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 | struct net *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(const struct tcp_metrics_block *tm) |
55 | { |
56 | /* Paired with the WRITE_ONCE() in tcpm_new() */ |
57 | return READ_ONCE(tm->tcpm_net); |
58 | } |
59 | |
60 | static bool tcp_metric_locked(struct tcp_metrics_block *tm, |
61 | enum tcp_metric_index idx) |
62 | { |
63 | /* Paired with WRITE_ONCE() in tcpm_suck_dst() */ |
64 | return READ_ONCE(tm->tcpm_lock) & (1 << idx); |
65 | } |
66 | |
67 | static u32 tcp_metric_get(const struct tcp_metrics_block *tm, |
68 | enum tcp_metric_index idx) |
69 | { |
70 | /* Paired with WRITE_ONCE() in tcp_metric_set() */ |
71 | return READ_ONCE(tm->tcpm_vals[idx]); |
72 | } |
73 | |
74 | static void tcp_metric_set(struct tcp_metrics_block *tm, |
75 | enum tcp_metric_index idx, |
76 | u32 val) |
77 | { |
78 | /* Paired with READ_ONCE() in tcp_metric_get() */ |
79 | WRITE_ONCE(tm->tcpm_vals[idx], val); |
80 | } |
81 | |
82 | static bool addr_same(const struct inetpeer_addr *a, |
83 | const struct inetpeer_addr *b) |
84 | { |
85 | return (a->family == b->family) && !inetpeer_addr_cmp(a, b); |
86 | } |
87 | |
88 | struct tcpm_hash_bucket { |
89 | struct tcp_metrics_block __rcu *chain; |
90 | }; |
91 | |
92 | static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly; |
93 | static unsigned int tcp_metrics_hash_log __read_mostly; |
94 | |
95 | static DEFINE_SPINLOCK(tcp_metrics_lock); |
96 | static DEFINE_SEQLOCK(fastopen_seqlock); |
97 | |
98 | static void tcpm_suck_dst(struct tcp_metrics_block *tm, |
99 | const struct dst_entry *dst, |
100 | bool fastopen_clear) |
101 | { |
102 | u32 msval; |
103 | u32 val; |
104 | |
105 | WRITE_ONCE(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 | /* Paired with READ_ONCE() in tcp_metric_locked() */ |
119 | WRITE_ONCE(tm->tcpm_lock, val); |
120 | |
121 | msval = dst_metric_raw(dst, RTAX_RTT); |
122 | tcp_metric_set(tm, idx: TCP_METRIC_RTT, val: msval * USEC_PER_MSEC); |
123 | |
124 | msval = dst_metric_raw(dst, RTAX_RTTVAR); |
125 | tcp_metric_set(tm, idx: TCP_METRIC_RTTVAR, val: msval * USEC_PER_MSEC); |
126 | tcp_metric_set(tm, idx: TCP_METRIC_SSTHRESH, |
127 | val: dst_metric_raw(dst, RTAX_SSTHRESH)); |
128 | tcp_metric_set(tm, idx: TCP_METRIC_CWND, |
129 | val: dst_metric_raw(dst, RTAX_CWND)); |
130 | tcp_metric_set(tm, idx: TCP_METRIC_REORDERING, |
131 | val: dst_metric_raw(dst, RTAX_REORDERING)); |
132 | if (fastopen_clear) { |
133 | write_seqlock(sl: &fastopen_seqlock); |
134 | tm->tcpm_fastopen.mss = 0; |
135 | tm->tcpm_fastopen.syn_loss = 0; |
136 | tm->tcpm_fastopen.try_exp = 0; |
137 | tm->tcpm_fastopen.cookie.exp = false; |
138 | tm->tcpm_fastopen.cookie.len = 0; |
139 | write_sequnlock(sl: &fastopen_seqlock); |
140 | } |
141 | } |
142 | |
143 | #define TCP_METRICS_TIMEOUT (60 * 60 * HZ) |
144 | |
145 | static void tcpm_check_stamp(struct tcp_metrics_block *tm, |
146 | const struct dst_entry *dst) |
147 | { |
148 | unsigned long limit; |
149 | |
150 | if (!tm) |
151 | return; |
152 | limit = READ_ONCE(tm->tcpm_stamp) + TCP_METRICS_TIMEOUT; |
153 | if (unlikely(time_after(jiffies, limit))) |
154 | tcpm_suck_dst(tm, dst, fastopen_clear: false); |
155 | } |
156 | |
157 | #define TCP_METRICS_RECLAIM_DEPTH 5 |
158 | #define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL |
159 | |
160 | #define deref_locked(p) \ |
161 | rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock)) |
162 | |
163 | static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, |
164 | struct inetpeer_addr *saddr, |
165 | struct inetpeer_addr *daddr, |
166 | unsigned int hash) |
167 | { |
168 | struct tcp_metrics_block *tm; |
169 | struct net *net; |
170 | bool reclaim = false; |
171 | |
172 | spin_lock_bh(lock: &tcp_metrics_lock); |
173 | net = dev_net(dev: dst->dev); |
174 | |
175 | /* While waiting for the spin-lock the cache might have been populated |
176 | * with this entry and so we have to check again. |
177 | */ |
178 | tm = __tcp_get_metrics(saddr, daddr, net, hash); |
179 | if (tm == TCP_METRICS_RECLAIM_PTR) { |
180 | reclaim = true; |
181 | tm = NULL; |
182 | } |
183 | if (tm) { |
184 | tcpm_check_stamp(tm, dst); |
185 | goto out_unlock; |
186 | } |
187 | |
188 | if (unlikely(reclaim)) { |
189 | struct tcp_metrics_block *oldest; |
190 | |
191 | oldest = deref_locked(tcp_metrics_hash[hash].chain); |
192 | for (tm = deref_locked(oldest->tcpm_next); tm; |
193 | tm = deref_locked(tm->tcpm_next)) { |
194 | if (time_before(READ_ONCE(tm->tcpm_stamp), |
195 | READ_ONCE(oldest->tcpm_stamp))) |
196 | oldest = tm; |
197 | } |
198 | tm = oldest; |
199 | } else { |
200 | tm = kzalloc(size: sizeof(*tm), GFP_ATOMIC); |
201 | if (!tm) |
202 | goto out_unlock; |
203 | } |
204 | /* Paired with the READ_ONCE() in tm_net() */ |
205 | WRITE_ONCE(tm->tcpm_net, net); |
206 | |
207 | tm->tcpm_saddr = *saddr; |
208 | tm->tcpm_daddr = *daddr; |
209 | |
210 | tcpm_suck_dst(tm, dst, fastopen_clear: reclaim); |
211 | |
212 | if (likely(!reclaim)) { |
213 | tm->tcpm_next = tcp_metrics_hash[hash].chain; |
214 | rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm); |
215 | } |
216 | |
217 | out_unlock: |
218 | spin_unlock_bh(lock: &tcp_metrics_lock); |
219 | return tm; |
220 | } |
221 | |
222 | static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth) |
223 | { |
224 | if (tm) |
225 | return tm; |
226 | if (depth > TCP_METRICS_RECLAIM_DEPTH) |
227 | return TCP_METRICS_RECLAIM_PTR; |
228 | return NULL; |
229 | } |
230 | |
231 | static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, |
232 | const struct inetpeer_addr *daddr, |
233 | struct net *net, unsigned int hash) |
234 | { |
235 | struct tcp_metrics_block *tm; |
236 | int depth = 0; |
237 | |
238 | for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
239 | tm = rcu_dereference(tm->tcpm_next)) { |
240 | if (addr_same(a: &tm->tcpm_saddr, b: saddr) && |
241 | addr_same(a: &tm->tcpm_daddr, b: daddr) && |
242 | net_eq(net1: tm_net(tm), net2: net)) |
243 | break; |
244 | depth++; |
245 | } |
246 | return tcp_get_encode(tm, depth); |
247 | } |
248 | |
249 | static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, |
250 | struct dst_entry *dst) |
251 | { |
252 | struct tcp_metrics_block *tm; |
253 | struct inetpeer_addr saddr, daddr; |
254 | unsigned int hash; |
255 | struct net *net; |
256 | |
257 | saddr.family = req->rsk_ops->family; |
258 | daddr.family = req->rsk_ops->family; |
259 | switch (daddr.family) { |
260 | case AF_INET: |
261 | inetpeer_set_addr_v4(iaddr: &saddr, ip: inet_rsk(sk: req)->ir_loc_addr); |
262 | inetpeer_set_addr_v4(iaddr: &daddr, ip: inet_rsk(sk: req)->ir_rmt_addr); |
263 | hash = ipv4_addr_hash(ip: inet_rsk(sk: req)->ir_rmt_addr); |
264 | break; |
265 | #if IS_ENABLED(CONFIG_IPV6) |
266 | case AF_INET6: |
267 | inetpeer_set_addr_v6(iaddr: &saddr, in6: &inet_rsk(sk: req)->ir_v6_loc_addr); |
268 | inetpeer_set_addr_v6(iaddr: &daddr, in6: &inet_rsk(sk: req)->ir_v6_rmt_addr); |
269 | hash = ipv6_addr_hash(a: &inet_rsk(sk: req)->ir_v6_rmt_addr); |
270 | break; |
271 | #endif |
272 | default: |
273 | return NULL; |
274 | } |
275 | |
276 | net = dev_net(dev: dst->dev); |
277 | hash ^= net_hash_mix(net); |
278 | hash = hash_32(val: hash, bits: tcp_metrics_hash_log); |
279 | |
280 | for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
281 | tm = rcu_dereference(tm->tcpm_next)) { |
282 | if (addr_same(a: &tm->tcpm_saddr, b: &saddr) && |
283 | addr_same(a: &tm->tcpm_daddr, b: &daddr) && |
284 | net_eq(net1: tm_net(tm), net2: net)) |
285 | break; |
286 | } |
287 | tcpm_check_stamp(tm, dst); |
288 | return tm; |
289 | } |
290 | |
291 | static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk, |
292 | struct dst_entry *dst, |
293 | bool create) |
294 | { |
295 | struct tcp_metrics_block *tm; |
296 | struct inetpeer_addr saddr, daddr; |
297 | unsigned int hash; |
298 | struct net *net; |
299 | |
300 | if (sk->sk_family == AF_INET) { |
301 | inetpeer_set_addr_v4(iaddr: &saddr, inet_sk(sk)->inet_saddr); |
302 | inetpeer_set_addr_v4(iaddr: &daddr, inet_sk(sk)->inet_daddr); |
303 | hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr); |
304 | } |
305 | #if IS_ENABLED(CONFIG_IPV6) |
306 | else if (sk->sk_family == AF_INET6) { |
307 | if (ipv6_addr_v4mapped(a: &sk->sk_v6_daddr)) { |
308 | inetpeer_set_addr_v4(iaddr: &saddr, inet_sk(sk)->inet_saddr); |
309 | inetpeer_set_addr_v4(iaddr: &daddr, inet_sk(sk)->inet_daddr); |
310 | hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr); |
311 | } else { |
312 | inetpeer_set_addr_v6(iaddr: &saddr, in6: &sk->sk_v6_rcv_saddr); |
313 | inetpeer_set_addr_v6(iaddr: &daddr, in6: &sk->sk_v6_daddr); |
314 | hash = ipv6_addr_hash(a: &sk->sk_v6_daddr); |
315 | } |
316 | } |
317 | #endif |
318 | else |
319 | return NULL; |
320 | |
321 | net = dev_net(dev: dst->dev); |
322 | hash ^= net_hash_mix(net); |
323 | hash = hash_32(val: hash, bits: tcp_metrics_hash_log); |
324 | |
325 | tm = __tcp_get_metrics(saddr: &saddr, daddr: &daddr, net, hash); |
326 | if (tm == TCP_METRICS_RECLAIM_PTR) |
327 | tm = NULL; |
328 | if (!tm && create) |
329 | tm = tcpm_new(dst, saddr: &saddr, daddr: &daddr, hash); |
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 net *net = sock_net(sk); |
346 | struct tcp_metrics_block *tm; |
347 | unsigned long rtt; |
348 | u32 val; |
349 | int m; |
350 | |
351 | sk_dst_confirm(sk); |
352 | if (READ_ONCE(net->ipv4.sysctl_tcp_nometrics_save) || !dst) |
353 | return; |
354 | |
355 | rcu_read_lock(); |
356 | if (icsk->icsk_backoff || !tp->srtt_us) { |
357 | /* This session failed to estimate rtt. Why? |
358 | * Probably, no packets returned in time. Reset our |
359 | * results. |
360 | */ |
361 | tm = tcp_get_metrics(sk, dst, create: false); |
362 | if (tm && !tcp_metric_locked(tm, idx: TCP_METRIC_RTT)) |
363 | tcp_metric_set(tm, idx: TCP_METRIC_RTT, val: 0); |
364 | goto out_unlock; |
365 | } else |
366 | tm = tcp_get_metrics(sk, dst, create: true); |
367 | |
368 | if (!tm) |
369 | goto out_unlock; |
370 | |
371 | rtt = tcp_metric_get(tm, idx: TCP_METRIC_RTT); |
372 | m = rtt - tp->srtt_us; |
373 | |
374 | /* If newly calculated rtt larger than stored one, store new |
375 | * one. Otherwise, use EWMA. Remember, rtt overestimation is |
376 | * always better than underestimation. |
377 | */ |
378 | if (!tcp_metric_locked(tm, idx: TCP_METRIC_RTT)) { |
379 | if (m <= 0) |
380 | rtt = tp->srtt_us; |
381 | else |
382 | rtt -= (m >> 3); |
383 | tcp_metric_set(tm, idx: TCP_METRIC_RTT, val: rtt); |
384 | } |
385 | |
386 | if (!tcp_metric_locked(tm, idx: TCP_METRIC_RTTVAR)) { |
387 | unsigned long var; |
388 | |
389 | if (m < 0) |
390 | m = -m; |
391 | |
392 | /* Scale deviation to rttvar fixed point */ |
393 | m >>= 1; |
394 | if (m < tp->mdev_us) |
395 | m = tp->mdev_us; |
396 | |
397 | var = tcp_metric_get(tm, idx: TCP_METRIC_RTTVAR); |
398 | if (m >= var) |
399 | var = m; |
400 | else |
401 | var -= (var - m) >> 2; |
402 | |
403 | tcp_metric_set(tm, idx: TCP_METRIC_RTTVAR, val: var); |
404 | } |
405 | |
406 | if (tcp_in_initial_slowstart(tp)) { |
407 | /* Slow start still did not finish. */ |
408 | if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && |
409 | !tcp_metric_locked(tm, idx: TCP_METRIC_SSTHRESH)) { |
410 | val = tcp_metric_get(tm, idx: TCP_METRIC_SSTHRESH); |
411 | if (val && (tcp_snd_cwnd(tp) >> 1) > val) |
412 | tcp_metric_set(tm, idx: TCP_METRIC_SSTHRESH, |
413 | val: tcp_snd_cwnd(tp) >> 1); |
414 | } |
415 | if (!tcp_metric_locked(tm, idx: TCP_METRIC_CWND)) { |
416 | val = tcp_metric_get(tm, idx: TCP_METRIC_CWND); |
417 | if (tcp_snd_cwnd(tp) > val) |
418 | tcp_metric_set(tm, idx: TCP_METRIC_CWND, |
419 | val: tcp_snd_cwnd(tp)); |
420 | } |
421 | } else if (!tcp_in_slow_start(tp) && |
422 | icsk->icsk_ca_state == TCP_CA_Open) { |
423 | /* Cong. avoidance phase, cwnd is reliable. */ |
424 | if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && |
425 | !tcp_metric_locked(tm, idx: TCP_METRIC_SSTHRESH)) |
426 | tcp_metric_set(tm, idx: TCP_METRIC_SSTHRESH, |
427 | max(tcp_snd_cwnd(tp) >> 1, tp->snd_ssthresh)); |
428 | if (!tcp_metric_locked(tm, idx: TCP_METRIC_CWND)) { |
429 | val = tcp_metric_get(tm, idx: TCP_METRIC_CWND); |
430 | tcp_metric_set(tm, idx: TCP_METRIC_CWND, val: (val + tcp_snd_cwnd(tp)) >> 1); |
431 | } |
432 | } else { |
433 | /* Else slow start did not finish, cwnd is non-sense, |
434 | * ssthresh may be also invalid. |
435 | */ |
436 | if (!tcp_metric_locked(tm, idx: TCP_METRIC_CWND)) { |
437 | val = tcp_metric_get(tm, idx: TCP_METRIC_CWND); |
438 | tcp_metric_set(tm, idx: TCP_METRIC_CWND, |
439 | val: (val + tp->snd_ssthresh) >> 1); |
440 | } |
441 | if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) && |
442 | !tcp_metric_locked(tm, idx: TCP_METRIC_SSTHRESH)) { |
443 | val = tcp_metric_get(tm, idx: TCP_METRIC_SSTHRESH); |
444 | if (val && tp->snd_ssthresh > val) |
445 | tcp_metric_set(tm, idx: TCP_METRIC_SSTHRESH, |
446 | val: tp->snd_ssthresh); |
447 | } |
448 | if (!tcp_metric_locked(tm, idx: TCP_METRIC_REORDERING)) { |
449 | val = tcp_metric_get(tm, idx: TCP_METRIC_REORDERING); |
450 | if (val < tp->reordering && |
451 | tp->reordering != |
452 | READ_ONCE(net->ipv4.sysctl_tcp_reordering)) |
453 | tcp_metric_set(tm, idx: TCP_METRIC_REORDERING, |
454 | val: tp->reordering); |
455 | } |
456 | } |
457 | WRITE_ONCE(tm->tcpm_stamp, jiffies); |
458 | out_unlock: |
459 | rcu_read_unlock(); |
460 | } |
461 | |
462 | /* Initialize metrics on socket. */ |
463 | |
464 | void tcp_init_metrics(struct sock *sk) |
465 | { |
466 | struct dst_entry *dst = __sk_dst_get(sk); |
467 | struct tcp_sock *tp = tcp_sk(sk); |
468 | struct net *net = sock_net(sk); |
469 | struct tcp_metrics_block *tm; |
470 | u32 val, crtt = 0; /* cached RTT scaled by 8 */ |
471 | |
472 | sk_dst_confirm(sk); |
473 | /* ssthresh may have been reduced unnecessarily during. |
474 | * 3WHS. Restore it back to its initial default. |
475 | */ |
476 | tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
477 | if (!dst) |
478 | goto reset; |
479 | |
480 | rcu_read_lock(); |
481 | tm = tcp_get_metrics(sk, dst, create: false); |
482 | if (!tm) { |
483 | rcu_read_unlock(); |
484 | goto reset; |
485 | } |
486 | |
487 | if (tcp_metric_locked(tm, idx: TCP_METRIC_CWND)) |
488 | tp->snd_cwnd_clamp = tcp_metric_get(tm, idx: TCP_METRIC_CWND); |
489 | |
490 | val = READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) ? |
491 | 0 : tcp_metric_get(tm, idx: TCP_METRIC_SSTHRESH); |
492 | if (val) { |
493 | tp->snd_ssthresh = val; |
494 | if (tp->snd_ssthresh > tp->snd_cwnd_clamp) |
495 | tp->snd_ssthresh = tp->snd_cwnd_clamp; |
496 | } |
497 | val = tcp_metric_get(tm, idx: TCP_METRIC_REORDERING); |
498 | if (val && tp->reordering != val) |
499 | tp->reordering = val; |
500 | |
501 | crtt = tcp_metric_get(tm, idx: 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_us) { |
525 | /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */ |
526 | crtt /= 8 * USEC_PER_SEC / HZ; |
527 | inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk)); |
528 | } else if (tp->srtt_us == 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->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK); |
536 | tp->mdev_us = tp->mdev_max_us = tp->rttvar_us; |
537 | |
538 | inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK; |
539 | } |
540 | } |
541 | |
542 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst) |
543 | { |
544 | struct tcp_metrics_block *tm; |
545 | bool ret; |
546 | |
547 | if (!dst) |
548 | return false; |
549 | |
550 | rcu_read_lock(); |
551 | tm = __tcp_get_metrics_req(req, dst); |
552 | if (tm && tcp_metric_get(tm, idx: TCP_METRIC_RTT)) |
553 | ret = true; |
554 | else |
555 | ret = false; |
556 | rcu_read_unlock(); |
557 | |
558 | return ret; |
559 | } |
560 | |
561 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
562 | struct tcp_fastopen_cookie *cookie) |
563 | { |
564 | struct tcp_metrics_block *tm; |
565 | |
566 | rcu_read_lock(); |
567 | tm = tcp_get_metrics(sk, dst: __sk_dst_get(sk), create: false); |
568 | if (tm) { |
569 | struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; |
570 | unsigned int seq; |
571 | |
572 | do { |
573 | seq = read_seqbegin(sl: &fastopen_seqlock); |
574 | if (tfom->mss) |
575 | *mss = tfom->mss; |
576 | *cookie = tfom->cookie; |
577 | if (cookie->len <= 0 && tfom->try_exp == 1) |
578 | cookie->exp = true; |
579 | } while (read_seqretry(sl: &fastopen_seqlock, start: seq)); |
580 | } |
581 | rcu_read_unlock(); |
582 | } |
583 | |
584 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
585 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
586 | u16 try_exp) |
587 | { |
588 | struct dst_entry *dst = __sk_dst_get(sk); |
589 | struct tcp_metrics_block *tm; |
590 | |
591 | if (!dst) |
592 | return; |
593 | rcu_read_lock(); |
594 | tm = tcp_get_metrics(sk, dst, create: true); |
595 | if (tm) { |
596 | struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; |
597 | |
598 | write_seqlock_bh(sl: &fastopen_seqlock); |
599 | if (mss) |
600 | tfom->mss = mss; |
601 | if (cookie && cookie->len > 0) |
602 | tfom->cookie = *cookie; |
603 | else if (try_exp > tfom->try_exp && |
604 | tfom->cookie.len <= 0 && !tfom->cookie.exp) |
605 | tfom->try_exp = try_exp; |
606 | if (syn_lost) { |
607 | ++tfom->syn_loss; |
608 | tfom->last_syn_loss = jiffies; |
609 | } else |
610 | tfom->syn_loss = 0; |
611 | write_sequnlock_bh(sl: &fastopen_seqlock); |
612 | } |
613 | rcu_read_unlock(); |
614 | } |
615 | |
616 | static struct genl_family tcp_metrics_nl_family; |
617 | |
618 | static const struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = { |
619 | [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, }, |
620 | [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY, |
621 | .len = sizeof(struct in6_addr), }, |
622 | /* Following attributes are not received for GET/DEL, |
623 | * we keep them for reference |
624 | */ |
625 | #if 0 |
626 | [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, }, |
627 | [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, }, |
628 | [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, }, |
629 | [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, }, |
630 | [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, }, |
631 | [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, }, |
632 | [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, }, |
633 | [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY, |
634 | .len = TCP_FASTOPEN_COOKIE_MAX, }, |
635 | #endif |
636 | }; |
637 | |
638 | /* Add attributes, caller cancels its header on failure */ |
639 | static int tcp_metrics_fill_info(struct sk_buff *msg, |
640 | struct tcp_metrics_block *tm) |
641 | { |
642 | struct nlattr *nest; |
643 | int i; |
644 | |
645 | switch (tm->tcpm_daddr.family) { |
646 | case AF_INET: |
647 | if (nla_put_in_addr(skb: msg, attrtype: TCP_METRICS_ATTR_ADDR_IPV4, |
648 | addr: inetpeer_get_addr_v4(iaddr: &tm->tcpm_daddr)) < 0) |
649 | goto nla_put_failure; |
650 | if (nla_put_in_addr(skb: msg, attrtype: TCP_METRICS_ATTR_SADDR_IPV4, |
651 | addr: inetpeer_get_addr_v4(iaddr: &tm->tcpm_saddr)) < 0) |
652 | goto nla_put_failure; |
653 | break; |
654 | case AF_INET6: |
655 | if (nla_put_in6_addr(skb: msg, attrtype: TCP_METRICS_ATTR_ADDR_IPV6, |
656 | addr: inetpeer_get_addr_v6(iaddr: &tm->tcpm_daddr)) < 0) |
657 | goto nla_put_failure; |
658 | if (nla_put_in6_addr(skb: msg, attrtype: TCP_METRICS_ATTR_SADDR_IPV6, |
659 | addr: inetpeer_get_addr_v6(iaddr: &tm->tcpm_saddr)) < 0) |
660 | goto nla_put_failure; |
661 | break; |
662 | default: |
663 | return -EAFNOSUPPORT; |
664 | } |
665 | |
666 | if (nla_put_msecs(skb: msg, attrtype: TCP_METRICS_ATTR_AGE, |
667 | njiffies: jiffies - READ_ONCE(tm->tcpm_stamp), |
668 | padattr: TCP_METRICS_ATTR_PAD) < 0) |
669 | goto nla_put_failure; |
670 | |
671 | { |
672 | int n = 0; |
673 | |
674 | nest = nla_nest_start_noflag(skb: msg, attrtype: TCP_METRICS_ATTR_VALS); |
675 | if (!nest) |
676 | goto nla_put_failure; |
677 | for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) { |
678 | u32 val = tcp_metric_get(tm, idx: i); |
679 | |
680 | if (!val) |
681 | continue; |
682 | if (i == TCP_METRIC_RTT) { |
683 | if (nla_put_u32(skb: msg, attrtype: TCP_METRIC_RTT_US + 1, |
684 | value: val) < 0) |
685 | goto nla_put_failure; |
686 | n++; |
687 | val = max(val / 1000, 1U); |
688 | } |
689 | if (i == TCP_METRIC_RTTVAR) { |
690 | if (nla_put_u32(skb: msg, attrtype: TCP_METRIC_RTTVAR_US + 1, |
691 | value: val) < 0) |
692 | goto nla_put_failure; |
693 | n++; |
694 | val = max(val / 1000, 1U); |
695 | } |
696 | if (nla_put_u32(skb: msg, attrtype: i + 1, value: val) < 0) |
697 | goto nla_put_failure; |
698 | n++; |
699 | } |
700 | if (n) |
701 | nla_nest_end(skb: msg, start: nest); |
702 | else |
703 | nla_nest_cancel(skb: msg, start: nest); |
704 | } |
705 | |
706 | { |
707 | struct tcp_fastopen_metrics tfom_copy[1], *tfom; |
708 | unsigned int seq; |
709 | |
710 | do { |
711 | seq = read_seqbegin(sl: &fastopen_seqlock); |
712 | tfom_copy[0] = tm->tcpm_fastopen; |
713 | } while (read_seqretry(sl: &fastopen_seqlock, start: seq)); |
714 | |
715 | tfom = tfom_copy; |
716 | if (tfom->mss && |
717 | nla_put_u16(skb: msg, attrtype: TCP_METRICS_ATTR_FOPEN_MSS, |
718 | value: tfom->mss) < 0) |
719 | goto nla_put_failure; |
720 | if (tfom->syn_loss && |
721 | (nla_put_u16(skb: msg, attrtype: TCP_METRICS_ATTR_FOPEN_SYN_DROPS, |
722 | value: tfom->syn_loss) < 0 || |
723 | nla_put_msecs(skb: msg, attrtype: TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS, |
724 | njiffies: jiffies - tfom->last_syn_loss, |
725 | padattr: TCP_METRICS_ATTR_PAD) < 0)) |
726 | goto nla_put_failure; |
727 | if (tfom->cookie.len > 0 && |
728 | nla_put(skb: msg, attrtype: TCP_METRICS_ATTR_FOPEN_COOKIE, |
729 | attrlen: tfom->cookie.len, data: tfom->cookie.val) < 0) |
730 | goto nla_put_failure; |
731 | } |
732 | |
733 | return 0; |
734 | |
735 | nla_put_failure: |
736 | return -EMSGSIZE; |
737 | } |
738 | |
739 | static int tcp_metrics_dump_info(struct sk_buff *skb, |
740 | struct netlink_callback *cb, |
741 | struct tcp_metrics_block *tm) |
742 | { |
743 | void *hdr; |
744 | |
745 | hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, seq: cb->nlh->nlmsg_seq, |
746 | family: &tcp_metrics_nl_family, NLM_F_MULTI, |
747 | cmd: TCP_METRICS_CMD_GET); |
748 | if (!hdr) |
749 | return -EMSGSIZE; |
750 | |
751 | if (tcp_metrics_fill_info(msg: skb, tm) < 0) |
752 | goto nla_put_failure; |
753 | |
754 | genlmsg_end(skb, hdr); |
755 | return 0; |
756 | |
757 | nla_put_failure: |
758 | genlmsg_cancel(skb, hdr); |
759 | return -EMSGSIZE; |
760 | } |
761 | |
762 | static int tcp_metrics_nl_dump(struct sk_buff *skb, |
763 | struct netlink_callback *cb) |
764 | { |
765 | struct net *net = sock_net(sk: skb->sk); |
766 | unsigned int max_rows = 1U << tcp_metrics_hash_log; |
767 | unsigned int row, s_row = cb->args[0]; |
768 | int s_col = cb->args[1], col = s_col; |
769 | |
770 | for (row = s_row; row < max_rows; row++, s_col = 0) { |
771 | struct tcp_metrics_block *tm; |
772 | struct tcpm_hash_bucket *hb = tcp_metrics_hash + row; |
773 | |
774 | rcu_read_lock(); |
775 | for (col = 0, tm = rcu_dereference(hb->chain); tm; |
776 | tm = rcu_dereference(tm->tcpm_next), col++) { |
777 | if (!net_eq(net1: tm_net(tm), net2: net)) |
778 | continue; |
779 | if (col < s_col) |
780 | continue; |
781 | if (tcp_metrics_dump_info(skb, cb, tm) < 0) { |
782 | rcu_read_unlock(); |
783 | goto done; |
784 | } |
785 | } |
786 | rcu_read_unlock(); |
787 | } |
788 | |
789 | done: |
790 | cb->args[0] = row; |
791 | cb->args[1] = col; |
792 | return skb->len; |
793 | } |
794 | |
795 | static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, |
796 | unsigned int *hash, int optional, int v4, int v6) |
797 | { |
798 | struct nlattr *a; |
799 | |
800 | a = info->attrs[v4]; |
801 | if (a) { |
802 | inetpeer_set_addr_v4(iaddr: addr, ip: nla_get_in_addr(nla: a)); |
803 | if (hash) |
804 | *hash = ipv4_addr_hash(ip: inetpeer_get_addr_v4(iaddr: addr)); |
805 | return 0; |
806 | } |
807 | a = info->attrs[v6]; |
808 | if (a) { |
809 | struct in6_addr in6; |
810 | |
811 | if (nla_len(nla: a) != sizeof(struct in6_addr)) |
812 | return -EINVAL; |
813 | in6 = nla_get_in6_addr(nla: a); |
814 | inetpeer_set_addr_v6(iaddr: addr, in6: &in6); |
815 | if (hash) |
816 | *hash = ipv6_addr_hash(a: inetpeer_get_addr_v6(iaddr: addr)); |
817 | return 0; |
818 | } |
819 | return optional ? 1 : -EAFNOSUPPORT; |
820 | } |
821 | |
822 | static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, |
823 | unsigned int *hash, int optional) |
824 | { |
825 | return __parse_nl_addr(info, addr, hash, optional, |
826 | v4: TCP_METRICS_ATTR_ADDR_IPV4, |
827 | v6: TCP_METRICS_ATTR_ADDR_IPV6); |
828 | } |
829 | |
830 | static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr) |
831 | { |
832 | return __parse_nl_addr(info, addr, NULL, optional: 0, |
833 | v4: TCP_METRICS_ATTR_SADDR_IPV4, |
834 | v6: TCP_METRICS_ATTR_SADDR_IPV6); |
835 | } |
836 | |
837 | static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info) |
838 | { |
839 | struct tcp_metrics_block *tm; |
840 | struct inetpeer_addr saddr, daddr; |
841 | unsigned int hash; |
842 | struct sk_buff *msg; |
843 | struct net *net = genl_info_net(info); |
844 | void *reply; |
845 | int ret; |
846 | bool src = true; |
847 | |
848 | ret = parse_nl_addr(info, addr: &daddr, hash: &hash, optional: 0); |
849 | if (ret < 0) |
850 | return ret; |
851 | |
852 | ret = parse_nl_saddr(info, addr: &saddr); |
853 | if (ret < 0) |
854 | src = false; |
855 | |
856 | msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
857 | if (!msg) |
858 | return -ENOMEM; |
859 | |
860 | reply = genlmsg_put_reply(skb: msg, info, family: &tcp_metrics_nl_family, flags: 0, |
861 | cmd: info->genlhdr->cmd); |
862 | if (!reply) |
863 | goto nla_put_failure; |
864 | |
865 | hash ^= net_hash_mix(net); |
866 | hash = hash_32(val: hash, bits: tcp_metrics_hash_log); |
867 | ret = -ESRCH; |
868 | rcu_read_lock(); |
869 | for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
870 | tm = rcu_dereference(tm->tcpm_next)) { |
871 | if (addr_same(a: &tm->tcpm_daddr, b: &daddr) && |
872 | (!src || addr_same(a: &tm->tcpm_saddr, b: &saddr)) && |
873 | net_eq(net1: tm_net(tm), net2: net)) { |
874 | ret = tcp_metrics_fill_info(msg, tm); |
875 | break; |
876 | } |
877 | } |
878 | rcu_read_unlock(); |
879 | if (ret < 0) |
880 | goto out_free; |
881 | |
882 | genlmsg_end(skb: msg, hdr: reply); |
883 | return genlmsg_reply(skb: msg, info); |
884 | |
885 | nla_put_failure: |
886 | ret = -EMSGSIZE; |
887 | |
888 | out_free: |
889 | nlmsg_free(skb: msg); |
890 | return ret; |
891 | } |
892 | |
893 | static void tcp_metrics_flush_all(struct net *net) |
894 | { |
895 | unsigned int max_rows = 1U << tcp_metrics_hash_log; |
896 | struct tcpm_hash_bucket *hb = tcp_metrics_hash; |
897 | struct tcp_metrics_block *tm; |
898 | unsigned int row; |
899 | |
900 | for (row = 0; row < max_rows; row++, hb++) { |
901 | struct tcp_metrics_block __rcu **pp = &hb->chain; |
902 | bool match; |
903 | |
904 | if (!rcu_access_pointer(*pp)) |
905 | continue; |
906 | |
907 | spin_lock_bh(lock: &tcp_metrics_lock); |
908 | for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { |
909 | match = net ? net_eq(net1: tm_net(tm), net2: net) : |
910 | !refcount_read(r: &tm_net(tm)->ns.count); |
911 | if (match) { |
912 | rcu_assign_pointer(*pp, tm->tcpm_next); |
913 | kfree_rcu(tm, rcu_head); |
914 | } else { |
915 | pp = &tm->tcpm_next; |
916 | } |
917 | } |
918 | spin_unlock_bh(lock: &tcp_metrics_lock); |
919 | cond_resched(); |
920 | } |
921 | } |
922 | |
923 | static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info) |
924 | { |
925 | struct tcpm_hash_bucket *hb; |
926 | struct tcp_metrics_block *tm; |
927 | struct tcp_metrics_block __rcu **pp; |
928 | struct inetpeer_addr saddr, daddr; |
929 | unsigned int hash; |
930 | struct net *net = genl_info_net(info); |
931 | int ret; |
932 | bool src = true, found = false; |
933 | |
934 | ret = parse_nl_addr(info, addr: &daddr, hash: &hash, optional: 1); |
935 | if (ret < 0) |
936 | return ret; |
937 | if (ret > 0) { |
938 | tcp_metrics_flush_all(net); |
939 | return 0; |
940 | } |
941 | ret = parse_nl_saddr(info, addr: &saddr); |
942 | if (ret < 0) |
943 | src = false; |
944 | |
945 | hash ^= net_hash_mix(net); |
946 | hash = hash_32(val: hash, bits: tcp_metrics_hash_log); |
947 | hb = tcp_metrics_hash + hash; |
948 | pp = &hb->chain; |
949 | spin_lock_bh(lock: &tcp_metrics_lock); |
950 | for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { |
951 | if (addr_same(a: &tm->tcpm_daddr, b: &daddr) && |
952 | (!src || addr_same(a: &tm->tcpm_saddr, b: &saddr)) && |
953 | net_eq(net1: tm_net(tm), net2: net)) { |
954 | rcu_assign_pointer(*pp, tm->tcpm_next); |
955 | kfree_rcu(tm, rcu_head); |
956 | found = true; |
957 | } else { |
958 | pp = &tm->tcpm_next; |
959 | } |
960 | } |
961 | spin_unlock_bh(lock: &tcp_metrics_lock); |
962 | if (!found) |
963 | return -ESRCH; |
964 | return 0; |
965 | } |
966 | |
967 | static const struct genl_small_ops tcp_metrics_nl_ops[] = { |
968 | { |
969 | .cmd = TCP_METRICS_CMD_GET, |
970 | .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
971 | .doit = tcp_metrics_nl_cmd_get, |
972 | .dumpit = tcp_metrics_nl_dump, |
973 | }, |
974 | { |
975 | .cmd = TCP_METRICS_CMD_DEL, |
976 | .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
977 | .doit = tcp_metrics_nl_cmd_del, |
978 | .flags = GENL_ADMIN_PERM, |
979 | }, |
980 | }; |
981 | |
982 | static struct genl_family tcp_metrics_nl_family __ro_after_init = { |
983 | .hdrsize = 0, |
984 | .name = TCP_METRICS_GENL_NAME, |
985 | .version = TCP_METRICS_GENL_VERSION, |
986 | .maxattr = TCP_METRICS_ATTR_MAX, |
987 | .policy = tcp_metrics_nl_policy, |
988 | .netnsok = true, |
989 | .module = THIS_MODULE, |
990 | .small_ops = tcp_metrics_nl_ops, |
991 | .n_small_ops = ARRAY_SIZE(tcp_metrics_nl_ops), |
992 | .resv_start_op = TCP_METRICS_CMD_DEL + 1, |
993 | }; |
994 | |
995 | static unsigned int tcpmhash_entries __initdata; |
996 | static int __init set_tcpmhash_entries(char *str) |
997 | { |
998 | ssize_t ret; |
999 | |
1000 | if (!str) |
1001 | return 0; |
1002 | |
1003 | ret = kstrtouint(s: str, base: 0, res: &tcpmhash_entries); |
1004 | if (ret) |
1005 | return 0; |
1006 | |
1007 | return 1; |
1008 | } |
1009 | __setup("tcpmhash_entries=" , set_tcpmhash_entries); |
1010 | |
1011 | static void __init tcp_metrics_hash_alloc(void) |
1012 | { |
1013 | unsigned int slots = tcpmhash_entries; |
1014 | size_t size; |
1015 | |
1016 | if (!slots) { |
1017 | if (totalram_pages() >= 128 * 1024) |
1018 | slots = 16 * 1024; |
1019 | else |
1020 | slots = 8 * 1024; |
1021 | } |
1022 | |
1023 | tcp_metrics_hash_log = order_base_2(slots); |
1024 | size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log; |
1025 | |
1026 | tcp_metrics_hash = kvzalloc(size, GFP_KERNEL); |
1027 | if (!tcp_metrics_hash) |
1028 | panic(fmt: "Could not allocate the tcp_metrics hash table\n" ); |
1029 | } |
1030 | |
1031 | static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_list) |
1032 | { |
1033 | tcp_metrics_flush_all(NULL); |
1034 | } |
1035 | |
1036 | static __net_initdata struct pernet_operations tcp_net_metrics_ops = { |
1037 | .exit_batch = tcp_net_metrics_exit_batch, |
1038 | }; |
1039 | |
1040 | void __init tcp_metrics_init(void) |
1041 | { |
1042 | int ret; |
1043 | |
1044 | tcp_metrics_hash_alloc(); |
1045 | |
1046 | ret = register_pernet_subsys(&tcp_net_metrics_ops); |
1047 | if (ret < 0) |
1048 | panic(fmt: "Could not register tcp_net_metrics_ops\n" ); |
1049 | |
1050 | ret = genl_register_family(family: &tcp_metrics_nl_family); |
1051 | if (ret < 0) |
1052 | panic(fmt: "Could not register tcp_metrics generic netlink\n" ); |
1053 | } |
1054 | |