xref: /dragonfly/usr.sbin/pw/edgroup.c (revision 500b62b4)
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  * $FreeBSD: src/usr.sbin/pw/edgroup.c,v 1.9 2004/03/08 20:31:37 kensmith Exp $
27  */
28 
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33 #include <stdarg.h>
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <pwd.h>
37 #include <grp.h>
38 #include <fcntl.h>
39 #include <sys/param.h>
40 #include <ctype.h>
41 
42 #include "pwupd.h"
43 
44 static int
isingroup(char const * name,char ** mem)45 isingroup(char const * name, char **mem)
46 {
47 	int             i;
48 
49 	for (i = 0; mem[i] != NULL; i++)
50 		if (strcmp(name, mem[i]) == 0)
51 			return i;
52 	return -1;
53 }
54 
55 int
editgroups(char * name,char ** groups)56 editgroups(char *name, char **groups)
57 {
58 	int             rc = 0;
59 	int             infd;
60 	char		groupfile[MAXPATHLEN];
61 	char		grouptmp[MAXPATHLEN];
62 
63 	strncpy(groupfile, getgrpath(_GROUP), MAXPATHLEN - 5);
64 	groupfile[MAXPATHLEN - 5] = '\0';
65 	strcpy(grouptmp, groupfile);
66 	strcat(grouptmp, ".new");
67 
68 	if ((infd = open(groupfile, O_RDWR | O_CREAT | O_EXLOCK, 0644)) != -1) {
69 		FILE           *infp;
70 
71 		if ((infp = fdopen(infd, "r+")) == NULL)
72 			close(infd);
73 		else {
74 			int             outfd;
75 
76 			if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC, 0644)) != -1) {
77 				FILE           *outfp;
78 
79 				if ((outfp = fdopen(outfd, "w+")) == NULL)
80 					close(outfd);
81 				else {
82 					int		linelen = PWBUFSZ;
83 					int		outlen =  PWBUFSZ;
84 					int		memlen = 200; /* Arbitrary */
85 					char           *line = malloc(linelen);
86 					char           *outl = malloc(outlen);
87 					char	      **mems = malloc(memlen * sizeof(char *));
88 					int		namlen = strlen(name);
89 
90 					if (line == NULL || outl == NULL || mems == NULL) {
91 					    mem_abort:
92 						rc = 0;
93 					} else {
94 						while (fgets(line, linelen, infp) != NULL) {
95 							char           *p;
96 							int		l;
97 
98 							while ((p = strchr(line, '\n')) == NULL)
99 							{
100 								if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
101 									goto mem_abort;
102 								}
103 								l = strlen(line);
104 								if (fgets(line + l, linelen - l, infp) == NULL)
105 									break;	/* No newline terminator on last line */
106 							}
107 							l = strlen(line) + namlen + 1;
108 							if (extendline(&outl, &outlen, l) == -1) {
109 								goto mem_abort;
110 							}
111 							if (*line == '#')
112 								strcpy(outl, line);
113 							else if (*line == '\n')
114 								*outl = '\0';
115 							else {
116 								int             i,
117 									        mno = 0;
118 								char           *cp = line;
119 								char const     *sep = ":\n";
120 								struct group    grp;
121 
122 								memset(&grp, 0, sizeof grp);
123 								for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
124 									switch (i) {
125 									case 0:	/* Group name */
126 										grp.gr_name = p;
127 										break;
128 									case 1:	/* Group password */
129 										grp.gr_passwd = p;
130 										break;
131 									case 2:	/* Group id */
132 										grp.gr_gid = atoi(p);
133 										break;
134 									case 3:	/* Member list */
135 										cp = p;
136 										sep = ",\n";
137 										break;
138 									default:	/* Individual members */
139 										if (*p) {
140 											if (extendarray(&mems, &memlen, mno + 2) == -1) {
141 												goto mem_abort;
142 											}
143 											mems[mno++] = p;
144 										}
145 										break;
146 									}
147 								}
148 								if (i < 2)	/* Bail out - insufficient fields */
149 									continue;
150 
151 								grp.gr_mem = mems;
152 								for (i = mno; i < memlen; i++)
153 									mems[i] = NULL;
154 
155 								/*
156 								 * Delete from group, or add to group?
157 								 */
158 								if (groups == NULL || isingroup(grp.gr_name, groups) == -1) {	/* Delete */
159 									int             idx;
160 
161 									while ((idx = isingroup(name, mems)) != -1) {
162 										for (i = idx; i < (memlen - 1); i++)
163 											mems[i] = mems[i + 1];
164 										mems[i] = NULL;
165 										--mno;
166 									}
167 									/*
168 									 * Special case - deleting user and group may be user's own
169 									 */
170 									if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
171 										/*
172 										 * First, make _sure_ we don't have other members
173 										 */
174 										struct passwd  *pwd;
175 
176 										SETPWENT();
177 										while ((pwd = GETPWENT()) != NULL && (gid_t)pwd->pw_gid != (gid_t)grp.gr_gid);
178 										ENDPWENT();
179 										if (pwd == NULL)	/* No members at all */
180 											continue;	/* Drop the group */
181 									}
182 								} else if (isingroup(name, mems) == -1) {
183 									if (extendarray(&mems, &memlen, mno + 2) == -1) {
184 										goto mem_abort;
185 									}
186 									grp.gr_mem = mems;    /* May have realloced() */
187 									mems[mno++] = name;
188 									mems[mno  ] = NULL;
189 								}
190 								fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
191 							}
192 							fputs(outl, outfp);
193 						}
194 						if (fflush(outfp) != EOF) {
195 							rc = 1;
196 
197 							/*
198 							 * Copy data back into the original file and truncate
199 							 */
200 							rewind(infp);
201 							rewind(outfp);
202 							while (fgets(outl, outlen, outfp) != NULL)
203 								fputs(outl, infp);
204 
205 							/*
206 							 * This is a gross hack, but we may have corrupted the
207 							 * original file.
208 							 */
209 							if (fflush(infp) == EOF || ferror(infp))
210 								rc = rename(grouptmp, groupfile) == 0;
211 							else
212 								ftruncate(infd, ftell(infp));
213 						}
214 					}
215 					free(mems);
216 					free(outl);
217 			    		free(line);
218 					fclose(outfp);
219 				}
220 				remove(grouptmp);
221 			}
222 			fclose(infp);
223 		}
224 	}
225 	return rc;
226 }
227