xref: /illumos-gate/usr/src/cmd/oamuser/user/groups.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 #include <sys/types.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <ctype.h>
34 #include <sys/stat.h>
35 #include <grp.h>
36 #include <unistd.h>
37 #include <userdefs.h>
38 #include <errno.h>
39 #include <limits.h>
40 #include "users.h"
41 #include "messages.h"
42 
43 #define	MYBUFSIZE (LINE_MAX)
44 	/* Corresponds to MYBUFSIZE in grpck.c, BUFCONST in nss_dbdefs.c */
45 
46 int
47 edit_group(char *login, char *new_login, gid_t gids[], int overwrite)
48 {
49 	char **memptr;
50 	char t_name[] = "/etc/gtmp.XXXXXX";
51 	int fd;
52 	FILE *e_fptr, *t_fptr;
53 	struct group *g_ptr;	/* group structure from fgetgrent */
54 	int i;
55 	int modified = 0;
56 	struct stat sbuf;
57 
58 	int bufsize, g_length, sav_errno;
59 	long g_curr = 0L;
60 	char *g_string, *new_g_string, *gstr_off;
61 
62 	if ((e_fptr = fopen(GROUP, "r")) == NULL)
63 		return (EX_UPDATE);
64 
65 	if (fstat(fileno(e_fptr), &sbuf) != 0) {
66 		(void) fclose(e_fptr);
67 		return (EX_UPDATE);
68 	}
69 
70 	if ((fd = mkstemp(t_name)) == -1) {
71 		(void) fclose(e_fptr);
72 		return (EX_UPDATE);
73 	}
74 
75 	if ((t_fptr = fdopen(fd, "w")) == NULL) {
76 		(void) close(fd);
77 		(void) unlink(t_name);
78 		(void) fclose(e_fptr);
79 		return (EX_UPDATE);
80 	}
81 
82 	/*
83 	 * Get ownership and permissions correct
84 	 */
85 
86 	if (fchmod(fd, sbuf.st_mode) != 0 ||
87 	    fchown(fd, sbuf.st_uid, sbuf.st_gid) != 0) {
88 		(void) fclose(t_fptr);
89 		(void) fclose(e_fptr);
90 		(void) unlink(t_name);
91 		return (EX_UPDATE);
92 	}
93 
94 	g_curr = ftell(e_fptr);
95 
96 	/* Make TMP file look like we want GROUP file to look */
97 
98 	bufsize = MYBUFSIZE;
99 	if ((g_string = malloc(bufsize)) == NULL) {
100 		(void) fclose(t_fptr);
101 		(void) fclose(e_fptr);
102 		(void) unlink(t_name);
103 		return (EX_UPDATE);
104 	}
105 	/*
106 	 * bufsize contains the size of the currently allocated buffer
107 	 * buffer size, which is initially MYBUFSIZE but when a line
108 	 * greater than MYBUFSIZE is encountered then bufsize gets increased
109 	 * by MYBUFSIZE.
110 	 * g_string always points to the beginning of the buffer (even after
111 	 * realloc()).
112 	 * gstr_off = g_string + MYBUFSIZE * (n), where n >= 0.
113 	 */
114 	while (!feof(e_fptr) && !ferror(e_fptr)) {
115 		g_length = 0;
116 		gstr_off = g_string;
117 		while (fgets(gstr_off, (bufsize - g_length), e_fptr) != NULL) {
118 			g_length += strlen(gstr_off);
119 			if (g_string[g_length - 1] == '\n' || feof(e_fptr))
120 				break;
121 			new_g_string = realloc(g_string, (bufsize + MYBUFSIZE));
122 			if (new_g_string == NULL) {
123 				free(g_string);
124 				(void) fclose(t_fptr);
125 				(void) fclose(e_fptr);
126 				(void) unlink(t_name);
127 				return (EX_UPDATE);
128 			}
129 			bufsize += MYBUFSIZE;
130 			g_string = new_g_string;
131 			gstr_off = g_string + g_length;
132 		}
133 		if (g_length == 0) {
134 			continue;
135 		}
136 
137 		/* While there is another group string */
138 
139 		(void) fseek(e_fptr, g_curr, SEEK_SET);
140 		errno = 0;
141 		g_ptr = fgetgrent(e_fptr);
142 		sav_errno = errno;
143 		g_curr = ftell(e_fptr);
144 
145 		if (g_ptr == NULL) {
146 			/* tried to parse a group string over MYBUFSIZ char */
147 			if (sav_errno == ERANGE)
148 				errmsg(M_GROUP_ENTRY_OVF);
149 			else
150 				errmsg(M_READ_ERROR);
151 
152 			modified = 0; /* bad group file: cannot rebuild */
153 			break;
154 		}
155 
156 		/* first delete the login from the group, if it's there */
157 		if (overwrite || !gids) {
158 			if (g_ptr->gr_mem != NULL) {
159 				for (memptr = g_ptr->gr_mem; *memptr;
160 				    memptr++) {
161 					if (strcmp(*memptr, login) == 0) {
162 						/* Delete this one */
163 						char **from = memptr + 1;
164 
165 						g_length -= (strlen(*memptr)+1);
166 
167 						do {
168 							*(from - 1) = *from;
169 						} while (*from++);
170 
171 						modified++;
172 						break;
173 					}
174 				}
175 			}
176 		}
177 
178 		/* now check to see if group is one to add to */
179 		if (gids) {
180 			for (i = 0; gids[i] != -1; i++) {
181 				if (g_ptr->gr_gid == gids[i]) {
182 					/* Find end */
183 					for (memptr = g_ptr->gr_mem; *memptr;
184 						memptr++)
185 						;
186 					g_length += strlen(new_login ?
187 							new_login : login)+1;
188 
189 					*memptr++ = new_login ?
190 						new_login : login;
191 					*memptr = NULL;
192 
193 					modified++;
194 				}
195 			}
196 		}
197 		putgrent(g_ptr, t_fptr);
198 	}
199 	free(g_string);
200 
201 	(void) fclose(e_fptr);
202 
203 	if (fclose(t_fptr) != 0) {
204 		(void) unlink(t_name);
205 		return (EX_UPDATE);
206 	}
207 
208 	/* Now, update GROUP file, if it was modified */
209 	if (modified) {
210 		if (rename(t_name, GROUP) != 0) {
211 			(void) unlink(t_name);
212 			return (EX_UPDATE);
213 		}
214 		return (EX_SUCCESS);
215 	} else {
216 		(void) unlink(t_name);
217 		return (EX_SUCCESS);
218 	}
219 }
220