fetch.c revision 77583
112891Swpaul/*- 212891Swpaul * Copyright (c) 1980, 1992, 1993 312891Swpaul * The Regents of the University of California. All rights reserved. 412891Swpaul * 512891Swpaul * Redistribution and use in source and binary forms, with or without 612891Swpaul * modification, are permitted provided that the following conditions 712891Swpaul * are met: 812891Swpaul * 1. Redistributions of source code must retain the above copyright 912891Swpaul * notice, this list of conditions and the following disclaimer. 1012891Swpaul * 2. Redistributions in binary form must reproduce the above copyright 1112891Swpaul * notice, this list of conditions and the following disclaimer in the 1212891Swpaul * documentation and/or other materials provided with the distribution. 1312891Swpaul * 3. All advertising materials mentioning features or use of this software 1412891Swpaul * must display the following acknowledgement: 1512891Swpaul * This product includes software developed by the University of 1612891Swpaul * California, Berkeley and its contributors. 1712891Swpaul * 4. Neither the name of the University nor the names of its contributors 1812891Swpaul * may be used to endorse or promote products derived from this software 1912891Swpaul * without specific prior written permission. 2012891Swpaul * 2112891Swpaul * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2212891Swpaul * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2312891Swpaul * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2412891Swpaul * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2512891Swpaul * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2612891Swpaul * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2712891Swpaul * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2812891Swpaul * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2912891Swpaul * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3012891Swpaul * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3112891Swpaul * SUCH DAMAGE. 3212891Swpaul * 3312891Swpaul * $FreeBSD: head/usr.bin/systat/fetch.c 77583 2001-06-01 13:29:19Z tmm $ 3412891Swpaul */ 3512891Swpaul 3612891Swpaul#ifndef lint 3712891Swpaulstatic char sccsid[] = "@(#)fetch.c 8.1 (Berkeley) 6/6/93"; 3812891Swpaul#endif /* not lint */ 3912891Swpaul 4012891Swpaul#include <sys/types.h> 4112891Swpaul#include <sys/sysctl.h> 4212891Swpaul 4312891Swpaul#include <errno.h> 4412891Swpaul#include <err.h> 4512891Swpaul#include <string.h> 4612891Swpaul#include <stdlib.h> 4712891Swpaul 4812891Swpaul#include "systat.h" 4912891Swpaul#include "extern.h" 5012891Swpaul 5112891Swpaulint 5212891Swpaulkvm_ckread(a, b, l) 5312891Swpaul void *a, *b; 5412891Swpaul int l; 5512891Swpaul{ 5612891Swpaul if (kvm_read(kd, (u_long)a, b, l) != l) { 5712891Swpaul if (verbose) 5812891Swpaul error("error reading kmem at %x", a); 5912891Swpaul return (0); 6012891Swpaul } 6112891Swpaul else 6212891Swpaul return (1); 6312891Swpaul} 6412891Swpaul 6512891Swpaulvoid getsysctl(name, ptr, len) 6612891Swpaul char *name; 6712891Swpaul void *ptr; 6812891Swpaul size_t len; 6912891Swpaul{ 7012891Swpaul int err; 7112891Swpaul size_t nlen = len; 7212891Swpaul if ((err = sysctlbyname(name, ptr, &nlen, NULL, 0)) != 0) { 7312891Swpaul error("sysctl(%s...) failed: %s", name, 7412891Swpaul strerror(errno)); 7512891Swpaul } 7612891Swpaul if (nlen != len) { 7712891Swpaul error("sysctl(%s...) expected %lu, got %lu", name, 7812891Swpaul (unsigned long)len, (unsigned long)nlen); 7912891Swpaul } 8012891Swpaul} 8112891Swpaul 8212891Swpaul/* 8312891Swpaul * Read sysctl data with variable size. Try some times (with increasing 8412891Swpaul * buffers), fail if still too small. 8512891Swpaul * This is needed sysctls with possibly raplidly increasing data sizes, 8612891Swpaul * but imposes little overhead in the case of constant sizes. 8712891Swpaul * Returns NULL on error, or a pointer to freshly malloc()'ed memory that holds 8812891Swpaul * the requested data. 8912891Swpaul * If szp is not NULL, the size of the returned data will be written into *szp. 9012891Swpaul */ 9112891Swpaul 9212891Swpaul/* Some defines: Number of tries. */ 9312891Swpaul#define SD_NTRIES 10 9412891Swpaul/* Percent of over-allocation (initial) */ 9512891Swpaul#define SD_MARGIN 10 9612891Swpaul/* 9712891Swpaul * Factor for over-allocation in percent (the margin is increased by this on 9812891Swpaul * any failed try). 9912891Swpaul */ 10012891Swpaul#define SD_FACTOR 50 10112891Swpaul/* Maximum supported MIB depth */ 10212891Swpaul#define SD_MAXMIB 16 10312891Swpaul 10412891Swpaulchar * 10512891Swpaulsysctl_dynread(n, szp) 10612891Swpaul char *n; 10712891Swpaul size_t *szp; 10812891Swpaul{ 10912891Swpaul char *rv = NULL; 11012891Swpaul int mib[SD_MAXMIB]; 11112891Swpaul size_t mibsz = SD_MAXMIB; 11212891Swpaul size_t mrg = SD_MARGIN; 11312891Swpaul size_t sz; 11412891Swpaul int i; 11512891Swpaul 11612891Swpaul /* cache the MIB */ 11712891Swpaul if (sysctlnametomib(n, mib, &mibsz) == -1) { 11812891Swpaul if (errno == ENOMEM) { 11912891Swpaul error("XXX: SD_MAXMIB too small, please bump!"); 12012891Swpaul } 12112891Swpaul return NULL; 12212891Swpaul } 12312891Swpaul for (i = 0; i < SD_NTRIES; i++) { 12412891Swpaul /* get needed buffer size */ 12512891Swpaul if (sysctl(mib, mibsz, NULL, &sz, NULL, 0) == -1) 12612891Swpaul break; 12712891Swpaul sz += sz * mrg / 100; 12812891Swpaul if ((rv = (char *)malloc(sz)) == NULL) { 12912891Swpaul error("Out of memory!"); 13012891Swpaul return NULL; 13112891Swpaul } 13212891Swpaul if (sysctl(mib, mibsz, rv, &sz, NULL, 0) == -1) { 13312891Swpaul free(rv); 13412891Swpaul rv = NULL; 13512891Swpaul if (errno == ENOMEM) { 13612891Swpaul mrg += mrg * SD_FACTOR / 100; 13712891Swpaul } else 13812891Swpaul break; 13912891Swpaul } else { 14012891Swpaul /* success */ 14112891Swpaul if (szp != NULL) 14212891Swpaul *szp = sz; 14312891Swpaul break; 14412891Swpaul } 14512891Swpaul } 14612891Swpaul 14712891Swpaul return rv; 14812891Swpaul} 14912891Swpaul