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
mptcp_timer_demux(struct mptses * mpte,uint64_t now_msecs)72 mptcp_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
130 uint32_t
mptcp_timer(struct mppcbinfo * mppi)131 mptcp_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(&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(mpp);
148 socket_lock(mp_so, 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(mp_so, 1);
156 }
157
158 return resched_timer;
159 }
160
161 void
mptcp_start_timer(struct mptses * mpte,int timer_type)162 mptcp_start_timer(struct mptses *mpte, int timer_type)
163 {
164 struct timeval now;
165 struct mptcb *mp_tp = mpte->mpte_mptcb;
166
167 microuptime(&now);
168
169 DTRACE_MPTCP2(start__timer, struct mptcb *, mp_tp, int, timer_type);
170 mptcplog((LOG_DEBUG, "MPTCP Socket: %s: %d\n", __func__, timer_type),
171 MPTCP_SOCKET_DBG, MPTCP_LOGLVL_VERBOSE);
172
173 socket_lock_assert_owned(mptetoso(mpte));
174
175 switch (timer_type) {
176 case MPTT_REXMT:
177 mp_tp->mpt_timer_vals |= MPTT_REXMT;
178 mp_tp->mpt_rxtstart = TIMEVAL_TO_HZ(now);
179 mp_tp->mpt_rxtshift = 0;
180 mp_tp->mpt_rtseq = mp_tp->mpt_sndnxt;
181 break;
182 case MPTT_TW:
183 /* XXX: Not implemented yet */
184 mp_tp->mpt_timer_vals |= MPTT_TW;
185 mp_tp->mpt_timewait = TIMEVAL_TO_HZ(now);
186 break;
187 case MPTT_FASTCLOSE:
188 /* NO-OP */
189 break;
190 default:
191 VERIFY(0);
192 /* NOTREACHED */
193 }
194 mptcp_timer_sched();
195 }
196
197 void
mptcp_cancel_timer(struct mptcb * mp_tp,int timer_type)198 mptcp_cancel_timer(struct mptcb *mp_tp, int timer_type)
199 {
200 socket_lock_assert_owned(mptetoso(mp_tp->mpt_mpte));
201
202 switch (timer_type) {
203 case MPTT_REXMT:
204 mp_tp->mpt_rxtstart = 0;
205 mp_tp->mpt_rxtshift = 0;
206 mp_tp->mpt_timer_vals = 0;
207 break;
208 case MPTT_TW:
209 /* NO-OP */
210 break;
211 case MPTT_FASTCLOSE:
212 /* NO-OP */
213 break;
214 default:
215 break;
216 }
217 }
218
219 void
mptcp_cancel_all_timers(struct mptcb * mp_tp)220 mptcp_cancel_all_timers(struct mptcb *mp_tp)
221 {
222 struct mptses *mpte = mp_tp->mpt_mpte;
223
224 mptcp_cancel_urgency_timer(mpte);
225
226 mptcp_cancel_timer(mp_tp, MPTT_REXMT);
227 mptcp_cancel_timer(mp_tp, MPTT_TW);
228 mptcp_cancel_timer(mp_tp, MPTT_FASTCLOSE);
229 }
230
231 static void
mptcp_urgency_timer(void * param0,__unused void * param1)232 mptcp_urgency_timer(void *param0, __unused void *param1)
233 {
234 struct mptses *mpte = (struct mptses *)param0;
235 struct socket *mp_so = mptetoso(mpte);
236 uint64_t time_now;
237
238 socket_lock(mp_so, 1);
239
240 time_now = mach_continuous_time();
241 VERIFY(mp_so->so_usecount >= 0);
242
243 os_log(mptcp_log_handle, "%s - %lx: timer at %llu now %llu usecount %u\n",
244 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mpte->mpte_time_target, time_now, mp_so->so_usecount);
245
246 mptcp_check_subflows_and_add(mpte);
247
248 mp_so->so_usecount--;
249
250 socket_unlock(mp_so, 1);
251 }
252
253 static void
mptcp_urgency_stop(void * param0,__unused void * param1)254 mptcp_urgency_stop(void *param0, __unused void *param1)
255 {
256 struct mptses *mpte = (struct mptses *)param0;
257 struct socket *mp_so = mptetoso(mpte);
258
259 socket_lock(mp_so, 1);
260
261 VERIFY(mp_so->so_usecount >= 0);
262
263 os_log(mptcp_log_handle, "%s - %lx: usecount %u\n",
264 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mp_so->so_usecount);
265
266 mptcp_check_subflows_and_remove(mpte);
267
268 mp_so->so_usecount--;
269
270 socket_unlock(mp_so, 1);
271 }
272
273 void
mptcp_init_urgency_timer(struct mptses * mpte)274 mptcp_init_urgency_timer(struct mptses *mpte)
275 {
276 /* thread_call_allocate never fails */
277 mpte->mpte_time_thread = thread_call_allocate(mptcp_urgency_timer, mpte);
278 mpte->mpte_stop_urgency = thread_call_allocate(mptcp_urgency_stop, mpte);
279 }
280
281 void
mptcp_set_urgency_timer(struct mptses * mpte)282 mptcp_set_urgency_timer(struct mptses *mpte)
283 {
284 struct socket *mp_so = mptetoso(mpte);
285 uint64_t time_now = 0;
286 boolean_t ret = FALSE;
287
288 socket_lock_assert_owned(mp_so);
289
290 VERIFY(mp_so->so_usecount >= 0);
291 if (mp_so->so_usecount == 0) {
292 goto exit_log;
293 }
294
295 if (mpte->mpte_time_target == 0) {
296 /* Close subflows right now */
297
298 ret = thread_call_enter(mpte->mpte_stop_urgency);
299
300 if (!ret) {
301 mp_so->so_usecount++;
302 }
303
304 goto exit_log;
305 }
306
307 time_now = mach_continuous_time();
308
309 if ((int64_t)(mpte->mpte_time_target - time_now) > 0) {
310 ret = thread_call_enter(mpte->mpte_stop_urgency);
311
312 if (!ret) {
313 mp_so->so_usecount++;
314 }
315
316 ret = thread_call_enter_delayed_with_leeway(mpte->mpte_time_thread, NULL,
317 mpte->mpte_time_target, 0, THREAD_CALL_CONTINUOUS);
318
319 if (!ret) {
320 mp_so->so_usecount++;
321 }
322 } else if ((int64_t)(mpte->mpte_time_target - time_now) <= 0) {
323 /* Already passed the deadline, trigger subflows now */
324 ret = thread_call_enter(mpte->mpte_time_thread);
325
326 if (!ret) {
327 mp_so->so_usecount++;
328 }
329 }
330
331 exit_log:
332 os_log(mptcp_log_handle, "%s - %lx: timer at %llu now %llu usecount %u ret %u\n",
333 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mpte->mpte_time_target, time_now,
334 mp_so->so_usecount, ret);
335 }
336
337 static int
mptcp_cancel_urgency_timer(struct mptses * mpte)338 mptcp_cancel_urgency_timer(struct mptses *mpte)
339 {
340 struct socket *mp_so = mptetoso(mpte);
341 boolean_t ret;
342
343 ret = thread_call_cancel(mpte->mpte_time_thread);
344
345 os_log(mptcp_log_handle, "%s - %lx: Canceled timer thread usecount %u ret %u\n",
346 __func__, (unsigned long)VM_KERNEL_ADDRPERM(mpte), mp_so->so_usecount, ret);
347
348 mptcp_check_subflows_and_remove(mpte);
349
350 if (ret) {
351 mp_so->so_usecount--;
352 }
353
354 ret = thread_call_cancel(mpte->mpte_stop_urgency);
355 if (ret) {
356 mp_so->so_usecount--;
357 }
358
359 return 0;
360 }
361