--- /dev/null
+/**
+ * @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/ip_addr.h"
+#include "lwip/mem.h"
+#include "lwip/udp.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "lwip/snmp_asn1.h"
+#include "lwip/snmp_msg.h"
+#include "lwip/snmp_structs.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, struct ip_addr *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;
+ /* 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->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 *)mem_malloc(sizeof(struct 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;
+ vb->value_len = msg_ps->ext_object_def.v_len;
+ if (vb->value_len > 0)
+ {
+ vb->value = mem_malloc(vb->value_len);
+ 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;
+ mem_free(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)
+ {
+ 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 *)mem_malloc(sizeof(struct 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;
+ vb->value_len = object_def.v_len;
+ if (vb->value_len > 0)
+ {
+ vb->value = mem_malloc(vb->value_len);
+ 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;
+ mem_free(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;
+
+ vb = snmp_varbind_alloc(&msg_ps->ext_oid,
+ msg_ps->ext_object_def.asn_type,
+ 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);
+
+ vb = snmp_varbind_alloc(&oid, object_def.asn_type, 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_OBJECT_READ_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() @todo: use reply value?? */
+ en = msg_ps->ext_mib_node;
+ en->set_value_a(request_id, &msg_ps->ext_object_def, 0, NULL);
+
+ /** @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_OBJECT_READ_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, struct ip_addr *addr, u16_t port)
+{
+ struct udp_hdr *udphdr;
+
+ /* suppress unused argument warning */
+ LWIP_UNUSED_ARG(arg);
+ /* peek in the UDP header (goto IP payload) */
+ if(pbuf_header(p, UDP_HLEN)){
+ LWIP_ASSERT("Can't move to UDP header", 0);
+ pbuf_free(p);
+ return;
+ }
+ udphdr = p->payload;
+
+ /* check if datagram is really directed at us (including broadcast requests) */
+ if ((pcb == snmp1_pcb) && (ntohs(udphdr->dest) == SNMP_IN_PORT))
+ {
+ struct snmp_msg_pstat *msg_ps;
+ u8_t req_idx;
+
+ /* 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)
+ {
+ err_t err_ret;
+ u16_t payload_len;
+ u16_t payload_ofs;
+ u16_t varbind_ofs = 0;
+
+ /* 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;
+ /* read UDP payload length from UDP header */
+ payload_len = ntohs(udphdr->len) - UDP_HLEN;
+
+ /* adjust to UDP payload */
+ payload_ofs = UDP_HLEN;
+
+ /* check total length, version, community, pdu type */
+ err_ret = snmp_pdu_header_check(p, payload_ofs, payload_len, &varbind_ofs, msg_ps);
+ if (((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)) )
+ {
+ /* Only accept requests and requests without error (be robust) */
+ err_ret = err_ret;
+ }
+ else
+ {
+ /* Reject response and trap headers or error requests as input! */
+ err_ret = ERR_ARG;
+ }
+ if (err_ret == ERR_OK)
+ {
+ 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);
+ if ((err_ret == ERR_OK) && (msg_ps->invb.count > 0))
+ {
+ /* we've decoded the incoming message, release input msg now */
+ pbuf_free(p);
+
+ 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);
+ }
+ else
+ {
+ /* varbind-list decode failed, or varbind list empty.
+ drop request silently, do not return error!
+ (errors are only returned for a specific varbind failure) */
+ pbuf_free(p);
+ LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_dec_varbindlist() failed\n"));
+ }
+ }
+ else
+ {
+ /* header check failed
+ drop request silently, do not return error! */
+ pbuf_free(p);
+ LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_pdu_header_check() failed\n"));
+ }
+ }
+ else
+ {
+ /* exceeding number of concurrent requests */
+ pbuf_free(p);
+ }
+ }
+ else
+ {
+ /* datagram not for us */
+ pbuf_free(p);
+ }
+}
+
+/**
+ * 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 = 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 = 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 = 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):
+ vb = snmp_varbind_alloc(&oid, type, len);
+ if (vb != NULL)
+ {
+ derr = snmp_asn1_dec_raw(p, ofs + 1 + len_octets, len, vb->value_len, 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 = 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, 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 *)mem_malloc(sizeof(struct 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)
+ {
+ /* allocate array of s32_t for our object identifier */
+ vb->ident = (s32_t*)mem_malloc(sizeof(s32_t) * i);
+ LWIP_ASSERT("vb->ident != NULL",vb->ident != NULL);
+ if (vb->ident == NULL)
+ {
+ mem_free(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)
+ {
+ /* allocate raw bytes for our object value */
+ vb->value = mem_malloc(len);
+ LWIP_ASSERT("vb->value != NULL",vb->value != NULL);
+ if (vb->value == NULL)
+ {
+ if (vb->ident != NULL)
+ {
+ mem_free(vb->ident);
+ }
+ mem_free(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 )
+ {
+ mem_free(vb->value);
+ }
+ if (vb->ident != NULL )
+ {
+ mem_free(vb->ident);
+ }
+ mem_free(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 */
