From 6ed827a4ef0dfb9706dfd2b41309318107b891a4 Mon Sep 17 00:00:00 2001
From: Jason Ish <jason.ish@oisf.net>
Date: Sun, 12 Jan 2020 23:13:54 -0600
Subject: [PATCH] dns: use derive macro for DNSEvent

---
 rust/Makefile.am    |   2 +-
 rust/src/dns/dns.rs | 110 ++++++++++++--------------------------------
 rust/src/lib.rs     |   3 ++
 3 files changed, 33 insertions(+), 82 deletions(-)

diff --git a/rust/Makefile.am b/rust/Makefile.am
index 8efd135efc..aa2b571789 100644
--- a/rust/Makefile.am
+++ b/rust/Makefile.am
@@ -1,4 +1,4 @@
-EXTRA_DIST =	src \
+EXTRA_DIST =	src derive \
 		.cargo/config.in \
 		cbindgen.toml \
 		dist/rust-bindings.h
diff --git a/rust/src/dns/dns.rs b/rust/src/dns/dns.rs
index 467c5a9acb..3e0031e3e9 100644
--- a/rust/src/dns/dns.rs
+++ b/rust/src/dns/dns.rs
@@ -115,84 +115,12 @@ pub const DNS_RCODE_BADTRUNC: u16 = 22;
 
 static mut ALPROTO_DNS: AppProto = ALPROTO_UNKNOWN;
 
-#[repr(u32)]
+#[derive(Debug, PartialEq, AppLayerEvent)]
 pub enum DNSEvent {
-    MalformedData = 0,
-    NotRequest = 1,
-    NotResponse = 2,
-    ZFlagSet = 3,
-}
-
-impl DNSEvent {
-    pub fn to_cstring(&self) -> &str {
-        match *self {
-            DNSEvent::MalformedData => "MALFORMED_DATA\0",
-            DNSEvent::NotRequest => "NOT_A_REQUEST\0",
-            DNSEvent::NotResponse => "NOT_A_RESPONSE\0",
-            DNSEvent::ZFlagSet => "Z_FLAG_SET\0",
-        }
-    }
-
-    pub fn from_id(id: u32) -> Option<DNSEvent> {
-        match id {
-            0 => Some(DNSEvent::MalformedData),
-            1 => Some(DNSEvent::NotRequest),
-            2 => Some(DNSEvent::NotResponse),
-            4 => Some(DNSEvent::ZFlagSet),
-            _ => None,
-        }
-    }
-
-    pub fn from_string(s: &str) -> Option<DNSEvent> {
-        match s.to_lowercase().as_ref() {
-            "malformed_data" => Some(DNSEvent::MalformedData),
-            "not_a_request" => Some(DNSEvent::NotRequest),
-            "not_a_response" => Some(DNSEvent::NotRequest),
-            "z_flag_set" => Some(DNSEvent::ZFlagSet),
-            _ => None
-        }
-    }
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn rs_dns_state_get_event_info_by_id(
-    event_id: std::os::raw::c_int,
-    event_name: *mut *const std::os::raw::c_char,
-    event_type: *mut core::AppLayerEventType,
-) -> i8 {
-    if let Some(e) = DNSEvent::from_id(event_id as u32) {
-        *event_name = e.to_cstring().as_ptr() as *const std::os::raw::c_char;
-        *event_type = core::APP_LAYER_EVENT_TYPE_TRANSACTION;
-        return 0;
-    }
-    return -1;
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn rs_dns_state_get_event_info(
-    event_name: *const std::os::raw::c_char,
-    event_id: *mut std::os::raw::c_int,
-    event_type: *mut core::AppLayerEventType
-) -> std::os::raw::c_int {
-    if event_name == std::ptr::null() {
-        return -1;
-    }
-
-    let event_name = std::ffi::CStr::from_ptr(event_name);
-    if let Ok(event_name) = event_name.to_str() {
-        if let Some(event) = DNSEvent::from_string(event_name) {
-            *event_id = event as std::os::raw::c_int;
-            *event_type = core::APP_LAYER_EVENT_TYPE_TRANSACTION;
-        } else {
-            // Unknown event...
-            return -1;
-        }
-    } else {
-        // UTF-8 conversion failed. Should not happen.
-        return -1;
-    }
-
-    return 0;
+    MalformedData,
+    NotRequest,
+    NotResponse,
+    ZFlagSet,
 }
 
 #[derive(Debug,PartialEq)]
@@ -1058,8 +986,8 @@ pub unsafe extern "C" fn rs_dns_udp_register_parser() {
         tx_comp_st_tc: 1,
         tx_get_progress: rs_dns_tx_get_alstate_progress,
         get_events: Some(rs_dns_state_get_events),
-        get_eventinfo: Some(rs_dns_state_get_event_info),
-        get_eventinfo_byid: Some(rs_dns_state_get_event_info_by_id),
+        get_eventinfo: Some(DNSEvent::get_event_info),
+        get_eventinfo_byid: Some(DNSEvent::get_event_info_by_id),
         localstorage_new: None,
         localstorage_free: None,
         get_files: None,
@@ -1104,8 +1032,8 @@ pub unsafe extern "C" fn rs_dns_tcp_register_parser() {
         tx_comp_st_tc: 1,
         tx_get_progress: rs_dns_tx_get_alstate_progress,
         get_events: Some(rs_dns_state_get_events),
-        get_eventinfo: Some(rs_dns_state_get_event_info),
-        get_eventinfo_byid: Some(rs_dns_state_get_event_info_by_id),
+        get_eventinfo: Some(DNSEvent::get_event_info),
+        get_eventinfo_byid: Some(DNSEvent::get_event_info_by_id),
         localstorage_new: None,
         localstorage_free: None,
         get_files: None,
@@ -1532,4 +1460,24 @@ mod tests {
             state.parse_request_tcp(buf3)
         );
     }
+
+    #[test]
+    fn test_dns_event_from_id() {
+        assert_eq!(DNSEvent::from_id(0), Some(DNSEvent::MalformedData));
+        assert_eq!(DNSEvent::from_id(3), Some(DNSEvent::ZFlagSet));
+        assert_eq!(DNSEvent::from_id(9), None);
+    }
+
+    #[test]
+    fn test_dns_event_to_cstring() {
+        assert_eq!(DNSEvent::MalformedData.to_cstring(), "malformed_data\0");
+    }
+
+    #[test]
+    fn test_dns_event_from_string() {
+        let name = "malformed_data";
+        let event = DNSEvent::from_string(&name).unwrap();
+        assert_eq!(event, DNSEvent::MalformedData);
+        assert_eq!(event.to_cstring(), format!("{}\0", name));
+    }
 }
diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index f27f76b94d..f1b38edd5d 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -85,6 +85,9 @@ extern crate kerberos_parser;
 extern crate tls_parser;
 extern crate x509_parser;
 
+#[macro_use]
+extern crate suricata_derive;
+
 #[macro_use]
 pub mod log;
 
-- 
2.47.2