From: Stefan Eissing <stefan@eissing.org>
Date: Wed, 7 Jan 2026 11:12:29 +0000 (+0100)
Subject: http/3: add description for known server error codes
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f6e8531c03edcef9da222d1794d52d14247cd5ce;p=thirdparty%2Fcurl.git

http/3: add description for known server error codes

When a server resets a stream with an error code, list that code
and its known name in the failure message of the transfer.

Ref: #20195
Closes #20202
---

diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index 97ef98b971..43db734ef7 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -1372,7 +1372,9 @@ static CURLcode recv_closed_stream(struct Curl_cfilter *cf,
   (void)cf;
   *pnread = 0;
   if(stream->reset) {
-    failf(data, "HTTP/3 stream %" PRId64 " reset by server", stream->id);
+    failf(data, "HTTP/3 stream %" PRId64 " reset by server (error 0x%" PRIx64
+          " %s)", stream->id, stream->error3,
+          vquic_h3_err_str(stream->error3));
     return data->req.bytecount ? CURLE_PARTIAL_FILE : CURLE_HTTP3;
   }
   else if(!stream->resp_hds_complete) {
diff --git a/lib/vquic/curl_osslq.c b/lib/vquic/curl_osslq.c
index 464879788c..bcf9ab9549 100644
--- a/lib/vquic/curl_osslq.c
+++ b/lib/vquic/curl_osslq.c
@@ -2076,9 +2076,9 @@ static CURLcode recv_closed_stream(struct Curl_cfilter *cf,
   (void)cf;
   *pnread = 0;
   if(stream->reset) {
-    failf(data,
-          "HTTP/3 stream %" PRId64 " reset by server",
-          stream->s.id);
+    failf(data, "HTTP/3 stream %" PRId64 " reset by server (error 0x%" PRIx64
+          " %s)", stream->s.id, stream->error3,
+          vquic_h3_err_str(stream->error3));
     return data->req.bytecount ? CURLE_PARTIAL_FILE : CURLE_HTTP3;
   }
   else if(!stream->resp_hds_complete) {
diff --git a/lib/vquic/curl_quiche.c b/lib/vquic/curl_quiche.c
index e4140e776d..01f1bf5edd 100644
--- a/lib/vquic/curl_quiche.c
+++ b/lib/vquic/curl_quiche.c
@@ -855,7 +855,9 @@ static CURLcode recv_closed_stream(struct Curl_cfilter *cf,
   DEBUGASSERT(stream);
   *pnread = 0;
   if(stream->reset) {
-    failf(data, "HTTP/3 stream %" PRIu64 " reset by server", stream->id);
+    failf(data, "HTTP/3 stream %" PRId64 " reset by server (error 0x%" PRIx64
+          " %s)", stream->id, stream->error3,
+          vquic_h3_err_str(stream->error3));
     result = data->req.bytecount ? CURLE_PARTIAL_FILE : CURLE_HTTP3;
     CURL_TRC_CF(data, cf, "[%" PRIu64 "] cf_recv, was reset -> %d",
                 stream->id, result);
diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
index d7bfa99104..33ba12f476 100644
--- a/lib/vquic/vquic.c
+++ b/lib/vquic/vquic.c
@@ -742,6 +742,56 @@ CURLcode Curl_conn_may_http3(struct Curl_easy *data,
   return CURLE_OK;
 }
 
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+const char *vquic_h3_err_str(uint64_t error_code)
+{
+  if(error_code <= UINT_MAX) {
+    switch((unsigned int)error_code) {
+    case CURL_H3_ERR_NO_ERROR:
+      return "NO_ERROR";
+    case CURL_H3_ERR_GENERAL_PROTOCOL_ERROR:
+      return "GENERAL_PROTOCOL_ERROR";
+    case CURL_H3_ERR_INTERNAL_ERROR:
+      return "INTERNAL_ERROR";
+    case CURL_H3_ERR_STREAM_CREATION_ERROR:
+      return "STREAM_CREATION_ERROR";
+    case CURL_H3_ERR_CLOSED_CRITICAL_STREAM:
+      return "CLOSED_CRITICAL_STREAM";
+    case CURL_H3_ERR_FRAME_UNEXPECTED:
+      return "FRAME_UNEXPECTED";
+    case CURL_H3_ERR_FRAME_ERROR:
+      return "FRAME_ERROR";
+    case CURL_H3_ERR_EXCESSIVE_LOAD:
+      return "EXCESSIVE_LOAD";
+    case CURL_H3_ERR_ID_ERROR:
+      return "ID_ERROR";
+    case CURL_H3_ERR_SETTINGS_ERROR:
+      return "SETTINGS_ERROR";
+    case CURL_H3_ERR_MISSING_SETTINGS:
+      return "MISSING_SETTINGS";
+    case CURL_H3_ERR_REQUEST_REJECTED:
+      return "REQUEST_REJECTED";
+    case CURL_H3_ERR_REQUEST_CANCELLED:
+      return "REQUEST_CANCELLED";
+    case CURL_H3_ERR_REQUEST_INCOMPLETE:
+      return "REQUEST_INCOMPLETE";
+    case CURL_H3_ERR_MESSAGE_ERROR:
+      return "MESSAGE_ERROR";
+    case CURL_H3_ERR_CONNECT_ERROR:
+      return "CONNECT_ERROR";
+    case CURL_H3_ERR_VERSION_FALLBACK:
+      return "VERSION_FALLBACK";
+    default:
+      break;
+    }
+  }
+  /* RFC 9114 ch. 8.1 + 9, reserved future error codes that are NO_ERROR */
+  if((error_code >= 0x21) && !((error_code - 0x21) % 0x1f))
+    return "NO_ERROR";
+  return "unknown";
+}
+#endif /* CURL_DISABLE_VERBOSE_STRINGS */
+
 #if defined(USE_NGTCP2) || defined(USE_NGHTTP3)
 
 static void *vquic_ngtcp2_malloc(size_t size, void *user_data)
diff --git a/lib/vquic/vquic_int.h b/lib/vquic/vquic_int.h
index e602b7ee6d..a6d3d0ea54 100644
--- a/lib/vquic/vquic_int.h
+++ b/lib/vquic/vquic_int.h
@@ -32,6 +32,33 @@
 #define MAX_PKT_BURST         10
 #define MAX_UDP_PAYLOAD_SIZE  1452
 
+/* definitions from RFC 9114, ch 8.1 */
+typedef enum {
+  CURL_H3_ERR_NO_ERROR = 0x0100,
+  CURL_H3_ERR_GENERAL_PROTOCOL_ERROR = 0x0101,
+  CURL_H3_ERR_INTERNAL_ERROR = 0x0102,
+  CURL_H3_ERR_STREAM_CREATION_ERROR = 0x0103,
+  CURL_H3_ERR_CLOSED_CRITICAL_STREAM = 0x0104,
+  CURL_H3_ERR_FRAME_UNEXPECTED = 0x0105,
+  CURL_H3_ERR_FRAME_ERROR = 0x0106,
+  CURL_H3_ERR_EXCESSIVE_LOAD = 0x0107,
+  CURL_H3_ERR_ID_ERROR = 0x0108,
+  CURL_H3_ERR_SETTINGS_ERROR = 0x0109,
+  CURL_H3_ERR_MISSING_SETTINGS = 0x010a,
+  CURL_H3_ERR_REQUEST_REJECTED = 0x010b,
+  CURL_H3_ERR_REQUEST_CANCELLED = 0x010c,
+  CURL_H3_ERR_REQUEST_INCOMPLETE = 0x010d,
+  CURL_H3_ERR_MESSAGE_ERROR = 0x010e,
+  CURL_H3_ERR_CONNECT_ERROR = 0x010f,
+  CURL_H3_ERR_VERSION_FALLBACK = 0x0110,
+} vquic_h3_error;
+
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+const char *vquic_h3_err_str(uint64_t error_code);
+#else
+#define vquic_h3_err_str(x)   ""
+#endif /* CURL_DISABLE_VERBOSE_STRINGS */
+
 struct cf_quic_ctx {
   curl_socket_t sockfd;               /* connected UDP socket */
   struct sockaddr_storage local_addr; /* address socket is bound to */