| #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 */ |
| 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; |
| 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 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) |
| { |
| const struct in6_addr *a6, *b6; |
| |
| if (a->family != b->family) |
| return false; |
| if (a->family == AF_INET) |
| return a->addr.a4 == b->addr.a4; |
| |
| a6 = (const struct in6_addr *) &a->addr.a6[0]; |
| b6 = (const struct in6_addr *) &b->addr.a6[0]; |
| |
| return ipv6_addr_equal(a6, b6); |
| } |
| |
| struct tcpm_hash_bucket { |
| struct tcp_metrics_block __rcu *chain; |
| }; |
| |
| 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.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 |
| |
| 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 = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); |
| for (tm = rcu_dereference(oldest->tcpm_next); tm; |
| tm = rcu_dereference(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; |
| } |
| tm->tcpm_saddr = *saddr; |
| tm->tcpm_daddr = *daddr; |
| |
| tcpm_suck_dst(tm, dst, true); |
| |
| if (likely(!reclaim)) { |
| tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain; |
| rcu_assign_pointer(net->ipv4.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(net->ipv4.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)) |
| 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: |
| *(struct in6_addr *)saddr.addr.a6 = inet_rsk(req)->ir_v6_loc_addr; |
| *(struct in6_addr *)daddr.addr.a6 = 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 = hash_32(hash, net->ipv4.tcp_metrics_hash_log); |
| |
| for (tm = rcu_dereference(net->ipv4.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)) |
| 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; |
| *(struct in6_addr *)saddr.addr.a6 = tw->tw_v6_rcv_saddr; |
| daddr.family = AF_INET6; |
| *(struct in6_addr *)daddr.addr.a6 = tw->tw_v6_daddr; |
| hash = ipv6_addr_hash(&tw->tw_v6_daddr); |
| } |
| } |
| #endif |
| else |
| return NULL; |
| |
| net = twsk_net(tw); |
| hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log); |
| |
| for (tm = rcu_dereference(net->ipv4.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)) |
| 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; |
| *(struct in6_addr *)saddr.addr.a6 = sk->sk_v6_rcv_saddr; |
| daddr.family = AF_INET6; |
| *(struct in6_addr *)daddr.addr.a6 = sk->sk_v6_daddr; |
| hash = ipv6_addr_hash(&sk->sk_v6_daddr); |
| } |
| } |
| #endif |
| else |
| return NULL; |
| |
| net = dev_net(dst->dev); |
| hash = hash_32(hash, net->ipv4.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 == NULL) |
| 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) |
| { |
| 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) |
| 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; |
| *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) |
| { |
| 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; |
| 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_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4, |
| tm->tcpm_daddr.addr.a4) < 0) |
| goto nla_put_failure; |
| if (nla_put_be32(msg, TCP_METRICS_ATTR_SADDR_IPV4, |
| tm->tcpm_saddr.addr.a4) < 0) |
| goto nla_put_failure; |
| break; |
| case AF_INET6: |
| if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16, |
| tm->tcpm_daddr.addr.a6) < 0) |
| goto nla_put_failure; |
| if (nla_put(msg, TCP_METRICS_ATTR_SADDR_IPV6, 16, |
| tm->tcpm_saddr.addr.a6) < 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; |
| |
| return genlmsg_end(skb, hdr); |
| |
| 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 << net->ipv4.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 = net->ipv4.tcp_metrics_hash + row; |
| |
| rcu_read_lock(); |
| for (col = 0, tm = rcu_dereference(hb->chain); tm; |
| tm = rcu_dereference(tm->tcpm_next), col++) { |
| 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_be32(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; |
| memcpy(addr->addr.a6, nla_data(a), sizeof(addr->addr.a6)); |
| if (hash) |
| *hash = ipv6_addr_hash((struct in6_addr *) addr->addr.a6); |
| 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 = hash_32(hash, net->ipv4.tcp_metrics_hash_log); |
| ret = -ESRCH; |
| rcu_read_lock(); |
| for (tm = rcu_dereference(net->ipv4.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))) { |
| 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; |
| } |
| |
| #define deref_locked_genl(p) \ |
| rcu_dereference_protected(p, lockdep_genl_is_held() && \ |
| lockdep_is_held(&tcp_metrics_lock)) |
| |
| #define deref_genl(p) rcu_dereference_protected(p, lockdep_genl_is_held()) |
| |
| static int tcp_metrics_flush_all(struct net *net) |
| { |
| unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log; |
| struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash; |
| struct tcp_metrics_block *tm; |
| unsigned int row; |
| |
| for (row = 0; row < max_rows; row++, hb++) { |
| spin_lock_bh(&tcp_metrics_lock); |
| tm = deref_locked_genl(hb->chain); |
| if (tm) |
| hb->chain = NULL; |
| spin_unlock_bh(&tcp_metrics_lock); |
| while (tm) { |
| struct tcp_metrics_block *next; |
| |
| next = deref_genl(tm->tcpm_next); |
| kfree_rcu(tm, rcu_head); |
| tm = next; |
| } |
| } |
| return 0; |
| } |
| |
| 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) |
| return tcp_metrics_flush_all(net); |
| ret = parse_nl_saddr(info, &saddr); |
| if (ret < 0) |
| src = false; |
| |
| hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log); |
| hb = net->ipv4.tcp_metrics_hash + hash; |
| pp = &hb->chain; |
| spin_lock_bh(&tcp_metrics_lock); |
| for (tm = deref_locked_genl(*pp); tm; tm = deref_locked_genl(*pp)) { |
| if (addr_same(&tm->tcpm_daddr, &daddr) && |
| (!src || addr_same(&tm->tcpm_saddr, &saddr))) { |
| *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; |
| |
| slots = tcpmhash_entries; |
| if (!slots) { |
| if (totalram_pages >= 128 * 1024) |
| slots = 16 * 1024; |
| else |
| slots = 8 * 1024; |
| } |
| |
| net->ipv4.tcp_metrics_hash_log = order_base_2(slots); |
| size = sizeof(struct tcpm_hash_bucket) << net->ipv4.tcp_metrics_hash_log; |
| |
| net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL | __GFP_NOWARN); |
| if (!net->ipv4.tcp_metrics_hash) |
| net->ipv4.tcp_metrics_hash = vzalloc(size); |
| |
| if (!net->ipv4.tcp_metrics_hash) |
| return -ENOMEM; |
| |
| return 0; |
| } |
| |
| static void __net_exit tcp_net_metrics_exit(struct net *net) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < (1U << net->ipv4.tcp_metrics_hash_log) ; i++) { |
| struct tcp_metrics_block *tm, *next; |
| |
| tm = rcu_dereference_protected(net->ipv4.tcp_metrics_hash[i].chain, 1); |
| while (tm) { |
| next = rcu_dereference_protected(tm->tcpm_next, 1); |
| kfree(tm); |
| tm = next; |
| } |
| } |
| kvfree(net->ipv4.tcp_metrics_hash); |
| } |
| |
| 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) |
| goto cleanup; |
| ret = genl_register_family_with_ops(&tcp_metrics_nl_family, |
| tcp_metrics_nl_ops); |
| if (ret < 0) |
| goto cleanup_subsys; |
| return; |
| |
| cleanup_subsys: |
| unregister_pernet_subsys(&tcp_net_metrics_ops); |
| |
| cleanup: |
| return; |
| } |