[usm] add continuation_frames counter to ebpf.http2_telemetry_t

pkg/network/ebpf/c/protocols/http2/decoding-defs.h

@@ -226,8 +226,8 @@ typedef struct {
 // literal_value_exceeds_frame          Count of times we couldn't retrieve the literal value due to reaching the end of the frame.
 // exceeding_max_interesting_frames		Count of times we reached the max number of frames per iteration.
 // exceeding_max_frames_to_filter		Count of times we have left with more frames to filter than the max number of frames to filter.
+// continuation_frames                  Count of occurrences where a frame of type CONTINUATION was found.
 // path_size_bucket                     Count of path sizes and divided into buckets.
-// frames_split_count                   Count of times we tried to read more data than the end of the data end.
 typedef struct {
     __u64 request_seen;
     __u64 response_seen;
@@ -236,6 +236,7 @@ typedef struct {
     __u64 literal_value_exceeds_frame;
     __u64 exceeding_max_interesting_frames;
     __u64 exceeding_max_frames_to_filter;
+    __u64 continuation_frames;
     __u64 path_size_bucket[HTTP2_TELEMETRY_PATH_BUCKETS+1];
 } http2_telemetry_t;
 

pkg/network/ebpf/c/protocols/http2/decoding.h

@@ -896,12 +896,12 @@ static __always_inline void headers_parser(pktbuf_t pkt, void *map_key, conn_tup
     }
     bpf_memset(headers_to_process, 0, HTTP2_MAX_HEADERS_COUNT_FOR_PROCESSING * sizeof(http2_header_t));
 
-    __u8 interesting_headers = 0;
-
     __u64 *global_dynamic_counter = get_dynamic_counter(tup);
     if (global_dynamic_counter == NULL) {
         goto delete_iteration;
     }
+    __u8 interesting_headers = 0;
+    __u8 continuation_frames = 0;
 
     #pragma unroll(HTTP2_MAX_FRAMES_FOR_HEADERS_PARSER_PER_TAIL_CALL)
     for (__u16 index = 0; index < HTTP2_MAX_FRAMES_FOR_HEADERS_PARSER_PER_TAIL_CALL; index++) {
@@ -915,6 +915,9 @@ static __always_inline void headers_parser(pktbuf_t pkt, void *map_key, conn_tup
         current_frame = frames_array[tail_call_state->iteration];
         tail_call_state->iteration += 1;
 
+        if (current_frame.frame.type == kContinuationFrame) {
+            continuation_frames++;
+        }
         if (current_frame.frame.type != kHeadersFrame) {
             continue;
         }
@@ -930,6 +933,7 @@ static __always_inline void headers_parser(pktbuf_t pkt, void *map_key, conn_tup
         interesting_headers = pktbuf_filter_relevant_headers(pkt, global_dynamic_counter, &http2_ctx->dynamic_index, headers_to_process, current_frame.frame.length, http2_tel);
         pktbuf_process_headers(pkt, &http2_ctx->dynamic_index, current_stream, headers_to_process, interesting_headers, http2_tel);
     }
+    __sync_fetch_and_add(&http2_tel->continuation_frames, 1);
 
     if (tail_call_state->iteration < HTTP2_MAX_FRAMES_ITERATIONS &&
         tail_call_state->iteration < tail_call_state->frames_count &&

pkg/network/protocols/http2/model_linux.go

@@ -445,6 +445,7 @@ HTTP2Telemetry{
 	"literal values exceed message count": %d,
 	"messages with more frames than we can filter": %d,
 	"messages with more interesting frames than we can process": %d,
+    "continuation frames" : %d,
 	"path headers length distribution": {
 		"in range [0, 120)": %d,
 		"in range [120, 130)": %d,
@@ -456,7 +457,7 @@ HTTP2Telemetry{
 		"in range [180, infinity)": %d
 	}
 }`, t.Request_seen, t.Response_seen, t.End_of_stream, t.End_of_stream_rst, t.Literal_value_exceeds_frame,
-		t.Exceeding_max_frames_to_filter, t.Exceeding_max_interesting_frames, t.Path_size_bucket[0], t.Path_size_bucket[1],
-		t.Path_size_bucket[2], t.Path_size_bucket[3], t.Path_size_bucket[4], t.Path_size_bucket[5], t.Path_size_bucket[6],
-		t.Path_size_bucket[7])
+		t.Exceeding_max_frames_to_filter, t.Exceeding_max_interesting_frames, t.Continuation_frames,
+		t.Path_size_bucket[0], t.Path_size_bucket[1], t.Path_size_bucket[2], t.Path_size_bucket[3],
+		t.Path_size_bucket[4], t.Path_size_bucket[5], t.Path_size_bucket[6], t.Path_size_bucket[7])
 }

pkg/network/protocols/http2/telemetry.go

@@ -34,6 +34,8 @@ type kernelTelemetry struct {
 	exceedingMaxInterestingFrames *libtelemetry.TLSAwareCounter
 	// exceedingMaxFramesToFilter Count of times we have left with more frames to filter than the max number of frames to filter.
 	exceedingMaxFramesToFilter *libtelemetry.TLSAwareCounter
+	// continuationFramesCount Count of occurrences where a frame of type CONTINUATION was found.
+	continuationFramesCount *libtelemetry.TLSAwareCounter
 	// fragmentedFrameCountRST Count of times we have seen a fragmented RST frame.
 	fragmentedFrameCountRST *libtelemetry.TLSAwareCounter
 	// fragmentedHeadersFrameEOSCount Count of times we have seen a fragmented headers frame with EOS.
@@ -58,6 +60,7 @@ func newHTTP2KernelTelemetry() *kernelTelemetry {
 		literalValueExceedsFrame:       libtelemetry.NewTLSAwareCounter(metricGroup, "literal_value_exceeds_frame"),
 		exceedingMaxInterestingFrames:  libtelemetry.NewTLSAwareCounter(metricGroup, "exceeding_max_interesting_frames"),
 		exceedingMaxFramesToFilter:     libtelemetry.NewTLSAwareCounter(metricGroup, "exceeding_max_frames_to_filter"),
+		continuationFramesCount:        libtelemetry.NewTLSAwareCounter(metricGroup, "continuation_frames"),
 		fragmentedDataFrameEOSCount:    libtelemetry.NewTLSAwareCounter(metricGroup, "exceeding_data_end_data_eos"),
 		fragmentedHeadersFrameCount:    libtelemetry.NewTLSAwareCounter(metricGroup, "exceeding_data_end_headers"),
 		fragmentedHeadersFrameEOSCount: libtelemetry.NewTLSAwareCounter(metricGroup, "exceeding_data_end_headers_eos"),
@@ -81,6 +84,7 @@ func (t *kernelTelemetry) update(tel *HTTP2Telemetry, isTLS bool) {
 	t.literalValueExceedsFrame.Add(int64(telemetryDelta.Literal_value_exceeds_frame), isTLS)
 	t.exceedingMaxInterestingFrames.Add(int64(telemetryDelta.Exceeding_max_interesting_frames), isTLS)
 	t.exceedingMaxFramesToFilter.Add(int64(telemetryDelta.Exceeding_max_frames_to_filter), isTLS)
+	t.continuationFramesCount.Add(int64(telemetryDelta.Continuation_frames), isTLS)
 	for bucketIndex := range t.pathSizeBucket {
 		t.pathSizeBucket[bucketIndex].Add(int64(telemetryDelta.Path_size_bucket[bucketIndex]), isTLS)
 	}
@@ -104,6 +108,7 @@ func (t *HTTP2Telemetry) Sub(other HTTP2Telemetry) *HTTP2Telemetry {
 		Literal_value_exceeds_frame:      t.Literal_value_exceeds_frame - other.Literal_value_exceeds_frame,
 		Exceeding_max_interesting_frames: t.Exceeding_max_interesting_frames - other.Exceeding_max_interesting_frames,
 		Exceeding_max_frames_to_filter:   t.Exceeding_max_frames_to_filter - other.Exceeding_max_frames_to_filter,
+		Continuation_frames:              t.Continuation_frames - other.Continuation_frames,
 		Path_size_bucket:                 computePathSizeBucketDifferences(t.Path_size_bucket, other.Path_size_bucket),
 	}
 }