Fix attaching to a gdbserver with tuple gdb.attach(('0.0.0.0',12345)) (#2291)

* Patch for #issues/2290

* Return listening process on `pidof(("0.0.0.0", 1234))`

Instead of returning the process which is connected to port 1234,
return the process which is listening on that port.

* Update CHANGELOG

---------

Co-authored-by: Peace-Maker <[email protected]>

Author: ckxckx

CHANGELOG.md

@@ -84,6 +84,7 @@ The table below shows which release corresponds to each branch, and what date th
 - [#2482][2482] Throw error when using `sni` and setting `server_hostname` manually in `remote`
 - [#2478][2478] libcdb-cli: add `--offline-only`, refactor unstrip and add fetch parser for download libc-database
 - [#2484][2484] Allow to disable caching
+- [#2291][2291] Fix attaching to a gdbserver with tuple `gdb.attach(('0.0.0.0',12345))`
 
 [2471]: https://github.com/Gallopsled/pwntools/pull/2471
 [2358]: https://github.com/Gallopsled/pwntools/pull/2358
@@ -96,6 +97,7 @@ The table below shows which release corresponds to each branch, and what date th
 [2482]: https://github.com/Gallopsled/pwntools/pull/2482
 [2478]: https://github.com/Gallopsled/pwntools/pull/2478
 [2484]: https://github.com/Gallopsled/pwntools/pull/2484
+[2291]: https://github.com/Gallopsled/pwntools/pull/2291
 
 ## 4.14.0 (`beta`)
 

pwnlib/gdb.py

@@ -950,6 +950,8 @@ def attach(target, gdbscript = '', exe = None, gdb_args = None, ssh = None, sysr
             Process name.  The youngest process is selected.
         :obj:`tuple`
             Host, port pair of a listening ``gdbserver``
+            Tries to look up the target exe from the ``gdbserver`` commandline,
+            requires explicit ``exe`` argument if the target exe is not in the commandline.
         :class:`.process`
             Process to connect to
         :class:`.sock`
@@ -1034,6 +1036,30 @@ def attach(target, gdbscript = '', exe = None, gdb_args = None, ssh = None, sysr
         >>> io.sendline(b'echo Hello from bash && exit')
         >>> io.recvall()
         b'Hello from bash\n'
+        >>> server.close()
+
+        Attach to a gdbserver / gdbstub running on the local machine
+        by specifying the host and port tuple it is listening on.
+        (gdbserver always listens on 0.0.0.0)
+
+        >>> gdbserver = process(['gdbserver', '1.2.3.4:12345', '/bin/bash'])
+        >>> gdbserver.recvline_contains(b'Listening on port', timeout=10)
+        b'Listening on port 12345'
+        >>> pid = gdb.attach(('0.0.0.0', 12345), gdbscript='''
+        ... tbreak main
+        ... commands
+        ... call puts("Hello from gdbserver debugger!")
+        ... continue
+        ... end
+        ... ''')
+        >>> gdbserver.recvline(timeout=10)  # doctest: +ELLIPSIS
+        b'Remote debugging from host 127.0.0.1, ...\n'
+        >>> gdbserver.recvline(timeout=10)
+        b'Hello from gdbserver debugger!\n'
+        >>> gdbserver.sendline(b'echo Hello from bash && exit')
+        >>> gdbserver.recvline(timeout=10)
+        b'Hello from bash\n'
+        >>> gdbserver.close()
 
         Attach to processes running on a remote machine via an SSH :class:`.ssh` process
 

pwnlib/util/net.py

@@ -259,17 +259,17 @@ def sockinfos(addr, f, t):
                 infos |= set(socket.getaddrinfo(sockaddr[0], sockaddr[1], socket.AF_INET6, t, proto, socket.AI_V4MAPPED))
         return infos
 
-    if local is not None:
-        local = sockinfos(local, fam, typ)
-    remote = sockinfos(remote, fam, typ)
+    local = sockinfos(local, fam, typ)
+    if remote is not None:
+        remote = sockinfos(remote, fam, typ)
 
     def match(c):
         laddrs = sockinfos(c.laddr, c.family, c.type)
         raddrs = sockinfos(c.raddr, c.family, c.type)
-        if not (raddrs & remote):
+        if not (laddrs & local):
             return False
-        if local is None:
+        if remote is None:
             return True
-        return bool(laddrs & local)
+        return bool(raddrs & remote)
 
     return match

pwnlib/util/proc.py

@@ -27,6 +27,11 @@ def pidof(target):
     - :class:`pwnlib.tubes.sock.sock`: singleton list of the PID at the
       remote end of `target` if it is running on the host.  Otherwise an
       empty list.
+    - :class:`pwnlib.tubes.ssh.ssh_channel`: singleton list of the PID of
+      `target` on the remote system.
+    - :class:`tuple`: singleton list of the PID at the local end of the
+        connection to `target` if it is running on the host.  Otherwise an
+        empty list.
 
     Arguments:
         target(object):  The target whose PID(s) to find.
@@ -38,7 +43,7 @@ def pidof(target):
 
         >>> l = tubes.listen.listen()
         >>> p = process(['curl', '-s', 'http://127.0.0.1:%d'%l.lport])
-        >>> pidof(p) == pidof(l) == pidof(('127.0.0.1', l.lport))
+        >>> pidof(p) == pidof(l) == pidof(('127.0.0.1', l.rport))
         True
     """
     if isinstance(target, tubes.ssh.ssh_channel):
@@ -51,7 +56,7 @@ def pidof(target):
         return [c.pid for c in psutil.net_connections() if match(c)]
 
     elif isinstance(target, tuple):
-        match = sock_match(None, target)
+        match = sock_match(target, None)
         return [c.pid for c in psutil.net_connections() if match(c)]
 
     elif isinstance(target, tubes.process.process):