emmerik@utrcu1.UUCP (Emmerik P.J.L. van) (12/11/90)
Wanted: a way of obtaining a unique identifier for a SUN-workstation
from a program.
On some systems we use the ethernet address of a workstation as a unique
identifier, but on some, like SUN Sparcstations and DEC-stations running
Ultrix this does not seem to work.
The method we use works as follows:
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_arp.h>
int sock, st;
struct sock_addr_in sin, *parp_pa;
struct arpreq arpreq;
struct hostent *hp;
char chxx[200];
/* Create a socket */
sock = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
/* Set the Internet address for the request */
parp_pa = (struct sockaddr_in *)&arpreq.arp_pa;
parp_pa->sin_family = AF_INET;
parp_pa->sin_port = 0;
gethostname( chxx, 199 );
hp = gethostbyname( chxx );
parp_pa->sin_addr.s_addr = *(u_long *)hp->hp_addr;
/* Set the type of the requested address */
arpreq.arp_ha.sa_family = AF_UNSPEC;
/* Get the ethernet address */
st = ioctl( sock, SIOCGARP, (caddr_t)&arpreq )
if ( st< 0 )
{
perror( "ioctl" );
}
close( sock );
}
I have left some details, like error handling out.
This program will result in a message from perror:
ioctl: No such device or address
i.e. ERRNO = 6
Two questions:
- am i doing something wrong, if so what should i do?
- is there maybe another way of obtaining a uniqiue identifier,
e.g. a SUN specific routine to get a CPU-id?
Pleace send responces to emmerik@utwente.nl
--
Pieter van Emmerik | Phone: +31-74-483059
Hollandse Signaalapparaten b.v. | FAX: +31-74-425936
P.O.box 42 | E-mail: emmerik@utwente.nl
7550 GD Hengelo, The Netherlands | hp4nl!utrcu1!emmerikmjr@hussar.dco.dec.com (Marcus J. Ranum) (12/11/90)
In article <747@utrcu1.UUCP> emmerik@utrcu1.UUCP (Emmerik P.J.L. van) writes: > >Wanted: a way of obtaining a unique identifier for a SUN-workstation > from a program. > >On some systems we use the ethernet address of a workstation as a unique >identifier The Sun has a unique host id#, unless I'm mistaken. Take a look at the man page on "hostid" or something like that. Using the ethernet address as a unique identifier is questionably unique, since it can be changed with ioctl()s on some machines (which is what DECnet does). At least it guarantees that only one machine at a time on a local network will use that number, though. mjr. -- I'd trade all the CASE tools in the world for one real programmer. [From the programming notebooks of a heretic, 1990]
paquette@cs-sun-fsd.cpsc.ucalgary.ca (Trevor Paquette) (12/12/90)
Try using the hostid, gethostid(2).
--
______________________________________/Through the darkness, the future past,
Trevor Paquette ICBM:51'03"N/114'05"W|The magician longs to see.
{ubc-cs,utai,alberta}!calgary!paquette|One chants out, between two worlds,
paquette@cpsc.ucalgary.ca |"Fire, walk with me."cliffs@sunrock.East.Sun.COM (Clifford C. Skolnick) (12/14/90)
In article <747@utrcu1.UUCP> emmerik@utrcu1.UUCP (Emmerik P.J.L. van) writes: > >Wanted: a way of obtaining a unique identifier for a SUN-workstation > from a program. gethostid() will do the trick you want. Cliff -- Cliff Skolnick | "You give me the reason, you give me control. cliffs@sun.com | I gave you my purity, my purity you stole. Am I (716) 385-5049 | just too stupid to realize stale incense old sweat I think. I am. | and lies lies lies." -- Nine Inch Nails