--- /dev/null
+/**
+ * @file
+ * SNMP output message processing (RFC1157).
+ *
+ * Output responses and traps are build in two passes:
+ *
+ * Pass 0: iterate over the output message backwards to determine encoding lengths
+ * Pass 1: the actual forward encoding of internal form into ASN1
+ *
+ * The single-pass encoding method described by Comer & Stevens
+ * requires extra buffer space and copying for reversal of the packet.
+ * The buffer requirement can be prohibitively large for big payloads
+ * (>= 484) therefore we use the two encoding passes.
+ */
+
+/*
+ * 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/udp.h"
+#include "lwip/netif.h"
+#include "lwip/snmp.h"
+#include "lwip/snmp_asn1.h"
+#include "lwip/snmp_msg.h"
+
+struct snmp_trap_dst
+{
+ /* destination IP address in network order */
+ struct ip_addr dip;
+ /* set to 0 when disabled, >0 when enabled */
+ u8_t enable;
+};
+struct snmp_trap_dst trap_dst[SNMP_TRAP_DESTINATIONS];
+
+/** TRAP message structure */
+struct snmp_msg_trap trap_msg;
+
+static u16_t snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len);
+static u16_t snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len);
+static u16_t snmp_varbind_list_sum(struct snmp_varbind_root *root);
+
+static u16_t snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p);
+static u16_t snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p);
+static u16_t snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs);
+
+/**
+ * Sets enable switch for this trap destination.
+ * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
+ * @param enable switch if 0 destination is disabled >0 enabled.
+ */
+void
+snmp_trap_dst_enable(u8_t dst_idx, u8_t enable)
+{
+ if (dst_idx < SNMP_TRAP_DESTINATIONS)
+ {
+ trap_dst[dst_idx].enable = enable;
+ }
+}
+
+/**
+ * Sets IPv4 address for this trap destination.
+ * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
+ * @param dst IPv4 address in host order.
+ */
+void
+snmp_trap_dst_ip_set(u8_t dst_idx, struct ip_addr *dst)
+{
+ if (dst_idx < SNMP_TRAP_DESTINATIONS)
+ {
+ trap_dst[dst_idx].dip.addr = htonl(dst->addr);
+ }
+}
+
+/**
+ * Sends a 'getresponse' message to the request originator.
+ *
+ * @param m_stat points to the current message request state source
+ * @return ERR_OK when success, ERR_MEM if we're out of memory
+ *
+ * @note the caller is responsible for filling in outvb in the m_stat
+ * and provide error-status and index (except for tooBig errors) ...
+ */
+err_t
+snmp_send_response(struct snmp_msg_pstat *m_stat)
+{
+ struct snmp_varbind_root emptyvb = {NULL, NULL, 0, 0, 0};
+ struct pbuf *p;
+ u16_t tot_len;
+ err_t err;
+
+ /* pass 0, calculate length fields */
+ tot_len = snmp_varbind_list_sum(&m_stat->outvb);
+ tot_len = snmp_resp_header_sum(m_stat, tot_len);
+
+ /* try allocating pbuf(s) for complete response */
+ p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
+ if (p == NULL)
+ {
+ LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() tooBig\n"));
+
+ /* can't construct reply, return error-status tooBig */
+ m_stat->error_status = SNMP_ES_TOOBIG;
+ m_stat->error_index = 0;
+ /* pass 0, recalculate lengths, for empty varbind-list */
+ tot_len = snmp_varbind_list_sum(&emptyvb);
+ tot_len = snmp_resp_header_sum(m_stat, tot_len);
+ /* retry allocation once for header and empty varbind-list */
+ p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
+ }
+ if (p != NULL)
+ {
+ /* first pbuf alloc try or retry alloc success */
+ u16_t ofs;
+
+ LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() p != NULL\n"));
+
+ /* pass 1, size error, encode packet ino the pbuf(s) */
+ ofs = snmp_resp_header_enc(m_stat, p);
+ if (m_stat->error_status == SNMP_ES_TOOBIG)
+ {
+ snmp_varbind_list_enc(&emptyvb, p, ofs);
+ }
+ else
+ {
+ snmp_varbind_list_enc(&m_stat->outvb, p, ofs);
+ }
+
+ switch (m_stat->error_status)
+ {
+ case SNMP_ES_TOOBIG:
+ snmp_inc_snmpouttoobigs();
+ break;
+ case SNMP_ES_NOSUCHNAME:
+ snmp_inc_snmpoutnosuchnames();
+ break;
+ case SNMP_ES_BADVALUE:
+ snmp_inc_snmpoutbadvalues();
+ break;
+ case SNMP_ES_GENERROR:
+ snmp_inc_snmpoutgenerrs();
+ break;
+ }
+ snmp_inc_snmpoutgetresponses();
+ snmp_inc_snmpoutpkts();
+
+ /** @todo do we need separate rx and tx pcbs for threaded case? */
+ /** connect to the originating source */
+ udp_connect(m_stat->pcb, &m_stat->sip, m_stat->sp);
+ err = udp_send(m_stat->pcb, p);
+ if (err == ERR_MEM)
+ {
+ /** @todo release some memory, retry and return tooBig? tooMuchHassle? */
+ err = ERR_MEM;
+ }
+ else
+ {
+ err = ERR_OK;
+ }
+ /** disassociate remote address and port with this pcb */
+ udp_disconnect(m_stat->pcb);
+
+ pbuf_free(p);
+ LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() done\n"));
+ return err;
+ }
+ else
+ {
+ /* first pbuf alloc try or retry alloc failed
+ very low on memory, couldn't return tooBig */
+ return ERR_MEM;
+ }
+}
+
+
+/**
+ * Sends an generic or enterprise specific trap message.
+ *
+ * @param generic_trap is the trap code
+ * @param eoid points to enterprise object identifier
+ * @param specific_trap used for enterprise traps when generic_trap == 6
+ * @return ERR_OK when success, ERR_MEM if we're out of memory
+ *
+ * @note the caller is responsible for filling in outvb in the trap_msg
+ * @note the use of the enterpise identifier field
+ * is per RFC1215.
+ * Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps
+ * and .iso.org.dod.internet.private.enterprises.yourenterprise
+ * (sysObjectID) for specific traps.
+ */
+err_t
+snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap)
+{
+ struct snmp_trap_dst *td;
+ struct netif *dst_if;
+ struct ip_addr dst_ip;
+ struct pbuf *p;
+ u16_t i,tot_len;
+
+ for (i=0, td = &trap_dst[0]; i<SNMP_TRAP_DESTINATIONS; i++, td++)
+ {
+ if ((td->enable != 0) && (td->dip.addr != 0))
+ {
+ /* network order trap destination */
+ trap_msg.dip.addr = td->dip.addr;
+ /* lookup current source address for this dst */
+ dst_if = ip_route(&td->dip);
+ dst_ip.addr = ntohl(dst_if->ip_addr.addr);
+ trap_msg.sip_raw[0] = dst_ip.addr >> 24;
+ trap_msg.sip_raw[1] = dst_ip.addr >> 16;
+ trap_msg.sip_raw[2] = dst_ip.addr >> 8;
+ trap_msg.sip_raw[3] = dst_ip.addr;
+ trap_msg.gen_trap = generic_trap;
+ trap_msg.spc_trap = specific_trap;
+ if (generic_trap == SNMP_GENTRAP_ENTERPRISESPC)
+ {
+ /* enterprise-Specific trap */
+ trap_msg.enterprise = eoid;
+ }
+ else
+ {
+ /* generic (MIB-II) trap */
+ snmp_get_snmpgrpid_ptr(&trap_msg.enterprise);
+ }
+ snmp_get_sysuptime(&trap_msg.ts);
+
+ /* pass 0, calculate length fields */
+ tot_len = snmp_varbind_list_sum(&trap_msg.outvb);
+ tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
+
+ /* allocate pbuf(s) */
+ p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
+ if (p != NULL)
+ {
+ u16_t ofs;
+
+ /* pass 1, encode packet ino the pbuf(s) */
+ ofs = snmp_trap_header_enc(&trap_msg, p);
+ snmp_varbind_list_enc(&trap_msg.outvb, p, ofs);
+
+ snmp_inc_snmpouttraps();
+ snmp_inc_snmpoutpkts();
+
+ /** connect to the TRAP destination */
+ udp_connect(trap_msg.pcb, &trap_msg.dip, SNMP_TRAP_PORT);
+ udp_send(trap_msg.pcb, p);
+ /** disassociate remote address and port with this pcb */
+ udp_disconnect(trap_msg.pcb);
+
+ pbuf_free(p);
+ }
+ else
+ {
+ return ERR_MEM;
+ }
+ }
+ }
+ return ERR_OK;
+}
+
+void
+snmp_coldstart_trap(void)
+{
+ trap_msg.outvb.head = NULL;
+ trap_msg.outvb.tail = NULL;
+ trap_msg.outvb.count = 0;
+ snmp_send_trap(SNMP_GENTRAP_COLDSTART, NULL, 0);
+}
+
+void
+snmp_authfail_trap(void)
+{
+ u8_t enable;
+ snmp_get_snmpenableauthentraps(&enable);
+ if (enable == 1)
+ {
+ trap_msg.outvb.head = NULL;
+ trap_msg.outvb.tail = NULL;
+ trap_msg.outvb.count = 0;
+ snmp_send_trap(SNMP_GENTRAP_AUTHFAIL, NULL, 0);
+ }
+}
+
+/**
+ * Sums response header field lengths from tail to head and
+ * returns resp_header_lengths for second encoding pass.
+ *
+ * @param vb_len varbind-list length
+ * @param rhl points to returned header lengths
+ * @return the required lenght for encoding the response header
+ */
+static u16_t
+snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len)
+{
+ u16_t tot_len;
+ struct snmp_resp_header_lengths *rhl;
+
+ rhl = &m_stat->rhl;
+ tot_len = vb_len;
+ snmp_asn1_enc_s32t_cnt(m_stat->error_index, &rhl->erridxlen);
+ snmp_asn1_enc_length_cnt(rhl->erridxlen, &rhl->erridxlenlen);
+ tot_len += 1 + rhl->erridxlenlen + rhl->erridxlen;
+
+ snmp_asn1_enc_s32t_cnt(m_stat->error_status, &rhl->errstatlen);
+ snmp_asn1_enc_length_cnt(rhl->errstatlen, &rhl->errstatlenlen);
+ tot_len += 1 + rhl->errstatlenlen + rhl->errstatlen;
+
+ snmp_asn1_enc_s32t_cnt(m_stat->rid, &rhl->ridlen);
+ snmp_asn1_enc_length_cnt(rhl->ridlen, &rhl->ridlenlen);
+ tot_len += 1 + rhl->ridlenlen + rhl->ridlen;
+
+ rhl->pdulen = tot_len;
+ snmp_asn1_enc_length_cnt(rhl->pdulen, &rhl->pdulenlen);
+ tot_len += 1 + rhl->pdulenlen;
+
+ rhl->comlen = m_stat->com_strlen;
+ snmp_asn1_enc_length_cnt(rhl->comlen, &rhl->comlenlen);
+ tot_len += 1 + rhl->comlenlen + rhl->comlen;
+
+ snmp_asn1_enc_s32t_cnt(snmp_version, &rhl->verlen);
+ snmp_asn1_enc_length_cnt(rhl->verlen, &rhl->verlenlen);
+ tot_len += 1 + rhl->verlen + rhl->verlenlen;
+
+ rhl->seqlen = tot_len;
+ snmp_asn1_enc_length_cnt(rhl->seqlen, &rhl->seqlenlen);
+ tot_len += 1 + rhl->seqlenlen;
+
+ return tot_len;
+}
+
+/**
+ * Sums trap header field lengths from tail to head and
+ * returns trap_header_lengths for second encoding pass.
+ *
+ * @param vb_len varbind-list length
+ * @param thl points to returned header lengths
+ * @return the required lenght for encoding the trap header
+ */
+static u16_t
+snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len)
+{
+ u16_t tot_len;
+ struct snmp_trap_header_lengths *thl;
+
+ thl = &m_trap->thl;
+ tot_len = vb_len;
+
+ snmp_asn1_enc_u32t_cnt(m_trap->ts, &thl->tslen);
+ snmp_asn1_enc_length_cnt(thl->tslen, &thl->tslenlen);
+ tot_len += 1 + thl->tslen + thl->tslenlen;
+
+ snmp_asn1_enc_s32t_cnt(m_trap->spc_trap, &thl->strplen);
+ snmp_asn1_enc_length_cnt(thl->strplen, &thl->strplenlen);
+ tot_len += 1 + thl->strplen + thl->strplenlen;
+
+ snmp_asn1_enc_s32t_cnt(m_trap->gen_trap, &thl->gtrplen);
+ snmp_asn1_enc_length_cnt(thl->gtrplen, &thl->gtrplenlen);
+ tot_len += 1 + thl->gtrplen + thl->gtrplenlen;
+
+ thl->aaddrlen = 4;
+ snmp_asn1_enc_length_cnt(thl->aaddrlen, &thl->aaddrlenlen);
+ tot_len += 1 + thl->aaddrlen + thl->aaddrlenlen;
+
+ snmp_asn1_enc_oid_cnt(m_trap->enterprise->len, &m_trap->enterprise->id[0], &thl->eidlen);
+ snmp_asn1_enc_length_cnt(thl->eidlen, &thl->eidlenlen);
+ tot_len += 1 + thl->eidlen + thl->eidlenlen;
+
+ thl->pdulen = tot_len;
+ snmp_asn1_enc_length_cnt(thl->pdulen, &thl->pdulenlen);
+ tot_len += 1 + thl->pdulenlen;
+
+ thl->comlen = sizeof(snmp_publiccommunity) - 1;
+ snmp_asn1_enc_length_cnt(thl->comlen, &thl->comlenlen);
+ tot_len += 1 + thl->comlenlen + thl->comlen;
+
+ snmp_asn1_enc_s32t_cnt(snmp_version, &thl->verlen);
+ snmp_asn1_enc_length_cnt(thl->verlen, &thl->verlenlen);
+ tot_len += 1 + thl->verlen + thl->verlenlen;
+
+ thl->seqlen = tot_len;
+ snmp_asn1_enc_length_cnt(thl->seqlen, &thl->seqlenlen);
+ tot_len += 1 + thl->seqlenlen;
+
+ return tot_len;
+}
+
+/**
+ * Sums varbind lengths from tail to head and
+ * annotates lengths in varbind for second encoding pass.
+ *
+ * @param root points to the root of the variable binding list
+ * @return the required lenght for encoding the variable bindings
+ */
+static u16_t
+snmp_varbind_list_sum(struct snmp_varbind_root *root)
+{
+ struct snmp_varbind *vb;
+ u32_t *uint_ptr;
+ s32_t *sint_ptr;
+ u16_t tot_len;
+
+ tot_len = 0;
+ vb = root->tail;
+ while ( vb != NULL )
+ {
+ /* encoded value lenght depends on type */
+ switch (vb->value_type)
+ {
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
+ sint_ptr = vb->value;
+ snmp_asn1_enc_s32t_cnt(*sint_ptr, &vb->vlen);
+ 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):
+ uint_ptr = vb->value;
+ snmp_asn1_enc_u32t_cnt(*uint_ptr, &vb->vlen);
+ break;
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
+ case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
+ case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
+ vb->vlen = vb->value_len;
+ break;
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
+ sint_ptr = vb->value;
+ snmp_asn1_enc_oid_cnt(vb->value_len / sizeof(s32_t), sint_ptr, &vb->vlen);
+ break;
+ default:
+ /* unsupported type */
+ vb->vlen = 0;
+ break;
+ };
+ /* encoding length of value length field */
+ snmp_asn1_enc_length_cnt(vb->vlen, &vb->vlenlen);
+ snmp_asn1_enc_oid_cnt(vb->ident_len, vb->ident, &vb->olen);
+ snmp_asn1_enc_length_cnt(vb->olen, &vb->olenlen);
+
+ vb->seqlen = 1 + vb->vlenlen + vb->vlen;
+ vb->seqlen += 1 + vb->olenlen + vb->olen;
+ snmp_asn1_enc_length_cnt(vb->seqlen, &vb->seqlenlen);
+
+ /* varbind seq */
+ tot_len += 1 + vb->seqlenlen + vb->seqlen;
+
+ vb = vb->prev;
+ }
+
+ /* varbind-list seq */
+ root->seqlen = tot_len;
+ snmp_asn1_enc_length_cnt(root->seqlen, &root->seqlenlen);
+ tot_len += 1 + root->seqlenlen;
+
+ return tot_len;
+}
+
+/**
+ * Encodes response header from head to tail.
+ */
+static u16_t
+snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p)
+{
+ u16_t ofs;
+
+ ofs = 0;
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.seqlen);
+ ofs += m_stat->rhl.seqlenlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.verlen);
+ ofs += m_stat->rhl.verlenlen;
+ snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.verlen, snmp_version);
+ ofs += m_stat->rhl.verlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.comlen);
+ ofs += m_stat->rhl.comlenlen;
+ snmp_asn1_enc_raw(p, ofs, m_stat->rhl.comlen, m_stat->community);
+ ofs += m_stat->rhl.comlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.pdulen);
+ ofs += m_stat->rhl.pdulenlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.ridlen);
+ ofs += m_stat->rhl.ridlenlen;
+ snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.ridlen, m_stat->rid);
+ ofs += m_stat->rhl.ridlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.errstatlen);
+ ofs += m_stat->rhl.errstatlenlen;
+ snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.errstatlen, m_stat->error_status);
+ ofs += m_stat->rhl.errstatlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_stat->rhl.erridxlen);
+ ofs += m_stat->rhl.erridxlenlen;
+ snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.erridxlen, m_stat->error_index);
+ ofs += m_stat->rhl.erridxlen;
+
+ return ofs;
+}
+
+/**
+ * Encodes trap header from head to tail.
+ */
+static u16_t
+snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p)
+{
+ u16_t ofs;
+
+ ofs = 0;
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.seqlen);
+ ofs += m_trap->thl.seqlenlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.verlen);
+ ofs += m_trap->thl.verlenlen;
+ snmp_asn1_enc_s32t(p, ofs, m_trap->thl.verlen, snmp_version);
+ ofs += m_trap->thl.verlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.comlen);
+ ofs += m_trap->thl.comlenlen;
+ snmp_asn1_enc_raw(p, ofs, m_trap->thl.comlen, (u8_t *)&snmp_publiccommunity[0]);
+ ofs += m_trap->thl.comlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.pdulen);
+ ofs += m_trap->thl.pdulenlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.eidlen);
+ ofs += m_trap->thl.eidlenlen;
+ snmp_asn1_enc_oid(p, ofs, m_trap->enterprise->len, &m_trap->enterprise->id[0]);
+ ofs += m_trap->thl.eidlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.aaddrlen);
+ ofs += m_trap->thl.aaddrlenlen;
+ snmp_asn1_enc_raw(p, ofs, m_trap->thl.aaddrlen, &m_trap->sip_raw[0]);
+ ofs += m_trap->thl.aaddrlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.gtrplen);
+ ofs += m_trap->thl.gtrplenlen;
+ snmp_asn1_enc_u32t(p, ofs, m_trap->thl.gtrplen, m_trap->gen_trap);
+ ofs += m_trap->thl.gtrplen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.strplen);
+ ofs += m_trap->thl.strplenlen;
+ snmp_asn1_enc_u32t(p, ofs, m_trap->thl.strplen, m_trap->spc_trap);
+ ofs += m_trap->thl.strplen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, m_trap->thl.tslen);
+ ofs += m_trap->thl.tslenlen;
+ snmp_asn1_enc_u32t(p, ofs, m_trap->thl.tslen, m_trap->ts);
+ ofs += m_trap->thl.tslen;
+
+ return ofs;
+}
+
+/**
+ * Encodes varbind list from head to tail.
+ */
+static u16_t
+snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs)
+{
+ struct snmp_varbind *vb;
+ s32_t *sint_ptr;
+ u32_t *uint_ptr;
+ u8_t *raw_ptr;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, root->seqlen);
+ ofs += root->seqlenlen;
+
+ vb = root->head;
+ while ( vb != NULL )
+ {
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, vb->seqlen);
+ ofs += vb->seqlenlen;
+
+ snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, vb->olen);
+ ofs += vb->olenlen;
+ snmp_asn1_enc_oid(p, ofs, vb->ident_len, &vb->ident[0]);
+ ofs += vb->olen;
+
+ snmp_asn1_enc_type(p, ofs, vb->value_type);
+ ofs += 1;
+ snmp_asn1_enc_length(p, ofs, vb->vlen);
+ ofs += vb->vlenlen;
+
+ switch (vb->value_type)
+ {
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
+ sint_ptr = vb->value;
+ snmp_asn1_enc_s32t(p, ofs, vb->vlen, *sint_ptr);
+ 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):
+ uint_ptr = vb->value;
+ snmp_asn1_enc_u32t(p, ofs, vb->vlen, *uint_ptr);
+ break;
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
+ case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
+ case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
+ raw_ptr = vb->value;
+ snmp_asn1_enc_raw(p, ofs, vb->vlen, raw_ptr);
+ break;
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
+ break;
+ case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
+ sint_ptr = vb->value;
+ snmp_asn1_enc_oid(p, ofs, vb->value_len / sizeof(s32_t), sint_ptr);
+ break;
+ default:
+ /* unsupported type */
+ break;
+ };
+ ofs += vb->vlen;
+ vb = vb->next;
+ }
+ return ofs;
+}
+
+#endif /* LWIP_SNMP */
