File: [local] / src / usr.bin / wall / wall.c (download)
Revision 1.37, Wed Mar 8 04:43:12 2023 UTC (15 months ago) by guenther
Branch: MAIN
CVS Tags: OPENBSD_7_5_BASE, OPENBSD_7_5, OPENBSD_7_4_BASE, OPENBSD_7_4, OPENBSD_7_3_BASE, OPENBSD_7_3, HEAD Changes since 1.36: +1 -2 lines
Delete obsolete /* ARGSUSED */ lint comments.
ok miod@ millert@
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/* $OpenBSD: wall.c,v 1.37 2023/03/08 04:43:12 guenther Exp $ */
/* $NetBSD: wall.c,v 1.6 1994/11/17 07:17:58 jtc 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.
*/
/*
* This program is not related to David Wall, whose Stanford Ph.D. thesis
* is entitled "Mechanisms for Broadcast and Selective Broadcast".
*/
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <ctype.h>
#include <err.h>
#include <grp.h>
#include <limits.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <utmp.h>
struct wallgroup {
gid_t gid;
char *name;
char **mem;
struct wallgroup *next;
} *grouplist;
struct utmptty {
char *tty;
SLIST_ENTRY(utmptty) next;
};
void makemsg(char *);
void addgroup(struct group *, char *);
char *ttymsg(struct iovec *, int, char *, int);
__dead void usage(void);
static int isu8cont(unsigned char);
int nobanner;
int mbufsize;
char *mbuf;
int
main(int argc, char **argv)
{
FILE *fp;
int ch, ingroup;
struct iovec iov;
struct utmp utmp;
char *p, **mem;
char line[sizeof(utmp.ut_line) + 1];
char username[sizeof(utmp.ut_name) + 1];
struct passwd *pw;
struct group *grp;
struct wallgroup *g;
struct utmptty *un;
SLIST_HEAD(,utmptty) utmphead;
SLIST_INIT(&utmphead);
while ((ch = getopt(argc, argv, "ng:")) != -1)
switch (ch) {
case 'n':
/* undoc option for shutdown: suppress banner */
pw = getpwnam("nobody");
if (geteuid() == 0 || (pw && getuid() == pw->pw_uid))
nobanner = 1;
break;
case 'g':
if ((grp = getgrnam(optarg)) == NULL)
errx(1, "unknown group `%s'", optarg);
addgroup(grp, optarg);
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc > 1)
usage();
makemsg(*argv);
if (unveil(_PATH_UTMP, "r") == -1)
err(1, "unveil %s", _PATH_UTMP);
if (unveil(_PATH_DEV, "w") == -1)
err(1, "unveil %s", _PATH_DEV);
if (unveil(_PATH_DEVDB, "r") == -1)
err(1, "unveil %s", _PATH_DEVDB);
if (pledge("stdio rpath wpath getpw proc", NULL) == -1)
err(1, "pledge");
if (!(fp = fopen(_PATH_UTMP, "r")))
err(1, "cannot read %s", _PATH_UTMP);
iov.iov_base = mbuf;
iov.iov_len = mbufsize;
while (fread(&utmp, sizeof(utmp), 1, fp) == 1) {
if (!utmp.ut_name[0])
continue;
if (grouplist) {
ingroup = 0;
strncpy(username, utmp.ut_name, sizeof(utmp.ut_name));
username[sizeof(utmp.ut_name)] = '\0';
pw = getpwnam(username);
if (!pw)
continue;
for (g = grouplist; g && ingroup == 0; g = g->next) {
if (g->gid == pw->pw_gid)
ingroup = 1;
for (mem = g->mem; *mem && ingroup == 0; mem++)
if (strcmp(username, *mem) == 0)
ingroup = 1;
}
if (ingroup == 0)
continue;
}
strncpy(line, utmp.ut_line, sizeof(utmp.ut_line));
line[sizeof(utmp.ut_line)] = '\0';
un = malloc(sizeof(struct utmptty));
if (un == NULL)
err(1, "malloc");
un->tty = strndup(line, sizeof(utmp.ut_line));
if (un->tty == NULL)
err(1, "strndup");
SLIST_INSERT_HEAD(&utmphead, un, next);
}
fclose(fp);
if (pledge("stdio rpath wpath proc", NULL) == -1)
err(1, "pledge");
SLIST_FOREACH(un, &utmphead, next) {
if ((p = ttymsg(&iov, 1, un->tty, 60*5)) != NULL)
warnx("%s", p);
}
exit(0);
}
void
makemsg(char *fname)
{
int cnt;
struct tm *lt;
struct passwd *pw;
struct stat sbuf;
time_t now;
FILE *fp;
int fd;
char *p, *whom, hostname[HOST_NAME_MAX+1], lbuf[100], tmpname[PATH_MAX];
char *ttynam;
unsigned char ch;
snprintf(tmpname, sizeof(tmpname), "%s/wall.XXXXXXXXXX", _PATH_TMP);
if ((fd = mkstemp(tmpname)) >= 0) {
(void)unlink(tmpname);
fp = fdopen(fd, "r+");
}
if (fd == -1 || fp == NULL)
err(1, "can't open temporary file");
if (!nobanner) {
if (!(whom = getlogin()))
whom = (pw = getpwuid(getuid())) ? pw->pw_name : "???";
(void)gethostname(hostname, sizeof(hostname));
(void)time(&now);
lt = localtime(&now);
if ((ttynam = ttyname(STDERR_FILENO)) == NULL)
ttynam = "(not a tty)";
/*
* 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 ...", ttynam,
lt->tm_hour, lt->tm_min);
(void)fprintf(fp, "%-79.79s\r\n", lbuf);
}
(void)fprintf(fp, "%79s\r\n", " ");
if (fname) {
gid_t egid = getegid();
setegid(getgid());
if (freopen(fname, "r", stdin) == NULL)
err(1, "can't read %s", fname);
setegid(egid);
}
cnt = 0;
while (fgets(lbuf, sizeof(lbuf), stdin))
for (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')
p--;
} else if (!isu8cont(ch))
putc(isprint(ch) || isspace(ch) || ch == '\a' ?
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;
mbuf = malloc((u_int)mbufsize);
if (mbuf == NULL)
err(1, NULL);
if (fread(mbuf, sizeof(*mbuf), mbufsize, fp) != mbufsize)
err(1, "can't read temporary file");
(void)close(fd);
}
void
addgroup(struct group *grp, char *name)
{
int i;
struct wallgroup *g;
for (i = 0; grp->gr_mem[i]; i++)
;
g = malloc(sizeof *g);
if (g == NULL)
err(1, NULL);
g->gid = grp->gr_gid;
g->name = name;
g->mem = calloc(i + 1, sizeof(char *));
if (g->mem == NULL)
err(1, NULL);
for (i = 0; grp->gr_mem[i] != NULL; i++) {
g->mem[i] = strdup(grp->gr_mem[i]);
if (g->mem[i] == NULL)
err(1, NULL);
}
g->mem[i] = NULL;
g->next = grouplist;
grouplist = g;
}
void
usage(void)
{
extern char *__progname;
(void)fprintf(stderr, "usage: %s [-g group] [file]\n", __progname);
exit(1);
}
static int
isu8cont(unsigned char c)
{
return (c & (0x80 | 0x40)) == 0x80;
}