/* $NetBSD: comsat.c,v 1.42 2010/05/29 23:12:30 dholland Exp $ */ /* * Copyright (c) 1980, 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. 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. */ #include #ifndef lint __COPYRIGHT("@(#) Copyright (c) 1980, 1993\ The Regents of the University of California. All rights reserved."); #if 0 static char sccsid[] = "from: @(#)comsat.c 8.1 (Berkeley) 6/4/93"; #else __RCSID("$NetBSD: comsat.c,v 1.42 2010/05/29 23:12:30 dholland Exp $"); #endif #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef SUPPORT_UTMP #include #endif #ifdef SUPPORT_UTMPX #include #endif #include "utmpentry.h" #if !defined(SUPPORT_UTMP) && !defined(SUPPORT_UTMPX) #error "SUPPORT_UTMP and/or SUPPORT_UTMPX must be defined" #endif #define dsyslog if (debug) syslog #define MAXIDLE 120 static int logging; static int debug; static char hostname[MAXHOSTNAMELEN + 1]; static int nutmp; static struct utmpentry *utmp = NULL; static time_t lastmsgtime; static volatile sig_atomic_t needupdate; int main(int, char *[]); static void jkfprintf(FILE *, const char *, off_t, const char *); static void mailfor(char *); static void notify(const struct utmpentry *, off_t); static void onalrm(int); static void checkutmp(void); int main(int argc, char *argv[]) { struct sockaddr_storage from; int cc, ch; socklen_t fromlen; char msgbuf[100]; sigset_t nsigset, osigset; /* verify proper invocation */ fromlen = sizeof(from); if (getsockname(0, (struct sockaddr *)(void *)&from, &fromlen) == -1) err(1, "getsockname"); openlog("comsat", LOG_PID, LOG_DAEMON); while ((ch = getopt(argc, argv, "l")) != -1) switch (ch) { case 'l': logging = 1; break; default: syslog(LOG_ERR, "Usage: %s [-l]", getprogname()); exit(1); } if (chdir(_PATH_MAILDIR) == -1) { syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); (void)recv(0, msgbuf, sizeof(msgbuf) - 1, 0); exit(1); } (void)time(&lastmsgtime); (void)gethostname(hostname, sizeof(hostname)); hostname[sizeof(hostname) - 1] = '\0'; (void)signal(SIGALRM, onalrm); (void)signal(SIGTTOU, SIG_IGN); (void)signal(SIGCHLD, SIG_IGN); (void)sigemptyset(&nsigset); (void)sigaddset(&nsigset, SIGALRM); if (sigprocmask(SIG_SETMASK, NULL, &osigset) == -1) { syslog(LOG_ERR, "sigprocmask get failed (%m)"); exit(1); } needupdate = 1; for (;;) { cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); if (cc <= 0) { if (errno != EINTR) sleep(1); errno = 0; checkutmp(); continue; } else checkutmp(); if (!nutmp) /* no one has logged in yet */ continue; if (sigprocmask(SIG_SETMASK, &nsigset, NULL) == -1) { syslog(LOG_ERR, "sigprocmask set failed (%m)"); exit(1); } msgbuf[cc] = '\0'; (void)time(&lastmsgtime); mailfor(msgbuf); if (sigprocmask(SIG_SETMASK, &osigset, NULL) == -1) { syslog(LOG_ERR, "sigprocmask restore failed (%m)"); exit(1); } } } static void /*ARGSUSED*/ onalrm(int signo) { needupdate = 1; } static void checkutmp(void) { if (!needupdate) return; needupdate = 0; if (time(NULL) - lastmsgtime >= MAXIDLE) exit(0); (void)alarm((u_int)15); nutmp = getutentries(NULL, &utmp); } static void mailfor(char *name) { struct utmpentry *ep; char *cp, *fn; off_t offset; intmax_t val; if (!(cp = strchr(name, '@'))) return; *cp = '\0'; errno = 0; offset = val = strtoimax(cp + 1, &fn, 10); if (errno == ERANGE || offset != val) return; if (fn && *fn && *fn != '\n') { /* * Procmail sends messages to comsat with a trailing colon * and a pathname to the folder where the new message was * deposited. Since we can't reliably open only regular * files, we need to ignore these. With one exception: * if it mentions the user's system mailbox. */ char maildir[MAXPATHLEN]; int l = snprintf(maildir, sizeof(maildir), ":%s/%s", _PATH_MAILDIR, name); if (l >= (int)sizeof(maildir) || strcmp(maildir, fn) != 0) return; } for (ep = utmp; ep != NULL; ep = ep->next) if (strcmp(ep->name, name) == 0) notify(ep, offset); } static void notify(const struct utmpentry *ep, off_t offset) { FILE *tp; struct passwd *p; struct stat stb; struct termios ttybuf; char tty[sizeof(_PATH_DEV) + sizeof(ep->line) + 1]; const char *cr = ep->line; if (strncmp(cr, "pts/", 4) == 0) cr += 4; if (strchr(cr, '/')) { /* A slash is an attempt to break security... */ syslog(LOG_AUTH | LOG_NOTICE, "Unexpected `/' in `%s'", ep->line); return; } (void)snprintf(tty, sizeof(tty), "%s%s", _PATH_DEV, ep->line); if (stat(tty, &stb) == -1 || !(stb.st_mode & S_IEXEC)) { dsyslog(LOG_DEBUG, "%s: wrong mode on %s", ep->name, tty); return; } dsyslog(LOG_DEBUG, "notify %s on %s", ep->name, tty); switch (fork()) { case -1: syslog(LOG_NOTICE, "fork failed (%m)"); return; case 0: break; default: return; } (void)signal(SIGALRM, SIG_DFL); (void)alarm(30); if ((tp = fopen(tty, "w")) == NULL) { dsyslog(LOG_ERR, "open `%s' (%s)", tty, strerror(errno)); _exit(1); } if (tcgetattr(fileno(tp), &ttybuf) == -1) { dsyslog(LOG_ERR, "tcgetattr `%s' (%s)", tty, strerror(errno)); _exit(1); } cr = (ttybuf.c_oflag & ONLCR) && (ttybuf.c_oflag & OPOST) ? "\n" : "\n\r"; /* Set uid/gid/groups to user's in case mail drop is on nfs */ if ((p = getpwnam(ep->name)) == NULL || initgroups(p->pw_name, p->pw_gid) == -1 || setgid(p->pw_gid) == -1 || setuid(p->pw_uid) == -1) _exit(1); if (logging) syslog(LOG_INFO, "biff message for %s", ep->name); (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived:%s----%s", cr, ep->name, (int)sizeof(hostname), hostname, cr, cr); jkfprintf(tp, ep->name, offset, cr); (void)fclose(tp); _exit(0); } static void jkfprintf(FILE *tp, const char *name, off_t offset, const char *cr) { FILE *fi; int linecnt, charcnt, inheader; char line[BUFSIZ], visline[BUFSIZ * 4 + 1], *nl; if ((fi = fopen(name, "r")) == NULL) return; (void)fseeko(fi, offset, SEEK_SET); /* * Print the first 7 lines or 560 characters of the new mail * (whichever comes first). Skip header crap other than * From and Subject. */ linecnt = 7; charcnt = 560; inheader = 1; while (fgets(line, sizeof(line), fi) != NULL) { line[sizeof(line) - 1] = '\0'; if (inheader) { if (line[0] == '\n') { inheader = 0; continue; } if (line[0] == ' ' || line[0] == '\t' || (strncasecmp(line, "From:", 5) && strncasecmp(line, "Subject:", 8))) continue; } if (strncmp(line, "From ", 5) == 0) { (void)fprintf(tp, "----%s", cr); (void)fclose(fi); return; } if (linecnt <= 0 || charcnt <= 0) { (void)fprintf(tp, "...more...%s", cr); (void)fclose(fi); return; } if ((nl = strchr(line, '\n')) != NULL) *nl = '\0'; /* strip weird stuff so can't trojan horse stupid terminals */ (void)strvis(visline, line, VIS_CSTYLE); (void)fputs(visline, tp); (void)fputs(cr, tp); --linecnt; } (void)fprintf(tp, "----%s\n", cr); (void)fclose(fi); }