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![Yuchung Cheng](/assets/img/avatar_default.png)
Relocate the congestion window initialization from tcp_init_metrics() to tcp_init_transfer() to improve code readability. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1031 lines
26 KiB
C
1031 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#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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#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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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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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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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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struct tcpm_hash_bucket {
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struct tcp_metrics_block __rcu *chain;
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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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static DEFINE_SPINLOCK(tcp_metrics_lock);
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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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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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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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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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#define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
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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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#define deref_locked(p) \
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rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock))
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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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spin_lock_bh(&tcp_metrics_lock);
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net = dev_net(dst->dev);
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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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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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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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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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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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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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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?
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* 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);
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goto out_unlock;
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} else
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tm = tcp_get_metrics(sk, dst, true);
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if (!tm)
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goto out_unlock;
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rtt = tcp_metric_get(tm, TCP_METRIC_RTT);
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m = rtt - tp->srtt_us;
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/* If newly calculated rtt larger than stored one, store new
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* one. Otherwise, use EWMA. Remember, rtt overestimation is
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* always better than underestimation.
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*/
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if (!tcp_metric_locked(tm, TCP_METRIC_RTT)) {
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if (m <= 0)
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rtt = tp->srtt_us;
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else
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rtt -= (m >> 3);
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tcp_metric_set(tm, TCP_METRIC_RTT, rtt);
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}
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if (!tcp_metric_locked(tm, TCP_METRIC_RTTVAR)) {
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unsigned long var;
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if (m < 0)
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m = -m;
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/* Scale deviation to rttvar fixed point */
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m >>= 1;
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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);
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if (m >= var)
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var = m;
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else
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var -= (var - m) >> 2;
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tcp_metric_set(tm, TCP_METRIC_RTTVAR, var);
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}
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|
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if (tcp_in_initial_slowstart(tp)) {
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/* Slow start still did not finish. */
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if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
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val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
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if (val && (tp->snd_cwnd >> 1) > val)
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tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
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tp->snd_cwnd >> 1);
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}
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if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
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val = tcp_metric_get(tm, TCP_METRIC_CWND);
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if (tp->snd_cwnd > val)
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tcp_metric_set(tm, TCP_METRIC_CWND,
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tp->snd_cwnd);
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}
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} else if (!tcp_in_slow_start(tp) &&
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icsk->icsk_ca_state == TCP_CA_Open) {
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/* Cong. avoidance phase, cwnd is reliable. */
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if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH))
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tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
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max(tp->snd_cwnd >> 1, tp->snd_ssthresh));
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if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
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val = tcp_metric_get(tm, TCP_METRIC_CWND);
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tcp_metric_set(tm, TCP_METRIC_CWND, (val + tp->snd_cwnd) >> 1);
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}
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} else {
|
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/* Else slow start did not finish, cwnd is non-sense,
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* ssthresh may be also invalid.
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*/
|
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if (!tcp_metric_locked(tm, TCP_METRIC_CWND)) {
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val = tcp_metric_get(tm, TCP_METRIC_CWND);
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tcp_metric_set(tm, TCP_METRIC_CWND,
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(val + tp->snd_ssthresh) >> 1);
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}
|
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if (!tcp_metric_locked(tm, TCP_METRIC_SSTHRESH)) {
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val = tcp_metric_get(tm, TCP_METRIC_SSTHRESH);
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if (val && tp->snd_ssthresh > val)
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tcp_metric_set(tm, TCP_METRIC_SSTHRESH,
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tp->snd_ssthresh);
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}
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if (!tcp_metric_locked(tm, TCP_METRIC_REORDERING)) {
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val = tcp_metric_get(tm, TCP_METRIC_REORDERING);
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if (val < tp->reordering &&
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tp->reordering != net->ipv4.sysctl_tcp_reordering)
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tcp_metric_set(tm, TCP_METRIC_REORDERING,
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tp->reordering);
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}
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}
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tm->tcpm_stamp = jiffies;
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out_unlock:
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rcu_read_unlock();
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}
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|
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/* Initialize metrics on socket. */
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|
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void tcp_init_metrics(struct sock *sk)
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{
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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 tcp_metrics_block *tm;
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u32 val, crtt = 0; /* cached RTT scaled by 8 */
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|
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sk_dst_confirm(sk);
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if (!dst)
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goto reset;
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|
|
|
rcu_read_lock();
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tm = tcp_get_metrics(sk, dst, true);
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if (!tm) {
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rcu_read_unlock();
|
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goto reset;
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|
}
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|
|
if (tcp_metric_locked(tm, TCP_METRIC_CWND))
|
|
tp->snd_cwnd_clamp = tcp_metric_get(tm, TCP_METRIC_CWND);
|
|
|
|
val = 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)->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_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,
|
|
.ops = tcp_metrics_nl_ops,
|
|
.n_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");
|
|
}
|