sdp: add sdp.session_name sticky buffer

This adds a sticky buffer to match the "Session name" field in both
requests and responses.

Ticket #7291

rust/src/sdp/detect.rs

@@ -0,0 +1,100 @@
+/* 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.
+ */
+
+// written by Giuseppe Longo <giuseppe@glongo.it>
+
+use crate::detect::{
+    DetectBufferSetActiveList, DetectHelperBufferMpmRegister, DetectHelperGetData,
+    DetectHelperKeywordRegister, DetectSignatureSetAppProto, SCSigTableElmt, SIGMATCH_NOOPT,
+};
+use crate::direction::Direction;
+use crate::sip::sip::{SIPTransaction, ALPROTO_SIP};
+use std::os::raw::{c_int, c_void};
+use std::ptr;
+
+static mut G_SDP_SESSION_NAME_BUFFER_ID: c_int = 0;
+
+unsafe extern "C" fn sdp_session_name_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_SDP_SESSION_NAME_BUFFER_ID) < 0 {
+        return -1;
+    }
+    return 0;
+}
+
+unsafe extern "C" fn sdp_session_name_get(
+    de: *mut c_void, transforms: *const c_void, flow: *const c_void, flow_flags: u8,
+    tx: *const c_void, list_id: c_int,
+) -> *mut c_void {
+    return DetectHelperGetData(
+        de,
+        transforms,
+        flow,
+        flow_flags,
+        tx,
+        list_id,
+        sdp_session_name_get_data,
+    );
+}
+
+unsafe extern "C" fn sdp_session_name_get_data(
+    tx: *const c_void, direction: u8, buffer: *mut *const u8, buffer_len: *mut u32,
+) -> bool {
+    let tx = cast_pointer!(tx, SIPTransaction);
+    let sdp_message = match direction.into() {
+        Direction::ToServer => tx.request.as_ref().and_then(|req| req.body.as_ref()),
+        Direction::ToClient => tx.response.as_ref().and_then(|resp| resp.body.as_ref()),
+    };
+    if let Some(sdp) = sdp_message {
+        let session_name = &sdp.session_name;
+        if !session_name.is_empty() {
+            *buffer = session_name.as_ptr();
+            *buffer_len = session_name.len() as u32;
+            return true;
+        }
+    }
+    *buffer = ptr::null();
+    *buffer_len = 0;
+    false
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn ScDetectSdpRegister() {
+    let kw = SCSigTableElmt {
+        name: b"sdp.session_name\0".as_ptr() as *const libc::c_char,
+        desc: b"sticky buffer to match on the SDP session name field\0".as_ptr()
+            as *const libc::c_char,
+        url: b"/rules/sdp-keywords.html#sdp-session-name\0".as_ptr() as *const libc::c_char,
+        Setup: sdp_session_name_setup,
+        flags: SIGMATCH_NOOPT,
+        AppLayerTxMatch: None,
+        Free: None,
+    };
+    let _ = DetectHelperKeywordRegister(&kw);
+    G_SDP_SESSION_NAME_BUFFER_ID = DetectHelperBufferMpmRegister(
+        b"sdp.session_name\0".as_ptr() as *const libc::c_char,
+        b"sdp.session_name\0".as_ptr() as *const libc::c_char,
+        ALPROTO_SIP,
+        true,
+        true,
+        sdp_session_name_get,
+    );
+}

rust/src/sdp/mod.rs

@@ -1,2 +1,22 @@
+/* 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.
+ */
+
+// written by Giuseppe Longo <giuseppe@glongo.it>
+
+pub mod detect;
 pub mod logger;
 pub mod parser;

src/detect-engine-register.c

@@ -748,6 +748,7 @@ void SigTableSetup(void)
     SCDetectSipRegister();
     SCDetectTemplateRegister();
     SCDetectLdapRegister();
+    ScDetectSdpRegister();
 
     for (size_t i = 0; i < preregistered_callbacks_nb; i++) {
         PreregisteredCallbacks[i]();