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-rw-r--r--nscd/hstcache.c405
1 files changed, 405 insertions, 0 deletions
diff --git a/nscd/hstcache.c b/nscd/hstcache.c
new file mode 100644
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--- /dev/null
+++ b/nscd/hstcache.c
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+/* 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);
+}
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