Splits large TXT records into max 255-byte chunks, like BIND and friends.

04_split_content.diff

--- backup/pdns-2.9.21.2/pdns/dnswriter.cc	2007-04-21 07:56:36.000000000 -0600
+++ pdns-2.9.21.2/pdns/dnswriter.cc	2008-12-01 12:10:28.000000000 -0700
@@ -3,6 +3,7 @@
 #include "dnsparser.hh"
 #include <boost/tokenizer.hpp>
 #include <boost/algorithm/string.hpp>
+#include <limits.h>
 
 DNSPacketWriter::DNSPacketWriter(vector<uint8_t>& content, const string& qname, uint16_t  qtype, uint16_t qclass, uint8_t opcode)
   : d_pos(0), d_content(content), d_qname(qname), d_qtype(qtype), d_qclass(qclass)
@@ -117,6 +118,8 @@
   d_record.push_back(val);
 }
 
+#define MIN(a,b) (a < b ? a : b)
+
 void DNSPacketWriter::xfrText(const string& text, bool)
 {
   escaped_list_separator<char> sep('\\', ' ' , '"');
@@ -129,9 +132,11 @@
   }
   else 
     for(; beg!=tok.end(); ++beg){
-      d_record.push_back(beg->length());
-      const uint8_t* ptr=(uint8_t*)(beg->c_str());
-      d_record.insert(d_record.end(), ptr, ptr+beg->length());
+      for (unsigned int i = 0; i < beg->length(); i += UCHAR_MAX){
+        d_record.push_back(MIN(UCHAR_MAX, beg->length()-i));
+        const uint8_t* ptr=(uint8_t*)(beg->c_str()) + i;
+        d_record.insert(d_record.end(), ptr, ptr+MIN(UCHAR_MAX,beg->length()-i));
+      }
     }
 }