xref: /freebsd/usr.sbin/pw/pw_group.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*-
2  * Copyright (C) 1996
3  *	David L. Nugent.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #ifndef lint
28 static const char rcsid[] =
29   "$FreeBSD$";
30 #endif /* not lint */
31 
32 #include <ctype.h>
33 #include <err.h>
34 #include <termios.h>
35 #include <stdbool.h>
36 #include <unistd.h>
37 #include <grp.h>
38 #include <libutil.h>
39 
40 #include "pw.h"
41 #include "bitmap.h"
42 
43 
44 static struct passwd *lookup_pwent(const char *user);
45 static void	delete_members(char ***members, int *grmembers, int *i,
46     struct carg *arg, struct group *grp);
47 static int      print_group(struct group * grp, int pretty);
48 static gid_t    gr_gidpolicy(struct userconf * cnf, struct cargs * args);
49 
50 int
51 pw_group(struct userconf * cnf, int mode, struct cargs * args)
52 {
53 	int		rc;
54 	struct carg    *a_name = getarg(args, 'n');
55 	struct carg    *a_gid = getarg(args, 'g');
56 	struct carg    *arg;
57 	struct group   *grp = NULL;
58 	int	        grmembers = 0;
59 	char           **members = NULL;
60 
61 	static struct group fakegroup =
62 	{
63 		"nogroup",
64 		"*",
65 		-1,
66 		NULL
67 	};
68 
69 	if (mode == M_LOCK || mode == M_UNLOCK)
70 		errx(EX_USAGE, "'lock' command is not available for groups");
71 
72 	/*
73 	 * With M_NEXT, we only need to return the
74 	 * next gid to stdout
75 	 */
76 	if (mode == M_NEXT) {
77 		gid_t next = gr_gidpolicy(cnf, args);
78 		if (getarg(args, 'q'))
79 			return next;
80 		printf("%ld\n", (long)next);
81 		return EXIT_SUCCESS;
82 	}
83 
84 	if (mode == M_PRINT && getarg(args, 'a')) {
85 		int             pretty = getarg(args, 'P') != NULL;
86 
87 		SETGRENT();
88 		while ((grp = GETGRENT()) != NULL)
89 			print_group(grp, pretty);
90 		ENDGRENT();
91 		return EXIT_SUCCESS;
92 	}
93 	if (a_gid == NULL) {
94 		if (a_name == NULL)
95 			errx(EX_DATAERR, "group name or id required");
96 
97 		if (mode != M_ADD && grp == NULL && isdigit((unsigned char)*a_name->val)) {
98 			(a_gid = a_name)->ch = 'g';
99 			a_name = NULL;
100 		}
101 	}
102 	grp = (a_name != NULL) ? GETGRNAM(a_name->val) : GETGRGID((gid_t) atoi(a_gid->val));
103 
104 	if (mode == M_UPDATE || mode == M_DELETE || mode == M_PRINT) {
105 		if (a_name == NULL && grp == NULL)	/* Try harder */
106 			grp = GETGRGID(atoi(a_gid->val));
107 
108 		if (grp == NULL) {
109 			if (mode == M_PRINT && getarg(args, 'F')) {
110 				char	*fmems[1];
111 				fmems[0] = NULL;
112 				fakegroup.gr_name = a_name ? a_name->val : "nogroup";
113 				fakegroup.gr_gid = a_gid ? (gid_t) atol(a_gid->val) : -1;
114 				fakegroup.gr_mem = fmems;
115 				return print_group(&fakegroup, getarg(args, 'P') != NULL);
116 			}
117 			errx(EX_DATAERR, "unknown group `%s'", a_name ? a_name->val : a_gid->val);
118 		}
119 		if (a_name == NULL)	/* Needed later */
120 			a_name = addarg(args, 'n', grp->gr_name);
121 
122 		/*
123 		 * Handle deletions now
124 		 */
125 		if (mode == M_DELETE) {
126 			gid_t           gid = grp->gr_gid;
127 
128 			rc = delgrent(grp);
129 			if (rc == -1)
130 				err(EX_IOERR, "group '%s' not available (NIS?)", grp->gr_name);
131 			else if (rc != 0) {
132 				warn("group update");
133 				return EX_IOERR;
134 			}
135 			pw_log(cnf, mode, W_GROUP, "%s(%ld) removed", a_name->val, (long) gid);
136 			return EXIT_SUCCESS;
137 		} else if (mode == M_PRINT)
138 			return print_group(grp, getarg(args, 'P') != NULL);
139 
140 		if (a_gid)
141 			grp->gr_gid = (gid_t) atoi(a_gid->val);
142 
143 		if ((arg = getarg(args, 'l')) != NULL)
144 			grp->gr_name = pw_checkname((u_char *)arg->val, 0);
145 	} else {
146 		if (a_name == NULL)	/* Required */
147 			errx(EX_DATAERR, "group name required");
148 		else if (grp != NULL)	/* Exists */
149 			errx(EX_DATAERR, "group name `%s' already exists", a_name->val);
150 
151 		extendarray(&members, &grmembers, 200);
152 		members[0] = NULL;
153 		grp = &fakegroup;
154 		grp->gr_name = pw_checkname((u_char *)a_name->val, 0);
155 		grp->gr_passwd = "*";
156 		grp->gr_gid = gr_gidpolicy(cnf, args);
157 		grp->gr_mem = members;
158 	}
159 
160 	/*
161 	 * This allows us to set a group password Group passwords is an
162 	 * antique idea, rarely used and insecure (no secure database) Should
163 	 * be discouraged, but it is apparently still supported by some
164 	 * software.
165 	 */
166 
167 	if ((arg = getarg(args, 'h')) != NULL ||
168 	    (arg = getarg(args, 'H')) != NULL) {
169 		if (strcmp(arg->val, "-") == 0)
170 			grp->gr_passwd = "*";	/* No access */
171 		else {
172 			int             fd = atoi(arg->val);
173 			int		precrypt = (arg->ch == 'H');
174 			int             b;
175 			int             istty = isatty(fd);
176 			struct termios  t;
177 			char           *p, line[256];
178 
179 			if (istty) {
180 				if (tcgetattr(fd, &t) == -1)
181 					istty = 0;
182 				else {
183 					struct termios  n = t;
184 
185 					/* Disable echo */
186 					n.c_lflag &= ~(ECHO);
187 					tcsetattr(fd, TCSANOW, &n);
188 					printf("%sassword for group %s:", (mode == M_UPDATE) ? "New p" : "P", grp->gr_name);
189 					fflush(stdout);
190 				}
191 			}
192 			b = read(fd, line, sizeof(line) - 1);
193 			if (istty) {	/* Restore state */
194 				tcsetattr(fd, TCSANOW, &t);
195 				fputc('\n', stdout);
196 				fflush(stdout);
197 			}
198 			if (b < 0) {
199 				warn("-h file descriptor");
200 				return EX_OSERR;
201 			}
202 			line[b] = '\0';
203 			if ((p = strpbrk(line, " \t\r\n")) != NULL)
204 				*p = '\0';
205 			if (!*line)
206 				errx(EX_DATAERR, "empty password read on file descriptor %d", fd);
207 			if (precrypt) {
208 				if (strchr(line, ':') != NULL)
209 					return EX_DATAERR;
210 				grp->gr_passwd = line;
211 			} else
212 				grp->gr_passwd = pw_pwcrypt(line);
213 		}
214 	}
215 
216 	if (((arg = getarg(args, 'M')) != NULL ||
217 	    (arg = getarg(args, 'd')) != NULL ||
218 	    (arg = getarg(args, 'm')) != NULL) && arg->val) {
219 		int	i = 0;
220 		char   *p;
221 		struct passwd	*pwd;
222 
223 		/* Make sure this is not stay NULL with -M "" */
224 		extendarray(&members, &grmembers, 200);
225 		if (arg->ch == 'd')
226 			delete_members(&members, &grmembers, &i, arg, grp);
227 		else if (arg->ch == 'm') {
228 			int	k = 0;
229 
230 			if (grp->gr_mem != NULL) {
231 				while (grp->gr_mem[k] != NULL) {
232 					if (extendarray(&members, &grmembers, i + 2) != -1)
233 						members[i++] = grp->gr_mem[k];
234 					k++;
235 				}
236 			}
237 		}
238 
239 		if (arg->ch != 'd')
240 			for (p = strtok(arg->val, ", \t"); p != NULL; p = strtok(NULL, ", \t")) {
241 				int	j;
242 
243 				/*
244 				 * Check for duplicates
245 				 */
246 				pwd = lookup_pwent(p);
247 				for (j = 0; j < i && strcmp(members[j], pwd->pw_name) != 0; j++)
248 					;
249 				if (j == i && extendarray(&members, &grmembers, i + 2) != -1)
250 					members[i++] = newstr(pwd->pw_name);
251 			}
252 		while (i < grmembers)
253 			members[i++] = NULL;
254 		grp->gr_mem = members;
255 	}
256 
257 	if (getarg(args, 'N') != NULL)
258 		return print_group(grp, getarg(args, 'P') != NULL);
259 
260 	if (mode == M_ADD && (rc = addgrent(grp)) != 0) {
261 		if (rc == -1)
262 			warnx("group '%s' already exists", grp->gr_name);
263 		else
264 			warn("group update");
265 		return EX_IOERR;
266 	} else if (mode == M_UPDATE && (rc = chggrent(a_name->val, grp)) != 0) {
267 		if (rc == -1)
268 			warnx("group '%s' not available (NIS?)", grp->gr_name);
269 		else
270 			warn("group update");
271 		return EX_IOERR;
272 	}
273 	/* grp may have been invalidated */
274 	if ((grp = GETGRNAM(a_name->val)) == NULL)
275 		errx(EX_SOFTWARE, "group disappeared during update");
276 
277 	pw_log(cnf, mode, W_GROUP, "%s(%ld)", grp->gr_name, (long) grp->gr_gid);
278 
279 	free(members);
280 
281 	return EXIT_SUCCESS;
282 }
283 
284 
285 /*
286  * Lookup a passwd entry using a name or UID.
287  */
288 static struct passwd *
289 lookup_pwent(const char *user)
290 {
291 	struct passwd *pwd;
292 
293 	if ((pwd = GETPWNAM(user)) == NULL &&
294 	    (!isdigit((unsigned char)*user) ||
295 	    (pwd = getpwuid((uid_t) atoi(user))) == NULL))
296 		errx(EX_NOUSER, "user `%s' does not exist", user);
297 
298 	return (pwd);
299 }
300 
301 
302 /*
303  * Delete requested members from a group.
304  */
305 static void
306 delete_members(char ***members, int *grmembers, int *i, struct carg *arg,
307     struct group *grp)
308 {
309 	bool matchFound;
310 	char *user;
311 	char *valueCopy;
312 	char *valuePtr;
313 	int k;
314 	struct passwd *pwd;
315 
316 	if (grp->gr_mem == NULL)
317 		return;
318 
319 	k = 0;
320 	while (grp->gr_mem[k] != NULL) {
321 		matchFound = false;
322 		if ((valueCopy = strdup(arg->val)) == NULL)
323 			errx(EX_UNAVAILABLE, "out of memory");
324 		valuePtr = valueCopy;
325 		while ((user = strsep(&valuePtr, ", \t")) != NULL) {
326 			pwd = lookup_pwent(user);
327 			if (strcmp(grp->gr_mem[k], pwd->pw_name) == 0) {
328 				matchFound = true;
329 				break;
330 			}
331 		}
332 		free(valueCopy);
333 
334 		if (!matchFound &&
335 		    extendarray(members, grmembers, *i + 2) != -1)
336 			(*members)[(*i)++] = grp->gr_mem[k];
337 
338 		k++;
339 	}
340 
341 	return;
342 }
343 
344 
345 static          gid_t
346 gr_gidpolicy(struct userconf * cnf, struct cargs * args)
347 {
348 	struct group   *grp;
349 	gid_t           gid = (gid_t) - 1;
350 	struct carg    *a_gid = getarg(args, 'g');
351 
352 	/*
353 	 * Check the given gid, if any
354 	 */
355 	if (a_gid != NULL) {
356 		gid = (gid_t) atol(a_gid->val);
357 
358 		if ((grp = GETGRGID(gid)) != NULL && getarg(args, 'o') == NULL)
359 			errx(EX_DATAERR, "gid `%ld' has already been allocated", (long) grp->gr_gid);
360 	} else {
361 		struct bitmap   bm;
362 
363 		/*
364 		 * We need to allocate the next available gid under one of
365 		 * two policies a) Grab the first unused gid b) Grab the
366 		 * highest possible unused gid
367 		 */
368 		if (cnf->min_gid >= cnf->max_gid) {	/* Sanity claus^H^H^H^Hheck */
369 			cnf->min_gid = 1000;
370 			cnf->max_gid = 32000;
371 		}
372 		bm = bm_alloc(cnf->max_gid - cnf->min_gid + 1);
373 
374 		/*
375 		 * Now, let's fill the bitmap from the password file
376 		 */
377 		SETGRENT();
378 		while ((grp = GETGRENT()) != NULL)
379 			if ((gid_t)grp->gr_gid >= (gid_t)cnf->min_gid &&
380                             (gid_t)grp->gr_gid <= (gid_t)cnf->max_gid)
381 				bm_setbit(&bm, grp->gr_gid - cnf->min_gid);
382 		ENDGRENT();
383 
384 		/*
385 		 * Then apply the policy, with fallback to reuse if necessary
386 		 */
387 		if (cnf->reuse_gids)
388 			gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
389 		else {
390 			gid = (gid_t) (bm_lastset(&bm) + 1);
391 			if (!bm_isset(&bm, gid))
392 				gid += cnf->min_gid;
393 			else
394 				gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
395 		}
396 
397 		/*
398 		 * Another sanity check
399 		 */
400 		if (gid < cnf->min_gid || gid > cnf->max_gid)
401 			errx(EX_SOFTWARE, "unable to allocate a new gid - range fully used");
402 		bm_dealloc(&bm);
403 	}
404 	return gid;
405 }
406 
407 
408 static int
409 print_group(struct group * grp, int pretty)
410 {
411 	if (!pretty) {
412 		char           *buf = NULL;
413 
414 		buf = gr_make(grp);
415 		printf("%s\n", buf);
416 		free(buf);
417 	} else {
418 		int             i;
419 
420 		printf("Group Name: %-15s   #%lu\n"
421 		       "   Members: ",
422 		       grp->gr_name, (long) grp->gr_gid);
423 		if (grp->gr_mem != NULL) {
424 			for (i = 0; grp->gr_mem[i]; i++)
425 				printf("%s%s", i ? "," : "", grp->gr_mem[i]);
426 		}
427 		fputs("\n\n", stdout);
428 	}
429 	return EXIT_SUCCESS;
430 }
431