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12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/module.h>
15#include <linux/circ_buf.h>
16#include <linux/net.h>
17#include <linux/skbuff.h>
18#include <linux/slab.h>
19#include <linux/udp.h>
20#include <net/sock.h>
21#include <net/af_rxrpc.h>
22#include "ar-internal.h"
23
24
25
26
27void __rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
28 ktime_t now)
29{
30 unsigned long t_j, now_j = jiffies;
31 ktime_t t;
32 bool queue = false;
33
34 if (call->state < RXRPC_CALL_COMPLETE) {
35 t = call->expire_at;
36 if (!ktime_after(t, now)) {
37 trace_rxrpc_timer(call, why, now, now_j);
38 queue = true;
39 goto out;
40 }
41
42 if (!ktime_after(call->resend_at, now)) {
43 call->resend_at = call->expire_at;
44 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
45 queue = true;
46 } else if (ktime_before(call->resend_at, t)) {
47 t = call->resend_at;
48 }
49
50 if (!ktime_after(call->ack_at, now)) {
51 call->ack_at = call->expire_at;
52 if (!test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events))
53 queue = true;
54 } else if (ktime_before(call->ack_at, t)) {
55 t = call->ack_at;
56 }
57
58 if (!ktime_after(call->ping_at, now)) {
59 call->ping_at = call->expire_at;
60 if (!test_and_set_bit(RXRPC_CALL_EV_PING, &call->events))
61 queue = true;
62 } else if (ktime_before(call->ping_at, t)) {
63 t = call->ping_at;
64 }
65
66 t_j = nsecs_to_jiffies(ktime_to_ns(ktime_sub(t, now)));
67 t_j += jiffies;
68
69
70
71
72
73
74 t_j++;
75
76 if (call->timer.expires != t_j || !timer_pending(&call->timer)) {
77 mod_timer(&call->timer, t_j);
78 trace_rxrpc_timer(call, why, now, now_j);
79 }
80 }
81
82out:
83 if (queue)
84 rxrpc_queue_call(call);
85}
86
87
88
89
90void rxrpc_set_timer(struct rxrpc_call *call, enum rxrpc_timer_trace why,
91 ktime_t now)
92{
93 read_lock_bh(&call->state_lock);
94 __rxrpc_set_timer(call, why, now);
95 read_unlock_bh(&call->state_lock);
96}
97
98
99
100
101static void rxrpc_propose_ping(struct rxrpc_call *call,
102 bool immediate, bool background)
103{
104 if (immediate) {
105 if (background &&
106 !test_and_set_bit(RXRPC_CALL_EV_PING, &call->events))
107 rxrpc_queue_call(call);
108 } else {
109 ktime_t now = ktime_get_real();
110 ktime_t ping_at = ktime_add_ms(now, rxrpc_idle_ack_delay);
111
112 if (ktime_before(ping_at, call->ping_at)) {
113 call->ping_at = ping_at;
114 rxrpc_set_timer(call, rxrpc_timer_set_for_ping, now);
115 }
116 }
117}
118
119
120
121
122static void __rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
123 u16 skew, u32 serial, bool immediate,
124 bool background,
125 enum rxrpc_propose_ack_trace why)
126{
127 enum rxrpc_propose_ack_outcome outcome = rxrpc_propose_ack_use;
128 unsigned int expiry = rxrpc_soft_ack_delay;
129 ktime_t now, ack_at;
130 s8 prior = rxrpc_ack_priority[ack_reason];
131
132
133
134
135 if (ack_reason == RXRPC_ACK_PING) {
136 rxrpc_propose_ping(call, immediate, background);
137 goto trace;
138 }
139
140
141
142
143 _debug("prior %u %u vs %u %u",
144 ack_reason, prior,
145 call->ackr_reason, rxrpc_ack_priority[call->ackr_reason]);
146 if (ack_reason == call->ackr_reason) {
147 if (RXRPC_ACK_UPDATEABLE & (1 << ack_reason)) {
148 outcome = rxrpc_propose_ack_update;
149 call->ackr_serial = serial;
150 call->ackr_skew = skew;
151 }
152 if (!immediate)
153 goto trace;
154 } else if (prior > rxrpc_ack_priority[call->ackr_reason]) {
155 call->ackr_reason = ack_reason;
156 call->ackr_serial = serial;
157 call->ackr_skew = skew;
158 } else {
159 outcome = rxrpc_propose_ack_subsume;
160 }
161
162 switch (ack_reason) {
163 case RXRPC_ACK_REQUESTED:
164 if (rxrpc_requested_ack_delay < expiry)
165 expiry = rxrpc_requested_ack_delay;
166 if (serial == 1)
167 immediate = false;
168 break;
169
170 case RXRPC_ACK_DELAY:
171 if (rxrpc_soft_ack_delay < expiry)
172 expiry = rxrpc_soft_ack_delay;
173 break;
174
175 case RXRPC_ACK_IDLE:
176 if (rxrpc_idle_ack_delay < expiry)
177 expiry = rxrpc_idle_ack_delay;
178 break;
179
180 default:
181 immediate = true;
182 break;
183 }
184
185 if (test_bit(RXRPC_CALL_EV_ACK, &call->events)) {
186 _debug("already scheduled");
187 } else if (immediate || expiry == 0) {
188 _debug("immediate ACK %lx", call->events);
189 if (!test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events) &&
190 background)
191 rxrpc_queue_call(call);
192 } else {
193 now = ktime_get_real();
194 ack_at = ktime_add_ms(now, expiry);
195 if (ktime_before(ack_at, call->ack_at)) {
196 call->ack_at = ack_at;
197 rxrpc_set_timer(call, rxrpc_timer_set_for_ack, now);
198 }
199 }
200
201trace:
202 trace_rxrpc_propose_ack(call, why, ack_reason, serial, immediate,
203 background, outcome);
204}
205
206
207
208
209void rxrpc_propose_ACK(struct rxrpc_call *call, u8 ack_reason,
210 u16 skew, u32 serial, bool immediate, bool background,
211 enum rxrpc_propose_ack_trace why)
212{
213 spin_lock_bh(&call->lock);
214 __rxrpc_propose_ACK(call, ack_reason, skew, serial,
215 immediate, background, why);
216 spin_unlock_bh(&call->lock);
217}
218
219
220
221
222static void rxrpc_congestion_timeout(struct rxrpc_call *call)
223{
224 set_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags);
225}
226
227
228
229
230static void rxrpc_resend(struct rxrpc_call *call, ktime_t now)
231{
232 struct rxrpc_skb_priv *sp;
233 struct sk_buff *skb;
234 rxrpc_seq_t cursor, seq, top;
235 ktime_t max_age, oldest, ack_ts;
236 int ix;
237 u8 annotation, anno_type, retrans = 0, unacked = 0;
238
239 _enter("{%d,%d}", call->tx_hard_ack, call->tx_top);
240
241 max_age = ktime_sub_ms(now, rxrpc_resend_timeout);
242
243 spin_lock_bh(&call->lock);
244
245 cursor = call->tx_hard_ack;
246 top = call->tx_top;
247 ASSERT(before_eq(cursor, top));
248 if (cursor == top)
249 goto out_unlock;
250
251
252
253
254
255 oldest = now;
256 for (seq = cursor + 1; before_eq(seq, top); seq++) {
257 ix = seq & RXRPC_RXTX_BUFF_MASK;
258 annotation = call->rxtx_annotations[ix];
259 anno_type = annotation & RXRPC_TX_ANNO_MASK;
260 annotation &= ~RXRPC_TX_ANNO_MASK;
261 if (anno_type == RXRPC_TX_ANNO_ACK)
262 continue;
263
264 skb = call->rxtx_buffer[ix];
265 rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
266 sp = rxrpc_skb(skb);
267
268 if (anno_type == RXRPC_TX_ANNO_UNACK) {
269 if (ktime_after(skb->tstamp, max_age)) {
270 if (ktime_before(skb->tstamp, oldest))
271 oldest = skb->tstamp;
272 continue;
273 }
274 if (!(annotation & RXRPC_TX_ANNO_RESENT))
275 unacked++;
276 }
277
278
279 call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS | annotation;
280 retrans++;
281 trace_rxrpc_retransmit(call, seq, annotation | anno_type,
282 ktime_to_ns(ktime_sub(skb->tstamp, max_age)));
283 }
284
285 call->resend_at = ktime_add_ms(oldest, rxrpc_resend_timeout);
286
287 if (unacked)
288 rxrpc_congestion_timeout(call);
289
290
291
292
293
294 if (!retrans) {
295 rxrpc_set_timer(call, rxrpc_timer_set_for_resend, now);
296 spin_unlock_bh(&call->lock);
297 ack_ts = ktime_sub(now, call->acks_latest_ts);
298 if (ktime_to_ns(ack_ts) < call->peer->rtt)
299 goto out;
300 rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false,
301 rxrpc_propose_ack_ping_for_lost_ack);
302 rxrpc_send_ack_packet(call, true);
303 goto out;
304 }
305
306
307
308
309
310
311 for (seq = cursor + 1; before_eq(seq, top); seq++) {
312 ix = seq & RXRPC_RXTX_BUFF_MASK;
313 annotation = call->rxtx_annotations[ix];
314 anno_type = annotation & RXRPC_TX_ANNO_MASK;
315 if (anno_type != RXRPC_TX_ANNO_RETRANS)
316 continue;
317
318 skb = call->rxtx_buffer[ix];
319 rxrpc_get_skb(skb, rxrpc_skb_tx_got);
320 spin_unlock_bh(&call->lock);
321
322 if (rxrpc_send_data_packet(call, skb, true) < 0) {
323 rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
324 return;
325 }
326
327 if (rxrpc_is_client_call(call))
328 rxrpc_expose_client_call(call);
329
330 rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
331 spin_lock_bh(&call->lock);
332
333
334
335
336
337
338 if (after(seq, call->tx_hard_ack)) {
339 annotation = call->rxtx_annotations[ix];
340 anno_type = annotation & RXRPC_TX_ANNO_MASK;
341 if (anno_type == RXRPC_TX_ANNO_RETRANS ||
342 anno_type == RXRPC_TX_ANNO_NAK) {
343 annotation &= ~RXRPC_TX_ANNO_MASK;
344 annotation |= RXRPC_TX_ANNO_UNACK;
345 }
346 annotation |= RXRPC_TX_ANNO_RESENT;
347 call->rxtx_annotations[ix] = annotation;
348 }
349
350 if (after(call->tx_hard_ack, seq))
351 seq = call->tx_hard_ack;
352 }
353
354out_unlock:
355 spin_unlock_bh(&call->lock);
356out:
357 _leave("");
358}
359
360
361
362
363void rxrpc_process_call(struct work_struct *work)
364{
365 struct rxrpc_call *call =
366 container_of(work, struct rxrpc_call, processor);
367 ktime_t now;
368
369 rxrpc_see_call(call);
370
371
372 _enter("{%d,%s,%lx}",
373 call->debug_id, rxrpc_call_states[call->state], call->events);
374
375recheck_state:
376 if (test_and_clear_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
377 rxrpc_send_abort_packet(call);
378 goto recheck_state;
379 }
380
381 if (call->state == RXRPC_CALL_COMPLETE) {
382 del_timer_sync(&call->timer);
383 rxrpc_notify_socket(call);
384 goto out_put;
385 }
386
387 now = ktime_get_real();
388 if (ktime_before(call->expire_at, now)) {
389 rxrpc_abort_call("EXP", call, 0, RX_CALL_TIMEOUT, -ETIME);
390 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
391 goto recheck_state;
392 }
393
394 if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events)) {
395 if (call->ackr_reason) {
396 rxrpc_send_ack_packet(call, false);
397 goto recheck_state;
398 }
399 }
400
401 if (test_and_clear_bit(RXRPC_CALL_EV_PING, &call->events)) {
402 rxrpc_send_ack_packet(call, true);
403 goto recheck_state;
404 }
405
406 if (test_and_clear_bit(RXRPC_CALL_EV_RESEND, &call->events)) {
407 rxrpc_resend(call, now);
408 goto recheck_state;
409 }
410
411 rxrpc_set_timer(call, rxrpc_timer_set_for_resend, now);
412
413
414 if (call->events && call->state < RXRPC_CALL_COMPLETE) {
415 __rxrpc_queue_call(call);
416 goto out;
417 }
418
419out_put:
420 rxrpc_put_call(call, rxrpc_call_put);
421out:
422 _leave("");
423}
424