From 62e3bcc9d6a0066975fee797dad95ce2f28d8abc Mon Sep 17 00:00:00 2001
From: Florian Lehner <dev@der-flo.net>
Date: Sat, 29 Jun 2024 11:26:51 +0200
Subject: [PATCH] add SkipOptional

Signed-off-by: Florian Lehner <dev@der-flo.net>
---
 diag.go      | 13 ++++++++++---
 protocols.go |  2 +-
 types.go     |  5 +++++
 unix.go      |  2 +-
 4 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/diag.go b/diag.go
index cf17494..4a98307 100644
--- a/diag.go
+++ b/diag.go
@@ -25,7 +25,8 @@ var _ diagConn = &netlink.Conn{}
 
 // Diag represents a netlink wrapper
 type Diag struct {
-	con diagConn
+	con          diagConn
+	skipOptional bool
 }
 
 // Open establishes a netlink socket for traffic control
@@ -188,7 +189,7 @@ func (d *Diag) dumpQuery(header interface{}) ([]netlink.Message, error) {
 	return d.query(req)
 }
 
-func handleNetResponse(msgs []netlink.Message) ([]NetObject, error) {
+func handleNetResponse(msgs []netlink.Message, skipOptional bool) ([]NetObject, error) {
 	var results []NetObject
 	sizeOfRecvMsg := binary.Size(DiagMsg{})
 
@@ -197,6 +198,9 @@ func handleNetResponse(msgs []netlink.Message) ([]NetObject, error) {
 		if err := unmarshalStruct(msg.Data[:sizeOfRecvMsg], &result.DiagMsg); err != nil {
 			return nil, err
 		}
+		if skipOptional {
+			continue
+		}
 		if err := extractAttributes(msg.Data[sizeOfRecvMsg:], &result.NetAttribute); err != nil {
 			return nil, err
 		}
@@ -205,7 +209,7 @@ func handleNetResponse(msgs []netlink.Message) ([]NetObject, error) {
 	return results, nil
 }
 
-func handleUnixResponse(msgs []netlink.Message) ([]UnixObject, error) {
+func handleUnixResponse(msgs []netlink.Message, skipOptional bool) ([]UnixObject, error) {
 	var results []UnixObject
 	sizeOfRecvMsg := binary.Size(UnixDiagMsg{})
 
@@ -214,6 +218,9 @@ func handleUnixResponse(msgs []netlink.Message) ([]UnixObject, error) {
 		if err := unmarshalStruct(msg.Data[:sizeOfRecvMsg], &result.UnixDiagMsg); err != nil {
 			return nil, err
 		}
+		if skipOptional {
+			continue
+		}
 		if err := extractUnixAttributes(msg.Data[sizeOfRecvMsg:], &result.UnixAttribute); err != nil {
 			return nil, err
 		}
diff --git a/protocols.go b/protocols.go
index 4fd138a..e323aa6 100644
--- a/protocols.go
+++ b/protocols.go
@@ -169,7 +169,7 @@ func (d *Diag) NetDump(opt *NetOption) ([]NetObject, error) {
 	if err != nil {
 		return nil, err
 	}
-	return handleNetResponse(respMsgs)
+	return handleNetResponse(respMsgs, d.skipOptional)
 }
 
 // Dump returns all TCP connections.
diff --git a/types.go b/types.go
index 6bbcc3a..bc1f83c 100644
--- a/types.go
+++ b/types.go
@@ -11,6 +11,11 @@ import (
 type Config struct {
 	// NetNS defines the network namespace
 	NetNS int
+
+	// SkipOptional allows to skip decoding of
+	// optional values likes NetAttribute and
+	// UnixAttribute.
+	SkipOptional bool
 }
 
 const (
diff --git a/unix.go b/unix.go
index abb29c9..64c4f7a 100644
--- a/unix.go
+++ b/unix.go
@@ -85,7 +85,7 @@ func (d *Diag) UnixDump(opt *UnixOption) ([]UnixObject, error) {
 	if err != nil {
 		return nil, err
 	}
-	objs, err := handleUnixResponse(respMsgs)
+	objs, err := handleUnixResponse(respMsgs, d.skipOptional)
 	if err != nil {
 		return nil, err
 	}