diff options
Diffstat (limited to 'net/dccp/input.c')
| -rw-r--r-- | net/dccp/input.c | 739 |
1 files changed, 0 insertions, 739 deletions
diff --git a/net/dccp/input.c b/net/dccp/input.c deleted file mode 100644 index 2cbb757a894f..000000000000 --- a/net/dccp/input.c +++ /dev/null @@ -1,739 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * net/dccp/input.c - * - * An implementation of the DCCP protocol - * Arnaldo Carvalho de Melo <acme@conectiva.com.br> - */ - -#include <linux/dccp.h> -#include <linux/skbuff.h> -#include <linux/slab.h> - -#include <net/sock.h> - -#include "ackvec.h" -#include "ccid.h" -#include "dccp.h" - -/* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */ -int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8; - -static void dccp_enqueue_skb(struct sock *sk, struct sk_buff *skb) -{ - __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4); - __skb_queue_tail(&sk->sk_receive_queue, skb); - skb_set_owner_r(skb, sk); - sk->sk_data_ready(sk); -} - -static void dccp_fin(struct sock *sk, struct sk_buff *skb) -{ - /* - * On receiving Close/CloseReq, both RD/WR shutdown are performed. - * RFC 4340, 8.3 says that we MAY send further Data/DataAcks after - * receiving the closing segment, but there is no guarantee that such - * data will be processed at all. - */ - sk->sk_shutdown = SHUTDOWN_MASK; - sock_set_flag(sk, SOCK_DONE); - dccp_enqueue_skb(sk, skb); -} - -static int dccp_rcv_close(struct sock *sk, struct sk_buff *skb) -{ - int queued = 0; - - switch (sk->sk_state) { - /* - * We ignore Close when received in one of the following states: - * - CLOSED (may be a late or duplicate packet) - * - PASSIVE_CLOSEREQ (the peer has sent a CloseReq earlier) - * - RESPOND (already handled by dccp_check_req) - */ - case DCCP_CLOSING: - /* - * Simultaneous-close: receiving a Close after sending one. This - * can happen if both client and server perform active-close and - * will result in an endless ping-pong of crossing and retrans- - * mitted Close packets, which only terminates when one of the - * nodes times out (min. 64 seconds). Quicker convergence can be - * achieved when one of the nodes acts as tie-breaker. - * This is ok as both ends are done with data transfer and each - * end is just waiting for the other to acknowledge termination. - */ - if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) - break; - fallthrough; - case DCCP_REQUESTING: - case DCCP_ACTIVE_CLOSEREQ: - dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED); - dccp_done(sk); - break; - case DCCP_OPEN: - case DCCP_PARTOPEN: - /* Give waiting application a chance to read pending data */ - queued = 1; - dccp_fin(sk, skb); - dccp_set_state(sk, DCCP_PASSIVE_CLOSE); - fallthrough; - case DCCP_PASSIVE_CLOSE: - /* - * Retransmitted Close: we have already enqueued the first one. - */ - sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); - } - return queued; -} - -static int dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) -{ - int queued = 0; - - /* - * Step 7: Check for unexpected packet types - * If (S.is_server and P.type == CloseReq) - * Send Sync packet acknowledging P.seqno - * Drop packet and return - */ - if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) { - dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); - return queued; - } - - /* Step 13: process relevant Client states < CLOSEREQ */ - switch (sk->sk_state) { - case DCCP_REQUESTING: - dccp_send_close(sk, 0); - dccp_set_state(sk, DCCP_CLOSING); - break; - case DCCP_OPEN: - case DCCP_PARTOPEN: - /* Give waiting application a chance to read pending data */ - queued = 1; - dccp_fin(sk, skb); - dccp_set_state(sk, DCCP_PASSIVE_CLOSEREQ); - fallthrough; - case DCCP_PASSIVE_CLOSEREQ: - sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); - } - return queued; -} - -static u16 dccp_reset_code_convert(const u8 code) -{ - static const u16 error_code[] = { - [DCCP_RESET_CODE_CLOSED] = 0, /* normal termination */ - [DCCP_RESET_CODE_UNSPECIFIED] = 0, /* nothing known */ - [DCCP_RESET_CODE_ABORTED] = ECONNRESET, - - [DCCP_RESET_CODE_NO_CONNECTION] = ECONNREFUSED, - [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED, - [DCCP_RESET_CODE_TOO_BUSY] = EUSERS, - [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT, - - [DCCP_RESET_CODE_PACKET_ERROR] = ENOMSG, - [DCCP_RESET_CODE_BAD_INIT_COOKIE] = EBADR, - [DCCP_RESET_CODE_BAD_SERVICE_CODE] = EBADRQC, - [DCCP_RESET_CODE_OPTION_ERROR] = EILSEQ, - [DCCP_RESET_CODE_MANDATORY_ERROR] = EOPNOTSUPP, - }; - - return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code]; -} - -static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb) -{ - u16 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code); - - sk->sk_err = err; - - /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */ - dccp_fin(sk, skb); - - if (err && !sock_flag(sk, SOCK_DEAD)) - sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR); - dccp_time_wait(sk, DCCP_TIME_WAIT, 0); -} - -static void dccp_handle_ackvec_processing(struct sock *sk, struct sk_buff *skb) -{ - struct dccp_ackvec *av = dccp_sk(sk)->dccps_hc_rx_ackvec; - - if (av == NULL) - return; - if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) - dccp_ackvec_clear_state(av, DCCP_SKB_CB(skb)->dccpd_ack_seq); - dccp_ackvec_input(av, skb); -} - -static void dccp_deliver_input_to_ccids(struct sock *sk, struct sk_buff *skb) -{ - const struct dccp_sock *dp = dccp_sk(sk); - - /* Don't deliver to RX CCID when node has shut down read end. */ - if (!(sk->sk_shutdown & RCV_SHUTDOWN)) - ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); - /* - * Until the TX queue has been drained, we can not honour SHUT_WR, since - * we need received feedback as input to adjust congestion control. - */ - if (sk->sk_write_queue.qlen > 0 || !(sk->sk_shutdown & SEND_SHUTDOWN)) - ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); -} - -static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) -{ - const struct dccp_hdr *dh = dccp_hdr(skb); - struct dccp_sock *dp = dccp_sk(sk); - u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq, - ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq; - - /* - * Step 5: Prepare sequence numbers for Sync - * If P.type == Sync or P.type == SyncAck, - * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL, - * / * P is valid, so update sequence number variables - * accordingly. After this update, P will pass the tests - * in Step 6. A SyncAck is generated if necessary in - * Step 15 * / - * Update S.GSR, S.SWL, S.SWH - * Otherwise, - * Drop packet and return - */ - if (dh->dccph_type == DCCP_PKT_SYNC || - dh->dccph_type == DCCP_PKT_SYNCACK) { - if (between48(ackno, dp->dccps_awl, dp->dccps_awh) && - dccp_delta_seqno(dp->dccps_swl, seqno) >= 0) - dccp_update_gsr(sk, seqno); - else - return -1; - } - - /* - * Step 6: Check sequence numbers - * Let LSWL = S.SWL and LAWL = S.AWL - * If P.type == CloseReq or P.type == Close or P.type == Reset, - * LSWL := S.GSR + 1, LAWL := S.GAR - * If LSWL <= P.seqno <= S.SWH - * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH), - * Update S.GSR, S.SWL, S.SWH - * If P.type != Sync, - * Update S.GAR - */ - lswl = dp->dccps_swl; - lawl = dp->dccps_awl; - - if (dh->dccph_type == DCCP_PKT_CLOSEREQ || - dh->dccph_type == DCCP_PKT_CLOSE || - dh->dccph_type == DCCP_PKT_RESET) { - lswl = ADD48(dp->dccps_gsr, 1); - lawl = dp->dccps_gar; - } - - if (between48(seqno, lswl, dp->dccps_swh) && - (ackno == DCCP_PKT_WITHOUT_ACK_SEQ || - between48(ackno, lawl, dp->dccps_awh))) { - dccp_update_gsr(sk, seqno); - - if (dh->dccph_type != DCCP_PKT_SYNC && - ackno != DCCP_PKT_WITHOUT_ACK_SEQ && - after48(ackno, dp->dccps_gar)) - dp->dccps_gar = ackno; - } else { - unsigned long now = jiffies; - /* - * Step 6: Check sequence numbers - * Otherwise, - * If P.type == Reset, - * Send Sync packet acknowledging S.GSR - * Otherwise, - * Send Sync packet acknowledging P.seqno - * Drop packet and return - * - * These Syncs are rate-limited as per RFC 4340, 7.5.4: - * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second. - */ - if (time_before(now, (dp->dccps_rate_last + - sysctl_dccp_sync_ratelimit))) - return -1; - - DCCP_WARN("Step 6 failed for %s packet, " - "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and " - "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), " - "sending SYNC...\n", dccp_packet_name(dh->dccph_type), - (unsigned long long) lswl, (unsigned long long) seqno, - (unsigned long long) dp->dccps_swh, - (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist" - : "exists", - (unsigned long long) lawl, (unsigned long long) ackno, - (unsigned long long) dp->dccps_awh); - - dp->dccps_rate_last = now; - - if (dh->dccph_type == DCCP_PKT_RESET) - seqno = dp->dccps_gsr; - dccp_send_sync(sk, seqno, DCCP_PKT_SYNC); - return -1; - } - - return 0; -} - -static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, - const struct dccp_hdr *dh, const unsigned int len) -{ - struct dccp_sock *dp = dccp_sk(sk); - - switch (dccp_hdr(skb)->dccph_type) { - case DCCP_PKT_DATAACK: - case DCCP_PKT_DATA: - /* - * FIXME: schedule DATA_DROPPED (RFC 4340, 11.7.2) if and when - * - sk_shutdown == RCV_SHUTDOWN, use Code 1, "Not Listening" - * - sk_receive_queue is full, use Code 2, "Receive Buffer" - */ - dccp_enqueue_skb(sk, skb); - return 0; - case DCCP_PKT_ACK: - goto discard; - case DCCP_PKT_RESET: - /* - * Step 9: Process Reset - * If P.type == Reset, - * Tear down connection - * S.state := TIMEWAIT - * Set TIMEWAIT timer - * Drop packet and return - */ - dccp_rcv_reset(sk, skb); - return 0; - case DCCP_PKT_CLOSEREQ: - if (dccp_rcv_closereq(sk, skb)) - return 0; - goto discard; - case DCCP_PKT_CLOSE: - if (dccp_rcv_close(sk, skb)) - return 0; - goto discard; - case DCCP_PKT_REQUEST: - /* Step 7 - * or (S.is_server and P.type == Response) - * or (S.is_client and P.type == Request) - * or (S.state >= OPEN and P.type == Request - * and P.seqno >= S.OSR) - * or (S.state >= OPEN and P.type == Response - * and P.seqno >= S.OSR) - * or (S.state == RESPOND and P.type == Data), - * Send Sync packet acknowledging P.seqno - * Drop packet and return - */ - if (dp->dccps_role != DCCP_ROLE_LISTEN) - goto send_sync; - goto check_seq; - case DCCP_PKT_RESPONSE: - if (dp->dccps_role != DCCP_ROLE_CLIENT) - goto send_sync; -check_seq: - if (dccp_delta_seqno(dp->dccps_osr, - DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { -send_sync: - dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, - DCCP_PKT_SYNC); - } - break; - case DCCP_PKT_SYNC: - dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, - DCCP_PKT_SYNCACK); - /* - * From RFC 4340, sec. 5.7 - * - * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets - * MAY have non-zero-length application data areas, whose - * contents receivers MUST ignore. - */ - goto discard; - } - - DCCP_INC_STATS(DCCP_MIB_INERRS); -discard: - __kfree_skb(skb); - return 0; -} - -int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, - const struct dccp_hdr *dh, const unsigned int len) -{ - if (dccp_check_seqno(sk, skb)) - goto discard; - - if (dccp_parse_options(sk, NULL, skb)) - return 1; - - dccp_handle_ackvec_processing(sk, skb); - dccp_deliver_input_to_ccids(sk, skb); - - return __dccp_rcv_established(sk, skb, dh, len); -discard: - __kfree_skb(skb); - return 0; -} - -EXPORT_SYMBOL_GPL(dccp_rcv_established); - -static int dccp_rcv_request_sent_state_process(struct sock *sk, - struct sk_buff *skb, - const struct dccp_hdr *dh, - const unsigned int 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); - long tstamp = dccp_timestamp(); - - 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 option processing (Step 8) failed, return 1 here so that - * dccp_v4_do_rcv() sends a Reset. The Reset code depends on - * the option type and is set in dccp_parse_options(). - */ - if (dccp_parse_options(sk, NULL, skb)) - return 1; - - /* Obtain usec RTT sample from SYN exchange (used by TFRC). */ - if (likely(dp->dccps_options_received.dccpor_timestamp_echo)) - dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp - - dp->dccps_options_received.dccpor_timestamp_echo)); - - /* Stop the REQUEST timer */ - inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS); - WARN_ON(sk->sk_send_head == NULL); - kfree_skb(sk->sk_send_head); - sk->sk_send_head = NULL; - - /* - * Set ISR, GSR from packet. ISS was set in dccp_v{4,6}_connect - * and GSS in dccp_transmit_skb(). Setting AWL/AWH and SWL/SWH - * is done as part of activating the feature values below, since - * these settings depend on the local/remote Sequence Window - * features, which were undefined or not confirmed until now. - */ - dp->dccps_gsr = dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq; - - 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); - - /* - * If feature negotiation was successful, activate features now; - * an activation failure means that this host could not activate - * one ore more features (e.g. insufficient memory), which would - * leave at least one feature in an undefined state. - */ - if (dccp_feat_activate_values(sk, &dp->dccps_featneg)) - goto unable_to_proceed; - - /* 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, SOCK_WAKE_IO, POLL_OUT); - } - - if (sk->sk_write_pending || inet_csk_in_pingpong_mode(sk) || - 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; - -unable_to_proceed: - DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_ABORTED; - /* - * We mark this socket as no longer usable, so that the loop in - * dccp_sendmsg() terminates and the application gets notified. - */ - dccp_set_state(sk, DCCP_CLOSED); - sk->sk_err = ECOMM; - return 1; -} - -static int dccp_rcv_respond_partopen_state_process(struct sock *sk, - struct sk_buff *skb, - const struct dccp_hdr *dh, - const unsigned int len) -{ - struct dccp_sock *dp = dccp_sk(sk); - u32 sample = dp->dccps_options_received.dccpor_timestamp_echo; - int queued = 0; - - switch (dh->dccph_type) { - case DCCP_PKT_RESET: - inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); - break; - case DCCP_PKT_DATA: - if (sk->sk_state == DCCP_RESPOND) - break; - fallthrough; - case DCCP_PKT_DATAACK: - case DCCP_PKT_ACK: - /* - * FIXME: we should be resetting the PARTOPEN (DELACK) timer - * here but only if we haven't used the DELACK timer for - * something else, like sending a delayed ack for a TIMESTAMP - * echo, etc, for now were not clearing it, sending an extra - * ACK when there is nothing else to do in DELACK is not a big - * deal after all. - */ - - /* Stop the PARTOPEN timer */ - if (sk->sk_state == DCCP_PARTOPEN) - inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); - - /* Obtain usec RTT sample from SYN exchange (used by TFRC). */ - if (likely(sample)) { - long delta = dccp_timestamp() - sample; - - dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * delta); - } - - dp->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq; - dccp_set_state(sk, DCCP_OPEN); - - if (dh->dccph_type == DCCP_PKT_DATAACK || - dh->dccph_type == DCCP_PKT_DATA) { - __dccp_rcv_established(sk, skb, dh, len); - queued = 1; /* packet was queued - (by __dccp_rcv_established) */ - } - break; - } - - return queued; -} - -int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, - struct dccp_hdr *dh, unsigned int len) -{ - struct dccp_sock *dp = dccp_sk(sk); - struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); - const int old_state = sk->sk_state; - bool acceptable; - 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) { - /* It is possible that we process SYN packets from backlog, - * so we need to make sure to disable BH and RCU right there. - */ - rcu_read_lock(); - local_bh_disable(); - acceptable = inet_csk(sk)->icsk_af_ops->conn_request(sk, skb) >= 0; - local_bh_enable(); - rcu_read_unlock(); - if (!acceptable) - return 1; - consume_skb(skb); - return 0; - } - 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; - } else if (sk->sk_state == DCCP_CLOSED) { - dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION; - return 1; - } - - /* Step 6: Check sequence numbers (omitted in LISTEN/REQUEST state) */ - if (sk->sk_state != DCCP_REQUESTING && dccp_check_seqno(sk, skb)) - goto discard; - - /* - * Step 7: Check for unexpected packet types - * If (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 - */ - if ((dp->dccps_role != DCCP_ROLE_CLIENT && - dh->dccph_type == DCCP_PKT_RESPONSE) || - (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; - } - - /* Step 8: Process options */ - if (dccp_parse_options(sk, NULL, skb)) - return 1; - - /* - * 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) { - dccp_rcv_reset(sk, skb); - return 0; - } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */ - if (dccp_rcv_closereq(sk, skb)) - return 0; - goto discard; - } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */ - if (dccp_rcv_close(sk, skb)) - return 0; - goto discard; - } - - switch (sk->sk_state) { - case DCCP_REQUESTING: - queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len); - if (queued >= 0) - return queued; - - __kfree_skb(skb); - return 0; - - case DCCP_PARTOPEN: - /* Step 8: if using Ack Vectors, mark packet acknowledgeable */ - dccp_handle_ackvec_processing(sk, skb); - dccp_deliver_input_to_ccids(sk, skb); - fallthrough; - case DCCP_RESPOND: - 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, SOCK_WAKE_IO, POLL_OUT); - break; - } - } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) { - dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK); - goto discard; - } - - if (!queued) { -discard: - __kfree_skb(skb); - } - return 0; -} - -EXPORT_SYMBOL_GPL(dccp_rcv_state_process); - -/** - * dccp_sample_rtt - Validate and finalise computation of RTT sample - * @sk: socket structure - * @delta: number of microseconds between packet and acknowledgment - * - * The routine is kept generic to work in different contexts. It should be - * called immediately when the ACK used for the RTT sample arrives. - */ -u32 dccp_sample_rtt(struct sock *sk, long delta) -{ - /* dccpor_elapsed_time is either zeroed out or set and > 0 */ - delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10; - - if (unlikely(delta <= 0)) { - DCCP_WARN("unusable RTT sample %ld, using min\n", delta); - return DCCP_SANE_RTT_MIN; - } - if (unlikely(delta > DCCP_SANE_RTT_MAX)) { - DCCP_WARN("RTT sample %ld too large, using max\n", delta); - return DCCP_SANE_RTT_MAX; - } - - return delta; -} |