esgd/esgd.py

103 lines
2.8 KiB
Python

import socketserver
import subprocess
import os
class GopherError(BaseException): pass
class RequestError(GopherError): pass
print(os.getcwd())
def recieveRequest(context):
data = b''
while data[-2:] != b'\r\n':
data += context.request.recv(1)
decoded = data[:-2].decode('utf-8')
return decoded
def requestParser(request):
if '..' in request: raise RequestError
try:
if request[0] == '/': request = request[1:]
except IndexError: pass
request = request.replace('?', '\t').split('\t')
try: return (request[0], request[1])
except IndexError: return (request[0], "")
def returnRelative(file):
gph = False
if file == "":
ret = "gophermap"
gph = True
elif os.path.isdir(file):
ret = file + "/gophermap"
gph = True
elif os.path.isfile(file): ret = file
else: raise RequestError('unreachable state')
return (ret, gph)
def fileSendable(file): return os.access(file, os.F_OK|os.R_OK)
def fileCGI(file):
return os.access(file, os.F_OK|os.R_OK|os.X_OK)
def notFound(context):
context.request.sendall(b"3error: file not found!\r\n.\r\n")
def invalid(context):
context.request.sendall(b"3error: selector contains '..'!\r\n.\r\n")
def sendFile(file, context):
with open(file, "r") as fd:
[context.request.sendall(
(i.rstrip() + "\r\n").encode("utf-8")
) for i in fd.readlines()]
context.request.sendall(b".\r\n")
def cgi(file, query, context):
env = {}
env['QUERY_STRING'] = query
env['SCRIPT_NAME'] = "/" + file
env['REMOTE_ADDR'] = context.client_address[0]
proc = subprocess.Popen(
[os.getcwd() + "/" + file],
stdout = subprocess.PIPE,
env = env
)
try: out, err = proc.communicate(timeout=10)
except TimeoutExpired:
proc.kill()
out, err = proc.communicate()
return out.decode('utf-8').replace('\r', '').split('\n')
class gopherHandler(socketserver.BaseRequestHandler):
def handle(self):
decoded = recieveRequest(self)
try:
parsed = requestParser(decoded)
except RequestError:
invalid(self)
return
print(self.client_address)
try: file = returnRelative(parsed[0])
except RequestError:
notFound(self)
return
if fileCGI(file[0]):
ret = cgi(file[0], parsed[1], self)
for i in ret:
self.request.sendall((i + '\r\n').encode('utf-8'))
self.request.sendall(b'.\r\n')
elif fileSendable(file[0]): sendFile(file[0], self)
else: notFound(self)
if __name__ == "__main__":
HOST, PORT = "localhost", 72
with socketserver.TCPServer((HOST, PORT), gopherHandler) as server:
server.serve_forever()