gr_util.c revision 225736 
1/*-
2 * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
3 * 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 *    without modification, immediately at the beginning of the file.
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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/9/lib/libutil/gr_util.c 200423 2009-12-12 00:11:40Z scf $");
29
30#include <sys/param.h>
31
32#include <grp.h>
33#include <inttypes.h>
34#include <libutil.h>
35#include <stdbool.h>
36#include <stdio.h>
37#include <stdlib.h>
38#include <string.h>
39
40struct group_storage {
41	struct group	 gr;
42	char		*members[];
43};
44
45static const char group_line_format[] = "%s:%s:%ju:";
46
47/*
48 * Compares two struct group's.
49 */
50int
51gr_equal(const struct group *gr1, const struct group *gr2)
52{
53	int gr1_ndx;
54	int gr2_ndx;
55	bool found;
56
57	/* Check that the non-member information is the same. */
58	if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
59		if (gr1->gr_name != gr2->gr_name)
60			return (false);
61	} else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
62		return (false);
63	if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
64		if (gr1->gr_passwd != gr2->gr_passwd)
65			return (false);
66	} else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
67		return (false);
68	if (gr1->gr_gid != gr2->gr_gid)
69		return (false);
70
71	/* Check all members in both groups. */
72	if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) {
73		if (gr1->gr_mem != gr2->gr_mem)
74			return (false);
75	} else {
76		for (found = false, gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL;
77		    gr1_ndx++) {
78			for (gr2_ndx = 0; gr2->gr_mem[gr2_ndx] != NULL;
79			    gr2_ndx++)
80				if (strcmp(gr1->gr_mem[gr1_ndx],
81				    gr2->gr_mem[gr2_ndx]) == 0) {
82					found = true;
83					break;
84				}
85			if (!found)
86				return (false);
87		}
88
89		/* Check that group2 does not have more members than group1. */
90		if (gr2->gr_mem[gr1_ndx] != NULL)
91			return (false);
92	}
93
94	return (true);
95}
96
97/*
98 * Make a group line out of a struct group.
99 */
100char *
101gr_make(const struct group *gr)
102{
103	char *line;
104	size_t line_size;
105	int ndx;
106
107	/* Calculate the length of the group line. */
108	line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
109	    gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
110	if (gr->gr_mem != NULL) {
111		for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
112			line_size += strlen(gr->gr_mem[ndx]) + 1;
113		if (ndx > 0)
114			line_size--;
115	}
116
117	/* Create the group line and fill it. */
118	if ((line = malloc(line_size)) == NULL)
119		return (NULL);
120	snprintf(line, line_size, group_line_format, gr->gr_name, gr->gr_passwd,
121	    (uintmax_t)gr->gr_gid);
122	if (gr->gr_mem != NULL)
123		for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
124			strcat(line, gr->gr_mem[ndx]);
125			if (gr->gr_mem[ndx + 1] != NULL)
126				strcat(line, ",");
127		}
128
129	return (line);
130}
131
132/*
133 * Duplicate a struct group.
134 */
135struct group *
136gr_dup(const struct group *gr)
137{
138	char *dst;
139	size_t len;
140	struct group_storage *gs;
141	int ndx;
142	int num_mem;
143
144	/* Calculate size of the group. */
145	len = sizeof(*gs);
146	if (gr->gr_name != NULL)
147		len += strlen(gr->gr_name) + 1;
148	if (gr->gr_passwd != NULL)
149		len += strlen(gr->gr_passwd) + 1;
150	if (gr->gr_mem != NULL) {
151		for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++)
152			len += strlen(gr->gr_mem[num_mem]) + 1;
153		len += (num_mem + 1) * sizeof(*gr->gr_mem);
154	} else
155		num_mem = -1;
156
157	/* Create new group and copy old group into it. */
158	if ((gs = calloc(1, len)) == NULL)
159		return (NULL);
160	dst = (char *)&gs->members[num_mem + 1];
161	if (gr->gr_name != NULL) {
162		gs->gr.gr_name = dst;
163		dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
164	}
165	if (gr->gr_passwd != NULL) {
166		gs->gr.gr_passwd = dst;
167		dst = stpcpy(gs->gr.gr_passwd, gr->gr_passwd) + 1;
168	}
169	gs->gr.gr_gid = gr->gr_gid;
170	if (gr->gr_mem != NULL) {
171		gs->gr.gr_mem = gs->members;
172		for (ndx = 0; ndx < num_mem; ndx++) {
173			gs->gr.gr_mem[ndx] = dst;
174			dst = stpcpy(gs->gr.gr_mem[ndx], gr->gr_mem[ndx]) + 1;
175		}
176		gs->gr.gr_mem[ndx] = NULL;
177	}
178
179	return (&gs->gr);
180}
181
182/*
183 * Scan a line and place it into a group structure.
184 */
185static bool
186__gr_scan(char *line, struct group *gr)
187{
188	char *loc;
189	int ndx;
190
191	/* Assign non-member information to structure. */
192	gr->gr_name = line;
193	if ((loc = strchr(line, ':')) == NULL)
194		return (false);
195	*loc = '\0';
196	gr->gr_passwd = loc + 1;
197	if (*gr->gr_passwd == ':')
198		*gr->gr_passwd = '\0';
199	else {
200		if ((loc = strchr(loc + 1, ':')) == NULL)
201			return (false);
202		*loc = '\0';
203	}
204	if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
205		return (false);
206
207	/* Assign member information to structure. */
208	if ((loc = strchr(loc + 1, ':')) == NULL)
209		return (false);
210	line = loc + 1;
211	gr->gr_mem = NULL;
212	ndx = 0;
213	do {
214		gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
215		    (ndx + 1));
216		if (gr->gr_mem == NULL)
217			return (false);
218
219		/* Skip locations without members (i.e., empty string). */
220		do {
221			gr->gr_mem[ndx] = strsep(&line, ",");
222		} while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
223	} while (gr->gr_mem[ndx++] != NULL);
224
225	return (true);
226}
227
228/*
229 * Create a struct group from a line.
230 */
231struct group *
232gr_scan(const char *line)
233{
234	struct group gr;
235	char *line_copy;
236	struct group *new_gr;
237
238	if ((line_copy = strdup(line)) == NULL)
239		return (NULL);
240	if (!__gr_scan(line_copy, &gr)) {
241		free(line_copy);
242		return (NULL);
243	}
244	new_gr = gr_dup(&gr);
245	free(line_copy);
246	if (gr.gr_mem != NULL)
247		free(gr.gr_mem);
248
249	return (new_gr);
250}
251