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 mptcp_cancel_urgency_timer(struct mptses *mpte);
  70
  71 static int
  72 mptcp_timer_demux(struct mptses *mpte, uint32_t now_msecs)
  73 {
  74         struct mptcb *mp_tp = NULL;
  75         mp_tp = mpte->mpte_mptcb;
  76         int resched_timer = 0;
  77
  78         DTRACE_MPTCP2(timer, struct mptses *, mpte, struct mptcb *, mp_tp);
  79
  80         switch (mp_tp->mpt_timer_vals) {
  81         case MPTT_REXMT:
  82                 if (mp_tp->mpt_rxtstart == 0) {
  83                         break;
  84                 }
  85                 if ((now_msecs - mp_tp->mpt_rxtstart) >
  86                     (mptcp_rto * hz)) {
  87                         if (MPTCP_SEQ_GT(mp_tp->mpt_snduna, 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                                 os_log_info(mptcp_log_handle,
  99                                     "%s: REXMT %d sndnxt %u\n",
 100                                     __func__, mp_tp->mpt_rxtshift,
 101                                     (uint32_t)mp_tp->mpt_sndnxt);
 102                                 mptcp_output(mpte);
 103                         }
 104                 } else {
 105                         resched_timer = 1;
 106                 }
 107                 break;
 108         case MPTT_TW:
 109                 /* Allows for break before make XXX */
 110                 if (mp_tp->mpt_timewait == 0) {
 111                         VERIFY(0);
 112                 }
 113                 if ((now_msecs - mp_tp->mpt_timewait) >
 114                     (mptcp_tw * hz)) {
 115                         mp_tp->mpt_softerror = ETIMEDOUT;
 116                         DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
 117                 } else {
 118                         resched_timer = 1;
 119                 }
 120                 break;
 121         case MPTT_FASTCLOSE:
 122                 /* TODO XXX */
 123                 break;
 124         default:
 125                 break;
 126         }
 127
 128         return resched_timer;
 129 }
 130
 131 uint32_t
 132 mptcp_timer(struct mppcbinfo *mppi)
 133 {
 134         struct mppcb *mpp, *tmpp;
 135         struct timeval now;
 136         u_int32_t now_msecs;
 137         uint32_t resched_timer = 0;
 138
 139         LCK_MTX_ASSERT(&mppi->mppi_lock, LCK_MTX_ASSERT_OWNED);
 140
 141         microuptime(&now);
 142         now_msecs = TIMEVAL_TO_HZ(now);
 143         TAILQ_FOREACH_SAFE(mpp, &mppi->mppi_pcbs, mpp_entry, tmpp) {
 144                 struct socket *mp_so;
 145                 struct mptses *mpte;
 146
 147                 mp_so = mpp->mpp_socket;
 148                 mpte = mptompte(mpp);
 149                 socket_lock(mp_so, 1);
 150
 151                 VERIFY(mpp->mpp_flags & MPP_ATTACHED);
 152
 153                 if (mptcp_timer_demux(mpte, now_msecs)) {
 154                         resched_timer = 1;
 155                 }
 156                 socket_unlock(mp_so, 1);
 157         }
 158
 159         return resched_timer;
 160 }
 161
 162 void
 163 mptcp_start_timer(struct mptses *mpte, int timer_type)
 164 {
 165         struct timeval now;
 166         struct mptcb *mp_tp = mpte->mpte_mptcb;
 167
 168         microuptime(&now);
 169
 170         DTRACE_MPTCP2(start__timer, struct mptcb *, mp_tp, int, timer_type);
 171         mptcplog((LOG_DEBUG, "MPTCP Socket: %s: %d\n", __func__, timer_type),
 172             MPTCP_SOCKET_DBG, MPTCP_LOGLVL_VERBOSE);
 173
 174         socket_lock_assert_owned(mptetoso(mpte));
 175
 176         switch (timer_type) {
 177         case MPTT_REXMT:
 178                 mp_tp->mpt_timer_vals |= MPTT_REXMT;
 179                 mp_tp->mpt_rxtstart = TIMEVAL_TO_HZ(now);
 180                 mp_tp->mpt_rxtshift = 0;
 181                 mp_tp->mpt_rtseq = mp_tp->mpt_sndnxt;
 182                 break;
 183         case MPTT_TW:
 184                 /* XXX: Not implemented yet */
 185                 mp_tp->mpt_timer_vals |= MPTT_TW;
 186                 mp_tp->mpt_timewait = TIMEVAL_TO_HZ(now);
 187                 break;
 188         case MPTT_FASTCLOSE:
 189                 /* NO-OP */
 190                 break;
 191         default:
 192                 VERIFY(0);
 193                 /* NOTREACHED */
 194         }
 195         mptcp_timer_sched();
 196 }
 197
 198 void
 199 mptcp_cancel_timer(struct mptcb *mp_tp, int timer_type)
 200 {
 201         socket_lock_assert_owned(mptetoso(mp_tp->mpt_mpte));
 202
 203         switch (timer_type) {
 204         case MPTT_REXMT:
 205                 mp_tp->mpt_rxtstart = 0;
 206                 mp_tp->mpt_rxtshift = 0;
 207                 mp_tp->mpt_timer_vals = 0;
 208                 break;
 209         case MPTT_TW:
 210                 /* NO-OP */
 211                 break;
 212         case MPTT_FASTCLOSE:
 213                 /* NO-OP */
 214                 break;
 215         default:
 216                 break;
 217         }
 218 }
 219
 220 void
 221 mptcp_cancel_all_timers(struct mptcb *mp_tp)
 222 {
 223         struct mptses *mpte = mp_tp->mpt_mpte;
 224
 225         if (mpte->mpte_time_target) {
 226                 mptcp_cancel_urgency_timer(mpte);
 227         }
 228
 229         mptcp_cancel_timer(mp_tp, MPTT_REXMT);
 230         mptcp_cancel_timer(mp_tp, MPTT_TW);
 231         mptcp_cancel_timer(mp_tp, MPTT_FASTCLOSE);
 232 }
 233
 234 static void
 235 mptcp_urgency_timer_locked(struct mptses *mpte)
 236 {
 237         uint64_t time_now = mach_continuous_time();
 238         struct socket *mp_so = mptetoso(mpte);
 239
 240         VERIFY(mp_so->so_usecount >= 0);
 241
 242         os_log(mptcp_log_handle, "%s - %lx: timer at %llu now %llu usecount %u\n",
 243             __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mpte->mpte_time_target, time_now, mp_so->so_usecount);
 244
 245         mptcp_check_subflows_and_add(mpte);
 246
 247         mp_so->so_usecount--;
 248 }
 249
 250 static void
 251 mptcp_urgency_timer(void *param0, __unused void *param1)
 252 {
 253         struct mptses *mpte = (struct mptses *)param0;
 254         struct socket *mp_so = mptetoso(mpte);
 255
 256         socket_lock(mp_so, 1);
 257
 258         mptcp_urgency_timer_locked(mpte);
 259
 260         socket_unlock(mp_so, 1);
 261 }
 262
 263 void
 264 mptcp_init_urgency_timer(struct mptses *mpte)
 265 {
 266         /* thread_call_allocate never fails */
 267         mpte->mpte_time_thread = thread_call_allocate(mptcp_urgency_timer, mpte);
 268 }
 269
 270 void
 271 mptcp_set_urgency_timer(struct mptses *mpte)
 272 {
 273         struct socket *mp_so = mptetoso(mpte);
 274         uint64_t time_now = 0;
 275         boolean_t ret = FALSE;
 276
 277         socket_lock_assert_owned(mp_so);
 278
 279         VERIFY(mp_so->so_usecount >= 0);
 280         if (mp_so->so_usecount == 0) {
 281                 goto exit_log;
 282         }
 283
 284         if (mpte->mpte_time_target == 0) {
 285                 mptcp_cancel_urgency_timer(mpte);
 286
 287                 goto exit_log;
 288         }
 289
 290         time_now = mach_continuous_time();
 291
 292         if ((int64_t)(mpte->mpte_time_target - time_now) > 0) {
 293                 mptcp_check_subflows_and_remove(mpte);
 294
 295                 ret = thread_call_enter_delayed_with_leeway(mpte->mpte_time_thread, NULL,
 296                     mpte->mpte_time_target, 0, THREAD_CALL_CONTINUOUS);
 297
 298                 if (!ret) {
 299                         mp_so->so_usecount++;
 300                 }
 301         } else if ((int64_t)(mpte->mpte_time_target - time_now) <= 0) {
 302                 mp_so->so_usecount++;
 303
 304                 /* Already passed the deadline, trigger subflows now */
 305                 mptcp_urgency_timer_locked(mpte);
 306         }
 307
 308 exit_log:
 309         os_log(mptcp_log_handle, "%s - %lx: timer at %llu now %llu usecount %u ret %u\n",
 310             __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mpte->mpte_time_target, time_now,
 311             mp_so->so_usecount, ret);
 312 }
 313
 314 static int
 315 mptcp_cancel_urgency_timer(struct mptses *mpte)
 316 {
 317         struct socket *mp_so = mptetoso(mpte);
 318         boolean_t ret;
 319
 320         ret = thread_call_cancel(mpte->mpte_time_thread);
 321
 322         os_log(mptcp_log_handle, "%s - %lx: Canceled timer thread usecount %u ret %u\n",
 323             __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mp_so->so_usecount, ret);
 324
 325         mptcp_check_subflows_and_remove(mpte);
 326
 327         if (ret) {
 328                 mp_so->so_usecount--;
 329         }
 330
 331         return 0;
 332 }