1#!/usr/bin/env python2.7 2 3# Copyright 2015 gRPC authors. 4# 5# Licensed under the Apache License, Version 2.0 (the "License"); 6# you may not use this file except in compliance with the License. 7# You may obtain a copy of the License at 8# 9# http://www.apache.org/licenses/LICENSE-2.0 10# 11# Unless required by applicable law or agreed to in writing, software 12# distributed under the License is distributed on an "AS IS" BASIS, 13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14# See the License for the specific language governing permissions and 15# limitations under the License. 16"""Read from stdin a set of colon separated http headers: 17 :path: /foo/bar 18 content-type: application/grpc 19 Write a set of strings containing a hpack encoded http2 frame that 20 represents said headers.""" 21 22import json 23import sys 24import argparse 25 26 27def append_never_indexed(payload_line, n, count, key, value): 28 payload_line.append(0x10) 29 assert (len(key) <= 126) 30 payload_line.append(len(key)) 31 payload_line.extend(ord(c) for c in key) 32 assert (len(value) <= 126) 33 payload_line.append(len(value)) 34 payload_line.extend(ord(c) for c in value) 35 36 37def append_inc_indexed(payload_line, n, count, key, value): 38 payload_line.append(0x40) 39 assert (len(key) <= 126) 40 payload_line.append(len(key)) 41 payload_line.extend(ord(c) for c in key) 42 assert (len(value) <= 126) 43 payload_line.append(len(value)) 44 payload_line.extend(ord(c) for c in value) 45 46 47def append_pre_indexed(payload_line, n, count, key, value): 48 payload_line.append(0x80 + 61 + count - n) 49 50 51_COMPRESSORS = { 52 'never': append_never_indexed, 53 'inc': append_inc_indexed, 54 'pre': append_pre_indexed, 55} 56 57argp = argparse.ArgumentParser('Generate header frames') 58argp.add_argument('--set_end_stream', 59 default=False, 60 action='store_const', 61 const=True) 62argp.add_argument('--no_framing', 63 default=False, 64 action='store_const', 65 const=True) 66argp.add_argument('--compression', 67 choices=sorted(_COMPRESSORS.keys()), 68 default='never') 69argp.add_argument('--hex', default=False, action='store_const', const=True) 70args = argp.parse_args() 71 72# parse input, fill in vals 73vals = [] 74for line in sys.stdin: 75 line = line.strip() 76 if line == '': continue 77 if line[0] == '#': continue 78 key_tail, value = line[1:].split(':') 79 key = (line[0] + key_tail).strip() 80 value = value.strip() 81 vals.append((key, value)) 82 83# generate frame payload binary data 84payload_bytes = [] 85if not args.no_framing: 86 payload_bytes.append([]) # reserve space for header 87payload_len = 0 88n = 0 89for key, value in vals: 90 payload_line = [] 91 _COMPRESSORS[args.compression](payload_line, n, len(vals), key, value) 92 n += 1 93 payload_len += len(payload_line) 94 payload_bytes.append(payload_line) 95 96# fill in header 97if not args.no_framing: 98 flags = 0x04 # END_HEADERS 99 if args.set_end_stream: 100 flags |= 0x01 # END_STREAM 101 payload_bytes[0].extend([ 102 (payload_len >> 16) & 0xff, 103 (payload_len >> 8) & 0xff, 104 (payload_len) & 0xff, 105 # header frame 106 0x01, 107 # flags 108 flags, 109 # stream id 110 0x00, 111 0x00, 112 0x00, 113 0x01 114 ]) 115 116hex_bytes = [ord(c) for c in "abcdefABCDEF0123456789"] 117 118 119def esc_c(line): 120 out = "\"" 121 last_was_hex = False 122 for c in line: 123 if 32 <= c < 127: 124 if c in hex_bytes and last_was_hex: 125 out += "\"\"" 126 if c != ord('"'): 127 out += chr(c) 128 else: 129 out += "\\\"" 130 last_was_hex = False 131 else: 132 out += "\\x%02x" % c 133 last_was_hex = True 134 return out + "\"" 135 136 137# dump bytes 138if args.hex: 139 all_bytes = [] 140 for line in payload_bytes: 141 all_bytes.extend(line) 142 print '{%s}' % ', '.join('0x%02x' % c for c in all_bytes) 143else: 144 for line in payload_bytes: 145 print esc_c(line) 146