我使用 socat 1.7.3.1-r0
并在一个 alpine 3.3
的 Linux 服务器上运行以下命令:
socat -d -d -d PTY,link=/dev/ttyFOOBAR,echo=0,raw,unlink-close=0 TCP-LISTEN:7000,forever,reuseaddr
Socat
会监听客户端,并通过TCP将虚拟串口/dev/ttyFOOBAR
的数据传递给客户端,同时接收客户端的数据并传递回虚拟串口。当客户端断开连接后,socat
应该退出。
当连接建立时,socat将记录以下内容:
I socat by Gerhard Rieger - see www.dest-unreach.org
I This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit. (http://www.openssl.org/)
I This product includes software written by Tim Hudson (tjh@cryptsoft.com)
I setting option "symbolic-link" to "/dev/ttyFOOBAR"
I setting option "echo" to 0
I setting option "raw"
I setting option "unlink-close" to 0
I openpty({5}, {6}, {"/dev/pts/3"},,) -> 0
N PTY is /dev/pts/3
I setting option "forever" to 1
I setting option "so-reuseaddr" to 1
I socket(2, 1, 6) -> 7
I starting accept loop
N listening on AF=2 0.0.0.0:7000
I accept(7, {2, AF=2 CLIENT_IP:PORT}, 16) -> 8
N accepting connection from AF=2 CLIENT_IP:PORT on AF=2 172.20.0.2:7000
I permitting connection from AF=2 CLIENT_IP:PORT
I close(7)
I resolved and opened all sock addresses
N starting data transfer loop with FDs [5,5] and [8,8]
服务器上的ss
命令会输出以下内容:
Netid State Recv-Q Send-Q Local Address:Port Peer Address:Port
tcp ESTAB 0 0 172.20.0.2:7000 CLIENT_IP:PORT
问题是,当我断开客户端(关闭它)时,TCP连接仍然建立,并且没有来自socat的附加日志。
ss
仍显示连接为ESTAB。有什么想法吗?当我再次连接客户端时,以下内容出现在日志中:W read(8, 0x7fa8f48c4020, 8192): Connection reset by peer
N socket 2 to socket 1 is in error
N socket 2 (fd 8) is at EOF
I poll timed out (no data within 0.500000 seconds)
I close(5)
I shutdown(8, 2)
I shutdown(8, 2): Socket not connected
N exiting with status 0
但为什么这会在连接时发生而不是断开连接时发生呢?
socat
正在使用端口 5000。ss
在端口 7000 上报告了其他内容。 - user207421