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/*
* security service wrapper to support pluggable security models
*
* Portions of this file are subject to the following copyright(s). See
* the Net-SNMP's COPYING file for more details and other copyrights
* that may apply:
*
* Portions of this file are copyrighted by:
* Copyright (c) 2016 VMware, Inc. All rights reserved.
* Use is subject to license terms specified in the COPYING file
* distributed with the Net-SNMP package.
*/
#include <net-snmp/net-snmp-config.h>
#include <stdio.h>
#include <ctype.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#else
#include <strings.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <net-snmp/types.h>
#include <net-snmp/output_api.h>
#include <net-snmp/config_api.h>
#include <net-snmp/utilities.h>
#include <net-snmp/library/snmp_api.h>
#include <net-snmp/library/snmp_enum.h>
#include <net-snmp/library/callback.h>
#include <net-snmp/library/snmp_secmod.h>
#include <net-snmp/library/snmpv3-security-includes.h>
#include <net-snmp/net-snmp-features.h>
static struct snmp_secmod_list *registered_services = NULL;
static SNMPCallback set_default_secmod;
void
init_secmod(void)
{
snmp_register_callback(SNMP_CALLBACK_LIBRARY,
SNMP_CALLBACK_SESSION_INIT, set_default_secmod,
NULL);
netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "defSecurityModel",
NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_SECMODEL);
/*
* this file is generated by configure for all the stuff we're using
*/
#include "snmpsm_init.h"
}
void
shutdown_secmod(void)
{
#include "snmpsm_shutdown.h"
}
int
register_sec_mod(int secmod, const char *modname,
struct snmp_secmod_def *newdef)
{
int result = 0;
struct snmp_secmod_list *sptr;
char *othername, *modname2 = NULL;
for (sptr = registered_services; sptr; sptr = sptr->next) {
if (sptr->securityModel == secmod) {
return SNMPERR_GENERR;
}
}
sptr = SNMP_MALLOC_STRUCT(snmp_secmod_list);
if (sptr == NULL)
return SNMPERR_MALLOC;
sptr->secDef = newdef;
sptr->securityModel = secmod;
sptr->next = registered_services;
registered_services = sptr;
modname2 = strdup(modname);
if (!modname2)
result = SE_NOMEM;
else
result = se_add_pair_to_slist("snmp_secmods", modname2, secmod);
if (result != SE_OK) {
switch (result) {
case SE_NOMEM:
snmp_log(LOG_CRIT, "snmp_secmod: no memory\n");
break;
case SE_ALREADY_THERE:
othername = se_find_label_in_slist("snmp_secmods", secmod);
if (strcmp(othername, modname) != 0) {
snmp_log(LOG_ERR,
"snmp_secmod: two security modules %s and %s registered with the same security number\n",
modname, othername);
}
break;
default:
snmp_log(LOG_ERR,
"snmp_secmod: unknown error trying to register a new security module\n");
break;
}
return SNMPERR_GENERR;
}
return SNMPERR_SUCCESS;
}
netsnmp_feature_child_of(unregister_sec_mod, netsnmp_unused);
#ifndef NETSNMP_FEATURE_REMOVE_UNREGISTER_SEC_MOD
int
unregister_sec_mod(int secmod)
{
struct snmp_secmod_list *sptr, *lptr;
for (sptr = registered_services, lptr = NULL; sptr;
lptr = sptr, sptr = sptr->next) {
if (sptr->securityModel == secmod) {
if ( lptr )
lptr->next = sptr->next;
else
registered_services = sptr->next;
SNMP_FREE(sptr->secDef);
SNMP_FREE(sptr);
return SNMPERR_SUCCESS;
}
}
/*
* not registered
*/
return SNMPERR_GENERR;
}
#endif /* NETSNMP_FEATURE_REMOVE_UNREGISTER_SEC_MOD */
void
clear_sec_mod(void)
{
struct snmp_secmod_list *tmp = registered_services, *next = NULL;
while (tmp != NULL) {
next = tmp->next;
SNMP_FREE(tmp->secDef);
SNMP_FREE(tmp);
tmp = next;
}
registered_services = NULL;
}
struct snmp_secmod_def *
find_sec_mod(int secmod)
{
struct snmp_secmod_list *sptr;
for (sptr = registered_services; sptr; sptr = sptr->next) {
if (sptr->securityModel == secmod) {
return sptr->secDef;
}
}
/*
* not registered
*/
return NULL;
}
/* try to pick a reasonable security module default based on what was
compiled into the net-snmp package */
#ifdef USM_SEC_MODEL_NUMBER
#define NETSNMP_SECMOD_DEFAULT_MODEL USM_SEC_MODEL_NUMBER
#elif defined(TSM_SEC_MODEL_NUMBER)
#define NETSNMP_SECMOD_DEFAULT_MODEL TSM_SEC_MODEL_NUMBER
#elif defined(KSM_SEC_MODEL_NUMBER)
#define NETSNMP_SECMOD_DEFAULT_MODEL KSM_SEC_MODEL_NUMBER
#else
/* else we give up and leave it blank */
#define NETSNMP_SECMOD_DEFAULT_MODEL -1
#endif
static int
set_default_secmod(int major, int minor, void *serverarg, void *clientarg)
{
netsnmp_session *sess = (netsnmp_session *) serverarg;
char *cptr;
int model;
if (!sess)
return SNMPERR_GENERR;
if (sess->securityModel == SNMP_DEFAULT_SECMODEL) {
if ((cptr = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
NETSNMP_DS_LIB_SECMODEL)) != NULL) {
if ((model = se_find_value_in_slist("snmp_secmods", cptr))
!= SE_DNE) {
sess->securityModel = model;
} else {
snmp_log(LOG_ERR,
"unknown security model name: %s. Forcing USM instead.\n",
cptr);
sess->securityModel = NETSNMP_SECMOD_DEFAULT_MODEL;
return SNMPERR_GENERR;
}
} else {
sess->securityModel = NETSNMP_SECMOD_DEFAULT_MODEL;
}
}
return SNMPERR_SUCCESS;
}
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