lpc.c revision 50071 
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	"$Id: lpc.c,v 1.10 1999/08/19 04:10:32 mdodd Exp $";
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 __P((int, char *[]));
86static void		 cmdscanner __P((void));
87static struct cmd	*getcmd __P((char *));
88static void		 intr __P((int));
89static void		 makeargv __P((void));
90static int		 ingroup __P((char *));
91
92int
93main(argc, argv)
94	int argc;
95	char *argv[];
96{
97	register struct cmd *c;
98
99	euid = geteuid();
100	uid = getuid();
101	seteuid(uid);
102	name = argv[0];
103	openlog("lpd", 0, LOG_LPR);
104
105	if (--argc > 0) {
106		c = getcmd(*++argv);
107		if (c == (struct cmd *)-1) {
108			printf("?Ambiguous command\n");
109			exit(1);
110		}
111		if (c == 0) {
112			printf("?Invalid command\n");
113			exit(1);
114		}
115		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
116			printf("?Privileged command\n");
117			exit(1);
118		}
119		if (c->c_generic != 0)
120			generic(c->c_generic, argc, argv);
121		else
122			(*c->c_handler)(argc, argv);
123		exit(0);
124	}
125	fromatty = isatty(fileno(stdin));
126	if (!fromatty)
127		signal(SIGINT, intr);
128	for (;;) {
129		cmdscanner();
130	}
131}
132
133static void
134intr(signo)
135	int signo;
136{
137	exit(0);
138}
139
140static char *
141lpc_prompt()
142{
143	return("lpc> ");
144}
145
146/*
147 * Command parser.
148 */
149static void
150cmdscanner()
151{
152	register struct cmd *c;
153	static EditLine *el = NULL;
154	static History *hist = NULL;
155	int num = 0;
156	int len;
157	const char *bp = NULL;
158
159	for (;;) {
160		if (fromatty) {
161			if (!el) {
162				el = el_init("lpc", stdin, stdout);
163				hist = history_init();
164				history(hist, H_EVENT, 100);
165				el_set(el, EL_HIST, history, hist);
166				el_set(el, EL_EDITOR, "emacs");
167				el_set(el, EL_PROMPT, lpc_prompt);
168				el_set(el, EL_SIGNAL, 1);
169				el_source(el, NULL);
170			}
171			if ((bp = el_gets(el, &num)) == NULL || num == 0)
172				return;
173
174			len = (num > MAX_CMDLINE) ? MAX_CMDLINE : num);
175			memcpy(cmdline, bp, len);
176			cmdline[len] = 0;
177			history(hist, H_ENTER, bp);
178
179		} else {
180			if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
181				quit(0, NULL);
182			if (cmdline[0] == 0 || cmdline[0] == '\n')
183				break;
184		}
185
186		makeargv();
187		if (margc == 0)
188			continue;
189		if (el_parse(el, margc, margv) != -1)
190			continue;
191
192		c = getcmd(margv[0]);
193		if (c == (struct cmd *)-1) {
194			printf("?Ambiguous command\n");
195			continue;
196		}
197		if (c == 0) {
198			printf("?Invalid command\n");
199			continue;
200		}
201		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
202			printf("?Privileged command\n");
203			continue;
204		}
205		if (c->c_generic != 0)
206			generic(c->c_generic, margc, margv);
207		else
208			(*c->c_handler)(margc, margv);
209	}
210}
211
212static struct cmd *
213getcmd(name)
214	register char *name;
215{
216	register char *p, *q;
217	register struct cmd *c, *found;
218	register int nmatches, longest;
219
220	longest = 0;
221	nmatches = 0;
222	found = 0;
223	for (c = cmdtab; (p = c->c_name); c++) {
224		for (q = name; *q == *p++; q++)
225			if (*q == 0)		/* exact match? */
226				return(c);
227		if (!*q) {			/* the name was a prefix */
228			if (q - name > longest) {
229				longest = q - name;
230				nmatches = 1;
231				found = c;
232			} else if (q - name == longest)
233				nmatches++;
234		}
235	}
236	if (nmatches > 1)
237		return((struct cmd *)-1);
238	return(found);
239}
240
241/*
242 * Slice a string up into argc/argv.
243 */
244static void
245makeargv()
246{
247	register char *cp;
248	register char **argp = margv;
249	register int n = 0;
250
251	margc = 0;
252	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
253	    n < MAX_MARGV; n++) {
254		while (isspace(*cp))
255			cp++;
256		if (*cp == '\0')
257			break;
258		*argp++ = cp;
259		margc += 1;
260		while (*cp != '\0' && !isspace(*cp))
261			cp++;
262		if (*cp == '\0')
263			break;
264		*cp++ = '\0';
265	}
266	*argp++ = 0;
267}
268
269#define HELPINDENT (sizeof ("directory"))
270
271/*
272 * Help command.
273 */
274void
275help(argc, argv)
276	int argc;
277	char *argv[];
278{
279	register struct cmd *c;
280
281	if (argc == 1) {
282		register int i, j, w;
283		int columns, width = 0, lines;
284
285		printf("Commands may be abbreviated.  Commands are:\n\n");
286		for (c = cmdtab; c->c_name; c++) {
287			int len = strlen(c->c_name);
288
289			if (len > width)
290				width = len;
291		}
292		width = (width + 8) &~ 7;
293		columns = 80 / width;
294		if (columns == 0)
295			columns = 1;
296		lines = (NCMDS + columns - 1) / columns;
297		for (i = 0; i < lines; i++) {
298			for (j = 0; j < columns; j++) {
299				c = cmdtab + j * lines + i;
300				if (c->c_name)
301					printf("%s", c->c_name);
302				if (c + lines >= &cmdtab[NCMDS]) {
303					printf("\n");
304					break;
305				}
306				w = strlen(c->c_name);
307				while (w < width) {
308					w = (w + 8) &~ 7;
309					putchar('\t');
310				}
311			}
312		}
313		return;
314	}
315	while (--argc > 0) {
316		register char *arg;
317		arg = *++argv;
318		c = getcmd(arg);
319		if (c == (struct cmd *)-1)
320			printf("?Ambiguous help command %s\n", arg);
321		else if (c == (struct cmd *)0)
322			printf("?Invalid help command %s\n", arg);
323		else
324			printf("%-*s\t%s\n", (int) HELPINDENT,
325				c->c_name, c->c_help);
326	}
327}
328
329/*
330 * return non-zero if the user is a member of the given group
331 */
332static int
333ingroup(grname)
334	char *grname;
335{
336	static struct group *gptr=NULL;
337	static gid_t groups[NGROUPS];
338	register gid_t gid;
339	register int i;
340
341	if (gptr == NULL) {
342		if ((gptr = getgrnam(grname)) == NULL) {
343			warnx("warning: unknown group '%s'", grname);
344			return(0);
345		}
346		if (getgroups(NGROUPS, groups) < 0)
347			err(1, "getgroups");
348	}
349	gid = gptr->gr_gid;
350	for (i = 0; i < NGROUPS; i++)
351		if (gid == groups[i])
352			return(1);
353	return(0);
354}
355