HTTP/3: http3_max_field_size directive to limit string size.

Client streams may send literal strings which are now limited in size by the
new directive.  The default value is 4096.

The directive is similar to HTTP/2 directive http2_max_field_size.

diff --git a/src/http/v3/ngx_http_v3.h b/src/http/v3/ngx_http_v3.h
index 3c5bb721cdeb3de7888626c45a2380c207ce9f2f..d48f139226827e6cd520a31d7f839395629002ea 100644 (file)
--- a/src/http/v3/ngx_http_v3.h
+++ b/src/http/v3/ngx_http_v3.h
@@ -47,9 +47,12 @@
 #define NGX_HTTP_V3_STREAM_SERVER_DECODER          5
 #define NGX_HTTP_V3_MAX_KNOWN_STREAM               6
 
+#define NGX_HTTP_V3_DEFAULT_MAX_FIELD_SIZE         4096
+
 
 typedef struct {
     ngx_quic_tp_t           quic;
+    size_t                  max_field_size;
 } ngx_http_v3_srv_conf_t;
 
 

diff --git a/src/http/v3/ngx_http_v3_module.c b/src/http/v3/ngx_http_v3_module.c
index 550b706da4e3404fd8015b6f680e57aff6536610..17029934e34f727610d17becea99fd8fc2b2dbd9 100644 (file)
--- a/src/http/v3/ngx_http_v3_module.c
+++ b/src/http/v3/ngx_http_v3_module.c
@@ -118,6 +118,13 @@ static ngx_command_t  ngx_http_v3_commands[] = {
       offsetof(ngx_http_v3_srv_conf_t, quic.retry),
       NULL },
 
+    { ngx_string("http3_max_field_size"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_size_slot,
+      NGX_HTTP_SRV_CONF_OFFSET,
+      offsetof(ngx_http_v3_srv_conf_t, max_field_size),
+      NULL },
+
       ngx_null_command
 };
 
@@ -268,6 +275,8 @@ ngx_http_v3_create_srv_conf(ngx_conf_t *cf)
 
     v3cf->quic.retry = NGX_CONF_UNSET;
 
+    v3cf->max_field_size = NGX_CONF_UNSET_SIZE;
+
     return v3cf;
 }
 
@@ -329,6 +338,9 @@ ngx_http_v3_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
         }
     }
 
+    ngx_conf_merge_size_value(conf->max_field_size,
+                              prev->max_field_size,
+                              NGX_HTTP_V3_DEFAULT_MAX_FIELD_SIZE);
 
     return NGX_CONF_OK;
 }

diff --git a/src/http/v3/ngx_http_v3_parse.c b/src/http/v3/ngx_http_v3_parse.c
index 3be3802edcb2b60549806911be13878fc71154c9..71a643d70fe3dc8deb9ef8cc96fe4df7dd41915e 100644 (file)
--- a/src/http/v3/ngx_http_v3_parse.c
+++ b/src/http/v3/ngx_http_v3_parse.c
@@ -399,7 +399,8 @@ ngx_int_t
 ngx_http_v3_parse_literal(ngx_connection_t *c, ngx_http_v3_parse_literal_t *st,
     u_char ch)
 {
-    ngx_uint_t  n;
+    ngx_uint_t               n;
+    ngx_http_v3_srv_conf_t  *v3cf;
     enum {
         sw_start = 0,
         sw_value
@@ -415,6 +416,14 @@ ngx_http_v3_parse_literal(ngx_connection_t *c, ngx_http_v3_parse_literal_t *st,
 
         n = st->length;
 
+        v3cf = ngx_http_v3_get_module_srv_conf(c, ngx_http_v3_module);
+
+        if (n > v3cf->max_field_size) {
+            ngx_log_error(NGX_LOG_ERR, c->log, 0,
+                          "client exceeded http3_max_field_size limit");
+            return NGX_ERROR;
+        }
+
         if (st->huffman) {
             n = n * 8 / 5;
             st->huffstate = 0;