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>
10 #include <linux/hash.h>
11 #include <linux/tcp_metrics.h>
12 #include <linux/vmalloc.h>
14 #include <net/inet_connection_sock.h>
15 #include <net/net_namespace.h>
16 #include <net/request_sock.h>
17 #include <net/inetpeer.h>
22 #include <net/genetlink.h>
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);
28 struct tcp_fastopen_metrics {
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;
36 /* TCP_METRIC_MAX includes 2 extra fields for userspace compatibility
37 * Kernel only stores RTT and RTTVAR in usec resolution
39 #define TCP_METRIC_MAX_KERNEL (TCP_METRIC_MAX - 2)
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;
48 u32 tcpm_vals[TCP_METRIC_MAX_KERNEL + 1];
49 struct tcp_fastopen_metrics tcpm_fastopen;
51 struct rcu_head rcu_head;
54 static inline struct net *tm_net(struct tcp_metrics_block *tm)
56 return read_pnet(&tm->tcpm_net);
59 static bool tcp_metric_locked(struct tcp_metrics_block *tm,
60 enum tcp_metric_index idx)
62 return tm->tcpm_lock & (1 << idx);
65 static u32 tcp_metric_get(struct tcp_metrics_block *tm,
66 enum tcp_metric_index idx)
68 return tm->tcpm_vals[idx];
71 static void tcp_metric_set(struct tcp_metrics_block *tm,
72 enum tcp_metric_index idx,
75 tm->tcpm_vals[idx] = val;
78 static bool addr_same(const struct inetpeer_addr *a,
79 const struct inetpeer_addr *b)
81 return inetpeer_addr_cmp(a, b) == 0;
84 struct tcpm_hash_bucket {
85 struct tcp_metrics_block __rcu *chain;
88 static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly;
89 static unsigned int tcp_metrics_hash_log __read_mostly;
91 static DEFINE_SPINLOCK(tcp_metrics_lock);
93 static void tcpm_suck_dst(struct tcp_metrics_block *tm,
94 const struct dst_entry *dst,
100 tm->tcpm_stamp = jiffies;
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;
115 msval = dst_metric_raw(dst, RTAX_RTT);
116 tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC;
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;
132 #define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
134 static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
136 if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
137 tcpm_suck_dst(tm, dst, false);
140 #define TCP_METRICS_RECLAIM_DEPTH 5
141 #define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
143 #define deref_locked(p) \
144 rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock))
146 static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
147 struct inetpeer_addr *saddr,
148 struct inetpeer_addr *daddr,
151 struct tcp_metrics_block *tm;
153 bool reclaim = false;
155 spin_lock_bh(&tcp_metrics_lock);
156 net = dev_net(dst->dev);
158 /* While waiting for the spin-lock the cache might have been populated
159 * with this entry and so we have to check again.
161 tm = __tcp_get_metrics(saddr, daddr, net, hash);
162 if (tm == TCP_METRICS_RECLAIM_PTR) {
167 tcpm_check_stamp(tm, dst);
171 if (unlikely(reclaim)) {
172 struct tcp_metrics_block *oldest;
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))
182 tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
186 write_pnet(&tm->tcpm_net, net);
187 tm->tcpm_saddr = *saddr;
188 tm->tcpm_daddr = *daddr;
190 tcpm_suck_dst(tm, dst, true);
192 if (likely(!reclaim)) {
193 tm->tcpm_next = tcp_metrics_hash[hash].chain;
194 rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm);
198 spin_unlock_bh(&tcp_metrics_lock);
202 static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth)
206 if (depth > TCP_METRICS_RECLAIM_DEPTH)
207 return TCP_METRICS_RECLAIM_PTR;
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)
215 struct tcp_metrics_block *tm;
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))
226 return tcp_get_encode(tm, depth);
229 static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
230 struct dst_entry *dst)
232 struct tcp_metrics_block *tm;
233 struct inetpeer_addr saddr, daddr;
237 saddr.family = req->rsk_ops->family;
238 daddr.family = req->rsk_ops->family;
239 switch (daddr.family) {
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);
245 #if IS_ENABLED(CONFIG_IPV6)
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);
256 net = dev_net(dst->dev);
257 hash ^= net_hash_mix(net);
258 hash = hash_32(hash, tcp_metrics_hash_log);
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))
267 tcpm_check_stamp(tm, dst);
271 static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
272 struct dst_entry *dst,
275 struct tcp_metrics_block *tm;
276 struct inetpeer_addr saddr, daddr;
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);
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);
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);
301 net = dev_net(dst->dev);
302 hash ^= net_hash_mix(net);
303 hash = hash_32(hash, tcp_metrics_hash_log);
305 tm = __tcp_get_metrics(&saddr, &daddr, net, hash);
306 if (tm == TCP_METRICS_RECLAIM_PTR)
309 tm = tcpm_new(dst, &saddr, &daddr, hash);
311 tcpm_check_stamp(tm, dst);
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.
320 void tcp_update_metrics(struct sock *sk)
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;
332 if (READ_ONCE(net->ipv4.sysctl_tcp_nometrics_save) || !dst)
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
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);
346 tm = tcp_get_metrics(sk, dst, true);
351 rtt = tcp_metric_get(tm, TCP_METRIC_RTT);
352 m = rtt - tp->srtt_us;
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.
358 if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
363 tcp_metric_set(tm, TCP_METRIC_RTT, rtt);
366 if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
372 /* Scale deviation to rttvar fixed point */
377 var = tcp_metric_get(tm, TCP_METRIC_RTTVAR);
381 var -= (var - m) >> 2;
383 tcp_metric_set(tm, TCP_METRIC_RTTVAR, var);
386 if (tcp_in_initial_slowstart(tp)) {
387 /* Slow start still did not finish. */
388 if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) &&
389 !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
390 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
391 if (val && (tp->snd_cwnd >> 1) > val)
392 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
395 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
396 val = tcp_metric_get(tm, TCP_METRIC_CWND);
397 if (tp->snd_cwnd > val)
398 tcp_metric_set(tm, TCP_METRIC_CWND,
401 } else if (!tcp_in_slow_start(tp) &&
402 icsk->icsk_ca_state == TCP_CA_Open) {
403 /* Cong. avoidance phase, cwnd is reliable. */
404 if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) &&
405 !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))
406 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
407 max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
408 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
409 val = tcp_metric_get(tm, TCP_METRIC_CWND);
410 tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1);
413 /* Else slow start did not finish, cwnd is non-sense,
414 * ssthresh may be also invalid.
416 if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
417 val = tcp_metric_get(tm, TCP_METRIC_CWND);
418 tcp_metric_set(tm, TCP_METRIC_CWND,
419 (val + tp->snd_ssthresh) >> 1);
421 if (!READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) &&
422 !tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
423 val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
424 if (val && tp->snd_ssthresh > val)
425 tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
428 if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) {
429 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
430 if (val < tp->reordering &&
432 READ_ONCE(net->ipv4.sysctl_tcp_reordering))
433 tcp_metric_set(tm, TCP_METRIC_REORDERING,
437 tm->tcpm_stamp = jiffies;
442 /* Initialize metrics on socket. */
444 void tcp_init_metrics(struct sock *sk)
446 struct dst_entry *dst = __sk_dst_get(sk);
447 struct tcp_sock *tp = tcp_sk(sk);
448 struct net *net = sock_net(sk);
449 struct tcp_metrics_block *tm;
450 u32 val, crtt = 0; /* cached RTT scaled by 8 */
457 tm = tcp_get_metrics(sk, dst, true);
463 if (tcp_metric_locked(tm, TCP_METRIC_CWND))
464 tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND);
466 val = READ_ONCE(net->ipv4.sysctl_tcp_no_ssthresh_metrics_save) ?
467 0 : tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
469 tp->snd_ssthresh = val;
470 if (tp->snd_ssthresh > tp->snd_cwnd_clamp)
471 tp->snd_ssthresh = tp->snd_cwnd_clamp;
473 /* ssthresh may have been reduced unnecessarily during.
474 * 3WHS. Restore it back to its initial default.
476 tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
478 val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
479 if (val && tp->reordering != val)
480 tp->reordering = val;
482 crtt = tcp_metric_get(tm, TCP_METRIC_RTT);
485 /* The initial RTT measurement from the SYN/SYN-ACK is not ideal
486 * to seed the RTO for later data packets because SYN packets are
487 * small. Use the per-dst cached values to seed the RTO but keep
488 * the RTT estimator variables intact (e.g., srtt, mdev, rttvar).
489 * Later the RTO will be updated immediately upon obtaining the first
490 * data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only
491 * influences the first RTO but not later RTT estimation.
493 * But if RTT is not available from the SYN (due to retransmits or
494 * syn cookies) or the cache, force a conservative 3secs timeout.
496 * A bit of theory. RTT is time passed after "normal" sized packet
497 * is sent until it is ACKed. In normal circumstances sending small
498 * packets force peer to delay ACKs and calculation is correct too.
499 * The algorithm is adaptive and, provided we follow specs, it
500 * NEVER underestimate RTT. BUT! If peer tries to make some clever
501 * tricks sort of "quick acks" for time long enough to decrease RTT
502 * to low value, and then abruptly stops to do it and starts to delay
503 * ACKs, wait for troubles.
505 if (crtt > tp->srtt_us) {
506 /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
507 crtt /= 8 * USEC_PER_SEC / HZ;
508 inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
509 } else if (tp->srtt_us == 0) {
510 /* RFC6298: 5.7 We've failed to get a valid RTT sample from
511 * 3WHS. This is most likely due to retransmission,
512 * including spurious one. Reset the RTO back to 3secs
513 * from the more aggressive 1sec to avoid more spurious
516 tp->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK);
517 tp->mdev_us = tp->mdev_max_us = tp->rttvar_us;
519 inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK;
523 bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst)
525 struct tcp_metrics_block *tm;
532 tm = __tcp_get_metrics_req(req, dst);
533 if (tm && tcp_metric_get(tm, TCP_METRIC_RTT))
542 static DEFINE_SEQLOCK(fastopen_seqlock);
544 void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
545 struct tcp_fastopen_cookie *cookie)
547 struct tcp_metrics_block *tm;
550 tm = tcp_get_metrics(sk, __sk_dst_get(sk), false);
552 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
556 seq = read_seqbegin(&fastopen_seqlock);
559 *cookie = tfom->cookie;
560 if (cookie->len <= 0 && tfom->try_exp == 1)
562 } while (read_seqretry(&fastopen_seqlock, seq));
567 void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
568 struct tcp_fastopen_cookie *cookie, bool syn_lost,
571 struct dst_entry *dst = __sk_dst_get(sk);
572 struct tcp_metrics_block *tm;
577 tm = tcp_get_metrics(sk, dst, true);
579 struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;
581 write_seqlock_bh(&fastopen_seqlock);
584 if (cookie && cookie->len > 0)
585 tfom->cookie = *cookie;
586 else if (try_exp > tfom->try_exp &&
587 tfom->cookie.len <= 0 && !tfom->cookie.exp)
588 tfom->try_exp = try_exp;
591 tfom->last_syn_loss = jiffies;
594 write_sequnlock_bh(&fastopen_seqlock);
599 static struct genl_family tcp_metrics_nl_family;
601 static const struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = {
602 [TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, },
603 [TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY,
604 .len = sizeof(struct in6_addr), },
605 /* Following attributes are not received for GET/DEL,
606 * we keep them for reference
609 [TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, },
610 [TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, },
611 [TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, },
612 [TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, },
613 [TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, },
614 [TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, },
615 [TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, },
616 [TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY,
617 .len = TCP_FASTOPEN_COOKIE_MAX, },
621 /* Add attributes, caller cancels its header on failure */
622 static int tcp_metrics_fill_info(struct sk_buff *msg,
623 struct tcp_metrics_block *tm)
628 switch (tm->tcpm_daddr.family) {
630 if (nla_put_in_addr(msg, TCP_METRICS_ATTR_ADDR_IPV4,
631 inetpeer_get_addr_v4(&tm->tcpm_daddr)) < 0)
632 goto nla_put_failure;
633 if (nla_put_in_addr(msg, TCP_METRICS_ATTR_SADDR_IPV4,
634 inetpeer_get_addr_v4(&tm->tcpm_saddr)) < 0)
635 goto nla_put_failure;
638 if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_ADDR_IPV6,
639 inetpeer_get_addr_v6(&tm->tcpm_daddr)) < 0)
640 goto nla_put_failure;
641 if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_SADDR_IPV6,
642 inetpeer_get_addr_v6(&tm->tcpm_saddr)) < 0)
643 goto nla_put_failure;
646 return -EAFNOSUPPORT;
649 if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE,
650 jiffies - tm->tcpm_stamp,
651 TCP_METRICS_ATTR_PAD) < 0)
652 goto nla_put_failure;
657 nest = nla_nest_start_noflag(msg, TCP_METRICS_ATTR_VALS);
659 goto nla_put_failure;
660 for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) {
661 u32 val = tm->tcpm_vals[i];
665 if (i == TCP_METRIC_RTT) {
666 if (nla_put_u32(msg, TCP_METRIC_RTT_US + 1,
668 goto nla_put_failure;
670 val = max(val / 1000, 1U);
672 if (i == TCP_METRIC_RTTVAR) {
673 if (nla_put_u32(msg, TCP_METRIC_RTTVAR_US + 1,
675 goto nla_put_failure;
677 val = max(val / 1000, 1U);
679 if (nla_put_u32(msg, i + 1, val) < 0)
680 goto nla_put_failure;
684 nla_nest_end(msg, nest);
686 nla_nest_cancel(msg, nest);
690 struct tcp_fastopen_metrics tfom_copy[1], *tfom;
694 seq = read_seqbegin(&fastopen_seqlock);
695 tfom_copy[0] = tm->tcpm_fastopen;
696 } while (read_seqretry(&fastopen_seqlock, seq));
700 nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS,
702 goto nla_put_failure;
703 if (tfom->syn_loss &&
704 (nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS,
705 tfom->syn_loss) < 0 ||
706 nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,
707 jiffies - tfom->last_syn_loss,
708 TCP_METRICS_ATTR_PAD) < 0))
709 goto nla_put_failure;
710 if (tfom->cookie.len > 0 &&
711 nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE,
712 tfom->cookie.len, tfom->cookie.val) < 0)
713 goto nla_put_failure;
722 static int tcp_metrics_dump_info(struct sk_buff *skb,
723 struct netlink_callback *cb,
724 struct tcp_metrics_block *tm)
728 hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
729 &tcp_metrics_nl_family, NLM_F_MULTI,
730 TCP_METRICS_CMD_GET);
734 if (tcp_metrics_fill_info(skb, tm) < 0)
735 goto nla_put_failure;
737 genlmsg_end(skb, hdr);
741 genlmsg_cancel(skb, hdr);
745 static int tcp_metrics_nl_dump(struct sk_buff *skb,
746 struct netlink_callback *cb)
748 struct net *net = sock_net(skb->sk);
749 unsigned int max_rows = 1U << tcp_metrics_hash_log;
750 unsigned int row, s_row = cb->args[0];
751 int s_col = cb->args[1], col = s_col;
753 for (row = s_row; row < max_rows; row++, s_col = 0) {
754 struct tcp_metrics_block *tm;
755 struct tcpm_hash_bucket *hb = tcp_metrics_hash + row;
758 for (col = 0, tm = rcu_dereference(hb->chain); tm;
759 tm = rcu_dereference(tm->tcpm_next), col++) {
760 if (!net_eq(tm_net(tm), net))
764 if (tcp_metrics_dump_info(skb, cb, tm) < 0) {
778 static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
779 unsigned int *hash, int optional, int v4, int v6)
785 inetpeer_set_addr_v4(addr, nla_get_in_addr(a));
787 *hash = ipv4_addr_hash(inetpeer_get_addr_v4(addr));
794 if (nla_len(a) != sizeof(struct in6_addr))
796 in6 = nla_get_in6_addr(a);
797 inetpeer_set_addr_v6(addr, &in6);
799 *hash = ipv6_addr_hash(inetpeer_get_addr_v6(addr));
802 return optional ? 1 : -EAFNOSUPPORT;
805 static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
806 unsigned int *hash, int optional)
808 return __parse_nl_addr(info, addr, hash, optional,
809 TCP_METRICS_ATTR_ADDR_IPV4,
810 TCP_METRICS_ATTR_ADDR_IPV6);
813 static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr)
815 return __parse_nl_addr(info, addr, NULL, 0,
816 TCP_METRICS_ATTR_SADDR_IPV4,
817 TCP_METRICS_ATTR_SADDR_IPV6);
820 static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
822 struct tcp_metrics_block *tm;
823 struct inetpeer_addr saddr, daddr;
826 struct net *net = genl_info_net(info);
831 ret = parse_nl_addr(info, &daddr, &hash, 0);
835 ret = parse_nl_saddr(info, &saddr);
839 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
843 reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0,
846 goto nla_put_failure;
848 hash ^= net_hash_mix(net);
849 hash = hash_32(hash, tcp_metrics_hash_log);
852 for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm;
853 tm = rcu_dereference(tm->tcpm_next)) {
854 if (addr_same(&tm->tcpm_daddr, &daddr) &&
855 (!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
856 net_eq(tm_net(tm), net)) {
857 ret = tcp_metrics_fill_info(msg, tm);
865 genlmsg_end(msg, reply);
866 return genlmsg_reply(msg, info);
876 static void tcp_metrics_flush_all(struct net *net)
878 unsigned int max_rows = 1U << tcp_metrics_hash_log;
879 struct tcpm_hash_bucket *hb = tcp_metrics_hash;
880 struct tcp_metrics_block *tm;
883 for (row = 0; row < max_rows; row++, hb++) {
884 struct tcp_metrics_block __rcu **pp;
887 spin_lock_bh(&tcp_metrics_lock);
889 for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
890 match = net ? net_eq(tm_net(tm), net) :
891 !refcount_read(&tm_net(tm)->count);
894 kfree_rcu(tm, rcu_head);
899 spin_unlock_bh(&tcp_metrics_lock);
903 static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
905 struct tcpm_hash_bucket *hb;
906 struct tcp_metrics_block *tm;
907 struct tcp_metrics_block __rcu **pp;
908 struct inetpeer_addr saddr, daddr;
910 struct net *net = genl_info_net(info);
912 bool src = true, found = false;
914 ret = parse_nl_addr(info, &daddr, &hash, 1);
918 tcp_metrics_flush_all(net);
921 ret = parse_nl_saddr(info, &saddr);
925 hash ^= net_hash_mix(net);
926 hash = hash_32(hash, tcp_metrics_hash_log);
927 hb = tcp_metrics_hash + hash;
929 spin_lock_bh(&tcp_metrics_lock);
930 for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) {
931 if (addr_same(&tm->tcpm_daddr, &daddr) &&
932 (!src || addr_same(&tm->tcpm_saddr, &saddr)) &&
933 net_eq(tm_net(tm), net)) {
935 kfree_rcu(tm, rcu_head);
941 spin_unlock_bh(&tcp_metrics_lock);
947 static const struct genl_small_ops tcp_metrics_nl_ops[] = {
949 .cmd = TCP_METRICS_CMD_GET,
950 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
951 .doit = tcp_metrics_nl_cmd_get,
952 .dumpit = tcp_metrics_nl_dump,
955 .cmd = TCP_METRICS_CMD_DEL,
956 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
957 .doit = tcp_metrics_nl_cmd_del,
958 .flags = GENL_ADMIN_PERM,
962 static struct genl_family tcp_metrics_nl_family __ro_after_init = {
964 .name = TCP_METRICS_GENL_NAME,
965 .version = TCP_METRICS_GENL_VERSION,
966 .maxattr = TCP_METRICS_ATTR_MAX,
967 .policy = tcp_metrics_nl_policy,
969 .module = THIS_MODULE,
970 .small_ops = tcp_metrics_nl_ops,
971 .n_small_ops = ARRAY_SIZE(tcp_metrics_nl_ops),
974 static unsigned int tcpmhash_entries;
975 static int __init set_tcpmhash_entries(char *str)
982 ret = kstrtouint(str, 0, &tcpmhash_entries);
988 __setup("tcpmhash_entries=", set_tcpmhash_entries);
990 static int __net_init tcp_net_metrics_init(struct net *net)
995 if (!net_eq(net, &init_net))
998 slots = tcpmhash_entries;
1000 if (totalram_pages() >= 128 * 1024)
1006 tcp_metrics_hash_log = order_base_2(slots);
1007 size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log;
1009 tcp_metrics_hash = kvzalloc(size, GFP_KERNEL);
1010 if (!tcp_metrics_hash)
1016 static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_list)
1018 tcp_metrics_flush_all(NULL);
1021 static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
1022 .init = tcp_net_metrics_init,
1023 .exit_batch = tcp_net_metrics_exit_batch,
1026 void __init tcp_metrics_init(void)
1030 ret = register_pernet_subsys(&tcp_net_metrics_ops);
1032 panic("Could not allocate the tcp_metrics hash table\n");
1034 ret = genl_register_family(&tcp_metrics_nl_family);
1036 panic("Could not register tcp_metrics generic netlink\n");