/usr/lib/python2.7/CGIHTTPServer.py is in libpython2.7-stdlib 2.7.11-7ubuntu1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 | """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.
Note that status code 200 is sent prior to execution of a CGI script, so
scripts cannot send other status codes such as 302 (redirect).
"""
__version__ = "0.4"
__all__ = ["CGIHTTPRequestHandler"]
import os
import sys
import urllib
import BaseHTTPServer
import SimpleHTTPServer
import select
import copy
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.
Returns True and updates the cgi_info attribute to the tuple
(dir, rest) if self.path requires running a CGI script.
Returns False otherwise.
If any exception is raised, the caller should assume that
self.path was rejected as invalid and act accordingly.
The default implementation tests whether the normalized url
path begins with one of the strings in self.cgi_directories
(and the next character is a '/' or the end of the string).
"""
collapsed_path = _url_collapse_path(self.path)
dir_sep = collapsed_path.find('/', 1)
head, tail = collapsed_path[:dir_sep], collapsed_path[dir_sep+1:]
if head in self.cgi_directories:
self.cgi_info = head, tail
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
path = dir + '/' + rest
i = path.find('/', len(dir)+1)
while i >= 0:
nextdir = path[:i]
nextrest = path[i+1:]
scriptdir = self.translate_path(nextdir)
if os.path.isdir(scriptdir):
dir, rest = nextdir, nextrest
i = path.find('/', len(dir)+1)
else:
break
# find an explicit query string, if present.
rest, _, query = rest.partition('?')
# dissect the part after the directory name into a script name &
# a possible additional path, to be stored in PATH_INFO.
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 = copy.deepcopy(os.environ)
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]
authorization = self.headers.getheader("authorization")
if authorization:
authorization = authorization.split()
if len(authorization) == 2:
import base64, binascii
env['AUTH_TYPE'] = authorization[0]
if authorization[0].lower() == "basic":
try:
authorization = base64.decodestring(authorization[1])
except binascii.Error:
pass
else:
authorization = authorization.split(':')
if len(authorization) == 2:
env['REMOTE_USER'] = authorization[0]
# 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
referer = self.headers.getheader('referer')
if referer:
env['HTTP_REFERER'] = referer
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
# 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', 'HTTP_REFERER'):
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.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, env)
except:
self.server.handle_error(self.request, self.client_address)
os._exit(127)
else:
# Non Unix - use subprocess
import subprocess
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 = [interp, '-u'] + cmdline
if '=' not in query:
cmdline.append(query)
self.log_message("command: %s", subprocess.list2cmdline(cmdline))
try:
nbytes = int(length)
except (TypeError, ValueError):
nbytes = 0
p = subprocess.Popen(cmdline,
stdin = subprocess.PIPE,
stdout = subprocess.PIPE,
stderr = subprocess.PIPE,
env = env
)
if self.command.lower() == "post" and nbytes > 0:
data = self.rfile.read(nbytes)
else:
data = None
# throw away additional data [see bug #427345]
while select.select([self.rfile._sock], [], [], 0)[0]:
if not self.rfile._sock.recv(1):
break
stdout, stderr = p.communicate(data)
self.wfile.write(stdout)
if stderr:
self.log_error('%s', stderr)
p.stderr.close()
p.stdout.close()
status = p.returncode
if status:
self.log_error("CGI script exit status %#x", status)
else:
self.log_message("CGI script exited OK")
def _url_collapse_path(path):
"""
Given a URL path, remove extra '/'s and '.' path elements and collapse
any '..' references and returns a colllapsed path.
Implements something akin to RFC-2396 5.2 step 6 to parse relative paths.
The utility of this function is limited to is_cgi method and helps
preventing some security attacks.
Returns: The reconstituted URL, which will always start with a '/'.
Raises: IndexError if too many '..' occur within the path.
"""
# Query component should not be involved.
path, _, query = path.partition('?')
path = urllib.unquote(path)
# Similar to os.path.split(os.path.normpath(path)) but specific to URL
# path semantics rather than local operating system semantics.
path_parts = path.split('/')
head_parts = []
for part in path_parts[:-1]:
if part == '..':
head_parts.pop() # IndexError if more '..' than prior parts
elif part and part != '.':
head_parts.append( part )
if path_parts:
tail_part = path_parts.pop()
if tail_part:
if tail_part == '..':
head_parts.pop()
tail_part = ''
elif tail_part == '.':
tail_part = ''
else:
tail_part = ''
if query:
tail_part = '?'.join((tail_part, query))
splitpath = ('/' + '/'.join(head_parts), tail_part)
collapsed_path = "/".join(splitpath)
return collapsed_path
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()
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