nut-debian/tools/nut-scanner/nutscan-init.c
2022-07-10 09:23:45 +02:00

220 lines
6.1 KiB
C

/*
* Copyright (C) 2011-2021 - EATON
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*! \file nutscan-init.c
\brief init functions for nut scanner library
\author Frederic Bohe <fredericbohe@eaton.com>
\author Arnaud Quette <ArnaudQuette@Eaton.com>
*/
#include "common.h"
#include "nutscan-init.h"
#include <ltdl.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include "nut-scan.h"
int nutscan_avail_avahi = 0;
int nutscan_avail_ipmi = 0;
int nutscan_avail_nut = 0;
int nutscan_avail_snmp = 0;
int nutscan_avail_usb = 0;
int nutscan_avail_xml_http = 0;
int nutscan_load_usb_library(const char *libname_path);
int nutscan_load_snmp_library(const char *libname_path);
int nutscan_load_neon_library(const char *libname_path);
int nutscan_load_avahi_library(const char *libname_path);
int nutscan_load_ipmi_library(const char *libname_path);
int nutscan_load_upsclient_library(const char *libname_path);
#ifdef HAVE_PTHREAD
# ifdef HAVE_SEMAPHORE
/* Shared by library consumers, exposed by nutscan_semaphore() below */
static sem_t semaphore;
sem_t * nutscan_semaphore(void)
{
return &semaphore;
}
# endif /* HAVE_SEMAPHORE */
# ifdef HAVE_PTHREAD_TRYJOIN
pthread_mutex_t threadcount_mutex;
# endif
# if (defined HAVE_PTHREAD_TRYJOIN) || (defined HAVE_SEMAPHORE)
/* We have 3 networked scan types: nut, snmp, xml,
* and users typically give their /24 subnet as "-m" arg.
* With some systems having a 1024 default (u)limit to
* file descriptors, this should fit if those are involved.
* On some systems tested, a large amount of not-joined
* pthreads did cause various crashes; also RAM is limited.
* Note that each scan may be time consuming to query an
* IP address and wait for (no) reply, so while these threads
* are usually not resource-intensive (nor computationally),
* they spend much wallclock time each so parallelism helps.
*/
size_t max_threads = DEFAULT_THREAD;
size_t curr_threads = 0;
size_t max_threads_netxml = 1021; /* experimental finding, see PR#1158 */
size_t max_threads_oldnut = 1021;
size_t max_threads_netsnmp = 0; /* 10240; */
/* per reports in PR#1158, some versions of net-snmp could be limited
* to 1024 threads in the past; this was not found in practice.
* Still, some practical limit can be useful (configurable?)
* Here 0 means to not apply any special limit (beside max_threads).
*/
# endif /* HAVE_PTHREAD_TRYJOIN || HAVE_SEMAPHORE */
#endif /* HAVE_PTHREAD */
void nutscan_init(void)
{
#ifdef HAVE_PTHREAD
/* TOTHINK: Should semaphores to limit thread count
* and the more naive but portable methods be an
* if-else proposition? At least when initializing?
*/
# ifdef HAVE_SEMAPHORE
/* NOTE: This semaphore may get re-initialized in nut-scanner program
* after parsing command-line arguments. It calls nutscan_init() before
* parsing CLI, to know about available libs and to set defaults below.
*/
#ifdef HAVE_PRAGMAS_FOR_GCC_DIAGNOSTIC_IGNORED_UNREACHABLE_CODE
#pragma GCC diagnostic push
#endif
#ifdef HAVE_PRAGMA_GCC_DIAGNOSTIC_IGNORED_UNREACHABLE_CODE
#pragma GCC diagnostic ignored "-Wunreachable-code"
#endif
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunreachable-code"
#endif
/* Different platforms, different sizes, none fits all... */
if (SIZE_MAX > UINT_MAX && max_threads > UINT_MAX) {
#ifdef __clang__
#pragma clang diagnostic pop
#endif
#ifdef HAVE_PRAGMAS_FOR_GCC_DIAGNOSTIC_IGNORED_UNREACHABLE_CODE
#pragma GCC diagnostic pop
#endif
upsdebugx(1,
"WARNING: %s: Limiting max_threads to range acceptable for sem_init()",
__func__);
max_threads = UINT_MAX - 1;
}
sem_init(&semaphore, 0, (unsigned int)max_threads);
# endif
# ifdef HAVE_PTHREAD_TRYJOIN
pthread_mutex_init(&threadcount_mutex, NULL);
# endif
#endif /* HAVE_PTHREAD */
char *libname = NULL;
#ifdef WITH_USB
#if WITH_LIBUSB_1_0
libname = get_libname("libusb-1.0.so");
#else
libname = get_libname("libusb-0.1.so");
if (!libname) {
/* We can also use libusb-compat from newer libusb-1.0 releases */
libname = get_libname("libusb.so");
}
#endif
if (libname) {
nutscan_avail_usb = nutscan_load_usb_library(libname);
free(libname);
}
#endif
#ifdef WITH_SNMP
libname = get_libname("libnetsnmp.so");
if (libname) {
nutscan_avail_snmp = nutscan_load_snmp_library(libname);
free(libname);
}
#endif
#ifdef WITH_NEON
libname = get_libname("libneon.so");
if (!libname) {
libname = get_libname("libneon-gnutls.so");
}
if (libname) {
nutscan_avail_xml_http = nutscan_load_neon_library(libname);
free(libname);
}
#endif
#ifdef WITH_AVAHI
libname = get_libname("libavahi-client.so");
if (libname) {
nutscan_avail_avahi = nutscan_load_avahi_library(libname);
free(libname);
}
#endif
#ifdef WITH_FREEIPMI
libname = get_libname("libfreeipmi.so");
if (libname) {
nutscan_avail_ipmi = nutscan_load_ipmi_library(libname);
free(libname);
}
#endif
libname = get_libname("libupsclient.so");
if (libname) {
nutscan_avail_nut = nutscan_load_upsclient_library(libname);
free(libname);
}
}
void nutscan_free(void)
{
if (nutscan_avail_usb) {
lt_dlexit();
}
if (nutscan_avail_snmp) {
lt_dlexit();
}
if (nutscan_avail_xml_http) {
lt_dlexit();
}
if (nutscan_avail_avahi) {
lt_dlexit();
}
if (nutscan_avail_ipmi) {
lt_dlexit();
}
if (nutscan_avail_nut) {
lt_dlexit();
}
#ifdef HAVE_PTHREAD
/* TOTHINK: See comments near mutex/semaphore init code above */
# ifdef HAVE_SEMAPHORE
sem_destroy(nutscan_semaphore());
# endif
# ifdef HAVE_PTHREAD_TRYJOIN
pthread_mutex_destroy(&threadcount_mutex);
# endif
#endif
}