From 8af4846d74be31fe9d0baf3c2df7a40237db5b6e Mon Sep 17 00:00:00 2001
From: Giuseppe Longo <giuseppe@glongo.it>
Date: Sat, 10 Aug 2024 14:11:11 +0200
Subject: [PATCH] sip: add sip.via sticky buffer

This adds a sticky (multi) buffer to match the "Via" header field in
both requests and responses.

Ticket #6374
---
 rust/src/sip/detect.rs | 61 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/rust/src/sip/detect.rs b/rust/src/sip/detect.rs
index 5751c3f8f890..28669861fe48 100644
--- a/rust/src/sip/detect.rs
+++ b/rust/src/sip/detect.rs
@@ -35,6 +35,7 @@ static mut G_SIP_REQUEST_LINE_BUFFER_ID: c_int = 0;
 static mut G_SIP_RESPONSE_LINE_BUFFER_ID: c_int = 0;
 static mut G_SIP_FROM_HDR_BUFFER_ID: c_int = 0;
 static mut G_SIP_TO_HDR_BUFFER_ID: c_int = 0;
+static mut G_SIP_VIA_HDR_BUFFER_ID: c_int = 0;
 
 #[no_mangle]
 pub unsafe extern "C" fn rs_sip_tx_get_method(
@@ -413,6 +414,48 @@ unsafe extern "C" fn sip_to_hdr_get_data(
         "To\0".as_ptr() as *const c_char,
     )
 }
+
+unsafe extern "C" fn sip_via_hdr_setup(
+    de: *mut c_void, s: *mut c_void, _raw: *const std::os::raw::c_char,
+) -> c_int {
+    if DetectSignatureSetAppProto(s, ALPROTO_SIP) != 0 {
+        return -1;
+    }
+    if DetectBufferSetActiveList(de, s, G_SIP_VIA_HDR_BUFFER_ID) < 0 {
+        return -1;
+    }
+    return 0;
+}
+
+unsafe extern "C" fn sip_via_hdr_get(
+    de: *mut c_void, transforms: *const c_void, flow: *const c_void, flow_flags: u8,
+    tx: *const c_void, list_id: c_int, local_id: u32,
+) -> *mut c_void {
+    return DetectHelperGetMultiData(
+        de,
+        transforms,
+        flow,
+        flow_flags,
+        tx,
+        list_id,
+        local_id,
+        sip_via_hdr_get_data,
+    );
+}
+
+unsafe extern "C" fn sip_via_hdr_get_data(
+    tx: *const c_void, flow_flags: u8, local_id: u32, buffer: *mut *const u8, buffer_len: *mut u32,
+) -> bool {
+    sip_get_header_value(
+        tx,
+        local_id,
+        flow_flags,
+        buffer,
+        buffer_len,
+        "Via\0".as_ptr() as *const c_char,
+    )
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn ScDetectSipRegister() {
     let kw = SCSigTableElmt {
@@ -541,4 +584,22 @@ pub unsafe extern "C" fn ScDetectSipRegister() {
         true,
         sip_to_hdr_get,
     );
+    let kw = SCSigTableElmt {
+        name: b"sip.via\0".as_ptr() as *const libc::c_char,
+        desc: b"sticky buffer to match on the SIP Via header\0".as_ptr() as *const libc::c_char,
+        url: b"/rules/sip-keywords.html#sip-via\0".as_ptr() as *const libc::c_char,
+        Setup: sip_via_hdr_setup,
+        flags: SIGMATCH_NOOPT,
+        AppLayerTxMatch: None,
+        Free: None,
+    };
+    let _g_sip_via_hdr_kw_id = DetectHelperKeywordRegister(&kw);
+    G_SIP_VIA_HDR_BUFFER_ID = DetectHelperMultiBufferMpmRegister(
+        b"sip.via\0".as_ptr() as *const libc::c_char,
+        b"sip.via\0".as_ptr() as *const libc::c_char,
+        ALPROTO_SIP,
+        true,
+        true,
+        sip_via_hdr_get,
+    );
 }