80 lines
1.7 KiB
Go
80 lines
1.7 KiB
Go
package nl
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import (
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"encoding/binary"
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"fmt"
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"log"
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)
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type Attribute struct {
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Type uint16
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Value []byte
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}
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func ParseAttributes(data []byte) <-chan Attribute {
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native := NativeEndian()
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result := make(chan Attribute)
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go func() {
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i := 0
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for i+4 < len(data) {
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length := int(native.Uint16(data[i : i+2]))
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attrType := native.Uint16(data[i+2 : i+4])
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if length < 4 {
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log.Printf("attribute 0x%02x has invalid length of %d bytes", attrType, length)
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break
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}
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if len(data) < i+length {
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log.Printf("attribute 0x%02x of length %d is truncated, only %d bytes remaining", attrType, length, len(data)-i)
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break
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}
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result <- Attribute{
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Type: attrType,
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Value: data[i+4 : i+length],
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}
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i += rtaAlignOf(length)
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}
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close(result)
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}()
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return result
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}
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func PrintAttributes(data []byte) {
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printAttributes(data, 0)
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}
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func printAttributes(data []byte, level int) {
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for attr := range ParseAttributes(data) {
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for i := 0; i < level; i++ {
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print("> ")
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}
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nested := attr.Type&NLA_F_NESTED != 0
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fmt.Printf("type=%d nested=%v len=%v %v\n", attr.Type&NLA_TYPE_MASK, nested, len(attr.Value), attr.Value)
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if nested {
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printAttributes(attr.Value, level+1)
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}
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}
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}
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// Uint32 returns the uint32 value respecting the NET_BYTEORDER flag
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func (attr *Attribute) Uint32() uint32 {
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if attr.Type&NLA_F_NET_BYTEORDER != 0 {
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return binary.BigEndian.Uint32(attr.Value)
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} else {
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return NativeEndian().Uint32(attr.Value)
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}
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}
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// Uint64 returns the uint64 value respecting the NET_BYTEORDER flag
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func (attr *Attribute) Uint64() uint64 {
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if attr.Type&NLA_F_NET_BYTEORDER != 0 {
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return binary.BigEndian.Uint64(attr.Value)
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} else {
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return NativeEndian().Uint64(attr.Value)
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}
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}
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