POSIX +#include <sys/termios.h> +#include <sys/ioctl.h> +#include <ttyent.h> +#else +#include <sgtty.h> +#endif +#include <net/slip.h> + +#include <stdio.h> +#include <errno.h> +#include <ctype.h> +#include <string.h> +#include "pathnames.h" + +int unit; +int speed; +int uid; +char loginargs[BUFSIZ]; +char loginfile[MAXPATHLEN]; +char loginname[BUFSIZ]; + +void +findid(name) + char *name; +{ + FILE *fp; + static char slopt[5][16]; + static char laddr[16]; + static char raddr[16]; + static char mask[16]; + char user[16]; + int i, j, n; + + (void)strcpy(loginname, name); + if ((fp = fopen(_PATH_ACCESS, "r")) == NULL) { + (void)fprintf(stderr, "sliplogin: %s: %s\n", + _PATH_ACCESS, strerror(errno)); + syslog(LOG_ERR, "%s: %m\n", _PATH_ACCESS); + exit(1); + } + while (fgets(loginargs, sizeof(loginargs) - 1, fp)) { + if (ferror(fp)) + break; + n = sscanf(loginargs, "%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s\n", + user, laddr, raddr, mask, slopt[0], slopt[1], + slopt[2], slopt[3], slopt[4]); + if (user[0] == '#' || isspace(user[0])) + continue; + if (strcmp(user, name) != 0) + continue; + + /* + * we've found the guy we're looking for -- see if + * there's a login file we can use. First check for + * one specific to this host. If none found, try for + * a generic one. + */ + (void)sprintf(loginfile, "%s.%s", _PATH_LOGIN, name); + if (access(loginfile, R_OK|X_OK) != 0) { + (void)strcpy(loginfile, _PATH_LOGIN); + if (access(loginfile, R_OK|X_OK)) { + fputs("access denied - no login file\n", + stderr); + syslog(LOG_ERR, + "access denied for %s - no %s\n", + name, _PATH_LOGIN); + exit(5); + } + } + + (void) fclose(fp); + return; + } + (void)fprintf(stderr, "SLIP access denied for %s\n", name); + syslog(LOG_ERR, "SLIP access denied for %s\n", name); + exit(4); + /* NOTREACHED */ +} + +char * +sigstr(s) + int s; +{ + static char buf[32]; + + switch (s) { + case SIGHUP: return("HUP"); + case SIGINT: return("INT"); + case SIGQUIT: return("QUIT"); + case SIGILL: return("ILL"); + case SIGTRAP: return("TRAP"); + case SIGIOT: return("IOT"); + case SIGEMT: return("EMT"); + case SIGFPE: return("FPE"); + case SIGKILL: return("KILL"); + case SIGBUS: return("BUS"); + case SIGSEGV: return("SEGV"); + case SIGSYS: return("SYS"); + case SIGPIPE: return("PIPE"); + case SIGALRM: return("ALRM"); + case SIGTERM: return("TERM"); + case SIGURG: return("URG"); + case SIGSTOP: return("STOP"); + case SIGTSTP: return("TSTP"); + case SIGCONT: return("CONT"); + case SIGCHLD: return("CHLD"); + case SIGTTIN: return("TTIN"); + case SIGTTOU: return("TTOU"); + case SIGIO: return("IO"); + case SIGXCPU: return("XCPU"); + case SIGXFSZ: return("XFSZ"); + case SIGVTALRM: return("VTALRM"); + case SIGPROF: return("PROF"); + case SIGWINCH: return("WINCH"); +#ifdef SIGLOST + case SIGLOST: return("LOST"); +#endif + case SIGUSR1: return("USR1"); + case SIGUSR2: return("USR2"); + } + (void)sprintf(buf, "sig %d", s); + return(buf); +} + +void +hup_handler(s) + int s; +{ + char logoutfile[MAXPATHLEN]; + + (void)sprintf(logoutfile, "%s.%s", _PATH_LOGOUT, loginname); + if (access(logoutfile, R_OK|X_OK) != 0) + (void)strcpy(logoutfile, _PATH_LOGOUT); + if (access(logoutfile, R_OK|X_OK) == 0) { + char logincmd[2*MAXPATHLEN+32]; + + (void) sprintf(logincmd, "%s %d %d %s", logoutfile, unit, speed, + loginargs); + (void) system(logincmd); + } + (void) close(0); + syslog(LOG_INFO, "closed %s slip unit %d (%s)\n", loginname, unit, + sigstr(s)); + exit(1); + /* NOTREACHED */ +} + +main(argc, argv) + int argc; + char *argv[]; +{ + int fd, s, ldisc, odisc; + char *name; +#ifdef POSIX + struct termios tios, otios; +#else + struct sgttyb tty, otty; +#endif + char logincmd[2*BUFSIZ+32]; + extern uid_t getuid(); + + if ((name = strrchr(argv[0], '/')) == NULL) + name = argv[0]; + s = getdtablesize(); + for (fd = 3 ; fd < s ; fd++) + (void) close(fd); + openlog(name, LOG_PID, LOG_DAEMON); + uid = getuid(); + if (argc > 1) { + findid(argv[1]); + + /* + * Disassociate from current controlling terminal, if any, + * and ensure that the slip line is our controlling terminal. + */ +#ifdef POSIX + if (fork() > 0) + exit(0); + if (setsid() != 0) + perror("setsid"); +#else + if ((fd = open("/dev/tty", O_RDONLY, 0)) >= 0) { + extern char *ttyname(); + + (void) ioctl(fd, TIOCNOTTY, (caddr_t)0); + (void) close(fd); + /* open slip tty again to acquire as controlling tty? */ + fd = open(ttyname(0), O_RDWR, 0); + if (fd >= 0) + (void) close(fd); + } + (void) setpgrp(0, getpid()); +#endif + if (argc > 2) { + if ((fd = open(argv[2], O_RDWR)) == -1) { + perror(argv[2]); + exit(2); + } + (void) dup2(fd, 0); + if (fd > 2) + close(fd); + } +#ifdef TIOCSCTTY + if (ioctl(0, TIOCSCTTY, (caddr_t)0) != 0) + perror("ioctl (TIOCSCTTY)"); +#endif + } else { + extern char *getlogin(); + + if ((name = getlogin()) == NULL) { + (void) fprintf(stderr, "access denied - no username\n"); + syslog(LOG_ERR, "access denied - getlogin returned 0\n"); + exit(1); + } + findid(name); + } + (void) fchmod(0, 0600); + (void) fprintf(stderr, "starting slip login for %s\n", loginname); +#ifdef POSIX + /* set up the line parameters */ + if (tcgetattr(0, &tios) < 0) { + syslog(LOG_ERR, "tcgetattr: %m"); + exit(1); + } + otios = tios; + cfmakeraw(&tios); + tios.c_iflag &= ~IMAXBEL; + if (tcsetattr(0, TCSAFLUSH, &tios) < 0) { + syslog(LOG_ERR, "tcsetattr: %m"); + exit(1); + } + speed = cfgetispeed(&tios); +#else + /* set up the line parameters */ + if (ioctl(0, TIOCGETP, (caddr_t)&tty) < 0) { + syslog(LOG_ERR, "ioctl (TIOCGETP): %m"); + exit(1); + } + otty = tty; + speed = tty.sg_ispeed; + tty.sg_flags = RAW | ANYP; + if (ioctl(0, TIOCSETP, (caddr_t)&tty) < 0) { + syslog(LOG_ERR, "ioctl (TIOCSETP): %m"); + exit(1); + } +#endif + /* find out what ldisc we started with */ + if (ioctl(0, TIOCGETD, (caddr_t)&odisc) < 0) { + syslog(LOG_ERR, "ioctl(TIOCGETD) (1): %m"); + exit(1); + } + ldisc = SLIPDISC; + if (ioctl(0, TIOCSETD, (caddr_t)&ldisc) < 0) { + syslog(LOG_ERR, "ioctl(TIOCSETD): %m"); + exit(1); + } + /* find out what unit number we were assigned */ + if (ioctl(0, SLIOCGUNIT, (caddr_t)&unit) < 0) { + syslog(LOG_ERR, "ioctl (SLIOCGUNIT): %m"); + exit(1); + } + (void) signal(SIGHUP, hup_handler); + (void) signal(SIGTERM, hup_handler); + + syslog(LOG_INFO, "attaching slip unit %d for %s\n", unit, loginname); + (void)sprintf(logincmd, "%s %d %d %s", loginfile, unit, speed, + loginargs); + /* + * aim stdout and errout at /dev/null so logincmd output won't + * babble into the slip tty line. + */ + (void) close(1); + if ((fd = open(_PATH_DEVNULL, O_WRONLY)) != 1) { + if (fd < 0) { + syslog(LOG_ERR, "open /dev/null: %m"); + exit(1); + } + (void) dup2(fd, 1); + (void) close(fd); + } + (void) dup2(1, 2); + + /* + * Run login and logout scripts as root (real and effective); + * current route(8) is setuid root, and checks the real uid + * to see whether changes are allowed (or just "route get"). + */ + (void) setuid(0); + if (s = system(logincmd)) { + syslog(LOG_ERR, "%s login failed: exit status %d from %s", + loginname, s, loginfile); + (void) ioctl(0, TIOCSETD, (caddr_t)&odisc); + exit(6); + } + + /* twiddle thumbs until we get a signal */ + while (1) + sigpause(0); + + /* NOTREACHED */ +} |
