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Cleanup parser and add documentation

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This commit is contained in:
Arthur Bols
2021-03-27 16:58:48 +01:00
parent 3615c56152
commit ff32ce9b39
2 changed files with 33 additions and 141 deletions
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172
httplib/parser.py
View File

@@ -1,23 +1,18 @@
import logging
import os.path
import re
import urllib
from urllib.parse import urlparse, urlsplit
from httplib.exceptions import InvalidStatusLine, InvalidResponse, BadRequest, InvalidRequestLine
from httplib.httpsocket import HTTPSocket
def _get_start_line(client: HTTPSocket):
line = client.read_line().strip()
split = list(filter(None, line.split(" ", 2)))
if len(split) < 3:
raise InvalidStatusLine(line) # TODO fix exception
return line, split
def _is_valid_http_version(http_version: str):
"""
Returns True if the specified HTTP-version is valid.
@param http_version: the string to be checked
@return: True if the specified HTTP-version is valid.
"""
if len(http_version) < 8 or http_version[4] != "/":
return False
@@ -28,26 +23,19 @@ def _is_valid_http_version(http_version: str):
return True
def get_status_line(client: HTTPSocket):
line, (http_version, status, reason) = _get_start_line(client)
if not _is_valid_http_version(http_version):
raise InvalidStatusLine(line)
version = http_version[:4]
if not re.match(r"\d{3}", status):
raise InvalidStatusLine(line)
status = int(status)
if status < 100 or status > 999:
raise InvalidStatusLine(line)
return version, status, reason
def parse_status_line(line: str):
"""
Parses the specified line as an HTTP status-line.
@param line: the status-line to be parsed
@raise InvalidStatusLine: if the line couldn't be parsed, if the HTTP-version is invalid or if the status code
is invalid
@return: tuple of the HTTP-version, status and reason
"""
split = list(filter(None, line.strip().split(" ", 2)))
if len(split) < 3:
raise InvalidStatusLine(line) # TODO fix exception
raise InvalidStatusLine(line)
http_version, status, reason = split
@@ -65,122 +53,35 @@ def parse_status_line(line: str):
def parse_request_line(line: str):
"""
Parses the specified line as and HTTP request-line.
Returns the method, target as ParseResult and HTTP version from the request-line.
@param line: the request-line to be parsed
@raise InvalidRequestLine: if the line couldn't be parsed.
@raise BadRequest: Invalid HTTP method, Invalid HTTP-version or Invalid target
@return: tuple of the method, target and HTTP-version
"""
split = list(filter(None, line.rstrip().split(" ", 2)))
if len(split) < 3:
raise InvalidRequestLine(line)
method, target, version = split
if method not in ("CONNECT", "DELETE", "GET", "HEAD", "OPTIONS", "POST", "PUT", "TRACE"):
raise BadRequest()
raise BadRequest(f"Invalid method: {method}")
if not _is_valid_http_version(version):
logging.debug("[ABRT] request: invalid http-version=%r", version)
raise BadRequest()
raise BadRequest(f"Invalid HTTP-version: {version}")
if len(target) == "":
raise BadRequest()
parsed_target = urlparse(target)
if len(parsed_target.path) > 0 and parsed_target.path[0] != "/" and parsed_target.netloc != "":
parsed_target = urlparse(f"//{target}")
parsed_target = urlsplit(target)
return method, parsed_target, version.split("/")[1]
def retrieve_headers(client: HTTPSocket):
raw_headers = []
# first header after the status-line may not contain a space
while True:
line = client.read_line()
if line[0].isspace():
continue
else:
break
while True:
if line in ("\r\n", "\n", " "):
break
if line[0].isspace():
raw_headers[-1] = raw_headers[-1].rstrip("\r\n")
raw_headers.append(line.lstrip())
line = client.read_line()
result = []
header_str = "".join(raw_headers)
for line in header_str.splitlines():
pos = line.find(":")
if pos <= 0 or pos >= len(line) - 1:
continue
(header, value) = line.split(":", 1)
result.append((header.lower(), value.strip().lower()))
return result
def parse_request_headers(client: HTTPSocket):
raw_headers = retrieve_headers(client)
logging.debug("Received headers: %r", raw_headers)
headers = {}
key: str
for (key, value) in raw_headers:
if any((c.isspace()) for c in key):
raise BadRequest()
if key == "content-length":
if key in headers:
logging.error("Multiple content-length headers specified")
raise BadRequest()
if not value.isnumeric() or int(value) <= 0:
logging.error("Invalid content-length value: %r", value)
raise BadRequest()
elif key == "host":
if value != client.host and value != client.host.split(":")[0] or key in headers:
raise BadRequest()
headers[key] = value
return headers
def get_headers(client: HTTPSocket):
headers = []
# first header after the status-line may not start with a space
while True:
line = client.read_line()
if line[0].isspace():
continue
else:
break
while True:
if line in ("\r\n", "\n", " "):
break
if line[0].isspace():
headers[-1] = headers[-1].rstrip("\r\n")
headers.append(line.lstrip())
line = client.read_line()
result = {}
header_str = "".join(headers)
for line in header_str.splitlines():
pos = line.find(":")
if pos <= 0 or pos >= len(line) - 1:
continue
(header, value) = map(str.strip, line.split(":", 1))
check_next_header(result, header, value)
result[header.lower()] = value.lower()
return result
def parse_headers(lines):
headers = []
@@ -269,17 +170,8 @@ def get_uri(url: str):
return result
def base_url(uri: str):
parsed = urlsplit(uri)
path = parsed.path.rsplit("/", 1)[0]
return f"{parsed.scheme}://{parsed.hostname}{path}/"
def absolute_url(uri: str, rel_path: str):
parsed = urlsplit(uri)
path = os.path.normpath(os.path.join(parsed.path, rel_path))
return f"{parsed.scheme}://{parsed.hostname}{path}"
def urljoin(base, url):
"""
Join a base url and a URL to form a absolute url.
"""
return urllib.parse.urljoin(base, url)

2
server/requesthandler.py
View File

@@ -120,4 +120,4 @@ class RequestHandler:
message += "\r\n"
logging.debug("Sending: %r", message)
client.sendall(message.encode(FORMAT))
client.sendall(message.encode(FORMAT))