Add examples/benchmark/dtls_bench, a DTLS throughput benchmark that
completes a handshake and then measures bulk-send throughput. It
supports DTLS 1.2 and 1.3, selectable cipher suites, an end-to-end
mode, and a -z sink mode that discards records on the server after the
handshake to isolate the sender's record-layer cost. The socket is set
up with wolfSSL_set_dtls_fd_connected.
Optimize the send path exercised by the benchmark:
- wolfio (EmbedSendTo): cache the per-descriptor socket-type probe
(getsockopt SO_TYPE) in WOLFSSL_DTLS_CTX instead of running it on
every send, removing a syscall from the record send path. The cache
is invalidated whenever rfd/wfd is reassigned.
- internal (BuildMessage): for AEAD suites whose explicit nonce is the
8-byte record sequence number, write the sequence number directly as
nonce_explicit instead of drawing it from the RNG. This covers
AES-GCM (RFC 5288 sec 3), AES-CCM (RFC 6655 sec 3), SM4-GCM/CCM
(RFC 8998 sec 3), and Camellia-/ARIA-GCM which inherit the RFC 5288
construction; ChaCha20 uses an implicit nonce and is excluded. A new
read-only PeekSEQ() helper reads the sequence number without advancing
the per-direction counter, leaving the single mandated increment to
writeAeadAuthData().
Also ignore the built dtls_bench binary in .gitignore.
* Fixed some `tls_bench` build issues with various configure options.
* Moved the `WOLFSSL_PACK` and `WC_NORETURN` macros into types.h.
* Added support for `__builtin_bswap32` and `__builtin_bswap64`. Since the performance of the builtins varries by platform its off by default, but can be enabled by customer using `WOLF_ALLOW_BUILTIN`. Quick check on x86 showed the 32-bit swap performance matched, but 64-bit swap was slower.
Juliusz Sosinowicz
Chris Conlon
David Garske