[unix-history] / usr / src / usr.sbin / lpr / lpd / lpd.c

/*	lpd.c	4.5	83/06/15	*/
/*
 * lpd -- line printer daemon.
 *
 * Listen for a connection and perform the requested operation.
 * Operations are:
 *	\1printer\n
 *		check the queue for jobs and print any found.
 *	\2printer\n
 *		receive a job from another machine and queue it.
 *	\3printer [users ...] [jobs ...]\n
 *		return the current state of the queue (short form).
 *	\4printer [users ...] [jobs ...]\n
 *		return the current state of the queue (long form).
 *	\5printer person [users ...] [jobs ...]\n
 *		remove jobs from the queue.
 *	\6printer\n
 *		enable queuing on the specified printer queue.
 *	\7printer\n
 *		disable queuing on the specified printer queue.
 *	\8printer\n
 *		return the queue status (queuing enabled or disabled).
 *
 * Strategy to maintain protected spooling area:
 *	1. Spooling area is writable only by daemon and spooling group
 *	2. lpr runs setuid root and setgrp spooling group; it uses
 *	   root to access any file it wants (verifying things before
 *	   with an access call) and group id to know how it should
 *	   set up ownership of files in the spooling area.
 *	3. Files in spooling area are owned by root, group spooling
 *	   group, with mode 660.
 *	4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to
 *	   access files and printer.  Users can't get to anything
 *	   w/o help of lpq and lprm programs.
 */

#include "lp.h"

static int	lflag;				/* log requests flag */
static char	*logfile = DEFLOGF;
static struct	sockaddr_in sin = { AF_INET };

int	reapchild();
char	*inet_ntoa();

main(argc, argv)
	int argc;
	char **argv;
{
	int f, options;
	struct sockaddr_in fromaddr;
	struct servent *sp;

	gethostname(host, sizeof(host));
	name = argv[0];

	sp = getservbyname("printer", "tcp");
	if (sp == NULL) {
		fprintf(stderr, "printer/tcp: unknown service");
		exit(1);
	}
	sin.sin_port = sp->s_port;

	while (--argc > 0) {
		argv++;
		if (argv[0][0] == '-')
			switch (argv[0][1]) {
			case 'd':
				options |= SO_DEBUG;
				break;
			case 'l':
				lflag++;
				break;
			case 'L':
				argc--;
				logfile = *++argv;
				break;
			}
		else {
			int port = atoi(argv[0]);
			int c = argv[0][0];

			if (c < '0' || c > '9' || port < 0) {
				fprintf(stderr, "lpd: %s: bad port number\n", argv[0]);
				exit(1);
			}
			sin.sin_port = htons((u_short) port);
		}
	}
#ifndef DEBUG
	/*
	 * Set up standard environment by detaching from the parent.
	 */
	if (fork())
		exit(0);
	for (f = 0; f < 3; f++)
		(void) close(f);
	(void) open("/dev/null", O_RDONLY);
	(void) open("/dev/null", O_WRONLY);
	(void) open(logfile, O_WRONLY|O_APPEND);
	f = open("/dev/tty", O_RDWR);
	if (f > 0) {
		ioctl(f, TIOCNOTTY, 0);
		(void) close(f);
	}
#endif
	(void) umask(0);
	/*
	 * Restart all the printers.
	 */
	startup();
	f = socket(AF_INET, SOCK_STREAM, 0);
	if (f < 0) {
		logerror("socket");
		exit(1);
	}
	if (options & SO_DEBUG)
		if (setsockopt(f, SOL_SOCKET, SO_DEBUG, 0, 0) < 0) {
			logerror("setsockopt (SO_DEBUG)");
			exit(1);
		}
	if (bind(f, &sin, sizeof(sin), 0) < 0) {
		logerror("bind");
		exit(1);
	}
	/*
	 * Main loop: listen, accept, do a request, continue.
	 */
	signal(SIGCHLD, reapchild);
	listen(f, 10);
	for (;;) {
		int s, len = sizeof(fromaddr);

		s = accept(f, &fromaddr, &len, 0);
		if (s < 0) {
			if (errno == EINTR)
				continue;
			logerror("accept");
			exit(1);
		}
		if (fork() == 0) {
			signal(SIGCHLD, SIG_IGN);
			(void) close(f);
			doit(s, &fromaddr);
			exit(0);
		}
		(void) close(s);
	}
}

static
reapchild()
{
	union wait status;

	while (wait3(&status, WNOHANG, 0) > 0)
		;
}

/*
 * Stuff for handling job specifications
 */
char	*user[MAXUSERS];	/* users to process */
int	users;			/* # of users in user array */
int	requ[MAXREQUESTS];	/* job number of spool entries */
int	requests;		/* # of spool requests */
char	*person;		/* name of person doing lprm */

static char	fromb[32];	/* buffer for client's machine name */
static char	cbuf[BUFSIZ];	/* command line buffer */
static char	*cmdnames[] = {
	"null",
	"printjob",
	"recvjob",
	"displayq short",
	"displayq long",
	"rmjob"
};

static
doit(f, fromaddr)
	int f;
	struct sockaddr_in *fromaddr;
{
	register char *cp;
	register struct hostent *hp;
	register int n;
	char c;

	dup2(f, 1);
	(void) close(f);
	f = 1;
	fromaddr->sin_port = ntohs(fromaddr->sin_port);
	if (fromaddr->sin_family != AF_INET || fromaddr->sin_port >= IPPORT_RESERVED)
		fatal("Malformed from address");
	hp = gethostbyaddr(&fromaddr->sin_addr, sizeof(struct in_addr),
		fromaddr->sin_family);
	if (hp == 0)
		fatal("Host name for your address (%s) unknown",
			inet_ntoa(fromaddr->sin_addr));
	strcpy(fromb, hp->h_name);
	from = fromb;
	if (chkhost())
		fatal("Your host does not have line printer access");
	for (;;) {
		cp = cbuf;
		do {
			if ((n = read(f, &c, 1)) != 1) {
				if (n < 0)
					fatal("Lost connection");
				return;
			}
			if (cp >= &cbuf[sizeof(cbuf)])
				fatal("Command line too long");
			*cp++ = c;
		} while (c != '\n');
		*--cp = '\0';
		cp = cbuf;
		if (lflag && *cp >= '\1' && *cp <= '\5') {
			printer = NULL;
			log("%s requests %s %s", from, cmdnames[*cp], cp+1);
		}
		switch (*cp++) {
		case '\1':	/* check the queue and print any jobs there */
			printer = cp;
			printjob();
			break;
		case '\2':	/* receive files to be queued */
			printer = cp;
			recvjob();
			break;
		case '\3':	/* display the queue (short form) */
		case '\4':	/* display the queue (long form) */
			printer = cp;
			while (*cp) {
				if (*cp != ' ') {
					cp++;
					continue;
				}
				*cp++ = '\0';
				while (isspace(*cp))
					cp++;
				if (*cp == '\0')
					break;
				if (isdigit(*cp)) {
					if (requests >= MAXREQUESTS)
						fatal("Too many requests");
					requ[requests++] = atoi(cp);
				} else {
					if (users >= MAXUSERS)
						fatal("Too many users");
					user[users++] = cp;
				}
			}
			displayq(cbuf[0] - '\3');
			exit(0);
		case '\5':	/* remove a job from the queue */
			printer = cp;
			while (*cp && *cp != ' ')
				cp++;
			if (!*cp)
				break;
			*cp++ = '\0';
			person = cp;
			while (*cp) {
				if (*cp != ' ') {
					cp++;
					continue;
				}
				*cp++ = '\0';
				while (isspace(*cp))
					cp++;
				if (*cp == '\0')
					break;
				if (isdigit(*cp)) {
					if (requests >= MAXREQUESTS)
						fatal("Too many requests");
					requ[requests++] = atoi(cp);
				} else {
					if (users >= MAXUSERS)
						fatal("Too many users");
					user[users++] = cp;
				}
			}
			rmjob();
			break;
		}
		fatal("Illegal service request");
		exit(1);
	}
}

/*
 * Make a pass through the printcap database and start printing any
 * files left from the last time the machine went down.
 */
static
startup()
{
	char buf[BUFSIZ];
	register char *cp;
	int pid;

	printer = buf;

	/*
	 * Restart the daemons.
	 */
	while (getprent(buf) > 0) {
		for (cp = buf; *cp; cp++)
			if (*cp == '|' || *cp == ':') {
				*cp = '\0';
				break;
			}
		if ((pid = fork()) < 0) {
			log("startup: cannot fork");
			exit(1);
		}
		if (!pid) {
			endprent();
			printjob();
		}
	}
}

/*
 * Check to see if the from host has access to the line printer.
 */
static
chkhost()
{
	register FILE *hostf;
	register char *cp;
	char ahost[50];

	if (!strcmp(from, host))
		return(0);

	hostf = fopen("/etc/hosts.equiv", "r");
	while (fgets(ahost, sizeof(ahost), hostf)) {
		if (cp = index(ahost, '\n'))
			*cp = '\0';
		cp = index(ahost, ' ');
		if (!strcmp(from, ahost) && cp == NULL) {
			(void) fclose(hostf);
			return(0);
		}
	}
	(void) fclose(hostf);
	return(-1);
}

/*VARARGS1*/
log(msg, a1, a2, a3)
	char *msg;
{
	short console = isatty(fileno(stderr));

	fprintf(stderr, console ? "\r\n%s: " : "%s: ", name);
	if (printer)
		fprintf(stderr, "%s: ", printer);
	fprintf(stderr, msg, a1, a2, a3);
	if (console)
		putc('\r', stderr);
	putc('\n', stderr);
	fflush(stderr);
}

static
logerror(msg)
	char *msg;
{
	register int err = errno;
	short console = isatty(fileno(stderr));
	extern int sys_nerr;
	extern char *sys_errlist[];

	fprintf(stderr, console ? "\r\n%s: " : "%s: ", name);
	if (msg)
		fprintf(stderr, "%s: ", msg);
	fputs(err < sys_nerr ? sys_errlist[err] : "Unknown error" , stderr);
	if (console)
		putc('\r', stderr);
	putc('\n', stderr);
	fflush(stderr);
}
Commit	Line	Data
adec4d9e	1	/* lpd.c 4.5 83/06/15 */
7245937a RC	2	/*
	3	* lpd -- line printer daemon.
	4	*
	5	* Listen for a connection and perform the requested operation.
	6	* Operations are:
	7	* \1printer\n
	8	* check the queue for jobs and print any found.
	9	* \2printer\n
	10	* receive a job from another machine and queue it.
	11	* \3printer [users ...] [jobs ...]\n
	12	* return the current state of the queue (short form).
	13	* \4printer [users ...] [jobs ...]\n
	14	* return the current state of the queue (long form).
	15	* \5printer person [users ...] [jobs ...]\n
	16	* remove jobs from the queue.
4d4caa50 RC	17	* \6printer\n
	18	* enable queuing on the specified printer queue.
	19	* \7printer\n
	20	* disable queuing on the specified printer queue.
	21	* \8printer\n
	22	* return the queue status (queuing enabled or disabled).
7245937a RC	23	*
	24	* Strategy to maintain protected spooling area:
	25	* 1. Spooling area is writable only by daemon and spooling group
	26	* 2. lpr runs setuid root and setgrp spooling group; it uses
	27	* root to access any file it wants (verifying things before
	28	* with an access call) and group id to know how it should
	29	* set up ownership of files in the spooling area.
4d4caa50	30	* 3. Files in spooling area are owned by root, group spooling
7245937a RC	31	* group, with mode 660.
	32	* 4. lpd, lpq and lprm run setuid daemon and setgrp spooling group to
	33	* access files and printer. Users can't get to anything
	34	* w/o help of lpq and lprm programs.
	35	*/
	36
	37	#include "lp.h"
	38
54266d1f RC	39	static int lflag; /* log requests flag */
	40	static char *logfile = DEFLOGF;
	41	static struct sockaddr_in sin = { AF_INET };
	42
7245937a	43	int reapchild();
adec4d9e	44	char *inet_ntoa();
7245937a RC	45
	46	main(argc, argv)
	47	int argc;
	48	char **argv;
	49	{
	50	int f, options;
4d4caa50	51	struct sockaddr_in fromaddr;
7245937a RC	52	struct servent *sp;
	53
	54	gethostname(host, sizeof(host));
	55	name = argv[0];
	56
	57	sp = getservbyname("printer", "tcp");
	58	if (sp == NULL) {
4d4caa50	59	fprintf(stderr, "printer/tcp: unknown service");
7245937a RC	60	exit(1);
	61	}
	62	sin.sin_port = sp->s_port;
	63
	64	while (--argc > 0) {
	65	argv++;
	66	if (argv[0][0] == '-')
	67	switch (argv[0][1]) {
	68	case 'd':
	69	options \|= SO_DEBUG;
	70	break;
	71	case 'l':
4d4caa50 RC	72	lflag++;
	73	break;
	74	case 'L':
7245937a RC	75	argc--;
	76	logfile = *++argv;
	77	break;
	78	}
	79	else {
	80	int port = atoi(argv[0]);
4d4caa50	81	int c = argv[0][0];
7245937a	82
4d4caa50 RC	83	if (c < '0' \|\| c > '9' \|\| port < 0) {
4d4caa50 RC	84	fprintf(stderr, "lpd: %s: bad port number\n", argv[0]);
7245937a RC	85	exit(1);
	86	}
	87	sin.sin_port = htons((u_short) port);
	88	}
	89	}
	90	#ifndef DEBUG
	91	/*
	92	* Set up standard environment by detaching from the parent.
	93	*/
	94	if (fork())
	95	exit(0);
	96	for (f = 0; f < 3; f++)
	97	(void) close(f);
adec4d9e SL	98	(void) open("/dev/null", O_RDONLY);
	99	(void) open("/dev/null", O_WRONLY);
	100	(void) open(logfile, O_WRONLY\|O_APPEND);
	101	f = open("/dev/tty", O_RDWR);
7245937a RC	102	if (f > 0) {
	103	ioctl(f, TIOCNOTTY, 0);
	104	(void) close(f);
	105	}
	106	#endif
	107	(void) umask(0);
54266d1f RC	108	/*
	109	* Restart all the printers.
	110	*/
	111	startup();
7245937a RC	112	f = socket(AF_INET, SOCK_STREAM, 0);
	113	if (f < 0) {
	114	logerror("socket");
	115	exit(1);
	116	}
	117	if (options & SO_DEBUG)
4d4caa50	118	if (setsockopt(f, SOL_SOCKET, SO_DEBUG, 0, 0) < 0) {
7245937a	119	logerror("setsockopt (SO_DEBUG)");
4d4caa50 RC	120	exit(1);
4d4caa50 RC	121	}
7245937a RC	122	if (bind(f, &sin, sizeof(sin), 0) < 0) {
	123	logerror("bind");
	124	exit(1);
	125	}
7245937a RC	126	/*
	127	* Main loop: listen, accept, do a request, continue.
	128	*/
adec4d9e	129	signal(SIGCHLD, reapchild);
7245937a RC	130	listen(f, 10);
7245937a RC	131	for (;;) {
4d4caa50	132	int s, len = sizeof(fromaddr);
7245937a	133
4d4caa50	134	s = accept(f, &fromaddr, &len, 0);
7245937a RC	135	if (s < 0) {
	136	if (errno == EINTR)
	137	continue;
	138	logerror("accept");
4d4caa50	139	exit(1);
7245937a RC	140	}
7245937a RC	141	if (fork() == 0) {
adec4d9e	142	signal(SIGCHLD, SIG_IGN);
7245937a	143	(void) close(f);
4d4caa50	144	doit(s, &fromaddr);
7245937a RC	145	exit(0);
	146	}
	147	(void) close(s);
	148	}
	149	}
	150
54266d1f	151	static
7245937a RC	152	reapchild()
	153	{
	154	union wait status;
	155
	156	while (wait3(&status, WNOHANG, 0) > 0)
	157	;
	158	}
	159
	160	/*
	161	* Stuff for handling job specifications
	162	*/
	163	char user[MAXUSERS]; / users to process */
	164	int users; /* # of users in user array */
	165	int requ[MAXREQUESTS]; /* job number of spool entries */
	166	int requests; /* # of spool requests */
54266d1f	167	char person; / name of person doing lprm */
7245937a	168
54266d1f RC	169	static char fromb[32]; /* buffer for client's machine name */
	170	static char cbuf[BUFSIZ]; /* command line buffer */
	171	static char *cmdnames[] = {
4d4caa50 RC	172	"null",
	173	"printjob",
	174	"recvjob",
	175	"displayq short",
	176	"displayq long",
	177	"rmjob"
	178	};
7245937a	179
54266d1f	180	static
4d4caa50	181	doit(f, fromaddr)
7245937a	182	int f;
4d4caa50	183	struct sockaddr_in *fromaddr;
7245937a RC	184	{
	185	register char *cp;
	186	register struct hostent *hp;
	187	register int n;
7245937a RC	188	char c;
	189
	190	dup2(f, 1);
	191	(void) close(f);
	192	f = 1;
4d4caa50 RC	193	fromaddr->sin_port = ntohs(fromaddr->sin_port);
4d4caa50 RC	194	if (fromaddr->sin_family != AF_INET \|\| fromaddr->sin_port >= IPPORT_RESERVED)
7245937a	195	fatal("Malformed from address");
4d4caa50 RC	196	hp = gethostbyaddr(&fromaddr->sin_addr, sizeof(struct in_addr),
4d4caa50 RC	197	fromaddr->sin_family);
7245937a RC	198	if (hp == 0)
7245937a RC	199	fatal("Host name for your address (%s) unknown",
adec4d9e	200	inet_ntoa(fromaddr->sin_addr));
7245937a RC	201	strcpy(fromb, hp->h_name);
7245937a RC	202	from = fromb;
4d4caa50 RC	203	if (chkhost())
4d4caa50 RC	204	fatal("Your host does not have line printer access");
7245937a RC	205	for (;;) {
	206	cp = cbuf;
	207	do {
	208	if ((n = read(f, &c, 1)) != 1) {
	209	if (n < 0)
	210	fatal("Lost connection");
	211	return;
	212	}
	213	if (cp >= &cbuf[sizeof(cbuf)])
	214	fatal("Command line too long");
	215	*cp++ = c;
	216	} while (c != '\n');
	217	*--cp = '\0';
	218	cp = cbuf;
4d4caa50 RC	219	if (lflag && cp >= '\1' && cp <= '\5') {
	220	printer = NULL;
	221	log("%s requests %s %s", from, cmdnames[*cp], cp+1);
	222	}
7245937a RC	223	switch (*cp++) {
	224	case '\1': /* check the queue and print any jobs there */
	225	printer = cp;
	226	printjob();
	227	break;
	228	case '\2': /* receive files to be queued */
	229	printer = cp;
	230	recvjob();
	231	break;
4d4caa50 RC	232	case '\3': /* display the queue (short form) */
4d4caa50 RC	233	case '\4': /* display the queue (long form) */
7245937a RC	234	printer = cp;
	235	while (*cp) {
	236	if (*cp != ' ') {
	237	cp++;
	238	continue;
	239	}
	240	*cp++ = '\0';
	241	while (isspace(*cp))
	242	cp++;
	243	if (*cp == '\0')
	244	break;
	245	if (isdigit(*cp)) {
	246	if (requests >= MAXREQUESTS)
	247	fatal("Too many requests");
	248	requ[requests++] = atoi(cp);
	249	} else {
	250	if (users >= MAXUSERS)
	251	fatal("Too many users");
	252	user[users++] = cp;
	253	}
	254	}
	255	displayq(cbuf[0] - '\3');
	256	exit(0);
	257	case '\5': /* remove a job from the queue */
	258	printer = cp;
	259	while (cp && cp != ' ')
	260	cp++;
	261	if (!*cp)
	262	break;
	263	*cp++ = '\0';
	264	person = cp;
	265	while (*cp) {
	266	if (*cp != ' ') {
	267	cp++;
	268	continue;
	269	}
	270	*cp++ = '\0';
	271	while (isspace(*cp))
	272	cp++;
	273	if (*cp == '\0')
	274	break;
	275	if (isdigit(*cp)) {
	276	if (requests >= MAXREQUESTS)
	277	fatal("Too many requests");
	278	requ[requests++] = atoi(cp);
	279	} else {
	280	if (users >= MAXUSERS)
	281	fatal("Too many users");
	282	user[users++] = cp;
	283	}
	284	}
	285	rmjob();
	286	break;
	287	}
	288	fatal("Illegal service request");
	289	exit(1);
	290	}
	291	}
	292
4d4caa50 RC	293	/*
	294	* Make a pass through the printcap database and start printing any
	295	* files left from the last time the machine went down.
	296	*/
54266d1f	297	static
4d4caa50 RC	298	startup()
	299	{
	300	char buf[BUFSIZ];
	301	register char *cp;
	302	int pid;
	303
	304	printer = buf;
	305
	306	/*
	307	* Restart the daemons.
	308	*/
	309	while (getprent(buf) > 0) {
	310	for (cp = buf; *cp; cp++)
	311	if (cp == '\|' \|\| cp == ':') {
	312	*cp = '\0';
	313	break;
	314	}
	315	if ((pid = fork()) < 0) {
	316	log("startup: cannot fork");
	317	exit(1);
	318	}
	319	if (!pid) {
	320	endprent();
	321	printjob();
	322	}
	323	}
	324	}
	325
	326	/*
	327	* Check to see if the from host has access to the line printer.
	328	*/
54266d1f	329	static
4d4caa50 RC	330	chkhost()
	331	{
	332	register FILE *hostf;
	333	register char *cp;
	334	char ahost[50];
	335
219e8551 RC	336	if (!strcmp(from, host))
	337	return(0);
	338
4d4caa50 RC	339	hostf = fopen("/etc/hosts.equiv", "r");
	340	while (fgets(ahost, sizeof(ahost), hostf)) {
	341	if (cp = index(ahost, '\n'))
	342	*cp = '\0';
	343	cp = index(ahost, ' ');
	344	if (!strcmp(from, ahost) && cp == NULL) {
	345	(void) fclose(hostf);
	346	return(0);
	347	}
	348	}
	349	(void) fclose(hostf);
	350	return(-1);
	351	}
	352
7245937a RC	353	/VARARGS1/
	354	log(msg, a1, a2, a3)
	355	char *msg;
	356	{
	357	short console = isatty(fileno(stderr));
	358
	359	fprintf(stderr, console ? "\r\n%s: " : "%s: ", name);
	360	if (printer)
	361	fprintf(stderr, "%s: ", printer);
	362	fprintf(stderr, msg, a1, a2, a3);
	363	if (console)
	364	putc('\r', stderr);
	365	putc('\n', stderr);
	366	fflush(stderr);
	367	}
	368
54266d1f	369	static
7245937a RC	370	logerror(msg)
	371	char *msg;
	372	{
	373	register int err = errno;
	374	short console = isatty(fileno(stderr));
	375	extern int sys_nerr;
	376	extern char *sys_errlist[];
	377
	378	fprintf(stderr, console ? "\r\n%s: " : "%s: ", name);
4d4caa50	379	if (msg)
7245937a RC	380	fprintf(stderr, "%s: ", msg);
	381	fputs(err < sys_nerr ? sys_errlist[err] : "Unknown error" , stderr);
	382	if (console)
	383	putc('\r', stderr);
	384	putc('\n', stderr);
	385	fflush(stderr);
	386	}