Various further work on overlay mesh.

Now resolves some kinds of abbreviated address, and queues up
the need to remind peers of abbreviation schemes it does not support.

client.c

@@ -345,7 +345,7 @@ int getReplyPackets(int method,int peer,int batchP,struct response_set *response
       if (debug) fprintf(stderr,"Simulation mode: Dropped packet due to simulated link parameters.\n");
       continue;
     }
-    if (!packetOk(buffer,len,transaction_id,recvaddr,recvaddrlen,0)) {
+    if (!packetOk(-1,buffer,len,transaction_id,recvaddr,recvaddrlen,0)) {
       /* Packet passes tests - extract responses and append them to the end of the response list */
       if (extractResponses(client_addr,buffer,len,responses)) 
 	return setReason("Problem extracting response fields from reply packets");

mphlr.h

@@ -296,7 +296,7 @@ int server(char *backing_file,int size,int foregroundMode);
 int setReason(char *fmt, ...);
 int hexvalue(unsigned char c);
 int dump(char *name,unsigned char *addr,int len);
-int packetOk(unsigned char *packet,int len,unsigned char *transaction_id,
+int packetOk(int interface,unsigned char *packet,int len,unsigned char *transaction_id,
 	     struct sockaddr *recvaddr,int recvaddrlen,int parseP);
 int process_packet(unsigned char *packet,int len,struct sockaddr *sender,int sender_len);
 int packetMakeHeader(unsigned char *packet,int packet_maxlen,int *packet_len,unsigned char *transaction_id);
@@ -365,7 +365,7 @@ int runCommand(char *cmd);
 int asteriskObtainGateway(char *requestor_sid,char *did,char *uri_out);
 int packetOkDNA(unsigned char *packet,int len,unsigned char *transaction_id,
 		struct sockaddr *recvaddr,int recvaddrlen,int parseP);
-int packetOkOverlay(unsigned char *packet,int len,unsigned char *transaction_id,
+int packetOkOverlay(int interface,unsigned char *packet,int len,unsigned char *transaction_id,
 		    struct sockaddr *recvaddr,int recvaddrlen,int parseP);
 int prepareGateway(char *gatewayspec);
 int packetSendRequest(int method,unsigned char *packet,int packet_len,int batchP,
@@ -434,6 +434,14 @@ typedef struct overlay_interface {
 #define OVERLAY_MAX_INTERFACES 16
 extern overlay_interface overlay_interfaces[OVERLAY_MAX_INTERFACES];
 
+/* Has someone sent us an abbreviation of an unknown type recently? If so remind them
+   that we don't accept these.
+   XXX - This method assumes bidirectional links.  We should consider sending direct
+   to the perpetuator. We will deal with that in time, the main thing is that we have
+   a message type that can be used for the purpose.
+*/
+extern int overlay_interface_repeat_abbreviation_policy[OVERLAY_MAX_INTERFACES];
+
 /*
   For each peer we need to keep track of the routes that we know to reach it.
 
@@ -603,7 +611,7 @@ extern int overlay_interface_count;
 			      Limited to 255 bytes of payload. 
 			      1 byte channel/port indicator for each end */
 #define OF_TYPE_RHIZOME_ADVERT 0x50 /* Advertisment of file availability via Rhizome */
-#define OF_TYPE_RESERVED_06 0x60
+#define OF_TYPE_PLEASEEXPLAIN 0x60 /* Request for resolution of an abbreviated address */
 #define OF_TYPE_RESERVED_07 0x70
 #define OF_TYPE_RESERVED_08 0x80
 #define OF_TYPE_RESERVED_09 0x90
@@ -645,11 +653,12 @@ int overlay_address_cache_address(unsigned char *sid);
 int overlay_abbreviate_cache_lookup(unsigned char *in,unsigned char *out,int *ofs,
 				    int prefix_bytes,int index_bytes);
 int overlay_abbreviate_remember_index(int index_byte_count,unsigned char *in,unsigned char *index_bytes);
+extern int overlay_abbreviate_repeat_policy;
 
 /* Return codes for resolution of abbreviated addressses */
 #define OA_UNINITIALISED 0 /* Nothing has been written into the field */
 #define OA_RESOLVED 1      /* We expanded the abbreviation successfully */
-#define OA_PLEASEEXPLAIN 1 /* We need the sender to explain their abbreviation */
+#define OA_PLEASEEXPLAIN 2 /* We need the sender to explain their abbreviation */
 #define OA_UNSUPPORTED 3   /* We cannot expand the abbreviation as we do not understand this code */
 
 /* Codes used to describe abbreviated addresses.
@@ -696,3 +705,5 @@ typedef struct overlay_frame {
   int rfs; /* remainder of frame size */
 
 } overlay_frame;
+
+int overlay_frame_process(int interface,overlay_frame *f);

overlay.c

@@ -107,7 +107,58 @@ int overlayServerMode()
   return 0;
 }
 
-int overlay_frame_process(overlay_frame *f)
+int overlay_frame_process(int interface,overlay_frame *f)
 {
+  if (!f) return WHY("f==NULL");
+
+  /* First order of business is whether the nexthop address has been resolved.
+     If not, we need to think about asking for it to be resolved.
+     The trouble is that we do not want to trigger a Hanson Event (a storm of
+     please explains/resolution requests). Yet, we do not want to delay 
+     communications unnecessarily.  
+
+     The simple solution for now is to queue the address for resolution request
+     in our next tick.  If we see another resolution request for the same
+     address in the mean time, then we can cancel our request */
+  switch (f->nexthop_address_status)
+    {
+    case OA_UNINITIALISED:
+      /* Um? Right. */
+      return WHY("frame passed with ununitialised nexthop address");
+      break;
+    case OA_RESOLVED:
+      /* Great, we have the address, so we can get on with things */
+      break;
+    case OA_PLEASEEXPLAIN:
+      break;
+    case OA_UNSUPPORTED:
+    default:
+      /* If we don't support the address format, we should probably tell
+	 the sender. Again, we queue this up, and cancel it if someone else
+	 tells them in the meantime to avoid an Opposition Event (like a Hanson
+	 Event, but repeatedly berating any node that holds a different policy
+	 to itself. */
+      overlay_interface_repeat_abbreviation_policy[interface]=1;
+      return -1;
+      break;
+    }
+
+  /* Okay, nexthop is valid, so let's see if it is us */
+  int forMe=0,i;
+  for(i=0;i<SID_SIZE;i++) if (f->nexthop[i]!=0xff) break;
+  if (i==SID_SIZE) forMe=1;
+  for(i=0;i<SID_SIZE;i++) if (f->nexthop[i]!=hlr[4+i]) break;
+  if (i==SID_SIZE) forMe=1;
+
+  fprintf(stderr,"This frame is%s for me.\n",forMe?"":" not");
+  
+  switch(f->type)
+    {
+    case OF_TYPE_SELFANNOUNCE:
+      break;
+    default:
+      break;
+    }
+
   return WHY("Not implemented");
 }

overlay_abbreviations.c

@@ -294,7 +294,7 @@ int overlay_abbreviate_expand_address(unsigned char *in,int *inofs,unsigned char
     case OA_CODE_BROADCAST: /* broadcast */
       memset(&out[*ofs],0xff,SID_SIZE);
       (*inofs)++;
-      return 0;
+      return OA_RESOLVED;
     case OA_CODE_FULL_INDEX1: case OA_CODE_FULL_INDEX2: 
     default: /* Full address, optionally followed by index for us to remember */
       if (in[0]==OA_CODE_FULL_INDEX1) bytes=1; 
@@ -302,7 +302,7 @@ int overlay_abbreviate_expand_address(unsigned char *in,int *inofs,unsigned char
       bcopy(in,&out[*ofs],SID_SIZE);
       if (bytes) overlay_abbreviate_remember_index(bytes,in,&in[SID_SIZE]);
       (*inofs)+=SID_SIZE+bytes;
-      return 0;
+      return OA_RESOLVED;
     }
 }
 

overlay_interface.c

@@ -19,6 +19,9 @@ struct interface_rules {
 
 struct interface_rules *interface_filter=NULL;
 
+/* Do we need to repeat our abbreviation policy? */
+int overlay_interface_repeat_abbreviation_policy[OVERLAY_MAX_INTERFACES]={1};
+
 int overlay_interface_type(char *s)
 {
   if (!strcasecmp(s,"ethernet")) return OVERLAY_INTERFACE_ETHERNET;
@@ -249,7 +252,7 @@ int overlay_rx_messages()
 	      bzero(&transaction_id[0],8);
 	      bzero(&src_addr,sizeof(src_addr));
 	      if ((packet[0]==0x01)&&!(packet[1]|packet[2]|packet[3]))
-		{ if (!packetOk(&packet[128],plen,transaction_id,&src_addr,addrlen,1)) WHY("Malformed packet from dummy interface"); }
+		{ if (!packetOk(i,&packet[128],plen,transaction_id,&src_addr,addrlen,1)) WHY("Malformed packet from dummy interface"); }
 	      else WHY("Invalid packet version in dummy interface");
 	    }
 	  else { c[i]=0; count--; }
@@ -262,7 +265,7 @@ int overlay_rx_messages()
 	    if (debug&4)fprintf(stderr,"Received %d bytes on interface #%d\n",plen,i);
 	    
 	    bzero(&transaction_id[0],8);
-	    if (!packetOk(packet,plen,transaction_id,&src_addr,addrlen,1)) WHY("Malformed packet");	  
+	    if (!packetOk(i,packet,plen,transaction_id,&src_addr,addrlen,1)) WHY("Malformed packet");	  
 	  }
 	}
       }

overlay_packetformats.c

@@ -1,7 +1,7 @@
 #include "mphlr.h"
 
 
-int packetOkOverlay(unsigned char *packet,int len,unsigned char *transaction_id,
+int packetOkOverlay(int interface,unsigned char *packet,int len,unsigned char *transaction_id,
 		    struct sockaddr *recvaddr,int recvaddrlen,int parseP)
 {
   /* 
@@ -97,7 +97,6 @@ int packetOkOverlay(unsigned char *packet,int len,unsigned char *transaction_id,
 	  f.modifiers=0;
 	  ofs+=2;
 	  break;
-	case OF_TYPE_RESERVED_06:
 	case OF_TYPE_RESERVED_07:
 	case OF_TYPE_RESERVED_08:
 	case OF_TYPE_RESERVED_09:
@@ -110,6 +109,7 @@ int packetOkOverlay(unsigned char *packet,int len,unsigned char *transaction_id,
 	case OF_TYPE_DATA:
 	case OF_TYPE_DATA_VOICE:
 	case OF_TYPE_RHIZOME_ADVERT:
+	case OF_TYPE_PLEASEEXPLAIN:
 	  /* No extra bytes to deal with here */
 	  ofs++;
 	  break;
@@ -136,11 +136,11 @@ int packetOkOverlay(unsigned char *packet,int len,unsigned char *transaction_id,
       f.bytecount=f.rfs-(offset-ofs);
 
       /* Finally process the frame */
-      overlay_frame_process(&f);
+      overlay_frame_process(interface,&f);
       
       /* Skip the rest of the bytes in this frame so that we can examine the next one in this
 	 ensemble */
-      fprintf(stderr,"ofs=%d, f.rfs=%d, len=%d\n",ofs,f.rfs,len);
+      if (debug&4) fprintf(stderr,"ofs=%d, f.rfs=%d, len=%d\n",ofs,f.rfs,len);
       ofs+=f.rfs;
     }
 

packetformats.c

@@ -57,7 +57,7 @@ int process_packet(unsigned char *packet,int len,struct sockaddr *sender,int sen
   return 0;
 }
 
-int packetOk(unsigned char *packet,int len,unsigned char *transaction_id,
+int packetOk(int interface,unsigned char *packet,int len,unsigned char *transaction_id,
 	     struct sockaddr *recvaddr,int recvaddrlen,int parseP)
 {
   if (len<HEADERFIELDS_LEN) return setReason("Packet is too short");
@@ -66,7 +66,13 @@ int packetOk(unsigned char *packet,int len,unsigned char *transaction_id,
     return packetOkDNA(packet,len,transaction_id,recvaddr,recvaddrlen,parseP);
 
   if (packet[0]==0x4F&&packet[1]==0x10) 
-    return packetOkOverlay(packet,len,transaction_id,recvaddr,recvaddrlen,parseP);
+    {
+      if (interface>-1)
+	return packetOkOverlay(interface,packet,len,transaction_id,recvaddr,recvaddrlen,parseP);
+      else
+	/* We ignore overlay mesh packets in simple server mode, which is indicated by interface==-1 */
+	return -1;
+    }
 
   return setReason("Packet type not recognised.");
 }

server.c

@@ -530,7 +530,8 @@ int simpleServerMode()
       if (debug) fprintf(stderr,"Simulation mode: Dropped packet due to simulated link parameters.\n");
       continue;
     }
-    if (packetOk(buffer,len,NULL,&recvaddr,recvaddrlen,1)) { 
+    /* Simple server mode doesn't really use interface numbers, so lie and say interface -1 */
+    if (packetOk(-1,buffer,len,NULL,&recvaddr,recvaddrlen,1)) { 
       if (debug) setReason("Ignoring invalid packet");
     }
     if (debug>1) fprintf(stderr,"Finished processing packet, waiting for next one.\n");