1 /*- 2 * Copyright (c) 1980, 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 36 __FBSDID("$FreeBSD$"); 37 38 #ifdef lint 39 static const char sccsid[] = "@(#)fetch.c 8.1 (Berkeley) 6/6/93"; 40 #endif 41 42 #include <sys/types.h> 43 #include <sys/sysctl.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <stdlib.h> 48 #include <string.h> 49 50 #include "systat.h" 51 #include "extern.h" 52 53 int 54 kvm_ckread(a, b, l) 55 void *a, *b; 56 int l; 57 { 58 if (kvm_read(kd, (u_long)a, b, l) != l) { 59 if (verbose) 60 error("error reading kmem at %p", a); 61 return (0); 62 } 63 else 64 return (1); 65 } 66 67 void getsysctl(name, ptr, len) 68 const char *name; 69 void *ptr; 70 size_t len; 71 { 72 size_t nlen = len; 73 if (sysctlbyname(name, ptr, &nlen, NULL, 0) != 0) { 74 error("sysctl(%s...) failed: %s", name, 75 strerror(errno)); 76 } 77 if (nlen != len) { 78 error("sysctl(%s...) expected %lu, got %lu", name, 79 (unsigned long)len, (unsigned long)nlen); 80 } 81 } 82 83 /* 84 * Read sysctl data with variable size. Try some times (with increasing 85 * buffers), fail if still too small. 86 * This is needed sysctls with possibly raplidly increasing data sizes, 87 * but imposes little overhead in the case of constant sizes. 88 * Returns NULL on error, or a pointer to freshly malloc()'ed memory that holds 89 * the requested data. 90 * If szp is not NULL, the size of the returned data will be written into *szp. 91 */ 92 93 /* Some defines: Number of tries. */ 94 #define SD_NTRIES 10 95 /* Percent of over-allocation (initial) */ 96 #define SD_MARGIN 10 97 /* 98 * Factor for over-allocation in percent (the margin is increased by this on 99 * any failed try). 100 */ 101 #define SD_FACTOR 50 102 /* Maximum supported MIB depth */ 103 #define SD_MAXMIB 16 104 105 char * 106 sysctl_dynread(n, szp) 107 const char *n; 108 size_t *szp; 109 { 110 char *rv = NULL; 111 int mib[SD_MAXMIB]; 112 size_t mibsz = SD_MAXMIB; 113 size_t mrg = SD_MARGIN; 114 size_t sz; 115 int i; 116 117 /* cache the MIB */ 118 if (sysctlnametomib(n, mib, &mibsz) == -1) { 119 if (errno == ENOMEM) { 120 error("XXX: SD_MAXMIB too small, please bump!"); 121 } 122 return NULL; 123 } 124 for (i = 0; i < SD_NTRIES; i++) { 125 /* get needed buffer size */ 126 if (sysctl(mib, mibsz, NULL, &sz, NULL, 0) == -1) 127 break; 128 sz += sz * mrg / 100; 129 if ((rv = (char *)malloc(sz)) == NULL) { 130 error("Out of memory!"); 131 return NULL; 132 } 133 if (sysctl(mib, mibsz, rv, &sz, NULL, 0) == -1) { 134 free(rv); 135 rv = NULL; 136 if (errno == ENOMEM) { 137 mrg += mrg * SD_FACTOR / 100; 138 } else 139 break; 140 } else { 141 /* success */ 142 if (szp != NULL) 143 *szp = sz; 144 break; 145 } 146 } 147 148 return rv; 149 } 150