bsd/netinet/mptcp_timer.c

   1 /*
   2  * Copyright (c) 2012-2013 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         MPT_LOCK(mp_tp);
  80         switch (mp_tp->mpt_timer_vals) {
  81         case MPTT_REXMT:
  82                 if (mp_tp->mpt_rxtstart == 0)
  83                         break;
  84                 if ((now_msecs - mp_tp->mpt_rxtstart) >
  85                     (mptcp_rto*hz)) {
  86                         if (MPTCP_SEQ_GT(mp_tp->mpt_snduna,
  87                             mp_tp->mpt_rtseq)) {
  88                                 mp_tp->mpt_timer_vals = 0;
  89                                 mp_tp->mpt_rtseq = 0;
  90                                 break;
  91                         }
  92                         mp_tp->mpt_rxtshift++;
  93                         if (mp_tp->mpt_rxtshift > mptcp_nrtos) {
  94                                 mp_tp->mpt_softerror = ETIMEDOUT;
  95                                 DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
  96                         } else {
  97                                 mp_tp->mpt_sndnxt = mp_tp->mpt_rtseq;
  98                                 MPT_UNLOCK(mp_tp);
  99                                 mptcplog((LOG_DEBUG, "MPTCP Socket: "
 100                                    "%s: REXMT %d times.\n",
 101                                     __func__, mp_tp->mpt_rxtshift),
 102                                     MPTCP_SOCKET_DBG, MPTCP_LOGLVL_LOG);
 103                                 mptcp_output(mpte);
 104                                 MPT_LOCK(mp_tp);
 105                         }
 106                 } else {
 107                         resched_timer = 1;
 108                 }
 109                 break;
 110         case MPTT_TW:
 111                 /* Allows for break before make XXX */
 112                 if (mp_tp->mpt_timewait == 0)
 113                         VERIFY(0);
 114                 if ((now_msecs - mp_tp->mpt_timewait) >
 115                     (mptcp_tw * hz)) {
 116                         mp_tp->mpt_softerror = ETIMEDOUT;
 117                         DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
 118                 } else {
 119                         resched_timer = 1;
 120                 }
 121                 break;
 122         case MPTT_FASTCLOSE:
 123                 /* TODO XXX */
 124                 break;
 125         default:
 126                 break;
 127         }
 128         MPT_UNLOCK(mp_tp);
 129
 130         return (resched_timer);
 131 }
 132
 133 uint32_t
 134 mptcp_timer(struct mppcbinfo *mppi)
 135 {
 136         struct mppcb *mpp, *tmpp;
 137         struct timeval now;
 138         u_int32_t now_msecs;
 139         uint32_t resched_timer = 0;
 140
 141         lck_mtx_assert(&mppi->mppi_lock, LCK_MTX_ASSERT_OWNED);
 142
 143         microuptime(&now);
 144         now_msecs = TIMEVAL_TO_HZ(now);
 145         TAILQ_FOREACH_SAFE(mpp, &mppi->mppi_pcbs, mpp_entry, tmpp) {
 146                 struct socket *mp_so;
 147                 struct mptses *mpte;
 148
 149                 mp_so = mpp->mpp_socket;
 150                 VERIFY(mp_so != NULL);
 151                 mpte = mptompte(mpp);
 152                 VERIFY(mpte != NULL);
 153                 MPTE_LOCK(mpte);
 154                 VERIFY(mpp->mpp_flags & MPP_ATTACHED);
 155
 156                 if (mpp->mpp_flags & MPP_DEFUNCT) {
 157                         MPTE_UNLOCK(mpte);
 158                         continue;
 159                 }
 160
 161                 if (mptcp_timer_demux(mpte, now_msecs))
 162                         resched_timer = 1;
 163                 MPTE_UNLOCK(mpte);
 164         }
 165
 166         return (resched_timer);
 167 }
 168
 169 void
 170 mptcp_start_timer(struct mptses *mpte, int timer_type)
 171 {
 172         struct timeval now;
 173         struct mptcb *mp_tp = mpte->mpte_mptcb;
 174
 175         microuptime(&now);
 176
 177         DTRACE_MPTCP2(start__timer, struct mptcb *, mp_tp, int, timer_type);
 178         mptcplog((LOG_DEBUG, "MPTCP Socket: %s: %d\n", __func__, timer_type),
 179             MPTCP_SOCKET_DBG, MPTCP_LOGLVL_VERBOSE);
 180
 181         switch (timer_type) {
 182         case MPTT_REXMT:
 183                 MPT_LOCK(mp_tp);
 184                 mp_tp->mpt_timer_vals |= MPTT_REXMT;
 185                 mp_tp->mpt_rxtstart = TIMEVAL_TO_HZ(now);
 186                 mp_tp->mpt_rxtshift = 0;
 187                 mp_tp->mpt_rtseq = mp_tp->mpt_sndnxt;
 188                 MPT_UNLOCK(mp_tp);
 189                 break;
 190         case MPTT_TW:
 191                 /* XXX: Not implemented yet */
 192                 MPT_LOCK(mp_tp);
 193                 mp_tp->mpt_timer_vals |= MPTT_TW;
 194                 mp_tp->mpt_timewait = TIMEVAL_TO_HZ(now);
 195                 MPT_UNLOCK(mp_tp);
 196                 break;
 197         case MPTT_FASTCLOSE:
 198                 /* NO-OP */
 199                 break;
 200         default:
 201                 VERIFY(0);
 202                 /* NOTREACHED */
 203         }
 204         mptcp_timer_sched();
 205 }
 206
 207 void
 208 mptcp_cancel_timer(struct mptcb *mp_tp, int timer_type)
 209 {
 210         MPT_LOCK_ASSERT_HELD(mp_tp);
 211         DTRACE_MPTCP2(cancel__timer, struct mptcb *, mp_tp, int, timer_type);
 212
 213         switch (timer_type) {
 214         case MPTT_REXMT:
 215                 mp_tp->mpt_rxtstart = 0;
 216                 mp_tp->mpt_rxtshift = 0;
 217                 mp_tp->mpt_timer_vals = 0;
 218                 break;
 219         case MPTT_TW:
 220                 /* NO-OP */
 221                 break;
 222         case MPTT_FASTCLOSE:
 223                 /* NO-OP */
 224                 break;
 225         default:
 226                 break;
 227         }
 228 }
 229
 230 void
 231 mptcp_cancel_all_timers(struct mptcb *mp_tp)
 232 {
 233         mptcp_cancel_timer(mp_tp, MPTT_REXMT);
 234         mptcp_cancel_timer(mp_tp, MPTT_TW);
 235         mptcp_cancel_timer(mp_tp, MPTT_FASTCLOSE);
 236 }