diff options
Diffstat (limited to 'usr.bin/systat/fetch.c')
| -rw-r--r-- | usr.bin/systat/fetch.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/usr.bin/systat/fetch.c b/usr.bin/systat/fetch.c new file mode 100644 index 0000000..d159e51 --- /dev/null +++ b/usr.bin/systat/fetch.c @@ -0,0 +1,138 @@ +/*- + * Copyright (c) 1980, 1992, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> + +__FBSDID("$FreeBSD$"); + +#ifdef lint +static const char sccsid[] = "@(#)fetch.c 8.1 (Berkeley) 6/6/93"; +#endif + +#include <sys/types.h> +#include <sys/sysctl.h> + +#include <err.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> + +#include "systat.h" +#include "extern.h" + +int +kvm_ckread(void *a, void *b, int l) +{ + if (kvm_read(kd, (u_long)a, b, l) != l) { + if (verbose) + error("error reading kmem at %p", a); + return (0); + } + else + return (1); +} + +void getsysctl(const char *name, void *ptr, size_t len) +{ + size_t nlen = len; + if (sysctlbyname(name, ptr, &nlen, NULL, 0) != 0) { + error("sysctl(%s...) failed: %s", name, + strerror(errno)); + } + if (nlen != len) { + error("sysctl(%s...) expected %lu, got %lu", name, + (unsigned long)len, (unsigned long)nlen); + } +} + +/* + * Read sysctl data with variable size. Try some times (with increasing + * buffers), fail if still too small. + * This is needed sysctls with possibly raplidly increasing data sizes, + * but imposes little overhead in the case of constant sizes. + * Returns NULL on error, or a pointer to freshly malloc()'ed memory that holds + * the requested data. + * If szp is not NULL, the size of the returned data will be written into *szp. + */ + +/* Some defines: Number of tries. */ +#define SD_NTRIES 10 +/* Percent of over-allocation (initial) */ +#define SD_MARGIN 10 +/* + * Factor for over-allocation in percent (the margin is increased by this on + * any failed try). + */ +#define SD_FACTOR 50 +/* Maximum supported MIB depth */ +#define SD_MAXMIB 16 + +char * +sysctl_dynread(const char *n, size_t *szp) +{ + char *rv = NULL; + int mib[SD_MAXMIB]; + size_t mibsz = SD_MAXMIB; + size_t mrg = SD_MARGIN; + size_t sz; + int i; + + /* cache the MIB */ + if (sysctlnametomib(n, mib, &mibsz) == -1) { + if (errno == ENOMEM) { + error("XXX: SD_MAXMIB too small, please bump!"); + } + return NULL; + } + for (i = 0; i < SD_NTRIES; i++) { + /* get needed buffer size */ + if (sysctl(mib, mibsz, NULL, &sz, NULL, 0) == -1) + break; + sz += sz * mrg / 100; + if ((rv = (char *)malloc(sz)) == NULL) { + error("Out of memory!"); + return NULL; + } + if (sysctl(mib, mibsz, rv, &sz, NULL, 0) == -1) { + free(rv); + rv = NULL; + if (errno == ENOMEM) { + mrg += mrg * SD_FACTOR / 100; + } else + break; + } else { + /* success */ + if (szp != NULL) + *szp = sz; + break; + } + } + + return rv; +} |
