edgroup.c revision 37711 
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
27#ifndef lint
28static const char rcsid[] =
29	"$Id: edgroup.c,v 1.5 1997/10/10 06:23:30 charnier Exp $";
30#endif /* not lint */
31
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <unistd.h>
36#include <stdarg.h>
37#include <sys/types.h>
38#include <sys/stat.h>
39#include <pwd.h>
40#include <grp.h>
41#include <fcntl.h>
42#include <sys/param.h>
43#include <ctype.h>
44
45#include "pwupd.h"
46
47static int
48isingroup(char const * name, char **mem)
49{
50	int             i;
51
52	for (i = 0; mem[i] != NULL; i++)
53		if (strcmp(name, mem[i]) == 0)
54			return i;
55	return -1;
56}
57
58static char     groupfile[] = _PATH_GROUP;
59static char     grouptmp[] = _PATH_GROUP ".new";
60
61int
62editgroups(char *name, char **groups)
63{
64	int             rc = 0;
65	int             infd;
66
67	if ((infd = open(groupfile, O_RDWR | O_CREAT, 0644)) != -1) {
68		FILE           *infp;
69
70		if ((infp = fdopen(infd, "r+")) == NULL)
71			close(infd);
72		else {
73			int             outfd;
74
75			if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC | O_EXLOCK, 0644)) != -1) {
76				FILE           *outfp;
77
78				if ((outfp = fdopen(outfd, "w+")) == NULL)
79					close(outfd);
80				else {
81					int		linelen = PWBUFSZ;
82					int		outlen =  PWBUFSZ;
83					int		memlen = 200; /* Arbitrary */
84					char           *line = malloc(linelen);
85					char           *outl = malloc(outlen);
86					char	      **mems = malloc(memlen * sizeof(char *));
87					int		namlen = strlen(name);
88
89					if (line == NULL || outl == NULL || mems == NULL) {
90					    mem_abort:
91						rc = 0;
92					} else {
93						while (fgets(line, linelen, infp) != NULL) {
94							char           *p;
95							int		l;
96
97							while ((p = strchr(line, '\n')) == NULL)
98							{
99								if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
100									goto mem_abort;
101								}
102								l = strlen(line);
103								if (fgets(line + l, linelen - l, infp) == NULL)
104									break;	/* No newline terminator on last line */
105							}
106							l = strlen(line) + namlen + 1;
107							if (extendline(&outl, &outlen, l) == -1) {
108								goto mem_abort;
109							}
110							if (*line == '#')
111								strcpy(outl, line);
112							else if (*line == '\n')
113								*outl = '\0';
114							else {
115								int             i,
116									        mno = 0;
117								char           *cp = line;
118								char const     *sep = ":\n";
119								struct group    grp;
120
121								memset(&grp, 0, sizeof grp);
122								for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
123									switch (i) {
124									case 0:	/* Group name */
125										grp.gr_name = p;
126										break;
127									case 1:	/* Group password */
128										grp.gr_passwd = p;
129										break;
130									case 2:	/* Group id */
131										grp.gr_gid = atoi(p);
132										break;
133									case 3:	/* Member list */
134										cp = p;
135										sep = ",\n";
136										break;
137									default:	/* Individual members */
138										if (*p) {
139											if (extendarray(&mems, &memlen, mno + 2) == -1) {
140												goto mem_abort;
141											}
142											mems[mno++] = p;
143										}
144										break;
145									}
146								}
147								if (i < 2)	/* Bail out - insufficient fields */
148									continue;
149
150								grp.gr_mem = mems;
151								for (i = mno; i < memlen; i++)
152									mems[i] = NULL;
153
154								/*
155								 * Delete from group, or add to group?
156								 */
157								if (groups == NULL || isingroup(grp.gr_name, groups) == -1) {	/* Delete */
158									int             idx;
159
160									while ((idx = isingroup(name, mems)) != -1) {
161										for (i = idx; i < (memlen - 1); i++)
162											mems[i] = mems[i + 1];
163										mems[i] = NULL;
164										--mno;
165									}
166									/*
167									 * Special case - deleting user and group may be user's own
168									 */
169									if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
170										/*
171										 * First, make _sure_ we don't have other members
172										 */
173										struct passwd  *pwd;
174
175										setpwent();
176										while ((pwd = getpwent()) != NULL && pwd->pw_gid != grp.gr_gid);
177										endpwent();
178										if (pwd == NULL)	/* No members at all */
179											continue;	/* Drop the group */
180									}
181								} else if (isingroup(name, mems) == -1) {
182									if (extendarray(&mems, &memlen, mno + 2) == -1) {
183										goto mem_abort;
184									}
185									grp.gr_mem = mems;    /* May have realloced() */
186									mems[mno++] = name;
187									mems[mno  ] = NULL;
188								}
189								fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
190							}
191							fputs(outl, outfp);
192						}
193						if (fflush(outfp) != EOF) {
194							rc = 1;
195
196							/*
197							 * Copy data back into the original file and truncate
198							 */
199							rewind(infp);
200							rewind(outfp);
201							while (fgets(outl, outlen, outfp) != NULL)
202								fputs(outl, infp);
203
204							/*
205							 * This is a gross hack, but we may have corrupted the
206							 * original file. Unfortunately, it will lose preservation
207							 * of the inode.
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