Merge branch 'tcp-coalesce-merge-timestamps'
Martin KaFai Lau says:
====================
tcp: Merge timestamp info when coalescing skbs
This series is separated from the RFC series related to
tcp_sendmsg(MSG_EOR) and it is targeting for the net branch.
This patchset is focusing on fixing cases where TCP
timestamp could be lost after coalescing skbs.
A BPF prog is used to kprobe to sock_queue_err_skb()
and print out the value of serr->ee.ee_data. The BPF
prog (run-able from bcc) is attached here:
BPF prog used for testing:
~~~~~
from __future__ import print_function
from bcc import BPF
bpf_text = """
int trace_err_skb(struct pt_regs *ctx)
{
struct sk_buff *skb = (struct sk_buff *)ctx->si;
struct sock *sk = (struct sock *)ctx->di;
struct sock_exterr_skb *serr;
u32 ee_data = 0;
if (!sk || !skb)
return 0;
serr = SKB_EXT_ERR(skb);
bpf_probe_read(&ee_data, sizeof(ee_data), &serr->ee.ee_data);
bpf_trace_printk("ee_data:%u\\n", ee_data);
return 0;
};
"""
b = BPF(text=bpf_text)
b.attach_kprobe(event="sock_queue_err_skb", fn_name="trace_err_skb")
print("Attached to kprobe")
b.trace_print()
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
