[nginx] QUIC: improved packet and frames debug tracing.

[Sergey Kandaurov]

details:   https://hg.nginx.org/nginx/rev/7ec761f0365f
branches:  
changeset: 9184:7ec761f0365f
user:      Vladimir Khomutov <vl at wbsrv.ru>
date:      Thu Oct 26 23:35:09 2023 +0300
description:
QUIC: improved packet and frames debug tracing.

Currently, packets generated by ngx_quic_frame_sendto() and
ngx_quic_send_early_cc() are not logged, thus making it hard
to read logs due to gaps appearing in packet numbers sequence.

At frames level, it is handy to see immediately packet number
in which they arrived or being sent.

diffstat:

 src/event/quic/ngx_event_quic_frames.c    |   4 +-
 src/event/quic/ngx_event_quic_output.c    |  41 ++++++++++++++++++++----------
 src/event/quic/ngx_event_quic_transport.c |   3 ++
 3 files changed, 32 insertions(+), 16 deletions(-)

diffs (137 lines):

diff -r 8b1526a7e383 -r 7ec761f0365f src/event/quic/ngx_event_quic_frames.c
--- a/src/event/quic/ngx_event_quic_frames.c	Fri Oct 27 01:29:28 2023 +0400
+++ b/src/event/quic/ngx_event_quic_frames.c	Thu Oct 26 23:35:09 2023 +0300
@@ -886,8 +886,8 @@ ngx_quic_log_frame(ngx_log_t *log, ngx_q
         break;
     }
 
-    ngx_log_debug4(NGX_LOG_DEBUG_EVENT, log, 0, "quic frame %s %s %*s",
-                   tx ? "tx" : "rx", ngx_quic_level_name(f->level),
+    ngx_log_debug5(NGX_LOG_DEBUG_EVENT, log, 0, "quic frame %s %s:%uL %*s",
+                   tx ? "tx" : "rx", ngx_quic_level_name(f->level), f->pnum,
                    p - buf, buf);
 }
 
diff -r 8b1526a7e383 -r 7ec761f0365f src/event/quic/ngx_event_quic_output.c
--- a/src/event/quic/ngx_event_quic_output.c	Fri Oct 27 01:29:28 2023 +0400
+++ b/src/event/quic/ngx_event_quic_output.c	Thu Oct 26 23:35:09 2023 +0300
@@ -35,6 +35,15 @@
 #define NGX_QUIC_SOCKET_RETRY_DELAY      10 /* ms, for NGX_AGAIN on write */
 
 
+#define ngx_quic_log_packet(log, pkt)                                         \
+    ngx_log_debug6(NGX_LOG_DEBUG_EVENT, log, 0,                               \
+                   "quic packet tx %s bytes:%ui need_ack:%d"                  \
+                   " number:%L encoded nl:%d trunc:0x%xD",                    \
+                   ngx_quic_level_name((pkt)->level), (pkt)->payload.len,     \
+                   (pkt)->need_ack, (pkt)->number, (pkt)->num_len,            \
+                    (pkt)->trunc);
+
+
 static ngx_int_t ngx_quic_create_datagrams(ngx_connection_t *c);
 static void ngx_quic_commit_send(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx);
 static void ngx_quic_revert_send(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx,
@@ -578,6 +587,11 @@ ngx_quic_output_packet(ngx_connection_t 
             pkt.need_ack = 1;
         }
 
+        f->pnum = ctx->pnum;
+        f->first = now;
+        f->last = now;
+        f->plen = 0;
+
         ngx_quic_log_frame(c->log, f, 1);
 
         flen = ngx_quic_create_frame(p, f);
@@ -588,11 +602,6 @@ ngx_quic_output_packet(ngx_connection_t 
         len += flen;
         p += flen;
 
-        f->pnum = ctx->pnum;
-        f->first = now;
-        f->last = now;
-        f->plen = 0;
-
         nframes++;
     }
 
@@ -610,11 +619,7 @@ ngx_quic_output_packet(ngx_connection_t 
 
     res.data = data;
 
-    ngx_log_debug6(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "quic packet tx %s bytes:%ui"
-                   " need_ack:%d number:%L encoded nl:%d trunc:0x%xD",
-                   ngx_quic_level_name(ctx->level), pkt.payload.len,
-                   pkt.need_ack, pkt.number, pkt.num_len, pkt.trunc);
+    ngx_quic_log_packet(c->log, &pkt);
 
     if (ngx_quic_encrypt(&pkt, &res) != NGX_OK) {
         return NGX_ERROR;
@@ -899,13 +904,13 @@ ngx_quic_send_early_cc(ngx_connection_t 
     frame.u.close.reason.data = (u_char *) reason;
     frame.u.close.reason.len = ngx_strlen(reason);
 
+    ngx_quic_log_frame(c->log, &frame, 1);
+
     len = ngx_quic_create_frame(NULL, &frame);
     if (len > NGX_QUIC_MAX_UDP_PAYLOAD_SIZE) {
         return NGX_ERROR;
     }
 
-    ngx_quic_log_frame(c->log, &frame, 1);
-
     len = ngx_quic_create_frame(src, &frame);
     if (len == -1) {
         return NGX_ERROR;
@@ -940,6 +945,8 @@ ngx_quic_send_early_cc(ngx_connection_t 
 
     res.data = dst;
 
+    ngx_quic_log_packet(c->log, &pkt);
+
     if (ngx_quic_encrypt(&pkt, &res) != NGX_OK) {
         ngx_quic_keys_cleanup(pkt.keys);
         return NGX_ERROR;
@@ -1198,13 +1205,17 @@ ngx_quic_frame_sendto(ngx_connection_t *
     pad = 4 - pkt.num_len;
     min_payload = ngx_max(min_payload, pad);
 
+#if (NGX_DEBUG)
+    frame->pnum = pkt.number;
+#endif
+
+    ngx_quic_log_frame(c->log, frame, 1);
+
     len = ngx_quic_create_frame(NULL, frame);
     if (len > NGX_QUIC_MAX_UDP_PAYLOAD_SIZE) {
         return NGX_ERROR;
     }
 
-    ngx_quic_log_frame(c->log, frame, 1);
-
     len = ngx_quic_create_frame(src, frame);
     if (len == -1) {
         return NGX_ERROR;
@@ -1220,6 +1231,8 @@ ngx_quic_frame_sendto(ngx_connection_t *
 
     res.data = dst;
 
+    ngx_quic_log_packet(c->log, &pkt);
+
     if (ngx_quic_encrypt(&pkt, &res) != NGX_OK) {
         return NGX_ERROR;
     }
diff -r 8b1526a7e383 -r 7ec761f0365f src/event/quic/ngx_event_quic_transport.c
--- a/src/event/quic/ngx_event_quic_transport.c	Fri Oct 27 01:29:28 2023 +0400
+++ b/src/event/quic/ngx_event_quic_transport.c	Thu Oct 26 23:35:09 2023 +0300
@@ -1135,6 +1135,9 @@ ngx_quic_parse_frame(ngx_quic_header_t *
     }
 
     f->level = pkt->level;
+#if (NGX_DEBUG)
+    f->pnum = pkt->pn;
+#endif
 
     return p - start;