Patrick Ciccone
Ethernet for Nucleo and Disco board STM32F746 works with gcc and arm. IAC is untested
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Dieter Graef
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msg_in.c
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00001 /** 00002 * @file 00003 * SNMP input message processing (RFC1157). 00004 */ 00005 00006 /* 00007 * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. 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: Christiaan Simons <christiaan.simons@axon.tv> 00033 */ 00034 00035 #include "lwip/opt.h" 00036 00037 #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */ 00038 00039 #include "lwip/snmp.h" 00040 #include "lwip/snmp_asn1.h" 00041 #include "lwip/snmp_msg.h" 00042 #include "lwip/snmp_structs.h" 00043 #include "lwip/ip_addr.h" 00044 #include "lwip/memp.h" 00045 #include "lwip/udp.h" 00046 #include "lwip/stats.h" 00047 00048 #include <string.h> 00049 00050 /* public (non-static) constants */ 00051 /** SNMP v1 == 0 */ 00052 const s32_t snmp_version = 0; 00053 /** default SNMP community string */ 00054 const char snmp_publiccommunity[7] = "public"; 00055 00056 /* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */ 00057 struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS]; 00058 /* UDP Protocol Control Block */ 00059 struct udp_pcb *snmp1_pcb; 00060 00061 static void snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port); 00062 static err_t snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat); 00063 static err_t snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat); 00064 00065 00066 /** 00067 * Starts SNMP Agent. 00068 * Allocates UDP pcb and binds it to IP_ADDR_ANY port 161. 00069 */ 00070 void 00071 snmp_init(void) 00072 { 00073 struct snmp_msg_pstat *msg_ps; 00074 u8_t i; 00075 00076 snmp1_pcb = udp_new(); 00077 if (snmp1_pcb != NULL) 00078 { 00079 udp_recv(snmp1_pcb, snmp_recv, (void *)SNMP_IN_PORT); 00080 udp_bind(snmp1_pcb, IP_ADDR_ANY, SNMP_IN_PORT); 00081 } 00082 msg_ps = &msg_input_list[0]; 00083 for (i=0; i<SNMP_CONCURRENT_REQUESTS; i++) 00084 { 00085 msg_ps->state = SNMP_MSG_EMPTY; 00086 msg_ps->error_index = 0; 00087 msg_ps->error_status = SNMP_ES_NOERROR; 00088 msg_ps++; 00089 } 00090 trap_msg.pcb = snmp1_pcb; 00091 00092 #ifdef SNMP_PRIVATE_MIB_INIT 00093 /* If defined, this must be a function-like define to initialize the 00094 * private MIB after the stack has been initialized. 00095 * The private MIB can also be initialized in tcpip_callback (or after 00096 * the stack is initialized), this define is only for convenience. */ 00097 SNMP_PRIVATE_MIB_INIT(); 00098 #endif /* SNMP_PRIVATE_MIB_INIT */ 00099 00100 /* The coldstart trap will only be output 00101 if our outgoing interface is up & configured */ 00102 snmp_coldstart_trap(); 00103 } 00104 00105 static void 00106 snmp_error_response(struct snmp_msg_pstat *msg_ps, u8_t error) 00107 { 00108 /* move names back from outvb to invb */ 00109 int v; 00110 struct snmp_varbind *vbi = msg_ps->invb.head; 00111 struct snmp_varbind *vbo = msg_ps->outvb.head; 00112 for (v=0; v<msg_ps->vb_idx; v++) { 00113 vbi->ident_len = vbo->ident_len; 00114 vbo->ident_len = 0; 00115 vbi->ident = vbo->ident; 00116 vbo->ident = NULL; 00117 vbi = vbi->next; 00118 vbo = vbo->next; 00119 } 00120 /* free outvb */ 00121 snmp_varbind_list_free(&msg_ps->outvb); 00122 /* we send invb back */ 00123 msg_ps->outvb = msg_ps->invb; 00124 msg_ps->invb.head = NULL; 00125 msg_ps->invb.tail = NULL; 00126 msg_ps->invb.count = 0; 00127 msg_ps->error_status = error; 00128 /* error index must be 0 for error too big */ 00129 msg_ps->error_index = (error != SNMP_ES_TOOBIG) ? (1 + msg_ps->vb_idx) : 0; 00130 snmp_send_response(msg_ps); 00131 snmp_varbind_list_free(&msg_ps->outvb); 00132 msg_ps->state = SNMP_MSG_EMPTY; 00133 } 00134 00135 static void 00136 snmp_ok_response(struct snmp_msg_pstat *msg_ps) 00137 { 00138 err_t err_ret; 00139 00140 err_ret = snmp_send_response(msg_ps); 00141 if (err_ret == ERR_MEM) 00142 { 00143 /* serious memory problem, can't return tooBig */ 00144 } 00145 else 00146 { 00147 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event = %"S32_F"\n",msg_ps->error_status)); 00148 } 00149 /* free varbinds (if available) */ 00150 snmp_varbind_list_free(&msg_ps->invb); 00151 snmp_varbind_list_free(&msg_ps->outvb); 00152 msg_ps->state = SNMP_MSG_EMPTY; 00153 } 00154 00155 /** 00156 * Service an internal or external event for SNMP GET. 00157 * 00158 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) 00159 * @param msg_ps points to the assosicated message process state 00160 */ 00161 static void 00162 snmp_msg_get_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) 00163 { 00164 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_get_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); 00165 00166 if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) 00167 { 00168 struct mib_external_node *en; 00169 struct snmp_name_ptr np; 00170 00171 /* get_object_def() answer*/ 00172 en = msg_ps->ext_mib_node; 00173 np = msg_ps->ext_name_ptr; 00174 00175 /* translate answer into a known lifeform */ 00176 en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); 00177 if ((msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) && 00178 (msg_ps->ext_object_def.access & MIB_ACCESS_READ)) 00179 { 00180 msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE; 00181 en->get_value_q(request_id, &msg_ps->ext_object_def); 00182 } 00183 else 00184 { 00185 en->get_object_def_pc(request_id, np.ident_len, np.ident); 00186 /* search failed, object id points to unknown object (nosuchname) */ 00187 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00188 } 00189 } 00190 else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE) 00191 { 00192 struct mib_external_node *en; 00193 struct snmp_varbind *vb; 00194 00195 /* get_value() answer */ 00196 en = msg_ps->ext_mib_node; 00197 00198 /* allocate output varbind */ 00199 vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); 00200 if (vb != NULL) 00201 { 00202 vb->next = NULL; 00203 vb->prev = NULL; 00204 00205 /* move name from invb to outvb */ 00206 vb->ident = msg_ps->vb_ptr->ident; 00207 vb->ident_len = msg_ps->vb_ptr->ident_len; 00208 /* ensure this memory is refereced once only */ 00209 msg_ps->vb_ptr->ident = NULL; 00210 msg_ps->vb_ptr->ident_len = 0; 00211 00212 vb->value_type = msg_ps->ext_object_def.asn_type; 00213 LWIP_ASSERT("invalid length", msg_ps->ext_object_def.v_len <= 0xff); 00214 vb->value_len = (u8_t)msg_ps->ext_object_def.v_len; 00215 if (vb->value_len > 0) 00216 { 00217 LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", vb->value_len <= SNMP_MAX_VALUE_SIZE); 00218 vb->value = memp_malloc(MEMP_SNMP_VALUE); 00219 if (vb->value != NULL) 00220 { 00221 en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value); 00222 snmp_varbind_tail_add(&msg_ps->outvb, vb); 00223 /* search again (if vb_idx < msg_ps->invb.count) */ 00224 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00225 msg_ps->vb_idx += 1; 00226 } 00227 else 00228 { 00229 en->get_value_pc(request_id, &msg_ps->ext_object_def); 00230 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no variable space\n")); 00231 msg_ps->vb_ptr->ident = vb->ident; 00232 msg_ps->vb_ptr->ident_len = vb->ident_len; 00233 memp_free(MEMP_SNMP_VARBIND, vb); 00234 snmp_error_response(msg_ps,SNMP_ES_TOOBIG); 00235 } 00236 } 00237 else 00238 { 00239 /* vb->value_len == 0, empty value (e.g. empty string) */ 00240 en->get_value_a(request_id, &msg_ps->ext_object_def, 0, NULL); 00241 vb->value = NULL; 00242 snmp_varbind_tail_add(&msg_ps->outvb, vb); 00243 /* search again (if vb_idx < msg_ps->invb.count) */ 00244 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00245 msg_ps->vb_idx += 1; 00246 } 00247 } 00248 else 00249 { 00250 en->get_value_pc(request_id, &msg_ps->ext_object_def); 00251 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no outvb space\n")); 00252 snmp_error_response(msg_ps,SNMP_ES_TOOBIG); 00253 } 00254 } 00255 00256 while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && 00257 (msg_ps->vb_idx < msg_ps->invb.count)) 00258 { 00259 struct mib_node *mn; 00260 struct snmp_name_ptr np; 00261 00262 if (msg_ps->vb_idx == 0) 00263 { 00264 msg_ps->vb_ptr = msg_ps->invb.head; 00265 } 00266 else 00267 { 00268 msg_ps->vb_ptr = msg_ps->vb_ptr->next; 00269 } 00270 /** test object identifier for .iso.org.dod.internet prefix */ 00271 if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident)) 00272 { 00273 mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, 00274 msg_ps->vb_ptr->ident + 4, &np); 00275 if (mn != NULL) 00276 { 00277 if (mn->node_type == MIB_NODE_EX) 00278 { 00279 /* external object */ 00280 struct mib_external_node *en = (struct mib_external_node*)mn; 00281 00282 msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; 00283 /* save en && args in msg_ps!! */ 00284 msg_ps->ext_mib_node = en; 00285 msg_ps->ext_name_ptr = np; 00286 00287 en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); 00288 } 00289 else 00290 { 00291 /* internal object */ 00292 struct obj_def object_def; 00293 00294 msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; 00295 mn->get_object_def(np.ident_len, np.ident, &object_def); 00296 if ((object_def.instance != MIB_OBJECT_NONE) && 00297 (object_def.access & MIB_ACCESS_READ)) 00298 { 00299 mn = mn; 00300 } 00301 else 00302 { 00303 /* search failed, object id points to unknown object (nosuchname) */ 00304 mn = NULL; 00305 } 00306 if (mn != NULL) 00307 { 00308 struct snmp_varbind *vb; 00309 00310 msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE; 00311 /* allocate output varbind */ 00312 vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); 00313 if (vb != NULL) 00314 { 00315 vb->next = NULL; 00316 vb->prev = NULL; 00317 00318 /* move name from invb to outvb */ 00319 vb->ident = msg_ps->vb_ptr->ident; 00320 vb->ident_len = msg_ps->vb_ptr->ident_len; 00321 /* ensure this memory is refereced once only */ 00322 msg_ps->vb_ptr->ident = NULL; 00323 msg_ps->vb_ptr->ident_len = 0; 00324 00325 vb->value_type = object_def.asn_type; 00326 LWIP_ASSERT("invalid length", object_def.v_len <= 0xff); 00327 vb->value_len = (u8_t)object_def.v_len; 00328 if (vb->value_len > 0) 00329 { 00330 LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", 00331 vb->value_len <= SNMP_MAX_VALUE_SIZE); 00332 vb->value = memp_malloc(MEMP_SNMP_VALUE); 00333 if (vb->value != NULL) 00334 { 00335 mn->get_value(&object_def, vb->value_len, vb->value); 00336 snmp_varbind_tail_add(&msg_ps->outvb, vb); 00337 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00338 msg_ps->vb_idx += 1; 00339 } 00340 else 00341 { 00342 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate variable space\n")); 00343 msg_ps->vb_ptr->ident = vb->ident; 00344 msg_ps->vb_ptr->ident_len = vb->ident_len; 00345 vb->ident = NULL; 00346 vb->ident_len = 0; 00347 memp_free(MEMP_SNMP_VARBIND, vb); 00348 snmp_error_response(msg_ps,SNMP_ES_TOOBIG); 00349 } 00350 } 00351 else 00352 { 00353 /* vb->value_len == 0, empty value (e.g. empty string) */ 00354 vb->value = NULL; 00355 snmp_varbind_tail_add(&msg_ps->outvb, vb); 00356 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00357 msg_ps->vb_idx += 1; 00358 } 00359 } 00360 else 00361 { 00362 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate outvb space\n")); 00363 snmp_error_response(msg_ps,SNMP_ES_TOOBIG); 00364 } 00365 } 00366 } 00367 } 00368 } 00369 else 00370 { 00371 mn = NULL; 00372 } 00373 if (mn == NULL) 00374 { 00375 /* mn == NULL, noSuchName */ 00376 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00377 } 00378 } 00379 if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && 00380 (msg_ps->vb_idx == msg_ps->invb.count)) 00381 { 00382 snmp_ok_response(msg_ps); 00383 } 00384 } 00385 00386 /** 00387 * Service an internal or external event for SNMP GETNEXT. 00388 * 00389 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) 00390 * @param msg_ps points to the assosicated message process state 00391 */ 00392 static void 00393 snmp_msg_getnext_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) 00394 { 00395 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); 00396 00397 if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) 00398 { 00399 struct mib_external_node *en; 00400 00401 /* get_object_def() answer*/ 00402 en = msg_ps->ext_mib_node; 00403 00404 /* translate answer into a known lifeform */ 00405 en->get_object_def_a(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1], &msg_ps->ext_object_def); 00406 if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) 00407 { 00408 msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE; 00409 en->get_value_q(request_id, &msg_ps->ext_object_def); 00410 } 00411 else 00412 { 00413 en->get_object_def_pc(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1]); 00414 /* search failed, object id points to unknown object (nosuchname) */ 00415 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00416 } 00417 } 00418 else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE) 00419 { 00420 struct mib_external_node *en; 00421 struct snmp_varbind *vb; 00422 00423 /* get_value() answer */ 00424 en = msg_ps->ext_mib_node; 00425 00426 LWIP_ASSERT("invalid length", msg_ps->ext_object_def.v_len <= 0xff); 00427 vb = snmp_varbind_alloc(&msg_ps->ext_oid, 00428 msg_ps->ext_object_def.asn_type, 00429 (u8_t)msg_ps->ext_object_def.v_len); 00430 if (vb != NULL) 00431 { 00432 en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value); 00433 snmp_varbind_tail_add(&msg_ps->outvb, vb); 00434 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00435 msg_ps->vb_idx += 1; 00436 } 00437 else 00438 { 00439 en->get_value_pc(request_id, &msg_ps->ext_object_def); 00440 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: couldn't allocate outvb space\n")); 00441 snmp_error_response(msg_ps,SNMP_ES_TOOBIG); 00442 } 00443 } 00444 00445 while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && 00446 (msg_ps->vb_idx < msg_ps->invb.count)) 00447 { 00448 struct mib_node *mn; 00449 struct snmp_obj_id oid; 00450 00451 if (msg_ps->vb_idx == 0) 00452 { 00453 msg_ps->vb_ptr = msg_ps->invb.head; 00454 } 00455 else 00456 { 00457 msg_ps->vb_ptr = msg_ps->vb_ptr->next; 00458 } 00459 if (snmp_iso_prefix_expand(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident, &oid)) 00460 { 00461 if (msg_ps->vb_ptr->ident_len > 3) 00462 { 00463 /* can offset ident_len and ident */ 00464 mn = snmp_expand_tree((struct mib_node*)&internet, 00465 msg_ps->vb_ptr->ident_len - 4, 00466 msg_ps->vb_ptr->ident + 4, &oid); 00467 } 00468 else 00469 { 00470 /* can't offset ident_len -4, ident + 4 */ 00471 mn = snmp_expand_tree((struct mib_node*)&internet, 0, NULL, &oid); 00472 } 00473 } 00474 else 00475 { 00476 mn = NULL; 00477 } 00478 if (mn != NULL) 00479 { 00480 if (mn->node_type == MIB_NODE_EX) 00481 { 00482 /* external object */ 00483 struct mib_external_node *en = (struct mib_external_node*)mn; 00484 00485 msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; 00486 /* save en && args in msg_ps!! */ 00487 msg_ps->ext_mib_node = en; 00488 msg_ps->ext_oid = oid; 00489 00490 en->get_object_def_q(en->addr_inf, request_id, 1, &oid.id[oid.len - 1]); 00491 } 00492 else 00493 { 00494 /* internal object */ 00495 struct obj_def object_def; 00496 struct snmp_varbind *vb; 00497 00498 msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; 00499 mn->get_object_def(1, &oid.id[oid.len - 1], &object_def); 00500 00501 LWIP_ASSERT("invalid length", object_def.v_len <= 0xff); 00502 vb = snmp_varbind_alloc(&oid, object_def.asn_type, (u8_t)object_def.v_len); 00503 if (vb != NULL) 00504 { 00505 msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE; 00506 mn->get_value(&object_def, object_def.v_len, vb->value); 00507 snmp_varbind_tail_add(&msg_ps->outvb, vb); 00508 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00509 msg_ps->vb_idx += 1; 00510 } 00511 else 00512 { 00513 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv couldn't allocate outvb space\n")); 00514 snmp_error_response(msg_ps,SNMP_ES_TOOBIG); 00515 } 00516 } 00517 } 00518 if (mn == NULL) 00519 { 00520 /* mn == NULL, noSuchName */ 00521 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00522 } 00523 } 00524 if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && 00525 (msg_ps->vb_idx == msg_ps->invb.count)) 00526 { 00527 snmp_ok_response(msg_ps); 00528 } 00529 } 00530 00531 /** 00532 * Service an internal or external event for SNMP SET. 00533 * 00534 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) 00535 * @param msg_ps points to the assosicated message process state 00536 */ 00537 static void 00538 snmp_msg_set_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) 00539 { 00540 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_set_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); 00541 00542 if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) 00543 { 00544 struct mib_external_node *en; 00545 struct snmp_name_ptr np; 00546 00547 /* get_object_def() answer*/ 00548 en = msg_ps->ext_mib_node; 00549 np = msg_ps->ext_name_ptr; 00550 00551 /* translate answer into a known lifeform */ 00552 en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); 00553 if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) 00554 { 00555 msg_ps->state = SNMP_MSG_EXTERNAL_SET_TEST; 00556 en->set_test_q(request_id, &msg_ps->ext_object_def); 00557 } 00558 else 00559 { 00560 en->get_object_def_pc(request_id, np.ident_len, np.ident); 00561 /* search failed, object id points to unknown object (nosuchname) */ 00562 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00563 } 00564 } 00565 else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_TEST) 00566 { 00567 struct mib_external_node *en; 00568 00569 /* set_test() answer*/ 00570 en = msg_ps->ext_mib_node; 00571 00572 if (msg_ps->ext_object_def.access & MIB_ACCESS_WRITE) 00573 { 00574 if ((msg_ps->ext_object_def.asn_type == msg_ps->vb_ptr->value_type) && 00575 (en->set_test_a(request_id,&msg_ps->ext_object_def, 00576 msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0)) 00577 { 00578 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00579 msg_ps->vb_idx += 1; 00580 } 00581 else 00582 { 00583 en->set_test_pc(request_id,&msg_ps->ext_object_def); 00584 /* bad value */ 00585 snmp_error_response(msg_ps,SNMP_ES_BADVALUE); 00586 } 00587 } 00588 else 00589 { 00590 en->set_test_pc(request_id,&msg_ps->ext_object_def); 00591 /* object not available for set */ 00592 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00593 } 00594 } 00595 else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF_S) 00596 { 00597 struct mib_external_node *en; 00598 struct snmp_name_ptr np; 00599 00600 /* get_object_def() answer*/ 00601 en = msg_ps->ext_mib_node; 00602 np = msg_ps->ext_name_ptr; 00603 00604 /* translate answer into a known lifeform */ 00605 en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); 00606 if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) 00607 { 00608 msg_ps->state = SNMP_MSG_EXTERNAL_SET_VALUE; 00609 en->set_value_q(request_id, &msg_ps->ext_object_def, 00610 msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value); 00611 } 00612 else 00613 { 00614 en->get_object_def_pc(request_id, np.ident_len, np.ident); 00615 /* set_value failed, object has disappeared for some odd reason?? */ 00616 snmp_error_response(msg_ps,SNMP_ES_GENERROR); 00617 } 00618 } 00619 else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_VALUE) 00620 { 00621 struct mib_external_node *en; 00622 00623 /** set_value_a() */ 00624 en = msg_ps->ext_mib_node; 00625 en->set_value_a(request_id, &msg_ps->ext_object_def, 00626 msg_ps->vb_ptr->value_len, msg_ps->vb_ptr->value); 00627 00628 /** @todo use set_value_pc() if toobig */ 00629 msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; 00630 msg_ps->vb_idx += 1; 00631 } 00632 00633 /* test all values before setting */ 00634 while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && 00635 (msg_ps->vb_idx < msg_ps->invb.count)) 00636 { 00637 struct mib_node *mn; 00638 struct snmp_name_ptr np; 00639 00640 if (msg_ps->vb_idx == 0) 00641 { 00642 msg_ps->vb_ptr = msg_ps->invb.head; 00643 } 00644 else 00645 { 00646 msg_ps->vb_ptr = msg_ps->vb_ptr->next; 00647 } 00648 /** test object identifier for .iso.org.dod.internet prefix */ 00649 if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident)) 00650 { 00651 mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, 00652 msg_ps->vb_ptr->ident + 4, &np); 00653 if (mn != NULL) 00654 { 00655 if (mn->node_type == MIB_NODE_EX) 00656 { 00657 /* external object */ 00658 struct mib_external_node *en = (struct mib_external_node*)mn; 00659 00660 msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; 00661 /* save en && args in msg_ps!! */ 00662 msg_ps->ext_mib_node = en; 00663 msg_ps->ext_name_ptr = np; 00664 00665 en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); 00666 } 00667 else 00668 { 00669 /* internal object */ 00670 struct obj_def object_def; 00671 00672 msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; 00673 mn->get_object_def(np.ident_len, np.ident, &object_def); 00674 if (object_def.instance != MIB_OBJECT_NONE) 00675 { 00676 mn = mn; 00677 } 00678 else 00679 { 00680 /* search failed, object id points to unknown object (nosuchname) */ 00681 mn = NULL; 00682 } 00683 if (mn != NULL) 00684 { 00685 msg_ps->state = SNMP_MSG_INTERNAL_SET_TEST; 00686 00687 if (object_def.access & MIB_ACCESS_WRITE) 00688 { 00689 if ((object_def.asn_type == msg_ps->vb_ptr->value_type) && 00690 (mn->set_test(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0)) 00691 { 00692 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00693 msg_ps->vb_idx += 1; 00694 } 00695 else 00696 { 00697 /* bad value */ 00698 snmp_error_response(msg_ps,SNMP_ES_BADVALUE); 00699 } 00700 } 00701 else 00702 { 00703 /* object not available for set */ 00704 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00705 } 00706 } 00707 } 00708 } 00709 } 00710 else 00711 { 00712 mn = NULL; 00713 } 00714 if (mn == NULL) 00715 { 00716 /* mn == NULL, noSuchName */ 00717 snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); 00718 } 00719 } 00720 00721 if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && 00722 (msg_ps->vb_idx == msg_ps->invb.count)) 00723 { 00724 msg_ps->vb_idx = 0; 00725 msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; 00726 } 00727 00728 /* set all values "atomically" (be as "atomic" as possible) */ 00729 while ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) && 00730 (msg_ps->vb_idx < msg_ps->invb.count)) 00731 { 00732 struct mib_node *mn; 00733 struct snmp_name_ptr np; 00734 00735 if (msg_ps->vb_idx == 0) 00736 { 00737 msg_ps->vb_ptr = msg_ps->invb.head; 00738 } 00739 else 00740 { 00741 msg_ps->vb_ptr = msg_ps->vb_ptr->next; 00742 } 00743 /* skip iso prefix test, was done previously while settesting() */ 00744 mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, 00745 msg_ps->vb_ptr->ident + 4, &np); 00746 /* check if object is still available 00747 (e.g. external hot-plug thingy present?) */ 00748 if (mn != NULL) 00749 { 00750 if (mn->node_type == MIB_NODE_EX) 00751 { 00752 /* external object */ 00753 struct mib_external_node *en = (struct mib_external_node*)mn; 00754 00755 msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF_S; 00756 /* save en && args in msg_ps!! */ 00757 msg_ps->ext_mib_node = en; 00758 msg_ps->ext_name_ptr = np; 00759 00760 en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); 00761 } 00762 else 00763 { 00764 /* internal object */ 00765 struct obj_def object_def; 00766 00767 msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF_S; 00768 mn->get_object_def(np.ident_len, np.ident, &object_def); 00769 msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; 00770 mn->set_value(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value); 00771 msg_ps->vb_idx += 1; 00772 } 00773 } 00774 } 00775 if ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) && 00776 (msg_ps->vb_idx == msg_ps->invb.count)) 00777 { 00778 /* simply echo the input if we can set it 00779 @todo do we need to return the actual value? 00780 e.g. if value is silently modified or behaves sticky? */ 00781 msg_ps->outvb = msg_ps->invb; 00782 msg_ps->invb.head = NULL; 00783 msg_ps->invb.tail = NULL; 00784 msg_ps->invb.count = 0; 00785 snmp_ok_response(msg_ps); 00786 } 00787 } 00788 00789 00790 /** 00791 * Handle one internal or external event. 00792 * Called for one async event. (recv external/private answer) 00793 * 00794 * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) 00795 */ 00796 void 00797 snmp_msg_event(u8_t request_id) 00798 { 00799 struct snmp_msg_pstat *msg_ps; 00800 00801 if (request_id < SNMP_CONCURRENT_REQUESTS) 00802 { 00803 msg_ps = &msg_input_list[request_id]; 00804 if (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ) 00805 { 00806 snmp_msg_getnext_event(request_id, msg_ps); 00807 } 00808 else if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ) 00809 { 00810 snmp_msg_get_event(request_id, msg_ps); 00811 } 00812 else if(msg_ps->rt == SNMP_ASN1_PDU_SET_REQ) 00813 { 00814 snmp_msg_set_event(request_id, msg_ps); 00815 } 00816 } 00817 } 00818 00819 00820 /* lwIP UDP receive callback function */ 00821 static void 00822 snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) 00823 { 00824 struct snmp_msg_pstat *msg_ps; 00825 u8_t req_idx; 00826 err_t err_ret; 00827 u16_t payload_len = p->tot_len; 00828 u16_t payload_ofs = 0; 00829 u16_t varbind_ofs = 0; 00830 00831 /* suppress unused argument warning */ 00832 LWIP_UNUSED_ARG(arg); 00833 00834 /* traverse input message process list, look for SNMP_MSG_EMPTY */ 00835 msg_ps = &msg_input_list[0]; 00836 req_idx = 0; 00837 while ((req_idx < SNMP_CONCURRENT_REQUESTS) && (msg_ps->state != SNMP_MSG_EMPTY)) 00838 { 00839 req_idx++; 00840 msg_ps++; 00841 } 00842 if (req_idx == SNMP_CONCURRENT_REQUESTS) 00843 { 00844 /* exceeding number of concurrent requests */ 00845 pbuf_free(p); 00846 return; 00847 } 00848 00849 /* accepting request */ 00850 snmp_inc_snmpinpkts(); 00851 /* record used 'protocol control block' */ 00852 msg_ps->pcb = pcb; 00853 /* source address (network order) */ 00854 msg_ps->sip = *addr; 00855 /* source port (host order (lwIP oddity)) */ 00856 msg_ps->sp = port; 00857 00858 /* check total length, version, community, pdu type */ 00859 err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps); 00860 /* Only accept requests and requests without error (be robust) */ 00861 /* Reject response and trap headers or error requests as input! */ 00862 if ((err_ret != ERR_OK) || 00863 ((msg_ps->rt != SNMP_ASN1_PDU_GET_REQ) && 00864 (msg_ps->rt != SNMP_ASN1_PDU_GET_NEXT_REQ) && 00865 (msg_ps->rt != SNMP_ASN1_PDU_SET_REQ)) || 00866 ((msg_ps->error_status != SNMP_ES_NOERROR) || 00867 (msg_ps->error_index != 0)) ) 00868 { 00869 /* header check failed drop request silently, do not return error! */ 00870 pbuf_free(p); 00871 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n")); 00872 return; 00873 } 00874 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community)); 00875 00876 /* Builds a list of variable bindings. Copy the varbinds from the pbuf 00877 chain to glue them when these are divided over two or more pbuf's. */ 00878 err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps); 00879 /* we've decoded the incoming message, release input msg now */ 00880 pbuf_free(p); 00881 if ((err_ret != ERR_OK) || (msg_ps->invb.count == 0)) 00882 { 00883 /* varbind-list decode failed, or varbind list empty. 00884 drop request silently, do not return error! 00885 (errors are only returned for a specific varbind failure) */ 00886 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n")); 00887 return; 00888 } 00889 00890 msg_ps->error_status = SNMP_ES_NOERROR; 00891 msg_ps->error_index = 0; 00892 /* find object for each variable binding */ 00893 msg_ps->state = SNMP_MSG_SEARCH_OBJ; 00894 /* first variable binding from list to inspect */ 00895 msg_ps->vb_idx = 0; 00896 00897 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count)); 00898 00899 /* handle input event and as much objects as possible in one go */ 00900 snmp_msg_event(req_idx); 00901 } 00902 00903 /** 00904 * Checks and decodes incoming SNMP message header, logs header errors. 00905 * 00906 * @param p points to pbuf chain of SNMP message (UDP payload) 00907 * @param ofs points to first octet of SNMP message 00908 * @param pdu_len the length of the UDP payload 00909 * @param ofs_ret returns the ofset of the variable bindings 00910 * @param m_stat points to the current message request state return 00911 * @return 00912 * - ERR_OK SNMP header is sane and accepted 00913 * - ERR_ARG SNMP header is either malformed or rejected 00914 */ 00915 static err_t 00916 snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) 00917 { 00918 err_t derr; 00919 u16_t len, ofs_base; 00920 u8_t len_octets; 00921 u8_t type; 00922 s32_t version; 00923 00924 ofs_base = ofs; 00925 snmp_asn1_dec_type(p, ofs, &type); 00926 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 00927 if ((derr != ERR_OK) || 00928 (pdu_len != (1 + len_octets + len)) || 00929 (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) 00930 { 00931 snmp_inc_snmpinasnparseerrs(); 00932 return ERR_ARG; 00933 } 00934 ofs += (1 + len_octets); 00935 snmp_asn1_dec_type(p, ofs, &type); 00936 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 00937 if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) 00938 { 00939 /* can't decode or no integer (version) */ 00940 snmp_inc_snmpinasnparseerrs(); 00941 return ERR_ARG; 00942 } 00943 derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &version); 00944 if (derr != ERR_OK) 00945 { 00946 /* can't decode */ 00947 snmp_inc_snmpinasnparseerrs(); 00948 return ERR_ARG; 00949 } 00950 if (version != 0) 00951 { 00952 /* not version 1 */ 00953 snmp_inc_snmpinbadversions(); 00954 return ERR_ARG; 00955 } 00956 ofs += (1 + len_octets + len); 00957 snmp_asn1_dec_type(p, ofs, &type); 00958 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 00959 if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR))) 00960 { 00961 /* can't decode or no octet string (community) */ 00962 snmp_inc_snmpinasnparseerrs(); 00963 return ERR_ARG; 00964 } 00965 derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, SNMP_COMMUNITY_STR_LEN, m_stat->community); 00966 if (derr != ERR_OK) 00967 { 00968 snmp_inc_snmpinasnparseerrs(); 00969 return ERR_ARG; 00970 } 00971 /* add zero terminator */ 00972 len = ((len < (SNMP_COMMUNITY_STR_LEN))?(len):(SNMP_COMMUNITY_STR_LEN)); 00973 m_stat->community[len] = 0; 00974 m_stat->com_strlen = (u8_t)len; 00975 if (strncmp(snmp_publiccommunity, (const char*)m_stat->community, SNMP_COMMUNITY_STR_LEN) != 0) 00976 { 00977 /** @todo: move this if we need to check more names */ 00978 snmp_inc_snmpinbadcommunitynames(); 00979 snmp_authfail_trap(); 00980 return ERR_ARG; 00981 } 00982 ofs += (1 + len_octets + len); 00983 snmp_asn1_dec_type(p, ofs, &type); 00984 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 00985 if (derr != ERR_OK) 00986 { 00987 snmp_inc_snmpinasnparseerrs(); 00988 return ERR_ARG; 00989 } 00990 switch(type) 00991 { 00992 case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_REQ): 00993 /* GetRequest PDU */ 00994 snmp_inc_snmpingetrequests(); 00995 derr = ERR_OK; 00996 break; 00997 case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_NEXT_REQ): 00998 /* GetNextRequest PDU */ 00999 snmp_inc_snmpingetnexts(); 01000 derr = ERR_OK; 01001 break; 01002 case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP): 01003 /* GetResponse PDU */ 01004 snmp_inc_snmpingetresponses(); 01005 derr = ERR_ARG; 01006 break; 01007 case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_SET_REQ): 01008 /* SetRequest PDU */ 01009 snmp_inc_snmpinsetrequests(); 01010 derr = ERR_OK; 01011 break; 01012 case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP): 01013 /* Trap PDU */ 01014 snmp_inc_snmpintraps(); 01015 derr = ERR_ARG; 01016 break; 01017 default: 01018 snmp_inc_snmpinasnparseerrs(); 01019 derr = ERR_ARG; 01020 break; 01021 } 01022 if (derr != ERR_OK) 01023 { 01024 /* unsupported input PDU for this agent (no parse error) */ 01025 return ERR_ARG; 01026 } 01027 m_stat->rt = type & 0x1F; 01028 ofs += (1 + len_octets); 01029 if (len != (pdu_len - (ofs - ofs_base))) 01030 { 01031 /* decoded PDU length does not equal actual payload length */ 01032 snmp_inc_snmpinasnparseerrs(); 01033 return ERR_ARG; 01034 } 01035 snmp_asn1_dec_type(p, ofs, &type); 01036 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 01037 if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) 01038 { 01039 /* can't decode or no integer (request ID) */ 01040 snmp_inc_snmpinasnparseerrs(); 01041 return ERR_ARG; 01042 } 01043 derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->rid); 01044 if (derr != ERR_OK) 01045 { 01046 /* can't decode */ 01047 snmp_inc_snmpinasnparseerrs(); 01048 return ERR_ARG; 01049 } 01050 ofs += (1 + len_octets + len); 01051 snmp_asn1_dec_type(p, ofs, &type); 01052 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 01053 if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) 01054 { 01055 /* can't decode or no integer (error-status) */ 01056 snmp_inc_snmpinasnparseerrs(); 01057 return ERR_ARG; 01058 } 01059 /* must be noError (0) for incoming requests. 01060 log errors for mib-2 completeness and for debug purposes */ 01061 derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_status); 01062 if (derr != ERR_OK) 01063 { 01064 /* can't decode */ 01065 snmp_inc_snmpinasnparseerrs(); 01066 return ERR_ARG; 01067 } 01068 switch (m_stat->error_status) 01069 { 01070 case SNMP_ES_TOOBIG: 01071 snmp_inc_snmpintoobigs(); 01072 break; 01073 case SNMP_ES_NOSUCHNAME: 01074 snmp_inc_snmpinnosuchnames(); 01075 break; 01076 case SNMP_ES_BADVALUE: 01077 snmp_inc_snmpinbadvalues(); 01078 break; 01079 case SNMP_ES_READONLY: 01080 snmp_inc_snmpinreadonlys(); 01081 break; 01082 case SNMP_ES_GENERROR: 01083 snmp_inc_snmpingenerrs(); 01084 break; 01085 } 01086 ofs += (1 + len_octets + len); 01087 snmp_asn1_dec_type(p, ofs, &type); 01088 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 01089 if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) 01090 { 01091 /* can't decode or no integer (error-index) */ 01092 snmp_inc_snmpinasnparseerrs(); 01093 return ERR_ARG; 01094 } 01095 /* must be 0 for incoming requests. 01096 decode anyway to catch bad integers (and dirty tricks) */ 01097 derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_index); 01098 if (derr != ERR_OK) 01099 { 01100 /* can't decode */ 01101 snmp_inc_snmpinasnparseerrs(); 01102 return ERR_ARG; 01103 } 01104 ofs += (1 + len_octets + len); 01105 *ofs_ret = ofs; 01106 return ERR_OK; 01107 } 01108 01109 static err_t 01110 snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) 01111 { 01112 err_t derr; 01113 u16_t len, vb_len; 01114 u8_t len_octets; 01115 u8_t type; 01116 01117 /* variable binding list */ 01118 snmp_asn1_dec_type(p, ofs, &type); 01119 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &vb_len); 01120 if ((derr != ERR_OK) || 01121 (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) 01122 { 01123 snmp_inc_snmpinasnparseerrs(); 01124 return ERR_ARG; 01125 } 01126 ofs += (1 + len_octets); 01127 01128 /* start with empty list */ 01129 m_stat->invb.count = 0; 01130 m_stat->invb.head = NULL; 01131 m_stat->invb.tail = NULL; 01132 01133 while (vb_len > 0) 01134 { 01135 struct snmp_obj_id oid, oid_value; 01136 struct snmp_varbind *vb; 01137 01138 snmp_asn1_dec_type(p, ofs, &type); 01139 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 01140 if ((derr != ERR_OK) || 01141 (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)) || 01142 (len == 0) || (len > vb_len)) 01143 { 01144 snmp_inc_snmpinasnparseerrs(); 01145 /* free varbinds (if available) */ 01146 snmp_varbind_list_free(&m_stat->invb); 01147 return ERR_ARG; 01148 } 01149 ofs += (1 + len_octets); 01150 vb_len -= (1 + len_octets); 01151 01152 snmp_asn1_dec_type(p, ofs, &type); 01153 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 01154 if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID))) 01155 { 01156 /* can't decode object name length */ 01157 snmp_inc_snmpinasnparseerrs(); 01158 /* free varbinds (if available) */ 01159 snmp_varbind_list_free(&m_stat->invb); 01160 return ERR_ARG; 01161 } 01162 derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid); 01163 if (derr != ERR_OK) 01164 { 01165 /* can't decode object name */ 01166 snmp_inc_snmpinasnparseerrs(); 01167 /* free varbinds (if available) */ 01168 snmp_varbind_list_free(&m_stat->invb); 01169 return ERR_ARG; 01170 } 01171 ofs += (1 + len_octets + len); 01172 vb_len -= (1 + len_octets + len); 01173 01174 snmp_asn1_dec_type(p, ofs, &type); 01175 derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); 01176 if (derr != ERR_OK) 01177 { 01178 /* can't decode object value length */ 01179 snmp_inc_snmpinasnparseerrs(); 01180 /* free varbinds (if available) */ 01181 snmp_varbind_list_free(&m_stat->invb); 01182 return ERR_ARG; 01183 } 01184 01185 switch (type) 01186 { 01187 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG): 01188 vb = snmp_varbind_alloc(&oid, type, sizeof(s32_t)); 01189 if (vb != NULL) 01190 { 01191 s32_t *vptr = (s32_t*)vb->value; 01192 01193 derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, vptr); 01194 snmp_varbind_tail_add(&m_stat->invb, vb); 01195 } 01196 else 01197 { 01198 derr = ERR_ARG; 01199 } 01200 break; 01201 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER): 01202 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE): 01203 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS): 01204 vb = snmp_varbind_alloc(&oid, type, sizeof(u32_t)); 01205 if (vb != NULL) 01206 { 01207 u32_t *vptr = (u32_t*)vb->value; 01208 01209 derr = snmp_asn1_dec_u32t(p, ofs + 1 + len_octets, len, vptr); 01210 snmp_varbind_tail_add(&m_stat->invb, vb); 01211 } 01212 else 01213 { 01214 derr = ERR_ARG; 01215 } 01216 break; 01217 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR): 01218 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE): 01219 LWIP_ASSERT("invalid length", len <= 0xff); 01220 vb = snmp_varbind_alloc(&oid, type, (u8_t)len); 01221 if (vb != NULL) 01222 { 01223 derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, (u8_t*)vb->value); 01224 snmp_varbind_tail_add(&m_stat->invb, vb); 01225 } 01226 else 01227 { 01228 derr = ERR_ARG; 01229 } 01230 break; 01231 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL): 01232 vb = snmp_varbind_alloc(&oid, type, 0); 01233 if (vb != NULL) 01234 { 01235 snmp_varbind_tail_add(&m_stat->invb, vb); 01236 derr = ERR_OK; 01237 } 01238 else 01239 { 01240 derr = ERR_ARG; 01241 } 01242 break; 01243 case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID): 01244 derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid_value); 01245 if (derr == ERR_OK) 01246 { 01247 vb = snmp_varbind_alloc(&oid, type, oid_value.len * sizeof(s32_t)); 01248 if (vb != NULL) 01249 { 01250 u8_t i = oid_value.len; 01251 s32_t *vptr = (s32_t*)vb->value; 01252 01253 while(i > 0) 01254 { 01255 i--; 01256 vptr[i] = oid_value.id[i]; 01257 } 01258 snmp_varbind_tail_add(&m_stat->invb, vb); 01259 derr = ERR_OK; 01260 } 01261 else 01262 { 01263 derr = ERR_ARG; 01264 } 01265 } 01266 break; 01267 case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR): 01268 if (len == 4) 01269 { 01270 /* must be exactly 4 octets! */ 01271 vb = snmp_varbind_alloc(&oid, type, 4); 01272 if (vb != NULL) 01273 { 01274 derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, (u8_t*)vb->value); 01275 snmp_varbind_tail_add(&m_stat->invb, vb); 01276 } 01277 else 01278 { 01279 derr = ERR_ARG; 01280 } 01281 } 01282 else 01283 { 01284 derr = ERR_ARG; 01285 } 01286 break; 01287 default: 01288 derr = ERR_ARG; 01289 break; 01290 } 01291 if (derr != ERR_OK) 01292 { 01293 snmp_inc_snmpinasnparseerrs(); 01294 /* free varbinds (if available) */ 01295 snmp_varbind_list_free(&m_stat->invb); 01296 return ERR_ARG; 01297 } 01298 ofs += (1 + len_octets + len); 01299 vb_len -= (1 + len_octets + len); 01300 } 01301 01302 if (m_stat->rt == SNMP_ASN1_PDU_SET_REQ) 01303 { 01304 snmp_add_snmpintotalsetvars(m_stat->invb.count); 01305 } 01306 else 01307 { 01308 snmp_add_snmpintotalreqvars(m_stat->invb.count); 01309 } 01310 01311 *ofs_ret = ofs; 01312 return ERR_OK; 01313 } 01314 01315 struct snmp_varbind* 01316 snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len) 01317 { 01318 struct snmp_varbind *vb; 01319 01320 vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); 01321 if (vb != NULL) 01322 { 01323 u8_t i; 01324 01325 vb->next = NULL; 01326 vb->prev = NULL; 01327 i = oid->len; 01328 vb->ident_len = i; 01329 if (i > 0) 01330 { 01331 LWIP_ASSERT("SNMP_MAX_TREE_DEPTH is configured too low", i <= SNMP_MAX_TREE_DEPTH); 01332 /* allocate array of s32_t for our object identifier */ 01333 vb->ident = (s32_t*)memp_malloc(MEMP_SNMP_VALUE); 01334 if (vb->ident == NULL) 01335 { 01336 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_varbind_alloc: couldn't allocate ident value space\n")); 01337 memp_free(MEMP_SNMP_VARBIND, vb); 01338 return NULL; 01339 } 01340 while(i > 0) 01341 { 01342 i--; 01343 vb->ident[i] = oid->id[i]; 01344 } 01345 } 01346 else 01347 { 01348 /* i == 0, pass zero length object identifier */ 01349 vb->ident = NULL; 01350 } 01351 vb->value_type = type; 01352 vb->value_len = len; 01353 if (len > 0) 01354 { 01355 LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", vb->value_len <= SNMP_MAX_VALUE_SIZE); 01356 /* allocate raw bytes for our object value */ 01357 vb->value = memp_malloc(MEMP_SNMP_VALUE); 01358 if (vb->value == NULL) 01359 { 01360 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_varbind_alloc: couldn't allocate value space\n")); 01361 if (vb->ident != NULL) 01362 { 01363 memp_free(MEMP_SNMP_VALUE, vb->ident); 01364 } 01365 memp_free(MEMP_SNMP_VARBIND, vb); 01366 return NULL; 01367 } 01368 } 01369 else 01370 { 01371 /* ASN1_NUL type, or zero length ASN1_OC_STR */ 01372 vb->value = NULL; 01373 } 01374 } 01375 else 01376 { 01377 LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_varbind_alloc: couldn't allocate varbind space\n")); 01378 } 01379 return vb; 01380 } 01381 01382 void 01383 snmp_varbind_free(struct snmp_varbind *vb) 01384 { 01385 if (vb->value != NULL ) 01386 { 01387 memp_free(MEMP_SNMP_VALUE, vb->value); 01388 } 01389 if (vb->ident != NULL ) 01390 { 01391 memp_free(MEMP_SNMP_VALUE, vb->ident); 01392 } 01393 memp_free(MEMP_SNMP_VARBIND, vb); 01394 } 01395 01396 void 01397 snmp_varbind_list_free(struct snmp_varbind_root *root) 01398 { 01399 struct snmp_varbind *vb, *prev; 01400 01401 vb = root->tail; 01402 while ( vb != NULL ) 01403 { 01404 prev = vb->prev; 01405 snmp_varbind_free(vb); 01406 vb = prev; 01407 } 01408 root->count = 0; 01409 root->head = NULL; 01410 root->tail = NULL; 01411 } 01412 01413 void 01414 snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb) 01415 { 01416 if (root->count == 0) 01417 { 01418 /* add first varbind to list */ 01419 root->head = vb; 01420 root->tail = vb; 01421 } 01422 else 01423 { 01424 /* add nth varbind to list tail */ 01425 root->tail->next = vb; 01426 vb->prev = root->tail; 01427 root->tail = vb; 01428 } 01429 root->count += 1; 01430 } 01431 01432 struct snmp_varbind* 01433 snmp_varbind_tail_remove(struct snmp_varbind_root *root) 01434 { 01435 struct snmp_varbind* vb; 01436 01437 if (root->count > 0) 01438 { 01439 /* remove tail varbind */ 01440 vb = root->tail; 01441 root->tail = vb->prev; 01442 vb->prev->next = NULL; 01443 root->count -= 1; 01444 } 01445 else 01446 { 01447 /* nothing to remove */ 01448 vb = NULL; 01449 } 01450 return vb; 01451 } 01452 01453 #endif /* LWIP_SNMP */
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