lwip_snmp_threadsync.c

00001 /**
00002  * @file
00003  * SNMP thread synchronization implementation.
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * Author: Dirk Ziegelmeier <dziegel@gmx.de>
00033  */
00034 
00035 #include "lwip/apps/snmp_opts.h"
00036 
00037 #if LWIP_SNMP && (NO_SYS == 0) /* don't build if not configured for use in lwipopts.h */
00038 
00039 #include "lwip/apps/snmp_threadsync.h"
00040 #include "lwip/apps/snmp_core.h"
00041 #include "lwip/sys.h"
00042 #include <string.h>
00043         
00044 static void
00045 call_synced_function(struct threadsync_data *call_data, snmp_threadsync_called_fn fn)
00046 {
00047   sys_mutex_lock(&call_data->threadsync_node->instance->sem_usage_mutex);
00048   call_data->threadsync_node->instance->sync_fn(fn, call_data);
00049   sys_sem_wait(&call_data->threadsync_node->instance->sem);
00050   sys_mutex_unlock(&call_data->threadsync_node->instance->sem_usage_mutex);
00051 }
00052 
00053 static void
00054 threadsync_get_value_synced(void *ctx)
00055 {
00056   struct threadsync_data *call_data = (struct threadsync_data*)ctx;
00057 
00058   call_data->retval.s16 = call_data->proxy_instance.get_value(&call_data->proxy_instance, call_data->arg1.value);
00059 
00060   sys_sem_signal(&call_data->threadsync_node->instance->sem);
00061 }
00062 
00063 static s16_t
00064 threadsync_get_value(struct snmp_node_instance* instance, void* value)
00065 {
00066   struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
00067 
00068   call_data->arg1.value = value;
00069   call_synced_function(call_data, threadsync_get_value_synced);
00070 
00071   return call_data->retval.s16;
00072 }
00073 
00074 static void
00075 threadsync_set_test_synced(void *ctx)
00076 {
00077   struct threadsync_data *call_data = (struct threadsync_data*)ctx;
00078 
00079   call_data->retval.err = call_data->proxy_instance.set_test(&call_data->proxy_instance, call_data->arg2.len, call_data->arg1.value);
00080 
00081   sys_sem_signal(&call_data->threadsync_node->instance->sem);
00082 }
00083 
00084 static snmp_err_t
00085 threadsync_set_test(struct snmp_node_instance* instance, u16_t len, void *value)
00086 {
00087   struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
00088 
00089   call_data->arg1.value = value;
00090   call_data->arg2.len = len;
00091   call_synced_function(call_data, threadsync_set_test_synced);
00092 
00093   return call_data->retval.err;
00094 }
00095 
00096 static void
00097 threadsync_set_value_synced(void *ctx)
00098 {
00099   struct threadsync_data *call_data = (struct threadsync_data*)ctx;
00100 
00101   call_data->retval.err = call_data->proxy_instance.set_value(&call_data->proxy_instance, call_data->arg2.len, call_data->arg1.value);
00102 
00103   sys_sem_signal(&call_data->threadsync_node->instance->sem);
00104 }
00105 
00106 static snmp_err_t
00107 threadsync_set_value(struct snmp_node_instance* instance, u16_t len, void *value)
00108 {
00109   struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
00110 
00111   call_data->arg1.value = value;
00112   call_data->arg2.len = len;
00113   call_synced_function(call_data, threadsync_set_value_synced);
00114   
00115   return call_data->retval.err;
00116 }
00117 
00118 static void
00119 threadsync_release_instance_synced(void* ctx)
00120 {
00121   struct threadsync_data *call_data = (struct threadsync_data*)ctx;
00122   
00123   call_data->proxy_instance.release_instance(&call_data->proxy_instance);
00124 
00125   sys_sem_signal(&call_data->threadsync_node->instance->sem);
00126 }
00127 
00128 static void
00129 threadsync_release_instance(struct snmp_node_instance *instance)
00130 {
00131   struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
00132   
00133   if (call_data->proxy_instance.release_instance != NULL) {
00134     call_synced_function(call_data, threadsync_release_instance_synced);
00135   }
00136 }
00137 
00138 static void
00139 get_instance_synced(void* ctx)
00140 {
00141   struct threadsync_data *call_data   = (struct threadsync_data*)ctx;
00142   const struct snmp_leaf_node *leaf   = (const struct snmp_leaf_node*)(const void*)call_data->proxy_instance.node;
00143 
00144   call_data->retval.err = leaf->get_instance(call_data->arg1.root_oid, call_data->arg2.root_oid_len, &call_data->proxy_instance);
00145 
00146   sys_sem_signal(&call_data->threadsync_node->instance->sem);
00147 }
00148 
00149 static void
00150 get_next_instance_synced(void* ctx)
00151 {
00152   struct threadsync_data *call_data   = (struct threadsync_data*)ctx;
00153   const struct snmp_leaf_node *leaf   = (const struct snmp_leaf_node*)(const void*)call_data->proxy_instance.node;
00154 
00155   call_data->retval.err = leaf->get_next_instance(call_data->arg1.root_oid, call_data->arg2.root_oid_len, &call_data->proxy_instance);
00156 
00157   sys_sem_signal(&call_data->threadsync_node->instance->sem);
00158 }
00159 
00160 static snmp_err_t
00161 do_sync(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance, snmp_threadsync_called_fn fn)
00162 {
00163   const struct snmp_threadsync_node *threadsync_node = (const struct snmp_threadsync_node*)(const void*)instance->node;
00164   struct threadsync_data *call_data = &threadsync_node->instance->data;
00165 
00166   if (threadsync_node->node.node.oid != threadsync_node->target->node.oid) {
00167     LWIP_DEBUGF(SNMP_DEBUG, ("Sync node OID does not match target node OID"));
00168     return SNMP_ERR_NOSUCHINSTANCE;
00169   }
00170 
00171   memset(&call_data->proxy_instance, 0, sizeof(call_data->proxy_instance));
00172 
00173   instance->reference.ptr = call_data;
00174   snmp_oid_assign(&call_data->proxy_instance.instance_oid, instance->instance_oid.id, instance->instance_oid.len);
00175 
00176   call_data->proxy_instance.node = &threadsync_node->target->node;
00177   call_data->threadsync_node     = threadsync_node;
00178 
00179   call_data->arg1.root_oid       = root_oid;
00180   call_data->arg2.root_oid_len   = root_oid_len;
00181   call_synced_function(call_data, fn);
00182 
00183   if (call_data->retval.err == SNMP_ERR_NOERROR) {
00184     instance->access           = call_data->proxy_instance.access;
00185     instance->asn1_type        = call_data->proxy_instance.asn1_type;
00186     instance->release_instance = threadsync_release_instance;
00187     instance->get_value        = (call_data->proxy_instance.get_value != NULL)? threadsync_get_value : NULL;
00188     instance->set_value        = (call_data->proxy_instance.set_value != NULL)? threadsync_set_value : NULL;
00189     instance->set_test         = (call_data->proxy_instance.set_test != NULL)?  threadsync_set_test  : NULL;
00190     snmp_oid_assign(&instance->instance_oid, call_data->proxy_instance.instance_oid.id, call_data->proxy_instance.instance_oid.len);
00191   }
00192 
00193   return call_data->retval.err;
00194 }
00195 
00196 snmp_err_t
00197 snmp_threadsync_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
00198 {
00199   return do_sync(root_oid, root_oid_len, instance, get_instance_synced);
00200 }
00201 
00202 snmp_err_t
00203 snmp_threadsync_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
00204 {
00205   return do_sync(root_oid, root_oid_len, instance, get_next_instance_synced);
00206 }
00207 
00208 /** Initializes thread synchronization instance */
00209 void snmp_threadsync_init(struct snmp_threadsync_instance *instance, snmp_threadsync_synchronizer_fn sync_fn)
00210 {
00211   err_t err = sys_mutex_new(&instance->sem_usage_mutex);
00212   LWIP_ASSERT("Failed to set up mutex", err == ERR_OK);
00213   err = sys_sem_new(&instance->sem, 0);
00214   LWIP_ASSERT("Failed to set up semaphore", err == ERR_OK);
00215   instance->sync_fn = sync_fn;
00216 }
00217 
00218 #endif /* LWIP_SNMP */