Import glibc-mainline for 2006-08-16

git-svn-id: svn://svn.eglibc.org/fsf/trunk@4 7b3dc134-2b1b-0410-93df-9e9f96275f8d

1 files changed, 389 insertions, 0 deletions

diff --git a/libc/nscd/nscd_gethst_r.c b/libc/nscd/nscd_gethst_r.c
new file mode 100644
index 000000000..516977bcc
--- /dev/null
+++ b/libc/nscd/nscd_gethst_r.c
@@ -0,0 +1,389 @@
+/* Copyright (C) 1998-2005, 2006 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 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 <netdb.h>
+#include <resolv.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <arpa/nameser.h>
+#include <not-cancel.h>
+
+#include "nscd-client.h"
+#include "nscd_proto.h"
+
+int __nss_not_use_nscd_hosts;
+
+static int nscd_gethst_r (const char *key, size_t keylen, request_type type,
+			  struct hostent *resultbuf, char *buffer,
+			  size_t buflen, struct hostent **result,
+			  int *h_errnop) internal_function;
+
+
+int
+__nscd_gethostbyname_r (const char *name, struct hostent *resultbuf,
+			char *buffer, size_t buflen, struct hostent **result,
+			int *h_errnop)
+{
+  request_type reqtype;
+
+  reqtype = (_res.options & RES_USE_INET6) ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
+
+  return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
+			buffer, buflen, result, h_errnop);
+}
+
+
+int
+__nscd_gethostbyname2_r (const char *name, int af, struct hostent *resultbuf,
+			 char *buffer, size_t buflen, struct hostent **result,
+			 int *h_errnop)
+{
+  request_type reqtype;
+
+  reqtype = af == AF_INET6 ? GETHOSTBYNAMEv6 : GETHOSTBYNAME;
+
+  return nscd_gethst_r (name, strlen (name) + 1, reqtype, resultbuf,
+			buffer, buflen, result, h_errnop);
+}
+
+
+int
+__nscd_gethostbyaddr_r (const void *addr, socklen_t len, int type,
+			struct hostent *resultbuf, char *buffer, size_t buflen,
+			struct hostent **result, int *h_errnop)
+{
+  request_type reqtype;
+
+  if (!((len == INADDRSZ && type == AF_INET)
+	|| (len == IN6ADDRSZ && type == AF_INET6)))
+    /* LEN and TYPE do not match.  */
+    return -1;
+
+  reqtype = type == AF_INET6 ? GETHOSTBYADDRv6 : GETHOSTBYADDR;
+
+  return nscd_gethst_r (addr, len, reqtype, resultbuf, buffer, buflen, result,
+			h_errnop);
+}
+
+
+libc_locked_map_ptr (, __hst_map_handle) attribute_hidden;
+/* Note that we only free the structure if necessary.  The memory
+   mapping is not removed since it is not visible to the malloc
+   handling.  */
+libc_freeres_fn (hst_map_free)
+{
+  if (__hst_map_handle.mapped != NO_MAPPING)
+    {
+      void *p = __hst_map_handle.mapped;
+      __hst_map_handle.mapped = NO_MAPPING;
+      free (p);
+    }
+}
+
+
+static int
+internal_function
+nscd_gethst_r (const char *key, size_t keylen, request_type type,
+	       struct hostent *resultbuf, char *buffer, size_t buflen,
+	       struct hostent **result, int *h_errnop)
+{
+  int gc_cycle;
+  int nretries = 0;
+
+  /* If the mapping is available, try to search there instead of
+     communicating with the nscd.  */
+  struct mapped_database *mapped;
+  mapped = __nscd_get_map_ref (GETFDHST, "hosts", &__hst_map_handle,
+			       &gc_cycle);
+
+ retry:;
+  const hst_response_header *hst_resp = NULL;
+  const char *h_name = NULL;
+  const uint32_t *aliases_len = NULL;
+  const char *addr_list = NULL;
+  size_t addr_list_len = 0;
+  int retval = -1;
+  const char *recend = (const char *) ~UINTMAX_C (0);
+  int sock = -1;
+  if (mapped != NO_MAPPING)
+    {
+      const struct datahead *found = __nscd_cache_search (type, key, keylen,
+							  mapped);
+      if (found != NULL)
+	{
+	  hst_resp = &found->data[0].hstdata;
+	  h_name = (char *) (hst_resp + 1);
+	  aliases_len = (uint32_t *) (h_name + hst_resp->h_name_len);
+	  addr_list = ((char *) aliases_len
+		       + hst_resp->h_aliases_cnt * sizeof (uint32_t));
+	  addr_list_len = hst_resp->h_addr_list_cnt * INADDRSZ;
+
+#ifndef _STRING_ARCH_unaligned
+	  /* The aliases_len array in the mapped database might very
+	     well be unaligned.  We will access it word-wise so on
+	     platforms which do not tolerate unaligned accesses we
+	     need to make an aligned copy.  */
+	  if (((uintptr_t) aliases_len & (__alignof__ (*aliases_len) - 1))
+	      != 0)
+	    {
+	      uint32_t *tmp = alloca (hst_resp->h_aliases_cnt
+				      * sizeof (uint32_t));
+	      aliases_len = memcpy (tmp, aliases_len,
+				    hst_resp->h_aliases_cnt
+				    * sizeof (uint32_t));
+	    }
+#endif
+	  if (type != GETHOSTBYADDR && type != GETHOSTBYNAME)
+	    {
+	      if (hst_resp->h_length == INADDRSZ)
+		addr_list += addr_list_len;
+	      addr_list_len = hst_resp->h_addr_list_cnt * IN6ADDRSZ;
+	    }
+	  recend = (const char *) found->data + found->recsize;
+	  if (__builtin_expect ((const char *) addr_list + addr_list_len
+				> recend, 0))
+	    goto out_close;
+	}
+    }
+
+  hst_response_header hst_resp_mem;
+  if (hst_resp == NULL)
+    {
+      sock = __nscd_open_socket (key, keylen, type, &hst_resp_mem,
+				 sizeof (hst_resp_mem));
+      if (sock == -1)
+	{
+	  __nss_not_use_nscd_hosts = 1;
+	  goto out;;
+	}
+
+      hst_resp = &hst_resp_mem;
+    }
+
+  /* No value found so far.  */
+  *result = NULL;
+
+  if (__builtin_expect (hst_resp->found == -1, 0))
+    {
+      /* The daemon does not cache this database.  */
+      __nss_not_use_nscd_hosts = 1;
+      goto out_close;
+    }
+
+  if (hst_resp->found == 1)
+    {
+      struct iovec vec[4];
+      char *cp = buffer;
+      uintptr_t align1;
+      uintptr_t align2;
+      size_t total_len;
+      ssize_t cnt;
+      char *ignore;
+      int n;
+
+      /* A first check whether the buffer is sufficiently large is possible.  */
+      /* Now allocate the buffer the array for the group members.  We must
+	 align the pointer and the base of the h_addr_list pointers.  */
+      align1 = ((__alignof__ (char *) - (cp - ((char *) 0)))
+		& (__alignof__ (char *) - 1));
+      align2 = ((__alignof__ (char *) - ((cp + align1 + hst_resp->h_name_len)
+					 - ((char *) 0)))
+		& (__alignof__ (char *) - 1));
+      if (buflen < (align1 + hst_resp->h_name_len + align2
+		    + ((hst_resp->h_aliases_cnt + hst_resp->h_addr_list_cnt
+			+ 2)
+		       * sizeof (char *))
+		    + hst_resp->h_addr_list_cnt * (type == AF_INET
+						   ? INADDRSZ : IN6ADDRSZ)))
+	{
+	no_room:
+	  *h_errnop = NETDB_INTERNAL;
+	  __set_errno (ERANGE);
+	  retval = ERANGE;
+	  goto out_close;
+	}
+      cp += align1;
+
+      /* Prepare the result as far as we can.  */
+      resultbuf->h_aliases = (char **) cp;
+      cp += (hst_resp->h_aliases_cnt + 1) * sizeof (char *);
+      resultbuf->h_addr_list = (char **) cp;
+      cp += (hst_resp->h_addr_list_cnt + 1) * sizeof (char *);
+
+      resultbuf->h_name = cp;
+      cp += hst_resp->h_name_len + align2;
+
+      if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
+	{
+	  resultbuf->h_addrtype = AF_INET;
+	  resultbuf->h_length = INADDRSZ;
+	}
+      else
+	{
+	  resultbuf->h_addrtype = AF_INET6;
+	  resultbuf->h_length = IN6ADDRSZ;
+	}
+      for (cnt = 0; cnt < hst_resp->h_addr_list_cnt; ++cnt)
+	{
+	  resultbuf->h_addr_list[cnt] = cp;
+	  cp += resultbuf->h_length;
+	}
+      resultbuf->h_addr_list[cnt] = NULL;
+
+      if (h_name == NULL)
+	{
+	  vec[0].iov_base = resultbuf->h_name;
+	  vec[0].iov_len = hst_resp->h_name_len;
+	  total_len = hst_resp->h_name_len;
+	  n = 1;
+
+	  if (hst_resp->h_aliases_cnt > 0)
+	    {
+	      aliases_len = alloca (hst_resp->h_aliases_cnt
+				    * sizeof (uint32_t));
+	      vec[n].iov_base = (void *) aliases_len;
+	      vec[n].iov_len = hst_resp->h_aliases_cnt * sizeof (uint32_t);
+
+	      total_len += hst_resp->h_aliases_cnt * sizeof (uint32_t);
+	      ++n;
+	    }
+
+	  if (type == GETHOSTBYADDR || type == GETHOSTBYNAME)
+	    {
+	      vec[n].iov_base = resultbuf->h_addr_list[0];
+	      vec[n].iov_len = hst_resp->h_addr_list_cnt * INADDRSZ;
+
+	      total_len += hst_resp->h_addr_list_cnt * INADDRSZ;
+
+	      ++n;
+	    }
+	  else
+	    {
+	      if (hst_resp->h_length == INADDRSZ)
+		{
+		  ignore = alloca (hst_resp->h_addr_list_cnt * INADDRSZ);
+		  vec[n].iov_base = ignore;
+		  vec[n].iov_len = hst_resp->h_addr_list_cnt * INADDRSZ;
+
+		  total_len += hst_resp->h_addr_list_cnt * INADDRSZ;
+
+		  ++n;
+		}
+
+	      vec[n].iov_base = resultbuf->h_addr_list[0];
+	      vec[n].iov_len = hst_resp->h_addr_list_cnt * IN6ADDRSZ;
+
+	      total_len += hst_resp->h_addr_list_cnt * IN6ADDRSZ;
+
+	      ++n;
+	    }
+
+	  if ((size_t) __readvall (sock, vec, n) != total_len)
+	    goto out_close;
+	}
+      else
+	{
+	  memcpy (resultbuf->h_name, h_name, hst_resp->h_name_len);
+	  memcpy (resultbuf->h_addr_list[0], addr_list, addr_list_len);
+	}
+
+      /*  Now we also can read the aliases.  */
+      total_len = 0;
+      for (cnt = 0; cnt < hst_resp->h_aliases_cnt; ++cnt)
+	{
+	  resultbuf->h_aliases[cnt] = cp;
+	  cp += aliases_len[cnt];
+	  total_len += aliases_len[cnt];
+	}
+      resultbuf->h_aliases[cnt] = NULL;
+
+      if (__builtin_expect ((const char *) addr_list + addr_list_len
+			    + total_len > recend, 0))
+	goto out_close;
+      /* See whether this would exceed the buffer capacity.  */
+      if (__builtin_expect (cp > buffer + buflen, 0))
+	goto no_room;
+
+      /* And finally read the aliases.  */
+      if (addr_list == NULL)
+	{
+	  if (total_len == 0
+	      || ((size_t) __readall (sock, resultbuf->h_aliases[0], total_len)
+		  == total_len))
+	    {
+	      retval = 0;
+	      *result = resultbuf;
+	    }
+	}
+      else
+	{
+	  memcpy (resultbuf->h_aliases[0],
+		  (const char *) addr_list + addr_list_len, total_len);
+
+	  /* Try to detect corrupt databases.  */
+	  if (resultbuf->h_name[hst_resp->h_name_len - 1] != '\0'
+	      || ({for (cnt = 0; cnt < hst_resp->h_aliases_cnt; ++cnt)
+		     if (resultbuf->h_aliases[cnt][aliases_len[cnt] - 1]
+			 != '\0')
+		       break;
+		   cnt < hst_resp->h_aliases_cnt; }))
+	    /* We cannot use the database.  */
+	    goto out_close;
+
+	  retval = 0;
+	  *result = resultbuf;
+	}
+    }
+  else
+    {
+      /* Store the error number.  */
+      *h_errnop = hst_resp->error;
+
+      /* The `errno' to some value != ERANGE.  */
+      __set_errno (ENOENT);
+      /* Even though we have not found anything, the result is zero.  */
+      retval = 0;
+    }
+
+ out_close:
+  if (sock != -1)
+    close_not_cancel_no_status (sock);
+ out:
+  if (__nscd_drop_map_ref (mapped, &gc_cycle) != 0 && retval != -1)
+    {
+      /* When we come here this means there has been a GC cycle while we
+	 were looking for the data.  This means the data might have been
+	 inconsistent.  Retry if possible.  */
+      if ((gc_cycle & 1) != 0 || ++nretries == 5)
+	{
+	  /* nscd is just running gc now.  Disable using the mapping.  */
+	  __nscd_unmap (mapped);
+	  mapped = NO_MAPPING;
+	}
+
+      goto retry;
+    }
+
+  return retval;
+}