1 | /* |
2 | * Copyright (c) 2000-2017 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 | * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 |
30 | * The Regents of the University of California. All rights reserved. |
31 | * |
32 | * Redistribution and use in source and binary forms, with or without |
33 | * modification, are permitted provided that the following conditions |
34 | * are met: |
35 | * 1. Redistributions of source code must retain the above copyright |
36 | * notice, this list of conditions and the following disclaimer. |
37 | * 2. Redistributions in binary form must reproduce the above copyright |
38 | * notice, this list of conditions and the following disclaimer in the |
39 | * documentation and/or other materials provided with the distribution. |
40 | * 3. All advertising materials mentioning features or use of this software |
41 | * must display the following acknowledgement: |
42 | * This product includes software developed by the University of |
43 | * California, Berkeley and its contributors. |
44 | * 4. Neither the name of the University nor the names of its contributors |
45 | * may be used to endorse or promote products derived from this software |
46 | * without specific prior written permission. |
47 | * |
48 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
49 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
50 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
51 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
52 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
53 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
54 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
55 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
56 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
57 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
58 | * SUCH DAMAGE. |
59 | * |
60 | * @(#)tcp_timer.c 8.2 (Berkeley) 5/24/95 |
61 | * $FreeBSD: src/sys/netinet/tcp_timer.c,v 1.34.2.11 2001/08/22 00:59:12 silby Exp $ |
62 | */ |
63 | |
64 | |
65 | #include <sys/param.h> |
66 | #include <sys/systm.h> |
67 | #include <sys/kernel.h> |
68 | #include <sys/mbuf.h> |
69 | #include <sys/sysctl.h> |
70 | #include <sys/socket.h> |
71 | #include <sys/socketvar.h> |
72 | #include <sys/protosw.h> |
73 | #include <sys/domain.h> |
74 | #include <sys/mcache.h> |
75 | #include <sys/queue.h> |
76 | #include <kern/locks.h> |
77 | #include <kern/cpu_number.h> /* before tcp_seq.h, for tcp_random18() */ |
78 | #include <mach/boolean.h> |
79 | |
80 | #include <net/route.h> |
81 | #include <net/if_var.h> |
82 | #include <net/ntstat.h> |
83 | |
84 | #include <netinet/in.h> |
85 | #include <netinet/in_systm.h> |
86 | #include <netinet/in_pcb.h> |
87 | #if INET6 |
88 | #include <netinet6/in6_pcb.h> |
89 | #endif |
90 | #include <netinet/ip_var.h> |
91 | #include <netinet/tcp.h> |
92 | #include <netinet/tcp_cache.h> |
93 | #include <netinet/tcp_fsm.h> |
94 | #include <netinet/tcp_seq.h> |
95 | #include <netinet/tcp_timer.h> |
96 | #include <netinet/tcp_var.h> |
97 | #include <netinet/tcp_cc.h> |
98 | #if INET6 |
99 | #include <netinet6/tcp6_var.h> |
100 | #endif |
101 | #include <netinet/tcpip.h> |
102 | #if TCPDEBUG |
103 | #include <netinet/tcp_debug.h> |
104 | #endif |
105 | #include <sys/kdebug.h> |
106 | #include <mach/sdt.h> |
107 | #include <netinet/mptcp_var.h> |
108 | |
109 | /* Max number of times a stretch ack can be delayed on a connection */ |
110 | #define TCP_STRETCHACK_DELAY_THRESHOLD 5 |
111 | |
112 | /* |
113 | * If the host processor has been sleeping for too long, this is the threshold |
114 | * used to avoid sending stale retransmissions. |
115 | */ |
116 | #define TCP_SLEEP_TOO_LONG (10 * 60 * 1000) /* 10 minutes in ms */ |
117 | |
118 | /* tcp timer list */ |
119 | struct tcptimerlist tcp_timer_list; |
120 | |
121 | /* List of pcbs in timewait state, protected by tcbinfo's ipi_lock */ |
122 | struct tcptailq tcp_tw_tailq; |
123 | |
124 | static int |
125 | sysctl_msec_to_ticks SYSCTL_HANDLER_ARGS |
126 | { |
127 | #pragma unused(arg2) |
128 | int error, s, tt; |
129 | |
130 | tt = *(int *)arg1; |
131 | s = tt * 1000 / TCP_RETRANSHZ;; |
132 | |
133 | error = sysctl_handle_int(oidp, &s, 0, req); |
134 | if (error || !req->newptr) |
135 | return (error); |
136 | |
137 | tt = s * TCP_RETRANSHZ / 1000; |
138 | if (tt < 1) |
139 | return (EINVAL); |
140 | |
141 | *(int *)arg1 = tt; |
142 | SYSCTL_SKMEM_UPDATE_AT_OFFSET(arg2, *(int*)arg1); |
143 | return (0); |
144 | } |
145 | |
146 | #if SYSCTL_SKMEM |
147 | int tcp_keepinit = TCPTV_KEEP_INIT; |
148 | SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit, |
149 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
150 | &tcp_keepinit, offsetof(skmem_sysctl, tcp.keepinit), |
151 | sysctl_msec_to_ticks, "I" , "" ); |
152 | |
153 | int tcp_keepidle = TCPTV_KEEP_IDLE; |
154 | SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle, |
155 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
156 | &tcp_keepidle, offsetof(skmem_sysctl, tcp.keepidle), |
157 | sysctl_msec_to_ticks, "I" , "" ); |
158 | |
159 | int tcp_keepintvl = TCPTV_KEEPINTVL; |
160 | SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, |
161 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
162 | &tcp_keepintvl, offsetof(skmem_sysctl, tcp.keepintvl), |
163 | sysctl_msec_to_ticks, "I" , "" ); |
164 | |
165 | SYSCTL_SKMEM_TCP_INT(OID_AUTO, keepcnt, |
166 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
167 | int, tcp_keepcnt, TCPTV_KEEPCNT, "number of times to repeat keepalive" ); |
168 | |
169 | int tcp_msl = TCPTV_MSL; |
170 | SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, |
171 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
172 | &tcp_msl, offsetof(skmem_sysctl, tcp.msl), |
173 | sysctl_msec_to_ticks, "I" , "Maximum segment lifetime" ); |
174 | #else /* SYSCTL_SKMEM */ |
175 | int tcp_keepinit; |
176 | SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit, |
177 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
178 | &tcp_keepinit, 0, sysctl_msec_to_ticks, "I" , "" ); |
179 | |
180 | int tcp_keepidle; |
181 | SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle, |
182 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
183 | &tcp_keepidle, 0, sysctl_msec_to_ticks, "I" , "" ); |
184 | |
185 | int tcp_keepintvl; |
186 | SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, |
187 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
188 | &tcp_keepintvl, 0, sysctl_msec_to_ticks, "I" , "" ); |
189 | |
190 | int tcp_keepcnt; |
191 | SYSCTL_INT(_net_inet_tcp, OID_AUTO, keepcnt, |
192 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
193 | &tcp_keepcnt, 0, "number of times to repeat keepalive" ); |
194 | |
195 | int tcp_msl; |
196 | SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, |
197 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
198 | &tcp_msl, 0, sysctl_msec_to_ticks, "I" , "Maximum segment lifetime" ); |
199 | #endif /* SYSCTL_SKMEM */ |
200 | |
201 | /* |
202 | * Avoid DoS via TCP Robustness in Persist Condition |
203 | * (see http://www.ietf.org/id/draft-ananth-tcpm-persist-02.txt) |
204 | * by allowing a system wide maximum persistence timeout value when in |
205 | * Zero Window Probe mode. |
206 | * |
207 | * Expressed in milliseconds to be consistent without timeout related |
208 | * values, the TCP socket option is in seconds. |
209 | */ |
210 | #if SYSCTL_SKMEM |
211 | u_int32_t tcp_max_persist_timeout = 0; |
212 | SYSCTL_PROC(_net_inet_tcp, OID_AUTO, max_persist_timeout, |
213 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
214 | &tcp_max_persist_timeout, offsetof(skmem_sysctl, tcp.max_persist_timeout), |
215 | sysctl_msec_to_ticks, "I" , "Maximum persistence timeout for ZWP" ); |
216 | #else /* SYSCTL_SKMEM */ |
217 | u_int32_t tcp_max_persist_timeout = 0; |
218 | SYSCTL_PROC(_net_inet_tcp, OID_AUTO, max_persist_timeout, |
219 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, |
220 | &tcp_max_persist_timeout, 0, sysctl_msec_to_ticks, "I" , |
221 | "Maximum persistence timeout for ZWP" ); |
222 | #endif /* SYSCTL_SKMEM */ |
223 | |
224 | SYSCTL_SKMEM_TCP_INT(OID_AUTO, always_keepalive, |
225 | CTLFLAG_RW | CTLFLAG_LOCKED, static int, always_keepalive, 0, |
226 | "Assume SO_KEEPALIVE on all TCP connections" ); |
227 | |
228 | /* |
229 | * This parameter determines how long the timer list will stay in fast or |
230 | * quick mode even though all connections are idle. In this state, the |
231 | * timer will run more frequently anticipating new data. |
232 | */ |
233 | SYSCTL_SKMEM_TCP_INT(OID_AUTO, timer_fastmode_idlemax, |
234 | CTLFLAG_RW | CTLFLAG_LOCKED, int, timer_fastmode_idlemax, |
235 | TCP_FASTMODE_IDLERUN_MAX, "Maximum idle generations in fast mode" ); |
236 | |
237 | /* |
238 | * See tcp_syn_backoff[] for interval values between SYN retransmits; |
239 | * the value set below defines the number of retransmits, before we |
240 | * disable the timestamp and window scaling options during subsequent |
241 | * SYN retransmits. Setting it to 0 disables the dropping off of those |
242 | * two options. |
243 | */ |
244 | SYSCTL_SKMEM_TCP_INT(OID_AUTO, broken_peer_syn_rexmit_thres, |
245 | CTLFLAG_RW | CTLFLAG_LOCKED, static int, tcp_broken_peer_syn_rxmit_thres, |
246 | 10, "Number of retransmitted SYNs before disabling RFC 1323 " |
247 | "options on local connections" ); |
248 | |
249 | static int tcp_timer_advanced = 0; |
250 | SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_timer_advanced, |
251 | CTLFLAG_RD | CTLFLAG_LOCKED, &tcp_timer_advanced, 0, |
252 | "Number of times one of the timers was advanced" ); |
253 | |
254 | static int tcp_resched_timerlist = 0; |
255 | SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcp_resched_timerlist, |
256 | CTLFLAG_RD | CTLFLAG_LOCKED, &tcp_resched_timerlist, 0, |
257 | "Number of times timer list was rescheduled as part of processing a packet" ); |
258 | |
259 | SYSCTL_SKMEM_TCP_INT(OID_AUTO, pmtud_blackhole_detection, |
260 | CTLFLAG_RW | CTLFLAG_LOCKED, int, tcp_pmtud_black_hole_detect, 1, |
261 | "Path MTU Discovery Black Hole Detection" ); |
262 | |
263 | SYSCTL_SKMEM_TCP_INT(OID_AUTO, pmtud_blackhole_mss, |
264 | CTLFLAG_RW | CTLFLAG_LOCKED, int, tcp_pmtud_black_hole_mss, 1200, |
265 | "Path MTU Discovery Black Hole Detection lowered MSS" ); |
266 | |
267 | static u_int32_t tcp_mss_rec_medium = 1200; |
268 | static u_int32_t tcp_mss_rec_low = 512; |
269 | |
270 | #define TCP_REPORT_STATS_INTERVAL 43200 /* 12 hours, in seconds */ |
271 | int tcp_report_stats_interval = TCP_REPORT_STATS_INTERVAL; |
272 | |
273 | /* performed garbage collection of "used" sockets */ |
274 | static boolean_t tcp_gc_done = FALSE; |
275 | |
276 | /* max idle probes */ |
277 | int tcp_maxpersistidle = TCPTV_KEEP_IDLE; |
278 | |
279 | /* |
280 | * TCP delack timer is set to 100 ms. Since the processing of timer list |
281 | * in fast mode will happen no faster than 100 ms, the delayed ack timer |
282 | * will fire some where between 100 and 200 ms. |
283 | */ |
284 | int tcp_delack = TCP_RETRANSHZ / 10; |
285 | |
286 | #if MPTCP |
287 | /* |
288 | * MP_JOIN retransmission of 3rd ACK will be every 500 msecs without backoff |
289 | */ |
290 | int tcp_jack_rxmt = TCP_RETRANSHZ / 2; |
291 | #endif /* MPTCP */ |
292 | |
293 | static boolean_t tcp_itimer_done = FALSE; |
294 | |
295 | static void tcp_remove_timer(struct tcpcb *tp); |
296 | static void tcp_sched_timerlist(uint32_t offset); |
297 | static u_int32_t tcp_run_conn_timer(struct tcpcb *tp, u_int16_t *mode, |
298 | u_int16_t probe_if_index); |
299 | static void tcp_sched_timers(struct tcpcb *tp); |
300 | static inline void tcp_set_lotimer_index(struct tcpcb *); |
301 | __private_extern__ void tcp_remove_from_time_wait(struct inpcb *inp); |
302 | static inline void tcp_update_mss_core(struct tcpcb *tp, struct ifnet *ifp); |
303 | __private_extern__ void tcp_report_stats(void); |
304 | |
305 | static u_int64_t tcp_last_report_time; |
306 | |
307 | /* |
308 | * Structure to store previously reported stats so that we can send |
309 | * incremental changes in each report interval. |
310 | */ |
311 | struct tcp_last_report_stats { |
312 | u_int32_t tcps_connattempt; |
313 | u_int32_t tcps_accepts; |
314 | u_int32_t tcps_ecn_client_setup; |
315 | u_int32_t tcps_ecn_server_setup; |
316 | u_int32_t tcps_ecn_client_success; |
317 | u_int32_t tcps_ecn_server_success; |
318 | u_int32_t tcps_ecn_not_supported; |
319 | u_int32_t tcps_ecn_lost_syn; |
320 | u_int32_t tcps_ecn_lost_synack; |
321 | u_int32_t tcps_ecn_recv_ce; |
322 | u_int32_t tcps_ecn_recv_ece; |
323 | u_int32_t tcps_ecn_sent_ece; |
324 | u_int32_t tcps_ecn_conn_recv_ce; |
325 | u_int32_t tcps_ecn_conn_recv_ece; |
326 | u_int32_t tcps_ecn_conn_plnoce; |
327 | u_int32_t tcps_ecn_conn_pl_ce; |
328 | u_int32_t tcps_ecn_conn_nopl_ce; |
329 | u_int32_t tcps_ecn_fallback_synloss; |
330 | u_int32_t tcps_ecn_fallback_reorder; |
331 | u_int32_t tcps_ecn_fallback_ce; |
332 | |
333 | /* TFO-related statistics */ |
334 | u_int32_t tcps_tfo_syn_data_rcv; |
335 | u_int32_t tcps_tfo_cookie_req_rcv; |
336 | u_int32_t tcps_tfo_cookie_sent; |
337 | u_int32_t tcps_tfo_cookie_invalid; |
338 | u_int32_t tcps_tfo_cookie_req; |
339 | u_int32_t tcps_tfo_cookie_rcv; |
340 | u_int32_t tcps_tfo_syn_data_sent; |
341 | u_int32_t tcps_tfo_syn_data_acked; |
342 | u_int32_t tcps_tfo_syn_loss; |
343 | u_int32_t tcps_tfo_blackhole; |
344 | u_int32_t tcps_tfo_cookie_wrong; |
345 | u_int32_t tcps_tfo_no_cookie_rcv; |
346 | u_int32_t tcps_tfo_heuristics_disable; |
347 | u_int32_t tcps_tfo_sndblackhole; |
348 | |
349 | /* MPTCP-related statistics */ |
350 | u_int32_t tcps_mptcp_handover_attempt; |
351 | u_int32_t tcps_mptcp_interactive_attempt; |
352 | u_int32_t tcps_mptcp_aggregate_attempt; |
353 | u_int32_t tcps_mptcp_fp_handover_attempt; |
354 | u_int32_t tcps_mptcp_fp_interactive_attempt; |
355 | u_int32_t tcps_mptcp_fp_aggregate_attempt; |
356 | u_int32_t tcps_mptcp_heuristic_fallback; |
357 | u_int32_t tcps_mptcp_fp_heuristic_fallback; |
358 | u_int32_t tcps_mptcp_handover_success_wifi; |
359 | u_int32_t tcps_mptcp_handover_success_cell; |
360 | u_int32_t tcps_mptcp_interactive_success; |
361 | u_int32_t tcps_mptcp_aggregate_success; |
362 | u_int32_t tcps_mptcp_fp_handover_success_wifi; |
363 | u_int32_t tcps_mptcp_fp_handover_success_cell; |
364 | u_int32_t tcps_mptcp_fp_interactive_success; |
365 | u_int32_t tcps_mptcp_fp_aggregate_success; |
366 | u_int32_t tcps_mptcp_handover_cell_from_wifi; |
367 | u_int32_t tcps_mptcp_handover_wifi_from_cell; |
368 | u_int32_t tcps_mptcp_interactive_cell_from_wifi; |
369 | u_int64_t tcps_mptcp_handover_cell_bytes; |
370 | u_int64_t tcps_mptcp_interactive_cell_bytes; |
371 | u_int64_t tcps_mptcp_aggregate_cell_bytes; |
372 | u_int64_t tcps_mptcp_handover_all_bytes; |
373 | u_int64_t tcps_mptcp_interactive_all_bytes; |
374 | u_int64_t tcps_mptcp_aggregate_all_bytes; |
375 | u_int32_t tcps_mptcp_back_to_wifi; |
376 | u_int32_t tcps_mptcp_wifi_proxy; |
377 | u_int32_t tcps_mptcp_cell_proxy; |
378 | u_int32_t tcps_mptcp_triggered_cell; |
379 | }; |
380 | |
381 | |
382 | /* Returns true if the timer is on the timer list */ |
383 | #define TIMER_IS_ON_LIST(tp) ((tp)->t_flags & TF_TIMER_ONLIST) |
384 | |
385 | /* Run the TCP timerlist atleast once every hour */ |
386 | #define TCP_TIMERLIST_MAX_OFFSET (60 * 60 * TCP_RETRANSHZ) |
387 | |
388 | |
389 | static void add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay); |
390 | static boolean_t tcp_garbage_collect(struct inpcb *, int); |
391 | |
392 | #define TIMERENTRY_TO_TP(te) ((struct tcpcb *)((uintptr_t)te - offsetof(struct tcpcb, tentry.le.le_next))) |
393 | |
394 | #define VERIFY_NEXT_LINK(elm,field) do { \ |
395 | if (LIST_NEXT((elm),field) != NULL && \ |
396 | LIST_NEXT((elm),field)->field.le_prev != \ |
397 | &((elm)->field.le_next)) \ |
398 | panic("Bad link elm %p next->prev != elm", (elm)); \ |
399 | } while(0) |
400 | |
401 | #define VERIFY_PREV_LINK(elm,field) do { \ |
402 | if (*(elm)->field.le_prev != (elm)) \ |
403 | panic("Bad link elm %p prev->next != elm", (elm)); \ |
404 | } while(0) |
405 | |
406 | #define TCP_SET_TIMER_MODE(mode, i) do { \ |
407 | if (IS_TIMER_HZ_10MS(i)) \ |
408 | (mode) |= TCP_TIMERLIST_10MS_MODE; \ |
409 | else if (IS_TIMER_HZ_100MS(i)) \ |
410 | (mode) |= TCP_TIMERLIST_100MS_MODE; \ |
411 | else \ |
412 | (mode) |= TCP_TIMERLIST_500MS_MODE; \ |
413 | } while(0) |
414 | |
415 | #if (DEVELOPMENT || DEBUG) |
416 | SYSCTL_UINT(_net_inet_tcp, OID_AUTO, mss_rec_medium, |
417 | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_mss_rec_medium, 0, |
418 | "Medium MSS based on recommendation in link status report" ); |
419 | SYSCTL_UINT(_net_inet_tcp, OID_AUTO, mss_rec_low, |
420 | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_mss_rec_low, 0, |
421 | "Low MSS based on recommendation in link status report" ); |
422 | |
423 | static int32_t tcp_change_mss_recommended = 0; |
424 | static int |
425 | sysctl_change_mss_recommended SYSCTL_HANDLER_ARGS |
426 | { |
427 | #pragma unused(oidp, arg1, arg2) |
428 | int i, err = 0, changed = 0; |
429 | struct ifnet *ifp; |
430 | struct if_link_status ifsr; |
431 | struct if_cellular_status_v1 *new_cell_sr; |
432 | err = sysctl_io_number(req, tcp_change_mss_recommended, |
433 | sizeof (int32_t), &i, &changed); |
434 | if (changed) { |
435 | ifnet_head_lock_shared(); |
436 | TAILQ_FOREACH(ifp, &ifnet_head, if_link) { |
437 | if (IFNET_IS_CELLULAR(ifp)) { |
438 | bzero(&ifsr, sizeof (ifsr)); |
439 | new_cell_sr = &ifsr.ifsr_u.ifsr_cell.if_cell_u.if_status_v1; |
440 | ifsr.ifsr_version = IF_CELLULAR_STATUS_REPORT_CURRENT_VERSION; |
441 | ifsr.ifsr_len = sizeof(*new_cell_sr); |
442 | |
443 | /* Set MSS recommended */ |
444 | new_cell_sr->valid_bitmask |= IF_CELL_UL_MSS_RECOMMENDED_VALID; |
445 | new_cell_sr->mss_recommended = i; |
446 | err = ifnet_link_status_report(ifp, new_cell_sr, sizeof (new_cell_sr)); |
447 | if (err == 0) { |
448 | tcp_change_mss_recommended = i; |
449 | } else { |
450 | break; |
451 | } |
452 | } |
453 | } |
454 | ifnet_head_done(); |
455 | } |
456 | return (err); |
457 | } |
458 | |
459 | SYSCTL_PROC(_net_inet_tcp, OID_AUTO, change_mss_recommended, |
460 | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_change_mss_recommended, |
461 | 0, sysctl_change_mss_recommended, "IU" , "Change MSS recommended" ); |
462 | |
463 | SYSCTL_INT(_net_inet_tcp, OID_AUTO, report_stats_interval, |
464 | CTLFLAG_RW | CTLFLAG_LOCKED, &tcp_report_stats_interval, 0, |
465 | "Report stats interval" ); |
466 | #endif /* (DEVELOPMENT || DEBUG) */ |
467 | |
468 | /* |
469 | * Macro to compare two timers. If there is a reset of the sign bit, |
470 | * it is safe to assume that the timer has wrapped around. By doing |
471 | * signed comparision, we take care of wrap around such that the value |
472 | * with the sign bit reset is actually ahead of the other. |
473 | */ |
474 | inline int32_t |
475 | timer_diff(uint32_t t1, uint32_t toff1, uint32_t t2, uint32_t toff2) { |
476 | return (int32_t)((t1 + toff1) - (t2 + toff2)); |
477 | }; |
478 | |
479 | /* |
480 | * Add to tcp timewait list, delay is given in milliseconds. |
481 | */ |
482 | static void |
483 | add_to_time_wait_locked(struct tcpcb *tp, uint32_t delay) |
484 | { |
485 | struct inpcbinfo *pcbinfo = &tcbinfo; |
486 | struct inpcb *inp = tp->t_inpcb; |
487 | uint32_t timer; |
488 | |
489 | /* pcb list should be locked when we get here */ |
490 | LCK_RW_ASSERT(pcbinfo->ipi_lock, LCK_RW_ASSERT_EXCLUSIVE); |
491 | |
492 | /* We may get here multiple times, so check */ |
493 | if (!(inp->inp_flags2 & INP2_TIMEWAIT)) { |
494 | pcbinfo->ipi_twcount++; |
495 | inp->inp_flags2 |= INP2_TIMEWAIT; |
496 | |
497 | /* Remove from global inp list */ |
498 | LIST_REMOVE(inp, inp_list); |
499 | } else { |
500 | TAILQ_REMOVE(&tcp_tw_tailq, tp, t_twentry); |
501 | } |
502 | |
503 | /* Compute the time at which this socket can be closed */ |
504 | timer = tcp_now + delay; |
505 | |
506 | /* We will use the TCPT_2MSL timer for tracking this delay */ |
507 | |
508 | if (TIMER_IS_ON_LIST(tp)) |
509 | tcp_remove_timer(tp); |
510 | tp->t_timer[TCPT_2MSL] = timer; |
511 | |
512 | TAILQ_INSERT_TAIL(&tcp_tw_tailq, tp, t_twentry); |
513 | } |
514 | |
515 | void |
516 | add_to_time_wait(struct tcpcb *tp, uint32_t delay) |
517 | { |
518 | struct inpcbinfo *pcbinfo = &tcbinfo; |
519 | if (tp->t_inpcb->inp_socket->so_options & SO_NOWAKEFROMSLEEP) |
520 | socket_post_kev_msg_closed(tp->t_inpcb->inp_socket); |
521 | |
522 | /* 19182803: Notify nstat that connection is closing before waiting. */ |
523 | nstat_pcb_detach(tp->t_inpcb); |
524 | |
525 | if (!lck_rw_try_lock_exclusive(pcbinfo->ipi_lock)) { |
526 | socket_unlock(tp->t_inpcb->inp_socket, 0); |
527 | lck_rw_lock_exclusive(pcbinfo->ipi_lock); |
528 | socket_lock(tp->t_inpcb->inp_socket, 0); |
529 | } |
530 | add_to_time_wait_locked(tp, delay); |
531 | lck_rw_done(pcbinfo->ipi_lock); |
532 | |
533 | inpcb_gc_sched(pcbinfo, INPCB_TIMER_LAZY); |
534 | } |
535 | |
536 | /* If this is on time wait queue, remove it. */ |
537 | void |
538 | tcp_remove_from_time_wait(struct inpcb *inp) |
539 | { |
540 | struct tcpcb *tp = intotcpcb(inp); |
541 | if (inp->inp_flags2 & INP2_TIMEWAIT) |
542 | TAILQ_REMOVE(&tcp_tw_tailq, tp, t_twentry); |
543 | } |
544 | |
545 | static boolean_t |
546 | tcp_garbage_collect(struct inpcb *inp, int istimewait) |
547 | { |
548 | boolean_t active = FALSE; |
549 | struct socket *so, *mp_so = NULL; |
550 | struct tcpcb *tp; |
551 | |
552 | so = inp->inp_socket; |
553 | tp = intotcpcb(inp); |
554 | |
555 | if (so->so_flags & SOF_MP_SUBFLOW) { |
556 | mp_so = mptetoso(tptomptp(tp)->mpt_mpte); |
557 | if (!socket_try_lock(mp_so)) { |
558 | mp_so = NULL; |
559 | active = TRUE; |
560 | goto out; |
561 | } |
562 | mp_so->so_usecount++; |
563 | } |
564 | |
565 | /* |
566 | * Skip if still in use or busy; it would have been more efficient |
567 | * if we were to test so_usecount against 0, but this isn't possible |
568 | * due to the current implementation of tcp_dropdropablreq() where |
569 | * overflow sockets that are eligible for garbage collection have |
570 | * their usecounts set to 1. |
571 | */ |
572 | if (!lck_mtx_try_lock_spin(&inp->inpcb_mtx)) { |
573 | active = TRUE; |
574 | goto out; |
575 | } |
576 | |
577 | /* Check again under the lock */ |
578 | if (so->so_usecount > 1) { |
579 | if (inp->inp_wantcnt == WNT_STOPUSING) |
580 | active = TRUE; |
581 | lck_mtx_unlock(&inp->inpcb_mtx); |
582 | goto out; |
583 | } |
584 | |
585 | if (istimewait && TSTMP_GEQ(tcp_now, tp->t_timer[TCPT_2MSL]) && |
586 | tp->t_state != TCPS_CLOSED) { |
587 | /* Become a regular mutex */ |
588 | lck_mtx_convert_spin(&inp->inpcb_mtx); |
589 | tcp_close(tp); |
590 | } |
591 | |
592 | /* |
593 | * Overflowed socket dropped from the listening queue? Do this |
594 | * only if we are called to clean up the time wait slots, since |
595 | * tcp_dropdropablreq() considers a socket to have been fully |
596 | * dropped after add_to_time_wait() is finished. |
597 | * Also handle the case of connections getting closed by the peer |
598 | * while in the queue as seen with rdar://6422317 |
599 | * |
600 | */ |
601 | if (so->so_usecount == 1 && |
602 | ((istimewait && (so->so_flags & SOF_OVERFLOW)) || |
603 | ((tp != NULL) && (tp->t_state == TCPS_CLOSED) && |
604 | (so->so_head != NULL) && |
605 | ((so->so_state & (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE)) == |
606 | (SS_INCOMP|SS_CANTSENDMORE|SS_CANTRCVMORE))))) { |
607 | |
608 | if (inp->inp_state != INPCB_STATE_DEAD) { |
609 | /* Become a regular mutex */ |
610 | lck_mtx_convert_spin(&inp->inpcb_mtx); |
611 | #if INET6 |
612 | if (SOCK_CHECK_DOM(so, PF_INET6)) |
613 | in6_pcbdetach(inp); |
614 | else |
615 | #endif /* INET6 */ |
616 | in_pcbdetach(inp); |
617 | } |
618 | VERIFY(so->so_usecount > 0); |
619 | so->so_usecount--; |
620 | if (inp->inp_wantcnt == WNT_STOPUSING) |
621 | active = TRUE; |
622 | lck_mtx_unlock(&inp->inpcb_mtx); |
623 | goto out; |
624 | } else if (inp->inp_wantcnt != WNT_STOPUSING) { |
625 | lck_mtx_unlock(&inp->inpcb_mtx); |
626 | active = FALSE; |
627 | goto out; |
628 | } |
629 | |
630 | /* |
631 | * We get here because the PCB is no longer searchable |
632 | * (WNT_STOPUSING); detach (if needed) and dispose if it is dead |
633 | * (usecount is 0). This covers all cases, including overflow |
634 | * sockets and those that are considered as "embryonic", |
635 | * i.e. created by sonewconn() in TCP input path, and have |
636 | * not yet been committed. For the former, we reduce the usecount |
637 | * to 0 as done by the code above. For the latter, the usecount |
638 | * would have reduced to 0 as part calling soabort() when the |
639 | * socket is dropped at the end of tcp_input(). |
640 | */ |
641 | if (so->so_usecount == 0) { |
642 | DTRACE_TCP4(state__change, void, NULL, struct inpcb *, inp, |
643 | struct tcpcb *, tp, int32_t, TCPS_CLOSED); |
644 | /* Become a regular mutex */ |
645 | lck_mtx_convert_spin(&inp->inpcb_mtx); |
646 | |
647 | /* |
648 | * If this tp still happens to be on the timer list, |
649 | * take it out |
650 | */ |
651 | if (TIMER_IS_ON_LIST(tp)) { |
652 | tcp_remove_timer(tp); |
653 | } |
654 | |
655 | if (inp->inp_state != INPCB_STATE_DEAD) { |
656 | #if INET6 |
657 | if (SOCK_CHECK_DOM(so, PF_INET6)) |
658 | in6_pcbdetach(inp); |
659 | else |
660 | #endif /* INET6 */ |
661 | in_pcbdetach(inp); |
662 | } |
663 | |
664 | if (mp_so) { |
665 | mptcp_subflow_del(tptomptp(tp)->mpt_mpte, tp->t_mpsub); |
666 | |
667 | /* so is now unlinked from mp_so - let's drop the lock */ |
668 | socket_unlock(mp_so, 1); |
669 | mp_so = NULL; |
670 | } |
671 | |
672 | in_pcbdispose(inp); |
673 | active = FALSE; |
674 | goto out; |
675 | } |
676 | |
677 | lck_mtx_unlock(&inp->inpcb_mtx); |
678 | active = TRUE; |
679 | |
680 | out: |
681 | if (mp_so) |
682 | socket_unlock(mp_so, 1); |
683 | |
684 | return (active); |
685 | } |
686 | |
687 | /* |
688 | * TCP garbage collector callback (inpcb_timer_func_t). |
689 | * |
690 | * Returns the number of pcbs that will need to be gc-ed soon, |
691 | * returnining > 0 will keep timer active. |
692 | */ |
693 | void |
694 | tcp_gc(struct inpcbinfo *ipi) |
695 | { |
696 | struct inpcb *inp, *nxt; |
697 | struct tcpcb *tw_tp, *tw_ntp; |
698 | #if TCPDEBUG |
699 | int ostate; |
700 | #endif |
701 | #if KDEBUG |
702 | static int tws_checked = 0; |
703 | #endif |
704 | |
705 | KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_START, 0, 0, 0, 0, 0); |
706 | |
707 | /* |
708 | * Update tcp_now here as it may get used while |
709 | * processing the slow timer. |
710 | */ |
711 | calculate_tcp_clock(); |
712 | |
713 | /* |
714 | * Garbage collect socket/tcpcb: We need to acquire the list lock |
715 | * exclusively to do this |
716 | */ |
717 | |
718 | if (lck_rw_try_lock_exclusive(ipi->ipi_lock) == FALSE) { |
719 | /* don't sweat it this time; cleanup was done last time */ |
720 | if (tcp_gc_done == TRUE) { |
721 | tcp_gc_done = FALSE; |
722 | KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, |
723 | tws_checked, cur_tw_slot, 0, 0, 0); |
724 | /* Lock upgrade failed, give up this round */ |
725 | atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1); |
726 | return; |
727 | } |
728 | /* Upgrade failed, lost lock now take it again exclusive */ |
729 | lck_rw_lock_exclusive(ipi->ipi_lock); |
730 | } |
731 | tcp_gc_done = TRUE; |
732 | |
733 | LIST_FOREACH_SAFE(inp, &tcb, inp_list, nxt) { |
734 | if (tcp_garbage_collect(inp, 0)) |
735 | atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1); |
736 | } |
737 | |
738 | /* Now cleanup the time wait ones */ |
739 | TAILQ_FOREACH_SAFE(tw_tp, &tcp_tw_tailq, t_twentry, tw_ntp) { |
740 | /* |
741 | * We check the timestamp here without holding the |
742 | * socket lock for better performance. If there are |
743 | * any pcbs in time-wait, the timer will get rescheduled. |
744 | * Hence some error in this check can be tolerated. |
745 | * |
746 | * Sometimes a socket on time-wait queue can be closed if |
747 | * 2MSL timer expired but the application still has a |
748 | * usecount on it. |
749 | */ |
750 | if (tw_tp->t_state == TCPS_CLOSED || |
751 | TSTMP_GEQ(tcp_now, tw_tp->t_timer[TCPT_2MSL])) { |
752 | if (tcp_garbage_collect(tw_tp->t_inpcb, 1)) |
753 | atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, 1); |
754 | } |
755 | } |
756 | |
757 | /* take into account pcbs that are still in time_wait_slots */ |
758 | atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, ipi->ipi_twcount); |
759 | |
760 | lck_rw_done(ipi->ipi_lock); |
761 | |
762 | /* Clean up the socache while we are here */ |
763 | if (so_cache_timer()) |
764 | atomic_add_32(&ipi->ipi_gc_req.intimer_lazy, 1); |
765 | |
766 | KERNEL_DEBUG(DBG_FNC_TCP_SLOW | DBG_FUNC_END, tws_checked, |
767 | cur_tw_slot, 0, 0, 0); |
768 | |
769 | return; |
770 | } |
771 | |
772 | /* |
773 | * Cancel all timers for TCP tp. |
774 | */ |
775 | void |
776 | tcp_canceltimers(struct tcpcb *tp) |
777 | { |
778 | int i; |
779 | |
780 | tcp_remove_timer(tp); |
781 | for (i = 0; i < TCPT_NTIMERS; i++) |
782 | tp->t_timer[i] = 0; |
783 | tp->tentry.timer_start = tcp_now; |
784 | tp->tentry.index = TCPT_NONE; |
785 | } |
786 | |
787 | int tcp_syn_backoff[TCP_MAXRXTSHIFT + 1] = |
788 | { 1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 64, 64, 64 }; |
789 | |
790 | int tcp_backoff[TCP_MAXRXTSHIFT + 1] = |
791 | { 1, 2, 4, 8, 16, 32, 64, 64, 64, 64, 64, 64, 64 }; |
792 | |
793 | static int tcp_totbackoff = 511; /* sum of tcp_backoff[] */ |
794 | |
795 | void |
796 | tcp_rexmt_save_state(struct tcpcb *tp) |
797 | { |
798 | u_int32_t fsize; |
799 | if (TSTMP_SUPPORTED(tp)) { |
800 | /* |
801 | * Since timestamps are supported on the connection, |
802 | * we can do recovery as described in rfc 4015. |
803 | */ |
804 | fsize = tp->snd_max - tp->snd_una; |
805 | tp->snd_ssthresh_prev = max(fsize, tp->snd_ssthresh); |
806 | tp->snd_recover_prev = tp->snd_recover; |
807 | } else { |
808 | /* |
809 | * Timestamp option is not supported on this connection. |
810 | * Record ssthresh and cwnd so they can |
811 | * be recovered if this turns out to be a "bad" retransmit. |
812 | * A retransmit is considered "bad" if an ACK for this |
813 | * segment is received within RTT/2 interval; the assumption |
814 | * here is that the ACK was already in flight. See |
815 | * "On Estimating End-to-End Network Path Properties" by |
816 | * Allman and Paxson for more details. |
817 | */ |
818 | tp->snd_cwnd_prev = tp->snd_cwnd; |
819 | tp->snd_ssthresh_prev = tp->snd_ssthresh; |
820 | tp->snd_recover_prev = tp->snd_recover; |
821 | if (IN_FASTRECOVERY(tp)) |
822 | tp->t_flags |= TF_WASFRECOVERY; |
823 | else |
824 | tp->t_flags &= ~TF_WASFRECOVERY; |
825 | } |
826 | tp->t_srtt_prev = (tp->t_srtt >> TCP_RTT_SHIFT) + 2; |
827 | tp->t_rttvar_prev = (tp->t_rttvar >> TCP_RTTVAR_SHIFT); |
828 | tp->t_flagsext &= ~(TF_RECOMPUTE_RTT); |
829 | } |
830 | |
831 | /* |
832 | * Revert to the older segment size if there is an indication that PMTU |
833 | * blackhole detection was not needed. |
834 | */ |
835 | void |
836 | tcp_pmtud_revert_segment_size(struct tcpcb *tp) |
837 | { |
838 | int32_t optlen; |
839 | |
840 | VERIFY(tp->t_pmtud_saved_maxopd > 0); |
841 | tp->t_flags |= TF_PMTUD; |
842 | tp->t_flags &= ~TF_BLACKHOLE; |
843 | optlen = tp->t_maxopd - tp->t_maxseg; |
844 | tp->t_maxopd = tp->t_pmtud_saved_maxopd; |
845 | tp->t_maxseg = tp->t_maxopd - optlen; |
846 | |
847 | /* |
848 | * Reset the slow-start flight size as it |
849 | * may depend on the new MSS |
850 | */ |
851 | if (CC_ALGO(tp)->cwnd_init != NULL) |
852 | CC_ALGO(tp)->cwnd_init(tp); |
853 | tp->t_pmtud_start_ts = 0; |
854 | tcpstat.tcps_pmtudbh_reverted++; |
855 | |
856 | /* change MSS according to recommendation, if there was one */ |
857 | tcp_update_mss_locked(tp->t_inpcb->inp_socket, NULL); |
858 | } |
859 | |
860 | /* |
861 | * TCP timer processing. |
862 | */ |
863 | struct tcpcb * |
864 | tcp_timers(struct tcpcb *tp, int timer) |
865 | { |
866 | int32_t rexmt, optlen = 0, idle_time = 0; |
867 | struct socket *so; |
868 | struct tcptemp *t_template; |
869 | #if TCPDEBUG |
870 | int ostate; |
871 | #endif |
872 | |
873 | #if INET6 |
874 | int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV4) == 0; |
875 | #endif /* INET6 */ |
876 | u_int64_t accsleep_ms; |
877 | u_int32_t last_sleep_ms = 0; |
878 | |
879 | so = tp->t_inpcb->inp_socket; |
880 | idle_time = tcp_now - tp->t_rcvtime; |
881 | |
882 | switch (timer) { |
883 | |
884 | /* |
885 | * 2 MSL timeout in shutdown went off. If we're closed but |
886 | * still waiting for peer to close and connection has been idle |
887 | * too long, or if 2MSL time is up from TIME_WAIT or FIN_WAIT_2, |
888 | * delete connection control block. |
889 | * Otherwise, (this case shouldn't happen) check again in a bit |
890 | * we keep the socket in the main list in that case. |
891 | */ |
892 | case TCPT_2MSL: |
893 | tcp_free_sackholes(tp); |
894 | if (tp->t_state != TCPS_TIME_WAIT && |
895 | tp->t_state != TCPS_FIN_WAIT_2 && |
896 | ((idle_time > 0) && (idle_time < TCP_CONN_MAXIDLE(tp)))) { |
897 | tp->t_timer[TCPT_2MSL] = OFFSET_FROM_START(tp, |
898 | (u_int32_t)TCP_CONN_KEEPINTVL(tp)); |
899 | } else { |
900 | tp = tcp_close(tp); |
901 | return(tp); |
902 | } |
903 | break; |
904 | |
905 | /* |
906 | * Retransmission timer went off. Message has not |
907 | * been acked within retransmit interval. Back off |
908 | * to a longer retransmit interval and retransmit one segment. |
909 | */ |
910 | case TCPT_REXMT: |
911 | absolutetime_to_nanoseconds(mach_absolutetime_asleep, |
912 | &accsleep_ms); |
913 | accsleep_ms = accsleep_ms / 1000000UL; |
914 | if (accsleep_ms > tp->t_accsleep_ms) |
915 | last_sleep_ms = accsleep_ms - tp->t_accsleep_ms; |
916 | /* |
917 | * Drop a connection in the retransmit timer |
918 | * 1. If we have retransmitted more than TCP_MAXRXTSHIFT |
919 | * times |
920 | * 2. If the time spent in this retransmission episode is |
921 | * more than the time limit set with TCP_RXT_CONNDROPTIME |
922 | * socket option |
923 | * 3. If TCP_RXT_FINDROP socket option was set and |
924 | * we have already retransmitted the FIN 3 times without |
925 | * receiving an ack |
926 | */ |
927 | if (++tp->t_rxtshift > TCP_MAXRXTSHIFT || |
928 | (tp->t_rxt_conndroptime > 0 && tp->t_rxtstart > 0 && |
929 | (tcp_now - tp->t_rxtstart) >= tp->t_rxt_conndroptime) || |
930 | ((tp->t_flagsext & TF_RXTFINDROP) != 0 && |
931 | (tp->t_flags & TF_SENTFIN) != 0 && tp->t_rxtshift >= 4) || |
932 | (tp->t_rxtshift > 4 && last_sleep_ms >= TCP_SLEEP_TOO_LONG)) { |
933 | if (tp->t_state == TCPS_ESTABLISHED && |
934 | tp->t_rxt_minimum_timeout > 0) { |
935 | /* |
936 | * Avoid dropping a connection if minimum |
937 | * timeout is set and that time did not |
938 | * pass. We will retry sending |
939 | * retransmissions at the maximum interval |
940 | */ |
941 | if (TSTMP_LT(tcp_now, (tp->t_rxtstart + |
942 | tp->t_rxt_minimum_timeout))) { |
943 | tp->t_rxtshift = TCP_MAXRXTSHIFT - 1; |
944 | goto retransmit_packet; |
945 | } |
946 | } |
947 | if ((tp->t_flagsext & TF_RXTFINDROP) != 0) { |
948 | tcpstat.tcps_rxtfindrop++; |
949 | } else if (last_sleep_ms >= TCP_SLEEP_TOO_LONG) { |
950 | tcpstat.tcps_drop_after_sleep++; |
951 | } else { |
952 | tcpstat.tcps_timeoutdrop++; |
953 | } |
954 | if (tp->t_rxtshift >= TCP_MAXRXTSHIFT) { |
955 | if (TCP_ECN_ENABLED(tp)) { |
956 | INP_INC_IFNET_STAT(tp->t_inpcb, |
957 | ecn_on.rxmit_drop); |
958 | } else { |
959 | INP_INC_IFNET_STAT(tp->t_inpcb, |
960 | ecn_off.rxmit_drop); |
961 | } |
962 | } |
963 | tp->t_rxtshift = TCP_MAXRXTSHIFT; |
964 | postevent(so, 0, EV_TIMEOUT); |
965 | soevent(so, |
966 | (SO_FILT_HINT_LOCKED|SO_FILT_HINT_TIMEOUT)); |
967 | |
968 | if (TCP_ECN_ENABLED(tp) && |
969 | tp->t_state == TCPS_ESTABLISHED) |
970 | tcp_heuristic_ecn_droprxmt(tp); |
971 | |
972 | tp = tcp_drop(tp, tp->t_softerror ? |
973 | tp->t_softerror : ETIMEDOUT); |
974 | |
975 | break; |
976 | } |
977 | retransmit_packet: |
978 | tcpstat.tcps_rexmttimeo++; |
979 | tp->t_accsleep_ms = accsleep_ms; |
980 | |
981 | if (tp->t_rxtshift == 1 && |
982 | tp->t_state == TCPS_ESTABLISHED) { |
983 | /* Set the time at which retransmission started. */ |
984 | tp->t_rxtstart = tcp_now; |
985 | |
986 | /* |
987 | * if this is the first retransmit timeout, save |
988 | * the state so that we can recover if the timeout |
989 | * is spurious. |
990 | */ |
991 | tcp_rexmt_save_state(tp); |
992 | } |
993 | #if MPTCP |
994 | if ((tp->t_rxtshift >= mptcp_fail_thresh) && |
995 | (tp->t_state == TCPS_ESTABLISHED) && |
996 | (tp->t_mpflags & TMPF_MPTCP_TRUE)) |
997 | mptcp_act_on_txfail(so); |
998 | |
999 | if (so->so_flags & SOF_MP_SUBFLOW) { |
1000 | struct mptses *mpte = tptomptp(tp)->mpt_mpte; |
1001 | |
1002 | mptcp_check_subflows_and_add(mpte); |
1003 | } |
1004 | #endif /* MPTCP */ |
1005 | |
1006 | if (tp->t_adaptive_wtimo > 0 && |
1007 | tp->t_rxtshift > tp->t_adaptive_wtimo && |
1008 | TCPS_HAVEESTABLISHED(tp->t_state)) { |
1009 | /* Send an event to the application */ |
1010 | soevent(so, |
1011 | (SO_FILT_HINT_LOCKED| |
1012 | SO_FILT_HINT_ADAPTIVE_WTIMO)); |
1013 | } |
1014 | |
1015 | /* |
1016 | * If this is a retransmit timeout after PTO, the PTO |
1017 | * was not effective |
1018 | */ |
1019 | if (tp->t_flagsext & TF_SENT_TLPROBE) { |
1020 | tp->t_flagsext &= ~(TF_SENT_TLPROBE); |
1021 | tcpstat.tcps_rto_after_pto++; |
1022 | } |
1023 | |
1024 | if (tp->t_flagsext & TF_DELAY_RECOVERY) { |
1025 | /* |
1026 | * Retransmit timer fired before entering recovery |
1027 | * on a connection with packet re-ordering. This |
1028 | * suggests that the reordering metrics computed |
1029 | * are not accurate. |
1030 | */ |
1031 | tp->t_reorderwin = 0; |
1032 | tp->t_timer[TCPT_DELAYFR] = 0; |
1033 | tp->t_flagsext &= ~(TF_DELAY_RECOVERY); |
1034 | } |
1035 | |
1036 | if (tp->t_state == TCPS_SYN_RECEIVED) |
1037 | tcp_disable_tfo(tp); |
1038 | |
1039 | if (!(tp->t_tfo_flags & TFO_F_HEURISTIC_DONE) && |
1040 | (tp->t_tfo_stats & TFO_S_SYN_DATA_SENT) && |
1041 | !(tp->t_tfo_flags & TFO_F_NO_SNDPROBING) && |
1042 | ((tp->t_state != TCPS_SYN_SENT && tp->t_rxtshift > 1) || |
1043 | tp->t_rxtshift > 4)) { |
1044 | /* |
1045 | * For regular retransmissions, a first one is being |
1046 | * done for tail-loss probe. |
1047 | * Thus, if rxtshift > 1, this means we have sent the segment |
1048 | * a total of 3 times. |
1049 | * |
1050 | * If we are in SYN-SENT state, then there is no tail-loss |
1051 | * probe thus we have to let rxtshift go up to 3. |
1052 | */ |
1053 | tcp_heuristic_tfo_middlebox(tp); |
1054 | |
1055 | so->so_error = ENODATA; |
1056 | sorwakeup(so); |
1057 | sowwakeup(so); |
1058 | |
1059 | tp->t_tfo_stats |= TFO_S_SEND_BLACKHOLE; |
1060 | tcpstat.tcps_tfo_sndblackhole++; |
1061 | } |
1062 | |
1063 | if (!(tp->t_tfo_flags & TFO_F_HEURISTIC_DONE) && |
1064 | (tp->t_tfo_stats & TFO_S_SYN_DATA_ACKED) && |
1065 | tp->t_rxtshift > 3) { |
1066 | if (TSTMP_GT(tp->t_sndtime - 10 * TCP_RETRANSHZ, tp->t_rcvtime)) { |
1067 | tcp_heuristic_tfo_middlebox(tp); |
1068 | |
1069 | so->so_error = ENODATA; |
1070 | sorwakeup(so); |
1071 | sowwakeup(so); |
1072 | } |
1073 | } |
1074 | |
1075 | if (tp->t_state == TCPS_SYN_SENT) { |
1076 | rexmt = TCP_REXMTVAL(tp) * tcp_syn_backoff[tp->t_rxtshift]; |
1077 | tp->t_stat.synrxtshift = tp->t_rxtshift; |
1078 | |
1079 | /* When retransmitting, disable TFO */ |
1080 | if (tfo_enabled(tp) && |
1081 | (!(so->so_flags1 & SOF1_DATA_AUTHENTICATED) || |
1082 | (tp->t_flagsext & TF_FASTOPEN_HEUR))) { |
1083 | tp->t_flagsext &= ~TF_FASTOPEN; |
1084 | tp->t_tfo_flags |= TFO_F_SYN_LOSS; |
1085 | } |
1086 | } else { |
1087 | rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift]; |
1088 | } |
1089 | |
1090 | TCPT_RANGESET(tp->t_rxtcur, rexmt, tp->t_rttmin, TCPTV_REXMTMAX, |
1091 | TCP_ADD_REXMTSLOP(tp)); |
1092 | tp->t_timer[TCPT_REXMT] = OFFSET_FROM_START(tp, tp->t_rxtcur); |
1093 | |
1094 | if (INP_WAIT_FOR_IF_FEEDBACK(tp->t_inpcb)) |
1095 | goto fc_output; |
1096 | |
1097 | tcp_free_sackholes(tp); |
1098 | /* |
1099 | * Check for potential Path MTU Discovery Black Hole |
1100 | */ |
1101 | if (tcp_pmtud_black_hole_detect && |
1102 | !(tp->t_flagsext & TF_NOBLACKHOLE_DETECTION) && |
1103 | (tp->t_state == TCPS_ESTABLISHED)) { |
1104 | if ((tp->t_flags & TF_PMTUD) && |
1105 | ((tp->t_flags & TF_MAXSEGSNT) |
1106 | || tp->t_pmtud_lastseg_size > tcp_pmtud_black_hole_mss) && |
1107 | tp->t_rxtshift == 2) { |
1108 | /* |
1109 | * Enter Path MTU Black-hole Detection mechanism: |
1110 | * - Disable Path MTU Discovery (IP "DF" bit). |
1111 | * - Reduce MTU to lower value than what we |
1112 | * negotiated with the peer. |
1113 | */ |
1114 | /* Disable Path MTU Discovery for now */ |
1115 | tp->t_flags &= ~TF_PMTUD; |
1116 | /* Record that we may have found a black hole */ |
1117 | tp->t_flags |= TF_BLACKHOLE; |
1118 | optlen = tp->t_maxopd - tp->t_maxseg; |
1119 | /* Keep track of previous MSS */ |
1120 | tp->t_pmtud_saved_maxopd = tp->t_maxopd; |
1121 | tp->t_pmtud_start_ts = tcp_now; |
1122 | if (tp->t_pmtud_start_ts == 0) |
1123 | tp->t_pmtud_start_ts++; |
1124 | /* Reduce the MSS to intermediary value */ |
1125 | if (tp->t_maxopd > tcp_pmtud_black_hole_mss) { |
1126 | tp->t_maxopd = tcp_pmtud_black_hole_mss; |
1127 | } else { |
1128 | tp->t_maxopd = /* use the default MSS */ |
1129 | #if INET6 |
1130 | isipv6 ? tcp_v6mssdflt : |
1131 | #endif /* INET6 */ |
1132 | tcp_mssdflt; |
1133 | } |
1134 | tp->t_maxseg = tp->t_maxopd - optlen; |
1135 | |
1136 | /* |
1137 | * Reset the slow-start flight size |
1138 | * as it may depend on the new MSS |
1139 | */ |
1140 | if (CC_ALGO(tp)->cwnd_init != NULL) |
1141 | CC_ALGO(tp)->cwnd_init(tp); |
1142 | tp->snd_cwnd = tp->t_maxseg; |
1143 | } |
1144 | /* |
1145 | * If further retransmissions are still |
1146 | * unsuccessful with a lowered MTU, maybe this |
1147 | * isn't a Black Hole and we restore the previous |
1148 | * MSS and blackhole detection flags. |
1149 | */ |
1150 | else { |
1151 | |
1152 | if ((tp->t_flags & TF_BLACKHOLE) && |
1153 | (tp->t_rxtshift > 4)) { |
1154 | tcp_pmtud_revert_segment_size(tp); |
1155 | tp->snd_cwnd = tp->t_maxseg; |
1156 | } |
1157 | } |
1158 | } |
1159 | |
1160 | |
1161 | /* |
1162 | * Disable rfc1323 and rfc1644 if we haven't got any |
1163 | * response to our SYN (after we reach the threshold) |
1164 | * to work-around some broken terminal servers (most of |
1165 | * which have hopefully been retired) that have bad VJ |
1166 | * header compression code which trashes TCP segments |
1167 | * containing unknown-to-them TCP options. |
1168 | * Do this only on non-local connections. |
1169 | */ |
1170 | if (tp->t_state == TCPS_SYN_SENT && |
1171 | tp->t_rxtshift == tcp_broken_peer_syn_rxmit_thres) |
1172 | tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_REQ_CC); |
1173 | |
1174 | /* |
1175 | * If losing, let the lower level know and try for |
1176 | * a better route. Also, if we backed off this far, |
1177 | * our srtt estimate is probably bogus. Clobber it |
1178 | * so we'll take the next rtt measurement as our srtt; |
1179 | * move the current srtt into rttvar to keep the current |
1180 | * retransmit times until then. |
1181 | */ |
1182 | if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) { |
1183 | #if INET6 |
1184 | if (isipv6) |
1185 | in6_losing(tp->t_inpcb); |
1186 | else |
1187 | #endif /* INET6 */ |
1188 | in_losing(tp->t_inpcb); |
1189 | tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT); |
1190 | tp->t_srtt = 0; |
1191 | } |
1192 | tp->snd_nxt = tp->snd_una; |
1193 | /* |
1194 | * Note: We overload snd_recover to function also as the |
1195 | * snd_last variable described in RFC 2582 |
1196 | */ |
1197 | tp->snd_recover = tp->snd_max; |
1198 | /* |
1199 | * Force a segment to be sent. |
1200 | */ |
1201 | tp->t_flags |= TF_ACKNOW; |
1202 | |
1203 | /* If timing a segment in this window, stop the timer */ |
1204 | tp->t_rtttime = 0; |
1205 | |
1206 | if (!IN_FASTRECOVERY(tp) && tp->t_rxtshift == 1) |
1207 | tcpstat.tcps_tailloss_rto++; |
1208 | |
1209 | |
1210 | /* |
1211 | * RFC 5681 says: when a TCP sender detects segment loss |
1212 | * using retransmit timer and the given segment has already |
1213 | * been retransmitted by way of the retransmission timer at |
1214 | * least once, the value of ssthresh is held constant |
1215 | */ |
1216 | if (tp->t_rxtshift == 1 && |
1217 | CC_ALGO(tp)->after_timeout != NULL) { |
1218 | CC_ALGO(tp)->after_timeout(tp); |
1219 | /* |
1220 | * CWR notifications are to be sent on new data |
1221 | * right after Fast Retransmits and ECE |
1222 | * notification receipts. |
1223 | */ |
1224 | if (TCP_ECN_ENABLED(tp)) |
1225 | tp->ecn_flags |= TE_SENDCWR; |
1226 | } |
1227 | |
1228 | EXIT_FASTRECOVERY(tp); |
1229 | |
1230 | /* Exit cwnd non validated phase */ |
1231 | tp->t_flagsext &= ~TF_CWND_NONVALIDATED; |
1232 | |
1233 | |
1234 | fc_output: |
1235 | tcp_ccdbg_trace(tp, NULL, TCP_CC_REXMT_TIMEOUT); |
1236 | |
1237 | (void) tcp_output(tp); |
1238 | break; |
1239 | |
1240 | /* |
1241 | * Persistance timer into zero window. |
1242 | * Force a byte to be output, if possible. |
1243 | */ |
1244 | case TCPT_PERSIST: |
1245 | tcpstat.tcps_persisttimeo++; |
1246 | /* |
1247 | * Hack: if the peer is dead/unreachable, we do not |
1248 | * time out if the window is closed. After a full |
1249 | * backoff, drop the connection if the idle time |
1250 | * (no responses to probes) reaches the maximum |
1251 | * backoff that we would use if retransmitting. |
1252 | * |
1253 | * Drop the connection if we reached the maximum allowed time for |
1254 | * Zero Window Probes without a non-zero update from the peer. |
1255 | * See rdar://5805356 |
1256 | */ |
1257 | if ((tp->t_rxtshift == TCP_MAXRXTSHIFT && |
1258 | (idle_time >= tcp_maxpersistidle || |
1259 | idle_time >= TCP_REXMTVAL(tp) * tcp_totbackoff)) || |
1260 | ((tp->t_persist_stop != 0) && |
1261 | TSTMP_LEQ(tp->t_persist_stop, tcp_now))) { |
1262 | tcpstat.tcps_persistdrop++; |
1263 | postevent(so, 0, EV_TIMEOUT); |
1264 | soevent(so, |
1265 | (SO_FILT_HINT_LOCKED|SO_FILT_HINT_TIMEOUT)); |
1266 | tp = tcp_drop(tp, ETIMEDOUT); |
1267 | break; |
1268 | } |
1269 | tcp_setpersist(tp); |
1270 | tp->t_flagsext |= TF_FORCE; |
1271 | (void) tcp_output(tp); |
1272 | tp->t_flagsext &= ~TF_FORCE; |
1273 | break; |
1274 | |
1275 | /* |
1276 | * Keep-alive timer went off; send something |
1277 | * or drop connection if idle for too long. |
1278 | */ |
1279 | case TCPT_KEEP: |
1280 | tcpstat.tcps_keeptimeo++; |
1281 | #if MPTCP |
1282 | /* |
1283 | * Regular TCP connections do not send keepalives after closing |
1284 | * MPTCP must not also, after sending Data FINs. |
1285 | */ |
1286 | struct mptcb *mp_tp = tptomptp(tp); |
1287 | if ((tp->t_mpflags & TMPF_MPTCP_TRUE) && |
1288 | (tp->t_state > TCPS_ESTABLISHED)) { |
1289 | goto dropit; |
1290 | } else if (mp_tp != NULL) { |
1291 | if ((mptcp_ok_to_keepalive(mp_tp) == 0)) |
1292 | goto dropit; |
1293 | } |
1294 | #endif /* MPTCP */ |
1295 | if (tp->t_state < TCPS_ESTABLISHED) |
1296 | goto dropit; |
1297 | if ((always_keepalive || |
1298 | (tp->t_inpcb->inp_socket->so_options & SO_KEEPALIVE) || |
1299 | (tp->t_flagsext & TF_DETECT_READSTALL) || |
1300 | (tp->t_tfo_probe_state == TFO_PROBE_PROBING)) && |
1301 | (tp->t_state <= TCPS_CLOSING || tp->t_state == TCPS_FIN_WAIT_2)) { |
1302 | if (idle_time >= TCP_CONN_KEEPIDLE(tp) + TCP_CONN_MAXIDLE(tp)) |
1303 | goto dropit; |
1304 | /* |
1305 | * Send a packet designed to force a response |
1306 | * if the peer is up and reachable: |
1307 | * either an ACK if the connection is still alive, |
1308 | * or an RST if the peer has closed the connection |
1309 | * due to timeout or reboot. |
1310 | * Using sequence number tp->snd_una-1 |
1311 | * causes the transmitted zero-length segment |
1312 | * to lie outside the receive window; |
1313 | * by the protocol spec, this requires the |
1314 | * correspondent TCP to respond. |
1315 | */ |
1316 | tcpstat.tcps_keepprobe++; |
1317 | t_template = tcp_maketemplate(tp); |
1318 | if (t_template) { |
1319 | struct inpcb *inp = tp->t_inpcb; |
1320 | struct tcp_respond_args tra; |
1321 | |
1322 | bzero(&tra, sizeof(tra)); |
1323 | tra.nocell = INP_NO_CELLULAR(inp); |
1324 | tra.noexpensive = INP_NO_EXPENSIVE(inp); |
1325 | tra.awdl_unrestricted = INP_AWDL_UNRESTRICTED(inp); |
1326 | tra.intcoproc_allowed = INP_INTCOPROC_ALLOWED(inp); |
1327 | if (tp->t_inpcb->inp_flags & INP_BOUND_IF) |
1328 | tra.ifscope = tp->t_inpcb->inp_boundifp->if_index; |
1329 | else |
1330 | tra.ifscope = IFSCOPE_NONE; |
1331 | tcp_respond(tp, t_template->tt_ipgen, |
1332 | &t_template->tt_t, (struct mbuf *)NULL, |
1333 | tp->rcv_nxt, tp->snd_una - 1, 0, &tra); |
1334 | (void) m_free(dtom(t_template)); |
1335 | if (tp->t_flagsext & TF_DETECT_READSTALL) |
1336 | tp->t_rtimo_probes++; |
1337 | } |
1338 | tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, |
1339 | TCP_CONN_KEEPINTVL(tp)); |
1340 | } else { |
1341 | tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, |
1342 | TCP_CONN_KEEPIDLE(tp)); |
1343 | } |
1344 | if (tp->t_flagsext & TF_DETECT_READSTALL) { |
1345 | struct ifnet *outifp = tp->t_inpcb->inp_last_outifp; |
1346 | bool reenable_probe = false; |
1347 | /* |
1348 | * The keep alive packets sent to detect a read |
1349 | * stall did not get a response from the |
1350 | * peer. Generate more keep-alives to confirm this. |
1351 | * If the number of probes sent reaches the limit, |
1352 | * generate an event. |
1353 | */ |
1354 | if (tp->t_adaptive_rtimo > 0) { |
1355 | if (tp->t_rtimo_probes > tp->t_adaptive_rtimo) { |
1356 | /* Generate an event */ |
1357 | soevent(so, |
1358 | (SO_FILT_HINT_LOCKED | |
1359 | SO_FILT_HINT_ADAPTIVE_RTIMO)); |
1360 | tcp_keepalive_reset(tp); |
1361 | } else { |
1362 | reenable_probe = true; |
1363 | } |
1364 | } else if (outifp != NULL && |
1365 | (outifp->if_eflags & IFEF_PROBE_CONNECTIVITY) && |
1366 | tp->t_rtimo_probes <= TCP_CONNECTIVITY_PROBES_MAX) { |
1367 | reenable_probe = true; |
1368 | } else { |
1369 | tp->t_flagsext &= ~TF_DETECT_READSTALL; |
1370 | } |
1371 | if (reenable_probe) { |
1372 | int ind = min(tp->t_rtimo_probes, |
1373 | TCP_MAXRXTSHIFT); |
1374 | tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START( |
1375 | tp, tcp_backoff[ind] * TCP_REXMTVAL(tp)); |
1376 | } |
1377 | } |
1378 | if (tp->t_tfo_probe_state == TFO_PROBE_PROBING) { |
1379 | int ind; |
1380 | |
1381 | tp->t_tfo_probes++; |
1382 | ind = min(tp->t_tfo_probes, TCP_MAXRXTSHIFT); |
1383 | |
1384 | /* |
1385 | * We take the minimum among the time set by true |
1386 | * keepalive (see above) and the backoff'd RTO. That |
1387 | * way we backoff in case of packet-loss but will never |
1388 | * timeout slower than regular keepalive due to the |
1389 | * backing off. |
1390 | */ |
1391 | tp->t_timer[TCPT_KEEP] = min(OFFSET_FROM_START( |
1392 | tp, tcp_backoff[ind] * TCP_REXMTVAL(tp)), |
1393 | tp->t_timer[TCPT_KEEP]); |
1394 | } else if (!(tp->t_tfo_flags & TFO_F_HEURISTIC_DONE) && |
1395 | tp->t_tfo_probe_state == TFO_PROBE_WAIT_DATA) { |
1396 | /* Still no data! Let's assume a TFO-error and err out... */ |
1397 | tcp_heuristic_tfo_middlebox(tp); |
1398 | |
1399 | so->so_error = ENODATA; |
1400 | sorwakeup(so); |
1401 | tp->t_tfo_stats |= TFO_S_RECV_BLACKHOLE; |
1402 | tcpstat.tcps_tfo_blackhole++; |
1403 | } |
1404 | break; |
1405 | case TCPT_DELACK: |
1406 | if (tcp_delack_enabled && (tp->t_flags & TF_DELACK)) { |
1407 | tp->t_flags &= ~TF_DELACK; |
1408 | tp->t_timer[TCPT_DELACK] = 0; |
1409 | tp->t_flags |= TF_ACKNOW; |
1410 | |
1411 | /* |
1412 | * If delayed ack timer fired while stretching |
1413 | * acks, count the number of times the streaming |
1414 | * detection was not correct. If this exceeds a |
1415 | * threshold, disable strech ack on this |
1416 | * connection |
1417 | * |
1418 | * Also, go back to acking every other packet. |
1419 | */ |
1420 | if ((tp->t_flags & TF_STRETCHACK)) { |
1421 | if (tp->t_unacksegs > 1 && |
1422 | tp->t_unacksegs < maxseg_unacked) |
1423 | tp->t_stretchack_delayed++; |
1424 | |
1425 | if (tp->t_stretchack_delayed > |
1426 | TCP_STRETCHACK_DELAY_THRESHOLD) { |
1427 | tp->t_flagsext |= TF_DISABLE_STRETCHACK; |
1428 | /* |
1429 | * Note the time at which stretch |
1430 | * ack was disabled automatically |
1431 | */ |
1432 | tp->rcv_nostrack_ts = tcp_now; |
1433 | tcpstat.tcps_nostretchack++; |
1434 | tp->t_stretchack_delayed = 0; |
1435 | tp->rcv_nostrack_pkts = 0; |
1436 | } |
1437 | tcp_reset_stretch_ack(tp); |
1438 | } |
1439 | |
1440 | /* |
1441 | * If we are measuring inter packet arrival jitter |
1442 | * for throttling a connection, this delayed ack |
1443 | * might be the reason for accumulating some |
1444 | * jitter. So let's restart the measurement. |
1445 | */ |
1446 | CLEAR_IAJ_STATE(tp); |
1447 | |
1448 | tcpstat.tcps_delack++; |
1449 | (void) tcp_output(tp); |
1450 | } |
1451 | break; |
1452 | |
1453 | #if MPTCP |
1454 | case TCPT_JACK_RXMT: |
1455 | if ((tp->t_state == TCPS_ESTABLISHED) && |
1456 | (tp->t_mpflags & TMPF_PREESTABLISHED) && |
1457 | (tp->t_mpflags & TMPF_JOINED_FLOW)) { |
1458 | if (++tp->t_mprxtshift > TCP_MAXRXTSHIFT) { |
1459 | tcpstat.tcps_timeoutdrop++; |
1460 | postevent(so, 0, EV_TIMEOUT); |
1461 | soevent(so, |
1462 | (SO_FILT_HINT_LOCKED| |
1463 | SO_FILT_HINT_TIMEOUT)); |
1464 | tp = tcp_drop(tp, tp->t_softerror ? |
1465 | tp->t_softerror : ETIMEDOUT); |
1466 | break; |
1467 | } |
1468 | tcpstat.tcps_join_rxmts++; |
1469 | tp->t_mpflags |= TMPF_SND_JACK; |
1470 | tp->t_flags |= TF_ACKNOW; |
1471 | |
1472 | /* |
1473 | * No backoff is implemented for simplicity for this |
1474 | * corner case. |
1475 | */ |
1476 | (void) tcp_output(tp); |
1477 | } |
1478 | break; |
1479 | #endif /* MPTCP */ |
1480 | |
1481 | case TCPT_PTO: |
1482 | { |
1483 | int32_t snd_len; |
1484 | tp->t_flagsext &= ~(TF_SENT_TLPROBE); |
1485 | |
1486 | /* |
1487 | * Check if the connection is in the right state to |
1488 | * send a probe |
1489 | */ |
1490 | if (tp->t_state != TCPS_ESTABLISHED || |
1491 | (tp->t_rxtshift > 0 && !(tp->t_flagsext & TF_PROBING)) || |
1492 | tp->snd_max == tp->snd_una || |
1493 | !SACK_ENABLED(tp) || |
1494 | !TAILQ_EMPTY(&tp->snd_holes) || |
1495 | IN_FASTRECOVERY(tp)) |
1496 | break; |
1497 | |
1498 | /* |
1499 | * If there is no new data to send or if the |
1500 | * connection is limited by receive window then |
1501 | * retransmit the last segment, otherwise send |
1502 | * new data. |
1503 | */ |
1504 | snd_len = min(so->so_snd.sb_cc, tp->snd_wnd) |
1505 | - (tp->snd_max - tp->snd_una); |
1506 | if (snd_len > 0) { |
1507 | tp->snd_nxt = tp->snd_max; |
1508 | } else { |
1509 | snd_len = min((tp->snd_max - tp->snd_una), |
1510 | tp->t_maxseg); |
1511 | tp->snd_nxt = tp->snd_max - snd_len; |
1512 | } |
1513 | |
1514 | tcpstat.tcps_pto++; |
1515 | if (tp->t_flagsext & TF_PROBING) |
1516 | tcpstat.tcps_probe_if++; |
1517 | |
1518 | /* If timing a segment in this window, stop the timer */ |
1519 | tp->t_rtttime = 0; |
1520 | /* Note that tail loss probe is being sent */ |
1521 | tp->t_flagsext |= TF_SENT_TLPROBE; |
1522 | tp->t_tlpstart = tcp_now; |
1523 | |
1524 | tp->snd_cwnd += tp->t_maxseg; |
1525 | |
1526 | /* |
1527 | * When tail-loss-probe fires, we reset the RTO timer, because |
1528 | * a probe just got sent, so we are good to push out the timer. |
1529 | * |
1530 | * Set to 0 to ensure that tcp_output() will reschedule it |
1531 | */ |
1532 | tp->t_timer[TCPT_REXMT] = 0; |
1533 | |
1534 | (void )tcp_output(tp); |
1535 | tp->snd_cwnd -= tp->t_maxseg; |
1536 | |
1537 | tp->t_tlphighrxt = tp->snd_nxt; |
1538 | break; |
1539 | } |
1540 | case TCPT_DELAYFR: |
1541 | tp->t_flagsext &= ~TF_DELAY_RECOVERY; |
1542 | |
1543 | /* |
1544 | * Don't do anything if one of the following is true: |
1545 | * - the connection is already in recovery |
1546 | * - sequence until snd_recover has been acknowledged. |
1547 | * - retransmit timeout has fired |
1548 | */ |
1549 | if (IN_FASTRECOVERY(tp) || |
1550 | SEQ_GEQ(tp->snd_una, tp->snd_recover) || |
1551 | tp->t_rxtshift > 0) |
1552 | break; |
1553 | |
1554 | VERIFY(SACK_ENABLED(tp)); |
1555 | tcp_rexmt_save_state(tp); |
1556 | if (CC_ALGO(tp)->pre_fr != NULL) { |
1557 | CC_ALGO(tp)->pre_fr(tp); |
1558 | if (TCP_ECN_ENABLED(tp)) |
1559 | tp->ecn_flags |= TE_SENDCWR; |
1560 | } |
1561 | ENTER_FASTRECOVERY(tp); |
1562 | |
1563 | tp->t_timer[TCPT_REXMT] = 0; |
1564 | tcpstat.tcps_sack_recovery_episode++; |
1565 | tp->t_sack_recovery_episode++; |
1566 | tp->sack_newdata = tp->snd_nxt; |
1567 | tp->snd_cwnd = tp->t_maxseg; |
1568 | tcp_ccdbg_trace(tp, NULL, TCP_CC_ENTER_FASTRECOVERY); |
1569 | (void) tcp_output(tp); |
1570 | break; |
1571 | dropit: |
1572 | tcpstat.tcps_keepdrops++; |
1573 | postevent(so, 0, EV_TIMEOUT); |
1574 | soevent(so, |
1575 | (SO_FILT_HINT_LOCKED|SO_FILT_HINT_TIMEOUT)); |
1576 | tp = tcp_drop(tp, ETIMEDOUT); |
1577 | break; |
1578 | } |
1579 | #if TCPDEBUG |
1580 | if (tp->t_inpcb->inp_socket->so_options & SO_DEBUG) |
1581 | tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0, |
1582 | PRU_SLOWTIMO); |
1583 | #endif |
1584 | return (tp); |
1585 | } |
1586 | |
1587 | /* Remove a timer entry from timer list */ |
1588 | void |
1589 | tcp_remove_timer(struct tcpcb *tp) |
1590 | { |
1591 | struct tcptimerlist *listp = &tcp_timer_list; |
1592 | |
1593 | socket_lock_assert_owned(tp->t_inpcb->inp_socket); |
1594 | if (!(TIMER_IS_ON_LIST(tp))) { |
1595 | return; |
1596 | } |
1597 | lck_mtx_lock(listp->mtx); |
1598 | |
1599 | /* Check if pcb is on timer list again after acquiring the lock */ |
1600 | if (!(TIMER_IS_ON_LIST(tp))) { |
1601 | lck_mtx_unlock(listp->mtx); |
1602 | return; |
1603 | } |
1604 | |
1605 | if (listp->next_te != NULL && listp->next_te == &tp->tentry) |
1606 | listp->next_te = LIST_NEXT(&tp->tentry, le); |
1607 | |
1608 | LIST_REMOVE(&tp->tentry, le); |
1609 | tp->t_flags &= ~(TF_TIMER_ONLIST); |
1610 | |
1611 | listp->entries--; |
1612 | |
1613 | tp->tentry.le.le_next = NULL; |
1614 | tp->tentry.le.le_prev = NULL; |
1615 | lck_mtx_unlock(listp->mtx); |
1616 | } |
1617 | |
1618 | /* |
1619 | * Function to check if the timerlist needs to be rescheduled to run |
1620 | * the timer entry correctly. Basically, this is to check if we can avoid |
1621 | * taking the list lock. |
1622 | */ |
1623 | |
1624 | static boolean_t |
1625 | need_to_resched_timerlist(u_int32_t runtime, u_int16_t mode) |
1626 | { |
1627 | struct tcptimerlist *listp = &tcp_timer_list; |
1628 | int32_t diff; |
1629 | |
1630 | /* |
1631 | * If the list is being processed then the state of the list is |
1632 | * in flux. In this case always acquire the lock and set the state |
1633 | * correctly. |
1634 | */ |
1635 | if (listp->running) |
1636 | return (TRUE); |
1637 | |
1638 | if (!listp->scheduled) |
1639 | return (TRUE); |
1640 | |
1641 | diff = timer_diff(listp->runtime, 0, runtime, 0); |
1642 | if (diff <= 0) { |
1643 | /* The list is going to run before this timer */ |
1644 | return (FALSE); |
1645 | } else { |
1646 | if (mode & TCP_TIMERLIST_10MS_MODE) { |
1647 | if (diff <= TCP_TIMER_10MS_QUANTUM) |
1648 | return (FALSE); |
1649 | } else if (mode & TCP_TIMERLIST_100MS_MODE) { |
1650 | if (diff <= TCP_TIMER_100MS_QUANTUM) |
1651 | return (FALSE); |
1652 | } else { |
1653 | if (diff <= TCP_TIMER_500MS_QUANTUM) |
1654 | return (FALSE); |
1655 | } |
1656 | } |
1657 | return (TRUE); |
1658 | } |
1659 | |
1660 | void |
1661 | tcp_sched_timerlist(uint32_t offset) |
1662 | { |
1663 | uint64_t deadline = 0; |
1664 | struct tcptimerlist *listp = &tcp_timer_list; |
1665 | |
1666 | LCK_MTX_ASSERT(listp->mtx, LCK_MTX_ASSERT_OWNED); |
1667 | |
1668 | offset = min(offset, TCP_TIMERLIST_MAX_OFFSET); |
1669 | listp->runtime = tcp_now + offset; |
1670 | listp->schedtime = tcp_now; |
1671 | if (listp->runtime == 0) { |
1672 | listp->runtime++; |
1673 | offset++; |
1674 | } |
1675 | |
1676 | clock_interval_to_deadline(offset, USEC_PER_SEC, &deadline); |
1677 | |
1678 | thread_call_enter_delayed(listp->call, deadline); |
1679 | listp->scheduled = TRUE; |
1680 | } |
1681 | |
1682 | /* |
1683 | * Function to run the timers for a connection. |
1684 | * |
1685 | * Returns the offset of next timer to be run for this connection which |
1686 | * can be used to reschedule the timerlist. |
1687 | * |
1688 | * te_mode is an out parameter that indicates the modes of active |
1689 | * timers for this connection. |
1690 | */ |
1691 | u_int32_t |
1692 | tcp_run_conn_timer(struct tcpcb *tp, u_int16_t *te_mode, |
1693 | u_int16_t probe_if_index) |
1694 | { |
1695 | struct socket *so; |
1696 | u_int16_t i = 0, index = TCPT_NONE, lo_index = TCPT_NONE; |
1697 | u_int32_t timer_val, offset = 0, lo_timer = 0; |
1698 | int32_t diff; |
1699 | boolean_t needtorun[TCPT_NTIMERS]; |
1700 | int count = 0; |
1701 | |
1702 | VERIFY(tp != NULL); |
1703 | bzero(needtorun, sizeof(needtorun)); |
1704 | *te_mode = 0; |
1705 | |
1706 | socket_lock(tp->t_inpcb->inp_socket, 1); |
1707 | |
1708 | so = tp->t_inpcb->inp_socket; |
1709 | /* Release the want count on inp */ |
1710 | if (in_pcb_checkstate(tp->t_inpcb, WNT_RELEASE, 1) |
1711 | == WNT_STOPUSING) { |
1712 | if (TIMER_IS_ON_LIST(tp)) { |
1713 | tcp_remove_timer(tp); |
1714 | } |
1715 | |
1716 | /* Looks like the TCP connection got closed while we |
1717 | * were waiting for the lock.. Done |
1718 | */ |
1719 | goto done; |
1720 | } |
1721 | |
1722 | /* |
1723 | * If this connection is over an interface that needs to |
1724 | * be probed, send probe packets to reinitiate communication. |
1725 | */ |
1726 | if (probe_if_index > 0 && tp->t_inpcb->inp_last_outifp != NULL && |
1727 | tp->t_inpcb->inp_last_outifp->if_index == probe_if_index) { |
1728 | tp->t_flagsext |= TF_PROBING; |
1729 | tcp_timers(tp, TCPT_PTO); |
1730 | tp->t_timer[TCPT_PTO] = 0; |
1731 | tp->t_flagsext &= ~TF_PROBING; |
1732 | } |
1733 | |
1734 | /* |
1735 | * Since the timer thread needs to wait for tcp lock, it may race |
1736 | * with another thread that can cancel or reschedule the timer |
1737 | * that is about to run. Check if we need to run anything. |
1738 | */ |
1739 | if ((index = tp->tentry.index) == TCPT_NONE) |
1740 | goto done; |
1741 | |
1742 | timer_val = tp->t_timer[index]; |
1743 | |
1744 | diff = timer_diff(tp->tentry.runtime, 0, tcp_now, 0); |
1745 | if (diff > 0) { |
1746 | if (tp->tentry.index != TCPT_NONE) { |
1747 | offset = diff; |
1748 | *(te_mode) = tp->tentry.mode; |
1749 | } |
1750 | goto done; |
1751 | } |
1752 | |
1753 | tp->t_timer[index] = 0; |
1754 | if (timer_val > 0) { |
1755 | tp = tcp_timers(tp, index); |
1756 | if (tp == NULL) |
1757 | goto done; |
1758 | } |
1759 | |
1760 | /* |
1761 | * Check if there are any other timers that need to be run. |
1762 | * While doing it, adjust the timer values wrt tcp_now. |
1763 | */ |
1764 | tp->tentry.mode = 0; |
1765 | for (i = 0; i < TCPT_NTIMERS; ++i) { |
1766 | if (tp->t_timer[i] != 0) { |
1767 | diff = timer_diff(tp->tentry.timer_start, |
1768 | tp->t_timer[i], tcp_now, 0); |
1769 | if (diff <= 0) { |
1770 | needtorun[i] = TRUE; |
1771 | count++; |
1772 | } else { |
1773 | tp->t_timer[i] = diff; |
1774 | needtorun[i] = FALSE; |
1775 | if (lo_timer == 0 || diff < lo_timer) { |
1776 | lo_timer = diff; |
1777 | lo_index = i; |
1778 | } |
1779 | TCP_SET_TIMER_MODE(tp->tentry.mode, i); |
1780 | } |
1781 | } |
1782 | } |
1783 | |
1784 | tp->tentry.timer_start = tcp_now; |
1785 | tp->tentry.index = lo_index; |
1786 | VERIFY(tp->tentry.index == TCPT_NONE || tp->tentry.mode > 0); |
1787 | |
1788 | if (tp->tentry.index != TCPT_NONE) { |
1789 | tp->tentry.runtime = tp->tentry.timer_start + |
1790 | tp->t_timer[tp->tentry.index]; |
1791 | if (tp->tentry.runtime == 0) |
1792 | tp->tentry.runtime++; |
1793 | } |
1794 | |
1795 | if (count > 0) { |
1796 | /* run any other timers outstanding at this time. */ |
1797 | for (i = 0; i < TCPT_NTIMERS; ++i) { |
1798 | if (needtorun[i]) { |
1799 | tp->t_timer[i] = 0; |
1800 | tp = tcp_timers(tp, i); |
1801 | if (tp == NULL) { |
1802 | offset = 0; |
1803 | *(te_mode) = 0; |
1804 | goto done; |
1805 | } |
1806 | } |
1807 | } |
1808 | tcp_set_lotimer_index(tp); |
1809 | } |
1810 | |
1811 | if (tp->tentry.index < TCPT_NONE) { |
1812 | offset = tp->t_timer[tp->tentry.index]; |
1813 | *(te_mode) = tp->tentry.mode; |
1814 | } |
1815 | |
1816 | done: |
1817 | if (tp != NULL && tp->tentry.index == TCPT_NONE) { |
1818 | tcp_remove_timer(tp); |
1819 | offset = 0; |
1820 | } |
1821 | |
1822 | socket_unlock(so, 1); |
1823 | return(offset); |
1824 | } |
1825 | |
1826 | void |
1827 | tcp_run_timerlist(void * arg1, void * arg2) |
1828 | { |
1829 | #pragma unused(arg1, arg2) |
1830 | struct tcptimerentry *te, *next_te; |
1831 | struct tcptimerlist *listp = &tcp_timer_list; |
1832 | struct tcpcb *tp; |
1833 | uint32_t next_timer = 0; /* offset of the next timer on the list */ |
1834 | u_int16_t te_mode = 0; /* modes of all active timers in a tcpcb */ |
1835 | u_int16_t list_mode = 0; /* cumulative of modes of all tcpcbs */ |
1836 | uint32_t active_count = 0; |
1837 | |
1838 | calculate_tcp_clock(); |
1839 | |
1840 | lck_mtx_lock(listp->mtx); |
1841 | |
1842 | int32_t drift = tcp_now - listp->runtime; |
1843 | if (drift <= 1) { |
1844 | tcpstat.tcps_timer_drift_le_1_ms++; |
1845 | } else if (drift <= 10) { |
1846 | tcpstat.tcps_timer_drift_le_10_ms++; |
1847 | } else if (drift <= 20) { |
1848 | tcpstat.tcps_timer_drift_le_20_ms++; |
1849 | } else if (drift <= 50) { |
1850 | tcpstat.tcps_timer_drift_le_50_ms++; |
1851 | } else if (drift <= 100) { |
1852 | tcpstat.tcps_timer_drift_le_100_ms++; |
1853 | } else if (drift <= 200) { |
1854 | tcpstat.tcps_timer_drift_le_200_ms++; |
1855 | } else if (drift <= 500) { |
1856 | tcpstat.tcps_timer_drift_le_500_ms++; |
1857 | } else if (drift <= 1000) { |
1858 | tcpstat.tcps_timer_drift_le_1000_ms++; |
1859 | } else { |
1860 | tcpstat.tcps_timer_drift_gt_1000_ms++; |
1861 | } |
1862 | |
1863 | listp->running = TRUE; |
1864 | |
1865 | LIST_FOREACH_SAFE(te, &listp->lhead, le, next_te) { |
1866 | uint32_t offset = 0; |
1867 | uint32_t runtime = te->runtime; |
1868 | if (te->index < TCPT_NONE && TSTMP_GT(runtime, tcp_now)) { |
1869 | offset = timer_diff(runtime, 0, tcp_now, 0); |
1870 | if (next_timer == 0 || offset < next_timer) { |
1871 | next_timer = offset; |
1872 | } |
1873 | list_mode |= te->mode; |
1874 | continue; |
1875 | } |
1876 | |
1877 | tp = TIMERENTRY_TO_TP(te); |
1878 | |
1879 | /* |
1880 | * Acquire an inp wantcnt on the inpcb so that the socket |
1881 | * won't get detached even if tcp_close is called |
1882 | */ |
1883 | if (in_pcb_checkstate(tp->t_inpcb, WNT_ACQUIRE, 0) |
1884 | == WNT_STOPUSING) { |
1885 | /* |
1886 | * Some how this pcb went into dead state while |
1887 | * on the timer list, just take it off the list. |
1888 | * Since the timer list entry pointers are |
1889 | * protected by the timer list lock, we can |
1890 | * do it here without the socket lock. |
1891 | */ |
1892 | if (TIMER_IS_ON_LIST(tp)) { |
1893 | tp->t_flags &= ~(TF_TIMER_ONLIST); |
1894 | LIST_REMOVE(&tp->tentry, le); |
1895 | listp->entries--; |
1896 | |
1897 | tp->tentry.le.le_next = NULL; |
1898 | tp->tentry.le.le_prev = NULL; |
1899 | } |
1900 | continue; |
1901 | } |
1902 | active_count++; |
1903 | |
1904 | /* |
1905 | * Store the next timerentry pointer before releasing the |
1906 | * list lock. If that entry has to be removed when we |
1907 | * release the lock, this pointer will be updated to the |
1908 | * element after that. |
1909 | */ |
1910 | listp->next_te = next_te; |
1911 | |
1912 | VERIFY_NEXT_LINK(&tp->tentry, le); |
1913 | VERIFY_PREV_LINK(&tp->tentry, le); |
1914 | |
1915 | lck_mtx_unlock(listp->mtx); |
1916 | |
1917 | offset = tcp_run_conn_timer(tp, &te_mode, |
1918 | listp->probe_if_index); |
1919 | |
1920 | lck_mtx_lock(listp->mtx); |
1921 | |
1922 | next_te = listp->next_te; |
1923 | listp->next_te = NULL; |
1924 | |
1925 | if (offset > 0 && te_mode != 0) { |
1926 | list_mode |= te_mode; |
1927 | |
1928 | if (next_timer == 0 || offset < next_timer) |
1929 | next_timer = offset; |
1930 | } |
1931 | } |
1932 | |
1933 | if (!LIST_EMPTY(&listp->lhead)) { |
1934 | u_int16_t next_mode = 0; |
1935 | if ((list_mode & TCP_TIMERLIST_10MS_MODE) || |
1936 | (listp->pref_mode & TCP_TIMERLIST_10MS_MODE)) |
1937 | next_mode = TCP_TIMERLIST_10MS_MODE; |
1938 | else if ((list_mode & TCP_TIMERLIST_100MS_MODE) || |
1939 | (listp->pref_mode & TCP_TIMERLIST_100MS_MODE)) |
1940 | next_mode = TCP_TIMERLIST_100MS_MODE; |
1941 | else |
1942 | next_mode = TCP_TIMERLIST_500MS_MODE; |
1943 | |
1944 | if (next_mode != TCP_TIMERLIST_500MS_MODE) { |
1945 | listp->idleruns = 0; |
1946 | } else { |
1947 | /* |
1948 | * the next required mode is slow mode, but if |
1949 | * the last one was a faster mode and we did not |
1950 | * have enough idle runs, repeat the last mode. |
1951 | * |
1952 | * We try to keep the timer list in fast mode for |
1953 | * some idle time in expectation of new data. |
1954 | */ |
1955 | if (listp->mode != next_mode && |
1956 | listp->idleruns < timer_fastmode_idlemax) { |
1957 | listp->idleruns++; |
1958 | next_mode = listp->mode; |
1959 | next_timer = TCP_TIMER_100MS_QUANTUM; |
1960 | } else { |
1961 | listp->idleruns = 0; |
1962 | } |
1963 | } |
1964 | listp->mode = next_mode; |
1965 | if (listp->pref_offset != 0) |
1966 | next_timer = min(listp->pref_offset, next_timer); |
1967 | |
1968 | if (listp->mode == TCP_TIMERLIST_500MS_MODE) |
1969 | next_timer = max(next_timer, |
1970 | TCP_TIMER_500MS_QUANTUM); |
1971 | |
1972 | tcp_sched_timerlist(next_timer); |
1973 | } else { |
1974 | /* |
1975 | * No need to reschedule this timer, but always run |
1976 | * periodically at a much higher granularity. |
1977 | */ |
1978 | tcp_sched_timerlist(TCP_TIMERLIST_MAX_OFFSET); |
1979 | } |
1980 | |
1981 | listp->running = FALSE; |
1982 | listp->pref_mode = 0; |
1983 | listp->pref_offset = 0; |
1984 | listp->probe_if_index = 0; |
1985 | |
1986 | lck_mtx_unlock(listp->mtx); |
1987 | } |
1988 | |
1989 | /* |
1990 | * Function to check if the timerlist needs to be rescheduled to run this |
1991 | * connection's timers correctly. |
1992 | */ |
1993 | void |
1994 | tcp_sched_timers(struct tcpcb *tp) |
1995 | { |
1996 | struct tcptimerentry *te = &tp->tentry; |
1997 | u_int16_t index = te->index; |
1998 | u_int16_t mode = te->mode; |
1999 | struct tcptimerlist *listp = &tcp_timer_list; |
2000 | int32_t offset = 0; |
2001 | boolean_t list_locked = FALSE; |
2002 | |
2003 | if (tp->t_inpcb->inp_state == INPCB_STATE_DEAD) { |
2004 | /* Just return without adding the dead pcb to the list */ |
2005 | if (TIMER_IS_ON_LIST(tp)) { |
2006 | tcp_remove_timer(tp); |
2007 | } |
2008 | return; |
2009 | } |
2010 | |
2011 | if (index == TCPT_NONE) { |
2012 | /* Nothing to run */ |
2013 | tcp_remove_timer(tp); |
2014 | return; |
2015 | } |
2016 | |
2017 | /* |
2018 | * compute the offset at which the next timer for this connection |
2019 | * has to run. |
2020 | */ |
2021 | offset = timer_diff(te->runtime, 0, tcp_now, 0); |
2022 | if (offset <= 0) { |
2023 | offset = 1; |
2024 | tcp_timer_advanced++; |
2025 | } |
2026 | |
2027 | if (!TIMER_IS_ON_LIST(tp)) { |
2028 | if (!list_locked) { |
2029 | lck_mtx_lock(listp->mtx); |
2030 | list_locked = TRUE; |
2031 | } |
2032 | |
2033 | if (!TIMER_IS_ON_LIST(tp)) { |
2034 | LIST_INSERT_HEAD(&listp->lhead, te, le); |
2035 | tp->t_flags |= TF_TIMER_ONLIST; |
2036 | |
2037 | listp->entries++; |
2038 | if (listp->entries > listp->maxentries) |
2039 | listp->maxentries = listp->entries; |
2040 | |
2041 | /* if the list is not scheduled, just schedule it */ |
2042 | if (!listp->scheduled) |
2043 | goto schedule; |
2044 | } |
2045 | } |
2046 | |
2047 | /* |
2048 | * Timer entry is currently on the list, check if the list needs |
2049 | * to be rescheduled. |
2050 | */ |
2051 | if (need_to_resched_timerlist(te->runtime, mode)) { |
2052 | tcp_resched_timerlist++; |
2053 | |
2054 | if (!list_locked) { |
2055 | lck_mtx_lock(listp->mtx); |
2056 | list_locked = TRUE; |
2057 | } |
2058 | |
2059 | VERIFY_NEXT_LINK(te, le); |
2060 | VERIFY_PREV_LINK(te, le); |
2061 | |
2062 | if (listp->running) { |
2063 | listp->pref_mode |= mode; |
2064 | if (listp->pref_offset == 0 || |
2065 | offset < listp->pref_offset) { |
2066 | listp->pref_offset = offset; |
2067 | } |
2068 | } else { |
2069 | /* |
2070 | * The list could have got rescheduled while |
2071 | * this thread was waiting for the lock |
2072 | */ |
2073 | if (listp->scheduled) { |
2074 | int32_t diff; |
2075 | diff = timer_diff(listp->runtime, 0, |
2076 | tcp_now, offset); |
2077 | if (diff <= 0) |
2078 | goto done; |
2079 | else |
2080 | goto schedule; |
2081 | } else { |
2082 | goto schedule; |
2083 | } |
2084 | } |
2085 | } |
2086 | goto done; |
2087 | |
2088 | schedule: |
2089 | /* |
2090 | * Since a connection with timers is getting scheduled, the timer |
2091 | * list moves from idle to active state and that is why idlegen is |
2092 | * reset |
2093 | */ |
2094 | if (mode & TCP_TIMERLIST_10MS_MODE) { |
2095 | listp->mode = TCP_TIMERLIST_10MS_MODE; |
2096 | listp->idleruns = 0; |
2097 | offset = min(offset, TCP_TIMER_10MS_QUANTUM); |
2098 | } else if (mode & TCP_TIMERLIST_100MS_MODE) { |
2099 | if (listp->mode > TCP_TIMERLIST_100MS_MODE) |
2100 | listp->mode = TCP_TIMERLIST_100MS_MODE; |
2101 | listp->idleruns = 0; |
2102 | offset = min(offset, TCP_TIMER_100MS_QUANTUM); |
2103 | } |
2104 | tcp_sched_timerlist(offset); |
2105 | |
2106 | done: |
2107 | if (list_locked) |
2108 | lck_mtx_unlock(listp->mtx); |
2109 | |
2110 | return; |
2111 | } |
2112 | |
2113 | static inline void |
2114 | tcp_set_lotimer_index(struct tcpcb *tp) |
2115 | { |
2116 | uint16_t i, lo_index = TCPT_NONE, mode = 0; |
2117 | uint32_t lo_timer = 0; |
2118 | for (i = 0; i < TCPT_NTIMERS; ++i) { |
2119 | if (tp->t_timer[i] != 0) { |
2120 | TCP_SET_TIMER_MODE(mode, i); |
2121 | if (lo_timer == 0 || tp->t_timer[i] < lo_timer) { |
2122 | lo_timer = tp->t_timer[i]; |
2123 | lo_index = i; |
2124 | } |
2125 | } |
2126 | } |
2127 | tp->tentry.index = lo_index; |
2128 | tp->tentry.mode = mode; |
2129 | VERIFY(tp->tentry.index == TCPT_NONE || tp->tentry.mode > 0); |
2130 | |
2131 | if (tp->tentry.index != TCPT_NONE) { |
2132 | tp->tentry.runtime = tp->tentry.timer_start |
2133 | + tp->t_timer[tp->tentry.index]; |
2134 | if (tp->tentry.runtime == 0) |
2135 | tp->tentry.runtime++; |
2136 | } |
2137 | } |
2138 | |
2139 | void |
2140 | tcp_check_timer_state(struct tcpcb *tp) |
2141 | { |
2142 | socket_lock_assert_owned(tp->t_inpcb->inp_socket); |
2143 | |
2144 | if (tp->t_inpcb->inp_flags2 & INP2_TIMEWAIT) |
2145 | return; |
2146 | |
2147 | tcp_set_lotimer_index(tp); |
2148 | |
2149 | tcp_sched_timers(tp); |
2150 | return; |
2151 | } |
2152 | |
2153 | static inline void |
2154 | tcp_cumulative_stat(u_int32_t cur, u_int32_t *prev, u_int32_t *dest) |
2155 | { |
2156 | /* handle wrap around */ |
2157 | int32_t diff = (int32_t) (cur - *prev); |
2158 | if (diff > 0) |
2159 | *dest = diff; |
2160 | else |
2161 | *dest = 0; |
2162 | *prev = cur; |
2163 | return; |
2164 | } |
2165 | |
2166 | static inline void |
2167 | tcp_cumulative_stat64(u_int64_t cur, u_int64_t *prev, u_int64_t *dest) |
2168 | { |
2169 | /* handle wrap around */ |
2170 | int64_t diff = (int64_t) (cur - *prev); |
2171 | if (diff > 0) |
2172 | *dest = diff; |
2173 | else |
2174 | *dest = 0; |
2175 | *prev = cur; |
2176 | return; |
2177 | } |
2178 | |
2179 | __private_extern__ void |
2180 | tcp_report_stats(void) |
2181 | { |
2182 | struct nstat_sysinfo_data data; |
2183 | struct sockaddr_in dst; |
2184 | struct sockaddr_in6 dst6; |
2185 | struct rtentry *rt = NULL; |
2186 | static struct tcp_last_report_stats prev; |
2187 | u_int64_t var, uptime; |
2188 | |
2189 | #define stat data.u.tcp_stats |
2190 | if (((uptime = net_uptime()) - tcp_last_report_time) < |
2191 | tcp_report_stats_interval) |
2192 | return; |
2193 | |
2194 | tcp_last_report_time = uptime; |
2195 | |
2196 | bzero(&data, sizeof(data)); |
2197 | data.flags = NSTAT_SYSINFO_TCP_STATS; |
2198 | |
2199 | bzero(&dst, sizeof(dst)); |
2200 | dst.sin_len = sizeof(dst); |
2201 | dst.sin_family = AF_INET; |
2202 | |
2203 | /* ipv4 avg rtt */ |
2204 | lck_mtx_lock(rnh_lock); |
2205 | rt = rt_lookup(TRUE, (struct sockaddr *)&dst, NULL, |
2206 | rt_tables[AF_INET], IFSCOPE_NONE); |
2207 | lck_mtx_unlock(rnh_lock); |
2208 | if (rt != NULL) { |
2209 | RT_LOCK(rt); |
2210 | if (rt_primary_default(rt, rt_key(rt)) && |
2211 | rt->rt_stats != NULL) { |
2212 | stat.ipv4_avgrtt = rt->rt_stats->nstat_avg_rtt; |
2213 | } |
2214 | RT_UNLOCK(rt); |
2215 | rtfree(rt); |
2216 | rt = NULL; |
2217 | } |
2218 | |
2219 | /* ipv6 avg rtt */ |
2220 | bzero(&dst6, sizeof(dst6)); |
2221 | dst6.sin6_len = sizeof(dst6); |
2222 | dst6.sin6_family = AF_INET6; |
2223 | |
2224 | lck_mtx_lock(rnh_lock); |
2225 | rt = rt_lookup(TRUE,(struct sockaddr *)&dst6, NULL, |
2226 | rt_tables[AF_INET6], IFSCOPE_NONE); |
2227 | lck_mtx_unlock(rnh_lock); |
2228 | if (rt != NULL) { |
2229 | RT_LOCK(rt); |
2230 | if (rt_primary_default(rt, rt_key(rt)) && |
2231 | rt->rt_stats != NULL) { |
2232 | stat.ipv6_avgrtt = rt->rt_stats->nstat_avg_rtt; |
2233 | } |
2234 | RT_UNLOCK(rt); |
2235 | rtfree(rt); |
2236 | rt = NULL; |
2237 | } |
2238 | |
2239 | /* send packet loss rate, shift by 10 for precision */ |
2240 | if (tcpstat.tcps_sndpack > 0 && tcpstat.tcps_sndrexmitpack > 0) { |
2241 | var = tcpstat.tcps_sndrexmitpack << 10; |
2242 | stat.send_plr = (var * 100) / tcpstat.tcps_sndpack; |
2243 | } |
2244 | |
2245 | /* recv packet loss rate, shift by 10 for precision */ |
2246 | if (tcpstat.tcps_rcvpack > 0 && tcpstat.tcps_recovered_pkts > 0) { |
2247 | var = tcpstat.tcps_recovered_pkts << 10; |
2248 | stat.recv_plr = (var * 100) / tcpstat.tcps_rcvpack; |
2249 | } |
2250 | |
2251 | /* RTO after tail loss, shift by 10 for precision */ |
2252 | if (tcpstat.tcps_sndrexmitpack > 0 |
2253 | && tcpstat.tcps_tailloss_rto > 0) { |
2254 | var = tcpstat.tcps_tailloss_rto << 10; |
2255 | stat.send_tlrto_rate = |
2256 | (var * 100) / tcpstat.tcps_sndrexmitpack; |
2257 | } |
2258 | |
2259 | /* packet reordering */ |
2260 | if (tcpstat.tcps_sndpack > 0 && tcpstat.tcps_reordered_pkts > 0) { |
2261 | var = tcpstat.tcps_reordered_pkts << 10; |
2262 | stat.send_reorder_rate = |
2263 | (var * 100) / tcpstat.tcps_sndpack; |
2264 | } |
2265 | |
2266 | if (tcp_ecn_outbound == 1) |
2267 | stat.ecn_client_enabled = 1; |
2268 | if (tcp_ecn_inbound == 1) |
2269 | stat.ecn_server_enabled = 1; |
2270 | tcp_cumulative_stat(tcpstat.tcps_connattempt, |
2271 | &prev.tcps_connattempt, &stat.connection_attempts); |
2272 | tcp_cumulative_stat(tcpstat.tcps_accepts, |
2273 | &prev.tcps_accepts, &stat.connection_accepts); |
2274 | tcp_cumulative_stat(tcpstat.tcps_ecn_client_setup, |
2275 | &prev.tcps_ecn_client_setup, &stat.ecn_client_setup); |
2276 | tcp_cumulative_stat(tcpstat.tcps_ecn_server_setup, |
2277 | &prev.tcps_ecn_server_setup, &stat.ecn_server_setup); |
2278 | tcp_cumulative_stat(tcpstat.tcps_ecn_client_success, |
2279 | &prev.tcps_ecn_client_success, &stat.ecn_client_success); |
2280 | tcp_cumulative_stat(tcpstat.tcps_ecn_server_success, |
2281 | &prev.tcps_ecn_server_success, &stat.ecn_server_success); |
2282 | tcp_cumulative_stat(tcpstat.tcps_ecn_not_supported, |
2283 | &prev.tcps_ecn_not_supported, &stat.ecn_not_supported); |
2284 | tcp_cumulative_stat(tcpstat.tcps_ecn_lost_syn, |
2285 | &prev.tcps_ecn_lost_syn, &stat.ecn_lost_syn); |
2286 | tcp_cumulative_stat(tcpstat.tcps_ecn_lost_synack, |
2287 | &prev.tcps_ecn_lost_synack, &stat.ecn_lost_synack); |
2288 | tcp_cumulative_stat(tcpstat.tcps_ecn_recv_ce, |
2289 | &prev.tcps_ecn_recv_ce, &stat.ecn_recv_ce); |
2290 | tcp_cumulative_stat(tcpstat.tcps_ecn_recv_ece, |
2291 | &prev.tcps_ecn_recv_ece, &stat.ecn_recv_ece); |
2292 | tcp_cumulative_stat(tcpstat.tcps_ecn_recv_ece, |
2293 | &prev.tcps_ecn_recv_ece, &stat.ecn_recv_ece); |
2294 | tcp_cumulative_stat(tcpstat.tcps_ecn_sent_ece, |
2295 | &prev.tcps_ecn_sent_ece, &stat.ecn_sent_ece); |
2296 | tcp_cumulative_stat(tcpstat.tcps_ecn_sent_ece, |
2297 | &prev.tcps_ecn_sent_ece, &stat.ecn_sent_ece); |
2298 | tcp_cumulative_stat(tcpstat.tcps_ecn_conn_recv_ce, |
2299 | &prev.tcps_ecn_conn_recv_ce, &stat.ecn_conn_recv_ce); |
2300 | tcp_cumulative_stat(tcpstat.tcps_ecn_conn_recv_ece, |
2301 | &prev.tcps_ecn_conn_recv_ece, &stat.ecn_conn_recv_ece); |
2302 | tcp_cumulative_stat(tcpstat.tcps_ecn_conn_plnoce, |
2303 | &prev.tcps_ecn_conn_plnoce, &stat.ecn_conn_plnoce); |
2304 | tcp_cumulative_stat(tcpstat.tcps_ecn_conn_pl_ce, |
2305 | &prev.tcps_ecn_conn_pl_ce, &stat.ecn_conn_pl_ce); |
2306 | tcp_cumulative_stat(tcpstat.tcps_ecn_conn_nopl_ce, |
2307 | &prev.tcps_ecn_conn_nopl_ce, &stat.ecn_conn_nopl_ce); |
2308 | tcp_cumulative_stat(tcpstat.tcps_ecn_fallback_synloss, |
2309 | &prev.tcps_ecn_fallback_synloss, &stat.ecn_fallback_synloss); |
2310 | tcp_cumulative_stat(tcpstat.tcps_ecn_fallback_reorder, |
2311 | &prev.tcps_ecn_fallback_reorder, &stat.ecn_fallback_reorder); |
2312 | tcp_cumulative_stat(tcpstat.tcps_ecn_fallback_ce, |
2313 | &prev.tcps_ecn_fallback_ce, &stat.ecn_fallback_ce); |
2314 | tcp_cumulative_stat(tcpstat.tcps_tfo_syn_data_rcv, |
2315 | &prev.tcps_tfo_syn_data_rcv, &stat.tfo_syn_data_rcv); |
2316 | tcp_cumulative_stat(tcpstat.tcps_tfo_cookie_req_rcv, |
2317 | &prev.tcps_tfo_cookie_req_rcv, &stat.tfo_cookie_req_rcv); |
2318 | tcp_cumulative_stat(tcpstat.tcps_tfo_cookie_sent, |
2319 | &prev.tcps_tfo_cookie_sent, &stat.tfo_cookie_sent); |
2320 | tcp_cumulative_stat(tcpstat.tcps_tfo_cookie_invalid, |
2321 | &prev.tcps_tfo_cookie_invalid, &stat.tfo_cookie_invalid); |
2322 | tcp_cumulative_stat(tcpstat.tcps_tfo_cookie_req, |
2323 | &prev.tcps_tfo_cookie_req, &stat.tfo_cookie_req); |
2324 | tcp_cumulative_stat(tcpstat.tcps_tfo_cookie_rcv, |
2325 | &prev.tcps_tfo_cookie_rcv, &stat.tfo_cookie_rcv); |
2326 | tcp_cumulative_stat(tcpstat.tcps_tfo_syn_data_sent, |
2327 | &prev.tcps_tfo_syn_data_sent, &stat.tfo_syn_data_sent); |
2328 | tcp_cumulative_stat(tcpstat.tcps_tfo_syn_data_acked, |
2329 | &prev.tcps_tfo_syn_data_acked, &stat.tfo_syn_data_acked); |
2330 | tcp_cumulative_stat(tcpstat.tcps_tfo_syn_loss, |
2331 | &prev.tcps_tfo_syn_loss, &stat.tfo_syn_loss); |
2332 | tcp_cumulative_stat(tcpstat.tcps_tfo_blackhole, |
2333 | &prev.tcps_tfo_blackhole, &stat.tfo_blackhole); |
2334 | tcp_cumulative_stat(tcpstat.tcps_tfo_cookie_wrong, |
2335 | &prev.tcps_tfo_cookie_wrong, &stat.tfo_cookie_wrong); |
2336 | tcp_cumulative_stat(tcpstat.tcps_tfo_no_cookie_rcv, |
2337 | &prev.tcps_tfo_no_cookie_rcv, &stat.tfo_no_cookie_rcv); |
2338 | tcp_cumulative_stat(tcpstat.tcps_tfo_heuristics_disable, |
2339 | &prev.tcps_tfo_heuristics_disable, &stat.tfo_heuristics_disable); |
2340 | tcp_cumulative_stat(tcpstat.tcps_tfo_sndblackhole, |
2341 | &prev.tcps_tfo_sndblackhole, &stat.tfo_sndblackhole); |
2342 | |
2343 | |
2344 | tcp_cumulative_stat(tcpstat.tcps_mptcp_handover_attempt, |
2345 | &prev.tcps_mptcp_handover_attempt , &stat.mptcp_handover_attempt); |
2346 | tcp_cumulative_stat(tcpstat.tcps_mptcp_interactive_attempt, |
2347 | &prev.tcps_mptcp_interactive_attempt , &stat.mptcp_interactive_attempt); |
2348 | tcp_cumulative_stat(tcpstat.tcps_mptcp_aggregate_attempt, |
2349 | &prev.tcps_mptcp_aggregate_attempt , &stat.mptcp_aggregate_attempt); |
2350 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_handover_attempt, |
2351 | &prev.tcps_mptcp_fp_handover_attempt , &stat.mptcp_fp_handover_attempt); |
2352 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_interactive_attempt, |
2353 | &prev.tcps_mptcp_fp_interactive_attempt , &stat.mptcp_fp_interactive_attempt); |
2354 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_aggregate_attempt, |
2355 | &prev.tcps_mptcp_fp_aggregate_attempt , &stat.mptcp_fp_aggregate_attempt); |
2356 | tcp_cumulative_stat(tcpstat.tcps_mptcp_heuristic_fallback, |
2357 | &prev.tcps_mptcp_heuristic_fallback , &stat.mptcp_heuristic_fallback); |
2358 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_heuristic_fallback, |
2359 | &prev.tcps_mptcp_fp_heuristic_fallback , &stat.mptcp_fp_heuristic_fallback); |
2360 | tcp_cumulative_stat(tcpstat.tcps_mptcp_handover_success_wifi, |
2361 | &prev.tcps_mptcp_handover_success_wifi , &stat.mptcp_handover_success_wifi); |
2362 | tcp_cumulative_stat(tcpstat.tcps_mptcp_handover_success_cell, |
2363 | &prev.tcps_mptcp_handover_success_cell , &stat.mptcp_handover_success_cell); |
2364 | tcp_cumulative_stat(tcpstat.tcps_mptcp_interactive_success, |
2365 | &prev.tcps_mptcp_interactive_success , &stat.mptcp_interactive_success); |
2366 | tcp_cumulative_stat(tcpstat.tcps_mptcp_aggregate_success, |
2367 | &prev.tcps_mptcp_aggregate_success , &stat.mptcp_aggregate_success); |
2368 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_handover_success_wifi, |
2369 | &prev.tcps_mptcp_fp_handover_success_wifi , &stat.mptcp_fp_handover_success_wifi); |
2370 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_handover_success_cell, |
2371 | &prev.tcps_mptcp_fp_handover_success_cell , &stat.mptcp_fp_handover_success_cell); |
2372 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_interactive_success, |
2373 | &prev.tcps_mptcp_fp_interactive_success , &stat.mptcp_fp_interactive_success); |
2374 | tcp_cumulative_stat(tcpstat.tcps_mptcp_fp_aggregate_success, |
2375 | &prev.tcps_mptcp_fp_aggregate_success , &stat.mptcp_fp_aggregate_success); |
2376 | tcp_cumulative_stat(tcpstat.tcps_mptcp_handover_cell_from_wifi, |
2377 | &prev.tcps_mptcp_handover_cell_from_wifi , &stat.mptcp_handover_cell_from_wifi); |
2378 | tcp_cumulative_stat(tcpstat.tcps_mptcp_handover_wifi_from_cell, |
2379 | &prev.tcps_mptcp_handover_wifi_from_cell , &stat.mptcp_handover_wifi_from_cell); |
2380 | tcp_cumulative_stat(tcpstat.tcps_mptcp_interactive_cell_from_wifi, |
2381 | &prev.tcps_mptcp_interactive_cell_from_wifi , &stat.mptcp_interactive_cell_from_wifi); |
2382 | tcp_cumulative_stat64(tcpstat.tcps_mptcp_handover_cell_bytes, |
2383 | &prev.tcps_mptcp_handover_cell_bytes , &stat.mptcp_handover_cell_bytes); |
2384 | tcp_cumulative_stat64(tcpstat.tcps_mptcp_interactive_cell_bytes, |
2385 | &prev.tcps_mptcp_interactive_cell_bytes , &stat.mptcp_interactive_cell_bytes); |
2386 | tcp_cumulative_stat64(tcpstat.tcps_mptcp_aggregate_cell_bytes, |
2387 | &prev.tcps_mptcp_aggregate_cell_bytes , &stat.mptcp_aggregate_cell_bytes); |
2388 | tcp_cumulative_stat64(tcpstat.tcps_mptcp_handover_all_bytes, |
2389 | &prev.tcps_mptcp_handover_all_bytes , &stat.mptcp_handover_all_bytes); |
2390 | tcp_cumulative_stat64(tcpstat.tcps_mptcp_interactive_all_bytes, |
2391 | &prev.tcps_mptcp_interactive_all_bytes , &stat.mptcp_interactive_all_bytes); |
2392 | tcp_cumulative_stat64(tcpstat.tcps_mptcp_aggregate_all_bytes, |
2393 | &prev.tcps_mptcp_aggregate_all_bytes , &stat.mptcp_aggregate_all_bytes); |
2394 | tcp_cumulative_stat(tcpstat.tcps_mptcp_back_to_wifi, |
2395 | &prev.tcps_mptcp_back_to_wifi , &stat.mptcp_back_to_wifi); |
2396 | tcp_cumulative_stat(tcpstat.tcps_mptcp_wifi_proxy, |
2397 | &prev.tcps_mptcp_wifi_proxy , &stat.mptcp_wifi_proxy); |
2398 | tcp_cumulative_stat(tcpstat.tcps_mptcp_cell_proxy, |
2399 | &prev.tcps_mptcp_cell_proxy , &stat.mptcp_cell_proxy); |
2400 | tcp_cumulative_stat(tcpstat.tcps_mptcp_triggered_cell, |
2401 | &prev.tcps_mptcp_triggered_cell, &stat.mptcp_triggered_cell); |
2402 | |
2403 | nstat_sysinfo_send_data(&data); |
2404 | |
2405 | #undef stat |
2406 | } |
2407 | |
2408 | void |
2409 | tcp_interface_send_probe(u_int16_t probe_if_index) |
2410 | { |
2411 | int32_t offset = 0; |
2412 | struct tcptimerlist *listp = &tcp_timer_list; |
2413 | |
2414 | /* Make sure TCP clock is up to date */ |
2415 | calculate_tcp_clock(); |
2416 | |
2417 | lck_mtx_lock(listp->mtx); |
2418 | if (listp->probe_if_index > 0) { |
2419 | tcpstat.tcps_probe_if_conflict++; |
2420 | goto done; |
2421 | } |
2422 | |
2423 | listp->probe_if_index = probe_if_index; |
2424 | if (listp->running) |
2425 | goto done; |
2426 | |
2427 | /* |
2428 | * Reschedule the timerlist to run within the next 10ms, which is |
2429 | * the fastest that we can do. |
2430 | */ |
2431 | offset = TCP_TIMER_10MS_QUANTUM; |
2432 | if (listp->scheduled) { |
2433 | int32_t diff; |
2434 | diff = timer_diff(listp->runtime, 0, tcp_now, offset); |
2435 | if (diff <= 0) { |
2436 | /* The timer will fire sooner than what's needed */ |
2437 | goto done; |
2438 | } |
2439 | } |
2440 | listp->mode = TCP_TIMERLIST_10MS_MODE; |
2441 | listp->idleruns = 0; |
2442 | |
2443 | tcp_sched_timerlist(offset); |
2444 | |
2445 | done: |
2446 | lck_mtx_unlock(listp->mtx); |
2447 | return; |
2448 | } |
2449 | |
2450 | /* |
2451 | * Enable read probes on this connection, if: |
2452 | * - it is in established state |
2453 | * - doesn't have any data outstanding |
2454 | * - the outgoing ifp matches |
2455 | * - we have not already sent any read probes |
2456 | */ |
2457 | static void |
2458 | tcp_enable_read_probe(struct tcpcb *tp, struct ifnet *ifp) |
2459 | { |
2460 | if (tp->t_state == TCPS_ESTABLISHED && |
2461 | tp->snd_max == tp->snd_una && |
2462 | tp->t_inpcb->inp_last_outifp == ifp && |
2463 | !(tp->t_flagsext & TF_DETECT_READSTALL) && |
2464 | tp->t_rtimo_probes == 0) { |
2465 | tp->t_flagsext |= TF_DETECT_READSTALL; |
2466 | tp->t_rtimo_probes = 0; |
2467 | tp->t_timer[TCPT_KEEP] = OFFSET_FROM_START(tp, |
2468 | TCP_TIMER_10MS_QUANTUM); |
2469 | if (tp->tentry.index == TCPT_NONE) { |
2470 | tp->tentry.index = TCPT_KEEP; |
2471 | tp->tentry.runtime = tcp_now + |
2472 | TCP_TIMER_10MS_QUANTUM; |
2473 | } else { |
2474 | int32_t diff = 0; |
2475 | |
2476 | /* Reset runtime to be in next 10ms */ |
2477 | diff = timer_diff(tp->tentry.runtime, 0, |
2478 | tcp_now, TCP_TIMER_10MS_QUANTUM); |
2479 | if (diff > 0) { |
2480 | tp->tentry.index = TCPT_KEEP; |
2481 | tp->tentry.runtime = tcp_now + |
2482 | TCP_TIMER_10MS_QUANTUM; |
2483 | if (tp->tentry.runtime == 0) |
2484 | tp->tentry.runtime++; |
2485 | } |
2486 | } |
2487 | } |
2488 | } |
2489 | |
2490 | /* |
2491 | * Disable read probe and reset the keep alive timer |
2492 | */ |
2493 | static void |
2494 | tcp_disable_read_probe(struct tcpcb *tp) |
2495 | { |
2496 | if (tp->t_adaptive_rtimo == 0 && |
2497 | ((tp->t_flagsext & TF_DETECT_READSTALL) || |
2498 | tp->t_rtimo_probes > 0)) { |
2499 | tcp_keepalive_reset(tp); |
2500 | |
2501 | if (tp->t_mpsub) |
2502 | mptcp_reset_keepalive(tp); |
2503 | } |
2504 | } |
2505 | |
2506 | /* |
2507 | * Reschedule the tcp timerlist in the next 10ms to re-enable read/write |
2508 | * probes on connections going over a particular interface. |
2509 | */ |
2510 | void |
2511 | tcp_probe_connectivity(struct ifnet *ifp, u_int32_t enable) |
2512 | { |
2513 | int32_t offset; |
2514 | struct tcptimerlist *listp = &tcp_timer_list; |
2515 | struct inpcbinfo *pcbinfo = &tcbinfo; |
2516 | struct inpcb *inp, *nxt; |
2517 | |
2518 | if (ifp == NULL) |
2519 | return; |
2520 | |
2521 | /* update clock */ |
2522 | calculate_tcp_clock(); |
2523 | |
2524 | /* |
2525 | * Enable keep alive timer on all connections that are |
2526 | * active/established on this interface. |
2527 | */ |
2528 | lck_rw_lock_shared(pcbinfo->ipi_lock); |
2529 | |
2530 | LIST_FOREACH_SAFE(inp, pcbinfo->ipi_listhead, inp_list, nxt) { |
2531 | struct tcpcb *tp = NULL; |
2532 | if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == |
2533 | WNT_STOPUSING) |
2534 | continue; |
2535 | |
2536 | /* Acquire lock to look at the state of the connection */ |
2537 | socket_lock(inp->inp_socket, 1); |
2538 | |
2539 | /* Release the want count */ |
2540 | if (inp->inp_ppcb == NULL || |
2541 | (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING)) { |
2542 | socket_unlock(inp->inp_socket, 1); |
2543 | continue; |
2544 | } |
2545 | tp = intotcpcb(inp); |
2546 | if (enable) |
2547 | tcp_enable_read_probe(tp, ifp); |
2548 | else |
2549 | tcp_disable_read_probe(tp); |
2550 | |
2551 | socket_unlock(inp->inp_socket, 1); |
2552 | } |
2553 | lck_rw_done(pcbinfo->ipi_lock); |
2554 | |
2555 | lck_mtx_lock(listp->mtx); |
2556 | if (listp->running) { |
2557 | listp->pref_mode |= TCP_TIMERLIST_10MS_MODE; |
2558 | goto done; |
2559 | } |
2560 | |
2561 | /* Reschedule within the next 10ms */ |
2562 | offset = TCP_TIMER_10MS_QUANTUM; |
2563 | if (listp->scheduled) { |
2564 | int32_t diff; |
2565 | diff = timer_diff(listp->runtime, 0, tcp_now, offset); |
2566 | if (diff <= 0) { |
2567 | /* The timer will fire sooner than what's needed */ |
2568 | goto done; |
2569 | } |
2570 | } |
2571 | listp->mode = TCP_TIMERLIST_10MS_MODE; |
2572 | listp->idleruns = 0; |
2573 | |
2574 | tcp_sched_timerlist(offset); |
2575 | done: |
2576 | lck_mtx_unlock(listp->mtx); |
2577 | return; |
2578 | } |
2579 | |
2580 | inline void |
2581 | tcp_update_mss_core(struct tcpcb *tp, struct ifnet *ifp) |
2582 | { |
2583 | struct if_cellular_status_v1 *ifsr; |
2584 | u_int32_t optlen; |
2585 | ifsr = &ifp->if_link_status->ifsr_u.ifsr_cell.if_cell_u.if_status_v1; |
2586 | if (ifsr->valid_bitmask & IF_CELL_UL_MSS_RECOMMENDED_VALID) { |
2587 | optlen = tp->t_maxopd - tp->t_maxseg; |
2588 | |
2589 | if (ifsr->mss_recommended == |
2590 | IF_CELL_UL_MSS_RECOMMENDED_NONE && |
2591 | tp->t_cached_maxopd > 0 && |
2592 | tp->t_maxopd < tp->t_cached_maxopd) { |
2593 | tp->t_maxopd = tp->t_cached_maxopd; |
2594 | tcpstat.tcps_mss_to_default++; |
2595 | } else if (ifsr->mss_recommended == |
2596 | IF_CELL_UL_MSS_RECOMMENDED_MEDIUM && |
2597 | tp->t_maxopd > tcp_mss_rec_medium) { |
2598 | tp->t_cached_maxopd = tp->t_maxopd; |
2599 | tp->t_maxopd = tcp_mss_rec_medium; |
2600 | tcpstat.tcps_mss_to_medium++; |
2601 | } else if (ifsr->mss_recommended == |
2602 | IF_CELL_UL_MSS_RECOMMENDED_LOW && |
2603 | tp->t_maxopd > tcp_mss_rec_low) { |
2604 | tp->t_cached_maxopd = tp->t_maxopd; |
2605 | tp->t_maxopd = tcp_mss_rec_low; |
2606 | tcpstat.tcps_mss_to_low++; |
2607 | } |
2608 | tp->t_maxseg = tp->t_maxopd - optlen; |
2609 | |
2610 | /* |
2611 | * clear the cached value if it is same as the current |
2612 | */ |
2613 | if (tp->t_maxopd == tp->t_cached_maxopd) |
2614 | tp->t_cached_maxopd = 0; |
2615 | } |
2616 | } |
2617 | |
2618 | void |
2619 | tcp_update_mss_locked(struct socket *so, struct ifnet *ifp) |
2620 | { |
2621 | struct inpcb *inp = sotoinpcb(so); |
2622 | struct tcpcb *tp = intotcpcb(inp); |
2623 | |
2624 | if (ifp == NULL && (ifp = inp->inp_last_outifp) == NULL) |
2625 | return; |
2626 | |
2627 | if (!IFNET_IS_CELLULAR(ifp)) { |
2628 | /* |
2629 | * This optimization is implemented for cellular |
2630 | * networks only |
2631 | */ |
2632 | return; |
2633 | } |
2634 | if ( tp->t_state <= TCPS_CLOSE_WAIT) { |
2635 | /* |
2636 | * If the connection is currently doing or has done PMTU |
2637 | * blackhole detection, do not change the MSS |
2638 | */ |
2639 | if (tp->t_flags & TF_BLACKHOLE) |
2640 | return; |
2641 | if (ifp->if_link_status == NULL) |
2642 | return; |
2643 | tcp_update_mss_core(tp, ifp); |
2644 | } |
2645 | } |
2646 | |
2647 | void |
2648 | tcp_itimer(struct inpcbinfo *ipi) |
2649 | { |
2650 | struct inpcb *inp, *nxt; |
2651 | |
2652 | if (lck_rw_try_lock_exclusive(ipi->ipi_lock) == FALSE) { |
2653 | if (tcp_itimer_done == TRUE) { |
2654 | tcp_itimer_done = FALSE; |
2655 | atomic_add_32(&ipi->ipi_timer_req.intimer_fast, 1); |
2656 | return; |
2657 | } |
2658 | /* Upgrade failed, lost lock now take it again exclusive */ |
2659 | lck_rw_lock_exclusive(ipi->ipi_lock); |
2660 | } |
2661 | tcp_itimer_done = TRUE; |
2662 | |
2663 | LIST_FOREACH_SAFE(inp, &tcb, inp_list, nxt) { |
2664 | struct socket *so; |
2665 | struct ifnet *ifp; |
2666 | |
2667 | if (inp->inp_ppcb == NULL || |
2668 | in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING) |
2669 | continue; |
2670 | so = inp->inp_socket; |
2671 | ifp = inp->inp_last_outifp; |
2672 | socket_lock(so, 1); |
2673 | if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) { |
2674 | socket_unlock(so, 1); |
2675 | continue; |
2676 | } |
2677 | so_check_extended_bk_idle_time(so); |
2678 | if (ipi->ipi_flags & INPCBINFO_UPDATE_MSS) { |
2679 | tcp_update_mss_locked(so, NULL); |
2680 | } |
2681 | socket_unlock(so, 1); |
2682 | |
2683 | /* |
2684 | * Defunct all system-initiated background sockets if the |
2685 | * socket is using the cellular interface and the interface |
2686 | * has its LQM set to abort. |
2687 | */ |
2688 | if ((ipi->ipi_flags & INPCBINFO_HANDLE_LQM_ABORT) && |
2689 | IS_SO_TC_BACKGROUNDSYSTEM(so->so_traffic_class) && |
2690 | ifp != NULL && IFNET_IS_CELLULAR(ifp) && |
2691 | (ifp->if_interface_state.valid_bitmask & |
2692 | IF_INTERFACE_STATE_LQM_STATE_VALID) && |
2693 | ifp->if_interface_state.lqm_state == |
2694 | IFNET_LQM_THRESH_ABORT) { |
2695 | socket_defunct(current_proc(), so, |
2696 | SHUTDOWN_SOCKET_LEVEL_DISCONNECT_ALL); |
2697 | } |
2698 | } |
2699 | |
2700 | ipi->ipi_flags &= ~(INPCBINFO_UPDATE_MSS | INPCBINFO_HANDLE_LQM_ABORT); |
2701 | lck_rw_done(ipi->ipi_lock); |
2702 | } |
2703 | |