nghttpx: Bring per-connection rate limit back

--read-burst=0 still does not work.  But specifying n > 0 workarounds
this.

src/shrpx.cc

@@ -770,6 +770,11 @@ void fill_default_config()
   mod_config()->downstream_http_proxy_host = nullptr;
   mod_config()->downstream_http_proxy_port = 0;
   mod_config()->downstream_http_proxy_addrlen = 0;
+  mod_config()->rate_limit_cfg = nullptr;
+  mod_config()->read_rate = 0;
+  mod_config()->read_burst = 1 << 30;
+  mod_config()->write_rate = 0;
+  mod_config()->write_burst = 0;
   mod_config()->worker_read_rate = 0;
   mod_config()->worker_read_burst = 0;
   mod_config()->worker_write_rate = 0;
@@ -864,6 +869,29 @@ Performance:
                      Set the number of worker threads.
                      Default: )"
       << get_config()->num_worker << R"(
+  --read-rate=<RATE>
+                     Set  maximum   average  read  rate   on  frontend
+                     connection.  Setting 0 to  this option means read
+                     rate is unlimited.
+                     Default: )"
+      << get_config()->read_rate << R"(
+  --read-burst=<SIZE>
+                     Set   maximum  read   burst   size  on   frontend
+                     connection.  Setting 0 does not work.
+                     Default: )"
+      << get_config()->read_burst << R"(
+  --write-rate=<RATE>
+                     Set  maximum  average   write  rate  on  frontend
+                     connection.  Setting 0 to this option means write
+                     rate is unlimited.
+                     Default: )"
+      << get_config()->write_rate << R"(
+  --write-burst=<SIZE>
+                     Set   maximum  write   burst  size   on  frontend
+                     connection.  Setting 0 to this option means write
+                     burst size is unlimited.
+                     Default: )"
+      << get_config()->write_burst << R"(
   --worker-read-rate=<RATE>
                      Set  maximum   average  read  rate   on  frontend
                      connection per worker.  Setting  0 to this option
@@ -1229,6 +1257,10 @@ int main(int argc, char **argv)
       {"frontend-no-tls", no_argument, &flag, 29},
       {"backend-tls-sni-field", required_argument, &flag, 31},
       {"dh-param-file", required_argument, &flag, 33},
+      {"read-rate", required_argument, &flag, 34},
+      {"read-burst", required_argument, &flag, 35},
+      {"write-rate", required_argument, &flag, 36},
+      {"write-burst", required_argument, &flag, 37},
       {"npn-list", required_argument, &flag, 38},
       {"verify-client", no_argument, &flag, 39},
       {"verify-client-cacert", required_argument, &flag, 40},
@@ -1423,6 +1455,22 @@ int main(int argc, char **argv)
         // --dh-param-file
         cmdcfgs.emplace_back(SHRPX_OPT_DH_PARAM_FILE, optarg);
         break;
+      case 34:
+        // --read-rate
+        cmdcfgs.emplace_back(SHRPX_OPT_READ_RATE, optarg);
+        break;
+      case 35:
+        // --read-burst
+        cmdcfgs.emplace_back(SHRPX_OPT_READ_BURST, optarg);
+        break;
+      case 36:
+        // --write-rate
+        cmdcfgs.emplace_back(SHRPX_OPT_WRITE_RATE, optarg);
+        break;
+      case 37:
+        // --write-burst
+        cmdcfgs.emplace_back(SHRPX_OPT_WRITE_BURST, optarg);
+        break;
       case 38:
         // --npn-list
         cmdcfgs.emplace_back(SHRPX_OPT_NPN_LIST, optarg);
@@ -1771,6 +1819,13 @@ int main(int argc, char **argv)
     }
   }
 
+  mod_config()->rate_limit_cfg = ev_token_bucket_cfg_new
+    (get_rate_limit(get_config()->read_rate),
+     get_rate_limit(get_config()->read_burst),
+     get_rate_limit(get_config()->write_rate),
+     get_rate_limit(get_config()->write_burst),
+     nullptr);
+
   mod_config()->worker_rate_limit_cfg = ev_token_bucket_cfg_new
     (get_rate_limit(get_config()->worker_read_rate),
      get_rate_limit(get_config()->worker_read_burst),

src/shrpx_client_handler.cc

@@ -238,6 +238,11 @@ ClientHandler::ClientHandler(bufferevent *bev,
 
   ++worker_stat->num_connections;
 
+  rv = bufferevent_set_rate_limit(bev_, get_config()->rate_limit_cfg);
+  if(rv == -1) {
+    CLOG(FATAL, this) << "bufferevent_set_rate_limit() failed";
+  }
+
   rv = bufferevent_add_to_rate_limit_group(bev_, rate_limit_group);
   if(rv == -1) {
     CLOG(FATAL, this) << "bufferevent_add_to_rate_limit_group() failed";

src/shrpx_config.cc

@@ -103,6 +103,10 @@ const char SHRPX_OPT_CACERT[] = "cacert";
 const char SHRPX_OPT_BACKEND_IPV4[] = "backend-ipv4";
 const char SHRPX_OPT_BACKEND_IPV6[] = "backend-ipv6";
 const char SHRPX_OPT_BACKEND_HTTP_PROXY_URI[] = "backend-http-proxy-uri";
+const char SHRPX_OPT_READ_RATE[] = "read-rate";
+const char SHRPX_OPT_READ_BURST[] = "read-burst";
+const char SHRPX_OPT_WRITE_RATE[] = "write-rate";
+const char SHRPX_OPT_WRITE_BURST[] = "write-burst";
 const char SHRPX_OPT_WORKER_READ_RATE[] = "worker-read-rate";
 const char SHRPX_OPT_WORKER_READ_BURST[] = "worker-read-burst";
 const char SHRPX_OPT_WORKER_WRITE_RATE[] = "worker-write-rate";
@@ -670,6 +674,40 @@ int parse_config(const char *opt, const char *optarg)
     return 0;
   }
 
+  if(util::strieq(opt, SHRPX_OPT_READ_RATE)) {
+    mod_config()->read_rate = strtoul(optarg, nullptr, 10);
+
+    return 0;
+  }
+
+  if(util::strieq(opt, SHRPX_OPT_READ_BURST)) {
+    errno = 0;
+    auto n = strtoul(optarg, nullptr, 10);
+
+    if(errno != 0 || n == 0) {
+      LOG(ERROR) << SHRPX_OPT_READ_BURST
+                 << ": specify integer strictly larger than 0";
+
+      return -1;
+    }
+
+    mod_config()->read_burst = n;
+
+    return 0;
+  }
+
+  if(util::strieq(opt, SHRPX_OPT_WRITE_RATE)) {
+    mod_config()->write_rate = strtoul(optarg, nullptr, 10);
+
+    return 0;
+  }
+
+  if(util::strieq(opt, SHRPX_OPT_WRITE_BURST)) {
+    mod_config()->write_burst = strtoul(optarg, nullptr, 10);
+
+    return 0;
+  }
+
   if(util::strieq(opt, SHRPX_OPT_WORKER_READ_RATE)) {
     mod_config()->worker_read_rate = strtoul(optarg, nullptr, 10);
 

src/shrpx_config.h

@@ -96,6 +96,10 @@ extern const char SHRPX_OPT_BACKEND_IPV4[];
 extern const char SHRPX_OPT_BACKEND_IPV6[];
 extern const char SHRPX_OPT_BACKEND_HTTP_PROXY_URI[];
 extern const char SHRPX_OPT_BACKEND_TLS_SNI_FIELD[];
+extern const char SHRPX_OPT_READ_RATE[];
+extern const char SHRPX_OPT_READ_BURST[];
+extern const char SHRPX_OPT_WRITE_RATE[];
+extern const char SHRPX_OPT_WRITE_BURST[];
 extern const char SHRPX_OPT_WORKER_READ_RATE[];
 extern const char SHRPX_OPT_WORKER_READ_BURST[];
 extern const char SHRPX_OPT_WORKER_WRITE_RATE[];
@@ -190,6 +194,8 @@ struct Config {
   std::unique_ptr<char[]> downstream_http_proxy_host;
   std::unique_ptr<char[]> http2_upstream_dump_request_header_file;
   std::unique_ptr<char[]> http2_upstream_dump_response_header_file;
+  // Rate limit configuration per connection
+  ev_token_bucket_cfg *rate_limit_cfg;
   // Rate limit configuration per worker (thread)
   ev_token_bucket_cfg *worker_rate_limit_cfg;
   // list of supported NPN/ALPN protocol strings in the order of