Relax the NLQ content‑type check to properly parse media types

- Adding an isNLQContentType helper that uses mime.ParseMediaType + strings.EqualFold
- Updating SelectAndRewrite to use http.MethodPost + isNLQContentType(...) instead of an exact string match
- Covering the new helper with a small table‑driven unit test

Signed-off-by: Julien Barbot <jubarbot@cisco.com>

Author: jubarbot-cisco

plugins/agent_bridge.go

@@ -8,6 +8,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"mime"
 	"net/http"
 	"strings"
 
@@ -41,6 +42,15 @@ const (
 
 var logger = log.Get()
 
+// isNLQContentType parses a Content-Type header and returns true if it denotes application/nlq
+func isNLQContentType(contentType string) bool {
+	mediaType, _, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return false
+	}
+	return strings.EqualFold(mediaType, CONTENT_TYPE_NLQ)
+}
+
 func SelectAndRewrite(rw http.ResponseWriter, r *http.Request) {
 	logger.Debugf("[+] Inside SelectAndRewrite ...")
 	apiConfig, err := getPluginFromRequest(r)
@@ -71,8 +81,8 @@ func SelectAndRewrite(rw http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// POST and Content-Type: application/nlq are expected
-	if !(r.Method == "POST" && r.Header.Get("Content-Type") == CONTENT_TYPE_NLQ) {
+	// Only proceed for POST with Content-Type: application/nlq (parameters are allowed)
+	if r.Method != http.MethodPost || !isNLQContentType(r.Header.Get("Content-Type")) {
 		logger.Debugf("[+] Query is not POST or Content-Type is not %s, ignoring ...", CONTENT_TYPE_NLQ)
 		return
 	}

plugins/agent_bridge_acp.go

@@ -58,8 +58,8 @@ func ProcessACPQuery(rw http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	// POST and Content-Type: application/nlq are expected
-	if !(r.Method == "POST" && r.Header.Get("Content-Type") == CONTENT_TYPE_NLQ) {
+	// Only proceed for POST with Content-Type: application/nlq (parameters are allowed)
+	if r.Method != http.MethodPost || !isNLQContentType(r.Header.Get("Content-Type")) {
 		logger.Debugf("[+] Query is not POST or Content-Type is not %s, ignoring ...", CONTENT_TYPE_NLQ)
 		return
 	}

plugins/agent_bridge_contenttype_test.go

@@ -0,0 +1,27 @@
+package main
+
+import "testing"
+
+// TestIsNLQContentType verifies that various Content-Type header values
+// are correctly recognized (or not) as application/nlq.
+func TestIsNLQContentType(t *testing.T) {
+   tests := []struct {
+       ct   string
+       want bool
+   }{
+       {"application/nlq", true},
+       {"application/nlq; charset=utf-8", true},
+       {"APPLICATION/NLQ", true},
+       {"application/NLQ; param=val", true},
+       {"application/json", false},
+       {"application/nlq+xml", false},
+       {"", false},
+       {"invalid/md", false},
+   }
+   for _, tc := range tests {
+       got := isNLQContentType(tc.ct)
+       if got != tc.want {
+           t.Errorf("isNLQContentType(%q) = %v; want %v", tc.ct, got, tc.want)
+       }
+   }
+}