tools/generate-wire.py: only use 'struct node_id' in announcements.

Naturally, it's a struct pubkey.  However, those are large, and take
time to marshal, so gossipd treats them as node_id which is a simple
array.  It adds explicit checks at the right points to make sure
they're valid pubkeys.

However, the next commit adds TLV test vectors, which assumes we treat
node_id as a point (thus catch invalid values when parsing).  The best
solution is to restrain our types here to exactly those we've
optimized for.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

tools/generate-wire.py

@@ -219,13 +219,14 @@ class Type(FieldSet):
     ]
 
     # Some BOLT types are re-typed based on their field name
-    # ('fieldname partial', 'original type'): ('true type', 'collapse array?')
+    # ('fieldname partial', 'original type', 'outer type'): ('true type', 'collapse array?')
     name_field_map = {
         ('txid', 'sha256'): ('bitcoin_txid', False),
         ('amt', 'u64'): ('amount_msat', False),
         ('msat', 'u64'): ('amount_msat', False),
         ('satoshis', 'u64'): ('amount_sat', False),
-        ('node_id', 'pubkey'): ('node_id', False),
+        ('node_id', 'pubkey', 'channel_announcement'): ('node_id', False),
+        ('node_id', 'pubkey', 'node_announcement'): ('node_id', False),
         ('temporary_channel_id', 'u8'): ('channel_id', True),
         ('secret', 'u8'): ('secret', True),
         ('preimage', 'u8'): ('preimage', True),
@@ -242,7 +243,7 @@ class Type(FieldSet):
     }
 
     @staticmethod
-    def true_type(type_name, field_name=None):
+    def true_type(type_name, field_name=None, outer_name=None):
         """ Returns 'true' type of a given type and a flag if
             we've remapped a variable size/array type to a single struct
             (an example of this is 'temporary_channel_id' which is specified
@@ -252,9 +253,10 @@ class Type(FieldSet):
             type_name = Type.name_remap[type_name]
 
         if field_name:
-            for (partial, t), true_type in Type.name_field_map.items():
+            for t, true_type in Type.name_field_map.items():
-                if partial in field_name and t == type_name:
+                if t[0] in field_name and t[1] == type_name:
-                    return true_type
+                    if len(t) == 2 or outer_name == t[2]:
+                        return true_type
         return (type_name, False)
 
     def __init__(self, name):
@@ -407,13 +409,14 @@ class Master(object):
     def add_extension_msg(self, name, msg):
         self.extension_msgs[name] = msg
 
-    def add_type(self, type_name, field_name=None):
+    def add_type(self, type_name, field_name=None, outer_name=None):
         optional = False
         if type_name.startswith('?'):
             type_name = type_name[1:]
             optional = True
         # Check for special type name re-mapping
-        type_name, collapse_original = Type.true_type(type_name, field_name)
+        type_name, collapse_original = Type.true_type(type_name, field_name,
+                                                      outer_name)
 
         if type_name not in self.types:
             self.types[type_name] = Type(type_name)
@@ -522,7 +525,7 @@ def main(options, args=None, output=sys.stdout, lines=None):
                 if not subtype:
                     raise ValueError('Unknown subtype {} for data.\nat {}:{}'
                                      .format(tokens[1], ln, line))
-                type_obj, collapse, optional = master.add_type(tokens[3], tokens[2])
+                type_obj, collapse, optional = master.add_type(tokens[3], tokens[2], tokens[1])
                 if optional:
                     raise ValueError('Subtypes cannot have optional fields {}.{}\n at {}:{}'
                                      .format(subtype.name, tokens[2], ln, line))
@@ -540,7 +543,7 @@ def main(options, args=None, output=sys.stdout, lines=None):
 
                 comment_set = []
             elif token_type == 'tlvdata':
-                type_obj, collapse, optional = master.add_type(tokens[4], tokens[3])
+                type_obj, collapse, optional = master.add_type(tokens[4], tokens[3], tokens[1])
                 if optional:
                     raise ValueError('TLV messages cannot have optional fields {}.{}\n at {}:{}'
                                      .format(tokens[2], tokens[3], ln, line))
@@ -568,7 +571,7 @@ def main(options, args=None, output=sys.stdout, lines=None):
                 msg = master.find_message(tokens[1])
                 if not msg:
                     raise ValueError('Unknown message type {}. {}:{}'.format(tokens[1], ln, line))
-                type_obj, collapse, optional = master.add_type(tokens[3], tokens[2])
+                type_obj, collapse, optional = master.add_type(tokens[3], tokens[2], tokens[1])
 
                 # if this is an 'extension' field*, we want to add a new 'message' type
                 # in the future, extensions will be handled as TLV's