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 * $FreeBSD$ 34 */ 35 36 #ifndef lint 37 static char sccsid[] = "@(#)fetch.c 8.1 (Berkeley) 6/6/93"; 38 #endif /* not lint */ 39 40 #include <sys/types.h> 41 #include <sys/sysctl.h> 42 43 #include <errno.h> 44 #include <err.h> 45 #include <string.h> 46 #include <stdlib.h> 47 48 #include "systat.h" 49 #include "extern.h" 50 51 int 52 kvm_ckread(a, b, l) 53 void *a, *b; 54 int l; 55 { 56 if (kvm_read(kd, (u_long)a, b, l) != l) { 57 if (verbose) 58 error("error reading kmem at %x", a); 59 return (0); 60 } 61 else 62 return (1); 63 } 64 65 void getsysctl(name, ptr, len) 66 char *name; 67 void *ptr; 68 size_t len; 69 { 70 int err; 71 size_t nlen = len; 72 if ((err = sysctlbyname(name, ptr, &nlen, NULL, 0)) != 0) { 73 error("sysctl(%s...) failed: %s", name, 74 strerror(errno)); 75 } 76 if (nlen != len) { 77 error("sysctl(%s...) expected %d, got %d", name, 78 len, nlen); 79 } 80 } 81 82 /* 83 * Read sysctl data with variable size. Try some times (with increasing 84 * buffers), fail if still too small. 85 * This is needed sysctls with possibly raplidly increasing data sizes, 86 * but imposes little overhead in the case of constant sizes. 87 * Returns NULL on error, or a pointer to freshly malloc()'ed memory that holds 88 * the requested data. 89 * If szp is not NULL, the size of the returned data will be written into *szp. 90 */ 91 92 /* Some defines: Number of tries. */ 93 #define SD_NTRIES 10 94 /* Percent of over-allocation (initial) */ 95 #define SD_MARGIN 10 96 /* 97 * Factor for over-allocation in percent (the margin is increased by this on 98 * any failed try). 99 */ 100 #define SD_FACTOR 50 101 /* Maximum supported MIB depth */ 102 #define SD_MAXMIB 16 103 104 char * 105 sysctl_dynread(n, szp) 106 char *n; 107 size_t *szp; 108 { 109 char *rv = NULL; 110 int mib[SD_MAXMIB]; 111 size_t mibsz = SD_MAXMIB; 112 size_t mrg = SD_MARGIN; 113 size_t sz; 114 int i; 115 116 /* cache the MIB */ 117 if (sysctlnametomib(n, mib, &mibsz) == -1) { 118 if (errno == ENOMEM) { 119 error("XXX: SD_MAXMIB too small, please bump!"); 120 } 121 return NULL; 122 } 123 for (i = 0; i < SD_NTRIES; i++) { 124 /* get needed buffer size */ 125 if (sysctl(mib, mibsz, NULL, &sz, NULL, 0) == -1) 126 break; 127 sz += sz * mrg / 100; 128 if ((rv = (char *)malloc(sz)) == NULL) { 129 error("Out of memory!"); 130 return NULL; 131 } 132 if (sysctl(mib, mibsz, rv, &sz, NULL, 0) == -1) { 133 free(rv); 134 rv = NULL; 135 if (errno == ENOMEM) { 136 mrg += mrg * SD_FACTOR / 100; 137 } else 138 break; 139 } else { 140 /* success */ 141 if (szp != NULL) 142 *szp = sz; 143 break; 144 } 145 } 146 147 return rv; 148 } 149