blob: 4a2a84110dfb2ef68f8154d23958fbddae772775 [file] [log] [blame]
David S. Miller51c5d0c2012-07-10 00:49:14 -07001#include <linux/rcupdate.h>
2#include <linux/spinlock.h>
3#include <linux/jiffies.h>
David S. Millerab92bb22012-07-09 16:19:30 -07004#include <linux/module.h>
David S. Miller4aabd8e2012-07-09 16:07:30 -07005#include <linux/cache.h>
David S. Miller51c5d0c2012-07-10 00:49:14 -07006#include <linux/slab.h>
7#include <linux/init.h>
David S. Miller4aabd8e2012-07-09 16:07:30 -07008#include <linux/tcp.h>
Eric Dumazet5815d5e2012-07-19 23:02:34 +00009#include <linux/hash.h>
Julian Anastasovd23ff702012-09-04 11:03:15 +000010#include <linux/tcp_metrics.h>
Eric Dumazet976a7022012-11-16 05:31:53 +000011#include <linux/vmalloc.h>
David S. Miller4aabd8e2012-07-09 16:07:30 -070012
13#include <net/inet_connection_sock.h>
David S. Miller51c5d0c2012-07-10 00:49:14 -070014#include <net/net_namespace.h>
David S. Millerab92bb22012-07-09 16:19:30 -070015#include <net/request_sock.h>
David S. Miller51c5d0c2012-07-10 00:49:14 -070016#include <net/inetpeer.h>
David S. Miller4aabd8e2012-07-09 16:07:30 -070017#include <net/sock.h>
David S. Miller51c5d0c2012-07-10 00:49:14 -070018#include <net/ipv6.h>
David S. Miller4aabd8e2012-07-09 16:07:30 -070019#include <net/dst.h>
20#include <net/tcp.h>
Julian Anastasovd23ff702012-09-04 11:03:15 +000021#include <net/genetlink.h>
David S. Miller4aabd8e2012-07-09 16:07:30 -070022
23int sysctl_tcp_nometrics_save __read_mostly;
24
Yuchung Cheng1fe4c482012-07-19 06:43:06 +000025struct tcp_fastopen_metrics {
26 u16 mss;
Yuchung Chengaab48742012-07-19 06:43:10 +000027 u16 syn_loss:10; /* Recurring Fast Open SYN losses */
28 unsigned long last_syn_loss; /* Last Fast Open SYN loss */
Yuchung Cheng1fe4c482012-07-19 06:43:06 +000029 struct tcp_fastopen_cookie cookie;
30};
31
David S. Miller51c5d0c2012-07-10 00:49:14 -070032struct tcp_metrics_block {
33 struct tcp_metrics_block __rcu *tcpm_next;
34 struct inetpeer_addr tcpm_addr;
35 unsigned long tcpm_stamp;
David S. Miller81166dd2012-07-10 03:14:24 -070036 u32 tcpm_ts;
37 u32 tcpm_ts_stamp;
David S. Miller51c5d0c2012-07-10 00:49:14 -070038 u32 tcpm_lock;
Julian Anastasovd23ff702012-09-04 11:03:15 +000039 u32 tcpm_vals[TCP_METRIC_MAX + 1];
Yuchung Cheng1fe4c482012-07-19 06:43:06 +000040 struct tcp_fastopen_metrics tcpm_fastopen;
Julian Anastasovd23ff702012-09-04 11:03:15 +000041
42 struct rcu_head rcu_head;
David S. Miller51c5d0c2012-07-10 00:49:14 -070043};
44
45static bool tcp_metric_locked(struct tcp_metrics_block *tm,
46 enum tcp_metric_index idx)
47{
48 return tm->tcpm_lock & (1 << idx);
49}
50
51static u32 tcp_metric_get(struct tcp_metrics_block *tm,
52 enum tcp_metric_index idx)
53{
54 return tm->tcpm_vals[idx];
55}
56
57static u32 tcp_metric_get_jiffies(struct tcp_metrics_block *tm,
58 enum tcp_metric_index idx)
59{
60 return msecs_to_jiffies(tm->tcpm_vals[idx]);
61}
62
63static void tcp_metric_set(struct tcp_metrics_block *tm,
64 enum tcp_metric_index idx,
65 u32 val)
66{
67 tm->tcpm_vals[idx] = val;
68}
69
70static void tcp_metric_set_msecs(struct tcp_metrics_block *tm,
71 enum tcp_metric_index idx,
72 u32 val)
73{
74 tm->tcpm_vals[idx] = jiffies_to_msecs(val);
75}
76
77static bool addr_same(const struct inetpeer_addr *a,
78 const struct inetpeer_addr *b)
79{
80 const struct in6_addr *a6, *b6;
81
82 if (a->family != b->family)
83 return false;
84 if (a->family == AF_INET)
85 return a->addr.a4 == b->addr.a4;
86
87 a6 = (const struct in6_addr *) &a->addr.a6[0];
88 b6 = (const struct in6_addr *) &b->addr.a6[0];
89
90 return ipv6_addr_equal(a6, b6);
91}
92
93struct tcpm_hash_bucket {
94 struct tcp_metrics_block __rcu *chain;
95};
96
97static DEFINE_SPINLOCK(tcp_metrics_lock);
98
Eric Dumazetefeaa552013-05-03 19:12:45 +000099static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst,
100 bool fastopen_clear)
David S. Miller51c5d0c2012-07-10 00:49:14 -0700101{
102 u32 val;
103
Julian Anastasov9a0a9502012-07-23 10:46:38 +0300104 tm->tcpm_stamp = jiffies;
105
David S. Miller51c5d0c2012-07-10 00:49:14 -0700106 val = 0;
107 if (dst_metric_locked(dst, RTAX_RTT))
108 val |= 1 << TCP_METRIC_RTT;
109 if (dst_metric_locked(dst, RTAX_RTTVAR))
110 val |= 1 << TCP_METRIC_RTTVAR;
111 if (dst_metric_locked(dst, RTAX_SSTHRESH))
112 val |= 1 << TCP_METRIC_SSTHRESH;
113 if (dst_metric_locked(dst, RTAX_CWND))
114 val |= 1 << TCP_METRIC_CWND;
115 if (dst_metric_locked(dst, RTAX_REORDERING))
116 val |= 1 << TCP_METRIC_REORDERING;
117 tm->tcpm_lock = val;
118
119 tm->tcpm_vals[TCP_METRIC_RTT] = dst_metric_raw(dst, RTAX_RTT);
120 tm->tcpm_vals[TCP_METRIC_RTTVAR] = dst_metric_raw(dst, RTAX_RTTVAR);
121 tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH);
122 tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND);
123 tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
David S. Miller81166dd2012-07-10 03:14:24 -0700124 tm->tcpm_ts = 0;
125 tm->tcpm_ts_stamp = 0;
Eric Dumazetefeaa552013-05-03 19:12:45 +0000126 if (fastopen_clear) {
127 tm->tcpm_fastopen.mss = 0;
128 tm->tcpm_fastopen.syn_loss = 0;
129 tm->tcpm_fastopen.cookie.len = 0;
130 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700131}
132
133static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
134 struct inetpeer_addr *addr,
135 unsigned int hash,
136 bool reclaim)
137{
138 struct tcp_metrics_block *tm;
139 struct net *net;
140
141 spin_lock_bh(&tcp_metrics_lock);
142 net = dev_net(dst->dev);
143 if (unlikely(reclaim)) {
144 struct tcp_metrics_block *oldest;
145
146 oldest = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain);
147 for (tm = rcu_dereference(oldest->tcpm_next); tm;
148 tm = rcu_dereference(tm->tcpm_next)) {
149 if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
150 oldest = tm;
151 }
152 tm = oldest;
153 } else {
154 tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
155 if (!tm)
156 goto out_unlock;
157 }
158 tm->tcpm_addr = *addr;
David S. Miller51c5d0c2012-07-10 00:49:14 -0700159
Eric Dumazetefeaa552013-05-03 19:12:45 +0000160 tcpm_suck_dst(tm, dst, true);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700161
162 if (likely(!reclaim)) {
163 tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
164 rcu_assign_pointer(net->ipv4.tcp_metrics_hash[hash].chain, tm);
165 }
166
167out_unlock:
168 spin_unlock_bh(&tcp_metrics_lock);
169 return tm;
170}
171
172#define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
173
174static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
175{
176 if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
Eric Dumazetefeaa552013-05-03 19:12:45 +0000177 tcpm_suck_dst(tm, dst, false);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700178}
179
180#define TCP_METRICS_RECLAIM_DEPTH 5
181#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
182
183static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth)
184{
185 if (tm)
186 return tm;
187 if (depth > TCP_METRICS_RECLAIM_DEPTH)
188 return TCP_METRICS_RECLAIM_PTR;
189 return NULL;
190}
191
192static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *addr,
193 struct net *net, unsigned int hash)
194{
195 struct tcp_metrics_block *tm;
196 int depth = 0;
197
198 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
199 tm = rcu_dereference(tm->tcpm_next)) {
200 if (addr_same(&tm->tcpm_addr, addr))
201 break;
202 depth++;
203 }
204 return tcp_get_encode(tm, depth);
205}
206
207static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
208 struct dst_entry *dst)
209{
210 struct tcp_metrics_block *tm;
211 struct inetpeer_addr addr;
212 unsigned int hash;
213 struct net *net;
214
215 addr.family = req->rsk_ops->family;
216 switch (addr.family) {
217 case AF_INET:
Eric Dumazet634fb9792013-10-09 15:21:29 -0700218 addr.addr.a4 = inet_rsk(req)->ir_rmt_addr;
David S. Miller51c5d0c2012-07-10 00:49:14 -0700219 hash = (__force unsigned int) addr.addr.a4;
220 break;
Eric Dumazet634fb9792013-10-09 15:21:29 -0700221#if IS_ENABLED(CONFIG_IPV6)
David S. Miller51c5d0c2012-07-10 00:49:14 -0700222 case AF_INET6:
Eric Dumazet634fb9792013-10-09 15:21:29 -0700223 *(struct in6_addr *)addr.addr.a6 = inet_rsk(req)->ir_v6_rmt_addr;
224 hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700225 break;
Eric Dumazet634fb9792013-10-09 15:21:29 -0700226#endif
David S. Miller51c5d0c2012-07-10 00:49:14 -0700227 default:
228 return NULL;
229 }
230
David S. Miller51c5d0c2012-07-10 00:49:14 -0700231 net = dev_net(dst->dev);
Eric Dumazet5815d5e2012-07-19 23:02:34 +0000232 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700233
234 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
235 tm = rcu_dereference(tm->tcpm_next)) {
236 if (addr_same(&tm->tcpm_addr, &addr))
237 break;
238 }
239 tcpm_check_stamp(tm, dst);
240 return tm;
241}
242
David S. Miller81166dd2012-07-10 03:14:24 -0700243static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock *tw)
244{
David S. Miller81166dd2012-07-10 03:14:24 -0700245 struct tcp_metrics_block *tm;
246 struct inetpeer_addr addr;
247 unsigned int hash;
248 struct net *net;
249
250 addr.family = tw->tw_family;
251 switch (addr.family) {
252 case AF_INET:
253 addr.addr.a4 = tw->tw_daddr;
254 hash = (__force unsigned int) addr.addr.a4;
255 break;
Eric Dumazetc2bb06d2013-10-09 03:05:48 -0700256#if IS_ENABLED(CONFIG_IPV6)
David S. Miller81166dd2012-07-10 03:14:24 -0700257 case AF_INET6:
Eric Dumazetefe42082013-10-03 15:42:29 -0700258 *(struct in6_addr *)addr.addr.a6 = tw->tw_v6_daddr;
259 hash = ipv6_addr_hash(&tw->tw_v6_daddr);
David S. Miller81166dd2012-07-10 03:14:24 -0700260 break;
Eric Dumazetc2bb06d2013-10-09 03:05:48 -0700261#endif
David S. Miller81166dd2012-07-10 03:14:24 -0700262 default:
263 return NULL;
264 }
265
David S. Miller81166dd2012-07-10 03:14:24 -0700266 net = twsk_net(tw);
Eric Dumazet5815d5e2012-07-19 23:02:34 +0000267 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
David S. Miller81166dd2012-07-10 03:14:24 -0700268
269 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
270 tm = rcu_dereference(tm->tcpm_next)) {
271 if (addr_same(&tm->tcpm_addr, &addr))
272 break;
273 }
274 return tm;
275}
276
David S. Miller51c5d0c2012-07-10 00:49:14 -0700277static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
278 struct dst_entry *dst,
279 bool create)
280{
281 struct tcp_metrics_block *tm;
282 struct inetpeer_addr addr;
283 unsigned int hash;
284 struct net *net;
285 bool reclaim;
286
287 addr.family = sk->sk_family;
288 switch (addr.family) {
289 case AF_INET:
290 addr.addr.a4 = inet_sk(sk)->inet_daddr;
291 hash = (__force unsigned int) addr.addr.a4;
292 break;
Eric Dumazetc2bb06d2013-10-09 03:05:48 -0700293#if IS_ENABLED(CONFIG_IPV6)
David S. Miller51c5d0c2012-07-10 00:49:14 -0700294 case AF_INET6:
Eric Dumazetefe42082013-10-03 15:42:29 -0700295 *(struct in6_addr *)addr.addr.a6 = sk->sk_v6_daddr;
296 hash = ipv6_addr_hash(&sk->sk_v6_daddr);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700297 break;
Eric Dumazetc2bb06d2013-10-09 03:05:48 -0700298#endif
David S. Miller51c5d0c2012-07-10 00:49:14 -0700299 default:
300 return NULL;
301 }
302
David S. Miller51c5d0c2012-07-10 00:49:14 -0700303 net = dev_net(dst->dev);
Eric Dumazet5815d5e2012-07-19 23:02:34 +0000304 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700305
306 tm = __tcp_get_metrics(&addr, net, hash);
307 reclaim = false;
308 if (tm == TCP_METRICS_RECLAIM_PTR) {
309 reclaim = true;
310 tm = NULL;
311 }
312 if (!tm && create)
313 tm = tcpm_new(dst, &addr, hash, reclaim);
314 else
315 tcpm_check_stamp(tm, dst);
316
317 return tm;
318}
319
David S. Miller4aabd8e2012-07-09 16:07:30 -0700320/* Save metrics learned by this TCP session. This function is called
321 * only, when TCP finishes successfully i.e. when it enters TIME-WAIT
322 * or goes from LAST-ACK to CLOSE.
323 */
324void tcp_update_metrics(struct sock *sk)
325{
David S. Miller51c5d0c2012-07-10 00:49:14 -0700326 const struct inet_connection_sock *icsk = inet_csk(sk);
David S. Miller4aabd8e2012-07-09 16:07:30 -0700327 struct dst_entry *dst = __sk_dst_get(sk);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700328 struct tcp_sock *tp = tcp_sk(sk);
329 struct tcp_metrics_block *tm;
330 unsigned long rtt;
331 u32 val;
332 int m;
David S. Miller4aabd8e2012-07-09 16:07:30 -0700333
David S. Miller51c5d0c2012-07-10 00:49:14 -0700334 if (sysctl_tcp_nometrics_save || !dst)
David S. Miller4aabd8e2012-07-09 16:07:30 -0700335 return;
336
David S. Miller51c5d0c2012-07-10 00:49:14 -0700337 if (dst->flags & DST_HOST)
David S. Miller4aabd8e2012-07-09 16:07:30 -0700338 dst_confirm(dst);
339
David S. Miller51c5d0c2012-07-10 00:49:14 -0700340 rcu_read_lock();
341 if (icsk->icsk_backoff || !tp->srtt) {
342 /* This session failed to estimate rtt. Why?
343 * Probably, no packets returned in time. Reset our
344 * results.
David S. Miller4aabd8e2012-07-09 16:07:30 -0700345 */
David S. Miller51c5d0c2012-07-10 00:49:14 -0700346 tm = tcp_get_metrics(sk, dst, false);
347 if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT))
348 tcp_metric_set(tm, TCP_METRIC_RTT, 0);
349 goto out_unlock;
350 } else
351 tm = tcp_get_metrics(sk, dst, true);
352
353 if (!tm)
354 goto out_unlock;
355
356 rtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
357 m = rtt - tp->srtt;
358
359 /* If newly calculated rtt larger than stored one, store new
360 * one. Otherwise, use EWMA. Remember, rtt overestimation is
361 * always better than underestimation.
362 */
363 if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
364 if (m <= 0)
365 rtt = tp->srtt;
366 else
367 rtt -= (m >> 3);
368 tcp_metric_set_msecs(tm, TCP_METRIC_RTT, rtt);
369 }
370
371 if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
372 unsigned long var;
373
374 if (m < 0)
375 m = -m;
376
377 /* Scale deviation to rttvar fixed point */
378 m >>= 1;
379 if (m < tp->mdev)
380 m = tp->mdev;
381
382 var = tcp_metric_get_jiffies(tm, TCP_METRIC_RTTVAR);
383 if (m >= var)
384 var = m;
385 else
386 var -= (var - m) >> 2;
387
388 tcp_metric_set_msecs(tm, TCP_METRIC_RTTVAR, var);
389 }
390
391 if (tcp_in_initial_slowstart(tp)) {
392 /* Slow start still did not finish. */
393 if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
394 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
395 if (val && (tp->snd_cwnd >> 1) > val)
396 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
397 tp->snd_cwnd >> 1);
David S. Miller4aabd8e2012-07-09 16:07:30 -0700398 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700399 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
400 val = tcp_metric_get(tm, TCP_METRIC_CWND);
401 if (tp->snd_cwnd > val)
402 tcp_metric_set(tm, TCP_METRIC_CWND,
403 tp->snd_cwnd);
David S. Miller4aabd8e2012-07-09 16:07:30 -0700404 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700405 } else if (tp->snd_cwnd > tp->snd_ssthresh &&
406 icsk->icsk_ca_state == TCP_CA_Open) {
407 /* Cong. avoidance phase, cwnd is reliable. */
408 if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))
409 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
410 max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
411 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
412 val = tcp_metric_get(tm, TCP_METRIC_CWND);
Alexander Duyck21008442012-07-11 17:18:04 -0700413 tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1);
David S. Miller4aabd8e2012-07-09 16:07:30 -0700414 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700415 } else {
416 /* Else slow start did not finish, cwnd is non-sense,
417 * ssthresh may be also invalid.
418 */
419 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
420 val = tcp_metric_get(tm, TCP_METRIC_CWND);
421 tcp_metric_set(tm, TCP_METRIC_CWND,
422 (val + tp->snd_ssthresh) >> 1);
423 }
424 if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
425 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
426 if (val && tp->snd_ssthresh > val)
427 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
428 tp->snd_ssthresh);
429 }
430 if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) {
431 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
432 if (val < tp->reordering &&
David S. Miller4aabd8e2012-07-09 16:07:30 -0700433 tp->reordering != sysctl_tcp_reordering)
David S. Miller51c5d0c2012-07-10 00:49:14 -0700434 tcp_metric_set(tm, TCP_METRIC_REORDERING,
435 tp->reordering);
David S. Miller4aabd8e2012-07-09 16:07:30 -0700436 }
437 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700438 tm->tcpm_stamp = jiffies;
439out_unlock:
440 rcu_read_unlock();
David S. Miller4aabd8e2012-07-09 16:07:30 -0700441}
442
443/* Initialize metrics on socket. */
444
445void tcp_init_metrics(struct sock *sk)
446{
David S. Miller4aabd8e2012-07-09 16:07:30 -0700447 struct dst_entry *dst = __sk_dst_get(sk);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700448 struct tcp_sock *tp = tcp_sk(sk);
449 struct tcp_metrics_block *tm;
Yuchung Cheng1b7fdd22013-08-30 08:35:53 -0700450 u32 val, crtt = 0; /* cached RTT scaled by 8 */
David S. Miller4aabd8e2012-07-09 16:07:30 -0700451
452 if (dst == NULL)
453 goto reset;
454
455 dst_confirm(dst);
456
David S. Miller51c5d0c2012-07-10 00:49:14 -0700457 rcu_read_lock();
458 tm = tcp_get_metrics(sk, dst, true);
459 if (!tm) {
460 rcu_read_unlock();
461 goto reset;
462 }
463
464 if (tcp_metric_locked(tm, TCP_METRIC_CWND))
465 tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND);
466
467 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
468 if (val) {
469 tp->snd_ssthresh = val;
David S. Miller4aabd8e2012-07-09 16:07:30 -0700470 if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
471 tp->snd_ssthresh = tp->snd_cwnd_clamp;
472 } else {
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 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700478 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
479 if (val && tp->reordering != val) {
David S. Miller4aabd8e2012-07-09 16:07:30 -0700480 tcp_disable_fack(tp);
481 tcp_disable_early_retrans(tp);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700482 tp->reordering = val;
David S. Miller4aabd8e2012-07-09 16:07:30 -0700483 }
484
Yuchung Cheng1b7fdd22013-08-30 08:35:53 -0700485 crtt = tcp_metric_get_jiffies(tm, TCP_METRIC_RTT);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700486 rcu_read_unlock();
David S. Miller4aabd8e2012-07-09 16:07:30 -0700487reset:
Yuchung Cheng52f20e62013-09-03 14:14:35 -0700488 /* The initial RTT measurement from the SYN/SYN-ACK is not ideal
489 * to seed the RTO for later data packets because SYN packets are
490 * small. Use the per-dst cached values to seed the RTO but keep
491 * the RTT estimator variables intact (e.g., srtt, mdev, rttvar).
492 * Later the RTO will be updated immediately upon obtaining the first
493 * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only
494 * influences the first RTO but not later RTT estimation.
495 *
496 * But if RTT is not available from the SYN (due to retransmits or
497 * syn cookies) or the cache, force a conservative 3secs timeout.
498 *
499 * A bit of theory. RTT is time passed after "normal" sized packet
500 * is sent until it is ACKed. In normal circumstances sending small
501 * packets force peer to delay ACKs and calculation is correct too.
502 * The algorithm is adaptive and, provided we follow specs, it
503 * NEVER underestimate RTT. BUT! If peer tries to make some clever
504 * tricks sort of "quick acks" for time long enough to decrease RTT
505 * to low value, and then abruptly stops to do it and starts to delay
506 * ACKs, wait for troubles.
507 */
Yuchung Cheng1b7fdd22013-08-30 08:35:53 -0700508 if (crtt > tp->srtt) {
Neal Cardwell269aa752013-09-16 21:44:20 -0400509 /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
510 crtt >>= 3;
511 inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
Yuchung Cheng1b7fdd22013-08-30 08:35:53 -0700512 } else if (tp->srtt == 0) {
David S. Miller4aabd8e2012-07-09 16:07:30 -0700513 /* RFC6298: 5.7 We've failed to get a valid RTT sample from
514 * 3WHS. This is most likely due to retransmission,
515 * including spurious one. Reset the RTO back to 3secs
516 * from the more aggressive 1sec to avoid more spurious
517 * retransmission.
518 */
519 tp->mdev = tp->mdev_max = tp->rttvar = TCP_TIMEOUT_FALLBACK;
520 inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
521 }
522 /* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been
523 * retransmitted. In light of RFC6298 more aggressive 1sec
524 * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK
525 * retransmission has occurred.
526 */
527 if (tp->total_retrans > 1)
528 tp->snd_cwnd = 1;
529 else
530 tp->snd_cwnd = tcp_init_cwnd(tp, dst);
531 tp->snd_cwnd_stamp = tcp_time_stamp;
532}
David S. Millerab92bb22012-07-09 16:19:30 -0700533
David S. Miller81166dd2012-07-10 03:14:24 -0700534bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, bool paws_check)
David S. Millerab92bb22012-07-09 16:19:30 -0700535{
David S. Miller51c5d0c2012-07-10 00:49:14 -0700536 struct tcp_metrics_block *tm;
537 bool ret;
538
David S. Millerab92bb22012-07-09 16:19:30 -0700539 if (!dst)
540 return false;
David S. Miller51c5d0c2012-07-10 00:49:14 -0700541
542 rcu_read_lock();
543 tm = __tcp_get_metrics_req(req, dst);
David S. Miller81166dd2012-07-10 03:14:24 -0700544 if (paws_check) {
545 if (tm &&
546 (u32)get_seconds() - tm->tcpm_ts_stamp < TCP_PAWS_MSL &&
547 (s32)(tm->tcpm_ts - req->ts_recent) > TCP_PAWS_WINDOW)
548 ret = false;
549 else
550 ret = true;
551 } else {
552 if (tm && tcp_metric_get(tm, TCP_METRIC_RTT) && tm->tcpm_ts_stamp)
553 ret = true;
554 else
555 ret = false;
556 }
David S. Miller51c5d0c2012-07-10 00:49:14 -0700557 rcu_read_unlock();
558
559 return ret;
David S. Millerab92bb22012-07-09 16:19:30 -0700560}
561EXPORT_SYMBOL_GPL(tcp_peer_is_proven);
David S. Miller51c5d0c2012-07-10 00:49:14 -0700562
David S. Miller81166dd2012-07-10 03:14:24 -0700563void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst)
564{
565 struct tcp_metrics_block *tm;
566
567 rcu_read_lock();
568 tm = tcp_get_metrics(sk, dst, true);
569 if (tm) {
570 struct tcp_sock *tp = tcp_sk(sk);
571
572 if ((u32)get_seconds() - tm->tcpm_ts_stamp <= TCP_PAWS_MSL) {
573 tp->rx_opt.ts_recent_stamp = tm->tcpm_ts_stamp;
574 tp->rx_opt.ts_recent = tm->tcpm_ts;
575 }
576 }
577 rcu_read_unlock();
578}
579EXPORT_SYMBOL_GPL(tcp_fetch_timewait_stamp);
580
581/* VJ's idea. Save last timestamp seen from this destination and hold
582 * it at least for normal timewait interval to use for duplicate
583 * segment detection in subsequent connections, before they enter
584 * synchronized state.
585 */
586bool tcp_remember_stamp(struct sock *sk)
587{
588 struct dst_entry *dst = __sk_dst_get(sk);
589 bool ret = false;
590
591 if (dst) {
592 struct tcp_metrics_block *tm;
593
594 rcu_read_lock();
595 tm = tcp_get_metrics(sk, dst, true);
596 if (tm) {
597 struct tcp_sock *tp = tcp_sk(sk);
598
599 if ((s32)(tm->tcpm_ts - tp->rx_opt.ts_recent) <= 0 ||
600 ((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL &&
601 tm->tcpm_ts_stamp <= (u32)tp->rx_opt.ts_recent_stamp)) {
602 tm->tcpm_ts_stamp = (u32)tp->rx_opt.ts_recent_stamp;
603 tm->tcpm_ts = tp->rx_opt.ts_recent;
604 }
605 ret = true;
606 }
607 rcu_read_unlock();
608 }
609 return ret;
610}
611
612bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw)
613{
614 struct tcp_metrics_block *tm;
615 bool ret = false;
616
617 rcu_read_lock();
618 tm = __tcp_get_metrics_tw(tw);
Julian Anastasov9a0a9502012-07-23 10:46:38 +0300619 if (tm) {
David S. Miller81166dd2012-07-10 03:14:24 -0700620 const struct tcp_timewait_sock *tcptw;
621 struct sock *sk = (struct sock *) tw;
622
623 tcptw = tcp_twsk(sk);
624 if ((s32)(tm->tcpm_ts - tcptw->tw_ts_recent) <= 0 ||
625 ((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL &&
626 tm->tcpm_ts_stamp <= (u32)tcptw->tw_ts_recent_stamp)) {
627 tm->tcpm_ts_stamp = (u32)tcptw->tw_ts_recent_stamp;
628 tm->tcpm_ts = tcptw->tw_ts_recent;
629 }
630 ret = true;
631 }
632 rcu_read_unlock();
633
634 return ret;
635}
636
Yuchung Cheng1fe4c482012-07-19 06:43:06 +0000637static DEFINE_SEQLOCK(fastopen_seqlock);
638
639void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
Yuchung Chengaab48742012-07-19 06:43:10 +0000640 struct tcp_fastopen_cookie *cookie,
641 int *syn_loss, unsigned long *last_syn_loss)
Yuchung Cheng1fe4c482012-07-19 06:43:06 +0000642{
643 struct tcp_metrics_block *tm;
644
645 rcu_read_lock();
646 tm = tcp_get_metrics(sk, __sk_dst_get(sk), false);
647 if (tm) {
648 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
649 unsigned int seq;
650
651 do {
652 seq = read_seqbegin(&fastopen_seqlock);
653 if (tfom->mss)
654 *mss = tfom->mss;
655 *cookie = tfom->cookie;
Yuchung Chengaab48742012-07-19 06:43:10 +0000656 *syn_loss = tfom->syn_loss;
657 *last_syn_loss = *syn_loss ? tfom->last_syn_loss : 0;
Yuchung Cheng1fe4c482012-07-19 06:43:06 +0000658 } while (read_seqretry(&fastopen_seqlock, seq));
659 }
660 rcu_read_unlock();
661}
662
Yuchung Cheng1fe4c482012-07-19 06:43:06 +0000663void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
Yuchung Chengaab48742012-07-19 06:43:10 +0000664 struct tcp_fastopen_cookie *cookie, bool syn_lost)
Yuchung Cheng1fe4c482012-07-19 06:43:06 +0000665{
666 struct tcp_metrics_block *tm;
667
668 rcu_read_lock();
669 tm = tcp_get_metrics(sk, __sk_dst_get(sk), true);
670 if (tm) {
671 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
672
673 write_seqlock_bh(&fastopen_seqlock);
674 tfom->mss = mss;
675 if (cookie->len > 0)
676 tfom->cookie = *cookie;
Yuchung Chengaab48742012-07-19 06:43:10 +0000677 if (syn_lost) {
678 ++tfom->syn_loss;
679 tfom->last_syn_loss = jiffies;
680 } else
681 tfom->syn_loss = 0;
Yuchung Cheng1fe4c482012-07-19 06:43:06 +0000682 write_sequnlock_bh(&fastopen_seqlock);
683 }
684 rcu_read_unlock();
685}
686
Julian Anastasovd23ff702012-09-04 11:03:15 +0000687static struct genl_family tcp_metrics_nl_family = {
688 .id = GENL_ID_GENERATE,
689 .hdrsize = 0,
690 .name = TCP_METRICS_GENL_NAME,
691 .version = TCP_METRICS_GENL_VERSION,
692 .maxattr = TCP_METRICS_ATTR_MAX,
693 .netnsok = true,
694};
695
696static struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = {
697 [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, },
698 [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY,
699 .len = sizeof(struct in6_addr), },
700 /* Following attributes are not received for GET/DEL,
701 * we keep them for reference
702 */
703#if 0
704 [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, },
705 [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, },
706 [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, },
707 [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, },
708 [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, },
709 [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, },
710 [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, },
711 [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY,
712 .len = TCP_FASTOPEN_COOKIE_MAX, },
713#endif
714};
715
716/* Add attributes, caller cancels its header on failure */
717static int tcp_metrics_fill_info(struct sk_buff *msg,
718 struct tcp_metrics_block *tm)
719{
720 struct nlattr *nest;
721 int i;
722
723 switch (tm->tcpm_addr.family) {
724 case AF_INET:
725 if (nla_put_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4,
726 tm->tcpm_addr.addr.a4) < 0)
727 goto nla_put_failure;
728 break;
729 case AF_INET6:
730 if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16,
731 tm->tcpm_addr.addr.a6) < 0)
732 goto nla_put_failure;
733 break;
734 default:
735 return -EAFNOSUPPORT;
736 }
737
738 if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE,
739 jiffies - tm->tcpm_stamp) < 0)
740 goto nla_put_failure;
741 if (tm->tcpm_ts_stamp) {
742 if (nla_put_s32(msg, TCP_METRICS_ATTR_TW_TS_STAMP,
743 (s32) (get_seconds() - tm->tcpm_ts_stamp)) < 0)
744 goto nla_put_failure;
745 if (nla_put_u32(msg, TCP_METRICS_ATTR_TW_TSVAL,
746 tm->tcpm_ts) < 0)
747 goto nla_put_failure;
748 }
749
750 {
751 int n = 0;
752
753 nest = nla_nest_start(msg, TCP_METRICS_ATTR_VALS);
754 if (!nest)
755 goto nla_put_failure;
756 for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
757 if (!tm->tcpm_vals[i])
758 continue;
759 if (nla_put_u32(msg, i + 1, tm->tcpm_vals[i]) < 0)
760 goto nla_put_failure;
761 n++;
762 }
763 if (n)
764 nla_nest_end(msg, nest);
765 else
766 nla_nest_cancel(msg, nest);
767 }
768
769 {
770 struct tcp_fastopen_metrics tfom_copy[1], *tfom;
771 unsigned int seq;
772
773 do {
774 seq = read_seqbegin(&fastopen_seqlock);
775 tfom_copy[0] = tm->tcpm_fastopen;
776 } while (read_seqretry(&fastopen_seqlock, seq));
777
778 tfom = tfom_copy;
779 if (tfom->mss &&
780 nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS,
781 tfom->mss) < 0)
782 goto nla_put_failure;
783 if (tfom->syn_loss &&
784 (nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS,
785 tfom->syn_loss) < 0 ||
786 nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,
787 jiffies - tfom->last_syn_loss) < 0))
788 goto nla_put_failure;
789 if (tfom->cookie.len > 0 &&
790 nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE,
791 tfom->cookie.len, tfom->cookie.val) < 0)
792 goto nla_put_failure;
793 }
794
795 return 0;
796
797nla_put_failure:
798 return -EMSGSIZE;
799}
800
801static int tcp_metrics_dump_info(struct sk_buff *skb,
802 struct netlink_callback *cb,
803 struct tcp_metrics_block *tm)
804{
805 void *hdr;
806
Eric W. Biederman15e47302012-09-07 20:12:54 +0000807 hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
Julian Anastasovd23ff702012-09-04 11:03:15 +0000808 &tcp_metrics_nl_family, NLM_F_MULTI,
809 TCP_METRICS_CMD_GET);
810 if (!hdr)
811 return -EMSGSIZE;
812
813 if (tcp_metrics_fill_info(skb, tm) < 0)
814 goto nla_put_failure;
815
816 return genlmsg_end(skb, hdr);
817
818nla_put_failure:
819 genlmsg_cancel(skb, hdr);
820 return -EMSGSIZE;
821}
822
823static int tcp_metrics_nl_dump(struct sk_buff *skb,
824 struct netlink_callback *cb)
825{
826 struct net *net = sock_net(skb->sk);
827 unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
828 unsigned int row, s_row = cb->args[0];
829 int s_col = cb->args[1], col = s_col;
830
831 for (row = s_row; row < max_rows; row++, s_col = 0) {
832 struct tcp_metrics_block *tm;
833 struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash + row;
834
835 rcu_read_lock();
836 for (col = 0, tm = rcu_dereference(hb->chain); tm;
837 tm = rcu_dereference(tm->tcpm_next), col++) {
838 if (col < s_col)
839 continue;
840 if (tcp_metrics_dump_info(skb, cb, tm) < 0) {
841 rcu_read_unlock();
842 goto done;
843 }
844 }
845 rcu_read_unlock();
846 }
847
848done:
849 cb->args[0] = row;
850 cb->args[1] = col;
851 return skb->len;
852}
853
854static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
855 unsigned int *hash, int optional)
856{
857 struct nlattr *a;
858
859 a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV4];
860 if (a) {
861 addr->family = AF_INET;
862 addr->addr.a4 = nla_get_be32(a);
863 *hash = (__force unsigned int) addr->addr.a4;
864 return 0;
865 }
866 a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV6];
867 if (a) {
Julian Anastasov2c42a3f2012-10-30 12:03:09 +0000868 if (nla_len(a) != sizeof(struct in6_addr))
Julian Anastasovd23ff702012-09-04 11:03:15 +0000869 return -EINVAL;
870 addr->family = AF_INET6;
871 memcpy(addr->addr.a6, nla_data(a), sizeof(addr->addr.a6));
872 *hash = ipv6_addr_hash((struct in6_addr *) addr->addr.a6);
873 return 0;
874 }
875 return optional ? 1 : -EAFNOSUPPORT;
876}
877
878static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
879{
880 struct tcp_metrics_block *tm;
881 struct inetpeer_addr addr;
882 unsigned int hash;
883 struct sk_buff *msg;
884 struct net *net = genl_info_net(info);
885 void *reply;
886 int ret;
887
888 ret = parse_nl_addr(info, &addr, &hash, 0);
889 if (ret < 0)
890 return ret;
891
892 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
893 if (!msg)
894 return -ENOMEM;
895
896 reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0,
897 info->genlhdr->cmd);
898 if (!reply)
899 goto nla_put_failure;
900
901 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
902 ret = -ESRCH;
903 rcu_read_lock();
904 for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
905 tm = rcu_dereference(tm->tcpm_next)) {
906 if (addr_same(&tm->tcpm_addr, &addr)) {
907 ret = tcp_metrics_fill_info(msg, tm);
908 break;
909 }
910 }
911 rcu_read_unlock();
912 if (ret < 0)
913 goto out_free;
914
915 genlmsg_end(msg, reply);
916 return genlmsg_reply(msg, info);
917
918nla_put_failure:
919 ret = -EMSGSIZE;
920
921out_free:
922 nlmsg_free(msg);
923 return ret;
924}
925
926#define deref_locked_genl(p) \
927 rcu_dereference_protected(p, lockdep_genl_is_held() && \
928 lockdep_is_held(&tcp_metrics_lock))
929
930#define deref_genl(p) rcu_dereference_protected(p, lockdep_genl_is_held())
931
932static int tcp_metrics_flush_all(struct net *net)
933{
934 unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
935 struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash;
936 struct tcp_metrics_block *tm;
937 unsigned int row;
938
939 for (row = 0; row < max_rows; row++, hb++) {
940 spin_lock_bh(&tcp_metrics_lock);
941 tm = deref_locked_genl(hb->chain);
942 if (tm)
943 hb->chain = NULL;
944 spin_unlock_bh(&tcp_metrics_lock);
945 while (tm) {
946 struct tcp_metrics_block *next;
947
948 next = deref_genl(tm->tcpm_next);
949 kfree_rcu(tm, rcu_head);
950 tm = next;
951 }
952 }
953 return 0;
954}
955
956static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
957{
958 struct tcpm_hash_bucket *hb;
959 struct tcp_metrics_block *tm;
960 struct tcp_metrics_block __rcu **pp;
961 struct inetpeer_addr addr;
962 unsigned int hash;
963 struct net *net = genl_info_net(info);
964 int ret;
965
966 ret = parse_nl_addr(info, &addr, &hash, 1);
967 if (ret < 0)
968 return ret;
969 if (ret > 0)
970 return tcp_metrics_flush_all(net);
971
972 hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
973 hb = net->ipv4.tcp_metrics_hash + hash;
974 pp = &hb->chain;
975 spin_lock_bh(&tcp_metrics_lock);
976 for (tm = deref_locked_genl(*pp); tm;
977 pp = &tm->tcpm_next, tm = deref_locked_genl(*pp)) {
978 if (addr_same(&tm->tcpm_addr, &addr)) {
979 *pp = tm->tcpm_next;
980 break;
981 }
982 }
983 spin_unlock_bh(&tcp_metrics_lock);
984 if (!tm)
985 return -ESRCH;
986 kfree_rcu(tm, rcu_head);
987 return 0;
988}
989
990static struct genl_ops tcp_metrics_nl_ops[] = {
991 {
992 .cmd = TCP_METRICS_CMD_GET,
993 .doit = tcp_metrics_nl_cmd_get,
994 .dumpit = tcp_metrics_nl_dump,
995 .policy = tcp_metrics_nl_policy,
996 .flags = GENL_ADMIN_PERM,
997 },
998 {
999 .cmd = TCP_METRICS_CMD_DEL,
1000 .doit = tcp_metrics_nl_cmd_del,
1001 .policy = tcp_metrics_nl_policy,
1002 .flags = GENL_ADMIN_PERM,
1003 },
1004};
1005
Eric Dumazet5815d5e2012-07-19 23:02:34 +00001006static unsigned int tcpmhash_entries;
David S. Miller51c5d0c2012-07-10 00:49:14 -07001007static int __init set_tcpmhash_entries(char *str)
1008{
1009 ssize_t ret;
1010
1011 if (!str)
1012 return 0;
1013
Eric Dumazet5815d5e2012-07-19 23:02:34 +00001014 ret = kstrtouint(str, 0, &tcpmhash_entries);
David S. Miller51c5d0c2012-07-10 00:49:14 -07001015 if (ret)
1016 return 0;
1017
1018 return 1;
1019}
1020__setup("tcpmhash_entries=", set_tcpmhash_entries);
1021
1022static int __net_init tcp_net_metrics_init(struct net *net)
1023{
Eric Dumazet5815d5e2012-07-19 23:02:34 +00001024 size_t size;
1025 unsigned int slots;
David S. Miller51c5d0c2012-07-10 00:49:14 -07001026
1027 slots = tcpmhash_entries;
1028 if (!slots) {
1029 if (totalram_pages >= 128 * 1024)
1030 slots = 16 * 1024;
1031 else
1032 slots = 8 * 1024;
1033 }
1034
Eric Dumazet5815d5e2012-07-19 23:02:34 +00001035 net->ipv4.tcp_metrics_hash_log = order_base_2(slots);
1036 size = sizeof(struct tcpm_hash_bucket) << net->ipv4.tcp_metrics_hash_log;
David S. Miller51c5d0c2012-07-10 00:49:14 -07001037
Eric Dumazet976a7022012-11-16 05:31:53 +00001038 net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
1039 if (!net->ipv4.tcp_metrics_hash)
1040 net->ipv4.tcp_metrics_hash = vzalloc(size);
1041
David S. Miller51c5d0c2012-07-10 00:49:14 -07001042 if (!net->ipv4.tcp_metrics_hash)
1043 return -ENOMEM;
1044
David S. Miller51c5d0c2012-07-10 00:49:14 -07001045 return 0;
1046}
1047
1048static void __net_exit tcp_net_metrics_exit(struct net *net)
1049{
Eric Dumazet36471012012-08-09 11:19:13 +02001050 unsigned int i;
1051
1052 for (i = 0; i < (1U << net->ipv4.tcp_metrics_hash_log) ; i++) {
1053 struct tcp_metrics_block *tm, *next;
1054
1055 tm = rcu_dereference_protected(net->ipv4.tcp_metrics_hash[i].chain, 1);
1056 while (tm) {
1057 next = rcu_dereference_protected(tm->tcpm_next, 1);
1058 kfree(tm);
1059 tm = next;
1060 }
1061 }
Eric Dumazet976a7022012-11-16 05:31:53 +00001062 if (is_vmalloc_addr(net->ipv4.tcp_metrics_hash))
1063 vfree(net->ipv4.tcp_metrics_hash);
1064 else
1065 kfree(net->ipv4.tcp_metrics_hash);
David S. Miller51c5d0c2012-07-10 00:49:14 -07001066}
1067
1068static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
1069 .init = tcp_net_metrics_init,
1070 .exit = tcp_net_metrics_exit,
1071};
1072
1073void __init tcp_metrics_init(void)
1074{
Julian Anastasovd23ff702012-09-04 11:03:15 +00001075 int ret;
1076
1077 ret = register_pernet_subsys(&tcp_net_metrics_ops);
1078 if (ret < 0)
1079 goto cleanup;
1080 ret = genl_register_family_with_ops(&tcp_metrics_nl_family,
1081 tcp_metrics_nl_ops,
1082 ARRAY_SIZE(tcp_metrics_nl_ops));
1083 if (ret < 0)
1084 goto cleanup_subsys;
1085 return;
1086
1087cleanup_subsys:
1088 unregister_pernet_subsys(&tcp_net_metrics_ops);
1089
1090cleanup:
1091 return;
David S. Miller51c5d0c2012-07-10 00:49:14 -07001092}