python - 为什么 pcap_dispatch 只返回 1 个数据包？

Question

为什么pcap_dispatch(count=10)只返回1个数据包？

如果我不执行任何操作，它会等待，然后显示 1 个数据包，但如果我单击链接，它会立即停止并显示 1 个数据包。

我是否应该有这样的循环？:

for i in range(0,10):
        p.dispatch(10, savePacket)

这是Python，但我在C中遇到了同样的问题。

Answer 1

来自手册页:

       pcap_dispatch() processes packets from a live capture or ``savefile'' until       cnt  packets  are processed, the end of the current bufferful of packets is       reached when doing a live capture, the end of the ``savefile''  is  reached       when  reading  from a ``savefile'', pcap_breakloop() is called, or an error       occurs.  Thus, when doing a live capture, cnt  is  the  maximum  number  of       packets  to  process  before  returning,  but is not a minimum number; when       reading a live capture, only one bufferful of packets is read at a time, so       fewer  than cnt packets may be processed. A value of -1 or 0 for cnt causes       all the packets received in one buffer to be processed when reading a  live       capture,  and causes all the packets in the file to be processed when read‐       ing a ``savefile''.

请注意下面的内容:“可以处理的数据包数量少于 cnt” - 也就是说，这取决于 pcap 实现的作用。

关于 Python 的注释:我不知道 python 实现的作用是什么，但在 C 中，无论如何都会为每个数据包调用一次回调。