要求：需要使用 C 语言中的 TCP 套接字编程从通过 wifi 连接的两个设备发送和接收消息。
客户端套接字接收连接失败。我可以使用相同的 C 语言套接字程序通过 USB 连接相同的客户端。以下是配置详细信息。
两个 IP 位于同一子网。
系统：Ubuntu 14.04 防火墙：已禁用
abhishek@vidyut:~$sudo ufw status
Status: inactive
客户端配置详情：
root@swi-mdm9x15:~# ifconfig
eth0 Link encap:Ethernet HWaddr 2A:DF:53:54:15:A2
inet addr:192.168.17.1 Bcast:192.168.17.255 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:125 errors:0 dropped:0 overruns:0 frame:0
TX packets:125 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:8851 (8.6 KiB) TX bytes:8851 (8.6 KiB)
rmnet0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet addr:100.81.198.219 Mask:255.255.255.248
inet6 addr: fe80::a5e8:cd72:5a0:d0ab/64 Scope:Link
UP RUNNING MTU:1430 Metric:1
RX packets:29 errors:0 dropped:0 overruns:0 frame:0
TX packets:38 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3394 (3.3 KiB) TX bytes:3912 (3.8 KiB)
usb0 Link encap:Ethernet HWaddr BE:B3:25:7B:2A:D1
inet addr:192.168.2.2 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::bcb3:25ff:fe7b:2ad1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:185 errors:0 dropped:0 overruns:0 frame:0
TX packets:87 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:19533 (19.0 KiB) TX bytes:11725 (11.4 KiB)
wlan0 Link encap:Ethernet HWaddr 7C:DD:90:CB:FE:1D
inet addr:**192.168.1.4** Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::7edd:90ff:fecb:fe1d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:2004 (1.9 KiB)
root@swi-mdm9x15:~#
==============================================================
服务器端配置详细信息：
abhishek@vidyut:~$ifconfig
eth0 Link encap:Ethernet HWaddr d0:bf:9c:05:bd:65
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:23702 errors:0 dropped:0 overruns:0 frame:0
TX packets:23702 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:1997818 (1.9 MB) TX bytes:1997818 (1.9 MB)
usb0 Link encap:Ethernet HWaddr 02:a5:2c:72:e1:95
inet addr:192.168.2.3 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::a5:2cff:fe72:e195/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:520 errors:0 dropped:0 overruns:0 frame:0
TX packets:652 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:286008 (286.0 KB) TX bytes:66095 (66.0 KB)
wlan0 Link encap:Ethernet HWaddr 74:29:af:18:6a:e9
inet addr:**192.168.1.32** Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::7629:afff:fe18:6ae9/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:137395 errors:0 dropped:0 overruns:0 frame:0
TX packets:81588 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:107297162 (107.2 MB) TX bytes:15416536 (15.4 MB)