/* * Copyright (c) 1983, 1993, 1994 * 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 const char copyright[] = "@(#) Copyright (c) 1983, 1993, 1994\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint #if 0 static char sccsid[] = "@(#)lpd.c 8.7 (Berkeley) 5/10/95"; #endif static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ /* * lpd -- line printer daemon. * * Listen for a connection and perform the requested operation. * Operations are: * \1printer\n * check the queue for jobs and print any found. * \2printer\n * receive a job from another machine and queue it. * \3printer [users ...] [jobs ...]\n * return the current state of the queue (short form). * \4printer [users ...] [jobs ...]\n * return the current state of the queue (long form). * \5printer person [users ...] [jobs ...]\n * remove jobs from the queue. * * Strategy to maintain protected spooling area: * 1. Spooling area is writable only by daemon and spooling group * 2. lpr runs setuid root and setgrp spooling group; it uses * root to access any file it wants (verifying things before * with an access call) and group id to know how it should * set up ownership of files in the spooling area. * 3. Files in spooling area are owned by root, group spooling * group, with mode 660. * 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to * access files and printer. Users can't get to anything * w/o help of lpq and lprm programs. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "lp.h" #include "lp.local.h" #include "pathnames.h" #include "extern.h" int lflag; /* log requests flag */ int pflag; /* no incoming port flag */ int from_remote; /* from remote socket */ int main(int argc, char **_argv); static void reapchild(int _signo); static void mcleanup(int _signo); static void doit(void); static void startup(void); static void chkhost(struct sockaddr *_f); static int ckqueue(struct printer *_pp); static int *socksetup(int _af, int _debuglvl); static void usage(void); /* XXX from libc/net/rcmd.c */ extern int __ivaliduser_sa __P((FILE *, struct sockaddr *, socklen_t, const char *, const char *)); uid_t uid, euid; int main(int argc, char **argv) { int errs, f, funix, *finet, fromlen, i, options, socket_debug; fd_set defreadfds; struct sockaddr_un un, fromunix; struct sockaddr_storage frominet; int lfd; sigset_t omask, nmask; struct servent *sp, serv; int inet_flag = 0, inet6_flag = 0; euid = geteuid(); /* these shouldn't be different */ uid = getuid(); socket_debug = 0; gethostname(local_host, sizeof(local_host)); progname = "lpd"; if (euid != 0) errx(EX_NOPERM,"must run as root"); errs = 0; while ((i = getopt(argc, argv, "dlp46")) != -1) switch (i) { case 'd': socket_debug++; break; case 'l': lflag++; break; case 'p': pflag++; break; case '4': family = PF_INET; inet_flag++; break; case '6': #ifdef INET6 family = PF_INET6; inet6_flag++; #else errx(EX_USAGE, "lpd compiled sans INET6 (IPv6 support)"); #endif break; default: errs++; } if (inet_flag && inet6_flag) family = PF_UNSPEC; argc -= optind; argv += optind; if (errs) usage(); if (argc == 1) { if ((i = atoi(argv[0])) == 0) usage(); if (i < 0 || i > USHRT_MAX) errx(EX_USAGE, "port # %d is invalid", i); serv.s_port = htons(i); sp = &serv; argc--; } else { sp = getservbyname("printer", "tcp"); if (sp == NULL) errx(EX_OSFILE, "printer/tcp: unknown service"); } if (argc != 0) usage(); /* * We run chkprintcap right away to catch any errors and blat them * to stderr while we still have it open, rather than sending them * to syslog and leaving the user wondering why lpd started and * then stopped. There should probably be a command-line flag to * ignore errors from chkprintcap. */ { pid_t pid; int status; pid = fork(); if (pid < 0) { err(EX_OSERR, "cannot fork"); } else if (pid == 0) { /* child */ execl(_PATH_CHKPRINTCAP, _PATH_CHKPRINTCAP, (char *)0); err(EX_OSERR, "cannot execute %s", _PATH_CHKPRINTCAP); } if (waitpid(pid, &status, 0) < 0) { err(EX_OSERR, "cannot wait"); } if (WIFEXITED(status) && WEXITSTATUS(status) != 0) errx(EX_OSFILE, "%d errors in printcap file, exiting", WEXITSTATUS(status)); } #ifndef DEBUG /* * Set up standard environment by detaching from the parent. */ daemon(0, 0); #endif openlog("lpd", LOG_PID, LOG_LPR); syslog(LOG_INFO, "lpd startup: logging=%d%s", lflag, socket_debug ? " dbg" : ""); (void) umask(0); /* * NB: This depends on O_NONBLOCK semantics doing the right thing; * i.e., applying only to the O_EXLOCK and not to the rest of the * open/creation. As of 1997-12-02, this is the case for commonly- * used filesystems. There are other places in this code which * make the same assumption. */ lfd = open(_PATH_MASTERLOCK, O_WRONLY|O_CREAT|O_EXLOCK|O_NONBLOCK, LOCK_FILE_MODE); if (lfd < 0) { if (errno == EWOULDBLOCK) /* active deamon present */ exit(0); syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); exit(1); } fcntl(lfd, F_SETFL, 0); /* turn off non-blocking mode */ ftruncate(lfd, 0); /* * write process id for others to know */ sprintf(line, "%u\n", getpid()); f = strlen(line); if (write(lfd, line, f) != f) { syslog(LOG_ERR, "%s: %m", _PATH_MASTERLOCK); exit(1); } signal(SIGCHLD, reapchild); /* * Restart all the printers. */ startup(); (void) unlink(_PATH_SOCKETNAME); funix = socket(AF_UNIX, SOCK_STREAM, 0); if (funix < 0) { syslog(LOG_ERR, "socket: %m"); exit(1); } sigemptyset(&nmask); sigaddset(&nmask, SIGHUP); sigaddset(&nmask, SIGINT); sigaddset(&nmask, SIGQUIT); sigaddset(&nmask, SIGTERM); sigprocmask(SIG_BLOCK, &nmask, &omask); (void) umask(07); signal(SIGHUP, mcleanup); signal(SIGINT, mcleanup); signal(SIGQUIT, mcleanup); signal(SIGTERM, mcleanup); memset(&un, 0, sizeof(un)); un.sun_family = AF_UNIX; strcpy(un.sun_path, _PATH_SOCKETNAME); #ifndef SUN_LEN #define SUN_LEN(unp) (strlen((unp)->sun_path) + 2) #endif if (bind(funix, (struct sockaddr *)&un, SUN_LEN(&un)) < 0) { syslog(LOG_ERR, "ubind: %m"); exit(1); } (void) umask(0); sigprocmask(SIG_SETMASK, &omask, (sigset_t *)0); FD_ZERO(&defreadfds); FD_SET(funix, &defreadfds); listen(funix, 5); if (pflag == 0) { finet = socksetup(family, socket_debug); } else finet = NULL; /* pretend we couldn't open TCP socket. */ if (finet) { for (i = 1; i <= *finet; i++) { FD_SET(finet[i], &defreadfds); listen(finet[i], 5); } } /* * Main loop: accept, do a request, continue. */ memset(&frominet, 0, sizeof(frominet)); memset(&fromunix, 0, sizeof(fromunix)); if (lflag) syslog(LOG_INFO, "lpd startup: ready to accept requests"); /* * XXX - should be redone for multi-protocol */ for (;;) { int domain, nfds, s; fd_set readfds; FD_COPY(&defreadfds, &readfds); nfds = select(20, &readfds, 0, 0, 0); if (nfds <= 0) { if (nfds < 0 && errno != EINTR) syslog(LOG_WARNING, "select: %m"); continue; } domain = -1; /* avoid compile-time warning */ s = -1; /* avoid compile-time warning */ if (FD_ISSET(funix, &readfds)) { domain = AF_UNIX, fromlen = sizeof(fromunix); s = accept(funix, (struct sockaddr *)&fromunix, &fromlen); } else { for (i = 1; i <= *finet; i++) if (FD_ISSET(finet[i], &readfds)) { domain = AF_INET; fromlen = sizeof(frominet); s = accept(finet[i], (struct sockaddr *)&frominet, &fromlen); } } if (s < 0) { if (errno != EINTR) syslog(LOG_WARNING, "accept: %m"); continue; } if (fork() == 0) { signal(SIGCHLD, SIG_IGN); signal(SIGHUP, SIG_IGN); signal(SIGINT, SIG_IGN); signal(SIGQUIT, SIG_IGN); signal(SIGTERM, SIG_IGN); (void) close(funix); if (pflag == 0 && finet) { for (i = 1; i <= *finet; i++) (void)close(finet[i]); } dup2(s, 1); (void) close(s); if (domain == AF_INET) { /* for both AF_INET and AF_INET6 */ from_remote = 1; chkhost((struct sockaddr *)&frominet); } else from_remote = 0; doit(); exit(0); } (void) close(s); } } static void reapchild(int signo __unused) { union wait status; while (wait3((int *)&status, WNOHANG, 0) > 0) ; } static void mcleanup(int signo) { /* * XXX syslog(3) is not signal-safe. */ if (lflag) { if (signo) syslog(LOG_INFO, "exiting on signal %d", signo); else syslog(LOG_INFO, "exiting"); } unlink(_PATH_SOCKETNAME); exit(0); } /* * Stuff for handling job specifications */ char *user[MAXUSERS]; /* users to process */ int users; /* # of users in user array */ int requ[MAXREQUESTS]; /* job number of spool entries */ int requests; /* # of spool requests */ char *person; /* name of person doing lprm */ /* buffer to hold the client's machine-name */ static char frombuf[MAXHOSTNAMELEN]; char cbuf[BUFSIZ]; /* command line buffer */ const char *cmdnames[] = { "null", "printjob", "recvjob", "displayq short", "displayq long", "rmjob" }; static void doit(void) { char *cp, *printer; int n; int status; struct printer myprinter, *pp = &myprinter; init_printer(&myprinter); for (;;) { cp = cbuf; do { if (cp >= &cbuf[sizeof(cbuf) - 1]) fatal(0, "Command line too long"); if ((n = read(1, cp, 1)) != 1) { if (n < 0) fatal(0, "Lost connection"); return; } } while (*cp++ != '\n'); *--cp = '\0'; cp = cbuf; if (lflag) { if (*cp >= '\1' && *cp <= '\5') syslog(LOG_INFO, "%s requests %s %s", from_host, cmdnames[(u_char)*cp], cp+1); else syslog(LOG_INFO, "bad request (%d) from %s", *cp, from_host); } switch (*cp++) { case CMD_CHECK_QUE: /* check the queue, print any jobs there */ startprinting(cp); break; case CMD_TAKE_THIS: /* receive files to be queued */ if (!from_remote) { syslog(LOG_INFO, "illegal request (%d)", *cp); exit(1); } recvjob(cp); break; case CMD_SHOWQ_SHORT: /* display the queue (short form) */ case CMD_SHOWQ_LONG: /* display the queue (long form) */ /* XXX - this all needs to be redone. */ printer = cp; while (*cp) { if (*cp != ' ') { cp++; continue; } *cp++ = '\0'; while (isspace(*cp)) cp++; if (*cp == '\0') break; if (isdigit(*cp)) { if (requests >= MAXREQUESTS) fatal(0, "Too many requests"); requ[requests++] = atoi(cp); } else { if (users >= MAXUSERS) fatal(0, "Too many users"); user[users++] = cp; } } status = getprintcap(printer, pp); if (status < 0) fatal(pp, pcaperr(status)); displayq(pp, cbuf[0] == CMD_SHOWQ_LONG); exit(0); case CMD_RMJOB: /* remove a job from the queue */ if (!from_remote) { syslog(LOG_INFO, "illegal request (%d)", *cp); exit(1); } printer = cp; while (*cp && *cp != ' ') cp++; if (!*cp) break; *cp++ = '\0'; person = cp; while (*cp) { if (*cp != ' ') { cp++; continue; } *cp++ = '\0'; while (isspace(*cp)) cp++; if (*cp == '\0') break; if (isdigit(*cp)) { if (requests >= MAXREQUESTS) fatal(0, "Too many requests"); requ[requests++] = atoi(cp); } else { if (users >= MAXUSERS) fatal(0, "Too many users"); user[users++] = cp; } } rmjob(printer); break; } fatal(0, "Illegal service request"); } } /* * Make a pass through the printcap database and start printing any * files left from the last time the machine went down. */ static void startup(void) { int pid, status, more; struct printer myprinter, *pp = &myprinter; more = firstprinter(pp, &status); if (status) goto errloop; while (more) { if (ckqueue(pp) <= 0) { goto next; } if (lflag) syslog(LOG_INFO, "lpd startup: work for %s", pp->printer); if ((pid = fork()) < 0) { syslog(LOG_WARNING, "lpd startup: cannot fork for %s", pp->printer); mcleanup(0); } if (pid == 0) { lastprinter(); printjob(pp); /* NOTREACHED */ } do { next: more = nextprinter(pp, &status); errloop: if (status) syslog(LOG_WARNING, "lpd startup: printcap entry for %s has errors, skipping", pp->printer ? pp->printer : ""); } while (more && status); } } /* * Make sure there's some work to do before forking off a child */ static int ckqueue(struct printer *pp) { register struct dirent *d; DIR *dirp; char *spooldir; spooldir = pp->spool_dir; if ((dirp = opendir(spooldir)) == NULL) return (-1); while ((d = readdir(dirp)) != NULL) { if (d->d_name[0] != 'c' || d->d_name[1] != 'f') continue; /* daemon control files only */ closedir(dirp); return (1); /* found something */ } closedir(dirp); return (0); } #define DUMMY ":nobody::" /* * Check to see if the from host has access to the line printer. */ static void chkhost(struct sockaddr *f) { struct addrinfo hints, *res, *r; register FILE *hostf; int first = 1; int good = 0; char hostbuf[NI_MAXHOST], ip[NI_MAXHOST]; char serv[NI_MAXSERV]; int error, addrlen; caddr_t addr; error = getnameinfo(f, f->sa_len, NULL, 0, serv, sizeof(serv), NI_NUMERICSERV); if (error || atoi(serv) >= IPPORT_RESERVED) fatal(0, "Malformed from address"); /* Need real hostname for temporary filenames */ error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0, NI_NAMEREQD); if (error) { error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID); if (error) fatal(0, "Host name for your address unknown"); else fatal(0, "Host name for your address (%s) unknown", hostbuf); } strlcpy(frombuf, hostbuf, sizeof(frombuf)); from_host = frombuf; /* Need address in stringform for comparison (no DNS lookup here) */ error = getnameinfo(f, f->sa_len, hostbuf, sizeof(hostbuf), NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID); if (error) fatal(0, "Cannot print address"); from_ip = strdup(hostbuf); /* Reject numeric addresses */ memset(&hints, 0, sizeof(hints)); hints.ai_family = family; hints.ai_socktype = SOCK_DGRAM; /*dummy*/ hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST; if (getaddrinfo(from_host, NULL, &hints, &res) == 0) { freeaddrinfo(res); fatal(0, "reverse lookup results in non-FQDN %s", from_host); } /* Check for spoof, ala rlogind */ memset(&hints, 0, sizeof(hints)); hints.ai_family = family; hints.ai_socktype = SOCK_DGRAM; /*dummy*/ error = getaddrinfo(from_host, NULL, &hints, &res); if (error) { fatal(0, "hostname for your address (%s) unknown: %s", from_ip, gai_strerror(error)); } good = 0; for (r = res; good == 0 && r; r = r->ai_next) { error = getnameinfo(r->ai_addr, r->ai_addrlen, ip, sizeof(ip), NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID); if (!error && !strcmp(from_ip, ip)) good = 1; } if (res) freeaddrinfo(res); if (good == 0) fatal(0, "address for your hostname (%s) not matched", from_ip); hostf = fopen(_PATH_HOSTSEQUIV, "r"); again: if (hostf) { if (__ivaliduser_sa(hostf, f, f->sa_len, DUMMY, DUMMY) == 0) { (void) fclose(hostf); return; } (void) fclose(hostf); } if (first == 1) { first = 0; hostf = fopen(_PATH_HOSTSLPD, "r"); goto again; } fatal(0, "Your host does not have line printer access"); /*NOTREACHED*/ } /* setup server socket for specified address family */ /* if af is PF_UNSPEC more than one socket may be returned */ /* the returned list is dynamically allocated, so caller needs to free it */ static int * socksetup(int af, int debuglvl) { struct addrinfo hints, *res, *r; int error, maxs, *s, *socks; const int on = 1; memset(&hints, 0, sizeof(hints)); hints.ai_flags = AI_PASSIVE; hints.ai_family = af; hints.ai_socktype = SOCK_STREAM; error = getaddrinfo(NULL, "printer", &hints, &res); if (error) { syslog(LOG_ERR, "%s", gai_strerror(error)); mcleanup(0); } /* Count max number of sockets we may open */ for (maxs = 0, r = res; r; r = r->ai_next, maxs++) ; socks = malloc((maxs + 1) * sizeof(int)); if (!socks) { syslog(LOG_ERR, "couldn't allocate memory for sockets"); mcleanup(0); } *socks = 0; /* num of sockets counter at start of array */ s = socks + 1; for (r = res; r; r = r->ai_next) { *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol); if (*s < 0) { syslog(LOG_DEBUG, "socket(): %m"); continue; } if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0) { syslog(LOG_ERR, "setsockopt(SO_REUSEADDR): %m"); close(*s); continue; } if (debuglvl) if (setsockopt(*s, SOL_SOCKET, SO_DEBUG, &debuglvl, sizeof(debuglvl)) < 0) { syslog(LOG_ERR, "setsockopt (SO_DEBUG): %m"); close(*s); continue; } #ifdef IPV6_BINDV6ONLY if (r->ai_family == AF_INET6) { if (setsockopt(*s, IPPROTO_IPV6, IPV6_BINDV6ONLY, &on, sizeof(on)) < 0) { syslog(LOG_ERR, "setsockopt (IPV6_BINDV6ONLY): %m"); close(*s); continue; } } #endif if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) { syslog(LOG_DEBUG, "bind(): %m"); close(*s); continue; } (*socks)++; s++; } if (res) freeaddrinfo(res); if (*socks == 0) { syslog(LOG_ERR, "Couldn't bind to any socket"); free(socks); mcleanup(0); } return(socks); } static void usage(void) { #ifdef INET6 fprintf(stderr, "usage: lpd [-dlp46] [port#]\n"); #else fprintf(stderr, "usage: lpd [-dlp] [port#]\n"); #endif exit(EX_USAGE); }