prep protocol spec for exit/snode stuff

docs/proto_v0.txt

@@ -455,7 +455,7 @@ on the currently unspecified stateless routing protocol.
 TODO: implement routing protocol :^)
 
 {
-  a: protocol_id_uint16
+  a: protocol_id_uint16,
   r: "<32 bytes public identity key of recipiant>",
   s: "<32 bytes public identity key of sender>",
   t: "<1280 bytes payload>",
@@ -528,12 +528,13 @@ variant 2, response, generated by the endpoint that recieved the request.
 
 obtain exit address message (OXAM)
 
-sent to an exit router to obtain a NAT ip address for ip exit traffic.
+sent to an exit router to obtain ip exit traffic context.
 replies are sent down the path that messages originate from.
 
 {
   A: "X",
   B: [list, of, permitted, blacklisted, traffic, policies],
+  E: 0 for snode communication or 1 for internet access,
   I: "<32 bytes signing public key for future communication>",
   S: uint64_sequence_number,
   T: uint64_transaction_id,
@@ -550,21 +551,14 @@ ip address used for exit traffic.
 
 {
   A: "G",
-  E: XR,
-  I: "<32 bytes signing public key of requester>",
   S: uint64_sequence_number,
   T: transaction_id_uint64,
   V: 0,
-  Z: "<64 bytes signature using exit info's signing key>"
+  Z: "<64 bytes signature using router identity signing key>"
 }
 
-E contains an exit route that was granted to the requester that can be used with
-IP exit traffic.
-
-The requester will now have any ip traffic going to address S forwarded to them
-via the path that originally sent the OXAM and any TDFM will is recieved on the
-same path will be forwarded out to the internet, given that they have
-valid signatures and addresses.
+any TITM recieved on the same path will be forwarded out to the internet if 
+OXAM.E is not 0, otherwise it is interpreted as service node traffic.
 
 
 reject exit address message (RXAM)
@@ -575,12 +569,11 @@ was denied.
 {
   A: "J",
   B: backoff_milliseconds_uint64,
-  I: "<32 bytes signing public key of requester>",
   R: [list, of, rejected, traffic, policies],
   S: uint64_sequence_number,
   T: transaction_id_uint64,
   V: 0,
-  Z: "<64 bytes signature signed by exit info's signing key>"
+  Z: "<64 bytes signature signed by router's signing key>"
 }
 
 
@@ -744,11 +737,10 @@ transfer ip traffic message (TITM)
 transfer ip traffic for exit
 
 {
-  A: "E",
+  A: "I",
   S: uint64_sequence_number,
   V: 0,
   X: "<N bytes ip packet>",
-  Y: "<16 bytes nounce>",
   Z: "<64 bytes signature using previously provided signing key>"
 }
 
@@ -769,26 +761,34 @@ should use the new path that this message came from.
 
 {
   A: "U",
+  R: "<16 bytes previous rx path id>",
   S: uint64_sequence_number,
-  T: transaction_id_uint64,
+  T: "<16 bytes previous tx path id>",
+  U: uint64_unique_id,
   V: 0,
-  Y: "<16 bytes nounce>",
   Z: "<64 bytes signature using previously provided signing key>"
 }
 
-T is the transaction ID from the GXAM
+update exit verify message (EXVM)
+
+sent in reply to a UXPM to verify that the path handover was accepted
+
+{
+  A: "V",
+  U: uint64_unique_id,
+  V: 0,
+  Z: "<64 bytes signature from router's signing key>"
+}
 
 close exit path message (CXPM)
 
 client sends a CXPM when the exit is no longer needed.
-The address used in exit MAY be reused later.
 
 {
   A: "C",
   S: uint64_sequence_number,
   T: transaction_id_uint64,
   V: 0,
-  Y: "<16 bytes nounce>",
   Z: "<64 bytes signagure using previously provided signing key>"
 }