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>
This commit is contained in:
Julian Anastasov
David S. Miller
parent
ab868256f8
commit
d23ff70164
@ -363,6 +363,7 @@ header-y += sysctl.h
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header-y += sysinfo.h
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header-y += taskstats.h
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header-y += tcp.h
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header-y += tcp_metrics.h
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header-y += telephony.h
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header-y += termios.h
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header-y += time.h
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54
include/linux/tcp_metrics.h
Normal file
54
include/linux/tcp_metrics.h
Normal file
@ -0,0 +1,54 @@
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/* tcp_metrics.h - TCP Metrics Interface */
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#ifndef _LINUX_TCP_METRICS_H
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#define _LINUX_TCP_METRICS_H
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#include <linux/types.h>
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/* NETLINK_GENERIC related info
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*/
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#define TCP_METRICS_GENL_NAME "tcp_metrics"
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#define TCP_METRICS_GENL_VERSION 0x1
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enum tcp_metric_index {
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TCP_METRIC_RTT,
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TCP_METRIC_RTTVAR,
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TCP_METRIC_SSTHRESH,
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TCP_METRIC_CWND,
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TCP_METRIC_REORDERING,
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/* Always last. */
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__TCP_METRIC_MAX,
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};
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#define TCP_METRIC_MAX (__TCP_METRIC_MAX - 1)
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enum {
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TCP_METRICS_ATTR_UNSPEC,
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TCP_METRICS_ATTR_ADDR_IPV4, /* u32 */
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TCP_METRICS_ATTR_ADDR_IPV6, /* binary */
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TCP_METRICS_ATTR_AGE, /* msecs */
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TCP_METRICS_ATTR_TW_TSVAL, /* u32, raw, rcv tsval */
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TCP_METRICS_ATTR_TW_TS_STAMP, /* s32, sec age */
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TCP_METRICS_ATTR_VALS, /* nested +1, u32 */
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TCP_METRICS_ATTR_FOPEN_MSS, /* u16 */
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TCP_METRICS_ATTR_FOPEN_SYN_DROPS, /* u16, count of drops */
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TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS, /* msecs age */
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TCP_METRICS_ATTR_FOPEN_COOKIE, /* binary */
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__TCP_METRICS_ATTR_MAX,
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};
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#define TCP_METRICS_ATTR_MAX (__TCP_METRICS_ATTR_MAX - 1)
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enum {
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TCP_METRICS_CMD_UNSPEC,
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TCP_METRICS_CMD_GET,
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TCP_METRICS_CMD_DEL,
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__TCP_METRICS_CMD_MAX,
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};
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#define TCP_METRICS_CMD_MAX (__TCP_METRICS_CMD_MAX - 1)
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#endif /* _LINUX_TCP_METRICS_H */
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@ -8,6 +8,7 @@
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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 <net/inet_connection_sock.h>
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#include <net/net_namespace.h>
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@ -17,20 +18,10 @@
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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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int sysctl_tcp_nometrics_save __read_mostly;
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enum tcp_metric_index {
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TCP_METRIC_RTT,
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TCP_METRIC_RTTVAR,
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TCP_METRIC_SSTHRESH,
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TCP_METRIC_CWND,
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TCP_METRIC_REORDERING,
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/* Always last. */
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TCP_METRIC_MAX,
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};
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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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@ -45,8 +36,10 @@ struct tcp_metrics_block {
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u32 tcpm_ts;
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u32 tcpm_ts_stamp;
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u32 tcpm_lock;
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u32 tcpm_vals[TCP_METRIC_MAX];
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u32 tcpm_vals[TCP_METRIC_MAX + 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 bool tcp_metric_locked(struct tcp_metrics_block *tm,
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@ -690,6 +683,325 @@ void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
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rcu_read_unlock();
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}
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static struct genl_family tcp_metrics_nl_family = {
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.id = GENL_ID_GENERATE,
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.hdrsize = 0,
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.name = TCP_METRICS_GENL_NAME,
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.version = TCP_METRICS_GENL_VERSION,
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.maxattr = TCP_METRICS_ATTR_MAX,
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.netnsok = true,
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};
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static struct nla_policy tcp_metrics_nl_policy[TCP_METRICS_ATTR_MAX + 1] = {
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[TCP_METRICS_ATTR_ADDR_IPV4] = { .type = NLA_U32, },
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[TCP_METRICS_ATTR_ADDR_IPV6] = { .type = NLA_BINARY,
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.len = sizeof(struct in6_addr), },
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/* Following attributes are not received for GET/DEL,
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* we keep them for reference
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*/
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#if 0
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[TCP_METRICS_ATTR_AGE] = { .type = NLA_MSECS, },
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[TCP_METRICS_ATTR_TW_TSVAL] = { .type = NLA_U32, },
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[TCP_METRICS_ATTR_TW_TS_STAMP] = { .type = NLA_S32, },
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[TCP_METRICS_ATTR_VALS] = { .type = NLA_NESTED, },
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[TCP_METRICS_ATTR_FOPEN_MSS] = { .type = NLA_U16, },
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[TCP_METRICS_ATTR_FOPEN_SYN_DROPS] = { .type = NLA_U16, },
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[TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS] = { .type = NLA_MSECS, },
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[TCP_METRICS_ATTR_FOPEN_COOKIE] = { .type = NLA_BINARY,
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.len = TCP_FASTOPEN_COOKIE_MAX, },
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#endif
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};
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/* Add attributes, caller cancels its header on failure */
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static int tcp_metrics_fill_info(struct sk_buff *msg,
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struct tcp_metrics_block *tm)
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{
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struct nlattr *nest;
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int i;
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switch (tm->tcpm_addr.family) {
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case AF_INET:
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if (nla_put_be32(msg, TCP_METRICS_ATTR_ADDR_IPV4,
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tm->tcpm_addr.addr.a4) < 0)
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goto nla_put_failure;
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break;
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case AF_INET6:
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if (nla_put(msg, TCP_METRICS_ATTR_ADDR_IPV6, 16,
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tm->tcpm_addr.addr.a6) < 0)
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goto nla_put_failure;
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break;
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default:
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return -EAFNOSUPPORT;
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}
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if (nla_put_msecs(msg, TCP_METRICS_ATTR_AGE,
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jiffies - tm->tcpm_stamp) < 0)
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goto nla_put_failure;
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if (tm->tcpm_ts_stamp) {
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if (nla_put_s32(msg, TCP_METRICS_ATTR_TW_TS_STAMP,
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(s32) (get_seconds() - tm->tcpm_ts_stamp)) < 0)
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goto nla_put_failure;
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if (nla_put_u32(msg, TCP_METRICS_ATTR_TW_TSVAL,
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tm->tcpm_ts) < 0)
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goto nla_put_failure;
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}
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{
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int n = 0;
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nest = nla_nest_start(msg, TCP_METRICS_ATTR_VALS);
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if (!nest)
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goto nla_put_failure;
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for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
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if (!tm->tcpm_vals[i])
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continue;
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if (nla_put_u32(msg, i + 1, tm->tcpm_vals[i]) < 0)
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goto nla_put_failure;
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n++;
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}
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if (n)
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nla_nest_end(msg, nest);
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else
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nla_nest_cancel(msg, nest);
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}
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{
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struct tcp_fastopen_metrics tfom_copy[1], *tfom;
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unsigned int seq;
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do {
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seq = read_seqbegin(&fastopen_seqlock);
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tfom_copy[0] = tm->tcpm_fastopen;
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} while (read_seqretry(&fastopen_seqlock, seq));
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tfom = tfom_copy;
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if (tfom->mss &&
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nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_MSS,
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tfom->mss) < 0)
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goto nla_put_failure;
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if (tfom->syn_loss &&
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(nla_put_u16(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROPS,
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tfom->syn_loss) < 0 ||
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nla_put_msecs(msg, TCP_METRICS_ATTR_FOPEN_SYN_DROP_TS,
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jiffies - tfom->last_syn_loss) < 0))
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goto nla_put_failure;
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if (tfom->cookie.len > 0 &&
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nla_put(msg, TCP_METRICS_ATTR_FOPEN_COOKIE,
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tfom->cookie.len, tfom->cookie.val) < 0)
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goto nla_put_failure;
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}
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int tcp_metrics_dump_info(struct sk_buff *skb,
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struct netlink_callback *cb,
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struct tcp_metrics_block *tm)
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{
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void *hdr;
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hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
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&tcp_metrics_nl_family, NLM_F_MULTI,
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TCP_METRICS_CMD_GET);
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if (!hdr)
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return -EMSGSIZE;
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if (tcp_metrics_fill_info(skb, tm) < 0)
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goto nla_put_failure;
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return genlmsg_end(skb, hdr);
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nla_put_failure:
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genlmsg_cancel(skb, hdr);
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return -EMSGSIZE;
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}
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static int tcp_metrics_nl_dump(struct sk_buff *skb,
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struct netlink_callback *cb)
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{
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struct net *net = sock_net(skb->sk);
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unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
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unsigned int row, s_row = cb->args[0];
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int s_col = cb->args[1], col = s_col;
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for (row = s_row; row < max_rows; row++, s_col = 0) {
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struct tcp_metrics_block *tm;
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struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash + row;
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rcu_read_lock();
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for (col = 0, tm = rcu_dereference(hb->chain); tm;
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tm = rcu_dereference(tm->tcpm_next), col++) {
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if (col < s_col)
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continue;
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if (tcp_metrics_dump_info(skb, cb, tm) < 0) {
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rcu_read_unlock();
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goto done;
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}
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}
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rcu_read_unlock();
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}
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done:
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cb->args[0] = row;
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cb->args[1] = col;
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return skb->len;
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}
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static int parse_nl_addr(struct genl_info *info, struct inetpeer_addr *addr,
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unsigned int *hash, int optional)
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{
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struct nlattr *a;
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a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV4];
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if (a) {
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addr->family = AF_INET;
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addr->addr.a4 = nla_get_be32(a);
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*hash = (__force unsigned int) addr->addr.a4;
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return 0;
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}
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a = info->attrs[TCP_METRICS_ATTR_ADDR_IPV6];
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if (a) {
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if (nla_len(a) != sizeof(sizeof(struct in6_addr)))
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return -EINVAL;
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addr->family = AF_INET6;
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memcpy(addr->addr.a6, nla_data(a), sizeof(addr->addr.a6));
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*hash = ipv6_addr_hash((struct in6_addr *) addr->addr.a6);
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return 0;
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}
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return optional ? 1 : -EAFNOSUPPORT;
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}
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static int tcp_metrics_nl_cmd_get(struct sk_buff *skb, struct genl_info *info)
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{
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struct tcp_metrics_block *tm;
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struct inetpeer_addr addr;
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unsigned int hash;
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struct sk_buff *msg;
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struct net *net = genl_info_net(info);
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void *reply;
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int ret;
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ret = parse_nl_addr(info, &addr, &hash, 0);
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if (ret < 0)
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return ret;
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msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
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if (!msg)
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return -ENOMEM;
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reply = genlmsg_put_reply(msg, info, &tcp_metrics_nl_family, 0,
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info->genlhdr->cmd);
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if (!reply)
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goto nla_put_failure;
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hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
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ret = -ESRCH;
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rcu_read_lock();
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for (tm = rcu_dereference(net->ipv4.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_addr, &addr)) {
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ret = tcp_metrics_fill_info(msg, tm);
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break;
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}
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}
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rcu_read_unlock();
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if (ret < 0)
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goto out_free;
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genlmsg_end(msg, reply);
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return genlmsg_reply(msg, info);
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nla_put_failure:
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ret = -EMSGSIZE;
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out_free:
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nlmsg_free(msg);
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return ret;
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}
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#define deref_locked_genl(p) \
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rcu_dereference_protected(p, lockdep_genl_is_held() && \
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lockdep_is_held(&tcp_metrics_lock))
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#define deref_genl(p) rcu_dereference_protected(p, lockdep_genl_is_held())
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static int tcp_metrics_flush_all(struct net *net)
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{
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unsigned int max_rows = 1U << net->ipv4.tcp_metrics_hash_log;
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struct tcpm_hash_bucket *hb = net->ipv4.tcp_metrics_hash;
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struct tcp_metrics_block *tm;
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unsigned int row;
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for (row = 0; row < max_rows; row++, hb++) {
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spin_lock_bh(&tcp_metrics_lock);
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tm = deref_locked_genl(hb->chain);
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if (tm)
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hb->chain = NULL;
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spin_unlock_bh(&tcp_metrics_lock);
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while (tm) {
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struct tcp_metrics_block *next;
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next = deref_genl(tm->tcpm_next);
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kfree_rcu(tm, rcu_head);
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tm = next;
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}
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}
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return 0;
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}
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static int tcp_metrics_nl_cmd_del(struct sk_buff *skb, struct genl_info *info)
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{
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struct tcpm_hash_bucket *hb;
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struct tcp_metrics_block *tm;
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struct tcp_metrics_block __rcu **pp;
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struct inetpeer_addr addr;
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unsigned int hash;
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struct net *net = genl_info_net(info);
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int ret;
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ret = parse_nl_addr(info, &addr, &hash, 1);
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if (ret < 0)
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return ret;
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if (ret > 0)
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return tcp_metrics_flush_all(net);
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hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
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hb = net->ipv4.tcp_metrics_hash + hash;
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pp = &hb->chain;
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spin_lock_bh(&tcp_metrics_lock);
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for (tm = deref_locked_genl(*pp); tm;
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pp = &tm->tcpm_next, tm = deref_locked_genl(*pp)) {
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if (addr_same(&tm->tcpm_addr, &addr)) {
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*pp = tm->tcpm_next;
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break;
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}
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}
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spin_unlock_bh(&tcp_metrics_lock);
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if (!tm)
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return -ESRCH;
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kfree_rcu(tm, rcu_head);
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return 0;
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}
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static struct genl_ops tcp_metrics_nl_ops[] = {
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{
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.cmd = TCP_METRICS_CMD_GET,
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.doit = tcp_metrics_nl_cmd_get,
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.dumpit = tcp_metrics_nl_dump,
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.policy = tcp_metrics_nl_policy,
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.flags = GENL_ADMIN_PERM,
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},
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{
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.cmd = TCP_METRICS_CMD_DEL,
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.doit = tcp_metrics_nl_cmd_del,
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.policy = tcp_metrics_nl_policy,
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.flags = GENL_ADMIN_PERM,
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},
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};
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static unsigned int tcpmhash_entries;
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static int __init set_tcpmhash_entries(char *str)
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{
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@ -753,5 +1065,21 @@ static __net_initdata struct pernet_operations tcp_net_metrics_ops = {
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void __init tcp_metrics_init(void)
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{
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register_pernet_subsys(&tcp_net_metrics_ops);
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int ret;
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ret = register_pernet_subsys(&tcp_net_metrics_ops);
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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;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user