lpc.c revision 84261 
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 84261 2001-10-01 08:43:58Z obrien $";
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;
152	static History *hist;
153	HistEvent he;
154	size_t len;
155	int num;
156	const char *bp;
157
158	num = 0;
159	bp = NULL;
160	el = NULL;
161	hist = NULL;
162	for (;;) {
163		if (fromatty) {
164			if (!el) {
165				el = el_init("lpc", stdin, stdout, stderr);
166				hist = history_init();
167				history(hist, &he, H_EVENT, 100);
168				el_set(el, EL_HIST, history, hist);
169				el_set(el, EL_EDITOR, "emacs");
170				el_set(el, EL_PROMPT, lpc_prompt);
171				el_set(el, EL_SIGNAL, 1);
172				el_source(el, NULL);
173				/*
174				 * EditLine init may call 'cgetset()' to set a
175				 * capability-db meant for termcap (eg: to set
176				 * terminal type 'xterm').  Reset that now, or
177				 * that same db-information will be used for
178				 * printcap (giving us an "xterm" printer, with
179				 * all kinds of invalid capabilities...).
180				 */
181				cgetset(NULL);
182			}
183			if ((bp = el_gets(el, &num)) == NULL || num == 0)
184				quit(0, NULL);
185
186			len = (num > MAX_CMDLINE) ? MAX_CMDLINE : num;
187			memcpy(cmdline, bp, len);
188			cmdline[len] = 0;
189			history(hist, &he, H_ENTER, bp);
190
191		} else {
192			if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
193				quit(0, NULL);
194			if (cmdline[0] == 0 || cmdline[0] == '\n')
195				break;
196		}
197
198		makeargv();
199		if (margc == 0)
200			continue;
201		if (el_parse(el, margc, margv) != -1)
202			continue;
203
204		c = getcmd(margv[0]);
205		if (c == (struct cmd *)-1) {
206			printf("?Ambiguous command\n");
207			continue;
208		}
209		if (c == 0) {
210			printf("?Invalid command\n");
211			continue;
212		}
213		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
214			printf("?Privileged command\n");
215			continue;
216		}
217
218		/*
219		 * Two different commands might have the same generic rtn
220		 * (eg: "clean" and "tclean"), and just use different
221		 * handler routines for distinct command-setup.  The handler
222		 * routine might also be set on a generic routine for
223		 * initial parameter processing.
224		 */
225		if (c->c_generic != 0)
226			generic(c->c_generic, c->c_handler, margc, margv);
227		else
228			(*c->c_handler)(margc, margv);
229	}
230}
231
232static struct cmd *
233getcmd(const char *name)
234{
235	register const char *p, *q;
236	register struct cmd *c, *found;
237	register int nmatches, longest;
238
239	longest = 0;
240	nmatches = 0;
241	found = 0;
242	for (c = cmdtab; (p = c->c_name); c++) {
243		for (q = name; *q == *p++; q++)
244			if (*q == 0)		/* exact match? */
245				return(c);
246		if (!*q) {			/* the name was a prefix */
247			if (q - name > longest) {
248				longest = q - name;
249				nmatches = 1;
250				found = c;
251			} else if (q - name == longest)
252				nmatches++;
253		}
254	}
255	if (nmatches > 1)
256		return((struct cmd *)-1);
257	return(found);
258}
259
260/*
261 * Slice a string up into argc/argv.
262 */
263static void
264makeargv(void)
265{
266	register char *cp;
267	register char **argp = margv;
268	register int n = 0;
269
270	margc = 0;
271	for (cp = cmdline; *cp && (size_t)(cp - cmdline) < sizeof(cmdline) &&
272	    n < MAX_MARGV; n++) {
273		while (isspace(*cp))
274			cp++;
275		if (*cp == '\0')
276			break;
277		*argp++ = cp;
278		margc += 1;
279		while (*cp != '\0' && !isspace(*cp))
280			cp++;
281		if (*cp == '\0')
282			break;
283		*cp++ = '\0';
284	}
285	*argp++ = 0;
286}
287
288#define HELPINDENT (sizeof ("directory"))
289
290/*
291 * Help command.
292 */
293void
294help(int argc, char *argv[])
295{
296	register struct cmd *c;
297
298	if (argc == 1) {
299		register int i, j, w;
300		int columns, width = 0, lines;
301
302		printf("Commands may be abbreviated.  Commands are:\n\n");
303		for (c = cmdtab; c->c_name; c++) {
304			int len = strlen(c->c_name);
305
306			if (len > width)
307				width = len;
308		}
309		width = (width + 8) &~ 7;
310		columns = 80 / width;
311		if (columns == 0)
312			columns = 1;
313		lines = (NCMDS + columns - 1) / columns;
314		for (i = 0; i < lines; i++) {
315			for (j = 0; j < columns; j++) {
316				c = cmdtab + j * lines + i;
317				if (c->c_name)
318					printf("%s", c->c_name);
319				if (c + lines >= &cmdtab[NCMDS]) {
320					printf("\n");
321					break;
322				}
323				w = strlen(c->c_name);
324				while (w < width) {
325					w = (w + 8) &~ 7;
326					putchar('\t');
327				}
328			}
329		}
330		return;
331	}
332	while (--argc > 0) {
333		register char *arg;
334		arg = *++argv;
335		c = getcmd(arg);
336		if (c == (struct cmd *)-1)
337			printf("?Ambiguous help command %s\n", arg);
338		else if (c == (struct cmd *)0)
339			printf("?Invalid help command %s\n", arg);
340		else
341			printf("%-*s\t%s\n", (int) HELPINDENT,
342				c->c_name, c->c_help);
343	}
344}
345
346/*
347 * return non-zero if the user is a member of the given group
348 */
349static int
350ingroup(const char *grname)
351{
352	static struct group *gptr=NULL;
353	static int ngroups = 0;
354	static gid_t groups[NGROUPS];
355	register gid_t gid;
356	register int i;
357
358	if (gptr == NULL) {
359		if ((gptr = getgrnam(grname)) == NULL) {
360			warnx("warning: unknown group '%s'", grname);
361			return(0);
362		}
363		ngroups = getgroups(NGROUPS, groups);
364		if (ngroups < 0)
365			err(1, "getgroups");
366	}
367	gid = gptr->gr_gid;
368	for (i = 0; i < ngroups; i++)
369		if (gid == groups[i])
370			return(1);
371	return(0);
372}
373