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#! /usr/bin/python3
# Read from stdin, spit out C header or body.
from optparse import OptionParser
from collections import namedtuple
import fileinput
import re
Enumtype = namedtuple('Enumtype', ['name', 'value'])
class Field(object):
def __init__(self,message,name,size):
self.message = message
self.name = name.replace('-', '_')
(self.typename, self.basesize) = Field._guess_type(message,self.name,size)
try:
if int(size) % self.basesize != 0:
raise ValueError('Invalid size {} for {}.{} not a multiple of {}'.format(size,self.message,self.name,self.basesize))
self.num_elems = int(int(size) / self.basesize)
except ValueError:
self.num_elems = 0
# If it's a multiplicitive expression, must end in basesize.
if '*' in size:
tail='*' + str(self.basesize)
if not size.endswith(tail):
raise ValueError('Invalid size {} for {}.{} not a multiple of {}'.format(size,self.message,self.name,self.basesize))
size = size[:-len(tail)]
else:
if self.basesize != 1:
raise ValueError('Invalid size {} for {}.{} not expressed as a multiple of {}'.format(size,self.message,self.name,self.basesize))
self.lenvar = size.replace('-','_')
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.num_elems == 0
def is_assignable(self):
if self.is_array() or self.is_variable_size():
return False
return self.typename == 'u8' or self.typename == 'u16' or self.typename == 'u32' or self.typename == 'u64'
# Returns typename and base size
@staticmethod
def _guess_type(message, fieldname, sizestr):
if fieldname.startswith('pad'):
return ('pad',1)
if fieldname.endswith('channel_id'):
return ('struct channel_id',8)
if message == 'node_announcement' and fieldname == 'ipv6':
return ('struct ipv6',16)
if fieldname.endswith('features'):
return ('u8',1)
if fieldname == 'addresses':
return ('u8', 1)
# We translate signatures and pubkeys.
if 'signature' in fieldname:
return ('struct signature',64)
# The remainder should be fixed sizes.
if sizestr == '33':
return ('struct pubkey',33)
if sizestr == '32':
return ('struct sha256',32)
if sizestr == '8':
return ('u64',8)
if sizestr == '4':
return ('u32',4)
if sizestr == '2':
return ('u16',2)
if sizestr == '1':
return ('u8',1)
# We whitelist specific things here, otherwise we'd treat everything
# as a u8 array.
if message == 'update_fail_htlc' and fieldname == 'reason':
return ('u8', 1)
if message == 'update_add_htlc' and fieldname == 'onion_routing_packet':
return ('u8', 1)
if message == 'node_announcement' and fieldname == 'alias':
return ('u8',1)
if message == 'error' and fieldname == 'data':
return ('u8',1)
if message == 'shutdown' and fieldname == 'scriptpubkey':
return ('u8',1)
if message == 'node_announcement' and fieldname == 'rgb_color':
return ('u8',1)
raise ValueError('Unknown size {} for {}'.format(sizestr,fieldname))
class Message(object):
def __init__(self,name,enum):
self.name = name
self.enum = enum
self.fields = []
def checkLenField(self,field):
for f in self.fields:
if f.name == field.lenvar:
if f.typename != 'u16':
raise ValueError('Field {} has non-u16 length variable {}'
.format(field.name, field.lenvar))
if f.is_array() or f.is_variable_size():
raise ValueError('Field {} has non-simple length variable {}'
.format(field.name, field.lenvar))
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.fields.append(field)
def print_structure(self):
print('struct msg_{} {{'.format(self.name));
for f in self.fields:
# If size isn't known, it's a pointer.
if f.is_array():
print('\t{} {}[{}];'.format(f.typename, f.name, f.num_elems))
elif f.is_variable_size():
print('\t{} *{};'.format(f.typename, f.name))
else:
print('\t{} {};'.format(f.typename, f.name))
print('};')
def print_fromwire(self,is_header):
print('struct msg_{0} *fromwire_{0}(const tal_t *ctx, const void *p, size_t *len)'.format(self.name), end='')
if is_header:
print(';')
return
print('\n'
'{{\n'
'\tconst u8 *cursor = p;\n'
'\tstruct msg_{} *in = tal(ctx, struct msg_{});\n'
''.format(self.name, self.name));
for f in self.fields:
basetype=f.typename
if f.typename.startswith('struct '):
basetype=f.typename[7:]
if f.is_array():
print("\t//1th case", f.name)
print('\tfromwire_{}_array(&cursor, len, in->{}, {});'
.format(basetype, f.name, f.num_elems))
elif f.is_variable_size():
print("\t//2th case", f.name)
print('\tin->{} = tal_arr(in, {}, in->{});'
.format(f.name, f.typename, f.lenvar))
print('\tfromwire_{}_array(&cursor, len, in->{}, in->{});'
.format(basetype, f.name, f.lenvar))
elif f.is_assignable():
print("\t//3th case", f.name)
print('\tin->{} = fromwire_{}(&cursor, len);'
.format(f.name, basetype))
else:
print("\t//4th case", f.name)
print('\tfromwire_{}(&cursor, len, &in->{});'
.format(basetype, f.name))
print('\n'
'\tif (!cursor)\n'
'\t\treturn tal_free(in);\n'
'\treturn in;\n'
'}\n')
def print_towire(self,is_header):
print('u8 *towire_{0}(const tal_t *ctx, const struct msg_{0} *out)'.format(self.name), end='')
if is_header:
print(';')
return
print('\n'
'{\n'
'\tu8 *p = tal_arr(ctx, u8, 0);\n'
'')
for f in self.fields:
basetype=f.typename
if f.typename.startswith('struct '):
basetype=f.typename[7:]
if f.is_array():
print('\ttowire_{}_array(&p, out->{}, {});'
.format(basetype, f.name, f.num_elems))
elif f.is_variable_size():
print('\ttowire_{}_array(&p, out->{}, out->{});'
.format(basetype, f.name, f.lenvar))
elif f.is_assignable():
print('\ttowire_{}(&p, out->{});'
.format(basetype, f.name))
else:
print('\ttowire_{}(&p, &out->{});'
.format(basetype, f.name))
print('\n'
'\treturn p;\n'
'}\n')
parser = OptionParser()
parser.add_option("--header",
action="store_true", dest="output_header", default=False,
help="Create gen_wire.h")
(options, args) = parser.parse_args()
if options.output_header:
print('#ifndef LIGHTNING_WIRE_GEN_WIRE_H\n'
'#define LIGHTNING_WIRE_GEN_WIRE_H\n'
'#include <ccan/tal/tal.h>\n'
'#include <wire/wire.h>\n'
'\n'
'typedef u8 pad;\n'
'')
else:
print('#include "gen_wire.h"\n'
'')
# Maps message names to messages
messages = { }
# Read csv lines. Single comma is the message values, more is offset/len.
for line in fileinput.input(args):
parts = line.rstrip().split(',')
if len(parts) == 2:
# eg commit_sig,132
messages[parts[0]] = Message(parts[0],Enumtype("WIRE_" + parts[0].upper(), int(parts[1])))
else:
# eg commit_sig,0,channel-id,8
messages[parts[0]].addField(Field(parts[0], parts[2], parts[3]))
if options.output_header:
# Dump out enum, sorted by value order.
print('enum wire_type {')
for m in sorted(messages.values(),key=lambda x:x.enum.value):
print('\t{} = {},'.format(m.enum.name, m.enum.value))
print('};')
# Dump out structure definitions.
for m in messages.values():
m.print_structure()
for m in messages.values():
m.print_fromwire(options.output_header)
for m in messages.values():
m.print_towire(options.output_header)
if options.output_header:
print('#endif /* LIGHTNING_WIRE_GEN_WIRE_H */\n')