How to obtain (almost) unique system identifier in a cross platform way?
To generate a mostly unique machine id, you can get a few serial numbers from various pieces of hardware on the system. Most processors will have a CPU serial number, the hard disks each have a number, and each network card will have a unique MAC address.
You can get these and build a fingerprint for the machine. You might want to allow some of these numbers to change before declaring it a new machine. ( e.g. if the 2 out of three are the same, then the machine is the same ). So you can deal somewhat gracefully from having a component upgraded.
I've clipped some code from one of my projects that gets these numbers.
Windows:
#include "machine_id.h"
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <intrin.h>
#include <iphlpapi.h>
#ifndef _MSC_VER
#include <cpuid.h>
#else
#include <intrin.h>
#endif
// we just need this for purposes of unique machine id. So any one or two mac's is
// fine.
u16 hashMacAddress( PIP_ADAPTER_INFO info )
{
u16 hash = 0;
for ( u32 i = 0; i < info->AddressLength; i++ )
{
hash += ( info->Address[i] << (( i & 1 ) * 8 ));
}
return hash;
}
void getMacHash( u16& mac1, u16& mac2 )
{
IP_ADAPTER_INFO AdapterInfo[32];
DWORD dwBufLen = sizeof( AdapterInfo );
DWORD dwStatus = GetAdaptersInfo( AdapterInfo, &dwBufLen );
if ( dwStatus != ERROR_SUCCESS )
return; // no adapters.
PIP_ADAPTER_INFO pAdapterInfo = AdapterInfo;
mac1 = hashMacAddress( pAdapterInfo );
if ( pAdapterInfo->Next )
mac2 = hashMacAddress( pAdapterInfo->Next );
// sort the mac addresses. We don't want to invalidate
// both macs if they just change order.
if ( mac1 > mac2 )
{
u16 tmp = mac2;
mac2 = mac1;
mac1 = tmp;
}
}
u16 getVolumeHash()
{
DWORD serialNum = 0;
// Determine if this volume uses an NTFS file system.
GetVolumeInformation( "c:\\", NULL, 0, &serialNum, NULL, NULL, NULL, 0 );
u16 hash = (u16)(( serialNum + ( serialNum >> 16 )) & 0xFFFF );
return hash;
}
u16 getCpuHash()
{
int cpuinfo[4] = { 0, 0, 0, 0 };
__cpuid( cpuinfo, 0 );
u16 hash = 0;
u16* ptr = (u16*)(&cpuinfo[0]);
for ( u32 i = 0; i < 8; i++ )
hash += ptr[i];
return hash;
}
const char* getMachineName()
{
static char computerName[1024];
DWORD size = 1024;
GetComputerName( computerName, &size );
return &(computerName[0]);
}
Linux and OsX:
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/utsname.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <assert.h>
#ifdef DARWIN
#include <net/if_dl.h>
#include <ifaddrs.h>
#include <net/if_types.h>
#else //!DARWIN
// #include <linux/if.h>
// #include <linux/sockios.h>
#endif //!DARWIN
const char* getMachineName()
{
static struct utsname u;
if ( uname( &u ) < 0 )
{
assert(0);
return "unknown";
}
return u.nodename;
}
//---------------------------------get MAC addresses ------------------------------------unsigned short-unsigned short----------
// we just need this for purposes of unique machine id. So any one or two mac's is fine.
unsigned short hashMacAddress( unsigned char* mac )
{
unsigned short hash = 0;
for ( unsigned int i = 0; i < 6; i++ )
{
hash += ( mac[i] << (( i & 1 ) * 8 ));
}
return hash;
}
void getMacHash( unsigned short& mac1, unsigned short& mac2 )
{
mac1 = 0;
mac2 = 0;
#ifdef DARWIN
struct ifaddrs* ifaphead;
if ( getifaddrs( &ifaphead ) != 0 )
return;
// iterate over the net interfaces
bool foundMac1 = false;
struct ifaddrs* ifap;
for ( ifap = ifaphead; ifap; ifap = ifap->ifa_next )
{
struct sockaddr_dl* sdl = (struct sockaddr_dl*)ifap->ifa_addr;
if ( sdl && ( sdl->sdl_family == AF_LINK ) && ( sdl->sdl_type == IFT_ETHER ))
{
if ( !foundMac1 )
{
foundMac1 = true;
mac1 = hashMacAddress( (unsigned char*)(LLADDR(sdl))); //sdl->sdl_data) + sdl->sdl_nlen) );
} else {
mac2 = hashMacAddress( (unsigned char*)(LLADDR(sdl))); //sdl->sdl_data) + sdl->sdl_nlen) );
break;
}
}
}
freeifaddrs( ifaphead );
#else // !DARWIN
int sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP );
if ( sock < 0 ) return;
// enumerate all IP addresses of the system
struct ifconf conf;
char ifconfbuf[ 128 * sizeof(struct ifreq) ];
memset( ifconfbuf, 0, sizeof( ifconfbuf ));
conf.ifc_buf = ifconfbuf;
conf.ifc_len = sizeof( ifconfbuf );
if ( ioctl( sock, SIOCGIFCONF, &conf ))
{
assert(0);
return;
}
// get MAC address
bool foundMac1 = false;
struct ifreq* ifr;
for ( ifr = conf.ifc_req; (char*)ifr < (char*)conf.ifc_req + conf.ifc_len; ifr++ )
{
if ( ifr->ifr_addr.sa_data == (ifr+1)->ifr_addr.sa_data )
continue; // duplicate, skip it
if ( ioctl( sock, SIOCGIFFLAGS, ifr ))
continue; // failed to get flags, skip it
if ( ioctl( sock, SIOCGIFHWADDR, ifr ) == 0 )
{
if ( !foundMac1 )
{
foundMac1 = true;
mac1 = hashMacAddress( (unsigned char*)&(ifr->ifr_addr.sa_data));
} else {
mac2 = hashMacAddress( (unsigned char*)&(ifr->ifr_addr.sa_data));
break;
}
}
}
close( sock );
#endif // !DARWIN
// sort the mac addresses. We don't want to invalidate
// both macs if they just change order.
if ( mac1 > mac2 )
{
unsigned short tmp = mac2;
mac2 = mac1;
mac1 = tmp;
}
}
unsigned short getVolumeHash()
{
// we don't have a 'volume serial number' like on windows. Lets hash the system name instead.
unsigned char* sysname = (unsigned char*)getMachineName();
unsigned short hash = 0;
for ( unsigned int i = 0; sysname[i]; i++ )
hash += ( sysname[i] << (( i & 1 ) * 8 ));
return hash;
}
#ifdef DARWIN
#include <mach-o/arch.h>
unsigned short getCpuHash()
{
const NXArchInfo* info = NXGetLocalArchInfo();
unsigned short val = 0;
val += (unsigned short)info->cputype;
val += (unsigned short)info->cpusubtype;
return val;
}
#else // !DARWIN
static void getCpuid( unsigned int* p, unsigned int ax )
{
__asm __volatile
( "movl %%ebx, %%esi\n\t"
"cpuid\n\t"
"xchgl %%ebx, %%esi"
: "=a" (p[0]), "=S" (p[1]),
"=c" (p[2]), "=d" (p[3])
: "0" (ax)
);
}
unsigned short getCpuHash()
{
unsigned int cpuinfo[4] = { 0, 0, 0, 0 };
getCpuid( cpuinfo, 0 );
unsigned short hash = 0;
unsigned int* ptr = (&cpuinfo[0]);
for ( unsigned int i = 0; i < 4; i++ )
hash += (ptr[i] & 0xFFFF) + ( ptr[i] >> 16 );
return hash;
}
#endif // !DARWIN
int main()
{
printf("Machine: %s\n", getMachineName());
printf("CPU: %d\n", getCpuHash());
printf("Volume: %d\n", getVolumeHash());
return 0;
}
I know, the question is bit too old to be answered. But I have on many occasions faced this issue. I like the accept solution, but if you have tried the code then you will know that it has issues.
firstly the CPU id is the product ID- it is not the serial. So if you have same CPU in another Server then it is just not going to work. also the MAC Address can be changed with ease.
If you are only trying to get this done on Linux- you could try like hal services. ie.
hal-get-property --udi /org/freedesktop/Hal/devices/computer --key system.hardware.uuid
But best thing probably to do is if you can enforce root access and if you want to get your hands dirty- is to look at the code for dmidecode. It will allow you to extract UUID of Chasis, Bios, Video and System. You cannot beat that :) and with a few tweaking you can convert it to a class.