/* Copyright (C) 2024 Open Information Security Foundation * * You can copy, redistribute or modify this Program under the terms of * the GNU General Public License version 2 as published by the Free * Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * version 2 along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. */ #include "suricata-common.h" #include "detect-parse.h" #include "detect-engine.h" #include "detect-dns-rcode.h" #include "rust.h" #include "detect-engine-uint.h" static int dns_rcode_list_id = 0; static void DetectDnsRcodeFree(DetectEngineCtx *, void *ptr); static int DetectDnsRcodeSetup(DetectEngineCtx *de_ctx, Signature *s, const char *str) { SCEnter(); if (DetectSignatureSetAppProto(s, ALPROTO_DNS) != 0) { SCReturnInt(-1); } void *detect = DetectU8Parse(str); if (detect == NULL) { SCLogError("failed to parse dns.rcode: %s", str); SCReturnInt(-1); } if (SigMatchAppendSMToList( de_ctx, s, DETECT_AL_DNS_RCODE, (SigMatchCtx *)detect, dns_rcode_list_id) == NULL) { DetectDnsRcodeFree(de_ctx, detect); SCReturnInt(-1); } SCReturnInt(0); } static void DetectDnsRcodeFree(DetectEngineCtx *de_ctx, void *ptr) { SCEnter(); if (ptr != NULL) { rs_detect_u8_free(ptr); } SCReturn; } static int DetectDnsRcodeMatch(DetectEngineThreadCtx *det_ctx, Flow *f, uint8_t flags, void *state, void *txv, const Signature *s, const SigMatchCtx *ctx) { return SCDnsDetectRcodeMatch(txv, (void *)ctx, flags); } void DetectDnsRcodeRegister(void) { sigmatch_table[DETECT_AL_DNS_RCODE].name = "dns.rcode"; sigmatch_table[DETECT_AL_DNS_RCODE].desc = "Match the DNS header rcode flag."; sigmatch_table[DETECT_AL_DNS_RCODE].url = "/rules/dns-keywords.html#dns-rcode"; sigmatch_table[DETECT_AL_DNS_RCODE].Setup = DetectDnsRcodeSetup; sigmatch_table[DETECT_AL_DNS_RCODE].Free = DetectDnsRcodeFree; sigmatch_table[DETECT_AL_DNS_RCODE].Match = NULL; sigmatch_table[DETECT_AL_DNS_RCODE].AppLayerTxMatch = DetectDnsRcodeMatch; DetectAppLayerInspectEngineRegister( "dns.rcode", ALPROTO_DNS, SIG_FLAG_TOSERVER, 0, DetectEngineInspectGenericList, NULL); DetectAppLayerInspectEngineRegister( "dns.rcode", ALPROTO_DNS, SIG_FLAG_TOCLIENT, 0, DetectEngineInspectGenericList, NULL); dns_rcode_list_id = DetectBufferTypeGetByName("dns.rcode"); }