ares 1.1.1 with collected applied patches

1 files changed, 173 insertions, 0 deletions

diff --git a/ares_parse_a_reply.c b/ares_parse_a_reply.c
new file mode 100644
index 0000000..737eee7
--- /dev/null
+++ b/ares_parse_a_reply.c
@@ -0,0 +1,173 @@
+/* Copyright 1998 by the Massachusetts Institute of Technology.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting
+ * documentation, and that the name of M.I.T. not be used in
+ * advertising or publicity pertaining to distribution of the
+ * software without specific, written prior permission.
+ * M.I.T. makes no representations about the suitability of
+ * this software for any purpose.  It is provided "as is"
+ * without express or implied warranty.
+ */
+
+static const char rcsid[] = "$Id$";
+
+#include <sys/types.h>
+
+#ifdef WIN32
+#include "nameser.h"
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <arpa/nameser.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include "ares.h"
+#include "ares_dns.h"
+#include "ares_private.h"
+
+int ares_parse_a_reply(const unsigned char *abuf, int alen,
+		       struct hostent **host)
+{
+  unsigned int qdcount, ancount;
+  int status, i, len, rr_type, rr_class, rr_len, naddrs;
+  int naliases;
+  const unsigned char *aptr;
+  char *hostname, *rr_name, *rr_data, **aliases;
+  struct in_addr *addrs;
+  struct hostent *hostent;
+
+  /* Set *host to NULL for all failure cases. */
+  *host = NULL;
+
+  /* Give up if abuf doesn't have room for a header. */
+  if (alen < HFIXEDSZ)
+    return ARES_EBADRESP;
+
+  /* Fetch the question and answer count from the header. */
+  qdcount = DNS_HEADER_QDCOUNT(abuf);
+  ancount = DNS_HEADER_ANCOUNT(abuf);
+  if (qdcount != 1)
+    return ARES_EBADRESP;
+
+  /* Expand the name from the question, and skip past the question. */
+  aptr = abuf + HFIXEDSZ;
+  status = ares_expand_name(aptr, abuf, alen, &hostname, &len);
+  if (status != ARES_SUCCESS)
+    return status;
+  if (aptr + len + QFIXEDSZ > abuf + alen)
+    {
+      free(hostname);
+      return ARES_EBADRESP;
+    }
+  aptr += len + QFIXEDSZ;
+
+  /* Allocate addresses and aliases; ancount gives an upper bound for both. */
+  addrs = malloc(ancount * sizeof(struct in_addr));
+  if (!addrs)
+    {
+      free(hostname);
+      return ARES_ENOMEM;
+    }
+  aliases = malloc((ancount + 1) * sizeof(char *));
+  if (!aliases)
+    {
+      free(hostname);
+      free(addrs);
+      return ARES_ENOMEM;
+    }
+  naddrs = 0;
+  naliases = 0;
+
+  /* Examine each answer resource record (RR) in turn. */
+  for (i = 0; i < ancount; i++)
+    {
+      /* Decode the RR up to the data field. */
+      status = ares_expand_name(aptr, abuf, alen, &rr_name, &len);
+      if (status != ARES_SUCCESS)
+	break;
+      aptr += len;
+      if (aptr + RRFIXEDSZ > abuf + alen)
+	{
+	  status = ARES_EBADRESP;
+	  break;
+	}
+      rr_type = DNS_RR_TYPE(aptr);
+      rr_class = DNS_RR_CLASS(aptr);
+      rr_len = DNS_RR_LEN(aptr);
+      aptr += RRFIXEDSZ;
+
+      if (rr_class == C_IN && rr_type == T_A
+	  && rr_len == sizeof(struct in_addr)
+	  && strcasecmp(rr_name, hostname) == 0)
+	{
+	  memcpy(&addrs[naddrs], aptr, sizeof(struct in_addr));
+	  naddrs++;
+	  status = ARES_SUCCESS;
+	}
+
+      if (rr_class == C_IN && rr_type == T_CNAME)
+	{
+	  /* Record the RR name as an alias. */
+	  aliases[naliases] = rr_name;
+	  naliases++;
+
+	  /* Decode the RR data and replace the hostname with it. */
+	  status = ares_expand_name(aptr, abuf, alen, &rr_data, &len);
+	  if (status != ARES_SUCCESS)
+	    break;
+	  free(hostname);
+	  hostname = rr_data;
+	}
+      else
+	free(rr_name);
+
+      aptr += rr_len;
+      if (aptr > abuf + alen)
+	{
+	  status = ARES_EBADRESP;
+	  break;
+	}
+    }
+
+  if (status == ARES_SUCCESS && naddrs == 0)
+    status = ARES_ENODATA;
+  if (status == ARES_SUCCESS)
+    {
+      /* We got our answer.  Allocate memory to build the host entry. */
+      aliases[naliases] = NULL;
+      hostent = malloc(sizeof(struct hostent));
+      if (hostent)
+	{
+	  hostent->h_addr_list = malloc((naddrs + 1) * sizeof(char *));
+	  if (hostent->h_addr_list)
+	    {
+	      /* Fill in the hostent and return successfully. */
+	      hostent->h_name = hostname;
+	      hostent->h_aliases = aliases;
+	      hostent->h_addrtype = AF_INET;
+	      hostent->h_length = sizeof(struct in_addr);
+	      for (i = 0; i < naddrs; i++)
+		hostent->h_addr_list[i] = (char *) &addrs[i];
+	      hostent->h_addr_list[naddrs] = NULL;
+	      *host = hostent;
+	      return ARES_SUCCESS;
+	    }
+	  free(hostent);
+	}
+      status = ARES_ENOMEM;
+    }
+  for (i = 0; i < naliases; i++)
+    free(aliases[i]);
+  free(aliases);
+  free(addrs);
+  free(hostname);
+  return status;
+}