IGMP¶
Internet Group Management Protocol(IGMP) packet parser/serializer
[RFC 1112] IGMP v1 format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Version| Type | Unused | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
[RFC 2236] IGMP v2 format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Max Resp Time | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
[RFC 3376] IGMP v3 Membership Query format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0x11 | Max Resp Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Resv |S| QRV | QQIC | Number of Sources (N) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Address [1] |
+- -+
| Source Address [2] |
+- . -+
. . .
. . .
+- -+
| Source Address [N] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IGMP v3 Membership Report format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0x22 | Reserved | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Number of Group Records (M) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Group Record [1] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Group Record [2] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . |
. . .
| . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Group Record [M] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Where each Group Record has the following internal format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Record Type | Aux Data Len | Number of Sources (N) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Multicast Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Address [1] |
+- -+
| Source Address [2] |
+- -+
. . .
. . .
. . .
+- -+
| Source Address [N] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Auxiliary Data .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-
class
ryu.lib.packet.igmp.igmp(msgtype=17, maxresp=0, csum=0, address='0.0.0.0')¶ Internet Group Management Protocol(IGMP, RFC 1112, RFC 2236) header encoder/decoder class.
http://www.ietf.org/rfc/rfc1112.txt
http://www.ietf.org/rfc/rfc2236.txt
An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.
Attribute Description msgtype a message type for v2, or a combination of version and a message type for v1. maxresp max response time in unit of 1/10 second. it is meaningful only in Query Message. csum a check sum value. 0 means automatically-calculate when encoding. address a group address value. -
classmethod
parser(buf)¶ Decode a protocol header.
This method is used only when decoding a packet.
Decode a protocol header at offset 0 in bytearray buf. Returns the following three objects.
- An object to describe the decoded header.
- A packet_base.PacketBase subclass appropriate for the rest of the packet. None when the rest of the packet should be considered as raw payload.
- The rest of packet.
-
serialize(payload, prev)¶ Encode a protocol header.
This method is used only when encoding a packet.
Encode a protocol header. Returns a bytearray which contains the header.
payload is the rest of the packet which will immediately follow this header.
prev is a packet_base.PacketBase subclass for the outer protocol header. prev is None if the current header is the outer-most. For example, prev is ipv4 or ipv6 for tcp.serialize.
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classmethod
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class
ryu.lib.packet.igmp.igmpv3_query(msgtype=17, maxresp=100, csum=0, address='0.0.0.0', s_flg=0, qrv=2, qqic=0, num=0, srcs=None)¶ Internet Group Management Protocol(IGMP, RFC 3376) Membership Query message encoder/decoder class.
http://www.ietf.org/rfc/rfc3376.txt
An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.
Attribute Description msgtype a message type for v3. maxresp max response time in unit of 1/10 second. csum a check sum value. 0 means automatically-calculate when encoding. address a group address value. s_flg when set to 1, routers suppress the timer process. qrv robustness variable for a querier. qqic an interval time for a querier in unit of seconds. num a number of the multicast servers. srcs a list of IPv4 addresses of the multicast servers. -
classmethod
parser(buf)¶ Decode a protocol header.
This method is used only when decoding a packet.
Decode a protocol header at offset 0 in bytearray buf. Returns the following three objects.
- An object to describe the decoded header.
- A packet_base.PacketBase subclass appropriate for the rest of the packet. None when the rest of the packet should be considered as raw payload.
- The rest of packet.
-
serialize(payload, prev)¶ Encode a protocol header.
This method is used only when encoding a packet.
Encode a protocol header. Returns a bytearray which contains the header.
payload is the rest of the packet which will immediately follow this header.
prev is a packet_base.PacketBase subclass for the outer protocol header. prev is None if the current header is the outer-most. For example, prev is ipv4 or ipv6 for tcp.serialize.
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classmethod
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class
ryu.lib.packet.igmp.igmpv3_report(msgtype=34, csum=0, record_num=0, records=None)¶ Internet Group Management Protocol(IGMP, RFC 3376) Membership Report message encoder/decoder class.
http://www.ietf.org/rfc/rfc3376.txt
An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.
Attribute Description msgtype a message type for v3. csum a check sum value. 0 means automatically-calculate when encoding. record_num a number of the group records. records a list of ryu.lib.packet.igmp.igmpv3_report_group. None if no records. -
classmethod
parser(buf)¶ Decode a protocol header.
This method is used only when decoding a packet.
Decode a protocol header at offset 0 in bytearray buf. Returns the following three objects.
- An object to describe the decoded header.
- A packet_base.PacketBase subclass appropriate for the rest of the packet. None when the rest of the packet should be considered as raw payload.
- The rest of packet.
-
serialize(payload, prev)¶ Encode a protocol header.
This method is used only when encoding a packet.
Encode a protocol header. Returns a bytearray which contains the header.
payload is the rest of the packet which will immediately follow this header.
prev is a packet_base.PacketBase subclass for the outer protocol header. prev is None if the current header is the outer-most. For example, prev is ipv4 or ipv6 for tcp.serialize.
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classmethod
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class
ryu.lib.packet.igmp.igmpv3_report_group(type_=0, aux_len=0, num=0, address='0.0.0.0', srcs=None, aux=None)¶ Internet Group Management Protocol(IGMP, RFC 3376) Membership Report Group Record message encoder/decoder class.
http://www.ietf.org/rfc/rfc3376.txt
This is used with ryu.lib.packet.igmp.igmpv3_report.
An instance has the following attributes at least. Most of them are same to the on-wire counterparts but in host byte order. __init__ takes the corresponding args in this order.
Attribute Description type_ a group record type for v3. aux_len the length of the auxiliary data. num a number of the multicast servers. address a group address value. srcs a list of IPv4 addresses of the multicast servers. aux the auxiliary data.