Update.

2004-09-15  Ulrich Drepper  <drepper@redhat.com>

	* nscd/Makefile (rountines): Add nscd_getai.
	(nscd-modules): Add aicache.
	* nscd/aicache.c: New file.
	* nscd/nscd_getai.c: New file.
	* nscd/cache.c (prune_cache): Handle GETAI request type.
	* nscd/connections.c: Add GETAI support in request handling.
	* nscd/nscd-client.h (request_type): Add GETAI.
	Define ai_response_header and struct nscd_ai_result types.
	(struct datahead): Add aidata field.
	Declare __nscd_getai.
	* nscd/nscd.c: Add getaddrinfo definition to catch problems.
	* nscd/nscd.h: Declare addhstai and readdhstai.

	* sysdeps/posix/getaddrinfo.c: Add support for using cached results.

	* nscd/nscd-client.h  (struct datahead): Use uint8_t instead of bool.

1 files changed, 428 insertions, 0 deletions

diff --git a/nscd/aicache.c b/nscd/aicache.c
new file mode 100644
index 0000000000..e7489065d4
--- /dev/null
+++ b/nscd/aicache.c
@@ -0,0 +1,428 @@
+/* Cache handling for host lookup.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+   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 <assert.h>
+#include <errno.h>
+#include <libintl.h>
+#include <netdb.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <dbg_log.h>
+#include <nscd.h>
+
+
+typedef enum nss_status (*nss_gethostbyname2_r)
+  (const char *name, int af, struct hostent *host,
+   char *buffer, size_t buflen, int *errnop,
+   int *h_errnop);
+typedef enum nss_status (*nss_getcanonname_r)
+  (const char *name, char *buffer, size_t buflen, char **result,
+   int *errnop, int *h_errnop);
+
+
+static const ai_response_header notfound =
+{
+  .version = NSCD_VERSION,
+  .found = 0,
+  .naddrs = 0,
+  .addrslen = 0,
+  .canonlen = 0,
+  .error = 0
+};
+
+
+static void
+addhstaiX (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.  */
+  uid_t oldeuid = 0;
+
+  /* We allocate all data in one memory block: the iov vector,
+     the response header and the dataset itself.  */
+  struct dataset
+  {
+    struct datahead head;
+    ai_response_header resp;
+    char strdata[0];
+  } *dataset = NULL;
+
+  if (__builtin_expect (debug_level > 0, 0))
+    {
+      if (he == NULL)
+	dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *) key);
+      else
+	dbg_log (_("Reloading \"%s\" in hosts cache!"), (char *) key);
+    }
+
+  if (db->secure)
+    {
+      oldeuid = geteuid ();
+      seteuid (uid);
+    }
+
+  static service_user *hosts_database;
+  service_user *nip = NULL;
+  int no_more;
+  int rc6 = 0;
+  int rc4 = 0;
+  int herrno = 0;
+
+  if (hosts_database != NULL)
+    {
+      nip = hosts_database;
+      no_more = 0;
+    }
+  else
+    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 = 512;
+  char *tmpbuf6 = alloca (tmpbuf6len);
+  size_t tmpbuf4len = 0;
+  char *tmpbuf4 = NULL;
+  char *canon = NULL;
+  ssize_t total = 0;
+  char *key_copy = NULL;
+  bool alloca_used = false;
+
+  while (!no_more)
+    {
+      nss_gethostbyname2_r fct = __nss_lookup_function (nip,
+							"gethostbyname2_r");
+      int status[2] = { NSS_STATUS_UNAVAIL, NSS_STATUS_UNAVAIL };
+
+      if (fct != NULL)
+	{
+ printf("fct=%p\n",fct);
+	  struct hostent th[2];
+
+	  /* Collect IPv6 information first.  */
+	  while (1)
+	    {
+	      rc6 = 0;
+	      status[0] = DL_CALL_FCT (fct, (key, AF_INET6, &th[0], tmpbuf6,
+					     tmpbuf6len, &rc6, &herrno));
+	      if (rc6 != ERANGE || herrno != NETDB_INTERNAL)
+		break;
+	      tmpbuf6 = extend_alloca (tmpbuf6, tmpbuf6len, 2 * tmpbuf6len);
+	    }
+
+	  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 first.  */
+	  while (1)
+	    {
+	      rc4 = 0;
+	      status[1] = DL_CALL_FCT (fct, (key, AF_INET, &th[1], tmpbuf4,
+					     tmpbuf4len, &rc4, &herrno));
+	      if (rc4 != ERANGE || herrno != NETDB_INTERNAL)
+		break;
+	      tmpbuf4 = extend_alloca (tmpbuf6, tmpbuf6len, 2 * tmpbuf6len);
+	    }
+
+	  if (rc4 != 0 || herrno == NETDB_INTERNAL)
+	    goto out;
+
+	  if (status[0] == NSS_STATUS_SUCCESS
+	      || status[1] == NSS_STATUS_SUCCESS)
+	    {
+	      /* We found the data.  Count the addresses and the size.  */
+	      int naddrs = 0;
+	      size_t addrslen = 0;
+	      for (int j = 0; j < 2; ++j)
+		if (status[j] == NSS_STATUS_SUCCESS)
+		  for (int i = 0; th[j].h_addr_list[i] != NULL; ++i)
+		    {
+		      ++naddrs;
+		      addrslen += th[j].h_length;
+		    }
+
+	      /* Determine the canonical name.  */
+	      nss_getcanonname_r cfct;
+	      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)) == NSS_STATUS_SUCCESS)
+		    canon = s;
+		  else
+		    /* Set to name now to avoid using gethostbyaddr.  */
+		    canon = key;
+		}
+	      else
+		{
+		  // XXX use gethostbyaddr
+		}
+	      size_t canonlen = canon == NULL ? 0 : (strlen (canon) + 1);
+
+	      total = sizeof (*dataset) + naddrs + addrslen + canonlen;
+
+	      /* Now we can allocate the data structure.  */
+	      if (he == NULL)
+		{
+		  dataset = (struct dataset *) mempool_alloc (db,
+							      total
+							      + req->key_len);
+		  if (dataset == NULL)
+		    ++db->head->addfailed;
+		}
+
+	      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.timeout = time (NULL) + db->postimeout;
+
+	      dataset->resp.version = NSCD_VERSION;
+	      dataset->resp.found = 1;
+	      dataset->resp.naddrs = naddrs;
+	      dataset->resp.addrslen = addrslen;
+	      dataset->resp.canonlen = canonlen;
+	      dataset->resp.error = NETDB_SUCCESS;
+
+	      char *addrs = (char *) (&dataset->resp + 1);
+	      uint8_t *family = (uint8_t *) (addrs + addrslen);
+
+	      for (int j = 0; j < 2; ++j)
+		if (status[j] == NSS_STATUS_SUCCESS)
+		  for (int i = 0; th[j].h_addr_list[i] != NULL; ++i)
+		    {
+		      addrs = mempcpy (addrs, th[j].h_addr_list[i],
+				       th[j].h_length);
+		      *family++ = th[j].h_addrtype;
+		    }
+
+	      char *cp = family;
+	      if (canon != NULL)
+		cp = mempcpy (cp, canon, canonlen);
+
+	      key_copy = memcpy (cp, key, req->key_len);
+
+	      /* Now we can determine whether on refill we have to
+		 create a new record or not.  */
+	      if (he != NULL)
+		{
+		  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.  */
+		      dh->timeout = dataset->head.timeout;
+		      ++dh->nreloads;
+		    }
+		  else
+		    {
+		      /* 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);
+		      if (newp != NULL)
+			{
+			  /* Adjust pointer into the memory block.  */
+			  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;
+		    }
+		}
+	      else
+		{
+		  /* 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.  */
+		  assert (fd != -1);
+
+		  TEMP_FAILURE_RETRY (write (fd, &dataset->resp, total));
+		}
+
+	      goto out;
+	    }
+
+	}
+
+      if (nss_next_action (nip, status[1]) == NSS_ACTION_RETURN)
+	break;
+
+      if (nip->next == NULL)
+	no_more = -1;
+      else
+	nip = nip->next;
+    }
+
+  /* No result found.  Create a negative result record.  */
+  if (he != NULL && rc4 == 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 && dh->nreloads == reload_count)
+	/* Do not reset the value if we never not reload the record.  */
+	dh->nreloads = reload_count - 1;
+    }
+  else
+    {
+      /* We have no data.  This means we send the standard reply for
+	 this case.  */
+      total = sizeof (notfound);
+
+      if (fd != -1)
+	TEMP_FAILURE_RETRY (write (fd, &notfound, total));
+
+      dataset = mempool_alloc (db, sizeof (struct dataset) + req->key_len);
+      /* If we cannot permanently store the result, so be it.  */
+      if (dataset != 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.timeout = time (NULL) + db->negtimeout;
+
+	  /* This is the reply.  */
+	  memcpy (&dataset->resp, &notfound, total);
+
+	  /* Copy the key data.  */
+	  key_copy = memcpy (dataset->strdata, key, req->key_len);
+	}
+      else
+	++db->head->addfailed;
+   }
+
+ out:
+  _res.options = old_res_options;
+
+  if (db->secure)
+    seteuid (oldeuid);
+
+  if (dataset != NULL && !alloca_used)
+    {
+      /* 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);
+	}
+
+      /* Now get the lock to safely insert the records.  */
+      pthread_rwlock_rdlock (&db->lock);
+
+      if (cache_add (req->type, key_copy, req->key_len, &dataset->head, true,
+		     db, uid) < 0)
+	/* Ensure the data can be recovered.  */
+	dataset->head.usable = false;
+
+      pthread_rwlock_unlock (&db->lock);
+
+      /* Mark the old entry as obsolete.  */
+      if (dh != NULL)
+	dh->usable = false;
+    }
+}
+
+
+void
+addhstai (struct database_dyn *db, int fd, request_header *req, void *key,
+	  uid_t uid)
+{
+  addhstaiX (db, fd, req, key, uid, NULL, NULL);
+}
+
+
+void
+readdhstai (struct database_dyn *db, struct hashentry *he, struct datahead *dh)
+{
+  request_header req =
+    {
+      .type = GETAI,
+      .key_len = he->len
+    };
+
+  addhstaiX (db, -1, &req, db->data + he->key, he->owner, he, dh);
+}