awk: hping:打印icmp发起/接收之间的差异

Question

我在OpenBSD上有以下来自hping的输出：

# hping --icmp-ts www.openbsd.org
HPING www.openbsd.org (re0 129.128.5.194): icmp mode set, 28 headers + 0 data bytes
len=46 ip=129.128.5.194 ttl=237 id=23807 icmp_seq=0 rtt=155.3 ms
ICMP timestamp: Originate=22085077 Receive=22085171 Transmit=22085171
ICMP timestamp RTT tsrtt=156

len=46 ip=129.128.5.194 ttl=237 id=4150 icmp_seq=1 rtt=154.8 ms
ICMP timestamp: Originate=22086078 Receive=22086171 Transmit=22086171
ICMP timestamp RTT tsrtt=155

^C
--- www.openbsd.org hping statistic ---
2 packets tramitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 154.8/155.0/155.3 ms

我需要一些额外的算术to troubleshoot asymmetric routes，就像a patch in some bugreport中提供的那样，但我不想重新编译软件。

TL;DR，这两个新字段被计算为Receive − Originate和Originate + tsrtt − Transmit，结果如下所示(不必跨越4行)。

len=46 ip=129.128.5.194 ttl=237 id=23807 icmp_seq=0 rtt=155.3 ms
ICMP timestamp: Originate=22085077 Receive=22085171 Transmit=22085171
ICMP timestamp RTT tsrtt=156  src->dst=94  dst->src=62

如何使用awk实现这一点？(我也可以使用任何其他*BSD工具。)

Answer 1

使用perl，您可以这样做：

#!/usr/bin/perl -n
#
if (/Originate=(\d+) Receive=(\d+) Transmit=(\d+)/) {
    ($o, $r, $t) = ($1, $2, $3);
} elsif (/tsrtt=(\d+)/) {
    print $r - $o, " ", $o + $1 - $t, "\n";
}

如果你调用这个icmpstats.pl，你可以使用as hping | perl icmpstats.pl。

Answer 2

对janos的解决方案进行了修改，以提供可用的代码片段。

请注意，当重定向到管道时，hping的输出变得完全缓冲，这在解决方案的可移植性方面非常令人惊讶。参见https://unix.stackexchange.com/questions/25372/turn-off-buffering-in-pipe和https://unix.stackexchange.com/questions/102403/turn-off-buffering-for-hping-in-openbsd。

在安装expect软件包后，以下命令可在OpenBSD上运行：

unbuffer hping --icmp-ts ntp1.yycix.ca \
| perl -ne 'if (/icmp_seq=(\d+) rtt=(\d+\.\d)/) {($s, $p) = ($1, $2);} \
if (/ate=(\d+) Receive=(\d+) Transmit=(\d+)/) {($o, $r, $t) = ($1, $2, $3);} \
if (/tsrtt=(\d+)/) { \
print $s, "\t", $p, "\t", $1, " = ", $r - $o, " + ", $o + $1 - $t, "\n"; }'

由于OS X的expect不附带unbuffer，因此在OS X上需要安装以下程序

script -q /dev/null hping3 --icmp-ts ntp1.yycix.ca \
| perl -ne 'if (/icmp_seq=(\d+) rtt=(\d+\.\d)/) {($s, $p) = ($1, $2);} \
if (/ate=(\d+) Receive=(\d+) Transmit=(\d+)/) {($o, $r, $t) = ($1, $2, $3);} \
if (/tsrtt=(\d+)/) { \
print $s, "\t", $p, "\t", $1, " = ", $r - $o, " + ", $o + $1 - $t, "\r\n"; }'

这是脚本的示例输出，它显示前向路径拥塞，而返回路径很可能不拥塞：

0       145.5   146 = 75 + 71
1       142.7   142 = 72 + 70
2       140.7   140 = 70 + 70
3       146.7   146 = 76 + 70
4       148.3   148 = 77 + 71
5       157.5   157 = 87 + 70
6       167.1   167 = 96 + 71
7       166.3   166 = 95 + 71
8       167.7   167 = 97 + 70
9       159.0   159 = 88 + 71
10      156.7   156 = 86 + 70
11      154.9   155 = 84 + 71
12      151.9   152 = 81 + 71
13      157.3   157 = 86 + 71
14      155.0   155 = 84 + 71
15      157.7   158 = 87 + 71
16      156.6   156 = 86 + 70
17      157.8   158 = 87 + 71
18      161.9   162 = 91 + 71
19      160.1   160 = 89 + 71
20      166.3   166 = 95 + 71
21      163.9   164 = 93 + 71
22      172.0   172 = 101 + 71
23      177.9   178 = 107 + 71
24      177.0   177 = 106 + 71
25      172.1   172 = 101 + 71
26      167.4   167 = 97 + 70
27      167.1   167 = 96 + 71
28      161.0   161 = 90 + 71
29      150.5   150 = 80 + 70
30      155.6   155 = 85 + 70
31      162.0   162 = 91 + 71
32      154.3   154 = 84 + 70

​

请注意，如果时钟不同步，那么您将变为负值，尽管如此，这仍然可以很好地指示哪一端正在经历拥塞。

​

下面的示例是通过相同的路径；请注意一个值仍然随机上下移动，而另一个值单调变化。

0       165.9   166 = -142113 + 142279
1       160.2   160 = -142118 + 142278
2       155.2   155 = -142122 + 142277
3       156.5   156 = -142121 + 142277
4       164.7   165 = -142112 + 142277
5       164.4   164 = -142111 + 142275
6       160.9   161 = -142114 + 142275
7       158.1   158 = -142117 + 142275
8       155.6   156 = -142119 + 142275
9       143.0   143 = -142131 + 142274
10      153.2   153 = -142120 + 142273
11      157.1   157 = -142115 + 142272
12      158.3   158 = -142114 + 142272
13      148.6   149 = -142123 + 142272
14      144.3   144 = -142127 + 142271
15      145.3   145 = -142125 + 142270
16      141.9   142 = -142128 + 142270