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linux/include/trace/events/tcp.h

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tcp: add a tracepoint for tcp retransmission We need a real-time notification for tcp retransmission for monitoring. Of course we could use ftrace to dynamically instrument this kernel function too, however we can't retrieve the connection information at the same time, for example perf-tools [1] reads /proc/net/tcp for socket details, which is slow when we have a lots of connections. Therefore, this patch adds a tracepoint for __tcp_retransmit_skb() and exposes src/dst IP addresses and ports of the connection. This also makes it easier to integrate into perf. Note, I expose both IPv4 and IPv6 addresses at the same time: for a IPv4 socket, v4 mapped address is used as IPv6 addresses, for a IPv6 socket, LOOPBACK4_IPV6 is already filled by kernel. Also, add sk and skb pointers as they are useful for BPF. 1. https://github.com/brendangregg/perf-tools/blob/master/net/tcpretrans Cc: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Brendan Gregg <bgregg@netflix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13 13:03:16 -07:00
#undef TRACE_SYSTEM
#define TRACE_SYSTEM tcp
#if !defined(_TRACE_TCP_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_TCP_H
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/tracepoint.h>
#include <net/ipv6.h>
TRACE_EVENT(tcp_retransmit_skb,
TP_PROTO(struct sock *sk, struct sk_buff *skb),
TP_ARGS(sk, skb),
TP_STRUCT__entry(
__field(void *, skbaddr)
__field(void *, skaddr)
__field(__u16, sport)
__field(__u16, dport)
__array(__u8, saddr, 4)
__array(__u8, daddr, 4)
__array(__u8, saddr_v6, 16)
__array(__u8, daddr_v6, 16)
),
TP_fast_assign(
struct ipv6_pinfo *np = inet6_sk(sk);
struct inet_sock *inet = inet_sk(sk);
struct in6_addr *pin6;
__be32 *p32;
__entry->skbaddr = skb;
__entry->skaddr = sk;
__entry->sport = ntohs(inet->inet_sport);
__entry->dport = ntohs(inet->inet_dport);
p32 = (__be32 *) __entry->saddr;
*p32 = inet->inet_saddr;
p32 = (__be32 *) __entry->daddr;
*p32 = inet->inet_daddr;
if (np) {
pin6 = (struct in6_addr *)__entry->saddr_v6;
*pin6 = np->saddr;
pin6 = (struct in6_addr *)__entry->daddr_v6;
*pin6 = *(np->daddr_cache);
} else {
pin6 = (struct in6_addr *)__entry->saddr_v6;
ipv6_addr_set_v4mapped(inet->inet_saddr, pin6);
pin6 = (struct in6_addr *)__entry->daddr_v6;
ipv6_addr_set_v4mapped(inet->inet_daddr, pin6);
}
),
tcp: Use pI6c in tcp tracepoint The compact form for IPv6 addresses is more user friendly than the full version. For example: compact: 2001:db8:1::1 full: 2001:0db8:0001:0000:0000:0000:0000:0004i Update the tcp tracepoint to show the compact form. Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16 14:24:02 -07:00
TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c",
tcp: add a tracepoint for tcp retransmission We need a real-time notification for tcp retransmission for monitoring. Of course we could use ftrace to dynamically instrument this kernel function too, however we can't retrieve the connection information at the same time, for example perf-tools [1] reads /proc/net/tcp for socket details, which is slow when we have a lots of connections. Therefore, this patch adds a tracepoint for __tcp_retransmit_skb() and exposes src/dst IP addresses and ports of the connection. This also makes it easier to integrate into perf. Note, I expose both IPv4 and IPv6 addresses at the same time: for a IPv4 socket, v4 mapped address is used as IPv6 addresses, for a IPv6 socket, LOOPBACK4_IPV6 is already filled by kernel. Also, add sk and skb pointers as they are useful for BPF. 1. https://github.com/brendangregg/perf-tools/blob/master/net/tcpretrans Cc: Eric Dumazet <edumazet@google.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Brendan Gregg <bgregg@netflix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13 13:03:16 -07:00
__entry->sport, __entry->dport, __entry->saddr, __entry->daddr,
__entry->saddr_v6, __entry->daddr_v6)
);
#endif /* _TRACE_TCP_H */
/* This part must be outside protection */
#include <trace/define_trace.h>
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