Add some historic code just for the heck of it.

attic/historic/anode/libanode/impl/dns_txt.c

@@ -0,0 +1,93 @@
+/* libanode: the Anode C reference implementation
+ * Copyright (C) 2009-2010 Adam Ierymenko <adam.ierymenko@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+#include <netdb.h>
+#include "dns_txt.h"
+
+#ifndef C_IN
+#define C_IN ns_c_in
+#endif
+#ifndef T_TXT
+#define T_TXT ns_t_txt
+#endif
+
+static volatile int Anode_resolver_initialized = 0;
+
+int Anode_sync_resolve_txt(const char *host,char *txt,unsigned int txt_len)
+{
+  unsigned char answer[16384],*pptr,*end;
+  char name[16384];
+  int len,explen,i;
+
+  if (!Anode_resolver_initialized) {
+    Anode_resolver_initialized = 1;
+    res_init();
+  }
+
+  /* Do not taunt happy fun ball. */
+
+  len = res_search(host,C_IN,T_TXT,answer,sizeof(answer));
+  if (len > 12) {
+    pptr = answer + 12;
+    end = answer + len;
+
+    explen = dn_expand(answer,end,pptr,name,sizeof(name));
+    if (explen > 0) {
+      pptr += explen;
+
+      if ((pptr + 2) >= end) return 2;
+      if (ntohs(*((uint16_t *)pptr)) == T_TXT) {
+        pptr += 4;
+        if (pptr >= end) return 2;
+
+        explen = dn_expand(answer,end,pptr,name,sizeof(name));
+        if (explen > 0) {
+          pptr += explen;
+
+          if ((pptr + 2) >= end) return 2;
+          if (ntohs(*((uint16_t *)pptr)) == T_TXT) {
+            pptr += 10;
+            if (pptr >= end) return 2;
+
+            len = *(pptr++);
+            if (len <= 0) return 2;
+            if ((pptr + len) > end) return 2;
+
+            if (txt_len < (len + 1))
+              return 4;
+            else {
+              for(i=0;i<len;++i)
+                txt[i] = pptr[i];
+              txt[len] = (char)0;
+              return 0;
+            }
+          }
+        }
+      }
+    }
+  }
+
+  return 1;
+}
+