/* $NetBSD: wall.c,v 1.30 2015/11/21 14:59:51 christos Exp $ */ /* * Copyright (c) 1988, 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. 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) 1988, 1990, 1993\ The Regents of the University of California. All rights reserved."); #endif /* not lint */ #ifndef lint #if 0 static char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93"; #endif __RCSID("$NetBSD: wall.c,v 1.30 2015/11/21 14:59:51 christos Exp $"); #endif /* not lint */ /* * This program is not related to David Wall, whose Stanford Ph.D. thesis * is entitled "Mechanisms for Broadcast and Selective Broadcast". */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "utmpentry.h" #include "term_chk.h" static void addgroup(char *); static void makemsg(struct iovec *, const char *, int); __dead static void usage(void); static struct wallgroup { gid_t gid; char *name; char **mem; struct wallgroup *next; } *grouplist; int main(int argc, char **argv) { int ch; struct iovec iov; char *p, **mem; struct utmpentry *ep; gid_t egid; struct wallgroup *wg; struct passwd *pw; int nobanner; setprogname(argv[0]); egid = getegid(); if (setegid(getgid()) == -1) err(EXIT_FAILURE, "setegid"); pw = getpwnam("nobody"); if (pw == NULL) errx(EXIT_FAILURE, "Can't find passwd entry for `nobody'"); (void)check_sender(NULL, getuid(), egid); nobanner = 0; while ((ch = getopt(argc, argv, "g:n")) != -1) switch (ch) { case 'n': /* undoc option for shutdown: suppress banner */ if (geteuid() == 0 || (pw && getuid() == pw->pw_uid)) nobanner = 1; break; case 'g': addgroup(optarg); break; case '?': default: usage(); } argc -= optind; argv += optind; if (argc > 1) usage(); makemsg(&iov, *argv, nobanner); (void)getutentries(NULL, &ep); (void)setegid(egid); for (; ep; ep = ep->next) { if (grouplist) { int ingroup; ingroup = 0; pw = getpwnam(ep->name); if (!pw) continue; for (wg = grouplist; wg && !ingroup; wg = wg->next) { if (wg->gid == pw->pw_gid) ingroup = 1; for (mem = wg->mem; *mem && !ingroup; mem++) if (strcmp(ep->name, *mem) == 0) ingroup = 1; } if (ingroup == 0) continue; } /* skip [xgk]dm/xserver entries (":0", ":1", etc.) */ if (ep->line[0] == ':' && isdigit((unsigned char)ep->line[1])) continue; if ((p = ttymsg(&iov, 1, ep->line, 60*5)) != NULL) warnx("%s", p); } return EXIT_SUCCESS; } static void addgroup(char *name) { size_t i; struct group *grp; struct wallgroup *g; grp = getgrnam(name); if ((grp = getgrnam(name)) == NULL) errx(EXIT_FAILURE, "unknown group `%s'", name); for (i = 0; grp->gr_mem[i]; i++) continue; g = malloc(sizeof(*g)); if (g == NULL) err(EXIT_FAILURE, "malloc"); g->gid = grp->gr_gid; g->name = name; g->mem = calloc(i + 1, sizeof(*g->mem)); if (g->mem == NULL) err(EXIT_FAILURE, "calloc"); for (i = 0; grp->gr_mem[i] != NULL; i++) { g->mem[i] = strdup(grp->gr_mem[i]); if (g->mem[i] == NULL) err(EXIT_FAILURE, "strdup"); } g->mem[i] = NULL; g->next = grouplist; grouplist = g; } static void makebanner(FILE *fp) { const char *whom, *tty; char hostname[MAXHOSTNAMELEN + 1], lbuf[100]; time_t now; struct tm *lt; struct passwd *pw; if (!(whom = getlogin())) whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???"; (void)gethostname(hostname, sizeof(hostname)); hostname[sizeof(hostname) - 1] = '\0'; (void)time(&now); lt = localtime(&now); /* * all this stuff is to blank out a square for the message; * we wrap message lines at column 79, not 80, because some * terminals wrap after 79, some do not, and we can't tell. * Which means that we may leave a non-blank character * in column 80, but that can't be helped. */ (void)fprintf(fp, "\r%79s\r\n", " "); (void)snprintf(lbuf, sizeof lbuf, "Broadcast Message from %s@%s", whom, hostname); (void)fprintf(fp, "%-79.79s\007\007\r\n", lbuf); tty = ttyname(STDERR_FILENO); if (tty == NULL) tty = "??"; (void)snprintf(lbuf, sizeof lbuf, " (%s) at %d:%02d %s...", tty, lt->tm_hour, lt->tm_min, lt->tm_zone); (void)fprintf(fp, "%-79.79s\r\n", lbuf); } static void makemsg(struct iovec *iov, const char *fname, int nobanner) { int ch, cnt; struct stat sbuf; FILE *fp; int fd; char *p, tmpname[MAXPATHLEN], lbuf[100]; size_t mbufsize; char *mbuf; (void)snprintf(tmpname, sizeof tmpname, "%s/wall.XXXXXX", _PATH_TMP); if ((fd = mkstemp(tmpname)) == -1) err(EXIT_FAILURE, "can't open temporary file"); (void)unlink(tmpname); if (!(fp = fdopen(fd, "r+"))) err(EXIT_FAILURE, "can't open temporary file"); if (!nobanner) makebanner(fp); (void)fprintf(fp, "%79s\r\n", " "); if (fname && !(freopen(fname, "r", stdin))) err(EXIT_FAILURE, "can't read %s", fname); while (fgets(lbuf, sizeof(lbuf), stdin)) for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) { if (cnt == 79 || ch == '\n') { for (; cnt < 79; ++cnt) putc(' ', fp); putc('\r', fp); putc('\n', fp); cnt = -1; } if (ch != '\n') putc(ch, fp); } (void)fprintf(fp, "%79s\r\n", " "); rewind(fp); if (fstat(fd, &sbuf) == -1) err(EXIT_FAILURE, "can't stat temporary file"); if ((uint64_t)sbuf.st_size > SIZE_T_MAX) errx(EXIT_FAILURE, "file too big"); mbufsize = (size_t)sbuf.st_size; if (!(mbuf = malloc(mbufsize))) err(EXIT_FAILURE, "malloc"); if (fread(mbuf, 1, mbufsize, fp) != mbufsize) err(EXIT_FAILURE, "can't read temporary file"); (void)fclose(fp); iov->iov_base = mbuf; iov->iov_len = mbufsize; } static void usage(void) { (void)fprintf(stderr, "Usage: %s [-g group] [file]\n", getprogname()); exit(EXIT_FAILURE); }