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Diffstat (limited to 'vendor/github.com/pion/stun/attributes.go')
| -rw-r--r-- | vendor/github.com/pion/stun/attributes.go | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/vendor/github.com/pion/stun/attributes.go b/vendor/github.com/pion/stun/attributes.go new file mode 100644 index 0000000..7238234 --- /dev/null +++ b/vendor/github.com/pion/stun/attributes.go @@ -0,0 +1,226 @@ +package stun + +import ( + "errors" + "fmt" +) + +// Attributes is list of message attributes. +type Attributes []RawAttribute + +// Get returns first attribute from list by the type. +// If attribute is present the RawAttribute is returned and the +// boolean is true. Otherwise the returned RawAttribute will be +// empty and boolean will be false. +func (a Attributes) Get(t AttrType) (RawAttribute, bool) { + for _, candidate := range a { + if candidate.Type == t { + return candidate, true + } + } + return RawAttribute{}, false +} + +// AttrType is attribute type. +type AttrType uint16 + +// Required returns true if type is from comprehension-required range (0x0000-0x7FFF). +func (t AttrType) Required() bool { + return t <= 0x7FFF +} + +// Optional returns true if type is from comprehension-optional range (0x8000-0xFFFF). +func (t AttrType) Optional() bool { + return t >= 0x8000 +} + +// Attributes from comprehension-required range (0x0000-0x7FFF). +const ( + AttrMappedAddress AttrType = 0x0001 // MAPPED-ADDRESS + AttrUsername AttrType = 0x0006 // USERNAME + AttrMessageIntegrity AttrType = 0x0008 // MESSAGE-INTEGRITY + AttrErrorCode AttrType = 0x0009 // ERROR-CODE + AttrUnknownAttributes AttrType = 0x000A // UNKNOWN-ATTRIBUTES + AttrRealm AttrType = 0x0014 // REALM + AttrNonce AttrType = 0x0015 // NONCE + AttrXORMappedAddress AttrType = 0x0020 // XOR-MAPPED-ADDRESS +) + +// Attributes from comprehension-optional range (0x8000-0xFFFF). +const ( + AttrSoftware AttrType = 0x8022 // SOFTWARE + AttrAlternateServer AttrType = 0x8023 // ALTERNATE-SERVER + AttrFingerprint AttrType = 0x8028 // FINGERPRINT +) + +// Attributes from RFC 5245 ICE. +const ( + AttrPriority AttrType = 0x0024 // PRIORITY + AttrUseCandidate AttrType = 0x0025 // USE-CANDIDATE + AttrICEControlled AttrType = 0x8029 // ICE-CONTROLLED + AttrICEControlling AttrType = 0x802A // ICE-CONTROLLING +) + +// Attributes from RFC 5766 TURN. +const ( + AttrChannelNumber AttrType = 0x000C // CHANNEL-NUMBER + AttrLifetime AttrType = 0x000D // LIFETIME + AttrXORPeerAddress AttrType = 0x0012 // XOR-PEER-ADDRESS + AttrData AttrType = 0x0013 // DATA + AttrXORRelayedAddress AttrType = 0x0016 // XOR-RELAYED-ADDRESS + AttrEvenPort AttrType = 0x0018 // EVEN-PORT + AttrRequestedTransport AttrType = 0x0019 // REQUESTED-TRANSPORT + AttrDontFragment AttrType = 0x001A // DONT-FRAGMENT + AttrReservationToken AttrType = 0x0022 // RESERVATION-TOKEN +) + +// Attributes from RFC 5780 NAT Behavior Discovery +const ( + AttrOtherAddress AttrType = 0x802C // OTHER-ADDRESS + AttrChangeRequest AttrType = 0x0003 // CHANGE-REQUEST +) + +// Attributes from RFC 6062 TURN Extensions for TCP Allocations. +const ( + AttrConnectionID AttrType = 0x002a // CONNECTION-ID +) + +// Attributes from RFC 6156 TURN IPv6. +const ( + AttrRequestedAddressFamily AttrType = 0x0017 // REQUESTED-ADDRESS-FAMILY +) + +// Attributes from An Origin Attribute for the STUN Protocol. +const ( + AttrOrigin AttrType = 0x802F +) + +// Value returns uint16 representation of attribute type. +func (t AttrType) Value() uint16 { + return uint16(t) +} + +var attrNames = map[AttrType]string{ + AttrMappedAddress: "MAPPED-ADDRESS", + AttrUsername: "USERNAME", + AttrErrorCode: "ERROR-CODE", + AttrMessageIntegrity: "MESSAGE-INTEGRITY", + AttrUnknownAttributes: "UNKNOWN-ATTRIBUTES", + AttrRealm: "REALM", + AttrNonce: "NONCE", + AttrXORMappedAddress: "XOR-MAPPED-ADDRESS", + AttrSoftware: "SOFTWARE", + AttrAlternateServer: "ALTERNATE-SERVER", + AttrOtherAddress: "OTHER-ADDRESS", + AttrChangeRequest: "CHANGE-REQUEST", + AttrFingerprint: "FINGERPRINT", + AttrPriority: "PRIORITY", + AttrUseCandidate: "USE-CANDIDATE", + AttrICEControlled: "ICE-CONTROLLED", + AttrICEControlling: "ICE-CONTROLLING", + AttrChannelNumber: "CHANNEL-NUMBER", + AttrLifetime: "LIFETIME", + AttrXORPeerAddress: "XOR-PEER-ADDRESS", + AttrData: "DATA", + AttrXORRelayedAddress: "XOR-RELAYED-ADDRESS", + AttrEvenPort: "EVEN-PORT", + AttrRequestedTransport: "REQUESTED-TRANSPORT", + AttrDontFragment: "DONT-FRAGMENT", + AttrReservationToken: "RESERVATION-TOKEN", + AttrConnectionID: "CONNECTION-ID", + AttrRequestedAddressFamily: "REQUESTED-ADDRESS-FAMILY", + AttrOrigin: "ORIGIN", +} + +func (t AttrType) String() string { + s, ok := attrNames[t] + if !ok { + // Just return hex representation of unknown attribute type. + return fmt.Sprintf("0x%x", uint16(t)) + } + return s +} + +// RawAttribute is a Type-Length-Value (TLV) object that +// can be added to a STUN message. Attributes are divided into two +// types: comprehension-required and comprehension-optional. STUN +// agents can safely ignore comprehension-optional attributes they +// don't understand, but cannot successfully process a message if it +// contains comprehension-required attributes that are not +// understood. +type RawAttribute struct { + Type AttrType + Length uint16 // ignored while encoding + Value []byte +} + +// AddTo implements Setter, adding attribute as a.Type with a.Value and ignoring +// the Length field. +func (a RawAttribute) AddTo(m *Message) error { + m.Add(a.Type, a.Value) + return nil +} + +// Equal returns true if a == b. +func (a RawAttribute) Equal(b RawAttribute) bool { + if a.Type != b.Type { + return false + } + if a.Length != b.Length { + return false + } + if len(b.Value) != len(a.Value) { + return false + } + for i, v := range a.Value { + if b.Value[i] != v { + return false + } + } + return true +} + +func (a RawAttribute) String() string { + return fmt.Sprintf("%s: 0x%x", a.Type, a.Value) +} + +// ErrAttributeNotFound means that attribute with provided attribute +// type does not exist in message. +var ErrAttributeNotFound = errors.New("attribute not found") + +// Get returns byte slice that represents attribute value, +// if there is no attribute with such type, +// ErrAttributeNotFound is returned. +func (m *Message) Get(t AttrType) ([]byte, error) { + v, ok := m.Attributes.Get(t) + if !ok { + return nil, ErrAttributeNotFound + } + return v.Value, nil +} + +// STUN aligns attributes on 32-bit boundaries, attributes whose content +// is not a multiple of 4 bytes are padded with 1, 2, or 3 bytes of +// padding so that its value contains a multiple of 4 bytes. The +// padding bits are ignored, and may be any value. +// +// https://tools.ietf.org/html/rfc5389#section-15 +const padding = 4 + +func nearestPaddedValueLength(l int) int { + n := padding * (l / padding) + if n < l { + n += padding + } + return n +} + +// This method converts uint16 vlue to AttrType. If it finds an old attribute +// type value, it also translates it to the new value to enable backward +// compatibility. (See: https://github.com/pion/stun/issues/21) +func compatAttrType(val uint16) AttrType { + if val == 0x8020 { + return AttrXORMappedAddress // new: 0x0020 + } + return AttrType(val) +} |