From f709631cf7997f106d093a577161daacc0a28f2a Mon Sep 17 00:00:00 2001 From: Shivani Bhardwaj Date: Mon, 19 May 2025 11:03:49 +0530 Subject: [PATCH] pop3: trigger raw stream inspection Internals --------- Suricata's stream engine returns data for inspection to the detection engine from the stream when the chunk size is reached. Bug --- Inspection triggered only in the specified chunk sizes may be too late when it comes to inspection of smaller protocol specific data which could result in delayed inspection, incorrect data logged with a transaction and logs misindicating the pkt that triggered an alert. Fix --- Fix this by making an explicit call from all respective applayer parsers to trigger raw stream inspection which shall make the data available for inspection in the following call of the stream engine. This needs to happen per direction on the completion of an entity like a request or a response. Important notes --------------- 1. The above mentioned behavior with and without this patch is affected internally by the following conditions. - inspection depth - stream depth In these special cases, the inspection window will be affected and Suricata may not consider all the data that could be expected to be inspected. 2. This only applies to applayer protocols running over TCP. 3. The inspection window is only considered up to the ACK'd data. 4. This entire issue is about IDS mode only. POP3 has a classic request response model where a request is mapped to a response although not by any ID. Appropriate calls to trigger raw stream inspection have been added on completion of each request and response. Task 7026 Bug 7004 --- rust/src/pop3/pop3.rs | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/rust/src/pop3/pop3.rs b/rust/src/pop3/pop3.rs index 1cb7f8d1f5..9980a0db15 100644 --- a/rust/src/pop3/pop3.rs +++ b/rust/src/pop3/pop3.rs @@ -21,7 +21,7 @@ use crate::applayer::*; use crate::conf::{conf_get, get_memval}; -use crate::core::{ALPROTO_FAILED, ALPROTO_UNKNOWN, IPPROTO_TCP}; +use crate::core::{ALPROTO_FAILED, ALPROTO_UNKNOWN, IPPROTO_TCP, sc_app_layer_parser_trigger_raw_stream_inspection}; use crate::flow::Flow; use crate::direction; use std; @@ -169,7 +169,7 @@ impl POP3State { .find(|tx| tx.response.is_none()) } - fn parse_request(&mut self, input: &[u8]) -> AppLayerResult { + fn parse_request(&mut self, flow: *const Flow, input: &[u8]) -> AppLayerResult { // We're not interested in empty requests. if input.is_empty() { return AppLayerResult::ok(); @@ -203,6 +203,7 @@ impl POP3State { tx.error_flags_to_events(msg.error_flags); tx.request = Some(command); self.transactions.push_back(tx); + sc_app_layer_parser_trigger_raw_stream_inspection(flow, direction::Direction::ToServer as i32); } start = rem; @@ -278,6 +279,7 @@ impl POP3State { tx.error_flags_to_events(msg.error_flags); tx.complete = true; + sc_app_layer_parser_trigger_raw_stream_inspection(flow, direction::Direction::ToClient as i32); if response.status == sawp_pop3::Status::OK && tx.request.is_some() { let command = tx.request.as_ref().unwrap(); @@ -397,7 +399,7 @@ unsafe extern "C" fn pop3_state_tx_free(state: *mut c_void, tx_id: u64) { } unsafe extern "C" fn pop3_parse_request( - _flow: *const Flow, state: *mut c_void, pstate: *mut c_void, stream_slice: StreamSlice, + 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; @@ -416,7 +418,7 @@ unsafe extern "C" fn pop3_parse_request( AppLayerResult::ok() } else { let buf = stream_slice.as_slice(); - state.parse_request(buf) + state.parse_request(flow, buf) } }