/* Cache handling for host lookup.
- Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ Copyright (C) 1998-2008, 2009, 2011 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.
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published
+ by the Free Software Foundation; 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,
+ This program 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.
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU 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. */
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
+#include <libintl.h>
#include <netdb.h>
+#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
-#include <libintl.h>
#include <arpa/inet.h>
+#include <arpa/nameser.h>
+#include <sys/mman.h>
+#include <stackinfo.h>
#include "nscd.h"
#include "dbg_log.h"
-
-/* Get implementation for some internal functions. */
-#include "../resolv/mapv4v6addr.h"
+#ifdef HAVE_SENDFILE
+# include <kernel-features.h>
+#endif
/* 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
+ .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)
+ .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 *) ¬found,
- iov_len: sizeof (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
};
-struct hostdata
+/* This is the standard reply in case there are temporary problems. */
+static const hst_response_header tryagain =
{
- hst_response_header resp;
- char strdata[0];
+ .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 = TRY_AGAIN
};
-static void
-cache_addhst (struct database *db, int fd, request_header *req, void *key,
- struct hostent *hst, uid_t owner)
+static time_t
+cache_addhst (struct database_dyn *db, int fd, request_header *req,
+ const void *key, struct hostent *hst, uid_t owner,
+ struct hashentry *const he, struct datahead *dh, int errval,
+ int32_t ttl)
{
- ssize_t total;
- ssize_t written;
+ bool all_written = true;
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);
+ /* We allocate all data in one memory block: the iov vector,
+ the response header and the dataset itself. */
+ struct dataset
+ {
+ struct datahead head;
+ hst_response_header resp;
+ char strdata[0];
+ } *dataset;
- cache_add (req->type, copy, req->key_len, ¬found,
- sizeof (notfound), (void *) -1, 0, t, db, owner);
+ assert (offsetof (struct dataset, resp) == offsetof (struct datahead, data));
- pthread_rwlock_unlock (&db->lock);
+ time_t timeout = MAX_TIMEOUT_VALUE;
+ if (hst == NULL)
+ {
+ if (he != NULL && errval == EAGAIN)
+ {
+ /* If we have an old record available but cannot find one
+ now because the service is not available we keep the old
+ record and make sure it does not get removed. */
+ if (reload_count != UINT_MAX)
+ /* Do not reset the value if we never not reload the record. */
+ dh->nreloads = reload_count - 1;
+
+ /* Reload with the same time-to-live value. */
+ timeout = dh->timeout = t + dh->ttl;
+ }
+ else
+ {
+ /* We have no data. This means we send the standard reply for this
+ case. Possibly this is only temporary. */
+ ssize_t total = sizeof (notfound);
+ assert (sizeof (notfound) == sizeof (tryagain));
+
+ const hst_response_header *resp = (errval == EAGAIN
+ ? &tryagain : ¬found);
+
+ if (fd != -1 &&
+ TEMP_FAILURE_RETRY (send (fd, resp, total,
+ MSG_NOSIGNAL)) != total)
+ all_written = false;
+
+ /* If we cannot permanently store the result, so be it. */
+ if (__builtin_expect (db->negtimeout == 0, 0))
+ {
+ /* Mark the old entry as obsolete. */
+ if (dh != NULL)
+ dh->usable = false;
+ }
+ else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
+ + req->key_len), 1)) != NULL)
+ {
+ dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
+ dataset->head.recsize = total;
+ dataset->head.notfound = true;
+ dataset->head.nreloads = 0;
+ dataset->head.usable = true;
+
+ /* Compute the timeout time. */
+ dataset->head.ttl = ttl == INT32_MAX ? db->negtimeout : ttl;
+ timeout = dataset->head.timeout = t + dataset->head.ttl;
+
+ /* This is the reply. */
+ memcpy (&dataset->resp, resp, total);
+
+ /* Copy the key data. */
+ memcpy (dataset->strdata, key, req->key_len);
+
+ /* If necessary, we also propagate the data to disk. */
+ if (db->persistent)
+ {
+ // XXX async OK?
+ uintptr_t pval = (uintptr_t) dataset & ~pagesize_m1;
+ msync ((void *) pval,
+ ((uintptr_t) dataset & pagesize_m1)
+ + sizeof (struct dataset) + req->key_len, MS_ASYNC);
+ }
+
+ (void) cache_add (req->type, &dataset->strdata, req->key_len,
+ &dataset->head, true, db, owner, he == NULL);
+
+ pthread_rwlock_unlock (&db->lock);
+
+ /* Mark the old entry as obsolete. */
+ if (dh != NULL)
+ dh->usable = false;
+ }
+ }
}
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;
+ uint32_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;
+ ssize_t total;
/* 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));
+ h_aliases_len = (uint32_t *) alloca (h_aliases_cnt * sizeof (uint32_t));
total = 0;
for (cnt = 0; cnt < h_aliases_cnt; ++cnt)
{
/* Determine the number of addresses. */
h_addr_list_cnt = 0;
- for (cnt = 0; hst->h_addr_list[cnt]; ++cnt)
+ while (hst->h_addr_list[h_addr_list_cnt] != NULL)
++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)
+ if (h_addr_list_cnt == 0)
+ /* Invalid entry. */
+ return MAX_TIMEOUT_VALUE;
+
+ total += (sizeof (struct dataset)
+ 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;
+ + h_aliases_cnt * sizeof (uint32_t)
+ + h_addr_list_cnt * hst->h_length);
+
+ /* If we refill the cache, first assume the reconrd did not
+ change. Allocate memory on the cache since it is likely
+ discarded anyway. If it turns out to be necessary to have a
+ new record we can still allocate real memory. */
+ bool alloca_used = false;
+ dataset = NULL;
+
+ /* If the record contains more than one IP address (used for
+ load balancing etc) don't cache the entry. This is something
+ the current cache handling cannot handle and it is more than
+ questionable whether it is worthwhile complicating the cache
+ handling just for handling such a special case. */
+ if (he == NULL && h_addr_list_cnt == 1)
+ dataset = (struct dataset *) mempool_alloc (db, total + req->key_len,
+ 1);
+
+ if (dataset == NULL)
+ {
+ /* We cannot permanently add the result in the moment. But
+ we can provide the result as is. Store the data in some
+ temporary memory. */
+ dataset = (struct dataset *) alloca (total + req->key_len);
+
+ /* We cannot add this record to the permanent database. */
+ alloca_used = true;
+ }
+
+ dataset->head.allocsize = total + req->key_len;
+ dataset->head.recsize = total - offsetof (struct dataset, resp);
+ dataset->head.notfound = false;
+ dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
+ dataset->head.usable = true;
+
+ /* Compute the timeout time. */
+ dataset->head.ttl = ttl == INT32_MAX ? db->postimeout : ttl;
+ timeout = dataset->head.timeout = t + dataset->head.ttl;
+
+ dataset->resp.version = NSCD_VERSION;
+ dataset->resp.found = 1;
+ dataset->resp.h_name_len = h_name_len;
+ dataset->resp.h_aliases_cnt = h_aliases_cnt;
+ dataset->resp.h_addrtype = hst->h_addrtype;
+ dataset->resp.h_length = hst->h_length;
+ dataset->resp.h_addr_list_cnt = h_addr_list_cnt;
+ dataset->resp.error = NETDB_SUCCESS;
+
+ /* Make sure there is no gap. */
+ assert ((char *) (&dataset->resp.error + 1) == dataset->strdata);
+
+ cp = dataset->strdata;
cp = mempcpy (cp, hst->h_name, h_name_len);
- cp = mempcpy (cp, h_aliases_len, h_aliases_cnt * sizeof (size_t));
+ cp = mempcpy (cp, h_aliases_len, h_aliases_cnt * sizeof (uint32_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));
+ assert (cp
+ == dataset->strdata + total - offsetof (struct dataset,
+ strdata));
/* 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);
+ key_copy = memcpy (cp, key, req->key_len);
- addr_list_type = (hst->h_length == INADDRSZ
- ? GETHOSTBYADDR : GETHOSTBYADDRv6);
-
- /* Compute the timeout time. */
- t += db->postimeout;
+ assert ((char *) &dataset->resp + dataset->head.recsize == cp);
- /* 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)
+ /* Now we can determine whether on refill we have to create a new
+ record or not. */
+ if (he != NULL)
{
- if (addr_list_type == GETHOSTBYADDR)
- cache_add (GETHOSTBYNAME, aliases, h_aliases_len[cnt], data, total,
- data, 0, t, db, owner);
-
- cache_add (GETHOSTBYNAMEv6, aliases, h_aliases_len[cnt], data, total,
- data, 0, t, db, owner);
-
- aliases += h_aliases_len[cnt];
+ assert (fd == -1);
+
+ if (total + req->key_len == dh->allocsize
+ && total - offsetof (struct dataset, resp) == dh->recsize
+ && memcmp (&dataset->resp, dh->data,
+ dh->allocsize - offsetof (struct dataset, resp)) == 0)
+ {
+ /* The data has not changed. We will just bump the
+ timeout value. Note that the new record has been
+ allocated on the stack and need not be freed. */
+ assert (h_addr_list_cnt == 1);
+ dh->ttl = dataset->head.ttl;
+ dh->timeout = dataset->head.timeout;
+ ++dh->nreloads;
+ }
+ else
+ {
+ if (h_addr_list_cnt == 1)
+ {
+ /* We have to create a new record. Just allocate
+ appropriate memory and copy it. */
+ struct dataset *newp
+ = (struct dataset *) mempool_alloc (db,
+ total + req->key_len,
+ 1);
+ if (newp != NULL)
+ {
+ /* Adjust pointers into the memory block. */
+ addresses = (char *) newp + (addresses
+ - (char *) dataset);
+ aliases = (char *) newp + (aliases - (char *) dataset);
+ assert (key_copy != NULL);
+ key_copy = (char *) newp + (key_copy - (char *) dataset);
+
+ dataset = memcpy (newp, dataset, total + req->key_len);
+ alloca_used = false;
+ }
+ }
+
+ /* Mark the old record as obsolete. */
+ dh->usable = false;
+ }
}
-
- /* Next the normal addresses. */
- for (cnt = 0; cnt < h_addr_list_cnt; ++cnt)
+ else
{
- cache_add (addr_list_type, addresses, hst->h_length, data, total,
- data, 0, t, db, owner);
- addresses += hst->h_length;
+ /* We write the dataset before inserting it to the database
+ since while inserting this thread might block and so would
+ unnecessarily keep the receiver waiting. */
+ assert (fd != -1);
+
+#ifdef HAVE_SENDFILE
+ if (__builtin_expect (db->mmap_used, 1) && !alloca_used)
+ {
+ assert (db->wr_fd != -1);
+ assert ((char *) &dataset->resp > (char *) db->data);
+ assert ((char *) dataset - (char *) db->head
+ + total
+ <= (sizeof (struct database_pers_head)
+ + db->head->module * sizeof (ref_t)
+ + db->head->data_size));
+ ssize_t written = sendfileall (fd, db->wr_fd,
+ (char *) &dataset->resp
+ - (char *) db->head,
+ dataset->head.recsize);
+ if (written != dataset->head.recsize)
+ {
+# ifndef __ASSUME_SENDFILE
+ if (written == -1 && errno == ENOSYS)
+ goto use_write;
+# endif
+ all_written = false;
+ }
+ }
+ else
+# ifndef __ASSUME_SENDFILE
+ use_write:
+# endif
+#endif
+ if (writeall (fd, &dataset->resp, dataset->head.recsize)
+ != dataset->head.recsize)
+ all_written = false;
}
- /* 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, owner);
- addresses += IN6ADDRSZ;
- }
+ /* Add the record to the database. But only if it has not been
+ stored on the stack.
- /* If necessary add the key for this request. */
- if (req->type == GETHOSTBYNAME || req->type == GETHOSTBYNAMEv6)
+ If the record contains more than one IP address (used for
+ load balancing etc) don't cache the entry. This is something
+ the current cache handling cannot handle and it is more than
+ questionable whether it is worthwhile complicating the cache
+ handling just for handling such a special case. */
+ if (! alloca_used)
{
- if (addr_list_type == GETHOSTBYADDR)
- cache_add (GETHOSTBYNAME, key_copy, req->key_len, data, total,
- data, 0, t, db, owner);
- cache_add (GETHOSTBYNAMEv6, key_copy, req->key_len, data,
- total, data, 0, t, db, owner);
+ /* If necessary, we also propagate the data to disk. */
+ if (db->persistent)
+ {
+ // XXX async OK?
+ uintptr_t pval = (uintptr_t) dataset & ~pagesize_m1;
+ msync ((void *) pval,
+ ((uintptr_t) dataset & pagesize_m1)
+ + total + req->key_len, MS_ASYNC);
+ }
+
+ /* NB: the following code is really complicated. It has
+ seemlingly duplicated code paths which do the same. The
+ problem is that we always must add the hash table entry
+ with the FIRST flag set first. Otherwise we get dangling
+ pointers in case memory allocation fails. */
+ assert (hst->h_addr_list[1] == NULL);
+
+ /* Avoid adding names if more than one address is available. See
+ above for more info. */
+ assert (req->type == GETHOSTBYNAME
+ || req->type == GETHOSTBYNAMEv6
+ || req->type == GETHOSTBYADDR
+ || req->type == GETHOSTBYADDRv6);
+
+ (void) cache_add (req->type, key_copy, req->key_len,
+ &dataset->head, true, db, owner, he == NULL);
+
+ pthread_rwlock_unlock (&db->lock);
}
-
- /* 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, owner);
- cache_add (GETHOSTBYNAMEv6, data->strdata, h_name_len, data,
- total, data, 1, t, db, owner);
-
- pthread_rwlock_unlock (&db->lock);
}
- if (written != total)
+ if (__builtin_expect (!all_written, 0) && debug_level > 0)
{
char buf[256];
dbg_log (_("short write in %s: %s"), __FUNCTION__,
strerror_r (errno, buf, sizeof (buf)));
}
+
+ return timeout;
}
-void
-addhstbyname (struct database *db, int fd, request_header *req,
- void *key, uid_t uid)
+static int
+lookup (int type, void *key, struct hostent *resultbufp, char *buffer,
+ size_t buflen, struct hostent **hst, int32_t *ttlp)
+{
+ if (type == GETHOSTBYNAME)
+ return __gethostbyname3_r (key, AF_INET, resultbufp, buffer, buflen, hst,
+ &h_errno, ttlp, NULL);
+ if (type == GETHOSTBYNAMEv6)
+ return __gethostbyname3_r (key, AF_INET6, resultbufp, buffer, buflen, hst,
+ &h_errno, ttlp, NULL);
+ if (type == GETHOSTBYADDR)
+ return __gethostbyaddr2_r (key, NS_INADDRSZ, AF_INET, resultbufp, buffer,
+ buflen, hst, &h_errno, ttlp);
+ return __gethostbyaddr2_r (key, NS_IN6ADDRSZ, AF_INET6, resultbufp, buffer,
+ buflen, hst, &h_errno, ttlp);
+}
+
+
+static time_t
+addhstbyX (struct database_dyn *db, int fd, request_header *req,
+ void *key, uid_t uid, struct hashentry *he, struct datahead *dh)
{
/* 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);
+ int buflen = 1024;
+ char *buffer = (char *) alloca (buflen);
struct hostent resultbuf;
struct hostent *hst;
- uid_t oldeuid = 0;
-
- if (debug_level > 0)
- dbg_log (_("Haven't found \"%s\" in hosts cache!"), key);
+ bool use_malloc = false;
+ int errval = 0;
+ int32_t ttl = INT32_MAX;
- if (secure[hstdb])
+ if (__builtin_expect (debug_level > 0, 0))
{
- oldeuid = geteuid ();
- seteuid (uid);
+ const char *str;
+ char buf[INET6_ADDRSTRLEN + 1];
+ if (req->type == GETHOSTBYNAME || req->type == GETHOSTBYNAMEv6)
+ str = key;
+ else
+ str = inet_ntop (req->type == GETHOSTBYADDR ? AF_INET : AF_INET6,
+ key, buf, sizeof (buf));
+
+ if (he == NULL)
+ dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *) str);
+ else
+ dbg_log (_("Reloading \"%s\" in hosts cache!"), (char *) str);
}
- while (__gethostbyname2_r (key, AF_INET, &resultbuf, buffer, buflen,
- &hst, &h_errno) != 0
+ while (lookup (req->type, key, &resultbuf, buffer, buflen, &hst, &ttl) != 0
&& h_errno == NETDB_INTERNAL
- && errno == ERANGE)
+ && (errval = errno) == ERANGE)
{
errno = 0;
- buflen += 256;
- buffer = alloca (buflen);
+
+ if (__builtin_expect (buflen > 32768, 0))
+ {
+ char *old_buffer = buffer;
+ buflen *= 2;
+ buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+ if (buffer == NULL)
+ {
+ /* We ran out of memory. We cannot do anything but
+ sending a negative response. In reality this should
+ never happen. */
+ hst = NULL;
+ buffer = old_buffer;
+
+ /* We set the error to indicate this is (possibly) a
+ temporary error and that it does not mean the entry
+ is not available at all. */
+ h_errno = TRY_AGAIN;
+ errval = EAGAIN;
+ break;
+ }
+ use_malloc = true;
+ }
+ else
+ /* Allocate a new buffer on the stack. If possible combine it
+ with the previously allocated buffer. */
+ buffer = (char *) extend_alloca (buffer, buflen, 2 * buflen);
}
- if (secure[hstdb])
- seteuid (uid);
+ time_t timeout = cache_addhst (db, fd, req, key, hst, uid, he, dh,
+ h_errno == TRY_AGAIN ? errval : 0, ttl);
+
+ if (use_malloc)
+ free (buffer);
- cache_addhst (db, fd, req, key, hst, uid);
+ return timeout;
}
void
-addhstbyaddr (struct database *db, int fd, request_header *req,
+addhstbyname (struct database_dyn *db, int fd, request_header *req,
void *key, uid_t uid)
{
- /* 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;
- uid_t oldeuid = 0;
-
- if (debug_level > 0)
- {
- char buf[INET_ADDRSTRLEN];
- dbg_log (_("Haven't found \"%s\" in hosts cache!"),
- inet_ntop (AF_INET, key, buf, sizeof (buf)));
- }
+ addhstbyX (db, fd, req, key, uid, NULL, NULL);
+}
- if (secure[hstdb])
- {
- oldeuid = geteuid ();
- seteuid (uid);
- }
- while (__gethostbyaddr_r (key, INADDRSZ, AF_INET, &resultbuf, buffer,
- buflen, &hst, &h_errno) != 0
- && h_errno == NETDB_INTERNAL
- && errno == ERANGE)
+time_t
+readdhstbyname (struct database_dyn *db, struct hashentry *he,
+ struct datahead *dh)
+{
+ request_header req =
{
- errno = 0;
- buflen += 256;
- buffer = alloca (buflen);
- }
-
- if (secure[hstdb])
- seteuid (oldeuid);
+ .type = GETHOSTBYNAME,
+ .key_len = he->len
+ };
- cache_addhst (db, fd, req, key, hst, uid);
+ return addhstbyX (db, -1, &req, db->data + he->key, he->owner, he, dh);
}
void
-addhstbynamev6 (struct database *db, int fd, request_header *req,
- void *key, uid_t uid)
+addhstbyaddr (struct database_dyn *db, int fd, request_header *req,
+ void *key, uid_t uid)
{
- /* 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;
- uid_t oldeuid = 0;
+ addhstbyX (db, fd, req, key, uid, NULL, NULL);
+}
+
- if (debug_level > 0)
+time_t
+readdhstbyaddr (struct database_dyn *db, struct hashentry *he,
+ struct datahead *dh)
+{
+ request_header req =
{
- char buf[INET6_ADDRSTRLEN];
+ .type = GETHOSTBYADDR,
+ .key_len = he->len
+ };
- dbg_log (_("Haven't found \"%s\" in hosts cache!"),
- inet_ntop (AF_INET6, key, buf, sizeof (buf)));
- }
+ return addhstbyX (db, -1, &req, db->data + he->key, he->owner, he, dh);
+}
- if (secure[hstdb])
- {
- oldeuid = geteuid ();
- seteuid (uid);
- }
- 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);
- }
+void
+addhstbynamev6 (struct database_dyn *db, int fd, request_header *req,
+ void *key, uid_t uid)
+{
+ addhstbyX (db, fd, req, key, uid, NULL, NULL);
+}
- if (secure[hstdb])
- seteuid (oldeuid);
- cache_addhst (db, fd, req, key, hst, uid);
+time_t
+readdhstbynamev6 (struct database_dyn *db, struct hashentry *he,
+ struct datahead *dh)
+{
+ request_header req =
+ {
+ .type = GETHOSTBYNAMEv6,
+ .key_len = he->len
+ };
+
+ return addhstbyX (db, -1, &req, db->data + he->key, he->owner, he, dh);
}
void
-addhstbyaddrv6 (struct database *db, int fd, request_header *req,
+addhstbyaddrv6 (struct database_dyn *db, int fd, request_header *req,
void *key, uid_t uid)
{
- /* 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;
- uid_t oldeuid = 0;
+ addhstbyX (db, fd, req, key, uid, NULL, NULL);
+}
- if (debug_level > 0)
- {
- char buf[INET6_ADDRSTRLEN];
- dbg_log (_("Haven't found \"%s\" in hosts cache!"),
- inet_ntop (AF_INET6, key, buf, sizeof (buf)));
- }
- if (secure[hstdb])
- {
- oldeuid = geteuid ();
- seteuid (uid);
- }
-
- while (__gethostbyaddr_r (key, IN6ADDRSZ, AF_INET6, &resultbuf,
- buffer, buflen, &hst, &h_errno) != 0
- && h_errno == NETDB_INTERNAL
- && errno == ERANGE)
+time_t
+readdhstbyaddrv6 (struct database_dyn *db, struct hashentry *he,
+ struct datahead *dh)
+{
+ request_header req =
{
- errno = 0;
- buflen += 256;
- buffer = alloca (buflen);
- }
-
- if (secure[hstdb])
- seteuid (oldeuid);
+ .type = GETHOSTBYADDRv6,
+ .key_len = he->len
+ };
- cache_addhst (db, fd, req, key, hst, uid);
+ return addhstbyX (db, -1, &req, db->data + he->key, he->owner, he, dh);
}
projects / platform / upstream / glibc.git / blobdiff