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ac79cbb9 | 1 | /* Copyright (C) 2012-2017 B.A.T.M.A.N. contributors: |
33a3bb4a AQ |
2 | * |
3 | * Edo Monticelli, Antonio Quartulli | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of version 2 of the GNU General Public | |
7 | * License as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | #include "tp_meter.h" | |
19 | #include "main.h" | |
20 | ||
21 | #include <linux/atomic.h> | |
22 | #include <linux/bug.h> | |
23 | #include <linux/byteorder/generic.h> | |
24 | #include <linux/cache.h> | |
25 | #include <linux/compiler.h> | |
3e7514af | 26 | #include <linux/err.h> |
33a3bb4a AQ |
27 | #include <linux/etherdevice.h> |
28 | #include <linux/fs.h> | |
29 | #include <linux/if_ether.h> | |
d1aa5142 | 30 | #include <linux/init.h> |
33a3bb4a AQ |
31 | #include <linux/jiffies.h> |
32 | #include <linux/kernel.h> | |
33 | #include <linux/kref.h> | |
34 | #include <linux/kthread.h> | |
35 | #include <linux/list.h> | |
36 | #include <linux/netdevice.h> | |
37 | #include <linux/param.h> | |
38 | #include <linux/printk.h> | |
39 | #include <linux/random.h> | |
40 | #include <linux/rculist.h> | |
41 | #include <linux/rcupdate.h> | |
42 | #include <linux/sched.h> | |
43 | #include <linux/skbuff.h> | |
44 | #include <linux/slab.h> | |
45 | #include <linux/spinlock.h> | |
46 | #include <linux/stddef.h> | |
47 | #include <linux/string.h> | |
48 | #include <linux/timer.h> | |
49 | #include <linux/wait.h> | |
50 | #include <linux/workqueue.h> | |
51 | #include <uapi/linux/batman_adv.h> | |
52 | ||
53 | #include "hard-interface.h" | |
54 | #include "log.h" | |
55 | #include "netlink.h" | |
56 | #include "originator.h" | |
57 | #include "packet.h" | |
58 | #include "send.h" | |
59 | ||
60 | /** | |
61 | * BATADV_TP_DEF_TEST_LENGTH - Default test length if not specified by the user | |
62 | * in milliseconds | |
63 | */ | |
64 | #define BATADV_TP_DEF_TEST_LENGTH 10000 | |
65 | ||
66 | /** | |
67 | * BATADV_TP_AWND - Advertised window by the receiver (in bytes) | |
68 | */ | |
69 | #define BATADV_TP_AWND 0x20000000 | |
70 | ||
71 | /** | |
72 | * BATADV_TP_RECV_TIMEOUT - Receiver activity timeout. If the receiver does not | |
73 | * get anything for such amount of milliseconds, the connection is killed | |
74 | */ | |
75 | #define BATADV_TP_RECV_TIMEOUT 1000 | |
76 | ||
77 | /** | |
78 | * BATADV_TP_MAX_RTO - Maximum sender timeout. If the sender RTO gets beyond | |
79 | * such amound of milliseconds, the receiver is considered unreachable and the | |
80 | * connection is killed | |
81 | */ | |
82 | #define BATADV_TP_MAX_RTO 30000 | |
83 | ||
84 | /** | |
85 | * BATADV_TP_FIRST_SEQ - First seqno of each session. The number is rather high | |
86 | * in order to immediately trigger a wrap around (test purposes) | |
87 | */ | |
88 | #define BATADV_TP_FIRST_SEQ ((u32)-1 - 2000) | |
89 | ||
90 | /** | |
91 | * BATADV_TP_PLEN - length of the payload (data after the batadv_unicast header) | |
92 | * to simulate | |
93 | */ | |
94 | #define BATADV_TP_PLEN (BATADV_TP_PACKET_LEN - ETH_HLEN - \ | |
95 | sizeof(struct batadv_unicast_packet)) | |
96 | ||
97 | static u8 batadv_tp_prerandom[4096] __read_mostly; | |
98 | ||
99 | /** | |
100 | * batadv_tp_session_cookie - generate session cookie based on session ids | |
101 | * @session: TP session identifier | |
102 | * @icmp_uid: icmp pseudo uid of the tp session | |
103 | * | |
104 | * Return: 32 bit tp_meter session cookie | |
105 | */ | |
106 | static u32 batadv_tp_session_cookie(const u8 session[2], u8 icmp_uid) | |
107 | { | |
108 | u32 cookie; | |
109 | ||
110 | cookie = icmp_uid << 16; | |
111 | cookie |= session[0] << 8; | |
112 | cookie |= session[1]; | |
113 | ||
114 | return cookie; | |
115 | } | |
116 | ||
117 | /** | |
118 | * batadv_tp_cwnd - compute the new cwnd size | |
119 | * @base: base cwnd size value | |
120 | * @increment: the value to add to base to get the new size | |
121 | * @min: minumim cwnd value (usually MSS) | |
122 | * | |
123 | * Return the new cwnd size and ensures it does not exceed the Advertised | |
124 | * Receiver Window size. It is wrap around safe. | |
125 | * For details refer to Section 3.1 of RFC5681 | |
126 | * | |
127 | * Return: new congestion window size in bytes | |
128 | */ | |
129 | static u32 batadv_tp_cwnd(u32 base, u32 increment, u32 min) | |
130 | { | |
131 | u32 new_size = base + increment; | |
132 | ||
133 | /* check for wrap-around */ | |
134 | if (new_size < base) | |
135 | new_size = (u32)ULONG_MAX; | |
136 | ||
137 | new_size = min_t(u32, new_size, BATADV_TP_AWND); | |
138 | ||
139 | return max_t(u32, new_size, min); | |
140 | } | |
141 | ||
142 | /** | |
143 | * batadv_tp_updated_cwnd - update the Congestion Windows | |
144 | * @tp_vars: the private data of the current TP meter session | |
145 | * @mss: maximum segment size of transmission | |
146 | * | |
147 | * 1) if the session is in Slow Start, the CWND has to be increased by 1 | |
148 | * MSS every unique received ACK | |
149 | * 2) if the session is in Congestion Avoidance, the CWND has to be | |
150 | * increased by MSS * MSS / CWND for every unique received ACK | |
151 | */ | |
152 | static void batadv_tp_update_cwnd(struct batadv_tp_vars *tp_vars, u32 mss) | |
153 | { | |
154 | spin_lock_bh(&tp_vars->cwnd_lock); | |
155 | ||
156 | /* slow start... */ | |
157 | if (tp_vars->cwnd <= tp_vars->ss_threshold) { | |
158 | tp_vars->dec_cwnd = 0; | |
159 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss); | |
160 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
161 | return; | |
162 | } | |
163 | ||
164 | /* increment CWND at least of 1 (section 3.1 of RFC5681) */ | |
165 | tp_vars->dec_cwnd += max_t(u32, 1U << 3, | |
166 | ((mss * mss) << 6) / (tp_vars->cwnd << 3)); | |
167 | if (tp_vars->dec_cwnd < (mss << 3)) { | |
168 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
169 | return; | |
170 | } | |
171 | ||
172 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss); | |
173 | tp_vars->dec_cwnd = 0; | |
174 | ||
175 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
176 | } | |
177 | ||
178 | /** | |
179 | * batadv_tp_update_rto - calculate new retransmission timeout | |
180 | * @tp_vars: the private data of the current TP meter session | |
181 | * @new_rtt: new roundtrip time in msec | |
182 | */ | |
183 | static void batadv_tp_update_rto(struct batadv_tp_vars *tp_vars, | |
184 | u32 new_rtt) | |
185 | { | |
186 | long m = new_rtt; | |
187 | ||
188 | /* RTT update | |
189 | * Details in Section 2.2 and 2.3 of RFC6298 | |
190 | * | |
191 | * It's tricky to understand. Don't lose hair please. | |
192 | * Inspired by tcp_rtt_estimator() tcp_input.c | |
193 | */ | |
194 | if (tp_vars->srtt != 0) { | |
195 | m -= (tp_vars->srtt >> 3); /* m is now error in rtt est */ | |
196 | tp_vars->srtt += m; /* rtt = 7/8 srtt + 1/8 new */ | |
197 | if (m < 0) | |
198 | m = -m; | |
199 | ||
200 | m -= (tp_vars->rttvar >> 2); | |
201 | tp_vars->rttvar += m; /* mdev ~= 3/4 rttvar + 1/4 new */ | |
202 | } else { | |
203 | /* first measure getting in */ | |
204 | tp_vars->srtt = m << 3; /* take the measured time to be srtt */ | |
205 | tp_vars->rttvar = m << 1; /* new_rtt / 2 */ | |
206 | } | |
207 | ||
208 | /* rto = srtt + 4 * rttvar. | |
209 | * rttvar is scaled by 4, therefore doesn't need to be multiplied | |
210 | */ | |
211 | tp_vars->rto = (tp_vars->srtt >> 3) + tp_vars->rttvar; | |
212 | } | |
213 | ||
214 | /** | |
215 | * batadv_tp_batctl_notify - send client status result to client | |
216 | * @reason: reason for tp meter session stop | |
217 | * @dst: destination of tp_meter session | |
218 | * @bat_priv: the bat priv with all the soft interface information | |
219 | * @start_time: start of transmission in jiffies | |
220 | * @total_sent: bytes acked to the receiver | |
221 | * @cookie: cookie of tp_meter session | |
222 | */ | |
223 | static void batadv_tp_batctl_notify(enum batadv_tp_meter_reason reason, | |
224 | const u8 *dst, struct batadv_priv *bat_priv, | |
225 | unsigned long start_time, u64 total_sent, | |
226 | u32 cookie) | |
227 | { | |
228 | u32 test_time; | |
229 | u8 result; | |
230 | u32 total_bytes; | |
231 | ||
232 | if (!batadv_tp_is_error(reason)) { | |
233 | result = BATADV_TP_REASON_COMPLETE; | |
234 | test_time = jiffies_to_msecs(jiffies - start_time); | |
235 | total_bytes = total_sent; | |
236 | } else { | |
237 | result = reason; | |
238 | test_time = 0; | |
239 | total_bytes = 0; | |
240 | } | |
241 | ||
242 | batadv_netlink_tpmeter_notify(bat_priv, dst, result, test_time, | |
243 | total_bytes, cookie); | |
244 | } | |
245 | ||
246 | /** | |
247 | * batadv_tp_batctl_error_notify - send client error result to client | |
248 | * @reason: reason for tp meter session stop | |
249 | * @dst: destination of tp_meter session | |
250 | * @bat_priv: the bat priv with all the soft interface information | |
251 | * @cookie: cookie of tp_meter session | |
252 | */ | |
253 | static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason, | |
254 | const u8 *dst, | |
255 | struct batadv_priv *bat_priv, | |
256 | u32 cookie) | |
257 | { | |
258 | batadv_tp_batctl_notify(reason, dst, bat_priv, 0, 0, cookie); | |
259 | } | |
260 | ||
261 | /** | |
262 | * batadv_tp_list_find - find a tp_vars object in the global list | |
263 | * @bat_priv: the bat priv with all the soft interface information | |
264 | * @dst: the other endpoint MAC address to look for | |
265 | * | |
266 | * Look for a tp_vars object matching dst as end_point and return it after | |
267 | * having incremented the refcounter. Return NULL is not found | |
268 | * | |
269 | * Return: matching tp_vars or NULL when no tp_vars with @dst was found | |
270 | */ | |
271 | static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, | |
272 | const u8 *dst) | |
273 | { | |
274 | struct batadv_tp_vars *pos, *tp_vars = NULL; | |
275 | ||
276 | rcu_read_lock(); | |
277 | hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) { | |
278 | if (!batadv_compare_eth(pos->other_end, dst)) | |
279 | continue; | |
280 | ||
281 | /* most of the time this function is invoked during the normal | |
282 | * process..it makes sens to pay more when the session is | |
283 | * finished and to speed the process up during the measurement | |
284 | */ | |
285 | if (unlikely(!kref_get_unless_zero(&pos->refcount))) | |
286 | continue; | |
287 | ||
288 | tp_vars = pos; | |
289 | break; | |
290 | } | |
291 | rcu_read_unlock(); | |
292 | ||
293 | return tp_vars; | |
294 | } | |
295 | ||
296 | /** | |
297 | * batadv_tp_list_find_session - find tp_vars session object in the global list | |
298 | * @bat_priv: the bat priv with all the soft interface information | |
299 | * @dst: the other endpoint MAC address to look for | |
300 | * @session: session identifier | |
301 | * | |
302 | * Look for a tp_vars object matching dst as end_point, session as tp meter | |
303 | * session and return it after having incremented the refcounter. Return NULL | |
304 | * is not found | |
305 | * | |
306 | * Return: matching tp_vars or NULL when no tp_vars was found | |
307 | */ | |
308 | static struct batadv_tp_vars * | |
309 | batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst, | |
310 | const u8 *session) | |
311 | { | |
312 | struct batadv_tp_vars *pos, *tp_vars = NULL; | |
313 | ||
314 | rcu_read_lock(); | |
315 | hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) { | |
316 | if (!batadv_compare_eth(pos->other_end, dst)) | |
317 | continue; | |
318 | ||
319 | if (memcmp(pos->session, session, sizeof(pos->session)) != 0) | |
320 | continue; | |
321 | ||
322 | /* most of the time this function is invoked during the normal | |
323 | * process..it makes sense to pay more when the session is | |
324 | * finished and to speed the process up during the measurement | |
325 | */ | |
326 | if (unlikely(!kref_get_unless_zero(&pos->refcount))) | |
327 | continue; | |
328 | ||
329 | tp_vars = pos; | |
330 | break; | |
331 | } | |
332 | rcu_read_unlock(); | |
333 | ||
334 | return tp_vars; | |
335 | } | |
336 | ||
337 | /** | |
338 | * batadv_tp_vars_release - release batadv_tp_vars from lists and queue for | |
339 | * free after rcu grace period | |
340 | * @ref: kref pointer of the batadv_tp_vars | |
341 | */ | |
342 | static void batadv_tp_vars_release(struct kref *ref) | |
343 | { | |
344 | struct batadv_tp_vars *tp_vars; | |
345 | struct batadv_tp_unacked *un, *safe; | |
346 | ||
347 | tp_vars = container_of(ref, struct batadv_tp_vars, refcount); | |
348 | ||
349 | /* lock should not be needed because this object is now out of any | |
350 | * context! | |
351 | */ | |
352 | spin_lock_bh(&tp_vars->unacked_lock); | |
353 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { | |
354 | list_del(&un->list); | |
355 | kfree(un); | |
356 | } | |
357 | spin_unlock_bh(&tp_vars->unacked_lock); | |
358 | ||
359 | kfree_rcu(tp_vars, rcu); | |
360 | } | |
361 | ||
362 | /** | |
363 | * batadv_tp_vars_put - decrement the batadv_tp_vars refcounter and possibly | |
364 | * release it | |
365 | * @tp_vars: the private data of the current TP meter session to be free'd | |
366 | */ | |
367 | static void batadv_tp_vars_put(struct batadv_tp_vars *tp_vars) | |
368 | { | |
369 | kref_put(&tp_vars->refcount, batadv_tp_vars_release); | |
370 | } | |
371 | ||
372 | /** | |
373 | * batadv_tp_sender_cleanup - cleanup sender data and drop and timer | |
374 | * @bat_priv: the bat priv with all the soft interface information | |
375 | * @tp_vars: the private data of the current TP meter session to cleanup | |
376 | */ | |
377 | static void batadv_tp_sender_cleanup(struct batadv_priv *bat_priv, | |
378 | struct batadv_tp_vars *tp_vars) | |
379 | { | |
380 | cancel_delayed_work(&tp_vars->finish_work); | |
381 | ||
382 | spin_lock_bh(&tp_vars->bat_priv->tp_list_lock); | |
383 | hlist_del_rcu(&tp_vars->list); | |
384 | spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock); | |
385 | ||
386 | /* drop list reference */ | |
387 | batadv_tp_vars_put(tp_vars); | |
388 | ||
389 | atomic_dec(&tp_vars->bat_priv->tp_num); | |
390 | ||
391 | /* kill the timer and remove its reference */ | |
392 | del_timer_sync(&tp_vars->timer); | |
393 | /* the worker might have rearmed itself therefore we kill it again. Note | |
394 | * that if the worker should run again before invoking the following | |
395 | * del_timer(), it would not re-arm itself once again because the status | |
396 | * is OFF now | |
397 | */ | |
398 | del_timer(&tp_vars->timer); | |
399 | batadv_tp_vars_put(tp_vars); | |
400 | } | |
401 | ||
402 | /** | |
403 | * batadv_tp_sender_end - print info about ended session and inform client | |
404 | * @bat_priv: the bat priv with all the soft interface information | |
405 | * @tp_vars: the private data of the current TP meter session | |
406 | */ | |
407 | static void batadv_tp_sender_end(struct batadv_priv *bat_priv, | |
408 | struct batadv_tp_vars *tp_vars) | |
409 | { | |
410 | u32 session_cookie; | |
411 | ||
412 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
413 | "Test towards %pM finished..shutting down (reason=%d)\n", | |
414 | tp_vars->other_end, tp_vars->reason); | |
415 | ||
416 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
417 | "Last timing stats: SRTT=%ums RTTVAR=%ums RTO=%ums\n", | |
418 | tp_vars->srtt >> 3, tp_vars->rttvar >> 2, tp_vars->rto); | |
419 | ||
420 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
421 | "Final values: cwnd=%u ss_threshold=%u\n", | |
422 | tp_vars->cwnd, tp_vars->ss_threshold); | |
423 | ||
424 | session_cookie = batadv_tp_session_cookie(tp_vars->session, | |
425 | tp_vars->icmp_uid); | |
426 | ||
427 | batadv_tp_batctl_notify(tp_vars->reason, | |
428 | tp_vars->other_end, | |
429 | bat_priv, | |
430 | tp_vars->start_time, | |
431 | atomic64_read(&tp_vars->tot_sent), | |
432 | session_cookie); | |
433 | } | |
434 | ||
435 | /** | |
436 | * batadv_tp_sender_shutdown - let sender thread/timer stop gracefully | |
437 | * @tp_vars: the private data of the current TP meter session | |
438 | * @reason: reason for tp meter session stop | |
439 | */ | |
440 | static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars, | |
441 | enum batadv_tp_meter_reason reason) | |
442 | { | |
443 | if (!atomic_dec_and_test(&tp_vars->sending)) | |
444 | return; | |
445 | ||
446 | tp_vars->reason = reason; | |
447 | } | |
448 | ||
449 | /** | |
450 | * batadv_tp_sender_finish - stop sender session after test_length was reached | |
451 | * @work: delayed work reference of the related tp_vars | |
452 | */ | |
453 | static void batadv_tp_sender_finish(struct work_struct *work) | |
454 | { | |
455 | struct delayed_work *delayed_work; | |
456 | struct batadv_tp_vars *tp_vars; | |
457 | ||
458 | delayed_work = to_delayed_work(work); | |
459 | tp_vars = container_of(delayed_work, struct batadv_tp_vars, | |
460 | finish_work); | |
461 | ||
462 | batadv_tp_sender_shutdown(tp_vars, BATADV_TP_REASON_COMPLETE); | |
463 | } | |
464 | ||
465 | /** | |
466 | * batadv_tp_reset_sender_timer - reschedule the sender timer | |
467 | * @tp_vars: the private TP meter data for this session | |
468 | * | |
469 | * Reschedule the timer using tp_vars->rto as delay | |
470 | */ | |
471 | static void batadv_tp_reset_sender_timer(struct batadv_tp_vars *tp_vars) | |
472 | { | |
473 | /* most of the time this function is invoked while normal packet | |
474 | * reception... | |
475 | */ | |
476 | if (unlikely(atomic_read(&tp_vars->sending) == 0)) | |
477 | /* timer ref will be dropped in batadv_tp_sender_cleanup */ | |
478 | return; | |
479 | ||
480 | mod_timer(&tp_vars->timer, jiffies + msecs_to_jiffies(tp_vars->rto)); | |
481 | } | |
482 | ||
483 | /** | |
484 | * batadv_tp_sender_timeout - timer that fires in case of packet loss | |
974a6b20 | 485 | * @t: address to timer_list inside tp_vars |
33a3bb4a AQ |
486 | * |
487 | * If fired it means that there was packet loss. | |
488 | * Switch to Slow Start, set the ss_threshold to half of the current cwnd and | |
489 | * reset the cwnd to 3*MSS | |
490 | */ | |
e99e88a9 | 491 | static void batadv_tp_sender_timeout(struct timer_list *t) |
33a3bb4a | 492 | { |
e99e88a9 | 493 | struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer); |
33a3bb4a AQ |
494 | struct batadv_priv *bat_priv = tp_vars->bat_priv; |
495 | ||
496 | if (atomic_read(&tp_vars->sending) == 0) | |
497 | return; | |
498 | ||
499 | /* if the user waited long enough...shutdown the test */ | |
500 | if (unlikely(tp_vars->rto >= BATADV_TP_MAX_RTO)) { | |
501 | batadv_tp_sender_shutdown(tp_vars, | |
502 | BATADV_TP_REASON_DST_UNREACHABLE); | |
503 | return; | |
504 | } | |
505 | ||
506 | /* RTO exponential backoff | |
507 | * Details in Section 5.5 of RFC6298 | |
508 | */ | |
509 | tp_vars->rto <<= 1; | |
510 | ||
511 | spin_lock_bh(&tp_vars->cwnd_lock); | |
512 | ||
513 | tp_vars->ss_threshold = tp_vars->cwnd >> 1; | |
514 | if (tp_vars->ss_threshold < BATADV_TP_PLEN * 2) | |
515 | tp_vars->ss_threshold = BATADV_TP_PLEN * 2; | |
516 | ||
517 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
518 | "Meter: RTO fired during test towards %pM! cwnd=%u new ss_thr=%u, resetting last_sent to %u\n", | |
519 | tp_vars->other_end, tp_vars->cwnd, tp_vars->ss_threshold, | |
520 | atomic_read(&tp_vars->last_acked)); | |
521 | ||
522 | tp_vars->cwnd = BATADV_TP_PLEN * 3; | |
523 | ||
524 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
525 | ||
526 | /* resend the non-ACKed packets.. */ | |
527 | tp_vars->last_sent = atomic_read(&tp_vars->last_acked); | |
528 | wake_up(&tp_vars->more_bytes); | |
529 | ||
530 | batadv_tp_reset_sender_timer(tp_vars); | |
531 | } | |
532 | ||
533 | /** | |
534 | * batadv_tp_fill_prerandom - Fill buffer with prefetched random bytes | |
535 | * @tp_vars: the private TP meter data for this session | |
536 | * @buf: Buffer to fill with bytes | |
537 | * @nbytes: amount of pseudorandom bytes | |
538 | */ | |
539 | static void batadv_tp_fill_prerandom(struct batadv_tp_vars *tp_vars, | |
540 | u8 *buf, size_t nbytes) | |
541 | { | |
542 | u32 local_offset; | |
543 | size_t bytes_inbuf; | |
544 | size_t to_copy; | |
545 | size_t pos = 0; | |
546 | ||
547 | spin_lock_bh(&tp_vars->prerandom_lock); | |
548 | local_offset = tp_vars->prerandom_offset; | |
549 | tp_vars->prerandom_offset += nbytes; | |
550 | tp_vars->prerandom_offset %= sizeof(batadv_tp_prerandom); | |
551 | spin_unlock_bh(&tp_vars->prerandom_lock); | |
552 | ||
553 | while (nbytes) { | |
554 | local_offset %= sizeof(batadv_tp_prerandom); | |
555 | bytes_inbuf = sizeof(batadv_tp_prerandom) - local_offset; | |
556 | to_copy = min(nbytes, bytes_inbuf); | |
557 | ||
558 | memcpy(&buf[pos], &batadv_tp_prerandom[local_offset], to_copy); | |
559 | pos += to_copy; | |
560 | nbytes -= to_copy; | |
561 | local_offset = 0; | |
562 | } | |
563 | } | |
564 | ||
565 | /** | |
566 | * batadv_tp_send_msg - send a single message | |
567 | * @tp_vars: the private TP meter data for this session | |
568 | * @src: source mac address | |
569 | * @orig_node: the originator of the destination | |
570 | * @seqno: sequence number of this packet | |
571 | * @len: length of the entire packet | |
572 | * @session: session identifier | |
573 | * @uid: local ICMP "socket" index | |
574 | * @timestamp: timestamp in jiffies which is replied in ack | |
575 | * | |
576 | * Create and send a single TP Meter message. | |
577 | * | |
578 | * Return: 0 on success, BATADV_TP_REASON_DST_UNREACHABLE if the destination is | |
579 | * not reachable, BATADV_TP_REASON_MEMORY_ERROR if the packet couldn't be | |
580 | * allocated | |
581 | */ | |
582 | static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src, | |
583 | struct batadv_orig_node *orig_node, | |
584 | u32 seqno, size_t len, const u8 *session, | |
585 | int uid, u32 timestamp) | |
586 | { | |
587 | struct batadv_icmp_tp_packet *icmp; | |
588 | struct sk_buff *skb; | |
589 | int r; | |
590 | u8 *data; | |
591 | size_t data_len; | |
592 | ||
593 | skb = netdev_alloc_skb_ip_align(NULL, len + ETH_HLEN); | |
594 | if (unlikely(!skb)) | |
595 | return BATADV_TP_REASON_MEMORY_ERROR; | |
596 | ||
597 | skb_reserve(skb, ETH_HLEN); | |
4df864c1 | 598 | icmp = skb_put(skb, sizeof(*icmp)); |
33a3bb4a AQ |
599 | |
600 | /* fill the icmp header */ | |
601 | ether_addr_copy(icmp->dst, orig_node->orig); | |
602 | ether_addr_copy(icmp->orig, src); | |
603 | icmp->version = BATADV_COMPAT_VERSION; | |
604 | icmp->packet_type = BATADV_ICMP; | |
605 | icmp->ttl = BATADV_TTL; | |
606 | icmp->msg_type = BATADV_TP; | |
607 | icmp->uid = uid; | |
608 | ||
609 | icmp->subtype = BATADV_TP_MSG; | |
610 | memcpy(icmp->session, session, sizeof(icmp->session)); | |
611 | icmp->seqno = htonl(seqno); | |
612 | icmp->timestamp = htonl(timestamp); | |
613 | ||
614 | data_len = len - sizeof(*icmp); | |
4df864c1 | 615 | data = skb_put(skb, data_len); |
33a3bb4a AQ |
616 | batadv_tp_fill_prerandom(tp_vars, data, data_len); |
617 | ||
618 | r = batadv_send_skb_to_orig(skb, orig_node, NULL); | |
33a3bb4a AQ |
619 | if (r == NET_XMIT_SUCCESS) |
620 | return 0; | |
621 | ||
622 | return BATADV_TP_REASON_CANT_SEND; | |
623 | } | |
624 | ||
625 | /** | |
626 | * batadv_tp_recv_ack - ACK receiving function | |
627 | * @bat_priv: the bat priv with all the soft interface information | |
628 | * @skb: the buffer containing the received packet | |
629 | * | |
630 | * Process a received TP ACK packet | |
631 | */ | |
632 | static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, | |
633 | const struct sk_buff *skb) | |
634 | { | |
635 | struct batadv_hard_iface *primary_if = NULL; | |
636 | struct batadv_orig_node *orig_node = NULL; | |
637 | const struct batadv_icmp_tp_packet *icmp; | |
638 | struct batadv_tp_vars *tp_vars; | |
639 | size_t packet_len, mss; | |
640 | u32 rtt, recv_ack, cwnd; | |
641 | unsigned char *dev_addr; | |
642 | ||
643 | packet_len = BATADV_TP_PLEN; | |
644 | mss = BATADV_TP_PLEN; | |
645 | packet_len += sizeof(struct batadv_unicast_packet); | |
646 | ||
647 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
648 | ||
649 | /* find the tp_vars */ | |
650 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, | |
651 | icmp->session); | |
652 | if (unlikely(!tp_vars)) | |
653 | return; | |
654 | ||
655 | if (unlikely(atomic_read(&tp_vars->sending) == 0)) | |
656 | goto out; | |
657 | ||
658 | /* old ACK? silently drop it.. */ | |
659 | if (batadv_seq_before(ntohl(icmp->seqno), | |
660 | (u32)atomic_read(&tp_vars->last_acked))) | |
661 | goto out; | |
662 | ||
663 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
664 | if (unlikely(!primary_if)) | |
665 | goto out; | |
666 | ||
667 | orig_node = batadv_orig_hash_find(bat_priv, icmp->orig); | |
668 | if (unlikely(!orig_node)) | |
669 | goto out; | |
670 | ||
671 | /* update RTO with the new sampled RTT, if any */ | |
672 | rtt = jiffies_to_msecs(jiffies) - ntohl(icmp->timestamp); | |
673 | if (icmp->timestamp && rtt) | |
674 | batadv_tp_update_rto(tp_vars, rtt); | |
675 | ||
676 | /* ACK for new data... reset the timer */ | |
677 | batadv_tp_reset_sender_timer(tp_vars); | |
678 | ||
679 | recv_ack = ntohl(icmp->seqno); | |
680 | ||
681 | /* check if this ACK is a duplicate */ | |
682 | if (atomic_read(&tp_vars->last_acked) == recv_ack) { | |
683 | atomic_inc(&tp_vars->dup_acks); | |
684 | if (atomic_read(&tp_vars->dup_acks) != 3) | |
685 | goto out; | |
686 | ||
687 | if (recv_ack >= tp_vars->recover) | |
688 | goto out; | |
689 | ||
690 | /* if this is the third duplicate ACK do Fast Retransmit */ | |
691 | batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, | |
692 | orig_node, recv_ack, packet_len, | |
693 | icmp->session, icmp->uid, | |
694 | jiffies_to_msecs(jiffies)); | |
695 | ||
696 | spin_lock_bh(&tp_vars->cwnd_lock); | |
697 | ||
698 | /* Fast Recovery */ | |
699 | tp_vars->fast_recovery = true; | |
700 | /* Set recover to the last outstanding seqno when Fast Recovery | |
701 | * is entered. RFC6582, Section 3.2, step 1 | |
702 | */ | |
703 | tp_vars->recover = tp_vars->last_sent; | |
704 | tp_vars->ss_threshold = tp_vars->cwnd >> 1; | |
705 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
706 | "Meter: Fast Recovery, (cur cwnd=%u) ss_thr=%u last_sent=%u recv_ack=%u\n", | |
707 | tp_vars->cwnd, tp_vars->ss_threshold, | |
708 | tp_vars->last_sent, recv_ack); | |
709 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 3 * mss, | |
710 | mss); | |
711 | tp_vars->dec_cwnd = 0; | |
712 | tp_vars->last_sent = recv_ack; | |
713 | ||
714 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
715 | } else { | |
716 | /* count the acked data */ | |
717 | atomic64_add(recv_ack - atomic_read(&tp_vars->last_acked), | |
718 | &tp_vars->tot_sent); | |
719 | /* reset the duplicate ACKs counter */ | |
720 | atomic_set(&tp_vars->dup_acks, 0); | |
721 | ||
722 | if (tp_vars->fast_recovery) { | |
723 | /* partial ACK */ | |
724 | if (batadv_seq_before(recv_ack, tp_vars->recover)) { | |
725 | /* this is another hole in the window. React | |
726 | * immediately as specified by NewReno (see | |
727 | * Section 3.2 of RFC6582 for details) | |
728 | */ | |
729 | dev_addr = primary_if->net_dev->dev_addr; | |
730 | batadv_tp_send_msg(tp_vars, dev_addr, | |
731 | orig_node, recv_ack, | |
732 | packet_len, icmp->session, | |
733 | icmp->uid, | |
734 | jiffies_to_msecs(jiffies)); | |
735 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, | |
736 | mss, mss); | |
737 | } else { | |
738 | tp_vars->fast_recovery = false; | |
739 | /* set cwnd to the value of ss_threshold at the | |
740 | * moment that Fast Recovery was entered. | |
741 | * RFC6582, Section 3.2, step 3 | |
742 | */ | |
743 | cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 0, | |
744 | mss); | |
745 | tp_vars->cwnd = cwnd; | |
746 | } | |
747 | goto move_twnd; | |
748 | } | |
749 | ||
750 | if (recv_ack - atomic_read(&tp_vars->last_acked) >= mss) | |
751 | batadv_tp_update_cwnd(tp_vars, mss); | |
752 | move_twnd: | |
753 | /* move the Transmit Window */ | |
754 | atomic_set(&tp_vars->last_acked, recv_ack); | |
755 | } | |
756 | ||
757 | wake_up(&tp_vars->more_bytes); | |
758 | out: | |
759 | if (likely(primary_if)) | |
760 | batadv_hardif_put(primary_if); | |
761 | if (likely(orig_node)) | |
762 | batadv_orig_node_put(orig_node); | |
763 | if (likely(tp_vars)) | |
764 | batadv_tp_vars_put(tp_vars); | |
765 | } | |
766 | ||
767 | /** | |
768 | * batadv_tp_avail - check if congestion window is not full | |
769 | * @tp_vars: the private data of the current TP meter session | |
770 | * @payload_len: size of the payload of a single message | |
771 | * | |
772 | * Return: true when congestion window is not full, false otherwise | |
773 | */ | |
774 | static bool batadv_tp_avail(struct batadv_tp_vars *tp_vars, | |
775 | size_t payload_len) | |
776 | { | |
777 | u32 win_left, win_limit; | |
778 | ||
779 | win_limit = atomic_read(&tp_vars->last_acked) + tp_vars->cwnd; | |
780 | win_left = win_limit - tp_vars->last_sent; | |
781 | ||
782 | return win_left >= payload_len; | |
783 | } | |
784 | ||
785 | /** | |
786 | * batadv_tp_wait_available - wait until congestion window becomes free or | |
787 | * timeout is reached | |
788 | * @tp_vars: the private data of the current TP meter session | |
789 | * @plen: size of the payload of a single message | |
790 | * | |
791 | * Return: 0 if the condition evaluated to false after the timeout elapsed, | |
792 | * 1 if the condition evaluated to true after the timeout elapsed, the | |
793 | * remaining jiffies (at least 1) if the condition evaluated to true before | |
794 | * the timeout elapsed, or -ERESTARTSYS if it was interrupted by a signal. | |
795 | */ | |
796 | static int batadv_tp_wait_available(struct batadv_tp_vars *tp_vars, size_t plen) | |
797 | { | |
798 | int ret; | |
799 | ||
800 | ret = wait_event_interruptible_timeout(tp_vars->more_bytes, | |
801 | batadv_tp_avail(tp_vars, plen), | |
802 | HZ / 10); | |
803 | ||
804 | return ret; | |
805 | } | |
806 | ||
807 | /** | |
808 | * batadv_tp_send - main sending thread of a tp meter session | |
809 | * @arg: address of the related tp_vars | |
810 | * | |
811 | * Return: nothing, this function never returns | |
812 | */ | |
813 | static int batadv_tp_send(void *arg) | |
814 | { | |
815 | struct batadv_tp_vars *tp_vars = arg; | |
816 | struct batadv_priv *bat_priv = tp_vars->bat_priv; | |
817 | struct batadv_hard_iface *primary_if = NULL; | |
818 | struct batadv_orig_node *orig_node = NULL; | |
819 | size_t payload_len, packet_len; | |
820 | int err = 0; | |
821 | ||
822 | if (unlikely(tp_vars->role != BATADV_TP_SENDER)) { | |
823 | err = BATADV_TP_REASON_DST_UNREACHABLE; | |
824 | tp_vars->reason = err; | |
825 | goto out; | |
826 | } | |
827 | ||
828 | orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); | |
829 | if (unlikely(!orig_node)) { | |
830 | err = BATADV_TP_REASON_DST_UNREACHABLE; | |
831 | tp_vars->reason = err; | |
832 | goto out; | |
833 | } | |
834 | ||
835 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
836 | if (unlikely(!primary_if)) { | |
837 | err = BATADV_TP_REASON_DST_UNREACHABLE; | |
e13258f3 | 838 | tp_vars->reason = err; |
33a3bb4a AQ |
839 | goto out; |
840 | } | |
841 | ||
842 | /* assume that all the hard_interfaces have a correctly | |
843 | * configured MTU, so use the soft_iface MTU as MSS. | |
844 | * This might not be true and in that case the fragmentation | |
845 | * should be used. | |
846 | * Now, try to send the packet as it is | |
847 | */ | |
848 | payload_len = BATADV_TP_PLEN; | |
849 | BUILD_BUG_ON(sizeof(struct batadv_icmp_tp_packet) > BATADV_TP_PLEN); | |
850 | ||
851 | batadv_tp_reset_sender_timer(tp_vars); | |
852 | ||
853 | /* queue the worker in charge of terminating the test */ | |
854 | queue_delayed_work(batadv_event_workqueue, &tp_vars->finish_work, | |
855 | msecs_to_jiffies(tp_vars->test_length)); | |
856 | ||
857 | while (atomic_read(&tp_vars->sending) != 0) { | |
858 | if (unlikely(!batadv_tp_avail(tp_vars, payload_len))) { | |
859 | batadv_tp_wait_available(tp_vars, payload_len); | |
860 | continue; | |
861 | } | |
862 | ||
863 | /* to emulate normal unicast traffic, add to the payload len | |
864 | * the size of the unicast header | |
865 | */ | |
866 | packet_len = payload_len + sizeof(struct batadv_unicast_packet); | |
867 | ||
868 | err = batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, | |
869 | orig_node, tp_vars->last_sent, | |
870 | packet_len, | |
871 | tp_vars->session, tp_vars->icmp_uid, | |
872 | jiffies_to_msecs(jiffies)); | |
873 | ||
874 | /* something went wrong during the preparation/transmission */ | |
875 | if (unlikely(err && err != BATADV_TP_REASON_CANT_SEND)) { | |
876 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
4e09991a SE |
877 | "Meter: %s() cannot send packets (%d)\n", |
878 | __func__, err); | |
33a3bb4a AQ |
879 | /* ensure nobody else tries to stop the thread now */ |
880 | if (atomic_dec_and_test(&tp_vars->sending)) | |
881 | tp_vars->reason = err; | |
882 | break; | |
883 | } | |
884 | ||
885 | /* right-shift the TWND */ | |
886 | if (!err) | |
887 | tp_vars->last_sent += payload_len; | |
888 | ||
889 | cond_resched(); | |
890 | } | |
891 | ||
892 | out: | |
893 | if (likely(primary_if)) | |
894 | batadv_hardif_put(primary_if); | |
895 | if (likely(orig_node)) | |
896 | batadv_orig_node_put(orig_node); | |
897 | ||
898 | batadv_tp_sender_end(bat_priv, tp_vars); | |
899 | batadv_tp_sender_cleanup(bat_priv, tp_vars); | |
900 | ||
901 | batadv_tp_vars_put(tp_vars); | |
902 | ||
903 | do_exit(0); | |
904 | } | |
905 | ||
906 | /** | |
907 | * batadv_tp_start_kthread - start new thread which manages the tp meter sender | |
908 | * @tp_vars: the private data of the current TP meter session | |
909 | */ | |
910 | static void batadv_tp_start_kthread(struct batadv_tp_vars *tp_vars) | |
911 | { | |
912 | struct task_struct *kthread; | |
913 | struct batadv_priv *bat_priv = tp_vars->bat_priv; | |
914 | u32 session_cookie; | |
915 | ||
916 | kref_get(&tp_vars->refcount); | |
917 | kthread = kthread_create(batadv_tp_send, tp_vars, "kbatadv_tp_meter"); | |
918 | if (IS_ERR(kthread)) { | |
919 | session_cookie = batadv_tp_session_cookie(tp_vars->session, | |
920 | tp_vars->icmp_uid); | |
921 | pr_err("batadv: cannot create tp meter kthread\n"); | |
922 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, | |
923 | tp_vars->other_end, | |
924 | bat_priv, session_cookie); | |
925 | ||
926 | /* drop reserved reference for kthread */ | |
927 | batadv_tp_vars_put(tp_vars); | |
928 | ||
929 | /* cleanup of failed tp meter variables */ | |
930 | batadv_tp_sender_cleanup(bat_priv, tp_vars); | |
931 | return; | |
932 | } | |
933 | ||
934 | wake_up_process(kthread); | |
935 | } | |
936 | ||
937 | /** | |
938 | * batadv_tp_start - start a new tp meter session | |
939 | * @bat_priv: the bat priv with all the soft interface information | |
940 | * @dst: the receiver MAC address | |
941 | * @test_length: test length in milliseconds | |
942 | * @cookie: session cookie | |
943 | */ | |
944 | void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, | |
945 | u32 test_length, u32 *cookie) | |
946 | { | |
947 | struct batadv_tp_vars *tp_vars; | |
948 | u8 session_id[2]; | |
949 | u8 icmp_uid; | |
950 | u32 session_cookie; | |
951 | ||
952 | get_random_bytes(session_id, sizeof(session_id)); | |
953 | get_random_bytes(&icmp_uid, 1); | |
954 | session_cookie = batadv_tp_session_cookie(session_id, icmp_uid); | |
955 | *cookie = session_cookie; | |
956 | ||
957 | /* look for an already existing test towards this node */ | |
958 | spin_lock_bh(&bat_priv->tp_list_lock); | |
959 | tp_vars = batadv_tp_list_find(bat_priv, dst); | |
960 | if (tp_vars) { | |
961 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
962 | batadv_tp_vars_put(tp_vars); | |
963 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
964 | "Meter: test to or from the same node already ongoing, aborting\n"); | |
965 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_ALREADY_ONGOING, | |
966 | dst, bat_priv, session_cookie); | |
967 | return; | |
968 | } | |
969 | ||
970 | if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) { | |
971 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
972 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
973 | "Meter: too many ongoing sessions, aborting (SEND)\n"); | |
974 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_TOO_MANY, dst, | |
975 | bat_priv, session_cookie); | |
976 | return; | |
977 | } | |
978 | ||
979 | tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); | |
980 | if (!tp_vars) { | |
981 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
982 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
4e09991a SE |
983 | "Meter: %s cannot allocate list elements\n", |
984 | __func__); | |
33a3bb4a AQ |
985 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, |
986 | dst, bat_priv, session_cookie); | |
987 | return; | |
988 | } | |
989 | ||
990 | /* initialize tp_vars */ | |
991 | ether_addr_copy(tp_vars->other_end, dst); | |
992 | kref_init(&tp_vars->refcount); | |
993 | tp_vars->role = BATADV_TP_SENDER; | |
994 | atomic_set(&tp_vars->sending, 1); | |
995 | memcpy(tp_vars->session, session_id, sizeof(session_id)); | |
996 | tp_vars->icmp_uid = icmp_uid; | |
997 | ||
998 | tp_vars->last_sent = BATADV_TP_FIRST_SEQ; | |
999 | atomic_set(&tp_vars->last_acked, BATADV_TP_FIRST_SEQ); | |
1000 | tp_vars->fast_recovery = false; | |
1001 | tp_vars->recover = BATADV_TP_FIRST_SEQ; | |
1002 | ||
1003 | /* initialise the CWND to 3*MSS (Section 3.1 in RFC5681). | |
1004 | * For batman-adv the MSS is the size of the payload received by the | |
1005 | * soft_interface, hence its MTU | |
1006 | */ | |
1007 | tp_vars->cwnd = BATADV_TP_PLEN * 3; | |
1008 | /* at the beginning initialise the SS threshold to the biggest possible | |
1009 | * window size, hence the AWND size | |
1010 | */ | |
1011 | tp_vars->ss_threshold = BATADV_TP_AWND; | |
1012 | ||
1013 | /* RTO initial value is 3 seconds. | |
1014 | * Details in Section 2.1 of RFC6298 | |
1015 | */ | |
1016 | tp_vars->rto = 1000; | |
1017 | tp_vars->srtt = 0; | |
1018 | tp_vars->rttvar = 0; | |
1019 | ||
1020 | atomic64_set(&tp_vars->tot_sent, 0); | |
1021 | ||
1022 | kref_get(&tp_vars->refcount); | |
e99e88a9 | 1023 | timer_setup(&tp_vars->timer, batadv_tp_sender_timeout, 0); |
33a3bb4a AQ |
1024 | |
1025 | tp_vars->bat_priv = bat_priv; | |
1026 | tp_vars->start_time = jiffies; | |
1027 | ||
1028 | init_waitqueue_head(&tp_vars->more_bytes); | |
1029 | ||
1030 | spin_lock_init(&tp_vars->unacked_lock); | |
1031 | INIT_LIST_HEAD(&tp_vars->unacked_list); | |
1032 | ||
1033 | spin_lock_init(&tp_vars->cwnd_lock); | |
1034 | ||
1035 | tp_vars->prerandom_offset = 0; | |
1036 | spin_lock_init(&tp_vars->prerandom_lock); | |
1037 | ||
1038 | kref_get(&tp_vars->refcount); | |
1039 | hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list); | |
1040 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
1041 | ||
1042 | tp_vars->test_length = test_length; | |
1043 | if (!tp_vars->test_length) | |
1044 | tp_vars->test_length = BATADV_TP_DEF_TEST_LENGTH; | |
1045 | ||
1046 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1047 | "Meter: starting throughput meter towards %pM (length=%ums)\n", | |
1048 | dst, test_length); | |
1049 | ||
1050 | /* init work item for finished tp tests */ | |
1051 | INIT_DELAYED_WORK(&tp_vars->finish_work, batadv_tp_sender_finish); | |
1052 | ||
1053 | /* start tp kthread. This way the write() call issued from userspace can | |
1054 | * happily return and avoid to block | |
1055 | */ | |
1056 | batadv_tp_start_kthread(tp_vars); | |
1057 | ||
1058 | /* don't return reference to new tp_vars */ | |
1059 | batadv_tp_vars_put(tp_vars); | |
1060 | } | |
1061 | ||
1062 | /** | |
1063 | * batadv_tp_stop - stop currently running tp meter session | |
1064 | * @bat_priv: the bat priv with all the soft interface information | |
1065 | * @dst: the receiver MAC address | |
1066 | * @return_value: reason for tp meter session stop | |
1067 | */ | |
1068 | void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, | |
1069 | u8 return_value) | |
1070 | { | |
1071 | struct batadv_orig_node *orig_node; | |
1072 | struct batadv_tp_vars *tp_vars; | |
1073 | ||
1074 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1075 | "Meter: stopping test towards %pM\n", dst); | |
1076 | ||
1077 | orig_node = batadv_orig_hash_find(bat_priv, dst); | |
1078 | if (!orig_node) | |
1079 | return; | |
1080 | ||
1081 | tp_vars = batadv_tp_list_find(bat_priv, orig_node->orig); | |
1082 | if (!tp_vars) { | |
1083 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1084 | "Meter: trying to interrupt an already over connection\n"); | |
1085 | goto out; | |
1086 | } | |
1087 | ||
1088 | batadv_tp_sender_shutdown(tp_vars, return_value); | |
1089 | batadv_tp_vars_put(tp_vars); | |
1090 | out: | |
1091 | batadv_orig_node_put(orig_node); | |
1092 | } | |
1093 | ||
1094 | /** | |
1095 | * batadv_tp_reset_receiver_timer - reset the receiver shutdown timer | |
1096 | * @tp_vars: the private data of the current TP meter session | |
1097 | * | |
1098 | * start the receiver shutdown timer or reset it if already started | |
1099 | */ | |
1100 | static void batadv_tp_reset_receiver_timer(struct batadv_tp_vars *tp_vars) | |
1101 | { | |
1102 | mod_timer(&tp_vars->timer, | |
1103 | jiffies + msecs_to_jiffies(BATADV_TP_RECV_TIMEOUT)); | |
1104 | } | |
1105 | ||
1106 | /** | |
1107 | * batadv_tp_receiver_shutdown - stop a tp meter receiver when timeout is | |
1108 | * reached without received ack | |
974a6b20 | 1109 | * @t: address to timer_list inside tp_vars |
33a3bb4a | 1110 | */ |
e99e88a9 | 1111 | static void batadv_tp_receiver_shutdown(struct timer_list *t) |
33a3bb4a | 1112 | { |
e99e88a9 | 1113 | struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer); |
33a3bb4a AQ |
1114 | struct batadv_tp_unacked *un, *safe; |
1115 | struct batadv_priv *bat_priv; | |
1116 | ||
1117 | bat_priv = tp_vars->bat_priv; | |
1118 | ||
1119 | /* if there is recent activity rearm the timer */ | |
1120 | if (!batadv_has_timed_out(tp_vars->last_recv_time, | |
1121 | BATADV_TP_RECV_TIMEOUT)) { | |
1122 | /* reset the receiver shutdown timer */ | |
1123 | batadv_tp_reset_receiver_timer(tp_vars); | |
1124 | return; | |
1125 | } | |
1126 | ||
1127 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1128 | "Shutting down for inactivity (more than %dms) from %pM\n", | |
1129 | BATADV_TP_RECV_TIMEOUT, tp_vars->other_end); | |
1130 | ||
1131 | spin_lock_bh(&tp_vars->bat_priv->tp_list_lock); | |
1132 | hlist_del_rcu(&tp_vars->list); | |
1133 | spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock); | |
1134 | ||
1135 | /* drop list reference */ | |
1136 | batadv_tp_vars_put(tp_vars); | |
1137 | ||
1138 | atomic_dec(&bat_priv->tp_num); | |
1139 | ||
1140 | spin_lock_bh(&tp_vars->unacked_lock); | |
1141 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { | |
1142 | list_del(&un->list); | |
1143 | kfree(un); | |
1144 | } | |
1145 | spin_unlock_bh(&tp_vars->unacked_lock); | |
1146 | ||
1147 | /* drop reference of timer */ | |
1148 | batadv_tp_vars_put(tp_vars); | |
1149 | } | |
1150 | ||
1151 | /** | |
1152 | * batadv_tp_send_ack - send an ACK packet | |
1153 | * @bat_priv: the bat priv with all the soft interface information | |
1154 | * @dst: the mac address of the destination originator | |
1155 | * @seq: the sequence number to ACK | |
1156 | * @timestamp: the timestamp to echo back in the ACK | |
1157 | * @session: session identifier | |
1158 | * @socket_index: local ICMP socket identifier | |
1159 | * | |
1160 | * Return: 0 on success, a positive integer representing the reason of the | |
1161 | * failure otherwise | |
1162 | */ | |
1163 | static int batadv_tp_send_ack(struct batadv_priv *bat_priv, const u8 *dst, | |
1164 | u32 seq, __be32 timestamp, const u8 *session, | |
1165 | int socket_index) | |
1166 | { | |
1167 | struct batadv_hard_iface *primary_if = NULL; | |
1168 | struct batadv_orig_node *orig_node; | |
1169 | struct batadv_icmp_tp_packet *icmp; | |
1170 | struct sk_buff *skb; | |
1171 | int r, ret; | |
1172 | ||
1173 | orig_node = batadv_orig_hash_find(bat_priv, dst); | |
1174 | if (unlikely(!orig_node)) { | |
1175 | ret = BATADV_TP_REASON_DST_UNREACHABLE; | |
1176 | goto out; | |
1177 | } | |
1178 | ||
1179 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
1180 | if (unlikely(!primary_if)) { | |
1181 | ret = BATADV_TP_REASON_DST_UNREACHABLE; | |
1182 | goto out; | |
1183 | } | |
1184 | ||
1185 | skb = netdev_alloc_skb_ip_align(NULL, sizeof(*icmp) + ETH_HLEN); | |
1186 | if (unlikely(!skb)) { | |
1187 | ret = BATADV_TP_REASON_MEMORY_ERROR; | |
1188 | goto out; | |
1189 | } | |
1190 | ||
1191 | skb_reserve(skb, ETH_HLEN); | |
4df864c1 | 1192 | icmp = skb_put(skb, sizeof(*icmp)); |
33a3bb4a AQ |
1193 | icmp->packet_type = BATADV_ICMP; |
1194 | icmp->version = BATADV_COMPAT_VERSION; | |
1195 | icmp->ttl = BATADV_TTL; | |
1196 | icmp->msg_type = BATADV_TP; | |
1197 | ether_addr_copy(icmp->dst, orig_node->orig); | |
1198 | ether_addr_copy(icmp->orig, primary_if->net_dev->dev_addr); | |
1199 | icmp->uid = socket_index; | |
1200 | ||
1201 | icmp->subtype = BATADV_TP_ACK; | |
1202 | memcpy(icmp->session, session, sizeof(icmp->session)); | |
1203 | icmp->seqno = htonl(seq); | |
1204 | icmp->timestamp = timestamp; | |
1205 | ||
1206 | /* send the ack */ | |
1207 | r = batadv_send_skb_to_orig(skb, orig_node, NULL); | |
825ffe1f | 1208 | if (unlikely(r < 0) || r == NET_XMIT_DROP) { |
33a3bb4a AQ |
1209 | ret = BATADV_TP_REASON_DST_UNREACHABLE; |
1210 | goto out; | |
1211 | } | |
1212 | ret = 0; | |
1213 | ||
1214 | out: | |
1215 | if (likely(orig_node)) | |
1216 | batadv_orig_node_put(orig_node); | |
1217 | if (likely(primary_if)) | |
1218 | batadv_hardif_put(primary_if); | |
1219 | ||
1220 | return ret; | |
1221 | } | |
1222 | ||
1223 | /** | |
1224 | * batadv_tp_handle_out_of_order - store an out of order packet | |
1225 | * @tp_vars: the private data of the current TP meter session | |
1226 | * @skb: the buffer containing the received packet | |
1227 | * | |
1228 | * Store the out of order packet in the unacked list for late processing. This | |
1229 | * packets are kept in this list so that they can be ACKed at once as soon as | |
1230 | * all the previous packets have been received | |
1231 | * | |
1232 | * Return: true if the packed has been successfully processed, false otherwise | |
1233 | */ | |
1234 | static bool batadv_tp_handle_out_of_order(struct batadv_tp_vars *tp_vars, | |
1235 | const struct sk_buff *skb) | |
1236 | { | |
1237 | const struct batadv_icmp_tp_packet *icmp; | |
1238 | struct batadv_tp_unacked *un, *new; | |
1239 | u32 payload_len; | |
1240 | bool added = false; | |
1241 | ||
1242 | new = kmalloc(sizeof(*new), GFP_ATOMIC); | |
1243 | if (unlikely(!new)) | |
1244 | return false; | |
1245 | ||
1246 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
1247 | ||
1248 | new->seqno = ntohl(icmp->seqno); | |
1249 | payload_len = skb->len - sizeof(struct batadv_unicast_packet); | |
1250 | new->len = payload_len; | |
1251 | ||
1252 | spin_lock_bh(&tp_vars->unacked_lock); | |
1253 | /* if the list is empty immediately attach this new object */ | |
1254 | if (list_empty(&tp_vars->unacked_list)) { | |
1255 | list_add(&new->list, &tp_vars->unacked_list); | |
1256 | goto out; | |
1257 | } | |
1258 | ||
1259 | /* otherwise loop over the list and either drop the packet because this | |
1260 | * is a duplicate or store it at the right position. | |
1261 | * | |
1262 | * The iteration is done in the reverse way because it is likely that | |
1263 | * the last received packet (the one being processed now) has a bigger | |
1264 | * seqno than all the others already stored. | |
1265 | */ | |
1266 | list_for_each_entry_reverse(un, &tp_vars->unacked_list, list) { | |
1267 | /* check for duplicates */ | |
1268 | if (new->seqno == un->seqno) { | |
1269 | if (new->len > un->len) | |
1270 | un->len = new->len; | |
1271 | kfree(new); | |
1272 | added = true; | |
1273 | break; | |
1274 | } | |
1275 | ||
1276 | /* look for the right position */ | |
1277 | if (batadv_seq_before(new->seqno, un->seqno)) | |
1278 | continue; | |
1279 | ||
1280 | /* as soon as an entry having a bigger seqno is found, the new | |
1281 | * one is attached _after_ it. In this way the list is kept in | |
1282 | * ascending order | |
1283 | */ | |
1284 | list_add_tail(&new->list, &un->list); | |
1285 | added = true; | |
1286 | break; | |
1287 | } | |
1288 | ||
1289 | /* received packet with smallest seqno out of order; add it to front */ | |
1290 | if (!added) | |
1291 | list_add(&new->list, &tp_vars->unacked_list); | |
1292 | ||
1293 | out: | |
1294 | spin_unlock_bh(&tp_vars->unacked_lock); | |
1295 | ||
1296 | return true; | |
1297 | } | |
1298 | ||
1299 | /** | |
1300 | * batadv_tp_ack_unordered - update number received bytes in current stream | |
1301 | * without gaps | |
1302 | * @tp_vars: the private data of the current TP meter session | |
1303 | */ | |
1304 | static void batadv_tp_ack_unordered(struct batadv_tp_vars *tp_vars) | |
1305 | { | |
1306 | struct batadv_tp_unacked *un, *safe; | |
1307 | u32 to_ack; | |
1308 | ||
1309 | /* go through the unacked packet list and possibly ACK them as | |
1310 | * well | |
1311 | */ | |
1312 | spin_lock_bh(&tp_vars->unacked_lock); | |
1313 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { | |
1314 | /* the list is ordered, therefore it is possible to stop as soon | |
1315 | * there is a gap between the last acked seqno and the seqno of | |
1316 | * the packet under inspection | |
1317 | */ | |
1318 | if (batadv_seq_before(tp_vars->last_recv, un->seqno)) | |
1319 | break; | |
1320 | ||
1321 | to_ack = un->seqno + un->len - tp_vars->last_recv; | |
1322 | ||
1323 | if (batadv_seq_before(tp_vars->last_recv, un->seqno + un->len)) | |
1324 | tp_vars->last_recv += to_ack; | |
1325 | ||
1326 | list_del(&un->list); | |
1327 | kfree(un); | |
1328 | } | |
1329 | spin_unlock_bh(&tp_vars->unacked_lock); | |
1330 | } | |
1331 | ||
1332 | /** | |
1333 | * batadv_tp_init_recv - return matching or create new receiver tp_vars | |
1334 | * @bat_priv: the bat priv with all the soft interface information | |
1335 | * @icmp: received icmp tp msg | |
1336 | * | |
1337 | * Return: corresponding tp_vars or NULL on errors | |
1338 | */ | |
1339 | static struct batadv_tp_vars * | |
1340 | batadv_tp_init_recv(struct batadv_priv *bat_priv, | |
1341 | const struct batadv_icmp_tp_packet *icmp) | |
1342 | { | |
1343 | struct batadv_tp_vars *tp_vars; | |
1344 | ||
1345 | spin_lock_bh(&bat_priv->tp_list_lock); | |
1346 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, | |
1347 | icmp->session); | |
1348 | if (tp_vars) | |
1349 | goto out_unlock; | |
1350 | ||
1351 | if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) { | |
1352 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1353 | "Meter: too many ongoing sessions, aborting (RECV)\n"); | |
1354 | goto out_unlock; | |
1355 | } | |
1356 | ||
1357 | tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); | |
1358 | if (!tp_vars) | |
1359 | goto out_unlock; | |
1360 | ||
1361 | ether_addr_copy(tp_vars->other_end, icmp->orig); | |
1362 | tp_vars->role = BATADV_TP_RECEIVER; | |
1363 | memcpy(tp_vars->session, icmp->session, sizeof(tp_vars->session)); | |
1364 | tp_vars->last_recv = BATADV_TP_FIRST_SEQ; | |
1365 | tp_vars->bat_priv = bat_priv; | |
1366 | kref_init(&tp_vars->refcount); | |
1367 | ||
1368 | spin_lock_init(&tp_vars->unacked_lock); | |
1369 | INIT_LIST_HEAD(&tp_vars->unacked_list); | |
1370 | ||
1371 | kref_get(&tp_vars->refcount); | |
1372 | hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list); | |
1373 | ||
1374 | kref_get(&tp_vars->refcount); | |
e99e88a9 | 1375 | timer_setup(&tp_vars->timer, batadv_tp_receiver_shutdown, 0); |
33a3bb4a AQ |
1376 | |
1377 | batadv_tp_reset_receiver_timer(tp_vars); | |
1378 | ||
1379 | out_unlock: | |
1380 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
1381 | ||
1382 | return tp_vars; | |
1383 | } | |
1384 | ||
1385 | /** | |
1386 | * batadv_tp_recv_msg - process a single data message | |
1387 | * @bat_priv: the bat priv with all the soft interface information | |
1388 | * @skb: the buffer containing the received packet | |
1389 | * | |
1390 | * Process a received TP MSG packet | |
1391 | */ | |
1392 | static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, | |
1393 | const struct sk_buff *skb) | |
1394 | { | |
1395 | const struct batadv_icmp_tp_packet *icmp; | |
1396 | struct batadv_tp_vars *tp_vars; | |
1397 | size_t packet_size; | |
1398 | u32 seqno; | |
1399 | ||
1400 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
1401 | ||
1402 | seqno = ntohl(icmp->seqno); | |
1403 | /* check if this is the first seqno. This means that if the | |
1404 | * first packet is lost, the tp meter does not work anymore! | |
1405 | */ | |
1406 | if (seqno == BATADV_TP_FIRST_SEQ) { | |
1407 | tp_vars = batadv_tp_init_recv(bat_priv, icmp); | |
1408 | if (!tp_vars) { | |
1409 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1410 | "Meter: seqno != BATADV_TP_FIRST_SEQ cannot initiate connection\n"); | |
1411 | goto out; | |
1412 | } | |
1413 | } else { | |
1414 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, | |
1415 | icmp->session); | |
1416 | if (!tp_vars) { | |
1417 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1418 | "Unexpected packet from %pM!\n", | |
1419 | icmp->orig); | |
1420 | goto out; | |
1421 | } | |
1422 | } | |
1423 | ||
1424 | if (unlikely(tp_vars->role != BATADV_TP_RECEIVER)) { | |
1425 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1426 | "Meter: dropping packet: not expected (role=%u)\n", | |
1427 | tp_vars->role); | |
1428 | goto out; | |
1429 | } | |
1430 | ||
1431 | tp_vars->last_recv_time = jiffies; | |
1432 | ||
1433 | /* if the packet is a duplicate, it may be the case that an ACK has been | |
1434 | * lost. Resend the ACK | |
1435 | */ | |
1436 | if (batadv_seq_before(seqno, tp_vars->last_recv)) | |
1437 | goto send_ack; | |
1438 | ||
1439 | /* if the packet is out of order enqueue it */ | |
1440 | if (ntohl(icmp->seqno) != tp_vars->last_recv) { | |
1441 | /* exit immediately (and do not send any ACK) if the packet has | |
1442 | * not been enqueued correctly | |
1443 | */ | |
1444 | if (!batadv_tp_handle_out_of_order(tp_vars, skb)) | |
1445 | goto out; | |
1446 | ||
1447 | /* send a duplicate ACK */ | |
1448 | goto send_ack; | |
1449 | } | |
1450 | ||
1451 | /* if everything was fine count the ACKed bytes */ | |
1452 | packet_size = skb->len - sizeof(struct batadv_unicast_packet); | |
1453 | tp_vars->last_recv += packet_size; | |
1454 | ||
1455 | /* check if this ordered message filled a gap.... */ | |
1456 | batadv_tp_ack_unordered(tp_vars); | |
1457 | ||
1458 | send_ack: | |
1459 | /* send the ACK. If the received packet was out of order, the ACK that | |
1460 | * is going to be sent is a duplicate (the sender will count them and | |
1461 | * possibly enter Fast Retransmit as soon as it has reached 3) | |
1462 | */ | |
1463 | batadv_tp_send_ack(bat_priv, icmp->orig, tp_vars->last_recv, | |
1464 | icmp->timestamp, icmp->session, icmp->uid); | |
1465 | out: | |
1466 | if (likely(tp_vars)) | |
1467 | batadv_tp_vars_put(tp_vars); | |
1468 | } | |
1469 | ||
1470 | /** | |
1471 | * batadv_tp_meter_recv - main TP Meter receiving function | |
1472 | * @bat_priv: the bat priv with all the soft interface information | |
1473 | * @skb: the buffer containing the received packet | |
1474 | */ | |
1475 | void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb) | |
1476 | { | |
1477 | struct batadv_icmp_tp_packet *icmp; | |
1478 | ||
1479 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
1480 | ||
1481 | switch (icmp->subtype) { | |
1482 | case BATADV_TP_MSG: | |
1483 | batadv_tp_recv_msg(bat_priv, skb); | |
1484 | break; | |
1485 | case BATADV_TP_ACK: | |
1486 | batadv_tp_recv_ack(bat_priv, skb); | |
1487 | break; | |
1488 | default: | |
1489 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1490 | "Received unknown TP Metric packet type %u\n", | |
1491 | icmp->subtype); | |
1492 | } | |
1493 | consume_skb(skb); | |
1494 | } | |
1495 | ||
1496 | /** | |
1497 | * batadv_tp_meter_init - initialize global tp_meter structures | |
1498 | */ | |
d1aa5142 | 1499 | void __init batadv_tp_meter_init(void) |
33a3bb4a AQ |
1500 | { |
1501 | get_random_bytes(batadv_tp_prerandom, sizeof(batadv_tp_prerandom)); | |
1502 | } |