1 /** 2 * @file 3 * SNMP thread synchronization implementation. 4 */ 5 6 /* 7 * Copyright (c) 2001-2004 Swedish Institute of Computer Science. 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without modification, 11 * are permitted provided that the following conditions are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright notice, 14 * this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright notice, 16 * this list of conditions and the following disclaimer in the documentation 17 * and/or other materials provided with the distribution. 18 * 3. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 24 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 26 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 29 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 30 * OF SUCH DAMAGE. 31 * 32 * Author: Dirk Ziegelmeier <dziegel@gmx.de> 33 */ 34 35 #include "lwip/apps/snmp_opts.h" 36 37 #if LWIP_SNMP && (NO_SYS == 0) /* don't build if not configured for use in lwipopts.h */ 38 39 #include "lwip/apps/snmp_threadsync.h" 40 #include "lwip/apps/snmp_core.h" 41 #include "lwip/sys.h" 42 #include <string.h> 43 44 static void 45 call_synced_function(struct threadsync_data *call_data, snmp_threadsync_called_fn fn) 46 { 47 sys_mutex_lock(&call_data->threadsync_node->instance->sem_usage_mutex); 48 call_data->threadsync_node->instance->sync_fn(fn, call_data); 49 sys_sem_wait(&call_data->threadsync_node->instance->sem); 50 sys_mutex_unlock(&call_data->threadsync_node->instance->sem_usage_mutex); 51 } 52 53 static void 54 threadsync_get_value_synced(void *ctx) 55 { 56 struct threadsync_data *call_data = (struct threadsync_data*)ctx; 57 58 call_data->retval.s16 = call_data->proxy_instance.get_value(&call_data->proxy_instance, call_data->arg1.value); 59 60 sys_sem_signal(&call_data->threadsync_node->instance->sem); 61 } 62 63 static s16_t 64 threadsync_get_value(struct snmp_node_instance* instance, void* value) 65 { 66 struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr; 67 68 call_data->arg1.value = value; 69 call_synced_function(call_data, threadsync_get_value_synced); 70 71 return call_data->retval.s16; 72 } 73 74 static void 75 threadsync_set_test_synced(void *ctx) 76 { 77 struct threadsync_data *call_data = (struct threadsync_data*)ctx; 78 79 call_data->retval.err = call_data->proxy_instance.set_test(&call_data->proxy_instance, call_data->arg2.len, call_data->arg1.value); 80 81 sys_sem_signal(&call_data->threadsync_node->instance->sem); 82 } 83 84 static snmp_err_t 85 threadsync_set_test(struct snmp_node_instance* instance, u16_t len, void *value) 86 { 87 struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr; 88 89 call_data->arg1.value = value; 90 call_data->arg2.len = len; 91 call_synced_function(call_data, threadsync_set_test_synced); 92 93 return call_data->retval.err; 94 } 95 96 static void 97 threadsync_set_value_synced(void *ctx) 98 { 99 struct threadsync_data *call_data = (struct threadsync_data*)ctx; 100 101 call_data->retval.err = call_data->proxy_instance.set_value(&call_data->proxy_instance, call_data->arg2.len, call_data->arg1.value); 102 103 sys_sem_signal(&call_data->threadsync_node->instance->sem); 104 } 105 106 static snmp_err_t 107 threadsync_set_value(struct snmp_node_instance* instance, u16_t len, void *value) 108 { 109 struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr; 110 111 call_data->arg1.value = value; 112 call_data->arg2.len = len; 113 call_synced_function(call_data, threadsync_set_value_synced); 114 115 return call_data->retval.err; 116 } 117 118 static void 119 threadsync_release_instance_synced(void* ctx) 120 { 121 struct threadsync_data *call_data = (struct threadsync_data*)ctx; 122 123 call_data->proxy_instance.release_instance(&call_data->proxy_instance); 124 125 sys_sem_signal(&call_data->threadsync_node->instance->sem); 126 } 127 128 static void 129 threadsync_release_instance(struct snmp_node_instance *instance) 130 { 131 struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr; 132 133 if (call_data->proxy_instance.release_instance != NULL) { 134 call_synced_function(call_data, threadsync_release_instance_synced); 135 } 136 } 137 138 static void 139 get_instance_synced(void* ctx) 140 { 141 struct threadsync_data *call_data = (struct threadsync_data*)ctx; 142 const struct snmp_leaf_node *leaf = (const struct snmp_leaf_node*)(const void*)call_data->proxy_instance.node; 143 144 call_data->retval.err = leaf->get_instance(call_data->arg1.root_oid, call_data->arg2.root_oid_len, &call_data->proxy_instance); 145 146 sys_sem_signal(&call_data->threadsync_node->instance->sem); 147 } 148 149 static void 150 get_next_instance_synced(void* ctx) 151 { 152 struct threadsync_data *call_data = (struct threadsync_data*)ctx; 153 const struct snmp_leaf_node *leaf = (const struct snmp_leaf_node*)(const void*)call_data->proxy_instance.node; 154 155 call_data->retval.err = leaf->get_next_instance(call_data->arg1.root_oid, call_data->arg2.root_oid_len, &call_data->proxy_instance); 156 157 sys_sem_signal(&call_data->threadsync_node->instance->sem); 158 } 159 160 static snmp_err_t 161 do_sync(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance, snmp_threadsync_called_fn fn) 162 { 163 const struct snmp_threadsync_node *threadsync_node = (const struct snmp_threadsync_node*)(const void*)instance->node; 164 struct threadsync_data *call_data = &threadsync_node->instance->data; 165 166 if (threadsync_node->node.node.oid != threadsync_node->target->node.oid) { 167 LWIP_DEBUGF(SNMP_DEBUG, ("Sync node OID does not match target node OID")); 168 return SNMP_ERR_NOSUCHINSTANCE; 169 } 170 171 memset(&call_data->proxy_instance, 0, sizeof(call_data->proxy_instance)); 172 173 instance->reference.ptr = call_data; 174 snmp_oid_assign(&call_data->proxy_instance.instance_oid, instance->instance_oid.id, instance->instance_oid.len); 175 176 call_data->proxy_instance.node = &threadsync_node->target->node; 177 call_data->threadsync_node = threadsync_node; 178 179 call_data->arg1.root_oid = root_oid; 180 call_data->arg2.root_oid_len = root_oid_len; 181 call_synced_function(call_data, fn); 182 183 if (call_data->retval.err == SNMP_ERR_NOERROR) { 184 instance->access = call_data->proxy_instance.access; 185 instance->asn1_type = call_data->proxy_instance.asn1_type; 186 instance->release_instance = threadsync_release_instance; 187 instance->get_value = (call_data->proxy_instance.get_value != NULL)? threadsync_get_value : NULL; 188 instance->set_value = (call_data->proxy_instance.set_value != NULL)? threadsync_set_value : NULL; 189 instance->set_test = (call_data->proxy_instance.set_test != NULL)? threadsync_set_test : NULL; 190 snmp_oid_assign(&instance->instance_oid, call_data->proxy_instance.instance_oid.id, call_data->proxy_instance.instance_oid.len); 191 } 192 193 return call_data->retval.err; 194 } 195 196 snmp_err_t 197 snmp_threadsync_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance) 198 { 199 return do_sync(root_oid, root_oid_len, instance, get_instance_synced); 200 } 201 202 snmp_err_t 203 snmp_threadsync_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance) 204 { 205 return do_sync(root_oid, root_oid_len, instance, get_next_instance_synced); 206 } 207 208 /** Initializes thread synchronization instance */ 209 void snmp_threadsync_init(struct snmp_threadsync_instance *instance, snmp_threadsync_synchronizer_fn sync_fn) 210 { 211 err_t err = sys_mutex_new(&instance->sem_usage_mutex); 212 LWIP_ASSERT("Failed to set up mutex", err == ERR_OK); 213 err = sys_sem_new(&instance->sem, 0); 214 LWIP_UNUSED_ARG(err); /* in case of LWIP_NOASSERT */ 215 LWIP_ASSERT("Failed to set up semaphore", err == ERR_OK); 216 instance->sync_fn = sync_fn; 217 } 218 219 #endif /* LWIP_SNMP */ 220