You're right, this diff does some massive pointer juggling that I overlooked.
I'll drop the diff. On 1/22/20 10:59 AM, Otto Moerbeek wrote: > On Wed, Jan 22, 2020 at 10:51:45AM +0100, Martijn van Duren wrote: > >> Trying to wrap my head around some of the snmpd code I found this pearl >> that appears to do nothing more than warm up the room. > > Do you really want to get rid of the init of snmpd_env->sc_cpustates ? > > -Otto > >> >> OK? >> >> martijn@ >> >> Index: Makefile >> =================================================================== >> RCS file: /cvs/src/usr.sbin/snmpd/Makefile,v >> retrieving revision 1.16 >> diff -u -p -r1.16 Makefile >> --- Makefile 11 May 2019 17:46:02 -0000 1.16 >> +++ Makefile 22 Jan 2020 09:50:51 -0000 >> @@ -3,7 +3,7 @@ >> PROG= snmpd >> MAN= snmpd.8 snmpd.conf.5 >> SRCS= parse.y log.c control.c snmpe.c \ >> - mps.c trap.c mib.c smi.c kroute.c snmpd.c timer.c \ >> + mps.c trap.c mib.c smi.c kroute.c snmpd.c \ >> pf.c proc.c usm.c agentx.c traphandler.c util.c >> >> LDADD= -levent -lutil -lkvm -lcrypto >> Index: snmpd.h >> =================================================================== >> RCS file: /cvs/src/usr.sbin/snmpd/snmpd.h,v >> retrieving revision 1.86 >> diff -u -p -r1.86 snmpd.h >> --- snmpd.h 2 Jan 2020 10:55:53 -0000 1.86 >> +++ snmpd.h 22 Jan 2020 09:50:51 -0000 >> @@ -745,9 +745,6 @@ unsigned int smi_application(struct ber >> void smi_debug_elements(struct ber_element *); >> char *smi_print_element(struct ber_element *); >> >> -/* timer.c */ >> -void timer_init(void); >> - >> /* snmpd.c */ >> int snmpd_socket_af(struct sockaddr_storage *, in_port_t, int); >> u_long snmpd_engine_time(void); >> Index: snmpe.c >> =================================================================== >> RCS file: /cvs/src/usr.sbin/snmpd/snmpe.c,v >> retrieving revision 1.60 >> diff -u -p -r1.60 snmpe.c >> --- snmpe.c 24 Oct 2019 12:39:27 -0000 1.60 >> +++ snmpe.c 22 Jan 2020 09:50:51 -0000 >> @@ -103,7 +103,6 @@ snmpe_init(struct privsep *ps, struct pr >> >> kr_init(); >> trap_init(); >> - timer_init(); >> usm_generate_keys(); >> >> /* listen for incoming SNMP UDP/TCP messages */ >> Index: timer.c >> =================================================================== >> RCS file: timer.c >> diff -N timer.c >> --- timer.c 28 Oct 2016 08:01:53 -0000 1.7 >> +++ /dev/null 1 Jan 1970 00:00:00 -0000 >> @@ -1,169 +0,0 @@ >> -/* $OpenBSD: timer.c,v 1.7 2016/10/28 08:01:53 rzalamena Exp $ */ >> - >> -/* >> - * Copyright (c) 2008 Reyk Floeter <[email protected]> >> - * >> - * Permission to use, copy, modify, and distribute this software for any >> - * purpose with or without fee is hereby granted, provided that the above >> - * copyright notice and this permission notice appear in all copies. >> - * >> - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES >> - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF >> - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR >> - * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES >> - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN >> - * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF >> - * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. >> - */ >> - >> -#include <sys/queue.h> >> -#include <sys/types.h> >> -#include <sys/time.h> >> -#include <sys/sched.h> >> -#include <sys/socket.h> >> -#include <sys/sysctl.h> >> - >> -#include <net/if.h> >> -#include <net/if_types.h> >> -#include <netinet/in.h> >> -#include <netinet/ip.h> >> -#include <netinet/ip_var.h> >> -#include <arpa/inet.h> >> - >> -#include <stdlib.h> >> -#include <stdio.h> >> -#include <errno.h> >> -#include <event.h> >> -#include <fcntl.h> >> -#include <string.h> >> -#include <unistd.h> >> -#include <pwd.h> >> - >> -#include "snmpd.h" >> -#include "mib.h" >> - >> -void timer_cpu(int, short, void *); >> -int percentages(int, int64_t *, int64_t *, int64_t *, int64_t *); >> - >> -static int64_t **cp_time; >> -static int64_t **cp_old; >> -static int64_t **cp_diff; >> -struct event cpu_ev; >> - >> -void >> -timer_cpu(int fd, short event, void *arg) >> -{ >> - struct event *ev = (struct event *)arg; >> - struct timeval tv = { 60, 0 }; /* every 60 seconds */ >> - int mib[3] = { CTL_KERN, KERN_CPTIME2, 0 }, n; >> - size_t len; >> - int64_t *cptime2; >> - >> - len = CPUSTATES * sizeof(int64_t); >> - for (n = 0; n < snmpd_env->sc_ncpu; n++) { >> - mib[2] = n; >> - cptime2 = snmpd_env->sc_cpustates + (CPUSTATES * n); >> - if (sysctl(mib, 3, cp_time[n], &len, NULL, 0) == -1) >> - continue; >> - (void)percentages(CPUSTATES, cptime2, cp_time[n], >> - cp_old[n], cp_diff[n]); >> -#ifdef DEBUG >> - log_debug("timer_cpu: cpu%d %lld%% idle in %llds", n, >> - (cptime2[CP_IDLE] > 1000 ? >> - 1000 : (cptime2[CP_IDLE] / 10)), (long long) tv.tv_sec); >> -#endif >> - } >> - >> - evtimer_add(ev, &tv); >> -} >> - >> -void >> -timer_init(void) >> -{ >> - int mib[] = { CTL_HW, HW_NCPU }, i; >> - size_t len; >> - >> - len = sizeof(snmpd_env->sc_ncpu); >> - if (sysctl(mib, 2, &snmpd_env->sc_ncpu, &len, NULL, 0) == -1) >> - fatal("sysctl"); >> - >> - snmpd_env->sc_cpustates = calloc(snmpd_env->sc_ncpu, >> - CPUSTATES * sizeof(int64_t)); >> - cp_time = calloc(snmpd_env->sc_ncpu, sizeof(int64_t *)); >> - cp_old = calloc(snmpd_env->sc_ncpu, sizeof(int64_t *)); >> - cp_diff = calloc(snmpd_env->sc_ncpu, sizeof(int64_t *)); >> - if (snmpd_env->sc_cpustates == NULL || >> - cp_time == NULL || cp_old == NULL || cp_diff == NULL) >> - fatal("calloc"); >> - for (i = 0; i < snmpd_env->sc_ncpu; i++) { >> - cp_time[i] = calloc(CPUSTATES, sizeof(int64_t)); >> - cp_old[i] = calloc(CPUSTATES, sizeof(int64_t)); >> - cp_diff[i] = calloc(CPUSTATES, sizeof(int64_t)); >> - if (cp_time[i] == NULL || cp_old[i] == NULL || >> - cp_diff[i] == NULL) >> - fatal("calloc"); >> - } >> - >> - evtimer_set(&cpu_ev, timer_cpu, &cpu_ev); >> - timer_cpu(0, EV_TIMEOUT, &cpu_ev); >> -} >> - >> -/* >> - * percentages() function to calculate CPU utilization. >> - * Source code derived from the top(1) utility: >> - * >> - * Copyright (c) 1984, 1989, William LeFebvre, Rice University >> - * Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University >> - * >> - * 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. >> - * >> - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR OR HIS EMPLOYER 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. >> - */ >> -int >> -percentages(int cnt, int64_t *out, int64_t *new, int64_t *old, int64_t >> *diffs) >> -{ >> - int64_t change, total_change, *dp, half_total; >> - int i; >> - >> - /* initialization */ >> - total_change = 0; >> - dp = diffs; >> - >> - /* calculate changes for each state and the overall change */ >> - for (i = 0; i < cnt; i++) { >> - if ((change = *new - *old) < 0) { >> - /* this only happens when the counter wraps */ >> - change = (*new - *old); >> - } >> - total_change += (*dp++ = change); >> - *old++ = *new++; >> - } >> - >> - /* avoid divide by zero potential */ >> - if (total_change == 0) >> - total_change = 1; >> - >> - /* calculate percentages based on overall change, rounding up */ >> - half_total = total_change / 2l; >> - for (i = 0; i < cnt; i++) >> - *out++ = ((*diffs++ * 1000 + half_total) / total_change); >> - >> - /* return the total in case the caller wants to use it */ >> - return (total_change); >> -} >> >
