Linux下获取CPUID、硬盘序列号与MAC地址

Linux下获取CPUID、硬盘序列号与 MAC地址在很多系统软件的开发中，需要使用一些系统的唯一性信息。

所以，得到主机的CPUID、硬盘序列号及网卡的MAC地址，就成个一件很重要的应用。

本人经过一番google即自己的钻研，基本上实现了这几个功能。

需要的准备知识有：1.GCC的嵌入汇编，具体的GCC嵌入汇编知识，请参考相关手册2.ioctl系统调用，具体的调用方法，请查看手册页获取CPUID按照网上提供的说明，CPUID并不是所有的Intel CPU都支持的。

如果支持，汇编调用为：eax置0000_0003，调用cpuid。

以下为实现代码（在我的CPU上，并没有得到）：#define cpuid(in,a,b,c,d) asm("cpuid": "=a" (a), "=b" (b), "=c" (c), "=d" (d) : "a" (in)); static intgetcpuid (char *id, size_t max){int i;unsigned long li, maxi, maxei, ebx, ecx, edx, unused;cpuid (0, maxi, unused, unused, unused);maxi &= 0xffff;if (maxi < 3){return -1;}cpuid (3, eax, ebx, ecx, edx);snprintf (id, max, "%08lx %08lx %08lx %08lx", eax, ebx, ecx, edx);fprintf (stdout, "get cpu id: %s\n", id);return 0;}获取硬盘序列号这个的实现，采用的是读取/etc/mtab文件，找到/（即根目录）挂载的设备文件，然后打开它，再用系统调用 ioctl来实现的。

ioctl第二个参数为HDIO_GET_IDENTITY, 获得指定文件描述符的标志号ioctl的第三个参数为struct hd_driveid *，在linux/hdreg.h中，struct hd_driveid 的声明有struct hd_driveid {unsigned short config; /* lots of obsolete bit flags */unsigned short cyls; /* Obsolete, "physical" cyls */unsigned short reserved2; /* reserved (word 2) */unsigned short heads; /* Obsolete, "physical" heads */unsigned short track_bytes; /* unformatted bytes per track */unsigned short sector_bytes; /* unformatted bytes per sector */unsigned short sectors; /* Obsolete, "physical" sectors per track */unsigned short vendor0; /* vendor unique */unsigned short vendor1; /* vendor unique */unsigned short vendor2; /* Retired vendor unique */ unsigned char serial_no[20]; /* 0 = not_specified */unsigned short buf_type; /* Retired */unsigned short buf_size; /* Retired, 512 byte increments* 0 = not_specified*/……};，这其中，serial_no为硬盘的序列号。

如果此项为0，则为没有提供。

思路明确了，以下为实现代码：static intgetdiskid (char *id, size_t max){int fd;struct hd_driveid hid;FILE *fp;char line[0x100], *disk, *root, *p;fp = fopen ("/etc/mtab", "r");if (fp == NULL){fprintf (stderr, "No /etc/mtab file.\n");return -1;}fd = -1;while (fgets (line, sizeof line, fp) != NULL){disk = strtok (line, " ");if (disk == NULL){continue;}root = strtok (NULL, " ");if (root == NULL){continue;}if (strcmp (root, "/") == 0){for (p = disk + strlen (disk) - 1; isdigit (*p); p --){*p = '\0';}fd = open (disk, O_RDONLY);break;}}fclose (fp);if (fd < 0){fprintf (stderr, "open hard disk device failed.\n");return -1;}if (ioctl (fd, HDIO_GET_IDENTITY, &hid) < 0){fprintf (stderr, "ioctl error.\n");return -1;}close (fd);snprintf (id, max, "%s", hid.serial_no);fprintf (stdout, "get hard disk serial number: %s\n", id); return 0;}获取MAC地址通过创建一个socket，然后bind特定的IP地址，就可以通过ioctl得到这个套按地绑定的网络接口名称。

然后再通过网络接口名称，得到MAC地址。

如果ioctl的第二个参数为SIOCGIFNAME, 则获得指定网络接口的名称；如果ioctl的第二个参数为SIOCGIFHWADDR，则获得指定网络接口的MAC地址ioctl的第三个参数为struct ifreq *，在linux/if.h头文件里，struct ifreq声明如下：struct ifreq{#define IFHWADDRLEN 6union{char ifrn_name[IFNAMSIZ]; /* if name, e.g. "en0" */} ifr_ifrn;union {struct sockaddr ifru_addr;struct sockaddr ifru_dstaddr;struct sockaddr ifru_broadaddr;struct sockaddr ifru_netmask;struct sockaddr ifru_hwaddr;short ifru_flags;int ifru_ivalue;int ifru_mtu;struct ifmap ifru_map;char ifru_slave[IFNAMSIZ]; /* Just fits the size */char ifru_newname[IFNAMSIZ];void * ifru_data;struct if_settings ifru_settings;} ifr_ifru;}，其中，ifrn_name为网络接口的名称，ifr_ifru.ifru_hwaddr为网络接口的MAC地址。

#ifndef MAX_IFINDEX# define MAX_IFINDEX 8#endifstatic intgetmacaddr (const char *ip, char *id, size_t max){int i, sockfd;struct sockaddr_in *loc;struct ifreq req[1];sockfd = socket (AF_INET, SOCK_DGRAM, 0);if (sockfd < 0){fprintf (stderr, "Unable to create socket.\n");return -1;}for (i = 0; i <= MAX_IFINDEX; ++ i){req->ifr_ifindex = i;if (ioctl (sockfd, SIOCGIFNAME, req) < 0)fprintf (stderr, "ioctl error: %s\n", strerror (errno)); continue;}if (ioctl (sockfd, SIOCGIFADDR, req) < 0)fprintf (stderr, "ioctl interface index [%d] error: %s\n", i, strerror (errno));continue;}loc = (struct sockaddr_in *) (&(req->ifr_ifru.ifru_addr));if (loc->sin_addr.s_addr == inet_addr (ip)){fprintf (stderr, "%s bind at %s.\n", ip, req->ifr_name);break;}}if (i == MAX_IFINDEX){fprintf (stderr, "input IP error.\n");close (sockfd);return -1;}if (ioctl (sockfd, SIOCGIFHWADDR, req) < 0){fprintf (stderr, "ioctl error: %s\n", strerror (errno));close (sockfd);return -1;}close (sockfd);snprintf (id, max, "%02X%02X%02X%02X%02X%02X",req->ifr_hwaddr.sa_data[0] & 0xff,req->ifr_hwaddr.sa_data[1] & 0xff,req->ifr_hwaddr.sa_data[2] & 0xff,req->ifr_hwaddr.sa_data[3] & 0xff,req->ifr_hwaddr.sa_data[4] & 0xff,req->ifr_hwaddr.sa_data[5] & 0xff);fprintf (stdout, "MAC address of %s: [%s].\n", req->ifr_name, id);return 0;}（注：文档可能无法思考全面，请浏览后下载，供参考。