int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, const struct dccp_hdr *dh, const unsigned len) { struct dccp_sock *dp = dccp_sk(sk); if (dccp_check_seqno(sk, skb)) goto discard; if (dccp_parse_options(sk, skb)) goto discard; if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) dccp_event_ack_recv(sk, skb); if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_ACKVEC_STATE_RECEIVED)) goto discard; ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); return __dccp_rcv_established(sk, skb, dh, len); discard: __kfree_skb(skb); return 0; }
int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, const struct dccp_hdr *dh, const unsigned len) { struct dccp_sock *dp = dccp_sk(sk); if (dccp_check_seqno(sk, skb)) goto discard; if (dccp_parse_options(sk, skb)) goto discard; if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) dccp_event_ack_recv(sk, skb); if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_ACKVEC_STATE_RECEIVED)) goto discard; /* * Deliver to the CCID module in charge. * FIXME: Currently DCCP operates one-directional only, i.e. a listening * server is not at the same time a connecting client. There is * not much sense in delivering to both rx/tx sides at the moment * (only one is active at a time); when moving to bidirectional * service, this needs to be revised. */ if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER) ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); else ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); return __dccp_rcv_established(sk, skb, dh, len); discard: __kfree_skb(skb); return 0; }
int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, struct dccp_hdr *dh, unsigned len) { struct dccp_sock *dp = dccp_sk(sk); struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); const int old_state = sk->sk_state; int queued = 0; /* * Step 3: Process LISTEN state * * If S.state == LISTEN, * If P.type == Request or P contains a valid Init Cookie option, * (* Must scan the packet's options to check for Init * Cookies. Only Init Cookies are processed here, * however; other options are processed in Step 8. This * scan need only be performed if the endpoint uses Init * Cookies *) * (* Generate a new socket and switch to that socket *) * Set S := new socket for this port pair * S.state = RESPOND * Choose S.ISS (initial seqno) or set from Init Cookies * Initialize S.GAR := S.ISS * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init * Cookies Continue with S.state == RESPOND * (* A Response packet will be generated in Step 11 *) * Otherwise, * Generate Reset(No Connection) unless P.type == Reset * Drop packet and return */ if (sk->sk_state == DCCP_LISTEN) { if (dh->dccph_type == DCCP_PKT_REQUEST) { if (inet_csk(sk)->icsk_af_ops->conn_request(sk, skb) < 0) return 1; /* FIXME: do congestion control initialization */ goto discard; } if (dh->dccph_type == DCCP_PKT_RESET) goto discard; /* Caller (dccp_v4_do_rcv) will send Reset */ dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; return 1; } if (sk->sk_state != DCCP_REQUESTING) { if (dccp_check_seqno(sk, skb)) goto discard; /* * Step 8: Process options and mark acknowledgeable */ if (dccp_parse_options(sk, skb)) goto discard; if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) dccp_event_ack_recv(sk, skb); if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_ACKVEC_STATE_RECEIVED)) goto discard; /* XXX see the comments in dccp_rcv_established about this */ if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER) ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); else ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); } /* * Step 9: Process Reset * If P.type == Reset, * Tear down connection * S.state := TIMEWAIT * Set TIMEWAIT timer * Drop packet and return */ if (dh->dccph_type == DCCP_PKT_RESET) { /* * Queue the equivalent of TCP fin so that dccp_recvmsg * exits the loop */ dccp_fin(sk, skb); dccp_time_wait(sk, DCCP_TIME_WAIT, 0); return 0; /* * Step 7: Check for unexpected packet types * If (S.is_server and P.type == CloseReq) * or (S.is_server and P.type == Response) * or (S.is_client and P.type == Request) * or (S.state == RESPOND and P.type == Data), * Send Sync packet acknowledging P.seqno * Drop packet and return */ } else if ((dp->dccps_role != DCCP_ROLE_CLIENT && (dh->dccph_type == DCCP_PKT_RESPONSE || dh->dccph_type == DCCP_PKT_CLOSEREQ)) || (dp->dccps_role == DCCP_ROLE_CLIENT && dh->dccph_type == DCCP_PKT_REQUEST) || (sk->sk_state == DCCP_RESPOND && dh->dccph_type == DCCP_PKT_DATA)) { dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC); goto discard; } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { dccp_rcv_closereq(sk, skb); goto discard; } else if (dh->dccph_type == DCCP_PKT_CLOSE) { dccp_rcv_close(sk, skb); return 0; } if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) { dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK); goto discard; } switch (sk->sk_state) { case DCCP_CLOSED: dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; return 1; case DCCP_REQUESTING: /* FIXME: do congestion control initialization */ queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); if (queued >= 0) return queued; __kfree_skb(skb); return 0; case DCCP_RESPOND: case DCCP_PARTOPEN: queued = dccp_rcv_respond_partopen_state_process(sk, skb, dh, len); break; } if (dh->dccph_type == DCCP_PKT_ACK || dh->dccph_type == DCCP_PKT_DATAACK) { switch (old_state) { case DCCP_PARTOPEN: sk->sk_state_change(sk); sk_wake_async(sk, 0, POLL_OUT); break; } } if (!queued) { discard: __kfree_skb(skb); } return 0; }
static int dccp_rcv_request_sent_state_process(struct sock *sk, struct sk_buff *skb, const struct dccp_hdr *dh, const unsigned len) { /* * Step 4: Prepare sequence numbers in REQUEST * If S.state == REQUEST, * If (P.type == Response or P.type == Reset) * and S.AWL <= P.ackno <= S.AWH, * / * Set sequence number variables corresponding to the * other endpoint, so P will pass the tests in Step 6 * / * Set S.GSR, S.ISR, S.SWL, S.SWH * / * Response processing continues in Step 10; Reset * processing continues in Step 9 * / */ if (dh->dccph_type == DCCP_PKT_RESPONSE) { const struct inet_connection_sock *icsk = inet_csk(sk); struct dccp_sock *dp = dccp_sk(sk); /* Stop the REQUEST timer */ inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); BUG_TRAP(sk->sk_send_head != NULL); __kfree_skb(sk->sk_send_head); sk->sk_send_head = NULL; if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, dp->dccps_awl, dp->dccps_awh)) { dccp_pr_debug("invalid ackno: S.AWL=%llu, " "P.ackno=%llu, S.AWH=%llu \n", (unsigned long long)dp->dccps_awl, (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq, (unsigned long long)dp->dccps_awh); goto out_invalid_packet; } if (dccp_parse_options(sk, skb)) goto out_invalid_packet; if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_ACKVEC_STATE_RECEIVED)) goto out_invalid_packet; /* FIXME: change error code */ dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; dccp_update_gsr(sk, dp->dccps_isr); /* * SWL and AWL are initially adjusted so that they are not less than * the initial Sequence Numbers received and sent, respectively: * SWL := max(GSR + 1 - floor(W/4), ISR), * AWL := max(GSS - W' + 1, ISS). * These adjustments MUST be applied only at the beginning of the * connection. * * AWL was adjusted in dccp_v4_connect -acme */ dccp_set_seqno(&dp->dccps_swl, max48(dp->dccps_swl, dp->dccps_isr)); dccp_sync_mss(sk, icsk->icsk_pmtu_cookie); /* * Step 10: Process REQUEST state (second part) * If S.state == REQUEST, * / * If we get here, P is a valid Response from the * server (see Step 4), and we should move to * PARTOPEN state. PARTOPEN means send an Ack, * don't send Data packets, retransmit Acks * periodically, and always include any Init Cookie * from the Response * / * S.state := PARTOPEN * Set PARTOPEN timer * Continue with S.state == PARTOPEN * / * Step 12 will send the Ack completing the * three-way handshake * / */ dccp_set_state(sk, DCCP_PARTOPEN); /* Make sure socket is routed, for correct metrics. */ icsk->icsk_af_ops->rebuild_header(sk); if (!sock_flag(sk, SOCK_DEAD)) { sk->sk_state_change(sk); sk_wake_async(sk, 0, POLL_OUT); } if (sk->sk_write_pending || icsk->icsk_ack.pingpong || icsk->icsk_accept_queue.rskq_defer_accept) { /* Save one ACK. Data will be ready after * several ticks, if write_pending is set. * * It may be deleted, but with this feature tcpdumps * look so _wonderfully_ clever, that I was not able * to stand against the temptation 8) --ANK */ /* * OK, in DCCP we can as well do a similar trick, its * even in the draft, but there is no need for us to * schedule an ack here, as dccp_sendmsg does this for * us, also stated in the draft. -acme */ __kfree_skb(skb); return 0; } dccp_send_ack(sk); return -1; } out_invalid_packet: /* dccp_v4_do_rcv will send a reset */ DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR; return 1; }