diff options
Diffstat (limited to 'net/ipv4/tcp_metrics.c')
| -rw-r--r-- | net/ipv4/tcp_metrics.c | 1198 |
1 files changed, 1198 insertions, 0 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c new file mode 100644 index 000000000..a51d63a43 --- /dev/null +++ b/net/ipv4/tcp_metrics.c @@ -0,0 +1,1198 @@ +#include <linux/rcupdate.h> +#include <linux/spinlock.h> +#include <linux/jiffies.h> +#include <linux/module.h> +#include <linux/cache.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/tcp.h> +#include <linux/hash.h> +#include <linux/tcp_metrics.h> +#include <linux/vmalloc.h> + +#include <net/inet_connection_sock.h> +#include <net/net_namespace.h> +#include <net/request_sock.h> +#include <net/inetpeer.h> +#include <net/sock.h> +#include <net/ipv6.h> +#include <net/dst.h> +#include <net/tcp.h> +#include <net/genetlink.h> + +int sysctl_tcp_nometrics_save __read_mostly; + +static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, + const struct inetpeer_addr *daddr, + struct net *net, unsigned int hash); + +struct tcp_fastopen_metrics { + u16 mss; + u16 syn_loss:10, /* Recurring Fast Open SYN losses */ + try_exp:2; /* Request w/ exp. option (once) */ + unsigned long last_syn_loss; /* Last Fast Open SYN loss */ + struct tcp_fastopen_cookie cookie; +}; + +/* TCP_METRIC_MAX includes 2 extra fields for userspace compatibility + * Kernel only stores RTT and RTTVAR in usec resolution + */ +#define TCP_METRIC_MAX_KERNEL (TCP_METRIC_MAX - 2) + +struct tcp_metrics_block { + struct tcp_metrics_block __rcu *tcpm_next; + possible_net_t tcpm_net; + struct inetpeer_addr tcpm_saddr; + struct inetpeer_addr tcpm_daddr; + unsigned long tcpm_stamp; + u32 tcpm_ts; + u32 tcpm_ts_stamp; + u32 tcpm_lock; + u32 tcpm_vals[TCP_METRIC_MAX_KERNEL + 1]; + struct tcp_fastopen_metrics tcpm_fastopen; + + struct rcu_head rcu_head; +}; + +static inline struct net *tm_net(struct tcp_metrics_block *tm) +{ + return read_pnet(&tm->tcpm_net); +} + +static bool tcp_metric_locked(struct tcp_metrics_block *tm, + enum tcp_metric_index idx) +{ + return tm->tcpm_lock & (1 << idx); +} + +static u32 tcp_metric_get(struct tcp_metrics_block *tm, + enum tcp_metric_index idx) +{ + return tm->tcpm_vals[idx]; +} + +static void tcp_metric_set(struct tcp_metrics_block *tm, + enum tcp_metric_index idx, + u32 val) +{ + tm->tcpm_vals[idx] = val; +} + +static bool addr_same(const struct inetpeer_addr *a, + const struct inetpeer_addr *b) +{ + if (a->family != b->family) + return false; + if (a->family == AF_INET) + return a->addr.a4 == b->addr.a4; + return ipv6_addr_equal(&a->addr.in6, &b->addr.in6); +} + +struct tcpm_hash_bucket { + struct tcp_metrics_block __rcu *chain; +}; + +static struct tcpm_hash_bucket *tcp_metrics_hash __read_mostly; +static unsigned int tcp_metrics_hash_log __read_mostly; + +static DEFINE_SPINLOCK(tcp_metrics_lock); + +static void tcpm_suck_dst(struct tcp_metrics_block *tm, + const struct dst_entry *dst, + bool fastopen_clear) +{ + u32 msval; + u32 val; + + tm->tcpm_stamp = jiffies; + + val = 0; + if (dst_metric_locked(dst, RTAX_RTT)) + val |= 1 << TCP_METRIC_RTT; + if (dst_metric_locked(dst, RTAX_RTTVAR)) + val |= 1 << TCP_METRIC_RTTVAR; + if (dst_metric_locked(dst, RTAX_SSTHRESH)) + val |= 1 << TCP_METRIC_SSTHRESH; + if (dst_metric_locked(dst, RTAX_CWND)) + val |= 1 << TCP_METRIC_CWND; + if (dst_metric_locked(dst, RTAX_REORDERING)) + val |= 1 << TCP_METRIC_REORDERING; + tm->tcpm_lock = val; + + msval = dst_metric_raw(dst, RTAX_RTT); + tm->tcpm_vals[TCP_METRIC_RTT] = msval * USEC_PER_MSEC; + + msval = dst_metric_raw(dst, RTAX_RTTVAR); + tm->tcpm_vals[TCP_METRIC_RTTVAR] = msval * USEC_PER_MSEC; + tm->tcpm_vals[TCP_METRIC_SSTHRESH] = dst_metric_raw(dst, RTAX_SSTHRESH); + tm->tcpm_vals[TCP_METRIC_CWND] = dst_metric_raw(dst, RTAX_CWND); + tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING); + tm->tcpm_ts = 0; + tm->tcpm_ts_stamp = 0; + if (fastopen_clear) { + tm->tcpm_fastopen.mss = 0; + tm->tcpm_fastopen.syn_loss = 0; + tm->tcpm_fastopen.try_exp = 0; + tm->tcpm_fastopen.cookie.exp = false; + tm->tcpm_fastopen.cookie.len = 0; + } +} + +#define TCP_METRICS_TIMEOUT (60 * 60 * HZ) + +static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst) +{ + if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT))) + tcpm_suck_dst(tm, dst, false); +} + +#define TCP_METRICS_RECLAIM_DEPTH 5 +#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL + +#define deref_locked(p) \ + rcu_dereference_protected(p, lockdep_is_held(&tcp_metrics_lock)) + +static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst, + struct inetpeer_addr *saddr, + struct inetpeer_addr *daddr, + unsigned int hash) +{ + struct tcp_metrics_block *tm; + struct net *net; + bool reclaim = false; + + spin_lock_bh(&tcp_metrics_lock); + net = dev_net(dst->dev); + + /* While waiting for the spin-lock the cache might have been populated + * with this entry and so we have to check again. + */ + tm = __tcp_get_metrics(saddr, daddr, net, hash); + if (tm == TCP_METRICS_RECLAIM_PTR) { + reclaim = true; + tm = NULL; + } + if (tm) { + tcpm_check_stamp(tm, dst); + goto out_unlock; + } + + if (unlikely(reclaim)) { + struct tcp_metrics_block *oldest; + + oldest = deref_locked(tcp_metrics_hash[hash].chain); + for (tm = deref_locked(oldest->tcpm_next); tm; + tm = deref_locked(tm->tcpm_next)) { + if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp)) + oldest = tm; + } + tm = oldest; + } else { + tm = kmalloc(sizeof(*tm), GFP_ATOMIC); + if (!tm) + goto out_unlock; + } + write_pnet(&tm->tcpm_net, net); + tm->tcpm_saddr = *saddr; + tm->tcpm_daddr = *daddr; + + tcpm_suck_dst(tm, dst, true); + + if (likely(!reclaim)) { + tm->tcpm_next = tcp_metrics_hash[hash].chain; + rcu_assign_pointer(tcp_metrics_hash[hash].chain, tm); + } + +out_unlock: + spin_unlock_bh(&tcp_metrics_lock); + return tm; +} + +static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth) +{ + if (tm) + return tm; + if (depth > TCP_METRICS_RECLAIM_DEPTH) + return TCP_METRICS_RECLAIM_PTR; + return NULL; +} + +static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *saddr, + const struct inetpeer_addr *daddr, + struct net *net, unsigned int hash) +{ + struct tcp_metrics_block *tm; + int depth = 0; + + for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; + tm = rcu_dereference(tm->tcpm_next)) { + if (addr_same(&tm->tcpm_saddr, saddr) && + addr_same(&tm->tcpm_daddr, daddr) && + net_eq(tm_net(tm), net)) + break; + depth++; + } + return tcp_get_encode(tm, depth); +} + +static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req, + struct dst_entry *dst) +{ + struct tcp_metrics_block *tm; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct net *net; + + saddr.family = req->rsk_ops->family; + daddr.family = req->rsk_ops->family; + switch (daddr.family) { + case AF_INET: + saddr.addr.a4 = inet_rsk(req)->ir_loc_addr; + daddr.addr.a4 = inet_rsk(req)->ir_rmt_addr; + hash = (__force unsigned int) daddr.addr.a4; + break; +#if IS_ENABLED(CONFIG_IPV6) + case AF_INET6: + saddr.addr.in6 = inet_rsk(req)->ir_v6_loc_addr; + daddr.addr.in6 = inet_rsk(req)->ir_v6_rmt_addr; + hash = ipv6_addr_hash(&inet_rsk(req)->ir_v6_rmt_addr); + break; +#endif + default: + return NULL; + } + + net = dev_net(dst->dev); + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + + for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; + tm = rcu_dereference(tm->tcpm_next)) { + if (addr_same(&tm->tcpm_saddr, &saddr) && + addr_same(&tm->tcpm_daddr, &daddr) && + net_eq(tm_net(tm), net)) + break; + } + tcpm_check_stamp(tm, dst); + return tm; +} + +static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock *tw) +{ + struct tcp_metrics_block *tm; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct net *net; + + if (tw->tw_family == AF_INET) { + saddr.family = AF_INET; + saddr.addr.a4 = tw->tw_rcv_saddr; + daddr.family = AF_INET; + daddr.addr.a4 = tw->tw_daddr; + hash = (__force unsigned int) daddr.addr.a4; + } +#if IS_ENABLED(CONFIG_IPV6) + else if (tw->tw_family == AF_INET6) { + if (ipv6_addr_v4mapped(&tw->tw_v6_daddr)) { + saddr.family = AF_INET; + saddr.addr.a4 = tw->tw_rcv_saddr; + daddr.family = AF_INET; + daddr.addr.a4 = tw->tw_daddr; + hash = (__force unsigned int) daddr.addr.a4; + } else { + saddr.family = AF_INET6; + saddr.addr.in6 = tw->tw_v6_rcv_saddr; + daddr.family = AF_INET6; + daddr.addr.in6 = tw->tw_v6_daddr; + hash = ipv6_addr_hash(&tw->tw_v6_daddr); + } + } +#endif + else + return NULL; + + net = twsk_net(tw); + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + + for (tm = rcu_dereference(tcp_metrics_hash[hash].chain); tm; + tm = rcu_dereference(tm->tcpm_next)) { + if (addr_same(&tm->tcpm_saddr, &saddr) && + addr_same(&tm->tcpm_daddr, &daddr) && + net_eq(tm_net(tm), net)) + break; + } + return tm; +} + +static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk, + struct dst_entry *dst, + bool create) +{ + struct tcp_metrics_block *tm; + struct inetpeer_addr saddr, daddr; + unsigned int hash; + struct net *net; + + if (sk->sk_family == AF_INET) { + saddr.family = AF_INET; + saddr.addr.a4 = inet_sk(sk)->inet_saddr; + daddr.family = AF_INET; + daddr.addr.a4 = inet_sk(sk)->inet_daddr; + hash = (__force unsigned int) daddr.addr.a4; + } +#if IS_ENABLED(CONFIG_IPV6) + else if (sk->sk_family == AF_INET6) { + if (ipv6_addr_v4mapped(&sk->sk_v6_daddr)) { + saddr.family = AF_INET; + saddr.addr.a4 = inet_sk(sk)->inet_saddr; + daddr.family = AF_INET; + daddr.addr.a4 = inet_sk(sk)->inet_daddr; + hash = (__force unsigned int) daddr.addr.a4; + } else { + saddr.family = AF_INET6; + saddr.addr.in6 = sk->sk_v6_rcv_saddr; + daddr.family = AF_INET6; + daddr.addr.in6 = sk->sk_v6_daddr; + hash = ipv6_addr_hash(&sk->sk_v6_daddr); + } + } +#endif + else + return NULL; + + net = dev_net(dst->dev); + hash ^= net_hash_mix(net); + hash = hash_32(hash, tcp_metrics_hash_log); + + tm = __tcp_get_metrics(&saddr, &daddr, net, hash); + if (tm == TCP_METRICS_RECLAIM_PTR) + tm = NULL; + if (!tm && create) + tm = tcpm_new(dst, &saddr, &daddr, hash); + else + tcpm_check_stamp(tm, dst); + + return tm; +} + +/* Save metrics learned by this TCP session. This function is called + * only, when TCP finishes successfully i.e. when it enters TIME-WAIT + * or goes from LAST-ACK to CLOSE. + */ +void tcp_update_metrics(struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + struct dst_entry *dst = __sk_dst_get(sk); + struct tcp_sock *tp = tcp_sk(sk); + struct tcp_metrics_block *tm; + unsigned long rtt; + u32 val; + int m; + + if (sysctl_tcp_nometrics_save || !dst) + return; + + if (dst->flags & DST_HOST) + dst_confirm(dst); + + rcu_read_lock(); + if (icsk->icsk_backoff || !tp->srtt_us) { + /* This session failed to estimate rtt. Why? + * Probably, no packets returned in time. Reset our + * results. + */ + tm = tcp_get_metrics(sk, dst, false); + if (tm && !tcp_metric_locked(tm, TCP_METRIC_RTT)) + tcp_metric_set(tm, TCP_METRIC_RTT, 0); + goto out_unlock; + } else + tm = tcp_get_metrics(sk, dst, true); + + if (!tm) + 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. + */ + 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) + m = -m; + + /* Scale deviation to rttvar fixed point */ + m >>= 1; + if (m < tp->mdev_us) + m = tp->mdev_us; + + var = tcp_metric_get(tm, TCP_METRIC_RTTVAR); + if (m >= var) + var = m; + else + 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 (!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, + 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 (tp->snd_cwnd > tp->snd_ssthresh && + icsk->icsk_ca_state == TCP_CA_Open) { + /* Cong. avoidance phase, cwnd is reliable. */ + if (!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 (!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 != 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 tcp_metrics_block *tm; + u32 val, crtt = 0; /* cached RTT scaled by 8 */ + + if (!dst) + goto reset; + + dst_confirm(dst); + + 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 = 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) { + tcp_disable_fack(tp); + tcp_disable_early_retrans(tp); + 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_MSEC; + 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; + } + /* Cut cwnd down to 1 per RFC5681 if SYN or SYN-ACK has been + * retransmitted. In light of RFC6298 more aggressive 1sec + * initRTO, we only reset cwnd when more than 1 SYN/SYN-ACK + * retransmission has occurred. + */ + if (tp->total_retrans > 1) + tp->snd_cwnd = 1; + else + tp->snd_cwnd = tcp_init_cwnd(tp, dst); + tp->snd_cwnd_stamp = tcp_time_stamp; +} + +bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, + bool paws_check, bool timestamps) +{ + struct tcp_metrics_block *tm; + bool ret; + + if (!dst) + return false; + + rcu_read_lock(); + tm = __tcp_get_metrics_req(req, dst); + if (paws_check) { + if (tm && + (u32)get_seconds() - tm->tcpm_ts_stamp < TCP_PAWS_MSL && + ((s32)(tm->tcpm_ts - req->ts_recent) > TCP_PAWS_WINDOW || + !timestamps)) + ret = false; + else + ret = true; + } else { + if (tm && tcp_metric_get(tm, TCP_METRIC_RTT) && tm->tcpm_ts_stamp) + ret = true; + else + ret = false; + } + rcu_read_unlock(); + + return ret; +} +EXPORT_SYMBOL_GPL(tcp_peer_is_proven); + +void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst) +{ + struct tcp_metrics_block *tm; + + rcu_read_lock(); + tm = tcp_get_metrics(sk, dst, true); + if (tm) { + struct tcp_sock *tp = tcp_sk(sk); + + if ((u32)get_seconds() - tm->tcpm_ts_stamp <= TCP_PAWS_MSL) { + tp->rx_opt.ts_recent_stamp = tm->tcpm_ts_stamp; + tp->rx_opt.ts_recent = tm->tcpm_ts; + } + } + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(tcp_fetch_timewait_stamp); + +/* VJ's idea. Save last timestamp seen from this destination and hold + * it at least for normal timewait interval to use for duplicate + * segment detection in subsequent connections, before they enter + * synchronized state. + */ +bool tcp_remember_stamp(struct sock *sk) +{ + struct dst_entry *dst = __sk_dst_get(sk); + bool ret = false; + + if (dst) { + struct tcp_metrics_block *tm; + + rcu_read_lock(); + tm = tcp_get_metrics(sk, dst, true); + if (tm) { + struct tcp_sock *tp = tcp_sk(sk); + + if ((s32)(tm->tcpm_ts - tp->rx_opt.ts_recent) <= 0 || + ((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL && + tm->tcpm_ts_stamp <= (u32)tp->rx_opt.ts_recent_stamp)) { + tm->tcpm_ts_stamp = (u32)tp->rx_opt.ts_recent_stamp; + tm->tcpm_ts = tp->rx_opt.ts_recent; + } + ret = true; + } + rcu_read_unlock(); + } + return ret; +} + +bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw) +{ + struct tcp_metrics_block *tm; + bool ret = false; + + rcu_read_lock(); + tm = __tcp_get_metrics_tw(tw); + if (tm) { + const struct tcp_timewait_sock *tcptw; + struct sock *sk = (struct sock *) tw; + + tcptw = tcp_twsk(sk); + if ((s32)(tm->tcpm_ts - tcptw->tw_ts_recent) <= 0 || + ((u32)get_seconds() - tm->tcpm_ts_stamp > TCP_PAWS_MSL && + tm->tcpm_ts_stamp <= (u32)tcptw->tw_ts_recent_stamp)) { + tm->tcpm_ts_stamp = (u32)tcptw->tw_ts_recent_stamp; + tm->tcpm_ts = tcptw->tw_ts_recent; + } + ret = true; + } + 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, + int *syn_loss, unsigned long *last_syn_loss) +{ + 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; + *syn_loss = tfom->syn_loss; + *last_syn_loss = *syn_loss ? tfom->last_syn_loss : 0; + } 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 = { + .id = GENL_ID_GENERATE, + .hdrsize = 0, + .name = TCP_METRICS_GENL_NAME, + .version = TCP_METRICS_GENL_VERSION, + .maxattr = TCP_METRICS_ATTR_MAX, + .netnsok = true, +}; + +static 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, + tm->tcpm_daddr.addr.a4) < 0) + goto nla_put_failure; + if (nla_put_in_addr(msg, TCP_METRICS_ATTR_SADDR_IPV4, + tm->tcpm_saddr.addr.a4) < 0) + goto nla_put_failure; + break; + case AF_INET6: + if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_ADDR_IPV6, + &tm->tcpm_daddr.addr.in6) < 0) + goto nla_put_failure; + if (nla_put_in6_addr(msg, TCP_METRICS_ATTR_SADDR_IPV6, + &tm->tcpm_saddr.addr.in6) < 0) + goto nla_put_failure; + break; + default: + return -EAFNOSUPPORT; + } + + if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE, + jiffies - tm->tcpm_stamp) < 0) + goto nla_put_failure; + if (tm->tcpm_ts_stamp) { + if (nla_put_s32(msg, TCP_METRICS_ATTR_TW_TS_STAMP, + (s32) (get_seconds() - tm->tcpm_ts_stamp)) < 0) + goto nla_put_failure; + if (nla_put_u32(msg, TCP_METRICS_ATTR_TW_TSVAL, + tm->tcpm_ts) < 0) + goto nla_put_failure; + } + + { + int n = 0; + + nest = nla_nest_start(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) < 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) { + addr->family = AF_INET; + addr->addr.a4 = nla_get_in_addr(a); + if (hash) + *hash = (__force unsigned int) addr->addr.a4; + return 0; + } + a = info->attrs[v6]; + if (a) { + if (nla_len(a) != sizeof(struct in6_addr)) + return -EINVAL; + addr->family = AF_INET6; + addr->addr.in6 = nla_get_in6_addr(a); + if (hash) + *hash = ipv6_addr_hash(&addr->addr.in6); + 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; + spin_lock_bh(&tcp_metrics_lock); + pp = &hb->chain; + for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { + if (net_eq(tm_net(tm), net)) { + *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, + .doit = tcp_metrics_nl_cmd_get, + .dumpit = tcp_metrics_nl_dump, + .policy = tcp_metrics_nl_policy, + }, + { + .cmd = TCP_METRICS_CMD_DEL, + .doit = tcp_metrics_nl_cmd_del, + .policy = tcp_metrics_nl_policy, + .flags = GENL_ADMIN_PERM, + }, +}; + +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 = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); + if (!tcp_metrics_hash) + tcp_metrics_hash = vzalloc(size); + + if (!tcp_metrics_hash) + return -ENOMEM; + + return 0; +} + +static void __net_exit tcp_net_metrics_exit(struct net *net) +{ + tcp_metrics_flush_all(net); +} + +static __net_initdata struct pernet_operations tcp_net_metrics_ops = { + .init = tcp_net_metrics_init, + .exit = tcp_net_metrics_exit, +}; + +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_with_ops(&tcp_metrics_nl_family, + tcp_metrics_nl_ops); + if (ret < 0) + panic("Could not register tcp_metrics generic netlink\n"); +} |