Diff: services/mDNS/mDNSResponder.h

Revision:

0:1a198985f183

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/services/mDNS/mDNSResponder.h	Wed Aug 11 09:49:48 2010 +0000
@@ -0,0 +1,147 @@
+#ifndef MDNS_RESPONDER_H
+#define MDNS_RESPONDER_H
+
+
+#include "lwip/opt.h"
+
+#if LWIP_DNS /* don't build if not configured for use in lwipopts.h */
+
+#include "if/net/net.h"
+#include "api/UDPSocket.h"
+#include "api/DNSRequest.h"
+#include "mbed.h"
+
+#include "lwip/udp.h"
+#include "lwip/mem.h"
+#include "lwip/memp.h"
+#include "lwip/dns.h"
+
+// As defined by IANA.
+//
+#define MDNS_PORT (5353)
+#define MCAST 224,0,0,251
+
+// How long we announce our IP and URLs to be valid. Should
+// ideally be 1/3 or so of the DHCP lease time. But we do 
+// not know that.
+//
+#define MDNS_TTL ( 100 )
+
+// Rebroadcast our details more regularly than the TTL as 
+// we otherwise get dropped.
+//
+#ifndef MDNS_INTERVAL
+#define MDNS_INTERVAL ( MDNS_TTL * 2 / 3 )
+#endif
+
+#ifndef MDNS_QCACHE
+#define MDNS_QCACHE 1
+#endif
+
+#ifndef MDNS_MAXCACHEDNSLABELS
+#define MDNS_MAXCACHEDNSLABELS (10)
+#endif
+
+class mDNSResponder : protected NetService
+{
+public:
+  mDNSResponder();
+  virtual ~mDNSResponder();
+  void close();
+  void announce(IpAddr ip, const char * ldn, const char * proto, uint16_t port, const char * name, char ** txts);
+  
+protected:
+  virtual void poll(); //Called by NetServices - not actually needed.
+  
+private:
+  void process(); // Needed for timer, to fire off regular updates.
+  
+  // Main inbound packet handler
+  void onUDPSocketEvent(UDPSocketEvent e);
+
+  // 3 functions to keep a QName chace. If enabled with MDNS_QCACHE
+  void initLabelCache(char * off);
+  uint16_t checkLabelCache(char * name);
+  void addLabelCache(char * p, char * name);
+  
+  // Handing functions
+  char * breakname(char *p, char *name); // Break FQDNs at the dots, understanding QCaching.
+  
+  // reply building functions; see RFC for names/defintion.
+  char * mRR(char *p, char * name, uint16_t tpe, uint16_t cls, uint32_t ttl);
+  char * mRRLABEL(char *p, char * name, uint16_t tpe, char ** rr); 
+  char * mPTR(char *p, char * name, char * r); 
+  char * mTXT(char *p, char * name, char ** rr);
+  char * mARR(char *p, char * name, IpAddr ip);
+  char * mSRV(char *p, char * name, uint16_t port, char * rr);
+  char * qANY(char *p, char * name, uint16_t tpe, uint16_t cls);
+
+  // build query part of a reply.
+  char * qPTR(char *p, char *name);
+  char * qA(char *p, char *name);
+  char * qSRV(char *p, char *name);
+  
+  // Sent out the actual DNS packet.
+  void sendReply(uint16_t t, uint16_t tid, Host dst);
+  
+  // Decode the query part of a DNS inbound packet.
+  char * decodeQBlock(char * udp, int len, char *p, char  * fqdn, int fqdn_size, uint32_t *Qclass, uint32_t *Qtype);
+
+PACK_STRUCT_BEGIN
+struct DNSPacket
+  {
+    PACK_STRUCT_FIELD(uint16_t tid);
+    PACK_STRUCT_FIELD(uint16_t flags);
+    PACK_STRUCT_FIELD(uint16_t question_count);
+    PACK_STRUCT_FIELD(uint16_t answer_count);
+    PACK_STRUCT_FIELD(uint16_t a_count);
+    PACK_STRUCT_FIELD(uint16_t aa_count);
+    PACK_STRUCT_FIELD(char answers);
+  } PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+  
+  // Services
+  char ** moi_txt; /* Null terminated list */
+  
+  // Endpoint
+  uint16_t moi_port;
+  IpAddr moi_ip;
+  
+  // Local name construction.
+  const char * moi_name, * moi_proto;
+  char * moi_local_proto, * moi_local_name, * moi_local_pglue;
+  
+  Timer announcer;
+    
+  UDPSocket* m_pUDPSocket;
+
+  // For the QCache
+#ifdef MDNS_QCACHE
+  int labelCacheCnt;
+  char * labelCacheOffset;
+  
+  uint16_t _cache_off[MDNS_MAXCACHEDNSLABELS];
+  char * _cache_och[MDNS_MAXCACHEDNSLABELS];
+#endif
+};
+
+
+
+#endif
+
+// Just in case - there is prolly some nice ARM6 assembler already linked in.
+//
+#ifndef htons
+#define htons( x ) ( (( x << 8 ) & 0xFF00) | (( x >> 8 ) & 0x00FF) )
+#define ntohs( x ) (htons(x))
+#endif
+
+#ifndef htonl
+#define htonl( x ) ( (( x << 24 ) & 0xff000000)  \
+                   | (( x <<  8 ) & 0x00ff0000)  \
+                   | (( x >>  8 ) & 0x0000ff00)  \
+                   | (( x >> 24 ) & 0x000000ff)  )
+#define ntohl( x ) (htonl(x))
+#endif
+
+#endif