core-lightning/tools/generate-wire.py
2018-02-24 11:44:32 +01:00

707 lines
24 KiB
Python
Executable File

#! /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,
'u64': 8,
'u32': 4,
'u16': 2,
'u8': 1,
'bool': 1
}
# These struct array helpers require a context to allocate from.
varlen_structs = [
'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')
}
# 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
# If it's an arraysize, swallow prefix.
if '*' 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 is_assignable(self):
if self.is_array() or self.is_variable_size():
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}
const u8 *cursor = p;
size_t plen = tal_len(p);
if (fromwire_u16(&cursor, &plen) != {enum.name})
return false;
{subcalls}
return 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}
u8 *p = tal_arr(ctx, u8, 0);
towire_u16(&p, {enumname});
{subcalls}
return memcheck(p, tal_count(p));
}}
"""
printwire_header_templ = """void printwire_{name}(const u8 *cursor);
"""
printwire_impl_templ = """void printwire_{name}(const u8 *cursor)
{{
size_t plen = tal_len(cursor);
if (fromwire_u16(&cursor, &plen) != {enum.name}) {{
printf("WRONG TYPE?!\\n");
return;
}}
{subcalls}
if (plen != 0)
printf("EXTRA: %s\\n", tal_hexstr(NULL, cursor, plen));
}}
"""
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):
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.is_variable_size():
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:
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('\tfromwire_{}_array(&cursor, &plen, {}, {});'
.format(basetype, name, num_elems))
else:
subcalls.append('\tfor (size_t i = 0; i < {}; i++)'
.format(num_elems))
if f.fieldtype.is_assignable():
subcalls.append('\t\t({})[i] = fromwire_{}(&cursor, &plen);'
.format(name, basetype))
elif basetype in varlen_structs:
subcalls.append('\t\t({})[i] = fromwire_{}(ctx, &cursor, &plen);'
.format(name, basetype))
else:
subcalls.append('\t\tfromwire_{}(&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.is_variable_size():
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 = []
for f in self.fields:
basetype = f.basetype()
for c in f.comments:
subcalls.append('\t/*{} */'.format(c))
if f.is_padding():
subcalls.append('\tfromwire_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("\t//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('\t*{} = {} ? tal_arr(ctx, {}, {}) : NULL;'
.format(f.name, f.lenvar, typename, f.lenvar))
self.print_fromwire_array(subcalls, basetype, f, '*' + f.name,
f.lenvar)
elif f.is_assignable():
subcalls.append("\t//3th case {name}".format(name=f.name))
if f.is_len_var:
subcalls.append('\t{} = fromwire_{}(&cursor, &plen);'
.format(f.name, basetype))
else:
subcalls.append('\t*{} = fromwire_{}(&cursor, &plen);'
.format(f.name, basetype))
elif basetype in varlen_structs:
subcalls.append('\t*{} = fromwire_{}(ctx, &cursor, &plen);'
.format(f.name, basetype))
else:
subcalls.append('\tfromwire_{}(&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='\n'.join(subcalls)
)
def print_towire_array(self, subcalls, basetype, f, num_elems):
if f.has_array_helper():
subcalls.append('\ttowire_{}_array(&p, {}, {});'
.format(basetype, f.name, num_elems))
else:
subcalls.append('\tfor (size_t i = 0; i < {}; i++)\n'
.format(num_elems))
if f.fieldtype.is_assignable() or basetype in varlen_structs:
subcalls.append('\t\ttowire_{}(&p, {}[i]);'
.format(basetype, f.name))
else:
subcalls.append('\t\ttowire_{}(&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 = []
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('\t/*{} */'.format(c))
if f.is_padding():
subcalls.append('\ttowire_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:
subcalls.append('\ttowire_{}(&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='\n'.join(subcalls),
)
def add_truncate_check(self, subcalls, indent='\t'):
# Report if truncated, otherwise print.
subcalls.append(indent + 'if (!cursor) {')
subcalls.append(indent + '\tprintf("**TRUNCATED**\\n");')
subcalls.append(indent + '\treturn;')
subcalls.append(indent + '}')
def print_printwire_array(self, subcalls, basetype, f, num_elems):
if f.has_array_helper():
subcalls.append('\tprintwire_{}_array(&cursor, &plen, {});'
.format(basetype, num_elems))
else:
subcalls.append('\tprintf("[");')
subcalls.append('\tfor (size_t i = 0; i < {}; i++) {{'
.format(num_elems))
subcalls.append('\t\t{} v;'.format(f.fieldtype.name))
if f.fieldtype.is_assignable():
subcalls.append('\t\tv = fromwire_{}(&cursor, plen);'
.format(f.fieldtype.name, basetype))
else:
# We don't handle this yet!
assert(basetype not in varlen_structs)
subcalls.append('\t\tfromwire_{}(&cursor, &plen, &v);'
.format(basetype))
self.add_truncate_check(subcalls, indent='\t\t')
subcalls.append('\t\tprintwire_{}(&v);'.format(basetype))
subcalls.append('\t}')
subcalls.append('\tprintf("]");')
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 = []
for f in self.fields:
basetype = f.basetype()
for c in f.comments:
subcalls.append('\t/*{} */'.format(c))
if f.is_len_var:
subcalls.append('\t{} {} = fromwire_{}(&cursor, &plen);'
.format(f.fieldtype.name, f.name, basetype))
self.add_truncate_check(subcalls)
continue
subcalls.append('\tprintf("{}=");'.format(f.name))
if f.is_padding():
subcalls.append('\tprintwire_pad(&cursor, &plen, {});'
.format(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.is_assignable():
subcalls.append('\t{} {} = fromwire_{}(&cursor, &plen);'
.format(f.fieldtype.name, f.name, basetype))
else:
# Don't handle these yet.
assert(basetype not in varlen_structs)
subcalls.append('\t{} {};'.
format(f.fieldtype.name, f.name))
subcalls.append('\tfromwire_{}(&cursor, &plen, &{});'
.format(basetype, f.name))
self.add_truncate_check(subcalls)
subcalls.append('\tprintwire_{}(&{});'
.format(basetype, f.name))
return template.format(
name=self.name,
fields=''.join(fields),
enum=self.enum,
subcalls='\n'.join(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 <ccan/tal/tal.h>
#include <wire/wire.h>
{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 <ccan/mem/mem.h>
#include <ccan/tal/str/str.h>
#include <stdio.h>
const char *{enumname}_name(int e)
{{
static char invalidbuf[sizeof("INVALID ") + STR_MAX_CHARS(e)];
switch ((enum {enumname})e) {{
{cases}
}}
sprintf(invalidbuf, "INVALID %i", e);
return 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 <ccan/tal/tal.h>
#include <devtools/print_wire.h>
{includes}
void print_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 <ccan/mem/mem.h>
#include <ccan/tal/str/str.h>
#include <common/utils.h>
#include <stdio.h>
void print_message(const u8 *msg)
{{
switch ((enum {enumname})fromwire_peektype(msg)) {{
{printcases}
}}
printf("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}(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)))