获取一个socket的相关信息。

tcp_info.py

import socket 
import cStringIO
import struct 

def parse_struct(b, fmt): 
    d = {}
    fmts = "".join([x[1] for x in fmt])
    raw = b.read(struct.calcsize(fmts)) 
    raw = struct.unpack(fmts, raw)   
    for i, item in enumerate(fmt):
        d[item[0]]= raw[i]
    return d 

tcp_info = (
        ("state", "B"),
        ("ca_state", "B"),
        ("retransmits", "B"),
        ("probes", "B"),
        ("backoff", "B"),
        ("options", "B"),
        ("snd_wscale", "B"),

        ("rto", "I"),
        ("ato", "I"),
        ("snd_mss", "I"),
        ("rcv_mss", "I"),
        
        ("unpacked", "I"),
        ("sacked", "I"),
        ("lost", "I"),
        ("retrans", "I"),
        ("fackets", "I"),

        ("last_data_sent", "I"),
        ("last_ack_sent", "I"),
        ("last_data_recv", "I"),
        ("last_ack_recv", "I"),

        ("mtu", "I"),
        ("rcv_ssthresh", "I"),
        ("rtt", "I"),
        ("rttvar", "I"),
        ("snd_ssthresh", "I"),
        ("snd_cwnd", "I"),
        ("advmss", "I"),
        ("reordering", "I"),

        ("rcv_rtt", "I"),
        ("rcv_space", "I"),
        ("total_retrans", "I") 
    )

def get_tcp_info(sock): 
    size = struct.calcsize("".join([x[1] for x in tcp_info])) 
    raw = sock.getsockopt(socket.IPPROTO_TCP, socket.TCP_INFO, size)
    info = parse_struct(cStringIO.StringIO(raw), tcp_info)
    info["rcv_wscale"] = info["snd_wscale"] & 0xf
    info["snd_wscale"] >>= 4
    return info