lpc.c revision 50042 
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 1.9 1999/08/19 03:29:13 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	const char *bp = NULL;
157
158	for (;;) {
159		if (fromatty) {
160			if (!el) {
161				el = el_init("lpc", stdin, stdout);
162				hist = history_init();
163				history(hist, H_EVENT, 100);
164				el_set(el, EL_HIST, history, hist);
165				el_set(el, EL_EDITOR, "emacs");
166				el_set(el, EL_PROMPT, lpc_prompt);
167				el_set(el, EL_SIGNAL, 1);
168				el_source(el, NULL);
169			}
170			if ((bp = el_gets(el, &num)) == NULL || num == 0)
171				return;
172
173			memcpy(cmdline, bp, (MAX_CMDLINE > num ? MAX_CMDLINE : num));
174			cmdline[num] = 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(name)
212	register char *name;
213{
214	register char *p, *q;
215	register struct cmd *c, *found;
216	register int nmatches, longest;
217
218	longest = 0;
219	nmatches = 0;
220	found = 0;
221	for (c = cmdtab; (p = c->c_name); c++) {
222		for (q = name; *q == *p++; q++)
223			if (*q == 0)		/* exact match? */
224				return(c);
225		if (!*q) {			/* the name was a prefix */
226			if (q - name > longest) {
227				longest = q - name;
228				nmatches = 1;
229				found = c;
230			} else if (q - name == longest)
231				nmatches++;
232		}
233	}
234	if (nmatches > 1)
235		return((struct cmd *)-1);
236	return(found);
237}
238
239/*
240 * Slice a string up into argc/argv.
241 */
242static void
243makeargv()
244{
245	register char *cp;
246	register char **argp = margv;
247	register int n = 0;
248
249	margc = 0;
250	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
251	    n < MAX_MARGV; n++) {
252		while (isspace(*cp))
253			cp++;
254		if (*cp == '\0')
255			break;
256		*argp++ = cp;
257		margc += 1;
258		while (*cp != '\0' && !isspace(*cp))
259			cp++;
260		if (*cp == '\0')
261			break;
262		*cp++ = '\0';
263	}
264	*argp++ = 0;
265}
266
267#define HELPINDENT (sizeof ("directory"))
268
269/*
270 * Help command.
271 */
272void
273help(argc, argv)
274	int argc;
275	char *argv[];
276{
277	register struct cmd *c;
278
279	if (argc == 1) {
280		register int i, j, w;
281		int columns, width = 0, lines;
282
283		printf("Commands may be abbreviated.  Commands are:\n\n");
284		for (c = cmdtab; c->c_name; c++) {
285			int len = strlen(c->c_name);
286
287			if (len > width)
288				width = len;
289		}
290		width = (width + 8) &~ 7;
291		columns = 80 / width;
292		if (columns == 0)
293			columns = 1;
294		lines = (NCMDS + columns - 1) / columns;
295		for (i = 0; i < lines; i++) {
296			for (j = 0; j < columns; j++) {
297				c = cmdtab + j * lines + i;
298				if (c->c_name)
299					printf("%s", c->c_name);
300				if (c + lines >= &cmdtab[NCMDS]) {
301					printf("\n");
302					break;
303				}
304				w = strlen(c->c_name);
305				while (w < width) {
306					w = (w + 8) &~ 7;
307					putchar('\t');
308				}
309			}
310		}
311		return;
312	}
313	while (--argc > 0) {
314		register char *arg;
315		arg = *++argv;
316		c = getcmd(arg);
317		if (c == (struct cmd *)-1)
318			printf("?Ambiguous help command %s\n", arg);
319		else if (c == (struct cmd *)0)
320			printf("?Invalid help command %s\n", arg);
321		else
322			printf("%-*s\t%s\n", (int) HELPINDENT,
323				c->c_name, c->c_help);
324	}
325}
326
327/*
328 * return non-zero if the user is a member of the given group
329 */
330static int
331ingroup(grname)
332	char *grname;
333{
334	static struct group *gptr=NULL;
335	static gid_t groups[NGROUPS];
336	register gid_t gid;
337	register int i;
338
339	if (gptr == NULL) {
340		if ((gptr = getgrnam(grname)) == NULL) {
341			warnx("warning: unknown group '%s'", grname);
342			return(0);
343		}
344		if (getgroups(NGROUPS, groups) < 0)
345			err(1, "getgroups");
346	}
347	gid = gptr->gr_gid;
348	for (i = 0; i < NGROUPS; i++)
349		if (gid == groups[i])
350			return(1);
351	return(0);
352}
353