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mirror of https://git.FreeBSD.org/src.git synced 2024-12-24 11:29:10 +00:00
freebsd/lib/libc/gen/getgrent.c
Wolfram Schneider 4ccb26e49a Allow comments in group database.
The character `#' introduces a comment. Leading spaces and tabs are
ignored: '^[ \t]*#.*\n$'

Count an empty line - only spaces, tabs or newline - also as a comment.
(to be compatibel with password database comments). '^[ \t]*\n$'
1997-03-08 16:21:40 +00:00

554 lines
12 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getgrent.c 8.2 (Berkeley) 3/21/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <grp.h>
static FILE *_gr_fp;
static struct group _gr_group;
static int _gr_stayopen;
static int grscan(), start_gr();
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
static int _gr_stepping_yp;
static int _gr_yp_enabled;
static int _getypgroup(struct group *, const char *, char *);
static int _nextypgroup(struct group *);
#endif
/* initial size for malloc and increase steps for realloc */
#define MAXGRP 64
#define MAXLINELENGTH 256
static char **members; /* list of group members */
static int maxgrp; /* current length of **mebers */
static char *line; /* temp buffer for group line */
static int maxlinelength; /* current length of *line */
/*
* Lines longer than MAXLINELENGTHLIMIT will be count as an error.
* <= 0 disable check for maximum line length
* 256K is enough for 64,000 uids
*/
#define MAXLINELENGTHLIMIT (256 * 1024)
#define GROUP_IGNORE_COMMENTS 1 /* allow comments in /etc/group */
struct group *
getgrent()
{
if (!_gr_fp && !start_gr()) {
return NULL;
}
#ifdef YP
if (_gr_stepping_yp) {
if (_nextypgroup(&_gr_group))
return(&_gr_group);
}
tryagain:
#endif
if (!grscan(0, 0, NULL))
return(NULL);
#ifdef YP
if(_gr_group.gr_name[0] == '+' && _gr_group.gr_name[1]) {
_getypgroup(&_gr_group, &_gr_group.gr_name[1],
"group.byname");
} else if(_gr_group.gr_name[0] == '+') {
if (!_nextypgroup(&_gr_group))
goto tryagain;
else
return(&_gr_group);
}
#endif
return(&_gr_group);
}
struct group *
getgrnam(name)
const char *name;
{
int rval;
if (!start_gr())
return(NULL);
#ifdef YP
tryagain:
#endif
rval = grscan(1, 0, name);
#ifdef YP
if(rval == -1 && (_gr_yp_enabled < 0 || (_gr_yp_enabled &&
_gr_group.gr_name[0] == '+'))) {
if (!(rval = _getypgroup(&_gr_group, name, "group.byname")))
goto tryagain;
}
#endif
if (!_gr_stayopen)
endgrent();
return(rval ? &_gr_group : NULL);
}
struct group *
#ifdef __STDC__
getgrgid(gid_t gid)
#else
getgrgid(gid)
gid_t gid;
#endif
{
int rval;
if (!start_gr())
return(NULL);
#ifdef YP
tryagain:
#endif
rval = grscan(1, gid, NULL);
#ifdef YP
if(rval == -1 && _gr_yp_enabled) {
char buf[16];
snprintf(buf, sizeof buf, "%d", (unsigned)gid);
if (!(rval = _getypgroup(&_gr_group, buf, "group.bygid")))
goto tryagain;
}
#endif
if (!_gr_stayopen)
endgrent();
return(rval ? &_gr_group : NULL);
}
static int
start_gr()
{
if (_gr_fp) {
rewind(_gr_fp);
return(1);
}
_gr_fp = fopen(_PATH_GROUP, "r");
if(!_gr_fp) return 0;
#ifdef YP
/*
* This is a disgusting hack, used to determine when YP is enabled.
* This would be easier if we had a group database to go along with
* the password database.
*/
{
char *line;
size_t linelen;
_gr_yp_enabled = 0;
while((line = fgetln(_gr_fp, &linelen)) != NULL) {
if(line[0] == '+') {
if(line[1] && line[1] != ':' && !_gr_yp_enabled) {
_gr_yp_enabled = 1;
} else {
_gr_yp_enabled = -1;
break;
}
}
}
rewind(_gr_fp);
}
#endif
if (maxlinelength == 0) {
if ((line = (char *)malloc(sizeof(char) *
MAXLINELENGTH)) == NULL)
return(0);
maxlinelength += MAXLINELENGTH;
}
if (maxgrp == 0) {
if ((members = (char **)malloc(sizeof(char **) *
MAXGRP)) == NULL)
return(0);
maxgrp += MAXGRP;
}
return 1;
}
int
setgrent()
{
return(setgroupent(0));
}
int
setgroupent(stayopen)
int stayopen;
{
if (!start_gr())
return(0);
_gr_stayopen = stayopen;
#ifdef YP
_gr_stepping_yp = 0;
#endif
return(1);
}
void
endgrent()
{
#ifdef YP
_gr_stepping_yp = 0;
#endif
if (_gr_fp) {
(void)fclose(_gr_fp);
_gr_fp = NULL;
}
}
static int
grscan(search, gid, name)
register int search, gid;
register char *name;
{
register char *cp, **m;
char *bp;
#ifdef YP
int _ypfound;
#endif
for (;;) {
#ifdef YP
_ypfound = 0;
#endif
if (fgets(line, maxlinelength, _gr_fp) == NULL)
return(0);
if (!index(line, '\n')) {
do {
if (feof(_gr_fp))
return(0);
/* don't allocate infinite memory */
if (MAXLINELENGTHLIMIT > 0 &&
maxlinelength >= MAXLINELENGTHLIMIT)
return(0);
if ((line = (char *)realloc(line,
sizeof(char) *
(maxlinelength + MAXLINELENGTH))) == NULL)
return(0);
if (fgets(line + maxlinelength - 1,
MAXLINELENGTH + 1, _gr_fp) == NULL)
return(0);
maxlinelength += MAXLINELENGTH;
} while (!index(line + maxlinelength -
MAXLINELENGTH - 1, '\n'));
}
#ifdef GROUP_IGNORE_COMMENTS
/*
* Ignore comments: ^[ \t]*#
*/
for (cp = line; *cp != '\0'; cp++)
if (*cp != ' ' && *cp != '\t')
break;
if (*cp == '#' || *cp == '\0')
continue;
#endif
bp = line;
if ((_gr_group.gr_name = strsep(&bp, ":\n")) == NULL)
break;
#ifdef YP
/*
* XXX We need to be careful to avoid proceeding
* past this point under certain circumstances or
* we risk dereferencing null pointers down below.
*/
if (_gr_group.gr_name[0] == '+') {
if (strlen(_gr_group.gr_name) == 1) {
switch(search) {
case 0:
return(1);
case 1:
return(-1);
default:
return(0);
}
} else {
cp = &_gr_group.gr_name[1];
if (search && name != NULL)
if (strcmp(cp, name))
continue;
if (!_getypgroup(&_gr_group, cp,
"group.byname"))
continue;
if (search && name == NULL)
if (gid != _gr_group.gr_gid)
continue;
/* We're going to override -- tell the world. */
_ypfound++;
}
}
#else
if (_gr_group.gr_name[0] == '+')
continue;
#endif /* YP */
if (search && name) {
if(strcmp(_gr_group.gr_name, name)) {
continue;
}
}
#ifdef YP
if ((cp = strsep(&bp, ":\n")) == NULL)
if (_ypfound)
return(1);
else
break;
if (strlen(cp) || !_ypfound)
_gr_group.gr_passwd = cp;
#else
if ((_gr_group.gr_passwd = strsep(&bp, ":\n")) == NULL)
break;
#endif
if (!(cp = strsep(&bp, ":\n")))
#ifdef YP
if (_ypfound)
return(1);
else
#endif
continue;
#ifdef YP
/*
* Hurm. Should we be doing this? We allow UIDs to
* be overridden -- what about GIDs?
*/
if (!_ypfound)
#endif
_gr_group.gr_gid = atoi(cp);
if (search && name == NULL && _gr_group.gr_gid != gid)
continue;
cp = NULL;
if (bp == NULL) /* !!! Must check for this! */
break;
#ifdef YP
if ((cp = strsep(&bp, ":\n")) == NULL)
break;
if (!strlen(cp) && _ypfound)
return(1);
else
members[0] = NULL;
bp = cp;
cp = NULL;
#endif
for (m = members; ; bp++) {
if (m == (members + maxgrp - 1)) {
if ((members = (char **)
realloc(members,
sizeof(char **) *
(maxgrp + MAXGRP))) == NULL)
return(0);
m = members + maxgrp - 1;
maxgrp += MAXGRP;
}
if (*bp == ',') {
if (cp) {
*bp = '\0';
*m++ = cp;
cp = NULL;
}
} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
if (cp) {
*bp = '\0';
*m++ = cp;
}
break;
} else if (cp == NULL)
cp = bp;
}
_gr_group.gr_mem = members;
*m = NULL;
return(1);
}
/* NOTREACHED */
return (0);
}
#ifdef YP
static int
_gr_breakout_yp(struct group *gr, char *result)
{
char *s, *cp;
char **m;
/*
* XXX If 's' ends up being a NULL pointer, punt on this group.
* It means the NIS group entry is badly formatted and should
* be skipped.
*/
if ((s = strsep(&result, ":")) == NULL) return 0; /* name */
gr->gr_name = s;
if ((s = strsep(&result, ":")) == NULL) return 0; /* password */
gr->gr_passwd = s;
if ((s = strsep(&result, ":")) == NULL) return 0; /* gid */
gr->gr_gid = atoi(s);
if ((s = result) == NULL) return 0;
cp = 0;
for (m = members; ; s++) {
if (m == members + maxgrp - 1) {
if ((members = (char **)realloc(members,
sizeof(char **) * (maxgrp + MAXGRP))) == NULL)
return(0);
m = members + maxgrp - 1;
maxgrp += MAXGRP;
}
if (*s == ',') {
if (cp) {
*s = '\0';
*m++ = cp;
cp = NULL;
}
} else if (*s == '\0' || *s == '\n' || *s == ' ') {
if (cp) {
*s = '\0';
*m++ = cp;
}
break;
} else if (cp == NULL) {
cp = s;
}
}
_gr_group.gr_mem = members;
*m = NULL;
return 1;
}
static char *_gr_yp_domain;
static int
_getypgroup(struct group *gr, const char *name, char *map)
{
char *result, *s;
static char resultbuf[YPMAXRECORD + 2];
int resultlen;
if(!_gr_yp_domain) {
if(yp_get_default_domain(&_gr_yp_domain))
return 0;
}
if(yp_match(_gr_yp_domain, map, name, strlen(name),
&result, &resultlen))
return 0;
s = strchr(result, '\n');
if(s) *s = '\0';
if(resultlen >= sizeof resultbuf) return 0;
strncpy(resultbuf, result, resultlen);
resultbuf[resultlen] = '\0';
free(result);
return(_gr_breakout_yp(gr, resultbuf));
}
static int
_nextypgroup(struct group *gr)
{
static char *key;
static int keylen;
char *lastkey, *result;
static char resultbuf[YPMAXRECORD + 2];
int resultlen;
int rv;
if(!_gr_yp_domain) {
if(yp_get_default_domain(&_gr_yp_domain))
return 0;
}
if(!_gr_stepping_yp) {
if(key) free(key);
rv = yp_first(_gr_yp_domain, "group.byname",
&key, &keylen, &result, &resultlen);
if(rv) {
return 0;
}
_gr_stepping_yp = 1;
goto unpack;
} else {
tryagain:
lastkey = key;
rv = yp_next(_gr_yp_domain, "group.byname", key, keylen,
&key, &keylen, &result, &resultlen);
free(lastkey);
unpack:
if(rv) {
_gr_stepping_yp = 0;
return 0;
}
if(resultlen > sizeof(resultbuf)) {
free(result);
goto tryagain;
}
strncpy(resultbuf, result, resultlen);
resultbuf[resultlen] = '\0';
free(result);
if((result = strchr(resultbuf, '\n')) != NULL)
*result = '\0';
if (_gr_breakout_yp(gr, resultbuf))
return(1);
else
goto tryagain;
}
}
#endif /* YP */