1/* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.org> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 * 9 */ 10 11#include <sys/cdefs.h> 12__FBSDID("$FreeBSD: src/lib/libc/gen/sysctlbyname.c,v 1.5 2002/02/01 00:57:29 obrien Exp $"); 13 14#include <sys/types.h> 15#include <sys/sysctl.h> 16#include <string.h> 17#include <sys/errno.h> 18#include <TargetConditionals.h> 19 20extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, 21 void *newp, size_t newlen); 22extern int 23__sysctlbyname(const char *name, size_t namelen, void *oldp, size_t *oldlenp, void *newp, 24 size_t newlen); 25 26int 27sysctlbyname(const char *name, void *oldp, size_t *oldlenp, void *newp, 28 size_t newlen) 29{ 30 int name2oid_oid[2]; 31 int real_oid[CTL_MAXNAME+2]; 32 int error; 33 size_t oidlen; 34 35#if !TARGET_IPHONE_SIMULATOR 36 /* Try primary system call first, fall back if not supported */ 37 error = __sysctlbyname(name, strlen(name), oldp, oldlenp, newp, newlen); 38 if ((error == 0) || (errno != ENOSYS)) 39 return error; 40#endif /* !TARGET_IPHONE_SIMULATOR */ 41 42 name2oid_oid[0] = 0; /* This is magic & undocumented! */ 43 name2oid_oid[1] = 3; 44 45 oidlen = sizeof(real_oid); 46 error = __sysctl(name2oid_oid, 2, real_oid, &oidlen, (void *)name, 47 strlen(name)); 48 if (error < 0) 49 return error; 50 oidlen /= sizeof (int); 51 error = __sysctl(real_oid, oidlen, oldp, oldlenp, newp, newlen); 52 return (error); 53} 54 55