^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/output.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/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <net/inet_sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include "ackvec.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include "ccid.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include "dccp.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) static inline void dccp_event_ack_sent(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) /* enqueue @skb on sk_send_head for retransmission, return clone to send now */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static struct sk_buff *dccp_skb_entail(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) skb_set_owner_w(skb, sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) WARN_ON(sk->sk_send_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) sk->sk_send_head = skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) return skb_clone(sk->sk_send_head, gfp_any());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * All SKB's seen here are completely headerless. It is our
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * job to build the DCCP header, and pass the packet down to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * IP so it can do the same plus pass the packet off to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) if (likely(skb != NULL)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) struct inet_sock *inet = inet_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) const struct inet_connection_sock *icsk = inet_csk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) struct dccp_hdr *dh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) /* XXX For now we're using only 48 bits sequence numbers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) const u32 dccp_header_size = sizeof(*dh) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) sizeof(struct dccp_hdr_ext) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) dccp_packet_hdr_len(dcb->dccpd_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) int err, set_ack = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) u64 ackno = dp->dccps_gsr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * Increment GSS here already in case the option code needs it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * Update GSS for real only if option processing below succeeds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) dcb->dccpd_seq = ADD48(dp->dccps_gss, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) switch (dcb->dccpd_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) case DCCP_PKT_DATA:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) set_ack = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) case DCCP_PKT_DATAACK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) case DCCP_PKT_RESET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) case DCCP_PKT_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) set_ack = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) /* Use ISS on the first (non-retransmitted) Request. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) if (icsk->icsk_retransmits == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) dcb->dccpd_seq = dp->dccps_iss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) case DCCP_PKT_SYNC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) case DCCP_PKT_SYNCACK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) ackno = dcb->dccpd_ack_seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * Set owner/destructor: some skbs are allocated via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * alloc_skb (e.g. when retransmission may happen).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * Only Data, DataAck, and Reset packets should come
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * through here with skb->sk set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) WARN_ON(skb->sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) skb_set_owner_w(skb, sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (dccp_insert_options(sk, skb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) return -EPROTO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) /* Build DCCP header and checksum it. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) dh = dccp_zeroed_hdr(skb, dccp_header_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) dh->dccph_type = dcb->dccpd_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) dh->dccph_sport = inet->inet_sport;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) dh->dccph_dport = inet->inet_dport;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) dh->dccph_ccval = dcb->dccpd_ccval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) dh->dccph_cscov = dp->dccps_pcslen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) /* XXX For now we're using only 48 bits sequence numbers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) dh->dccph_x = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) dccp_update_gss(sk, dcb->dccpd_seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) dccp_hdr_set_seq(dh, dp->dccps_gss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) if (set_ack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) switch (dcb->dccpd_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) case DCCP_PKT_REQUEST:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) dccp_hdr_request(skb)->dccph_req_service =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) dp->dccps_service;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * Limit Ack window to ISS <= P.ackno <= GSS, so that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * only Responses to Requests we sent are considered.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) dp->dccps_awl = dp->dccps_iss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) case DCCP_PKT_RESET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) dccp_hdr_reset(skb)->dccph_reset_code =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) dcb->dccpd_reset_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) icsk->icsk_af_ops->send_check(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (set_ack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) dccp_event_ack_sent(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) return net_xmit_eval(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return -ENOBUFS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) }
^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) * dccp_determine_ccmps - Find out about CCID-specific packet-size limits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * since the RX CCID is restricted to feedback packets (Acks), which are small
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * in comparison with the data traffic. A value of 0 means "no current CCMPS".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) static u32 dccp_determine_ccmps(const struct dccp_sock *dp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) return tx_ccid->ccid_ops->ccid_ccmps;
^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) unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) struct inet_connection_sock *icsk = inet_csk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) u32 ccmps = dccp_determine_ccmps(dp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) u32 cur_mps = ccmps ? min(pmtu, ccmps) : pmtu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) /* Account for header lengths and IPv4/v6 option overhead */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * Leave enough headroom for common DCCP header options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) * This only considers options which may appear on DCCP-Data packets, as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * per table 3 in RFC 4340, 5.8. When running out of space for other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * options (eg. Ack Vector which can take up to 255 bytes), it is better
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * to schedule a separate Ack. Thus we leave headroom for the following:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) * - 1 byte for Slow Receiver (11.6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * - 6 bytes for Timestamp (13.1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) * - 10 bytes for Timestamp Echo (13.3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) * - 8 bytes for NDP count (7.7, when activated)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) * - 6 bytes for Data Checksum (9.3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) * - %DCCPAV_MIN_OPTLEN bytes for Ack Vector size (11.4, when enabled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) /* And store cached results */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) icsk->icsk_pmtu_cookie = pmtu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) dp->dccps_mss_cache = cur_mps;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) return cur_mps;
^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) EXPORT_SYMBOL_GPL(dccp_sync_mss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) void dccp_write_space(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) struct socket_wq *wq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) wq = rcu_dereference(sk->sk_wq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) if (skwq_has_sleeper(wq))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) wake_up_interruptible(&wq->wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) /* Should agree with poll, otherwise some programs break */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) if (sock_writeable(sk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) * dccp_wait_for_ccid - Await CCID send permission
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) * @sk: socket to wait for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) * @delay: timeout in jiffies
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * This is used by CCIDs which need to delay the send time in process context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) static int dccp_wait_for_ccid(struct sock *sk, unsigned long delay)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) DEFINE_WAIT(wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) long remaining;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) sk->sk_write_pending++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) release_sock(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) remaining = schedule_timeout(delay);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) lock_sock(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) sk->sk_write_pending--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) finish_wait(sk_sleep(sk), &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) if (signal_pending(current) || sk->sk_err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) return remaining;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) * dccp_xmit_packet - Send data packet under control of CCID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) * Transmits next-queued payload and informs CCID to account for the packet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) static void dccp_xmit_packet(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) int err, len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) struct sk_buff *skb = dccp_qpolicy_pop(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) if (unlikely(skb == NULL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) len = skb->len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (sk->sk_state == DCCP_PARTOPEN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * See 8.1.5 - Handshake Completion.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) * For robustness we resend Confirm options until the client has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) * entered OPEN. During the initial feature negotiation, the MPS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) * is smaller than usual, reduced by the Change/Confirm options.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) if (!list_empty(&dp->dccps_featneg) && len > cur_mps) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) DCCP_WARN("Payload too large (%d) for featneg.\n", len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) dccp_send_ack(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) dccp_feat_list_purge(&dp->dccps_featneg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) inet_csk_schedule_ack(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) inet_csk(sk)->icsk_rto,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) DCCP_RTO_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) } else if (dccp_ack_pending(sk)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) err = dccp_transmit_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) dccp_pr_debug("transmit_skb() returned err=%d\n", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * Register this one as sent even if an error occurred. To the remote
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * end a local packet drop is indistinguishable from network loss, i.e.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * any local drop will eventually be reported via receiver feedback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * If the CCID needs to transfer additional header options out-of-band
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * (e.g. Ack Vectors or feature-negotiation options), it activates this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * flag to schedule a Sync. The Sync will automatically incorporate all
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * currently pending header options, thus clearing the backlog.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) if (dp->dccps_sync_scheduled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * dccp_flush_write_queue - Drain queue at end of connection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) * Since dccp_sendmsg queues packets without waiting for them to be sent, it may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) * happen that the TX queue is not empty at the end of a connection. We give the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) * HC-sender CCID a grace period of up to @time_budget jiffies. If this function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * returns with a non-empty write queue, it will be purged later.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) void dccp_flush_write_queue(struct sock *sk, long *time_budget)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) long delay, rc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) while (*time_budget > 0 && (skb = skb_peek(&sk->sk_write_queue))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) switch (ccid_packet_dequeue_eval(rc)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) case CCID_PACKET_WILL_DEQUEUE_LATER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * If the CCID determines when to send, the next sending
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) * time is unknown or the CCID may not even send again
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) * (e.g. remote host crashes or lost Ack packets).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) DCCP_WARN("CCID did not manage to send all packets\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) case CCID_PACKET_DELAY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) delay = msecs_to_jiffies(rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) if (delay > *time_budget)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) rc = dccp_wait_for_ccid(sk, delay);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if (rc < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) *time_budget -= (delay - rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) /* check again if we can send now */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) case CCID_PACKET_SEND_AT_ONCE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) dccp_xmit_packet(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) case CCID_PACKET_ERR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) skb_dequeue(&sk->sk_write_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) dccp_pr_debug("packet discarded due to err=%ld\n", rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) void dccp_write_xmit(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) while ((skb = dccp_qpolicy_top(sk))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) switch (ccid_packet_dequeue_eval(rc)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) case CCID_PACKET_WILL_DEQUEUE_LATER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) case CCID_PACKET_DELAY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) sk_reset_timer(sk, &dp->dccps_xmit_timer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) jiffies + msecs_to_jiffies(rc));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) case CCID_PACKET_SEND_AT_ONCE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) dccp_xmit_packet(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) case CCID_PACKET_ERR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) dccp_qpolicy_drop(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) dccp_pr_debug("packet discarded due to err=%d\n", rc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) * dccp_retransmit_skb - Retransmit Request, Close, or CloseReq packets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) * There are only four retransmittable packet types in DCCP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) * - Request in client-REQUEST state (sec. 8.1.1),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) * - CloseReq in server-CLOSEREQ state (sec. 8.3),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) * - Close in node-CLOSING state (sec. 8.3),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * - Acks in client-PARTOPEN state (sec. 8.1.5, handled by dccp_delack_timer()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * This function expects sk->sk_send_head to contain the original skb.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) int dccp_retransmit_skb(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) WARN_ON(sk->sk_send_head == NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) return -EHOSTUNREACH; /* Routing failure or similar. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) /* this count is used to distinguish original and retransmitted skb */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) inet_csk(sk)->icsk_retransmits++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) return dccp_transmit_skb(sk, skb_clone(sk->sk_send_head, GFP_ATOMIC));
^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) struct sk_buff *dccp_make_response(const struct sock *sk, struct dst_entry *dst,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) struct request_sock *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) struct dccp_hdr *dh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) struct dccp_request_sock *dreq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) const u32 dccp_header_size = sizeof(struct dccp_hdr) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) sizeof(struct dccp_hdr_ext) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) sizeof(struct dccp_hdr_response);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) /* sk is marked const to clearly express we dont hold socket lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) * sock_wmalloc() will atomically change sk->sk_wmem_alloc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) * it is safe to promote sk to non const.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) skb = sock_wmalloc((struct sock *)sk, MAX_DCCP_HEADER, 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) if (!skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) skb_reserve(skb, MAX_DCCP_HEADER);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) skb_dst_set(skb, dst_clone(dst));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) dreq = dccp_rsk(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) if (inet_rsk(req)->acked) /* increase GSS upon retransmission */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) dccp_inc_seqno(&dreq->dreq_gss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_gss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) /* Resolve feature dependencies resulting from choice of CCID */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) if (dccp_feat_server_ccid_dependencies(dreq))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) goto response_failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) if (dccp_insert_options_rsk(dreq, skb))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) goto response_failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) /* Build and checksum header */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) dh = dccp_zeroed_hdr(skb, dccp_header_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) dh->dccph_sport = htons(inet_rsk(req)->ir_num);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) dh->dccph_dport = inet_rsk(req)->ir_rmt_port;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) dh->dccph_doff = (dccp_header_size +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) dh->dccph_type = DCCP_PKT_RESPONSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) dh->dccph_x = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) dccp_hdr_set_seq(dh, dreq->dreq_gss);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) dccp_csum_outgoing(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) /* We use `acked' to remember that a Response was already sent. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) inet_rsk(req)->acked = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) response_failed:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) EXPORT_SYMBOL_GPL(dccp_make_response);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) /* answer offending packet in @rcv_skb with Reset from control socket @ctl */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *rcv_skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) sizeof(struct dccp_hdr_ext) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) sizeof(struct dccp_hdr_reset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) struct dccp_hdr_reset *dhr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (skb == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) skb_reserve(skb, sk->sk_prot->max_header);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) /* Swap the send and the receive. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) dh->dccph_type = DCCP_PKT_RESET;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) dh->dccph_sport = rxdh->dccph_dport;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) dh->dccph_dport = rxdh->dccph_sport;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) dh->dccph_doff = dccp_hdr_reset_len / 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) dh->dccph_x = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) dhr = dccp_hdr_reset(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) dhr->dccph_reset_code = dcb->dccpd_reset_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) switch (dcb->dccpd_reset_code) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) case DCCP_RESET_CODE_PACKET_ERROR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) dhr->dccph_reset_data[0] = rxdh->dccph_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) case DCCP_RESET_CODE_OPTION_ERROR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) case DCCP_RESET_CODE_MANDATORY_ERROR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * From RFC 4340, 8.3.1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) * If P.ackno exists, set R.seqno := P.ackno + 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * Else set R.seqno := 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) dccp_csum_outgoing(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) return skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) EXPORT_SYMBOL_GPL(dccp_ctl_make_reset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) /* send Reset on established socket, to close or abort the connection */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * FIXME: what if rebuild_header fails?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * Should we be doing a rebuild_header here?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) if (err != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) if (skb == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) return -ENOBUFS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) /* Reserve space for headers and prepare control bits. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) skb_reserve(skb, sk->sk_prot->max_header);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) DCCP_SKB_CB(skb)->dccpd_reset_code = code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) return dccp_transmit_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) * Do all connect socket setups that can be done AF independent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) int dccp_connect(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) struct dst_entry *dst = __sk_dst_get(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) struct inet_connection_sock *icsk = inet_csk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) sk->sk_err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) sock_reset_flag(sk, SOCK_DONE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) dccp_sync_mss(sk, dst_mtu(dst));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) /* do not connect if feature negotiation setup fails */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) if (dccp_feat_finalise_settings(dccp_sk(sk)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) return -EPROTO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) dp->dccps_gar = dp->dccps_iss;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) if (unlikely(skb == NULL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) return -ENOBUFS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) /* Reserve space for headers. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) skb_reserve(skb, sk->sk_prot->max_header);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) dccp_transmit_skb(sk, dccp_skb_entail(sk, skb));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) /* Timer for repeating the REQUEST until an answer. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) icsk->icsk_retransmits = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) icsk->icsk_rto, DCCP_RTO_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) EXPORT_SYMBOL_GPL(dccp_connect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) void dccp_send_ack(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) /* If we have been reset, we may not send again. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) if (sk->sk_state != DCCP_CLOSED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) if (skb == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) inet_csk_schedule_ack(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) TCP_DELACK_MAX,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) DCCP_RTO_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) /* Reserve space for headers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) skb_reserve(skb, sk->sk_prot->max_header);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) dccp_transmit_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) EXPORT_SYMBOL_GPL(dccp_send_ack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) #if 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) /* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) void dccp_send_delayed_ack(struct sock *sk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) struct inet_connection_sock *icsk = inet_csk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) * FIXME: tune this timer. elapsed time fixes the skew, so no problem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) * with using 2s, and active senders also piggyback the ACK into a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) * DATAACK packet, so this is really for quiescent senders.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) unsigned long timeout = jiffies + 2 * HZ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) /* Use new timeout only if there wasn't a older one earlier. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) /* If delack timer was blocked or is about to expire,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) * send ACK now.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) * FIXME: check the "about to expire" part
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) if (icsk->icsk_ack.blocked) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) dccp_send_ack(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) if (!time_before(timeout, icsk->icsk_ack.timeout))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) timeout = icsk->icsk_ack.timeout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) icsk->icsk_ack.timeout = timeout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) void dccp_send_sync(struct sock *sk, const u64 ackno,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) const enum dccp_pkt_type pkt_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * We are not putting this on the write queue, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) * dccp_transmit_skb() will set the ownership to this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) * sock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) if (skb == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) /* FIXME: how to make sure the sync is sent? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) /* Reserve space for headers and prepare control bits. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) skb_reserve(skb, sk->sk_prot->max_header);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) * Clear the flag in case the Sync was scheduled for out-of-band data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) * such as carrying a long Ack Vector.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) dccp_sk(sk)->dccps_sync_scheduled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) dccp_transmit_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) EXPORT_SYMBOL_GPL(dccp_send_sync);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) * any circumstances.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) void dccp_send_close(struct sock *sk, const int active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) struct dccp_sock *dp = dccp_sk(sk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) struct sk_buff *skb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) skb = alloc_skb(sk->sk_prot->max_header, prio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) if (skb == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) /* Reserve space for headers and prepare control bits. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) skb_reserve(skb, sk->sk_prot->max_header);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) if (active) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) skb = dccp_skb_entail(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) * Retransmission timer for active-close: RFC 4340, 8.3 requires
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) * state can be left. The initial timeout is 2 RTTs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) * Since RTT measurement is done by the CCIDs, there is no easy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) * is too low (200ms); we use a high value to avoid unnecessary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) * retransmissions when the link RTT is > 0.2 seconds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) * FIXME: Let main module sample RTTs and use that instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) DCCP_TIMEOUT_INIT, DCCP_RTO_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) dccp_transmit_skb(sk, skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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