Files
ice/renomination.go
2025-08-25 10:44:44 -04:00

87 lines
2.5 KiB
Go

// SPDX-FileCopyrightText: 2025 The Pion community <https://pion.ly>
// SPDX-License-Identifier: MIT
package ice
import (
"fmt"
"github.com/pion/stun/v3"
)
// Default STUN Nomination attribute type for ICE renomination.
// Following the specification draft-thatcher-ice-renomination-01.
const (
// DefaultNominationAttribute represents the default STUN Nomination attribute.
// This is a custom attribute for ICE renomination support.
// This value can be overridden via AgentConfig.NominationAttribute.
DefaultNominationAttribute stun.AttrType = 0x0030 // Using a value in the reserved range
)
// NominationAttribute represents a STUN Nomination attribute.
type NominationAttribute struct {
Value uint32
}
// GetFrom decodes a Nomination attribute from a STUN message.
func (a *NominationAttribute) GetFrom(m *stun.Message) error {
return a.GetFromWithType(m, DefaultNominationAttribute)
}
// GetFromWithType decodes a Nomination attribute from a STUN message using a specific attribute type.
func (a *NominationAttribute) GetFromWithType(m *stun.Message, attrType stun.AttrType) error {
v, err := m.Get(attrType)
if err != nil {
return err
}
if len(v) < 4 {
return stun.ErrAttributeSizeInvalid
}
// Extract 24-bit value from the last 3 bytes
a.Value = uint32(v[1])<<16 | uint32(v[2])<<8 | uint32(v[3])
return nil
}
// AddTo adds a Nomination attribute to a STUN message.
func (a NominationAttribute) AddTo(m *stun.Message) error {
return a.AddToWithType(m, DefaultNominationAttribute)
}
// AddToWithType adds a Nomination attribute to a STUN message using a specific attribute type.
func (a NominationAttribute) AddToWithType(m *stun.Message, attrType stun.AttrType) error {
// Store as 4 bytes with first byte as 0
v := make([]byte, 4)
v[1] = byte(a.Value >> 16)
v[2] = byte(a.Value >> 8)
v[3] = byte(a.Value)
m.Add(attrType, v)
return nil
}
// String returns string representation of the nomination attribute.
func (a NominationAttribute) String() string {
return fmt.Sprintf("NOMINATION: %d", a.Value)
}
// Nomination creates a new STUN nomination attribute.
func Nomination(value uint32) NominationAttribute {
return NominationAttribute{Value: value}
}
// NominationSetter is a STUN setter for nomination attribute with configurable type.
type NominationSetter struct {
Value uint32
AttrType stun.AttrType
}
// AddTo adds a Nomination attribute to a STUN message using the configured attribute type.
func (n NominationSetter) AddTo(m *stun.Message) error {
attr := NominationAttribute{Value: n.Value}
return attr.AddToWithType(m, n.AttrType)
}