lpc.c revision 78146
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 const 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
42#if 0
43static char sccsid[] = "@(#)lpc.c	8.3 (Berkeley) 4/28/95";
44#endif
45static const char rcsid[] =
46  "$FreeBSD: head/usr.sbin/lpr/lpc/lpc.c 78146 2001-06-12 16:38:20Z gad $";
47#endif /* not lint */
48
49#include <sys/param.h>
50
51#include <ctype.h>
52#include <dirent.h>
53#include <err.h>
54#include <grp.h>
55#include <setjmp.h>
56#include <signal.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <syslog.h>
60#include <string.h>
61#include <unistd.h>
62#include <histedit.h>
63
64#include "lp.h"
65#include "lpc.h"
66#include "extern.h"
67
68#ifndef LPR_OPER
69#define LPR_OPER	"operator"	/* group name of lpr operators */
70#endif
71
72/*
73 * lpc -- line printer control program
74 */
75
76#define MAX_CMDLINE	200
77#define MAX_MARGV	20
78static int	fromatty;
79
80static char	cmdline[MAX_CMDLINE];
81static int	margc;
82static char	*margv[MAX_MARGV];
83uid_t		uid, euid;
84
85int			 main(int _argc, char *_argv[]);
86static void		 cmdscanner(void);
87static struct cmd	*getcmd(const char *_name);
88static void		 intr(int _signo);
89static void		 makeargv(void);
90static int		 ingroup(const char *_grname);
91
92int
93main(int argc, char *argv[])
94{
95	register struct cmd *c;
96
97	euid = geteuid();
98	uid = getuid();
99	seteuid(uid);
100	name = argv[0];
101	openlog("lpd", 0, LOG_LPR);
102
103	if (--argc > 0) {
104		c = getcmd(*++argv);
105		if (c == (struct cmd *)-1) {
106			printf("?Ambiguous command\n");
107			exit(1);
108		}
109		if (c == 0) {
110			printf("?Invalid command\n");
111			exit(1);
112		}
113		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
114			printf("?Privileged command\n");
115			exit(1);
116		}
117		if (c->c_generic != 0)
118			generic(c->c_generic, argc, argv);
119		else
120			(*c->c_handler)(argc, argv);
121		exit(0);
122	}
123	fromatty = isatty(fileno(stdin));
124	if (!fromatty)
125		signal(SIGINT, intr);
126	for (;;) {
127		cmdscanner();
128	}
129}
130
131static void
132intr(int signo __unused)
133{
134	/* (the '__unused' is just to avoid a compile-time warning) */
135	exit(0);
136}
137
138static const char *
139lpc_prompt(void)
140{
141	return ("lpc> ");
142}
143
144/*
145 * Command parser.
146 */
147static void
148cmdscanner(void)
149{
150	register struct cmd *c;
151	static EditLine *el = NULL;
152	static History *hist = NULL;
153	int num = 0;
154	int len;
155	const char *bp = NULL;
156
157	for (;;) {
158		if (fromatty) {
159			if (!el) {
160				el = el_init("lpc", stdin, stdout);
161				hist = history_init();
162				history(hist, H_EVENT, 100);
163				el_set(el, EL_HIST, history, hist);
164				el_set(el, EL_EDITOR, "emacs");
165				el_set(el, EL_PROMPT, lpc_prompt);
166				el_set(el, EL_SIGNAL, 1);
167				el_source(el, NULL);
168			}
169			if ((bp = el_gets(el, &num)) == NULL || num == 0)
170				quit(0, NULL);
171
172			len = (num > MAX_CMDLINE) ? MAX_CMDLINE : num;
173			memcpy(cmdline, bp, len);
174			cmdline[len] = 0;
175			history(hist, H_ENTER, bp);
176
177		} else {
178			if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
179				quit(0, NULL);
180			if (cmdline[0] == 0 || cmdline[0] == '\n')
181				break;
182		}
183
184		makeargv();
185		if (margc == 0)
186			continue;
187		if (el_parse(el, margc, margv) != -1)
188			continue;
189
190		c = getcmd(margv[0]);
191		if (c == (struct cmd *)-1) {
192			printf("?Ambiguous command\n");
193			continue;
194		}
195		if (c == 0) {
196			printf("?Invalid command\n");
197			continue;
198		}
199		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
200			printf("?Privileged command\n");
201			continue;
202		}
203		if (c->c_generic != 0)
204			generic(c->c_generic, margc, margv);
205		else
206			(*c->c_handler)(margc, margv);
207	}
208}
209
210static struct cmd *
211getcmd(const char *name)
212{
213	register const char *p, *q;
214	register struct cmd *c, *found;
215	register int nmatches, longest;
216
217	longest = 0;
218	nmatches = 0;
219	found = 0;
220	for (c = cmdtab; (p = c->c_name); c++) {
221		for (q = name; *q == *p++; q++)
222			if (*q == 0)		/* exact match? */
223				return(c);
224		if (!*q) {			/* the name was a prefix */
225			if (q - name > longest) {
226				longest = q - name;
227				nmatches = 1;
228				found = c;
229			} else if (q - name == longest)
230				nmatches++;
231		}
232	}
233	if (nmatches > 1)
234		return((struct cmd *)-1);
235	return(found);
236}
237
238/*
239 * Slice a string up into argc/argv.
240 */
241static void
242makeargv(void)
243{
244	register char *cp;
245	register char **argp = margv;
246	register int n = 0;
247
248	margc = 0;
249	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
250	    n < MAX_MARGV; n++) {
251		while (isspace(*cp))
252			cp++;
253		if (*cp == '\0')
254			break;
255		*argp++ = cp;
256		margc += 1;
257		while (*cp != '\0' && !isspace(*cp))
258			cp++;
259		if (*cp == '\0')
260			break;
261		*cp++ = '\0';
262	}
263	*argp++ = 0;
264}
265
266#define HELPINDENT (sizeof ("directory"))
267
268/*
269 * Help command.
270 */
271void
272help(int argc, char *argv[])
273{
274	register struct cmd *c;
275
276	if (argc == 1) {
277		register int i, j, w;
278		int columns, width = 0, lines;
279
280		printf("Commands may be abbreviated.  Commands are:\n\n");
281		for (c = cmdtab; c->c_name; c++) {
282			int len = strlen(c->c_name);
283
284			if (len > width)
285				width = len;
286		}
287		width = (width + 8) &~ 7;
288		columns = 80 / width;
289		if (columns == 0)
290			columns = 1;
291		lines = (NCMDS + columns - 1) / columns;
292		for (i = 0; i < lines; i++) {
293			for (j = 0; j < columns; j++) {
294				c = cmdtab + j * lines + i;
295				if (c->c_name)
296					printf("%s", c->c_name);
297				if (c + lines >= &cmdtab[NCMDS]) {
298					printf("\n");
299					break;
300				}
301				w = strlen(c->c_name);
302				while (w < width) {
303					w = (w + 8) &~ 7;
304					putchar('\t');
305				}
306			}
307		}
308		return;
309	}
310	while (--argc > 0) {
311		register char *arg;
312		arg = *++argv;
313		c = getcmd(arg);
314		if (c == (struct cmd *)-1)
315			printf("?Ambiguous help command %s\n", arg);
316		else if (c == (struct cmd *)0)
317			printf("?Invalid help command %s\n", arg);
318		else
319			printf("%-*s\t%s\n", (int) HELPINDENT,
320				c->c_name, c->c_help);
321	}
322}
323
324/*
325 * return non-zero if the user is a member of the given group
326 */
327static int
328ingroup(const char *grname)
329{
330	static struct group *gptr=NULL;
331	static int ngroups = 0;
332	static gid_t groups[NGROUPS];
333	register gid_t gid;
334	register int i;
335
336	if (gptr == NULL) {
337		if ((gptr = getgrnam(grname)) == NULL) {
338			warnx("warning: unknown group '%s'", grname);
339			return(0);
340		}
341		ngroups = getgroups(NGROUPS, groups);
342		if (ngroups < 0)
343			err(1, "getgroups");
344	}
345	gid = gptr->gr_gid;
346	for (i = 0; i < ngroups; i++)
347		if (gid == groups[i])
348			return(1);
349	return(0);
350}
351