http2: use a reference counter for headers

Ticket: 6892

As HTTP hpack header compression allows one single byte to
express a previously seen arbitrary-size header block (name+value)
we should avoid to copy the vectors data, but just point
to the same data, while reamining memory safe, even in the case
of later headers eviction from the dybnamic table.

Rust std solution is Rc, and the use of clone, so long as the
data is accessed by only one thread.

diff --git a/rust/src/http2/detect.rs b/rust/src/http2/detect.rs
index 52b41190555bc55656ed771047e208e33d3e5dbb..67933b6c24461e0721ae0bf8da0bb853693fc6eb 100644 (file)
--- a/rust/src/http2/detect.rs
+++ b/rust/src/http2/detect.rs
@@ -23,6 +23,7 @@ use crate::core::Direction;
 use crate::detect::uint::{detect_match_uint, DetectUintData};
 use std::ffi::CStr;
 use std::str::FromStr;
+use std::rc::Rc;
 
 fn http2_tx_has_frametype(
     tx: &mut HTTP2Transaction, direction: Direction, value: u8,
@@ -404,7 +405,7 @@ fn http2_frames_get_header_firstvalue<'a>(
     for frame in frames {
         if let Some(blocks) = http2_header_blocks(frame) {
             for block in blocks.iter() {
-                if block.name == name.as_bytes() {
+                if block.name.as_ref() == name.as_bytes() {
                     return Ok(&block.value);
                 }
             }
@@ -428,7 +429,7 @@ pub fn http2_frames_get_header_value_vec(
     for frame in frames {
         if let Some(blocks) = http2_header_blocks(frame) {
             for block in blocks.iter() {
-                if block.name == name.as_bytes() {
+                if block.name.as_ref() == name.as_bytes() {
                     if found == 0 {
                         vec.extend_from_slice(&block.value);
                         found = 1;
@@ -465,7 +466,7 @@ fn http2_frames_get_header_value<'a>(
     for frame in frames {
         if let Some(blocks) = http2_header_blocks(frame) {
             for block in blocks.iter() {
-                if block.name == name.as_bytes() {
+                if block.name.as_ref() == name.as_bytes() {
                     if found == 0 {
                         single = Ok(&block.value);
                         found = 1;
@@ -920,8 +921,8 @@ fn http2_tx_set_header(state: &mut HTTP2State, name: &[u8], input: &[u8]) {
     };
     let mut blocks = Vec::new();
     let b = parser::HTTP2FrameHeaderBlock {
-        name: name.to_vec(),
-        value: input.to_vec(),
+        name: Rc::new(name.to_vec()),
+        value: Rc::new(input.to_vec()),
         error: parser::HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess,
         sizeupdate: 0,
     };
@@ -1063,15 +1064,15 @@ mod tests {
         };
         let mut blocks = Vec::new();
         let b = parser::HTTP2FrameHeaderBlock {
-            name: "Host".as_bytes().to_vec(),
-            value: "abc.com".as_bytes().to_vec(),
+            name: "Host".as_bytes().to_vec().into(),
+            value: "abc.com".as_bytes().to_vec().into(),
             error: parser::HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess,
             sizeupdate: 0,
         };
         blocks.push(b);
         let b2 = parser::HTTP2FrameHeaderBlock {
-            name: "Host".as_bytes().to_vec(),
-            value: "efg.net".as_bytes().to_vec(),
+            name: "Host".as_bytes().to_vec().into(),
+            value: "efg.net".as_bytes().to_vec().into(),
             error: parser::HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess,
             sizeupdate: 0,
         };

diff --git a/rust/src/http2/http2.rs b/rust/src/http2/http2.rs
index 1a45881949c6230c9c8e0fb083de335971ba9daf..d620eb77fadc8b5b8d47974e8579304cf1251170 100644 (file)
--- a/rust/src/http2/http2.rs
+++ b/rust/src/http2/http2.rs
@@ -208,7 +208,7 @@ impl HTTP2Transaction {
         let mut authority = None;
         let mut host = None;
         for block in blocks {
-            if block.name == b"content-encoding" {
+            if block.name.as_ref() == b"content-encoding" {
                 self.decoder.http2_encoding_fromvec(&block.value, dir);
             } else if block.name.eq_ignore_ascii_case(b":authority") {
                 authority = Some(&block.value);

diff --git a/rust/src/http2/parser.rs b/rust/src/http2/parser.rs
index 39df368a84163456fe81368a17e88c8a7bf26fb4..b4681cba300814b5b12e1900424c0b2c9fea76e6 100644 (file)
--- a/rust/src/http2/parser.rs
+++ b/rust/src/http2/parser.rs
@@ -30,6 +30,7 @@ use nom7::sequence::tuple;
 use nom7::{Err, IResult};
 use std::fmt;
 use std::str::FromStr;
+use std::rc::Rc;
 
 #[repr(u8)]
 #[derive(Clone, Copy, PartialEq, Eq, FromPrimitive, Debug)]
@@ -295,8 +296,8 @@ fn http2_frame_header_static(n: u64, dyn_headers: &HTTP2DynTable) -> Option<HTTP
     };
     if !name.is_empty() {
         return Some(HTTP2FrameHeaderBlock {
-            name: name.as_bytes().to_vec(),
-            value: value.as_bytes().to_vec(),
+            name: Rc::new(name.as_bytes().to_vec()),
+            value: Rc::new(value.as_bytes().to_vec()),
             error: HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess,
             sizeupdate: 0,
         });
@@ -304,23 +305,23 @@ fn http2_frame_header_static(n: u64, dyn_headers: &HTTP2DynTable) -> Option<HTTP
         //use dynamic table
         if n == 0 {
             return Some(HTTP2FrameHeaderBlock {
-                name: Vec::new(),
-                value: Vec::new(),
+                name: Rc::new(Vec::new()),
+                value: Rc::new(Vec::new()),
                 error: HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeIndex0,
                 sizeupdate: 0,
             });
         } else if dyn_headers.table.len() + HTTP2_STATIC_HEADERS_NUMBER < n as usize {
             return Some(HTTP2FrameHeaderBlock {
-                name: Vec::new(),
-                value: Vec::new(),
+                name: Rc::new(Vec::new()),
+                value: Rc::new(Vec::new()),
                 error: HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeNotIndexed,
                 sizeupdate: 0,
             });
         } else {
             let indyn = dyn_headers.table.len() - (n as usize - HTTP2_STATIC_HEADERS_NUMBER);
             let headcopy = HTTP2FrameHeaderBlock {
-                name: dyn_headers.table[indyn].name.to_vec(),
-                value: dyn_headers.table[indyn].value.to_vec(),
+                name: dyn_headers.table[indyn].name.clone(),
+                value: dyn_headers.table[indyn].value.clone(),
                 error: HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess,
                 sizeupdate: 0,
             };
@@ -348,8 +349,10 @@ impl fmt::Display for HTTP2HeaderDecodeStatus {
 
 #[derive(Clone, Debug)]
 pub struct HTTP2FrameHeaderBlock {
-    pub name: Vec<u8>,
-    pub value: Vec<u8>,
+    // Use Rc reference counted so that indexed headers do not get copied.
+    // Otherwise, this leads to quadratic complexity in memory occupation.
+    pub name: Rc<Vec<u8>>,
+    pub value: Rc<Vec<u8>>,
     pub error: HTTP2HeaderDecodeStatus,
     pub sizeupdate: u64,
 }
@@ -391,7 +394,7 @@ fn http2_parse_headers_block_literal_common<'a>(
 ) -> IResult<&'a [u8], HTTP2FrameHeaderBlock> {
     let (i3, name, error) = if index == 0 {
         match http2_parse_headers_block_string(input) {
-            Ok((r, n)) => Ok((r, n, HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess)),
+            Ok((r, n)) => Ok((r, Rc::new(n), HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSuccess)),
             Err(e) => Err(e),
         }
     } else {
@@ -403,7 +406,7 @@ fn http2_parse_headers_block_literal_common<'a>(
             )),
             None => Ok((
                 input,
-                Vec::new(),
+                Rc::new(Vec::new()),
                 HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeNotIndexed,
             )),
         }
@@ -413,7 +416,7 @@ fn http2_parse_headers_block_literal_common<'a>(
         i4,
         HTTP2FrameHeaderBlock {
             name,
-            value,
+            value: Rc::new(value),
             error,
             sizeupdate: 0,
         },
@@ -435,8 +438,8 @@ fn http2_parse_headers_block_literal_incindex<'a>(
     match r {
         Ok((r, head)) => {
             let headcopy = HTTP2FrameHeaderBlock {
-                name: head.name.to_vec(),
-                value: head.value.to_vec(),
+                name: head.name.clone(),
+                value: head.value.clone(),
                 error: head.error,
                 sizeupdate: 0,
             };
@@ -556,8 +559,8 @@ fn http2_parse_headers_block_dynamic_size<'a>(
     return Ok((
         i3,
         HTTP2FrameHeaderBlock {
-            name: Vec::new(),
-            value: Vec::new(),
+            name: Rc::new(Vec::new()),
+            value: Rc::new(Vec::new()),
             error: HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeSizeUpdate,
             sizeupdate: maxsize2,
         },
@@ -614,8 +617,8 @@ fn http2_parse_headers_blocks<'a>(
                 // if we error from http2_parse_var_uint, we keep the first parsed headers
                 if err.code == ErrorKind::LengthValue {
                     blocks.push(HTTP2FrameHeaderBlock {
-                        name: Vec::new(),
-                        value: Vec::new(),
+                        name: Rc::new(Vec::new()),
+                        value: Rc::new(Vec::new()),
                         error: HTTP2HeaderDecodeStatus::HTTP2HeaderDecodeIntegerOverflow,
                         sizeupdate: 0,
                     });
@@ -769,8 +772,8 @@ mod tests {
         match r0 {
             Ok((remainder, hd)) => {
                 // Check the first message.
-                assert_eq!(hd.name, ":method".as_bytes().to_vec());
-                assert_eq!(hd.value, "GET".as_bytes().to_vec());
+                assert_eq!(hd.name, ":method".as_bytes().to_vec().into());
+                assert_eq!(hd.value, "GET".as_bytes().to_vec().into());
                 // And we should have no bytes left.
                 assert_eq!(remainder.len(), 0);
             }
@@ -786,8 +789,8 @@ mod tests {
         match r1 {
             Ok((remainder, hd)) => {
                 // Check the first message.
-                assert_eq!(hd.name, "accept".as_bytes().to_vec());
-                assert_eq!(hd.value, "*/*".as_bytes().to_vec());
+                assert_eq!(hd.name, "accept".as_bytes().to_vec().into());
+                assert_eq!(hd.value, "*/*".as_bytes().to_vec().into());
                 // And we should have no bytes left.
                 assert_eq!(remainder.len(), 0);
                 assert_eq!(dynh.table.len(), 1);
@@ -806,8 +809,8 @@ mod tests {
         match result {
             Ok((remainder, hd)) => {
                 // Check the first message.
-                assert_eq!(hd.name, ":authority".as_bytes().to_vec());
-                assert_eq!(hd.value, "localhost:3000".as_bytes().to_vec());
+                assert_eq!(hd.name, ":authority".as_bytes().to_vec().into());
+                assert_eq!(hd.value, "localhost:3000".as_bytes().to_vec().into());
                 // And we should have no bytes left.
                 assert_eq!(remainder.len(), 0);
                 assert_eq!(dynh.table.len(), 2);
@@ -824,8 +827,8 @@ mod tests {
         match r3 {
             Ok((remainder, hd)) => {
                 // same as before
-                assert_eq!(hd.name, ":authority".as_bytes().to_vec());
-                assert_eq!(hd.value, "localhost:3000".as_bytes().to_vec());
+                assert_eq!(hd.name, ":authority".as_bytes().to_vec().into());
+                assert_eq!(hd.value, "localhost:3000".as_bytes().to_vec().into());
                 // And we should have no bytes left.
                 assert_eq!(remainder.len(), 0);
                 assert_eq!(dynh.table.len(), 2);
@@ -860,8 +863,8 @@ mod tests {
         match r2 {
             Ok((remainder, hd)) => {
                 // Check the first message.
-                assert_eq!(hd.name, ":path".as_bytes().to_vec());
-                assert_eq!(hd.value, "/doc/manual/html/index.html".as_bytes().to_vec());
+                assert_eq!(hd.name, ":path".as_bytes().to_vec().into());
+                assert_eq!(hd.value, "/doc/manual/html/index.html".as_bytes().to_vec().into());
                 // And we should have no bytes left.
                 assert_eq!(remainder.len(), 0);
                 assert_eq!(dynh.table.len(), 2);