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mirror of https://git.FreeBSD.org/src.git synced 2024-12-22 11:17:19 +00:00
freebsd/usr.sbin/pw/edgroup.c
Ken Smith fc1007e186 Shift file locking to source file instead of temp file. This fixes
data buffering issue that corrupts files if two pw(8)'s run at the
same time as well as changing pw(8) so it uses the same locking
mechanism as PAM, vipw(8), pwd_mkdb(8), etc.

PR:		bin/23501
Submitted by:	Alex Kapranoff <alex (at) kapran (dot) bitmcnit (dot) bryansk (dot) su>
Approved by:	rwatson (mentor)
MFC after:	5 days
2004-03-08 20:31:37 +00:00

230 lines
6.4 KiB
C

/*-
* Copyright (C) 1996
* David L. Nugent. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <pwd.h>
#include <grp.h>
#include <fcntl.h>
#include <sys/param.h>
#include <ctype.h>
#include "pwupd.h"
static int
isingroup(char const * name, char **mem)
{
int i;
for (i = 0; mem[i] != NULL; i++)
if (strcmp(name, mem[i]) == 0)
return i;
return -1;
}
int
editgroups(char *name, char **groups)
{
int rc = 0;
int infd;
char groupfile[MAXPATHLEN];
char grouptmp[MAXPATHLEN];
strncpy(groupfile, getgrpath(_GROUP), MAXPATHLEN - 5);
groupfile[MAXPATHLEN - 5] = '\0';
strcpy(grouptmp, groupfile);
strcat(grouptmp, ".new");
if ((infd = open(groupfile, O_RDWR | O_CREAT | O_EXLOCK, 0644)) != -1) {
FILE *infp;
if ((infp = fdopen(infd, "r+")) == NULL)
close(infd);
else {
int outfd;
if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC, 0644)) != -1) {
FILE *outfp;
if ((outfp = fdopen(outfd, "w+")) == NULL)
close(outfd);
else {
int linelen = PWBUFSZ;
int outlen = PWBUFSZ;
int memlen = 200; /* Arbitrary */
char *line = malloc(linelen);
char *outl = malloc(outlen);
char **mems = malloc(memlen * sizeof(char *));
int namlen = strlen(name);
if (line == NULL || outl == NULL || mems == NULL) {
mem_abort:
rc = 0;
} else {
while (fgets(line, linelen, infp) != NULL) {
char *p;
int l;
while ((p = strchr(line, '\n')) == NULL)
{
if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
goto mem_abort;
}
l = strlen(line);
if (fgets(line + l, linelen - l, infp) == NULL)
break; /* No newline terminator on last line */
}
l = strlen(line) + namlen + 1;
if (extendline(&outl, &outlen, l) == -1) {
goto mem_abort;
}
if (*line == '#')
strcpy(outl, line);
else if (*line == '\n')
*outl = '\0';
else {
int i,
mno = 0;
char *cp = line;
char const *sep = ":\n";
struct group grp;
memset(&grp, 0, sizeof grp);
for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
switch (i) {
case 0: /* Group name */
grp.gr_name = p;
break;
case 1: /* Group password */
grp.gr_passwd = p;
break;
case 2: /* Group id */
grp.gr_gid = atoi(p);
break;
case 3: /* Member list */
cp = p;
sep = ",\n";
break;
default: /* Individual members */
if (*p) {
if (extendarray(&mems, &memlen, mno + 2) == -1) {
goto mem_abort;
}
mems[mno++] = p;
}
break;
}
}
if (i < 2) /* Bail out - insufficient fields */
continue;
grp.gr_mem = mems;
for (i = mno; i < memlen; i++)
mems[i] = NULL;
/*
* Delete from group, or add to group?
*/
if (groups == NULL || isingroup(grp.gr_name, groups) == -1) { /* Delete */
int idx;
while ((idx = isingroup(name, mems)) != -1) {
for (i = idx; i < (memlen - 1); i++)
mems[i] = mems[i + 1];
mems[i] = NULL;
--mno;
}
/*
* Special case - deleting user and group may be user's own
*/
if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
/*
* First, make _sure_ we don't have other members
*/
struct passwd *pwd;
SETPWENT();
while ((pwd = GETPWENT()) != NULL && (gid_t)pwd->pw_gid != (gid_t)grp.gr_gid);
ENDPWENT();
if (pwd == NULL) /* No members at all */
continue; /* Drop the group */
}
} else if (isingroup(name, mems) == -1) {
if (extendarray(&mems, &memlen, mno + 2) == -1) {
goto mem_abort;
}
grp.gr_mem = mems; /* May have realloced() */
mems[mno++] = name;
mems[mno ] = NULL;
}
fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
}
fputs(outl, outfp);
}
if (fflush(outfp) != EOF) {
rc = 1;
/*
* Copy data back into the original file and truncate
*/
rewind(infp);
rewind(outfp);
while (fgets(outl, outlen, outfp) != NULL)
fputs(outl, infp);
/*
* This is a gross hack, but we may have corrupted the
* original file.
*/
if (fflush(infp) == EOF || ferror(infp))
rc = rename(grouptmp, groupfile) == 0;
else
ftruncate(infd, ftell(infp));
}
}
free(mems);
free(outl);
free(line);
fclose(outfp);
}
remove(grouptmp);
}
fclose(infp);
}
}
return rc;
}