--- /dev/null
+
+/* Copyright 1998 by the Massachusetts Institute of Technology.
+ * Copyright (C) 2009 by Jakub Hrozek <jhrozek@redhat.com>
+ *
+ * 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.
+ */
+
+#include "ares_setup.h"
+
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+#ifdef HAVE_NETDB_H
+# include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+# include <arpa/inet.h>
+#endif
+#ifdef HAVE_ARPA_NAMESER_H
+# include <arpa/nameser.h>
+#else
+# include "nameser.h"
+#endif
+#ifdef HAVE_ARPA_NAMESER_COMPAT_H
+# include <arpa/nameser_compat.h>
+#endif
+
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif
+
+#include "ares.h"
+#include "ares_dns.h"
+#include "ares_data.h"
+#include "ares_private.h"
+
+static int
+ares__parse_txt_reply (const unsigned char *abuf, int alen,
+ int ex, void **txt_out)
+{
+ size_t substr_len;
+ unsigned int qdcount, ancount, i;
+ const unsigned char *aptr;
+ const unsigned char *strptr;
+ int status, rr_type, rr_class, rr_len;
+ long len;
+ char *hostname = NULL, *rr_name = NULL;
+ struct ares_txt_ext *txt_head = NULL;
+ struct ares_txt_ext *txt_last = NULL;
+ struct ares_txt_ext *txt_curr;
+
+ /* Set *txt_out to NULL for all failure cases. */
+ *txt_out = 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;
+ if (ancount == 0)
+ return ARES_ENODATA;
+
+ /* 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)
+ {
+ ares_free (hostname);
+ return ARES_EBADRESP;
+ }
+ aptr += len + QFIXEDSZ;
+
+ /* 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 (aptr + rr_len > abuf + alen)
+ {
+ status = ARES_EBADRESP;
+ break;
+ }
+
+ /* Check if we are really looking at a TXT record */
+ if (rr_class == C_IN && rr_type == T_TXT)
+ {
+ /*
+ * There may be multiple substrings in a single TXT record. Each
+ * substring may be up to 255 characters in length, with a
+ * "length byte" indicating the size of the substring payload.
+ * RDATA contains both the length-bytes and payloads of all
+ * substrings contained therein.
+ */
+
+ strptr = aptr;
+ while (strptr < (aptr + rr_len))
+ {
+ substr_len = (unsigned char)*strptr;
+ if (strptr + substr_len + 1 > aptr + rr_len)
+ {
+ status = ARES_EBADRESP;
+ break;
+ }
+
+ /* Allocate storage for this TXT answer appending it to the list */
+ txt_curr = ares_malloc_data(ex ? ARES_DATATYPE_TXT_EXT :
+ ARES_DATATYPE_TXT_REPLY);
+ if (!txt_curr)
+ {
+ status = ARES_ENOMEM;
+ break;
+ }
+ if (txt_last)
+ {
+ txt_last->next = txt_curr;
+ }
+ else
+ {
+ txt_head = txt_curr;
+ }
+ txt_last = txt_curr;
+
+ if (ex)
+ txt_curr->record_start = (strptr == aptr);
+ txt_curr->length = substr_len;
+ txt_curr->txt = ares_malloc (substr_len + 1/* Including null byte */);
+ if (txt_curr->txt == NULL)
+ {
+ status = ARES_ENOMEM;
+ break;
+ }
+
+ ++strptr;
+ memcpy ((char *) txt_curr->txt, strptr, substr_len);
+
+ /* Make sure we NULL-terminate */
+ txt_curr->txt[substr_len] = 0;
+
+ strptr += substr_len;
+ }
+ }
+
+ /* Propagate any failures */
+ if (status != ARES_SUCCESS)
+ {
+ break;
+ }
+
+ /* Don't lose memory in the next iteration */
+ ares_free (rr_name);
+ rr_name = NULL;
+
+ /* Move on to the next record */
+ aptr += rr_len;
+ }
+
+ if (hostname)
+ ares_free (hostname);
+ if (rr_name)
+ ares_free (rr_name);
+
+ /* clean up on error */
+ if (status != ARES_SUCCESS)
+ {
+ if (txt_head)
+ ares_free_data (txt_head);
+ return status;
+ }
+
+ /* everything looks fine, return the data */
+ *txt_out = txt_head;
+
+ return ARES_SUCCESS;
+}
+
+int
+ares_parse_txt_reply (const unsigned char *abuf, int alen,
+ struct ares_txt_reply **txt_out)
+{
+ return ares__parse_txt_reply(abuf, alen, 0, (void **) txt_out);
+}
+
+
+int
+ares_parse_txt_reply_ext (const unsigned char *abuf, int alen,
+ struct ares_txt_ext **txt_out)
+{
+ return ares__parse_txt_reply(abuf, alen, 1, (void **) txt_out);
+}
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