dns: add dns.response sticky buffer

Feature: 7012
Add dns.response sticky buffer to match on dns response fields.
Add rust functions to return dns response packet data.
Unit tests verifying signature matching.

rust/src/dns/dns.rs

@@ -1023,6 +1023,121 @@ pub unsafe extern "C" fn SCDnsTxGetAnswerName(
     false
 }
 
+/// Get the DNS response authority name at index i.
+#[no_mangle]
+pub unsafe extern "C" fn SCDnsTxGetAuthorityName(
+    tx: &mut DNSTransaction, i: u32, buf: *mut *const u8, len: *mut u32,
+) -> bool { 
+    let index = i as usize;
+
+    if let Some(response) = &tx.response {
+        if let Some(record) = response.authorities.get(index) {
+            if !record.name.value.is_empty() {
+                *buf = record.name.value.as_ptr();
+                *len = record.name.value.len() as u32;
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+/// Get the DNS response additional name at index i.
+#[no_mangle]
+pub unsafe extern "C" fn SCDnsTxGetAdditionalName(
+    tx: &mut DNSTransaction, i: u32, buf: *mut *const u8, len: *mut u32,
+) -> bool { 
+    let index = i as usize;
+
+    if let Some(response) = &tx.response {
+        if let Some(record) = response.additionals.get(index) {
+            if !record.name.value.is_empty() {
+                *buf = record.name.value.as_ptr();
+                *len = record.name.value.len() as u32;
+                return true;
+            }
+        }
+    }
+
+    false
+}
+
+#[inline]
+unsafe fn dns_get_record_rdata(data: &DNSRData, buf: *mut *const u8, len: *mut u32) -> bool {
+    match data {
+        DNSRData::CNAME(bytes)
+        | DNSRData::PTR(bytes)
+        | DNSRData::MX(bytes)
+        | DNSRData::NS(bytes) => {
+            if !bytes.value.is_empty() {
+                *len = bytes.value.len() as u32;
+                *buf = bytes.value.as_ptr();
+                return true;
+            }
+        }
+        DNSRData::SOA(soa) => {
+            if !soa.mname.value.is_empty() {
+                *len = soa.mname.value.len() as u32;
+                *buf = soa.mname.value.as_ptr();
+                return true;
+            }
+        }
+        _ => {
+            return false;
+        }
+    }
+    return false;
+}
+
+/// Get the DNS response answer rdata at index i that could be a domain name.
+#[no_mangle]
+pub unsafe extern "C" fn SCDnsTxGetAnswerRdata(
+    tx: &mut DNSTransaction, i: u32, buf: *mut *const u8, len: *mut u32,
+) -> bool { 
+    let index = i as usize;
+
+    if let Some(response) = &tx.response {
+        if let Some(record) = response.answers.get(index) {
+            return dns_get_record_rdata(&record.data, buf, len);
+        }
+    }
+
+    false
+}
+
+/// Get the DNS response authority rdata at index i that could be a domain name.
+#[no_mangle]
+pub unsafe extern "C" fn SCDnsTxGetAuthorityRdata(
+    tx: &mut DNSTransaction, i: u32, buf: *mut *const u8, len: *mut u32,
+) -> bool { 
+    let index = i as usize;
+
+    if let Some(response) = &tx.response {
+        if let Some(record) = response.authorities.get(index) {
+            return dns_get_record_rdata(&record.data, buf, len);
+        }
+    }
+
+    false
+}
+
+/// Get the DNS response additional rdata at index i that could be a domain name.
+#[no_mangle]
+pub unsafe extern "C" fn SCDnsTxGetAdditionalRdata(
+    tx: &mut DNSTransaction, i: u32, buf: *mut *const u8, len: *mut u32,
+) -> bool { 
+    let index = i as usize;
+
+    if let Some(response) = &tx.response {
+        if let Some(record) = response.additionals.get(index) {
+            return dns_get_record_rdata(&record.data, buf, len);
+        }
+    }
+
+    false
+}
+
 /// Get the DNS response flags for a transaction.
 ///
 /// extern uint16_t SCDnsTxGetResponseFlags(RSDNSTransaction *);

src/Makefile.am

@@ -115,6 +115,7 @@ noinst_HEADERS = \
 	detect-dns-answer-name.h \
 	detect-dns-opcode.h \
 	detect-dns-rcode.h \
+	detect-dns-response.h \
 	detect-dns-rrtype.h \
 	detect-dns-query.h \
 	detect-dns-query-name.h \
@@ -691,6 +692,7 @@ libsuricata_c_a_SOURCES = \
 	detect-dns-answer-name.c \
 	detect-dns-opcode.c \
 	detect-dns-rcode.c \
+	detect-dns-response.c \
 	detect-dns-rrtype.c \
 	detect-dns-query.c \
 	detect-dns-query-name.c \

src/detect-dns-response.h

@@ -0,0 +1,23 @@
+/* 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.
+ */
+
+#ifndef SURICATA_DETECT_DNS_RESPONSE_H
+#define SURICATA_DETECT_DNS_RESPONSE_H
+
+void DetectDnsResponseRegister(void);
+
+#endif /* SURICATA_DETECT_DNS_RESPONSE_H */

src/detect-engine-register.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2017 Open Information Security Foundation
+/* Copyright (C) 2007-2024 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
@@ -53,6 +53,7 @@
 #include "detect-dns-query.h"
 #include "detect-dns-answer-name.h"
 #include "detect-dns-query-name.h"
+#include "detect-dns-response.h"
 #include "detect-tls-sni.h"
 #include "detect-tls-certs.h"
 #include "detect-tls-cert-fingerprint.h"
@@ -559,6 +560,7 @@ void SigTableSetup(void)
     DetectDnsRrtypeRegister();
     DetectDnsAnswerNameRegister();
     DetectDnsQueryNameRegister();
+    DetectDnsResponseRegister();
     DetectModbusRegister();
     DetectDNP3Register();
 

src/detect-engine-register.h

@@ -246,6 +246,7 @@ enum DetectKeywordId {
     DETECT_DNS_QUERY,
     DETECT_DNS_OPCODE,
     DETECT_DNS_RCODE,
+    DETECT_DNS_RESPONSE,
     DETECT_DNS_RRTYPE,
     DETECT_DNS_ANSWER_NAME,
     DETECT_DNS_QUERY_NAME,