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如何从 Linux 中的 C 程序获取网络接口的类型名称？

我尝试使用getifaddr来访问网络接口，并且得到了我需要的一切，除了它的类型名称。有什么想法可以做到吗？

我还是 Linux 的新手，因此对任何变通方法或示例代码的任何评论都将不胜感激。

编辑

详细说明问题。基本上，在做的时候ifconfig我可以得到这样的东西：

eth0 链路封装：以太网 HWaddr 00:0C:29:40:93:9C
inet 地址：192.168.154.102 广播：192.168.154.255 掩码：255.255.255.0
inet6 地址：fe80::20c:29ff:fe40:939c/64 范围：链接
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX 数据包：14785 错误：0 丢弃：0 超限：0 帧：0
TX 数据包：429 错误：0 丢弃：0 超限：0 运营商：0
碰撞：0 txqueuelen：1000
RX 字节：961439 (938.9 KiB) TX 字节：71866 (70.1 KiB)
中断：67 基地址：0x2000

这是我理解的 eth0 是接口名称。虽然可以有多个网络接口（eth0、eth1、eth2）和多个虚拟接口（tap0、tap1 等）和无线接口，但它们都是以太网接口。

loopbacks 也一样，lo 作为接口名，它的接口是Local Loopback。

所以问题是，当我事先不知道使用了哪些接口以及有多少他们在机器里。

希望我能正确解释这一点。

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5 回答 5

3

You might try to use RTNETLINK from Netlink(1,2). See Manipulating the Networking Environment Using RTNETLINK for an exemple.

于 2012-12-27T10:10:19.687 回答
1

There's no ioctl that returns the link encapsulation, if you strace ifconfig or have a look at its source code you will see that it uses a table look-up to find the name of the link encapsulation. This is from net-tools source code, as you can see the names are statically initialized:

//lib/hw.c
void hwinit()
{
    loop_hwtype.title = _("Local Loopback");
    unspec_hwtype.title = _("UNSPEC");
#if HAVE_HWSLIP
    slip_hwtype.title = _("Serial Line IP");
    cslip_hwtype.title = _("VJ Serial Line IP");
    slip6_hwtype.title = _("6-bit Serial Line IP");
    cslip6_hwtype.title = _("VJ 6-bit Serial Line IP");
    adaptive_hwtype.title = _("Adaptive Serial Line IP");
#endif
#if HAVE_HWETHER
    ether_hwtype.title = _("Ethernet");
#endif
....
于 2012-12-27T10:31:28.397 回答
1

A simple way would be:

cat /sys/class/net/X/type

(where X is your netdev name, e.g. eth0)

Then compare the number to: http://lxr.linux.no/linux+v3.0/include/linux/if_arp.h#L30

for example:

cat /sys/class/net/eth0/type

output:

1

=> where 1=ARPHRD_ETHER accoridng to if_arp.h header file.

于 2012-12-28T02:35:02.910 回答
0

真正广泛的问题。

Under linux the OS itself can be considered a network interface, the so called "loopback interfaces" admit this kind of options and they are "network interfaces" even if they are virtual and not a real piece of hardware they look the same as your PCI network card or your USB dongle. if you are looking for the networking hardware is suggest to take a look at lshw or to spend time studying how the kernel interfaces itself with the networking resources.

于 2012-12-27T09:31:17.457 回答
0

Unrelated to the question but, in case someone wants to find it on the shell here one way to find the wifi interfaces:

for iface in ` ifconfig | cut -f 1 -d ' ' | sort | grep -v '^$'`
do
if [ -d /sys/class/net/$iface/wireless ];then echo $iface ; fi
done
于 2016-02-06T05:10:39.927 回答