bsd/netinet/mptcp_timer.c

   1 /*
   2  * Copyright (c) 2012-2017 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <sys/param.h>
  30 #include <sys/systm.h>
  31 #include <sys/kernel.h>
  32 #include <sys/mcache.h>
  33 #include <sys/socket.h>
  34 #include <sys/socketvar.h>
  35 #include <sys/syslog.h>
  36 #include <sys/protosw.h>
  37 #include <sys/sysctl.h>
  38
  39 #include <mach/sdt.h>
  40
  41 #include <netinet/mp_pcb.h>
  42 #include <netinet/mptcp_var.h>
  43 #include <netinet/mptcp_timer.h>
  44 #include <netinet/mptcp_seq.h>
  45
  46 #include <kern/locks.h>
  47
  48 /*
  49  * MPTCP Retransmission Timer comes into play only when subflow level
  50  * data is acked, but Data ACK is not received. Time is in seconds.
  51  */
  52 static u_int32_t mptcp_rto = 3;
  53 SYSCTL_INT(_net_inet_mptcp, OID_AUTO, rto, CTLFLAG_RW | CTLFLAG_LOCKED,
  54         &mptcp_rto, 0, "MPTCP Retransmission Timeout");
  55
  56 static int mptcp_nrtos = 3;
  57 SYSCTL_INT(_net_inet_mptcp, OID_AUTO, nrto, CTLFLAG_RW | CTLFLAG_LOCKED,
  58         &mptcp_rto, 0, "MPTCP Retransmissions");
  59
  60 /*
  61  * MPTCP connections timewait interval in seconds.
  62  */
  63 static u_int32_t mptcp_tw = 60;
  64 SYSCTL_INT(_net_inet_mptcp, OID_AUTO, tw, CTLFLAG_RW | CTLFLAG_LOCKED,
  65         &mptcp_tw, 0, "MPTCP Timewait Period");
  66
  67 #define TIMEVAL_TO_HZ(_tv_)     ((_tv_).tv_sec * hz + (_tv_).tv_usec / hz)
  68
  69 static int
  70 mptcp_timer_demux(struct mptses *mpte, uint32_t now_msecs)
  71 {
  72         struct mptcb *mp_tp = NULL;
  73         mp_tp = mpte->mpte_mptcb;
  74         int resched_timer = 0;
  75
  76         DTRACE_MPTCP2(timer, struct mptses *, mpte, struct mptcb *, mp_tp);
  77
  78         mpte_lock_assert_held(mpte);
  79         switch (mp_tp->mpt_timer_vals) {
  80         case MPTT_REXMT:
  81                 if (mp_tp->mpt_rxtstart == 0)
  82                         break;
  83                 if ((now_msecs - mp_tp->mpt_rxtstart) >
  84                     (mptcp_rto*hz)) {
  85                         if (MPTCP_SEQ_GT(mp_tp->mpt_snduna, mp_tp->mpt_rtseq)) {
  86                                 mp_tp->mpt_timer_vals = 0;
  87                                 mp_tp->mpt_rtseq = 0;
  88                                 break;
  89                         }
  90                         mp_tp->mpt_rxtshift++;
  91                         if (mp_tp->mpt_rxtshift > mptcp_nrtos) {
  92                                 mp_tp->mpt_softerror = ETIMEDOUT;
  93                                 DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
  94                         } else {
  95                                 mp_tp->mpt_sndnxt = mp_tp->mpt_rtseq;
  96                                 os_log_info(mptcp_log_handle,
  97                                             "%s: REXMT %d sndnxt %u\n",
  98                                             __func__, mp_tp->mpt_rxtshift,
  99                                             (uint32_t)mp_tp->mpt_sndnxt);
 100                                 mptcp_output(mpte);
 101                         }
 102                 } else {
 103                         resched_timer = 1;
 104                 }
 105                 break;
 106         case MPTT_TW:
 107                 /* Allows for break before make XXX */
 108                 if (mp_tp->mpt_timewait == 0)
 109                         VERIFY(0);
 110                 if ((now_msecs - mp_tp->mpt_timewait) >
 111                     (mptcp_tw * hz)) {
 112                         mp_tp->mpt_softerror = ETIMEDOUT;
 113                         DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
 114                 } else {
 115                         resched_timer = 1;
 116                 }
 117                 break;
 118         case MPTT_FASTCLOSE:
 119                 /* TODO XXX */
 120                 break;
 121         default:
 122                 break;
 123         }
 124
 125         return (resched_timer);
 126 }
 127
 128 uint32_t
 129 mptcp_timer(struct mppcbinfo *mppi)
 130 {
 131         struct mppcb *mpp, *tmpp;
 132         struct timeval now;
 133         u_int32_t now_msecs;
 134         uint32_t resched_timer = 0;
 135
 136         LCK_MTX_ASSERT(&mppi->mppi_lock, LCK_MTX_ASSERT_OWNED);
 137
 138         microuptime(&now);
 139         now_msecs = TIMEVAL_TO_HZ(now);
 140         TAILQ_FOREACH_SAFE(mpp, &mppi->mppi_pcbs, mpp_entry, tmpp) {
 141                 struct socket *mp_so;
 142                 struct mptses *mpte;
 143
 144                 mp_so = mpp->mpp_socket;
 145                 VERIFY(mp_so != NULL);
 146                 mpte = mptompte(mpp);
 147                 VERIFY(mpte != NULL);
 148                 mpte_lock(mpte);
 149                 VERIFY(mpp->mpp_flags & MPP_ATTACHED);
 150
 151                 if (mptcp_timer_demux(mpte, now_msecs))
 152                         resched_timer = 1;
 153                 mpte_unlock(mpte);
 154         }
 155
 156         return (resched_timer);
 157 }
 158
 159 void
 160 mptcp_start_timer(struct mptses *mpte, int timer_type)
 161 {
 162         struct timeval now;
 163         struct mptcb *mp_tp = mpte->mpte_mptcb;
 164
 165         microuptime(&now);
 166
 167         DTRACE_MPTCP2(start__timer, struct mptcb *, mp_tp, int, timer_type);
 168         mptcplog((LOG_DEBUG, "MPTCP Socket: %s: %d\n", __func__, timer_type),
 169             MPTCP_SOCKET_DBG, MPTCP_LOGLVL_VERBOSE);
 170
 171         mpte_lock_assert_held(mpte);
 172
 173         switch (timer_type) {
 174         case MPTT_REXMT:
 175                 mp_tp->mpt_timer_vals |= MPTT_REXMT;
 176                 mp_tp->mpt_rxtstart = TIMEVAL_TO_HZ(now);
 177                 mp_tp->mpt_rxtshift = 0;
 178                 mp_tp->mpt_rtseq = mp_tp->mpt_sndnxt;
 179                 break;
 180         case MPTT_TW:
 181                 /* XXX: Not implemented yet */
 182                 mp_tp->mpt_timer_vals |= MPTT_TW;
 183                 mp_tp->mpt_timewait = TIMEVAL_TO_HZ(now);
 184                 break;
 185         case MPTT_FASTCLOSE:
 186                 /* NO-OP */
 187                 break;
 188         default:
 189                 VERIFY(0);
 190                 /* NOTREACHED */
 191         }
 192         mptcp_timer_sched();
 193 }
 194
 195 void
 196 mptcp_cancel_timer(struct mptcb *mp_tp, int timer_type)
 197 {
 198         mpte_lock_assert_held(mp_tp->mpt_mpte);
 199         DTRACE_MPTCP2(cancel__timer, struct mptcb *, mp_tp, int, timer_type);
 200
 201         switch (timer_type) {
 202         case MPTT_REXMT:
 203                 mp_tp->mpt_rxtstart = 0;
 204                 mp_tp->mpt_rxtshift = 0;
 205                 mp_tp->mpt_timer_vals = 0;
 206                 break;
 207         case MPTT_TW:
 208                 /* NO-OP */
 209                 break;
 210         case MPTT_FASTCLOSE:
 211                 /* NO-OP */
 212                 break;
 213         default:
 214                 break;
 215         }
 216 }
 217
 218 void
 219 mptcp_cancel_all_timers(struct mptcb *mp_tp)
 220 {
 221         mptcp_cancel_timer(mp_tp, MPTT_REXMT);
 222         mptcp_cancel_timer(mp_tp, MPTT_TW);
 223         mptcp_cancel_timer(mp_tp, MPTT_FASTCLOSE);
 224 }