Files
CN2021/client.py
2021-03-15 18:54:57 +01:00

173 lines
4.6 KiB
Python

#!/usr/bin/env python3
import argparse
import logging
import sys
import socket
import re
FORMAT = 'utf-8'
BUFSIZE = 4096
def receive_bytes_chunk(client: socket.socket):
buffering = True
buffer = b''
while buffering:
received = client.recv(BUFSIZE)
received_size = len(received)
logging.debug("Received size: %s", received_size)
logging.debug("Received: %r", received)
def receive_bytes(client: socket.socket):
buffering = True
buffer = b''
while buffering:
received = client.recv(BUFSIZE)
received_size = len(received)
logging.debug("Received size: %s", received_size)
logging.debug("Received: %r", received)
if received_size < BUFSIZE:
buffering = False
buffer += received
lf_pos = buffer.find(b"\n\n")
crlf_pos = buffer.find(b"\r\n\r\n")
if lf_pos != -1 and lf_pos < crlf_pos:
buffer_split = buffer.split(b"\n\n")
else:
buffer_split = buffer.split(b"\r\n\r\n")
buffer = buffer_split[-1]
for part in buffer_split[:-1]:
yield part + b"\r\n\r\n"
if buffer:
buffering = True
if buffer:
yield buffer
def parse_header(data: bytes):
headers = {}
# decode bytes, split into lines and filter
header_split = list(
filter(lambda l: l is not "" and not l[0].isspace(), map(str.strip, data.decode("utf-8").split("\n"))))
if len(header_split) == 0:
raise Exception("No start-line")
start_line = header_split.pop(0)
logging.debug("start-line: %r", start_line)
for line in header_split:
pos = line.find(":")
if pos <= 0 or pos >= len(line) - 1:
continue
(header, value) = map(str.strip, line.split(":", 1))
headers[header.upper()] = value
logging.debug("Parsed headers: %r", headers)
return start_line, headers
def validate_status_line(status_line: str):
split = list(filter(None, status_line.split(" ")))
if len(split) < 3:
return False
# Check HTTP version
http_version = split.pop(0)
if len(http_version) < 8 or http_version[4] != "/":
return False
(name, version) = http_version[:4], http_version[5:]
if name != "HTTP" or not re.match(r"1\.[0|1]", version):
return False
if not re.match(r"\d{3}", split[0]):
return False
return True
def http_parser(client: socket.socket):
headers = {}
start_line = ""
receiver = receive_bytes(client)
(status_line, headers) = parse_header(next(receiver))
if not validate_status_line(status_line):
raise Exception("Invalid header")
logging.debug("valid status-line: %r", status_line)
for chunk in receiver:
logging.debug("chunk: %r", chunk)
def main():
parser = argparse.ArgumentParser(description='HTTP Client')
parser.add_argument("--verbose", "-v", action='count', default=0, help="Increase verbosity level of logging")
parser.add_argument("--command", "-c", help="HEAD, GET, PUT or POST", default="GET")
parser.add_argument("--port", "-p", help="The port used to connect with the server", default=80)
parser.add_argument("URI", help="The URI to connect to")
arguments = parser.parse_args()
logging.basicConfig(level=logging.ERROR - (10 * arguments.verbose))
logging.debug("Arguments: %s", arguments)
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect((arguments.URI, arguments.port))
message = "GET / HTTP/1.1\r\nHost: www.google.com:80\r\n\r\n".encode(FORMAT)
client.sendall(message)
http_parser(client)
# tmp = b''
# keep = False
# count = 0
# for line in receive_bytes(client):
#
# if count > 0:
# tmp += line.rstrip(b"\r\n")
# if keep:
# count += 1
#
# if line == b'\r\n':
# keep = True
#
# logging.debug('end of part 1')
#
# logging.debug("attempt 2")
# while True:
# logging.debug("attempt")
# keep = False
# for line in receive_bytes(client):
# if line == b"0\r\n":
# break
# if keep:
# tmp += line.rstrip(b"\r\n")
# keep = True
#
# if b"0\r\n" == line:
# break
# logging.debug("content: %s", tmp)
# # logging.debug("content: %r", tmp.replace(b"\r\n", b"").decode("utf-8"))
#
# f = open("test.jpeg", "wb")
# f.write(tmp)
try:
main()
except Exception as e:
print("[ABRT] Internal error: " + str(e), file=sys.stderr)
logging.debug("Internal error", exc_info=e)
sys.exit(70)