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/* -*-C++-*- */
// ============================================================================
//
// = LIBRARY
// asnmp
//
// = FILENAME
// transaction.cpp
//
// = DESCRIPTION
// implements blocking SNMPv1 API using a simple state machine
// transactions over UDP/IP networks
//
// = AUTHOR
// Michael R MacFaden mrm@cisco.com - remove v2c, async, rework for ACE
// ============================================================================
#include "ace/Reactor.h"
#include "asnmp/transaction.h"
// pre: pdu, target report valid() == 1
// post: pdu sent out over the wire
inline void reset_receive_buffer(iovec& io)
{
io.iov_base = 0;
io.iov_len = 0;
}
transaction::transaction(const Pdu& pdu, const UdpTarget& target,
ACE_SOCK_Dgram& io):
wp_(pdu,target), params_(target), session_(io)
{
// last step, convert address (get ride of this once we have merged address
UdpAddress udp;
target.get_address(udp);
// via string conversion "dotted-quad:port"
ACE_INET_Addr tmp(udp);
addr_ = tmp;
reset_receive_buffer(receive_iovec_);
}
transaction::~transaction()
{
delete [] receive_iovec_.iov_base;
}
// implement state machine, send, wait (timeout/results) return
int transaction::run()
{
int rc, done = FALSE;
unsigned retry_counter = 0;
ACE_Time_Value to(params_.get_timeout(), 0); // seconds
ACE_Reactor reactor;
// 1. register io port for read access
if (reactor.register_handler(session_.get_handle(), this,
ACE_Event_Handler::READ_MASK) == -1)
return SNMP_CLASS_INTERNAL_ERROR;
// register a time handler and a socket with this
while (!done) {
if ((rc = send()) < 0) // send pkt to agent
return rc;
else {
if (retry_counter++ > params_.get_retry())
return SNMP_CLASS_TIMEOUT;
}
// 2. wait for events (timeout, returned msg)
if (( rc = reactor.handle_events (to)) == 1) // one handler registered
return 0;
else {
if (rc == 0) {
to.set(params_.get_timeout(), 0);
}
else
return SNMP_CLASS_INTERNAL_ERROR;
}
}
}
// got back response from SNMPv1 agent - process it
int transaction::handle_input (ACE_HANDLE fd)
{
// OS allocates iovec_.iov_base ptr and len
int rc = session_.recv(&receive_iovec_, receive_addr_, 0);
if (rc == -1) {
return SNMP_CLASS_RESOURCE_UNAVAIL;
}
return rc;
}
const ACE_INET_Addr& transaction::get_from_addr() const
{
return receive_addr_;
}
// return pdu to caller
int transaction::result(Pdu& pdu, char *comm_str, ACE_INET_Addr *from) const
{
// TODO: check to see the sender matches the receiver address..
// remove any vbs existing in this pdu
pdu.delete_all_vbs();
// any data to return?
if (receive_iovec_.iov_len == 0)
return -1;
wpdu tmp(receive_iovec_);
snmp_version ver;
// return comm str and from address of incomming pdu if requested
int rc = tmp.get_pdu(pdu, ver);
if (comm_str)
ACE_OS::strcpy(comm_str, (char *)tmp.get_community());
if (from)
*from = receive_addr_;
return rc;
}
int transaction::send()
{
iovec io = wp_.get_buffer();
if (io.iov_len == 0) {
// NO DATA ?
return -1;
}
ssize_t rc = session_.send (io.iov_base, io.iov_len, addr_ , 0);
return rc;
}
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