feat: limit concurrent DoQ streams and goroutines (#7296)

plugin/quic/setup.go

@@ -0,0 +1,79 @@
+package quic
+
+import (
+	"strconv"
+
+	"github.com/coredns/caddy"
+	"github.com/coredns/coredns/core/dnsserver"
+	"github.com/coredns/coredns/plugin"
+)
+
+func init() {
+	caddy.RegisterPlugin("quic", caddy.Plugin{
+		ServerType: "dns",
+		Action:     setup,
+	})
+}
+
+func setup(c *caddy.Controller) error {
+	err := parseQuic(c)
+	if err != nil {
+		return plugin.Error("quic", err)
+	}
+	return nil
+}
+
+func parseQuic(c *caddy.Controller) error {
+	config := dnsserver.GetConfig(c)
+
+	// Skip the "quic" directive itself
+	c.Next()
+
+	// Get any arguments on the "quic" line
+	args := c.RemainingArgs()
+	if len(args) > 0 {
+		return c.ArgErr()
+	}
+
+	// Process all nested directives in the block
+	for c.NextBlock() {
+		switch c.Val() {
+		case "max_streams":
+			args := c.RemainingArgs()
+			if len(args) != 1 {
+				return c.ArgErr()
+			}
+			val, err := strconv.Atoi(args[0])
+			if err != nil {
+				return c.Errf("invalid max_streams value '%s': %v", args[0], err)
+			}
+			if val <= 0 {
+				return c.Errf("max_streams must be a positive integer: %d", val)
+			}
+			if config.MaxQUICStreams != nil {
+				return c.Err("max_streams already defined for this server block")
+			}
+			config.MaxQUICStreams = &val
+		case "worker_pool_size":
+			args := c.RemainingArgs()
+			if len(args) != 1 {
+				return c.ArgErr()
+			}
+			val, err := strconv.Atoi(args[0])
+			if err != nil {
+				return c.Errf("invalid worker_pool_size value '%s': %v", args[0], err)
+			}
+			if val <= 0 {
+				return c.Errf("worker_pool_size must be a positive integer: %d", val)
+			}
+			if config.MaxQUICWorkerPoolSize != nil {
+				return c.Err("worker_pool_size already defined for this server block")
+			}
+			config.MaxQUICWorkerPoolSize = &val
+		default:
+			return c.Errf("unknown property '%s'", c.Val())
+		}
+	}
+
+	return nil
+}