"""HTTP server base class.
Note: the class in this module doesn't implement any HTTP request; see
SimpleHTTPServer for simple implementations of GET, HEAD and POST
(including CGI scripts). It does, however, optionally implement HTTP/1.1
persistent connections, as of version 0.3.
- BaseHTTPRequestHandler: HTTP request handler base class
- log requests even later (to capture byte count)
- log user-agent header and other interesting goodies
- send error log to separate file
# HTTP Working Group T. Berners-Lee
# INTERNET-DRAFT R. T. Fielding
# <draft-ietf-http-v10-spec-00.txt> H. Frystyk Nielsen
# Expires September 8, 1995 March 8, 1995
# URL: http://www.ics.uci.edu/pub/ietf/http/draft-ietf-http-v10-spec-00.txt
# Network Working Group R. Fielding
# Request for Comments: 2616 et al
# Obsoletes: 2068 June 1999
# Category: Standards Track
# URL: http://www.faqs.org/rfcs/rfc2616.html
# Here's a quote from the NCSA httpd docs about log file format.
# | The logfile format is as follows. Each line consists of:
# | host rfc931 authuser [DD/Mon/YYYY:hh:mm:ss] "request" ddd bbbb
# | host: Either the DNS name or the IP number of the remote client
# | rfc931: Any information returned by identd for this person,
# | authuser: If user sent a userid for authentication, the user name,
# | Mon: Month (calendar name)
# | hh: hour (24-hour format, the machine's timezone)
# | request: The first line of the HTTP request as sent by the client.
# | ddd: the status code returned by the server, - if not available.
# | bbbb: the total number of bytes sent,
# | *not including the HTTP/1.0 header*, - if not available
# | You can determine the name of the file accessed through request.
# (Actually, the latter is only true if you know the server configuration
# at the time the request was made!)
__all__ = ["HTTPServer", "BaseHTTPRequestHandler"]
import socket # For gethostbyaddr()
from warnings import filterwarnings, catch_warnings
filterwarnings("ignore", ".*mimetools has been removed",
# Default error message template
DEFAULT_ERROR_MESSAGE = """\
<title>Error response</title>
<p>Error code explanation: %(code)s = %(explain)s.
DEFAULT_ERROR_CONTENT_TYPE = "text/html"
return html.replace("&", "&").replace("<", "<").replace(">", ">")
class HTTPServer(SocketServer.TCPServer):
allow_reuse_address = 1 # Seems to make sense in testing environment
"""Override server_bind to store the server name."""
SocketServer.TCPServer.server_bind(self)
host, port = self.socket.getsockname()[:2]
self.server_name = socket.getfqdn(host)
class BaseHTTPRequestHandler(SocketServer.StreamRequestHandler):
"""HTTP request handler base class.
The following explanation of HTTP serves to guide you through the
code as well as to expose any misunderstandings I may have about
HTTP (so you don't need to read the code to figure out I'm wrong
HTTP (HyperText Transfer Protocol) is an extensible protocol on
top of a reliable stream transport (e.g. TCP/IP). The protocol
recognizes three parts to a request:
1. One line identifying the request type and path
2. An optional set of RFC-822-style headers
The headers and data are separated by a blank line.
The first line of the request has the form
<command> <path> <version>
where <command> is a (case-sensitive) keyword such as GET or POST,
<path> is a string containing path information for the request,
and <version> should be the string "HTTP/1.0" or "HTTP/1.1".
<path> is encoded using the URL encoding scheme (using %xx to signify
the ASCII character with hex code xx).
The specification specifies that lines are separated by CRLF but
for compatibility with the widest range of clients recommends
servers also handle LF. Similarly, whitespace in the request line
is treated sensibly (allowing multiple spaces between components
and allowing trailing whitespace).
Similarly, for output, lines ought to be separated by CRLF pairs
but most clients grok LF characters just fine.
If the first line of the request has the form
(i.e. <version> is left out) then this is assumed to be an HTTP
0.9 request; this form has no optional headers and data part and
the reply consists of just the data.
The reply form of the HTTP 1.x protocol again has three parts:
1. One line giving the response code
2. An optional set of RFC-822-style headers
Again, the headers and data are separated by a blank line.
The response code line has the form
<version> <responsecode> <responsestring>
where <version> is the protocol version ("HTTP/1.0" or "HTTP/1.1"),
<responsecode> is a 3-digit response code indicating success or
failure of the request, and <responsestring> is an optional
human-readable string explaining what the response code means.
This server parses the request and the headers, and then calls a
function specific to the request type (<command>). Specifically,
a request SPAM will be handled by a method do_SPAM(). If no
such method exists the server sends an error response to the
client. If it exists, it is called with no arguments:
Note that the request name is case sensitive (i.e. SPAM and spam
The various request details are stored in instance variables:
- client_address is the client IP address in the form (host,
- command, path and version are the broken-down request line;
- headers is an instance of mimetools.Message (or a derived
class) containing the header information;
- rfile is a file object open for reading positioned at the
start of the optional input data part;
- wfile is a file object open for writing.
IT IS IMPORTANT TO ADHERE TO THE PROTOCOL FOR WRITING!
The first thing to be written must be the response line. Then
follow 0 or more header lines, then a blank line, and then the
actual data (if any). The meaning of the header lines depends on
the command executed by the server; in most cases, when data is
returned, there should be at least one header line of the form
Content-type: <type>/<subtype>
where <type> and <subtype> should be registered MIME types,
e.g. "text/html" or "text/plain".
# The Python system version, truncated to its first component.
sys_version = "Python/" + sys.version.split()[0]
# The server software version. You may want to override this.
# The format is multiple whitespace-separated strings,
# where each string is of the form name[/version].
server_version = "BaseHTTP/" + __version__
# The default request version. This only affects responses up until
# the point where the request line is parsed, so it mainly decides what
# the client gets back when sending a malformed request line.
# Most web servers default to HTTP 0.9, i.e. don't send a status line.
default_request_version = "HTTP/0.9"
"""Parse a request (internal).
The request should be stored in self.raw_requestline; the results
are in self.command, self.path, self.request_version and
Return True for success, False for failure; on failure, an
self.command = None # set in case of error on the first line
self.request_version = version = self.default_request_version
self.close_connection = 1
requestline = self.raw_requestline
requestline = requestline.rstrip('\r\n')
self.requestline = requestline
words = requestline.split()
command, path, version = words
if version[:5] != 'HTTP/':
self.send_error(400, "Bad request version (%r)" % version)
base_version_number = version.split('/', 1)[1]
version_number = base_version_number.split(".")
# RFC 2145 section 3.1 says there can be only one "." and
# - major and minor numbers MUST be treated as
# - HTTP/2.4 is a lower version than HTTP/2.13, which in
# turn is lower than HTTP/12.3;
# - Leading zeros MUST be ignored by recipients.
if len(version_number) != 2:
version_number = int(version_number[0]), int(version_number[1])
except (ValueError, IndexError):
self.send_error(400, "Bad request version (%r)" % version)
if version_number >= (1, 1) and self.protocol_version >= "HTTP/1.1":
self.close_connection = 0
if version_number >= (2, 0):
"Invalid HTTP Version (%s)" % base_version_number)
self.close_connection = 1
"Bad HTTP/0.9 request type (%r)" % command)
self.send_error(400, "Bad request syntax (%r)" % requestline)
self.command, self.path, self.request_version = command, path, version
# Examine the headers and look for a Connection directive
self.headers = self.MessageClass(self.rfile, 0)
conntype = self.headers.get('Connection', "")
if conntype.lower() == 'close':
self.close_connection = 1
elif (conntype.lower() == 'keep-alive' and
self.protocol_version >= "HTTP/1.1"):
self.close_connection = 0
def handle_one_request(self):
"""Handle a single HTTP request.
You normally don't need to override this method; see the class
__doc__ string for information on how to handle specific HTTP
commands such as GET and POST.
self.raw_requestline = self.rfile.readline(65537)
if len(self.raw_requestline) > 65536:
self.request_version = ''
if not self.raw_requestline:
self.close_connection = 1
if not self.parse_request():
# An error code has been sent, just exit
mname = 'do_' + self.command
if not hasattr(self, mname):
self.send_error(501, "Unsupported method (%r)" % self.command)
method = getattr(self, mname)
self.wfile.flush() #actually send the response if not already done.
except socket.timeout, e:
#a read or a write timed out. Discard this connection
self.log_error("Request timed out: %r", e)
self.close_connection = 1
"""Handle multiple requests if necessary."""
self.close_connection = 1
self.handle_one_request()
while not self.close_connection:
self.handle_one_request()
def send_error(self, code, message=None):
"""Send and log an error reply.
Arguments are the error code, and a detailed message.
The detailed message defaults to the short entry matching the
This sends an error response (so it must be called before any
output has been generated), logs the error, and finally sends
a piece of HTML explaining the error to the user.
short, long = self.responses[code]
short, long = '???', '???'
self.log_error("code %d, message %s", code, message)
self.send_response(code, message)
self.send_header('Connection', 'close')
# Message body is omitted for cases described in:
# - RFC7230: 3.3. 1xx, 204(No Content), 304(Not Modified)
# - RFC7231: 6.3.6. 205(Reset Content)
if code >= 200 and code not in (204, 205, 304):
# HTML encode to prevent Cross Site Scripting attacks
content = (self.error_message_format % {
'message': _quote_html(message),
self.send_header("Content-Type", self.error_content_type)
if self.command != 'HEAD' and content:
self.wfile.write(content)
error_message_format = DEFAULT_ERROR_MESSAGE
error_content_type = DEFAULT_ERROR_CONTENT_TYPE
def send_response(self, code, message=None):
"""Send the response header and log the response code.
Also send two standard headers with the server software
version and the current date.
if code in self.responses:
message = self.responses[code][0]
if self.request_version != 'HTTP/0.9':
self.wfile.write("%s %d %s\r\n" %
(self.protocol_version, code, message))
# print (self.protocol_version, code, message)
self.send_header('Server', self.version_string())
self.send_header('Date', self.date_time_string())
def send_header(self, keyword, value):
"""Send a MIME header."""
if self.request_version != 'HTTP/0.9':
self.wfile.write("%s: %s\r\n" % (keyword, value))
if keyword.lower() == 'connection':
if value.lower() == 'close':
self.close_connection = 1
elif value.lower() == 'keep-alive':
self.close_connection = 0
"""Send the blank line ending the MIME headers."""
if self.request_version != 'HTTP/0.9':
def log_request(self, code='-', size='-'):
"""Log an accepted request.
This is called by send_response().
self.log_message('"%s" %s %s',
self.requestline, str(code), str(size))
def log_error(self, format, *args):
This is called when a request cannot be fulfilled. By
default it passes the message on to log_message().
Arguments are the same as for log_message().
XXX This should go to the separate error log.
self.log_message(format, *args)
def log_message(self, format, *args):
"""Log an arbitrary message.
This is used by all other logging functions. Override
it if you have specific logging wishes.
The first argument, FORMAT, is a format string for the
message to be logged. If the format string contains
any % escapes requiring parameters, they should be
specified as subsequent arguments (it's just like
The client ip address and current date/time are prefixed to every
sys.stderr.write("%s - - [%s] %s\n" %
self.log_date_time_string(),
def version_string(self):
"""Return the server software version string."""
return self.server_version + ' ' + self.sys_version
def date_time_string(self, timestamp=None):
"""Return the current date and time formatted for a message header."""
year, month, day, hh, mm, ss, wd, y, z = time.gmtime(timestamp)
s = "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
day, self.monthname[month], year,
def log_date_time_string(self):
"""Return the current time formatted for logging."""
year, month, day, hh, mm, ss, x, y, z = time.localtime(now)
s = "%02d/%3s/%04d %02d:%02d:%02d" % (
day, self.monthname[month], year, hh, mm, ss)
weekdayname = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
def address_string(self):