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Diffstat (limited to 'net/ipv4/tcp_metrics.c')
-rw-r--r--net/ipv4/tcp_metrics.c425
1 files changed, 378 insertions, 47 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 0abe67bb4d3a..52f3c6b971d2 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -1,13 +1,14 @@
#include <linux/rcupdate.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
-#include <linux/bootmem.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>
@@ -17,20 +18,10 @@
#include <net/ipv6.h>
#include <net/dst.h>
#include <net/tcp.h>
+#include <net/genetlink.h>
int sysctl_tcp_nometrics_save __read_mostly;
-enum tcp_metric_index {
- TCP_METRIC_RTT,
- TCP_METRIC_RTTVAR,
- TCP_METRIC_SSTHRESH,
- TCP_METRIC_CWND,
- TCP_METRIC_REORDERING,
-
- /* Always last. */
- TCP_METRIC_MAX,
-};
-
struct tcp_fastopen_metrics {
u16 mss;
u16 syn_loss:10; /* Recurring Fast Open SYN losses */
@@ -45,8 +36,10 @@ struct tcp_metrics_block {
u32 tcpm_ts;
u32 tcpm_ts_stamp;
u32 tcpm_lock;
- u32 tcpm_vals[TCP_METRIC_MAX];
+ u32 tcpm_vals[TCP_METRIC_MAX + 1];
struct tcp_fastopen_metrics tcpm_fastopen;
+
+ struct rcu_head rcu_head;
};
static bool tcp_metric_locked(struct tcp_metrics_block *tm,
@@ -103,7 +96,8 @@ struct tcpm_hash_bucket {
static DEFINE_SPINLOCK(tcp_metrics_lock);
-static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst)
+static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst,
+ bool fastopen_clear)
{
u32 val;
@@ -129,9 +123,11 @@ static void tcpm_suck_dst(struct tcp_metrics_block *tm, struct dst_entry *dst)
tm->tcpm_vals[TCP_METRIC_REORDERING] = dst_metric_raw(dst, RTAX_REORDERING);
tm->tcpm_ts = 0;
tm->tcpm_ts_stamp = 0;
- tm->tcpm_fastopen.mss = 0;
- tm->tcpm_fastopen.syn_loss = 0;
- tm->tcpm_fastopen.cookie.len = 0;
+ if (fastopen_clear) {
+ tm->tcpm_fastopen.mss = 0;
+ tm->tcpm_fastopen.syn_loss = 0;
+ tm->tcpm_fastopen.cookie.len = 0;
+ }
}
static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
@@ -161,7 +157,7 @@ static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
}
tm->tcpm_addr = *addr;
- tcpm_suck_dst(tm, dst);
+ tcpm_suck_dst(tm, dst, true);
if (likely(!reclaim)) {
tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
@@ -178,7 +174,7 @@ out_unlock:
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);
+ tcpm_suck_dst(tm, dst, false);
}
#define TCP_METRICS_RECLAIM_DEPTH 5
@@ -447,7 +443,7 @@ 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;
+ u32 val, crtt = 0; /* cached RTT scaled by 8 */
if (dst == NULL)
goto reset;
@@ -482,15 +478,19 @@ void tcp_init_metrics(struct sock *sk)
tp->reordering = val;
}
- val = tcp_metric_get(tm, TCP_METRIC_RTT);
- if (val == 0 || tp->srtt == 0) {
- rcu_read_unlock();
- goto reset;
- }
- /* Initial rtt is determined from SYN,SYN-ACK.
- * The segment is small and rtt may appear much
- * less than real one. Use per-dst memory
- * to make it more realistic.
+ crtt = tcp_metric_get_jiffies(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
@@ -501,21 +501,11 @@ void tcp_init_metrics(struct sock *sk)
* to low value, and then abruptly stops to do it and starts to delay
* ACKs, wait for troubles.
*/
- val = msecs_to_jiffies(val);
- if (val > tp->srtt) {
- tp->srtt = val;
- tp->rtt_seq = tp->snd_nxt;
- }
- val = tcp_metric_get_jiffies(tm, TCP_METRIC_RTTVAR);
- if (val > tp->mdev) {
- tp->mdev = val;
- tp->mdev_max = tp->rttvar = max(tp->mdev, tcp_rto_min(sk));
- }
- rcu_read_unlock();
-
- tcp_set_rto(sk);
-reset:
- if (tp->srtt == 0) {
+ if (crtt > tp->srtt) {
+ /* Set RTO like tcp_rtt_estimator(), but from cached RTT. */
+ crtt >>= 3;
+ inet_csk(sk)->icsk_rto = crtt + max(2 * crtt, tcp_rto_min(sk));
+ } else if (tp->srtt == 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
@@ -690,6 +680,325 @@ void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
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_addr.family) {
+ case AF_INET:
+ if (nla_put_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4,
+ tm->tcpm_addr.addr.a4) < 0)
+ goto nla_put_failure;
+ break;
+ case AF_INET6:
+ if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16,
+ tm->tcpm_addr.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 + 1; i++) {
+ if (!tm->tcpm_vals[i])
+ continue;
+ if (nla_put_u32(msg, i + 1, tm->tcpm_vals[i]) < 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)
+{
+ struct nlattr *a;
+
+ a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV4];
+ if (a) {
+ addr->family = AF_INET;
+ addr->addr.a4 = nla_get_be32(a);
+ *hash = (__force unsigned int) addr->addr.a4;
+ return 0;
+ }
+ a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV6];
+ 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));
+ *hash = ipv6_addr_hash((struct in6_addr *) addr->addr.a6);
+ return 0;
+ }
+ return optional ? 1 : -EAFNOSUPPORT;
+}
+
+static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
+{
+ struct tcp_metrics_block *tm;
+ struct inetpeer_addr addr;
+ unsigned int hash;
+ struct sk_buff *msg;
+ struct net *net = genl_info_net(info);
+ void *reply;
+ int ret;
+
+ ret = parse_nl_addr(info, &addr, &hash, 0);
+ if (ret < 0)
+ return ret;
+
+ 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_addr, &addr)) {
+ 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 addr;
+ unsigned int hash;
+ struct net *net = genl_info_net(info);
+ int ret;
+
+ ret = parse_nl_addr(info, &addr, &hash, 1);
+ if (ret < 0)
+ return ret;
+ if (ret > 0)
+ return tcp_metrics_flush_all(net);
+
+ 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;
+ pp = &tm->tcpm_next, tm = deref_locked_genl(*pp)) {
+ if (addr_same(&tm->tcpm_addr, &addr)) {
+ *pp = tm->tcpm_next;
+ break;
+ }
+ }
+ spin_unlock_bh(&tcp_metrics_lock);
+ if (!tm)
+ return -ESRCH;
+ kfree_rcu(tm, rcu_head);
+ return 0;
+}
+
+static 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,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .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)
{
@@ -722,7 +1031,10 @@ static int __net_init tcp_net_metrics_init(struct net *net)
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);
+ 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;
@@ -743,7 +1055,10 @@ static void __net_exit tcp_net_metrics_exit(struct net *net)
tm = next;
}
}
- kfree(net->ipv4.tcp_metrics_hash);
+ if (is_vmalloc_addr(net->ipv4.tcp_metrics_hash))
+ vfree(net->ipv4.tcp_metrics_hash);
+ else
+ kfree(net->ipv4.tcp_metrics_hash);
}
static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
@@ -753,5 +1068,21 @@ static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
void __init tcp_metrics_init(void)
{
- register_pernet_subsys(&tcp_net_metrics_ops);
+ 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,
+ ARRAY_SIZE(tcp_metrics_nl_ops));
+ if (ret < 0)
+ goto cleanup_subsys;
+ return;
+
+cleanup_subsys:
+ unregister_pernet_subsys(&tcp_net_metrics_ops);
+
+cleanup:
+ return;
}
generated by cgit (git 2.34.1) at 2025-08-13 02:48:13 +0000