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 (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { |
389 | val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); |
390 | if (val && (tp->snd_cwnd >> 1) > val) |
391 | tcp_metric_set(tm, TCP_METRIC_SSTHRESH, |
392 | tp->snd_cwnd >> 1); |
393 | } |
394 | if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { |
395 | val = tcp_metric_get(tm, TCP_METRIC_CWND); |
396 | if (tp->snd_cwnd > val) |
397 | tcp_metric_set(tm, TCP_METRIC_CWND, |
398 | tp->snd_cwnd); |
399 | } |
400 | } else if (!tcp_in_slow_start(tp) && |
401 | icsk->icsk_ca_state == TCP_CA_Open) { |
402 | /* Cong. avoidance phase, cwnd is reliable. */ |
403 | if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) |
404 | tcp_metric_set(tm, TCP_METRIC_SSTHRESH, |
405 | max(tp->snd_cwnd >> 1, tp->snd_ssthresh)); |
406 | if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { |
407 | val = tcp_metric_get(tm, TCP_METRIC_CWND); |
408 | tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1); |
409 | } |
410 | } else { |
411 | /* Else slow start did not finish, cwnd is non-sense, |
412 | * ssthresh may be also invalid. |
413 | */ |
414 | if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { |
415 | val = tcp_metric_get(tm, TCP_METRIC_CWND); |
416 | tcp_metric_set(tm, TCP_METRIC_CWND, |
417 | (val + tp->snd_ssthresh) >> 1); |
418 | } |
419 | if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { |
420 | val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); |
421 | if (val && tp->snd_ssthresh > val) |
422 | tcp_metric_set(tm, TCP_METRIC_SSTHRESH, |
423 | tp->snd_ssthresh); |
424 | } |
425 | if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) { |
426 | val = tcp_metric_get(tm, TCP_METRIC_REORDERING); |
427 | if (val < tp->reordering && |
428 | tp->reordering != net->ipv4.sysctl_tcp_reordering) |
429 | tcp_metric_set(tm, TCP_METRIC_REORDERING, |
430 | tp->reordering); |
431 | } |
432 | } |
433 | tm->tcpm_stamp = jiffies; |
434 | out_unlock: |
435 | rcu_read_unlock(); |
436 | } |
437 | |
438 | /* Initialize metrics on socket. */ |
439 | |
440 | void tcp_init_metrics(struct sock *sk) |
441 | { |
442 | struct dst_entry *dst = __sk_dst_get(sk); |
443 | struct tcp_sock *tp = tcp_sk(sk); |
444 | struct tcp_metrics_block *tm; |
445 | u32 val, crtt = 0; /* cached RTT scaled by 8 */ |
446 | |
447 | sk_dst_confirm(sk); |
448 | if (!dst) |
449 | goto reset; |
450 | |
451 | rcu_read_lock(); |
452 | tm = tcp_get_metrics(sk, dst, true); |
453 | if (!tm) { |
454 | rcu_read_unlock(); |
455 | goto reset; |
456 | } |
457 | |
458 | if (tcp_metric_locked(tm, TCP_METRIC_CWND)) |
459 | tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND); |
460 | |
461 | val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); |
462 | if (val) { |
463 | tp->snd_ssthresh = val; |
464 | if (tp->snd_ssthresh > tp->snd_cwnd_clamp) |
465 | tp->snd_ssthresh = tp->snd_cwnd_clamp; |
466 | } else { |
467 | /* ssthresh may have been reduced unnecessarily during. |
468 | * 3WHS. Restore it back to its initial default. |
469 | */ |
470 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
471 | } |
472 | val = tcp_metric_get(tm, TCP_METRIC_REORDERING); |
473 | if (val && tp->reordering != val) |
474 | tp->reordering = val; |
475 | |
476 | crtt = tcp_metric_get(tm, TCP_METRIC_RTT); |
477 | rcu_read_unlock(); |
478 | reset: |
479 | /* The initial RTT measurement from the SYN/SYN-ACK is not ideal |
480 | * to seed the RTO for later data packets because SYN packets are |
481 | * small. Use the per-dst cached values to seed the RTO but keep |
482 | * the RTT estimator variables intact (e.g., srtt, mdev, rttvar). |
483 | * Later the RTO will be updated immediately upon obtaining the first |
484 | * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only |
485 | * influences the first RTO but not later RTT estimation. |
486 | * |
487 | * But if RTT is not available from the SYN (due to retransmits or |
488 | * syn cookies) or the cache, force a conservative 3secs timeout. |
489 | * |
490 | * A bit of theory. RTT is time passed after "normal" sized packet |
491 | * is sent until it is ACKed. In normal circumstances sending small |
492 | * packets force peer to delay ACKs and calculation is correct too. |
493 | * The algorithm is adaptive and, provided we follow specs, it |
494 | * NEVER underestimate RTT. BUT! If peer tries to make some clever |
495 | * tricks sort of "quick acks" for time long enough to decrease RTT |
496 | * to low value, and then abruptly stops to do it and starts to delay |
497 | * ACKs, wait for troubles. |
498 | */ |
499 | if (crtt > tp->srtt_us) { |
500 | /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */ |
501 | crtt /= 8 * USEC_PER_SEC / HZ; |
502 | inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk)); |
503 | } else if (tp->srtt_us == 0) { |
504 | /* RFC6298: 5.7 We've failed to get a valid RTT sample from |
505 | * 3WHS. This is most likely due to retransmission, |
506 | * including spurious one. Reset the RTO back to 3secs |
507 | * from the more aggressive 1sec to avoid more spurious |
508 | * retransmission. |
509 | */ |
510 | tp->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK); |
511 | tp->mdev_us = tp->mdev_max_us = tp->rttvar_us; |
512 | |
513 | inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK; |
514 | } |
515 | /* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been |
516 | * retransmitted. In light of RFC6298 more aggressive 1sec |
517 | * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK |
518 | * retransmission has occurred. |
519 | */ |
520 | if (tp->total_retrans > 1) |
521 | tp->snd_cwnd = 1; |
522 | else |
523 | tp->snd_cwnd = tcp_init_cwnd(tp, dst); |
524 | tp->snd_cwnd_stamp = tcp_jiffies32; |
525 | } |
526 | |
527 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst) |
528 | { |
529 | struct tcp_metrics_block *tm; |
530 | bool ret; |
531 | |
532 | if (!dst) |
533 | return false; |
534 | |
535 | rcu_read_lock(); |
536 | tm = __tcp_get_metrics_req(req, dst); |
537 | if (tm && tcp_metric_get(tm, TCP_METRIC_RTT)) |
538 | ret = true; |
539 | else |
540 | ret = false; |
541 | rcu_read_unlock(); |
542 | |
543 | return ret; |
544 | } |
545 | |
546 | static DEFINE_SEQLOCK(fastopen_seqlock); |
547 | |
548 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
549 | struct tcp_fastopen_cookie *cookie) |
550 | { |
551 | struct tcp_metrics_block *tm; |
552 | |
553 | rcu_read_lock(); |
554 | tm = tcp_get_metrics(sk, __sk_dst_get(sk), false); |
555 | if (tm) { |
556 | struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; |
557 | unsigned int seq; |
558 | |
559 | do { |
560 | seq = read_seqbegin(&fastopen_seqlock); |
561 | if (tfom->mss) |
562 | *mss = tfom->mss; |
563 | *cookie = tfom->cookie; |
564 | if (cookie->len <= 0 && tfom->try_exp == 1) |
565 | cookie->exp = true; |
566 | } while (read_seqretry(&fastopen_seqlock, seq)); |
567 | } |
568 | rcu_read_unlock(); |
569 | } |
570 | |
571 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
572 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
573 | u16 try_exp) |
574 | { |
575 | struct dst_entry *dst = __sk_dst_get(sk); |
576 | struct tcp_metrics_block *tm; |
577 | |
578 | if (!dst) |
579 | return; |
580 | rcu_read_lock(); |
581 | tm = tcp_get_metrics(sk, dst, true); |
582 | if (tm) { |
583 | struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; |
584 | |
585 | write_seqlock_bh(&fastopen_seqlock); |
586 | if (mss) |
587 | tfom->mss = mss; |
588 | if (cookie && cookie->len > 0) |
589 | tfom->cookie = *cookie; |
590 | else if (try_exp > tfom->try_exp && |
591 | tfom->cookie.len <= 0 && !tfom->cookie.exp) |
592 | tfom->try_exp = try_exp; |
593 | if (syn_lost) { |
594 | ++tfom->syn_loss; |
595 | tfom->last_syn_loss = jiffies; |
596 | } else |
597 | tfom->syn_loss = 0; |
598 | write_sequnlock_bh(&fastopen_seqlock); |
599 | } |
600 | rcu_read_unlock(); |
601 | } |
602 | |
603 | static struct genl_family tcp_metrics_nl_family; |
604 | |
605 | static const struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = { |
606 | [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, }, |
607 | [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY, |
608 | .len = sizeof(struct in6_addr), }, |
609 | /* Following attributes are not received for GET/DEL, |
610 | * we keep them for reference |
611 | */ |
612 | #if 0 |
613 | [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, }, |
614 | [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, }, |
615 | [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, }, |
616 | [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, }, |
617 | [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, }, |
618 | [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, }, |
619 | [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, }, |
620 | [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY, |
621 | .len = TCP_FASTOPEN_COOKIE_MAX, }, |
622 | #endif |
623 | }; |
624 | |
625 | /* Add attributes, caller cancels its header on failure */ |
626 | static int tcp_metrics_fill_info(struct sk_buff *msg, |
627 | struct tcp_metrics_block *tm) |
628 | { |
629 | struct nlattr *nest; |
630 | int i; |
631 | |
632 | switch (tm->tcpm_daddr.family) { |
633 | case AF_INET: |
634 | if (nla_put_in_addr(msg, TCP_METRICS_ATTR_ADDR_IPV4, |
635 | inetpeer_get_addr_v4(&tm->tcpm_daddr)) < 0) |
636 | goto nla_put_failure; |
637 | if (nla_put_in_addr(msg, TCP_METRICS_ATTR_SADDR_IPV4, |
638 | inetpeer_get_addr_v4(&tm->tcpm_saddr)) < 0) |
639 | goto nla_put_failure; |
640 | break; |
641 | case AF_INET6: |
642 | if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_ADDR_IPV6, |
643 | inetpeer_get_addr_v6(&tm->tcpm_daddr)) < 0) |
644 | goto nla_put_failure; |
645 | if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_SADDR_IPV6, |
646 | inetpeer_get_addr_v6(&tm->tcpm_saddr)) < 0) |
647 | goto nla_put_failure; |
648 | break; |
649 | default: |
650 | return -EAFNOSUPPORT; |
651 | } |
652 | |
653 | if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE, |
654 | jiffies - tm->tcpm_stamp, |
655 | TCP_METRICS_ATTR_PAD) < 0) |
656 | goto nla_put_failure; |
657 | |
658 | { |
659 | int n = 0; |
660 | |
661 | nest = nla_nest_start(msg, TCP_METRICS_ATTR_VALS); |
662 | if (!nest) |
663 | goto nla_put_failure; |
664 | for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) { |
665 | u32 val = tm->tcpm_vals[i]; |
666 | |
667 | if (!val) |
668 | continue; |
669 | if (i == TCP_METRIC_RTT) { |
670 | if (nla_put_u32(msg, TCP_METRIC_RTT_US + 1, |
671 | val) < 0) |
672 | goto nla_put_failure; |
673 | n++; |
674 | val = max(val / 1000, 1U); |
675 | } |
676 | if (i == TCP_METRIC_RTTVAR) { |
677 | if (nla_put_u32(msg, TCP_METRIC_RTTVAR_US + 1, |
678 | val) < 0) |
679 | goto nla_put_failure; |
680 | n++; |
681 | val = max(val / 1000, 1U); |
682 | } |
683 | if (nla_put_u32(msg, i + 1, val) < 0) |
684 | goto nla_put_failure; |
685 | n++; |
686 | } |
687 | if (n) |
688 | nla_nest_end(msg, nest); |
689 | else |
690 | nla_nest_cancel(msg, nest); |
691 | } |
692 | |
693 | { |
694 | struct tcp_fastopen_metrics tfom_copy[1], *tfom; |
695 | unsigned int seq; |
696 | |
697 | do { |
698 | seq = read_seqbegin(&fastopen_seqlock); |
699 | tfom_copy[0] = tm->tcpm_fastopen; |
700 | } while (read_seqretry(&fastopen_seqlock, seq)); |
701 | |
702 | tfom = tfom_copy; |
703 | if (tfom->mss && |
704 | nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS, |
705 | tfom->mss) < 0) |
706 | goto nla_put_failure; |
707 | if (tfom->syn_loss && |
708 | (nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS, |
709 | tfom->syn_loss) < 0 || |
710 | nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS, |
711 | jiffies - tfom->last_syn_loss, |
712 | TCP_METRICS_ATTR_PAD) < 0)) |
713 | goto nla_put_failure; |
714 | if (tfom->cookie.len > 0 && |
715 | nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE, |
716 | tfom->cookie.len, tfom->cookie.val) < 0) |
717 | goto nla_put_failure; |
718 | } |
719 | |
720 | return 0; |
721 | |
722 | nla_put_failure: |
723 | return -EMSGSIZE; |
724 | } |
725 | |
726 | static int tcp_metrics_dump_info(struct sk_buff *skb, |
727 | struct netlink_callback *cb, |
728 | struct tcp_metrics_block *tm) |
729 | { |
730 | void *hdr; |
731 | |
732 | hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, |
733 | &tcp_metrics_nl_family, NLM_F_MULTI, |
734 | TCP_METRICS_CMD_GET); |
735 | if (!hdr) |
736 | return -EMSGSIZE; |
737 | |
738 | if (tcp_metrics_fill_info(skb, tm) < 0) |
739 | goto nla_put_failure; |
740 | |
741 | genlmsg_end(skb, hdr); |
742 | return 0; |
743 | |
744 | nla_put_failure: |
745 | genlmsg_cancel(skb, hdr); |
746 | return -EMSGSIZE; |
747 | } |
748 | |
749 | static int tcp_metrics_nl_dump(struct sk_buff *skb, |
750 | struct netlink_callback *cb) |
751 | { |
752 | struct net *net = sock_net(skb->sk); |
753 | unsigned int max_rows = 1U << tcp_metrics_hash_log; |
754 | unsigned int row, s_row = cb->args[0]; |
755 | int s_col = cb->args[1], col = s_col; |
756 | |
757 | for (row = s_row; row < max_rows; row++, s_col = 0) { |
758 | struct tcp_metrics_block *tm; |
759 | struct tcpm_hash_bucket *hb = tcp_metrics_hash + row; |
760 | |
761 | rcu_read_lock(); |
762 | for (col = 0, tm = rcu_dereference(hb->chain); tm; |
763 | tm = rcu_dereference(tm->tcpm_next), col++) { |
764 | if (!net_eq(tm_net(tm), net)) |
765 | continue; |
766 | if (col < s_col) |
767 | continue; |
768 | if (tcp_metrics_dump_info(skb, cb, tm) < 0) { |
769 | rcu_read_unlock(); |
770 | goto done; |
771 | } |
772 | } |
773 | rcu_read_unlock(); |
774 | } |
775 | |
776 | done: |
777 | cb->args[0] = row; |
778 | cb->args[1] = col; |
779 | return skb->len; |
780 | } |
781 | |
782 | static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, |
783 | unsigned int *hash, int optional, int v4, int v6) |
784 | { |
785 | struct nlattr *a; |
786 | |
787 | a = info->attrs[v4]; |
788 | if (a) { |
789 | inetpeer_set_addr_v4(addr, nla_get_in_addr(a)); |
790 | if (hash) |
791 | *hash = ipv4_addr_hash(inetpeer_get_addr_v4(addr)); |
792 | return 0; |
793 | } |
794 | a = info->attrs[v6]; |
795 | if (a) { |
796 | struct in6_addr in6; |
797 | |
798 | if (nla_len(a) != sizeof(struct in6_addr)) |
799 | return -EINVAL; |
800 | in6 = nla_get_in6_addr(a); |
801 | inetpeer_set_addr_v6(addr, &in6); |
802 | if (hash) |
803 | *hash = ipv6_addr_hash(inetpeer_get_addr_v6(addr)); |
804 | return 0; |
805 | } |
806 | return optional ? 1 : -EAFNOSUPPORT; |
807 | } |
808 | |
809 | static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, |
810 | unsigned int *hash, int optional) |
811 | { |
812 | return __parse_nl_addr(info, addr, hash, optional, |
813 | TCP_METRICS_ATTR_ADDR_IPV4, |
814 | TCP_METRICS_ATTR_ADDR_IPV6); |
815 | } |
816 | |
817 | static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr) |
818 | { |
819 | return __parse_nl_addr(info, addr, NULL, 0, |
820 | TCP_METRICS_ATTR_SADDR_IPV4, |
821 | TCP_METRICS_ATTR_SADDR_IPV6); |
822 | } |
823 | |
824 | static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info) |
825 | { |
826 | struct tcp_metrics_block *tm; |
827 | struct inetpeer_addr saddr, daddr; |
828 | unsigned int hash; |
829 | struct sk_buff *msg; |
830 | struct net *net = genl_info_net(info); |
831 | void *reply; |
832 | int ret; |
833 | bool src = true; |
834 | |
835 | ret = parse_nl_addr(info, &daddr, &hash, 0); |
836 | if (ret < 0) |
837 | return ret; |
838 | |
839 | ret = parse_nl_saddr(info, &saddr); |
840 | if (ret < 0) |
841 | src = false; |
842 | |
843 | msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
844 | if (!msg) |
845 | return -ENOMEM; |
846 | |
847 | reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0, |
848 | info->genlhdr->cmd); |
849 | if (!reply) |
850 | goto nla_put_failure; |
851 | |
852 | hash ^= net_hash_mix(net); |
853 | hash = hash_32(hash, tcp_metrics_hash_log); |
854 | ret = -ESRCH; |
855 | rcu_read_lock(); |
856 | for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
857 | tm = rcu_dereference(tm->tcpm_next)) { |
858 | if (addr_same(&tm->tcpm_daddr, &daddr) && |
859 | (!src || addr_same(&tm->tcpm_saddr, &saddr)) && |
860 | net_eq(tm_net(tm), net)) { |
861 | ret = tcp_metrics_fill_info(msg, tm); |
862 | break; |
863 | } |
864 | } |
865 | rcu_read_unlock(); |
866 | if (ret < 0) |
867 | goto out_free; |
868 | |
869 | genlmsg_end(msg, reply); |
870 | return genlmsg_reply(msg, info); |
871 | |
872 | nla_put_failure: |
873 | ret = -EMSGSIZE; |
874 | |
875 | out_free: |
876 | nlmsg_free(msg); |
877 | return ret; |
878 | } |
879 | |
880 | static void tcp_metrics_flush_all(struct net *net) |
881 | { |
882 | unsigned int max_rows = 1U << tcp_metrics_hash_log; |
883 | struct tcpm_hash_bucket *hb = tcp_metrics_hash; |
884 | struct tcp_metrics_block *tm; |
885 | unsigned int row; |
886 | |
887 | for (row = 0; row < max_rows; row++, hb++) { |
888 | struct tcp_metrics_block __rcu **pp; |
889 | bool match; |
890 | |
891 | spin_lock_bh(&tcp_metrics_lock); |
892 | pp = &hb->chain; |
893 | for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { |
894 | match = net ? net_eq(tm_net(tm), net) : |
895 | !refcount_read(&tm_net(tm)->count); |
896 | if (match) { |
897 | *pp = tm->tcpm_next; |
898 | kfree_rcu(tm, rcu_head); |
899 | } else { |
900 | pp = &tm->tcpm_next; |
901 | } |
902 | } |
903 | spin_unlock_bh(&tcp_metrics_lock); |
904 | } |
905 | } |
906 | |
907 | static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info) |
908 | { |
909 | struct tcpm_hash_bucket *hb; |
910 | struct tcp_metrics_block *tm; |
911 | struct tcp_metrics_block __rcu **pp; |
912 | struct inetpeer_addr saddr, daddr; |
913 | unsigned int hash; |
914 | struct net *net = genl_info_net(info); |
915 | int ret; |
916 | bool src = true, found = false; |
917 | |
918 | ret = parse_nl_addr(info, &daddr, &hash, 1); |
919 | if (ret < 0) |
920 | return ret; |
921 | if (ret > 0) { |
922 | tcp_metrics_flush_all(net); |
923 | return 0; |
924 | } |
925 | ret = parse_nl_saddr(info, &saddr); |
926 | if (ret < 0) |
927 | src = false; |
928 | |
929 | hash ^= net_hash_mix(net); |
930 | hash = hash_32(hash, tcp_metrics_hash_log); |
931 | hb = tcp_metrics_hash + hash; |
932 | pp = &hb->chain; |
933 | spin_lock_bh(&tcp_metrics_lock); |
934 | for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { |
935 | if (addr_same(&tm->tcpm_daddr, &daddr) && |
936 | (!src || addr_same(&tm->tcpm_saddr, &saddr)) && |
937 | net_eq(tm_net(tm), net)) { |
938 | *pp = tm->tcpm_next; |
939 | kfree_rcu(tm, rcu_head); |
940 | found = true; |
941 | } else { |
942 | pp = &tm->tcpm_next; |
943 | } |
944 | } |
945 | spin_unlock_bh(&tcp_metrics_lock); |
946 | if (!found) |
947 | return -ESRCH; |
948 | return 0; |
949 | } |
950 | |
951 | static const struct genl_ops tcp_metrics_nl_ops[] = { |
952 | { |
953 | .cmd = TCP_METRICS_CMD_GET, |
954 | .doit = tcp_metrics_nl_cmd_get, |
955 | .dumpit = tcp_metrics_nl_dump, |
956 | .policy = tcp_metrics_nl_policy, |
957 | }, |
958 | { |
959 | .cmd = TCP_METRICS_CMD_DEL, |
960 | .doit = tcp_metrics_nl_cmd_del, |
961 | .policy = tcp_metrics_nl_policy, |
962 | .flags = GENL_ADMIN_PERM, |
963 | }, |
964 | }; |
965 | |
966 | static struct genl_family tcp_metrics_nl_family __ro_after_init = { |
967 | .hdrsize = 0, |
968 | .name = TCP_METRICS_GENL_NAME, |
969 | .version = TCP_METRICS_GENL_VERSION, |
970 | .maxattr = TCP_METRICS_ATTR_MAX, |
971 | .netnsok = true, |
972 | .module = THIS_MODULE, |
973 | .ops = tcp_metrics_nl_ops, |
974 | .n_ops = ARRAY_SIZE(tcp_metrics_nl_ops), |
975 | }; |
976 | |
977 | static unsigned int tcpmhash_entries; |
978 | static int __init set_tcpmhash_entries(char *str) |
979 | { |
980 | ssize_t ret; |
981 | |
982 | if (!str) |
983 | return 0; |
984 | |
985 | ret = kstrtouint(str, 0, &tcpmhash_entries); |
986 | if (ret) |
987 | return 0; |
988 | |
989 | return 1; |
990 | } |
991 | __setup("tcpmhash_entries=" , set_tcpmhash_entries); |
992 | |
993 | static int __net_init tcp_net_metrics_init(struct net *net) |
994 | { |
995 | size_t size; |
996 | unsigned int slots; |
997 | |
998 | if (!net_eq(net, &init_net)) |
999 | return 0; |
1000 | |
1001 | slots = tcpmhash_entries; |
1002 | if (!slots) { |
1003 | if (totalram_pages() >= 128 * 1024) |
1004 | slots = 16 * 1024; |
1005 | else |
1006 | slots = 8 * 1024; |
1007 | } |
1008 | |
1009 | tcp_metrics_hash_log = order_base_2(slots); |
1010 | size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log; |
1011 | |
1012 | tcp_metrics_hash = kvzalloc(size, GFP_KERNEL); |
1013 | if (!tcp_metrics_hash) |
1014 | return -ENOMEM; |
1015 | |
1016 | return 0; |
1017 | } |
1018 | |
1019 | static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_list) |
1020 | { |
1021 | tcp_metrics_flush_all(NULL); |
1022 | } |
1023 | |
1024 | static __net_initdata struct pernet_operations tcp_net_metrics_ops = { |
1025 | .init = tcp_net_metrics_init, |
1026 | .exit_batch = tcp_net_metrics_exit_batch, |
1027 | }; |
1028 | |
1029 | void __init tcp_metrics_init(void) |
1030 | { |
1031 | int ret; |
1032 | |
1033 | ret = register_pernet_subsys(&tcp_net_metrics_ops); |
1034 | if (ret < 0) |
1035 | panic("Could not allocate the tcp_metrics hash table\n" ); |
1036 | |
1037 | ret = genl_register_family(&tcp_metrics_nl_family); |
1038 | if (ret < 0) |
1039 | panic("Could not register tcp_metrics generic netlink\n" ); |
1040 | } |
1041 | |