我正在使用Ubuntu系统。如何在C程序中获取我的计算机或某个接口(如eth0)的MAC地址?
相较于所有的套接字或shell繁琐,更好的方法是使用sysfs来完成此操作:
位于/sys/class/net/eth0/address
的文件作为一个简单字符串包含着您的MAC地址,只需使用fopen()
/fscanf()
/fclose()
即可读取。这再简单不过了。
如果您想要支持除eth0以外的其他网络接口(您可能需要这么做),那么只需要对/sys/class/net/
使用opendir()
/readdir()
/closedir()
即可。
您需要遍历计算机上所有可用的接口,并使用带有SIOCGIFHWADDR
标志的ioctl
来获取MAC地址。 MAC地址将作为一个6字节的二进制数组获得。 您还需要跳过回环接口。
#include <sys/ioctl.h>
#include <net/if.h>
#include <unistd.h>
#include <netinet/in.h>
#include <string.h>
int main()
{
struct ifreq ifr;
struct ifconf ifc;
char buf[1024];
int success = 0;
int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
if (sock == -1) { /* handle error*/ };
ifc.ifc_len = sizeof(buf);
ifc.ifc_buf = buf;
if (ioctl(sock, SIOCGIFCONF, &ifc) == -1) { /* handle error */ }
struct ifreq* it = ifc.ifc_req;
const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));
for (; it != end; ++it) {
strcpy(ifr.ifr_name, it->ifr_name);
if (ioctl(sock, SIOCGIFFLAGS, &ifr) == 0) {
if (! (ifr.ifr_flags & IFF_LOOPBACK)) { // don't count loopback
if (ioctl(sock, SIOCGIFHWADDR, &ifr) == 0) {
success = 1;
break;
}
}
}
else { /* handle error */ }
}
unsigned char mac_address[6];
if (success) memcpy(mac_address, ifr.ifr_hwaddr.sa_data, 6);
}
您想查看getifaddrs(3)手册页。该页中有一个C语言的示例代码可以使用。您需要获取类型为AF_LINK
的地址。
AF_LINK
。也许这已被 AF_PACKET
取代? - mpromonet#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/if.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
int main()
{
struct ifreq s;
int fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
strcpy(s.ifr_name, "eth0");
if (0 == ioctl(fd, SIOCGIFHWADDR, &s)) {
int i;
for (i = 0; i < 6; ++i)
printf(" %02x", (unsigned char) s.ifr_addr.sa_data[i]);
puts("\n");
return 0;
}
return 1;
}
AF_PACKET
中获取MAC地址。为了显示每个接口的MAC地址,您可以按如下方式进行:#include <stdio.h>
#include <ifaddrs.h>
#include <netpacket/packet.h>
int main (int argc, const char * argv[])
{
struct ifaddrs *ifaddr=NULL;
struct ifaddrs *ifa = NULL;
int i = 0;
if (getifaddrs(&ifaddr) == -1)
{
perror("getifaddrs");
}
else
{
for ( ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next)
{
if ( (ifa->ifa_addr) && (ifa->ifa_addr->sa_family == AF_PACKET) )
{
struct sockaddr_ll *s = (struct sockaddr_ll*)ifa->ifa_addr;
printf("%-8s ", ifa->ifa_name);
for (i=0; i <s->sll_halen; i++)
{
printf("%02x%c", (s->sll_addr[i]), (i+1!=s->sll_halen)?':':'\n');
}
}
}
freeifaddrs(ifaddr);
}
return 0;
}
我刚刚在VirtualBox上安装了Gentoo并测试了一个程序。
// get_mac.c
#include <stdio.h> //printf
#include <string.h> //strncpy
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h> //ifreq
#include <unistd.h> //close
int main()
{
int fd;
struct ifreq ifr;
char *iface = "enp0s3";
unsigned char *mac = NULL;
memset(&ifr, 0, sizeof(ifr));
fd = socket(AF_INET, SOCK_DGRAM, 0);
ifr.ifr_addr.sa_family = AF_INET;
strncpy(ifr.ifr_name , iface , IFNAMSIZ-1);
if (0 == ioctl(fd, SIOCGIFHWADDR, &ifr)) {
mac = (unsigned char *)ifr.ifr_hwaddr.sa_data;
//display mac address
printf("Mac : %.2X:%.2X:%.2X:%.2X:%.2X:%.2X\n" , mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
}
close(fd);
return 0;
}
#include <cstdint>
#include <fstream>
#include <streambuf>
#include <regex>
using namespace std;
uint64_t getIFMAC(const string &ifname) {
ifstream iface("/sys/class/net/" + ifname + "/address");
string str((istreambuf_iterator<char>(iface)), istreambuf_iterator<char>());
if (str.length() > 0) {
string hex = regex_replace(str, std::regex(":"), "");
return stoull(hex, 0, 16);
} else {
return 0;
}
}
int main()
{
string iface = "eth0";
printf("%s: mac=%016llX\n", iface.c_str(), getIFMAC(iface));
}
在Linux上,可以通过DBus使用“Network Manager”服务。
还有一个古老的shell程序,可以调用并获取结果(在C语言中使用exec函数):
$ /sbin/ifconfig | grep HWaddr
ifconfig | awk '$0 ~ /HWaddr/ { print $5 }'
如果当前用户有权限运行ifconfig(通常是可以的),并且已安装awk(通常也是这样),则可以提供此操作。这将为您提供机器的MAC地址。
ifconfig
命令的输出中不包含“HWaddr”文本。 - dreamlaxifconfig
命令,完全不可移植。 - totten在 @user175104 给出的答案上进行扩展...
std::vector<std::string> GetAllFiles(const std::string& folder, bool recursive = false)
{
// uses opendir, readdir, and struct dirent.
// left as an exercise to the reader, as it isn't the point of this OP and answer.
}
bool ReadFileContents(const std::string& folder, const std::string& fname, std::string& contents)
{
// uses ifstream to read entire contents
// left as an exercise to the reader, as it isn't the point of this OP and answer.
}
std::vector<std::string> GetAllMacAddresses()
{
std::vector<std::string> macs;
std::string address;
// from: https://dev59.com/ll_Va4cB1Zd3GeqPWsIx
// ... just read /sys/class/net/eth0/address
// NOTE: there may be more than one: /sys/class/net/*/address
// (1) so walk /sys/class/net/* to find the names to read the address of.
std::vector<std::string> nets = GetAllFiles("/sys/class/net/", false);
for (auto it = nets.begin(); it != nets.end(); ++it)
{
// we don't care about the local loopback interface
if (0 == strcmp((*it).substr(-3).c_str(), "/lo"))
continue;
address.clear();
if (ReadFileContents(*it, "address", address))
{
if (!address.empty())
{
macs.push_back(address);
}
}
}
return macs;
}