# HG changeset patch
# User XingY Wang <winshining@163.com>
# Date 1698714765 -28800
#      Tue Oct 31 09:12:45 2023 +0800
# Node ID 760857905505f91c9627f3bfeb5b6e496f4992a8
# Parent  7ec761f0365f418511e30b82e9adf80bc56681df
QUIC: improved huffman decode debug tracing.

Previously, only HTTP2 used huffman encoding (gRPC is util now
HTTP2 based), as HTTP3 becomes available, both of them uses huffman
encoding. But existed debug log in huffman decode function is hard
coded using "http2" prefixes, if a client transports an incorrect
huffman encoded field value in an HTTP3 request, it will give an
erroneous log. With the patch, it will properly log a bad field value.
Alternatively, removing "http2" prefixes only is ok, but it can not
differentiate whether it is caused by an HTTP2 or an HTTP3 request.

diff -r 7ec761f0365f -r 760857905505 src/http/modules/ngx_http_grpc_module.c
--- a/src/http/modules/ngx_http_grpc_module.c	Thu Oct 26 23:35:09 2023 +0300
+++ b/src/http/modules/ngx_http_grpc_module.c	Tue Oct 31 09:12:45 2023 +0800
@@ -3189,6 +3189,7 @@
                 if (ngx_http_huff_decode(&ctx->field_state, p, size,
                                          &ctx->field_end,
                                          ctx->field_rest == 0,
+                                         NGX_HTTP_VERSION_20,
                                          r->connection->log)
                     != NGX_OK)
                 {
@@ -3298,6 +3299,7 @@
                 if (ngx_http_huff_decode(&ctx->field_state, p, size,
                                          &ctx->field_end,
                                          ctx->field_rest == 0,
+                                         NGX_HTTP_VERSION_20,
                                          r->connection->log)
                     != NGX_OK)
                 {
diff -r 7ec761f0365f -r 760857905505 src/http/ngx_http.h
--- a/src/http/ngx_http.h	Thu Oct 26 23:35:09 2023 +0300
+++ b/src/http/ngx_http.h	Tue Oct 31 09:12:45 2023 +0800
@@ -179,7 +179,7 @@
 
 #if (NGX_HTTP_V2 || NGX_HTTP_V3)
 ngx_int_t ngx_http_huff_decode(u_char *state, u_char *src, size_t len,
-    u_char **dst, ngx_uint_t last, ngx_log_t *log);
+    u_char **dst, ngx_uint_t last, ngx_uint_t http_version, ngx_log_t *log);
 size_t ngx_http_huff_encode(u_char *src, size_t len, u_char *dst,
     ngx_uint_t lower);
 #endif
diff -r 7ec761f0365f -r 760857905505 src/http/ngx_http_huff_decode.c
--- a/src/http/ngx_http_huff_decode.c	Thu Oct 26 23:35:09 2023 +0300
+++ b/src/http/ngx_http_huff_decode.c	Tue Oct 31 09:12:45 2023 +0800
@@ -2641,9 +2641,22 @@
 
 ngx_int_t
 ngx_http_huff_decode(u_char *state, u_char *src, size_t len, u_char **dst,
-    ngx_uint_t last, ngx_log_t *log)
+    ngx_uint_t last, ngx_uint_t http_version, ngx_log_t *log)
 {
     u_char  *end, ch, ending;
+#if (NGX_DEBUG)
+    char    *from = NULL;
+
+    switch (http_version) {
+
+    case NGX_HTTP_VERSION_30:
+        from = "http3";
+        break;
+
+    default:
+        from = "http2";
+    }
+#endif
 
     ch = 0;
     ending = 1;
@@ -2656,9 +2669,9 @@
         if (ngx_http_huff_decode_bits(state, &ending, ch >> 4, dst)
             != NGX_OK)
         {
-            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, log, 0,
-                           "http2 huffman decoding error at state %d: "
-                           "bad code 0x%Xd", *state, ch >> 4);
+            ngx_log_debug3(NGX_LOG_DEBUG_HTTP, log, 0,
+                           "%s huffman decoding error at state %d: "
+                           "bad code 0x%Xd", from, *state, ch >> 4);
 
             return NGX_ERROR;
         }
@@ -2666,9 +2679,9 @@
         if (ngx_http_huff_decode_bits(state, &ending, ch & 0xf, dst)
             != NGX_OK)
         {
-            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, log, 0,
-                           "http2 huffman decoding error at state %d: "
-                           "bad code 0x%Xd", *state, ch & 0xf);
+            ngx_log_debug3(NGX_LOG_DEBUG_HTTP, log, 0,
+                           "%s huffman decoding error at state %d: "
+                           "bad code 0x%Xd", from, *state, ch & 0xf);
 
             return NGX_ERROR;
         }
@@ -2676,9 +2689,9 @@
 
     if (last) {
         if (!ending) {
-            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, log, 0,
-                           "http2 huffman decoding error: "
-                           "incomplete code 0x%Xd", ch);
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, log, 0,
+                           "%s huffman decoding error: "
+                           "incomplete code 0x%Xd", from, ch);
 
             return NGX_ERROR;
         }
diff -r 7ec761f0365f -r 760857905505 src/http/v2/ngx_http_v2.c
--- a/src/http/v2/ngx_http_v2.c	Thu Oct 26 23:35:09 2023 +0300
+++ b/src/http/v2/ngx_http_v2.c	Tue Oct 31 09:12:45 2023 +0800
@@ -1579,6 +1579,7 @@
     if (ngx_http_huff_decode(&h2c->state.field_state, pos, size,
                              &h2c->state.field_end,
                              h2c->state.field_rest == 0,
+                             NGX_HTTP_VERSION_20,
                              h2c->connection->log)
         != NGX_OK)
     {
diff -r 7ec761f0365f -r 760857905505 src/http/v3/ngx_http_v3_parse.c
--- a/src/http/v3/ngx_http_v3_parse.c	Thu Oct 26 23:35:09 2023 +0300
+++ b/src/http/v3/ngx_http_v3_parse.c	Tue Oct 31 09:12:45 2023 +0800
@@ -647,7 +647,8 @@
 
             if (st->huffman) {
                 if (ngx_http_huff_decode(&st->huffstate, &ch, 1, &st->last,
-                                         st->length == 1, c->log)
+                                         st->length == 1, NGX_HTTP_VERSION_30,
+                                         c->log)
                     != NGX_OK)
                 {
                     return NGX_ERROR;