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 */
52static u_int32_t mptcp_rto = 3;
53SYSCTL_INT(_net_inet_mptcp, OID_AUTO, rto, CTLFLAG_RW | CTLFLAG_LOCKED,
54 &mptcp_rto, 0, "MPTCP Retransmission Timeout");
55
56static int mptcp_nrtos = 3;
57SYSCTL_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 */
63static u_int32_t mptcp_tw = 60;
64SYSCTL_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
69static int mptcp_cancel_urgency_timer(struct mptses *mpte);
70
71static int
72mptcp_timer_demux(struct mptses *mpte, uint64_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) > (mptcp_rto * hz)) {
86 if (MPTCP_SEQ_GT(mp_tp->mpt_snduna, mp_tp->mpt_rtseq)) {
87 mp_tp->mpt_timer_vals = 0;
88 mp_tp->mpt_rtseq = 0;
89 break;
90 }
91 mp_tp->mpt_rxtshift++;
92 if (mp_tp->mpt_rxtshift > mptcp_nrtos) {
93 mp_tp->mpt_softerror = ETIMEDOUT;
94 DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
95 } else {
96 mp_tp->mpt_sndnxt = mp_tp->mpt_rtseq;
97 os_log_info(mptcp_log_handle,
98 "%s: REXMT %d sndnxt %u\n",
99 __func__, mp_tp->mpt_rxtshift,
100 (uint32_t)mp_tp->mpt_sndnxt);
101 mptcp_output(mpte);
102 }
103 } else {
104 resched_timer = 1;
105 }
106 break;
107 case MPTT_TW:
108 /* Allows for break before make XXX */
109 if (mp_tp->mpt_timewait == 0) {
110 VERIFY(0);
111 }
112 if ((now_msecs - mp_tp->mpt_timewait) >
113 (mptcp_tw * hz)) {
114 mp_tp->mpt_softerror = ETIMEDOUT;
115 DTRACE_MPTCP1(error, struct mptcb *, mp_tp);
116 } else {
117 resched_timer = 1;
118 }
119 break;
120 case MPTT_FASTCLOSE:
121 /* TODO XXX */
122 break;
123 default:
124 break;
125 }
126
127 return resched_timer;
128}
129
130uint32_t
131mptcp_timer(struct mppcbinfo *mppi)
132{
133 struct mppcb *mpp, *tmpp;
134 struct timeval now;
135 uint32_t resched_timer = 0;
136 uint64_t now_msecs;
137
138 LCK_MTX_ASSERT(&mppi->mppi_lock, LCK_MTX_ASSERT_OWNED);
139
140 microuptime(tv: &now);
141 now_msecs = TIMEVAL_TO_HZ(now);
142 TAILQ_FOREACH_SAFE(mpp, &mppi->mppi_pcbs, mpp_entry, tmpp) {
143 struct socket *mp_so;
144 struct mptses *mpte;
145
146 mp_so = mpp->mpp_socket;
147 mpte = mptompte(mp: mpp);
148 socket_lock(so: mp_so, refcount: 1);
149
150 VERIFY(mpp->mpp_flags & MPP_ATTACHED);
151
152 if (mptcp_timer_demux(mpte, now_msecs)) {
153 resched_timer = 1;
154 }
155 socket_unlock(so: mp_so, refcount: 1);
156 }
157
158 return resched_timer;
159}
160
161void
162mptcp_start_timer(struct mptses *mpte, int timer_type)
163{
164 struct timeval now;
165 struct mptcb *mp_tp = mpte->mpte_mptcb;
166
167 microuptime(tv: &now);
168
169 DTRACE_MPTCP2(start__timer, struct mptcb *, mp_tp, int, timer_type);
170
171 socket_lock_assert_owned(so: mptetoso(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
195void
196mptcp_cancel_timer(struct mptcb *mp_tp, int timer_type)
197{
198 socket_lock_assert_owned(so: mptetoso(mpte: mp_tp->mpt_mpte));
199
200 switch (timer_type) {
201 case MPTT_REXMT:
202 mp_tp->mpt_rxtstart = 0;
203 mp_tp->mpt_rxtshift = 0;
204 mp_tp->mpt_timer_vals = 0;
205 break;
206 case MPTT_TW:
207 /* NO-OP */
208 break;
209 case MPTT_FASTCLOSE:
210 /* NO-OP */
211 break;
212 default:
213 break;
214 }
215}
216
217void
218mptcp_cancel_all_timers(struct mptcb *mp_tp)
219{
220 struct mptses *mpte = mp_tp->mpt_mpte;
221
222 mptcp_cancel_urgency_timer(mpte);
223
224 mptcp_cancel_timer(mp_tp, MPTT_REXMT);
225 mptcp_cancel_timer(mp_tp, MPTT_TW);
226 mptcp_cancel_timer(mp_tp, MPTT_FASTCLOSE);
227}
228
229static void
230mptcp_urgency_timer(void *param0, __unused void *param1)
231{
232 struct mptses *mpte = (struct mptses *)param0;
233 struct socket *mp_so = mptetoso(mpte);
234 uint64_t time_now;
235
236 socket_lock(so: mp_so, refcount: 1);
237
238 time_now = mach_continuous_time();
239 VERIFY(mp_so->so_usecount >= 0);
240
241 os_log(mptcp_log_handle, "%s - %lx: timer at %llu now %llu usecount %u\n",
242 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mpte->mpte_time_target, time_now, mp_so->so_usecount);
243
244 mptcp_check_subflows_and_add(mpte);
245
246 mp_so->so_usecount--;
247
248 socket_unlock(so: mp_so, refcount: 1);
249}
250
251static void
252mptcp_urgency_stop(void *param0, __unused void *param1)
253{
254 struct mptses *mpte = (struct mptses *)param0;
255 struct socket *mp_so = mptetoso(mpte);
256
257 socket_lock(so: mp_so, refcount: 1);
258
259 VERIFY(mp_so->so_usecount >= 1);
260
261 os_log(mptcp_log_handle, "%s - %lx: usecount %u\n",
262 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mp_so->so_usecount);
263
264 mptcp_check_subflows_and_remove(mpte);
265
266 mp_so->so_usecount--;
267
268 socket_unlock(so: mp_so, refcount: 1);
269}
270
271void
272mptcp_init_urgency_timer(struct mptses *mpte)
273{
274 /* thread_call_allocate never fails */
275 mpte->mpte_time_thread = thread_call_allocate(func: mptcp_urgency_timer, param0: mpte);
276 mpte->mpte_stop_urgency = thread_call_allocate(func: mptcp_urgency_stop, param0: mpte);
277}
278
279void
280mptcp_set_urgency_timer(struct mptses *mpte)
281{
282 struct socket *mp_so = mptetoso(mpte);
283 uint64_t time_now = 0;
284 boolean_t ret = FALSE;
285
286 socket_lock_assert_owned(so: mp_so);
287
288 VERIFY(mp_so->so_usecount >= 1);
289
290 if (mpte->mpte_time_target == 0) {
291 /* Close subflows right now */
292
293 ret = thread_call_enter(call: mpte->mpte_stop_urgency);
294
295 if (!ret) {
296 mp_so->so_usecount++;
297 }
298
299 goto exit_log;
300 }
301
302 time_now = mach_continuous_time();
303
304 if ((int64_t)(mpte->mpte_time_target - time_now) > 0) {
305 ret = thread_call_enter(call: mpte->mpte_stop_urgency);
306
307 if (!ret) {
308 mp_so->so_usecount++;
309 }
310
311 ret = thread_call_enter_delayed_with_leeway(call: mpte->mpte_time_thread, NULL,
312 deadline: mpte->mpte_time_target, leeway: 0, THREAD_CALL_CONTINUOUS);
313
314 if (!ret) {
315 mp_so->so_usecount++;
316 }
317 } else if ((int64_t)(mpte->mpte_time_target - time_now) <= 0) {
318 /* Already passed the deadline, trigger subflows now */
319 ret = thread_call_enter(call: mpte->mpte_time_thread);
320
321 if (!ret) {
322 mp_so->so_usecount++;
323 }
324 }
325
326exit_log:
327 os_log(mptcp_log_handle, "%s - %lx: timer at %llu now %llu usecount %u ret %u\n",
328 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mpte->mpte_time_target, time_now,
329 mp_so->so_usecount, ret);
330}
331
332static int
333mptcp_cancel_urgency_timer(struct mptses *mpte)
334{
335 struct socket *mp_so = mptetoso(mpte);
336 boolean_t ret;
337
338 ret = thread_call_cancel(call: mpte->mpte_time_thread);
339
340 os_log(mptcp_log_handle, "%s - %lx: Canceled timer thread usecount %u ret %u\n",
341 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mp_so->so_usecount, ret);
342
343 mptcp_check_subflows_and_remove(mpte);
344
345 if (ret) {
346 VERIFY(mp_so->so_usecount >= 1);
347 mp_so->so_usecount--;
348 }
349
350 ret = thread_call_cancel(call: mpte->mpte_stop_urgency);
351 if (ret) {
352 VERIFY(mp_so->so_usecount >= 1);
353 mp_so->so_usecount--;
354 }
355
356 return 0;
357}
358