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36#include <linux/string.h>
37#include <linux/slab.h>
38#include "packet_history.h"
39#include "../../dccp.h"
40
41
42
43
44
45
46
47struct tfrc_tx_hist_entry {
48 struct tfrc_tx_hist_entry *next;
49 u64 seqno;
50 ktime_t stamp;
51};
52
53
54
55
56static struct kmem_cache *tfrc_tx_hist_slab;
57
58int __init tfrc_tx_packet_history_init(void)
59{
60 tfrc_tx_hist_slab = kmem_cache_create("tfrc_tx_hist",
61 sizeof(struct tfrc_tx_hist_entry),
62 0, SLAB_HWCACHE_ALIGN, NULL);
63 return tfrc_tx_hist_slab == NULL ? -ENOBUFS : 0;
64}
65
66void tfrc_tx_packet_history_exit(void)
67{
68 if (tfrc_tx_hist_slab != NULL) {
69 kmem_cache_destroy(tfrc_tx_hist_slab);
70 tfrc_tx_hist_slab = NULL;
71 }
72}
73
74static struct tfrc_tx_hist_entry *
75 tfrc_tx_hist_find_entry(struct tfrc_tx_hist_entry *head, u64 seqno)
76{
77 while (head != NULL && head->seqno != seqno)
78 head = head->next;
79
80 return head;
81}
82
83int tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno)
84{
85 struct tfrc_tx_hist_entry *entry = kmem_cache_alloc(tfrc_tx_hist_slab, gfp_any());
86
87 if (entry == NULL)
88 return -ENOBUFS;
89 entry->seqno = seqno;
90 entry->stamp = ktime_get_real();
91 entry->next = *headp;
92 *headp = entry;
93 return 0;
94}
95
96void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp)
97{
98 struct tfrc_tx_hist_entry *head = *headp;
99
100 while (head != NULL) {
101 struct tfrc_tx_hist_entry *next = head->next;
102
103 kmem_cache_free(tfrc_tx_hist_slab, head);
104 head = next;
105 }
106
107 *headp = NULL;
108}
109
110u32 tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head, const u64 seqno,
111 const ktime_t now)
112{
113 u32 rtt = 0;
114 struct tfrc_tx_hist_entry *packet = tfrc_tx_hist_find_entry(head, seqno);
115
116 if (packet != NULL) {
117 rtt = ktime_us_delta(now, packet->stamp);
118
119
120
121 tfrc_tx_hist_purge(&packet->next);
122 }
123
124 return rtt;
125}
126
127
128
129
130
131static struct kmem_cache *tfrc_rx_hist_slab;
132
133int __init tfrc_rx_packet_history_init(void)
134{
135 tfrc_rx_hist_slab = kmem_cache_create("tfrc_rxh_cache",
136 sizeof(struct tfrc_rx_hist_entry),
137 0, SLAB_HWCACHE_ALIGN, NULL);
138 return tfrc_rx_hist_slab == NULL ? -ENOBUFS : 0;
139}
140
141void tfrc_rx_packet_history_exit(void)
142{
143 if (tfrc_rx_hist_slab != NULL) {
144 kmem_cache_destroy(tfrc_rx_hist_slab);
145 tfrc_rx_hist_slab = NULL;
146 }
147}
148
149static inline void tfrc_rx_hist_entry_from_skb(struct tfrc_rx_hist_entry *entry,
150 const struct sk_buff *skb,
151 const u64 ndp)
152{
153 const struct dccp_hdr *dh = dccp_hdr(skb);
154
155 entry->tfrchrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
156 entry->tfrchrx_ccval = dh->dccph_ccval;
157 entry->tfrchrx_type = dh->dccph_type;
158 entry->tfrchrx_ndp = ndp;
159 entry->tfrchrx_tstamp = ktime_get_real();
160}
161
162void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h,
163 const struct sk_buff *skb,
164 const u64 ndp)
165{
166 struct tfrc_rx_hist_entry *entry = tfrc_rx_hist_last_rcv(h);
167
168 tfrc_rx_hist_entry_from_skb(entry, skb, ndp);
169}
170
171
172int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb)
173{
174 const u64 seq = DCCP_SKB_CB(skb)->dccpd_seq;
175 int i;
176
177 if (dccp_delta_seqno(tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, seq) <= 0)
178 return 1;
179
180 for (i = 1; i <= h->loss_count; i++)
181 if (tfrc_rx_hist_entry(h, i)->tfrchrx_seqno == seq)
182 return 1;
183
184 return 0;
185}
186
187static void tfrc_rx_hist_swap(struct tfrc_rx_hist *h, const u8 a, const u8 b)
188{
189 const u8 idx_a = tfrc_rx_hist_index(h, a),
190 idx_b = tfrc_rx_hist_index(h, b);
191 struct tfrc_rx_hist_entry *tmp = h->ring[idx_a];
192
193 h->ring[idx_a] = h->ring[idx_b];
194 h->ring[idx_b] = tmp;
195}
196
197
198
199
200
201
202
203
204
205
206static void __do_track_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u64 n1)
207{
208 u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno,
209 s1 = DCCP_SKB_CB(skb)->dccpd_seq;
210
211 if (!dccp_loss_free(s0, s1, n1)) {
212 h->loss_count = 1;
213 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n1);
214 }
215}
216
217static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2)
218{
219 u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno,
220 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno,
221 s2 = DCCP_SKB_CB(skb)->dccpd_seq;
222
223 if (likely(dccp_delta_seqno(s1, s2) > 0)) {
224 h->loss_count = 2;
225 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n2);
226 return;
227 }
228
229
230
231 if (dccp_loss_free(s0, s2, n2)) {
232 u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp;
233
234 if (dccp_loss_free(s2, s1, n1)) {
235
236 h->loss_count = 0;
237 h->loss_start = tfrc_rx_hist_index(h, 1);
238 } else
239
240 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n2);
241
242 } else {
243
244
245
246 tfrc_rx_hist_swap(h, 0, 3);
247 h->loss_start = tfrc_rx_hist_index(h, 3);
248 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n2);
249 h->loss_count = 2;
250 }
251}
252
253
254static int __two_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n3)
255{
256 u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno,
257 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno,
258 s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno,
259 s3 = DCCP_SKB_CB(skb)->dccpd_seq;
260
261 if (likely(dccp_delta_seqno(s2, s3) > 0)) {
262 h->loss_count = 3;
263 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 3), skb, n3);
264 return 1;
265 }
266
267
268
269 if (dccp_delta_seqno(s1, s3) > 0) {
270
271
272
273 tfrc_rx_hist_swap(h, 2, 3);
274 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 2), skb, n3);
275 h->loss_count = 3;
276 return 1;
277 }
278
279
280
281 if (dccp_loss_free(s0, s3, n3)) {
282 u64 n1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_ndp;
283
284 if (dccp_loss_free(s3, s1, n1)) {
285
286 u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp;
287
288 if (dccp_loss_free(s1, s2, n2)) {
289
290 h->loss_start = tfrc_rx_hist_index(h, 2);
291 h->loss_count = 0;
292 } else {
293
294 h->loss_start = tfrc_rx_hist_index(h, 1);
295 h->loss_count = 1;
296 }
297
298 } else
299 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_loss_prev(h), skb, n3);
300
301 return 0;
302 }
303
304
305
306
307
308 tfrc_rx_hist_swap(h, 0, 3);
309 h->loss_start = tfrc_rx_hist_index(h, 3);
310 tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n3);
311 h->loss_count = 3;
312
313 return 1;
314}
315
316
317static void __three_after_loss(struct tfrc_rx_hist *h)
318{
319
320
321
322
323
324
325 u64 s1 = tfrc_rx_hist_entry(h, 1)->tfrchrx_seqno,
326 s2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_seqno,
327 s3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_seqno;
328 u64 n2 = tfrc_rx_hist_entry(h, 2)->tfrchrx_ndp,
329 n3 = tfrc_rx_hist_entry(h, 3)->tfrchrx_ndp;
330
331 if (dccp_loss_free(s1, s2, n2)) {
332
333 if (dccp_loss_free(s2, s3, n3)) {
334
335 h->loss_start = tfrc_rx_hist_index(h, 3);
336 h->loss_count = 0;
337 } else {
338
339 h->loss_start = tfrc_rx_hist_index(h, 2);
340 h->loss_count = 1;
341 }
342
343 } else {
344 h->loss_start = tfrc_rx_hist_index(h, 1);
345 h->loss_count = 2;
346 }
347}
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364int tfrc_rx_handle_loss(struct tfrc_rx_hist *h,
365 struct tfrc_loss_hist *lh,
366 struct sk_buff *skb, const u64 ndp,
367 u32 (*calc_first_li)(struct sock *), struct sock *sk)
368{
369 int is_new_loss = 0;
370
371 if (h->loss_count == 0) {
372 __do_track_loss(h, skb, ndp);
373 } else if (h->loss_count == 1) {
374 __one_after_loss(h, skb, ndp);
375 } else if (h->loss_count != 2) {
376 DCCP_BUG("invalid loss_count %d", h->loss_count);
377 } else if (__two_after_loss(h, skb, ndp)) {
378
379
380
381 is_new_loss = tfrc_lh_interval_add(lh, h, calc_first_li, sk);
382 __three_after_loss(h);
383 }
384 return is_new_loss;
385}
386
387int tfrc_rx_hist_alloc(struct tfrc_rx_hist *h)
388{
389 int i;
390
391 for (i = 0; i <= TFRC_NDUPACK; i++) {
392 h->ring[i] = kmem_cache_alloc(tfrc_rx_hist_slab, GFP_ATOMIC);
393 if (h->ring[i] == NULL)
394 goto out_free;
395 }
396
397 h->loss_count = h->loss_start = 0;
398 return 0;
399
400out_free:
401 while (i-- != 0) {
402 kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]);
403 h->ring[i] = NULL;
404 }
405 return -ENOBUFS;
406}
407
408void tfrc_rx_hist_purge(struct tfrc_rx_hist *h)
409{
410 int i;
411
412 for (i = 0; i <= TFRC_NDUPACK; ++i)
413 if (h->ring[i] != NULL) {
414 kmem_cache_free(tfrc_rx_hist_slab, h->ring[i]);
415 h->ring[i] = NULL;
416 }
417}
418
419
420
421
422static inline struct tfrc_rx_hist_entry *
423 tfrc_rx_hist_rtt_last_s(const struct tfrc_rx_hist *h)
424{
425 return h->ring[0];
426}
427
428
429
430
431static inline struct tfrc_rx_hist_entry *
432 tfrc_rx_hist_rtt_prev_s(const struct tfrc_rx_hist *h)
433{
434 return h->ring[h->rtt_sample_prev];
435}
436
437
438
439
440
441
442u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb)
443{
444 u32 sample = 0,
445 delta_v = SUB16(dccp_hdr(skb)->dccph_ccval,
446 tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval);
447
448 if (delta_v < 1 || delta_v > 4) {
449 if (h->rtt_sample_prev == 2) {
450 sample = SUB16(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval,
451 tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval);
452 if (sample)
453 sample = 4 / sample *
454 ktime_us_delta(tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_tstamp,
455 tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp);
456 else
457
458
459
460
461
462 DCCP_BUG("please report to dccp@vger.kernel.org"
463 " => prev = %u, last = %u",
464 tfrc_rx_hist_rtt_prev_s(h)->tfrchrx_ccval,
465 tfrc_rx_hist_rtt_last_s(h)->tfrchrx_ccval);
466 } else if (delta_v < 1) {
467 h->rtt_sample_prev = 1;
468 goto keep_ref_for_next_time;
469 }
470
471 } else if (delta_v == 4)
472 sample = ktime_to_us(net_timedelta(tfrc_rx_hist_rtt_last_s(h)->tfrchrx_tstamp));
473 else {
474 h->rtt_sample_prev = 2;
475 goto keep_ref_for_next_time;
476 }
477
478 if (unlikely(sample > DCCP_SANE_RTT_MAX)) {
479 DCCP_WARN("RTT sample %u too large, using max\n", sample);
480 sample = DCCP_SANE_RTT_MAX;
481 }
482
483 h->rtt_sample_prev = 0;
484keep_ref_for_next_time:
485
486 return sample;
487}
488