xref: /illumos-gate/usr/src/cmd/oamuser/user/groups.c (revision 7c478bd9)
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 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include <sys/types.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <ctype.h>
37 #include <sys/stat.h>
38 #include <grp.h>
39 #include <unistd.h>
40 #include <userdefs.h>
41 #include <errno.h>
42 #include <limits.h>
43 #include "users.h"
44 #include "messages.h"
45 
46 #define	MYBUFSIZE (LINE_MAX)
47 	/* Corresponds to MYBUFSIZE in grpck.c, BUFCONST in nss_dbdefs.c */
48 
49 int
edit_group(char * login,char * new_login,gid_t gids[],int overwrite)50 edit_group(char *login, char *new_login, gid_t gids[], int overwrite)
51 {
52 	char **memptr;
53 	char t_name[] = "/etc/gtmp.XXXXXX";
54 	int fd;
55 	FILE *e_fptr, *t_fptr;
56 	struct group *g_ptr;	/* group structure from fgetgrent */
57 	int i;
58 	int modified = 0;
59 	struct stat sbuf;
60 
61 	int bufsize, g_length, sav_errno;
62 	long g_curr = 0L;
63 	char *g_string, *new_g_string, *gstr_off;
64 
65 	if ((e_fptr = fopen(GROUP, "r")) == NULL)
66 		return (EX_UPDATE);
67 
68 	if (fstat(fileno(e_fptr), &sbuf) != 0) {
69 		(void) fclose(e_fptr);
70 		return (EX_UPDATE);
71 	}
72 
73 	if ((fd = mkstemp(t_name)) == -1) {
74 		(void) fclose(e_fptr);
75 		return (EX_UPDATE);
76 	}
77 
78 	if ((t_fptr = fdopen(fd, "w")) == NULL) {
79 		(void) close(fd);
80 		(void) unlink(t_name);
81 		(void) fclose(e_fptr);
82 		return (EX_UPDATE);
83 	}
84 
85 	/*
86 	 * Get ownership and permissions correct
87 	 */
88 
89 	if (fchmod(fd, sbuf.st_mode) != 0 ||
90 	    fchown(fd, sbuf.st_uid, sbuf.st_gid) != 0) {
91 		(void) fclose(t_fptr);
92 		(void) fclose(e_fptr);
93 		(void) unlink(t_name);
94 		return (EX_UPDATE);
95 	}
96 
97 	g_curr = ftell(e_fptr);
98 
99 	/* Make TMP file look like we want GROUP file to look */
100 
101 	bufsize = MYBUFSIZE;
102 	if ((g_string = malloc(bufsize)) == NULL) {
103 		(void) fclose(t_fptr);
104 		(void) fclose(e_fptr);
105 		(void) unlink(t_name);
106 		return (EX_UPDATE);
107 	}
108 	/*
109 	 * bufsize contains the size of the currently allocated buffer
110 	 * buffer size, which is initially MYBUFSIZE but when a line
111 	 * greater than MYBUFSIZE is encountered then bufsize gets increased
112 	 * by MYBUFSIZE.
113 	 * g_string always points to the beginning of the buffer (even after
114 	 * realloc()).
115 	 * gstr_off = g_string + MYBUFSIZE * (n), where n >= 0.
116 	 */
117 	while (!feof(e_fptr) && !ferror(e_fptr)) {
118 		g_length = 0;
119 		gstr_off = g_string;
120 		while (fgets(gstr_off, (bufsize - g_length), e_fptr) != NULL) {
121 			g_length += strlen(gstr_off);
122 			if (g_string[g_length - 1] == '\n' || feof(e_fptr))
123 				break;
124 			new_g_string = realloc(g_string, (bufsize + MYBUFSIZE));
125 			if (new_g_string == NULL) {
126 				free(g_string);
127 				(void) fclose(t_fptr);
128 				(void) fclose(e_fptr);
129 				(void) unlink(t_name);
130 				return (EX_UPDATE);
131 			}
132 			bufsize += MYBUFSIZE;
133 			g_string = new_g_string;
134 			gstr_off = g_string + g_length;
135 		}
136 		if (g_length == 0) {
137 			continue;
138 		}
139 
140 		/* While there is another group string */
141 
142 		(void) fseek(e_fptr, g_curr, SEEK_SET);
143 		errno = 0;
144 		g_ptr = fgetgrent(e_fptr);
145 		sav_errno = errno;
146 		g_curr = ftell(e_fptr);
147 
148 		if (g_ptr == NULL) {
149 			/* tried to parse a group string over MYBUFSIZ char */
150 			if (sav_errno == ERANGE)
151 				errmsg(M_GROUP_ENTRY_OVF);
152 			else
153 				errmsg(M_READ_ERROR);
154 
155 			modified = 0; /* bad group file: cannot rebuild */
156 			break;
157 		}
158 
159 		/* first delete the login from the group, if it's there */
160 		if (overwrite || !gids) {
161 			if (g_ptr->gr_mem != NULL) {
162 				for (memptr = g_ptr->gr_mem; *memptr;
163 				    memptr++) {
164 					if (strcmp(*memptr, login) == 0) {
165 						/* Delete this one */
166 						char **from = memptr + 1;
167 
168 						g_length -= (strlen(*memptr)+1);
169 
170 						do {
171 							*(from - 1) = *from;
172 						} while (*from++);
173 
174 						modified++;
175 						break;
176 					}
177 				}
178 			}
179 		}
180 
181 		/* now check to see if group is one to add to */
182 		if (gids) {
183 			for (i = 0; gids[i] != -1; i++) {
184 				if (g_ptr->gr_gid == gids[i]) {
185 					/* Find end */
186 					for (memptr = g_ptr->gr_mem; *memptr;
187 						memptr++)
188 						;
189 					g_length += strlen(new_login ?
190 							new_login : login)+1;
191 
192 					*memptr++ = new_login ?
193 						new_login : login;
194 					*memptr = NULL;
195 
196 					modified++;
197 				}
198 			}
199 		}
200 		putgrent(g_ptr, t_fptr);
201 	}
202 	free(g_string);
203 
204 	(void) fclose(e_fptr);
205 
206 	if (fclose(t_fptr) != 0) {
207 		(void) unlink(t_name);
208 		return (EX_UPDATE);
209 	}
210 
211 	/* Now, update GROUP file, if it was modified */
212 	if (modified) {
213 		if (rename(t_name, GROUP) != 0) {
214 			(void) unlink(t_name);
215 			return (EX_UPDATE);
216 		}
217 		return (EX_SUCCESS);
218 	} else {
219 		(void) unlink(t_name);
220 		return (EX_SUCCESS);
221 	}
222 }
223