1 // SPDX-License-Identifier: GPL-2.0 2 /* MPTCP Fast Open Mechanism 3 * 4 * Copyright (c) 2021-2022, Dmytro SHYTYI 5 */ 6 7 #include "protocol.h" 8 9 void mptcp_fastopen_subflow_synack_set_params(struct mptcp_subflow_context *subflow, 10 struct request_sock *req) 11 { 12 struct sock *sk, *ssk; 13 struct sk_buff *skb; 14 struct tcp_sock *tp; 15 16 /* on early fallback the subflow context is deleted by 17 * subflow_syn_recv_sock() 18 */ 19 if (!subflow) 20 return; 21 22 ssk = subflow->tcp_sock; 23 sk = subflow->conn; 24 tp = tcp_sk(ssk); 25 26 subflow->is_mptfo = 1; 27 28 skb = skb_peek(&ssk->sk_receive_queue); 29 if (WARN_ON_ONCE(!skb)) 30 return; 31 32 /* dequeue the skb from sk receive queue */ 33 __skb_unlink(skb, &ssk->sk_receive_queue); 34 skb_ext_reset(skb); 35 skb_orphan(skb); 36 37 /* We copy the fastopen data, but that don't belong to the mptcp sequence 38 * space, need to offset it in the subflow sequence, see mptcp_subflow_get_map_offset() 39 */ 40 tp->copied_seq += skb->len; 41 subflow->ssn_offset += skb->len; 42 43 /* initialize a dummy sequence number, we will update it at MPC 44 * completion, if needed 45 */ 46 MPTCP_SKB_CB(skb)->map_seq = -skb->len; 47 MPTCP_SKB_CB(skb)->end_seq = 0; 48 MPTCP_SKB_CB(skb)->offset = 0; 49 MPTCP_SKB_CB(skb)->has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp; 50 51 mptcp_data_lock(sk); 52 53 mptcp_set_owner_r(skb, sk); 54 __skb_queue_tail(&sk->sk_receive_queue, skb); 55 56 sk->sk_data_ready(sk); 57 58 mptcp_data_unlock(sk); 59 } 60 61 void mptcp_fastopen_gen_msk_ackseq(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow, 62 const struct mptcp_options_received *mp_opt) 63 { 64 struct sock *sk = (struct sock *)msk; 65 struct sk_buff *skb; 66 67 mptcp_data_lock(sk); 68 skb = skb_peek_tail(&sk->sk_receive_queue); 69 if (skb) { 70 WARN_ON_ONCE(MPTCP_SKB_CB(skb)->end_seq); 71 pr_debug("msk %p moving seq %llx -> %llx end_seq %llx -> %llx", sk, 72 MPTCP_SKB_CB(skb)->map_seq, MPTCP_SKB_CB(skb)->map_seq + msk->ack_seq, 73 MPTCP_SKB_CB(skb)->end_seq, MPTCP_SKB_CB(skb)->end_seq + msk->ack_seq); 74 MPTCP_SKB_CB(skb)->map_seq += msk->ack_seq; 75 MPTCP_SKB_CB(skb)->end_seq += msk->ack_seq; 76 } 77 78 pr_debug("msk=%p ack_seq=%llx", msk, msk->ack_seq); 79 mptcp_data_unlock(sk); 80 } 81