FreeBSD-5.3/usr.bin/wall/wall.c
/*
* 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. 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.bin/wall/wall.c,v 1.23 2003/02/21 08:46:44 tjr Exp $");
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1988, 1990, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif
#ifndef lint
static const char sccsid[] = "@(#)wall.c 8.2 (Berkeley) 11/16/93";
#endif
/*
* This program is not related to David Wall, whose Stanford Ph.D. thesis
* is entitled "Mechanisms for Broadcast and Selective Broadcast".
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <ctype.h>
#include <err.h>
#include <grp.h>
#include <locale.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>
#include "ttymsg.h"
static void makemsg(char *);
static void usage(void);
struct wallgroup {
struct wallgroup *next;
char *name;
gid_t gid;
} *grouplist;
int nobanner;
int mbufsize;
char *mbuf;
int
main(int argc, char *argv[])
{
struct iovec iov;
struct utmp utmp;
int ch;
int ingroup;
FILE *fp;
struct wallgroup *g;
struct group *grp;
char **np;
const char *p;
struct passwd *pw;
char line[sizeof(utmp.ut_line) + 1];
char username[sizeof(utmp.ut_name) + 1];
(void)setlocale(LC_CTYPE, "");
while ((ch = getopt(argc, argv, "g:n")) != -1)
switch (ch) {
case 'n':
/* undoc option for shutdown: suppress banner */
if (geteuid() == 0)
nobanner = 1;
break;
case 'g':
g = (struct wallgroup *)malloc(sizeof *g);
g->next = grouplist;
g->name = optarg;
g->gid = -1;
grouplist = g;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc > 1)
usage();
for (g = grouplist; g; g = g->next) {
grp = getgrnam(g->name);
if (grp != NULL)
g->gid = grp->gr_gid;
else
warnx("%s: no such group", g->name);
}
makemsg(*argv);
if (!(fp = fopen(_PATH_UTMP, "r")))
err(1, "cannot read %s", _PATH_UTMP);
iov.iov_base = mbuf;
iov.iov_len = mbufsize;
/* NOSTRICT */
while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) {
if (!utmp.ut_name[0])
continue;
if (grouplist) {
ingroup = 0;
strlcpy(username, utmp.ut_name, sizeof(utmp.ut_name));
pw = getpwnam(username);
if (!pw)
continue;
for (g = grouplist; g && ingroup == 0; g = g->next) {
if (g->gid == (gid_t)-1)
continue;
if (g->gid == pw->pw_gid)
ingroup = 1;
else if ((grp = getgrgid(g->gid)) != NULL) {
for (np = grp->gr_mem; *np; np++) {
if (strcmp(*np, username) == 0) {
ingroup = 1;
break;
}
}
}
}
if (ingroup == 0)
continue;
}
strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
line[sizeof(utmp.ut_line)] = '\0';
if ((p = ttymsg(&iov, 1, line, 60*5)) != NULL)
warnx("%s", p);
}
exit(0);
}
static void
usage()
{
(void)fprintf(stderr, "usage: wall [-g group] [file]\n");
exit(1);
}
void
makemsg(char *fname)
{
int cnt;
unsigned char ch;
struct tm *lt;
struct passwd *pw;
struct stat sbuf;
time_t now;
FILE *fp;
int fd;
char *p, hostname[MAXHOSTNAMELEN], lbuf[256], tmpname[64];
const char *tty;
const char *whom;
gid_t egid;
(void)snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXX", _PATH_TMP);
if ((fd = mkstemp(tmpname)) == -1 || !(fp = fdopen(fd, "r+")))
err(1, "can't open temporary file");
(void)unlink(tmpname);
if (!nobanner) {
tty = ttyname(STDERR_FILENO);
if (tty == NULL)
tty = "no tty";
if (!(whom = getlogin()))
whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
(void)gethostname(hostname, sizeof(hostname));
(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);
(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);
}
(void)fprintf(fp, "%79s\r\n", " ");
if (fname) {
egid = getegid();
setegid(getgid());
if (freopen(fname, "r", stdin) == NULL)
err(1, "can't read %s", fname);
setegid(egid);
}
while (fgets(lbuf, sizeof(lbuf), stdin))
for (cnt = 0, p = lbuf; (ch = *p) != '\0'; ++p, ++cnt) {
if (ch == '\r') {
cnt = 0;
} else if (cnt == 79 || ch == '\n') {
for (; cnt < 79; ++cnt)
putc(' ', fp);
putc('\r', fp);
putc('\n', fp);
cnt = 0;
} else if (((ch & 0x80) && ch < 0xA0) ||
/* disable upper controls */
(!isprint(ch) && !isspace(ch) &&
ch != '\a' && ch != '\b')
) {
if (ch & 0x80) {
ch &= 0x7F;
putc('M', fp);
if (++cnt == 79) {
putc('\r', fp);
putc('\n', fp);
cnt = 0;
}
putc('-', fp);
if (++cnt == 79) {
putc('\r', fp);
putc('\n', fp);
cnt = 0;
}
}
if (iscntrl(ch)) {
ch ^= 040;
putc('^', fp);
if (++cnt == 79) {
putc('\r', fp);
putc('\n', fp);
cnt = 0;
}
}
putc(ch, fp);
} else {
putc(ch, fp);
}
}
(void)fprintf(fp, "%79s\r\n", " ");
rewind(fp);
if (fstat(fd, &sbuf))
err(1, "can't stat temporary file");
mbufsize = sbuf.st_size;
if (!(mbuf = malloc((u_int)mbufsize)))
err(1, "out of memory");
if ((int)fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
err(1, "can't read temporary file");
(void)close(fd);
}