edgroup.c revision 20747 
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 *	$Id: edgroup.c,v 1.1.1.2 1996/12/10 23:58:54 joerg 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 <errno.h>
35#include <sys/types.h>
36#include <sys/stat.h>
37#include <pwd.h>
38#include <grp.h>
39#include <fcntl.h>
40#include <sys/param.h>
41#include <ctype.h>
42
43#include "pwupd.h"
44
45static int
46isingroup(char const * name, char **mem)
47{
48	int             i;
49
50	for (i = 0; mem[i] != NULL; i++)
51		if (strcmp(name, mem[i]) == 0)
52			return i;
53	return -1;
54}
55
56static char     groupfile[] = _PATH_GROUP;
57static char     grouptmp[] = _PATH_GROUP ".new";
58
59int
60editgroups(char *name, char **groups)
61{
62	int             rc = 0;
63	int             infd;
64
65	if ((infd = open(groupfile, O_RDWR | O_CREAT | O_EXLOCK, 0644)) != -1) {
66		FILE           *infp;
67
68		if ((infp = fdopen(infd, "r+")) == NULL)
69			close(infd);
70		else {
71			int             outfd;
72
73			if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC | O_EXLOCK, 0644)) != -1) {
74				FILE           *outfp;
75
76				if ((outfp = fdopen(outfd, "w+")) == NULL)
77					close(outfd);
78				else {
79					int		linelen = PWBUFSZ;
80					int		outlen =  PWBUFSZ;
81					int		memlen = 200; /* Arbitrary */
82					char           *line = malloc(linelen);
83					char           *outl = malloc(outlen);
84					char	      **mems = malloc(memlen * sizeof(char *));
85					int		namlen = strlen(name);
86
87					if (line == NULL || outl == NULL || mems == NULL) {
88					    mem_abort:
89						rc = 0;
90					} else {
91						while (fgets(line, linelen, infp) != NULL) {
92							char           *p;
93							int		l;
94
95							while ((p = strchr(line, '\n')) == NULL)
96							{
97								if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
98									goto mem_abort;
99								}
100								l = strlen(line);
101								if (fgets(line + l, linelen - l, infp) == NULL)
102									break;	/* No newline terminator on last line */
103							}
104							l = strlen(line) + namlen + 1;
105							if (extendline(&outl, &outlen, l) == -1) {
106								goto mem_abort;
107							}
108							if (*line == '#')
109								strcpy(outl, line);
110							else if (*line == '\n')
111								*outl = '\0';
112							else {
113								int             i,
114									        mno = 0;
115								char           *cp = line;
116								char const     *sep = ":\n";
117								struct group    grp;
118
119								memset(&grp, 0, sizeof grp);
120								for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
121									switch (i) {
122									case 0:	/* Group name */
123										grp.gr_name = p;
124										break;
125									case 1:	/* Group password */
126										grp.gr_passwd = p;
127										break;
128									case 2:	/* Group id */
129										grp.gr_gid = atoi(p);
130										break;
131									case 3:	/* Member list */
132										cp = p;
133										sep = ",\n";
134										break;
135									default:	/* Individual members */
136										if (*p) {
137											if (extendarray(&mems, &memlen, mno + 2) == -1) {
138												goto mem_abort;
139											}
140											mems[mno++] = p;
141										}
142										break;
143									}
144								}
145								if (i < 2)	/* Bail out - insufficient fields */
146									continue;
147
148								grp.gr_mem = mems;
149								for (i = mno; i < memlen; i++)
150									mems[i] = NULL;
151
152								/*
153								 * Delete from group, or add to group?
154								 */
155								if (groups == NULL || isingroup(grp.gr_name, groups) == -1) {	/* Delete */
156									int             idx;
157
158									while ((idx = isingroup(name, mems)) != -1) {
159										for (i = idx; i < (memlen - 1); i++)
160											mems[i] = mems[i + 1];
161										mems[i] = NULL;
162										--mno;
163									}
164									/*
165									 * Special case - deleting user and group may be user's own
166									 */
167									if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
168										/*
169										 * First, make _sure_ we don't have other members
170										 */
171										struct passwd  *pwd;
172
173										setpwent();
174										while ((pwd = getpwent()) != NULL && pwd->pw_gid != grp.gr_gid);
175										endpwent();
176										if (pwd == NULL)	/* No members at all */
177											continue;	/* Drop the group */
178									}
179								} else if (isingroup(name, mems) == -1) {
180									if (extendarray(&mems, &memlen, mno + 2) == -1) {
181										goto mem_abort;
182									}
183									grp.gr_mem = mems;    /* May have realloced() */
184									mems[mno++] = name;
185									mems[mno  ] = NULL;
186								}
187								fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
188							}
189							fputs(outl, outfp);
190						}
191						if (fflush(outfp) != EOF) {
192							rc = 1;
193
194							/*
195							 * Copy data back into the original file and truncate
196							 */
197							rewind(infp);
198							rewind(outfp);
199							while (fgets(outl, outlen, outfp) != NULL)
200								fputs(outl, infp);
201
202							/*
203							 * This is a gross hack, but we may have corrupted the
204							 * original file. Unfortunately, it will lose preservation
205							 * of the inode.
206							 */
207							if (fflush(infp) == EOF || ferror(infp))
208								rc = rename(grouptmp, groupfile) == 0;
209							else
210								ftruncate(infd, ftell(infp));
211						}
212					}
213					free(mems);
214					free(outl);
215			    		free(line);
216					fclose(outfp);
217				}
218				remove(grouptmp);
219			}
220			fclose(infp);
221		}
222	}
223	return rc;
224}
225