88 lines
2.5 KiB
Go
88 lines
2.5 KiB
Go
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package ice
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import (
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"encoding/binary"
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"github.com/pion/stun"
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)
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// tiebreaker is common helper for ICE-{CONTROLLED,CONTROLLING}
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// and represents the so-called tiebreaker number.
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type tiebreaker uint64
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const tiebreakerSize = 8 // 64 bit
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// AddToAs adds tiebreaker value to m as t attribute.
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func (a tiebreaker) AddToAs(m *stun.Message, t stun.AttrType) error {
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v := make([]byte, tiebreakerSize)
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binary.BigEndian.PutUint64(v, uint64(a))
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m.Add(t, v)
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return nil
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}
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// GetFromAs decodes tiebreaker value in message getting it as for t type.
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func (a *tiebreaker) GetFromAs(m *stun.Message, t stun.AttrType) error {
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v, err := m.Get(t)
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if err != nil {
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return err
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}
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if err = stun.CheckSize(t, len(v), tiebreakerSize); err != nil {
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return err
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}
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*a = tiebreaker(binary.BigEndian.Uint64(v))
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return nil
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}
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// AttrControlled represents ICE-CONTROLLED attribute.
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type AttrControlled uint64
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// AddTo adds ICE-CONTROLLED to message.
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func (c AttrControlled) AddTo(m *stun.Message) error {
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return tiebreaker(c).AddToAs(m, stun.AttrICEControlled)
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}
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// GetFrom decodes ICE-CONTROLLED from message.
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func (c *AttrControlled) GetFrom(m *stun.Message) error {
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return (*tiebreaker)(c).GetFromAs(m, stun.AttrICEControlled)
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}
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// AttrControlling represents ICE-CONTROLLING attribute.
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type AttrControlling uint64
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// AddTo adds ICE-CONTROLLING to message.
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func (c AttrControlling) AddTo(m *stun.Message) error {
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return tiebreaker(c).AddToAs(m, stun.AttrICEControlling)
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}
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// GetFrom decodes ICE-CONTROLLING from message.
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func (c *AttrControlling) GetFrom(m *stun.Message) error {
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return (*tiebreaker)(c).GetFromAs(m, stun.AttrICEControlling)
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}
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// AttrControl is helper that wraps ICE-{CONTROLLED,CONTROLLING}.
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type AttrControl struct {
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Role Role
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Tiebreaker uint64
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}
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// AddTo adds ICE-CONTROLLED or ICE-CONTROLLING attribute depending on Role.
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func (c AttrControl) AddTo(m *stun.Message) error {
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if c.Role == Controlling {
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return tiebreaker(c.Tiebreaker).AddToAs(m, stun.AttrICEControlling)
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}
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return tiebreaker(c.Tiebreaker).AddToAs(m, stun.AttrICEControlled)
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}
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// GetFrom decodes Role and Tiebreaker value from message.
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func (c *AttrControl) GetFrom(m *stun.Message) error {
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if m.Contains(stun.AttrICEControlling) {
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c.Role = Controlling
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return (*tiebreaker)(&c.Tiebreaker).GetFromAs(m, stun.AttrICEControlling)
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}
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if m.Contains(stun.AttrICEControlled) {
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c.Role = Controlled
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return (*tiebreaker)(&c.Tiebreaker).GetFromAs(m, stun.AttrICEControlled)
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}
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return stun.ErrAttributeNotFound
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}
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