Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 202 insertions, 0 deletions

diff --git a/src/c-ares/ares_create_query.c b/src/c-ares/ares_create_query.c
new file mode 100644
index 000000000..7f4c52d41
--- /dev/null
+++ b/src/c-ares/ares_create_query.c
@@ -0,0 +1,202 @@
+
+/* 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.
+ */
+
+#include "ares_setup.h"
+
+#ifdef HAVE_NETINET_IN_H
+#  include <netinet/in.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
+
+#include "ares.h"
+#include "ares_dns.h"
+#include "ares_private.h"
+
+#ifndef T_OPT
+#  define T_OPT  41 /* EDNS0 option (meta-RR) */
+#endif
+
+/* Header format, from RFC 1035:
+ *                                  1  1  1  1  1  1
+ *    0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                      ID                       |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                    QDCOUNT                    |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                    ANCOUNT                    |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                    NSCOUNT                    |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                    ARCOUNT                    |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *
+ * AA, TC, RA, and RCODE are only set in responses.  Brief description
+ * of the remaining fields:
+ *      ID      Identifier to match responses with queries
+ *      QR      Query (0) or response (1)
+ *      Opcode  For our purposes, always QUERY
+ *      RD      Recursion desired
+ *      Z       Reserved (zero)
+ *      QDCOUNT Number of queries
+ *      ANCOUNT Number of answers
+ *      NSCOUNT Number of name server records
+ *      ARCOUNT Number of additional records
+ *
+ * Question format, from RFC 1035:
+ *                                  1  1  1  1  1  1
+ *    0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                                               |
+ *  /                     QNAME                     /
+ *  /                                               /
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                     QTYPE                     |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *  |                     QCLASS                    |
+ *  +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+ *
+ * The query name is encoded as a series of labels, each represented
+ * as a one-byte length (maximum 63) followed by the text of the
+ * label.  The list is terminated by a label of length zero (which can
+ * be thought of as the root domain).
+ */
+
+int ares_create_query(const char *name, int dnsclass, int type,
+                      unsigned short id, int rd, unsigned char **bufp,
+                      int *buflenp, int max_udp_size)
+{
+  size_t len;
+  unsigned char *q;
+  const char *p;
+  size_t buflen;
+  unsigned char *buf;
+
+  /* Set our results early, in case we bail out early with an error. */
+  *buflenp = 0;
+  *bufp = NULL;
+
+  /* Allocate a memory area for the maximum size this packet might need. +2
+   * is for the length byte and zero termination if no dots or ecscaping is
+   * used.
+   */
+  len = strlen(name) + 2 + HFIXEDSZ + QFIXEDSZ +
+    (max_udp_size ? EDNSFIXEDSZ : 0);
+  buf = ares_malloc(len);
+  if (!buf)
+    return ARES_ENOMEM;
+
+  /* Set up the header. */
+  q = buf;
+  memset(q, 0, HFIXEDSZ);
+  DNS_HEADER_SET_QID(q, id);
+  DNS_HEADER_SET_OPCODE(q, QUERY);
+  if (rd) {
+    DNS_HEADER_SET_RD(q, 1);
+  }
+  else {
+    DNS_HEADER_SET_RD(q, 0);
+  }
+  DNS_HEADER_SET_QDCOUNT(q, 1);
+
+  if (max_udp_size) {
+      DNS_HEADER_SET_ARCOUNT(q, 1);
+  }
+
+  /* A name of "." is a screw case for the loop below, so adjust it. */
+  if (strcmp(name, ".") == 0)
+    name++;
+
+  /* Start writing out the name after the header. */
+  q += HFIXEDSZ;
+  while (*name)
+    {
+      if (*name == '.') {
+        free (buf);
+        return ARES_EBADNAME;
+      }
+
+      /* Count the number of bytes in this label. */
+      len = 0;
+      for (p = name; *p && *p != '.'; p++)
+        {
+          if (*p == '\\' && *(p + 1) != 0)
+            p++;
+          len++;
+        }
+      if (len > MAXLABEL) {
+        free (buf);
+        return ARES_EBADNAME;
+      }
+
+      /* Encode the length and copy the data. */
+      *q++ = (unsigned char)len;
+      for (p = name; *p && *p != '.'; p++)
+        {
+          if (*p == '\\' && *(p + 1) != 0)
+            p++;
+          *q++ = *p;
+        }
+
+      /* Go to the next label and repeat, unless we hit the end. */
+      if (!*p)
+        break;
+      name = p + 1;
+    }
+
+  /* Add the zero-length label at the end. */
+  *q++ = 0;
+
+  /* Finish off the question with the type and class. */
+  DNS_QUESTION_SET_TYPE(q, type);
+  DNS_QUESTION_SET_CLASS(q, dnsclass);
+
+  q += QFIXEDSZ;
+  if (max_udp_size)
+  {
+      memset(q, 0, EDNSFIXEDSZ);
+      q++;
+      DNS_RR_SET_TYPE(q, T_OPT);
+      DNS_RR_SET_CLASS(q, max_udp_size);
+      q += (EDNSFIXEDSZ-1);
+  }
+  buflen = (q - buf);
+
+  /* Reject names that are longer than the maximum of 255 bytes that's
+   * specified in RFC 1035 ("To simplify implementations, the total length of
+   * a domain name (i.e., label octets and label length octets) is restricted
+   * to 255 octets or less."). */
+  if (buflen > (MAXCDNAME + HFIXEDSZ + QFIXEDSZ +
+                (max_udp_size ? EDNSFIXEDSZ : 0))) {
+    free (buf);
+    return ARES_EBADNAME;
+  }
+
+  /* we know this fits in an int at this point */
+  *buflenp = (int) buflen;
+  *bufp = buf;
+
+  return ARES_SUCCESS;
+}