[PATCH 0/5] Add AFL++ fuzzing support for passt

[Anshu Kumari <anskuma@redhat.com>]

This series adds integrated AFL++ fuzzing support for passt,
extending the earlier work by AbdAlRahman Gad with
persistent mode, bidirectional protocol fuzzing, and real
TCP connection coverage via a companion test server.

Architecture
------------
The fuzzer runs passt in AFL++ persistent mode (__AFL_LOOP)
with shared memory fuzzing. A separate test server process
connects to passt's UNIX socket and listens on 127.0.0.1:9999
for real TCP connections:

Deterministic wrappers replace clock_gettime, getrandom,
getsockopt, and recv-family calls to eliminate kernel-level
non-determinism. Per-iteration reset of the flow table,
epoll instance, and clock.

*** BLURB HERE ***

Anshu Kumari (5):
  fuzz: Add deterministic wrappers for system calls
  fuzz: Add flow type guards for fuzzing stability
  fuzz: Bypass isolation and adapt sockets for AFL++
  fuzz: Add AFL++ persistent mode fuzz loop
  fuzz: Add test server for bidirectional protocol fuzzing

 Makefile                       |  28 +-
 fuzz-server.c                  | 490 +++++++++++++++++++++++++++++++++
 fuzz.c                         | 275 ++++++++++++++++++
 fuzz.h                         |  62 +++++
 fuzzing/README.fuzzing.md      |  95 +++++++
 fuzzing/testcase_dir/empty.bin | Bin 0 -> 12 bytes
 icmp.c                         |  14 +-
 isolation.c                    |  11 +
 passt.c                        | 189 +++++++++++++
 passt.h                        |   4 +
 tap.c                          |  21 ++
 tcp.c                          |  19 +-
 tcp_buf.c                      |   1 +
 tcp_splice.c                   |  10 +
 udp.c                          |  29 +-
 udp_flow.c                     |   5 +
 util.c                         |  10 +
 17 files changed, 1251 insertions(+), 12 deletions(-)
 create mode 100644 fuzz-server.c
 create mode 100644 fuzz.c
 create mode 100644 fuzz.h
 create mode 100644 fuzzing/README.fuzzing.md
 create mode 100644 fuzzing/testcase_dir/empty.bin

-- 
2.55.0