^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * net/dccp/input.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * An implementation of the DCCP protocol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/dccp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "ackvec.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include "ccid.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include "dccp.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) static void dccp_enqueue_skb(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) __skb_queue_tail(&sk->sk_receive_queue, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) skb_set_owner_r(skb, sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) sk->sk_data_ready(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) static void dccp_fin(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * On receiving Close/CloseReq, both RD/WR shutdown are performed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * RFC 4340, 8.3 says that we MAY send further Data/DataAcks after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * receiving the closing segment, but there is no guarantee that such
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * data will be processed at all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) sk->sk_shutdown = SHUTDOWN_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) sock_set_flag(sk, SOCK_DONE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) dccp_enqueue_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static int dccp_rcv_close(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) int queued = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) switch (sk->sk_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * We ignore Close when received in one of the following states:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) * - CLOSED (may be a late or duplicate packet)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) * - PASSIVE_CLOSEREQ (the peer has sent a CloseReq earlier)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) * - RESPOND (already handled by dccp_check_req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) case DCCP_CLOSING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * Simultaneous-close: receiving a Close after sending one. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * can happen if both client and server perform active-close and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * will result in an endless ping-pong of crossing and retrans-
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * mitted Close packets, which only terminates when one of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * nodes times out (min. 64 seconds). Quicker convergence can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * achieved when one of the nodes acts as tie-breaker.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * This is ok as both ends are done with data transfer and each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * end is just waiting for the other to acknowledge termination.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) case DCCP_REQUESTING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) case DCCP_ACTIVE_CLOSEREQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) dccp_done(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) case DCCP_OPEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) case DCCP_PARTOPEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) /* Give waiting application a chance to read pending data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) queued = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) dccp_fin(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) dccp_set_state(sk, DCCP_PASSIVE_CLOSE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) case DCCP_PASSIVE_CLOSE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * Retransmitted Close: we have already enqueued the first one.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return queued;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) static int dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) int queued = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * Step 7: Check for unexpected packet types
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * If (S.is_server and P.type == CloseReq)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * Send Sync packet acknowledging P.seqno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (dccp_sk(sk)->dccps_role != DCCP_ROLE_CLIENT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) return queued;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) /* Step 13: process relevant Client states < CLOSEREQ */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) switch (sk->sk_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) case DCCP_REQUESTING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) dccp_send_close(sk, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) dccp_set_state(sk, DCCP_CLOSING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) case DCCP_OPEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) case DCCP_PARTOPEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) /* Give waiting application a chance to read pending data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) queued = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) dccp_fin(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) dccp_set_state(sk, DCCP_PASSIVE_CLOSEREQ);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) case DCCP_PASSIVE_CLOSEREQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) return queued;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) static u16 dccp_reset_code_convert(const u8 code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) static const u16 error_code[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) [DCCP_RESET_CODE_CLOSED] = 0, /* normal termination */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) [DCCP_RESET_CODE_UNSPECIFIED] = 0, /* nothing known */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) [DCCP_RESET_CODE_ABORTED] = ECONNRESET,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) [DCCP_RESET_CODE_NO_CONNECTION] = ECONNREFUSED,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) [DCCP_RESET_CODE_TOO_BUSY] = EUSERS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) [DCCP_RESET_CODE_PACKET_ERROR] = ENOMSG,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) [DCCP_RESET_CODE_BAD_INIT_COOKIE] = EBADR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) [DCCP_RESET_CODE_BAD_SERVICE_CODE] = EBADRQC,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) [DCCP_RESET_CODE_OPTION_ERROR] = EILSEQ,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) [DCCP_RESET_CODE_MANDATORY_ERROR] = EOPNOTSUPP,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) u16 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) sk->sk_err = err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) dccp_fin(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (err && !sock_flag(sk, SOCK_DEAD))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) static void dccp_handle_ackvec_processing(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) struct dccp_ackvec *av = dccp_sk(sk)->dccps_hc_rx_ackvec;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) if (av == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) dccp_ackvec_clear_state(av, DCCP_SKB_CB(skb)->dccpd_ack_seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) dccp_ackvec_input(av, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static void dccp_deliver_input_to_ccids(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) const struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) /* Don't deliver to RX CCID when node has shut down read end. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) if (!(sk->sk_shutdown & RCV_SHUTDOWN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) * Until the TX queue has been drained, we can not honour SHUT_WR, since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) * we need received feedback as input to adjust congestion control.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) if (sk->sk_write_queue.qlen > 0 || !(sk->sk_shutdown & SEND_SHUTDOWN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) const struct dccp_hdr *dh = dccp_hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) u64 lswl, lawl, seqno = DCCP_SKB_CB(skb)->dccpd_seq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * Step 5: Prepare sequence numbers for Sync
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) * If P.type == Sync or P.type == SyncAck,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * If S.AWL <= P.ackno <= S.AWH and P.seqno >= S.SWL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * / * P is valid, so update sequence number variables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) * accordingly. After this update, P will pass the tests
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) * in Step 6. A SyncAck is generated if necessary in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) * Step 15 * /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) * Update S.GSR, S.SWL, S.SWH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) * Otherwise,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) if (dh->dccph_type == DCCP_PKT_SYNC ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) dh->dccph_type == DCCP_PKT_SYNCACK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (between48(ackno, dp->dccps_awl, dp->dccps_awh) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) dccp_delta_seqno(dp->dccps_swl, seqno) >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) dccp_update_gsr(sk, seqno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) * Step 6: Check sequence numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * Let LSWL = S.SWL and LAWL = S.AWL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) * If P.type == CloseReq or P.type == Close or P.type == Reset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * LSWL := S.GSR + 1, LAWL := S.GAR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) * If LSWL <= P.seqno <= S.SWH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * and (P.ackno does not exist or LAWL <= P.ackno <= S.AWH),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * Update S.GSR, S.SWL, S.SWH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * If P.type != Sync,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) * Update S.GAR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) lswl = dp->dccps_swl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) lawl = dp->dccps_awl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) if (dh->dccph_type == DCCP_PKT_CLOSEREQ ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) dh->dccph_type == DCCP_PKT_CLOSE ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) dh->dccph_type == DCCP_PKT_RESET) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) lswl = ADD48(dp->dccps_gsr, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) lawl = dp->dccps_gar;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) if (between48(seqno, lswl, dp->dccps_swh) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) (ackno == DCCP_PKT_WITHOUT_ACK_SEQ ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) between48(ackno, lawl, dp->dccps_awh))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) dccp_update_gsr(sk, seqno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) if (dh->dccph_type != DCCP_PKT_SYNC &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) ackno != DCCP_PKT_WITHOUT_ACK_SEQ &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) after48(ackno, dp->dccps_gar))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) dp->dccps_gar = ackno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) unsigned long now = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) * Step 6: Check sequence numbers
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) * Otherwise,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) * If P.type == Reset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) * Send Sync packet acknowledging S.GSR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) * Otherwise,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) * Send Sync packet acknowledging P.seqno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * These Syncs are rate-limited as per RFC 4340, 7.5.4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) * at most 1 / (dccp_sync_rate_limit * HZ) Syncs per second.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) if (time_before(now, (dp->dccps_rate_last +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) sysctl_dccp_sync_ratelimit)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) DCCP_WARN("Step 6 failed for %s packet, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) "(P.ackno %s or LAWL(%llu) <= P.ackno(%llu) <= S.AWH(%llu), "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) "sending SYNC...\n", dccp_packet_name(dh->dccph_type),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) (unsigned long long) lswl, (unsigned long long) seqno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) (unsigned long long) dp->dccps_swh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) (ackno == DCCP_PKT_WITHOUT_ACK_SEQ) ? "doesn't exist"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) : "exists",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) (unsigned long long) lawl, (unsigned long long) ackno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) (unsigned long long) dp->dccps_awh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) dp->dccps_rate_last = now;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) if (dh->dccph_type == DCCP_PKT_RESET)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) seqno = dp->dccps_gsr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) dccp_send_sync(sk, seqno, DCCP_PKT_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) const struct dccp_hdr *dh, const unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) switch (dccp_hdr(skb)->dccph_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) case DCCP_PKT_DATAACK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) case DCCP_PKT_DATA:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * FIXME: schedule DATA_DROPPED (RFC 4340, 11.7.2) if and when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * - sk_shutdown == RCV_SHUTDOWN, use Code 1, "Not Listening"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * - sk_receive_queue is full, use Code 2, "Receive Buffer"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) dccp_enqueue_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) case DCCP_PKT_ACK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) case DCCP_PKT_RESET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * Step 9: Process Reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * If P.type == Reset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * Tear down connection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) * S.state := TIMEWAIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) * Set TIMEWAIT timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) dccp_rcv_reset(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) case DCCP_PKT_CLOSEREQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) if (dccp_rcv_closereq(sk, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) case DCCP_PKT_CLOSE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) if (dccp_rcv_close(sk, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) case DCCP_PKT_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) /* Step 7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) * or (S.is_server and P.type == Response)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * or (S.is_client and P.type == Request)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * or (S.state >= OPEN and P.type == Request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * and P.seqno >= S.OSR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * or (S.state >= OPEN and P.type == Response
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * and P.seqno >= S.OSR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * or (S.state == RESPOND and P.type == Data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * Send Sync packet acknowledging P.seqno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (dp->dccps_role != DCCP_ROLE_LISTEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) goto send_sync;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) goto check_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) case DCCP_PKT_RESPONSE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) if (dp->dccps_role != DCCP_ROLE_CLIENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) goto send_sync;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) check_seq:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) if (dccp_delta_seqno(dp->dccps_osr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) DCCP_SKB_CB(skb)->dccpd_seq) >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) send_sync:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) DCCP_PKT_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) case DCCP_PKT_SYNC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) DCCP_PKT_SYNCACK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * From RFC 4340, sec. 5.7
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * As with DCCP-Ack packets, DCCP-Sync and DCCP-SyncAck packets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) * MAY have non-zero-length application data areas, whose
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * contents receivers MUST ignore.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) DCCP_INC_STATS(DCCP_MIB_INERRS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) discard:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) __kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) const struct dccp_hdr *dh, const unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) if (dccp_check_seqno(sk, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) if (dccp_parse_options(sk, NULL, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) dccp_handle_ackvec_processing(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) dccp_deliver_input_to_ccids(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) return __dccp_rcv_established(sk, skb, dh, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) discard:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) __kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) EXPORT_SYMBOL_GPL(dccp_rcv_established);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) static int dccp_rcv_request_sent_state_process(struct sock *sk,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) const struct dccp_hdr *dh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) const unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) * Step 4: Prepare sequence numbers in REQUEST
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) * If S.state == REQUEST,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) * If (P.type == Response or P.type == Reset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) * and S.AWL <= P.ackno <= S.AWH,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) * / * Set sequence number variables corresponding to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * other endpoint, so P will pass the tests in Step 6 * /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) * Set S.GSR, S.ISR, S.SWL, S.SWH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) * / * Response processing continues in Step 10; Reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) * processing continues in Step 9 * /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if (dh->dccph_type == DCCP_PKT_RESPONSE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) const struct inet_connection_sock *icsk = inet_csk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) long tstamp = dccp_timestamp();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) if (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) dp->dccps_awl, dp->dccps_awh)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) dccp_pr_debug("invalid ackno: S.AWL=%llu, "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) "P.ackno=%llu, S.AWH=%llu\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) (unsigned long long)dp->dccps_awl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) (unsigned long long)DCCP_SKB_CB(skb)->dccpd_ack_seq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) (unsigned long long)dp->dccps_awh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) goto out_invalid_packet;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * If option processing (Step 8) failed, return 1 here so that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * dccp_v4_do_rcv() sends a Reset. The Reset code depends on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * the option type and is set in dccp_parse_options().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) if (dccp_parse_options(sk, NULL, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) /* Obtain usec RTT sample from SYN exchange (used by TFRC). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) if (likely(dp->dccps_options_received.dccpor_timestamp_echo))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * (tstamp -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) dp->dccps_options_received.dccpor_timestamp_echo));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) /* Stop the REQUEST timer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) WARN_ON(sk->sk_send_head == NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) kfree_skb(sk->sk_send_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) sk->sk_send_head = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) * Set ISR, GSR from packet. ISS was set in dccp_v{4,6}_connect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) * and GSS in dccp_transmit_skb(). Setting AWL/AWH and SWL/SWH
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) * is done as part of activating the feature values below, since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) * these settings depend on the local/remote Sequence Window
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * features, which were undefined or not confirmed until now.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) dp->dccps_gsr = dp->dccps_isr = DCCP_SKB_CB(skb)->dccpd_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) dccp_sync_mss(sk, icsk->icsk_pmtu_cookie);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * Step 10: Process REQUEST state (second part)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) * If S.state == REQUEST,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * / * If we get here, P is a valid Response from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * server (see Step 4), and we should move to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * PARTOPEN state. PARTOPEN means send an Ack,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * don't send Data packets, retransmit Acks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) * periodically, and always include any Init Cookie
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * from the Response * /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) * S.state := PARTOPEN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) * Set PARTOPEN timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) * Continue with S.state == PARTOPEN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) * / * Step 12 will send the Ack completing the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) * three-way handshake * /
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) dccp_set_state(sk, DCCP_PARTOPEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) * If feature negotiation was successful, activate features now;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) * an activation failure means that this host could not activate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) * one ore more features (e.g. insufficient memory), which would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) * leave at least one feature in an undefined state.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) if (dccp_feat_activate_values(sk, &dp->dccps_featneg))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) goto unable_to_proceed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) /* Make sure socket is routed, for correct metrics. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) icsk->icsk_af_ops->rebuild_header(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) if (!sock_flag(sk, SOCK_DEAD)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) sk->sk_state_change(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) if (sk->sk_write_pending || inet_csk_in_pingpong_mode(sk) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) icsk->icsk_accept_queue.rskq_defer_accept) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) /* Save one ACK. Data will be ready after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) * several ticks, if write_pending is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) * It may be deleted, but with this feature tcpdumps
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) * look so _wonderfully_ clever, that I was not able
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) * to stand against the temptation 8) --ANK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) * OK, in DCCP we can as well do a similar trick, its
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * even in the draft, but there is no need for us to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) * schedule an ack here, as dccp_sendmsg does this for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * us, also stated in the draft. -acme
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) __kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) dccp_send_ack(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) out_invalid_packet:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) /* dccp_v4_do_rcv will send a reset */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) unable_to_proceed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_ABORTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * We mark this socket as no longer usable, so that the loop in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * dccp_sendmsg() terminates and the application gets notified.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) dccp_set_state(sk, DCCP_CLOSED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) sk->sk_err = ECOMM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) static int dccp_rcv_respond_partopen_state_process(struct sock *sk,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) const struct dccp_hdr *dh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) const unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) u32 sample = dp->dccps_options_received.dccpor_timestamp_echo;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) int queued = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) switch (dh->dccph_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) case DCCP_PKT_RESET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) case DCCP_PKT_DATA:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) if (sk->sk_state == DCCP_RESPOND)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) case DCCP_PKT_DATAACK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) case DCCP_PKT_ACK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) * FIXME: we should be resetting the PARTOPEN (DELACK) timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) * here but only if we haven't used the DELACK timer for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) * something else, like sending a delayed ack for a TIMESTAMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) * echo, etc, for now were not clearing it, sending an extra
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) * ACK when there is nothing else to do in DELACK is not a big
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) * deal after all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) /* Stop the PARTOPEN timer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) if (sk->sk_state == DCCP_PARTOPEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) /* Obtain usec RTT sample from SYN exchange (used by TFRC). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) if (likely(sample)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) long delta = dccp_timestamp() - sample;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) dp->dccps_syn_rtt = dccp_sample_rtt(sk, 10 * delta);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) dp->dccps_osr = DCCP_SKB_CB(skb)->dccpd_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) dccp_set_state(sk, DCCP_OPEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) if (dh->dccph_type == DCCP_PKT_DATAACK ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) dh->dccph_type == DCCP_PKT_DATA) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) __dccp_rcv_established(sk, skb, dh, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) queued = 1; /* packet was queued
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) (by __dccp_rcv_established) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) return queued;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) struct dccp_hdr *dh, unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) const int old_state = sk->sk_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) bool acceptable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) int queued = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) * Step 3: Process LISTEN state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) * If S.state == LISTEN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) * If P.type == Request or P contains a valid Init Cookie option,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) * (* Must scan the packet's options to check for Init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) * Cookies. Only Init Cookies are processed here,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) * however; other options are processed in Step 8. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) * scan need only be performed if the endpoint uses Init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) * Cookies *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) * (* Generate a new socket and switch to that socket *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) * Set S := new socket for this port pair
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) * S.state = RESPOND
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) * Choose S.ISS (initial seqno) or set from Init Cookies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) * Initialize S.GAR := S.ISS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) * Cookies Continue with S.state == RESPOND
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) * (* A Response packet will be generated in Step 11 *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) * Otherwise,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) * Generate Reset(No Connection) unless P.type == Reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) if (sk->sk_state == DCCP_LISTEN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) if (dh->dccph_type == DCCP_PKT_REQUEST) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) /* It is possible that we process SYN packets from backlog,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) * so we need to make sure to disable BH and RCU right there.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) local_bh_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) acceptable = inet_csk(sk)->icsk_af_ops->conn_request(sk, skb) >= 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) local_bh_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) if (!acceptable)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) consume_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) if (dh->dccph_type == DCCP_PKT_RESET)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) /* Caller (dccp_v4_do_rcv) will send Reset */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) } else if (sk->sk_state == DCCP_CLOSED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) dcb->dccpd_reset_code = DCCP_RESET_CODE_NO_CONNECTION;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) /* Step 6: Check sequence numbers (omitted in LISTEN/REQUEST state) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) if (sk->sk_state != DCCP_REQUESTING && dccp_check_seqno(sk, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) * Step 7: Check for unexpected packet types
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * If (S.is_server and P.type == Response)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) * or (S.is_client and P.type == Request)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) * or (S.state == RESPOND and P.type == Data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) * Send Sync packet acknowledging P.seqno
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) if ((dp->dccps_role != DCCP_ROLE_CLIENT &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) dh->dccph_type == DCCP_PKT_RESPONSE) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) (dp->dccps_role == DCCP_ROLE_CLIENT &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) dh->dccph_type == DCCP_PKT_REQUEST) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) (sk->sk_state == DCCP_RESPOND && dh->dccph_type == DCCP_PKT_DATA)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) /* Step 8: Process options */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) if (dccp_parse_options(sk, NULL, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) * Step 9: Process Reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) * If P.type == Reset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) * Tear down connection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) * S.state := TIMEWAIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) * Set TIMEWAIT timer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) * Drop packet and return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) if (dh->dccph_type == DCCP_PKT_RESET) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) dccp_rcv_reset(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { /* Step 13 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) if (dccp_rcv_closereq(sk, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) } else if (dh->dccph_type == DCCP_PKT_CLOSE) { /* Step 14 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) if (dccp_rcv_close(sk, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) switch (sk->sk_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) case DCCP_REQUESTING:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) queued = dccp_rcv_request_sent_state_process(sk, skb, dh, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) if (queued >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) return queued;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) __kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) case DCCP_PARTOPEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) /* Step 8: if using Ack Vectors, mark packet acknowledgeable */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) dccp_handle_ackvec_processing(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) dccp_deliver_input_to_ccids(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) case DCCP_RESPOND:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) queued = dccp_rcv_respond_partopen_state_process(sk, skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) dh, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) if (dh->dccph_type == DCCP_PKT_ACK ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) dh->dccph_type == DCCP_PKT_DATAACK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) switch (old_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) case DCCP_PARTOPEN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) sk->sk_state_change(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) } else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) dccp_send_sync(sk, dcb->dccpd_seq, DCCP_PKT_SYNCACK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) goto discard;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) if (!queued) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) discard:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) __kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) EXPORT_SYMBOL_GPL(dccp_rcv_state_process);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) * dccp_sample_rtt - Validate and finalise computation of RTT sample
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) * @sk: socket structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) * @delta: number of microseconds between packet and acknowledgment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) * The routine is kept generic to work in different contexts. It should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) * called immediately when the ACK used for the RTT sample arrives.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) u32 dccp_sample_rtt(struct sock *sk, long delta)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) /* dccpor_elapsed_time is either zeroed out or set and > 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) delta -= dccp_sk(sk)->dccps_options_received.dccpor_elapsed_time * 10;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) if (unlikely(delta <= 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) DCCP_WARN("unusable RTT sample %ld, using min\n", delta);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) return DCCP_SANE_RTT_MIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) if (unlikely(delta > DCCP_SANE_RTT_MAX)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) DCCP_WARN("RTT sample %ld too large, using max\n", delta);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) return DCCP_SANE_RTT_MAX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) return delta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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