cpython/Lib/CGIHTTPServer.py
Tim Peters 27f49610af SF patch 508730 CGIHTTPServer execfile should save cwd
UNTESTED!!!

This simple two-line patch has been sitting on SF for more than 2 years.
I'm guessing it's because nobody knows how to test it -- I sure don't.
It doesn't look like you can get to this part of the code on Unixish
or Windows systems, so the "how to test it?" puzzle has more than one
part.  OTOH, if this is dead code, it doesn't matter either if I just
broke it <wink>.
2004-03-20 21:51:12 +00:00

329 lines
11 KiB
Python

"""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
import select
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')
have_popen3 = hasattr(os, 'popen3')
# 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 True
return False
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 (%r)" % scriptname)
return
if not os.path.isfile(scriptfile):
self.send_error(403, "CGI script is not a plain file (%r)" %
scriptname)
return
ispy = self.is_python(scriptname)
if not ispy:
if not (self.have_fork or self.have_popen2 or self.have_popen3):
self.send_error(403, "CGI script is not a Python script (%r)" %
scriptname)
return
if not self.is_executable(scriptfile):
self.send_error(403, "CGI script is not executable (%r)" %
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, "")
os.environ.update(env)
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.wfile.flush() # Always flush before forking
pid = os.fork()
if pid != 0:
# Parent
pid, sts = os.waitpid(pid, 0)
# throw away additional data [see bug #427345]
while select.select([self.rfile], [], [], 0)[0]:
if not self.rfile.read(1):
break
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, os.environ)
except:
self.server.handle_error(self.request, self.client_address)
os._exit(127)
elif self.have_popen2 or self.have_popen3:
# Windows -- use popen2 or popen3 to create a subprocess
import shutil
if self.have_popen3:
popenx = os.popen3
else:
popenx = os.popen2
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 (TypeError, ValueError):
nbytes = 0
files = popenx(cmdline, 'b')
fi = files[0]
fo = files[1]
if self.have_popen3:
fe = files[2]
if self.command.lower() == "post" and nbytes > 0:
data = self.rfile.read(nbytes)
fi.write(data)
# throw away additional data [see bug #427345]
while select.select([self.rfile._sock], [], [], 0)[0]:
if not self.rfile._sock.recv(1):
break
fi.close()
shutil.copyfileobj(fo, self.wfile)
if self.have_popen3:
errors = fe.read()
fe.close()
if errors:
self.log_error('%s', errors)
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
save_argv = sys.argv
save_stdin = sys.stdin
save_stdout = sys.stdout
save_stderr = sys.stderr
try:
save_cwd = os.getcwd()
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
os.chdir(save_cwd)
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 False
return st.st_mode & 0111 != 0
def test(HandlerClass = CGIHTTPRequestHandler,
ServerClass = BaseHTTPServer.HTTPServer):
SimpleHTTPServer.test(HandlerClass, ServerClass)
if __name__ == '__main__':
test()