xref: /freebsd/usr.sbin/pw/pw_group.c (revision 9268022b74279434ed6300244e3f977e56a8ceb5)
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_newname = getarg(args, 'l');
55 	struct carg    *a_name = getarg(args, 'n');
56 	struct carg    *a_gid = getarg(args, 'g');
57 	struct carg    *arg;
58 	struct group   *grp = NULL;
59 	int	        grmembers = 0;
60 	char           **members = NULL;
61 
62 	static struct group fakegroup =
63 	{
64 		"nogroup",
65 		"*",
66 		-1,
67 		NULL
68 	};
69 
70 	if (a_gid != NULL) {
71 		if (strspn(a_gid->val, "0123456789") != strlen(a_gid->val))
72 			errx(EX_USAGE, "-g expects a number");
73 	}
74 
75 	if (mode == M_LOCK || mode == M_UNLOCK)
76 		errx(EX_USAGE, "'lock' command is not available for groups");
77 
78 	/*
79 	 * With M_NEXT, we only need to return the
80 	 * next gid to stdout
81 	 */
82 	if (mode == M_NEXT) {
83 		gid_t next = gr_gidpolicy(cnf, args);
84 		if (getarg(args, 'q'))
85 			return next;
86 		printf("%ld\n", (long)next);
87 		return EXIT_SUCCESS;
88 	}
89 
90 	if (mode == M_PRINT && getarg(args, 'a')) {
91 		int             pretty = getarg(args, 'P') != NULL;
92 
93 		SETGRENT();
94 		while ((grp = GETGRENT()) != NULL)
95 			print_group(grp, pretty);
96 		ENDGRENT();
97 		return EXIT_SUCCESS;
98 	}
99 	if (a_gid == NULL) {
100 		if (a_name == NULL)
101 			errx(EX_DATAERR, "group name or id required");
102 
103 		if (mode != M_ADD && grp == NULL && isdigit((unsigned char)*a_name->val)) {
104 			(a_gid = a_name)->ch = 'g';
105 			a_name = NULL;
106 		}
107 	}
108 	grp = (a_name != NULL) ? GETGRNAM(a_name->val) : GETGRGID((gid_t) atoi(a_gid->val));
109 
110 	if (mode == M_UPDATE || mode == M_DELETE || mode == M_PRINT) {
111 		if (a_name == NULL && grp == NULL)	/* Try harder */
112 			grp = GETGRGID(atoi(a_gid->val));
113 
114 		if (grp == NULL) {
115 			if (mode == M_PRINT && getarg(args, 'F')) {
116 				char	*fmems[1];
117 				fmems[0] = NULL;
118 				fakegroup.gr_name = a_name ? a_name->val : "nogroup";
119 				fakegroup.gr_gid = a_gid ? (gid_t) atol(a_gid->val) : -1;
120 				fakegroup.gr_mem = fmems;
121 				return print_group(&fakegroup, getarg(args, 'P') != NULL);
122 			}
123 			errx(EX_DATAERR, "unknown group `%s'", a_name ? a_name->val : a_gid->val);
124 		}
125 		if (a_name == NULL)	/* Needed later */
126 			a_name = addarg(args, 'n', grp->gr_name);
127 
128 		/*
129 		 * Handle deletions now
130 		 */
131 		if (mode == M_DELETE) {
132 			gid_t           gid = grp->gr_gid;
133 
134 			rc = delgrent(grp);
135 			if (rc == -1)
136 				err(EX_IOERR, "group '%s' not available (NIS?)", grp->gr_name);
137 			else if (rc != 0) {
138 				warn("group update");
139 				return EX_IOERR;
140 			}
141 			pw_log(cnf, mode, W_GROUP, "%s(%ld) removed", a_name->val, (long) gid);
142 			return EXIT_SUCCESS;
143 		} else if (mode == M_PRINT)
144 			return print_group(grp, getarg(args, 'P') != NULL);
145 
146 		if (a_gid)
147 			grp->gr_gid = (gid_t) atoi(a_gid->val);
148 
149 		if (a_newname != NULL)
150 			grp->gr_name = pw_checkname((u_char *)a_newname->val, 0);
151 	} else {
152 		if (a_name == NULL)	/* Required */
153 			errx(EX_DATAERR, "group name required");
154 		else if (grp != NULL)	/* Exists */
155 			errx(EX_DATAERR, "group name `%s' already exists", a_name->val);
156 
157 		extendarray(&members, &grmembers, 200);
158 		members[0] = NULL;
159 		grp = &fakegroup;
160 		grp->gr_name = pw_checkname((u_char *)a_name->val, 0);
161 		grp->gr_passwd = "*";
162 		grp->gr_gid = gr_gidpolicy(cnf, args);
163 		grp->gr_mem = members;
164 	}
165 
166 	/*
167 	 * This allows us to set a group password Group passwords is an
168 	 * antique idea, rarely used and insecure (no secure database) Should
169 	 * be discouraged, but it is apparently still supported by some
170 	 * software.
171 	 */
172 
173 	if ((arg = getarg(args, 'h')) != NULL ||
174 	    (arg = getarg(args, 'H')) != NULL) {
175 		if (strcmp(arg->val, "-") == 0)
176 			grp->gr_passwd = "*";	/* No access */
177 		else {
178 			int             fd = atoi(arg->val);
179 			int		precrypt = (arg->ch == 'H');
180 			int             b;
181 			int             istty = isatty(fd);
182 			struct termios  t;
183 			char           *p, line[256];
184 
185 			if (istty) {
186 				if (tcgetattr(fd, &t) == -1)
187 					istty = 0;
188 				else {
189 					struct termios  n = t;
190 
191 					/* Disable echo */
192 					n.c_lflag &= ~(ECHO);
193 					tcsetattr(fd, TCSANOW, &n);
194 					printf("%sassword for group %s:", (mode == M_UPDATE) ? "New p" : "P", grp->gr_name);
195 					fflush(stdout);
196 				}
197 			}
198 			b = read(fd, line, sizeof(line) - 1);
199 			if (istty) {	/* Restore state */
200 				tcsetattr(fd, TCSANOW, &t);
201 				fputc('\n', stdout);
202 				fflush(stdout);
203 			}
204 			if (b < 0) {
205 				warn("-h file descriptor");
206 				return EX_OSERR;
207 			}
208 			line[b] = '\0';
209 			if ((p = strpbrk(line, " \t\r\n")) != NULL)
210 				*p = '\0';
211 			if (!*line)
212 				errx(EX_DATAERR, "empty password read on file descriptor %d", fd);
213 			if (precrypt) {
214 				if (strchr(line, ':') != NULL)
215 					return EX_DATAERR;
216 				grp->gr_passwd = line;
217 			} else
218 				grp->gr_passwd = pw_pwcrypt(line);
219 		}
220 	}
221 
222 	if (((arg = getarg(args, 'M')) != NULL ||
223 	    (arg = getarg(args, 'd')) != NULL ||
224 	    (arg = getarg(args, 'm')) != NULL) && arg->val) {
225 		int	i = 0;
226 		char   *p;
227 		struct passwd	*pwd;
228 
229 		/* Make sure this is not stay NULL with -M "" */
230 		extendarray(&members, &grmembers, 200);
231 		if (arg->ch == 'd')
232 			delete_members(&members, &grmembers, &i, arg, grp);
233 		else if (arg->ch == 'm') {
234 			int	k = 0;
235 
236 			if (grp->gr_mem != NULL) {
237 				while (grp->gr_mem[k] != NULL) {
238 					if (extendarray(&members, &grmembers, i + 2) != -1)
239 						members[i++] = grp->gr_mem[k];
240 					k++;
241 				}
242 			}
243 		}
244 
245 		if (arg->ch != 'd')
246 			for (p = strtok(arg->val, ", \t"); p != NULL; p = strtok(NULL, ", \t")) {
247 				int	j;
248 
249 				/*
250 				 * Check for duplicates
251 				 */
252 				pwd = lookup_pwent(p);
253 				for (j = 0; j < i && strcmp(members[j], pwd->pw_name) != 0; j++)
254 					;
255 				if (j == i && extendarray(&members, &grmembers, i + 2) != -1)
256 					members[i++] = newstr(pwd->pw_name);
257 			}
258 		while (i < grmembers)
259 			members[i++] = NULL;
260 		grp->gr_mem = members;
261 	}
262 
263 	if (getarg(args, 'N') != NULL)
264 		return print_group(grp, getarg(args, 'P') != NULL);
265 
266 	if (mode == M_ADD && (rc = addgrent(grp)) != 0) {
267 		if (rc == -1)
268 			warnx("group '%s' already exists", grp->gr_name);
269 		else
270 			warn("group update");
271 		return EX_IOERR;
272 	} else if (mode == M_UPDATE && (rc = chggrent(a_name->val, grp)) != 0) {
273 		if (rc == -1)
274 			warnx("group '%s' not available (NIS?)", grp->gr_name);
275 		else
276 			warn("group update");
277 		return EX_IOERR;
278 	}
279 
280 	arg = a_newname != NULL ? a_newname : a_name;
281 	/* grp may have been invalidated */
282 	if ((grp = GETGRNAM(arg->val)) == NULL)
283 		errx(EX_SOFTWARE, "group disappeared during update");
284 
285 	pw_log(cnf, mode, W_GROUP, "%s(%ld)", grp->gr_name, (long) grp->gr_gid);
286 
287 	free(members);
288 
289 	return EXIT_SUCCESS;
290 }
291 
292 
293 /*
294  * Lookup a passwd entry using a name or UID.
295  */
296 static struct passwd *
297 lookup_pwent(const char *user)
298 {
299 	struct passwd *pwd;
300 
301 	if ((pwd = GETPWNAM(user)) == NULL &&
302 	    (!isdigit((unsigned char)*user) ||
303 	    (pwd = getpwuid((uid_t) atoi(user))) == NULL))
304 		errx(EX_NOUSER, "user `%s' does not exist", user);
305 
306 	return (pwd);
307 }
308 
309 
310 /*
311  * Delete requested members from a group.
312  */
313 static void
314 delete_members(char ***members, int *grmembers, int *i, struct carg *arg,
315     struct group *grp)
316 {
317 	bool matchFound;
318 	char *user;
319 	char *valueCopy;
320 	char *valuePtr;
321 	int k;
322 	struct passwd *pwd;
323 
324 	if (grp->gr_mem == NULL)
325 		return;
326 
327 	k = 0;
328 	while (grp->gr_mem[k] != NULL) {
329 		matchFound = false;
330 		if ((valueCopy = strdup(arg->val)) == NULL)
331 			errx(EX_UNAVAILABLE, "out of memory");
332 		valuePtr = valueCopy;
333 		while ((user = strsep(&valuePtr, ", \t")) != NULL) {
334 			pwd = lookup_pwent(user);
335 			if (strcmp(grp->gr_mem[k], pwd->pw_name) == 0) {
336 				matchFound = true;
337 				break;
338 			}
339 		}
340 		free(valueCopy);
341 
342 		if (!matchFound &&
343 		    extendarray(members, grmembers, *i + 2) != -1)
344 			(*members)[(*i)++] = grp->gr_mem[k];
345 
346 		k++;
347 	}
348 
349 	return;
350 }
351 
352 
353 static          gid_t
354 gr_gidpolicy(struct userconf * cnf, struct cargs * args)
355 {
356 	struct group   *grp;
357 	gid_t           gid = (gid_t) - 1;
358 	struct carg    *a_gid = getarg(args, 'g');
359 
360 	/*
361 	 * Check the given gid, if any
362 	 */
363 	if (a_gid != NULL) {
364 		gid = (gid_t) atol(a_gid->val);
365 
366 		if ((grp = GETGRGID(gid)) != NULL && getarg(args, 'o') == NULL)
367 			errx(EX_DATAERR, "gid `%ld' has already been allocated", (long) grp->gr_gid);
368 	} else {
369 		struct bitmap   bm;
370 
371 		/*
372 		 * We need to allocate the next available gid under one of
373 		 * two policies a) Grab the first unused gid b) Grab the
374 		 * highest possible unused gid
375 		 */
376 		if (cnf->min_gid >= cnf->max_gid) {	/* Sanity claus^H^H^H^Hheck */
377 			cnf->min_gid = 1000;
378 			cnf->max_gid = 32000;
379 		}
380 		bm = bm_alloc(cnf->max_gid - cnf->min_gid + 1);
381 
382 		/*
383 		 * Now, let's fill the bitmap from the password file
384 		 */
385 		SETGRENT();
386 		while ((grp = GETGRENT()) != NULL)
387 			if ((gid_t)grp->gr_gid >= (gid_t)cnf->min_gid &&
388                             (gid_t)grp->gr_gid <= (gid_t)cnf->max_gid)
389 				bm_setbit(&bm, grp->gr_gid - cnf->min_gid);
390 		ENDGRENT();
391 
392 		/*
393 		 * Then apply the policy, with fallback to reuse if necessary
394 		 */
395 		if (cnf->reuse_gids)
396 			gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
397 		else {
398 			gid = (gid_t) (bm_lastset(&bm) + 1);
399 			if (!bm_isset(&bm, gid))
400 				gid += cnf->min_gid;
401 			else
402 				gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
403 		}
404 
405 		/*
406 		 * Another sanity check
407 		 */
408 		if (gid < cnf->min_gid || gid > cnf->max_gid)
409 			errx(EX_SOFTWARE, "unable to allocate a new gid - range fully used");
410 		bm_dealloc(&bm);
411 	}
412 	return gid;
413 }
414 
415 
416 static int
417 print_group(struct group * grp, int pretty)
418 {
419 	if (!pretty) {
420 		char           *buf = NULL;
421 
422 		buf = gr_make(grp);
423 		printf("%s\n", buf);
424 		free(buf);
425 	} else {
426 		int             i;
427 
428 		printf("Group Name: %-15s   #%lu\n"
429 		       "   Members: ",
430 		       grp->gr_name, (long) grp->gr_gid);
431 		if (grp->gr_mem != NULL) {
432 			for (i = 0; grp->gr_mem[i]; i++)
433 				printf("%s%s", i ? "," : "", grp->gr_mem[i]);
434 		}
435 		fputs("\n\n", stdout);
436 	}
437 	return EXIT_SUCCESS;
438 }
439