37
37
# working on smaller output
39
39
CGI_BLOCK_SIZE = 65535
40
PATH = "/usr/local/bin:/usr/bin:/bin"
42
41
def interpret_file(req, owner, jail_dir, filename, interpreter, gentle=True):
43
42
"""Serves a file by interpreting it using one of IVLE's builtin
74
73
# (Note that paths "relative" to the jail actually begin with a '/' as
75
74
# they are absolute in the jailspace)
77
return interpreter(owner, jail_dir, working_dir, filename_abs, req,
76
return interpreter(owner.unixid, jail_dir, working_dir, filename_abs, req,
90
89
self.headers = {} # Header names : values
92
def execute_cgi(interpreter, owner, jail_dir, working_dir, script_path,
91
def execute_cgi(interpreter, uid, jail_dir, working_dir, script_path,
95
94
trampoline: Full path on the local system to the CGI wrapper program
97
owner: User object of the owner of the file.
96
uid: User ID of the owner of the file.
98
97
jail_dir: Absolute path of owner's jail directory.
99
98
working_dir: Directory containing the script file relative to owner's
130
129
f.seek(0) # Rewind, for reading
132
131
# Set up the environment
133
environ = cgi_environ(req, script_path, owner)
132
# This automatically asks mod_python to load up the CGI variables into the
133
# environment (which is a good first approximation)
134
old_env = os.environ.copy()
135
for k in os.environ.keys():
137
for (k,v) in req.get_cgi_environ().items():
139
fixup_environ(req, script_path)
135
141
# usage: tramp uid jail_dir working_dir script_path
136
cmd_line = [trampoline, str(owner.unixid),
137
req.config['paths']['jails']['mounts'],
138
req.config['paths']['jails']['src'],
139
req.config['paths']['jails']['template'],
140
jail_dir, working_dir, interpreter, script_path]
141
# Popen doesn't like unicode strings. It hateses them.
142
cmd_line = [(s.encode('utf-8') if isinstance(s, unicode) else s)
144
pid = subprocess.Popen(cmd_line,
142
pid = subprocess.Popen(
143
[trampoline, str(uid), req.config['paths']['jails']['mounts'],
144
req.config['paths']['jails']['src'],
145
req.config['paths']['jails']['template'],
146
jail_dir, working_dir, interpreter, script_path],
145
147
stdin=f, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
146
cwd=tramp_dir, env=environ)
150
# Restore the environment
151
for k in os.environ.keys():
153
for (k,v) in old_env.items():
148
156
# We don't want any output! Bail out after the process terminates.
215
223
if len(split) == 1:
216
224
split = headers.split('\n', 1)
218
# If not executing in gentle mode (which presents CGI violations
219
# to users nicely), check if this an internal IVLE error
221
if not cgiflags.gentle:
222
hs = cgiflags.headers
223
if 'X-IVLE-Error-Type' in hs:
226
# Is this an internal IVLE error condition?
227
hs = cgiflags.headers
228
if 'X-IVLE-Error-Type' in hs:
229
t = hs['X-IVLE-Error-Type']
230
if t == IVLEError.__name__:
231
raise IVLEError(int(hs['X-IVLE-Error-Code']),
232
hs['X-IVLE-Error-Message'])
225
235
raise IVLEJailError(hs['X-IVLE-Error-Type'],
226
236
hs['X-IVLE-Error-Message'],
227
237
hs['X-IVLE-Error-Info'])
229
raise AssertionError("Bad error headers written by CGI.")
239
raise IVLEError(500, 'bad error headers written by CGI')
231
241
# Check to make sure the required headers were written
232
242
if cgiflags.wrote_html_warning or not cgiflags.gentle:
348
358
# python-server-page
351
def cgi_environ(req, script_path, user):
352
"""Gets CGI variables from apache and makes a few changes for security and
361
def fixup_environ(req, script_path):
362
"""Assuming os.environ has been written with the CGI variables from
363
apache, make a few changes for security and correctness.
355
365
Does not modify req, only reads it.
358
368
# Comments here are on the heavy side, explained carefully for security
359
369
# reasons. Please read carefully before making changes.
361
# This automatically asks mod_python to load up the CGI variables into the
362
# environment (which is a good first approximation)
363
for (k,v) in req.get_cgi_environ().items():
366
371
# Remove DOCUMENT_ROOT and SCRIPT_FILENAME. Not part of CGI spec and
367
372
# exposes unnecessary details about server.
410
415
env['SERVER_SOFTWARE'] = "IVLE/" + ivle.__version__
412
417
# Additional environment variables
413
username = user.login
418
username = split_path(req.path)[0]
414
419
env['HOME'] = os.path.join('/home', username)
418
421
class ExecutionError(Exception):
429
432
tramp_dir = os.path.split(tramp)[0]
431
434
# Fire up trampoline. Vroom, vroom.
432
cmd_line = [tramp, str(user.unixid), config['paths']['jails']['mounts'],
435
proc = subprocess.Popen(
436
[tramp, str(user.unixid), config['paths']['jails']['mounts'],
433
437
config['paths']['jails']['src'],
434
438
config['paths']['jails']['template'],
435
jail_dir, working_dir, binary] + args
436
# Popen doesn't like unicode strings. It hateses them.
437
cmd_line = [(s.encode('utf-8') if isinstance(s, unicode) else s)
439
proc = subprocess.Popen(cmd_line,
439
jail_dir, working_dir, binary] + args,
440
440
stdin=subprocess.PIPE, stdout=subprocess.PIPE,
441
stderr=subprocess.PIPE, cwd=tramp_dir, close_fds=True,
442
env={'HOME': os.path.join('/home', user.login),
445
'LOGNAME': user.login})
441
stderr=subprocess.PIPE, cwd=tramp_dir, close_fds=True)
447
443
(stdout, stderr) = proc.communicate()
448
444
exitcode = proc.returncode
450
446
if exitcode != 0:
451
raise ExecutionError('subprocess ended with code %d, stderr: "%s"' %
447
raise ExecutionError('subprocess ended with code %d, stderr %s' %
448
(exitcode, proc.stderr.read()))
453
449
return (stdout, stderr)
added
removed
ivle/interpret.py
