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freebsd-dev/lib/libc/gen/getgrent.c
Edward Tomasz Napierala 8bb6c72e63 Get rid unneccessary useless calls to lseek(2) from getgrent(3). 
Looks like this:

 fstatat(AT_FDCWD,"/etc/nsswitch.conf",{ mode=-rw-r--r-- ,inode=2167001,size=390,blksize=32768 },0x0) = 0 (0x0)
 open("/etc/group",O_RDONLY|O_CLOEXEC,0666)      = 3 (0x3)
 fstat(3,{ mode=-rw-r--r-- ,inode=2166927,size=919,blksize=32768 }) = 0 (0x0)
-lseek(3,0x0,SEEK_CUR)                           = 0 (0x0)
-lseek(3,0x0,SEEK_SET)                           = 0 (0x0)
 read(3,"# $FreeBSD: release/10.0.0/etc/g"...,32768) = 919 (0x397)
 close(3)                                        = 0 (0x0)

Reviewed by:	kib
Approved by:	re (gjb)
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D17571
2018-10-16 18:17:07 +00:00

1569 lines
34 KiB
C
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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed for the FreeBSD Project by
* Jacques A. Vidrine, Safeport Network Services, and Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* 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 THE AUTHOR 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 AUTHOR 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/param.h>
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#ifdef HESIOD
#include <hesiod.h>
#endif
#include <grp.h>
#include <nsswitch.h>
#include <pthread.h>
#include <pthread_np.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "nss_tls.h"
#ifdef NS_CACHING
#include "nscache.h"
#endif
enum constants {
GRP_STORAGE_INITIAL = 1 << 10, /* 1 KByte */
GRP_STORAGE_MAX = 1 << 20, /* 1 MByte */
SETGRENT = 1,
ENDGRENT = 2,
HESIOD_NAME_MAX = 256,
};
static const ns_src defaultsrc[] = {
{ NSSRC_COMPAT, NS_SUCCESS },
{ NULL, 0 }
};
int __getgroupmembership(const char *, gid_t, gid_t *, int, int *);
int __gr_match_entry(const char *, size_t, enum nss_lookup_type,
const char *, gid_t);
int __gr_parse_entry(char *, size_t, struct group *, char *, size_t,
int *);
static int is_comment_line(const char *, size_t);
union key {
const char *name;
gid_t gid;
};
static struct group *getgr(int (*)(union key, struct group *, char *, size_t,
struct group **), union key);
static int wrap_getgrnam_r(union key, struct group *, char *, size_t,
struct group **);
static int wrap_getgrgid_r(union key, struct group *, char *, size_t,
struct group **);
static int wrap_getgrent_r(union key, struct group *, char *, size_t,
struct group **);
struct files_state {
FILE *fp;
int stayopen;
};
static void files_endstate(void *);
NSS_TLS_HANDLING(files);
static int files_setgrent(void *, void *, va_list);
static int files_group(void *, void *, va_list);
#ifdef HESIOD
struct dns_state {
long counter;
};
static void dns_endstate(void *);
NSS_TLS_HANDLING(dns);
static int dns_setgrent(void *, void *, va_list);
static int dns_group(void *, void *, va_list);
#endif
#ifdef YP
struct nis_state {
char domain[MAXHOSTNAMELEN];
int done;
char *key;
int keylen;
};
static void nis_endstate(void *);
NSS_TLS_HANDLING(nis);
static int nis_setgrent(void *, void *, va_list);
static int nis_group(void *, void *, va_list);
#endif
struct compat_state {
FILE *fp;
int stayopen;
char *name;
enum _compat {
COMPAT_MODE_OFF = 0,
COMPAT_MODE_ALL,
COMPAT_MODE_NAME
} compat;
};
static void compat_endstate(void *);
NSS_TLS_HANDLING(compat);
static int compat_setgrent(void *, void *, va_list);
static int compat_group(void *, void *, va_list);
static int gr_addgid(gid_t, gid_t *, int, int *);
static int getgroupmembership_fallback(void *, void *, va_list);
#ifdef NS_CACHING
static int grp_id_func(char *, size_t *, va_list, void *);
static int grp_marshal_func(char *, size_t *, void *, va_list, void *);
static int grp_unmarshal_func(char *, size_t, void *, va_list, void *);
static int
grp_id_func(char *buffer, size_t *buffer_size, va_list ap, void *cache_mdata)
{
char *name;
gid_t gid;
size_t desired_size, size;
int res = NS_UNAVAIL;
enum nss_lookup_type lookup_type;
lookup_type = (enum nss_lookup_type)cache_mdata;
switch (lookup_type) {
case nss_lt_name:
name = va_arg(ap, char *);
size = strlen(name);
desired_size = sizeof(enum nss_lookup_type) + size + 1;
if (desired_size > *buffer_size) {
res = NS_RETURN;
goto fin;
}
memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
memcpy(buffer + sizeof(enum nss_lookup_type), name, size + 1);
res = NS_SUCCESS;
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
desired_size = sizeof(enum nss_lookup_type) + sizeof(gid_t);
if (desired_size > *buffer_size) {
res = NS_RETURN;
goto fin;
}
memcpy(buffer, &lookup_type, sizeof(enum nss_lookup_type));
memcpy(buffer + sizeof(enum nss_lookup_type), &gid,
sizeof(gid_t));
res = NS_SUCCESS;
break;
default:
/* should be unreachable */
return (NS_UNAVAIL);
}
fin:
*buffer_size = desired_size;
return (res);
}
static int
grp_marshal_func(char *buffer, size_t *buffer_size, void *retval, va_list ap,
void *cache_mdata)
{
char *name;
gid_t gid;
struct group *grp;
char *orig_buf;
size_t orig_buf_size;
struct group new_grp;
size_t desired_size, size, mem_size;
char *p, **mem;
switch ((enum nss_lookup_type)cache_mdata) {
case nss_lt_name:
name = va_arg(ap, char *);
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
break;
case nss_lt_all:
break;
default:
/* should be unreachable */
return (NS_UNAVAIL);
}
grp = va_arg(ap, struct group *);
orig_buf = va_arg(ap, char *);
orig_buf_size = va_arg(ap, size_t);
desired_size = _ALIGNBYTES + sizeof(struct group) + sizeof(char *);
if (grp->gr_name != NULL)
desired_size += strlen(grp->gr_name) + 1;
if (grp->gr_passwd != NULL)
desired_size += strlen(grp->gr_passwd) + 1;
if (grp->gr_mem != NULL) {
mem_size = 0;
for (mem = grp->gr_mem; *mem; ++mem) {
desired_size += strlen(*mem) + 1;
++mem_size;
}
desired_size += _ALIGNBYTES + (mem_size + 1) * sizeof(char *);
}
if (desired_size > *buffer_size) {
/* this assignment is here for future use */
*buffer_size = desired_size;
return (NS_RETURN);
}
memcpy(&new_grp, grp, sizeof(struct group));
memset(buffer, 0, desired_size);
*buffer_size = desired_size;
p = buffer + sizeof(struct group) + sizeof(char *);
memcpy(buffer + sizeof(struct group), &p, sizeof(char *));
p = (char *)_ALIGN(p);
if (new_grp.gr_name != NULL) {
size = strlen(new_grp.gr_name);
memcpy(p, new_grp.gr_name, size);
new_grp.gr_name = p;
p += size + 1;
}
if (new_grp.gr_passwd != NULL) {
size = strlen(new_grp.gr_passwd);
memcpy(p, new_grp.gr_passwd, size);
new_grp.gr_passwd = p;
p += size + 1;
}
if (new_grp.gr_mem != NULL) {
p = (char *)_ALIGN(p);
memcpy(p, new_grp.gr_mem, sizeof(char *) * mem_size);
new_grp.gr_mem = (char **)p;
p += sizeof(char *) * (mem_size + 1);
for (mem = new_grp.gr_mem; *mem; ++mem) {
size = strlen(*mem);
memcpy(p, *mem, size);
*mem = p;
p += size + 1;
}
}
memcpy(buffer, &new_grp, sizeof(struct group));
return (NS_SUCCESS);
}
static int
grp_unmarshal_func(char *buffer, size_t buffer_size, void *retval, va_list ap,
void *cache_mdata)
{
char *name;
gid_t gid;
struct group *grp;
char *orig_buf;
size_t orig_buf_size;
int *ret_errno;
char *p;
char **mem;
switch ((enum nss_lookup_type)cache_mdata) {
case nss_lt_name:
name = va_arg(ap, char *);
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
break;
case nss_lt_all:
break;
default:
/* should be unreachable */
return (NS_UNAVAIL);
}
grp = va_arg(ap, struct group *);
orig_buf = va_arg(ap, char *);
orig_buf_size = va_arg(ap, size_t);
ret_errno = va_arg(ap, int *);
if (orig_buf_size <
buffer_size - sizeof(struct group) - sizeof(char *)) {
*ret_errno = ERANGE;
return (NS_RETURN);
}
memcpy(grp, buffer, sizeof(struct group));
memcpy(&p, buffer + sizeof(struct group), sizeof(char *));
orig_buf = (char *)_ALIGN(orig_buf);
memcpy(orig_buf, buffer + sizeof(struct group) + sizeof(char *) +
_ALIGN(p) - (size_t)p,
buffer_size - sizeof(struct group) - sizeof(char *) -
_ALIGN(p) + (size_t)p);
p = (char *)_ALIGN(p);
NS_APPLY_OFFSET(grp->gr_name, orig_buf, p, char *);
NS_APPLY_OFFSET(grp->gr_passwd, orig_buf, p, char *);
if (grp->gr_mem != NULL) {
NS_APPLY_OFFSET(grp->gr_mem, orig_buf, p, char **);
for (mem = grp->gr_mem; *mem; ++mem)
NS_APPLY_OFFSET(*mem, orig_buf, p, char *);
}
if (retval != NULL)
*((struct group **)retval) = grp;
return (NS_SUCCESS);
}
NSS_MP_CACHE_HANDLING(group);
#endif /* NS_CACHING */
#ifdef NS_CACHING
static const nss_cache_info setgrent_cache_info = NS_MP_CACHE_INFO_INITIALIZER(
group, (void *)nss_lt_all,
NULL, NULL);
#endif
static const ns_dtab setgrent_dtab[] = {
{ NSSRC_FILES, files_setgrent, (void *)SETGRENT },
#ifdef HESIOD
{ NSSRC_DNS, dns_setgrent, (void *)SETGRENT },
#endif
#ifdef YP
{ NSSRC_NIS, nis_setgrent, (void *)SETGRENT },
#endif
{ NSSRC_COMPAT, compat_setgrent, (void *)SETGRENT },
#ifdef NS_CACHING
NS_CACHE_CB(&setgrent_cache_info)
#endif
{ NULL, NULL, NULL }
};
#ifdef NS_CACHING
static const nss_cache_info endgrent_cache_info = NS_MP_CACHE_INFO_INITIALIZER(
group, (void *)nss_lt_all,
NULL, NULL);
#endif
static const ns_dtab endgrent_dtab[] = {
{ NSSRC_FILES, files_setgrent, (void *)ENDGRENT },
#ifdef HESIOD
{ NSSRC_DNS, dns_setgrent, (void *)ENDGRENT },
#endif
#ifdef YP
{ NSSRC_NIS, nis_setgrent, (void *)ENDGRENT },
#endif
{ NSSRC_COMPAT, compat_setgrent, (void *)ENDGRENT },
#ifdef NS_CACHING
NS_CACHE_CB(&endgrent_cache_info)
#endif
{ NULL, NULL, NULL }
};
#ifdef NS_CACHING
static const nss_cache_info getgrent_r_cache_info = NS_MP_CACHE_INFO_INITIALIZER(
group, (void *)nss_lt_all,
grp_marshal_func, grp_unmarshal_func);
#endif
static const ns_dtab getgrent_r_dtab[] = {
{ NSSRC_FILES, files_group, (void *)nss_lt_all },
#ifdef HESIOD
{ NSSRC_DNS, dns_group, (void *)nss_lt_all },
#endif
#ifdef YP
{ NSSRC_NIS, nis_group, (void *)nss_lt_all },
#endif
{ NSSRC_COMPAT, compat_group, (void *)nss_lt_all },
#ifdef NS_CACHING
NS_CACHE_CB(&getgrent_r_cache_info)
#endif
{ NULL, NULL, NULL }
};
static int
gr_addgid(gid_t gid, gid_t *groups, int maxgrp, int *grpcnt)
{
int ret, dupc;
for (dupc = 1; dupc < MIN(maxgrp, *grpcnt); dupc++) {
if (groups[dupc] == gid)
return 1;
}
ret = 1;
if (*grpcnt < maxgrp)
groups[*grpcnt] = gid;
else
ret = 0;
(*grpcnt)++;
return ret;
}
static int
getgroupmembership_fallback(void *retval, void *mdata, va_list ap)
{
const ns_src src[] = {
{ mdata, NS_SUCCESS },
{ NULL, 0}
};
struct group grp;
struct group *grp_p;
char *buf;
size_t bufsize;
const char *uname;
gid_t *groups;
gid_t agroup;
int maxgrp, *grpcnt;
int i, rv, ret_errno;
/*
* As this is a fallback method, only provided src
* list will be respected during methods search.
*/
assert(src[0].name != NULL);
uname = va_arg(ap, const char *);
agroup = va_arg(ap, gid_t);
groups = va_arg(ap, gid_t *);
maxgrp = va_arg(ap, int);
grpcnt = va_arg(ap, int *);
rv = NS_UNAVAIL;
buf = malloc(GRP_STORAGE_INITIAL);
if (buf == NULL)
goto out;
bufsize = GRP_STORAGE_INITIAL;
gr_addgid(agroup, groups, maxgrp, grpcnt);
_nsdispatch(NULL, setgrent_dtab, NSDB_GROUP, "setgrent", src, 0);
for (;;) {
do {
ret_errno = 0;
grp_p = NULL;
rv = _nsdispatch(&grp_p, getgrent_r_dtab, NSDB_GROUP,
"getgrent_r", src, &grp, buf, bufsize, &ret_errno);
if (grp_p == NULL && ret_errno == ERANGE) {
free(buf);
if ((bufsize << 1) > GRP_STORAGE_MAX) {
buf = NULL;
errno = ERANGE;
goto out;
}
bufsize <<= 1;
buf = malloc(bufsize);
if (buf == NULL) {
goto out;
}
}
} while (grp_p == NULL && ret_errno == ERANGE);
if (ret_errno != 0) {
errno = ret_errno;
goto out;
}
if (grp_p == NULL)
break;
for (i = 0; grp.gr_mem[i]; i++) {
if (strcmp(grp.gr_mem[i], uname) == 0)
gr_addgid(grp.gr_gid, groups, maxgrp, grpcnt);
}
}
_nsdispatch(NULL, endgrent_dtab, NSDB_GROUP, "endgrent", src);
out:
free(buf);
return (rv);
}
void
setgrent(void)
{
(void)_nsdispatch(NULL, setgrent_dtab, NSDB_GROUP, "setgrent", defaultsrc, 0);
}
int
setgroupent(int stayopen)
{
(void)_nsdispatch(NULL, setgrent_dtab, NSDB_GROUP, "setgrent", defaultsrc,
stayopen);
return (1);
}
void
endgrent(void)
{
(void)_nsdispatch(NULL, endgrent_dtab, NSDB_GROUP, "endgrent", defaultsrc);
}
int
getgrent_r(struct group *grp, char *buffer, size_t bufsize,
struct group **result)
{
int rv, ret_errno;
ret_errno = 0;
*result = NULL;
rv = _nsdispatch(result, getgrent_r_dtab, NSDB_GROUP, "getgrent_r", defaultsrc,
grp, buffer, bufsize, &ret_errno);
if (rv == NS_SUCCESS)
return (0);
else
return (ret_errno);
}
int
getgrnam_r(const char *name, struct group *grp, char *buffer, size_t bufsize,
struct group **result)
{
#ifdef NS_CACHING
static const nss_cache_info cache_info =
NS_COMMON_CACHE_INFO_INITIALIZER(
group, (void *)nss_lt_name,
grp_id_func, grp_marshal_func, grp_unmarshal_func);
#endif
static const ns_dtab dtab[] = {
{ NSSRC_FILES, files_group, (void *)nss_lt_name },
#ifdef HESIOD
{ NSSRC_DNS, dns_group, (void *)nss_lt_name },
#endif
#ifdef YP
{ NSSRC_NIS, nis_group, (void *)nss_lt_name },
#endif
{ NSSRC_COMPAT, compat_group, (void *)nss_lt_name },
#ifdef NS_CACHING
NS_CACHE_CB(&cache_info)
#endif
{ NULL, NULL, NULL }
};
int rv, ret_errno;
ret_errno = 0;
*result = NULL;
rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrnam_r", defaultsrc,
name, grp, buffer, bufsize, &ret_errno);
if (rv == NS_SUCCESS)
return (0);
else
return (ret_errno);
}
int
getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t bufsize,
struct group **result)
{
#ifdef NS_CACHING
static const nss_cache_info cache_info =
NS_COMMON_CACHE_INFO_INITIALIZER(
group, (void *)nss_lt_id,
grp_id_func, grp_marshal_func, grp_unmarshal_func);
#endif
static const ns_dtab dtab[] = {
{ NSSRC_FILES, files_group, (void *)nss_lt_id },
#ifdef HESIOD
{ NSSRC_DNS, dns_group, (void *)nss_lt_id },
#endif
#ifdef YP
{ NSSRC_NIS, nis_group, (void *)nss_lt_id },
#endif
{ NSSRC_COMPAT, compat_group, (void *)nss_lt_id },
#ifdef NS_CACHING
NS_CACHE_CB(&cache_info)
#endif
{ NULL, NULL, NULL }
};
int rv, ret_errno;
ret_errno = 0;
*result = NULL;
rv = _nsdispatch(result, dtab, NSDB_GROUP, "getgrgid_r", defaultsrc,
gid, grp, buffer, bufsize, &ret_errno);
if (rv == NS_SUCCESS)
return (0);
else
return (ret_errno);
}
int
__getgroupmembership(const char *uname, gid_t agroup, gid_t *groups,
int maxgrp, int *grpcnt)
{
static const ns_dtab dtab[] = {
NS_FALLBACK_CB(getgroupmembership_fallback)
{ NULL, NULL, NULL }
};
assert(uname != NULL);
/* groups may be NULL if just sizing when invoked with maxgrp = 0 */
assert(grpcnt != NULL);
*grpcnt = 0;
(void)_nsdispatch(NULL, dtab, NSDB_GROUP, "getgroupmembership",
defaultsrc, uname, agroup, groups, maxgrp, grpcnt);
/* too many groups found? */
return (*grpcnt > maxgrp ? -1 : 0);
}
static struct group grp;
static char *grp_storage;
static size_t grp_storage_size;
static struct group *
getgr(int (*fn)(union key, struct group *, char *, size_t, struct group **),
union key key)
{
int rv;
struct group *res;
if (grp_storage == NULL) {
grp_storage = malloc(GRP_STORAGE_INITIAL);
if (grp_storage == NULL)
return (NULL);
grp_storage_size = GRP_STORAGE_INITIAL;
}
do {
rv = fn(key, &grp, grp_storage, grp_storage_size, &res);
if (res == NULL && rv == ERANGE) {
free(grp_storage);
if ((grp_storage_size << 1) > GRP_STORAGE_MAX) {
grp_storage = NULL;
errno = ERANGE;
return (NULL);
}
grp_storage_size <<= 1;
grp_storage = malloc(grp_storage_size);
if (grp_storage == NULL)
return (NULL);
}
} while (res == NULL && rv == ERANGE);
if (rv != 0)
errno = rv;
return (res);
}
static int
wrap_getgrnam_r(union key key, struct group *grp, char *buffer, size_t bufsize,
struct group **res)
{
return (getgrnam_r(key.name, grp, buffer, bufsize, res));
}
static int
wrap_getgrgid_r(union key key, struct group *grp, char *buffer, size_t bufsize,
struct group **res)
{
return (getgrgid_r(key.gid, grp, buffer, bufsize, res));
}
static int
wrap_getgrent_r(union key key __unused, struct group *grp, char *buffer,
size_t bufsize, struct group **res)
{
return (getgrent_r(grp, buffer, bufsize, res));
}
struct group *
getgrnam(const char *name)
{
union key key;
key.name = name;
return (getgr(wrap_getgrnam_r, key));
}
struct group *
getgrgid(gid_t gid)
{
union key key;
key.gid = gid;
return (getgr(wrap_getgrgid_r, key));
}
struct group *
getgrent(void)
{
union key key;
key.gid = 0; /* not used */
return (getgr(wrap_getgrent_r, key));
}
static int
is_comment_line(const char *s, size_t n)
{
const char *eom;
eom = &s[n];
for (; s < eom; s++)
if (*s == '#' || !isspace((unsigned char)*s))
break;
return (*s == '#' || s == eom);
}
/*
* files backend
*/
static void
files_endstate(void *p)
{
if (p == NULL)
return;
if (((struct files_state *)p)->fp != NULL)
fclose(((struct files_state *)p)->fp);
free(p);
}
static int
files_setgrent(void *retval, void *mdata, va_list ap)
{
struct files_state *st;
int rv, stayopen;
rv = files_getstate(&st);
if (rv != 0)
return (NS_UNAVAIL);
switch ((enum constants)mdata) {
case SETGRENT:
stayopen = va_arg(ap, int);
if (st->fp != NULL)
rewind(st->fp);
else if (stayopen)
st->fp = fopen(_PATH_GROUP, "re");
break;
case ENDGRENT:
if (st->fp != NULL) {
fclose(st->fp);
st->fp = NULL;
}
break;
default:
break;
}
return (NS_UNAVAIL);
}
static int
files_group(void *retval, void *mdata, va_list ap)
{
struct files_state *st;
enum nss_lookup_type how;
const char *name, *line;
struct group *grp;
gid_t gid;
char *buffer;
size_t bufsize, linesize;
off_t pos;
int fresh, rv, stayopen, *errnop;
fresh = 0;
name = NULL;
gid = (gid_t)-1;
how = (enum nss_lookup_type)mdata;
switch (how) {
case nss_lt_name:
name = va_arg(ap, const char *);
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
break;
case nss_lt_all:
break;
default:
return (NS_NOTFOUND);
}
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
*errnop = files_getstate(&st);
if (*errnop != 0)
return (NS_UNAVAIL);
if (st->fp == NULL) {
st->fp = fopen(_PATH_GROUP, "re");
if (st->fp == NULL) {
*errnop = errno;
return (NS_UNAVAIL);
}
fresh = 1;
}
if (how == nss_lt_all)
stayopen = 1;
else {
if (!fresh)
rewind(st->fp);
stayopen = st->stayopen;
}
rv = NS_NOTFOUND;
if (stayopen)
pos = ftello(st->fp);
while ((line = fgetln(st->fp, &linesize)) != NULL) {
if (line[linesize-1] == '\n')
linesize--;
rv = __gr_match_entry(line, linesize, how, name, gid);
if (rv != NS_SUCCESS)
continue;
/* We need room at least for the line, a string NUL
* terminator, alignment padding, and one (char *)
* pointer for the member list terminator.
*/
if (bufsize <= linesize + _ALIGNBYTES + sizeof(char *)) {
*errnop = ERANGE;
rv = NS_RETURN;
break;
}
memcpy(buffer, line, linesize);
buffer[linesize] = '\0';
rv = __gr_parse_entry(buffer, linesize, grp,
&buffer[linesize + 1], bufsize - linesize - 1, errnop);
if (rv & NS_TERMINATE)
break;
if (stayopen)
pos = ftello(st->fp);
}
if (st->fp != NULL && !stayopen) {
fclose(st->fp);
st->fp = NULL;
}
if (rv == NS_SUCCESS && retval != NULL)
*(struct group **)retval = grp;
else if (rv == NS_RETURN && *errnop == ERANGE && st->fp != NULL)
fseeko(st->fp, pos, SEEK_SET);
return (rv);
}
#ifdef HESIOD
/*
* dns backend
*/
static void
dns_endstate(void *p)
{
free(p);
}
static int
dns_setgrent(void *retval, void *cb_data, va_list ap)
{
struct dns_state *st;
int rv;
rv = dns_getstate(&st);
if (rv != 0)
return (NS_UNAVAIL);
st->counter = 0;
return (NS_UNAVAIL);
}
static int
dns_group(void *retval, void *mdata, va_list ap)
{
char buf[HESIOD_NAME_MAX];
struct dns_state *st;
struct group *grp;
const char *name, *label;
void *ctx;
char *buffer, **hes;
size_t bufsize, adjsize, linesize;
gid_t gid;
enum nss_lookup_type how;
int rv, *errnop;
ctx = NULL;
hes = NULL;
name = NULL;
gid = (gid_t)-1;
how = (enum nss_lookup_type)mdata;
switch (how) {
case nss_lt_name:
name = va_arg(ap, const char *);
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
break;
case nss_lt_all:
break;
}
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
*errnop = dns_getstate(&st);
if (*errnop != 0)
return (NS_UNAVAIL);
if (hesiod_init(&ctx) != 0) {
*errnop = errno;
rv = NS_UNAVAIL;
goto fin;
}
do {
rv = NS_NOTFOUND;
switch (how) {
case nss_lt_name:
label = name;
break;
case nss_lt_id:
if (snprintf(buf, sizeof(buf), "%lu",
(unsigned long)gid) >= sizeof(buf))
goto fin;
label = buf;
break;
case nss_lt_all:
if (st->counter < 0)
goto fin;
if (snprintf(buf, sizeof(buf), "group-%ld",
st->counter++) >= sizeof(buf))
goto fin;
label = buf;
break;
}
hes = hesiod_resolve(ctx, label,
how == nss_lt_id ? "gid" : "group");
if ((how == nss_lt_id && hes == NULL &&
(hes = hesiod_resolve(ctx, buf, "group")) == NULL) ||
hes == NULL) {
if (how == nss_lt_all)
st->counter = -1;
if (errno != ENOENT)
*errnop = errno;
goto fin;
}
rv = __gr_match_entry(hes[0], strlen(hes[0]), how, name, gid);
if (rv != NS_SUCCESS) {
hesiod_free_list(ctx, hes);
hes = NULL;
continue;
}
/* We need room at least for the line, a string NUL
* terminator, alignment padding, and one (char *)
* pointer for the member list terminator.
*/
adjsize = bufsize - _ALIGNBYTES - sizeof(char *);
linesize = strlcpy(buffer, hes[0], adjsize);
if (linesize >= adjsize) {
*errnop = ERANGE;
rv = NS_RETURN;
goto fin;
}
hesiod_free_list(ctx, hes);
hes = NULL;
rv = __gr_parse_entry(buffer, linesize, grp,
&buffer[linesize + 1], bufsize - linesize - 1, errnop);
} while (how == nss_lt_all && !(rv & NS_TERMINATE));
fin:
if (hes != NULL)
hesiod_free_list(ctx, hes);
if (ctx != NULL)
hesiod_end(ctx);
if (rv == NS_SUCCESS && retval != NULL)
*(struct group **)retval = grp;
return (rv);
}
#endif /* HESIOD */
#ifdef YP
/*
* nis backend
*/
static void
nis_endstate(void *p)
{
if (p == NULL)
return;
free(((struct nis_state *)p)->key);
free(p);
}
static int
nis_setgrent(void *retval, void *cb_data, va_list ap)
{
struct nis_state *st;
int rv;
rv = nis_getstate(&st);
if (rv != 0)
return (NS_UNAVAIL);
st->done = 0;
free(st->key);
st->key = NULL;
return (NS_UNAVAIL);
}
static int
nis_group(void *retval, void *mdata, va_list ap)
{
char *map;
struct nis_state *st;
struct group *grp;
const char *name;
char *buffer, *key, *result;
size_t bufsize;
gid_t gid;
enum nss_lookup_type how;
int *errnop, keylen, resultlen, rv;
name = NULL;
gid = (gid_t)-1;
how = (enum nss_lookup_type)mdata;
switch (how) {
case nss_lt_name:
name = va_arg(ap, const char *);
map = "group.byname";
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
map = "group.bygid";
break;
case nss_lt_all:
map = "group.byname";
break;
}
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
*errnop = nis_getstate(&st);
if (*errnop != 0)
return (NS_UNAVAIL);
if (st->domain[0] == '\0') {
if (getdomainname(st->domain, sizeof(st->domain)) != 0) {
*errnop = errno;
return (NS_UNAVAIL);
}
}
result = NULL;
do {
rv = NS_NOTFOUND;
switch (how) {
case nss_lt_name:
if (strlcpy(buffer, name, bufsize) >= bufsize)
goto erange;
break;
case nss_lt_id:
if (snprintf(buffer, bufsize, "%lu",
(unsigned long)gid) >= bufsize)
goto erange;
break;
case nss_lt_all:
if (st->done)
goto fin;
break;
}
result = NULL;
if (how == nss_lt_all) {
if (st->key == NULL)
rv = yp_first(st->domain, map, &st->key,
&st->keylen, &result, &resultlen);
else {
key = st->key;
keylen = st->keylen;
st->key = NULL;
rv = yp_next(st->domain, map, key, keylen,
&st->key, &st->keylen, &result,
&resultlen);
free(key);
}
if (rv != 0) {
free(result);
free(st->key);
st->key = NULL;
if (rv == YPERR_NOMORE) {
st->done = 1;
rv = NS_NOTFOUND;
} else
rv = NS_UNAVAIL;
goto fin;
}
} else {
rv = yp_match(st->domain, map, buffer, strlen(buffer),
&result, &resultlen);
if (rv == YPERR_KEY) {
rv = NS_NOTFOUND;
continue;
} else if (rv != 0) {
free(result);
rv = NS_UNAVAIL;
continue;
}
}
/* We need room at least for the line, a string NUL
* terminator, alignment padding, and one (char *)
* pointer for the member list terminator.
*/
if (resultlen >= bufsize - _ALIGNBYTES - sizeof(char *)) {
free(result);
goto erange;
}
memcpy(buffer, result, resultlen);
buffer[resultlen] = '\0';
free(result);
rv = __gr_match_entry(buffer, resultlen, how, name, gid);
if (rv == NS_SUCCESS)
rv = __gr_parse_entry(buffer, resultlen, grp,
&buffer[resultlen+1], bufsize - resultlen - 1,
errnop);
} while (how == nss_lt_all && !(rv & NS_TERMINATE));
fin:
if (rv == NS_SUCCESS && retval != NULL)
*(struct group **)retval = grp;
return (rv);
erange:
*errnop = ERANGE;
return (NS_RETURN);
}
#endif /* YP */
/*
* compat backend
*/
static void
compat_endstate(void *p)
{
struct compat_state *st;
if (p == NULL)
return;
st = (struct compat_state *)p;
free(st->name);
if (st->fp != NULL)
fclose(st->fp);
free(p);
}
static int
compat_setgrent(void *retval, void *mdata, va_list ap)
{
static const ns_src compatsrc[] = {
#ifdef YP
{ NSSRC_NIS, NS_SUCCESS },
#endif
{ NULL, 0 }
};
ns_dtab dtab[] = {
#ifdef HESIOD
{ NSSRC_DNS, dns_setgrent, NULL },
#endif
#ifdef YP
{ NSSRC_NIS, nis_setgrent, NULL },
#endif
{ NULL, NULL, NULL }
};
struct compat_state *st;
int rv, stayopen;
#define set_setent(x, y) do { \
int i; \
for (i = 0; i < (int)(nitems(x) - 1); i++) \
x[i].mdata = (void *)y; \
} while (0)
rv = compat_getstate(&st);
if (rv != 0)
return (NS_UNAVAIL);
switch ((enum constants)mdata) {
case SETGRENT:
stayopen = va_arg(ap, int);
if (st->fp != NULL)
rewind(st->fp);
else if (stayopen)
st->fp = fopen(_PATH_GROUP, "re");
set_setent(dtab, mdata);
(void)_nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "setgrent",
compatsrc, 0);
break;
case ENDGRENT:
if (st->fp != NULL) {
fclose(st->fp);
st->fp = NULL;
}
set_setent(dtab, mdata);
(void)_nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "endgrent",
compatsrc, 0);
break;
default:
break;
}
st->compat = COMPAT_MODE_OFF;
free(st->name);
st->name = NULL;
return (NS_UNAVAIL);
#undef set_setent
}
static int
compat_group(void *retval, void *mdata, va_list ap)
{
static const ns_src compatsrc[] = {
#ifdef YP
{ NSSRC_NIS, NS_SUCCESS },
#endif
{ NULL, 0 }
};
ns_dtab dtab[] = {
#ifdef YP
{ NSSRC_NIS, nis_group, NULL },
#endif
#ifdef HESIOD
{ NSSRC_DNS, dns_group, NULL },
#endif
{ NULL, NULL, NULL }
};
struct compat_state *st;
enum nss_lookup_type how;
const char *name, *line;
struct group *grp;
gid_t gid;
char *buffer, *p;
void *discard;
size_t bufsize, linesize;
off_t pos;
int fresh, rv, stayopen, *errnop;
#define set_lookup_type(x, y) do { \
int i; \
for (i = 0; i < (int)(nitems(x) - 1); i++) \
x[i].mdata = (void *)y; \
} while (0)
fresh = 0;
name = NULL;
gid = (gid_t)-1;
how = (enum nss_lookup_type)mdata;
switch (how) {
case nss_lt_name:
name = va_arg(ap, const char *);
break;
case nss_lt_id:
gid = va_arg(ap, gid_t);
break;
case nss_lt_all:
break;
default:
return (NS_NOTFOUND);
}
grp = va_arg(ap, struct group *);
buffer = va_arg(ap, char *);
bufsize = va_arg(ap, size_t);
errnop = va_arg(ap, int *);
*errnop = compat_getstate(&st);
if (*errnop != 0)
return (NS_UNAVAIL);
if (st->fp == NULL) {
st->fp = fopen(_PATH_GROUP, "re");
if (st->fp == NULL) {
*errnop = errno;
rv = NS_UNAVAIL;
goto fin;
}
fresh = 1;
}
if (how == nss_lt_all)
stayopen = 1;
else {
if (!fresh)
rewind(st->fp);
stayopen = st->stayopen;
}
docompat:
switch (st->compat) {
case COMPAT_MODE_ALL:
set_lookup_type(dtab, how);
switch (how) {
case nss_lt_all:
rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
"getgrent_r", compatsrc, grp, buffer, bufsize,
errnop);
break;
case nss_lt_id:
rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
"getgrgid_r", compatsrc, gid, grp, buffer, bufsize,
errnop);
break;
case nss_lt_name:
rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
"getgrnam_r", compatsrc, name, grp, buffer,
bufsize, errnop);
break;
}
if (rv & NS_TERMINATE)
goto fin;
st->compat = COMPAT_MODE_OFF;
break;
case COMPAT_MODE_NAME:
set_lookup_type(dtab, nss_lt_name);
rv = _nsdispatch(&discard, dtab, NSDB_GROUP_COMPAT,
"getgrnam_r", compatsrc, st->name, grp, buffer, bufsize,
errnop);
switch (rv) {
case NS_SUCCESS:
switch (how) {
case nss_lt_name:
if (strcmp(name, grp->gr_name) != 0)
rv = NS_NOTFOUND;
break;
case nss_lt_id:
if (gid != grp->gr_gid)
rv = NS_NOTFOUND;
break;
default:
break;
}
break;
case NS_RETURN:
goto fin;
default:
break;
}
free(st->name);
st->name = NULL;
st->compat = COMPAT_MODE_OFF;
if (rv == NS_SUCCESS)
goto fin;
break;
default:
break;
}
rv = NS_NOTFOUND;
if (stayopen)
pos = ftello(st->fp);
while ((line = fgetln(st->fp, &linesize)) != NULL) {
if (line[linesize-1] == '\n')
linesize--;
if (linesize > 2 && line[0] == '+') {
p = memchr(&line[1], ':', linesize);
if (p == NULL || p == &line[1])
st->compat = COMPAT_MODE_ALL;
else {
st->name = malloc(p - line);
if (st->name == NULL) {
syslog(LOG_ERR,
"getgrent memory allocation failure");
*errnop = ENOMEM;
rv = NS_UNAVAIL;
break;
}
memcpy(st->name, &line[1], p - line - 1);
st->name[p - line - 1] = '\0';
st->compat = COMPAT_MODE_NAME;
}
goto docompat;
}
rv = __gr_match_entry(line, linesize, how, name, gid);
if (rv != NS_SUCCESS)
continue;
/* We need room at least for the line, a string NUL
* terminator, alignment padding, and one (char *)
* pointer for the member list terminator.
*/
if (bufsize <= linesize + _ALIGNBYTES + sizeof(char *)) {
*errnop = ERANGE;
rv = NS_RETURN;
break;
}
memcpy(buffer, line, linesize);
buffer[linesize] = '\0';
rv = __gr_parse_entry(buffer, linesize, grp,
&buffer[linesize + 1], bufsize - linesize - 1, errnop);
if (rv & NS_TERMINATE)
break;
if (stayopen)
pos = ftello(st->fp);
}
fin:
if (st->fp != NULL && !stayopen) {
fclose(st->fp);
st->fp = NULL;
}
if (rv == NS_SUCCESS && retval != NULL)
*(struct group **)retval = grp;
else if (rv == NS_RETURN && *errnop == ERANGE && st->fp != NULL)
fseeko(st->fp, pos, SEEK_SET);
return (rv);
#undef set_lookup_type
}
/*
* common group line matching and parsing
*/
int
__gr_match_entry(const char *line, size_t linesize, enum nss_lookup_type how,
const char *name, gid_t gid)
{
size_t namesize;
const char *p, *eol;
char *q;
unsigned long n;
int i, needed;
if (linesize == 0 || is_comment_line(line, linesize))
return (NS_NOTFOUND);
switch (how) {
case nss_lt_name: needed = 1; break;
case nss_lt_id: needed = 2; break;
default: needed = 2; break;
}
eol = &line[linesize];
for (p = line, i = 0; i < needed && p < eol; p++)
if (*p == ':')
i++;
if (i < needed)
return (NS_NOTFOUND);
switch (how) {
case nss_lt_name:
namesize = strlen(name);
if (namesize + 1 == (size_t)(p - line) &&
memcmp(line, name, namesize) == 0)
return (NS_SUCCESS);
break;
case nss_lt_id:
n = strtoul(p, &q, 10);
if (q < eol && *q == ':' && gid == (gid_t)n)
return (NS_SUCCESS);
break;
case nss_lt_all:
return (NS_SUCCESS);
default:
break;
}
return (NS_NOTFOUND);
}
int
__gr_parse_entry(char *line, size_t linesize, struct group *grp, char *membuf,
size_t membufsize, int *errnop)
{
char *s_gid, *s_mem, *p, **members;
unsigned long n;
int maxmembers;
memset(grp, 0, sizeof(*grp));
members = (char **)_ALIGN(membuf);
membufsize -= (char *)members - membuf;
maxmembers = membufsize / sizeof(*members);
if (maxmembers <= 0 ||
(grp->gr_name = strsep(&line, ":")) == NULL ||
grp->gr_name[0] == '\0' ||
(grp->gr_passwd = strsep(&line, ":")) == NULL ||
(s_gid = strsep(&line, ":")) == NULL ||
s_gid[0] == '\0')
return (NS_NOTFOUND);
s_mem = line;
n = strtoul(s_gid, &s_gid, 10);
if (s_gid[0] != '\0')
return (NS_NOTFOUND);
grp->gr_gid = (gid_t)n;
grp->gr_mem = members;
while (maxmembers > 1 && s_mem != NULL) {
p = strsep(&s_mem, ",");
if (p != NULL && *p != '\0') {
*members++ = p;
maxmembers--;
}
}
*members = NULL;
if (s_mem == NULL)
return (NS_SUCCESS);
else {
*errnop = ERANGE;
return (NS_RETURN);
}
}
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