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octeontx2-pf: Fix error return code in otx2_probe()
[linux/fpc-iii.git] / net / ipv4 / tcp_metrics.c
blob279db8822439dadf8582eda047478429183652ed
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/rcupdate.h>
3 #include <linux/spinlock.h>
4 #include <linux/jiffies.h>
5 #include <linux/module.h>
6 #include <linux/cache.h>
7 #include <linux/slab.h>
8 #include <linux/init.h>
9 #include <linux/tcp.h>
10 #include <linux/hash.h>
11 #include <linux/tcp_metrics.h>
12 #include <linux/vmalloc.h>
13
14 #include <net/inet_connection_sock.h>
15 #include <net/net_namespace.h>
16 #include <net/request_sock.h>
17 #include <net/inetpeer.h>
18 #include <net/sock.h>
19 #include <net/ipv6.h>
20 #include <net/dst.h>
21 #include <net/tcp.h>
22 #include <net/genetlink.h>
23
24 static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr,
25 const struct inetpeer_addr *daddr,
26 struct net *net, unsigned int hash);
27
28 struct tcp_fastopen_metrics {
29 u16 mss;
30 u16 syn_loss:10, /* Recurring Fast Open SYN losses */
31 try_exp:2; /* Request w/ exp. option (once) */
32 unsigned long last_syn_loss; /* Last Fast Open SYN loss */
33 struct tcp_fastopen_cookie cookie;
34 };
35
36 /* TCP_METRIC_MAX includes 2 extra fields for userspace compatibility
37 * Kernel only stores RTT and RTTVAR in usec resolution
38 */
39 #define TCP_METRIC_MAX_KERNEL (TCP_METRIC_MAX - 2)
40
41 struct tcp_metrics_block {
42 struct tcp_metrics_block __rcu *tcpm_next;
43 possible_net_t tcpm_net;
44 struct inetpeer_addr tcpm_saddr;
45 struct inetpeer_addr tcpm_daddr;
46 unsigned long tcpm_stamp;
47 u32 tcpm_lock;
48 u32 tcpm_vals[TCP_METRIC_MAX_KERNEL + 1];
49 struct tcp_fastopen_metrics tcpm_fastopen;
50
51 struct rcu_head rcu_head;
52 };
53
54 static inline struct net *tm_net(struct tcp_metrics_block *tm)
55 {
56 return read_pnet(&tm->tcpm_net);
57 }
58
59 static bool tcp_metric_locked(struct tcp_metrics_block *tm,
60 enum tcp_metric_index idx)
61 {
62 return tm->tcpm_lock & (1 << idx);
63 }
64
65 static u32 tcp_metric_get(struct tcp_metrics_block *tm,
66 enum tcp_metric_index idx)
67 {
68 return tm->tcpm_vals[idx];
69 }
70
71 static void tcp_metric_set(struct tcp_metrics_block *tm,
72 enum tcp_metric_index idx,
73 u32 val)
74 {
75 tm->tcpm_vals[idx] = val;
76 }
77
78 static bool addr_same(const struct inetpeer_addr *a,
79 const struct inetpeer_addr *b)
80 {
81 return inetpeer_addr_cmp(a, b) == 0;
82 }
83
84 struct tcpm_hash_bucket {
85 struct tcp_metrics_block __rcu *chain;
86 };
87
88 static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly;
89 static unsigned int tcp_metrics_hash_log __read_mostly;
90
91 static DEFINE_SPINLOCK(tcp_metrics_lock);
92
93 static void tcpm_suck_dst(struct tcp_metrics_block *tm,
94 const struct dst_entry *dst,
95 bool fastopen_clear)
96 {
97 u32 msval;
98 u32 val;
99
100 tm->tcpm_stamp = jiffies;
101
102 val = 0;
103 if (dst_metric_locked(dst, RTAX_RTT))
104 val |= 1 << TCP_METRIC_RTT;
105 if (dst_metric_locked(dst, RTAX_RTTVAR))
106 val |= 1 << TCP_METRIC_RTTVAR;
107 if (dst_metric_locked(dst, RTAX_SSTHRESH))
108 val |= 1 << TCP_METRIC_SSTHRESH;
109 if (dst_metric_locked(dst, RTAX_CWND))
110 val |= 1 << TCP_METRIC_CWND;
111 if (dst_metric_locked(dst, RTAX_REORDERING))
112 val |= 1 << TCP_METRIC_REORDERING;
113 tm->tcpm_lock = val;
114
115 msval = dst_metric_raw(dst, RTAX_RTT);
116 tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC;
117
118 msval = dst_metric_raw(dst, RTAX_RTTVAR);
119 tm->tcpm_vals[TCP_METRIC_RTTVAR] = msval * USEC_PER_MSEC;
120 tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH);
121 tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
122 tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
123 if (fastopen_clear) {
124 tm->tcpm_fastopen.mss = 0;
125 tm->tcpm_fastopen.syn_loss = 0;
126 tm->tcpm_fastopen.try_exp = 0;
127 tm->tcpm_fastopen.cookie.exp = false;
128 tm->tcpm_fastopen.cookie.len = 0;
129 }
130 }
131
132 #define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
133
134 static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
135 {
136 if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
137 tcpm_suck_dst(tm, dst, false);
138 }
139
140 #define TCP_METRICS_RECLAIM_DEPTH 5
141 #define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
142
143 #define deref_locked(p) \
144 rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock))
145
146 static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
147 struct inetpeer_addr *saddr,
148 struct inetpeer_addr *daddr,
149 unsigned int hash)
150 {
151 struct tcp_metrics_block *tm;
152 struct net *net;
153 bool reclaim = false;
154
155 spin_lock_bh(&tcp_metrics_lock);
156 net = dev_net(dst->dev);
157
158 /* While waiting for the spin-lock the cache might have been populated
159 * with this entry and so we have to check again.
160 */
161 tm = __tcp_get_metrics(saddr, daddr, net, hash);
162 if (tm == TCP_METRICS_RECLAIM_PTR) {
163 reclaim = true;
164 tm = NULL;
165 }
166 if (tm) {
167 tcpm_check_stamp(tm, dst);
168 goto out_unlock;
169 }
170
171 if (unlikely(reclaim)) {
172 struct tcp_metrics_block *oldest;
173
174 oldest = deref_locked(tcp_metrics_hash[hash].chain);
175 for (tm = deref_locked(oldest->tcpm_next); tm;
176 tm = deref_locked(tm->tcpm_next)) {
177 if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
178 oldest = tm;
179 }
180 tm = oldest;
181 } else {
182 tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
183 if (!tm)
184 goto out_unlock;
185 }
186 write_pnet(&tm->tcpm_net, net);
187 tm->tcpm_saddr = *saddr;
188 tm->tcpm_daddr = *daddr;
189
190 tcpm_suck_dst(tm, dst, true);
191
192 if (likely(!reclaim)) {
193 tm->tcpm_next = tcp_metrics_hash[hash].chain;
194 rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm);
195 }
196
197 out_unlock:
198 spin_unlock_bh(&tcp_metrics_lock);
199 return tm;
200 }
201
202 static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth)
203 {
204 if (tm)
205 return tm;
206 if (depth > TCP_METRICS_RECLAIM_DEPTH)
207 return TCP_METRICS_RECLAIM_PTR;
208 return NULL;
209 }
210
211 static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr,
212 const struct inetpeer_addr *daddr,
213 struct net *net, unsigned int hash)
214 {
215 struct tcp_metrics_block *tm;
216 int depth = 0;
217
218 for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
219 tm = rcu_dereference(tm->tcpm_next)) {
220 if (addr_same(&tm->tcpm_saddr, saddr) &&
221 addr_same(&tm->tcpm_daddr, daddr) &&
222 net_eq(tm_net(tm), net))
223 break;
224 depth++;
225 }
226 return tcp_get_encode(tm, depth);
227 }
228
229 static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
230 struct dst_entry *dst)
231 {
232 struct tcp_metrics_block *tm;
233 struct inetpeer_addr saddr, daddr;
234 unsigned int hash;
235 struct net *net;
236
237 saddr.family = req->rsk_ops->family;
238 daddr.family = req->rsk_ops->family;
239 switch (daddr.family) {
240 case AF_INET:
241 inetpeer_set_addr_v4(&saddr, inet_rsk(req)->ir_loc_addr);
242 inetpeer_set_addr_v4(&daddr, inet_rsk(req)->ir_rmt_addr);
243 hash = ipv4_addr_hash(inet_rsk(req)->ir_rmt_addr);
244 break;
245 #if IS_ENABLED(CONFIG_IPV6)
246 case AF_INET6:
247 inetpeer_set_addr_v6(&saddr, &inet_rsk(req)->ir_v6_loc_addr);
248 inetpeer_set_addr_v6(&daddr, &inet_rsk(req)->ir_v6_rmt_addr);
249 hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr);
250 break;
251 #endif
252 default:
253 return NULL;
254 }
255
256 net = dev_net(dst->dev);
257 hash ^= net_hash_mix(net);
258 hash = hash_32(hash, tcp_metrics_hash_log);
259
260 for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
261 tm = rcu_dereference(tm->tcpm_next)) {
262 if (addr_same(&tm->tcpm_saddr, &saddr) &&
263 addr_same(&tm->tcpm_daddr, &daddr) &&
264 net_eq(tm_net(tm), net))
265 break;
266 }
267 tcpm_check_stamp(tm, dst);
268 return tm;
269 }
270
271 static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
272 struct dst_entry *dst,
273 bool create)
274 {
275 struct tcp_metrics_block *tm;
276 struct inetpeer_addr saddr, daddr;
277 unsigned int hash;
278 struct net *net;
279
280 if (sk->sk_family == AF_INET) {
281 inetpeer_set_addr_v4(&saddr, inet_sk(sk)->inet_saddr);
282 inetpeer_set_addr_v4(&daddr, inet_sk(sk)->inet_daddr);
283 hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr);
284 }
285 #if IS_ENABLED(CONFIG_IPV6)
286 else if (sk->sk_family == AF_INET6) {
287 if (ipv6_addr_v4mapped(&sk->sk_v6_daddr)) {
288 inetpeer_set_addr_v4(&saddr, inet_sk(sk)->inet_saddr);
289 inetpeer_set_addr_v4(&daddr, inet_sk(sk)->inet_daddr);
290 hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr);
291 } else {
292 inetpeer_set_addr_v6(&saddr, &sk->sk_v6_rcv_saddr);
293 inetpeer_set_addr_v6(&daddr, &sk->sk_v6_daddr);
294 hash = ipv6_addr_hash(&sk->sk_v6_daddr);
295 }
296 }
297 #endif
298 else
299 return NULL;
300
301 net = dev_net(dst->dev);
302 hash ^= net_hash_mix(net);
303 hash = hash_32(hash, tcp_metrics_hash_log);
304
305 tm = __tcp_get_metrics(&saddr, &daddr, net, hash);
306 if (tm == TCP_METRICS_RECLAIM_PTR)
307 tm = NULL;
308 if (!tm && create)
309 tm = tcpm_new(dst, &saddr, &daddr, hash);
310 else
311 tcpm_check_stamp(tm, dst);
312
313 return tm;
314 }
315
316 /* Save metrics learned by this TCP session. This function is called
317 * only, when TCP finishes successfully i.e. when it enters TIME-WAIT
318 * or goes from LAST-ACK to CLOSE.
319 */
320 void tcp_update_metrics(struct sock *sk)
321 {
322 const struct inet_connection_sock *icsk = inet_csk(sk);
323 struct dst_entry *dst = __sk_dst_get(sk);
324 struct tcp_sock *tp = tcp_sk(sk);
325 struct net *net = sock_net(sk);
326 struct tcp_metrics_block *tm;
327 unsigned long rtt;
328 u32 val;
329 int m;
330
331 sk_dst_confirm(sk);
332 if (net->ipv4.sysctl_tcp_nometrics_save || !dst)
333 return;
334
335 rcu_read_lock();
336 if (icsk->icsk_backoff || !tp->srtt_us) {
337 /* This session failed to estimate rtt. Why?
338 * Probably, no packets returned in time. Reset our
339 * results.
340 */
341 tm = tcp_get_metrics(sk, dst, false);
342 if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT))
343 tcp_metric_set(tm, TCP_METRIC_RTT, 0);
344 goto out_unlock;
345 } else
346 tm = tcp_get_metrics(sk, dst, true);
347
348 if (!tm)
349 goto out_unlock;
350
351 rtt = tcp_metric_get(tm, TCP_METRIC_RTT);
352 m = rtt - tp->srtt_us;
353
354 /* If newly calculated rtt larger than stored one, store new
355 * one. Otherwise, use EWMA. Remember, rtt overestimation is
356 * always better than underestimation.
357 */
358 if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
359 if (m <= 0)
360 rtt = tp->srtt_us;
361 else
362 rtt -= (m >> 3);
363 tcp_metric_set(tm, TCP_METRIC_RTT, rtt);
364 }
365
366 if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
367 unsigned long var;
368
369 if (m < 0)
370 m = -m;
371
372 /* Scale deviation to rttvar fixed point */
373 m >>= 1;
374 if (m < tp->mdev_us)
375 m = tp->mdev_us;
376
377 var = tcp_metric_get(tm, TCP_METRIC_RTTVAR);
378 if (m >= var)
379 var = m;
380 else
381 var -= (var - m) >> 2;
382
383 tcp_metric_set(tm, TCP_METRIC_RTTVAR, var);
384 }
385
386 if (tcp_in_initial_slowstart(tp)) {
387 /* Slow start still did not finish. */
388 if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save &&
389 !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
390 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
391 if (val && (tp->snd_cwnd >> 1) > val)
392 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
393 tp->snd_cwnd >> 1);
394 }
395 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
396 val = tcp_metric_get(tm, TCP_METRIC_CWND);
397 if (tp->snd_cwnd > val)
398 tcp_metric_set(tm, TCP_METRIC_CWND,
399 tp->snd_cwnd);
400 }
401 } else if (!tcp_in_slow_start(tp) &&
402 icsk->icsk_ca_state == TCP_CA_Open) {
403 /* Cong. avoidance phase, cwnd is reliable. */
404 if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save &&
405 !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))
406 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
407 max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
408 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
409 val = tcp_metric_get(tm, TCP_METRIC_CWND);
410 tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1);
411 }
412 } else {
413 /* Else slow start did not finish, cwnd is non-sense,
414 * ssthresh may be also invalid.
415 */
416 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
417 val = tcp_metric_get(tm, TCP_METRIC_CWND);
418 tcp_metric_set(tm, TCP_METRIC_CWND,
419 (val + tp->snd_ssthresh) >> 1);
420 }
421 if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save &&
422 !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
423 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
424 if (val && tp->snd_ssthresh > val)
425 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
426 tp->snd_ssthresh);
427 }
428 if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) {
429 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
430 if (val < tp->reordering &&
431 tp->reordering != net->ipv4.sysctl_tcp_reordering)
432 tcp_metric_set(tm, TCP_METRIC_REORDERING,
433 tp->reordering);
434 }
435 }
436 tm->tcpm_stamp = jiffies;
437 out_unlock:
438 rcu_read_unlock();
439 }
440
441 /* Initialize metrics on socket. */
442
443 void tcp_init_metrics(struct sock *sk)
444 {
445 struct dst_entry *dst = __sk_dst_get(sk);
446 struct tcp_sock *tp = tcp_sk(sk);
447 struct net *net = sock_net(sk);
448 struct tcp_metrics_block *tm;
449 u32 val, crtt = 0; /* cached RTT scaled by 8 */
450
451 sk_dst_confirm(sk);
452 if (!dst)
453 goto reset;
454
455 rcu_read_lock();
456 tm = tcp_get_metrics(sk, dst, true);
457 if (!tm) {
458 rcu_read_unlock();
459 goto reset;
460 }
461
462 if (tcp_metric_locked(tm, TCP_METRIC_CWND))
463 tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND);
464
465 val = net->ipv4.sysctl_tcp_no_ssthresh_metrics_save ?
466 0 : tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
467 if (val) {
468 tp->snd_ssthresh = val;
469 if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
470 tp->snd_ssthresh = tp->snd_cwnd_clamp;
471 } else {
472 /* ssthresh may have been reduced unnecessarily during.
473 * 3WHS. Restore it back to its initial default.
474 */
475 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
476 }
477 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
478 if (val && tp->reordering != val)
479 tp->reordering = val;
480
481 crtt = tcp_metric_get(tm, TCP_METRIC_RTT);
482 rcu_read_unlock();
483 reset:
484 /* The initial RTT measurement from the SYN/SYN-ACK is not ideal
485 * to seed the RTO for later data packets because SYN packets are
486 * small. Use the per-dst cached values to seed the RTO but keep
487 * the RTT estimator variables intact (e.g., srtt, mdev, rttvar).
488 * Later the RTO will be updated immediately upon obtaining the first
489 * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only
490 * influences the first RTO but not later RTT estimation.
491 *
492 * But if RTT is not available from the SYN (due to retransmits or
493 * syn cookies) or the cache, force a conservative 3secs timeout.
494 *
495 * A bit of theory. RTT is time passed after "normal" sized packet
496 * is sent until it is ACKed. In normal circumstances sending small
497 * packets force peer to delay ACKs and calculation is correct too.
498 * The algorithm is adaptive and, provided we follow specs, it
499 * NEVER underestimate RTT. BUT! If peer tries to make some clever
500 * tricks sort of "quick acks" for time long enough to decrease RTT
501 * to low value, and then abruptly stops to do it and starts to delay
502 * ACKs, wait for troubles.
503 */
504 if (crtt > tp->srtt_us) {
505 /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
506 crtt /= 8 * USEC_PER_SEC / HZ;
507 inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
508 } else if (tp->srtt_us == 0) {
509 /* RFC6298: 5.7 We've failed to get a valid RTT sample from
510 * 3WHS. This is most likely due to retransmission,
511 * including spurious one. Reset the RTO back to 3secs
512 * from the more aggressive 1sec to avoid more spurious
513 * retransmission.
514 */
515 tp->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK);
516 tp->mdev_us = tp->mdev_max_us = tp->rttvar_us;
517
518 inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
519 }
520 }
521
522 bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst)
523 {
524 struct tcp_metrics_block *tm;
525 bool ret;
526
527 if (!dst)
528 return false;
529
530 rcu_read_lock();
531 tm = __tcp_get_metrics_req(req, dst);
532 if (tm && tcp_metric_get(tm, TCP_METRIC_RTT))
533 ret = true;
534 else
535 ret = false;
536 rcu_read_unlock();
537
538 return ret;
539 }
540
541 static DEFINE_SEQLOCK(fastopen_seqlock);
542
543 void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
544 struct tcp_fastopen_cookie *cookie)
545 {
546 struct tcp_metrics_block *tm;
547
548 rcu_read_lock();
549 tm = tcp_get_metrics(sk, __sk_dst_get(sk), false);
550 if (tm) {
551 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
552 unsigned int seq;
553
554 do {
555 seq = read_seqbegin(&fastopen_seqlock);
556 if (tfom->mss)
557 *mss = tfom->mss;
558 *cookie = tfom->cookie;
559 if (cookie->len <= 0 && tfom->try_exp == 1)
560 cookie->exp = true;
561 } while (read_seqretry(&fastopen_seqlock, seq));
562 }
563 rcu_read_unlock();
564 }
565
566 void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
567 struct tcp_fastopen_cookie *cookie, bool syn_lost,
568 u16 try_exp)
569 {
570 struct dst_entry *dst = __sk_dst_get(sk);
571 struct tcp_metrics_block *tm;
572
573 if (!dst)
574 return;
575 rcu_read_lock();
576 tm = tcp_get_metrics(sk, dst, true);
577 if (tm) {
578 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
579
580 write_seqlock_bh(&fastopen_seqlock);
581 if (mss)
582 tfom->mss = mss;
583 if (cookie && cookie->len > 0)
584 tfom->cookie = *cookie;
585 else if (try_exp > tfom->try_exp &&
586 tfom->cookie.len <= 0 && !tfom->cookie.exp)
587 tfom->try_exp = try_exp;
588 if (syn_lost) {
589 ++tfom->syn_loss;
590 tfom->last_syn_loss = jiffies;
591 } else
592 tfom->syn_loss = 0;
593 write_sequnlock_bh(&fastopen_seqlock);
594 }
595 rcu_read_unlock();
596 }
597
598 static struct genl_family tcp_metrics_nl_family;
599
600 static const struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = {
601 [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, },
602 [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY,
603 .len = sizeof(struct in6_addr), },
604 /* Following attributes are not received for GET/DEL,
605 * we keep them for reference
606 */
607 #if 0
608 [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, },
609 [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, },
610 [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, },
611 [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, },
612 [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, },
613 [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, },
614 [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, },
615 [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY,
616 .len = TCP_FASTOPEN_COOKIE_MAX, },
617 #endif
618 };
619
620 /* Add attributes, caller cancels its header on failure */
621 static int tcp_metrics_fill_info(struct sk_buff *msg,
622 struct tcp_metrics_block *tm)
623 {
624 struct nlattr *nest;
625 int i;
626
627 switch (tm->tcpm_daddr.family) {
628 case AF_INET:
629 if (nla_put_in_addr(msg, TCP_METRICS_ATTR_ADDR_IPV4,
630 inetpeer_get_addr_v4(&tm->tcpm_daddr)) < 0)
631 goto nla_put_failure;
632 if (nla_put_in_addr(msg, TCP_METRICS_ATTR_SADDR_IPV4,
633 inetpeer_get_addr_v4(&tm->tcpm_saddr)) < 0)
634 goto nla_put_failure;
635 break;
636 case AF_INET6:
637 if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_ADDR_IPV6,
638 inetpeer_get_addr_v6(&tm->tcpm_daddr)) < 0)
639 goto nla_put_failure;
640 if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_SADDR_IPV6,
641 inetpeer_get_addr_v6(&tm->tcpm_saddr)) < 0)
642 goto nla_put_failure;
643 break;
644 default:
645 return -EAFNOSUPPORT;
646 }
647
648 if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE,
649 jiffies - tm->tcpm_stamp,
650 TCP_METRICS_ATTR_PAD) < 0)
651 goto nla_put_failure;
652
653 {
654 int n = 0;
655
656 nest = nla_nest_start_noflag(msg, TCP_METRICS_ATTR_VALS);
657 if (!nest)
658 goto nla_put_failure;
659 for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) {
660 u32 val = tm->tcpm_vals[i];
661
662 if (!val)
663 continue;
664 if (i == TCP_METRIC_RTT) {
665 if (nla_put_u32(msg, TCP_METRIC_RTT_US + 1,
666 val) < 0)
667 goto nla_put_failure;
668 n++;
669 val = max(val / 1000, 1U);
670 }
671 if (i == TCP_METRIC_RTTVAR) {
672 if (nla_put_u32(msg, TCP_METRIC_RTTVAR_US + 1,
673 val) < 0)
674 goto nla_put_failure;
675 n++;
676 val = max(val / 1000, 1U);
677 }
678 if (nla_put_u32(msg, i + 1, val) < 0)
679 goto nla_put_failure;
680 n++;
681 }
682 if (n)
683 nla_nest_end(msg, nest);
684 else
685 nla_nest_cancel(msg, nest);
686 }
687
688 {
689 struct tcp_fastopen_metrics tfom_copy[1], *tfom;
690 unsigned int seq;
691
692 do {
693 seq = read_seqbegin(&fastopen_seqlock);
694 tfom_copy[0] = tm->tcpm_fastopen;
695 } while (read_seqretry(&fastopen_seqlock, seq));
696
697 tfom = tfom_copy;
698 if (tfom->mss &&
699 nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS,
700 tfom->mss) < 0)
701 goto nla_put_failure;
702 if (tfom->syn_loss &&
703 (nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS,
704 tfom->syn_loss) < 0 ||
705 nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,
706 jiffies - tfom->last_syn_loss,
707 TCP_METRICS_ATTR_PAD) < 0))
708 goto nla_put_failure;
709 if (tfom->cookie.len > 0 &&
710 nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE,
711 tfom->cookie.len, tfom->cookie.val) < 0)
712 goto nla_put_failure;
713 }
714
715 return 0;
716
717 nla_put_failure:
718 return -EMSGSIZE;
719 }
720
721 static int tcp_metrics_dump_info(struct sk_buff *skb,
722 struct netlink_callback *cb,
723 struct tcp_metrics_block *tm)
724 {
725 void *hdr;
726
727 hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
728 &tcp_metrics_nl_family, NLM_F_MULTI,
729 TCP_METRICS_CMD_GET);
730 if (!hdr)
731 return -EMSGSIZE;
732
733 if (tcp_metrics_fill_info(skb, tm) < 0)
734 goto nla_put_failure;
735
736 genlmsg_end(skb, hdr);
737 return 0;
738
739 nla_put_failure:
740 genlmsg_cancel(skb, hdr);
741 return -EMSGSIZE;
742 }
743
744 static int tcp_metrics_nl_dump(struct sk_buff *skb,
745 struct netlink_callback *cb)
746 {
747 struct net *net = sock_net(skb->sk);
748 unsigned int max_rows = 1U << tcp_metrics_hash_log;
749 unsigned int row, s_row = cb->args[0];
750 int s_col = cb->args[1], col = s_col;
751
752 for (row = s_row; row < max_rows; row++, s_col = 0) {
753 struct tcp_metrics_block *tm;
754 struct tcpm_hash_bucket *hb = tcp_metrics_hash + row;
755
756 rcu_read_lock();
757 for (col = 0, tm = rcu_dereference(hb->chain); tm;
758 tm = rcu_dereference(tm->tcpm_next), col++) {
759 if (!net_eq(tm_net(tm), net))
760 continue;
761 if (col < s_col)
762 continue;
763 if (tcp_metrics_dump_info(skb, cb, tm) < 0) {
764 rcu_read_unlock();
765 goto done;
766 }
767 }
768 rcu_read_unlock();
769 }
770
771 done:
772 cb->args[0] = row;
773 cb->args[1] = col;
774 return skb->len;
775 }
776
777 static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
778 unsigned int *hash, int optional, int v4, int v6)
779 {
780 struct nlattr *a;
781
782 a = info->attrs[v4];
783 if (a) {
784 inetpeer_set_addr_v4(addr, nla_get_in_addr(a));
785 if (hash)
786 *hash = ipv4_addr_hash(inetpeer_get_addr_v4(addr));
787 return 0;
788 }
789 a = info->attrs[v6];
790 if (a) {
791 struct in6_addr in6;
792
793 if (nla_len(a) != sizeof(struct in6_addr))
794 return -EINVAL;
795 in6 = nla_get_in6_addr(a);
796 inetpeer_set_addr_v6(addr, &in6);
797 if (hash)
798 *hash = ipv6_addr_hash(inetpeer_get_addr_v6(addr));
799 return 0;
800 }
801 return optional ? 1 : -EAFNOSUPPORT;
802 }
803
804 static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
805 unsigned int *hash, int optional)
806 {
807 return __parse_nl_addr(info, addr, hash, optional,
808 TCP_METRICS_ATTR_ADDR_IPV4,
809 TCP_METRICS_ATTR_ADDR_IPV6);
810 }
811
812 static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr)
813 {
814 return __parse_nl_addr(info, addr, NULL, 0,
815 TCP_METRICS_ATTR_SADDR_IPV4,
816 TCP_METRICS_ATTR_SADDR_IPV6);
817 }
818
819 static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
820 {
821 struct tcp_metrics_block *tm;
822 struct inetpeer_addr saddr, daddr;
823 unsigned int hash;
824 struct sk_buff *msg;
825 struct net *net = genl_info_net(info);
826 void *reply;
827 int ret;
828 bool src = true;
829
830 ret = parse_nl_addr(info, &daddr, &hash, 0);
831 if (ret < 0)
832 return ret;
833
834 ret = parse_nl_saddr(info, &saddr);
835 if (ret < 0)
836 src = false;
837
838 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
839 if (!msg)
840 return -ENOMEM;
841
842 reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0,
843 info->genlhdr->cmd);
844 if (!reply)
845 goto nla_put_failure;
846
847 hash ^= net_hash_mix(net);
848 hash = hash_32(hash, tcp_metrics_hash_log);
849 ret = -ESRCH;
850 rcu_read_lock();
851 for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
852 tm = rcu_dereference(tm->tcpm_next)) {
853 if (addr_same(&tm->tcpm_daddr, &daddr) &&
854 (!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
855 net_eq(tm_net(tm), net)) {
856 ret = tcp_metrics_fill_info(msg, tm);
857 break;
858 }
859 }
860 rcu_read_unlock();
861 if (ret < 0)
862 goto out_free;
863
864 genlmsg_end(msg, reply);
865 return genlmsg_reply(msg, info);
866
867 nla_put_failure:
868 ret = -EMSGSIZE;
869
870 out_free:
871 nlmsg_free(msg);
872 return ret;
873 }
874
875 static void tcp_metrics_flush_all(struct net *net)
876 {
877 unsigned int max_rows = 1U << tcp_metrics_hash_log;
878 struct tcpm_hash_bucket *hb = tcp_metrics_hash;
879 struct tcp_metrics_block *tm;
880 unsigned int row;
881
882 for (row = 0; row < max_rows; row++, hb++) {
883 struct tcp_metrics_block __rcu **pp;
884 bool match;
885
886 spin_lock_bh(&tcp_metrics_lock);
887 pp = &hb->chain;
888 for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
889 match = net ? net_eq(tm_net(tm), net) :
890 !refcount_read(&tm_net(tm)->count);
891 if (match) {
892 *pp = tm->tcpm_next;
893 kfree_rcu(tm, rcu_head);
894 } else {
895 pp = &tm->tcpm_next;
896 }
897 }
898 spin_unlock_bh(&tcp_metrics_lock);
899 }
900 }
901
902 static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
903 {
904 struct tcpm_hash_bucket *hb;
905 struct tcp_metrics_block *tm;
906 struct tcp_metrics_block __rcu **pp;
907 struct inetpeer_addr saddr, daddr;
908 unsigned int hash;
909 struct net *net = genl_info_net(info);
910 int ret;
911 bool src = true, found = false;
912
913 ret = parse_nl_addr(info, &daddr, &hash, 1);
914 if (ret < 0)
915 return ret;
916 if (ret > 0) {
917 tcp_metrics_flush_all(net);
918 return 0;
919 }
920 ret = parse_nl_saddr(info, &saddr);
921 if (ret < 0)
922 src = false;
923
924 hash ^= net_hash_mix(net);
925 hash = hash_32(hash, tcp_metrics_hash_log);
926 hb = tcp_metrics_hash + hash;
927 pp = &hb->chain;
928 spin_lock_bh(&tcp_metrics_lock);
929 for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
930 if (addr_same(&tm->tcpm_daddr, &daddr) &&
931 (!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
932 net_eq(tm_net(tm), net)) {
933 *pp = tm->tcpm_next;
934 kfree_rcu(tm, rcu_head);
935 found = true;
936 } else {
937 pp = &tm->tcpm_next;
938 }
939 }
940 spin_unlock_bh(&tcp_metrics_lock);
941 if (!found)
942 return -ESRCH;
943 return 0;
944 }
945
946 static const struct genl_ops tcp_metrics_nl_ops[] = {
947 {
948 .cmd = TCP_METRICS_CMD_GET,
949 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
950 .doit = tcp_metrics_nl_cmd_get,
951 .dumpit = tcp_metrics_nl_dump,
952 },
953 {
954 .cmd = TCP_METRICS_CMD_DEL,
955 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
956 .doit = tcp_metrics_nl_cmd_del,
957 .flags = GENL_ADMIN_PERM,
958 },
959 };
960
961 static struct genl_family tcp_metrics_nl_family __ro_after_init = {
962 .hdrsize = 0,
963 .name = TCP_METRICS_GENL_NAME,
964 .version = TCP_METRICS_GENL_VERSION,
965 .maxattr = TCP_METRICS_ATTR_MAX,
966 .policy = tcp_metrics_nl_policy,
967 .netnsok = true,
968 .module = THIS_MODULE,
969 .ops = tcp_metrics_nl_ops,
970 .n_ops = ARRAY_SIZE(tcp_metrics_nl_ops),
971 };
972
973 static unsigned int tcpmhash_entries;
974 static int __init set_tcpmhash_entries(char *str)
975 {
976 ssize_t ret;
977
978 if (!str)
979 return 0;
980
981 ret = kstrtouint(str, 0, &tcpmhash_entries);
982 if (ret)
983 return 0;
984
985 return 1;
986 }
987 __setup("tcpmhash_entries=", set_tcpmhash_entries);
988
989 static int __net_init tcp_net_metrics_init(struct net *net)
990 {
991 size_t size;
992 unsigned int slots;
993
994 if (!net_eq(net, &init_net))
995 return 0;
996
997 slots = tcpmhash_entries;
998 if (!slots) {
999 if (totalram_pages() >= 128 * 1024)
1000 slots = 16 * 1024;
1001 else
1002 slots = 8 * 1024;
1003 }
1004
1005 tcp_metrics_hash_log = order_base_2(slots);
1006 size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log;
1007
1008 tcp_metrics_hash = kvzalloc(size, GFP_KERNEL);
1009 if (!tcp_metrics_hash)
1010 return -ENOMEM;
1011
1012 return 0;
1013 }
1014
1015 static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_list)
1016 {
1017 tcp_metrics_flush_all(NULL);
1018 }
1019
1020 static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
1021 .init = tcp_net_metrics_init,
1022 .exit_batch = tcp_net_metrics_exit_batch,
1023 };
1024
1025 void __init tcp_metrics_init(void)
1026 {
1027 int ret;
1028
1029 ret = register_pernet_subsys(&tcp_net_metrics_ops);
1030 if (ret < 0)
1031 panic("Could not allocate the tcp_metrics hash table\n");
1032
1033 ret = genl_register_family(&tcp_metrics_nl_family);
1034 if (ret < 0)
1035 panic("Could not register tcp_metrics generic netlink\n");
1036 }
Linux with added FPC-III support