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7db7d9f3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
68e039f9 | 2 | /* Copyright (C) 2012-2020 B.A.T.M.A.N. contributors: |
33a3bb4a AQ |
3 | * |
4 | * Edo Monticelli, Antonio Quartulli | |
33a3bb4a AQ |
5 | */ |
6 | ||
7 | #include "tp_meter.h" | |
8 | #include "main.h" | |
9 | ||
10 | #include <linux/atomic.h> | |
ecc36f5e | 11 | #include <linux/build_bug.h> |
33a3bb4a AQ |
12 | #include <linux/byteorder/generic.h> |
13 | #include <linux/cache.h> | |
14 | #include <linux/compiler.h> | |
3e7514af | 15 | #include <linux/err.h> |
33a3bb4a | 16 | #include <linux/etherdevice.h> |
b92b94ac | 17 | #include <linux/gfp.h> |
33a3bb4a | 18 | #include <linux/if_ether.h> |
d1aa5142 | 19 | #include <linux/init.h> |
33a3bb4a AQ |
20 | #include <linux/jiffies.h> |
21 | #include <linux/kernel.h> | |
22 | #include <linux/kref.h> | |
23 | #include <linux/kthread.h> | |
e1928752 | 24 | #include <linux/limits.h> |
33a3bb4a AQ |
25 | #include <linux/list.h> |
26 | #include <linux/netdevice.h> | |
27 | #include <linux/param.h> | |
28 | #include <linux/printk.h> | |
29 | #include <linux/random.h> | |
30 | #include <linux/rculist.h> | |
31 | #include <linux/rcupdate.h> | |
32 | #include <linux/sched.h> | |
33 | #include <linux/skbuff.h> | |
34 | #include <linux/slab.h> | |
35 | #include <linux/spinlock.h> | |
36 | #include <linux/stddef.h> | |
37 | #include <linux/string.h> | |
38 | #include <linux/timer.h> | |
39 | #include <linux/wait.h> | |
40 | #include <linux/workqueue.h> | |
fec149f5 | 41 | #include <uapi/linux/batadv_packet.h> |
33a3bb4a AQ |
42 | #include <uapi/linux/batman_adv.h> |
43 | ||
44 | #include "hard-interface.h" | |
45 | #include "log.h" | |
46 | #include "netlink.h" | |
47 | #include "originator.h" | |
33a3bb4a AQ |
48 | #include "send.h" |
49 | ||
50 | /** | |
51 | * BATADV_TP_DEF_TEST_LENGTH - Default test length if not specified by the user | |
52 | * in milliseconds | |
53 | */ | |
54 | #define BATADV_TP_DEF_TEST_LENGTH 10000 | |
55 | ||
56 | /** | |
57 | * BATADV_TP_AWND - Advertised window by the receiver (in bytes) | |
58 | */ | |
59 | #define BATADV_TP_AWND 0x20000000 | |
60 | ||
61 | /** | |
62 | * BATADV_TP_RECV_TIMEOUT - Receiver activity timeout. If the receiver does not | |
63 | * get anything for such amount of milliseconds, the connection is killed | |
64 | */ | |
65 | #define BATADV_TP_RECV_TIMEOUT 1000 | |
66 | ||
67 | /** | |
68 | * BATADV_TP_MAX_RTO - Maximum sender timeout. If the sender RTO gets beyond | |
bccb48c8 | 69 | * such amount of milliseconds, the receiver is considered unreachable and the |
33a3bb4a AQ |
70 | * connection is killed |
71 | */ | |
72 | #define BATADV_TP_MAX_RTO 30000 | |
73 | ||
74 | /** | |
75 | * BATADV_TP_FIRST_SEQ - First seqno of each session. The number is rather high | |
76 | * in order to immediately trigger a wrap around (test purposes) | |
77 | */ | |
78 | #define BATADV_TP_FIRST_SEQ ((u32)-1 - 2000) | |
79 | ||
80 | /** | |
81 | * BATADV_TP_PLEN - length of the payload (data after the batadv_unicast header) | |
82 | * to simulate | |
83 | */ | |
84 | #define BATADV_TP_PLEN (BATADV_TP_PACKET_LEN - ETH_HLEN - \ | |
85 | sizeof(struct batadv_unicast_packet)) | |
86 | ||
87 | static u8 batadv_tp_prerandom[4096] __read_mostly; | |
88 | ||
89 | /** | |
7e9a8c2c | 90 | * batadv_tp_session_cookie() - generate session cookie based on session ids |
33a3bb4a AQ |
91 | * @session: TP session identifier |
92 | * @icmp_uid: icmp pseudo uid of the tp session | |
93 | * | |
94 | * Return: 32 bit tp_meter session cookie | |
95 | */ | |
96 | static u32 batadv_tp_session_cookie(const u8 session[2], u8 icmp_uid) | |
97 | { | |
98 | u32 cookie; | |
99 | ||
100 | cookie = icmp_uid << 16; | |
101 | cookie |= session[0] << 8; | |
102 | cookie |= session[1]; | |
103 | ||
104 | return cookie; | |
105 | } | |
106 | ||
107 | /** | |
7e9a8c2c | 108 | * batadv_tp_cwnd() - compute the new cwnd size |
33a3bb4a AQ |
109 | * @base: base cwnd size value |
110 | * @increment: the value to add to base to get the new size | |
bccb48c8 | 111 | * @min: minimum cwnd value (usually MSS) |
33a3bb4a | 112 | * |
bccb48c8 SE |
113 | * Return the new cwnd size and ensure it does not exceed the Advertised |
114 | * Receiver Window size. It is wrapped around safely. | |
33a3bb4a AQ |
115 | * For details refer to Section 3.1 of RFC5681 |
116 | * | |
117 | * Return: new congestion window size in bytes | |
118 | */ | |
119 | static u32 batadv_tp_cwnd(u32 base, u32 increment, u32 min) | |
120 | { | |
121 | u32 new_size = base + increment; | |
122 | ||
123 | /* check for wrap-around */ | |
124 | if (new_size < base) | |
125 | new_size = (u32)ULONG_MAX; | |
126 | ||
127 | new_size = min_t(u32, new_size, BATADV_TP_AWND); | |
128 | ||
129 | return max_t(u32, new_size, min); | |
130 | } | |
131 | ||
132 | /** | |
7e9a8c2c | 133 | * batadv_tp_updated_cwnd() - update the Congestion Windows |
33a3bb4a AQ |
134 | * @tp_vars: the private data of the current TP meter session |
135 | * @mss: maximum segment size of transmission | |
136 | * | |
137 | * 1) if the session is in Slow Start, the CWND has to be increased by 1 | |
138 | * MSS every unique received ACK | |
139 | * 2) if the session is in Congestion Avoidance, the CWND has to be | |
140 | * increased by MSS * MSS / CWND for every unique received ACK | |
141 | */ | |
142 | static void batadv_tp_update_cwnd(struct batadv_tp_vars *tp_vars, u32 mss) | |
143 | { | |
144 | spin_lock_bh(&tp_vars->cwnd_lock); | |
145 | ||
146 | /* slow start... */ | |
147 | if (tp_vars->cwnd <= tp_vars->ss_threshold) { | |
148 | tp_vars->dec_cwnd = 0; | |
149 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss); | |
150 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
151 | return; | |
152 | } | |
153 | ||
154 | /* increment CWND at least of 1 (section 3.1 of RFC5681) */ | |
155 | tp_vars->dec_cwnd += max_t(u32, 1U << 3, | |
156 | ((mss * mss) << 6) / (tp_vars->cwnd << 3)); | |
157 | if (tp_vars->dec_cwnd < (mss << 3)) { | |
158 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
159 | return; | |
160 | } | |
161 | ||
162 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss); | |
163 | tp_vars->dec_cwnd = 0; | |
164 | ||
165 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
166 | } | |
167 | ||
168 | /** | |
7e9a8c2c | 169 | * batadv_tp_update_rto() - calculate new retransmission timeout |
33a3bb4a AQ |
170 | * @tp_vars: the private data of the current TP meter session |
171 | * @new_rtt: new roundtrip time in msec | |
172 | */ | |
173 | static void batadv_tp_update_rto(struct batadv_tp_vars *tp_vars, | |
174 | u32 new_rtt) | |
175 | { | |
176 | long m = new_rtt; | |
177 | ||
178 | /* RTT update | |
179 | * Details in Section 2.2 and 2.3 of RFC6298 | |
180 | * | |
181 | * It's tricky to understand. Don't lose hair please. | |
182 | * Inspired by tcp_rtt_estimator() tcp_input.c | |
183 | */ | |
184 | if (tp_vars->srtt != 0) { | |
185 | m -= (tp_vars->srtt >> 3); /* m is now error in rtt est */ | |
186 | tp_vars->srtt += m; /* rtt = 7/8 srtt + 1/8 new */ | |
187 | if (m < 0) | |
188 | m = -m; | |
189 | ||
190 | m -= (tp_vars->rttvar >> 2); | |
191 | tp_vars->rttvar += m; /* mdev ~= 3/4 rttvar + 1/4 new */ | |
192 | } else { | |
193 | /* first measure getting in */ | |
194 | tp_vars->srtt = m << 3; /* take the measured time to be srtt */ | |
195 | tp_vars->rttvar = m << 1; /* new_rtt / 2 */ | |
196 | } | |
197 | ||
198 | /* rto = srtt + 4 * rttvar. | |
199 | * rttvar is scaled by 4, therefore doesn't need to be multiplied | |
200 | */ | |
201 | tp_vars->rto = (tp_vars->srtt >> 3) + tp_vars->rttvar; | |
202 | } | |
203 | ||
204 | /** | |
7e9a8c2c | 205 | * batadv_tp_batctl_notify() - send client status result to client |
33a3bb4a AQ |
206 | * @reason: reason for tp meter session stop |
207 | * @dst: destination of tp_meter session | |
208 | * @bat_priv: the bat priv with all the soft interface information | |
209 | * @start_time: start of transmission in jiffies | |
210 | * @total_sent: bytes acked to the receiver | |
211 | * @cookie: cookie of tp_meter session | |
212 | */ | |
213 | static void batadv_tp_batctl_notify(enum batadv_tp_meter_reason reason, | |
214 | const u8 *dst, struct batadv_priv *bat_priv, | |
215 | unsigned long start_time, u64 total_sent, | |
216 | u32 cookie) | |
217 | { | |
218 | u32 test_time; | |
219 | u8 result; | |
220 | u32 total_bytes; | |
221 | ||
222 | if (!batadv_tp_is_error(reason)) { | |
223 | result = BATADV_TP_REASON_COMPLETE; | |
224 | test_time = jiffies_to_msecs(jiffies - start_time); | |
225 | total_bytes = total_sent; | |
226 | } else { | |
227 | result = reason; | |
228 | test_time = 0; | |
229 | total_bytes = 0; | |
230 | } | |
231 | ||
232 | batadv_netlink_tpmeter_notify(bat_priv, dst, result, test_time, | |
233 | total_bytes, cookie); | |
234 | } | |
235 | ||
236 | /** | |
7e9a8c2c | 237 | * batadv_tp_batctl_error_notify() - send client error result to client |
33a3bb4a AQ |
238 | * @reason: reason for tp meter session stop |
239 | * @dst: destination of tp_meter session | |
240 | * @bat_priv: the bat priv with all the soft interface information | |
241 | * @cookie: cookie of tp_meter session | |
242 | */ | |
243 | static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason, | |
244 | const u8 *dst, | |
245 | struct batadv_priv *bat_priv, | |
246 | u32 cookie) | |
247 | { | |
248 | batadv_tp_batctl_notify(reason, dst, bat_priv, 0, 0, cookie); | |
249 | } | |
250 | ||
251 | /** | |
7e9a8c2c | 252 | * batadv_tp_list_find() - find a tp_vars object in the global list |
33a3bb4a AQ |
253 | * @bat_priv: the bat priv with all the soft interface information |
254 | * @dst: the other endpoint MAC address to look for | |
255 | * | |
256 | * Look for a tp_vars object matching dst as end_point and return it after | |
bccb48c8 | 257 | * having increment the refcounter. Return NULL is not found |
33a3bb4a AQ |
258 | * |
259 | * Return: matching tp_vars or NULL when no tp_vars with @dst was found | |
260 | */ | |
261 | static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv, | |
262 | const u8 *dst) | |
263 | { | |
264 | struct batadv_tp_vars *pos, *tp_vars = NULL; | |
265 | ||
266 | rcu_read_lock(); | |
267 | hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) { | |
268 | if (!batadv_compare_eth(pos->other_end, dst)) | |
269 | continue; | |
270 | ||
271 | /* most of the time this function is invoked during the normal | |
272 | * process..it makes sens to pay more when the session is | |
273 | * finished and to speed the process up during the measurement | |
274 | */ | |
275 | if (unlikely(!kref_get_unless_zero(&pos->refcount))) | |
276 | continue; | |
277 | ||
278 | tp_vars = pos; | |
279 | break; | |
280 | } | |
281 | rcu_read_unlock(); | |
282 | ||
283 | return tp_vars; | |
284 | } | |
285 | ||
286 | /** | |
7e9a8c2c SE |
287 | * batadv_tp_list_find_session() - find tp_vars session object in the global |
288 | * list | |
33a3bb4a AQ |
289 | * @bat_priv: the bat priv with all the soft interface information |
290 | * @dst: the other endpoint MAC address to look for | |
291 | * @session: session identifier | |
292 | * | |
293 | * Look for a tp_vars object matching dst as end_point, session as tp meter | |
bccb48c8 | 294 | * session and return it after having increment the refcounter. Return NULL |
33a3bb4a AQ |
295 | * is not found |
296 | * | |
297 | * Return: matching tp_vars or NULL when no tp_vars was found | |
298 | */ | |
299 | static struct batadv_tp_vars * | |
300 | batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst, | |
301 | const u8 *session) | |
302 | { | |
303 | struct batadv_tp_vars *pos, *tp_vars = NULL; | |
304 | ||
305 | rcu_read_lock(); | |
306 | hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) { | |
307 | if (!batadv_compare_eth(pos->other_end, dst)) | |
308 | continue; | |
309 | ||
310 | if (memcmp(pos->session, session, sizeof(pos->session)) != 0) | |
311 | continue; | |
312 | ||
313 | /* most of the time this function is invoked during the normal | |
314 | * process..it makes sense to pay more when the session is | |
315 | * finished and to speed the process up during the measurement | |
316 | */ | |
317 | if (unlikely(!kref_get_unless_zero(&pos->refcount))) | |
318 | continue; | |
319 | ||
320 | tp_vars = pos; | |
321 | break; | |
322 | } | |
323 | rcu_read_unlock(); | |
324 | ||
325 | return tp_vars; | |
326 | } | |
327 | ||
328 | /** | |
7e9a8c2c | 329 | * batadv_tp_vars_release() - release batadv_tp_vars from lists and queue for |
33a3bb4a AQ |
330 | * free after rcu grace period |
331 | * @ref: kref pointer of the batadv_tp_vars | |
332 | */ | |
333 | static void batadv_tp_vars_release(struct kref *ref) | |
334 | { | |
335 | struct batadv_tp_vars *tp_vars; | |
336 | struct batadv_tp_unacked *un, *safe; | |
337 | ||
338 | tp_vars = container_of(ref, struct batadv_tp_vars, refcount); | |
339 | ||
340 | /* lock should not be needed because this object is now out of any | |
341 | * context! | |
342 | */ | |
343 | spin_lock_bh(&tp_vars->unacked_lock); | |
344 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { | |
345 | list_del(&un->list); | |
346 | kfree(un); | |
347 | } | |
348 | spin_unlock_bh(&tp_vars->unacked_lock); | |
349 | ||
350 | kfree_rcu(tp_vars, rcu); | |
351 | } | |
352 | ||
353 | /** | |
7e9a8c2c | 354 | * batadv_tp_vars_put() - decrement the batadv_tp_vars refcounter and possibly |
33a3bb4a AQ |
355 | * release it |
356 | * @tp_vars: the private data of the current TP meter session to be free'd | |
357 | */ | |
358 | static void batadv_tp_vars_put(struct batadv_tp_vars *tp_vars) | |
359 | { | |
360 | kref_put(&tp_vars->refcount, batadv_tp_vars_release); | |
361 | } | |
362 | ||
363 | /** | |
7e9a8c2c | 364 | * batadv_tp_sender_cleanup() - cleanup sender data and drop and timer |
33a3bb4a AQ |
365 | * @bat_priv: the bat priv with all the soft interface information |
366 | * @tp_vars: the private data of the current TP meter session to cleanup | |
367 | */ | |
368 | static void batadv_tp_sender_cleanup(struct batadv_priv *bat_priv, | |
369 | struct batadv_tp_vars *tp_vars) | |
370 | { | |
371 | cancel_delayed_work(&tp_vars->finish_work); | |
372 | ||
373 | spin_lock_bh(&tp_vars->bat_priv->tp_list_lock); | |
374 | hlist_del_rcu(&tp_vars->list); | |
375 | spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock); | |
376 | ||
377 | /* drop list reference */ | |
378 | batadv_tp_vars_put(tp_vars); | |
379 | ||
380 | atomic_dec(&tp_vars->bat_priv->tp_num); | |
381 | ||
382 | /* kill the timer and remove its reference */ | |
383 | del_timer_sync(&tp_vars->timer); | |
384 | /* the worker might have rearmed itself therefore we kill it again. Note | |
385 | * that if the worker should run again before invoking the following | |
386 | * del_timer(), it would not re-arm itself once again because the status | |
387 | * is OFF now | |
388 | */ | |
389 | del_timer(&tp_vars->timer); | |
390 | batadv_tp_vars_put(tp_vars); | |
391 | } | |
392 | ||
393 | /** | |
7e9a8c2c | 394 | * batadv_tp_sender_end() - print info about ended session and inform client |
33a3bb4a AQ |
395 | * @bat_priv: the bat priv with all the soft interface information |
396 | * @tp_vars: the private data of the current TP meter session | |
397 | */ | |
398 | static void batadv_tp_sender_end(struct batadv_priv *bat_priv, | |
399 | struct batadv_tp_vars *tp_vars) | |
400 | { | |
401 | u32 session_cookie; | |
402 | ||
403 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
404 | "Test towards %pM finished..shutting down (reason=%d)\n", | |
405 | tp_vars->other_end, tp_vars->reason); | |
406 | ||
407 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
408 | "Last timing stats: SRTT=%ums RTTVAR=%ums RTO=%ums\n", | |
409 | tp_vars->srtt >> 3, tp_vars->rttvar >> 2, tp_vars->rto); | |
410 | ||
411 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
412 | "Final values: cwnd=%u ss_threshold=%u\n", | |
413 | tp_vars->cwnd, tp_vars->ss_threshold); | |
414 | ||
415 | session_cookie = batadv_tp_session_cookie(tp_vars->session, | |
416 | tp_vars->icmp_uid); | |
417 | ||
418 | batadv_tp_batctl_notify(tp_vars->reason, | |
419 | tp_vars->other_end, | |
420 | bat_priv, | |
421 | tp_vars->start_time, | |
422 | atomic64_read(&tp_vars->tot_sent), | |
423 | session_cookie); | |
424 | } | |
425 | ||
426 | /** | |
7e9a8c2c | 427 | * batadv_tp_sender_shutdown() - let sender thread/timer stop gracefully |
33a3bb4a AQ |
428 | * @tp_vars: the private data of the current TP meter session |
429 | * @reason: reason for tp meter session stop | |
430 | */ | |
431 | static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars, | |
432 | enum batadv_tp_meter_reason reason) | |
433 | { | |
434 | if (!atomic_dec_and_test(&tp_vars->sending)) | |
435 | return; | |
436 | ||
437 | tp_vars->reason = reason; | |
438 | } | |
439 | ||
440 | /** | |
7e9a8c2c | 441 | * batadv_tp_sender_finish() - stop sender session after test_length was reached |
33a3bb4a AQ |
442 | * @work: delayed work reference of the related tp_vars |
443 | */ | |
444 | static void batadv_tp_sender_finish(struct work_struct *work) | |
445 | { | |
446 | struct delayed_work *delayed_work; | |
447 | struct batadv_tp_vars *tp_vars; | |
448 | ||
449 | delayed_work = to_delayed_work(work); | |
450 | tp_vars = container_of(delayed_work, struct batadv_tp_vars, | |
451 | finish_work); | |
452 | ||
453 | batadv_tp_sender_shutdown(tp_vars, BATADV_TP_REASON_COMPLETE); | |
454 | } | |
455 | ||
456 | /** | |
7e9a8c2c | 457 | * batadv_tp_reset_sender_timer() - reschedule the sender timer |
33a3bb4a AQ |
458 | * @tp_vars: the private TP meter data for this session |
459 | * | |
460 | * Reschedule the timer using tp_vars->rto as delay | |
461 | */ | |
462 | static void batadv_tp_reset_sender_timer(struct batadv_tp_vars *tp_vars) | |
463 | { | |
464 | /* most of the time this function is invoked while normal packet | |
465 | * reception... | |
466 | */ | |
467 | if (unlikely(atomic_read(&tp_vars->sending) == 0)) | |
468 | /* timer ref will be dropped in batadv_tp_sender_cleanup */ | |
469 | return; | |
470 | ||
471 | mod_timer(&tp_vars->timer, jiffies + msecs_to_jiffies(tp_vars->rto)); | |
472 | } | |
473 | ||
474 | /** | |
7e9a8c2c | 475 | * batadv_tp_sender_timeout() - timer that fires in case of packet loss |
974a6b20 | 476 | * @t: address to timer_list inside tp_vars |
33a3bb4a AQ |
477 | * |
478 | * If fired it means that there was packet loss. | |
479 | * Switch to Slow Start, set the ss_threshold to half of the current cwnd and | |
480 | * reset the cwnd to 3*MSS | |
481 | */ | |
e99e88a9 | 482 | static void batadv_tp_sender_timeout(struct timer_list *t) |
33a3bb4a | 483 | { |
e99e88a9 | 484 | struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer); |
33a3bb4a AQ |
485 | struct batadv_priv *bat_priv = tp_vars->bat_priv; |
486 | ||
487 | if (atomic_read(&tp_vars->sending) == 0) | |
488 | return; | |
489 | ||
490 | /* if the user waited long enough...shutdown the test */ | |
491 | if (unlikely(tp_vars->rto >= BATADV_TP_MAX_RTO)) { | |
492 | batadv_tp_sender_shutdown(tp_vars, | |
493 | BATADV_TP_REASON_DST_UNREACHABLE); | |
494 | return; | |
495 | } | |
496 | ||
497 | /* RTO exponential backoff | |
498 | * Details in Section 5.5 of RFC6298 | |
499 | */ | |
500 | tp_vars->rto <<= 1; | |
501 | ||
502 | spin_lock_bh(&tp_vars->cwnd_lock); | |
503 | ||
504 | tp_vars->ss_threshold = tp_vars->cwnd >> 1; | |
505 | if (tp_vars->ss_threshold < BATADV_TP_PLEN * 2) | |
506 | tp_vars->ss_threshold = BATADV_TP_PLEN * 2; | |
507 | ||
508 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
509 | "Meter: RTO fired during test towards %pM! cwnd=%u new ss_thr=%u, resetting last_sent to %u\n", | |
510 | tp_vars->other_end, tp_vars->cwnd, tp_vars->ss_threshold, | |
511 | atomic_read(&tp_vars->last_acked)); | |
512 | ||
513 | tp_vars->cwnd = BATADV_TP_PLEN * 3; | |
514 | ||
515 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
516 | ||
517 | /* resend the non-ACKed packets.. */ | |
518 | tp_vars->last_sent = atomic_read(&tp_vars->last_acked); | |
519 | wake_up(&tp_vars->more_bytes); | |
520 | ||
521 | batadv_tp_reset_sender_timer(tp_vars); | |
522 | } | |
523 | ||
524 | /** | |
7e9a8c2c | 525 | * batadv_tp_fill_prerandom() - Fill buffer with prefetched random bytes |
33a3bb4a AQ |
526 | * @tp_vars: the private TP meter data for this session |
527 | * @buf: Buffer to fill with bytes | |
528 | * @nbytes: amount of pseudorandom bytes | |
529 | */ | |
530 | static void batadv_tp_fill_prerandom(struct batadv_tp_vars *tp_vars, | |
531 | u8 *buf, size_t nbytes) | |
532 | { | |
533 | u32 local_offset; | |
534 | size_t bytes_inbuf; | |
535 | size_t to_copy; | |
536 | size_t pos = 0; | |
537 | ||
538 | spin_lock_bh(&tp_vars->prerandom_lock); | |
539 | local_offset = tp_vars->prerandom_offset; | |
540 | tp_vars->prerandom_offset += nbytes; | |
541 | tp_vars->prerandom_offset %= sizeof(batadv_tp_prerandom); | |
542 | spin_unlock_bh(&tp_vars->prerandom_lock); | |
543 | ||
544 | while (nbytes) { | |
545 | local_offset %= sizeof(batadv_tp_prerandom); | |
546 | bytes_inbuf = sizeof(batadv_tp_prerandom) - local_offset; | |
547 | to_copy = min(nbytes, bytes_inbuf); | |
548 | ||
549 | memcpy(&buf[pos], &batadv_tp_prerandom[local_offset], to_copy); | |
550 | pos += to_copy; | |
551 | nbytes -= to_copy; | |
552 | local_offset = 0; | |
553 | } | |
554 | } | |
555 | ||
556 | /** | |
7e9a8c2c | 557 | * batadv_tp_send_msg() - send a single message |
33a3bb4a AQ |
558 | * @tp_vars: the private TP meter data for this session |
559 | * @src: source mac address | |
560 | * @orig_node: the originator of the destination | |
561 | * @seqno: sequence number of this packet | |
562 | * @len: length of the entire packet | |
563 | * @session: session identifier | |
564 | * @uid: local ICMP "socket" index | |
565 | * @timestamp: timestamp in jiffies which is replied in ack | |
566 | * | |
567 | * Create and send a single TP Meter message. | |
568 | * | |
569 | * Return: 0 on success, BATADV_TP_REASON_DST_UNREACHABLE if the destination is | |
570 | * not reachable, BATADV_TP_REASON_MEMORY_ERROR if the packet couldn't be | |
571 | * allocated | |
572 | */ | |
573 | static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src, | |
574 | struct batadv_orig_node *orig_node, | |
575 | u32 seqno, size_t len, const u8 *session, | |
576 | int uid, u32 timestamp) | |
577 | { | |
578 | struct batadv_icmp_tp_packet *icmp; | |
579 | struct sk_buff *skb; | |
580 | int r; | |
581 | u8 *data; | |
582 | size_t data_len; | |
583 | ||
584 | skb = netdev_alloc_skb_ip_align(NULL, len + ETH_HLEN); | |
585 | if (unlikely(!skb)) | |
586 | return BATADV_TP_REASON_MEMORY_ERROR; | |
587 | ||
588 | skb_reserve(skb, ETH_HLEN); | |
4df864c1 | 589 | icmp = skb_put(skb, sizeof(*icmp)); |
33a3bb4a AQ |
590 | |
591 | /* fill the icmp header */ | |
592 | ether_addr_copy(icmp->dst, orig_node->orig); | |
593 | ether_addr_copy(icmp->orig, src); | |
594 | icmp->version = BATADV_COMPAT_VERSION; | |
595 | icmp->packet_type = BATADV_ICMP; | |
596 | icmp->ttl = BATADV_TTL; | |
597 | icmp->msg_type = BATADV_TP; | |
598 | icmp->uid = uid; | |
599 | ||
600 | icmp->subtype = BATADV_TP_MSG; | |
601 | memcpy(icmp->session, session, sizeof(icmp->session)); | |
602 | icmp->seqno = htonl(seqno); | |
603 | icmp->timestamp = htonl(timestamp); | |
604 | ||
605 | data_len = len - sizeof(*icmp); | |
4df864c1 | 606 | data = skb_put(skb, data_len); |
33a3bb4a AQ |
607 | batadv_tp_fill_prerandom(tp_vars, data, data_len); |
608 | ||
609 | r = batadv_send_skb_to_orig(skb, orig_node, NULL); | |
33a3bb4a AQ |
610 | if (r == NET_XMIT_SUCCESS) |
611 | return 0; | |
612 | ||
613 | return BATADV_TP_REASON_CANT_SEND; | |
614 | } | |
615 | ||
616 | /** | |
7e9a8c2c | 617 | * batadv_tp_recv_ack() - ACK receiving function |
33a3bb4a AQ |
618 | * @bat_priv: the bat priv with all the soft interface information |
619 | * @skb: the buffer containing the received packet | |
620 | * | |
621 | * Process a received TP ACK packet | |
622 | */ | |
623 | static void batadv_tp_recv_ack(struct batadv_priv *bat_priv, | |
624 | const struct sk_buff *skb) | |
625 | { | |
626 | struct batadv_hard_iface *primary_if = NULL; | |
627 | struct batadv_orig_node *orig_node = NULL; | |
628 | const struct batadv_icmp_tp_packet *icmp; | |
629 | struct batadv_tp_vars *tp_vars; | |
630 | size_t packet_len, mss; | |
631 | u32 rtt, recv_ack, cwnd; | |
632 | unsigned char *dev_addr; | |
633 | ||
634 | packet_len = BATADV_TP_PLEN; | |
635 | mss = BATADV_TP_PLEN; | |
636 | packet_len += sizeof(struct batadv_unicast_packet); | |
637 | ||
638 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
639 | ||
640 | /* find the tp_vars */ | |
641 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, | |
642 | icmp->session); | |
643 | if (unlikely(!tp_vars)) | |
644 | return; | |
645 | ||
646 | if (unlikely(atomic_read(&tp_vars->sending) == 0)) | |
647 | goto out; | |
648 | ||
649 | /* old ACK? silently drop it.. */ | |
650 | if (batadv_seq_before(ntohl(icmp->seqno), | |
651 | (u32)atomic_read(&tp_vars->last_acked))) | |
652 | goto out; | |
653 | ||
654 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
655 | if (unlikely(!primary_if)) | |
656 | goto out; | |
657 | ||
658 | orig_node = batadv_orig_hash_find(bat_priv, icmp->orig); | |
659 | if (unlikely(!orig_node)) | |
660 | goto out; | |
661 | ||
662 | /* update RTO with the new sampled RTT, if any */ | |
663 | rtt = jiffies_to_msecs(jiffies) - ntohl(icmp->timestamp); | |
664 | if (icmp->timestamp && rtt) | |
665 | batadv_tp_update_rto(tp_vars, rtt); | |
666 | ||
667 | /* ACK for new data... reset the timer */ | |
668 | batadv_tp_reset_sender_timer(tp_vars); | |
669 | ||
670 | recv_ack = ntohl(icmp->seqno); | |
671 | ||
672 | /* check if this ACK is a duplicate */ | |
673 | if (atomic_read(&tp_vars->last_acked) == recv_ack) { | |
674 | atomic_inc(&tp_vars->dup_acks); | |
675 | if (atomic_read(&tp_vars->dup_acks) != 3) | |
676 | goto out; | |
677 | ||
678 | if (recv_ack >= tp_vars->recover) | |
679 | goto out; | |
680 | ||
681 | /* if this is the third duplicate ACK do Fast Retransmit */ | |
682 | batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, | |
683 | orig_node, recv_ack, packet_len, | |
684 | icmp->session, icmp->uid, | |
685 | jiffies_to_msecs(jiffies)); | |
686 | ||
687 | spin_lock_bh(&tp_vars->cwnd_lock); | |
688 | ||
689 | /* Fast Recovery */ | |
690 | tp_vars->fast_recovery = true; | |
691 | /* Set recover to the last outstanding seqno when Fast Recovery | |
692 | * is entered. RFC6582, Section 3.2, step 1 | |
693 | */ | |
694 | tp_vars->recover = tp_vars->last_sent; | |
695 | tp_vars->ss_threshold = tp_vars->cwnd >> 1; | |
696 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
697 | "Meter: Fast Recovery, (cur cwnd=%u) ss_thr=%u last_sent=%u recv_ack=%u\n", | |
698 | tp_vars->cwnd, tp_vars->ss_threshold, | |
699 | tp_vars->last_sent, recv_ack); | |
700 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 3 * mss, | |
701 | mss); | |
702 | tp_vars->dec_cwnd = 0; | |
703 | tp_vars->last_sent = recv_ack; | |
704 | ||
705 | spin_unlock_bh(&tp_vars->cwnd_lock); | |
706 | } else { | |
707 | /* count the acked data */ | |
708 | atomic64_add(recv_ack - atomic_read(&tp_vars->last_acked), | |
709 | &tp_vars->tot_sent); | |
710 | /* reset the duplicate ACKs counter */ | |
711 | atomic_set(&tp_vars->dup_acks, 0); | |
712 | ||
713 | if (tp_vars->fast_recovery) { | |
714 | /* partial ACK */ | |
715 | if (batadv_seq_before(recv_ack, tp_vars->recover)) { | |
716 | /* this is another hole in the window. React | |
717 | * immediately as specified by NewReno (see | |
718 | * Section 3.2 of RFC6582 for details) | |
719 | */ | |
720 | dev_addr = primary_if->net_dev->dev_addr; | |
721 | batadv_tp_send_msg(tp_vars, dev_addr, | |
722 | orig_node, recv_ack, | |
723 | packet_len, icmp->session, | |
724 | icmp->uid, | |
725 | jiffies_to_msecs(jiffies)); | |
726 | tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, | |
727 | mss, mss); | |
728 | } else { | |
729 | tp_vars->fast_recovery = false; | |
730 | /* set cwnd to the value of ss_threshold at the | |
731 | * moment that Fast Recovery was entered. | |
732 | * RFC6582, Section 3.2, step 3 | |
733 | */ | |
734 | cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 0, | |
735 | mss); | |
736 | tp_vars->cwnd = cwnd; | |
737 | } | |
738 | goto move_twnd; | |
739 | } | |
740 | ||
741 | if (recv_ack - atomic_read(&tp_vars->last_acked) >= mss) | |
742 | batadv_tp_update_cwnd(tp_vars, mss); | |
743 | move_twnd: | |
744 | /* move the Transmit Window */ | |
745 | atomic_set(&tp_vars->last_acked, recv_ack); | |
746 | } | |
747 | ||
748 | wake_up(&tp_vars->more_bytes); | |
749 | out: | |
750 | if (likely(primary_if)) | |
751 | batadv_hardif_put(primary_if); | |
752 | if (likely(orig_node)) | |
753 | batadv_orig_node_put(orig_node); | |
754 | if (likely(tp_vars)) | |
755 | batadv_tp_vars_put(tp_vars); | |
756 | } | |
757 | ||
758 | /** | |
7e9a8c2c | 759 | * batadv_tp_avail() - check if congestion window is not full |
33a3bb4a AQ |
760 | * @tp_vars: the private data of the current TP meter session |
761 | * @payload_len: size of the payload of a single message | |
762 | * | |
763 | * Return: true when congestion window is not full, false otherwise | |
764 | */ | |
765 | static bool batadv_tp_avail(struct batadv_tp_vars *tp_vars, | |
766 | size_t payload_len) | |
767 | { | |
768 | u32 win_left, win_limit; | |
769 | ||
770 | win_limit = atomic_read(&tp_vars->last_acked) + tp_vars->cwnd; | |
771 | win_left = win_limit - tp_vars->last_sent; | |
772 | ||
773 | return win_left >= payload_len; | |
774 | } | |
775 | ||
776 | /** | |
7e9a8c2c | 777 | * batadv_tp_wait_available() - wait until congestion window becomes free or |
33a3bb4a AQ |
778 | * timeout is reached |
779 | * @tp_vars: the private data of the current TP meter session | |
780 | * @plen: size of the payload of a single message | |
781 | * | |
782 | * Return: 0 if the condition evaluated to false after the timeout elapsed, | |
783 | * 1 if the condition evaluated to true after the timeout elapsed, the | |
784 | * remaining jiffies (at least 1) if the condition evaluated to true before | |
785 | * the timeout elapsed, or -ERESTARTSYS if it was interrupted by a signal. | |
786 | */ | |
787 | static int batadv_tp_wait_available(struct batadv_tp_vars *tp_vars, size_t plen) | |
788 | { | |
789 | int ret; | |
790 | ||
791 | ret = wait_event_interruptible_timeout(tp_vars->more_bytes, | |
792 | batadv_tp_avail(tp_vars, plen), | |
793 | HZ / 10); | |
794 | ||
795 | return ret; | |
796 | } | |
797 | ||
798 | /** | |
7e9a8c2c | 799 | * batadv_tp_send() - main sending thread of a tp meter session |
33a3bb4a AQ |
800 | * @arg: address of the related tp_vars |
801 | * | |
802 | * Return: nothing, this function never returns | |
803 | */ | |
804 | static int batadv_tp_send(void *arg) | |
805 | { | |
806 | struct batadv_tp_vars *tp_vars = arg; | |
807 | struct batadv_priv *bat_priv = tp_vars->bat_priv; | |
808 | struct batadv_hard_iface *primary_if = NULL; | |
809 | struct batadv_orig_node *orig_node = NULL; | |
810 | size_t payload_len, packet_len; | |
811 | int err = 0; | |
812 | ||
813 | if (unlikely(tp_vars->role != BATADV_TP_SENDER)) { | |
814 | err = BATADV_TP_REASON_DST_UNREACHABLE; | |
815 | tp_vars->reason = err; | |
816 | goto out; | |
817 | } | |
818 | ||
819 | orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end); | |
820 | if (unlikely(!orig_node)) { | |
821 | err = BATADV_TP_REASON_DST_UNREACHABLE; | |
822 | tp_vars->reason = err; | |
823 | goto out; | |
824 | } | |
825 | ||
826 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
827 | if (unlikely(!primary_if)) { | |
828 | err = BATADV_TP_REASON_DST_UNREACHABLE; | |
e13258f3 | 829 | tp_vars->reason = err; |
33a3bb4a AQ |
830 | goto out; |
831 | } | |
832 | ||
833 | /* assume that all the hard_interfaces have a correctly | |
834 | * configured MTU, so use the soft_iface MTU as MSS. | |
835 | * This might not be true and in that case the fragmentation | |
836 | * should be used. | |
837 | * Now, try to send the packet as it is | |
838 | */ | |
839 | payload_len = BATADV_TP_PLEN; | |
840 | BUILD_BUG_ON(sizeof(struct batadv_icmp_tp_packet) > BATADV_TP_PLEN); | |
841 | ||
842 | batadv_tp_reset_sender_timer(tp_vars); | |
843 | ||
844 | /* queue the worker in charge of terminating the test */ | |
845 | queue_delayed_work(batadv_event_workqueue, &tp_vars->finish_work, | |
846 | msecs_to_jiffies(tp_vars->test_length)); | |
847 | ||
848 | while (atomic_read(&tp_vars->sending) != 0) { | |
849 | if (unlikely(!batadv_tp_avail(tp_vars, payload_len))) { | |
850 | batadv_tp_wait_available(tp_vars, payload_len); | |
851 | continue; | |
852 | } | |
853 | ||
854 | /* to emulate normal unicast traffic, add to the payload len | |
855 | * the size of the unicast header | |
856 | */ | |
857 | packet_len = payload_len + sizeof(struct batadv_unicast_packet); | |
858 | ||
859 | err = batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr, | |
860 | orig_node, tp_vars->last_sent, | |
861 | packet_len, | |
862 | tp_vars->session, tp_vars->icmp_uid, | |
863 | jiffies_to_msecs(jiffies)); | |
864 | ||
865 | /* something went wrong during the preparation/transmission */ | |
866 | if (unlikely(err && err != BATADV_TP_REASON_CANT_SEND)) { | |
867 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
4e09991a SE |
868 | "Meter: %s() cannot send packets (%d)\n", |
869 | __func__, err); | |
33a3bb4a AQ |
870 | /* ensure nobody else tries to stop the thread now */ |
871 | if (atomic_dec_and_test(&tp_vars->sending)) | |
872 | tp_vars->reason = err; | |
873 | break; | |
874 | } | |
875 | ||
876 | /* right-shift the TWND */ | |
877 | if (!err) | |
878 | tp_vars->last_sent += payload_len; | |
879 | ||
880 | cond_resched(); | |
881 | } | |
882 | ||
883 | out: | |
884 | if (likely(primary_if)) | |
885 | batadv_hardif_put(primary_if); | |
886 | if (likely(orig_node)) | |
887 | batadv_orig_node_put(orig_node); | |
888 | ||
889 | batadv_tp_sender_end(bat_priv, tp_vars); | |
890 | batadv_tp_sender_cleanup(bat_priv, tp_vars); | |
891 | ||
892 | batadv_tp_vars_put(tp_vars); | |
893 | ||
894 | do_exit(0); | |
895 | } | |
896 | ||
897 | /** | |
7e9a8c2c SE |
898 | * batadv_tp_start_kthread() - start new thread which manages the tp meter |
899 | * sender | |
33a3bb4a AQ |
900 | * @tp_vars: the private data of the current TP meter session |
901 | */ | |
902 | static void batadv_tp_start_kthread(struct batadv_tp_vars *tp_vars) | |
903 | { | |
904 | struct task_struct *kthread; | |
905 | struct batadv_priv *bat_priv = tp_vars->bat_priv; | |
906 | u32 session_cookie; | |
907 | ||
908 | kref_get(&tp_vars->refcount); | |
909 | kthread = kthread_create(batadv_tp_send, tp_vars, "kbatadv_tp_meter"); | |
910 | if (IS_ERR(kthread)) { | |
911 | session_cookie = batadv_tp_session_cookie(tp_vars->session, | |
912 | tp_vars->icmp_uid); | |
913 | pr_err("batadv: cannot create tp meter kthread\n"); | |
914 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, | |
915 | tp_vars->other_end, | |
916 | bat_priv, session_cookie); | |
917 | ||
918 | /* drop reserved reference for kthread */ | |
919 | batadv_tp_vars_put(tp_vars); | |
920 | ||
921 | /* cleanup of failed tp meter variables */ | |
922 | batadv_tp_sender_cleanup(bat_priv, tp_vars); | |
923 | return; | |
924 | } | |
925 | ||
926 | wake_up_process(kthread); | |
927 | } | |
928 | ||
929 | /** | |
7e9a8c2c | 930 | * batadv_tp_start() - start a new tp meter session |
33a3bb4a AQ |
931 | * @bat_priv: the bat priv with all the soft interface information |
932 | * @dst: the receiver MAC address | |
933 | * @test_length: test length in milliseconds | |
934 | * @cookie: session cookie | |
935 | */ | |
936 | void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, | |
937 | u32 test_length, u32 *cookie) | |
938 | { | |
939 | struct batadv_tp_vars *tp_vars; | |
940 | u8 session_id[2]; | |
941 | u8 icmp_uid; | |
942 | u32 session_cookie; | |
943 | ||
944 | get_random_bytes(session_id, sizeof(session_id)); | |
945 | get_random_bytes(&icmp_uid, 1); | |
946 | session_cookie = batadv_tp_session_cookie(session_id, icmp_uid); | |
947 | *cookie = session_cookie; | |
948 | ||
949 | /* look for an already existing test towards this node */ | |
950 | spin_lock_bh(&bat_priv->tp_list_lock); | |
951 | tp_vars = batadv_tp_list_find(bat_priv, dst); | |
952 | if (tp_vars) { | |
953 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
954 | batadv_tp_vars_put(tp_vars); | |
955 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
956 | "Meter: test to or from the same node already ongoing, aborting\n"); | |
957 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_ALREADY_ONGOING, | |
958 | dst, bat_priv, session_cookie); | |
959 | return; | |
960 | } | |
961 | ||
962 | if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) { | |
963 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
964 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
965 | "Meter: too many ongoing sessions, aborting (SEND)\n"); | |
966 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_TOO_MANY, dst, | |
967 | bat_priv, session_cookie); | |
968 | return; | |
969 | } | |
970 | ||
971 | tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); | |
972 | if (!tp_vars) { | |
973 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
974 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
4e09991a SE |
975 | "Meter: %s cannot allocate list elements\n", |
976 | __func__); | |
33a3bb4a AQ |
977 | batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, |
978 | dst, bat_priv, session_cookie); | |
979 | return; | |
980 | } | |
981 | ||
982 | /* initialize tp_vars */ | |
983 | ether_addr_copy(tp_vars->other_end, dst); | |
984 | kref_init(&tp_vars->refcount); | |
985 | tp_vars->role = BATADV_TP_SENDER; | |
986 | atomic_set(&tp_vars->sending, 1); | |
987 | memcpy(tp_vars->session, session_id, sizeof(session_id)); | |
988 | tp_vars->icmp_uid = icmp_uid; | |
989 | ||
990 | tp_vars->last_sent = BATADV_TP_FIRST_SEQ; | |
991 | atomic_set(&tp_vars->last_acked, BATADV_TP_FIRST_SEQ); | |
992 | tp_vars->fast_recovery = false; | |
993 | tp_vars->recover = BATADV_TP_FIRST_SEQ; | |
994 | ||
995 | /* initialise the CWND to 3*MSS (Section 3.1 in RFC5681). | |
996 | * For batman-adv the MSS is the size of the payload received by the | |
997 | * soft_interface, hence its MTU | |
998 | */ | |
999 | tp_vars->cwnd = BATADV_TP_PLEN * 3; | |
1000 | /* at the beginning initialise the SS threshold to the biggest possible | |
1001 | * window size, hence the AWND size | |
1002 | */ | |
1003 | tp_vars->ss_threshold = BATADV_TP_AWND; | |
1004 | ||
1005 | /* RTO initial value is 3 seconds. | |
1006 | * Details in Section 2.1 of RFC6298 | |
1007 | */ | |
1008 | tp_vars->rto = 1000; | |
1009 | tp_vars->srtt = 0; | |
1010 | tp_vars->rttvar = 0; | |
1011 | ||
1012 | atomic64_set(&tp_vars->tot_sent, 0); | |
1013 | ||
1014 | kref_get(&tp_vars->refcount); | |
e99e88a9 | 1015 | timer_setup(&tp_vars->timer, batadv_tp_sender_timeout, 0); |
33a3bb4a AQ |
1016 | |
1017 | tp_vars->bat_priv = bat_priv; | |
1018 | tp_vars->start_time = jiffies; | |
1019 | ||
1020 | init_waitqueue_head(&tp_vars->more_bytes); | |
1021 | ||
1022 | spin_lock_init(&tp_vars->unacked_lock); | |
1023 | INIT_LIST_HEAD(&tp_vars->unacked_list); | |
1024 | ||
1025 | spin_lock_init(&tp_vars->cwnd_lock); | |
1026 | ||
1027 | tp_vars->prerandom_offset = 0; | |
1028 | spin_lock_init(&tp_vars->prerandom_lock); | |
1029 | ||
1030 | kref_get(&tp_vars->refcount); | |
1031 | hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list); | |
1032 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
1033 | ||
1034 | tp_vars->test_length = test_length; | |
1035 | if (!tp_vars->test_length) | |
1036 | tp_vars->test_length = BATADV_TP_DEF_TEST_LENGTH; | |
1037 | ||
1038 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1039 | "Meter: starting throughput meter towards %pM (length=%ums)\n", | |
1040 | dst, test_length); | |
1041 | ||
1042 | /* init work item for finished tp tests */ | |
1043 | INIT_DELAYED_WORK(&tp_vars->finish_work, batadv_tp_sender_finish); | |
1044 | ||
1045 | /* start tp kthread. This way the write() call issued from userspace can | |
1046 | * happily return and avoid to block | |
1047 | */ | |
1048 | batadv_tp_start_kthread(tp_vars); | |
1049 | ||
1050 | /* don't return reference to new tp_vars */ | |
1051 | batadv_tp_vars_put(tp_vars); | |
1052 | } | |
1053 | ||
1054 | /** | |
7e9a8c2c | 1055 | * batadv_tp_stop() - stop currently running tp meter session |
33a3bb4a AQ |
1056 | * @bat_priv: the bat priv with all the soft interface information |
1057 | * @dst: the receiver MAC address | |
1058 | * @return_value: reason for tp meter session stop | |
1059 | */ | |
1060 | void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, | |
1061 | u8 return_value) | |
1062 | { | |
1063 | struct batadv_orig_node *orig_node; | |
1064 | struct batadv_tp_vars *tp_vars; | |
1065 | ||
1066 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1067 | "Meter: stopping test towards %pM\n", dst); | |
1068 | ||
1069 | orig_node = batadv_orig_hash_find(bat_priv, dst); | |
1070 | if (!orig_node) | |
1071 | return; | |
1072 | ||
1073 | tp_vars = batadv_tp_list_find(bat_priv, orig_node->orig); | |
1074 | if (!tp_vars) { | |
1075 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1076 | "Meter: trying to interrupt an already over connection\n"); | |
1077 | goto out; | |
1078 | } | |
1079 | ||
1080 | batadv_tp_sender_shutdown(tp_vars, return_value); | |
1081 | batadv_tp_vars_put(tp_vars); | |
1082 | out: | |
1083 | batadv_orig_node_put(orig_node); | |
1084 | } | |
1085 | ||
1086 | /** | |
7e9a8c2c | 1087 | * batadv_tp_reset_receiver_timer() - reset the receiver shutdown timer |
33a3bb4a AQ |
1088 | * @tp_vars: the private data of the current TP meter session |
1089 | * | |
1090 | * start the receiver shutdown timer or reset it if already started | |
1091 | */ | |
1092 | static void batadv_tp_reset_receiver_timer(struct batadv_tp_vars *tp_vars) | |
1093 | { | |
1094 | mod_timer(&tp_vars->timer, | |
1095 | jiffies + msecs_to_jiffies(BATADV_TP_RECV_TIMEOUT)); | |
1096 | } | |
1097 | ||
1098 | /** | |
7e9a8c2c | 1099 | * batadv_tp_receiver_shutdown() - stop a tp meter receiver when timeout is |
33a3bb4a | 1100 | * reached without received ack |
974a6b20 | 1101 | * @t: address to timer_list inside tp_vars |
33a3bb4a | 1102 | */ |
e99e88a9 | 1103 | static void batadv_tp_receiver_shutdown(struct timer_list *t) |
33a3bb4a | 1104 | { |
e99e88a9 | 1105 | struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer); |
33a3bb4a AQ |
1106 | struct batadv_tp_unacked *un, *safe; |
1107 | struct batadv_priv *bat_priv; | |
1108 | ||
1109 | bat_priv = tp_vars->bat_priv; | |
1110 | ||
1111 | /* if there is recent activity rearm the timer */ | |
1112 | if (!batadv_has_timed_out(tp_vars->last_recv_time, | |
1113 | BATADV_TP_RECV_TIMEOUT)) { | |
1114 | /* reset the receiver shutdown timer */ | |
1115 | batadv_tp_reset_receiver_timer(tp_vars); | |
1116 | return; | |
1117 | } | |
1118 | ||
1119 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1120 | "Shutting down for inactivity (more than %dms) from %pM\n", | |
1121 | BATADV_TP_RECV_TIMEOUT, tp_vars->other_end); | |
1122 | ||
1123 | spin_lock_bh(&tp_vars->bat_priv->tp_list_lock); | |
1124 | hlist_del_rcu(&tp_vars->list); | |
1125 | spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock); | |
1126 | ||
1127 | /* drop list reference */ | |
1128 | batadv_tp_vars_put(tp_vars); | |
1129 | ||
1130 | atomic_dec(&bat_priv->tp_num); | |
1131 | ||
1132 | spin_lock_bh(&tp_vars->unacked_lock); | |
1133 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { | |
1134 | list_del(&un->list); | |
1135 | kfree(un); | |
1136 | } | |
1137 | spin_unlock_bh(&tp_vars->unacked_lock); | |
1138 | ||
1139 | /* drop reference of timer */ | |
1140 | batadv_tp_vars_put(tp_vars); | |
1141 | } | |
1142 | ||
1143 | /** | |
7e9a8c2c | 1144 | * batadv_tp_send_ack() - send an ACK packet |
33a3bb4a AQ |
1145 | * @bat_priv: the bat priv with all the soft interface information |
1146 | * @dst: the mac address of the destination originator | |
1147 | * @seq: the sequence number to ACK | |
1148 | * @timestamp: the timestamp to echo back in the ACK | |
1149 | * @session: session identifier | |
1150 | * @socket_index: local ICMP socket identifier | |
1151 | * | |
1152 | * Return: 0 on success, a positive integer representing the reason of the | |
1153 | * failure otherwise | |
1154 | */ | |
1155 | static int batadv_tp_send_ack(struct batadv_priv *bat_priv, const u8 *dst, | |
1156 | u32 seq, __be32 timestamp, const u8 *session, | |
1157 | int socket_index) | |
1158 | { | |
1159 | struct batadv_hard_iface *primary_if = NULL; | |
1160 | struct batadv_orig_node *orig_node; | |
1161 | struct batadv_icmp_tp_packet *icmp; | |
1162 | struct sk_buff *skb; | |
1163 | int r, ret; | |
1164 | ||
1165 | orig_node = batadv_orig_hash_find(bat_priv, dst); | |
1166 | if (unlikely(!orig_node)) { | |
1167 | ret = BATADV_TP_REASON_DST_UNREACHABLE; | |
1168 | goto out; | |
1169 | } | |
1170 | ||
1171 | primary_if = batadv_primary_if_get_selected(bat_priv); | |
1172 | if (unlikely(!primary_if)) { | |
1173 | ret = BATADV_TP_REASON_DST_UNREACHABLE; | |
1174 | goto out; | |
1175 | } | |
1176 | ||
1177 | skb = netdev_alloc_skb_ip_align(NULL, sizeof(*icmp) + ETH_HLEN); | |
1178 | if (unlikely(!skb)) { | |
1179 | ret = BATADV_TP_REASON_MEMORY_ERROR; | |
1180 | goto out; | |
1181 | } | |
1182 | ||
1183 | skb_reserve(skb, ETH_HLEN); | |
4df864c1 | 1184 | icmp = skb_put(skb, sizeof(*icmp)); |
33a3bb4a AQ |
1185 | icmp->packet_type = BATADV_ICMP; |
1186 | icmp->version = BATADV_COMPAT_VERSION; | |
1187 | icmp->ttl = BATADV_TTL; | |
1188 | icmp->msg_type = BATADV_TP; | |
1189 | ether_addr_copy(icmp->dst, orig_node->orig); | |
1190 | ether_addr_copy(icmp->orig, primary_if->net_dev->dev_addr); | |
1191 | icmp->uid = socket_index; | |
1192 | ||
1193 | icmp->subtype = BATADV_TP_ACK; | |
1194 | memcpy(icmp->session, session, sizeof(icmp->session)); | |
1195 | icmp->seqno = htonl(seq); | |
1196 | icmp->timestamp = timestamp; | |
1197 | ||
1198 | /* send the ack */ | |
1199 | r = batadv_send_skb_to_orig(skb, orig_node, NULL); | |
825ffe1f | 1200 | if (unlikely(r < 0) || r == NET_XMIT_DROP) { |
33a3bb4a AQ |
1201 | ret = BATADV_TP_REASON_DST_UNREACHABLE; |
1202 | goto out; | |
1203 | } | |
1204 | ret = 0; | |
1205 | ||
1206 | out: | |
1207 | if (likely(orig_node)) | |
1208 | batadv_orig_node_put(orig_node); | |
1209 | if (likely(primary_if)) | |
1210 | batadv_hardif_put(primary_if); | |
1211 | ||
1212 | return ret; | |
1213 | } | |
1214 | ||
1215 | /** | |
7e9a8c2c | 1216 | * batadv_tp_handle_out_of_order() - store an out of order packet |
33a3bb4a AQ |
1217 | * @tp_vars: the private data of the current TP meter session |
1218 | * @skb: the buffer containing the received packet | |
1219 | * | |
1220 | * Store the out of order packet in the unacked list for late processing. This | |
1221 | * packets are kept in this list so that they can be ACKed at once as soon as | |
1222 | * all the previous packets have been received | |
1223 | * | |
1224 | * Return: true if the packed has been successfully processed, false otherwise | |
1225 | */ | |
1226 | static bool batadv_tp_handle_out_of_order(struct batadv_tp_vars *tp_vars, | |
1227 | const struct sk_buff *skb) | |
1228 | { | |
1229 | const struct batadv_icmp_tp_packet *icmp; | |
1230 | struct batadv_tp_unacked *un, *new; | |
1231 | u32 payload_len; | |
1232 | bool added = false; | |
1233 | ||
1234 | new = kmalloc(sizeof(*new), GFP_ATOMIC); | |
1235 | if (unlikely(!new)) | |
1236 | return false; | |
1237 | ||
1238 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
1239 | ||
1240 | new->seqno = ntohl(icmp->seqno); | |
1241 | payload_len = skb->len - sizeof(struct batadv_unicast_packet); | |
1242 | new->len = payload_len; | |
1243 | ||
1244 | spin_lock_bh(&tp_vars->unacked_lock); | |
1245 | /* if the list is empty immediately attach this new object */ | |
1246 | if (list_empty(&tp_vars->unacked_list)) { | |
1247 | list_add(&new->list, &tp_vars->unacked_list); | |
1248 | goto out; | |
1249 | } | |
1250 | ||
1251 | /* otherwise loop over the list and either drop the packet because this | |
1252 | * is a duplicate or store it at the right position. | |
1253 | * | |
1254 | * The iteration is done in the reverse way because it is likely that | |
1255 | * the last received packet (the one being processed now) has a bigger | |
1256 | * seqno than all the others already stored. | |
1257 | */ | |
1258 | list_for_each_entry_reverse(un, &tp_vars->unacked_list, list) { | |
1259 | /* check for duplicates */ | |
1260 | if (new->seqno == un->seqno) { | |
1261 | if (new->len > un->len) | |
1262 | un->len = new->len; | |
1263 | kfree(new); | |
1264 | added = true; | |
1265 | break; | |
1266 | } | |
1267 | ||
1268 | /* look for the right position */ | |
1269 | if (batadv_seq_before(new->seqno, un->seqno)) | |
1270 | continue; | |
1271 | ||
1272 | /* as soon as an entry having a bigger seqno is found, the new | |
1273 | * one is attached _after_ it. In this way the list is kept in | |
1274 | * ascending order | |
1275 | */ | |
1276 | list_add_tail(&new->list, &un->list); | |
1277 | added = true; | |
1278 | break; | |
1279 | } | |
1280 | ||
1281 | /* received packet with smallest seqno out of order; add it to front */ | |
1282 | if (!added) | |
1283 | list_add(&new->list, &tp_vars->unacked_list); | |
1284 | ||
1285 | out: | |
1286 | spin_unlock_bh(&tp_vars->unacked_lock); | |
1287 | ||
1288 | return true; | |
1289 | } | |
1290 | ||
1291 | /** | |
7e9a8c2c | 1292 | * batadv_tp_ack_unordered() - update number received bytes in current stream |
33a3bb4a AQ |
1293 | * without gaps |
1294 | * @tp_vars: the private data of the current TP meter session | |
1295 | */ | |
1296 | static void batadv_tp_ack_unordered(struct batadv_tp_vars *tp_vars) | |
1297 | { | |
1298 | struct batadv_tp_unacked *un, *safe; | |
1299 | u32 to_ack; | |
1300 | ||
1301 | /* go through the unacked packet list and possibly ACK them as | |
1302 | * well | |
1303 | */ | |
1304 | spin_lock_bh(&tp_vars->unacked_lock); | |
1305 | list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) { | |
1306 | /* the list is ordered, therefore it is possible to stop as soon | |
1307 | * there is a gap between the last acked seqno and the seqno of | |
1308 | * the packet under inspection | |
1309 | */ | |
1310 | if (batadv_seq_before(tp_vars->last_recv, un->seqno)) | |
1311 | break; | |
1312 | ||
1313 | to_ack = un->seqno + un->len - tp_vars->last_recv; | |
1314 | ||
1315 | if (batadv_seq_before(tp_vars->last_recv, un->seqno + un->len)) | |
1316 | tp_vars->last_recv += to_ack; | |
1317 | ||
1318 | list_del(&un->list); | |
1319 | kfree(un); | |
1320 | } | |
1321 | spin_unlock_bh(&tp_vars->unacked_lock); | |
1322 | } | |
1323 | ||
1324 | /** | |
7e9a8c2c | 1325 | * batadv_tp_init_recv() - return matching or create new receiver tp_vars |
33a3bb4a AQ |
1326 | * @bat_priv: the bat priv with all the soft interface information |
1327 | * @icmp: received icmp tp msg | |
1328 | * | |
1329 | * Return: corresponding tp_vars or NULL on errors | |
1330 | */ | |
1331 | static struct batadv_tp_vars * | |
1332 | batadv_tp_init_recv(struct batadv_priv *bat_priv, | |
1333 | const struct batadv_icmp_tp_packet *icmp) | |
1334 | { | |
1335 | struct batadv_tp_vars *tp_vars; | |
1336 | ||
1337 | spin_lock_bh(&bat_priv->tp_list_lock); | |
1338 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, | |
1339 | icmp->session); | |
1340 | if (tp_vars) | |
1341 | goto out_unlock; | |
1342 | ||
1343 | if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) { | |
1344 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1345 | "Meter: too many ongoing sessions, aborting (RECV)\n"); | |
1346 | goto out_unlock; | |
1347 | } | |
1348 | ||
1349 | tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC); | |
1350 | if (!tp_vars) | |
1351 | goto out_unlock; | |
1352 | ||
1353 | ether_addr_copy(tp_vars->other_end, icmp->orig); | |
1354 | tp_vars->role = BATADV_TP_RECEIVER; | |
1355 | memcpy(tp_vars->session, icmp->session, sizeof(tp_vars->session)); | |
1356 | tp_vars->last_recv = BATADV_TP_FIRST_SEQ; | |
1357 | tp_vars->bat_priv = bat_priv; | |
1358 | kref_init(&tp_vars->refcount); | |
1359 | ||
1360 | spin_lock_init(&tp_vars->unacked_lock); | |
1361 | INIT_LIST_HEAD(&tp_vars->unacked_list); | |
1362 | ||
1363 | kref_get(&tp_vars->refcount); | |
1364 | hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list); | |
1365 | ||
1366 | kref_get(&tp_vars->refcount); | |
e99e88a9 | 1367 | timer_setup(&tp_vars->timer, batadv_tp_receiver_shutdown, 0); |
33a3bb4a AQ |
1368 | |
1369 | batadv_tp_reset_receiver_timer(tp_vars); | |
1370 | ||
1371 | out_unlock: | |
1372 | spin_unlock_bh(&bat_priv->tp_list_lock); | |
1373 | ||
1374 | return tp_vars; | |
1375 | } | |
1376 | ||
1377 | /** | |
7e9a8c2c | 1378 | * batadv_tp_recv_msg() - process a single data message |
33a3bb4a AQ |
1379 | * @bat_priv: the bat priv with all the soft interface information |
1380 | * @skb: the buffer containing the received packet | |
1381 | * | |
1382 | * Process a received TP MSG packet | |
1383 | */ | |
1384 | static void batadv_tp_recv_msg(struct batadv_priv *bat_priv, | |
1385 | const struct sk_buff *skb) | |
1386 | { | |
1387 | const struct batadv_icmp_tp_packet *icmp; | |
1388 | struct batadv_tp_vars *tp_vars; | |
1389 | size_t packet_size; | |
1390 | u32 seqno; | |
1391 | ||
1392 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
1393 | ||
1394 | seqno = ntohl(icmp->seqno); | |
1395 | /* check if this is the first seqno. This means that if the | |
1396 | * first packet is lost, the tp meter does not work anymore! | |
1397 | */ | |
1398 | if (seqno == BATADV_TP_FIRST_SEQ) { | |
1399 | tp_vars = batadv_tp_init_recv(bat_priv, icmp); | |
1400 | if (!tp_vars) { | |
1401 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1402 | "Meter: seqno != BATADV_TP_FIRST_SEQ cannot initiate connection\n"); | |
1403 | goto out; | |
1404 | } | |
1405 | } else { | |
1406 | tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig, | |
1407 | icmp->session); | |
1408 | if (!tp_vars) { | |
1409 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1410 | "Unexpected packet from %pM!\n", | |
1411 | icmp->orig); | |
1412 | goto out; | |
1413 | } | |
1414 | } | |
1415 | ||
1416 | if (unlikely(tp_vars->role != BATADV_TP_RECEIVER)) { | |
1417 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1418 | "Meter: dropping packet: not expected (role=%u)\n", | |
1419 | tp_vars->role); | |
1420 | goto out; | |
1421 | } | |
1422 | ||
1423 | tp_vars->last_recv_time = jiffies; | |
1424 | ||
1425 | /* if the packet is a duplicate, it may be the case that an ACK has been | |
1426 | * lost. Resend the ACK | |
1427 | */ | |
1428 | if (batadv_seq_before(seqno, tp_vars->last_recv)) | |
1429 | goto send_ack; | |
1430 | ||
1431 | /* if the packet is out of order enqueue it */ | |
1432 | if (ntohl(icmp->seqno) != tp_vars->last_recv) { | |
1433 | /* exit immediately (and do not send any ACK) if the packet has | |
1434 | * not been enqueued correctly | |
1435 | */ | |
1436 | if (!batadv_tp_handle_out_of_order(tp_vars, skb)) | |
1437 | goto out; | |
1438 | ||
1439 | /* send a duplicate ACK */ | |
1440 | goto send_ack; | |
1441 | } | |
1442 | ||
1443 | /* if everything was fine count the ACKed bytes */ | |
1444 | packet_size = skb->len - sizeof(struct batadv_unicast_packet); | |
1445 | tp_vars->last_recv += packet_size; | |
1446 | ||
1447 | /* check if this ordered message filled a gap.... */ | |
1448 | batadv_tp_ack_unordered(tp_vars); | |
1449 | ||
1450 | send_ack: | |
1451 | /* send the ACK. If the received packet was out of order, the ACK that | |
1452 | * is going to be sent is a duplicate (the sender will count them and | |
1453 | * possibly enter Fast Retransmit as soon as it has reached 3) | |
1454 | */ | |
1455 | batadv_tp_send_ack(bat_priv, icmp->orig, tp_vars->last_recv, | |
1456 | icmp->timestamp, icmp->session, icmp->uid); | |
1457 | out: | |
1458 | if (likely(tp_vars)) | |
1459 | batadv_tp_vars_put(tp_vars); | |
1460 | } | |
1461 | ||
1462 | /** | |
7e9a8c2c | 1463 | * batadv_tp_meter_recv() - main TP Meter receiving function |
33a3bb4a AQ |
1464 | * @bat_priv: the bat priv with all the soft interface information |
1465 | * @skb: the buffer containing the received packet | |
1466 | */ | |
1467 | void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb) | |
1468 | { | |
1469 | struct batadv_icmp_tp_packet *icmp; | |
1470 | ||
1471 | icmp = (struct batadv_icmp_tp_packet *)skb->data; | |
1472 | ||
1473 | switch (icmp->subtype) { | |
1474 | case BATADV_TP_MSG: | |
1475 | batadv_tp_recv_msg(bat_priv, skb); | |
1476 | break; | |
1477 | case BATADV_TP_ACK: | |
1478 | batadv_tp_recv_ack(bat_priv, skb); | |
1479 | break; | |
1480 | default: | |
1481 | batadv_dbg(BATADV_DBG_TP_METER, bat_priv, | |
1482 | "Received unknown TP Metric packet type %u\n", | |
1483 | icmp->subtype); | |
1484 | } | |
1485 | consume_skb(skb); | |
1486 | } | |
1487 | ||
1488 | /** | |
7e9a8c2c | 1489 | * batadv_tp_meter_init() - initialize global tp_meter structures |
33a3bb4a | 1490 | */ |
d1aa5142 | 1491 | void __init batadv_tp_meter_init(void) |
33a3bb4a AQ |
1492 | { |
1493 | get_random_bytes(batadv_tp_prerandom, sizeof(batadv_tp_prerandom)); | |
1494 | } |