xref: /freebsd/usr.sbin/lpr/lpc/lpc.c (revision 0de89efe5c443f213c7ea28773ef2dc6cf3af2ed)
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 	"$Id$";
47 #endif /* not lint */
48 
49 #include <sys/param.h>
50 
51 #include <ctype.h>
52 #include <dirent.h>
53 #include <grp.h>
54 #include <setjmp.h>
55 #include <signal.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <syslog.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <sys/param.h>
62 #include "lp.h"
63 #include "lpc.h"
64 #include "extern.h"
65 
66 #ifndef LPR_OPER
67 #define LPR_OPER	"operator"	/* group name of lpr operators */
68 #endif
69 
70 /*
71  * lpc -- line printer control program
72  */
73 
74 #define MAX_CMDLINE	200
75 #define MAX_MARGV	20
76 int	fromatty;
77 
78 char	cmdline[MAX_CMDLINE];
79 int	margc;
80 char	*margv[MAX_MARGV];
81 int	top;
82 uid_t	uid, euid;
83 
84 jmp_buf	toplevel;
85 
86 static void		 cmdscanner __P((int));
87 static struct cmd	*getcmd __P((char *));
88 static void		 intr __P((int));
89 static void		 makeargv __P((void));
90 static int		 ingroup __P((char *));
91 
92 int
93 main(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 		(*c->c_handler)(argc, argv);
120 		exit(0);
121 	}
122 	fromatty = isatty(fileno(stdin));
123 	top = setjmp(toplevel) == 0;
124 	if (top)
125 		signal(SIGINT, intr);
126 	for (;;) {
127 		cmdscanner(top);
128 		top = 1;
129 	}
130 }
131 
132 static void
133 intr(signo)
134 	int signo;
135 {
136 	if (!fromatty)
137 		exit(0);
138 	longjmp(toplevel, 1);
139 }
140 
141 /*
142  * Command parser.
143  */
144 static void
145 cmdscanner(top)
146 	int top;
147 {
148 	register struct cmd *c;
149 
150 	if (!top)
151 		putchar('\n');
152 	for (;;) {
153 		if (fromatty) {
154 			printf("lpc> ");
155 			fflush(stdout);
156 		}
157 		if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
158 			quit(0, NULL);
159 		if (cmdline[0] == 0 || cmdline[0] == '\n')
160 			break;
161 		makeargv();
162 		c = getcmd(margv[0]);
163 		if (c == (struct cmd *)-1) {
164 			printf("?Ambiguous command\n");
165 			continue;
166 		}
167 		if (c == 0) {
168 			printf("?Invalid command\n");
169 			continue;
170 		}
171 		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
172 			printf("?Privileged command\n");
173 			continue;
174 		}
175 		(*c->c_handler)(margc, margv);
176 	}
177 	longjmp(toplevel, 0);
178 }
179 
180 static struct cmd *
181 getcmd(name)
182 	register char *name;
183 {
184 	register char *p, *q;
185 	register struct cmd *c, *found;
186 	register int nmatches, longest;
187 
188 	longest = 0;
189 	nmatches = 0;
190 	found = 0;
191 	for (c = cmdtab; (p = c->c_name); c++) {
192 		for (q = name; *q == *p++; q++)
193 			if (*q == 0)		/* exact match? */
194 				return(c);
195 		if (!*q) {			/* the name was a prefix */
196 			if (q - name > longest) {
197 				longest = q - name;
198 				nmatches = 1;
199 				found = c;
200 			} else if (q - name == longest)
201 				nmatches++;
202 		}
203 	}
204 	if (nmatches > 1)
205 		return((struct cmd *)-1);
206 	return(found);
207 }
208 
209 /*
210  * Slice a string up into argc/argv.
211  */
212 static void
213 makeargv()
214 {
215 	register char *cp;
216 	register char **argp = margv;
217 	register int n = 0;
218 
219 	margc = 0;
220 	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
221 	    n < MAX_MARGV; n++) {
222 		while (isspace(*cp))
223 			cp++;
224 		if (*cp == '\0')
225 			break;
226 		*argp++ = cp;
227 		margc += 1;
228 		while (*cp != '\0' && !isspace(*cp))
229 			cp++;
230 		if (*cp == '\0')
231 			break;
232 		*cp++ = '\0';
233 	}
234 	*argp++ = 0;
235 }
236 
237 #define HELPINDENT (sizeof ("directory"))
238 
239 /*
240  * Help command.
241  */
242 void
243 help(argc, argv)
244 	int argc;
245 	char *argv[];
246 {
247 	register struct cmd *c;
248 
249 	if (argc == 1) {
250 		register int i, j, w;
251 		int columns, width = 0, lines;
252 
253 		printf("Commands may be abbreviated.  Commands are:\n\n");
254 		for (c = cmdtab; c->c_name; c++) {
255 			int len = strlen(c->c_name);
256 
257 			if (len > width)
258 				width = len;
259 		}
260 		width = (width + 8) &~ 7;
261 		columns = 80 / width;
262 		if (columns == 0)
263 			columns = 1;
264 		lines = (NCMDS + columns - 1) / columns;
265 		for (i = 0; i < lines; i++) {
266 			for (j = 0; j < columns; j++) {
267 				c = cmdtab + j * lines + i;
268 				if (c->c_name)
269 					printf("%s", c->c_name);
270 				if (c + lines >= &cmdtab[NCMDS]) {
271 					printf("\n");
272 					break;
273 				}
274 				w = strlen(c->c_name);
275 				while (w < width) {
276 					w = (w + 8) &~ 7;
277 					putchar('\t');
278 				}
279 			}
280 		}
281 		return;
282 	}
283 	while (--argc > 0) {
284 		register char *arg;
285 		arg = *++argv;
286 		c = getcmd(arg);
287 		if (c == (struct cmd *)-1)
288 			printf("?Ambiguous help command %s\n", arg);
289 		else if (c == (struct cmd *)0)
290 			printf("?Invalid help command %s\n", arg);
291 		else
292 			printf("%-*s\t%s\n", HELPINDENT,
293 				c->c_name, c->c_help);
294 	}
295 }
296 
297 /*
298  * return non-zero if the user is a member of the given group
299  */
300 static int
301 ingroup(grname)
302 	char *grname;
303 {
304 	static struct group *gptr=NULL;
305 	static gid_t groups[NGROUPS];
306 	register gid_t gid;
307 	register int i;
308 
309 	if (gptr == NULL) {
310 		if ((gptr = getgrnam(grname)) == NULL) {
311 			warnx("warning: unknown group '%s'", grname);
312 			return(0);
313 		}
314 		if (getgroups(NGROUPS, groups) < 0)
315 			err(1, "getgroups");
316 	}
317 	gid = gptr->gr_gid;
318 	for (i = 0; i < NGROUPS; i++)
319 		if (gid == groups[i])
320 			return(1);
321 	return(0);
322 }
323