[dragonfly.git] / libexec / talkd / process.c

/*
 * Copyright (c) 1983, 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.
 *
 * @(#)process.c	8.2 (Berkeley) 11/16/93
 * $FreeBSD: src/libexec/talkd/process.c,v 1.9 1999/08/28 00:10:16 peter Exp $
 * $DragonFly: src/libexec/talkd/process.c,v 1.3 2003/11/14 03:54:31 dillon Exp $
 */

/*
 * process.c handles the requests, which can be of three types:
 *	ANNOUNCE - announce to a user that a talk is wanted
 *	LEAVE_INVITE - insert the request into the table
 *	LOOK_UP - look up to see if a request is waiting in
 *		  in the table for the local user
 *	DELETE - delete invitation
 */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <protocols/talkd.h>
#include <ctype.h>
#include <err.h>
#include <netdb.h>
#include <paths.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>

int announce (CTL_MSG *, char *);
int delete_invite (int);
void do_announce (CTL_MSG *, CTL_RESPONSE *);
CTL_MSG *find_request();
CTL_MSG *find_match();
int find_user (char *, char *);
void insert_table (CTL_MSG *, CTL_RESPONSE *);
int new_id (void);
void print_request (char *, CTL_MSG *);
void print_response (char *, CTL_RESPONSE *);

void
process_request(mp, rp)
	register CTL_MSG *mp;
	register CTL_RESPONSE *rp;
{
	register CTL_MSG *ptr;
	extern int debug;
	char *s;

	rp->vers = TALK_VERSION;
	rp->type = mp->type;
	rp->id_num = htonl(0);
	if (mp->vers != TALK_VERSION) {
		syslog(LOG_WARNING, "bad protocol version %d", mp->vers);
		rp->answer = BADVERSION;
		return;
	}
	mp->id_num = ntohl(mp->id_num);
	mp->addr.sa_family = ntohs(mp->addr.sa_family);
	if (mp->addr.sa_family != AF_INET) {
		syslog(LOG_WARNING, "bad address, family %d",
		    mp->addr.sa_family);
		rp->answer = BADADDR;
		return;
	}
	mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
	if (mp->ctl_addr.sa_family != AF_INET) {
		syslog(LOG_WARNING, "bad control address, family %d",
		    mp->ctl_addr.sa_family);
		rp->answer = BADCTLADDR;
		return;
	}
	for (s = mp->l_name; *s; s++)
		if (!isprint(*s)) {
			syslog(LOG_NOTICE, "illegal user name. Aborting");
			rp->answer = FAILED;
			return;
		}
	mp->pid = ntohl(mp->pid);
	if (debug)
		print_request("process_request", mp);
	switch (mp->type) {

	case ANNOUNCE:
		do_announce(mp, rp);
		break;

	case LEAVE_INVITE:
		ptr = find_request(mp);
		if (ptr != (CTL_MSG *)0) {
			rp->id_num = htonl(ptr->id_num);
			rp->answer = SUCCESS;
		} else
			insert_table(mp, rp);
		break;

	case LOOK_UP:
		ptr = find_match(mp);
		if (ptr != (CTL_MSG *)0) {
			rp->id_num = htonl(ptr->id_num);
			rp->addr = ptr->addr;
			rp->addr.sa_family = htons(ptr->addr.sa_family);
			rp->answer = SUCCESS;
		} else
			rp->answer = NOT_HERE;
		break;

	case DELETE:
		rp->answer = delete_invite(mp->id_num);
		break;

	default:
		rp->answer = UNKNOWN_REQUEST;
		break;
	}
	if (debug)
		print_response("process_request", rp);
}

void
do_announce(mp, rp)
	register CTL_MSG *mp;
	CTL_RESPONSE *rp;
{
	struct hostent *hp;
	CTL_MSG *ptr;
	int result;

	/* see if the user is logged */
	result = find_user(mp->r_name, mp->r_tty);
	if (result != SUCCESS) {
		rp->answer = result;
		return;
	}
#define	satosin(sa)	((struct sockaddr_in *)(sa))
	hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr,
		sizeof (struct in_addr), AF_INET);
	if (hp == (struct hostent *)0) {
		rp->answer = MACHINE_UNKNOWN;
		return;
	}
	ptr = find_request(mp);
	if (ptr == (CTL_MSG *) 0) {
		insert_table(mp, rp);
		rp->answer = announce(mp, hp->h_name);
		return;
	}
	if (mp->id_num > ptr->id_num) {
		/*
		 * This is an explicit re-announce, so update the id_num
		 * field to avoid duplicates and re-announce the talk.
		 */
		ptr->id_num = new_id();
		rp->id_num = htonl(ptr->id_num);
		rp->answer = announce(mp, hp->h_name);
	} else {
		/* a duplicated request, so ignore it */
		rp->id_num = htonl(ptr->id_num);
		rp->answer = SUCCESS;
	}
}

#include <utmp.h>

/*
 * Search utmp for the local user
 */
int
find_user(name, tty)
	char *name, *tty;
{
	struct utmp ubuf;
	int status;
	FILE *fd;
	struct stat statb;
	time_t best = 0;
	char line[sizeof(ubuf.ut_line) + 1];
	char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)];

	if ((fd = fopen(_PATH_UTMP, "r")) == NULL) {
		warnx("can't read %s", _PATH_UTMP);
		return (FAILED);
	}
#define SCMPN(a, b)	strncmp(a, b, sizeof (a))
	status = NOT_HERE;
	(void) strcpy(ftty, _PATH_DEV);
	while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1)
		if (SCMPN(ubuf.ut_name, name) == 0) {
			strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line));
			line[sizeof(ubuf.ut_line)] = '\0';
			if (*tty == '\0' || best != 0) {
				if (best == 0)
					status = PERMISSION_DENIED;
				/* no particular tty was requested */
				(void) strcpy(ftty + sizeof(_PATH_DEV) - 1,
				    line);
				if (stat(ftty, &statb) == 0) {
					if (!(statb.st_mode & 020))
						continue;
					if (statb.st_atime > best) {
						best = statb.st_atime;
						(void) strcpy(tty, line);
						status = SUCCESS;
						continue;
					}
				}
			}
			if (strcmp(line, tty) == 0) {
				status = SUCCESS;
				break;
			}
		}
	fclose(fd);
	return (status);
}
Commit	Line	Data
984263bc MD	1	/*
	2	* Copyright (c) 1983, 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.
1de703da MD	32	*
	33	* @(#)process.c 8.2 (Berkeley) 11/16/93
	34	* $FreeBSD: src/libexec/talkd/process.c,v 1.9 1999/08/28 00:10:16 peter Exp $
3eefb696	35	* $DragonFly: src/libexec/talkd/process.c,v 1.3 2003/11/14 03:54:31 dillon Exp $
984263bc MD	36	*/
984263bc MD	37
984263bc MD	38	/*
	39	* process.c handles the requests, which can be of three types:
	40	* ANNOUNCE - announce to a user that a talk is wanted
	41	* LEAVE_INVITE - insert the request into the table
	42	* LOOK_UP - look up to see if a request is waiting in
	43	* in the table for the local user
	44	* DELETE - delete invitation
	45	*/
	46	#include <sys/param.h>
	47	#include <sys/stat.h>
	48	#include <sys/socket.h>
	49	#include <netinet/in.h>
	50	#include <protocols/talkd.h>
	51	#include <ctype.h>
	52	#include <err.h>
	53	#include <netdb.h>
	54	#include <paths.h>
	55	#include <stdio.h>
	56	#include <string.h>
	57	#include <syslog.h>
	58
3eefb696 MD	59	int announce (CTL_MSG , char );
	60	int delete_invite (int);
	61	void do_announce (CTL_MSG , CTL_RESPONSE );
984263bc MD	62	CTL_MSG *find_request();
984263bc MD	63	CTL_MSG *find_match();
3eefb696 MD	64	int find_user (char , char );
	65	void insert_table (CTL_MSG , CTL_RESPONSE );
	66	int new_id (void);
	67	void print_request (char , CTL_MSG );
	68	void print_response (char , CTL_RESPONSE );
984263bc MD	69
	70	void
	71	process_request(mp, rp)
	72	register CTL_MSG *mp;
	73	register CTL_RESPONSE *rp;
	74	{
	75	register CTL_MSG *ptr;
	76	extern int debug;
	77	char *s;
	78
	79	rp->vers = TALK_VERSION;
	80	rp->type = mp->type;
	81	rp->id_num = htonl(0);
	82	if (mp->vers != TALK_VERSION) {
	83	syslog(LOG_WARNING, "bad protocol version %d", mp->vers);
	84	rp->answer = BADVERSION;
	85	return;
	86	}
	87	mp->id_num = ntohl(mp->id_num);
	88	mp->addr.sa_family = ntohs(mp->addr.sa_family);
	89	if (mp->addr.sa_family != AF_INET) {
	90	syslog(LOG_WARNING, "bad address, family %d",
	91	mp->addr.sa_family);
	92	rp->answer = BADADDR;
	93	return;
	94	}
	95	mp->ctl_addr.sa_family = ntohs(mp->ctl_addr.sa_family);
	96	if (mp->ctl_addr.sa_family != AF_INET) {
	97	syslog(LOG_WARNING, "bad control address, family %d",
	98	mp->ctl_addr.sa_family);
	99	rp->answer = BADCTLADDR;
	100	return;
	101	}
	102	for (s = mp->l_name; *s; s++)
	103	if (!isprint(*s)) {
	104	syslog(LOG_NOTICE, "illegal user name. Aborting");
	105	rp->answer = FAILED;
	106	return;
	107	}
	108	mp->pid = ntohl(mp->pid);
	109	if (debug)
	110	print_request("process_request", mp);
	111	switch (mp->type) {
	112
	113	case ANNOUNCE:
	114	do_announce(mp, rp);
	115	break;
	116
	117	case LEAVE_INVITE:
	118	ptr = find_request(mp);
	119	if (ptr != (CTL_MSG *)0) {
	120	rp->id_num = htonl(ptr->id_num);
	121	rp->answer = SUCCESS;
	122	} else
	123	insert_table(mp, rp);
	124	break;
	125
	126	case LOOK_UP:
	127	ptr = find_match(mp);
	128	if (ptr != (CTL_MSG *)0) {
	129	rp->id_num = htonl(ptr->id_num);
	130	rp->addr = ptr->addr;
	131	rp->addr.sa_family = htons(ptr->addr.sa_family);
	132	rp->answer = SUCCESS;
133	} else
134	rp->answer = NOT_HERE;
135	break;
136
137	case DELETE:
138	rp->answer = delete_invite(mp->id_num);
139	break;
140
141	default:
142	rp->answer = UNKNOWN_REQUEST;
143	break;
144	}
145	if (debug)
146	print_response("process_request", rp);
147	}
148
149	void
150	do_announce(mp, rp)
151	register CTL_MSG *mp;
152	CTL_RESPONSE *rp;
153	{
154	struct hostent *hp;
155	CTL_MSG *ptr;
156	int result;
157
158	/* see if the user is logged */
159	result = find_user(mp->r_name, mp->r_tty);
160	if (result != SUCCESS) {
161	rp->answer = result;
162	return;
163	}
164	#define satosin(sa) ((struct sockaddr_in *)(sa))
15b85273	165	hp = gethostbyaddr(&satosin(&mp->ctl_addr)->sin_addr,
984263bc MD	166	sizeof (struct in_addr), AF_INET);
	167	if (hp == (struct hostent *)0) {
	168	rp->answer = MACHINE_UNKNOWN;
	169	return;
	170	}
	171	ptr = find_request(mp);
	172	if (ptr == (CTL_MSG *) 0) {
	173	insert_table(mp, rp);
	174	rp->answer = announce(mp, hp->h_name);
	175	return;
	176	}
	177	if (mp->id_num > ptr->id_num) {
	178	/*
	179	* This is an explicit re-announce, so update the id_num
	180	* field to avoid duplicates and re-announce the talk.
	181	*/
	182	ptr->id_num = new_id();
	183	rp->id_num = htonl(ptr->id_num);
	184	rp->answer = announce(mp, hp->h_name);
	185	} else {
	186	/* a duplicated request, so ignore it */
	187	rp->id_num = htonl(ptr->id_num);
	188	rp->answer = SUCCESS;
	189	}
	190	}
	191
	192	#include <utmp.h>
	193
	194	/*
	195	* Search utmp for the local user
	196	*/
	197	int
	198	find_user(name, tty)
	199	char name, tty;
	200	{
	201	struct utmp ubuf;
	202	int status;
	203	FILE *fd;
	204	struct stat statb;
	205	time_t best = 0;
	206	char line[sizeof(ubuf.ut_line) + 1];
	207	char ftty[sizeof(_PATH_DEV) - 1 + sizeof(line)];
	208
	209	if ((fd = fopen(_PATH_UTMP, "r")) == NULL) {
	210	warnx("can't read %s", _PATH_UTMP);
	211	return (FAILED);
	212	}
	213	#define SCMPN(a, b) strncmp(a, b, sizeof (a))
	214	status = NOT_HERE;
	215	(void) strcpy(ftty, _PATH_DEV);
	216	while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1)
	217	if (SCMPN(ubuf.ut_name, name) == 0) {
	218	strncpy(line, ubuf.ut_line, sizeof(ubuf.ut_line));
	219	line[sizeof(ubuf.ut_line)] = '\0';
	220	if (*tty == '\0' \|\| best != 0) {
	221	if (best == 0)
	222	status = PERMISSION_DENIED;
	223	/* no particular tty was requested */
	224	(void) strcpy(ftty + sizeof(_PATH_DEV) - 1,
	225	line);
	226	if (stat(ftty, &statb) == 0) {
	227	if (!(statb.st_mode & 020))
	228	continue;
	229	if (statb.st_atime > best) {
230	best = statb.st_atime;
231	(void) strcpy(tty, line);
232	status = SUCCESS;
233	continue;
234	}
235	}
236	}
237	if (strcmp(line, tty) == 0) {
238	status = SUCCESS;
239	break;
240	}
241	}
242	fclose(fd);
243	return (status);
244	}