plugin: add in-tree app-layer template plugin for testing

Ticket: 7151
Ticket: 7152
Ticket: 7154

.github/workflows/builds.yml

@@ -180,6 +180,15 @@ jobs:
           cat eve.json | jq -c 'select(.dns)'
           test $(cat eve.json | jq -c 'select(.dns)' | wc -l) = "1"
 
+      - name: Test app-layer plugin
+        working-directory: examples/plugins/altemplate
+        run: |
+          cargo build
+          ../../../src/suricata -S altemplate.rules --set plugins.0=./target/debug/libsuricata_altemplate.so --runmode=single -l . -c altemplate.yaml -k none -r ../../../rust/src/applayertemplate/template.pcap
+          cat eve.json | jq -c 'select(.altemplate)'
+          test $(cat eve.json | jq -c 'select(.altemplate)' | wc -l) = "3"
+        # we get 2 alerts and 1 altemplate events
+
       - name: Test library build in tree
         working-directory: examples/lib/simple
         run: make clean all

examples/plugins/README.md

@@ -9,3 +9,8 @@ is useful if you want to send EVE output to custom destinations.
 
 A minimal capture plugin that can be used as a template, but also used
 for testing capture plugin loading and registration in CI.
+
+## altemplate
+
+An app-layer template plugin with logging and detection.
+Most code copied from rust/src/applayertemplate

examples/plugins/altemplate/.cargo/config.toml

@@ -0,0 +1,3 @@
+[build]
+# custom flags to pass to all compiler invocations
+rustflags = ["-Clink-args=-Wl,-undefined,dynamic_lookup"]

examples/plugins/altemplate/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "suricata-altemplate"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+nom7 = { version="7.0", package="nom" }
+libc = "~0.2.82"
+suricata = { path = "../../../rust/" }
+suricata-sys = { path = "../../../rust/sys" }
+
+[features]
+default = ["suricata8"]
+suricata8 = []

examples/plugins/altemplate/altemplate.rules

@@ -0,0 +1,2 @@
+alert altemplate any any -> any any (msg:"TEST"; altemplate.buffer; content:"Hello"; flow:established,to_server; sid:1; rev:1;)
+alert altemplate any any -> any any (msg:"TEST"; altemplate.buffer; content:"Bye"; flow:established,to_client; sid:2; rev:1;)

examples/plugins/altemplate/altemplate.yaml

@@ -0,0 +1,17 @@
+%YAML 1.1
+---
+
+outputs:
+  - eve-log:
+      enabled: yes
+      types:
+        - altemplate
+        - alert
+        - flow
+
+app-layer:
+  protocols:
+    altemplate:
+      enabled: yes
+      detection-ports:
+        dp: 7000

examples/plugins/altemplate/src/detect.rs

@@ -0,0 +1,104 @@
+/* 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.
+ */
+
+// same file as rust/src/applayertemplate/detect.rs except
+// TEMPLATE_START_REMOVE removed
+// different paths for use statements
+// keywords prefixed with altemplate instead of just template
+
+use super::template::{TemplateTransaction, ALPROTO_TEMPLATE};
+use std::os::raw::{c_int, c_void};
+use suricata::cast_pointer;
+use suricata::detect::{
+    DetectBufferSetActiveList, DetectHelperBufferMpmRegister, DetectHelperGetData,
+    DetectHelperKeywordRegister, DetectSignatureSetAppProto, SCSigTableElmt,
+    SIGMATCH_INFO_STICKY_BUFFER, SIGMATCH_NOOPT,
+};
+use suricata::direction::Direction;
+
+static mut G_TEMPLATE_BUFFER_BUFFER_ID: c_int = 0;
+
+unsafe extern "C" fn template_buffer_setup(
+    de: *mut c_void, s: *mut c_void, _raw: *const std::os::raw::c_char,
+) -> c_int {
+    if DetectSignatureSetAppProto(s, ALPROTO_TEMPLATE) != 0 {
+        return -1;
+    }
+    if DetectBufferSetActiveList(de, s, G_TEMPLATE_BUFFER_BUFFER_ID) < 0 {
+        return -1;
+    }
+    return 0;
+}
+
+/// Get the request/response buffer for a transaction from C.
+unsafe extern "C" fn template_buffer_get_data(
+    tx: *const c_void, flags: u8, buf: *mut *const u8, len: *mut u32,
+) -> bool {
+    let tx = cast_pointer!(tx, TemplateTransaction);
+    if flags & Direction::ToClient as u8 != 0 {
+        if let Some(ref response) = tx.response {
+            *len = response.len() as u32;
+            *buf = response.as_ptr();
+            return true;
+        }
+    } else if let Some(ref request) = tx.request {
+        *len = request.len() as u32;
+        *buf = request.as_ptr();
+        return true;
+    }
+    return false;
+}
+
+unsafe extern "C" fn template_buffer_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,
+        template_buffer_get_data,
+    );
+}
+
+pub(super) unsafe extern "C" fn detect_template_register() {
+    // TODO create a suricata-verify test
+    // Setup a keyword structure and register it
+    let kw = SCSigTableElmt {
+        name: b"altemplate.buffer\0".as_ptr() as *const libc::c_char,
+        desc: b"Template content modifier to match on the template buffer\0".as_ptr()
+            as *const libc::c_char,
+        // TODO use the right anchor for url and write doc
+        url: b"/rules/template-keywords.html#buffer\0".as_ptr() as *const libc::c_char,
+        Setup: template_buffer_setup,
+        flags: SIGMATCH_NOOPT | SIGMATCH_INFO_STICKY_BUFFER,
+        AppLayerTxMatch: None,
+        Free: None,
+    };
+    let _g_template_buffer_kw_id = DetectHelperKeywordRegister(&kw);
+    G_TEMPLATE_BUFFER_BUFFER_ID = DetectHelperBufferMpmRegister(
+        b"altemplate.buffer\0".as_ptr() as *const libc::c_char,
+        b"template.buffer intern description\0".as_ptr() as *const libc::c_char,
+        ALPROTO_TEMPLATE,
+        true, //toclient
+        true, //toserver
+        template_buffer_get,
+    );
+}

examples/plugins/altemplate/src/lib.rs

@@ -0,0 +1,5 @@
+mod detect;
+mod log;
+mod parser;
+pub mod plugin;
+mod template;

examples/plugins/altemplate/src/log.rs

@@ -0,0 +1,80 @@
+/* Copyright (C) 2018 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.
+ */
+
+// same file as rust/src/applayertemplate/logger.rs except
+// different paths for use statements
+// open_object using altemplate instead of just template
+// Addition of SCJsonBuilderWrapper to look like a rust app-layer
+// even if we must use C API for SCJsonBuilder (because of its rust repr)
+
+use super::template::TemplateTransaction;
+use std::ffi::CString;
+use suricata::cast_pointer;
+use suricata::jsonbuilder::JsonError;
+use suricata_sys::jsonbuilder::{SCJbClose, SCJbOpenObject, SCJbSetString, SCJsonBuilder};
+
+use std;
+
+// syntax sugar around C API of SCJsonBuilder to feel like a normal app-layer in log_template
+pub struct SCJsonBuilderWrapper {
+    inner: *mut SCJsonBuilder,
+}
+
+impl SCJsonBuilderWrapper {
+    fn close(&mut self) -> Result<(), JsonError> {
+        if unsafe { !SCJbClose(self.inner) } {
+            return Err(JsonError::Memory);
+        }
+        Ok(())
+    }
+    fn open_object(&mut self, key: &str) -> Result<(), JsonError> {
+        let keyc = CString::new(key).unwrap();
+        if unsafe { !SCJbOpenObject(self.inner, keyc.as_ptr()) } {
+            return Err(JsonError::Memory);
+        }
+        Ok(())
+    }
+    fn set_string(&mut self, key: &str, val: &str) -> Result<(), JsonError> {
+        let keyc = CString::new(key).unwrap();
+        let valc = CString::new(val.escape_default().to_string()).unwrap();
+        if unsafe { !SCJbSetString(self.inner, keyc.as_ptr(), valc.as_ptr()) } {
+            return Err(JsonError::Memory);
+        }
+        Ok(())
+    }
+}
+
+fn log_template(tx: &TemplateTransaction, js: &mut SCJsonBuilderWrapper) -> Result<(), JsonError> {
+    js.open_object("altemplate")?;
+    if let Some(ref request) = tx.request {
+        js.set_string("request", request)?;
+    }
+    if let Some(ref response) = tx.response {
+        js.set_string("response", response)?;
+    }
+    js.close()?;
+    Ok(())
+}
+
+pub(super) unsafe extern "C" fn template_logger_log(
+    tx: *const std::os::raw::c_void, js: *mut std::os::raw::c_void,
+) -> bool {
+    let tx = cast_pointer!(tx, TemplateTransaction);
+    let js = cast_pointer!(js, SCJsonBuilder);
+    let mut js = SCJsonBuilderWrapper { inner: js };
+    log_template(tx, &mut js).is_ok()
+}

examples/plugins/altemplate/src/parser.rs

@@ -0,0 +1,66 @@
+/* Copyright (C) 2018 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.
+ */
+
+// same file as rust/src/applayertemplate/parser.rs except this comment
+
+use nom7::{
+    bytes::streaming::{take, take_until},
+    combinator::map_res,
+    IResult,
+};
+use std;
+
+fn parse_len(input: &str) -> Result<u32, std::num::ParseIntError> {
+    input.parse::<u32>()
+}
+
+pub(super) fn parse_message(i: &[u8]) -> IResult<&[u8], String> {
+    let (i, len) = map_res(map_res(take_until(":"), std::str::from_utf8), parse_len)(i)?;
+    let (i, _sep) = take(1_usize)(i)?;
+    let (i, msg) = map_res(take(len as usize), std::str::from_utf8)(i)?;
+    let result = msg.to_string();
+    Ok((i, result))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use nom7::Err;
+
+    /// Simple test of some valid data.
+    #[test]
+    fn test_parse_valid() {
+        let buf = b"12:Hello World!4:Bye.";
+
+        let result = parse_message(buf);
+        match result {
+            Ok((remainder, message)) => {
+                // Check the first message.
+                assert_eq!(message, "Hello World!");
+
+                // And we should have 6 bytes left.
+                assert_eq!(remainder.len(), 6);
+            }
+            Err(Err::Incomplete(_)) => {
+                panic!("Result should not have been incomplete.");
+            }
+            Err(Err::Error(err)) | Err(Err::Failure(err)) => {
+                panic!("Result should not be an error: {:?}.", err);
+            }
+        }
+    }
+}

examples/plugins/altemplate/src/plugin.rs

@@ -0,0 +1,45 @@
+use super::template::template_register_parser;
+use crate::detect::detect_template_register;
+use crate::log::template_logger_log;
+use std::ffi::CString;
+use suricata::{SCLogError, SCLogNotice};
+use suricata_sys::sys::{
+    SCAppLayerPlugin, SCOutputJsonLogDirection, SCPlugin, SCPluginRegisterAppLayer, SC_API_VERSION,
+    SC_PACKAGE_VERSION,
+};
+
+extern "C" fn altemplate_plugin_init() {
+    suricata::plugin::init();
+    SCLogNotice!("Initializing altemplate plugin");
+    let plugin = SCAppLayerPlugin {
+        name: b"altemplate\0".as_ptr() as *const libc::c_char,
+        logname: b"JsonaltemplateLog\0".as_ptr() as *const libc::c_char,
+        confname: b"eve-log.altemplate\0".as_ptr() as *const libc::c_char,
+        dir: SCOutputJsonLogDirection::LOG_DIR_PACKET as u8,
+        Register: Some(template_register_parser),
+        Logger: Some(template_logger_log),
+        KeywordsRegister: Some(detect_template_register),
+    };
+    unsafe {
+        if SCPluginRegisterAppLayer(Box::into_raw(Box::new(plugin))) != 0 {
+            SCLogError!("Failed to register altemplate plugin");
+        }
+    }
+}
+
+#[no_mangle]
+extern "C" fn SCPluginRegister() -> *const SCPlugin {
+    // leak the CString
+    let plugin_version =
+        CString::new(env!("CARGO_PKG_VERSION")).unwrap().into_raw() as *const libc::c_char;
+    let plugin = SCPlugin {
+        version: SC_API_VERSION, // api version for suricata compatibility
+        suricata_version: SC_PACKAGE_VERSION.as_ptr() as *const libc::c_char,
+        name: b"altemplate\0".as_ptr() as *const libc::c_char,
+        plugin_version,
+        license: b"MIT\0".as_ptr() as *const libc::c_char,
+        author: b"Philippe Antoine\0".as_ptr() as *const libc::c_char,
+        Init: Some(altemplate_plugin_init),
+    };
+    Box::into_raw(Box::new(plugin))
+}

examples/plugins/altemplate/src/template.rs

@@ -0,0 +1,504 @@
+/* Copyright (C) 2018-2022 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.
+ */
+
+// same file as rust/src/applayertemplate/template.rs except
+// different paths for use statements
+// remove TEMPLATE_START_REMOVE
+// name is altemplate instead of template
+
+use super::parser;
+use nom7 as nom;
+use std;
+use std::collections::VecDeque;
+use std::ffi::CString;
+use std::os::raw::{c_char, c_int, c_void};
+use suricata::applayer::{
+    state_get_tx_iterator, AppLayerEvent, AppLayerParserConfParserEnabled,
+    AppLayerParserRegisterLogger, AppLayerParserStateIssetFlag,
+    AppLayerProtoDetectConfProtoDetectionEnabled, AppLayerRegisterParser,
+    AppLayerRegisterProtocolDetection, AppLayerResult, AppLayerStateData, AppLayerTxData,
+    RustParser, State, StreamSlice, Transaction, APP_LAYER_PARSER_EOF_TC, APP_LAYER_PARSER_EOF_TS,
+    APP_LAYER_PARSER_OPT_ACCEPT_GAPS,
+};
+use suricata::conf::conf_get;
+use suricata::core::{ALPROTO_UNKNOWN, IPPROTO_TCP};
+use suricata::flow::Flow;
+use suricata::{
+    build_slice, cast_pointer, export_state_data_get, export_tx_data_get, SCLogError, SCLogNotice,
+};
+use suricata_sys::sys::AppProto;
+
+static mut TEMPLATE_MAX_TX: usize = 256;
+
+pub(super) static mut ALPROTO_TEMPLATE: AppProto = ALPROTO_UNKNOWN;
+
+#[derive(AppLayerEvent)]
+enum TemplateEvent {
+    TooManyTransactions,
+}
+
+pub(super) struct TemplateTransaction {
+    tx_id: u64,
+    pub request: Option<String>,
+    pub response: Option<String>,
+
+    tx_data: AppLayerTxData,
+}
+
+impl Default for TemplateTransaction {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl TemplateTransaction {
+    pub fn new() -> TemplateTransaction {
+        Self {
+            tx_id: 0,
+            request: None,
+            response: None,
+            tx_data: AppLayerTxData::new(),
+        }
+    }
+}
+
+impl Transaction for TemplateTransaction {
+    fn id(&self) -> u64 {
+        self.tx_id
+    }
+}
+
+#[derive(Default)]
+struct TemplateState {
+    state_data: AppLayerStateData,
+    tx_id: u64,
+    transactions: VecDeque<TemplateTransaction>,
+    request_gap: bool,
+    response_gap: bool,
+}
+
+impl State<TemplateTransaction> for TemplateState {
+    fn get_transaction_count(&self) -> usize {
+        self.transactions.len()
+    }
+
+    fn get_transaction_by_index(&self, index: usize) -> Option<&TemplateTransaction> {
+        self.transactions.get(index)
+    }
+}
+
+impl TemplateState {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    // Free a transaction by ID.
+    fn free_tx(&mut self, tx_id: u64) {
+        let len = self.transactions.len();
+        let mut found = false;
+        let mut index = 0;
+        for i in 0..len {
+            let tx = &self.transactions[i];
+            if tx.tx_id == tx_id + 1 {
+                found = true;
+                index = i;
+                break;
+            }
+        }
+        if found {
+            self.transactions.remove(index);
+        }
+    }
+
+    pub fn get_tx(&mut self, tx_id: u64) -> Option<&TemplateTransaction> {
+        self.transactions.iter().find(|tx| tx.tx_id == tx_id + 1)
+    }
+
+    fn new_tx(&mut self) -> TemplateTransaction {
+        let mut tx = TemplateTransaction::new();
+        self.tx_id += 1;
+        tx.tx_id = self.tx_id;
+        return tx;
+    }
+
+    fn find_request(&mut self) -> Option<&mut TemplateTransaction> {
+        self.transactions
+            .iter_mut()
+            .find(|tx| tx.response.is_none())
+    }
+
+    fn parse_request(&mut self, input: &[u8]) -> AppLayerResult {
+        // We're not interested in empty requests.
+        if input.is_empty() {
+            return AppLayerResult::ok();
+        }
+
+        // If there was gap, check we can sync up again.
+        if self.request_gap {
+            if probe(input).is_err() {
+                // The parser now needs to decide what to do as we are not in sync.
+                // For this template, we'll just try again next time.
+                return AppLayerResult::ok();
+            }
+
+            // It looks like we're in sync with a message header, clear gap
+            // state and keep parsing.
+            self.request_gap = false;
+        }
+
+        let mut start = input;
+        while !start.is_empty() {
+            match parser::parse_message(start) {
+                Ok((rem, request)) => {
+                    start = rem;
+
+                    SCLogNotice!("Request: {}", request);
+                    let mut tx = self.new_tx();
+                    tx.request = Some(request);
+                    if self.transactions.len() >= unsafe { TEMPLATE_MAX_TX } {
+                        tx.tx_data
+                            .set_event(TemplateEvent::TooManyTransactions as u8);
+                    }
+                    self.transactions.push_back(tx);
+                    if self.transactions.len() >= unsafe { TEMPLATE_MAX_TX } {
+                        return AppLayerResult::err();
+                    }
+                }
+                Err(nom::Err::Incomplete(_)) => {
+                    // Not enough data. This parser doesn't give us a good indication
+                    // of how much data is missing so just ask for one more byte so the
+                    // parse is called as soon as more data is received.
+                    let consumed = input.len() - start.len();
+                    let needed = start.len() + 1;
+                    return AppLayerResult::incomplete(consumed as u32, needed as u32);
+                }
+                Err(_) => {
+                    return AppLayerResult::err();
+                }
+            }
+        }
+
+        // Input was fully consumed.
+        return AppLayerResult::ok();
+    }
+
+    fn parse_response(&mut self, input: &[u8]) -> AppLayerResult {
+        // We're not interested in empty responses.
+        if input.is_empty() {
+            return AppLayerResult::ok();
+        }
+
+        if self.response_gap {
+            if probe(input).is_err() {
+                // The parser now needs to decide what to do as we are not in sync.
+                // For this template, we'll just try again next time.
+                return AppLayerResult::ok();
+            }
+
+            // It looks like we're in sync with a message header, clear gap
+            // state and keep parsing.
+            self.response_gap = false;
+        }
+        let mut start = input;
+        while !start.is_empty() {
+            match parser::parse_message(start) {
+                Ok((rem, response)) => {
+                    start = rem;
+
+                    if let Some(tx) = self.find_request() {
+                        tx.tx_data.updated_tc = true;
+                        tx.response = Some(response);
+                        SCLogNotice!("Found response for request:");
+                        SCLogNotice!("- Request: {:?}", tx.request);
+                        SCLogNotice!("- Response: {:?}", tx.response);
+                    }
+                }
+                Err(nom::Err::Incomplete(_)) => {
+                    let consumed = input.len() - start.len();
+                    let needed = start.len() + 1;
+                    return AppLayerResult::incomplete(consumed as u32, needed as u32);
+                }
+                Err(_) => {
+                    return AppLayerResult::err();
+                }
+            }
+        }
+
+        // All input was fully consumed.
+        return AppLayerResult::ok();
+    }
+
+    fn on_request_gap(&mut self, _size: u32) {
+        self.request_gap = true;
+    }
+
+    fn on_response_gap(&mut self, _size: u32) {
+        self.response_gap = true;
+    }
+}
+
+/// Probe for a valid header.
+///
+/// As this template protocol uses messages prefixed with the size
+/// as a string followed by a ':', we look at up to the first 10
+/// characters for that pattern.
+fn probe(input: &[u8]) -> nom::IResult<&[u8], ()> {
+    let size = std::cmp::min(10, input.len());
+    let (rem, prefix) = nom::bytes::complete::take(size)(input)?;
+    nom::sequence::terminated(
+        nom::bytes::complete::take_while1(nom::character::is_digit),
+        nom::bytes::complete::tag(":"),
+    )(prefix)?;
+    Ok((rem, ()))
+}
+
+// C exports.
+
+/// C entry point for a probing parser.
+unsafe extern "C" fn rs_template_probing_parser(
+    _flow: *const Flow, _direction: u8, input: *const u8, input_len: u32, _rdir: *mut u8,
+) -> AppProto {
+    // Need at least 2 bytes.
+    if input_len > 1 && !input.is_null() {
+        let slice = build_slice!(input, input_len as usize);
+        if probe(slice).is_ok() {
+            return ALPROTO_TEMPLATE;
+        }
+    }
+    return ALPROTO_UNKNOWN;
+}
+
+extern "C" fn rs_template_state_new(
+    _orig_state: *mut c_void, _orig_proto: AppProto,
+) -> *mut c_void {
+    let state = TemplateState::new();
+    let boxed = Box::new(state);
+    return Box::into_raw(boxed) as *mut c_void;
+}
+
+unsafe extern "C" fn rs_template_state_free(state: *mut c_void) {
+    std::mem::drop(Box::from_raw(state as *mut TemplateState));
+}
+
+unsafe extern "C" fn rs_template_state_tx_free(state: *mut c_void, tx_id: u64) {
+    let state = cast_pointer!(state, TemplateState);
+    state.free_tx(tx_id);
+}
+
+unsafe extern "C" fn rs_template_parse_request(
+    _flow: *const Flow, state: *mut c_void, pstate: *mut c_void, stream_slice: StreamSlice,
+    _data: *const c_void,
+) -> AppLayerResult {
+    let eof = AppLayerParserStateIssetFlag(pstate, APP_LAYER_PARSER_EOF_TS) > 0;
+
+    if eof {
+        // If needed, handle EOF, or pass it into the parser.
+        return AppLayerResult::ok();
+    }
+
+    let state = cast_pointer!(state, TemplateState);
+
+    if stream_slice.is_gap() {
+        // Here we have a gap signaled by the input being null, but a greater
+        // than 0 input_len which provides the size of the gap.
+        state.on_request_gap(stream_slice.gap_size());
+        AppLayerResult::ok()
+    } else {
+        let buf = stream_slice.as_slice();
+        state.parse_request(buf)
+    }
+}
+
+unsafe extern "C" fn rs_template_parse_response(
+    _flow: *const Flow, state: *mut c_void, pstate: *mut c_void, stream_slice: StreamSlice,
+    _data: *const c_void,
+) -> AppLayerResult {
+    let _eof = AppLayerParserStateIssetFlag(pstate, APP_LAYER_PARSER_EOF_TC) > 0;
+    let state = cast_pointer!(state, TemplateState);
+
+    if stream_slice.is_gap() {
+        // Here we have a gap signaled by the input being null, but a greater
+        // than 0 input_len which provides the size of the gap.
+        state.on_response_gap(stream_slice.gap_size());
+        AppLayerResult::ok()
+    } else {
+        let buf = stream_slice.as_slice();
+        state.parse_response(buf)
+    }
+}
+
+unsafe extern "C" fn rs_template_state_get_tx(state: *mut c_void, tx_id: u64) -> *mut c_void {
+    let state = cast_pointer!(state, TemplateState);
+    match state.get_tx(tx_id) {
+        Some(tx) => {
+            return tx as *const _ as *mut _;
+        }
+        None => {
+            return std::ptr::null_mut();
+        }
+    }
+}
+
+unsafe extern "C" fn rs_template_state_get_tx_count(state: *mut c_void) -> u64 {
+    let state = cast_pointer!(state, TemplateState);
+    return state.tx_id;
+}
+
+unsafe extern "C" fn rs_template_tx_get_alstate_progress(tx: *mut c_void, _direction: u8) -> c_int {
+    let tx = cast_pointer!(tx, TemplateTransaction);
+
+    // Transaction is done if we have a response.
+    if tx.response.is_some() {
+        return 1;
+    }
+    return 0;
+}
+
+export_tx_data_get!(rs_template_get_tx_data, TemplateTransaction);
+export_state_data_get!(rs_template_get_state_data, TemplateState);
+
+// Parser name as a C style string.
+const PARSER_NAME: &[u8] = b"altemplate\0";
+
+pub(super) unsafe extern "C" fn template_register_parser() {
+    let default_port = CString::new("[7000]").unwrap();
+    let parser = RustParser {
+        name: PARSER_NAME.as_ptr() as *const c_char,
+        default_port: default_port.as_ptr(),
+        ipproto: IPPROTO_TCP,
+        probe_ts: Some(rs_template_probing_parser),
+        probe_tc: Some(rs_template_probing_parser),
+        min_depth: 0,
+        max_depth: 16,
+        state_new: rs_template_state_new,
+        state_free: rs_template_state_free,
+        tx_free: rs_template_state_tx_free,
+        parse_ts: rs_template_parse_request,
+        parse_tc: rs_template_parse_response,
+        get_tx_count: rs_template_state_get_tx_count,
+        get_tx: rs_template_state_get_tx,
+        tx_comp_st_ts: 1,
+        tx_comp_st_tc: 1,
+        tx_get_progress: rs_template_tx_get_alstate_progress,
+        get_eventinfo: Some(TemplateEvent::get_event_info),
+        get_eventinfo_byid: Some(TemplateEvent::get_event_info_by_id),
+        localstorage_new: None,
+        localstorage_free: None,
+        get_tx_files: None,
+        get_tx_iterator: Some(state_get_tx_iterator::<TemplateState, TemplateTransaction>),
+        get_tx_data: rs_template_get_tx_data,
+        get_state_data: rs_template_get_state_data,
+        apply_tx_config: None,
+        flags: APP_LAYER_PARSER_OPT_ACCEPT_GAPS,
+        get_frame_id_by_name: None,
+        get_frame_name_by_id: None,
+        get_state_id_by_name: None,
+        get_state_name_by_id: None,
+    };
+
+    let ip_proto_str = CString::new("tcp").unwrap();
+
+    if AppLayerProtoDetectConfProtoDetectionEnabled(ip_proto_str.as_ptr(), parser.name) != 0 {
+        let alproto = AppLayerRegisterProtocolDetection(&parser, 1);
+        ALPROTO_TEMPLATE = alproto;
+        if AppLayerParserConfParserEnabled(ip_proto_str.as_ptr(), parser.name) != 0 {
+            let _ = AppLayerRegisterParser(&parser, alproto);
+        }
+        if let Some(val) = conf_get("app-layer.protocols.template.max-tx") {
+            if let Ok(v) = val.parse::<usize>() {
+                TEMPLATE_MAX_TX = v;
+            } else {
+                SCLogError!("Invalid value for template.max-tx");
+            }
+        }
+        AppLayerParserRegisterLogger(IPPROTO_TCP, ALPROTO_TEMPLATE);
+        SCLogNotice!("Rust template parser registered.");
+    } else {
+        SCLogNotice!("Protocol detector and parser disabled for TEMPLATE.");
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_probe() {
+        assert!(probe(b"1").is_err());
+        assert!(probe(b"1:").is_ok());
+        assert!(probe(b"123456789:").is_ok());
+        assert!(probe(b"0123456789:").is_err());
+    }
+
+    #[test]
+    fn test_incomplete() {
+        let mut state = TemplateState::new();
+        let buf = b"5:Hello3:bye";
+
+        let r = state.parse_request(&buf[0..0]);
+        assert_eq!(
+            r,
+            AppLayerResult {
+                status: 0,
+                consumed: 0,
+                needed: 0
+            }
+        );
+
+        let r = state.parse_request(&buf[0..1]);
+        assert_eq!(
+            r,
+            AppLayerResult {
+                status: 1,
+                consumed: 0,
+                needed: 2
+            }
+        );
+
+        let r = state.parse_request(&buf[0..2]);
+        assert_eq!(
+            r,
+            AppLayerResult {
+                status: 1,
+                consumed: 0,
+                needed: 3
+            }
+        );
+
+        // This is the first message and only the first message.
+        let r = state.parse_request(&buf[0..7]);
+        assert_eq!(
+            r,
+            AppLayerResult {
+                status: 0,
+                consumed: 0,
+                needed: 0
+            }
+        );
+
+        // The first message and a portion of the second.
+        let r = state.parse_request(&buf[0..9]);
+        assert_eq!(
+            r,
+            AppLayerResult {
+                status: 1,
+                consumed: 7,
+                needed: 3
+            }
+        );
+    }
+}