Flesh out tests, clean up

Author: libumem

qiling/os/posix/const.py

@@ -1083,3 +1083,4 @@ class qnx_mmap_prot_flags(QlPrettyFlag):
 EPOLLWAKEUP = 1 << 29
 EPOLLONESHOT = 1 << 30
 EPOLLET = 1 << 31
+EPOLL_CLOEXEC = 0x02000000

qiling/os/posix/syscall/epoll.py

@@ -1,3 +1,16 @@
+import qiling
+from qiling.const import *
+from qiling.os.posix.const import *
+from qiling.os.const import *
+from qiling.os.filestruct import ql_file
+import select
+from ctypes import *
+from qiling.os import struct
+import struct
+from qiling.os.filestruct import PersistentQlFile
+from qiling.extensions import pipe
+import sys
+
 class QlEpollObj:
     def __init__(self, epoll_object):
         self._epoll_object = epoll_object
@@ -43,9 +56,14 @@ def is_present(self, fd):
             return 0
         return 1
 
-
+'''
+Recursively checks each epoll instance's 'watched'
+fds for an instance of epoll being watched.
+If a chain of over 5 levels is detected, return
+1, which will return ELOOP in ql_epoll_wait
+'''
 def check_epoll_depth(ql_fd_list, epolls_list, depth):
-    if depth == 6:
+    if depth == 7:
         return 1
     new_epolls_list = []
     flag = 0
@@ -59,7 +77,10 @@ def check_epoll_depth(ql_fd_list, epolls_list, depth):
             check_epoll_depth(ql_fd_list, new_epolls_list, depth + 1)
     return 0
 
-
+'''
+Modify an existing epoll
+man 7 epoll for more details
+'''
 def ql_epoll_ctl(ql: qiling.Qiling, epfd: int, op: int, fd: int, event: POINTER):
     # Basic sanity checks first
     if event != 0:
@@ -152,6 +173,10 @@ def ql_epoll_ctl(ql: qiling.Qiling, epfd: int, op: int, fd: int, event: POINTER)
     return 0
 
 
+'''
+Wait on an existing epoll for events specified
+earlier. man 7 epoll_wait for more info
+'''
 def ql_epoll_wait(
     ql: qiling.Qiling, epfd: int, epoll_events: POINTER, maxevents: int, timeout: int
 ):
@@ -203,8 +228,6 @@ def ql_epoll_wait(
 Use select.epoll for underlying implementation,
 just as select.poll is used for emulating poll()
 """
-
-
 def ql_epoll_create1(ql: qiling.Qiling, flags: int):
     if flags != select.EPOLL_CLOEXEC and flags != 0:
         return EINVAL
@@ -217,16 +240,13 @@ def ql_epoll_create1(ql: qiling.Qiling, flags: int):
 
 """
 Almost identical to above, but can't simply wrap
-because of the slightly different args and the different
-syscall number
+because of the slightly different prototype
 """
-
-
 def ql_epoll_create(ql: qiling.Qiling, size: int):
     if size < 0:
         return EINVAL
     ret = select.epoll(sizehint=size, flags=0)
     fd = ret.fileno()
     ql_obj = QlEpollObj(ret)
     ql.os.fd[fd] = ql_obj
-    return fd
+    return fd

tests/test_elf.py

@@ -9,8 +9,9 @@
 import os
 import io
 import re
-
+import socket
 import sys
+import time
 sys.path.append("..")
 
 from typing import Any, Sequence
@@ -771,17 +772,45 @@ def test_elf_linux_x8664_path_traversion(self):
         del ql
 
     def test_elf_linux_x8664_epoll_simple(self):
-        # TODO: Get the example in rootfs
+        # TODO: Get the example in rootfs, see https://github.com/qilingframework/rootfs/pull/35
+        # epoll-0 source: https://github.com/maxasm/epoll-c/blob/main/main.c
         rootfs = "../examples/rootfs/x8664_linux"
-        argv = r"../examples/rootfs/x8664_linux/epoll-0".split()
+        argv = r"../examples/rootfs/x8664_linux/bin/epoll-0".split()
         ql = qiling.Qiling(argv, rootfs, verbose=QL_VERBOSE.DEBUG)
-        ql.os.stdin = pipe.SimpleInStream(0)
-        ql.os.stdin.write(b"stop\n")
+        ql.os.stdin = pipe.InteractiveInStream(0)
+        ql.os.stdin.write(b'echo\n')
+        ql.os.stdin.write(b"stop\n") # signal to exit gracefully
         ql.run()
+        self.assertIn("echo", ql.os.stdout.read().decode("utf-8"))
         del ql
-
     def test_elf_linux_x8664_epoll_server(self):
-        pass
+        # TODO: https://github.com/qilingframework/rootfs/pull/35 must be merged
+        # Source for onestraw server: https://github.com/onestraw/epoll-example
+        # with a slight change to exit after the first request
+        def client():
+            time.sleep(3) # give time for the server to listen
+            s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            dest = ("127.0.0.1", 8000)
+            try:
+                s.connect(dest)
+            except Exception as e:
+                ql.log.debug('test failed')
+                ql.log.debug(e)
+
+            test = b"hello world"
+            s.send(test)
+            s.close()
+        # use threads here to test how the server
+        # handles the request
+        client_thread = threading.Thread(target=client, daemon=True)
+        client_thread.start()
+        rootfs = "../examples/rootfs/"
+        argv = r"../examples/rootfs/x8664_linux/bin/onestraw-server s".split() # s means 'server mode'
+        ql = qiling.Qiling(argv, rootfs, multithread=False, verbose=QL_VERBOSE.DEBUG)
+        ql.os.stdout = pipe.SimpleOutStream(1) # server prints data received to stdout
+        ql.filter = '^data:'
+        ql.run()
+        self.assertIn('hello world', ql.os.stdout.read().decode("utf-8"))
         del ql
 if __name__ == "__main__":
     unittest.main()

tests/test_elf_multithread.py

@@ -6,7 +6,6 @@
 import http.client
 import platform
 import re
-import socket
 import sys
 import os
 import threading
@@ -636,6 +635,5 @@ def picohttpd():
         feedback = response.read()
         self.assertEqual('httpd_test_successful', feedback.decode())
 
-
 if __name__ == "__main__":
     unittest.main()