/**
* 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;
ip_addr_t 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) && !ip_addr_isany(&td->dip)) {
/* network order trap destination */
ip_addr_copy(trap_msg.dip, td->dip);
/* lookup current source address for this dst */
dst_if = ip_route(&td->dip);
ip_addr_copy(dst_ip, dst_if->ip_addr);
/* @todo: what about IPv6? */
trap_msg.sip_raw[0] = ip4_addr1(&dst_ip);
trap_msg.sip_raw[1] = ip4_addr2(&dst_ip);
trap_msg.sip_raw[2] = ip4_addr3(&dst_ip);
trap_msg.sip_raw[3] = ip4_addr4(&dst_ip);
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();
/** send to the TRAP destination */
udp_sendto(trap_msg.pcb, p, &trap_msg.dip, SNMP_TRAP_PORT);
pbuf_free(p);
} else {
return ERR_MEM;
}
}
}
return ERR_OK;
}
/**
* 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;
}
}
}
/**
* 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;
}
}
