xref: /freebsd/usr.sbin/pw/pw_group.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
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 
38 #include "pw.h"
39 #include "bitmap.h"
40 
41 
42 static struct passwd *lookup_pwent(const char *user);
43 static void	delete_members(char ***members, int *grmembers, int *i,
44     struct carg *arg, struct group *grp);
45 static int      print_group(struct group * grp, int pretty);
46 static gid_t    gr_gidpolicy(struct userconf * cnf, struct cargs * args);
47 
48 int
49 pw_group(struct userconf * cnf, int mode, struct cargs * args)
50 {
51 	int		rc;
52 	struct carg    *a_name = getarg(args, 'n');
53 	struct carg    *a_gid = getarg(args, 'g');
54 	struct carg    *arg;
55 	struct group   *grp = NULL;
56 	int	        grmembers = 0;
57 	char           **members = NULL;
58 
59 	static struct group fakegroup =
60 	{
61 		"nogroup",
62 		"*",
63 		-1,
64 		NULL
65 	};
66 
67 	if (mode == M_LOCK || mode == M_UNLOCK)
68 		errx(EX_USAGE, "'lock' command is not available for groups");
69 
70 	/*
71 	 * With M_NEXT, we only need to return the
72 	 * next gid to stdout
73 	 */
74 	if (mode == M_NEXT) {
75 		gid_t next = gr_gidpolicy(cnf, args);
76 		if (getarg(args, 'q'))
77 			return next;
78 		printf("%ld\n", (long)next);
79 		return EXIT_SUCCESS;
80 	}
81 
82 	if (mode == M_PRINT && getarg(args, 'a')) {
83 		int             pretty = getarg(args, 'P') != NULL;
84 
85 		SETGRENT();
86 		while ((grp = GETGRENT()) != NULL)
87 			print_group(grp, pretty);
88 		ENDGRENT();
89 		return EXIT_SUCCESS;
90 	}
91 	if (a_gid == NULL) {
92 		if (a_name == NULL)
93 			errx(EX_DATAERR, "group name or id required");
94 
95 		if (mode != M_ADD && grp == NULL && isdigit((unsigned char)*a_name->val)) {
96 			(a_gid = a_name)->ch = 'g';
97 			a_name = NULL;
98 		}
99 	}
100 	grp = (a_name != NULL) ? GETGRNAM(a_name->val) : GETGRGID((gid_t) atoi(a_gid->val));
101 
102 	if (mode == M_UPDATE || mode == M_DELETE || mode == M_PRINT) {
103 		if (a_name == NULL && grp == NULL)	/* Try harder */
104 			grp = GETGRGID(atoi(a_gid->val));
105 
106 		if (grp == NULL) {
107 			if (mode == M_PRINT && getarg(args, 'F')) {
108 				char	*fmems[1];
109 				fmems[0] = NULL;
110 				fakegroup.gr_name = a_name ? a_name->val : "nogroup";
111 				fakegroup.gr_gid = a_gid ? (gid_t) atol(a_gid->val) : -1;
112 				fakegroup.gr_mem = fmems;
113 				return print_group(&fakegroup, getarg(args, 'P') != NULL);
114 			}
115 			errx(EX_DATAERR, "unknown group `%s'", a_name ? a_name->val : a_gid->val);
116 		}
117 		if (a_name == NULL)	/* Needed later */
118 			a_name = addarg(args, 'n', grp->gr_name);
119 
120 		/*
121 		 * Handle deletions now
122 		 */
123 		if (mode == M_DELETE) {
124 			gid_t           gid = grp->gr_gid;
125 
126 			rc = delgrent(grp);
127 			if (rc == -1)
128 				err(EX_IOERR, "group '%s' not available (NIS?)", grp->gr_name);
129 			else if (rc != 0) {
130 				warn("group update");
131 				return EX_IOERR;
132 			}
133 			pw_log(cnf, mode, W_GROUP, "%s(%ld) removed", a_name->val, (long) gid);
134 			return EXIT_SUCCESS;
135 		} else if (mode == M_PRINT)
136 			return print_group(grp, getarg(args, 'P') != NULL);
137 
138 		if (a_gid)
139 			grp->gr_gid = (gid_t) atoi(a_gid->val);
140 
141 		if ((arg = getarg(args, 'l')) != NULL)
142 			grp->gr_name = pw_checkname((u_char *)arg->val, 0);
143 	} else {
144 		if (a_name == NULL)	/* Required */
145 			errx(EX_DATAERR, "group name required");
146 		else if (grp != NULL)	/* Exists */
147 			errx(EX_DATAERR, "group name `%s' already exists", a_name->val);
148 
149 		extendarray(&members, &grmembers, 200);
150 		members[0] = NULL;
151 		grp = &fakegroup;
152 		grp->gr_name = pw_checkname((u_char *)a_name->val, 0);
153 		grp->gr_passwd = "*";
154 		grp->gr_gid = gr_gidpolicy(cnf, args);
155 		grp->gr_mem = members;
156 	}
157 
158 	/*
159 	 * This allows us to set a group password Group passwords is an
160 	 * antique idea, rarely used and insecure (no secure database) Should
161 	 * be discouraged, but it is apparently still supported by some
162 	 * software.
163 	 */
164 
165 	if ((arg = getarg(args, 'h')) != NULL ||
166 	    (arg = getarg(args, 'H')) != NULL) {
167 		if (strcmp(arg->val, "-") == 0)
168 			grp->gr_passwd = "*";	/* No access */
169 		else {
170 			int             fd = atoi(arg->val);
171 			int		precrypt = (arg->ch == 'H');
172 			int             b;
173 			int             istty = isatty(fd);
174 			struct termios  t;
175 			char           *p, line[256];
176 
177 			if (istty) {
178 				if (tcgetattr(fd, &t) == -1)
179 					istty = 0;
180 				else {
181 					struct termios  n = t;
182 
183 					/* Disable echo */
184 					n.c_lflag &= ~(ECHO);
185 					tcsetattr(fd, TCSANOW, &n);
186 					printf("%sassword for group %s:", (mode == M_UPDATE) ? "New p" : "P", grp->gr_name);
187 					fflush(stdout);
188 				}
189 			}
190 			b = read(fd, line, sizeof(line) - 1);
191 			if (istty) {	/* Restore state */
192 				tcsetattr(fd, TCSANOW, &t);
193 				fputc('\n', stdout);
194 				fflush(stdout);
195 			}
196 			if (b < 0) {
197 				warn("-h file descriptor");
198 				return EX_OSERR;
199 			}
200 			line[b] = '\0';
201 			if ((p = strpbrk(line, " \t\r\n")) != NULL)
202 				*p = '\0';
203 			if (!*line)
204 				errx(EX_DATAERR, "empty password read on file descriptor %d", fd);
205 			if (precrypt) {
206 				if (strchr(line, ':') != NULL)
207 					return EX_DATAERR;
208 				grp->gr_passwd = line;
209 			} else
210 				grp->gr_passwd = pw_pwcrypt(line);
211 		}
212 	}
213 
214 	if (((arg = getarg(args, 'M')) != NULL ||
215 	    (arg = getarg(args, 'd')) != NULL ||
216 	    (arg = getarg(args, 'm')) != NULL) && arg->val) {
217 		int	i = 0;
218 		char   *p;
219 		struct passwd	*pwd;
220 
221 		/* Make sure this is not stay NULL with -M "" */
222 		extendarray(&members, &grmembers, 200);
223 		if (arg->ch == 'd')
224 			delete_members(&members, &grmembers, &i, arg, grp);
225 		else if (arg->ch == 'm') {
226 			int	k = 0;
227 
228 			while (grp->gr_mem[k] != NULL) {
229 				if (extendarray(&members, &grmembers, i + 2) != -1)
230 					members[i++] = grp->gr_mem[k];
231 				k++;
232 			}
233 		}
234 
235 		if (arg->ch != 'd')
236 			for (p = strtok(arg->val, ", \t"); p != NULL; p = strtok(NULL, ", \t")) {
237 				int	j;
238 
239 				/*
240 				 * Check for duplicates
241 				 */
242 				pwd = lookup_pwent(p);
243 				for (j = 0; j < i && strcmp(members[j], pwd->pw_name) != 0; j++)
244 					;
245 				if (j == i && extendarray(&members, &grmembers, i + 2) != -1)
246 					members[i++] = newstr(pwd->pw_name);
247 			}
248 		while (i < grmembers)
249 			members[i++] = NULL;
250 		grp->gr_mem = members;
251 	}
252 
253 	if (getarg(args, 'N') != NULL)
254 		return print_group(grp, getarg(args, 'P') != NULL);
255 
256 	if (mode == M_ADD && (rc = addgrent(grp)) != 0) {
257 		if (rc == -1)
258 			warnx("group '%s' already exists", grp->gr_name);
259 		else
260 			warn("group update");
261 		return EX_IOERR;
262 	} else if (mode == M_UPDATE && (rc = chggrent(a_name->val, grp)) != 0) {
263 		if (rc == -1)
264 			warnx("group '%s' not available (NIS?)", grp->gr_name);
265 		else
266 			warn("group update");
267 		return EX_IOERR;
268 	}
269 	/* grp may have been invalidated */
270 	if ((grp = GETGRNAM(a_name->val)) == NULL)
271 		errx(EX_SOFTWARE, "group disappeared during update");
272 
273 	pw_log(cnf, mode, W_GROUP, "%s(%ld)", grp->gr_name, (long) grp->gr_gid);
274 
275 	if (members)
276 		free(members);
277 
278 	return EXIT_SUCCESS;
279 }
280 
281 
282 /*
283  * Lookup a passwd entry using a name or UID.
284  */
285 static struct passwd *
286 lookup_pwent(const char *user)
287 {
288 	struct passwd *pwd;
289 
290 	if ((pwd = GETPWNAM(user)) == NULL &&
291 	    (!isdigit((unsigned char)*user) ||
292 	    (pwd = getpwuid((uid_t) atoi(user))) == NULL))
293 		errx(EX_NOUSER, "user `%s' does not exist", user);
294 
295 	return (pwd);
296 }
297 
298 
299 /*
300  * Delete requested members from a group.
301  */
302 static void
303 delete_members(char ***members, int *grmembers, int *i, struct carg *arg,
304     struct group *grp)
305 {
306 	bool matchFound;
307 	char *user;
308 	char *valueCopy;
309 	char *valuePtr;
310 	int k;
311 	struct passwd *pwd;
312 
313 	k = 0;
314 	while (grp->gr_mem[k] != NULL) {
315 		matchFound = false;
316 		if ((valueCopy = strdup(arg->val)) == NULL)
317 			errx(EX_UNAVAILABLE, "out of memory");
318 		valuePtr = valueCopy;
319 		while ((user = strsep(&valuePtr, ", \t")) != NULL) {
320 			pwd = lookup_pwent(user);
321 			if (strcmp(grp->gr_mem[k], pwd->pw_name) == 0) {
322 				matchFound = true;
323 				break;
324 			}
325 		}
326 		free(valueCopy);
327 
328 		if (!matchFound &&
329 		    extendarray(members, grmembers, *i + 2) != -1)
330 			(*members)[(*i)++] = grp->gr_mem[k];
331 
332 		k++;
333 	}
334 
335 	return;
336 }
337 
338 
339 static          gid_t
340 gr_gidpolicy(struct userconf * cnf, struct cargs * args)
341 {
342 	struct group   *grp;
343 	gid_t           gid = (gid_t) - 1;
344 	struct carg    *a_gid = getarg(args, 'g');
345 
346 	/*
347 	 * Check the given gid, if any
348 	 */
349 	if (a_gid != NULL) {
350 		gid = (gid_t) atol(a_gid->val);
351 
352 		if ((grp = GETGRGID(gid)) != NULL && getarg(args, 'o') == NULL)
353 			errx(EX_DATAERR, "gid `%ld' has already been allocated", (long) grp->gr_gid);
354 	} else {
355 		struct bitmap   bm;
356 
357 		/*
358 		 * We need to allocate the next available gid under one of
359 		 * two policies a) Grab the first unused gid b) Grab the
360 		 * highest possible unused gid
361 		 */
362 		if (cnf->min_gid >= cnf->max_gid) {	/* Sanity claus^H^H^H^Hheck */
363 			cnf->min_gid = 1000;
364 			cnf->max_gid = 32000;
365 		}
366 		bm = bm_alloc(cnf->max_gid - cnf->min_gid + 1);
367 
368 		/*
369 		 * Now, let's fill the bitmap from the password file
370 		 */
371 		SETGRENT();
372 		while ((grp = GETGRENT()) != NULL)
373 			if ((gid_t)grp->gr_gid >= (gid_t)cnf->min_gid &&
374                             (gid_t)grp->gr_gid <= (gid_t)cnf->max_gid)
375 				bm_setbit(&bm, grp->gr_gid - cnf->min_gid);
376 		ENDGRENT();
377 
378 		/*
379 		 * Then apply the policy, with fallback to reuse if necessary
380 		 */
381 		if (cnf->reuse_gids)
382 			gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
383 		else {
384 			gid = (gid_t) (bm_lastset(&bm) + 1);
385 			if (!bm_isset(&bm, gid))
386 				gid += cnf->min_gid;
387 			else
388 				gid = (gid_t) (bm_firstunset(&bm) + cnf->min_gid);
389 		}
390 
391 		/*
392 		 * Another sanity check
393 		 */
394 		if (gid < cnf->min_gid || gid > cnf->max_gid)
395 			errx(EX_SOFTWARE, "unable to allocate a new gid - range fully used");
396 		bm_dealloc(&bm);
397 	}
398 	return gid;
399 }
400 
401 
402 static int
403 print_group(struct group * grp, int pretty)
404 {
405 	if (!pretty) {
406 		int		buflen = 0;
407 		char           *buf = NULL;
408 
409 		fmtgrent(&buf, &buflen, grp);
410 		fputs(buf, stdout);
411 		free(buf);
412 	} else {
413 		int             i;
414 
415 		printf("Group Name: %-15s   #%lu\n"
416 		       "   Members: ",
417 		       grp->gr_name, (long) grp->gr_gid);
418 		for (i = 0; grp->gr_mem[i]; i++)
419 			printf("%s%s", i ? "," : "", grp->gr_mem[i]);
420 		fputs("\n\n", stdout);
421 	}
422 	return EXIT_SUCCESS;
423 }
424