Used in Live Traffic Update Nokia LCD Display Project
Fork of NetServices by
Diff: lwip/core/snmp/msg_in.c
- Revision:
- 0:ac1725ba162c
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lwip/core/snmp/msg_in.c Tue Nov 09 20:54:15 2010 +0000 @@ -0,0 +1,1437 @@ +/** + * @file + * SNMP input message processing (RFC1157). + */ + +/* + * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT + * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT + * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + * + * Author: Christiaan Simons <christiaan.simons@axon.tv> + */ + +#include "lwip/opt.h" + +#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/snmp.h" +#include "lwip/snmp_asn1.h" +#include "lwip/snmp_msg.h" +#include "lwip/snmp_structs.h" +#include "lwip/ip_addr.h" +#include "lwip/memp.h" +#include "lwip/udp.h" +#include "lwip/stats.h" + +#include <string.h> + +/* public (non-static) constants */ +/** SNMP v1 == 0 */ +const s32_t snmp_version = 0; +/** default SNMP community string */ +const char snmp_publiccommunity[7] = "public"; + +/* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */ +struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS]; +/* UDP Protocol Control Block */ +struct udp_pcb *snmp1_pcb; + +static void snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port); +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); +static err_t snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat); + + +/** + * Starts SNMP Agent. + * Allocates UDP pcb and binds it to IP_ADDR_ANY port 161. + */ +void +snmp_init(void) +{ + struct snmp_msg_pstat *msg_ps; + u8_t i; + + snmp1_pcb = udp_new(); + if (snmp1_pcb != NULL) + { + udp_recv(snmp1_pcb, snmp_recv, (void *)SNMP_IN_PORT); + udp_bind(snmp1_pcb, IP_ADDR_ANY, SNMP_IN_PORT); + } + msg_ps = &msg_input_list[0]; + for (i=0; i<SNMP_CONCURRENT_REQUESTS; i++) + { + msg_ps->state = SNMP_MSG_EMPTY; + msg_ps->error_index = 0; + msg_ps->error_status = SNMP_ES_NOERROR; + msg_ps++; + } + trap_msg.pcb = snmp1_pcb; + +#ifdef SNMP_PRIVATE_MIB_INIT + /* If defined, rhis must be a function-like define to initialize the + * private MIB after the stack has been initialized. + * The private MIB can also be initialized in tcpip_callback (or after + * the stack is initialized), this define is only for convenience. */ + SNMP_PRIVATE_MIB_INIT(); +#endif /* SNMP_PRIVATE_MIB_INIT */ + + /* The coldstart trap will only be output + if our outgoing interface is up & configured */ + snmp_coldstart_trap(); +} + +static void +snmp_error_response(struct snmp_msg_pstat *msg_ps, u8_t error) +{ + snmp_varbind_list_free(&msg_ps->outvb); + msg_ps->outvb = msg_ps->invb; + msg_ps->invb.head = NULL; + msg_ps->invb.tail = NULL; + msg_ps->invb.count = 0; + msg_ps->error_status = error; + msg_ps->error_index = 1 + msg_ps->vb_idx; + snmp_send_response(msg_ps); + snmp_varbind_list_free(&msg_ps->outvb); + msg_ps->state = SNMP_MSG_EMPTY; +} + +static void +snmp_ok_response(struct snmp_msg_pstat *msg_ps) +{ + err_t err_ret; + + err_ret = snmp_send_response(msg_ps); + if (err_ret == ERR_MEM) + { + /* serious memory problem, can't return tooBig */ + } + else + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event = %"S32_F"\n",msg_ps->error_status)); + } + /* free varbinds (if available) */ + snmp_varbind_list_free(&msg_ps->invb); + snmp_varbind_list_free(&msg_ps->outvb); + msg_ps->state = SNMP_MSG_EMPTY; +} + +/** + * Service an internal or external event for SNMP GET. + * + * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) + * @param msg_ps points to the assosicated message process state + */ +static void +snmp_msg_get_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) +{ + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_get_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); + + if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) + { + struct mib_external_node *en; + struct snmp_name_ptr np; + + /* get_object_def() answer*/ + en = msg_ps->ext_mib_node; + np = msg_ps->ext_name_ptr; + + /* translate answer into a known lifeform */ + en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); + if ((msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) && + (msg_ps->ext_object_def.access & MIB_ACCESS_READ)) + { + msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE; + en->get_value_q(request_id, &msg_ps->ext_object_def); + } + else + { + en->get_object_def_pc(request_id, np.ident_len, np.ident); + /* search failed, object id points to unknown object (nosuchname) */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE) + { + struct mib_external_node *en; + struct snmp_varbind *vb; + + /* get_value() answer */ + en = msg_ps->ext_mib_node; + + /* allocate output varbind */ + vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); + LWIP_ASSERT("vb != NULL",vb != NULL); + if (vb != NULL) + { + vb->next = NULL; + vb->prev = NULL; + + /* move name from invb to outvb */ + vb->ident = msg_ps->vb_ptr->ident; + vb->ident_len = msg_ps->vb_ptr->ident_len; + /* ensure this memory is refereced once only */ + msg_ps->vb_ptr->ident = NULL; + msg_ps->vb_ptr->ident_len = 0; + + vb->value_type = msg_ps->ext_object_def.asn_type; + LWIP_ASSERT("invalid length", msg_ps->ext_object_def.v_len <= 0xff); + vb->value_len = (u8_t)msg_ps->ext_object_def.v_len; + if (vb->value_len > 0) + { + LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", vb->value_len <= SNMP_MAX_VALUE_SIZE); + vb->value = memp_malloc(MEMP_SNMP_VALUE); + LWIP_ASSERT("vb->value != NULL",vb->value != NULL); + if (vb->value != NULL) + { + en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value); + snmp_varbind_tail_add(&msg_ps->outvb, vb); + /* search again (if vb_idx < msg_ps->invb.count) */ + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + else + { + en->get_value_pc(request_id, &msg_ps->ext_object_def); + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no variable space\n")); + msg_ps->vb_ptr->ident = vb->ident; + msg_ps->vb_ptr->ident_len = vb->ident_len; + memp_free(MEMP_SNMP_VARBIND, vb); + snmp_error_response(msg_ps,SNMP_ES_TOOBIG); + } + } + else + { + /* vb->value_len == 0, empty value (e.g. empty string) */ + en->get_value_a(request_id, &msg_ps->ext_object_def, 0, NULL); + vb->value = NULL; + snmp_varbind_tail_add(&msg_ps->outvb, vb); + /* search again (if vb_idx < msg_ps->invb.count) */ + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + } + else + { + en->get_value_pc(request_id, &msg_ps->ext_object_def); + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: no outvb space\n")); + snmp_error_response(msg_ps,SNMP_ES_TOOBIG); + } + } + + while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && + (msg_ps->vb_idx < msg_ps->invb.count)) + { + struct mib_node *mn; + struct snmp_name_ptr np; + + if (msg_ps->vb_idx == 0) + { + msg_ps->vb_ptr = msg_ps->invb.head; + } + else + { + msg_ps->vb_ptr = msg_ps->vb_ptr->next; + } + /** test object identifier for .iso.org.dod.internet prefix */ + if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident)) + { + mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, + msg_ps->vb_ptr->ident + 4, &np); + if (mn != NULL) + { + if (mn->node_type == MIB_NODE_EX) + { + /* external object */ + struct mib_external_node *en = (struct mib_external_node*)mn; + + msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; + /* save en && args in msg_ps!! */ + msg_ps->ext_mib_node = en; + msg_ps->ext_name_ptr = np; + + en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); + } + else + { + /* internal object */ + struct obj_def object_def; + + msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; + mn->get_object_def(np.ident_len, np.ident, &object_def); + if ((object_def.instance != MIB_OBJECT_NONE) && + (object_def.access & MIB_ACCESS_READ)) + { + mn = mn; + } + else + { + /* search failed, object id points to unknown object (nosuchname) */ + mn = NULL; + } + if (mn != NULL) + { + struct snmp_varbind *vb; + + msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE; + /* allocate output varbind */ + vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); + LWIP_ASSERT("vb != NULL",vb != NULL); + if (vb != NULL) + { + vb->next = NULL; + vb->prev = NULL; + + /* move name from invb to outvb */ + vb->ident = msg_ps->vb_ptr->ident; + vb->ident_len = msg_ps->vb_ptr->ident_len; + /* ensure this memory is refereced once only */ + msg_ps->vb_ptr->ident = NULL; + msg_ps->vb_ptr->ident_len = 0; + + vb->value_type = object_def.asn_type; + LWIP_ASSERT("invalid length", object_def.v_len <= 0xff); + vb->value_len = (u8_t)object_def.v_len; + if (vb->value_len > 0) + { + LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", + vb->value_len <= SNMP_MAX_VALUE_SIZE); + vb->value = memp_malloc(MEMP_SNMP_VALUE); + LWIP_ASSERT("vb->value != NULL",vb->value != NULL); + if (vb->value != NULL) + { + mn->get_value(&object_def, vb->value_len, vb->value); + snmp_varbind_tail_add(&msg_ps->outvb, vb); + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + else + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate variable space\n")); + msg_ps->vb_ptr->ident = vb->ident; + msg_ps->vb_ptr->ident_len = vb->ident_len; + memp_free(MEMP_SNMP_VARBIND, vb); + snmp_error_response(msg_ps,SNMP_ES_TOOBIG); + } + } + else + { + /* vb->value_len == 0, empty value (e.g. empty string) */ + vb->value = NULL; + snmp_varbind_tail_add(&msg_ps->outvb, vb); + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + } + else + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_event: couldn't allocate outvb space\n")); + snmp_error_response(msg_ps,SNMP_ES_TOOBIG); + } + } + } + } + } + else + { + mn = NULL; + } + if (mn == NULL) + { + /* mn == NULL, noSuchName */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && + (msg_ps->vb_idx == msg_ps->invb.count)) + { + snmp_ok_response(msg_ps); + } +} + +/** + * Service an internal or external event for SNMP GETNEXT. + * + * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) + * @param msg_ps points to the assosicated message process state + */ +static void +snmp_msg_getnext_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) +{ + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); + + if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) + { + struct mib_external_node *en; + + /* get_object_def() answer*/ + en = msg_ps->ext_mib_node; + + /* translate answer into a known lifeform */ + en->get_object_def_a(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1], &msg_ps->ext_object_def); + if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) + { + msg_ps->state = SNMP_MSG_EXTERNAL_GET_VALUE; + en->get_value_q(request_id, &msg_ps->ext_object_def); + } + else + { + en->get_object_def_pc(request_id, 1, &msg_ps->ext_oid.id[msg_ps->ext_oid.len - 1]); + /* search failed, object id points to unknown object (nosuchname) */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_VALUE) + { + struct mib_external_node *en; + struct snmp_varbind *vb; + + /* get_value() answer */ + en = msg_ps->ext_mib_node; + + LWIP_ASSERT("invalid length", msg_ps->ext_object_def.v_len <= 0xff); + vb = snmp_varbind_alloc(&msg_ps->ext_oid, + msg_ps->ext_object_def.asn_type, + (u8_t)msg_ps->ext_object_def.v_len); + if (vb != NULL) + { + en->get_value_a(request_id, &msg_ps->ext_object_def, vb->value_len, vb->value); + snmp_varbind_tail_add(&msg_ps->outvb, vb); + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + else + { + en->get_value_pc(request_id, &msg_ps->ext_object_def); + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_getnext_event: couldn't allocate outvb space\n")); + snmp_error_response(msg_ps,SNMP_ES_TOOBIG); + } + } + + while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && + (msg_ps->vb_idx < msg_ps->invb.count)) + { + struct mib_node *mn; + struct snmp_obj_id oid; + + if (msg_ps->vb_idx == 0) + { + msg_ps->vb_ptr = msg_ps->invb.head; + } + else + { + msg_ps->vb_ptr = msg_ps->vb_ptr->next; + } + if (snmp_iso_prefix_expand(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident, &oid)) + { + if (msg_ps->vb_ptr->ident_len > 3) + { + /* can offset ident_len and ident */ + mn = snmp_expand_tree((struct mib_node*)&internet, + msg_ps->vb_ptr->ident_len - 4, + msg_ps->vb_ptr->ident + 4, &oid); + } + else + { + /* can't offset ident_len -4, ident + 4 */ + mn = snmp_expand_tree((struct mib_node*)&internet, 0, NULL, &oid); + } + } + else + { + mn = NULL; + } + if (mn != NULL) + { + if (mn->node_type == MIB_NODE_EX) + { + /* external object */ + struct mib_external_node *en = (struct mib_external_node*)mn; + + msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; + /* save en && args in msg_ps!! */ + msg_ps->ext_mib_node = en; + msg_ps->ext_oid = oid; + + en->get_object_def_q(en->addr_inf, request_id, 1, &oid.id[oid.len - 1]); + } + else + { + /* internal object */ + struct obj_def object_def; + struct snmp_varbind *vb; + + msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; + mn->get_object_def(1, &oid.id[oid.len - 1], &object_def); + + LWIP_ASSERT("invalid length", object_def.v_len <= 0xff); + vb = snmp_varbind_alloc(&oid, object_def.asn_type, (u8_t)object_def.v_len); + if (vb != NULL) + { + msg_ps->state = SNMP_MSG_INTERNAL_GET_VALUE; + mn->get_value(&object_def, object_def.v_len, vb->value); + snmp_varbind_tail_add(&msg_ps->outvb, vb); + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + else + { + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv couldn't allocate outvb space\n")); + snmp_error_response(msg_ps,SNMP_ES_TOOBIG); + } + } + } + if (mn == NULL) + { + /* mn == NULL, noSuchName */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && + (msg_ps->vb_idx == msg_ps->invb.count)) + { + snmp_ok_response(msg_ps); + } +} + +/** + * Service an internal or external event for SNMP SET. + * + * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) + * @param msg_ps points to the assosicated message process state + */ +static void +snmp_msg_set_event(u8_t request_id, struct snmp_msg_pstat *msg_ps) +{ + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_msg_set_event: msg_ps->state==%"U16_F"\n",(u16_t)msg_ps->state)); + + if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF) + { + struct mib_external_node *en; + struct snmp_name_ptr np; + + /* get_object_def() answer*/ + en = msg_ps->ext_mib_node; + np = msg_ps->ext_name_ptr; + + /* translate answer into a known lifeform */ + en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); + if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) + { + msg_ps->state = SNMP_MSG_EXTERNAL_SET_TEST; + en->set_test_q(request_id, &msg_ps->ext_object_def); + } + else + { + en->get_object_def_pc(request_id, np.ident_len, np.ident); + /* search failed, object id points to unknown object (nosuchname) */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_TEST) + { + struct mib_external_node *en; + + /* set_test() answer*/ + en = msg_ps->ext_mib_node; + + if (msg_ps->ext_object_def.access & MIB_ACCESS_WRITE) + { + if ((msg_ps->ext_object_def.asn_type == msg_ps->vb_ptr->value_type) && + (en->set_test_a(request_id,&msg_ps->ext_object_def, + msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0)) + { + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + else + { + en->set_test_pc(request_id,&msg_ps->ext_object_def); + /* bad value */ + snmp_error_response(msg_ps,SNMP_ES_BADVALUE); + } + } + else + { + en->set_test_pc(request_id,&msg_ps->ext_object_def); + /* object not available for set */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + else if (msg_ps->state == SNMP_MSG_EXTERNAL_GET_OBJDEF_S) + { + struct mib_external_node *en; + struct snmp_name_ptr np; + + /* get_object_def() answer*/ + en = msg_ps->ext_mib_node; + np = msg_ps->ext_name_ptr; + + /* translate answer into a known lifeform */ + en->get_object_def_a(request_id, np.ident_len, np.ident, &msg_ps->ext_object_def); + if (msg_ps->ext_object_def.instance != MIB_OBJECT_NONE) + { + msg_ps->state = SNMP_MSG_EXTERNAL_SET_VALUE; + en->set_value_q(request_id, &msg_ps->ext_object_def, + msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value); + } + else + { + en->get_object_def_pc(request_id, np.ident_len, np.ident); + /* set_value failed, object has disappeared for some odd reason?? */ + snmp_error_response(msg_ps,SNMP_ES_GENERROR); + } + } + else if (msg_ps->state == SNMP_MSG_EXTERNAL_SET_VALUE) + { + struct mib_external_node *en; + + /** set_value_a() */ + en = msg_ps->ext_mib_node; + en->set_value_a(request_id, &msg_ps->ext_object_def, + msg_ps->vb_ptr->value_len, msg_ps->vb_ptr->value); + + /** @todo use set_value_pc() if toobig */ + msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; + msg_ps->vb_idx += 1; + } + + /* test all values before setting */ + while ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && + (msg_ps->vb_idx < msg_ps->invb.count)) + { + struct mib_node *mn; + struct snmp_name_ptr np; + + if (msg_ps->vb_idx == 0) + { + msg_ps->vb_ptr = msg_ps->invb.head; + } + else + { + msg_ps->vb_ptr = msg_ps->vb_ptr->next; + } + /** test object identifier for .iso.org.dod.internet prefix */ + if (snmp_iso_prefix_tst(msg_ps->vb_ptr->ident_len, msg_ps->vb_ptr->ident)) + { + mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, + msg_ps->vb_ptr->ident + 4, &np); + if (mn != NULL) + { + if (mn->node_type == MIB_NODE_EX) + { + /* external object */ + struct mib_external_node *en = (struct mib_external_node*)mn; + + msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF; + /* save en && args in msg_ps!! */ + msg_ps->ext_mib_node = en; + msg_ps->ext_name_ptr = np; + + en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); + } + else + { + /* internal object */ + struct obj_def object_def; + + msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF; + mn->get_object_def(np.ident_len, np.ident, &object_def); + if (object_def.instance != MIB_OBJECT_NONE) + { + mn = mn; + } + else + { + /* search failed, object id points to unknown object (nosuchname) */ + mn = NULL; + } + if (mn != NULL) + { + msg_ps->state = SNMP_MSG_INTERNAL_SET_TEST; + + if (object_def.access & MIB_ACCESS_WRITE) + { + if ((object_def.asn_type == msg_ps->vb_ptr->value_type) && + (mn->set_test(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value) != 0)) + { + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + msg_ps->vb_idx += 1; + } + else + { + /* bad value */ + snmp_error_response(msg_ps,SNMP_ES_BADVALUE); + } + } + else + { + /* object not available for set */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + } + } + } + else + { + mn = NULL; + } + if (mn == NULL) + { + /* mn == NULL, noSuchName */ + snmp_error_response(msg_ps,SNMP_ES_NOSUCHNAME); + } + } + + if ((msg_ps->state == SNMP_MSG_SEARCH_OBJ) && + (msg_ps->vb_idx == msg_ps->invb.count)) + { + msg_ps->vb_idx = 0; + msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; + } + + /* set all values "atomically" (be as "atomic" as possible) */ + while ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) && + (msg_ps->vb_idx < msg_ps->invb.count)) + { + struct mib_node *mn; + struct snmp_name_ptr np; + + if (msg_ps->vb_idx == 0) + { + msg_ps->vb_ptr = msg_ps->invb.head; + } + else + { + msg_ps->vb_ptr = msg_ps->vb_ptr->next; + } + /* skip iso prefix test, was done previously while settesting() */ + mn = snmp_search_tree((struct mib_node*)&internet, msg_ps->vb_ptr->ident_len - 4, + msg_ps->vb_ptr->ident + 4, &np); + /* check if object is still available + (e.g. external hot-plug thingy present?) */ + if (mn != NULL) + { + if (mn->node_type == MIB_NODE_EX) + { + /* external object */ + struct mib_external_node *en = (struct mib_external_node*)mn; + + msg_ps->state = SNMP_MSG_EXTERNAL_GET_OBJDEF_S; + /* save en && args in msg_ps!! */ + msg_ps->ext_mib_node = en; + msg_ps->ext_name_ptr = np; + + en->get_object_def_q(en->addr_inf, request_id, np.ident_len, np.ident); + } + else + { + /* internal object */ + struct obj_def object_def; + + msg_ps->state = SNMP_MSG_INTERNAL_GET_OBJDEF_S; + mn->get_object_def(np.ident_len, np.ident, &object_def); + msg_ps->state = SNMP_MSG_INTERNAL_SET_VALUE; + mn->set_value(&object_def,msg_ps->vb_ptr->value_len,msg_ps->vb_ptr->value); + msg_ps->vb_idx += 1; + } + } + } + if ((msg_ps->state == SNMP_MSG_INTERNAL_SET_VALUE) && + (msg_ps->vb_idx == msg_ps->invb.count)) + { + /* simply echo the input if we can set it + @todo do we need to return the actual value? + e.g. if value is silently modified or behaves sticky? */ + msg_ps->outvb = msg_ps->invb; + msg_ps->invb.head = NULL; + msg_ps->invb.tail = NULL; + msg_ps->invb.count = 0; + snmp_ok_response(msg_ps); + } +} + + +/** + * Handle one internal or external event. + * Called for one async event. (recv external/private answer) + * + * @param request_id identifies requests from 0 to (SNMP_CONCURRENT_REQUESTS-1) + */ +void +snmp_msg_event(u8_t request_id) +{ + struct snmp_msg_pstat *msg_ps; + + if (request_id < SNMP_CONCURRENT_REQUESTS) + { + msg_ps = &msg_input_list[request_id]; + if (msg_ps->rt == SNMP_ASN1_PDU_GET_NEXT_REQ) + { + snmp_msg_getnext_event(request_id, msg_ps); + } + else if (msg_ps->rt == SNMP_ASN1_PDU_GET_REQ) + { + snmp_msg_get_event(request_id, msg_ps); + } + else if(msg_ps->rt == SNMP_ASN1_PDU_SET_REQ) + { + snmp_msg_set_event(request_id, msg_ps); + } + } +} + + +/* lwIP UDP receive callback function */ +static void +snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *addr, u16_t port) +{ + struct snmp_msg_pstat *msg_ps; + u8_t req_idx; + err_t err_ret; + u16_t payload_len = p->tot_len; + u16_t payload_ofs = 0; + u16_t varbind_ofs = 0; + + /* suppress unused argument warning */ + LWIP_UNUSED_ARG(arg); + + /* traverse input message process list, look for SNMP_MSG_EMPTY */ + msg_ps = &msg_input_list[0]; + req_idx = 0; + while ((req_idx < SNMP_CONCURRENT_REQUESTS) && (msg_ps->state != SNMP_MSG_EMPTY)) + { + req_idx++; + msg_ps++; + } + if (req_idx == SNMP_CONCURRENT_REQUESTS) + { + /* exceeding number of concurrent requests */ + pbuf_free(p); + return; + } + + /* accepting request */ + snmp_inc_snmpinpkts(); + /* record used 'protocol control block' */ + msg_ps->pcb = pcb; + /* source address (network order) */ + msg_ps->sip = *addr; + /* source port (host order (lwIP oddity)) */ + msg_ps->sp = port; + + /* check total length, version, community, pdu type */ + err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps); + /* Only accept requests and requests without error (be robust) */ + /* Reject response and trap headers or error requests as input! */ + if ((err_ret != ERR_OK) || + ((msg_ps->rt != SNMP_ASN1_PDU_GET_REQ) && + (msg_ps->rt != SNMP_ASN1_PDU_GET_NEXT_REQ) && + (msg_ps->rt != SNMP_ASN1_PDU_SET_REQ)) || + ((msg_ps->error_status != SNMP_ES_NOERROR) || + (msg_ps->error_index != 0)) ) + { + /* header check failed drop request silently, do not return error! */ + pbuf_free(p); + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n")); + return; + } + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv ok, community %s\n", msg_ps->community)); + + /* Builds a list of variable bindings. Copy the varbinds from the pbuf + chain to glue them when these are divided over two or more pbuf's. */ + err_ret = snmp_pdu_dec_varbindlist(p, varbind_ofs, &varbind_ofs, msg_ps); + /* we've decoded the incoming message, release input msg now */ + pbuf_free(p); + if ((err_ret != ERR_OK) || (msg_ps->invb.count == 0)) + { + /* varbind-list decode failed, or varbind list empty. + drop request silently, do not return error! + (errors are only returned for a specific varbind failure) */ + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n")); + return; + } + + msg_ps->error_status = SNMP_ES_NOERROR; + msg_ps->error_index = 0; + /* find object for each variable binding */ + msg_ps->state = SNMP_MSG_SEARCH_OBJ; + /* first variable binding from list to inspect */ + msg_ps->vb_idx = 0; + + LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_recv varbind cnt=%"U16_F"\n",(u16_t)msg_ps->invb.count)); + + /* handle input event and as much objects as possible in one go */ + snmp_msg_event(req_idx); +} + +/** + * Checks and decodes incoming SNMP message header, logs header errors. + * + * @param p points to pbuf chain of SNMP message (UDP payload) + * @param ofs points to first octet of SNMP message + * @param pdu_len the length of the UDP payload + * @param ofs_ret returns the ofset of the variable bindings + * @param m_stat points to the current message request state return + * @return + * - ERR_OK SNMP header is sane and accepted + * - ERR_ARG SNMP header is either malformed or rejected + */ +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) +{ + err_t derr; + u16_t len, ofs_base; + u8_t len_octets; + u8_t type; + s32_t version; + + ofs_base = ofs; + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || + (pdu_len != (1 + len_octets + len)) || + (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + ofs += (1 + len_octets); + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (version) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &version); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + if (version != 0) + { + /* not version 1 */ + snmp_inc_snmpinbadversions(); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR))) + { + /* can't decode or no octet string (community) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, SNMP_COMMUNITY_STR_LEN, m_stat->community); + if (derr != ERR_OK) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + /* add zero terminator */ + len = ((len < (SNMP_COMMUNITY_STR_LEN))?(len):(SNMP_COMMUNITY_STR_LEN)); + m_stat->community[len] = 0; + m_stat->com_strlen = (u8_t)len; + if (strncmp(snmp_publiccommunity, (const char*)m_stat->community, SNMP_COMMUNITY_STR_LEN) != 0) + { + /** @todo: move this if we need to check more names */ + snmp_inc_snmpinbadcommunitynames(); + snmp_authfail_trap(); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if (derr != ERR_OK) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + switch(type) + { + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_REQ): + /* GetRequest PDU */ + snmp_inc_snmpingetrequests(); + derr = ERR_OK; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_NEXT_REQ): + /* GetNextRequest PDU */ + snmp_inc_snmpingetnexts(); + derr = ERR_OK; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP): + /* GetResponse PDU */ + snmp_inc_snmpingetresponses(); + derr = ERR_ARG; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_SET_REQ): + /* SetRequest PDU */ + snmp_inc_snmpinsetrequests(); + derr = ERR_OK; + break; + case (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP): + /* Trap PDU */ + snmp_inc_snmpintraps(); + derr = ERR_ARG; + break; + default: + snmp_inc_snmpinasnparseerrs(); + derr = ERR_ARG; + break; + } + if (derr != ERR_OK) + { + /* unsupported input PDU for this agent (no parse error) */ + return ERR_ARG; + } + m_stat->rt = type & 0x1F; + ofs += (1 + len_octets); + if (len != (pdu_len - (ofs - ofs_base))) + { + /* decoded PDU length does not equal actual payload length */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (request ID) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->rid); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (error-status) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + /* must be noError (0) for incoming requests. + log errors for mib-2 completeness and for debug purposes */ + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_status); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + switch (m_stat->error_status) + { + case SNMP_ES_TOOBIG: + snmp_inc_snmpintoobigs(); + break; + case SNMP_ES_NOSUCHNAME: + snmp_inc_snmpinnosuchnames(); + break; + case SNMP_ES_BADVALUE: + snmp_inc_snmpinbadvalues(); + break; + case SNMP_ES_READONLY: + snmp_inc_snmpinreadonlys(); + break; + case SNMP_ES_GENERROR: + snmp_inc_snmpingenerrs(); + break; + } + ofs += (1 + len_octets + len); + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG))) + { + /* can't decode or no integer (error-index) */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + /* must be 0 for incoming requests. + decode anyway to catch bad integers (and dirty tricks) */ + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, &m_stat->error_index); + if (derr != ERR_OK) + { + /* can't decode */ + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + *ofs_ret = ofs; + return ERR_OK; +} + +static err_t +snmp_pdu_dec_varbindlist(struct pbuf *p, u16_t ofs, u16_t *ofs_ret, struct snmp_msg_pstat *m_stat) +{ + err_t derr; + u16_t len, vb_len; + u8_t len_octets; + u8_t type; + + /* variable binding list */ + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &vb_len); + if ((derr != ERR_OK) || + (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ))) + { + snmp_inc_snmpinasnparseerrs(); + return ERR_ARG; + } + ofs += (1 + len_octets); + + /* start with empty list */ + m_stat->invb.count = 0; + m_stat->invb.head = NULL; + m_stat->invb.tail = NULL; + + while (vb_len > 0) + { + struct snmp_obj_id oid, oid_value; + struct snmp_varbind *vb; + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || + (type != (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ)) || + (len == 0) || (len > vb_len)) + { + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + ofs += (1 + len_octets); + vb_len -= (1 + len_octets); + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if ((derr != ERR_OK) || (type != (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID))) + { + /* can't decode object name length */ + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid); + if (derr != ERR_OK) + { + /* can't decode object name */ + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + vb_len -= (1 + len_octets + len); + + snmp_asn1_dec_type(p, ofs, &type); + derr = snmp_asn1_dec_length(p, ofs+1, &len_octets, &len); + if (derr != ERR_OK) + { + /* can't decode object value length */ + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + + switch (type) + { + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG): + vb = snmp_varbind_alloc(&oid, type, sizeof(s32_t)); + if (vb != NULL) + { + s32_t *vptr = (s32_t*)vb->value; + + derr = snmp_asn1_dec_s32t(p, ofs + 1 + len_octets, len, vptr); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS): + vb = snmp_varbind_alloc(&oid, type, sizeof(u32_t)); + if (vb != NULL) + { + u32_t *vptr = (u32_t*)vb->value; + + derr = snmp_asn1_dec_u32t(p, ofs + 1 + len_octets, len, vptr); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR): + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE): + LWIP_ASSERT("invalid length", len <= 0xff); + vb = snmp_varbind_alloc(&oid, type, (u8_t)len); + if (vb != NULL) + { + derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, (u8_t*)vb->value); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL): + vb = snmp_varbind_alloc(&oid, type, 0); + if (vb != NULL) + { + snmp_varbind_tail_add(&m_stat->invb, vb); + derr = ERR_OK; + } + else + { + derr = ERR_ARG; + } + break; + case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID): + derr = snmp_asn1_dec_oid(p, ofs + 1 + len_octets, len, &oid_value); + if (derr == ERR_OK) + { + vb = snmp_varbind_alloc(&oid, type, oid_value.len * sizeof(s32_t)); + if (vb != NULL) + { + u8_t i = oid_value.len; + s32_t *vptr = (s32_t*)vb->value; + + while(i > 0) + { + i--; + vptr[i] = oid_value.id[i]; + } + snmp_varbind_tail_add(&m_stat->invb, vb); + derr = ERR_OK; + } + else + { + derr = ERR_ARG; + } + } + break; + case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR): + if (len == 4) + { + /* must be exactly 4 octets! */ + vb = snmp_varbind_alloc(&oid, type, 4); + if (vb != NULL) + { + derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, (u8_t*)vb->value); + snmp_varbind_tail_add(&m_stat->invb, vb); + } + else + { + derr = ERR_ARG; + } + } + else + { + derr = ERR_ARG; + } + break; + default: + derr = ERR_ARG; + break; + } + if (derr != ERR_OK) + { + snmp_inc_snmpinasnparseerrs(); + /* free varbinds (if available) */ + snmp_varbind_list_free(&m_stat->invb); + return ERR_ARG; + } + ofs += (1 + len_octets + len); + vb_len -= (1 + len_octets + len); + } + + if (m_stat->rt == SNMP_ASN1_PDU_SET_REQ) + { + snmp_add_snmpintotalsetvars(m_stat->invb.count); + } + else + { + snmp_add_snmpintotalreqvars(m_stat->invb.count); + } + + *ofs_ret = ofs; + return ERR_OK; +} + +struct snmp_varbind* +snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len) +{ + struct snmp_varbind *vb; + + vb = (struct snmp_varbind *)memp_malloc(MEMP_SNMP_VARBIND); + LWIP_ASSERT("vb != NULL",vb != NULL); + if (vb != NULL) + { + u8_t i; + + vb->next = NULL; + vb->prev = NULL; + i = oid->len; + vb->ident_len = i; + if (i > 0) + { + LWIP_ASSERT("SNMP_MAX_TREE_DEPTH is configured too low", i <= SNMP_MAX_TREE_DEPTH); + /* allocate array of s32_t for our object identifier */ + vb->ident = (s32_t*)memp_malloc(MEMP_SNMP_VALUE); + LWIP_ASSERT("vb->ident != NULL",vb->ident != NULL); + if (vb->ident == NULL) + { + memp_free(MEMP_SNMP_VARBIND, vb); + return NULL; + } + while(i > 0) + { + i--; + vb->ident[i] = oid->id[i]; + } + } + else + { + /* i == 0, pass zero length object identifier */ + vb->ident = NULL; + } + vb->value_type = type; + vb->value_len = len; + if (len > 0) + { + LWIP_ASSERT("SNMP_MAX_OCTET_STRING_LEN is configured too low", vb->value_len <= SNMP_MAX_VALUE_SIZE); + /* allocate raw bytes for our object value */ + vb->value = memp_malloc(MEMP_SNMP_VALUE); + LWIP_ASSERT("vb->value != NULL",vb->value != NULL); + if (vb->value == NULL) + { + if (vb->ident != NULL) + { + memp_free(MEMP_SNMP_VALUE, vb->ident); + } + memp_free(MEMP_SNMP_VARBIND, vb); + return NULL; + } + } + else + { + /* ASN1_NUL type, or zero length ASN1_OC_STR */ + vb->value = NULL; + } + } + return vb; +} + +void +snmp_varbind_free(struct snmp_varbind *vb) +{ + if (vb->value != NULL ) + { + memp_free(MEMP_SNMP_VALUE, vb->value); + } + if (vb->ident != NULL ) + { + memp_free(MEMP_SNMP_VALUE, vb->ident); + } + memp_free(MEMP_SNMP_VARBIND, vb); +} + +void +snmp_varbind_list_free(struct snmp_varbind_root *root) +{ + struct snmp_varbind *vb, *prev; + + vb = root->tail; + while ( vb != NULL ) + { + prev = vb->prev; + snmp_varbind_free(vb); + vb = prev; + } + root->count = 0; + root->head = NULL; + root->tail = NULL; +} + +void +snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb) +{ + if (root->count == 0) + { + /* add first varbind to list */ + root->head = vb; + root->tail = vb; + } + else + { + /* add nth varbind to list tail */ + root->tail->next = vb; + vb->prev = root->tail; + root->tail = vb; + } + root->count += 1; +} + +struct snmp_varbind* +snmp_varbind_tail_remove(struct snmp_varbind_root *root) +{ + struct snmp_varbind* vb; + + if (root->count > 0) + { + /* remove tail varbind */ + vb = root->tail; + root->tail = vb->prev; + vb->prev->next = NULL; + root->count -= 1; + } + else + { + /* nothing to remove */ + vb = NULL; + } + return vb; +} + +#endif /* LWIP_SNMP */