about summary refs log tree commit diff
path: root/inet/getipnodebynm.c
diff options
context:
space:
mode:
Diffstat (limited to 'inet/getipnodebynm.c')
-rw-r--r--inet/getipnodebynm.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/inet/getipnodebynm.c b/inet/getipnodebynm.c
new file mode 100644
index 0000000000..b0be882afb
--- /dev/null
+++ b/inet/getipnodebynm.c
@@ -0,0 +1,194 @@
+/* Copyright (C) 1999 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
+
+   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 <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdlib.h>
+#include <string.h>
+#include <arpa/inet.h>
+
+#include "nsswitch.h"
+
+
+/* We avoid using a too large buffer in case the user is accumulating the
+   results and there is lots of unused space in the allocated buffer.  */
+#define BUFLEN	512
+
+
+/* Internal function to test whether IPv4 and/or IPv6 are available.  */
+extern void __protocol_available (int *have_inet, int *have_inet6)
+     internal_function;
+
+
+/* Type of the lookup function we need here.  */
+typedef enum nss_status (*lookup_function) (const char *, int, int,
+					    struct hostent *, char *,
+					    size_t, int *, int *);
+
+/* The lookup function for the first entry of this service.  */
+extern int __nss_hosts_lookup (service_user **nip, const char *name,
+			       void **fctp);
+
+
+struct hostent *
+getipnodebyname (const char *name, int type, int flags, int *h_errnop)
+{
+  static service_user *startp;
+  static lookup_function start_fct;
+  service_user *nip;
+  lookup_function fct;
+  int no_more;
+  size_t buffer_size;
+  char *buffer;
+  struct hostent *result;
+  int save;
+  int have_inet = 1;
+  int have_inet6 = 1;
+
+  /* First determine whether we have the appropriate interfaces.
+     XXX I don't think we can cache the result since the system
+     can be reconfigured.  */
+  if ((flags & AI_ADDRCONFIG) != 0)
+    __protocol_available (&have_inet, &have_inet6);
+
+  /* Handle impossible requests first.  */
+  if ((type == AF_INET && have_inet == 0)
+      || (type == AF_INET6 && have_inet6 == 0 && ((flags & AI_V4MAPPED) == 0
+						  || have_inet == 0))
+      || (type != AF_INET && type != AF_INET6))
+    {
+      *h_errnop = NO_DATA;
+      return NULL;
+    }
+
+  buffer_size = BUFLEN;
+  buffer = (char *) malloc (buffer_size);
+
+  result = NULL;
+  if (buffer != NULL)
+    {
+#define HAVE_TYPE
+#define resbuf (*((struct hostent *) buffer))
+#include "../nss/digits_dots.c"
+    }
+
+  if (startp == NULL)
+    {
+      no_more = __nss_hosts_lookup (&nip, "getipnodebyname_r", (void **) &fct);
+      if (no_more)
+	startp = (service_user *) -1l;
+      else
+	{
+	  startp = nip;
+	  start_fct = fct;
+	}
+    }
+  else
+    {
+      fct = start_fct;
+      no_more = (nip = startp) == (service_user *) -1l;
+    }
+
+  /* First do a lookup with the original protocol type.  */
+  while (no_more == 0 && buffer != NULL)
+    {
+      enum nss_status status;
+
+      status = DL_CALL_FCT (fct, (name, type,
+				  ((flags & AI_ALL)
+				   ? flags : (flags & ~AI_V4MAPPED)),
+				  (struct hostent *) buffer,
+				  (char *) ((struct hostent *) buffer + 1),
+				  buffer_size - sizeof (struct hostent),
+				  &errno, h_errnop));
+
+      if (status == NSS_STATUS_SUCCESS)
+	{
+	  result = (struct hostent *) buffer;
+	  break;
+	}
+
+      if (status == NSS_STATUS_TRYAGAIN && *h_errnop == NETDB_INTERNAL
+	  && errno == ERANGE)
+	{
+	  /* Resize the buffer, it's too small.  */
+	  buffer_size += BUFLEN;
+	  buffer = (char *) realloc (buffer, buffer_size);
+	  continue;
+	}
+
+      no_more = __nss_next (&nip, "getipnodebyname_r",
+			    (void **) &fct, status, 0);
+    }
+
+  /* If we are looking for an IPv6 address but haven't found any and
+     do not have the AI_ALL but the AI_V4MAPPED flag set, now try
+     looking up an IPv4 address and map it.  */
+  if (buffer != NULL && result == NULL
+      && type == AF_INET6 && (flags & AI_V4MAPPED) != 0
+      && (no_more = (nip = startp) == (service_user *) -1l) == 0)
+    {
+      /* We have to use a new buffer if there is already a result.  */
+      fct = start_fct;
+
+      do
+	{
+	  enum nss_status status;
+
+	  status = DL_CALL_FCT (fct, (name, type, flags,
+				      (struct hostent *) buffer,
+				      (char *) ((struct hostent *) buffer + 1),
+				      buffer_size - sizeof (struct hostent),
+				      &errno, h_errnop));
+
+	  if (status == NSS_STATUS_SUCCESS)
+	    {
+	      result = (struct hostent *) buffer;
+	      break;
+	    }
+
+	  if (status == NSS_STATUS_TRYAGAIN && *h_errnop == NETDB_INTERNAL
+	      && errno == ERANGE)
+	    {
+	      /* Resize the buffer, it's too small.  */
+	      buffer_size += BUFLEN;
+	      buffer = (char *) realloc (buffer, buffer_size);
+	      continue;
+	    }
+
+	  no_more = __nss_next (&nip, "getipnodebyname_r",
+				(void **) &fct, status, 0);
+	}
+      while (no_more == 0 && buffer != NULL);
+    }
+
+ done:
+  if (buffer == NULL)
+    {
+      /* We are out of memory.  */
+      *h_errnop = TRY_AGAIN;
+      assert (result == NULL);
+    }
+  else if (result == NULL && buffer != NULL)
+    free (buffer);
+
+  return result;
+}