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tcp: metrics: Allow selective get/del of tcp-metrics based on src IP
[deliverable/linux.git] / net / ipv4 / tcp_metrics.c
1 #include <linux/rcupdate.h>
2 #include <linux/spinlock.h>
3 #include <linux/jiffies.h>
4 #include <linux/module.h>
5 #include <linux/cache.h>
6 #include <linux/slab.h>
7 #include <linux/init.h>
8 #include <linux/tcp.h>
9 #include <linux/hash.h>
10 #include <linux/tcp_metrics.h>
11 #include <linux/vmalloc.h>
12
13 #include <net/inet_connection_sock.h>
14 #include <net/net_namespace.h>
15 #include <net/request_sock.h>
16 #include <net/inetpeer.h>
17 #include <net/sock.h>
18 #include <net/ipv6.h>
19 #include <net/dst.h>
20 #include <net/tcp.h>
21 #include <net/genetlink.h>
22
23 int sysctl_tcp_nometrics_save __read_mostly;
24
25 struct tcp_fastopen_metrics {
26 u16 mss;
27 u16 syn_loss:10; /* Recurring Fast Open SYN losses */
28 unsigned long last_syn_loss; /* Last Fast Open SYN loss */
29 struct tcp_fastopen_cookie cookie;
30 };
31
32 struct tcp_metrics_block {
33 struct tcp_metrics_block __rcu *tcpm_next;
34 struct inetpeer_addr tcpm_saddr;
35 struct inetpeer_addr tcpm_daddr;
36 unsigned long tcpm_stamp;
37 u32 tcpm_ts;
38 u32 tcpm_ts_stamp;
39 u32 tcpm_lock;
40 u32 tcpm_vals[TCP_METRIC_MAX + 1];
41 struct tcp_fastopen_metrics tcpm_fastopen;
42
43 struct rcu_head rcu_head;
44 };
45
46 static bool tcp_metric_locked(struct tcp_metrics_block *tm,
47 enum tcp_metric_index idx)
48 {
49 return tm->tcpm_lock & (1 << idx);
50 }
51
52 static u32 tcp_metric_get(struct tcp_metrics_block *tm,
53 enum tcp_metric_index idx)
54 {
55 return tm->tcpm_vals[idx];
56 }
57
58 static u32 tcp_metric_get_jiffies(struct tcp_metrics_block *tm,
59 enum tcp_metric_index idx)
60 {
61 return msecs_to_jiffies(tm->tcpm_vals[idx]);
62 }
63
64 static void tcp_metric_set(struct tcp_metrics_block *tm,
65 enum tcp_metric_index idx,
66 u32 val)
67 {
68 tm->tcpm_vals[idx] = val;
69 }
70
71 static void tcp_metric_set_msecs(struct tcp_metrics_block *tm,
72 enum tcp_metric_index idx,
73 u32 val)
74 {
75 tm->tcpm_vals[idx] = jiffies_to_msecs(val);
76 }
77
78 static bool addr_same(const struct inetpeer_addr *a,
79 const struct inetpeer_addr *b)
80 {
81 const struct in6_addr *a6, *b6;
82
83 if (a->family != b->family)
84 return false;
85 if (a->family == AF_INET)
86 return a->addr.a4 == b->addr.a4;
87
88 a6 = (const struct in6_addr *) &a->addr.a6[0];
89 b6 = (const struct in6_addr *) &b->addr.a6[0];
90
91 return ipv6_addr_equal(a6, b6);
92 }
93
94 struct tcpm_hash_bucket {
95 struct tcp_metrics_block __rcu *chain;
96 };
97
98 static DEFINE_SPINLOCK(tcp_metrics_lock);
99
100 static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst,
101 bool fastopen_clear)
102 {
103 u32 val;
104
105 tm->tcpm_stamp = jiffies;
106
107 val = 0;
108 if (dst_metric_locked(dst, RTAX_RTT))
109 val |= 1 << TCP_METRIC_RTT;
110 if (dst_metric_locked(dst, RTAX_RTTVAR))
111 val |= 1 << TCP_METRIC_RTTVAR;
112 if (dst_metric_locked(dst, RTAX_SSTHRESH))
113 val |= 1 << TCP_METRIC_SSTHRESH;
114 if (dst_metric_locked(dst, RTAX_CWND))
115 val |= 1 << TCP_METRIC_CWND;
116 if (dst_metric_locked(dst, RTAX_REORDERING))
117 val |= 1 << TCP_METRIC_REORDERING;
118 tm->tcpm_lock = val;
119
120 tm->tcpm_vals[TCP_METRIC_RTT] = dst_metric_raw(dst, RTAX_RTT);
121 tm->tcpm_vals[TCP_METRIC_RTTVAR] = dst_metric_raw(dst, RTAX_RTTVAR);
122 tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH);
123 tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
124 tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
125 tm->tcpm_ts = 0;
126 tm->tcpm_ts_stamp = 0;
127 if (fastopen_clear) {
128 tm->tcpm_fastopen.mss = 0;
129 tm->tcpm_fastopen.syn_loss = 0;
130 tm->tcpm_fastopen.cookie.len = 0;
131 }
132 }
133
134 static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
135 struct inetpeer_addr *saddr,
136 struct inetpeer_addr *daddr,
137 unsigned int hash,
138 bool reclaim)
139 {
140 struct tcp_metrics_block *tm;
141 struct net *net;
142
143 spin_lock_bh(&tcp_metrics_lock);
144 net = dev_net(dst->dev);
145 if (unlikely(reclaim)) {
146 struct tcp_metrics_block *oldest;
147
148 oldest = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain);
149 for (tm = rcu_dereference(oldest->tcpm_next); tm;
150 tm = rcu_dereference(tm->tcpm_next)) {
151 if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
152 oldest = tm;
153 }
154 tm = oldest;
155 } else {
156 tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
157 if (!tm)
158 goto out_unlock;
159 }
160 tm->tcpm_saddr = *saddr;
161 tm->tcpm_daddr = *daddr;
162
163 tcpm_suck_dst(tm, dst, true);
164
165 if (likely(!reclaim)) {
166 tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
167 rcu_assign_pointer(net->ipv4.tcp_metrics_hash[hash].chain, tm);
168 }
169
170 out_unlock:
171 spin_unlock_bh(&tcp_metrics_lock);
172 return tm;
173 }
174
175 #define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
176
177 static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
178 {
179 if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
180 tcpm_suck_dst(tm, dst, false);
181 }
182
183 #define TCP_METRICS_RECLAIM_DEPTH 5
184 #define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
185
186 static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth)
187 {
188 if (tm)
189 return tm;
190 if (depth > TCP_METRICS_RECLAIM_DEPTH)
191 return TCP_METRICS_RECLAIM_PTR;
192 return NULL;
193 }
194
195 static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr,
196 const struct inetpeer_addr *daddr,
197 struct net *net, unsigned int hash)
198 {
199 struct tcp_metrics_block *tm;
200 int depth = 0;
201
202 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
203 tm = rcu_dereference(tm->tcpm_next)) {
204 if (addr_same(&tm->tcpm_saddr, saddr) &&
205 addr_same(&tm->tcpm_daddr, daddr))
206 break;
207 depth++;
208 }
209 return tcp_get_encode(tm, depth);
210 }
211
212 static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
213 struct dst_entry *dst)
214 {
215 struct tcp_metrics_block *tm;
216 struct inetpeer_addr saddr, daddr;
217 unsigned int hash;
218 struct net *net;
219
220 saddr.family = req->rsk_ops->family;
221 daddr.family = req->rsk_ops->family;
222 switch (daddr.family) {
223 case AF_INET:
224 saddr.addr.a4 = inet_rsk(req)->ir_loc_addr;
225 daddr.addr.a4 = inet_rsk(req)->ir_rmt_addr;
226 hash = (__force unsigned int) daddr.addr.a4;
227 break;
228 #if IS_ENABLED(CONFIG_IPV6)
229 case AF_INET6:
230 *(struct in6_addr *)saddr.addr.a6 = inet_rsk(req)->ir_v6_loc_addr;
231 *(struct in6_addr *)daddr.addr.a6 = inet_rsk(req)->ir_v6_rmt_addr;
232 hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr);
233 break;
234 #endif
235 default:
236 return NULL;
237 }
238
239 net = dev_net(dst->dev);
240 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
241
242 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
243 tm = rcu_dereference(tm->tcpm_next)) {
244 if (addr_same(&tm->tcpm_saddr, &saddr) &&
245 addr_same(&tm->tcpm_daddr, &daddr))
246 break;
247 }
248 tcpm_check_stamp(tm, dst);
249 return tm;
250 }
251
252 static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock *tw)
253 {
254 struct tcp_metrics_block *tm;
255 struct inetpeer_addr saddr, daddr;
256 unsigned int hash;
257 struct net *net;
258
259 saddr.family = tw->tw_family;
260 daddr.family = tw->tw_family;
261 switch (daddr.family) {
262 case AF_INET:
263 saddr.addr.a4 = tw->tw_rcv_saddr;
264 daddr.addr.a4 = tw->tw_daddr;
265 hash = (__force unsigned int) daddr.addr.a4;
266 break;
267 #if IS_ENABLED(CONFIG_IPV6)
268 case AF_INET6:
269 *(struct in6_addr *)saddr.addr.a6 = tw->tw_v6_rcv_saddr;
270 *(struct in6_addr *)daddr.addr.a6 = tw->tw_v6_daddr;
271 hash = ipv6_addr_hash(&tw->tw_v6_daddr);
272 break;
273 #endif
274 default:
275 return NULL;
276 }
277
278 net = twsk_net(tw);
279 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
280
281 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
282 tm = rcu_dereference(tm->tcpm_next)) {
283 if (addr_same(&tm->tcpm_saddr, &saddr) &&
284 addr_same(&tm->tcpm_daddr, &daddr))
285 break;
286 }
287 return tm;
288 }
289
290 static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
291 struct dst_entry *dst,
292 bool create)
293 {
294 struct tcp_metrics_block *tm;
295 struct inetpeer_addr saddr, daddr;
296 unsigned int hash;
297 struct net *net;
298 bool reclaim;
299
300 saddr.family = sk->sk_family;
301 daddr.family = sk->sk_family;
302 switch (daddr.family) {
303 case AF_INET:
304 saddr.addr.a4 = inet_sk(sk)->inet_saddr;
305 daddr.addr.a4 = inet_sk(sk)->inet_daddr;
306 hash = (__force unsigned int) daddr.addr.a4;
307 break;
308 #if IS_ENABLED(CONFIG_IPV6)
309 case AF_INET6:
310 *(struct in6_addr *)saddr.addr.a6 = sk->sk_v6_rcv_saddr;
311 *(struct in6_addr *)daddr.addr.a6 = sk->sk_v6_daddr;
312 hash = ipv6_addr_hash(&sk->sk_v6_daddr);
313 break;
314 #endif
315 default:
316 return NULL;
317 }
318
319 net = dev_net(dst->dev);
320 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
321
322 tm = __tcp_get_metrics(&saddr, &daddr, net, hash);
323 reclaim = false;
324 if (tm == TCP_METRICS_RECLAIM_PTR) {
325 reclaim = true;
326 tm = NULL;
327 }
328 if (!tm && create)
329 tm = tcpm_new(dst, &saddr, &daddr, hash, reclaim);
330 else
331 tcpm_check_stamp(tm, dst);
332
333 return tm;
334 }
335
336 /* Save metrics learned by this TCP session. This function is called
337 * only, when TCP finishes successfully i.e. when it enters TIME-WAIT
338 * or goes from LAST-ACK to CLOSE.
339 */
340 void tcp_update_metrics(struct sock *sk)
341 {
342 const struct inet_connection_sock *icsk = inet_csk(sk);
343 struct dst_entry *dst = __sk_dst_get(sk);
344 struct tcp_sock *tp = tcp_sk(sk);
345 struct tcp_metrics_block *tm;
346 unsigned long rtt;
347 u32 val;
348 int m;
349
350 if (sysctl_tcp_nometrics_save || !dst)
351 return;
352
353 if (dst->flags & DST_HOST)
354 dst_confirm(dst);
355
356 rcu_read_lock();
357 if (icsk->icsk_backoff || !tp->srtt) {
358 /* This session failed to estimate rtt. Why?
359 * Probably, no packets returned in time. Reset our
360 * results.
361 */
362 tm = tcp_get_metrics(sk, dst, false);
363 if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT))
364 tcp_metric_set(tm, TCP_METRIC_RTT, 0);
365 goto out_unlock;
366 } else
367 tm = tcp_get_metrics(sk, dst, true);
368
369 if (!tm)
370 goto out_unlock;
371
372 rtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
373 m = rtt - tp->srtt;
374
375 /* If newly calculated rtt larger than stored one, store new
376 * one. Otherwise, use EWMA. Remember, rtt overestimation is
377 * always better than underestimation.
378 */
379 if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
380 if (m <= 0)
381 rtt = tp->srtt;
382 else
383 rtt -= (m >> 3);
384 tcp_metric_set_msecs(tm, TCP_METRIC_RTT, rtt);
385 }
386
387 if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
388 unsigned long var;
389
390 if (m < 0)
391 m = -m;
392
393 /* Scale deviation to rttvar fixed point */
394 m >>= 1;
395 if (m < tp->mdev)
396 m = tp->mdev;
397
398 var = tcp_metric_get_jiffies(tm, TCP_METRIC_RTTVAR);
399 if (m >= var)
400 var = m;
401 else
402 var -= (var - m) >> 2;
403
404 tcp_metric_set_msecs(tm, TCP_METRIC_RTTVAR, var);
405 }
406
407 if (tcp_in_initial_slowstart(tp)) {
408 /* Slow start still did not finish. */
409 if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
410 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
411 if (val && (tp->snd_cwnd >> 1) > val)
412 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
413 tp->snd_cwnd >> 1);
414 }
415 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
416 val = tcp_metric_get(tm, TCP_METRIC_CWND);
417 if (tp->snd_cwnd > val)
418 tcp_metric_set(tm, TCP_METRIC_CWND,
419 tp->snd_cwnd);
420 }
421 } else if (tp->snd_cwnd > tp->snd_ssthresh &&
422 icsk->icsk_ca_state == TCP_CA_Open) {
423 /* Cong. avoidance phase, cwnd is reliable. */
424 if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))
425 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
426 max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
427 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
428 val = tcp_metric_get(tm, TCP_METRIC_CWND);
429 tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1);
430 }
431 } else {
432 /* Else slow start did not finish, cwnd is non-sense,
433 * ssthresh may be also invalid.
434 */
435 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
436 val = tcp_metric_get(tm, TCP_METRIC_CWND);
437 tcp_metric_set(tm, TCP_METRIC_CWND,
438 (val + tp->snd_ssthresh) >> 1);
439 }
440 if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
441 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
442 if (val && tp->snd_ssthresh > val)
443 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
444 tp->snd_ssthresh);
445 }
446 if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) {
447 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
448 if (val < tp->reordering &&
449 tp->reordering != sysctl_tcp_reordering)
450 tcp_metric_set(tm, TCP_METRIC_REORDERING,
451 tp->reordering);
452 }
453 }
454 tm->tcpm_stamp = jiffies;
455 out_unlock:
456 rcu_read_unlock();
457 }
458
459 /* Initialize metrics on socket. */
460
461 void tcp_init_metrics(struct sock *sk)
462 {
463 struct dst_entry *dst = __sk_dst_get(sk);
464 struct tcp_sock *tp = tcp_sk(sk);
465 struct tcp_metrics_block *tm;
466 u32 val, crtt = 0; /* cached RTT scaled by 8 */
467
468 if (dst == NULL)
469 goto reset;
470
471 dst_confirm(dst);
472
473 rcu_read_lock();
474 tm = tcp_get_metrics(sk, dst, true);
475 if (!tm) {
476 rcu_read_unlock();
477 goto reset;
478 }
479
480 if (tcp_metric_locked(tm, TCP_METRIC_CWND))
481 tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND);
482
483 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
484 if (val) {
485 tp->snd_ssthresh = val;
486 if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
487 tp->snd_ssthresh = tp->snd_cwnd_clamp;
488 } else {
489 /* ssthresh may have been reduced unnecessarily during.
490 * 3WHS. Restore it back to its initial default.
491 */
492 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
493 }
494 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
495 if (val && tp->reordering != val) {
496 tcp_disable_fack(tp);
497 tcp_disable_early_retrans(tp);
498 tp->reordering = val;
499 }
500
501 crtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
502 rcu_read_unlock();
503 reset:
504 /* The initial RTT measurement from the SYN/SYN-ACK is not ideal
505 * to seed the RTO for later data packets because SYN packets are
506 * small. Use the per-dst cached values to seed the RTO but keep
507 * the RTT estimator variables intact (e.g., srtt, mdev, rttvar).
508 * Later the RTO will be updated immediately upon obtaining the first
509 * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only
510 * influences the first RTO but not later RTT estimation.
511 *
512 * But if RTT is not available from the SYN (due to retransmits or
513 * syn cookies) or the cache, force a conservative 3secs timeout.
514 *
515 * A bit of theory. RTT is time passed after "normal" sized packet
516 * is sent until it is ACKed. In normal circumstances sending small
517 * packets force peer to delay ACKs and calculation is correct too.
518 * The algorithm is adaptive and, provided we follow specs, it
519 * NEVER underestimate RTT. BUT! If peer tries to make some clever
520 * tricks sort of "quick acks" for time long enough to decrease RTT
521 * to low value, and then abruptly stops to do it and starts to delay
522 * ACKs, wait for troubles.
523 */
524 if (crtt > tp->srtt) {
525 /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
526 crtt >>= 3;
527 inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
528 } else if (tp->srtt == 0) {
529 /* RFC6298: 5.7 We've failed to get a valid RTT sample from
530 * 3WHS. This is most likely due to retransmission,
531 * including spurious one. Reset the RTO back to 3secs
532 * from the more aggressive 1sec to avoid more spurious
533 * retransmission.
534 */
535 tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_FALLBACK;
536 inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
537 }
538 /* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been
539 * retransmitted. In light of RFC6298 more aggressive 1sec
540 * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK
541 * retransmission has occurred.
542 */
543 if (tp->total_retrans > 1)
544 tp->snd_cwnd = 1;
545 else
546 tp->snd_cwnd = tcp_init_cwnd(tp, dst);
547 tp->snd_cwnd_stamp = tcp_time_stamp;
548 }
549
550 bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, bool paws_check)
551 {
552 struct tcp_metrics_block *tm;
553 bool ret;
554
555 if (!dst)
556 return false;
557
558 rcu_read_lock();
559 tm = __tcp_get_metrics_req(req, dst);
560 if (paws_check) {
561 if (tm &&
562 (u32)get_seconds() - tm->tcpm_ts_stamp < TCP_PAWS_MSL &&
563 (s32)(tm->tcpm_ts - req->ts_recent) > TCP_PAWS_WINDOW)
564 ret = false;
565 else
566 ret = true;
567 } else {
568 if (tm && tcp_metric_get(tm, TCP_METRIC_RTT) && tm->tcpm_ts_stamp)
569 ret = true;
570 else
571 ret = false;
572 }
573 rcu_read_unlock();
574
575 return ret;
576 }
577 EXPORT_SYMBOL_GPL(tcp_peer_is_proven);
578
579 void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst)
580 {
581 struct tcp_metrics_block *tm;
582
583 rcu_read_lock();
584 tm = tcp_get_metrics(sk, dst, true);
585 if (tm) {
586 struct tcp_sock *tp = tcp_sk(sk);
587
588 if ((u32)get_seconds() - tm->tcpm_ts_stamp <= TCP_PAWS_MSL) {
589 tp->rx_opt.ts_recent_stamp = tm->tcpm_ts_stamp;
590 tp->rx_opt.ts_recent = tm->tcpm_ts;
591 }
592 }
593 rcu_read_unlock();
594 }
595 EXPORT_SYMBOL_GPL(tcp_fetch_timewait_stamp);
596
597 /* VJ's idea. Save last timestamp seen from this destination and hold
598 * it at least for normal timewait interval to use for duplicate
599 * segment detection in subsequent connections, before they enter
600 * synchronized state.
601 */
602 bool tcp_remember_stamp(struct sock *sk)
603 {
604 struct dst_entry *dst = __sk_dst_get(sk);
605 bool ret = false;
606
607 if (dst) {
608 struct tcp_metrics_block *tm;
609
610 rcu_read_lock();
611 tm = tcp_get_metrics(sk, dst, true);
612 if (tm) {
613 struct tcp_sock *tp = tcp_sk(sk);
614
615 if ((s32)(tm->tcpm_ts - tp->rx_opt.ts_recent) <= 0 ||
616 ((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL &&
617 tm->tcpm_ts_stamp <= (u32)tp->rx_opt.ts_recent_stamp)) {
618 tm->tcpm_ts_stamp = (u32)tp->rx_opt.ts_recent_stamp;
619 tm->tcpm_ts = tp->rx_opt.ts_recent;
620 }
621 ret = true;
622 }
623 rcu_read_unlock();
624 }
625 return ret;
626 }
627
628 bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw)
629 {
630 struct tcp_metrics_block *tm;
631 bool ret = false;
632
633 rcu_read_lock();
634 tm = __tcp_get_metrics_tw(tw);
635 if (tm) {
636 const struct tcp_timewait_sock *tcptw;
637 struct sock *sk = (struct sock *) tw;
638
639 tcptw = tcp_twsk(sk);
640 if ((s32)(tm->tcpm_ts - tcptw->tw_ts_recent) <= 0 ||
641 ((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL &&
642 tm->tcpm_ts_stamp <= (u32)tcptw->tw_ts_recent_stamp)) {
643 tm->tcpm_ts_stamp = (u32)tcptw->tw_ts_recent_stamp;
644 tm->tcpm_ts = tcptw->tw_ts_recent;
645 }
646 ret = true;
647 }
648 rcu_read_unlock();
649
650 return ret;
651 }
652
653 static DEFINE_SEQLOCK(fastopen_seqlock);
654
655 void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
656 struct tcp_fastopen_cookie *cookie,
657 int *syn_loss, unsigned long *last_syn_loss)
658 {
659 struct tcp_metrics_block *tm;
660
661 rcu_read_lock();
662 tm = tcp_get_metrics(sk, __sk_dst_get(sk), false);
663 if (tm) {
664 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
665 unsigned int seq;
666
667 do {
668 seq = read_seqbegin(&fastopen_seqlock);
669 if (tfom->mss)
670 *mss = tfom->mss;
671 *cookie = tfom->cookie;
672 *syn_loss = tfom->syn_loss;
673 *last_syn_loss = *syn_loss ? tfom->last_syn_loss : 0;
674 } while (read_seqretry(&fastopen_seqlock, seq));
675 }
676 rcu_read_unlock();
677 }
678
679 void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
680 struct tcp_fastopen_cookie *cookie, bool syn_lost)
681 {
682 struct dst_entry *dst = __sk_dst_get(sk);
683 struct tcp_metrics_block *tm;
684
685 if (!dst)
686 return;
687 rcu_read_lock();
688 tm = tcp_get_metrics(sk, dst, true);
689 if (tm) {
690 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
691
692 write_seqlock_bh(&fastopen_seqlock);
693 if (mss)
694 tfom->mss = mss;
695 if (cookie && cookie->len > 0)
696 tfom->cookie = *cookie;
697 if (syn_lost) {
698 ++tfom->syn_loss;
699 tfom->last_syn_loss = jiffies;
700 } else
701 tfom->syn_loss = 0;
702 write_sequnlock_bh(&fastopen_seqlock);
703 }
704 rcu_read_unlock();
705 }
706
707 static struct genl_family tcp_metrics_nl_family = {
708 .id = GENL_ID_GENERATE,
709 .hdrsize = 0,
710 .name = TCP_METRICS_GENL_NAME,
711 .version = TCP_METRICS_GENL_VERSION,
712 .maxattr = TCP_METRICS_ATTR_MAX,
713 .netnsok = true,
714 };
715
716 static struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = {
717 [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, },
718 [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY,
719 .len = sizeof(struct in6_addr), },
720 /* Following attributes are not received for GET/DEL,
721 * we keep them for reference
722 */
723 #if 0
724 [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, },
725 [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, },
726 [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, },
727 [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, },
728 [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, },
729 [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, },
730 [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, },
731 [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY,
732 .len = TCP_FASTOPEN_COOKIE_MAX, },
733 #endif
734 };
735
736 /* Add attributes, caller cancels its header on failure */
737 static int tcp_metrics_fill_info(struct sk_buff *msg,
738 struct tcp_metrics_block *tm)
739 {
740 struct nlattr *nest;
741 int i;
742
743 switch (tm->tcpm_daddr.family) {
744 case AF_INET:
745 if (nla_put_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4,
746 tm->tcpm_daddr.addr.a4) < 0)
747 goto nla_put_failure;
748 if (nla_put_be32(msg, TCP_METRICS_ATTR_SADDR_IPV4,
749 tm->tcpm_saddr.addr.a4) < 0)
750 goto nla_put_failure;
751 break;
752 case AF_INET6:
753 if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16,
754 tm->tcpm_daddr.addr.a6) < 0)
755 goto nla_put_failure;
756 if (nla_put(msg, TCP_METRICS_ATTR_SADDR_IPV6, 16,
757 tm->tcpm_saddr.addr.a6) < 0)
758 goto nla_put_failure;
759 break;
760 default:
761 return -EAFNOSUPPORT;
762 }
763
764 if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE,
765 jiffies - tm->tcpm_stamp) < 0)
766 goto nla_put_failure;
767 if (tm->tcpm_ts_stamp) {
768 if (nla_put_s32(msg, TCP_METRICS_ATTR_TW_TS_STAMP,
769 (s32) (get_seconds() - tm->tcpm_ts_stamp)) < 0)
770 goto nla_put_failure;
771 if (nla_put_u32(msg, TCP_METRICS_ATTR_TW_TSVAL,
772 tm->tcpm_ts) < 0)
773 goto nla_put_failure;
774 }
775
776 {
777 int n = 0;
778
779 nest = nla_nest_start(msg, TCP_METRICS_ATTR_VALS);
780 if (!nest)
781 goto nla_put_failure;
782 for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
783 if (!tm->tcpm_vals[i])
784 continue;
785 if (nla_put_u32(msg, i + 1, tm->tcpm_vals[i]) < 0)
786 goto nla_put_failure;
787 n++;
788 }
789 if (n)
790 nla_nest_end(msg, nest);
791 else
792 nla_nest_cancel(msg, nest);
793 }
794
795 {
796 struct tcp_fastopen_metrics tfom_copy[1], *tfom;
797 unsigned int seq;
798
799 do {
800 seq = read_seqbegin(&fastopen_seqlock);
801 tfom_copy[0] = tm->tcpm_fastopen;
802 } while (read_seqretry(&fastopen_seqlock, seq));
803
804 tfom = tfom_copy;
805 if (tfom->mss &&
806 nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS,
807 tfom->mss) < 0)
808 goto nla_put_failure;
809 if (tfom->syn_loss &&
810 (nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS,
811 tfom->syn_loss) < 0 ||
812 nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,
813 jiffies - tfom->last_syn_loss) < 0))
814 goto nla_put_failure;
815 if (tfom->cookie.len > 0 &&
816 nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE,
817 tfom->cookie.len, tfom->cookie.val) < 0)
818 goto nla_put_failure;
819 }
820
821 return 0;
822
823 nla_put_failure:
824 return -EMSGSIZE;
825 }
826
827 static int tcp_metrics_dump_info(struct sk_buff *skb,
828 struct netlink_callback *cb,
829 struct tcp_metrics_block *tm)
830 {
831 void *hdr;
832
833 hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
834 &tcp_metrics_nl_family, NLM_F_MULTI,
835 TCP_METRICS_CMD_GET);
836 if (!hdr)
837 return -EMSGSIZE;
838
839 if (tcp_metrics_fill_info(skb, tm) < 0)
840 goto nla_put_failure;
841
842 return genlmsg_end(skb, hdr);
843
844 nla_put_failure:
845 genlmsg_cancel(skb, hdr);
846 return -EMSGSIZE;
847 }
848
849 static int tcp_metrics_nl_dump(struct sk_buff *skb,
850 struct netlink_callback *cb)
851 {
852 struct net *net = sock_net(skb->sk);
853 unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
854 unsigned int row, s_row = cb->args[0];
855 int s_col = cb->args[1], col = s_col;
856
857 for (row = s_row; row < max_rows; row++, s_col = 0) {
858 struct tcp_metrics_block *tm;
859 struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash + row;
860
861 rcu_read_lock();
862 for (col = 0, tm = rcu_dereference(hb->chain); tm;
863 tm = rcu_dereference(tm->tcpm_next), col++) {
864 if (col < s_col)
865 continue;
866 if (tcp_metrics_dump_info(skb, cb, tm) < 0) {
867 rcu_read_unlock();
868 goto done;
869 }
870 }
871 rcu_read_unlock();
872 }
873
874 done:
875 cb->args[0] = row;
876 cb->args[1] = col;
877 return skb->len;
878 }
879
880 static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
881 unsigned int *hash, int optional, int v4, int v6)
882 {
883 struct nlattr *a;
884
885 a = info->attrs[v4];
886 if (a) {
887 addr->family = AF_INET;
888 addr->addr.a4 = nla_get_be32(a);
889 if (hash)
890 *hash = (__force unsigned int) addr->addr.a4;
891 return 0;
892 }
893 a = info->attrs[v6];
894 if (a) {
895 if (nla_len(a) != sizeof(struct in6_addr))
896 return -EINVAL;
897 addr->family = AF_INET6;
898 memcpy(addr->addr.a6, nla_data(a), sizeof(addr->addr.a6));
899 if (hash)
900 *hash = ipv6_addr_hash((struct in6_addr *) addr->addr.a6);
901 return 0;
902 }
903 return optional ? 1 : -EAFNOSUPPORT;
904 }
905
906 static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
907 unsigned int *hash, int optional)
908 {
909 return __parse_nl_addr(info, addr, hash, optional,
910 TCP_METRICS_ATTR_ADDR_IPV4,
911 TCP_METRICS_ATTR_ADDR_IPV6);
912 }
913
914 static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr)
915 {
916 return __parse_nl_addr(info, addr, NULL, 0,
917 TCP_METRICS_ATTR_SADDR_IPV4,
918 TCP_METRICS_ATTR_SADDR_IPV6);
919 }
920
921 static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
922 {
923 struct tcp_metrics_block *tm;
924 struct inetpeer_addr saddr, daddr;
925 unsigned int hash;
926 struct sk_buff *msg;
927 struct net *net = genl_info_net(info);
928 void *reply;
929 int ret;
930 bool src = true;
931
932 ret = parse_nl_addr(info, &daddr, &hash, 0);
933 if (ret < 0)
934 return ret;
935
936 ret = parse_nl_saddr(info, &saddr);
937 if (ret < 0)
938 src = false;
939
940 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
941 if (!msg)
942 return -ENOMEM;
943
944 reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0,
945 info->genlhdr->cmd);
946 if (!reply)
947 goto nla_put_failure;
948
949 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
950 ret = -ESRCH;
951 rcu_read_lock();
952 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
953 tm = rcu_dereference(tm->tcpm_next)) {
954 if (addr_same(&tm->tcpm_daddr, &daddr) &&
955 (!src || addr_same(&tm->tcpm_saddr, &saddr))) {
956 ret = tcp_metrics_fill_info(msg, tm);
957 break;
958 }
959 }
960 rcu_read_unlock();
961 if (ret < 0)
962 goto out_free;
963
964 genlmsg_end(msg, reply);
965 return genlmsg_reply(msg, info);
966
967 nla_put_failure:
968 ret = -EMSGSIZE;
969
970 out_free:
971 nlmsg_free(msg);
972 return ret;
973 }
974
975 #define deref_locked_genl(p) \
976 rcu_dereference_protected(p, lockdep_genl_is_held() && \
977 lockdep_is_held(&tcp_metrics_lock))
978
979 #define deref_genl(p) rcu_dereference_protected(p, lockdep_genl_is_held())
980
981 static int tcp_metrics_flush_all(struct net *net)
982 {
983 unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
984 struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash;
985 struct tcp_metrics_block *tm;
986 unsigned int row;
987
988 for (row = 0; row < max_rows; row++, hb++) {
989 spin_lock_bh(&tcp_metrics_lock);
990 tm = deref_locked_genl(hb->chain);
991 if (tm)
992 hb->chain = NULL;
993 spin_unlock_bh(&tcp_metrics_lock);
994 while (tm) {
995 struct tcp_metrics_block *next;
996
997 next = deref_genl(tm->tcpm_next);
998 kfree_rcu(tm, rcu_head);
999 tm = next;
1000 }
1001 }
1002 return 0;
1003 }
1004
1005 static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
1006 {
1007 struct tcpm_hash_bucket *hb;
1008 struct tcp_metrics_block *tm, *tmlist = NULL;
1009 struct tcp_metrics_block __rcu **pp;
1010 struct inetpeer_addr saddr, daddr;
1011 unsigned int hash;
1012 struct net *net = genl_info_net(info);
1013 int ret;
1014 bool src = true;
1015
1016 ret = parse_nl_addr(info, &daddr, &hash, 1);
1017 if (ret < 0)
1018 return ret;
1019 if (ret > 0)
1020 return tcp_metrics_flush_all(net);
1021 ret = parse_nl_saddr(info, &saddr);
1022 if (ret < 0)
1023 src = false;
1024
1025 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
1026 hb = net->ipv4.tcp_metrics_hash + hash;
1027 pp = &hb->chain;
1028 spin_lock_bh(&tcp_metrics_lock);
1029 for (tm = deref_locked_genl(*pp); tm; tm = deref_locked_genl(*pp)) {
1030 if (addr_same(&tm->tcpm_daddr, &daddr) &&
1031 (!src || addr_same(&tm->tcpm_saddr, &saddr))) {
1032 *pp = tm->tcpm_next;
1033 tm->tcpm_next = tmlist;
1034 tmlist = tm;
1035 } else {
1036 pp = &tm->tcpm_next;
1037 }
1038 }
1039 spin_unlock_bh(&tcp_metrics_lock);
1040 if (!tmlist)
1041 return -ESRCH;
1042 for (tm = tmlist; tm; tm = tmlist) {
1043 tmlist = tm->tcpm_next;
1044 kfree_rcu(tm, rcu_head);
1045 }
1046 return 0;
1047 }
1048
1049 static const struct genl_ops tcp_metrics_nl_ops[] = {
1050 {
1051 .cmd = TCP_METRICS_CMD_GET,
1052 .doit = tcp_metrics_nl_cmd_get,
1053 .dumpit = tcp_metrics_nl_dump,
1054 .policy = tcp_metrics_nl_policy,
1055 .flags = GENL_ADMIN_PERM,
1056 },
1057 {
1058 .cmd = TCP_METRICS_CMD_DEL,
1059 .doit = tcp_metrics_nl_cmd_del,
1060 .policy = tcp_metrics_nl_policy,
1061 .flags = GENL_ADMIN_PERM,
1062 },
1063 };
1064
1065 static unsigned int tcpmhash_entries;
1066 static int __init set_tcpmhash_entries(char *str)
1067 {
1068 ssize_t ret;
1069
1070 if (!str)
1071 return 0;
1072
1073 ret = kstrtouint(str, 0, &tcpmhash_entries);
1074 if (ret)
1075 return 0;
1076
1077 return 1;
1078 }
1079 __setup("tcpmhash_entries=", set_tcpmhash_entries);
1080
1081 static int __net_init tcp_net_metrics_init(struct net *net)
1082 {
1083 size_t size;
1084 unsigned int slots;
1085
1086 slots = tcpmhash_entries;
1087 if (!slots) {
1088 if (totalram_pages >= 128 * 1024)
1089 slots = 16 * 1024;
1090 else
1091 slots = 8 * 1024;
1092 }
1093
1094 net->ipv4.tcp_metrics_hash_log = order_base_2(slots);
1095 size = sizeof(struct tcpm_hash_bucket) << net->ipv4.tcp_metrics_hash_log;
1096
1097 net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
1098 if (!net->ipv4.tcp_metrics_hash)
1099 net->ipv4.tcp_metrics_hash = vzalloc(size);
1100
1101 if (!net->ipv4.tcp_metrics_hash)
1102 return -ENOMEM;
1103
1104 return 0;
1105 }
1106
1107 static void __net_exit tcp_net_metrics_exit(struct net *net)
1108 {
1109 unsigned int i;
1110
1111 for (i = 0; i < (1U << net->ipv4.tcp_metrics_hash_log) ; i++) {
1112 struct tcp_metrics_block *tm, *next;
1113
1114 tm = rcu_dereference_protected(net->ipv4.tcp_metrics_hash[i].chain, 1);
1115 while (tm) {
1116 next = rcu_dereference_protected(tm->tcpm_next, 1);
1117 kfree(tm);
1118 tm = next;
1119 }
1120 }
1121 if (is_vmalloc_addr(net->ipv4.tcp_metrics_hash))
1122 vfree(net->ipv4.tcp_metrics_hash);
1123 else
1124 kfree(net->ipv4.tcp_metrics_hash);
1125 }
1126
1127 static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
1128 .init = tcp_net_metrics_init,
1129 .exit = tcp_net_metrics_exit,
1130 };
1131
1132 void __init tcp_metrics_init(void)
1133 {
1134 int ret;
1135
1136 ret = register_pernet_subsys(&tcp_net_metrics_ops);
1137 if (ret < 0)
1138 goto cleanup;
1139 ret = genl_register_family_with_ops(&tcp_metrics_nl_family,
1140 tcp_metrics_nl_ops);
1141 if (ret < 0)
1142 goto cleanup_subsys;
1143 return;
1144
1145 cleanup_subsys:
1146 unregister_pernet_subsys(&tcp_net_metrics_ops);
1147
1148 cleanup:
1149 return;
1150 }
Linux kernel - Deliverables
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