netlink/nl/parse_attr_linux.go

80 lines
1.7 KiB
Go

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