Add support for suffix domains in allowed origins in http input plugin

plugin/input/http/http.go

@@ -1,6 +1,7 @@
 package http
 
 import (
+	"fmt"
 	"io"
 	"net"
 	"net/http"
@@ -198,22 +199,78 @@ type AuthConfig struct {
 	Secrets map[string]string `json:"secrets"` // *
 }
 
+type originDomain struct {
+	domain string
+	suffix string
+}
+
 type CORSConfig struct {
 	AllowedOrigins []string `json:"allowed_origins"`
 	DefaultOrigin  string   `json:"default_origin"  default:"*"`
 	AllowedHeaders []string `json:"allowed_headers"`
 	ExposedHeaders []string `json:"exposed_headers"`
+
+	allowedOriginsDomains []originDomain
+	allowedOriginsAll     bool
 }
 
-func (c *CORSConfig) getAllowedByOrigin(originHeader string) string {
-	for _, allowed := range c.AllowedOrigins {
-		if strings.HasSuffix(originHeader, allowed) || strings.HasPrefix(originHeader, allowed) {
-			return originHeader
+func (c *CORSConfig) getAllowedByOrigin(origin string) string {
+	u, err := url.Parse(origin)
+	if err != nil {
+		return c.DefaultOrigin
+	}
+
+	host := u.Host
+	if i := strings.IndexByte(host, ':'); i > -1 {
+		host = host[:i]
+	}
+
+	if c.allowedOriginsAll {
+		return host
+	}
+
+	for _, allowed := range c.allowedOriginsDomains {
+		if host == allowed.domain {
+			return host
+		}
+
+		if allowed.suffix != "" && strings.HasSuffix(host, allowed.suffix) {
+			return host
 		}
 	}
+
 	return c.DefaultOrigin
 }
 
+func (c *CORSConfig) prepareAllowedOrigins() error {
+	for _, ao := range c.AllowedOrigins {
+		ao = strings.ToLower(ao)
+		if ao == "*" {
+			c.allowedOriginsAll = true
+			c.allowedOriginsDomains = nil
+			break
+		}
+		if ao[0] == '*' {
+			if strings.Contains(ao[1:], "*") {
+				return fmt.Errorf("invalid origin: %q", ao)
+			}
+			domain := ao[1:]
+			if ao[1] == '.' {
+				domain = ao[2:]
+			}
+			c.allowedOriginsDomains = append(c.allowedOriginsDomains, originDomain{
+				domain: domain,
+				suffix: ao[1:],
+			})
+			continue
+		}
+		c.allowedOriginsDomains = append(c.allowedOriginsDomains, originDomain{
+			domain: ao,
+		})
+	}
+	return nil
+}
+
 func init() {
 	fd.DefaultPluginRegistry.RegisterInput(&pipeline.PluginStaticInfo{
 		Type:    "http",
@@ -239,6 +296,10 @@ func (p *Plugin) Start(config pipeline.AnyConfig, params *pipeline.InputPluginPa
 		}
 	}
 
+	if err := p.config.CORS.prepareAllowedOrigins(); err != nil {
+		p.logger.Fatal("failed to prepare allowed origins", zap.Error(err))
+	}
+
 	p.controller = params.Controller
 	p.controller.DisableStreams()
 	p.sourceIDs = make([]pipeline.SourceID, 0)