"""CGI-savvy HTTP Server.
This module builds on SimpleHTTPServer by implementing GET and POST
requests to cgi-bin scripts.
If the os.fork() function is not present (e.g. on Windows),
os.popen2() is used as a fallback, with slightly altered semantics; if
that function is not present either (e.g. on Macintosh), only Python
scripts are supported, and they are executed by the current process.
In all cases, the implementation is intentionally naive -- all
requests are executed sychronously.
SECURITY WARNING: DON'T USE THIS CODE UNLESS YOU ARE INSIDE A FIREWALL
-- it may execute arbitrary Python code or external programs.
"""
__version__ = "0.4"
__all__ = ["CGIHTTPRequestHandler"]
import os
import sys
import urllib
import BaseHTTPServer
import SimpleHTTPServer
class CGIHTTPRequestHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
"""Complete HTTP server with GET, HEAD and POST commands.
GET and HEAD also support running CGI scripts.
The POST command is *only* implemented for CGI scripts.
"""
# Determine platform specifics
have_fork = hasattr(os, 'fork')
have_popen2 = hasattr(os, 'popen2')
# Make rfile unbuffered -- we need to read one line and then pass
# the rest to a subprocess, so we can't use buffered input.
rbufsize = 0
def do_POST(self):
"""Serve a POST request.
This is only implemented for CGI scripts.
"""
if self.is_cgi():
self.run_cgi()
else:
self.send_error(501, "Can only POST to CGI scripts")
def send_head(self):
"""Version of send_head that support CGI scripts"""
if self.is_cgi():
return self.run_cgi()
else:
return SimpleHTTPServer.SimpleHTTPRequestHandler.send_head(self)
def is_cgi(self):
"""Test whether self.path corresponds to a CGI script.
Return a tuple (dir, rest) if self.path requires running a
CGI script, None if not. Note that rest begins with a
slash if it is not empty.
The default implementation tests whether the path
begins with one of the strings in the list
self.cgi_directories (and the next character is a '/'
or the end of the string).
"""
path = self.path
for x in self.cgi_directories:
i = len(x)
if path[:i] == x and (not path[i:] or path[i] == '/'):
self.cgi_info = path[:i], path[i+1:]
return 1
return 0
cgi_directories = ['/cgi-bin', '/htbin']
def is_executable(self, path):
"""Test whether argument path is an executable file."""
return executable(path)
def is_python(self, path):
"""Test whether argument path is a Python script."""
head, tail = os.path.splitext(path)
return tail.lower() in (".py", ".pyw")
def run_cgi(self):
"""Execute a CGI script."""
dir, rest = self.cgi_info
i = rest.rfind('?')
if i >= 0:
rest, query = rest[:i], rest[i+1:]
else:
query = ''
i = rest.find('/')
if i >= 0:
script, rest = rest[:i], rest[i:]
else:
script, rest = rest, ''
scriptname = dir + '/' + script
scriptfile = self.translate_path(scriptname)
if not os.path.exists(scriptfile):
self.send_error(404, "No such CGI script (%s)" % `scriptname`)
return
if not os.path.isfile(scriptfile):
self.send_error(403, "CGI script is not a plain file (%s)" %
`scriptname`)
return
ispy = self.is_python(scriptname)
if not ispy:
if not (self.have_fork or self.have_popen2):
self.send_error(403, "CGI script is not a Python script (%s)" %
`scriptname`)
return
if not self.is_executable(scriptfile):
self.send_error(403, "CGI script is not executable (%s)" %
`scriptname`)
return
# Reference: http://hoohoo.ncsa.uiuc.edu/cgi/env.html
# XXX Much of the following could be prepared ahead of time!
env = {}
env['SERVER_SOFTWARE'] = self.version_string()
env['SERVER_NAME'] = self.server.server_name
env['GATEWAY_INTERFACE'] = 'CGI/1.1'
env['SERVER_PROTOCOL'] = self.protocol_version
env['SERVER_PORT'] = str(self.server.server_port)
env['REQUEST_METHOD'] = self.command
uqrest = urllib.unquote(rest)
env['PATH_INFO'] = uqrest
env['PATH_TRANSLATED'] = self.translate_path(uqrest)
env['SCRIPT_NAME'] = scriptname
if query:
env['QUERY_STRING'] = query
host = self.address_string()
if host != self.client_address[0]:
env['REMOTE_HOST'] = host
env['REMOTE_ADDR'] = self.client_address[0]
# XXX AUTH_TYPE
# XXX REMOTE_USER
# XXX REMOTE_IDENT
if self.headers.typeheader is None:
env['CONTENT_TYPE'] = self.headers.type
else:
env['CONTENT_TYPE'] = self.headers.typeheader
length = self.headers.getheader('content-length')
if length:
env['CONTENT_LENGTH'] = length
accept = []
for line in self.headers.getallmatchingheaders('accept'):
if line[:1] in "\t\n\r ":
accept.append(line.strip())
else:
accept = accept + line[7:].split(',')
env['HTTP_ACCEPT'] = ','.join(accept)
ua = self.headers.getheader('user-agent')
if ua:
env['HTTP_USER_AGENT'] = ua
co = filter(None, self.headers.getheaders('cookie'))
if co:
env['HTTP_COOKIE'] = ', '.join(co)
# XXX Other HTTP_* headers
if not self.have_fork:
# Since we're setting the env in the parent, provide empty
# values to override previously set values
for k in ('QUERY_STRING', 'REMOTE_HOST', 'CONTENT_LENGTH',
'HTTP_USER_AGENT', 'HTTP_COOKIE'):
env.setdefault(k, "")
self.send_response(200, "Script output follows")
decoded_query = query.replace('+', ' ')
if self.have_fork:
# Unix -- fork as we should
args = [script]
if '=' not in decoded_query:
args.append(decoded_query)
nobody = nobody_uid()
self.rfile.flush() # Always flush before forking
self.wfile.flush() # Always flush before forking
pid = os.fork()
if pid != 0:
# Parent
pid, sts = os.waitpid(pid, 0)
if sts:
self.log_error("CGI script exit status %#x", sts)
return
# Child
try:
try:
os.setuid(nobody)
except os.error:
pass
os.dup2(self.rfile.fileno(), 0)
os.dup2(self.wfile.fileno(), 1)
os.execve(scriptfile, args, env)
except:
self.server.handle_error(self.request, self.client_address)
os._exit(127)
elif self.have_popen2:
# Windows -- use popen2 to create a subprocess
import shutil
os.environ.update(env)
cmdline = scriptfile
if self.is_python(scriptfile):
interp = sys.executable
if interp.lower().endswith("w.exe"):
# On Windows, use python.exe, not pythonw.exe
interp = interp[:-5] + interp[-4:]
cmdline = "%s -u %s" % (interp, cmdline)
if '=' not in query and '"' not in query:
cmdline = '%s "%s"' % (cmdline, query)
self.log_message("command: %s", cmdline)
try:
nbytes = int(length)
except:
nbytes = 0
fi, fo = os.popen2(cmdline, 'b')
if self.command.lower() == "post" and nbytes > 0:
data = self.rfile.read(nbytes)
fi.write(data)
fi.close()
shutil.copyfileobj(fo, self.wfile)
sts = fo.close()
if sts:
self.log_error("CGI script exit status %#x", sts)
else:
self.log_message("CGI script exited OK")
else:
# Other O.S. -- execute script in this process
os.environ.update(env)
save_argv = sys.argv
save_stdin = sys.stdin
save_stdout = sys.stdout
save_stderr = sys.stderr
try:
try:
sys.argv = [scriptfile]
if '=' not in decoded_query:
sys.argv.append(decoded_query)
sys.stdout = self.wfile
sys.stdin = self.rfile
execfile(scriptfile, {"__name__": "__main__"})
finally:
sys.argv = save_argv
sys.stdin = save_stdin
sys.stdout = save_stdout
sys.stderr = save_stderr
except SystemExit, sts:
self.log_error("CGI script exit status %s", str(sts))
else:
self.log_message("CGI script exited OK")
nobody = None
def nobody_uid():
"""Internal routine to get nobody's uid"""
global nobody
if nobody:
return nobody
try:
import pwd
except ImportError:
return -1
try:
nobody = pwd.getpwnam('nobody')[2]
except KeyError:
nobody = 1 + max(map(lambda x: x[2], pwd.getpwall()))
return nobody
def executable(path):
"""Test for executable file."""
try:
st = os.stat(path)
except os.error:
return 0
return st[0] & 0111 != 0
def test(HandlerClass = CGIHTTPRequestHandler,
ServerClass = BaseHTTPServer.HTTPServer):
SimpleHTTPServer.test(HandlerClass, ServerClass)
if __name__ == '__main__':
test()
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