Parses incoming DSS options and populates outgoing MPTCP ACK fields. MPTCP fields are parsed from the TCP option header and placed in an skb extension, allowing the upper MPTCP layer to access MPTCP options after the skb has gone through the TCP stack. The subflow implements its own data_ready() ops, which ensures that the pending data is in sequence - according to MPTCP seq number - dropping out-of-seq skbs. The DATA_READY bit flag is set if this is the case. This allows the MPTCP socket layer to determine if more data is available without having to consult the individual subflows. It additionally validates the current mapping and propagates EoF events to the connection socket.
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| @@ -82,9 +82,19 @@ struct tcp_sack_block { · 81 unmodified lines | ||
| 82 | 82 | struct mptcp_options_received { |
| 83 | 83 | u64 sndr_key; |
| 84 | 84 | u64 rcvr_key; |
| 85 | + u64 data_ack; | |
| 86 | + u64 data_seq; | |
| 87 | + u32 subflow_seq; | |
| 88 | + u16 data_len; | |
| 85 | 89 | u8 mp_capable : 1, |
| 86 | 90 | mp_join : 1, |
| 87 | 91 | dss : 1; |
| 92 | + u8 use_map:1, | |
| 93 | + dsn64:1, | |
| 94 | + data_fin:1, | |
| 95 | + use_ack:1, | |
| 96 | + ack64:1, | |
| 97 | + __unused:3; | |
| 88 | 98 | }; |
| 89 | 99 | #endif |
| 90 | 100 | |