lpc.c revision 27618 
1/*
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by the University of
17 *	California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifndef lint
36static char copyright[] =
37"@(#) Copyright (c) 1983, 1993\n\
38	The Regents of the University of California.  All rights reserved.\n";
39#endif /* not lint */
40
41#ifndef lint
42static char sccsid[] = "@(#)lpc.c	8.3 (Berkeley) 4/28/95";
43#endif /* not lint */
44
45#include <sys/param.h>
46
47#include <dirent.h>
48#include <signal.h>
49#include <setjmp.h>
50#include <syslog.h>
51#include <unistd.h>
52#include <stdlib.h>
53#include <stdio.h>
54#include <ctype.h>
55#include <string.h>
56#include <grp.h>
57#include <sys/param.h>
58#include "lp.h"
59#include "lpc.h"
60#include "extern.h"
61
62#ifndef LPR_OPER
63#define LPR_OPER	"operator"	/* group name of lpr operators */
64#endif
65
66/*
67 * lpc -- line printer control program
68 */
69
70#define MAX_CMDLINE	200
71#define MAX_MARGV	20
72int	fromatty;
73
74char	cmdline[MAX_CMDLINE];
75int	margc;
76char	*margv[MAX_MARGV];
77int	top;
78uid_t	uid, euid;
79
80jmp_buf	toplevel;
81
82static void		 cmdscanner __P((int));
83static struct cmd	*getcmd __P((char *));
84static void		 intr __P((int));
85static void		 makeargv __P((void));
86static int		 ingroup __P((char *));
87
88int
89main(argc, argv)
90	int argc;
91	char *argv[];
92{
93	register struct cmd *c;
94
95	euid = geteuid();
96	uid = getuid();
97	seteuid(uid);
98	name = argv[0];
99	openlog("lpd", 0, LOG_LPR);
100
101	if (--argc > 0) {
102		c = getcmd(*++argv);
103		if (c == (struct cmd *)-1) {
104			printf("?Ambiguous command\n");
105			exit(1);
106		}
107		if (c == 0) {
108			printf("?Invalid command\n");
109			exit(1);
110		}
111		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
112			printf("?Privileged command\n");
113			exit(1);
114		}
115		(*c->c_handler)(argc, argv);
116		exit(0);
117	}
118	fromatty = isatty(fileno(stdin));
119	top = setjmp(toplevel) == 0;
120	if (top)
121		signal(SIGINT, intr);
122	for (;;) {
123		cmdscanner(top);
124		top = 1;
125	}
126}
127
128static void
129intr(signo)
130	int signo;
131{
132	if (!fromatty)
133		exit(0);
134	longjmp(toplevel, 1);
135}
136
137/*
138 * Command parser.
139 */
140static void
141cmdscanner(top)
142	int top;
143{
144	register struct cmd *c;
145
146	if (!top)
147		putchar('\n');
148	for (;;) {
149		if (fromatty) {
150			printf("lpc> ");
151			fflush(stdout);
152		}
153		if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
154			quit(0, NULL);
155		if (cmdline[0] == 0 || cmdline[0] == '\n')
156			break;
157		makeargv();
158		c = getcmd(margv[0]);
159		if (c == (struct cmd *)-1) {
160			printf("?Ambiguous command\n");
161			continue;
162		}
163		if (c == 0) {
164			printf("?Invalid command\n");
165			continue;
166		}
167		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
168			printf("?Privileged command\n");
169			continue;
170		}
171		(*c->c_handler)(margc, margv);
172	}
173	longjmp(toplevel, 0);
174}
175
176static struct cmd *
177getcmd(name)
178	register char *name;
179{
180	register char *p, *q;
181	register struct cmd *c, *found;
182	register int nmatches, longest;
183
184	longest = 0;
185	nmatches = 0;
186	found = 0;
187	for (c = cmdtab; (p = c->c_name); c++) {
188		for (q = name; *q == *p++; q++)
189			if (*q == 0)		/* exact match? */
190				return(c);
191		if (!*q) {			/* the name was a prefix */
192			if (q - name > longest) {
193				longest = q - name;
194				nmatches = 1;
195				found = c;
196			} else if (q - name == longest)
197				nmatches++;
198		}
199	}
200	if (nmatches > 1)
201		return((struct cmd *)-1);
202	return(found);
203}
204
205/*
206 * Slice a string up into argc/argv.
207 */
208static void
209makeargv()
210{
211	register char *cp;
212	register char **argp = margv;
213	register int n = 0;
214
215	margc = 0;
216	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
217	    n < MAX_MARGV; n++) {
218		while (isspace(*cp))
219			cp++;
220		if (*cp == '\0')
221			break;
222		*argp++ = cp;
223		margc += 1;
224		while (*cp != '\0' && !isspace(*cp))
225			cp++;
226		if (*cp == '\0')
227			break;
228		*cp++ = '\0';
229	}
230	*argp++ = 0;
231}
232
233#define HELPINDENT (sizeof ("directory"))
234
235/*
236 * Help command.
237 */
238void
239help(argc, argv)
240	int argc;
241	char *argv[];
242{
243	register struct cmd *c;
244
245	if (argc == 1) {
246		register int i, j, w;
247		int columns, width = 0, lines;
248
249		printf("Commands may be abbreviated.  Commands are:\n\n");
250		for (c = cmdtab; c->c_name; c++) {
251			int len = strlen(c->c_name);
252
253			if (len > width)
254				width = len;
255		}
256		width = (width + 8) &~ 7;
257		columns = 80 / width;
258		if (columns == 0)
259			columns = 1;
260		lines = (NCMDS + columns - 1) / columns;
261		for (i = 0; i < lines; i++) {
262			for (j = 0; j < columns; j++) {
263				c = cmdtab + j * lines + i;
264				if (c->c_name)
265					printf("%s", c->c_name);
266				if (c + lines >= &cmdtab[NCMDS]) {
267					printf("\n");
268					break;
269				}
270				w = strlen(c->c_name);
271				while (w < width) {
272					w = (w + 8) &~ 7;
273					putchar('\t');
274				}
275			}
276		}
277		return;
278	}
279	while (--argc > 0) {
280		register char *arg;
281		arg = *++argv;
282		c = getcmd(arg);
283		if (c == (struct cmd *)-1)
284			printf("?Ambiguous help command %s\n", arg);
285		else if (c == (struct cmd *)0)
286			printf("?Invalid help command %s\n", arg);
287		else
288			printf("%-*s\t%s\n", HELPINDENT,
289				c->c_name, c->c_help);
290	}
291}
292
293/*
294 * return non-zero if the user is a member of the given group
295 */
296static int
297ingroup(grname)
298	char *grname;
299{
300	static struct group *gptr=NULL;
301	static gid_t groups[NGROUPS];
302	register gid_t gid;
303	register int i;
304
305	if (gptr == NULL) {
306		if ((gptr = getgrnam(grname)) == NULL) {
307			fprintf(stderr, "Warning: unknown group '%s'\n",
308				grname);
309			return(0);
310		}
311		if (getgroups(NGROUPS, groups) < 0) {
312			perror("getgroups");
313			exit(1);
314		}
315	}
316	gid = gptr->gr_gid;
317	for (i = 0; i < NGROUPS; i++)
318		if (gid == groups[i])
319			return(1);
320	return(0);
321}
322