lpc.c revision 78750 
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 78750 2001-06-25 02:05:03Z 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	progname = 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, c->c_handler, 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
204		/*
205		 * Two different commands might have the same generic rtn
206		 * (eg: "clean" and "tclean"), and just use different
207		 * handler routines for distinct command-setup.  The handler
208		 * routine might also be set on a generic routine for
209		 * initial parameter processing.
210		 */
211		if (c->c_generic != 0)
212			generic(c->c_generic, c->c_handler, margc, margv);
213		else
214			(*c->c_handler)(margc, margv);
215	}
216}
217
218static struct cmd *
219getcmd(const char *name)
220{
221	register const char *p, *q;
222	register struct cmd *c, *found;
223	register int nmatches, longest;
224
225	longest = 0;
226	nmatches = 0;
227	found = 0;
228	for (c = cmdtab; (p = c->c_name); c++) {
229		for (q = name; *q == *p++; q++)
230			if (*q == 0)		/* exact match? */
231				return(c);
232		if (!*q) {			/* the name was a prefix */
233			if (q - name > longest) {
234				longest = q - name;
235				nmatches = 1;
236				found = c;
237			} else if (q - name == longest)
238				nmatches++;
239		}
240	}
241	if (nmatches > 1)
242		return((struct cmd *)-1);
243	return(found);
244}
245
246/*
247 * Slice a string up into argc/argv.
248 */
249static void
250makeargv(void)
251{
252	register char *cp;
253	register char **argp = margv;
254	register int n = 0;
255
256	margc = 0;
257	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
258	    n < MAX_MARGV; n++) {
259		while (isspace(*cp))
260			cp++;
261		if (*cp == '\0')
262			break;
263		*argp++ = cp;
264		margc += 1;
265		while (*cp != '\0' && !isspace(*cp))
266			cp++;
267		if (*cp == '\0')
268			break;
269		*cp++ = '\0';
270	}
271	*argp++ = 0;
272}
273
274#define HELPINDENT (sizeof ("directory"))
275
276/*
277 * Help command.
278 */
279void
280help(int argc, char *argv[])
281{
282	register struct cmd *c;
283
284	if (argc == 1) {
285		register int i, j, w;
286		int columns, width = 0, lines;
287
288		printf("Commands may be abbreviated.  Commands are:\n\n");
289		for (c = cmdtab; c->c_name; c++) {
290			int len = strlen(c->c_name);
291
292			if (len > width)
293				width = len;
294		}
295		width = (width + 8) &~ 7;
296		columns = 80 / width;
297		if (columns == 0)
298			columns = 1;
299		lines = (NCMDS + columns - 1) / columns;
300		for (i = 0; i < lines; i++) {
301			for (j = 0; j < columns; j++) {
302				c = cmdtab + j * lines + i;
303				if (c->c_name)
304					printf("%s", c->c_name);
305				if (c + lines >= &cmdtab[NCMDS]) {
306					printf("\n");
307					break;
308				}
309				w = strlen(c->c_name);
310				while (w < width) {
311					w = (w + 8) &~ 7;
312					putchar('\t');
313				}
314			}
315		}
316		return;
317	}
318	while (--argc > 0) {
319		register char *arg;
320		arg = *++argv;
321		c = getcmd(arg);
322		if (c == (struct cmd *)-1)
323			printf("?Ambiguous help command %s\n", arg);
324		else if (c == (struct cmd *)0)
325			printf("?Invalid help command %s\n", arg);
326		else
327			printf("%-*s\t%s\n", (int) HELPINDENT,
328				c->c_name, c->c_help);
329	}
330}
331
332/*
333 * return non-zero if the user is a member of the given group
334 */
335static int
336ingroup(const char *grname)
337{
338	static struct group *gptr=NULL;
339	static int ngroups = 0;
340	static gid_t groups[NGROUPS];
341	register gid_t gid;
342	register int i;
343
344	if (gptr == NULL) {
345		if ((gptr = getgrnam(grname)) == NULL) {
346			warnx("warning: unknown group '%s'", grname);
347			return(0);
348		}
349		ngroups = getgroups(NGROUPS, groups);
350		if (ngroups < 0)
351			err(1, "getgroups");
352	}
353	gid = gptr->gr_gid;
354	for (i = 0; i < ngroups; i++)
355		if (gid == groups[i])
356			return(1);
357	return(0);
358}
359