/*
* check a session validity for connectivity to the master agent. If
* not functioning, close and start attempts to reopen the session
*/
void agentx_check_session (unsigned int clientreg, void *clientarg)
{
netsnmp_session *ss = (netsnmp_session *) clientarg;
if (!ss)
{
if (clientreg)
snmp_alarm_unregister (clientreg);
return;
}
DEBUGMSGTL (("agentx/subagent", "checking status of session %p\n", ss));
if (!agentx_send_ping (ss))
{
snmp_log (LOG_WARNING, "AgentX master agent failed to respond to ping. Attempting to re-register.\n");
/*
* master agent disappeared? Try and re-register.
* close first, just to be sure .
*/
agentx_unregister_callbacks (ss);
agentx_close_session (ss, AGENTX_CLOSE_TIMEOUT);
snmp_alarm_unregister (clientreg); /* delete ping alarm timer */
snmp_call_callbacks (SNMP_CALLBACK_APPLICATION, SNMPD_CALLBACK_INDEX_STOP, (void *) ss);
register_mib_detach ();
if (main_session != NULL)
{
remove_trap_session (ss);
snmp_close (main_session);
/*
* We need to remove the callbacks attached to the callback
* session because they have a magic callback data structure
* which includes a pointer to the main session
* (which is no longer valid).
*
* Given that the main session is not responsive anyway.
* it shoudn't matter if we lose some outstanding requests.
*/
if (agentx_callback_sess != NULL)
{
snmp_close (agentx_callback_sess);
agentx_callback_sess = NULL;
subagent_init_callback_session ();
}
main_session = NULL;
agentx_reopen_session (0, NULL);
}
else
{
snmp_close (main_session);
main_session = NULL;
}
}
else
{
DEBUGMSGTL (("agentx/subagent", "session %p responded to ping\n", ss));
}
}
static int
subagent_shutdown(int majorID, int minorID, void *serverarg, void *clientarg)
{
netsnmp_session *thesession = (netsnmp_session *)clientarg;
DEBUGMSGTL(("agentx/subagent", "shutting down session....\n"));
if (thesession == NULL) {
DEBUGMSGTL(("agentx/subagent", "Empty session to shutdown\n"));
main_session = NULL;
return 0;
}
agentx_close_session(thesession, AGENTX_CLOSE_SHUTDOWN);
snmp_close(thesession);
if (main_session != NULL) {
remove_trap_session(main_session);
main_session = NULL;
}
DEBUGMSGTL(("agentx/subagent", "shut down finished.\n"));
subagent_init_init = 0;
return 1;
}
/*
* check a session validity for connectivity to the master agent. If
* not functioning, close and start attempts to reopen the session
*/
void
agentx_check_session(unsigned int clientreg, void *clientarg)
{
netsnmp_session *ss = (netsnmp_session *) clientarg;
if (!ss) {
if (clientreg)
snmp_alarm_unregister(clientreg);
return;
}
DEBUGMSGTL(("agentx/subagent", "checking status of session %p\n", ss));
if (!agentx_send_ping(ss)) {
snmp_log(LOG_WARNING,
"AgentX master agent failed to respond to ping. Attempting to re-register.\n");
/*
* master agent disappeared? Try and re-register.
* close first, just to be sure .
*/
agentx_unregister_callbacks(ss);
agentx_close_session(ss, AGENTX_CLOSE_TIMEOUT);
snmp_alarm_unregister(clientreg); /* delete ping alarm timer */
snmp_call_callbacks(SNMP_CALLBACK_APPLICATION,
SNMPD_CALLBACK_INDEX_STOP, (void *) ss);
register_mib_detach();
if (main_session != NULL) {
remove_trap_session(ss);
snmp_close(main_session);
main_session = NULL;
agentx_reopen_session(0, NULL);
}
else {
snmp_close(main_session);
main_session = NULL;
}
} else {
DEBUGMSGTL(("agentx/subagent", "session %p responded to ping\n",
ss));
}
}
int
handle_agentx_packet(int operation, netsnmp_session * session, int reqid,
netsnmp_pdu *pdu, void *magic)
{
struct agent_netsnmp_set_info *asi = NULL;
snmp_callback mycallback;
netsnmp_pdu *internal_pdu = NULL;
void *retmagic = NULL;
ns_subagent_magic *smagic = NULL;
if (operation == NETSNMP_CALLBACK_OP_DISCONNECT) {
struct synch_state *state = (struct synch_state *) magic;
int period =
netsnmp_ds_get_int(NETSNMP_DS_APPLICATION_ID,
NETSNMP_DS_AGENT_AGENTX_PING_INTERVAL);
DEBUGMSGTL(("agentx/subagent",
"transport disconnect indication\n"));
/*
* deal with existing session. This happend if agentx sends
* a message to the master, but the master goes away before
* a response is sent. agentx will spin in snmp_synch_response_cb,
* waiting for a response. At the very least, the waiting
* flag must be set to break that loop. The rest is copied
* from disconnect handling in snmp_sync_input.
*/
if(state) {
state->waiting = 0;
state->pdu = NULL;
state->status = STAT_ERROR;
session->s_snmp_errno = SNMPERR_ABORT;
SET_SNMP_ERROR(SNMPERR_ABORT);
}
/*
* Deregister the ping alarm, if any, and invalidate all other
* references to this session.
*/
if (session->securityModel != SNMP_DEFAULT_SECMODEL) {
snmp_alarm_unregister(session->securityModel);
}
snmp_call_callbacks(SNMP_CALLBACK_APPLICATION,
SNMPD_CALLBACK_INDEX_STOP, (void *) session);
agentx_unregister_callbacks(session);
remove_trap_session(session);
register_mib_detach();
main_session = NULL;
if (period != 0) {
/*
* Pings are enabled, so periodically attempt to re-establish contact
* with the master agent. Don't worry about the handle,
* agentx_reopen_session unregisters itself if it succeeds in talking
* to the master agent.
*/
snmp_alarm_register(period, SA_REPEAT, agentx_reopen_session,
NULL);
}
return 0;
} else if (operation != NETSNMP_CALLBACK_OP_RECEIVED_MESSAGE) {
DEBUGMSGTL(("agentx/subagent", "unexpected callback op %d\n",
operation));
return 1;
}
/*
* ok, we have a pdu from the net. Modify as needed
*/
DEBUGMSGTL(("agentx/subagent", "handling agentx request (req=0x%x,trans="
"0x%x,sess=0x%x)\n", pdu->reqid,pdu->transid, pdu->sessid));
pdu->version = AGENTX_VERSION_1;
pdu->flags |= UCD_MSG_FLAG_ALWAYS_IN_VIEW;
if (pdu->command == AGENTX_MSG_GET
|| pdu->command == AGENTX_MSG_GETNEXT
|| pdu->command == AGENTX_MSG_GETBULK) {
smagic =
(ns_subagent_magic *) calloc(1, sizeof(ns_subagent_magic));
if (smagic == NULL) {
DEBUGMSGTL(("agentx/subagent", "couldn't malloc() smagic\n"));
return 1;
}
smagic->original_command = pdu->command;
smagic->session = session;
smagic->ovars = NULL;
retmagic = (void *) smagic;
}
switch (pdu->command) {
case AGENTX_MSG_GET:
DEBUGMSGTL(("agentx/subagent", " -> get\n"));
pdu->command = SNMP_MSG_GET;
mycallback = handle_subagent_response;
break;
case AGENTX_MSG_GETNEXT:
DEBUGMSGTL(("agentx/subagent", " -> getnext\n"));
pdu->command = SNMP_MSG_GETNEXT;
/*
* We have to save a copy of the original variable list here because
* if the master agent has requested scoping for some of the varbinds
* that information is stored there.
*/
smagic->ovars = snmp_clone_varbind(pdu->variables);
DEBUGMSGTL(("agentx/subagent", "saved variables\n"));
mycallback = handle_subagent_response;
break;
case AGENTX_MSG_GETBULK:
/*
* WWWXXX
*/
DEBUGMSGTL(("agentx/subagent", " -> getbulk\n"));
pdu->command = SNMP_MSG_GETBULK;
/*
* We have to save a copy of the original variable list here because
* if the master agent has requested scoping for some of the varbinds
* that information is stored there.
*/
smagic->ovars = snmp_clone_varbind(pdu->variables);
DEBUGMSGTL(("agentx/subagent", "saved variables at %p\n",
smagic->ovars));
mycallback = handle_subagent_response;
break;
case AGENTX_MSG_RESPONSE:
SNMP_FREE(smagic);
DEBUGMSGTL(("agentx/subagent", " -> response\n"));
return 1;
case AGENTX_MSG_TESTSET:
/*
* XXXWWW we have to map this twice to both RESERVE1 and RESERVE2
*/
DEBUGMSGTL(("agentx/subagent", " -> testset\n"));
asi = save_set_vars(session, pdu);
if (asi == NULL) {
SNMP_FREE(smagic);
snmp_log(LOG_WARNING, "save_set_vars() failed\n");
return 1;
}
asi->mode = pdu->command = SNMP_MSG_INTERNAL_SET_RESERVE1;
mycallback = handle_subagent_set_response;
retmagic = asi;
break;
case AGENTX_MSG_COMMITSET:
DEBUGMSGTL(("agentx/subagent", " -> commitset\n"));
asi = restore_set_vars(session, pdu);
if (asi == NULL) {
SNMP_FREE(smagic);
snmp_log(LOG_WARNING, "restore_set_vars() failed\n");
return 1;
}
if (asi->mode != SNMP_MSG_INTERNAL_SET_RESERVE2) {
SNMP_FREE(smagic);
snmp_log(LOG_WARNING,
"dropping bad AgentX request (wrong mode %d)\n",
asi->mode);
return 1;
}
asi->mode = pdu->command = SNMP_MSG_INTERNAL_SET_ACTION;
mycallback = handle_subagent_set_response;
retmagic = asi;
break;
case AGENTX_MSG_CLEANUPSET:
DEBUGMSGTL(("agentx/subagent", " -> cleanupset\n"));
asi = restore_set_vars(session, pdu);
if (asi == NULL) {
SNMP_FREE(smagic);
snmp_log(LOG_WARNING, "restore_set_vars() failed\n");
return 1;
}
if (asi->mode == SNMP_MSG_INTERNAL_SET_RESERVE1 ||
asi->mode == SNMP_MSG_INTERNAL_SET_RESERVE2) {
asi->mode = pdu->command = SNMP_MSG_INTERNAL_SET_FREE;
} else if (asi->mode == SNMP_MSG_INTERNAL_SET_ACTION) {
asi->mode = pdu->command = SNMP_MSG_INTERNAL_SET_COMMIT;
} else {
snmp_log(LOG_WARNING,
"dropping bad AgentX request (wrong mode %d)\n",
asi->mode);
SNMP_FREE(retmagic);
return 1;
}
mycallback = handle_subagent_set_response;
retmagic = asi;
break;
case AGENTX_MSG_UNDOSET:
DEBUGMSGTL(("agentx/subagent", " -> undoset\n"));
asi = restore_set_vars(session, pdu);
if (asi == NULL) {
SNMP_FREE(smagic);
snmp_log(LOG_WARNING, "restore_set_vars() failed\n");
return 1;
}
asi->mode = pdu->command = SNMP_MSG_INTERNAL_SET_UNDO;
mycallback = handle_subagent_set_response;
retmagic = asi;
break;
default:
SNMP_FREE(smagic);
DEBUGMSGTL(("agentx/subagent", " -> unknown command %d (%02x)\n",
pdu->command, pdu->command));
return 0;
}
/*
* submit the pdu to the internal handler
*/
/*
* We have to clone the PDU here, because when we return from this
* callback, sess_process_packet will free(pdu), but this call also
* free()s its argument PDU.
*/
internal_pdu = snmp_clone_pdu(pdu);
internal_pdu->contextName = internal_pdu->community;
internal_pdu->contextNameLen = internal_pdu->community_len;
internal_pdu->community = NULL;
internal_pdu->community_len = 0;
snmp_async_send(agentx_callback_sess, internal_pdu, mycallback,
retmagic);
return 1;
}
