xref: /freebsd/lib/libutil/gr_util.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <grp.h>
32 #include <inttypes.h>
33 #include <stdbool.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include <libutil.h>
39 
40 
41 static const char GroupLineFormat[] = "%s:%s:%ju:";
42 
43 
44 /*
45  * Compares two struct group's.
46  */
47 int
48 gr_equal(const struct group *gr1, const struct group *gr2)
49 {
50 	bool found;
51 	bool equal;
52 	int gr1Ndx;
53 	int gr2Ndx;
54 
55 	/* Check that the non-member information is the same. */
56 	equal = strcmp(gr1->gr_name, gr2->gr_name) == 0 &&
57 	    strcmp(gr1->gr_passwd, gr2->gr_passwd) == 0 &&
58 	    gr1->gr_gid == gr2->gr_gid;
59 
60 	/* Check all members in both groups. */
61 	if (equal) {
62 		for (found = false, gr1Ndx = 0; gr1->gr_mem[gr1Ndx] != NULL;
63 		    gr1Ndx++) {
64 			for (gr2Ndx = 0; gr2->gr_mem[gr2Ndx] != NULL; gr2Ndx++)
65 				if (strcmp(gr1->gr_mem[gr1Ndx],
66 				    gr2->gr_mem[gr2Ndx]) == 0) {
67 					found = true;
68 					break;
69 				}
70 			if (! found) {
71 				equal = false;
72 				break;
73 			}
74 		}
75 
76 		/* Check that group2 does not have more members than group1. */
77 		if (gr2->gr_mem[gr1Ndx] != NULL)
78 			equal = false;
79 	}
80 
81 	return (equal);
82 }
83 
84 
85 /*
86  * Make a group line out of a struct group.
87  */
88 char *
89 gr_make(const struct group *gr)
90 {
91 	char *line;
92 	int ndx;
93 	size_t lineSize;
94 
95 	/* Calculate the length of the group line. */
96 	lineSize = snprintf(NULL, 0, GroupLineFormat, gr->gr_name,
97 	    gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
98 	for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
99 		lineSize += strlen(gr->gr_mem[ndx]) + 1;
100 	if (ndx > 0)
101 		lineSize--;
102 
103 	/* Create the group line and fill it. */
104 	if ((line = malloc(lineSize)) == NULL)
105 		return (NULL);
106 	lineSize = snprintf(line, lineSize, GroupLineFormat, gr->gr_name,
107 	    gr->gr_passwd, (uintmax_t)gr->gr_gid);
108 	for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
109 		strcat(line, gr->gr_mem[ndx]);
110 		if (gr->gr_mem[ndx + 1] != NULL)
111 			strcat(line, ",");
112 	}
113 
114 	return (line);
115 }
116 
117 
118 /*
119  * Duplicate a struct group.
120  */
121 struct group *
122 gr_dup(const struct group *gr)
123 {
124 	int ndx;
125 	int numMem;
126 	size_t len;
127 	struct group *ngr;
128 
129 	/* Calculate size of group. */
130 	len = sizeof(*gr) +
131 	    (gr->gr_name != NULL ? strlen(gr->gr_name) + 1 : 0) +
132 	    (gr->gr_passwd != NULL ? strlen(gr->gr_passwd) + 1 : 0);
133 	numMem = 0;
134 	if (gr->gr_mem != NULL) {
135 		for (; gr->gr_mem[numMem] != NULL; numMem++)
136 			len += strlen(gr->gr_mem[numMem]) + 1;
137 		len += (numMem + 1) * sizeof(*(gr->gr_mem));
138 	}
139 
140 	/* Create new group and copy old group into it. */
141 	if ((ngr = calloc(1, len)) == NULL)
142 		return (NULL);
143 	len = sizeof(*ngr);
144 	ngr->gr_gid = gr->gr_gid;
145 	if (gr->gr_name != NULL) {
146 		ngr->gr_name = (char *)ngr + len;
147 		len += sprintf(ngr->gr_name, "%s", gr->gr_name) + 1;
148 	}
149 	if (gr->gr_passwd != NULL) {
150 		ngr->gr_passwd = (char *)ngr + len;
151 		len += sprintf(ngr->gr_passwd, "%s", gr->gr_passwd) + 1;
152 	}
153 	if (gr->gr_mem != NULL) {
154 		ngr->gr_mem = (char **)((char *)ngr + len);
155 		len += (numMem + 1) * sizeof(*(ngr->gr_mem));
156 		for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
157 			ngr->gr_mem[ndx] = (char *)ngr + len;
158 			len += sprintf(ngr->gr_mem[ndx], "%s",
159 			    gr->gr_mem[ndx]) + 1;
160 		}
161 		ngr->gr_mem[ndx] = NULL;
162 	}
163 
164 	return (ngr);
165 }
166 
167 
168 /*
169  * Scan a line and place it into a group structure.
170  */
171 static bool
172 __gr_scan(char *line, struct group *gr)
173 {
174 	char *loc;
175 	int ndx;
176 
177 	/* Assign non-member information to structure. */
178 	gr->gr_name = line;
179 	if ((loc = strchr(line, ':')) == NULL)
180 		return (false);
181 	*loc = '\0';
182 	gr->gr_passwd = loc + 1;
183 	if (*(gr->gr_passwd) == ':')
184 		*(gr->gr_passwd) = '\0';
185 	else {
186 		if ((loc = strchr(loc + 1, ':')) == NULL)
187 			return (false);
188 		*loc = '\0';
189 	}
190 	if (sscanf(loc + 1, "%u", &(gr->gr_gid)) != 1)
191 		return (false);
192 
193 	/* Assign member information to structure. */
194 	if ((loc = strchr(loc + 1, ':')) == NULL)
195 		return (false);
196 	line = loc + 1;
197 	gr->gr_mem = NULL;
198 	if (*line != '\0') {
199 		ndx = 0;
200 		do {
201 			if ((gr->gr_mem = reallocf(gr->gr_mem,
202 			    sizeof(*(gr->gr_mem)) * (ndx + 1))) == NULL)
203 				return (false);
204 			gr->gr_mem[ndx] = strsep(&line, ",");
205 		} while (gr->gr_mem[ndx++] != NULL);
206 	}
207 
208 	return (true);
209 }
210 
211 
212 /*
213  * Create a struct group from a line.
214  */
215 struct group *
216 gr_scan(const char *line)
217 {
218 	char *lineCopy;
219 	struct group *newGr;
220 	struct group gr;
221 
222 	if ((lineCopy = strdup(line)) == NULL)
223 		return (NULL);
224 	if (!__gr_scan(lineCopy, &gr)) {
225 		free(lineCopy);
226 		return (NULL);
227 	}
228 	newGr = gr_dup(&gr);
229 	free(lineCopy);
230 	if (gr.gr_mem != NULL)
231 		free(gr.gr_mem);
232 
233 	return (newGr);
234 }
235