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Author SHA1 Message Date
TheDiveO 139ffd651e
Merge 41a89e5c2e into 5e242ec578 2024-04-17 17:36:32 +02:00
thediveo 41a89e5c2e feat: add xt.Comment
Signed-off-by: thediveo <thediveo@gmx.eu>
2024-04-17 17:34:43 +02:00
2 changed files with 8 additions and 9 deletions

View File

@ -5,8 +5,7 @@ import (
"fmt" "fmt"
) )
// CommentSize is the fixed size of a comment info xt blob, see: // CommentSize is the fixed size of a comment info xt blob.
// https://elixir.bootlin.com/linux/v6.8.7/source/include/uapi/linux/netfilter/xt_comment.h#L5
const CommentSize = 256 const CommentSize = 256
// Comment gets marshalled and unmarshalled as a fixed-sized char array, filled // Comment gets marshalled and unmarshalled as a fixed-sized char array, filled
@ -16,8 +15,7 @@ type Comment string
func (c *Comment) marshal(fam TableFamily, rev uint32) ([]byte, error) { func (c *Comment) marshal(fam TableFamily, rev uint32) ([]byte, error) {
if len(*c) >= CommentSize { if len(*c) >= CommentSize {
return nil, fmt.Errorf("comment must be less than %d bytes, got %d bytes", return nil, fmt.Errorf("Comment must be less than %d bytes", CommentSize)
CommentSize, len(*c))
} }
data := make([]byte, CommentSize) data := make([]byte, CommentSize)
copy(data, []byte(*c)) copy(data, []byte(*c))
@ -26,8 +24,7 @@ func (c *Comment) marshal(fam TableFamily, rev uint32) ([]byte, error) {
func (c *Comment) unmarshal(fam TableFamily, rev uint32, data []byte) error { func (c *Comment) unmarshal(fam TableFamily, rev uint32, data []byte) error {
if len(data) != CommentSize { if len(data) != CommentSize {
return fmt.Errorf("malformed comment: got %d bytes, expected exactly %d bytes", return fmt.Errorf("Comment takes exactly %d bytes", CommentSize)
len(data), CommentSize)
} }
*c = Comment(bytes.TrimRight(data, "\x00")) *c = Comment(bytes.TrimRight(data, "\x00"))
return nil return nil

View File

@ -1,6 +1,7 @@
package xt package xt
import ( import (
"fmt"
"reflect" "reflect"
"strings" "strings"
"testing" "testing"
@ -22,7 +23,7 @@ func TestComment(t *testing.T) {
{ {
name: "marshal oversized Comment", name: "marshal oversized Comment",
info: &oversized, info: &oversized,
errmsg: "comment must be less than 256 bytes, got 600 bytes", errmsg: "Comment must be less than 256 bytes",
}, },
} }
@ -56,7 +57,8 @@ func TestComment(t *testing.T) {
oversizeddata := []byte(oversized) oversizeddata := []byte(oversized)
var comment Comment var comment Comment
if err := (&comment).unmarshal(0, 0, oversizeddata); err == nil { if err := (&comment).unmarshal(0, 0, oversizeddata); err == nil || err.Error() != fmt.Sprintf("Comment takes exactly %d bytes", CommentSize) {
t.Fatalf("unmarshal: expected error, but got nil") t.Fatalf("unmarshal: expected error: %v", err)
} }
} }