mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-24 14:00:30 +00:00
303 lines
8.6 KiB
C
303 lines
8.6 KiB
C
/* Common code for DB-based databases in nss_db module.
|
||
Copyright (C) 1996-2000, 2011 Free Software Foundation, Inc.
|
||
This file is part of the GNU C Library.
|
||
|
||
The GNU C Library is free software; you can redistribute it and/or
|
||
modify it under the terms of the GNU Lesser General Public
|
||
License as published by the Free Software Foundation; either
|
||
version 2.1 of the License, or (at your option) any later version.
|
||
|
||
The GNU C Library is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
Lesser General Public License for more details.
|
||
|
||
You should have received a copy of the GNU Lesser General Public
|
||
License along with the GNU C Library; if not, write to the Free
|
||
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
||
02111-1307 USA. */
|
||
|
||
#include <dlfcn.h>
|
||
#include <fcntl.h>
|
||
#include <sys/mman.h>
|
||
#include <bits/libc-lock.h>
|
||
#include "nsswitch.h"
|
||
#include "nss_db.h"
|
||
|
||
/* The hashing function we use. */
|
||
#include "../intl/hash-string.h"
|
||
|
||
/* These symbols are defined by the including source file:
|
||
|
||
ENTNAME -- database name of the structure and functions (hostent, pwent).
|
||
STRUCTURE -- struct name, define only if not ENTNAME (passwd, group).
|
||
DATABASE -- database file name, ("hosts", "passwd")
|
||
|
||
NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
|
||
*/
|
||
|
||
#define ENTNAME_r CONCAT(ENTNAME,_r)
|
||
|
||
#include <paths.h>
|
||
#define DBFILE _PATH_VARDB DATABASE ".db"
|
||
|
||
#ifdef NEED_H_ERRNO
|
||
# define H_ERRNO_PROTO , int *herrnop
|
||
# define H_ERRNO_ARG , herrnop
|
||
# define H_ERRNO_SET(val) (*herrnop = (val))
|
||
#else
|
||
# define H_ERRNO_PROTO
|
||
# define H_ERRNO_ARG
|
||
# define H_ERRNO_SET(val) ((void) 0)
|
||
#endif
|
||
|
||
/* State for this database. */
|
||
static struct nss_db_map state;
|
||
/* Lock to protect the state and global variables. */
|
||
__libc_lock_define (static , lock);
|
||
|
||
/* Maintenance of the shared handle open on the database. */
|
||
static int keep_db;
|
||
static const char *entidx;
|
||
|
||
|
||
/* Open the database. */
|
||
enum nss_status
|
||
CONCAT(_nss_db_set,ENTNAME) (int stayopen)
|
||
{
|
||
enum nss_status status;
|
||
|
||
__libc_lock_lock (lock);
|
||
|
||
status = internal_setent (DBFILE, &state);
|
||
|
||
if (status == NSS_STATUS_SUCCESS)
|
||
{
|
||
/* Remember STAYOPEN flag. */
|
||
keep_db |= stayopen;
|
||
|
||
/* Reset the sequential index. */
|
||
entidx = (const char *) state.header + state.header->valstroffset;
|
||
}
|
||
|
||
__libc_lock_unlock (lock);
|
||
|
||
return status;
|
||
}
|
||
|
||
|
||
/* Close it again. */
|
||
enum nss_status
|
||
CONCAT(_nss_db_end,ENTNAME) (void)
|
||
{
|
||
__libc_lock_lock (lock);
|
||
|
||
internal_endent (&state);
|
||
|
||
/* Reset STAYOPEN flag. */
|
||
keep_db = 0;
|
||
|
||
__libc_lock_unlock (lock);
|
||
|
||
return NSS_STATUS_SUCCESS;
|
||
}
|
||
|
||
|
||
/* Macro for defining lookup functions for this DB-based database.
|
||
|
||
NAME is the name of the lookup; e.g. `pwnam'.
|
||
|
||
DB_CHAR is index indicator for the database.
|
||
|
||
KEYPATTERN gives `printf' args to construct a key string;
|
||
e.g. `("%d", id)'.
|
||
|
||
KEYSIZE gives the allocation size of a buffer to construct it in;
|
||
e.g. `1 + sizeof (id) * 4'.
|
||
|
||
PROTO is the potentially empty list of other parameters.
|
||
|
||
BREAK_IF_MATCH is a block of code which compares `struct STRUCTURE *result'
|
||
to the lookup key arguments and does `break;' if they match. */
|
||
|
||
#define DB_LOOKUP(name, db_char, keysize, keypattern, break_if_match, proto...)\
|
||
enum nss_status \
|
||
_nss_db_get##name##_r (proto, struct STRUCTURE *result, \
|
||
char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO)\
|
||
{ \
|
||
struct parser_data *data = (void *) buffer; \
|
||
\
|
||
if (buflen < sizeof *data) \
|
||
{ \
|
||
*errnop = ERANGE; \
|
||
H_ERRNO_SET (NETDB_INTERNAL); \
|
||
return NSS_STATUS_TRYAGAIN; \
|
||
} \
|
||
\
|
||
struct nss_db_map state = { NULL, 0 }; \
|
||
enum nss_status status = internal_setent (DBFILE, &state); \
|
||
if (status != NSS_STATUS_SUCCESS) \
|
||
{ \
|
||
*errnop = errno; \
|
||
H_ERRNO_SET (NETDB_INTERNAL); \
|
||
return status; \
|
||
} \
|
||
\
|
||
const struct nss_db_header *header = state.header; \
|
||
int i; \
|
||
for (i = 0; i < header->ndbs; ++i) \
|
||
if (header->dbs[i].id == db_char) \
|
||
break; \
|
||
if (i == header->ndbs) \
|
||
{ \
|
||
status = NSS_STATUS_UNAVAIL; \
|
||
goto out; \
|
||
} \
|
||
\
|
||
char *key; \
|
||
if (db_char == '.') \
|
||
key = (char *) IGNOREPATTERN keypattern; \
|
||
else \
|
||
{ \
|
||
const size_t size = (keysize) + 1; \
|
||
key = alloca (size); \
|
||
\
|
||
KEYPRINTF keypattern; \
|
||
} \
|
||
\
|
||
const stridx_t *hashtable \
|
||
= (const stridx_t *) ((const char *) header \
|
||
+ header->dbs[i].hashoffset); \
|
||
const char *valstrtab = (const char *) header + header->valstroffset; \
|
||
uint32_t hashval = __hash_string (key); \
|
||
size_t hidx = hashval % header->dbs[i].hashsize; \
|
||
size_t hval2 = 1 + hashval % (header->dbs[i].hashsize - 2); \
|
||
\
|
||
status = NSS_STATUS_NOTFOUND; \
|
||
while (hashtable[hidx] != ~((stridx_t) 0)) \
|
||
{ \
|
||
const char *valstr = valstrtab + hashtable[hidx]; \
|
||
size_t len = strlen (valstr) + 1; \
|
||
if (len > buflen) \
|
||
{ \
|
||
/* No room to copy the data to. */ \
|
||
*errnop = ERANGE; \
|
||
H_ERRNO_SET (NETDB_INTERNAL); \
|
||
status = NSS_STATUS_TRYAGAIN; \
|
||
break; \
|
||
} \
|
||
\
|
||
/* Copy the string to a place where it can be modified. */ \
|
||
char *p = memcpy (buffer, valstr, len); \
|
||
\
|
||
int err = parse_line (p, result, data, buflen, errnop EXTRA_ARGS); \
|
||
if (err > 0) \
|
||
{ \
|
||
status = NSS_STATUS_SUCCESS; \
|
||
break_if_match; \
|
||
status = NSS_STATUS_NOTFOUND; \
|
||
} \
|
||
else if (err == -1) \
|
||
{ \
|
||
H_ERRNO_SET (NETDB_INTERNAL); \
|
||
status = NSS_STATUS_TRYAGAIN; \
|
||
break; \
|
||
} \
|
||
\
|
||
if ((hidx += hval2) >= header->dbs[i].hashsize) \
|
||
hidx -= header->dbs[i].hashsize; \
|
||
} \
|
||
\
|
||
if (status == NSS_STATUS_NOTFOUND) \
|
||
H_ERRNO_SET (HOST_NOT_FOUND); \
|
||
\
|
||
out: \
|
||
internal_endent (&state); \
|
||
\
|
||
return status; \
|
||
}
|
||
|
||
#define KEYPRINTF(pattern, args...) snprintf (key, size, pattern ,##args)
|
||
#define IGNOREPATTERN(pattern, arg1, args...) (char *) (uintptr_t) arg1
|
||
|
||
|
||
|
||
|
||
/* Return the next entry from the database file, doing locking. */
|
||
enum nss_status
|
||
CONCAT(_nss_db_get,ENTNAME_r) (struct STRUCTURE *result, char *buffer,
|
||
size_t buflen, int *errnop H_ERRNO_PROTO)
|
||
{
|
||
/* Return next entry in host file. */
|
||
enum nss_status status;
|
||
struct parser_data *data = (void *) buffer;
|
||
|
||
if (buflen < sizeof *data)
|
||
{
|
||
*errnop = ERANGE;
|
||
H_ERRNO_SET (NETDB_INTERNAL);
|
||
return NSS_STATUS_TRYAGAIN;
|
||
}
|
||
|
||
__libc_lock_lock (lock);
|
||
|
||
if (state.header == NULL)
|
||
{
|
||
status = internal_setent (DBFILE, &state);
|
||
if (status != NSS_STATUS_SUCCESS)
|
||
{
|
||
*errnop = errno;
|
||
H_ERRNO_SET (NETDB_INTERNAL);
|
||
goto out;
|
||
}
|
||
}
|
||
|
||
status = NSS_STATUS_UNAVAIL;
|
||
if (state.header != MAP_FAILED)
|
||
{
|
||
const char *const end = ((const char *) state.header
|
||
+ state.header->valstroffset
|
||
+ state.header->valstrlen);
|
||
while (entidx < end)
|
||
{
|
||
const char *next = rawmemchr (entidx, '\0') + 1;
|
||
size_t len = next - entidx;
|
||
|
||
if (len > buflen)
|
||
{
|
||
/* No room to copy the data to. */
|
||
*errnop = ERANGE;
|
||
H_ERRNO_SET (NETDB_INTERNAL);
|
||
status = NSS_STATUS_TRYAGAIN;
|
||
break;
|
||
}
|
||
|
||
/* Copy the string to a place where it can be modified. */
|
||
char *p = memcpy (buffer, entidx, len);
|
||
|
||
int err = parse_line (p, result, data, buflen, errnop EXTRA_ARGS);
|
||
|
||
if (err > 0)
|
||
{
|
||
status = NSS_STATUS_SUCCESS;
|
||
entidx = next;
|
||
break;
|
||
}
|
||
if (err < 0)
|
||
{
|
||
H_ERRNO_SET (HOST_NOT_FOUND);
|
||
status = NSS_STATUS_NOTFOUND;
|
||
break;
|
||
}
|
||
|
||
/* Continue with the next record, this one is ill-formed. */
|
||
entidx = next;
|
||
}
|
||
}
|
||
|
||
out:
|
||
__libc_lock_unlock (lock);
|
||
|
||
return status;
|
||
}
|