The termination condition implemented in gnrc_pktbuf_malloc does not
work when using the sock interface as sock copies packet data to a local
buffer and frees the packet afterwards. As such, the fuzzing application
would exit before performing any input processing.
For this reason, the termination condition in gnrc_pktbuf_malloc is
disabled when using sock. Instead, the application terminates if
gnrc_sock_recv previously returned the fuzzing packet. The underlying
assumption of this implementation is that gnrc_sock_recv is called in a
loop.
Since RIOT is an operating system the native binary will never terminate
[0]. The termination condition for fuzzing GNRC is that the packet was
handled by the network stack and therefore freed. If it is never freed
we will deadlock meaning a memory leak was found, afl should be able to
detect this through timeouts.
This is currently only supported for gnrc_pktbuf_malloc since this is
the pktbuf implementation I used for fuzzing. Implementing this in
pktbuf.h is not possible.
[0]: Except NATIVE_AUTO_EXIT is defined, however, even with that define
set RIOT will only terminate when all threads terminated. Unfortunately,
gnrc_udp and other network threads will never terminate.
This adds a utility module which is used to write applications for
fuzzing RIOT network modules. The module provides a dummy network
interface which is configured with a static IPv6 addresses for modules
which perform operations on the underlying network interface. Besides,
it contains a utility function for transforming data received on
standard input into a `gnrc_pktsnip_t`.
There were two subtle bugs that prevented the DHCPv6 client to request
multiple prefixes for different interfaces.
- `dhcpv6_client_req_ia_pd()` would fill up *all* leases with the same interface
- `_parse_reply()` would return after parsing the first answer
With this patch, `gnrc_border_router` gets a prefix on both interfaces of the at86rf215.
With lwIP we have a chunked UDP payload, so just providing the
stack-internal buffer is not possible. To be able to iterate over such
a chunked payload, this change allows the `sock_*_recv_buf()` functions
to use the internal buffer context as an iteration state.
As the internal buffer space can be released when the function would
return 0, `sock_recv_buf_free()` becomes unnecessary.
RFC4648 specifies an alternate alphabet for base64 encoding / decoding
where '+' and '/' are exchanged for '-' and '-' to make the resulting
string safe to use in filenames and URLs.
This adds a base64url_encode() function that uses the alternate alphabet.
The base64_decode() function is extended to accept both alphabets.
