/* Cache handling for host lookup.
- Copyright (C) 2004-2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+ Copyright (C) 2004-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
GNU General Public License for more details.
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. */
+ along with this program; if not, see <http://www.gnu.org/licenses/>. */
#include <assert.h>
#include <errno.h>
#include <time.h>
#include <unistd.h>
#include <sys/mman.h>
+#include <resolv/resolv-internal.h>
+#include <resolv/resolv_context.h>
+#include <scratch_buffer.h>
#include "dbg_log.h"
#include "nscd.h"
-#ifdef HAVE_SENDFILE
-# include <kernel-features.h>
-#endif
typedef enum nss_status (*nss_gethostbyname4_r)
char strdata[0];
} *dataset = NULL;
- if (__builtin_expect (debug_level > 0, 0))
+ if (__glibc_unlikely (debug_level > 0))
{
if (he == NULL)
dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *) key);
}
static service_user *hosts_database;
- service_user *nip = NULL;
+ service_user *nip;
int no_more;
int rc6 = 0;
int rc4 = 0;
int herrno = 0;
- if (hosts_database != NULL)
- {
- nip = hosts_database;
- no_more = 0;
- }
- else
+ if (hosts_database == NULL)
no_more = __nss_database_lookup ("hosts", NULL,
- "dns [!UNAVAIL=return] files", &nip);
-
- if (__res_maybe_init (&_res, 0) == -1)
- no_more = 1;
-
- /* If we are looking for both IPv4 and IPv6 address we don't want
- the lookup functions to automatically promote IPv4 addresses to
- IPv6 addresses. Currently this is decided by setting the
- RES_USE_INET6 bit in _res.options. */
- int old_res_options = _res.options;
- _res.options &= ~RES_USE_INET6;
-
- size_t tmpbuf6len = 1024;
- char *tmpbuf6 = alloca (tmpbuf6len);
- size_t tmpbuf4len = 0;
- char *tmpbuf4 = NULL;
+ "dns [!UNAVAIL=return] files",
+ &hosts_database);
+ else
+ no_more = 0;
+ nip = hosts_database;
+
+ /* Initialize configurations. */
+ struct resolv_context *ctx = __resolv_context_get ();
+ if (ctx == NULL)
+ no_more = 1;
+
+ struct scratch_buffer tmpbuf6;
+ scratch_buffer_init (&tmpbuf6);
+ struct scratch_buffer tmpbuf4;
+ scratch_buffer_init (&tmpbuf4);
+ struct scratch_buffer canonbuf;
+ scratch_buffer_init (&canonbuf);
+
int32_t ttl = INT32_MAX;
ssize_t total = 0;
char *key_copy = NULL;
int status[2] = { NSS_STATUS_UNAVAIL, NSS_STATUS_UNAVAIL };
int naddrs = 0;
size_t addrslen = 0;
+
char *canon = NULL;
size_t canonlen;
at = &atmem;
rc6 = 0;
herrno = 0;
- status[1] = DL_CALL_FCT (fct4, (key, &at, tmpbuf6, tmpbuf6len,
+ status[1] = DL_CALL_FCT (fct4, (key, &at,
+ tmpbuf6.data, tmpbuf6.length,
&rc6, &herrno, &ttl));
if (rc6 != ERANGE || (herrno != NETDB_INTERNAL
&& herrno != TRY_AGAIN))
break;
- tmpbuf6 = extend_alloca (tmpbuf6, tmpbuf6len, 2 * tmpbuf6len);
+ if (!scratch_buffer_grow (&tmpbuf6))
+ {
+ rc6 = ENOMEM;
+ break;
+ }
}
if (rc6 != 0 && herrno == NETDB_INTERNAL)
while (1)
{
rc6 = 0;
- status[0] = DL_CALL_FCT (fct, (key, AF_INET6, &th[0], tmpbuf6,
- tmpbuf6len, &rc6, &herrno, &ttl,
+ status[0] = DL_CALL_FCT (fct, (key, AF_INET6, &th[0],
+ tmpbuf6.data, tmpbuf6.length,
+ &rc6, &herrno, &ttl,
&canon));
if (rc6 != ERANGE || herrno != NETDB_INTERNAL)
break;
- tmpbuf6 = extend_alloca (tmpbuf6, tmpbuf6len, 2 * tmpbuf6len);
+ if (!scratch_buffer_grow (&tmpbuf6))
+ {
+ rc6 = ENOMEM;
+ break;
+ }
}
if (rc6 != 0 && herrno == NETDB_INTERNAL)
goto out;
- /* If the IPv6 lookup has been successful do not use the
- buffer used in that lookup, use a new one. */
- if (status[0] == NSS_STATUS_SUCCESS && rc6 == 0)
- {
- tmpbuf4len = 512;
- tmpbuf4 = alloca (tmpbuf4len);
- }
- else
- {
- tmpbuf4len = tmpbuf6len;
- tmpbuf4 = tmpbuf6;
- }
-
/* Next collect IPv4 information. */
while (1)
{
rc4 = 0;
- status[1] = DL_CALL_FCT (fct, (key, AF_INET, &th[1], tmpbuf4,
- tmpbuf4len, &rc4, &herrno,
+ status[1] = DL_CALL_FCT (fct, (key, AF_INET, &th[1],
+ tmpbuf4.data, tmpbuf4.length,
+ &rc4, &herrno,
ttl == INT32_MAX ? &ttl : NULL,
canon == NULL ? &canon : NULL));
if (rc4 != ERANGE || herrno != NETDB_INTERNAL)
break;
- tmpbuf4 = extend_alloca (tmpbuf4, tmpbuf4len, 2 * tmpbuf4len);
+ if (!scratch_buffer_grow (&tmpbuf4))
+ {
+ rc4 = ENOMEM;
+ break;
+ }
}
if (rc4 != 0 && herrno == NETDB_INTERNAL)
cfct = __nss_lookup_function (nip, "getcanonname_r");
if (cfct != NULL)
{
- const size_t max_fqdn_len = 256;
- char *buf = alloca (max_fqdn_len);
char *s;
int rc;
- if (DL_CALL_FCT (cfct, (key, buf, max_fqdn_len, &s,
- &rc, &herrno))
+ if (DL_CALL_FCT (cfct, (key, canonbuf.data, canonbuf.length,
+ &s, &rc, &herrno))
== NSS_STATUS_SUCCESS)
canon = s;
else
addrfamily = AF_INET6;
}
- size_t tmpbuflen = 512;
- char *tmpbuf = alloca (tmpbuflen);
int rc;
while (1)
{
rc = __gethostbyaddr2_r (addr, addrlen, addrfamily,
- &hstent_mem, tmpbuf, tmpbuflen,
+ &hstent_mem,
+ canonbuf.data, canonbuf.length,
&hstent, &herrno, NULL);
if (rc != ERANGE || herrno != NETDB_INTERNAL)
break;
- tmpbuf = extend_alloca (tmpbuf, tmpbuflen,
- tmpbuflen * 2);
+ if (!scratch_buffer_grow (&canonbuf))
+ {
+ rc = ENOMEM;
+ break;
+ }
}
if (rc == 0)
cp = family;
}
- /* Fill in the rest of the dataset. */
- 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 = time (NULL) + dataset->head.ttl;
+ timeout = datahead_init_pos (&dataset->head, total + req->key_len,
+ total - offsetof (struct dataset, resp),
+ he == NULL ? 0 : dh->nreloads + 1,
+ ttl == INT32_MAX ? db->postimeout : ttl);
+ /* Fill in the rest of the dataset. */
dataset->resp.version = NSCD_VERSION;
dataset->resp.found = 1;
dataset->resp.naddrs = naddrs;
struct dataset *newp
= (struct dataset *) mempool_alloc (db, total + req->key_len,
1);
- if (__builtin_expect (newp != NULL, 1))
+ if (__glibc_likely (newp != NULL))
{
/* Adjust pointer into the memory block. */
key_copy = (char *) newp + (key_copy - (char *) dataset);
would unnecessarily let the receiver wait. */
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;
- written = sendfileall (fd, db->wr_fd, (char *) &dataset->resp
- - (char *) db->head, dataset->head.recsize);
-# ifndef __ASSUME_SENDFILE
- if (written == -1 && errno == ENOSYS)
- goto use_write;
-# endif
- }
- else
-# ifndef __ASSUME_SENDFILE
- use_write:
-# endif
-#endif
- writeall (fd, &dataset->resp, dataset->head.recsize);
+ writeall (fd, &dataset->resp, dataset->head.recsize);
}
goto out;
if (fd != -1)
TEMP_FAILURE_RETRY (send (fd, ¬found, total, MSG_NOSIGNAL));
- dataset = mempool_alloc (db, sizeof (struct dataset) + req->key_len, 1);
- /* If we cannot permanently store the result, so be it. */
- if (dataset != NULL)
+ /* If we have a transient error or cannot permanently store the
+ result, so be it. */
+ if (rc4 == EAGAIN || __builtin_expect (db->negtimeout == 0, 0))
{
- 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. */
- timeout = dataset->head.timeout = time (NULL) + db->negtimeout;
- dataset->head.ttl = db->negtimeout;
+ /* Mark the old entry as obsolete. */
+ if (dh != NULL)
+ dh->usable = false;
+ dataset = NULL;
+ }
+ else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
+ + req->key_len), 1)) != NULL)
+ {
+ timeout = datahead_init_neg (&dataset->head,
+ sizeof (struct dataset) + req->key_len,
+ total, db->negtimeout);
/* This is the reply. */
memcpy (&dataset->resp, ¬found, total);
}
out:
- _res.options = old_res_options;
+ __resolv_context_put (ctx);
if (dataset != NULL && !alloca_used)
{
dh->usable = false;
}
+ scratch_buffer_free (&tmpbuf6);
+ scratch_buffer_free (&tmpbuf4);
+ scratch_buffer_free (&canonbuf);
+
return timeout;
}
projects / thirdparty / glibc.git / blobdiff