Anita-ctrl / mnl-demos

Linux libmnl库函数的初学者使用指南

libmnl样例代码

1. 使用libmnl向Linux内核查询各网卡接口的IP地址. demo-1 目录下的样例代码源自:

• https://git.netfilter.org/libmnl/tree/examples/rtnl/rtnl-addr-dump.c

引用的内核头文件

• 头文件<uapi/linux/if_addr.h> 其中包含结构体struct ifaddrmsg以及IFA_ADDRESS/IFA_MAX的定义:

struct ifaddrmsg {
	__u8		ifa_family;
	__u8		ifa_prefixlen;	/* The prefix length		*/
	__u8		ifa_flags;	/* Flags			*/
	__u8		ifa_scope;	/* Address scope		*/
	__u32		ifa_index;	/* Link index			*/
};

enum {
	IFA_UNSPEC,
	IFA_ADDRESS,
	IFA_LOCAL,
	IFA_LABEL,
	IFA_BROADCAST,
	IFA_ANYCAST,
	IFA_CACHEINFO,
	IFA_MULTICAST,
	IFA_FLAGS,
	IFA_RT_PRIORITY,  /* u32, priority/metric for prefix route */
	IFA_TARGET_NETNSID,
	__IFA_MAX,
};


#define IFA_MAX (__IFA_MAX - 1)