supports all ports when target_port is 0

[cfc4n]

当使用pcapng模式时，如果--port参数为0，则支持所有端口的网络包捕获。否则则只捕获--port对应的端口数据。默认是443 端口。

--port默认没有捕获所有网络包，是因为有很多场景，主机的网络流量很大，eBPF的map写入太快，用户空间消费过慢，导致丢包的问题。虽然用户空间在创建eBPF map时，已经申请了BufferSizeOfEbpfMap大的内存，但仍然还存在网络包过多导致数据丢失的可能。 而且，在Android上有内存大小限制，BufferSizeOfEbpfMap的值仅为1024。

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When using pcapng mode, if the --port parameter is set to 0, it supports capturing network packets from all ports. Otherwise, it only captures data from the port corresponding to --port. The default port is 443.

The reason why --port does not capture all network packets by default is that in many scenarios, the host's network traffic is high and eBPF map writes too fast while user space consumption is slow, resulting in packet loss issues. Although user space has already allocated memory of size BufferSizeOfEbpfMap when creating eBPF map, there still exists a problem of data loss due to excessive network packets. Moreover, on Android, there are memory size limitations and the value of BufferSizeOfEbpfMap is only 1024.

	rd, err := perf.NewReader(em, os.Getpagesize()*BufferSizeOfEbpfMap)

[cfc4n]

@Xeonacid Try it.

[Xeonacid]

Thanks! I owe you a beer. :)