tcp: Add skb addr and sock addr to arguments of tracepoint tcp_probe.

It is useful to expose skb addr and sock addr to user in tracepoint
tcp_probe, so that we can get more information while monitoring
receiving of tcp data, by ebpf or other ways.

For example, we need to identify a packet by seq and end_seq when
calculate transmit latency between layer 2 and layer 4 by ebpf, but which is
not available in tcp_probe, so we can only use kprobe hooking
tcp_rcv_established to get them. But we can use tcp_probe directly if skb
addr and sock addr are available, which is more efficient.

Signed-off-by: fuyuanli <fuyuanli@didiglobal.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
index 6ca3e0343666446873aea8a33fba28ca962d524d..699dafd204eadfe5a4d702d66fd8359dac31d950 100644 (file)
--- a/include/trace/events/tcp.h
+++ b/include/trace/events/tcp.h
@@ -259,6 +259,8 @@ TRACE_EVENT(tcp_probe,
                __field(__u32, srtt)
                __field(__u32, rcv_wnd)
                __field(__u64, sock_cookie)
+               __field(const void *, skbaddr)
+               __field(const void *, skaddr)
        ),
 
        TP_fast_assign(
@@ -286,14 +288,18 @@ TRACE_EVENT(tcp_probe,
                __entry->ssthresh = tcp_current_ssthresh(sk);
                __entry->srtt = tp->srtt_us >> 3;
                __entry->sock_cookie = sock_gen_cookie(sk);
+
+               __entry->skbaddr = skb;
+               __entry->skaddr = sk;
        ),
 
-       TP_printk("family=%s src=%pISpc dest=%pISpc mark=%#x data_len=%d snd_nxt=%#x snd_una=%#x snd_cwnd=%u ssthresh=%u snd_wnd=%u srtt=%u rcv_wnd=%u sock_cookie=%llx",
+       TP_printk("family=%s src=%pISpc dest=%pISpc mark=%#x data_len=%d snd_nxt=%#x snd_una=%#x snd_cwnd=%u ssthresh=%u snd_wnd=%u srtt=%u rcv_wnd=%u sock_cookie=%llx skbaddr=%p skaddr=%p",
                  show_family_name(__entry->family),
                  __entry->saddr, __entry->daddr, __entry->mark,
                  __entry->data_len, __entry->snd_nxt, __entry->snd_una,
                  __entry->snd_cwnd, __entry->ssthresh, __entry->snd_wnd,
-                 __entry->srtt, __entry->rcv_wnd, __entry->sock_cookie)
+                 __entry->srtt, __entry->rcv_wnd, __entry->sock_cookie,
+                 __entry->skbaddr, __entry->skaddr)
 );
 
 #define TP_STORE_ADDR_PORTS_SKB_V4(__entry, skb)                       \