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authorJulian Anastasov <ja@ssi.bg>2012-09-04 11:03:15 +0000
committerDavid S. Miller <davem@davemloft.net>2012-09-05 15:15:02 -0400
commitd23ff701643a4a725e2c7a8ba2d567d39daa29ea (patch)
tree039dbda9d59c1e18df6a89f600226924d452fbed /net/ipv4/tcp_metrics.c
parentab868256f8d6095e7200d928fcc054b66d0f13a3 (diff)
downloadlinux-stericsson-d23ff701643a4a725e2c7a8ba2d567d39daa29ea.tar.gz
tcp: add generic netlink support for tcp_metrics
Add support for genl "tcp_metrics". No locking is changed, only that now we can unlink and delete entries after grace period. We implement get/del for single entry and dump to support show/flush filtering in user space. Del without address attribute causes flush for all addresses, sadly under genl_mutex. v2: - remove rcu_assign_pointer as suggested by Eric Dumazet, it is not needed because there are no other writes under lock - move the flushing code in tcp_metrics_flush_all v3: - remove synchronize_rcu on flush as suggested by Eric Dumazet Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_metrics.c')
-rw-r--r--net/ipv4/tcp_metrics.c354
1 files changed, 341 insertions, 13 deletions
diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 0abe67bb4d3a..988edb63ee73 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -8,6 +8,7 @@
#include <linux/init.h>
#include <linux/tcp.h>
#include <linux/hash.h>
+#include <linux/tcp_metrics.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,
@@ -690,6 +683,325 @@ 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).pid, 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(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)
{
@@ -753,5 +1065,21 @@ 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;
}