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1036 lines
27 KiB
1036 lines
27 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
#include <linux/rcupdate.h> |
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#include <linux/spinlock.h> |
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#include <linux/jiffies.h> |
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#include <linux/module.h> |
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#include <linux/cache.h> |
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#include <linux/slab.h> |
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#include <linux/init.h> |
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#include <linux/tcp.h> |
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#include <linux/hash.h> |
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#include <linux/tcp_metrics.h> |
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#include <linux/vmalloc.h> |
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|
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#include <net/inet_connection_sock.h> |
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#include <net/net_namespace.h> |
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#include <net/request_sock.h> |
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#include <net/inetpeer.h> |
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#include <net/sock.h> |
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#include <net/ipv6.h> |
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#include <net/dst.h> |
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#include <net/tcp.h> |
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#include <net/genetlink.h> |
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|
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static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, |
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const struct inetpeer_addr *daddr, |
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struct net *net, unsigned int hash); |
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|
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struct tcp_fastopen_metrics { |
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u16 mss; |
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u16 syn_loss:10, /* Recurring Fast Open SYN losses */ |
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try_exp:2; /* Request w/ exp. option (once) */ |
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unsigned long last_syn_loss; /* Last Fast Open SYN loss */ |
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struct tcp_fastopen_cookie cookie; |
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}; |
|
|
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/* TCP_METRIC_MAX includes 2 extra fields for userspace compatibility |
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* Kernel only stores RTT and RTTVAR in usec resolution |
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*/ |
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#define TCP_METRIC_MAX_KERNEL (TCP_METRIC_MAX - 2) |
|
|
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struct tcp_metrics_block { |
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struct tcp_metrics_block __rcu *tcpm_next; |
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possible_net_t tcpm_net; |
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struct inetpeer_addr tcpm_saddr; |
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struct inetpeer_addr tcpm_daddr; |
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unsigned long tcpm_stamp; |
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u32 tcpm_lock; |
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u32 tcpm_vals[TCP_METRIC_MAX_KERNEL + 1]; |
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struct tcp_fastopen_metrics tcpm_fastopen; |
|
|
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struct rcu_head rcu_head; |
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}; |
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|
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static inline struct net *tm_net(struct tcp_metrics_block *tm) |
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{ |
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return read_pnet(&tm->tcpm_net); |
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} |
|
|
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static bool tcp_metric_locked(struct tcp_metrics_block *tm, |
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enum tcp_metric_index idx) |
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{ |
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return tm->tcpm_lock & (1 << idx); |
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} |
|
|
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static u32 tcp_metric_get(struct tcp_metrics_block *tm, |
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enum tcp_metric_index idx) |
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{ |
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return tm->tcpm_vals[idx]; |
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} |
|
|
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static void tcp_metric_set(struct tcp_metrics_block *tm, |
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enum tcp_metric_index idx, |
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u32 val) |
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{ |
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tm->tcpm_vals[idx] = val; |
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} |
|
|
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static bool addr_same(const struct inetpeer_addr *a, |
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const struct inetpeer_addr *b) |
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{ |
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return inetpeer_addr_cmp(a, b) == 0; |
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} |
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|
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struct tcpm_hash_bucket { |
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struct tcp_metrics_block __rcu *chain; |
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}; |
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|
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static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly; |
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static unsigned int tcp_metrics_hash_log __read_mostly; |
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|
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static DEFINE_SPINLOCK(tcp_metrics_lock); |
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|
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static void tcpm_suck_dst(struct tcp_metrics_block *tm, |
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const struct dst_entry *dst, |
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bool fastopen_clear) |
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{ |
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u32 msval; |
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u32 val; |
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|
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tm->tcpm_stamp = jiffies; |
|
|
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val = 0; |
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if (dst_metric_locked(dst, RTAX_RTT)) |
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val |= 1 << TCP_METRIC_RTT; |
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if (dst_metric_locked(dst, RTAX_RTTVAR)) |
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val |= 1 << TCP_METRIC_RTTVAR; |
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if (dst_metric_locked(dst, RTAX_SSTHRESH)) |
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val |= 1 << TCP_METRIC_SSTHRESH; |
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if (dst_metric_locked(dst, RTAX_CWND)) |
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val |= 1 << TCP_METRIC_CWND; |
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if (dst_metric_locked(dst, RTAX_REORDERING)) |
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val |= 1 << TCP_METRIC_REORDERING; |
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tm->tcpm_lock = val; |
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|
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msval = dst_metric_raw(dst, RTAX_RTT); |
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tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC; |
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|
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msval = dst_metric_raw(dst, RTAX_RTTVAR); |
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tm->tcpm_vals[TCP_METRIC_RTTVAR] = msval * USEC_PER_MSEC; |
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tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH); |
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tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND); |
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tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING); |
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if (fastopen_clear) { |
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tm->tcpm_fastopen.mss = 0; |
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tm->tcpm_fastopen.syn_loss = 0; |
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tm->tcpm_fastopen.try_exp = 0; |
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tm->tcpm_fastopen.cookie.exp = false; |
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tm->tcpm_fastopen.cookie.len = 0; |
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} |
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} |
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|
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#define TCP_METRICS_TIMEOUT (60 * 60 * HZ) |
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|
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static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst) |
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{ |
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if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT))) |
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tcpm_suck_dst(tm, dst, false); |
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} |
|
|
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#define TCP_METRICS_RECLAIM_DEPTH 5 |
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#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL |
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|
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#define deref_locked(p) \ |
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rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock)) |
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|
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static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, |
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struct inetpeer_addr *saddr, |
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struct inetpeer_addr *daddr, |
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unsigned int hash) |
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{ |
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struct tcp_metrics_block *tm; |
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struct net *net; |
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bool reclaim = false; |
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|
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spin_lock_bh(&tcp_metrics_lock); |
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net = dev_net(dst->dev); |
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|
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/* While waiting for the spin-lock the cache might have been populated |
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* with this entry and so we have to check again. |
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*/ |
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tm = __tcp_get_metrics(saddr, daddr, net, hash); |
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if (tm == TCP_METRICS_RECLAIM_PTR) { |
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reclaim = true; |
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tm = NULL; |
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} |
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if (tm) { |
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tcpm_check_stamp(tm, dst); |
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goto out_unlock; |
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} |
|
|
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if (unlikely(reclaim)) { |
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struct tcp_metrics_block *oldest; |
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|
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oldest = deref_locked(tcp_metrics_hash[hash].chain); |
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for (tm = deref_locked(oldest->tcpm_next); tm; |
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tm = deref_locked(tm->tcpm_next)) { |
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if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp)) |
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oldest = tm; |
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} |
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tm = oldest; |
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} else { |
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tm = kmalloc(sizeof(*tm), GFP_ATOMIC); |
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if (!tm) |
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goto out_unlock; |
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} |
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write_pnet(&tm->tcpm_net, net); |
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tm->tcpm_saddr = *saddr; |
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tm->tcpm_daddr = *daddr; |
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|
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tcpm_suck_dst(tm, dst, true); |
|
|
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if (likely(!reclaim)) { |
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tm->tcpm_next = tcp_metrics_hash[hash].chain; |
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rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm); |
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} |
|
|
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out_unlock: |
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spin_unlock_bh(&tcp_metrics_lock); |
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return tm; |
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} |
|
|
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static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth) |
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{ |
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if (tm) |
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return tm; |
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if (depth > TCP_METRICS_RECLAIM_DEPTH) |
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return TCP_METRICS_RECLAIM_PTR; |
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return NULL; |
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} |
|
|
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static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, |
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const struct inetpeer_addr *daddr, |
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struct net *net, unsigned int hash) |
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{ |
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struct tcp_metrics_block *tm; |
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int depth = 0; |
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|
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for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
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tm = rcu_dereference(tm->tcpm_next)) { |
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if (addr_same(&tm->tcpm_saddr, saddr) && |
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addr_same(&tm->tcpm_daddr, daddr) && |
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net_eq(tm_net(tm), net)) |
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break; |
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depth++; |
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} |
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return tcp_get_encode(tm, depth); |
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} |
|
|
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static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, |
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struct dst_entry *dst) |
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{ |
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struct tcp_metrics_block *tm; |
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struct inetpeer_addr saddr, daddr; |
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unsigned int hash; |
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struct net *net; |
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|
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saddr.family = req->rsk_ops->family; |
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daddr.family = req->rsk_ops->family; |
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switch (daddr.family) { |
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case AF_INET: |
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inetpeer_set_addr_v4(&saddr, inet_rsk(req)->ir_loc_addr); |
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inetpeer_set_addr_v4(&daddr, inet_rsk(req)->ir_rmt_addr); |
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hash = ipv4_addr_hash(inet_rsk(req)->ir_rmt_addr); |
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break; |
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#if IS_ENABLED(CONFIG_IPV6) |
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case AF_INET6: |
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inetpeer_set_addr_v6(&saddr, &inet_rsk(req)->ir_v6_loc_addr); |
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inetpeer_set_addr_v6(&daddr, &inet_rsk(req)->ir_v6_rmt_addr); |
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hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr); |
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break; |
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#endif |
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default: |
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return NULL; |
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} |
|
|
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net = dev_net(dst->dev); |
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hash ^= net_hash_mix(net); |
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hash = hash_32(hash, tcp_metrics_hash_log); |
|
|
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for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
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tm = rcu_dereference(tm->tcpm_next)) { |
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if (addr_same(&tm->tcpm_saddr, &saddr) && |
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addr_same(&tm->tcpm_daddr, &daddr) && |
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net_eq(tm_net(tm), net)) |
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break; |
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} |
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tcpm_check_stamp(tm, dst); |
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return tm; |
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} |
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|
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static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk, |
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struct dst_entry *dst, |
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bool create) |
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{ |
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struct tcp_metrics_block *tm; |
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struct inetpeer_addr saddr, daddr; |
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unsigned int hash; |
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struct net *net; |
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|
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if (sk->sk_family == AF_INET) { |
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inetpeer_set_addr_v4(&saddr, inet_sk(sk)->inet_saddr); |
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inetpeer_set_addr_v4(&daddr, inet_sk(sk)->inet_daddr); |
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hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr); |
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} |
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#if IS_ENABLED(CONFIG_IPV6) |
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else if (sk->sk_family == AF_INET6) { |
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if (ipv6_addr_v4mapped(&sk->sk_v6_daddr)) { |
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inetpeer_set_addr_v4(&saddr, inet_sk(sk)->inet_saddr); |
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inetpeer_set_addr_v4(&daddr, inet_sk(sk)->inet_daddr); |
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hash = ipv4_addr_hash(inet_sk(sk)->inet_daddr); |
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} else { |
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inetpeer_set_addr_v6(&saddr, &sk->sk_v6_rcv_saddr); |
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inetpeer_set_addr_v6(&daddr, &sk->sk_v6_daddr); |
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hash = ipv6_addr_hash(&sk->sk_v6_daddr); |
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} |
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} |
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#endif |
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else |
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return NULL; |
|
|
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net = dev_net(dst->dev); |
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hash ^= net_hash_mix(net); |
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hash = hash_32(hash, tcp_metrics_hash_log); |
|
|
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tm = __tcp_get_metrics(&saddr, &daddr, net, hash); |
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if (tm == TCP_METRICS_RECLAIM_PTR) |
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tm = NULL; |
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if (!tm && create) |
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tm = tcpm_new(dst, &saddr, &daddr, hash); |
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else |
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tcpm_check_stamp(tm, dst); |
|
|
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return tm; |
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} |
|
|
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/* Save metrics learned by this TCP session. This function is called |
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* only, when TCP finishes successfully i.e. when it enters TIME-WAIT |
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* or goes from LAST-ACK to CLOSE. |
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*/ |
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void tcp_update_metrics(struct sock *sk) |
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{ |
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const struct inet_connection_sock *icsk = inet_csk(sk); |
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struct dst_entry *dst = __sk_dst_get(sk); |
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struct tcp_sock *tp = tcp_sk(sk); |
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struct net *net = sock_net(sk); |
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struct tcp_metrics_block *tm; |
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unsigned long rtt; |
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u32 val; |
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int m; |
|
|
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sk_dst_confirm(sk); |
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if (net->ipv4.sysctl_tcp_nometrics_save || !dst) |
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return; |
|
|
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rcu_read_lock(); |
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if (icsk->icsk_backoff || !tp->srtt_us) { |
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/* This session failed to estimate rtt. Why? |
|
* Probably, no packets returned in time. Reset our |
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* results. |
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*/ |
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tm = tcp_get_metrics(sk, dst, false); |
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if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT)) |
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tcp_metric_set(tm, TCP_METRIC_RTT, 0); |
|
goto out_unlock; |
|
} else |
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tm = tcp_get_metrics(sk, dst, true); |
|
|
|
if (!tm) |
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goto out_unlock; |
|
|
|
rtt = tcp_metric_get(tm, TCP_METRIC_RTT); |
|
m = rtt - tp->srtt_us; |
|
|
|
/* If newly calculated rtt larger than stored one, store new |
|
* one. Otherwise, use EWMA. Remember, rtt overestimation is |
|
* always better than underestimation. |
|
*/ |
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if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) { |
|
if (m <= 0) |
|
rtt = tp->srtt_us; |
|
else |
|
rtt -= (m >> 3); |
|
tcp_metric_set(tm, TCP_METRIC_RTT, rtt); |
|
} |
|
|
|
if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) { |
|
unsigned long var; |
|
|
|
if (m < 0) |
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m = -m; |
|
|
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/* Scale deviation to rttvar fixed point */ |
|
m >>= 1; |
|
if (m < tp->mdev_us) |
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m = tp->mdev_us; |
|
|
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var = tcp_metric_get(tm, TCP_METRIC_RTTVAR); |
|
if (m >= var) |
|
var = m; |
|
else |
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var -= (var - m) >> 2; |
|
|
|
tcp_metric_set(tm, TCP_METRIC_RTTVAR, var); |
|
} |
|
|
|
if (tcp_in_initial_slowstart(tp)) { |
|
/* Slow start still did not finish. */ |
|
if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save && |
|
!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { |
|
val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); |
|
if (val && (tp->snd_cwnd >> 1) > val) |
|
tcp_metric_set(tm, TCP_METRIC_SSTHRESH, |
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tp->snd_cwnd >> 1); |
|
} |
|
if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { |
|
val = tcp_metric_get(tm, TCP_METRIC_CWND); |
|
if (tp->snd_cwnd > val) |
|
tcp_metric_set(tm, TCP_METRIC_CWND, |
|
tp->snd_cwnd); |
|
} |
|
} else if (!tcp_in_slow_start(tp) && |
|
icsk->icsk_ca_state == TCP_CA_Open) { |
|
/* Cong. avoidance phase, cwnd is reliable. */ |
|
if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save && |
|
!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) |
|
tcp_metric_set(tm, TCP_METRIC_SSTHRESH, |
|
max(tp->snd_cwnd >> 1, tp->snd_ssthresh)); |
|
if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { |
|
val = tcp_metric_get(tm, TCP_METRIC_CWND); |
|
tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1); |
|
} |
|
} else { |
|
/* Else slow start did not finish, cwnd is non-sense, |
|
* ssthresh may be also invalid. |
|
*/ |
|
if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) { |
|
val = tcp_metric_get(tm, TCP_METRIC_CWND); |
|
tcp_metric_set(tm, TCP_METRIC_CWND, |
|
(val + tp->snd_ssthresh) >> 1); |
|
} |
|
if (!net->ipv4.sysctl_tcp_no_ssthresh_metrics_save && |
|
!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) { |
|
val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH); |
|
if (val && tp->snd_ssthresh > val) |
|
tcp_metric_set(tm, TCP_METRIC_SSTHRESH, |
|
tp->snd_ssthresh); |
|
} |
|
if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) { |
|
val = tcp_metric_get(tm, TCP_METRIC_REORDERING); |
|
if (val < tp->reordering && |
|
tp->reordering != net->ipv4.sysctl_tcp_reordering) |
|
tcp_metric_set(tm, TCP_METRIC_REORDERING, |
|
tp->reordering); |
|
} |
|
} |
|
tm->tcpm_stamp = jiffies; |
|
out_unlock: |
|
rcu_read_unlock(); |
|
} |
|
|
|
/* Initialize metrics on socket. */ |
|
|
|
void tcp_init_metrics(struct sock *sk) |
|
{ |
|
struct dst_entry *dst = __sk_dst_get(sk); |
|
struct tcp_sock *tp = tcp_sk(sk); |
|
struct net *net = sock_net(sk); |
|
struct tcp_metrics_block *tm; |
|
u32 val, crtt = 0; /* cached RTT scaled by 8 */ |
|
|
|
sk_dst_confirm(sk); |
|
if (!dst) |
|
goto reset; |
|
|
|
rcu_read_lock(); |
|
tm = tcp_get_metrics(sk, dst, true); |
|
if (!tm) { |
|
rcu_read_unlock(); |
|
goto reset; |
|
} |
|
|
|
if (tcp_metric_locked(tm, TCP_METRIC_CWND)) |
|
tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND); |
|
|
|
val = net->ipv4.sysctl_tcp_no_ssthresh_metrics_save ? |
|
0 : tcp_metric_get(tm, TCP_METRIC_SSTHRESH); |
|
if (val) { |
|
tp->snd_ssthresh = val; |
|
if (tp->snd_ssthresh > tp->snd_cwnd_clamp) |
|
tp->snd_ssthresh = tp->snd_cwnd_clamp; |
|
} else { |
|
/* ssthresh may have been reduced unnecessarily during. |
|
* 3WHS. Restore it back to its initial default. |
|
*/ |
|
tp->snd_ssthresh = TCP_INFINITE_SSTHRESH; |
|
} |
|
val = tcp_metric_get(tm, TCP_METRIC_REORDERING); |
|
if (val && tp->reordering != val) |
|
tp->reordering = val; |
|
|
|
crtt = tcp_metric_get(tm, TCP_METRIC_RTT); |
|
rcu_read_unlock(); |
|
reset: |
|
/* The initial RTT measurement from the SYN/SYN-ACK is not ideal |
|
* to seed the RTO for later data packets because SYN packets are |
|
* small. Use the per-dst cached values to seed the RTO but keep |
|
* the RTT estimator variables intact (e.g., srtt, mdev, rttvar). |
|
* Later the RTO will be updated immediately upon obtaining the first |
|
* data RTT sample (tcp_rtt_estimator()). Hence the cached RTT only |
|
* influences the first RTO but not later RTT estimation. |
|
* |
|
* But if RTT is not available from the SYN (due to retransmits or |
|
* syn cookies) or the cache, force a conservative 3secs timeout. |
|
* |
|
* A bit of theory. RTT is time passed after "normal" sized packet |
|
* is sent until it is ACKed. In normal circumstances sending small |
|
* packets force peer to delay ACKs and calculation is correct too. |
|
* The algorithm is adaptive and, provided we follow specs, it |
|
* NEVER underestimate RTT. BUT! If peer tries to make some clever |
|
* tricks sort of "quick acks" for time long enough to decrease RTT |
|
* to low value, and then abruptly stops to do it and starts to delay |
|
* ACKs, wait for troubles. |
|
*/ |
|
if (crtt > tp->srtt_us) { |
|
/* Set RTO like tcp_rtt_estimator(), but from cached RTT. */ |
|
crtt /= 8 * USEC_PER_SEC / HZ; |
|
inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk)); |
|
} else if (tp->srtt_us == 0) { |
|
/* RFC6298: 5.7 We've failed to get a valid RTT sample from |
|
* 3WHS. This is most likely due to retransmission, |
|
* including spurious one. Reset the RTO back to 3secs |
|
* from the more aggressive 1sec to avoid more spurious |
|
* retransmission. |
|
*/ |
|
tp->rttvar_us = jiffies_to_usecs(TCP_TIMEOUT_FALLBACK); |
|
tp->mdev_us = tp->mdev_max_us = tp->rttvar_us; |
|
|
|
inet_csk(sk)->icsk_rto = TCP_TIMEOUT_FALLBACK; |
|
} |
|
} |
|
|
|
bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst) |
|
{ |
|
struct tcp_metrics_block *tm; |
|
bool ret; |
|
|
|
if (!dst) |
|
return false; |
|
|
|
rcu_read_lock(); |
|
tm = __tcp_get_metrics_req(req, dst); |
|
if (tm && tcp_metric_get(tm, TCP_METRIC_RTT)) |
|
ret = true; |
|
else |
|
ret = false; |
|
rcu_read_unlock(); |
|
|
|
return ret; |
|
} |
|
|
|
static DEFINE_SEQLOCK(fastopen_seqlock); |
|
|
|
void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
|
struct tcp_fastopen_cookie *cookie) |
|
{ |
|
struct tcp_metrics_block *tm; |
|
|
|
rcu_read_lock(); |
|
tm = tcp_get_metrics(sk, __sk_dst_get(sk), false); |
|
if (tm) { |
|
struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; |
|
unsigned int seq; |
|
|
|
do { |
|
seq = read_seqbegin(&fastopen_seqlock); |
|
if (tfom->mss) |
|
*mss = tfom->mss; |
|
*cookie = tfom->cookie; |
|
if (cookie->len <= 0 && tfom->try_exp == 1) |
|
cookie->exp = true; |
|
} while (read_seqretry(&fastopen_seqlock, seq)); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
|
struct tcp_fastopen_cookie *cookie, bool syn_lost, |
|
u16 try_exp) |
|
{ |
|
struct dst_entry *dst = __sk_dst_get(sk); |
|
struct tcp_metrics_block *tm; |
|
|
|
if (!dst) |
|
return; |
|
rcu_read_lock(); |
|
tm = tcp_get_metrics(sk, dst, true); |
|
if (tm) { |
|
struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen; |
|
|
|
write_seqlock_bh(&fastopen_seqlock); |
|
if (mss) |
|
tfom->mss = mss; |
|
if (cookie && cookie->len > 0) |
|
tfom->cookie = *cookie; |
|
else if (try_exp > tfom->try_exp && |
|
tfom->cookie.len <= 0 && !tfom->cookie.exp) |
|
tfom->try_exp = try_exp; |
|
if (syn_lost) { |
|
++tfom->syn_loss; |
|
tfom->last_syn_loss = jiffies; |
|
} else |
|
tfom->syn_loss = 0; |
|
write_sequnlock_bh(&fastopen_seqlock); |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
static struct genl_family tcp_metrics_nl_family; |
|
|
|
static const struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = { |
|
[TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, }, |
|
[TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY, |
|
.len = sizeof(struct in6_addr), }, |
|
/* Following attributes are not received for GET/DEL, |
|
* we keep them for reference |
|
*/ |
|
#if 0 |
|
[TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, }, |
|
[TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, }, |
|
[TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, }, |
|
[TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, }, |
|
[TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, }, |
|
[TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, }, |
|
[TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, }, |
|
[TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY, |
|
.len = TCP_FASTOPEN_COOKIE_MAX, }, |
|
#endif |
|
}; |
|
|
|
/* Add attributes, caller cancels its header on failure */ |
|
static int tcp_metrics_fill_info(struct sk_buff *msg, |
|
struct tcp_metrics_block *tm) |
|
{ |
|
struct nlattr *nest; |
|
int i; |
|
|
|
switch (tm->tcpm_daddr.family) { |
|
case AF_INET: |
|
if (nla_put_in_addr(msg, TCP_METRICS_ATTR_ADDR_IPV4, |
|
inetpeer_get_addr_v4(&tm->tcpm_daddr)) < 0) |
|
goto nla_put_failure; |
|
if (nla_put_in_addr(msg, TCP_METRICS_ATTR_SADDR_IPV4, |
|
inetpeer_get_addr_v4(&tm->tcpm_saddr)) < 0) |
|
goto nla_put_failure; |
|
break; |
|
case AF_INET6: |
|
if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_ADDR_IPV6, |
|
inetpeer_get_addr_v6(&tm->tcpm_daddr)) < 0) |
|
goto nla_put_failure; |
|
if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_SADDR_IPV6, |
|
inetpeer_get_addr_v6(&tm->tcpm_saddr)) < 0) |
|
goto nla_put_failure; |
|
break; |
|
default: |
|
return -EAFNOSUPPORT; |
|
} |
|
|
|
if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE, |
|
jiffies - tm->tcpm_stamp, |
|
TCP_METRICS_ATTR_PAD) < 0) |
|
goto nla_put_failure; |
|
|
|
{ |
|
int n = 0; |
|
|
|
nest = nla_nest_start_noflag(msg, TCP_METRICS_ATTR_VALS); |
|
if (!nest) |
|
goto nla_put_failure; |
|
for (i = 0; i < TCP_METRIC_MAX_KERNEL + 1; i++) { |
|
u32 val = tm->tcpm_vals[i]; |
|
|
|
if (!val) |
|
continue; |
|
if (i == TCP_METRIC_RTT) { |
|
if (nla_put_u32(msg, TCP_METRIC_RTT_US + 1, |
|
val) < 0) |
|
goto nla_put_failure; |
|
n++; |
|
val = max(val / 1000, 1U); |
|
} |
|
if (i == TCP_METRIC_RTTVAR) { |
|
if (nla_put_u32(msg, TCP_METRIC_RTTVAR_US + 1, |
|
val) < 0) |
|
goto nla_put_failure; |
|
n++; |
|
val = max(val / 1000, 1U); |
|
} |
|
if (nla_put_u32(msg, i + 1, val) < 0) |
|
goto nla_put_failure; |
|
n++; |
|
} |
|
if (n) |
|
nla_nest_end(msg, nest); |
|
else |
|
nla_nest_cancel(msg, nest); |
|
} |
|
|
|
{ |
|
struct tcp_fastopen_metrics tfom_copy[1], *tfom; |
|
unsigned int seq; |
|
|
|
do { |
|
seq = read_seqbegin(&fastopen_seqlock); |
|
tfom_copy[0] = tm->tcpm_fastopen; |
|
} while (read_seqretry(&fastopen_seqlock, seq)); |
|
|
|
tfom = tfom_copy; |
|
if (tfom->mss && |
|
nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS, |
|
tfom->mss) < 0) |
|
goto nla_put_failure; |
|
if (tfom->syn_loss && |
|
(nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS, |
|
tfom->syn_loss) < 0 || |
|
nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS, |
|
jiffies - tfom->last_syn_loss, |
|
TCP_METRICS_ATTR_PAD) < 0)) |
|
goto nla_put_failure; |
|
if (tfom->cookie.len > 0 && |
|
nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE, |
|
tfom->cookie.len, tfom->cookie.val) < 0) |
|
goto nla_put_failure; |
|
} |
|
|
|
return 0; |
|
|
|
nla_put_failure: |
|
return -EMSGSIZE; |
|
} |
|
|
|
static int tcp_metrics_dump_info(struct sk_buff *skb, |
|
struct netlink_callback *cb, |
|
struct tcp_metrics_block *tm) |
|
{ |
|
void *hdr; |
|
|
|
hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, |
|
&tcp_metrics_nl_family, NLM_F_MULTI, |
|
TCP_METRICS_CMD_GET); |
|
if (!hdr) |
|
return -EMSGSIZE; |
|
|
|
if (tcp_metrics_fill_info(skb, tm) < 0) |
|
goto nla_put_failure; |
|
|
|
genlmsg_end(skb, hdr); |
|
return 0; |
|
|
|
nla_put_failure: |
|
genlmsg_cancel(skb, hdr); |
|
return -EMSGSIZE; |
|
} |
|
|
|
static int tcp_metrics_nl_dump(struct sk_buff *skb, |
|
struct netlink_callback *cb) |
|
{ |
|
struct net *net = sock_net(skb->sk); |
|
unsigned int max_rows = 1U << tcp_metrics_hash_log; |
|
unsigned int row, s_row = cb->args[0]; |
|
int s_col = cb->args[1], col = s_col; |
|
|
|
for (row = s_row; row < max_rows; row++, s_col = 0) { |
|
struct tcp_metrics_block *tm; |
|
struct tcpm_hash_bucket *hb = tcp_metrics_hash + row; |
|
|
|
rcu_read_lock(); |
|
for (col = 0, tm = rcu_dereference(hb->chain); tm; |
|
tm = rcu_dereference(tm->tcpm_next), col++) { |
|
if (!net_eq(tm_net(tm), net)) |
|
continue; |
|
if (col < s_col) |
|
continue; |
|
if (tcp_metrics_dump_info(skb, cb, tm) < 0) { |
|
rcu_read_unlock(); |
|
goto done; |
|
} |
|
} |
|
rcu_read_unlock(); |
|
} |
|
|
|
done: |
|
cb->args[0] = row; |
|
cb->args[1] = col; |
|
return skb->len; |
|
} |
|
|
|
static int __parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, |
|
unsigned int *hash, int optional, int v4, int v6) |
|
{ |
|
struct nlattr *a; |
|
|
|
a = info->attrs[v4]; |
|
if (a) { |
|
inetpeer_set_addr_v4(addr, nla_get_in_addr(a)); |
|
if (hash) |
|
*hash = ipv4_addr_hash(inetpeer_get_addr_v4(addr)); |
|
return 0; |
|
} |
|
a = info->attrs[v6]; |
|
if (a) { |
|
struct in6_addr in6; |
|
|
|
if (nla_len(a) != sizeof(struct in6_addr)) |
|
return -EINVAL; |
|
in6 = nla_get_in6_addr(a); |
|
inetpeer_set_addr_v6(addr, &in6); |
|
if (hash) |
|
*hash = ipv6_addr_hash(inetpeer_get_addr_v6(addr)); |
|
return 0; |
|
} |
|
return optional ? 1 : -EAFNOSUPPORT; |
|
} |
|
|
|
static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr, |
|
unsigned int *hash, int optional) |
|
{ |
|
return __parse_nl_addr(info, addr, hash, optional, |
|
TCP_METRICS_ATTR_ADDR_IPV4, |
|
TCP_METRICS_ATTR_ADDR_IPV6); |
|
} |
|
|
|
static int parse_nl_saddr(struct genl_info *info, struct inetpeer_addr *addr) |
|
{ |
|
return __parse_nl_addr(info, addr, NULL, 0, |
|
TCP_METRICS_ATTR_SADDR_IPV4, |
|
TCP_METRICS_ATTR_SADDR_IPV6); |
|
} |
|
|
|
static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info) |
|
{ |
|
struct tcp_metrics_block *tm; |
|
struct inetpeer_addr saddr, daddr; |
|
unsigned int hash; |
|
struct sk_buff *msg; |
|
struct net *net = genl_info_net(info); |
|
void *reply; |
|
int ret; |
|
bool src = true; |
|
|
|
ret = parse_nl_addr(info, &daddr, &hash, 0); |
|
if (ret < 0) |
|
return ret; |
|
|
|
ret = parse_nl_saddr(info, &saddr); |
|
if (ret < 0) |
|
src = false; |
|
|
|
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); |
|
if (!msg) |
|
return -ENOMEM; |
|
|
|
reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0, |
|
info->genlhdr->cmd); |
|
if (!reply) |
|
goto nla_put_failure; |
|
|
|
hash ^= net_hash_mix(net); |
|
hash = hash_32(hash, tcp_metrics_hash_log); |
|
ret = -ESRCH; |
|
rcu_read_lock(); |
|
for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; |
|
tm = rcu_dereference(tm->tcpm_next)) { |
|
if (addr_same(&tm->tcpm_daddr, &daddr) && |
|
(!src || addr_same(&tm->tcpm_saddr, &saddr)) && |
|
net_eq(tm_net(tm), net)) { |
|
ret = tcp_metrics_fill_info(msg, tm); |
|
break; |
|
} |
|
} |
|
rcu_read_unlock(); |
|
if (ret < 0) |
|
goto out_free; |
|
|
|
genlmsg_end(msg, reply); |
|
return genlmsg_reply(msg, info); |
|
|
|
nla_put_failure: |
|
ret = -EMSGSIZE; |
|
|
|
out_free: |
|
nlmsg_free(msg); |
|
return ret; |
|
} |
|
|
|
static void tcp_metrics_flush_all(struct net *net) |
|
{ |
|
unsigned int max_rows = 1U << tcp_metrics_hash_log; |
|
struct tcpm_hash_bucket *hb = tcp_metrics_hash; |
|
struct tcp_metrics_block *tm; |
|
unsigned int row; |
|
|
|
for (row = 0; row < max_rows; row++, hb++) { |
|
struct tcp_metrics_block __rcu **pp; |
|
bool match; |
|
|
|
spin_lock_bh(&tcp_metrics_lock); |
|
pp = &hb->chain; |
|
for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { |
|
match = net ? net_eq(tm_net(tm), net) : |
|
!refcount_read(&tm_net(tm)->ns.count); |
|
if (match) { |
|
*pp = tm->tcpm_next; |
|
kfree_rcu(tm, rcu_head); |
|
} else { |
|
pp = &tm->tcpm_next; |
|
} |
|
} |
|
spin_unlock_bh(&tcp_metrics_lock); |
|
} |
|
} |
|
|
|
static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info) |
|
{ |
|
struct tcpm_hash_bucket *hb; |
|
struct tcp_metrics_block *tm; |
|
struct tcp_metrics_block __rcu **pp; |
|
struct inetpeer_addr saddr, daddr; |
|
unsigned int hash; |
|
struct net *net = genl_info_net(info); |
|
int ret; |
|
bool src = true, found = false; |
|
|
|
ret = parse_nl_addr(info, &daddr, &hash, 1); |
|
if (ret < 0) |
|
return ret; |
|
if (ret > 0) { |
|
tcp_metrics_flush_all(net); |
|
return 0; |
|
} |
|
ret = parse_nl_saddr(info, &saddr); |
|
if (ret < 0) |
|
src = false; |
|
|
|
hash ^= net_hash_mix(net); |
|
hash = hash_32(hash, tcp_metrics_hash_log); |
|
hb = tcp_metrics_hash + hash; |
|
pp = &hb->chain; |
|
spin_lock_bh(&tcp_metrics_lock); |
|
for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { |
|
if (addr_same(&tm->tcpm_daddr, &daddr) && |
|
(!src || addr_same(&tm->tcpm_saddr, &saddr)) && |
|
net_eq(tm_net(tm), net)) { |
|
*pp = tm->tcpm_next; |
|
kfree_rcu(tm, rcu_head); |
|
found = true; |
|
} else { |
|
pp = &tm->tcpm_next; |
|
} |
|
} |
|
spin_unlock_bh(&tcp_metrics_lock); |
|
if (!found) |
|
return -ESRCH; |
|
return 0; |
|
} |
|
|
|
static const struct genl_small_ops tcp_metrics_nl_ops[] = { |
|
{ |
|
.cmd = TCP_METRICS_CMD_GET, |
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
|
.doit = tcp_metrics_nl_cmd_get, |
|
.dumpit = tcp_metrics_nl_dump, |
|
}, |
|
{ |
|
.cmd = TCP_METRICS_CMD_DEL, |
|
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
|
.doit = tcp_metrics_nl_cmd_del, |
|
.flags = GENL_ADMIN_PERM, |
|
}, |
|
}; |
|
|
|
static struct genl_family tcp_metrics_nl_family __ro_after_init = { |
|
.hdrsize = 0, |
|
.name = TCP_METRICS_GENL_NAME, |
|
.version = TCP_METRICS_GENL_VERSION, |
|
.maxattr = TCP_METRICS_ATTR_MAX, |
|
.policy = tcp_metrics_nl_policy, |
|
.netnsok = true, |
|
.module = THIS_MODULE, |
|
.small_ops = tcp_metrics_nl_ops, |
|
.n_small_ops = ARRAY_SIZE(tcp_metrics_nl_ops), |
|
}; |
|
|
|
static unsigned int tcpmhash_entries; |
|
static int __init set_tcpmhash_entries(char *str) |
|
{ |
|
ssize_t ret; |
|
|
|
if (!str) |
|
return 0; |
|
|
|
ret = kstrtouint(str, 0, &tcpmhash_entries); |
|
if (ret) |
|
return 0; |
|
|
|
return 1; |
|
} |
|
__setup("tcpmhash_entries=", set_tcpmhash_entries); |
|
|
|
static int __net_init tcp_net_metrics_init(struct net *net) |
|
{ |
|
size_t size; |
|
unsigned int slots; |
|
|
|
if (!net_eq(net, &init_net)) |
|
return 0; |
|
|
|
slots = tcpmhash_entries; |
|
if (!slots) { |
|
if (totalram_pages() >= 128 * 1024) |
|
slots = 16 * 1024; |
|
else |
|
slots = 8 * 1024; |
|
} |
|
|
|
tcp_metrics_hash_log = order_base_2(slots); |
|
size = sizeof(struct tcpm_hash_bucket) << tcp_metrics_hash_log; |
|
|
|
tcp_metrics_hash = kvzalloc(size, GFP_KERNEL); |
|
if (!tcp_metrics_hash) |
|
return -ENOMEM; |
|
|
|
return 0; |
|
} |
|
|
|
static void __net_exit tcp_net_metrics_exit_batch(struct list_head *net_exit_list) |
|
{ |
|
tcp_metrics_flush_all(NULL); |
|
} |
|
|
|
static __net_initdata struct pernet_operations tcp_net_metrics_ops = { |
|
.init = tcp_net_metrics_init, |
|
.exit_batch = tcp_net_metrics_exit_batch, |
|
}; |
|
|
|
void __init tcp_metrics_init(void) |
|
{ |
|
int ret; |
|
|
|
ret = register_pernet_subsys(&tcp_net_metrics_ops); |
|
if (ret < 0) |
|
panic("Could not allocate the tcp_metrics hash table\n"); |
|
|
|
ret = genl_register_family(&tcp_metrics_nl_family); |
|
if (ret < 0) |
|
panic("Could not register tcp_metrics generic netlink\n"); |
|
}
|
|
|