- Adds 3 new "pseudo-random" filter expressions:
* random8 (8bit)
* random16 (16bit)
* random32 (32bit)
Not really "random", but these values are based
on a hash of the packet headers & timestamp.
These are useful for traffic sampling, e.g.:
"random8 < 100" matches ~39% of all packets.
- Add new WinDivertHelperHashPacket() helper
function. The algorithm is an xxHash variant.
This function allows the user application to
"shutdown" a handle in anticipation of a
call to WinDivertClose(). When a handle has
been shutdown, new packets will no longer be
queued. However, existing queued packets can
still be read by WinDivertRecv(). When the
queue is emptied, WinDivertRecv() will fail
with ERROR_NO_DATA.
The WinDivertShutdown() function is analogous
to the shutdown() socket function.
This change also simplifies events.
This change allows multiple packets to be
received/sent at once, reducing overheads. To
exploit this feature, applications need to use
the WinDivertRecvEx()/WinDivertSendEx()
functions with the new addrLen parameter. The
passthru example has been modified to use
batching.
The DEBUG flag has been retired since it
conflicts with batching, and was not very
useful anyway.
Adds a new SOCKET layer for monitoring socket
events, such as BIND, LISTEN, CONNECT,
and ACCEPT. These events occur before the
flow is established (and unlike the FLOW layer)
it is possible to block/drop SOCKET events.
Otherwise, this layer is very similar to the
FLOW layer, so the PID is available and injection
is not possible. This commit should be
considered to be a WIP.
Other changes:
- New socketdump.exe sample. Prints socket
events.
- Improve IPv6 address parsing.
- New helper functions:
* WinDivertHelperFormatIPv4Address
* WinDivertHelperFormatIPv6Address
- Fix REFLECT bugs.
- The network 5-tuple can now be accessed at
the NETWORK layer.
- Various cleanups.
Adds a new REFLECT layer for monitoring WinDivert
handles. This includes:
- three new REFLECT events: ESTABLISHED, OPEN and
CLOSE;
- modifying the ADDRESS for REFLECT data:
open time, process-id, layer, flags, and
priority of the opened handle; and
- allowing WinDivertRecv() to read a
representation of the opened filter.
This change also includes a new "object"
representation for WinDivert filter strings.
The API has been updated as follows:
- WinDivertHelperCompileFilter (replaces
CheckFilter) compiles filter strings into the
object form; and
- WinDivertHelperFormatFilter can "decompile" an
object back into a human-readable filter
string.
Other:
- New NO_INSTALL flag.
- New windivertctl.exe sample program.
This allows projects that are strictly "GPLv2
only" to use WinDivert without licensing issues.
See the FSF's compatibility matrix here:
https://www.gnu.org/licenses/gpl-faq.en.html
This change does not affect existing projects
that can continue to use the LGPLv3 as before.
Also, bump the WinDivert version to 1.4.1.
Most NIC cards support checksum offloading,
meaning that it is not necessary to calculate the
full IP/TCP/UDP checksums for injected packets.
WINDIVERT_ADDRESS has been extended to include 3
extra flags that indicate if the packet has full
or pseudo checksums. This is a WIP.
The WINDIVERT_HELPER_NO_REPLACE flag tells WinDivertHelperCalcChecksums not to
recalculate and replace non-zero checksum fields. This is useful for
reconstructing the checksums for packets returned by WinDivertRecv(), where
all non-zero checksum fields are already valid. This allows WinDivert1.2
to achieve similar efficiency as WinDivert1.1, where checksums were calculated
by the driver.
Note that for modified packets, the WINDIVERT_HELPER_NO_REPLACE flag should
not be used, as all checksums need to be recalculated from scratch anyway.
* WinDivert sublayers are created and inserted when the driver is loaded.
* All WinDivert callouts are installed at the same sublayer.
- Clean-up the implementation of priorities.
- Re-introduce deep copying for SNIFF mode. This avoids referencing the
sniffed packets.
- Fix-up the netfilter example:
* Don't send RSTs to RST/FINs, this can start a RST war.
* Don't inject ICMP outbound - this may not be a problem despite 1233 errors.
* Re-brand "DIVERT" to "WINDIVERT" throughout the code-base.
* New flags:
> WINDIVERT_FLAG_PASSTHRU: Do not drop nor capture packets. Useful
for injection-only handles.
> WINDIVERT_FLAG_NO_CHECKSUM: Do not guarantee that diverted packets
have a correct checksum.
NOTE: Not yet tested!
* New default values and limits for various WinDivert parameters,
including WINDIVERT_PARAM_QUEUE_LEN, WINDIVERT_PARAM_QUEUE_TIME, and
the maximum filter length.
* New extended WinDivert functions that support asynchronous I/O:
> WinDivertRecvEx(..)
> WinDivertSendEx(..)
NOTE: Not yet tested!
* The WinDivert driver now services reads (receives) out-of-band.
The motivation is because WFP callouts are run at DISPATCH_LEVEL, so
we should not be doing expensive work in the ClassifyFn. This is also
the same reason why the filter length has been restricted.
- VS2010 support added via msvc-build.bat and *.vcxproj files
- MinGW now also builds example programs
- Documentation and examples are now included in the binary packages
Name and version:
* Now officially called 'WinDivert'
* Now officially working towards a version 1.0 release
New features:
* WinDivert now supports a packet-sniffing mode. This mode merely
copies packets, and does not drop the original.
* WinDivert now also supports a packet-dropping mode.
* WinDivert now supports filter priorities.
* WinDivert now supports a forwarded packet layer (WARNING: untested).
* WinDivert now supports get/set parameters such as packet queue length and
time.
* WinDivert now supports larger filters (but use at own risk).
* WinDivert now uninstalls the driver on program exit/library unload
* Different versions of WinDivert can co-exist on the same machine
(WARNING: untested, as there is currently only one version).
New License:
* WinDivert is now LGPL. This is less restrictive than the GPL so WinDivert
can be linked to by commercial software (under the terms of the LGPL
license).
Technical:
* Cleaner IOCTL interface.
* Cleaner driver implementation.
* Thread local events in WinDivert.dll
* Many minor tweaks and fixes.
includes making the driver handle I/O requests in parallel, and changing
the library such that it uses overlapped I/O. Overall the package is
now significantly faster.
- The divert driver now only adds WFP callouts when a filter is set,
instead of when a handle is created.
- The divert driver now attempts to avoid adding WFP callouts that are
superfluous with respect to the filter.
- The divert driver now explicitly deletes filters and callouts during
cleanup. This appears to resolve a bug where network connectivity is
sometimes lost.
- Added a new sample program: passthru.exe. This example doesn't do anything
interesting but is useful for speed testing.
- Rename build.sh to mingw-build.sh to avoid confusion.
- Make the pAddr arg for DivertRecv() optional
- Make the i386 user binaries compatible with an amd64 driver.
(useful for projects not yet ported to amd64)
data itself. This makes for a much cleaner interface.
sys/divert.c
dll/divert.c
include/*.h
DivertRecv and DivertSend now use IOCTLs instead of reads/writes.
The 'address' parameter is passed by pointer to the driver, which
writes directly to it (after sanity checks).
This means that the data buffer now only contains the packet, which
help to avoid some messy code.
examples/*/*.c
Update the examples to reflect the new API.
doc/divert.html
Update the documentation to reflect the new API.
basil00