[thirdparty/util-linux.git] / term-utils / 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.
 *
 * Modified Sun Mar 12 10:34:34 1995, faith@cs.unc.edu, for Linux
 */

/*
 * This program is not related to David Wall, whose Stanford Ph.D. thesis
 * is entitled "Mechanisms for Broadcast and Selective Broadcast".
 *
 * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
 * - added Native Language Support
 *
 */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>

#include <errno.h>
#include <paths.h>
#include <ctype.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utmpx.h>
#include <getopt.h>
#include <sys/types.h>
#include <grp.h>

#if defined(USE_SYSTEMD) && HAVE_DECL_SD_SESSION_GET_USERNAME == 1
# include <systemd/sd-login.h>
# include <systemd/sd-daemon.h>
#endif

#include "nls.h"
#include "xalloc.h"
#include "strutils.h"
#include "ttymsg.h"
#include "pathnames.h"
#include "carefulputc.h"
#include "c.h"
#include "cctype.h"
#include "fileutils.h"
#include "closestream.h"
#include "timeutils.h"
#include "pwdutils.h"
#include "strv.h"

#define	TERM_WIDTH	79
#define	WRITE_TIME_OUT	300		/* in seconds */

/* Function prototypes */
static char *makemsg(char *fname, char **mvec, int mvecsz,
		    size_t *mbufsize, int print_banner);

static void __attribute__((__noreturn__)) usage(void)
{
	FILE *out = stdout;
	fputs(USAGE_HEADER, out);
	fprintf(out,
	      _(" %s [options] [<file> | <message>]\n"), program_invocation_short_name);

	fputs(USAGE_SEPARATOR, out);
	fputs(_("Write a message to all users.\n"), out);

	fputs(USAGE_OPTIONS, out);
	fputs(_(" -g, --group <group>     only send message to group\n"), out);
	fputs(_(" -n, --nobanner          do not print banner, works only for root\n"), out);
	fputs(_(" -t, --timeout <timeout> write timeout in seconds\n"), out);
	fputs(USAGE_SEPARATOR, out);
	fprintf(out, USAGE_HELP_OPTIONS(25));
	fprintf(out, USAGE_MAN_TAIL("wall(1)"));

	exit(EXIT_SUCCESS);
}

struct group_workspace {
	gid_t	requested_group;
	int	ngroups;

/* getgrouplist() on OSX takes int* not gid_t* */
#ifdef __APPLE__
	int	*groups;
#else
	gid_t	*groups;
#endif
};

static gid_t get_group_gid(const char *group)
{
	struct group *gr;
	gid_t gid;

	if ((gr = getgrnam(group)))
		return gr->gr_gid;

	gid = strtou32_or_err(group, _("invalid group argument"));
	if (!getgrgid(gid))
		errx(EXIT_FAILURE, _("%s: unknown gid"), group);

	return gid;
}

static struct group_workspace *init_group_workspace(const char *group)
{
	struct group_workspace *buf;
	long n;

	n = sysconf(_SC_NGROUPS_MAX);
	if (n < 0 || n > INT_MAX - 1)
		return NULL;

	buf = xmalloc(sizeof(struct group_workspace));
	buf->ngroups = n + 1;	/* room for the primary gid */

	buf->requested_group = get_group_gid(group);
	buf->groups = xcalloc(buf->ngroups, sizeof(*buf->groups));

	return buf;
}

static void free_group_workspace(struct group_workspace *buf)
{
	if (!buf)
		return;

	free(buf->groups);
	free(buf);
}

static int is_gr_member(const char *login, const struct group_workspace *buf)
{
	struct passwd *pw;
	int ngroups = buf->ngroups;
	int rc;

	pw = getpwnam(login);
	if (!pw)
		return 0;

	if (buf->requested_group == pw->pw_gid)
		return 1;

	rc = getgrouplist(login, pw->pw_gid, buf->groups, &ngroups);
	if (rc < 0) {
		/* buffer too small, not sure how this can happen, since
		   we used sysconf to get the size... */
		errx(EXIT_FAILURE,
			_("getgrouplist found more groups than sysconf allows"));
	}

	for (; ngroups >= 0; --ngroups) {
		if (buf->requested_group == (gid_t) buf->groups[ngroups])
			return 1;
	}

	return 0;
}

static int has_tty(char **ttys, char *name)
{
	char **str;

	UL_STRV_FOREACH(str, ttys) {
		if (strcmp(*str, name) == 0)
			return 1;
	}

	return 0;
}

int main(int argc, char **argv)
{
	int ch;
	struct iovec iov;
	struct utmpx *utmpptr;
	char line[sizeof(utmpptr->ut_line) + 1];
	int print_banner = TRUE;
	struct group_workspace *group_buf = NULL;
	char *mbuf, *fname = NULL;
	size_t mbufsize;
	unsigned timeout = WRITE_TIME_OUT;
	char **mvec = NULL, **ttys = NULL, **str;
	int mvecsz = 0;

	static const struct option longopts[] = {
		{ "nobanner",	no_argument,		NULL, 'n' },
		{ "timeout",	required_argument,	NULL, 't' },
		{ "group",	required_argument,	NULL, 'g' },
		{ "version",	no_argument,		NULL, 'V' },
		{ "help",	no_argument,		NULL, 'h' },
		{ NULL,	0, NULL, 0 }
	};

	setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);
	close_stdout_atexit();

	while ((ch = getopt_long(argc, argv, "nt:g:Vh", longopts, NULL)) != -1) {
		switch (ch) {
		case 'n':
			if (geteuid() == 0)
				print_banner = FALSE;
			else
				warnx(_("--nobanner is available only for root"));
			break;
		case 't':
			timeout = strtou32_or_err(optarg, _("invalid timeout argument"));
			if (timeout < 1)
				errx(EXIT_FAILURE, _("invalid timeout argument: %s"), optarg);
			break;
		case 'g':
			group_buf = init_group_workspace(optarg);
			break;

		case 'V':
			print_version(EXIT_SUCCESS);
		case 'h':
			usage();
		default:
			errtryhelp(EXIT_FAILURE);
		}
	}
	argc -= optind;
	argv += optind;

	if (argc == 1 && access(argv[0], F_OK) == 0)
		fname = argv[0];
	else if (argc >= 1) {
		mvec = argv;
		mvecsz = argc;
	}

	mbuf = makemsg(fname, mvec, mvecsz, &mbufsize, print_banner);

	iov.iov_base = mbuf;
	iov.iov_len = mbufsize;

#if defined(USE_SYSTEMD) && HAVE_DECL_SD_SESSION_GET_USERNAME == 1
	if (sd_booted() > 0) {
		char **sessions_list;
		int sessions;

		sessions = sd_get_sessions(&sessions_list);
		if (sessions < 0) {
			warnx(_("error getting sessions: %s"), strerror(-sessions));
			goto utmp;
		}

		for (int i = 0; i < sessions; i++) {
			char *name, *tty;
			int r;

			if ((r = sd_session_get_username(sessions_list[i], &name)) < 0) {
				warnx(_("get user name failed: %s"), strerror (-r));
				goto utmp;
			}
			if (!(group_buf && !is_gr_member(name, group_buf))
			    && sd_session_get_tty(sessions_list[i], &tty) >= 0
			    && ul_strv_consume(&ttys, tty) < 0)
				err(EXIT_FAILURE, _("failed to allocate lines list"));

			free(name);
			free(sessions_list[i]);
		}
		free(sessions_list);
	}
utmp:
#endif
	{
		while ((utmpptr = getutxent())) {
			if (!utmpptr->ut_user[0])
				continue;
#ifdef USER_PROCESS
			if (utmpptr->ut_type != USER_PROCESS)
				continue;
#endif
			/* Joey Hess reports that use-sessreg in /etc/X11/wdm/ produces
			 * ut_line entries like :0, and a write to /dev/:0 fails.
			 *
			 * It also seems that some login manager may produce empty ut_line.
			 */
			if (!*utmpptr->ut_line || *utmpptr->ut_line == ':')
				continue;

			if (group_buf && !is_gr_member(utmpptr->ut_user, group_buf))
				continue;

			mem2strcpy(line, utmpptr->ut_line, sizeof(utmpptr->ut_line), sizeof(line));
			if (has_tty(ttys, line))
				continue;
			if (ul_strv_extend(&ttys, line) < 0)
				err(EXIT_FAILURE, _("failed to allocate lines list"));
		}
		endutxent();
	}

	UL_STRV_FOREACH(str, ttys) {
		char *er = ttymsg(&iov, 1, *str, timeout);
		if (er)
			 warnx("%s", er);
	}

	ul_strv_free(ttys);
	free(mbuf);
	free_group_workspace(group_buf);
	exit(EXIT_SUCCESS);
}

static char *makemsg(char *fname, char **mvec, int mvecsz,
		     size_t *mbufsize, int print_banner)
{
	char *lbuf, *retbuf;
	FILE * fs = open_memstream(&retbuf, mbufsize);
	size_t lbuflen = 512;
	lbuf = xmalloc(lbuflen);

	if (print_banner == TRUE) {
		char *hostname = xgethostname();
		char *whombuf, *whom, *where, date[CTIME_BUFSIZ];
		time_t now;

		whombuf = whom = xgetlogin();
		if (!whom) {
			whom = "<someone>";
			warn(_("cannot get passwd uid"));
		}
		where = ttyname(STDOUT_FILENO);
		if (!where) {
			where = "somewhere";
		} else if (strncmp(where, "/dev/", 5) == 0)
			where += 5;

		time(&now);
		ctime_r(&now, date);
		date[strlen(date) - 1] = '\0';

		/*
		 * 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.
		 */
		/* snprintf is not always available, but the sprintf's here
		   will not overflow as long as %d takes at most 100 chars */
		fprintf(fs, "\r%*s\r\n", TERM_WIDTH, " ");

		snprintf(lbuf, lbuflen,
				_("Broadcast message from %s@%s (%s) (%s):"),
				whom, hostname, where, date);
		fprintf(fs, "%-*.*s\007\007\r\n", TERM_WIDTH, TERM_WIDTH, lbuf);
		free(hostname);
		free(whombuf);
	}
	fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");

	 if (mvec) {
		/*
		 * Read message from argv[]
		 */
		int i;

		for (i = 0; i < mvecsz; i++) {
			fputs_careful(mvec[i], fs, '^', true, TERM_WIDTH);
			if (i < mvecsz - 1)
				fputc(' ', fs);
		}
		fputs("\r\n", fs);
	} else {
		/*
		 * read message from <file>
		 */
		if (fname) {
			/*
			 * When we are not root, but suid or sgid, refuse to read files
			 * (e.g. device files) that the user may not have access to.
			 * After all, our invoker can easily do "wall < file"
			 * instead of "wall file".
			 */
			if (getuid() && is_privileged_execution())
				errx(EXIT_FAILURE, _("will not read %s - use stdin."),
				     fname);

			if (!freopen(fname, "r", stdin))
				err(EXIT_FAILURE, _("cannot open %s"), fname);

		}

		/*
		 * Read message from stdin.
		 */
		while (getline(&lbuf, &lbuflen, stdin) >= 0)
			fputs_careful(lbuf, fs, '^', true, TERM_WIDTH);
	}
	fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");

	free(lbuf);

	fclose(fs);
	return retbuf;
}
Commit	Line	Data
	1	/*
	2	* Copyright (c) 1988, 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*
	33	* Modified Sun Mar 12 10:34:34 1995, faith@cs.unc.edu, for Linux
	34	*/
	35
	36	/*
	37	* This program is not related to David Wall, whose Stanford Ph.D. thesis
	38	* is entitled "Mechanisms for Broadcast and Selective Broadcast".
	39	*
	40	* 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
	41	* - added Native Language Support
	42	*
	43	*/
	44
	45	#include <sys/param.h>
	46	#include <sys/stat.h>
	47	#include <sys/time.h>
	48	#include <sys/uio.h>
	49
	50	#include <errno.h>
	51	#include <paths.h>
	52	#include <ctype.h>
	53	#include <pwd.h>
	54	#include <stdio.h>
	55	#include <stdlib.h>
	56	#include <string.h>
	57	#include <time.h>
	58	#include <unistd.h>
	59	#include <utmpx.h>
	60	#include <getopt.h>
	61	#include <sys/types.h>
	62	#include <grp.h>
	63
	64	#if defined(USE_SYSTEMD) && HAVE_DECL_SD_SESSION_GET_USERNAME == 1
	65	# include <systemd/sd-login.h>
	66	# include <systemd/sd-daemon.h>
	67	#endif
	68
	69	#include "nls.h"
	70	#include "xalloc.h"
	71	#include "strutils.h"
	72	#include "ttymsg.h"
	73	#include "pathnames.h"
	74	#include "carefulputc.h"
	75	#include "c.h"
	76	#include "cctype.h"
	77	#include "fileutils.h"
	78	#include "closestream.h"
	79	#include "timeutils.h"
	80	#include "pwdutils.h"
	81	#include "strv.h"
	82
	83	#define TERM_WIDTH 79
	84	#define WRITE_TIME_OUT 300 /* in seconds */
	85
	86	/* Function prototypes */
	87	static char makemsg(char fname, char **mvec, int mvecsz,
	88	size_t *mbufsize, int print_banner);
	89
	90	static void __attribute__((__noreturn__)) usage(void)
	91	{
	92	FILE *out = stdout;
	93	fputs(USAGE_HEADER, out);
	94	fprintf(out,
	95	_(" %s [options] [<file> \| <message>]\n"), program_invocation_short_name);
	96
	97	fputs(USAGE_SEPARATOR, out);
	98	fputs(_("Write a message to all users.\n"), out);
	99
	100	fputs(USAGE_OPTIONS, out);
	101	fputs(_(" -g, --group <group> only send message to group\n"), out);
	102	fputs(_(" -n, --nobanner do not print banner, works only for root\n"), out);
	103	fputs(_(" -t, --timeout <timeout> write timeout in seconds\n"), out);
	104	fputs(USAGE_SEPARATOR, out);
	105	fprintf(out, USAGE_HELP_OPTIONS(25));
	106	fprintf(out, USAGE_MAN_TAIL("wall(1)"));
	107
	108	exit(EXIT_SUCCESS);
	109	}
	110
	111	struct group_workspace {
	112	gid_t requested_group;
	113	int ngroups;
	114
	115	/* getgrouplist() on OSX takes int* not gid_t* */
	116	#ifdef __APPLE__
	117	int *groups;
	118	#else
	119	gid_t *groups;
	120	#endif
	121	};
	122
	123	static gid_t get_group_gid(const char *group)
	124	{
	125	struct group *gr;
	126	gid_t gid;
	127
	128	if ((gr = getgrnam(group)))
	129	return gr->gr_gid;
	130
	131	gid = strtou32_or_err(group, _("invalid group argument"));
	132	if (!getgrgid(gid))
	133	errx(EXIT_FAILURE, _("%s: unknown gid"), group);
	134
	135	return gid;
	136	}
	137
	138	static struct group_workspace init_group_workspace(const char group)
	139	{
	140	struct group_workspace *buf;
	141	long n;
	142
	143	n = sysconf(_SC_NGROUPS_MAX);
	144	if (n < 0 \|\| n > INT_MAX - 1)
	145	return NULL;
	146
	147	buf = xmalloc(sizeof(struct group_workspace));
	148	buf->ngroups = n + 1; /* room for the primary gid */
	149
	150	buf->requested_group = get_group_gid(group);
	151	buf->groups = xcalloc(buf->ngroups, sizeof(*buf->groups));
	152
	153	return buf;
	154	}
	155
	156	static void free_group_workspace(struct group_workspace *buf)
	157	{
	158	if (!buf)
	159	return;
	160
	161	free(buf->groups);
	162	free(buf);
	163	}
	164
	165	static int is_gr_member(const char login, const struct group_workspace buf)
	166	{
	167	struct passwd *pw;
	168	int ngroups = buf->ngroups;
	169	int rc;
	170
	171	pw = getpwnam(login);
	172	if (!pw)
	173	return 0;
	174
	175	if (buf->requested_group == pw->pw_gid)
	176	return 1;
	177
	178	rc = getgrouplist(login, pw->pw_gid, buf->groups, &ngroups);
	179	if (rc < 0) {
	180	/* buffer too small, not sure how this can happen, since
	181	we used sysconf to get the size... */
	182	errx(EXIT_FAILURE,
	183	_("getgrouplist found more groups than sysconf allows"));
	184	}
	185
	186	for (; ngroups >= 0; --ngroups) {
	187	if (buf->requested_group == (gid_t) buf->groups[ngroups])
	188	return 1;
	189	}
	190
	191	return 0;
	192	}
	193
	194	static int has_tty(char *ttys, char name)
	195	{
	196	char **str;
	197
	198	UL_STRV_FOREACH(str, ttys) {
	199	if (strcmp(*str, name) == 0)
	200	return 1;
	201	}
	202
	203	return 0;
	204	}
	205
	206	int main(int argc, char **argv)
	207	{
	208	int ch;
	209	struct iovec iov;
	210	struct utmpx *utmpptr;
	211	char line[sizeof(utmpptr->ut_line) + 1];
	212	int print_banner = TRUE;
	213	struct group_workspace *group_buf = NULL;
	214	char mbuf, fname = NULL;
	215	size_t mbufsize;
	216	unsigned timeout = WRITE_TIME_OUT;
	217	char mvec = NULL, ttys = NULL, **str;
	218	int mvecsz = 0;
	219
	220	static const struct option longopts[] = {
	221	{ "nobanner", no_argument, NULL, 'n' },
	222	{ "timeout", required_argument, NULL, 't' },
	223	{ "group", required_argument, NULL, 'g' },
	224	{ "version", no_argument, NULL, 'V' },
	225	{ "help", no_argument, NULL, 'h' },
	226	{ NULL, 0, NULL, 0 }
	227	};
	228
	229	setlocale(LC_ALL, "");
	230	bindtextdomain(PACKAGE, LOCALEDIR);
	231	textdomain(PACKAGE);
	232	close_stdout_atexit();
	233
	234	while ((ch = getopt_long(argc, argv, "nt:g:Vh", longopts, NULL)) != -1) {
	235	switch (ch) {
	236	case 'n':
	237	if (geteuid() == 0)
	238	print_banner = FALSE;
	239	else
	240	warnx(_("--nobanner is available only for root"));
	241	break;
	242	case 't':
	243	timeout = strtou32_or_err(optarg, _("invalid timeout argument"));
	244	if (timeout < 1)
	245	errx(EXIT_FAILURE, _("invalid timeout argument: %s"), optarg);
	246	break;
	247	case 'g':
	248	group_buf = init_group_workspace(optarg);
	249	break;
	250
	251	case 'V':
	252	print_version(EXIT_SUCCESS);
	253	case 'h':
	254	usage();
	255	default:
	256	errtryhelp(EXIT_FAILURE);
	257	}
	258	}
	259	argc -= optind;
	260	argv += optind;
	261
	262	if (argc == 1 && access(argv[0], F_OK) == 0)
	263	fname = argv[0];
	264	else if (argc >= 1) {
	265	mvec = argv;
	266	mvecsz = argc;
	267	}
	268
	269	mbuf = makemsg(fname, mvec, mvecsz, &mbufsize, print_banner);
	270
	271	iov.iov_base = mbuf;
	272	iov.iov_len = mbufsize;
	273
	274	#if defined(USE_SYSTEMD) && HAVE_DECL_SD_SESSION_GET_USERNAME == 1
	275	if (sd_booted() > 0) {
	276	char **sessions_list;
	277	int sessions;
	278
	279	sessions = sd_get_sessions(&sessions_list);
	280	if (sessions < 0) {
	281	warnx(_("error getting sessions: %s"), strerror(-sessions));
	282	goto utmp;
	283	}
	284
	285	for (int i = 0; i < sessions; i++) {
	286	char name, tty;
	287	int r;
	288
	289	if ((r = sd_session_get_username(sessions_list[i], &name)) < 0) {
	290	warnx(_("get user name failed: %s"), strerror (-r));
	291	goto utmp;
	292	}
	293	if (!(group_buf && !is_gr_member(name, group_buf))
	294	&& sd_session_get_tty(sessions_list[i], &tty) >= 0
	295	&& ul_strv_consume(&ttys, tty) < 0)
	296	err(EXIT_FAILURE, _("failed to allocate lines list"));
	297
	298	free(name);
	299	free(sessions_list[i]);
	300	}
	301	free(sessions_list);
	302	}
	303	utmp:
	304	#endif
	305	{
	306	while ((utmpptr = getutxent())) {
	307	if (!utmpptr->ut_user[0])
	308	continue;
	309	#ifdef USER_PROCESS
	310	if (utmpptr->ut_type != USER_PROCESS)
	311	continue;
	312	#endif
	313	/* Joey Hess reports that use-sessreg in /etc/X11/wdm/ produces
	314	* ut_line entries like :0, and a write to /dev/:0 fails.
	315	*
	316	* It also seems that some login manager may produce empty ut_line.
	317	*/
	318	if (!utmpptr->ut_line \|\| utmpptr->ut_line == ':')
	319	continue;
	320
	321	if (group_buf && !is_gr_member(utmpptr->ut_user, group_buf))
	322	continue;
	323
	324	mem2strcpy(line, utmpptr->ut_line, sizeof(utmpptr->ut_line), sizeof(line));
	325	if (has_tty(ttys, line))
	326	continue;
	327	if (ul_strv_extend(&ttys, line) < 0)
	328	err(EXIT_FAILURE, _("failed to allocate lines list"));
	329	}
	330	endutxent();
	331	}
	332
	333	UL_STRV_FOREACH(str, ttys) {
	334	char er = ttymsg(&iov, 1, str, timeout);
	335	if (er)
	336	warnx("%s", er);
	337	}
	338
	339	ul_strv_free(ttys);
	340	free(mbuf);
	341	free_group_workspace(group_buf);
	342	exit(EXIT_SUCCESS);
	343	}
	344
	345	static char makemsg(char fname, char **mvec, int mvecsz,
	346	size_t *mbufsize, int print_banner)
	347	{
	348	char lbuf, retbuf;
	349	FILE * fs = open_memstream(&retbuf, mbufsize);
	350	size_t lbuflen = 512;
	351	lbuf = xmalloc(lbuflen);
	352
	353	if (print_banner == TRUE) {
	354	char *hostname = xgethostname();
	355	char whombuf, whom, *where, date[CTIME_BUFSIZ];
	356	time_t now;
	357
	358	whombuf = whom = xgetlogin();
	359	if (!whom) {
	360	whom = "<someone>";
	361	warn(_("cannot get passwd uid"));
	362	}
	363	where = ttyname(STDOUT_FILENO);
	364	if (!where) {
	365	where = "somewhere";
	366	} else if (strncmp(where, "/dev/", 5) == 0)
	367	where += 5;
	368
	369	time(&now);
	370	ctime_r(&now, date);
	371	date[strlen(date) - 1] = '\0';
	372
	373	/*
	374	* all this stuff is to blank out a square for the message;
	375	* we wrap message lines at column 79, not 80, because some
	376	* terminals wrap after 79, some do not, and we can't tell.
	377	* Which means that we may leave a non-blank character
	378	* in column 80, but that can't be helped.
	379	*/
	380	/* snprintf is not always available, but the sprintf's here
	381	will not overflow as long as %d takes at most 100 chars */
	382	fprintf(fs, "\r%*s\r\n", TERM_WIDTH, " ");
	383
	384	snprintf(lbuf, lbuflen,
	385	_("Broadcast message from %s@%s (%s) (%s):"),
	386	whom, hostname, where, date);
	387	fprintf(fs, "%-.s\007\007\r\n", TERM_WIDTH, TERM_WIDTH, lbuf);
	388	free(hostname);
	389	free(whombuf);
	390	}
	391	fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");
	392
	393	if (mvec) {
	394	/*
	395	* Read message from argv[]
	396	*/
	397	int i;
	398
	399	for (i = 0; i < mvecsz; i++) {
	400	fputs_careful(mvec[i], fs, '^', true, TERM_WIDTH);
	401	if (i < mvecsz - 1)
	402	fputc(' ', fs);
	403	}
	404	fputs("\r\n", fs);
	405	} else {
	406	/*
	407	* read message from <file>
	408	*/
	409	if (fname) {
	410	/*
	411	* When we are not root, but suid or sgid, refuse to read files
	412	* (e.g. device files) that the user may not have access to.
	413	* After all, our invoker can easily do "wall < file"
	414	* instead of "wall file".
	415	*/
	416	if (getuid() && is_privileged_execution())
	417	errx(EXIT_FAILURE, _("will not read %s - use stdin."),
	418	fname);
	419
	420	if (!freopen(fname, "r", stdin))
	421	err(EXIT_FAILURE, _("cannot open %s"), fname);
	422
	423	}
	424
	425	/*
	426	* Read message from stdin.
	427	*/
	428	while (getline(&lbuf, &lbuflen, stdin) >= 0)
	429	fputs_careful(lbuf, fs, '^', true, TERM_WIDTH);
	430	}
	431	fprintf(fs, "%*s\r\n", TERM_WIDTH, " ");
	432
	433	free(lbuf);
	434
	435	fclose(fs);
	436	return retbuf;
	437	}