#! /usr/bin/env python3 # Read from stdin, spit out C header or body. import argparse import copy import fileinput import re from collections import namedtuple Enumtype = namedtuple('Enumtype', ['name', 'value']) type2size = { 'pad': 1, 'struct channel_id': 32, 'struct short_channel_id': 8, 'struct ipv6': 16, 'secp256k1_ecdsa_signature': 64, 'struct preimage': 32, 'struct pubkey': 33, 'struct sha256': 32, 'struct bitcoin_blkid': 32, 'struct bitcoin_txid': 32, 'struct secret': 32, 'u64': 8, 'u32': 4, 'u16': 2, 'u8': 1, 'bool': 1 } # These struct array helpers require a context to allocate from. varlen_structs = [ 'peer_features', 'gossip_getnodes_entry', 'failed_htlc', 'utxo', 'bitcoin_tx', 'wirestring', ] class FieldType(object): def __init__(self, name): self.name = name def is_assignable(self): return self.name in ['u8', 'u16', 'u32', 'u64', 'bool'] or self.name.startswith('enum ') # We only accelerate the u8 case: it's common and trivial. def has_array_helper(self): return self.name in ['u8'] # Returns base size @staticmethod def _typesize(typename): if typename in type2size: return type2size[typename] elif typename.startswith('struct ') or typename.startswith('enum '): # We allow unknown structures/enums, for extensibility (can only happen # if explicitly specified in csv) return 0 else: raise ValueError('Unknown typename {}'.format(typename)) # Full (message, fieldname)-mappings typemap = { ('update_fail_htlc', 'reason'): FieldType('u8'), ('node_announcement', 'alias'): FieldType('u8'), ('update_add_htlc', 'onion_routing_packet'): FieldType('u8'), ('update_fulfill_htlc', 'payment_preimage'): FieldType('struct preimage'), ('error', 'data'): FieldType('u8'), ('shutdown', 'scriptpubkey'): FieldType('u8'), ('node_announcement', 'rgb_color'): FieldType('u8'), ('node_announcement', 'addresses'): FieldType('u8'), ('node_announcement', 'ipv6'): FieldType('struct ipv6'), ('announcement_signatures', 'short_channel_id'): FieldType('struct short_channel_id'), ('channel_announcement', 'short_channel_id'): FieldType('struct short_channel_id'), ('channel_update', 'short_channel_id'): FieldType('struct short_channel_id'), ('revoke_and_ack', 'per_commitment_secret'): FieldType('struct secret'), ('channel_reestablish_option_data_loss_protect', 'your_last_per_commitment_secret'): FieldType('struct secret') } # Partial names that map to a datatype partialtypemap = { 'signature': FieldType('secp256k1_ecdsa_signature'), 'features': FieldType('u8'), 'channel_id': FieldType('struct channel_id'), 'chain_hash': FieldType('struct bitcoin_blkid'), 'funding_txid': FieldType('struct bitcoin_txid'), 'pad': FieldType('pad'), } # Size to typename match sizetypemap = { 33: FieldType('struct pubkey'), 32: FieldType('struct sha256'), 8: FieldType('u64'), 4: FieldType('u32'), 2: FieldType('u16'), 1: FieldType('u8') } # It would be nicer if we had put '*u8' in spec and disallowed bare lenvar. # In practice we only recognize lenvar when it's the previous field. # size := baresize | arraysize # baresize := simplesize | lenvar # simplesize := number | type # arraysize := length '*' type # length := lenvar | number class Field(object): def __init__(self, message, name, size, comments, prevname): self.message = message self.comments = comments self.name = name self.is_len_var = False self.lenvar = None self.num_elems = 1 self.optional = False # ? means optional field (not supported for arrays) if size.startswith('?'): self.optional = True size = size[1:] # If it's an arraysize, swallow prefix. elif '*' in size: number = size.split('*')[0] if number == prevname: self.lenvar = number else: self.num_elems = int(number) size = size.split('*')[1] elif options.bolt and size == prevname: # Raw length field, implies u8. self.lenvar = size size = '1' # Bolts use just a number: Guess type based on size. if options.bolt: base_size = int(size) self.fieldtype = Field._guess_type(message, self.name, base_size) # There are some arrays which we have to guess, based on sizes. tsize = FieldType._typesize(self.fieldtype.name) if base_size % tsize != 0: raise ValueError('Invalid size {} for {}.{} not a multiple of {}' .format(base_size, self.message, self.name, tsize)) self.num_elems = int(base_size / tsize) else: # Real typename. self.fieldtype = FieldType(size) def basetype(self): base = self.fieldtype.name if base.startswith('struct '): base = base[7:] elif base.startswith('enum '): base = base[5:] return base def is_padding(self): return self.name.startswith('pad') # Padding is always treated as an array. def is_array(self): return self.num_elems > 1 or self.is_padding() def is_variable_size(self): return self.lenvar is not None def needs_ptr_to_ptr(self): return self.is_variable_size() or self.optional def is_assignable(self): if self.is_array() or self.needs_ptr_to_ptr(): return False return self.fieldtype.is_assignable() def has_array_helper(self): return self.fieldtype.has_array_helper() # Returns FieldType @staticmethod def _guess_type(message, fieldname, base_size): # Check for full (message, fieldname)-matches if (message, fieldname) in typemap: return typemap[(message, fieldname)] # Check for partial field names for k, v in partialtypemap.items(): if k in fieldname: return v # Check for size matches if base_size in sizetypemap: return sizetypemap[base_size] raise ValueError('Unknown size {} for {}'.format(base_size, fieldname)) fromwire_impl_templ = """bool fromwire_{name}({ctx}const void *p{args}) {{ {fields} \tconst u8 *cursor = p; \tsize_t plen = tal_count(p); \tif (fromwire_u16(&cursor, &plen) != {enum.name}) \t\treturn false; {subcalls} \treturn cursor != NULL; }} """ fromwire_header_templ = """bool fromwire_{name}({ctx}const void *p{args}); """ towire_header_templ = """u8 *towire_{name}(const tal_t *ctx{args}); """ towire_impl_templ = """u8 *towire_{name}(const tal_t *ctx{args}) {{ {field_decls} \tu8 *p = tal_arr(ctx, u8, 0); \ttowire_u16(&p, {enumname}); {subcalls} \treturn memcheck(p, tal_count(p)); }} """ printwire_header_templ = """void printwire_{name}(const char *fieldname, const u8 *cursor); """ printwire_impl_templ = """void printwire_{name}(const char *fieldname, const u8 *cursor) {{ \tsize_t plen = tal_count(cursor); \tif (fromwire_u16(&cursor, &plen) != {enum.name}) {{ \t\tprintf("WRONG TYPE?!\\n"); \t\treturn; \t}} {subcalls} \tif (plen != 0) \t\tprintf("EXTRA: %s\\n", tal_hexstr(NULL, cursor, plen)); }} """ class CCode(object): """Simple class to create indented C code""" def __init__(self): self.indent = 1 self.single_indent = False self.code = [] def append(self, lines): for line in lines.split('\n'): # Let us to the indenting please! assert '\t' not in line # Special case: } by itself is pre-unindented. if line == '}': self.indent -= 1 self.code.append("\t" * self.indent + line) continue self.code.append("\t" * self.indent + line) if self.single_indent: self.indent -= 1 self.single_indent = False if line.endswith('{'): self.indent += 1 elif line.endswith('}'): self.indent -= 1 elif line.startswith('for') or line.startswith('if'): self.indent += 1 self.single_indent = True def __str__(self): assert self.indent == 1 assert not self.single_indent return '\n'.join(self.code) class Message(object): def __init__(self, name, enum, comments): self.name = name self.enum = enum self.comments = comments self.fields = [] self.has_variable_fields = False def checkLenField(self, field): # Optional fields don't have a len. if field.optional: return for f in self.fields: if f.name == field.lenvar: if f.fieldtype.name != 'u16': raise ValueError('Field {} has non-u16 length variable {} (type {})' .format(field.name, field.lenvar, f.fieldtype.name)) if f.is_array() or f.needs_ptr_to_ptr(): raise ValueError('Field {} has non-simple length variable {}' .format(field.name, field.lenvar)) f.is_len_var = True f.lenvar_for = field return raise ValueError('Field {} unknown length variable {}' .format(field.name, field.lenvar)) def addField(self, field): # We assume field lengths are 16 bit, to avoid overflow issues and # massive allocations. if field.is_variable_size(): self.checkLenField(field) self.has_variable_fields = True elif field.basetype() in varlen_structs or field.optional: self.has_variable_fields = True self.fields.append(field) def print_fromwire_array(self, subcalls, basetype, f, name, num_elems): if f.has_array_helper(): subcalls.append('fromwire_{}_array(&cursor, &plen, {}, {});' .format(basetype, name, num_elems)) else: subcalls.append('for (size_t i = 0; i < {}; i++)' .format(num_elems)) if f.fieldtype.is_assignable(): subcalls.append('({})[i] = fromwire_{}(&cursor, &plen);' .format(name, basetype)) elif basetype in varlen_structs: subcalls.append('({})[i] = fromwire_{}(ctx, &cursor, &plen);' .format(name, basetype)) else: subcalls.append('fromwire_{}(&cursor, &plen, {} + i);' .format(basetype, name)) def print_fromwire(self, is_header): ctx_arg = 'const tal_t *ctx, ' if self.has_variable_fields else '' args = [] for f in self.fields: if f.is_len_var or f.is_padding(): continue elif f.is_array(): args.append(', {} {}[{}]'.format(f.fieldtype.name, f.name, f.num_elems)) else: ptrs = '*' # If we're handing a variable array, we need a ptr-to-ptr. if f.needs_ptr_to_ptr(): ptrs += '*' # If each type is a variable length, we need a ptr to that. if f.basetype() in varlen_structs: ptrs += '*' args.append(', {} {}{}'.format(f.fieldtype.name, ptrs, f.name)) template = fromwire_header_templ if is_header else fromwire_impl_templ fields = ['\t{} {};\n'.format(f.fieldtype.name, f.name) for f in self.fields if f.is_len_var] subcalls = CCode() for f in self.fields: basetype = f.basetype() for c in f.comments: subcalls.append('/*{} */'.format(c)) if f.is_padding(): subcalls.append('fromwire_pad(&cursor, &plen, {});' .format(f.num_elems)) elif f.is_array(): self.print_fromwire_array(subcalls, basetype, f, f.name, f.num_elems) elif f.is_variable_size(): subcalls.append("//2nd case {name}".format(name=f.name)) typename = f.fieldtype.name # If structs are varlen, need array of ptrs to them. if basetype in varlen_structs: typename += ' *' subcalls.append('*{} = {} ? tal_arr(ctx, {}, {}) : NULL;' .format(f.name, f.lenvar, typename, f.lenvar)) self.print_fromwire_array(subcalls, basetype, f, '*' + f.name, f.lenvar) else: if f.optional: subcalls.append("if (!fromwire_bool(&cursor, &plen))\n" "*{} = NULL;\n" "else {{\n" "*{} = tal(ctx, {});\n" "fromwire_{}(&cursor, &plen, *{});\n" "}}" .format(f.name, f.name, f.fieldtype.name, basetype, f.name)) elif f.is_assignable(): subcalls.append("//3rd case {name}".format(name=f.name)) if f.is_len_var: subcalls.append('{} = fromwire_{}(&cursor, &plen);' .format(f.name, basetype)) else: subcalls.append('*{} = fromwire_{}(&cursor, &plen);' .format(f.name, basetype)) elif basetype in varlen_structs: subcalls.append('*{} = fromwire_{}(ctx, &cursor, &plen);' .format(f.name, basetype)) else: subcalls.append('fromwire_{}(&cursor, &plen, {});' .format(basetype, f.name)) return template.format( name=self.name, ctx=ctx_arg, args=''.join(args), fields=''.join(fields), enum=self.enum, subcalls=str(subcalls) ) def print_towire_array(self, subcalls, basetype, f, num_elems): if f.has_array_helper(): subcalls.append('towire_{}_array(&p, {}, {});' .format(basetype, f.name, num_elems)) else: subcalls.append('for (size_t i = 0; i < {}; i++)' .format(num_elems)) if f.fieldtype.is_assignable() or basetype in varlen_structs: subcalls.append('towire_{}(&p, {}[i]);' .format(basetype, f.name)) else: subcalls.append('towire_{}(&p, {} + i);' .format(basetype, f.name)) def print_towire(self, is_header): template = towire_header_templ if is_header else towire_impl_templ args = [] for f in self.fields: if f.is_padding() or f.is_len_var: continue if f.is_array(): args.append(', const {} {}[{}]'.format(f.fieldtype.name, f.name, f.num_elems)) elif f.is_assignable(): args.append(', {} {}'.format(f.fieldtype.name, f.name)) elif f.is_variable_size() and f.basetype() in varlen_structs: args.append(', const {} **{}'.format(f.fieldtype.name, f.name)) else: args.append(', const {} *{}'.format(f.fieldtype.name, f.name)) field_decls = [] for f in self.fields: if f.is_len_var: field_decls.append('\t{0} {1} = tal_count({2});'.format( f.fieldtype.name, f.name, f.lenvar_for.name )) subcalls = CCode() for f in self.fields: basetype = f.fieldtype.name if basetype.startswith('struct '): basetype = basetype[7:] elif basetype.startswith('enum '): basetype = basetype[5:] for c in f.comments: subcalls.append('/*{} */'.format(c)) if f.is_padding(): subcalls.append('towire_pad(&p, {});' .format(f.num_elems)) elif f.is_array(): self.print_towire_array(subcalls, basetype, f, f.num_elems) elif f.is_variable_size(): self.print_towire_array(subcalls, basetype, f, f.lenvar) else: if f.optional: subcalls.append("if (!{})\n" "towire_bool(&p, false);\n" "else {{\n" "towire_bool(&p, true);\n" "towire_{}(&p, {});\n" "}}".format(f.name, basetype, f.name)) else: subcalls.append('towire_{}(&p, {});' .format(basetype, f.name)) return template.format( name=self.name, args=''.join(args), enumname=self.enum.name, field_decls='\n'.join(field_decls), subcalls=str(subcalls), ) def add_truncate_check(self, subcalls): # Report if truncated, otherwise print. subcalls.append('if (!cursor) {\n' 'printf("**TRUNCATED**\\n");\n' 'return;\n' '}') def print_printwire_array(self, subcalls, basetype, f, num_elems): if f.has_array_helper(): subcalls.append('printwire_{}_array(tal_fmt(NULL, "%s.{}", fieldname), &cursor, &plen, {});' .format(basetype, f.name, num_elems)) else: subcalls.append('printf("[");') subcalls.append('for (size_t i = 0; i < {}; i++) {{' .format(num_elems)) subcalls.append('{} v;'.format(f.fieldtype.name)) if f.fieldtype.is_assignable(): subcalls.append('v = fromwire_{}(&cursor, plen);' .format(f.fieldtype.name, basetype)) else: # We don't handle this yet! assert(basetype not in varlen_structs) subcalls.append('fromwire_{}(&cursor, &plen, &v);' .format(basetype)) self.add_truncate_check(subcalls) subcalls.append('printwire_{}(tal_fmt(NULL, "%s.{}", fieldname), &v);' .format(basetype, f.name)) subcalls.append('}') subcalls.append('printf("]");') def print_printwire(self, is_header): template = printwire_header_templ if is_header else printwire_impl_templ fields = ['\t{} {};\n'.format(f.fieldtype.name, f.name) for f in self.fields if f.is_len_var] subcalls = CCode() for f in self.fields: basetype = f.basetype() for c in f.comments: subcalls.append('/*{} */'.format(c)) if f.is_len_var: subcalls.append('{} {} = fromwire_{}(&cursor, &plen);' .format(f.fieldtype.name, f.name, basetype)) self.add_truncate_check(subcalls) continue subcalls.append('printf("{}=");'.format(f.name)) if f.is_padding(): subcalls.append('printwire_pad(tal_fmt(NULL, "%s.{}", fieldname), &cursor, &plen, {});' .format(f.name, f.num_elems)) self.add_truncate_check(subcalls) elif f.is_array(): self.print_printwire_array(subcalls, basetype, f, f.num_elems) self.add_truncate_check(subcalls) elif f.is_variable_size(): self.print_printwire_array(subcalls, basetype, f, f.lenvar) self.add_truncate_check(subcalls) else: if f.optional: subcalls.append("if (fromwire_bool(&cursor, &plen)) {") if f.is_assignable(): subcalls.append('{} {} = fromwire_{}(&cursor, &plen);' .format(f.fieldtype.name, f.name, basetype)) else: # Don't handle these yet. assert(basetype not in varlen_structs) subcalls.append('{} {};'. format(f.fieldtype.name, f.name)) subcalls.append('fromwire_{}(&cursor, &plen, &{});' .format(basetype, f.name)) self.add_truncate_check(subcalls) subcalls.append('printwire_{}(tal_fmt(NULL, "%s.{}", fieldname), &{});' .format(basetype, f.name, f.name)) if f.optional: subcalls.append("} else {") self.add_truncate_check(subcalls) subcalls.append("}") return template.format( name=self.name, fields=''.join(fields), enum=self.enum, subcalls=str(subcalls) ) def find_message(messages, name): for m in messages: if m.name == name: return m return None def find_message_with_option(messages, optional_messages, name, option): fullname = name + "_" + option.replace('-', '_') base = find_message(messages, name) if not base: raise ValueError('Unknown message {}'.format(name)) m = find_message(optional_messages, fullname) if not m: # Add a new option. m = copy.deepcopy(base) m.name = fullname optional_messages.append(m) return m parser = argparse.ArgumentParser(description='Generate C from CSV') parser.add_argument('--header', action='store_true', help="Create wire header") parser.add_argument('--bolt', action='store_true', help="Generate wire-format for BOLT") parser.add_argument('--printwire', action='store_true', help="Create print routines") parser.add_argument('headerfilename', help='The filename of the header') parser.add_argument('enumname', help='The name of the enum to produce') parser.add_argument('files', nargs='*', help='Files to read in (or stdin)') options = parser.parse_args() # Maps message names to messages messages = [] messages_with_option = [] comments = [] includes = [] prevfield = None # Read csv lines. Single comma is the message values, more is offset/len. for line in fileinput.input(options.files): # #include gets inserted into header if line.startswith('#include '): includes.append(line) continue by_comments = line.rstrip().split('#') # Emit a comment if they included one if by_comments[1:]: comments.append(' '.join(by_comments[1:])) parts = by_comments[0].split(',') if parts == ['']: continue if len(parts) == 2: # eg commit_sig,132 messages.append(Message(parts[0], Enumtype("WIRE_" + parts[0].upper(), parts[1]), comments)) comments = [] prevfield = None else: if len(parts) == 4: # eg commit_sig,0,channel-id,8 OR # commit_sig,0,channel-id,u64 m = find_message(messages, parts[0]) if m is None: raise ValueError('Unknown message {}'.format(parts[0])) elif len(parts) == 5: # eg. # channel_reestablish,48,your_last_per_commitment_secret,32,option209 m = find_message_with_option(messages, messages_with_option, parts[0], parts[4]) else: raise ValueError('Line {} malformed'.format(line.rstrip())) f = Field(m.name, parts[2], parts[3], comments, prevfield) m.addField(f) # If it used prevfield as lenvar, keep that for next # time (multiple fields can use the same lenvar). if not f.lenvar: prevfield = parts[2] comments = [] header_template = """/* This file was generated by generate-wire.py */ /* Do not modify this file! Modify the _csv file it was generated from. */ #ifndef LIGHTNING_{idem} #define LIGHTNING_{idem} #include #include {includes} enum {enumname} {{ {enums}}}; const char *{enumname}_name(int e); {func_decls} #endif /* LIGHTNING_{idem} */ """ impl_template = """/* This file was generated by generate-wire.py */ /* Do not modify this file! Modify the _csv file it was generated from. */ #include <{headerfilename}> #include #include #include const char *{enumname}_name(int e) {{ \tstatic char invalidbuf[sizeof("INVALID ") + STR_MAX_CHARS(e)]; \tswitch ((enum {enumname})e) {{ \t{cases} \t}} \tsnprintf(invalidbuf, sizeof(invalidbuf), "INVALID %i", e); \treturn invalidbuf; }} {func_decls} """ print_header_template = """/* This file was generated by generate-wire.py */ /* Do not modify this file! Modify the _csv file it was generated from. */ #ifndef LIGHTNING_{idem} #define LIGHTNING_{idem} #include #include {includes} void print{enumname}_message(const u8 *msg); {func_decls} #endif /* LIGHTNING_{idem} */ """ print_template = """/* This file was generated by generate-wire.py */ /* Do not modify this file! Modify the _csv file it was generated from. */ #include "{headerfilename}" #include #include #include #include void print{enumname}_message(const u8 *msg) {{ \tswitch ((enum {enumname})fromwire_peektype(msg)) {{ \t{printcases} \t}} \tprintf("UNKNOWN: %s\\n", tal_hex(msg, msg)); }} {func_decls} """ idem = re.sub(r'[^A-Z]+', '_', options.headerfilename.upper()) if options.printwire: if options.header: template = print_header_template else: template = print_template elif options.header: template = header_template else: template = impl_template # Dump out enum, sorted by value order. enums = "" for m in messages: for c in m.comments: enums += '\t/*{} */\n'.format(c) enums += '\t{} = {},\n'.format(m.enum.name, m.enum.value) includes = '\n'.join(includes) cases = ['case {enum.name}: return "{enum.name}";'.format(enum=m.enum) for m in messages] printcases = ['case {enum.name}: printf("{enum.name}:\\n"); printwire_{name}("{name}", msg); return;'.format(enum=m.enum, name=m.name) for m in messages] if options.printwire: decls = [m.print_printwire(options.header) for m in messages + messages_with_option] else: fromwire_decls = [m.print_fromwire(options.header) for m in messages + messages_with_option] towire_decls = towire_decls = [m.print_towire(options.header) for m in messages + messages_with_option] decls = fromwire_decls + towire_decls print(template.format( headerfilename=options.headerfilename, cases='\n\t'.join(cases), printcases='\n\t'.join(printcases), idem=idem, includes=includes, enumname=options.enumname, enums=enums, func_decls='\n'.join(decls)))