FDlucifer
diff --git a/‎README.rst
Lines changed: 76 additions & 24 deletions b/‎README.rst
Lines changed: 76 additions & 24 deletions
diff --git a/‎netfilterqueue.pxd
Lines changed: 1 addition & 2 deletions b/‎netfilterqueue.pxd
Lines changed: 1 addition & 2 deletions
diff --git a/‎netfilterqueue.pyx
Lines changed: 24 additions & 36 deletions b/‎netfilterqueue.pyx
Lines changed: 24 additions & 36 deletions
@@ -90,21 +90,17 @@ To install from source::
 API
 ===
 
-``NetfilterQueue.COPY_NONE``
-
-``NetfilterQueue.COPY_META``
-
-``NetfilterQueue.COPY_PACKET``
+``NetfilterQueue.COPY_NONE``, ``NetfilterQueue.COPY_META``, ``NetfilterQueue.COPY_PACKET``
     These constants specify how much of the packet should be given to the
-    script- nothing, metadata, or the whole packet.
+    script: nothing, metadata, or the whole packet.
 
 NetfilterQueue objects
 ----------------------
 
 A NetfilterQueue object represents a single queue. Configure your queue with
 a call to ``bind``, then start receiving packets with a call to ``run``.
 
-``QueueHandler.bind(queue_num, callback[, max_len[, mode[, range[, sock_len]]]])``
+``NetfilterQueue.bind(queue_num, callback, max_len=1024, mode=COPY_PACKET, range=65535, sock_len=...)``
     Create and bind to the queue. ``queue_num`` uniquely identifies this
     queue for the kernel. It must match the ``--queue-num`` in your iptables
     rule, but there is no ordering requirement: it's fine to either ``bind()``
@@ -118,22 +114,23 @@ a call to ``bind``, then start receiving packets with a call to ``run``.
     the source and destination IPs of a IPv4 packet, ``range`` could be 20.
     ``sock_len`` sets the receive socket buffer size.
 
-``QueueHandler.unbind()``
+``NetfilterQueue.unbind()``
     Remove the queue. Packets matched by your iptables rule will be dropped.
 
-``QueueHandler.get_fd()``
+``NetfilterQueue.get_fd()``
     Get the file descriptor of the socket used to receive queued
     packets and send verdicts. If you're using an async event loop,
     you can poll this FD for readability and call ``run(False)`` every
     time data appears on it.
 
-``QueueHandler.run([block])``
+``NetfilterQueue.run(block=True)``
     Send packets to your callback. By default, this method blocks, running
     until an exception is raised (such as by Ctrl+C). Set
-    block=False to process the pending messages without waiting for more.
-    You can get the file descriptor of the socket with the ``get_fd`` method.
+    ``block=False`` to process the pending messages without waiting for more;
+    in conjunction with the ``get_fd`` method, you can use this to integrate
+    with async event loops.
 
-``QueueHandler.run_socket(socket)``
+``NetfilterQueue.run_socket(socket)``
     Send packets to your callback, but use the supplied socket instead of
     recv, so that, for example, gevent can monkeypatch it. You can make a
     socket with ``socket.fromfd(nfqueue.get_fd(), socket.AF_NETLINK, socket.SOCK_RAW)``
@@ -148,6 +145,8 @@ Objects of this type are passed to your callback.
     Return the packet's payload as a bytes object. The returned value
     starts with the IP header. You must call ``retain()`` if you want
     to be able to ``get_payload()`` after your callback has returned.
+    If you have already called ``set_payload()``, then ``get_payload()``
+    returns what you passed to ``set_payload()``.
 
 ``Packet.set_payload(payload)``
     Set the packet payload. Call this before ``accept()`` if you want to
@@ -166,12 +165,46 @@ Objects of this type are passed to your callback.
     rules. ``mark`` is a 32-bit number.
 
 ``Packet.get_mark()``
-    Get the mark already on the packet (either the one you set using
+    Get the mark on the packet (either the one you set using
     ``set_mark()``, or the one it arrived with if you haven't called
     ``set_mark()``).
 
 ``Packet.get_hw()``
-    Return the hardware address as a Python string.
+    Return the source hardware address of the packet as a Python
+    bytestring, or ``None`` if the source hardware address was not
+    captured (packets captured by the ``OUTPUT`` or ``PREROUTING``
+    hooks). For example, on Ethernet the result will be a six-byte
+    MAC address. The destination hardware address is not available
+    because it is determined in the kernel only after packet filtering
+    is complete.
+
+``Packet.get_timestamp()``
+    Return the time at which this packet was received by the kernel,
+    as a floating-point Unix timestamp with microsecond precision
+    (comparable to the result of ``time.time()``, for example).
+    Packets captured by the ``OUTPUT`` or ``POSTROUTING`` hooks
+    do not have a timestamp, and ``get_timestamp()`` will return 0.0
+    for them.
+
+``Packet.id``
+    The identifier assigned to this packet by the kernel. Typically
+    the first packet received by your queue starts at 1 and later ones
+    count up from there.
+
+``Packet.hw_protocol``
+    The link-layer protocol for this packet. For example, IPv4 packets
+    on Ethernet would have this set to the EtherType for IPv4, which is
+    ``0x0800``.
+
+``Packet.mark``
+    The mark that had been assigned to this packet when it was enqueued.
+    Unlike the result of ``get_mark()``, this does not change if you call
+    ``set_mark()``.
+
+``Packet.hook``
+    The netfilter hook (iptables chain, roughly) that diverted this packet
+    into our queue. Values 0 through 4 correspond to PREROUTING, INPUT,
+    FORWARD, OUTPUT, and POSTROUTING respectively.
 
 ``Packet.retain()``
     Allocate a copy of the packet payload for use after the callback
@@ -249,20 +282,39 @@ The fields are:
 Limitations
 ===========
 
-* Compiled with a 4096-byte buffer for packets, so it probably won't work on
-  loopback or Ethernet with jumbo packets. If this is a problem, either lower
-  MTU on your loopback, disable jumbo packets, or get Cython,
-  change ``DEF BufferSize = 4096`` in ``netfilterqueue.pyx``, and rebuild.
-* Full libnetfilter_queue API is not yet implemented:
+* We use a fixed-size 4096-byte buffer for packets, so you are likely
+  to see truncation on loopback and on Ethernet with jumbo packets.
+  If this is a problem, either lower the MTU on your loopback, disable
+  jumbo packets, or get Cython, change ``DEF BufferSize = 4096`` in
+  ``netfilterqueue.pyx``, and rebuild.
+
+* Not all information available from libnetfilter_queue is exposed:
+  missing pieces include packet input/output network interface names,
+  checksum offload flags, UID/GID and security context data
+  associated with the packet (if any).
 
-    * Omits methods for getting information about the interface a packet has
-      arrived on or is leaving on
-    * Probably other stuff is omitted too
+* Not all information available from the kernel is even processed by
+  libnetfilter_queue: missing pieces include additional link-layer
+  header data for some packets (including VLAN tags), connection-tracking
+  state, and incoming packet length (if truncated for queueing).
+
+* We do not expose the libnetfilter_queue interface for changing queue flags.
+  Most of these pertain to other features we don't support (listed above),
+  but there's one that could set the queue to accept (rather than dropping)
+  packets received when it's full.
 
 Source
 ======
 
-https://github.com/kti/python-netfilterqueue
+https://github.com/oremanj/python-netfilterqueue
+
+Authorship
+==========
+
+python-netfilterqueue was originally written by Matthew Fox of
+Kerkhoff Technologies, Inc. Since 2022 it has been maintained by
+Joshua Oreman of Hudson River Trading LLC. Both authors wish to
+thank their employers for their support of open source.
 
 License
 =======
 
@@ -172,14 +172,14 @@ cdef class NetfilterQueue:
     cdef object user_callback # User callback
     cdef nfq_handle *h # Handle to NFQueue library
     cdef nfq_q_handle *qh # A handle to the queue
-    cdef bint unbinding
 
 cdef class Packet:
     cdef NetfilterQueue _queue
     cdef bint _verdict_is_set # True if verdict has been issued,
         # false otherwise
     cdef bint _mark_is_set # True if a mark has been given, false otherwise
     cdef bint _hwaddr_is_set
+    cdef bint _timestamp_is_set
     cdef u_int32_t _given_mark # Mark given to packet
     cdef bytes _given_payload # New payload of packet, or null
     cdef bytes _owned_payload
@@ -197,7 +197,6 @@ cdef class Packet:
     cdef u_int8_t hw_addr[8]
 
     # TODO: implement these
-    #cdef u_int8_t hw_addr[8] # A eui64-formatted address?
     #cdef readonly u_int32_t nfmark
     #cdef readonly u_int32_t indev
     #cdef readonly u_int32_t physindev
 
@@ -24,18 +24,6 @@ DEF SockCopySize = MaxCopySize + SockOverhead
 # Socket queue should hold max number of packets of copysize bytes
 DEF SockRcvSize = DEFAULT_MAX_QUEUELEN * SockCopySize // 2
 
-cdef extern from *:
-    """
-    static void do_write_unraisable(PyObject* obj) {
-        PyObject *ty, *val, *tb;
-        PyErr_GetExcInfo(&ty, &val, &tb);
-        PyErr_Restore(ty, val, tb);
-        PyErr_WriteUnraisable(obj);
-    }
-    """
-    cdef void do_write_unraisable(msg)
-
-
 from cpython.exc cimport PyErr_CheckSignals
 
 # A negative return value from this callback will stop processing and
@@ -45,17 +33,15 @@ cdef int global_callback(nfq_q_handle *qh, nfgenmsg *nfmsg,
     """Create a Packet and pass it to appropriate callback."""
     cdef NetfilterQueue nfqueue = <NetfilterQueue>data
     cdef object user_callback = <object>nfqueue.user_callback
+    if user_callback is None:
+        # Queue is being unbound; we can't send a verdict at this point
+        # so just ignore the packet. The kernel will drop it once we
+        # unbind.
+        return 1
     packet = Packet()
     packet.set_nfq_data(nfqueue, nfa)
     try:
         user_callback(packet)
-    except BaseException as exc:
-        if nfqueue.unbinding == True:
-            do_write_unraisable(
-                "netfilterqueue callback during unbind"
-            )
-        else:
-            raise
     finally:
         packet.drop_refs()
     return 1
@@ -104,7 +90,7 @@ cdef class Packet:
     cdef drop_refs(self):
         """
         Called at the end of the user_callback, when the storage passed to
-        set_nfq_data() is about to be deallocated.
+        set_nfq_data() is about to be reused.
         """
         self.payload = NULL
 
@@ -139,7 +125,11 @@ cdef class Packet:
         self._verdict_is_set = True
 
     def get_hw(self):
-        """Return the hardware address as Python string."""
+        """Return the packet's source MAC address as a Python bytestring, or
+        None if it's not available.
+        """
+        if not self._hwaddr_is_set:
+            return None
         cdef object py_string
         py_string = PyBytes_FromStringAndSize(<char*>self.hw_addr, 8)
         return py_string
@@ -209,11 +199,17 @@ cdef class NetfilterQueue:
         if nfq_bind_pf(self.h, af) < 0:
             raise OSError("Failed to bind family %s. Are you root?" % af)
 
-    def __dealloc__(self):
+    def __del__(self):
+        # unbind() can result in invocations of global_callback, so we
+        # must do it in __del__ (when this is still a valid
+        # NetfilterQueue object) rather than __dealloc__
         self.unbind()
+
+    def __dealloc__(self):
         # Don't call nfq_unbind_pf unless you want to disconnect any other
         # processes using this libnetfilter_queue on this protocol family!
-        nfq_close(self.h)
+        if self.h != NULL:
+            nfq_close(self.h)
 
     def bind(self, int queue_num, object user_callback,
                 u_int32_t max_len=DEFAULT_MAX_QUEUELEN,
@@ -254,12 +250,9 @@ cdef class NetfilterQueue:
 
     def unbind(self):
         """Destroy the queue."""
+        self.user_callback = None
         if self.qh != NULL:
-            self.unbinding = True
-            try:
-                nfq_destroy_queue(self.qh)
-            finally:
-                self.unbinding = False
+            nfq_destroy_queue(self.qh)
         self.qh = NULL
         # See warning about nfq_unbind_pf in __dealloc__ above.
 
@@ -288,9 +281,7 @@ cdef class NetfilterQueue:
                     PyErr_CheckSignals()
                     continue
                 raise OSError(errno, "recv failed")
-            rv = nfq_handle_packet(self.h, buf, rv)
-            if rv < 0:
-                raise OSError(errno, "nfq_handle_packet failed")
+            nfq_handle_packet(self.h, buf, rv)
 
     def run_socket(self, s):
         """Accept packets using socket.recv so that, for example, gevent can monkeypatch it."""
@@ -299,11 +290,6 @@ cdef class NetfilterQueue:
         while True:
             try:
                 buf = s.recv(BufferSize)
-                rv = len(buf)
-                if rv >= 0:
-                    nfq_handle_packet(self.h, buf, rv)
-                else:
-                    break
             except socket.error as e:
                 err = e.args[0]
                 if err == ENOBUFS:
@@ -315,6 +301,8 @@ cdef class NetfilterQueue:
                 else:
                     # This is bad. Let the caller handle it.
                     raise e
+            else:
+                nfq_handle_packet(self.h, buf, len(buf))
 
 PROTOCOLS = {
     0: "HOPOPT",