1/*	$NetBSD: lpc.c,v 1.25 2009/01/18 09:57:26 lukem Exp $	*/
2
3/*
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34#ifndef lint
35__COPYRIGHT("@(#) Copyright (c) 1983, 1993\
36 The Regents of the University of California.  All rights reserved.");
37#if 0
38static char sccsid[] = "@(#)lpc.c	8.3 (Berkeley) 4/28/95";
39#else
40__RCSID("$NetBSD: lpc.c,v 1.25 2009/01/18 09:57:26 lukem Exp $");
41#endif
42#endif /* not lint */
43
44#include <sys/param.h>
45
46#include <dirent.h>
47#include <signal.h>
48#include <setjmp.h>
49#include <syslog.h>
50#include <histedit.h>
51#include <unistd.h>
52#include <stdlib.h>
53#include <stdio.h>
54#include <ctype.h>
55#include <string.h>
56#include <grp.h>
57#include <err.h>
58#include "lp.h"
59#include "lpc.h"
60#include "extern.h"
61
62#ifndef LPR_OPER
63#define LPR_OPER	"operator"	/* group name of lpr operators */
64#endif
65
66/*
67 * lpc -- line printer control program
68 */
69
70#define MAX_MARGV	20
71int	fromatty;
72
73char	*cmdline;
74int	margc;
75char	*margv[MAX_MARGV];
76int	top;
77uid_t	uid, euid;
78
79jmp_buf	toplevel;
80
81History	*hist;
82HistEvent he;
83EditLine *elptr;
84
85__dead static void	 cmdscanner(int);
86static struct cmd	*getcmd(const char *);
87__dead static void	 intr(int);
88static void		 makeargv(void);
89static int		 ingroup(const char *);
90int			 main(int, char *p[]);
91const char		*prompt(void);
92static int		 parse(char *, char *p[], int);
93
94int
95main(int argc, char *argv[])
96{
97	euid = geteuid();
98	uid = getuid();
99	seteuid(uid);
100	setprogname(argv[0]);
101	openlog("lpd", 0, LOG_LPR);
102
103	if (--argc > 0) {
104		argv++;
105		exit(!parse(*argv, argv, argc));
106	}
107	fromatty = isatty(fileno(stdin));
108	top = setjmp(toplevel) == 0;
109	if (top)
110		signal(SIGINT, intr);
111	for (;;) {
112		cmdscanner(top);
113		top = 1;
114	}
115}
116
117static int
118parse(char *arg, char **pargv, int pargc)
119{
120	struct cmd *c;
121
122	c = getcmd(arg);
123	if (c == (struct cmd *)-1) {
124		printf("?Ambiguous command\n");
125		return(0);
126	}
127	if (c == 0) {
128		printf("?Invalid command\n");
129		return(0);
130	}
131	if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
132		printf("?Privileged command\n");
133		return(0);
134	}
135	(*c->c_handler)(pargc, pargv);
136	return(1);
137}
138
139static void
140intr(int signo)
141{
142	el_end(elptr);
143	history_end(hist);
144	if (!fromatty)
145		exit(0);
146	longjmp(toplevel, 1);
147}
148
149const char *
150prompt(void)
151{
152	return ("lpc> ");
153}
154
155/*
156 * Command parser.
157 */
158static void
159cmdscanner(int tp)
160{
161	int scratch;
162	const char *elline;
163
164	if (!tp)
165		putchar('\n');
166	hist = history_init();
167	history(hist, &he, H_SETSIZE, 100);	/* 100 elt history buffer */
168
169	elptr = el_init(getprogname(), stdin, stdout, stderr);
170	el_set(elptr, EL_EDITOR, "emacs");
171	el_set(elptr, EL_PROMPT, prompt);
172	el_set(elptr, EL_HIST, history, hist);
173	el_source(elptr, NULL);
174
175	for (;;) {
176		cmdline = NULL;
177		do {
178			if (((elline = el_gets(elptr, &scratch)) != NULL)
179			    && (scratch != 0)) {
180				history(hist, &he, H_ENTER, elline);
181				cmdline = strdup(elline);
182				makeargv();
183			} else {
184				margc = 0;
185				break;
186			}
187		} while (margc == 0);
188		if (margc == 0)
189			quit(0, NULL);
190		if (!parse(cmdline, margv, margc)) {
191			if (cmdline != NULL)
192				free(cmdline);
193			continue;
194		}
195		fflush(stdout);
196		if (cmdline != NULL)
197			free(cmdline);
198	}
199	longjmp(toplevel, 0);
200}
201
202static struct cmd *
203getcmd(const char *name)
204{
205	const char *p, *q;
206	struct cmd *c, *found;
207	int nmatches, longest;
208
209	longest = 0;
210	nmatches = 0;
211	found = 0;
212	for (c = cmdtab; (p = c->c_name) != NULL; c++) {
213		for (q = name; *q == *p++; q++)
214			if (*q == 0)		/* exact match? */
215				return(c);
216		if (!*q) {			/* the name was a prefix */
217			if (q - name > longest) {
218				longest = q - name;
219				nmatches = 1;
220				found = c;
221			} else if (q - name == longest)
222				nmatches++;
223		}
224	}
225	if (nmatches > 1)
226		return((struct cmd *)-1);
227	return(found);
228}
229
230/*
231 * Slice a string up into argc/argv.
232 */
233static void
234makeargv(void)
235{
236	char *cp;
237	char **argp = margv;
238	int n = 0;
239	size_t s;
240
241	s = strlen(cmdline) + 1;
242	margc = 0;
243	for (cp = cmdline; *cp && (size_t)(cp - cmdline) < s && n < MAX_MARGV; n++) {
244		while (isspace((unsigned char)*cp))
245			cp++;
246		if (*cp == '\0')
247			break;
248		*argp++ = cp;
249		margc += 1;
250		while (*cp != '\0' && !isspace((unsigned char)*cp))
251			cp++;
252		if (*cp == '\0')
253			break;
254		*cp++ = '\0';
255	}
256	*argp++ = 0;
257}
258
259#define HELPINDENT (sizeof ("directory"))
260
261/*
262 * Help command.
263 */
264void
265help(int argc, char *argv[])
266{
267	struct cmd *c;
268
269	if (argc == 1) {
270		size_t i, j, w;
271		size_t columns, width = 0, lines;
272
273		printf("Commands may be abbreviated.  Commands are:\n\n");
274		for (c = cmdtab; c->c_name; c++) {
275			size_t len = strlen(c->c_name);
276
277			if (len > width)
278				width = len;
279		}
280		width = (width + 8) &~ 7;
281		columns = 80 / width;
282		if (columns == 0)
283			columns = 1;
284		lines = (NCMDS + columns - 1) / columns;
285		for (i = 0; i < lines; i++) {
286			for (j = 0; j < columns; j++) {
287				c = cmdtab + j * lines + i;
288				printf("%s", c->c_name);
289				if (c + lines >= &cmdtab[NCMDS - 1]) {
290					printf("\n");
291					break;
292				}
293				w = strlen(c->c_name);
294				while (w < width) {
295					w = (w + 8) &~ 7;
296					putchar('\t');
297				}
298			}
299		}
300		return;
301	}
302	while (--argc > 0) {
303		char *arg;
304		arg = *++argv;
305		c = getcmd(arg);
306		if (c == (struct cmd *)-1)
307			printf("?Ambiguous help command %s\n", arg);
308		else if (c == (struct cmd *)0)
309			printf("?Invalid help command %s\n", arg);
310		else
311			printf("%-*s\t%s\n", (int)HELPINDENT,
312				c->c_name, c->c_help);
313	}
314}
315
316/*
317 * return non-zero if the user is a member of the given group
318 */
319static int
320ingroup(const char *grname)
321{
322	static struct group *gptr = NULL;
323	static gid_t groups[NGROUPS];
324	static int ngroups;
325	gid_t gid;
326	int i;
327
328	if (gptr == NULL) {
329		if ((gptr = getgrnam(grname)) == NULL) {
330			warnx("Warning: unknown group `%s'",
331				grname);
332			return(0);
333		}
334		ngroups = getgroups(NGROUPS, groups);
335		if (ngroups < 0)
336			err(1, "getgroups");
337	}
338	gid = gptr->gr_gid;
339	for (i = 0; i < ngroups; i++)
340		if (gid == groups[i])
341			return(1);
342	return(0);
343}
344