Greg Hartman | 76d05dc | 2016-11-23 15:51:27 -0800 | [diff] [blame^] | 1 | /** |
| 2 | * @file |
| 3 | * SNMP input message processing (RFC1157). |
| 4 | */ |
| 5 | |
| 6 | /* |
| 7 | * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. |
| 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: Christiaan Simons <christiaan.simons@axon.tv> |
| 33 | */ |
| 34 | |
| 35 | #include "lwip/opt.h" |
| 36 | |
| 37 | #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */ |
| 38 | |
| 39 | #include "lwip/snmp.h" |
| 40 | #include "lwip/snmp_asn1.h" |
| 41 | #include "lwip/snmp_msg.h" |
| 42 | #include "lwip/snmp_structs.h" |
| 43 | #include "lwip/ip_addr.h" |
| 44 | #include "lwip/memp.h" |
| 45 | #include "lwip/udp.h" |
| 46 | #include "lwip/stats.h" |
| 47 | |
| 48 | #include <string.h> |
| 49 | |
| 50 | /* public (non-static) constants */ |
| 51 | /** SNMP v1 == 0 */ |
| 52 | const s32_t snmp_version = 0; |
| 53 | /** default SNMP community string */ |
| 54 | const char snmp_publiccommunity[7] = "public"; |
| 55 | |
| 56 | /* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */ |
| 57 | struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS]; |
| 58 | /* UDP Protocol Control Block */ |
| 59 | struct udp_pcb *snmp1_pcb; |
| 60 | |
| 61 | static void snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port); |
| 62 | 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); |
| 63 | static err_t snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat); |
| 64 | |
| 65 | |
| 66 | /** |
| 67 | * Starts SNMP Agent. |
| 68 | * Allocates UDP pcb and binds it to IP_ADDR_ANY port 161. |
| 69 | */ |
| 70 | void |
| 71 | snmp_init(void) |
| 72 | { |
| 73 | struct snmp_msg_pstat *msg_ps; |
| 74 | u8_t i; |
| 75 | |
| 76 | snmp1_pcb = udp_new(); |
| 77 | if (snmp1_pcb != NULL) |
| 78 | { |
| 79 | udp_recv(snmp1_pcb, snmp_recv, (void *)SNMP_IN_PORT); |
| 80 | udp_bind(snmp1_pcb, IP_ADDR_ANY, SNMP_IN_PORT); |
| 81 | } |
| 82 | msg_ps = &msg_input_list[0]; |
| 83 | for (i=0; i<SNMP_CONCURRENT_REQUESTS; i++) |
| 84 | { |
| 85 | msg_ps->state = SNMP_MSG_EMPTY; |
| 86 | msg_ps->error_index = 0; |
| 87 | msg_ps->error_status = SNMP_ES_NOERROR; |
| 88 | msg_ps++; |
| 89 | } |
| 90 | trap_msg.pcb = snmp1_pcb; |
| 91 | |
| 92 | #ifdef SNMP_PRIVATE_MIB_INIT |
| 93 | /* If defined, rhis must be a function-like define to initialize the |
| 94 | * private MIB after the stack has been initialized. |
| 95 | * The private MIB can also be initialized in tcpip_callback (or after |
| 96 | * the stack is initialized), this define is only for convenience. */ |
| 97 | SNMP_PRIVATE_MIB_INIT(); |
| 98 | #endif /* SNMP_PRIVATE_MIB_INIT */ |
| 99 | |
| 100 | /* The coldstart trap will only be output |
| 101 | if our outgoing interface is up & configured */ |
| 102 | snmp_coldstart_trap(); |
| 103 | } |
| 104 | |
| 105 | static void |
| 106 | snmp_error_response(struct snmp_msg_pstat *msg_ps, u8_t error) |
| 107 | { |
| 108 | snmp_varbind_list_free(&msg_ps->outvb); |
| 109 | msg_ps->outvb = msg_ps->invb; |
| 110 | msg_ps->invb.head = NULL; |
| 111 | msg_ps->invb.tail = NULL; |
| 112 | msg_ps->invb.count = 0; |
| 113 | msg_ps->error_status = error; |
| 114 | msg_ps->error_index = 1 + msg_ps->vb_idx; |
| 115 | snmp_send_response(msg_ps); |
| 116 | snmp_varbind_list_free(&msg_ps->outvb); |
| 117 | msg_ps->state = SNMP_MSG_EMPTY; |
| 118 | } |
| 119 | |
| 120 | static void |
| 121 | snmp_ok_response(struct snmp_msg_pstat *msg_ps) |
| 122 | { |
| 123 | err_t err_ret; |
| 124 | |
| 125 | err_ret = snmp_send_response(msg_ps); |
| 126 | if (err_ret == ERR_MEM) |
| 127 | { |
| 128 | /* serious memory problem, can't return tooBig */ |
| 129 | } |
| 130 | else |
| 131 | { |
| 132 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event = %"S32_F"\n",msg_ps->error_status)); |
| 133 | } |
| 134 | /* free varbinds (if available) */ |
| 135 | snmp_varbind_list_free(&msg_ps->invb); |
| 136 | snmp_varbind_list_free(&msg_ps->outvb); |
| 137 | msg_ps->state = SNMP_MSG_EMPTY; |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Service an internal or external event for SNMP GET. |
| 142 | * |
| 143 | * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) |
| 144 | * @param msg_ps points to the assosicated message process state |
| 145 | */ |
| 146 | static void |
| 147 | snmp_msg_get_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) |
| 148 | { |
| 149 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_get_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); |
| 150 | |
| 151 | if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) |
| 152 | { |
| 153 | struct mib_external_node *en; |
| 154 | struct snmp_name_ptr np; |
| 155 | |
| 156 | /* get_object_def() answer*/ |
| 157 | en = msg_ps->ext_mib_node; |
| 158 | np = msg_ps->ext_name_ptr; |
| 159 | |
| 160 | /* translate answer into a known lifeform */ |
| 161 | en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); |
| 162 | if ((msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) && |
| 163 | (msg_ps->ext_object_def.access & MIB_ACCESS_READ)) |
| 164 | { |
| 165 | msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE; |
| 166 | en->get_value_q(request_id, &msg_ps->ext_object_def); |
| 167 | } |
| 168 | else |
| 169 | { |
| 170 | en->get_object_def_pc(request_id, np.ident_len, np.ident); |
| 171 | /* search failed, object id points to unknown object (nosuchname) */ |
| 172 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 173 | } |
| 174 | } |
| 175 | else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE) |
| 176 | { |
| 177 | struct mib_external_node *en; |
| 178 | struct snmp_varbind *vb; |
| 179 | |
| 180 | /* get_value() answer */ |
| 181 | en = msg_ps->ext_mib_node; |
| 182 | |
| 183 | /* allocate output varbind */ |
| 184 | vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); |
| 185 | LWIP_ASSERT("vb != NULL",vb != NULL); |
| 186 | if (vb != NULL) |
| 187 | { |
| 188 | vb->next = NULL; |
| 189 | vb->prev = NULL; |
| 190 | |
| 191 | /* move name from invb to outvb */ |
| 192 | vb->ident = msg_ps->vb_ptr->ident; |
| 193 | vb->ident_len = msg_ps->vb_ptr->ident_len; |
| 194 | /* ensure this memory is refereced once only */ |
| 195 | msg_ps->vb_ptr->ident = NULL; |
| 196 | msg_ps->vb_ptr->ident_len = 0; |
| 197 | |
| 198 | vb->value_type = msg_ps->ext_object_def.asn_type; |
| 199 | LWIP_ASSERT("invalid length", msg_ps->ext_object_def.v_len <= 0xff); |
| 200 | vb->value_len = (u8_t)msg_ps->ext_object_def.v_len; |
| 201 | if (vb->value_len > 0) |
| 202 | { |
| 203 | LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", vb->value_len <= SNMP_MAX_VALUE_SIZE); |
| 204 | vb->value = memp_malloc(MEMP_SNMP_VALUE); |
| 205 | LWIP_ASSERT("vb->value != NULL",vb->value != NULL); |
| 206 | if (vb->value != NULL) |
| 207 | { |
| 208 | en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value); |
| 209 | snmp_varbind_tail_add(&msg_ps->outvb, vb); |
| 210 | /* search again (if vb_idx < msg_ps->invb.count) */ |
| 211 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 212 | msg_ps->vb_idx += 1; |
| 213 | } |
| 214 | else |
| 215 | { |
| 216 | en->get_value_pc(request_id, &msg_ps->ext_object_def); |
| 217 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no variable space\n")); |
| 218 | msg_ps->vb_ptr->ident = vb->ident; |
| 219 | msg_ps->vb_ptr->ident_len = vb->ident_len; |
| 220 | memp_free(MEMP_SNMP_VARBIND, vb); |
| 221 | snmp_error_response(msg_ps,SNMP_ES_TOOBIG); |
| 222 | } |
| 223 | } |
| 224 | else |
| 225 | { |
| 226 | /* vb->value_len == 0, empty value (e.g. empty string) */ |
| 227 | en->get_value_a(request_id, &msg_ps->ext_object_def, 0, NULL); |
| 228 | vb->value = NULL; |
| 229 | snmp_varbind_tail_add(&msg_ps->outvb, vb); |
| 230 | /* search again (if vb_idx < msg_ps->invb.count) */ |
| 231 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 232 | msg_ps->vb_idx += 1; |
| 233 | } |
| 234 | } |
| 235 | else |
| 236 | { |
| 237 | en->get_value_pc(request_id, &msg_ps->ext_object_def); |
| 238 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no outvb space\n")); |
| 239 | snmp_error_response(msg_ps,SNMP_ES_TOOBIG); |
| 240 | } |
| 241 | } |
| 242 | |
| 243 | while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && |
| 244 | (msg_ps->vb_idx < msg_ps->invb.count)) |
| 245 | { |
| 246 | struct mib_node *mn; |
| 247 | struct snmp_name_ptr np; |
| 248 | |
| 249 | if (msg_ps->vb_idx == 0) |
| 250 | { |
| 251 | msg_ps->vb_ptr = msg_ps->invb.head; |
| 252 | } |
| 253 | else |
| 254 | { |
| 255 | msg_ps->vb_ptr = msg_ps->vb_ptr->next; |
| 256 | } |
| 257 | /** test object identifier for .iso.org.dod.internet prefix */ |
| 258 | if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident)) |
| 259 | { |
| 260 | mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, |
| 261 | msg_ps->vb_ptr->ident + 4, &np); |
| 262 | if (mn != NULL) |
| 263 | { |
| 264 | if (mn->node_type == MIB_NODE_EX) |
| 265 | { |
| 266 | /* external object */ |
| 267 | struct mib_external_node *en = (struct mib_external_node*)mn; |
| 268 | |
| 269 | msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; |
| 270 | /* save en && args in msg_ps!! */ |
| 271 | msg_ps->ext_mib_node = en; |
| 272 | msg_ps->ext_name_ptr = np; |
| 273 | |
| 274 | en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); |
| 275 | } |
| 276 | else |
| 277 | { |
| 278 | /* internal object */ |
| 279 | struct obj_def object_def; |
| 280 | |
| 281 | msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; |
| 282 | mn->get_object_def(np.ident_len, np.ident, &object_def); |
| 283 | if ((object_def.instance != MIB_OBJECT_NONE) && |
| 284 | (object_def.access & MIB_ACCESS_READ)) |
| 285 | { |
| 286 | mn = mn; |
| 287 | } |
| 288 | else |
| 289 | { |
| 290 | /* search failed, object id points to unknown object (nosuchname) */ |
| 291 | mn = NULL; |
| 292 | } |
| 293 | if (mn != NULL) |
| 294 | { |
| 295 | struct snmp_varbind *vb; |
| 296 | |
| 297 | msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE; |
| 298 | /* allocate output varbind */ |
| 299 | vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); |
| 300 | LWIP_ASSERT("vb != NULL",vb != NULL); |
| 301 | if (vb != NULL) |
| 302 | { |
| 303 | vb->next = NULL; |
| 304 | vb->prev = NULL; |
| 305 | |
| 306 | /* move name from invb to outvb */ |
| 307 | vb->ident = msg_ps->vb_ptr->ident; |
| 308 | vb->ident_len = msg_ps->vb_ptr->ident_len; |
| 309 | /* ensure this memory is refereced once only */ |
| 310 | msg_ps->vb_ptr->ident = NULL; |
| 311 | msg_ps->vb_ptr->ident_len = 0; |
| 312 | |
| 313 | vb->value_type = object_def.asn_type; |
| 314 | LWIP_ASSERT("invalid length", object_def.v_len <= 0xff); |
| 315 | vb->value_len = (u8_t)object_def.v_len; |
| 316 | if (vb->value_len > 0) |
| 317 | { |
| 318 | LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", |
| 319 | vb->value_len <= SNMP_MAX_VALUE_SIZE); |
| 320 | vb->value = memp_malloc(MEMP_SNMP_VALUE); |
| 321 | LWIP_ASSERT("vb->value != NULL",vb->value != NULL); |
| 322 | if (vb->value != NULL) |
| 323 | { |
| 324 | mn->get_value(&object_def, vb->value_len, vb->value); |
| 325 | snmp_varbind_tail_add(&msg_ps->outvb, vb); |
| 326 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 327 | msg_ps->vb_idx += 1; |
| 328 | } |
| 329 | else |
| 330 | { |
| 331 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate variable space\n")); |
| 332 | msg_ps->vb_ptr->ident = vb->ident; |
| 333 | msg_ps->vb_ptr->ident_len = vb->ident_len; |
| 334 | memp_free(MEMP_SNMP_VARBIND, vb); |
| 335 | snmp_error_response(msg_ps,SNMP_ES_TOOBIG); |
| 336 | } |
| 337 | } |
| 338 | else |
| 339 | { |
| 340 | /* vb->value_len == 0, empty value (e.g. empty string) */ |
| 341 | vb->value = NULL; |
| 342 | snmp_varbind_tail_add(&msg_ps->outvb, vb); |
| 343 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 344 | msg_ps->vb_idx += 1; |
| 345 | } |
| 346 | } |
| 347 | else |
| 348 | { |
| 349 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate outvb space\n")); |
| 350 | snmp_error_response(msg_ps,SNMP_ES_TOOBIG); |
| 351 | } |
| 352 | } |
| 353 | } |
| 354 | } |
| 355 | } |
| 356 | else |
| 357 | { |
| 358 | mn = NULL; |
| 359 | } |
| 360 | if (mn == NULL) |
| 361 | { |
| 362 | /* mn == NULL, noSuchName */ |
| 363 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 364 | } |
| 365 | } |
| 366 | if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && |
| 367 | (msg_ps->vb_idx == msg_ps->invb.count)) |
| 368 | { |
| 369 | snmp_ok_response(msg_ps); |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | /** |
| 374 | * Service an internal or external event for SNMP GETNEXT. |
| 375 | * |
| 376 | * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) |
| 377 | * @param msg_ps points to the assosicated message process state |
| 378 | */ |
| 379 | static void |
| 380 | snmp_msg_getnext_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) |
| 381 | { |
| 382 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); |
| 383 | |
| 384 | if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) |
| 385 | { |
| 386 | struct mib_external_node *en; |
| 387 | |
| 388 | /* get_object_def() answer*/ |
| 389 | en = msg_ps->ext_mib_node; |
| 390 | |
| 391 | /* translate answer into a known lifeform */ |
| 392 | en->get_object_def_a(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1], &msg_ps->ext_object_def); |
| 393 | if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) |
| 394 | { |
| 395 | msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE; |
| 396 | en->get_value_q(request_id, &msg_ps->ext_object_def); |
| 397 | } |
| 398 | else |
| 399 | { |
| 400 | en->get_object_def_pc(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1]); |
| 401 | /* search failed, object id points to unknown object (nosuchname) */ |
| 402 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 403 | } |
| 404 | } |
| 405 | else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE) |
| 406 | { |
| 407 | struct mib_external_node *en; |
| 408 | struct snmp_varbind *vb; |
| 409 | |
| 410 | /* get_value() answer */ |
| 411 | en = msg_ps->ext_mib_node; |
| 412 | |
| 413 | LWIP_ASSERT("invalid length", msg_ps->ext_object_def.v_len <= 0xff); |
| 414 | vb = snmp_varbind_alloc(&msg_ps->ext_oid, |
| 415 | msg_ps->ext_object_def.asn_type, |
| 416 | (u8_t)msg_ps->ext_object_def.v_len); |
| 417 | if (vb != NULL) |
| 418 | { |
| 419 | en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value); |
| 420 | snmp_varbind_tail_add(&msg_ps->outvb, vb); |
| 421 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 422 | msg_ps->vb_idx += 1; |
| 423 | } |
| 424 | else |
| 425 | { |
| 426 | en->get_value_pc(request_id, &msg_ps->ext_object_def); |
| 427 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: couldn't allocate outvb space\n")); |
| 428 | snmp_error_response(msg_ps,SNMP_ES_TOOBIG); |
| 429 | } |
| 430 | } |
| 431 | |
| 432 | while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && |
| 433 | (msg_ps->vb_idx < msg_ps->invb.count)) |
| 434 | { |
| 435 | struct mib_node *mn; |
| 436 | struct snmp_obj_id oid; |
| 437 | |
| 438 | if (msg_ps->vb_idx == 0) |
| 439 | { |
| 440 | msg_ps->vb_ptr = msg_ps->invb.head; |
| 441 | } |
| 442 | else |
| 443 | { |
| 444 | msg_ps->vb_ptr = msg_ps->vb_ptr->next; |
| 445 | } |
| 446 | if (snmp_iso_prefix_expand(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident, &oid)) |
| 447 | { |
| 448 | if (msg_ps->vb_ptr->ident_len > 3) |
| 449 | { |
| 450 | /* can offset ident_len and ident */ |
| 451 | mn = snmp_expand_tree((struct mib_node*)&internet, |
| 452 | msg_ps->vb_ptr->ident_len - 4, |
| 453 | msg_ps->vb_ptr->ident + 4, &oid); |
| 454 | } |
| 455 | else |
| 456 | { |
| 457 | /* can't offset ident_len -4, ident + 4 */ |
| 458 | mn = snmp_expand_tree((struct mib_node*)&internet, 0, NULL, &oid); |
| 459 | } |
| 460 | } |
| 461 | else |
| 462 | { |
| 463 | mn = NULL; |
| 464 | } |
| 465 | if (mn != NULL) |
| 466 | { |
| 467 | if (mn->node_type == MIB_NODE_EX) |
| 468 | { |
| 469 | /* external object */ |
| 470 | struct mib_external_node *en = (struct mib_external_node*)mn; |
| 471 | |
| 472 | msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; |
| 473 | /* save en && args in msg_ps!! */ |
| 474 | msg_ps->ext_mib_node = en; |
| 475 | msg_ps->ext_oid = oid; |
| 476 | |
| 477 | en->get_object_def_q(en->addr_inf, request_id, 1, &oid.id[oid.len - 1]); |
| 478 | } |
| 479 | else |
| 480 | { |
| 481 | /* internal object */ |
| 482 | struct obj_def object_def; |
| 483 | struct snmp_varbind *vb; |
| 484 | |
| 485 | msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; |
| 486 | mn->get_object_def(1, &oid.id[oid.len - 1], &object_def); |
| 487 | |
| 488 | LWIP_ASSERT("invalid length", object_def.v_len <= 0xff); |
| 489 | vb = snmp_varbind_alloc(&oid, object_def.asn_type, (u8_t)object_def.v_len); |
| 490 | if (vb != NULL) |
| 491 | { |
| 492 | msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE; |
| 493 | mn->get_value(&object_def, object_def.v_len, vb->value); |
| 494 | snmp_varbind_tail_add(&msg_ps->outvb, vb); |
| 495 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 496 | msg_ps->vb_idx += 1; |
| 497 | } |
| 498 | else |
| 499 | { |
| 500 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv couldn't allocate outvb space\n")); |
| 501 | snmp_error_response(msg_ps,SNMP_ES_TOOBIG); |
| 502 | } |
| 503 | } |
| 504 | } |
| 505 | if (mn == NULL) |
| 506 | { |
| 507 | /* mn == NULL, noSuchName */ |
| 508 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 509 | } |
| 510 | } |
| 511 | if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && |
| 512 | (msg_ps->vb_idx == msg_ps->invb.count)) |
| 513 | { |
| 514 | snmp_ok_response(msg_ps); |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | /** |
| 519 | * Service an internal or external event for SNMP SET. |
| 520 | * |
| 521 | * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) |
| 522 | * @param msg_ps points to the assosicated message process state |
| 523 | */ |
| 524 | static void |
| 525 | snmp_msg_set_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) |
| 526 | { |
| 527 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_set_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); |
| 528 | |
| 529 | if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) |
| 530 | { |
| 531 | struct mib_external_node *en; |
| 532 | struct snmp_name_ptr np; |
| 533 | |
| 534 | /* get_object_def() answer*/ |
| 535 | en = msg_ps->ext_mib_node; |
| 536 | np = msg_ps->ext_name_ptr; |
| 537 | |
| 538 | /* translate answer into a known lifeform */ |
| 539 | en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); |
| 540 | if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) |
| 541 | { |
| 542 | msg_ps->state = SNMP_MSG_EXTERNAL_SET_TEST; |
| 543 | en->set_test_q(request_id, &msg_ps->ext_object_def); |
| 544 | } |
| 545 | else |
| 546 | { |
| 547 | en->get_object_def_pc(request_id, np.ident_len, np.ident); |
| 548 | /* search failed, object id points to unknown object (nosuchname) */ |
| 549 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 550 | } |
| 551 | } |
| 552 | else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_TEST) |
| 553 | { |
| 554 | struct mib_external_node *en; |
| 555 | |
| 556 | /* set_test() answer*/ |
| 557 | en = msg_ps->ext_mib_node; |
| 558 | |
| 559 | if (msg_ps->ext_object_def.access & MIB_ACCESS_WRITE) |
| 560 | { |
| 561 | if ((msg_ps->ext_object_def.asn_type == msg_ps->vb_ptr->value_type) && |
| 562 | (en->set_test_a(request_id,&msg_ps->ext_object_def, |
| 563 | msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0)) |
| 564 | { |
| 565 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 566 | msg_ps->vb_idx += 1; |
| 567 | } |
| 568 | else |
| 569 | { |
| 570 | en->set_test_pc(request_id,&msg_ps->ext_object_def); |
| 571 | /* bad value */ |
| 572 | snmp_error_response(msg_ps,SNMP_ES_BADVALUE); |
| 573 | } |
| 574 | } |
| 575 | else |
| 576 | { |
| 577 | en->set_test_pc(request_id,&msg_ps->ext_object_def); |
| 578 | /* object not available for set */ |
| 579 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 580 | } |
| 581 | } |
| 582 | else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF_S) |
| 583 | { |
| 584 | struct mib_external_node *en; |
| 585 | struct snmp_name_ptr np; |
| 586 | |
| 587 | /* get_object_def() answer*/ |
| 588 | en = msg_ps->ext_mib_node; |
| 589 | np = msg_ps->ext_name_ptr; |
| 590 | |
| 591 | /* translate answer into a known lifeform */ |
| 592 | en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); |
| 593 | if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) |
| 594 | { |
| 595 | msg_ps->state = SNMP_MSG_EXTERNAL_SET_VALUE; |
| 596 | en->set_value_q(request_id, &msg_ps->ext_object_def, |
| 597 | msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value); |
| 598 | } |
| 599 | else |
| 600 | { |
| 601 | en->get_object_def_pc(request_id, np.ident_len, np.ident); |
| 602 | /* set_value failed, object has disappeared for some odd reason?? */ |
| 603 | snmp_error_response(msg_ps,SNMP_ES_GENERROR); |
| 604 | } |
| 605 | } |
| 606 | else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_VALUE) |
| 607 | { |
| 608 | struct mib_external_node *en; |
| 609 | |
| 610 | /** set_value_a() */ |
| 611 | en = msg_ps->ext_mib_node; |
| 612 | en->set_value_a(request_id, &msg_ps->ext_object_def, |
| 613 | msg_ps->vb_ptr->value_len, msg_ps->vb_ptr->value); |
| 614 | |
| 615 | /** @todo use set_value_pc() if toobig */ |
| 616 | msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; |
| 617 | msg_ps->vb_idx += 1; |
| 618 | } |
| 619 | |
| 620 | /* test all values before setting */ |
| 621 | while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && |
| 622 | (msg_ps->vb_idx < msg_ps->invb.count)) |
| 623 | { |
| 624 | struct mib_node *mn; |
| 625 | struct snmp_name_ptr np; |
| 626 | |
| 627 | if (msg_ps->vb_idx == 0) |
| 628 | { |
| 629 | msg_ps->vb_ptr = msg_ps->invb.head; |
| 630 | } |
| 631 | else |
| 632 | { |
| 633 | msg_ps->vb_ptr = msg_ps->vb_ptr->next; |
| 634 | } |
| 635 | /** test object identifier for .iso.org.dod.internet prefix */ |
| 636 | if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident)) |
| 637 | { |
| 638 | mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, |
| 639 | msg_ps->vb_ptr->ident + 4, &np); |
| 640 | if (mn != NULL) |
| 641 | { |
| 642 | if (mn->node_type == MIB_NODE_EX) |
| 643 | { |
| 644 | /* external object */ |
| 645 | struct mib_external_node *en = (struct mib_external_node*)mn; |
| 646 | |
| 647 | msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; |
| 648 | /* save en && args in msg_ps!! */ |
| 649 | msg_ps->ext_mib_node = en; |
| 650 | msg_ps->ext_name_ptr = np; |
| 651 | |
| 652 | en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); |
| 653 | } |
| 654 | else |
| 655 | { |
| 656 | /* internal object */ |
| 657 | struct obj_def object_def; |
| 658 | |
| 659 | msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; |
| 660 | mn->get_object_def(np.ident_len, np.ident, &object_def); |
| 661 | if (object_def.instance != MIB_OBJECT_NONE) |
| 662 | { |
| 663 | mn = mn; |
| 664 | } |
| 665 | else |
| 666 | { |
| 667 | /* search failed, object id points to unknown object (nosuchname) */ |
| 668 | mn = NULL; |
| 669 | } |
| 670 | if (mn != NULL) |
| 671 | { |
| 672 | msg_ps->state = SNMP_MSG_INTERNAL_SET_TEST; |
| 673 | |
| 674 | if (object_def.access & MIB_ACCESS_WRITE) |
| 675 | { |
| 676 | if ((object_def.asn_type == msg_ps->vb_ptr->value_type) && |
| 677 | (mn->set_test(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0)) |
| 678 | { |
| 679 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 680 | msg_ps->vb_idx += 1; |
| 681 | } |
| 682 | else |
| 683 | { |
| 684 | /* bad value */ |
| 685 | snmp_error_response(msg_ps,SNMP_ES_BADVALUE); |
| 686 | } |
| 687 | } |
| 688 | else |
| 689 | { |
| 690 | /* object not available for set */ |
| 691 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 692 | } |
| 693 | } |
| 694 | } |
| 695 | } |
| 696 | } |
| 697 | else |
| 698 | { |
| 699 | mn = NULL; |
| 700 | } |
| 701 | if (mn == NULL) |
| 702 | { |
| 703 | /* mn == NULL, noSuchName */ |
| 704 | snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); |
| 705 | } |
| 706 | } |
| 707 | |
| 708 | if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && |
| 709 | (msg_ps->vb_idx == msg_ps->invb.count)) |
| 710 | { |
| 711 | msg_ps->vb_idx = 0; |
| 712 | msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; |
| 713 | } |
| 714 | |
| 715 | /* set all values "atomically" (be as "atomic" as possible) */ |
| 716 | while ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) && |
| 717 | (msg_ps->vb_idx < msg_ps->invb.count)) |
| 718 | { |
| 719 | struct mib_node *mn; |
| 720 | struct snmp_name_ptr np; |
| 721 | |
| 722 | if (msg_ps->vb_idx == 0) |
| 723 | { |
| 724 | msg_ps->vb_ptr = msg_ps->invb.head; |
| 725 | } |
| 726 | else |
| 727 | { |
| 728 | msg_ps->vb_ptr = msg_ps->vb_ptr->next; |
| 729 | } |
| 730 | /* skip iso prefix test, was done previously while settesting() */ |
| 731 | mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, |
| 732 | msg_ps->vb_ptr->ident + 4, &np); |
| 733 | /* check if object is still available |
| 734 | (e.g. external hot-plug thingy present?) */ |
| 735 | if (mn != NULL) |
| 736 | { |
| 737 | if (mn->node_type == MIB_NODE_EX) |
| 738 | { |
| 739 | /* external object */ |
| 740 | struct mib_external_node *en = (struct mib_external_node*)mn; |
| 741 | |
| 742 | msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF_S; |
| 743 | /* save en && args in msg_ps!! */ |
| 744 | msg_ps->ext_mib_node = en; |
| 745 | msg_ps->ext_name_ptr = np; |
| 746 | |
| 747 | en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); |
| 748 | } |
| 749 | else |
| 750 | { |
| 751 | /* internal object */ |
| 752 | struct obj_def object_def; |
| 753 | |
| 754 | msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF_S; |
| 755 | mn->get_object_def(np.ident_len, np.ident, &object_def); |
| 756 | msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; |
| 757 | mn->set_value(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value); |
| 758 | msg_ps->vb_idx += 1; |
| 759 | } |
| 760 | } |
| 761 | } |
| 762 | if ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) && |
| 763 | (msg_ps->vb_idx == msg_ps->invb.count)) |
| 764 | { |
| 765 | /* simply echo the input if we can set it |
| 766 | @todo do we need to return the actual value? |
| 767 | e.g. if value is silently modified or behaves sticky? */ |
| 768 | msg_ps->outvb = msg_ps->invb; |
| 769 | msg_ps->invb.head = NULL; |
| 770 | msg_ps->invb.tail = NULL; |
| 771 | msg_ps->invb.count = 0; |
| 772 | snmp_ok_response(msg_ps); |
| 773 | } |
| 774 | } |
| 775 | |
| 776 | |
| 777 | /** |
| 778 | * Handle one internal or external event. |
| 779 | * Called for one async event. (recv external/private answer) |
| 780 | * |
| 781 | * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) |
| 782 | */ |
| 783 | void |
| 784 | snmp_msg_event(u8_t request_id) |
| 785 | { |
| 786 | struct snmp_msg_pstat *msg_ps; |
| 787 | |
| 788 | if (request_id < SNMP_CONCURRENT_REQUESTS) |
| 789 | { |
| 790 | msg_ps = &msg_input_list[request_id]; |
| 791 | if (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ) |
| 792 | { |
| 793 | snmp_msg_getnext_event(request_id, msg_ps); |
| 794 | } |
| 795 | else if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ) |
| 796 | { |
| 797 | snmp_msg_get_event(request_id, msg_ps); |
| 798 | } |
| 799 | else if(msg_ps->rt == SNMP_ASN1_PDU_SET_REQ) |
| 800 | { |
| 801 | snmp_msg_set_event(request_id, msg_ps); |
| 802 | } |
| 803 | } |
| 804 | } |
| 805 | |
| 806 | |
| 807 | /* lwIP UDP receive callback function */ |
| 808 | static void |
| 809 | snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) |
| 810 | { |
| 811 | struct snmp_msg_pstat *msg_ps; |
| 812 | u8_t req_idx; |
| 813 | err_t err_ret; |
| 814 | u16_t payload_len = p->tot_len; |
| 815 | u16_t payload_ofs = 0; |
| 816 | u16_t varbind_ofs = 0; |
| 817 | |
| 818 | /* suppress unused argument warning */ |
| 819 | LWIP_UNUSED_ARG(arg); |
| 820 | |
| 821 | /* traverse input message process list, look for SNMP_MSG_EMPTY */ |
| 822 | msg_ps = &msg_input_list[0]; |
| 823 | req_idx = 0; |
| 824 | while ((req_idx < SNMP_CONCURRENT_REQUESTS) && (msg_ps->state != SNMP_MSG_EMPTY)) |
| 825 | { |
| 826 | req_idx++; |
| 827 | msg_ps++; |
| 828 | } |
| 829 | if (req_idx == SNMP_CONCURRENT_REQUESTS) |
| 830 | { |
| 831 | /* exceeding number of concurrent requests */ |
| 832 | pbuf_free(p); |
| 833 | return; |
| 834 | } |
| 835 | |
| 836 | /* accepting request */ |
| 837 | snmp_inc_snmpinpkts(); |
| 838 | /* record used 'protocol control block' */ |
| 839 | msg_ps->pcb = pcb; |
| 840 | /* source address (network order) */ |
| 841 | msg_ps->sip = *addr; |
| 842 | /* source port (host order (lwIP oddity)) */ |
| 843 | msg_ps->sp = port; |
| 844 | |
| 845 | /* check total length, version, community, pdu type */ |
| 846 | err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps); |
| 847 | /* Only accept requests and requests without error (be robust) */ |
| 848 | /* Reject response and trap headers or error requests as input! */ |
| 849 | if ((err_ret != ERR_OK) || |
| 850 | ((msg_ps->rt != SNMP_ASN1_PDU_GET_REQ) && |
| 851 | (msg_ps->rt != SNMP_ASN1_PDU_GET_NEXT_REQ) && |
| 852 | (msg_ps->rt != SNMP_ASN1_PDU_SET_REQ)) || |
| 853 | ((msg_ps->error_status != SNMP_ES_NOERROR) || |
| 854 | (msg_ps->error_index != 0)) ) |
| 855 | { |
| 856 | /* header check failed drop request silently, do not return error! */ |
| 857 | pbuf_free(p); |
| 858 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n")); |
| 859 | return; |
| 860 | } |
| 861 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community)); |
| 862 | |
| 863 | /* Builds a list of variable bindings. Copy the varbinds from the pbuf |
| 864 | chain to glue them when these are divided over two or more pbuf's. */ |
| 865 | err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps); |
| 866 | /* we've decoded the incoming message, release input msg now */ |
| 867 | pbuf_free(p); |
| 868 | if ((err_ret != ERR_OK) || (msg_ps->invb.count == 0)) |
| 869 | { |
| 870 | /* varbind-list decode failed, or varbind list empty. |
| 871 | drop request silently, do not return error! |
| 872 | (errors are only returned for a specific varbind failure) */ |
| 873 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n")); |
| 874 | return; |
| 875 | } |
| 876 | |
| 877 | msg_ps->error_status = SNMP_ES_NOERROR; |
| 878 | msg_ps->error_index = 0; |
| 879 | /* find object for each variable binding */ |
| 880 | msg_ps->state = SNMP_MSG_SEARCH_OBJ; |
| 881 | /* first variable binding from list to inspect */ |
| 882 | msg_ps->vb_idx = 0; |
| 883 | |
| 884 | LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count)); |
| 885 | |
| 886 | /* handle input event and as much objects as possible in one go */ |
| 887 | snmp_msg_event(req_idx); |
| 888 | } |
| 889 | |
| 890 | /** |
| 891 | * Checks and decodes incoming SNMP message header, logs header errors. |
| 892 | * |
| 893 | * @param p points to pbuf chain of SNMP message (UDP payload) |
| 894 | * @param ofs points to first octet of SNMP message |
| 895 | * @param pdu_len the length of the UDP payload |
| 896 | * @param ofs_ret returns the ofset of the variable bindings |
| 897 | * @param m_stat points to the current message request state return |
| 898 | * @return |
| 899 | * - ERR_OK SNMP header is sane and accepted |
| 900 | * - ERR_ARG SNMP header is either malformed or rejected |
| 901 | */ |
| 902 | static err_t |
| 903 | snmp_pdu_header_check(struct pbuf *p, u16_t ofs, u16_t pdu_len, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) |
| 904 | { |
| 905 | err_t derr; |
| 906 | u16_t len, ofs_base; |
| 907 | u8_t len_octets; |
| 908 | u8_t type; |
| 909 | s32_t version; |
| 910 | |
| 911 | ofs_base = ofs; |
| 912 | snmp_asn1_dec_type(p, ofs, &type); |
| 913 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 914 | if ((derr != ERR_OK) || |
| 915 | (pdu_len != (1 + len_octets + len)) || |
| 916 | (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) |
| 917 | { |
| 918 | snmp_inc_snmpinasnparseerrs(); |
| 919 | return ERR_ARG; |
| 920 | } |
| 921 | ofs += (1 + len_octets); |
| 922 | snmp_asn1_dec_type(p, ofs, &type); |
| 923 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 924 | if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) |
| 925 | { |
| 926 | /* can't decode or no integer (version) */ |
| 927 | snmp_inc_snmpinasnparseerrs(); |
| 928 | return ERR_ARG; |
| 929 | } |
| 930 | derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &version); |
| 931 | if (derr != ERR_OK) |
| 932 | { |
| 933 | /* can't decode */ |
| 934 | snmp_inc_snmpinasnparseerrs(); |
| 935 | return ERR_ARG; |
| 936 | } |
| 937 | if (version != 0) |
| 938 | { |
| 939 | /* not version 1 */ |
| 940 | snmp_inc_snmpinbadversions(); |
| 941 | return ERR_ARG; |
| 942 | } |
| 943 | ofs += (1 + len_octets + len); |
| 944 | snmp_asn1_dec_type(p, ofs, &type); |
| 945 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 946 | if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR))) |
| 947 | { |
| 948 | /* can't decode or no octet string (community) */ |
| 949 | snmp_inc_snmpinasnparseerrs(); |
| 950 | return ERR_ARG; |
| 951 | } |
| 952 | derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, SNMP_COMMUNITY_STR_LEN, m_stat->community); |
| 953 | if (derr != ERR_OK) |
| 954 | { |
| 955 | snmp_inc_snmpinasnparseerrs(); |
| 956 | return ERR_ARG; |
| 957 | } |
| 958 | /* add zero terminator */ |
| 959 | len = ((len < (SNMP_COMMUNITY_STR_LEN))?(len):(SNMP_COMMUNITY_STR_LEN)); |
| 960 | m_stat->community[len] = 0; |
| 961 | m_stat->com_strlen = (u8_t)len; |
| 962 | if (strncmp(snmp_publiccommunity, (const char*)m_stat->community, SNMP_COMMUNITY_STR_LEN) != 0) |
| 963 | { |
| 964 | /** @todo: move this if we need to check more names */ |
| 965 | snmp_inc_snmpinbadcommunitynames(); |
| 966 | snmp_authfail_trap(); |
| 967 | return ERR_ARG; |
| 968 | } |
| 969 | ofs += (1 + len_octets + len); |
| 970 | snmp_asn1_dec_type(p, ofs, &type); |
| 971 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 972 | if (derr != ERR_OK) |
| 973 | { |
| 974 | snmp_inc_snmpinasnparseerrs(); |
| 975 | return ERR_ARG; |
| 976 | } |
| 977 | switch(type) |
| 978 | { |
| 979 | case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_REQ): |
| 980 | /* GetRequest PDU */ |
| 981 | snmp_inc_snmpingetrequests(); |
| 982 | derr = ERR_OK; |
| 983 | break; |
| 984 | case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_NEXT_REQ): |
| 985 | /* GetNextRequest PDU */ |
| 986 | snmp_inc_snmpingetnexts(); |
| 987 | derr = ERR_OK; |
| 988 | break; |
| 989 | case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP): |
| 990 | /* GetResponse PDU */ |
| 991 | snmp_inc_snmpingetresponses(); |
| 992 | derr = ERR_ARG; |
| 993 | break; |
| 994 | case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_SET_REQ): |
| 995 | /* SetRequest PDU */ |
| 996 | snmp_inc_snmpinsetrequests(); |
| 997 | derr = ERR_OK; |
| 998 | break; |
| 999 | case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP): |
| 1000 | /* Trap PDU */ |
| 1001 | snmp_inc_snmpintraps(); |
| 1002 | derr = ERR_ARG; |
| 1003 | break; |
| 1004 | default: |
| 1005 | snmp_inc_snmpinasnparseerrs(); |
| 1006 | derr = ERR_ARG; |
| 1007 | break; |
| 1008 | } |
| 1009 | if (derr != ERR_OK) |
| 1010 | { |
| 1011 | /* unsupported input PDU for this agent (no parse error) */ |
| 1012 | return ERR_ARG; |
| 1013 | } |
| 1014 | m_stat->rt = type & 0x1F; |
| 1015 | ofs += (1 + len_octets); |
| 1016 | if (len != (pdu_len - (ofs - ofs_base))) |
| 1017 | { |
| 1018 | /* decoded PDU length does not equal actual payload length */ |
| 1019 | snmp_inc_snmpinasnparseerrs(); |
| 1020 | return ERR_ARG; |
| 1021 | } |
| 1022 | snmp_asn1_dec_type(p, ofs, &type); |
| 1023 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 1024 | if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) |
| 1025 | { |
| 1026 | /* can't decode or no integer (request ID) */ |
| 1027 | snmp_inc_snmpinasnparseerrs(); |
| 1028 | return ERR_ARG; |
| 1029 | } |
| 1030 | derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->rid); |
| 1031 | if (derr != ERR_OK) |
| 1032 | { |
| 1033 | /* can't decode */ |
| 1034 | snmp_inc_snmpinasnparseerrs(); |
| 1035 | return ERR_ARG; |
| 1036 | } |
| 1037 | ofs += (1 + len_octets + len); |
| 1038 | snmp_asn1_dec_type(p, ofs, &type); |
| 1039 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 1040 | if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) |
| 1041 | { |
| 1042 | /* can't decode or no integer (error-status) */ |
| 1043 | snmp_inc_snmpinasnparseerrs(); |
| 1044 | return ERR_ARG; |
| 1045 | } |
| 1046 | /* must be noError (0) for incoming requests. |
| 1047 | log errors for mib-2 completeness and for debug purposes */ |
| 1048 | derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_status); |
| 1049 | if (derr != ERR_OK) |
| 1050 | { |
| 1051 | /* can't decode */ |
| 1052 | snmp_inc_snmpinasnparseerrs(); |
| 1053 | return ERR_ARG; |
| 1054 | } |
| 1055 | switch (m_stat->error_status) |
| 1056 | { |
| 1057 | case SNMP_ES_TOOBIG: |
| 1058 | snmp_inc_snmpintoobigs(); |
| 1059 | break; |
| 1060 | case SNMP_ES_NOSUCHNAME: |
| 1061 | snmp_inc_snmpinnosuchnames(); |
| 1062 | break; |
| 1063 | case SNMP_ES_BADVALUE: |
| 1064 | snmp_inc_snmpinbadvalues(); |
| 1065 | break; |
| 1066 | case SNMP_ES_READONLY: |
| 1067 | snmp_inc_snmpinreadonlys(); |
| 1068 | break; |
| 1069 | case SNMP_ES_GENERROR: |
| 1070 | snmp_inc_snmpingenerrs(); |
| 1071 | break; |
| 1072 | } |
| 1073 | ofs += (1 + len_octets + len); |
| 1074 | snmp_asn1_dec_type(p, ofs, &type); |
| 1075 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 1076 | if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) |
| 1077 | { |
| 1078 | /* can't decode or no integer (error-index) */ |
| 1079 | snmp_inc_snmpinasnparseerrs(); |
| 1080 | return ERR_ARG; |
| 1081 | } |
| 1082 | /* must be 0 for incoming requests. |
| 1083 | decode anyway to catch bad integers (and dirty tricks) */ |
| 1084 | derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_index); |
| 1085 | if (derr != ERR_OK) |
| 1086 | { |
| 1087 | /* can't decode */ |
| 1088 | snmp_inc_snmpinasnparseerrs(); |
| 1089 | return ERR_ARG; |
| 1090 | } |
| 1091 | ofs += (1 + len_octets + len); |
| 1092 | *ofs_ret = ofs; |
| 1093 | return ERR_OK; |
| 1094 | } |
| 1095 | |
| 1096 | static err_t |
| 1097 | snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) |
| 1098 | { |
| 1099 | err_t derr; |
| 1100 | u16_t len, vb_len; |
| 1101 | u8_t len_octets; |
| 1102 | u8_t type; |
| 1103 | |
| 1104 | /* variable binding list */ |
| 1105 | snmp_asn1_dec_type(p, ofs, &type); |
| 1106 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &vb_len); |
| 1107 | if ((derr != ERR_OK) || |
| 1108 | (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) |
| 1109 | { |
| 1110 | snmp_inc_snmpinasnparseerrs(); |
| 1111 | return ERR_ARG; |
| 1112 | } |
| 1113 | ofs += (1 + len_octets); |
| 1114 | |
| 1115 | /* start with empty list */ |
| 1116 | m_stat->invb.count = 0; |
| 1117 | m_stat->invb.head = NULL; |
| 1118 | m_stat->invb.tail = NULL; |
| 1119 | |
| 1120 | while (vb_len > 0) |
| 1121 | { |
| 1122 | struct snmp_obj_id oid, oid_value; |
| 1123 | struct snmp_varbind *vb; |
| 1124 | |
| 1125 | snmp_asn1_dec_type(p, ofs, &type); |
| 1126 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 1127 | if ((derr != ERR_OK) || |
| 1128 | (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)) || |
| 1129 | (len == 0) || (len > vb_len)) |
| 1130 | { |
| 1131 | snmp_inc_snmpinasnparseerrs(); |
| 1132 | /* free varbinds (if available) */ |
| 1133 | snmp_varbind_list_free(&m_stat->invb); |
| 1134 | return ERR_ARG; |
| 1135 | } |
| 1136 | ofs += (1 + len_octets); |
| 1137 | vb_len -= (1 + len_octets); |
| 1138 | |
| 1139 | snmp_asn1_dec_type(p, ofs, &type); |
| 1140 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 1141 | if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID))) |
| 1142 | { |
| 1143 | /* can't decode object name length */ |
| 1144 | snmp_inc_snmpinasnparseerrs(); |
| 1145 | /* free varbinds (if available) */ |
| 1146 | snmp_varbind_list_free(&m_stat->invb); |
| 1147 | return ERR_ARG; |
| 1148 | } |
| 1149 | derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid); |
| 1150 | if (derr != ERR_OK) |
| 1151 | { |
| 1152 | /* can't decode object name */ |
| 1153 | snmp_inc_snmpinasnparseerrs(); |
| 1154 | /* free varbinds (if available) */ |
| 1155 | snmp_varbind_list_free(&m_stat->invb); |
| 1156 | return ERR_ARG; |
| 1157 | } |
| 1158 | ofs += (1 + len_octets + len); |
| 1159 | vb_len -= (1 + len_octets + len); |
| 1160 | |
| 1161 | snmp_asn1_dec_type(p, ofs, &type); |
| 1162 | derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); |
| 1163 | if (derr != ERR_OK) |
| 1164 | { |
| 1165 | /* can't decode object value length */ |
| 1166 | snmp_inc_snmpinasnparseerrs(); |
| 1167 | /* free varbinds (if available) */ |
| 1168 | snmp_varbind_list_free(&m_stat->invb); |
| 1169 | return ERR_ARG; |
| 1170 | } |
| 1171 | |
| 1172 | switch (type) |
| 1173 | { |
| 1174 | case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG): |
| 1175 | vb = snmp_varbind_alloc(&oid, type, sizeof(s32_t)); |
| 1176 | if (vb != NULL) |
| 1177 | { |
| 1178 | s32_t *vptr = (s32_t*)vb->value; |
| 1179 | |
| 1180 | derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, vptr); |
| 1181 | snmp_varbind_tail_add(&m_stat->invb, vb); |
| 1182 | } |
| 1183 | else |
| 1184 | { |
| 1185 | derr = ERR_ARG; |
| 1186 | } |
| 1187 | break; |
| 1188 | case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER): |
| 1189 | case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE): |
| 1190 | case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS): |
| 1191 | vb = snmp_varbind_alloc(&oid, type, sizeof(u32_t)); |
| 1192 | if (vb != NULL) |
| 1193 | { |
| 1194 | u32_t *vptr = (u32_t*)vb->value; |
| 1195 | |
| 1196 | derr = snmp_asn1_dec_u32t(p, ofs + 1 + len_octets, len, vptr); |
| 1197 | snmp_varbind_tail_add(&m_stat->invb, vb); |
| 1198 | } |
| 1199 | else |
| 1200 | { |
| 1201 | derr = ERR_ARG; |
| 1202 | } |
| 1203 | break; |
| 1204 | case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR): |
| 1205 | case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE): |
| 1206 | LWIP_ASSERT("invalid length", len <= 0xff); |
| 1207 | vb = snmp_varbind_alloc(&oid, type, (u8_t)len); |
| 1208 | if (vb != NULL) |
| 1209 | { |
| 1210 | derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, (u8_t*)vb->value); |
| 1211 | snmp_varbind_tail_add(&m_stat->invb, vb); |
| 1212 | } |
| 1213 | else |
| 1214 | { |
| 1215 | derr = ERR_ARG; |
| 1216 | } |
| 1217 | break; |
| 1218 | case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL): |
| 1219 | vb = snmp_varbind_alloc(&oid, type, 0); |
| 1220 | if (vb != NULL) |
| 1221 | { |
| 1222 | snmp_varbind_tail_add(&m_stat->invb, vb); |
| 1223 | derr = ERR_OK; |
| 1224 | } |
| 1225 | else |
| 1226 | { |
| 1227 | derr = ERR_ARG; |
| 1228 | } |
| 1229 | break; |
| 1230 | case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID): |
| 1231 | derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid_value); |
| 1232 | if (derr == ERR_OK) |
| 1233 | { |
| 1234 | vb = snmp_varbind_alloc(&oid, type, oid_value.len * sizeof(s32_t)); |
| 1235 | if (vb != NULL) |
| 1236 | { |
| 1237 | u8_t i = oid_value.len; |
| 1238 | s32_t *vptr = (s32_t*)vb->value; |
| 1239 | |
| 1240 | while(i > 0) |
| 1241 | { |
| 1242 | i--; |
| 1243 | vptr[i] = oid_value.id[i]; |
| 1244 | } |
| 1245 | snmp_varbind_tail_add(&m_stat->invb, vb); |
| 1246 | derr = ERR_OK; |
| 1247 | } |
| 1248 | else |
| 1249 | { |
| 1250 | derr = ERR_ARG; |
| 1251 | } |
| 1252 | } |
| 1253 | break; |
| 1254 | case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR): |
| 1255 | if (len == 4) |
| 1256 | { |
| 1257 | /* must be exactly 4 octets! */ |
| 1258 | vb = snmp_varbind_alloc(&oid, type, 4); |
| 1259 | if (vb != NULL) |
| 1260 | { |
| 1261 | derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, (u8_t*)vb->value); |
| 1262 | snmp_varbind_tail_add(&m_stat->invb, vb); |
| 1263 | } |
| 1264 | else |
| 1265 | { |
| 1266 | derr = ERR_ARG; |
| 1267 | } |
| 1268 | } |
| 1269 | else |
| 1270 | { |
| 1271 | derr = ERR_ARG; |
| 1272 | } |
| 1273 | break; |
| 1274 | default: |
| 1275 | derr = ERR_ARG; |
| 1276 | break; |
| 1277 | } |
| 1278 | if (derr != ERR_OK) |
| 1279 | { |
| 1280 | snmp_inc_snmpinasnparseerrs(); |
| 1281 | /* free varbinds (if available) */ |
| 1282 | snmp_varbind_list_free(&m_stat->invb); |
| 1283 | return ERR_ARG; |
| 1284 | } |
| 1285 | ofs += (1 + len_octets + len); |
| 1286 | vb_len -= (1 + len_octets + len); |
| 1287 | } |
| 1288 | |
| 1289 | if (m_stat->rt == SNMP_ASN1_PDU_SET_REQ) |
| 1290 | { |
| 1291 | snmp_add_snmpintotalsetvars(m_stat->invb.count); |
| 1292 | } |
| 1293 | else |
| 1294 | { |
| 1295 | snmp_add_snmpintotalreqvars(m_stat->invb.count); |
| 1296 | } |
| 1297 | |
| 1298 | *ofs_ret = ofs; |
| 1299 | return ERR_OK; |
| 1300 | } |
| 1301 | |
| 1302 | struct snmp_varbind* |
| 1303 | snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len) |
| 1304 | { |
| 1305 | struct snmp_varbind *vb; |
| 1306 | |
| 1307 | vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); |
| 1308 | LWIP_ASSERT("vb != NULL",vb != NULL); |
| 1309 | if (vb != NULL) |
| 1310 | { |
| 1311 | u8_t i; |
| 1312 | |
| 1313 | vb->next = NULL; |
| 1314 | vb->prev = NULL; |
| 1315 | i = oid->len; |
| 1316 | vb->ident_len = i; |
| 1317 | if (i > 0) |
| 1318 | { |
| 1319 | LWIP_ASSERT("SNMP_MAX_TREE_DEPTH is configured too low", i <= SNMP_MAX_TREE_DEPTH); |
| 1320 | /* allocate array of s32_t for our object identifier */ |
| 1321 | vb->ident = (s32_t*)memp_malloc(MEMP_SNMP_VALUE); |
| 1322 | LWIP_ASSERT("vb->ident != NULL",vb->ident != NULL); |
| 1323 | if (vb->ident == NULL) |
| 1324 | { |
| 1325 | memp_free(MEMP_SNMP_VARBIND, vb); |
| 1326 | return NULL; |
| 1327 | } |
| 1328 | while(i > 0) |
| 1329 | { |
| 1330 | i--; |
| 1331 | vb->ident[i] = oid->id[i]; |
| 1332 | } |
| 1333 | } |
| 1334 | else |
| 1335 | { |
| 1336 | /* i == 0, pass zero length object identifier */ |
| 1337 | vb->ident = NULL; |
| 1338 | } |
| 1339 | vb->value_type = type; |
| 1340 | vb->value_len = len; |
| 1341 | if (len > 0) |
| 1342 | { |
| 1343 | LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", vb->value_len <= SNMP_MAX_VALUE_SIZE); |
| 1344 | /* allocate raw bytes for our object value */ |
| 1345 | vb->value = memp_malloc(MEMP_SNMP_VALUE); |
| 1346 | LWIP_ASSERT("vb->value != NULL",vb->value != NULL); |
| 1347 | if (vb->value == NULL) |
| 1348 | { |
| 1349 | if (vb->ident != NULL) |
| 1350 | { |
| 1351 | memp_free(MEMP_SNMP_VALUE, vb->ident); |
| 1352 | } |
| 1353 | memp_free(MEMP_SNMP_VARBIND, vb); |
| 1354 | return NULL; |
| 1355 | } |
| 1356 | } |
| 1357 | else |
| 1358 | { |
| 1359 | /* ASN1_NUL type, or zero length ASN1_OC_STR */ |
| 1360 | vb->value = NULL; |
| 1361 | } |
| 1362 | } |
| 1363 | return vb; |
| 1364 | } |
| 1365 | |
| 1366 | void |
| 1367 | snmp_varbind_free(struct snmp_varbind *vb) |
| 1368 | { |
| 1369 | if (vb->value != NULL ) |
| 1370 | { |
| 1371 | memp_free(MEMP_SNMP_VALUE, vb->value); |
| 1372 | } |
| 1373 | if (vb->ident != NULL ) |
| 1374 | { |
| 1375 | memp_free(MEMP_SNMP_VALUE, vb->ident); |
| 1376 | } |
| 1377 | memp_free(MEMP_SNMP_VARBIND, vb); |
| 1378 | } |
| 1379 | |
| 1380 | void |
| 1381 | snmp_varbind_list_free(struct snmp_varbind_root *root) |
| 1382 | { |
| 1383 | struct snmp_varbind *vb, *prev; |
| 1384 | |
| 1385 | vb = root->tail; |
| 1386 | while ( vb != NULL ) |
| 1387 | { |
| 1388 | prev = vb->prev; |
| 1389 | snmp_varbind_free(vb); |
| 1390 | vb = prev; |
| 1391 | } |
| 1392 | root->count = 0; |
| 1393 | root->head = NULL; |
| 1394 | root->tail = NULL; |
| 1395 | } |
| 1396 | |
| 1397 | void |
| 1398 | snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb) |
| 1399 | { |
| 1400 | if (root->count == 0) |
| 1401 | { |
| 1402 | /* add first varbind to list */ |
| 1403 | root->head = vb; |
| 1404 | root->tail = vb; |
| 1405 | } |
| 1406 | else |
| 1407 | { |
| 1408 | /* add nth varbind to list tail */ |
| 1409 | root->tail->next = vb; |
| 1410 | vb->prev = root->tail; |
| 1411 | root->tail = vb; |
| 1412 | } |
| 1413 | root->count += 1; |
| 1414 | } |
| 1415 | |
| 1416 | struct snmp_varbind* |
| 1417 | snmp_varbind_tail_remove(struct snmp_varbind_root *root) |
| 1418 | { |
| 1419 | struct snmp_varbind* vb; |
| 1420 | |
| 1421 | if (root->count > 0) |
| 1422 | { |
| 1423 | /* remove tail varbind */ |
| 1424 | vb = root->tail; |
| 1425 | root->tail = vb->prev; |
| 1426 | vb->prev->next = NULL; |
| 1427 | root->count -= 1; |
| 1428 | } |
| 1429 | else |
| 1430 | { |
| 1431 | /* nothing to remove */ |
| 1432 | vb = NULL; |
| 1433 | } |
| 1434 | return vb; |
| 1435 | } |
| 1436 | |
| 1437 | #endif /* LWIP_SNMP */ |