glibc/nscd/hstcache.c
Ulrich Drepper 67479a700e Update.
1998-10-18  Ulrich Drepper  <drepper@cygnus.com>

	* resolv/nss_dns/dns-host.c: Add missing errnop parameter to the
	NSS functions.
	* resolv/nss_dns/dns-network.c: Likewise.

	* grp/Makefile: Don't search for linuxhtreads in add-ons, use
	have-thread-library to determine whether threads are available.
	* pwd/Makefile: Remove wrong comment.

	* inet/Makefile: Define CFLAGS-gethstbyad_r.c, CFLAGS-gethstbynm_r.c,
	and CFLAGS-gethstbynm2_r.c to -DUSE_NSCD=1.

	* locale/C-messages.c: Define default strings for YESTR and NOSTR.

	* nss/Versions: Add __nss_hosts_lookup.

	* nss/getXXbyYY.c: Remove unneeded assignment.

	* nss/getXXbyYY_r.c: Include nscd/nscd_proto.h only if needed.

	Almost complete rewrite of the NSCD to make it smaller, faster,
	add more functionnality and make it easier to extend.
	* nscd/Makfile (routines): Add nscd_gethst_r.
	(nscd-modules): Add hstcache, gethstbyad_r, gethstbynm2_r, and cache.
	* nscd/cache.c: New file.
	* nscd/gethstbyad_r.c: New file.
	* nscd/gethstbynm2_r.c: New file.
	* nscd/hstcache.c: New file.
	* nscd/nscd_gethst_r.c: New file.
	* nscd/connections.c: Rewritten.  Don't start new thread for every
	new connection.  Use a fixed set of threads which handle all
	connections and also the cache cleanup.
	* nscd/grpcache.c: Rewritten to use generic cache handling functions
	in cache.c.
	* nscd/nscd.c: Recognize new parameter nthreads.  Adjust initialization
	for rewrite.  Remove handle_requests function.
	* nscd/nscd.h (NSCD_VERSION): Bump to 2.
	Define new data structure for the new unified cache and the host
	database entries.
	* nscd/nscd_conf.c: Rewrite parsing partly to allow adding of more
	databases easily.  Recognize check-files and threads definitions.
	* nscd/nscd.conf: Add definition of enable-cache and check-files to
	passwd and group definitions.  Add new set of definitions for hosts.
	* nscd/nscd_getgr_r.c: Rewrite for new protocol.
	* nscd/nscd_getpw_r.c: Likewise.
	* nscd/nscd_proto.h: Add prototype for host database functions.
	* nscd/nscd_stat.c: Rewrite to simplify printing of information
	for many databases.
	* nscd/dbg_log.c: Remove unnecessary variable initializations.
	Global variable debug_flag is renamed to dbg_level.
	* nscd/dbg_log.h: Declare set_logfile.
1998-10-18 15:16:22 +00:00

406 lines
12 KiB
C

/* Cache handling for host lookup.
Copyright (C) 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <netdb.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <arpa/inet.h>
#include "nscd.h"
#include "dbg_log.h"
/* Get implementation for some internal functions. */
#include "../resolv/mapv4v6addr.h"
/* This is the standard reply in case the service is disabled. */
static const hst_response_header disabled =
{
version: NSCD_VERSION,
found: -1,
h_name_len: 0,
h_aliases_cnt: 0,
h_addrtype: -1,
h_length: -1,
h_addr_list_cnt: 0,
error: NETDB_INTERNAL
};
/* This is the struct describing how to write this record. */
const struct iovec hst_iov_disabled =
{
iov_base: (void *) &disabled,
iov_len: sizeof (disabled)
};
/* This is the standard reply in case we haven't found the dataset. */
static const hst_response_header notfound =
{
version: NSCD_VERSION,
found: 0,
h_name_len: 0,
h_aliases_cnt: 0,
h_addrtype: -1,
h_length: -1,
h_addr_list_cnt: 0,
error: HOST_NOT_FOUND
};
/* This is the struct describing how to write this record. */
static const struct iovec iov_notfound =
{
iov_base: (void *) &notfound,
iov_len: sizeof (notfound)
};
struct hostdata
{
hst_response_header resp;
char strdata[0];
};
static void
cache_addhst (struct database *db, int fd, request_header *req, void *key,
struct hostent *hst)
{
ssize_t total;
ssize_t written;
time_t t = time (NULL);
if (hst == NULL)
{
/* We have no data. This means we send the standard reply for this
case. */
void *copy;
total = sizeof (notfound);
written = writev (fd, &iov_notfound, 1);
copy = malloc (req->key_len);
if (copy == NULL)
error (EXIT_FAILURE, errno, _("while allocating key copy"));
memcpy (copy, key, req->key_len);
/* Compute the timeout time. */
t += db->negtimeout;
/* Now get the lock to safely insert the records. */
pthread_rwlock_rdlock (&db->lock);
cache_add (req->type, copy, req->key_len, &iov_notfound,
sizeof (notfound), (void *) -1, 0, t, db);
pthread_rwlock_unlock (&db->lock);
}
else
{
/* Determine the I/O structure. */
struct hostdata *data;
size_t h_name_len = strlen (hst->h_name) + 1;
size_t h_aliases_cnt;
size_t *h_aliases_len;
size_t h_addr_list_cnt;
int addr_list_type;
char *addresses;
char *aliases;
char *key_copy = NULL;
char *cp;
size_t cnt;
/* Determine the number of aliases. */
h_aliases_cnt = 0;
for (cnt = 0; hst->h_aliases[cnt] != NULL; ++cnt)
++h_aliases_cnt;
/* Determine the length of all aliases. */
h_aliases_len = alloca (h_aliases_cnt * sizeof (size_t));
total = 0;
for (cnt = 0; cnt < h_aliases_cnt; ++cnt)
{
h_aliases_len[cnt] = strlen (hst->h_aliases[cnt]) + 1;
total += h_aliases_len[cnt];
}
/* Determine the number of addresses. */
h_addr_list_cnt = 0;
for (cnt = 0; hst->h_addr_list[cnt]; ++cnt)
++h_addr_list_cnt;
/* We allocate all data in one memory block: the iov vector,
the response header and the dataset itself. */
total += (sizeof (struct hostdata)
+ h_name_len
+ h_aliases_cnt * sizeof (size_t)
+ h_addr_list_cnt * (hst->h_length
+ (hst->h_length == INADDRSZ
? IN6ADDRSZ : 0)));
data = (struct hostdata *) malloc (total + req->key_len);
if (data == NULL)
/* There is no reason to go on. */
error (EXIT_FAILURE, errno, _("while allocating cache entry"));
data->resp.found = 1;
data->resp.h_name_len = h_name_len;
data->resp.h_aliases_cnt = h_aliases_cnt;
data->resp.h_addrtype = hst->h_addrtype;
data->resp.h_length = hst->h_length;
data->resp.h_addr_list_cnt = h_addr_list_cnt;
data->resp.error = NETDB_SUCCESS;
cp = data->strdata;
cp = mempcpy (cp, hst->h_name, h_name_len);
cp = mempcpy (cp, h_aliases_len, h_aliases_cnt * sizeof (size_t));
/* The normal addresses first. */
addresses = cp;
for (cnt = 0; cnt < h_addr_list_cnt; ++cnt)
cp = mempcpy (cp, hst->h_addr_list[cnt], hst->h_length);
/* And the generated IPv6 addresses if necessary. */
if (hst->h_length == INADDRSZ)
{
/* Generate the IPv6 addresses. */
for (cnt = 0; cnt < h_addr_list_cnt; cp += IN6ADDRSZ, ++cnt)
map_v4v6_address (hst->h_addr_list[cnt], cp);
}
/* Then the aliases. */
aliases = cp;
for (cnt = 0; cnt < h_aliases_cnt; ++cnt)
cp = mempcpy (cp, hst->h_aliases[cnt], h_aliases_len[cnt]);
assert (cp == data->strdata + total - sizeof (hst_response_header));
/* If we are adding a GETHOSTBYNAME{,v6} entry we must be prepared
that the answer we get from the NSS does not contain the key
itself. This is the case if the resolver is used and the name
is extended by the domainnames from /etc/resolv.conf. Therefore
we explicitly add the name here. */
if (req->type == GETHOSTBYNAME || req->type == GETHOSTBYNAMEv6)
key_copy = memcpy (cp, key, req->key_len);
/* We write the dataset before inserting it to the database
since while inserting this thread might block and so would
unnecessarily let the receiver wait. */
written = write (fd, data, total);
addr_list_type = (hst->h_length == INADDRSZ
? GETHOSTBYADDR : GETHOSTBYADDRv6);
/* Compute the timeout time. */
t += db->postimeout;
/* Now get the lock to safely insert the records. */
pthread_rwlock_rdlock (&db->lock);
/* First add all the aliases. */
for (cnt = 0; cnt < h_aliases_cnt; ++cnt)
{
if (addr_list_type == GETHOSTBYADDR)
cache_add (GETHOSTBYNAME, aliases, h_aliases_len[cnt], data, total,
data, 0, t, db);
cache_add (GETHOSTBYNAMEv6, aliases, h_aliases_len[cnt], data, total,
data, 0, t, db);
aliases += h_aliases_len[cnt];
}
/* Next the normal addresses. */
for (cnt = 0; cnt < h_addr_list_cnt; ++cnt)
{
cache_add (addr_list_type, addresses, hst->h_length, data, total,
data, 0, t, db);
addresses += hst->h_length;
}
/* If necessary the IPv6 addresses. */
if (addr_list_type == GETHOSTBYADDR)
for (cnt = 0; cnt < h_addr_list_cnt; ++cnt)
{
cache_add (GETHOSTBYADDRv6, addresses, IN6ADDRSZ, data, total,
data, 0, t, db);
addresses += IN6ADDRSZ;
}
/* If necessary add the key for this request. */
if (req->type == GETHOSTBYNAME || req->type == GETHOSTBYNAMEv6)
{
if (addr_list_type == GETHOSTBYADDR)
cache_add (GETHOSTBYNAME, key_copy, req->key_len, data, total,
data, 0, t, db);
cache_add (GETHOSTBYNAMEv6, key_copy, req->key_len, data,
total, data, 0, t, db);
}
/* And finally the name. We mark this as the last entry. */
if (addr_list_type == GETHOSTBYADDR)
cache_add (GETHOSTBYNAME, data->strdata, h_name_len, data, total, data,
0, t, db);
cache_add (GETHOSTBYNAMEv6, data->strdata, h_name_len, data,
total, data, 1, t, db);
pthread_rwlock_unlock (&db->lock);
}
if (written != total)
{
char buf[256];
dbg_log (_("short write in %s: %s"), __FUNCTION__,
strerror_r (errno, buf, sizeof (buf)));
}
}
void
addhstbyname (struct database *db, int fd, request_header *req, void *key)
{
/* Search for the entry matching the key. Please note that we don't
look again in the table whether the dataset is now available. We
simply insert it. It does not matter if it is in there twice. The
pruning function only will look at the timestamp. */
int buflen = 512;
char *buffer = alloca (buflen);
struct hostent resultbuf;
struct hostent *hst;
if (debug_level > 0)
dbg_log (_("Haven't found \"%s\" in hosts cache!"), key);
while (gethostbyname2_r (key, AF_INET, &resultbuf, buffer, buflen, &hst,
&h_errno) != 0
&& h_errno == NETDB_INTERNAL
&& errno == ERANGE)
{
errno = 0;
buflen += 256;
buffer = alloca (buflen);
}
cache_addhst (db, fd, req, key, hst);
}
void
addhstbyaddr (struct database *db, int fd, request_header *req, void *key)
{
/* Search for the entry matching the key. Please note that we don't
look again in the table whether the dataset is now available. We
simply insert it. It does not matter if it is in there twice. The
pruning function only will look at the timestamp. */
int buflen = 512;
char *buffer = alloca (buflen);
struct hostent resultbuf;
struct hostent *hst;
if (debug_level > 0)
{
char buf[64];
dbg_log (_("Haven't found \"%s\" in hosts cache!"),
inet_ntop (AF_INET, key, buf, sizeof (buf)));
}
while (gethostbyaddr_r (key, INADDRSZ, AF_INET, &resultbuf, buffer, buflen,
&hst, &h_errno) != 0
&& h_errno == NETDB_INTERNAL
&& errno == ERANGE)
{
errno = 0;
buflen += 256;
buffer = alloca (buflen);
}
cache_addhst (db, fd, req, key, hst);
}
void
addhstbynamev6 (struct database *db, int fd, request_header *req, void *key)
{
/* Search for the entry matching the key. Please note that we don't
look again in the table whether the dataset is now available. We
simply insert it. It does not matter if it is in there twice. The
pruning function only will look at the timestamp. */
int buflen = 512;
char *buffer = alloca (buflen);
struct hostent resultbuf;
struct hostent *hst;
if (debug_level > 0)
dbg_log (_("Haven't found \"%s\" in hosts cache!"), key);
while (gethostbyname2_r (key, AF_INET6, &resultbuf, buffer, buflen, &hst,
&h_errno) != 0
&& h_errno == NETDB_INTERNAL
&& errno == ERANGE)
{
errno = 0;
buflen += 256;
buffer = alloca (buflen);
}
cache_addhst (db, fd, req, key, hst);
}
void
addhstbyaddrv6 (struct database *db, int fd, request_header *req, void *key)
{
/* Search for the entry matching the key. Please note that we don't
look again in the table whether the dataset is now available. We
simply insert it. It does not matter if it is in there twice. The
pruning function only will look at the timestamp. */
int buflen = 512;
char *buffer = alloca (buflen);
struct hostent resultbuf;
struct hostent *hst;
if (debug_level > 0)
{
char buf[64];
dbg_log (_("Haven't found \"%s\" in hosts cache!"),
inet_ntop (AF_INET6, key, buf, sizeof (buf)));
}
while (gethostbyaddr_r (key, IN6ADDRSZ, AF_INET6, &resultbuf, buffer, buflen,
&hst, &h_errno) != 0
&& h_errno == NETDB_INTERNAL
&& errno == ERANGE)
{
errno = 0;
buflen += 256;
buffer = alloca (buflen);
}
cache_addhst (db, fd, req, key, hst);
}