From b51a2ac72a3cbd1b470890d0151a46da28e6754e Mon Sep 17 00:00:00 2001 From: Ivan Nardi <12729895+IvanNardi@users.noreply.github.com> Date: Thu, 9 Feb 2023 20:02:12 +0100 Subject: fuzz: some improvements and add two new fuzzers (#1881) Remove `FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION` define from `fuzz/Makefile.am`; it is already included by the main configure script (when fuzzing). Add a knob to force disabling of AESNI optimizations: this way we can fuzz also no-aesni crypto code. Move CRC32 algorithm into the library. Add some fake traces to extend fuzzing coverage. Note that these traces are hand-made (via scapy/curl) and must not be used as "proof" that the dissectors are really able to identify this kind of traffic. Some small updates to some dissectors: CSGO: remove a wrong rule (never triggered, BTW). Any UDP packet starting with "VS01" will be classified as STEAM (see steam.c around line 111). Googling it, it seems right so. XBOX: XBOX only analyses UDP flows while HTTP only TCP ones; therefore that condition is false. RTP, STUN: removed useless "break"s Zattoo: `flow->zattoo_stage` is never set to any values greater or equal to 5, so these checks are never true. PPStream: `flow->l4.udp.ppstream_stage` is never read. Delete it. TeamSpeak: we check for `flow->packet_counter == 3` just above, so the following check `flow->packet_counter >= 3` is always false. --- example/reader_util.c | 49 ------------------------------------------------- 1 file changed, 49 deletions(-) (limited to 'example/reader_util.c') diff --git a/example/reader_util.c b/example/reader_util.c index 62fa3046a..b1f72c650 100644 --- a/example/reader_util.c +++ b/example/reader_util.c @@ -2253,55 +2253,6 @@ struct ndpi_proto ndpi_workflow_process_packet(struct ndpi_workflow * workflow, flow_risk)); } -/* ********************************************************** */ -/* http://home.thep.lu.se/~bjorn/crc/crc32_fast.c */ -/* ********************************************************** */ - -static uint32_t crc32_for_byte(uint32_t r) { - int j; - for(j = 0; j < 8; ++j) - r = ((r & 1) ? 0 : (uint32_t)0xEDB88320L) ^ r >> 1; - return r ^ (uint32_t)0xFF000000L; -} - -/* Any unsigned integer type with at least 32 bits may be used as - * accumulator type for fast crc32-calulation, but unsigned long is - * probably the optimal choice for most systems. */ -typedef unsigned long accum_t; - -static void init_tables(uint32_t* table, uint32_t* wtable) { - size_t i, j, k, w; - for(i = 0; i < 0x100; ++i) - table[i] = crc32_for_byte(i); - for(k = 0; k < sizeof(accum_t); ++k) - for(i = 0; i < 0x100; ++i) { - for(j = w = 0; j < sizeof(accum_t); ++j) - w = table[(uint8_t)(j == k? w ^ i: w)] ^ w >> 8; - wtable[(k << 8) + i] = w ^ (k? wtable[0]: 0); - } -} - -static void __crc32(const void* data, size_t n_bytes, uint32_t* crc) { - static uint32_t table[0x100], wtable[0x100*sizeof(accum_t)]; - size_t n_accum = n_bytes/sizeof(accum_t); - size_t i, j; - if(!*table) - init_tables(table, wtable); - for(i = 0; i < n_accum; ++i) { - accum_t a = *crc ^ ((accum_t*)data)[i]; - for(j = *crc = 0; j < sizeof(accum_t); ++j) - *crc ^= wtable[(j << 8) + (uint8_t)(a >> 8*j)]; - } - for(i = n_accum*sizeof(accum_t); i < n_bytes; ++i) - *crc = table[(uint8_t)*crc ^ ((uint8_t*)data)[i]] ^ *crc >> 8; -} - -u_int32_t ethernet_crc32(const void* data, size_t n_bytes) { - u_int32_t crc = 0; - __crc32(data, n_bytes, &crc); - return crc; -} - /* *********************************************** */ #ifdef USE_DPDK -- cgit v1.2.3