xref: /freebsd/usr.sbin/lpr/lpc/lpc.c (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
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
36 static 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
43 static char sccsid[] = "@(#)lpc.c	8.3 (Berkeley) 4/28/95";
44 #endif
45 static const char rcsid[] =
46 	"$Id: lpc.c,v 1.7 1998/03/22 20:19:27 jb 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 
63 #include "lp.h"
64 #include "lpc.h"
65 #include "extern.h"
66 
67 #ifndef LPR_OPER
68 #define LPR_OPER	"operator"	/* group name of lpr operators */
69 #endif
70 
71 /*
72  * lpc -- line printer control program
73  */
74 
75 #define MAX_CMDLINE	200
76 #define MAX_MARGV	20
77 static int	fromatty;
78 
79 static char	cmdline[MAX_CMDLINE];
80 static int	margc;
81 static char	*margv[MAX_MARGV];
82 static int	top;
83 uid_t		uid, euid;
84 
85 static jmp_buf	toplevel;
86 
87 int			 main __P((int, char *[]));
88 static void		 cmdscanner __P((int));
89 static struct cmd	*getcmd __P((char *));
90 static void		 intr __P((int));
91 static void		 makeargv __P((void));
92 static int		 ingroup __P((char *));
93 
94 int
95 main(argc, argv)
96 	int argc;
97 	char *argv[];
98 {
99 	register struct cmd *c;
100 
101 	euid = geteuid();
102 	uid = getuid();
103 	seteuid(uid);
104 	name = argv[0];
105 	openlog("lpd", 0, LOG_LPR);
106 
107 	if (--argc > 0) {
108 		c = getcmd(*++argv);
109 		if (c == (struct cmd *)-1) {
110 			printf("?Ambiguous command\n");
111 			exit(1);
112 		}
113 		if (c == 0) {
114 			printf("?Invalid command\n");
115 			exit(1);
116 		}
117 		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
118 			printf("?Privileged command\n");
119 			exit(1);
120 		}
121 		if (c->c_generic != 0)
122 			generic(c->c_generic, argc, argv);
123 		else
124 			(*c->c_handler)(argc, argv);
125 		exit(0);
126 	}
127 	fromatty = isatty(fileno(stdin));
128 	top = setjmp(toplevel) == 0;
129 	if (top)
130 		signal(SIGINT, intr);
131 	for (;;) {
132 		cmdscanner(top);
133 		top = 1;
134 	}
135 }
136 
137 static void
138 intr(signo)
139 	int signo;
140 {
141 	if (!fromatty)
142 		exit(0);
143 	longjmp(toplevel, 1);
144 }
145 
146 /*
147  * Command parser.
148  */
149 static void
150 cmdscanner(top)
151 	int top;
152 {
153 	register struct cmd *c;
154 
155 	if (!top)
156 		putchar('\n');
157 	for (;;) {
158 		if (fromatty) {
159 			printf("lpc> ");
160 			fflush(stdout);
161 		}
162 		if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
163 			quit(0, NULL);
164 		if (cmdline[0] == 0 || cmdline[0] == '\n')
165 			break;
166 		makeargv();
167 		c = getcmd(margv[0]);
168 		if (c == (struct cmd *)-1) {
169 			printf("?Ambiguous command\n");
170 			continue;
171 		}
172 		if (c == 0) {
173 			printf("?Invalid command\n");
174 			continue;
175 		}
176 		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
177 			printf("?Privileged command\n");
178 			continue;
179 		}
180 		if (c->c_generic != 0)
181 			generic(c->c_generic, margc, margv);
182 		else
183 			(*c->c_handler)(margc, margv);
184 	}
185 	longjmp(toplevel, 0);
186 }
187 
188 static struct cmd *
189 getcmd(name)
190 	register char *name;
191 {
192 	register char *p, *q;
193 	register struct cmd *c, *found;
194 	register int nmatches, longest;
195 
196 	longest = 0;
197 	nmatches = 0;
198 	found = 0;
199 	for (c = cmdtab; (p = c->c_name); c++) {
200 		for (q = name; *q == *p++; q++)
201 			if (*q == 0)		/* exact match? */
202 				return(c);
203 		if (!*q) {			/* the name was a prefix */
204 			if (q - name > longest) {
205 				longest = q - name;
206 				nmatches = 1;
207 				found = c;
208 			} else if (q - name == longest)
209 				nmatches++;
210 		}
211 	}
212 	if (nmatches > 1)
213 		return((struct cmd *)-1);
214 	return(found);
215 }
216 
217 /*
218  * Slice a string up into argc/argv.
219  */
220 static void
221 makeargv()
222 {
223 	register char *cp;
224 	register char **argp = margv;
225 	register int n = 0;
226 
227 	margc = 0;
228 	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
229 	    n < MAX_MARGV; n++) {
230 		while (isspace(*cp))
231 			cp++;
232 		if (*cp == '\0')
233 			break;
234 		*argp++ = cp;
235 		margc += 1;
236 		while (*cp != '\0' && !isspace(*cp))
237 			cp++;
238 		if (*cp == '\0')
239 			break;
240 		*cp++ = '\0';
241 	}
242 	*argp++ = 0;
243 }
244 
245 #define HELPINDENT (sizeof ("directory"))
246 
247 /*
248  * Help command.
249  */
250 void
251 help(argc, argv)
252 	int argc;
253 	char *argv[];
254 {
255 	register struct cmd *c;
256 
257 	if (argc == 1) {
258 		register int i, j, w;
259 		int columns, width = 0, lines;
260 
261 		printf("Commands may be abbreviated.  Commands are:\n\n");
262 		for (c = cmdtab; c->c_name; c++) {
263 			int len = strlen(c->c_name);
264 
265 			if (len > width)
266 				width = len;
267 		}
268 		width = (width + 8) &~ 7;
269 		columns = 80 / width;
270 		if (columns == 0)
271 			columns = 1;
272 		lines = (NCMDS + columns - 1) / columns;
273 		for (i = 0; i < lines; i++) {
274 			for (j = 0; j < columns; j++) {
275 				c = cmdtab + j * lines + i;
276 				if (c->c_name)
277 					printf("%s", c->c_name);
278 				if (c + lines >= &cmdtab[NCMDS]) {
279 					printf("\n");
280 					break;
281 				}
282 				w = strlen(c->c_name);
283 				while (w < width) {
284 					w = (w + 8) &~ 7;
285 					putchar('\t');
286 				}
287 			}
288 		}
289 		return;
290 	}
291 	while (--argc > 0) {
292 		register char *arg;
293 		arg = *++argv;
294 		c = getcmd(arg);
295 		if (c == (struct cmd *)-1)
296 			printf("?Ambiguous help command %s\n", arg);
297 		else if (c == (struct cmd *)0)
298 			printf("?Invalid help command %s\n", arg);
299 		else
300 			printf("%-*s\t%s\n", (int) HELPINDENT,
301 				c->c_name, c->c_help);
302 	}
303 }
304 
305 /*
306  * return non-zero if the user is a member of the given group
307  */
308 static int
309 ingroup(grname)
310 	char *grname;
311 {
312 	static struct group *gptr=NULL;
313 	static gid_t groups[NGROUPS];
314 	register gid_t gid;
315 	register int i;
316 
317 	if (gptr == NULL) {
318 		if ((gptr = getgrnam(grname)) == NULL) {
319 			warnx("warning: unknown group '%s'", grname);
320 			return(0);
321 		}
322 		if (getgroups(NGROUPS, groups) < 0)
323 			err(1, "getgroups");
324 	}
325 	gid = gptr->gr_gid;
326 	for (i = 0; i < NGROUPS; i++)
327 		if (gid == groups[i])
328 			return(1);
329 	return(0);
330 }
331