1144091Sdas/*- 2144091Sdas * Copyright (c) 1980, 1992, 1993 3144091Sdas * The Regents of the University of California. All rights reserved. 4144091Sdas * 5144091Sdas * Redistribution and use in source and binary forms, with or without 6144091Sdas * modification, are permitted provided that the following conditions 7144091Sdas * are met: 8144091Sdas * 1. Redistributions of source code must retain the above copyright 9144091Sdas * notice, this list of conditions and the following disclaimer. 10144091Sdas * 2. Redistributions in binary form must reproduce the above copyright 11144091Sdas * notice, this list of conditions and the following disclaimer in the 12144091Sdas * documentation and/or other materials provided with the distribution. 13144091Sdas * 4. Neither the name of the University nor the names of its contributors 14144091Sdas * may be used to endorse or promote products derived from this software 15144091Sdas * without specific prior written permission. 16144091Sdas * 17144091Sdas * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18144091Sdas * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19144091Sdas * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20144091Sdas * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21144091Sdas * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22144091Sdas * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23144091Sdas * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24144091Sdas * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25144091Sdas * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26144091Sdas * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27144091Sdas * SUCH DAMAGE. 28144091Sdas */ 29144091Sdas 30144091Sdas#include <sys/cdefs.h> 31144091Sdas 32144091Sdas__FBSDID("$FreeBSD$"); 33144091Sdas 34144091Sdas#ifdef lint 35144091Sdasstatic const char sccsid[] = "@(#)fetch.c 8.1 (Berkeley) 6/6/93"; 36144091Sdas#endif 37144091Sdas 38144091Sdas#include <sys/types.h> 39144091Sdas#include <sys/sysctl.h> 40144091Sdas 41144091Sdas#include <err.h> 42144091Sdas#include <errno.h> 43144091Sdas#include <stdlib.h> 44144091Sdas#include <string.h> 45144091Sdas 46144091Sdas#include "systat.h" 47144091Sdas#include "extern.h" 48144091Sdas 49144091Sdasint 50144091Sdaskvm_ckread(void *a, void *b, int l) 51144091Sdas{ 52144091Sdas if (kvm_read(kd, (u_long)a, b, l) != l) { 53144091Sdas if (verbose) 54144091Sdas error("error reading kmem at %p", a); 55144091Sdas return (0); 56144091Sdas } 57144091Sdas else 58144091Sdas return (1); 59144091Sdas} 60144091Sdas 61144091Sdasvoid getsysctl(const char *name, void *ptr, size_t len) 62144091Sdas{ 63192760Sattilio size_t nlen = len; 64217108Skib if (sysctlbyname(name, ptr, &nlen, NULL, 0) != 0) { 65217108Skib error("sysctl(%s...) failed: %s", name, 66 strerror(errno)); 67 } 68 if (nlen != len) { 69 error("sysctl(%s...) expected %lu, got %lu", name, 70 (unsigned long)len, (unsigned long)nlen); 71 } 72} 73 74/* 75 * Read sysctl data with variable size. Try some times (with increasing 76 * buffers), fail if still too small. 77 * This is needed sysctls with possibly raplidly increasing data sizes, 78 * but imposes little overhead in the case of constant sizes. 79 * Returns NULL on error, or a pointer to freshly malloc()'ed memory that holds 80 * the requested data. 81 * If szp is not NULL, the size of the returned data will be written into *szp. 82 */ 83 84/* Some defines: Number of tries. */ 85#define SD_NTRIES 10 86/* Percent of over-allocation (initial) */ 87#define SD_MARGIN 10 88/* 89 * Factor for over-allocation in percent (the margin is increased by this on 90 * any failed try). 91 */ 92#define SD_FACTOR 50 93/* Maximum supported MIB depth */ 94#define SD_MAXMIB 16 95 96char * 97sysctl_dynread(const char *n, size_t *szp) 98{ 99 char *rv = NULL; 100 int mib[SD_MAXMIB]; 101 size_t mibsz = SD_MAXMIB; 102 size_t mrg = SD_MARGIN; 103 size_t sz; 104 int i; 105 106 /* cache the MIB */ 107 if (sysctlnametomib(n, mib, &mibsz) == -1) { 108 if (errno == ENOMEM) { 109 error("XXX: SD_MAXMIB too small, please bump!"); 110 } 111 return NULL; 112 } 113 for (i = 0; i < SD_NTRIES; i++) { 114 /* get needed buffer size */ 115 if (sysctl(mib, mibsz, NULL, &sz, NULL, 0) == -1) 116 break; 117 sz += sz * mrg / 100; 118 if ((rv = (char *)malloc(sz)) == NULL) { 119 error("Out of memory!"); 120 return NULL; 121 } 122 if (sysctl(mib, mibsz, rv, &sz, NULL, 0) == -1) { 123 free(rv); 124 rv = NULL; 125 if (errno == ENOMEM) { 126 mrg += mrg * SD_FACTOR / 100; 127 } else 128 break; 129 } else { 130 /* success */ 131 if (szp != NULL) 132 *szp = sz; 133 break; 134 } 135 } 136 137 return rv; 138} 139