/**
* 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 length 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 = (s32_t*)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 = (u32_t*)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 = (s32_t*)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;
}
/**
* 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 length for encoding the trap header
*/
static u16_t
snmp_trap_header_sum(struct snmp_msg_trap *trap)
{
u16_t tot_len;
u16_t len;
u8_t lenlen;
tot_len = 0;
snmp_asn1_enc_u32t_cnt(trap->ts, &len);
snmp_asn1_enc_length_cnt(len, &lenlen);
tot_len += 1 + len + lenlen;
snmp_asn1_enc_s32t_cnt(trap->spc_trap, &len);
snmp_asn1_enc_length_cnt(len, &lenlen);
tot_len += 1 + len + lenlen;
snmp_asn1_enc_s32t_cnt(trap->gen_trap, &len);
snmp_asn1_enc_length_cnt(len, &lenlen);
tot_len += 1 + len + lenlen;
if(IP_IS_V6_VAL(trap->sip)) {
#if LWIP_IPV6
len = sizeof(ip_2_ip6(&trap->sip)->addr);
#endif
} else {
#if LWIP_IPV4
len = sizeof(ip_2_ip4(&trap->sip)->addr);
#endif
}
snmp_asn1_enc_length_cnt(len, &lenlen);
tot_len += 1 + len + lenlen;
snmp_asn1_enc_oid_cnt(trap->enterprise->id, trap->enterprise->len, &len);
snmp_asn1_enc_length_cnt(len, &lenlen);
tot_len += 1 + len + lenlen;
trap->pdulen = tot_len;
snmp_asn1_enc_length_cnt(trap->pdulen, &lenlen);
tot_len += 1 + lenlen;
trap->comlen = (u16_t)strlen(snmp_community_trap);
snmp_asn1_enc_length_cnt(trap->comlen, &lenlen);
tot_len += 1 + lenlen + trap->comlen;
snmp_asn1_enc_s32t_cnt(trap->snmp_version, &len);
snmp_asn1_enc_length_cnt(len, &lenlen);
tot_len += 1 + len + lenlen;
trap->seqlen = tot_len;
snmp_asn1_enc_length_cnt(trap->seqlen, &lenlen);
tot_len += 1 + lenlen;
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;
}
/**
* Encodes trap header from head to tail.
*/
static void
snmp_trap_header_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream)
{
struct snmp_asn1_tlv tlv;
/* 'Message' sequence */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, 0, trap->seqlen);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
/* version */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_INTEGER, 0, 0);
snmp_asn1_enc_s32t_cnt(trap->snmp_version, &tlv.value_len);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->snmp_version);
/* community */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OCTET_STRING, 0, trap->comlen);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_raw(pbuf_stream, (const u8_t *)snmp_community_trap, trap->comlen);
/* 'PDU' sequence */
SNMP_ASN1_SET_TLV_PARAMS(tlv, (SNMP_ASN1_CLASS_CONTEXT | SNMP_ASN1_CONTENTTYPE_CONSTRUCTED | SNMP_ASN1_CONTEXT_PDU_TRAP), 0, trap->pdulen);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
/* object ID */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OBJECT_ID, 0, 0);
snmp_asn1_enc_oid_cnt(trap->enterprise->id, trap->enterprise->len, &tlv.value_len);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_oid(pbuf_stream, trap->enterprise->id, trap->enterprise->len);
/* IP addr */
if(IP_IS_V6_VAL(trap->sip)) {
#if LWIP_IPV6
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_IPADDR, 0, sizeof(ip_2_ip6(&trap->sip)->addr));
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_raw(pbuf_stream, (const u8_t *)&ip_2_ip6(&trap->sip)->addr, sizeof(ip_2_ip6(&trap->sip)->addr));
#endif
} else {
#if LWIP_IPV4
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_IPADDR, 0, sizeof(ip_2_ip4(&trap->sip)->addr));
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_raw(pbuf_stream, (const u8_t *)&ip_2_ip4(&trap->sip)->addr, sizeof(ip_2_ip4(&trap->sip)->addr));
#endif
}
/* trap length */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_INTEGER, 0, 0);
snmp_asn1_enc_s32t_cnt(trap->gen_trap, &tlv.value_len);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->gen_trap);
/* specific trap */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_INTEGER, 0, 0);
snmp_asn1_enc_s32t_cnt(trap->spc_trap, &tlv.value_len);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->spc_trap);
/* timestamp */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_TIMETICKS, 0, 0);
snmp_asn1_enc_s32t_cnt(trap->ts, &tlv.value_len);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->ts);
}
static err_t
snmp_append_outbound_varbind(struct snmp_request *request, struct snmp_varbind* varbind)
{
struct snmp_asn1_tlv tlv;
u8_t vb_len_len, oid_len_len, value_len_len;
u16_t vb_value_len, oid_value_len, value_value_len;
/* calculate required lengths */
snmp_asn1_enc_oid_cnt(varbind->oid.id, varbind->oid.len, &oid_value_len);
snmp_asn1_enc_length_cnt(oid_value_len, &oid_len_len);
if (varbind->value_len == 0) {
value_value_len = 0;
} else if (varbind->value_len & SNMP_GET_VALUE_RAW_DATA) {
value_value_len = varbind->value_len & (~SNMP_GET_VALUE_RAW_DATA);
} else {
switch (varbind->type)
{
case SNMP_ASN1_TYPE_INTEGER:
if (varbind->value_len != sizeof(s32_t)) {
return ERR_VAL;
}
snmp_asn1_enc_s32t_cnt(*((s32_t*)varbind->value) , &value_value_len);
break;
case SNMP_ASN1_TYPE_COUNTER:
case SNMP_ASN1_TYPE_GAUGE:
case SNMP_ASN1_TYPE_TIMETICKS:
if (varbind->value_len != sizeof(u32_t)) {
return ERR_VAL;
}
snmp_asn1_enc_u32t_cnt(*((u32_t*)varbind->value) , &value_value_len);
break;
case SNMP_ASN1_TYPE_OCTET_STRING:
case SNMP_ASN1_TYPE_IPADDR:
case SNMP_ASN1_TYPE_OPAQUE:
value_value_len = varbind->value_len;
break;
case SNMP_ASN1_TYPE_NULL:
if (varbind->value_len != 0) {
return ERR_VAL;
}
value_value_len = 0;
break;
case SNMP_ASN1_TYPE_OBJECT_ID:
if ((varbind->value_len % sizeof(u32_t)) != 0) {
return ERR_VAL;
}
snmp_asn1_enc_oid_cnt((u32_t*)varbind->value, varbind->value_len / sizeof(u32_t), &value_value_len);
break;
case SNMP_ASN1_TYPE_COUNTER64:
if (varbind->value_len != (2 * sizeof(u32_t))) {
return ERR_VAL;
}
snmp_asn1_enc_u64t_cnt((u32_t*)varbind->value , &value_value_len);
break;
default:
/* unsupported type */
return ERR_VAL;
}
}
snmp_asn1_enc_length_cnt(value_value_len, &value_len_len);
vb_value_len = 1 + oid_len_len + oid_value_len + 1 + value_len_len + value_value_len;
snmp_asn1_enc_length_cnt(vb_value_len, &vb_len_len);
/* check length already before adding first data because in case of GetBulk,
* data added so far is returned and therefore no partial data shall be added
*/
if ((1 + vb_len_len + vb_value_len) > request->outbound_pbuf_stream.length) {
return ERR_BUF;
}
/* 'VarBind' sequence */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, vb_len_len, vb_value_len);
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(&(request->outbound_pbuf_stream), &tlv) );
/* VarBind OID */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OBJECT_ID, oid_len_len, oid_value_len);
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(&(request->outbound_pbuf_stream), &tlv) );
OVB_BUILD_EXEC( snmp_asn1_enc_oid(&(request->outbound_pbuf_stream), varbind->oid.id, varbind->oid.len) );
/* VarBind value */
SNMP_ASN1_SET_TLV_PARAMS(tlv, varbind->type, value_len_len, value_value_len);
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(&(request->outbound_pbuf_stream), &tlv) );
if (value_value_len > 0) {
if (varbind->value_len & SNMP_GET_VALUE_RAW_DATA) {
OVB_BUILD_EXEC( snmp_asn1_enc_raw(&(request->outbound_pbuf_stream), (u8_t*)varbind->value, value_value_len) );
} else {
switch (varbind->type)
{
case SNMP_ASN1_TYPE_INTEGER:
OVB_BUILD_EXEC( snmp_asn1_enc_s32t(&(request->outbound_pbuf_stream), value_value_len, *((s32_t*)varbind->value)) );
break;
case SNMP_ASN1_TYPE_COUNTER:
case SNMP_ASN1_TYPE_GAUGE:
case SNMP_ASN1_TYPE_TIMETICKS:
OVB_BUILD_EXEC( snmp_asn1_enc_u32t(&(request->outbound_pbuf_stream), value_value_len, *((u32_t*)varbind->value)) );
break;
case SNMP_ASN1_TYPE_OCTET_STRING:
case SNMP_ASN1_TYPE_IPADDR:
case SNMP_ASN1_TYPE_OPAQUE:
OVB_BUILD_EXEC( snmp_asn1_enc_raw(&(request->outbound_pbuf_stream), (u8_t*)varbind->value, value_value_len) );
value_value_len = varbind->value_len;
break;
case SNMP_ASN1_TYPE_OBJECT_ID:
OVB_BUILD_EXEC( snmp_asn1_enc_oid(&(request->outbound_pbuf_stream), (u32_t*)varbind->value, varbind->value_len / sizeof(u32_t)) );
break;
case SNMP_ASN1_TYPE_COUNTER64:
OVB_BUILD_EXEC( snmp_asn1_enc_u64t(&(request->outbound_pbuf_stream), value_value_len, (u32_t*)varbind->value) );
break;
default:
LWIP_ASSERT("Unknown variable type", 0);
break;
}
}
}
return ERR_OK;
}