/*-------------------------------------------------------------------------
 * pgsnmpd.c
 *
 *      Global definitions for the main PostgreSQL SNMP Daemon.
 *
 *      Copyright (c) 2004-2005, PostgreSQL Global Development Group
 *      Author: Hiroshi Saito
 *
 *      $Id: pgsnmpd.c,v 1.30 2009/12/24 21:04:40 eggyknap Exp $
 *-------------------------------------------------------------------------
 */


/* TODO: Make this respond to all snmpd command opts when called as a standalone daemon */

#include "pgsnmpd.h"
 #include "rdbmsDbTable/rdbmsDbTable.h"
#include "rdbmsDbInfoTable/rdbmsDbInfoTable.h"
#include "rdbmsDbParamTable/rdbmsDbParamTable.h"
#include "rdbmsDbLimitedResourceTable/rdbmsDbLimitedResourceTable.h"
#include "rdbmsSrvTable/rdbmsSrvTable.h"
#include "rdbmsSrvParamTable/rdbmsSrvParamTable.h"
#include "rdbmsSrvInfoTable/rdbmsSrvInfoTable.h"
#include "rdbmsRelTable/rdbmsRelTable.h"

/*#include "PGSQL-MIB_src/pgsqlCatalogTables/pgsqlPgAggregateTable/pgsqlPgAggregateTable.h"
#include "PGSQL-MIB_src/pgsqlCatalogTables/pgsqlPgAmopTable/pgsqlPgAmopTable.h" */

#include "customquery.h"

#include <signal.h>
#include <ctype.h>

/*
 * define strings
 */

#define PGSNMP_DAEMON "PGSQL-SNMP-Ver1.0"

#define SUB_AGENT    1

char *pgsnmp_version = PG_VERSION_STR;

/* Official MIB object 
http://www.iana.org/assignments/enterprise-numbers

27645
  PostgreSQL Global Development Group
    Dave Page
      dpage&postgresql.org
*/

/*
 * PostgreSQL Connection
 */
PGconn     *dbconn = NULL;
char       *conninfo = {"dbname=template1"};
#define     SEARCH_PATH "set search_path to pgsnmpd"

static int keep_running = 0;
struct timeval snmp_boottime;
static int   pgsqlState = 0;

static PGconn
*db_connect(char *constring)
{
    PGconn     *dbconn;
    dbconn = PQconnectdb(constring);
    if (dbconn == NULL)
    {
        return NULL;
    }
    if (PQstatus(dbconn) != CONNECTION_OK)
    {
        snmp_log(LOG_ERR,"%s\n",PQerrorMessage(dbconn));
        PQfinish(dbconn);
        return NULL;
    }

    return dbconn;
}    

bool IsAlive()
{
    PGresult *qryRes;

    if (!pgsqlState)
    {
        if ((dbconn = db_connect(conninfo)))
            pgsqlState = 1;
        else
            return false;
    }

    /* TODO: Deal with setting the schema properly here */
    qryRes = PQexec(dbconn, "SELECT 1;");
    if (PQresultStatus(qryRes) != PGRES_TUPLES_OK)
    {
        PQclear(qryRes);
        PQfinish(dbconn);
        pgsqlState = 0;
        dbconn = NULL;
        return false;
    }

    PQclear(qryRes);
    return true;
}

static void
stop_server(int signo) 
{
    pgsqlState = keep_running = 0;
    snmp_log(LOG_ERR, "\nExiting on signal %d\n", signo);
}


static void init_mibs(void) {
    /* This initializes the table MIB.  */

    initialize_table_rdbmsDbTable();
    init_rdbmsDbInfoTable();
    init_rdbmsDbParamTable();
    init_rdbmsDbLimitedResourceTable();
    init_rdbmsSrvTable();
    init_rdbmsSrvParamTable();
    init_rdbmsSrvInfoTable();
    init_rdbmsRelTable();
/*    init_pgsqlPgAggregateTable();
     init_pgsqlPgAmopTable(); */
    init_custom_queries();
}

static void
usage(void)
{
    fprintf(stderr, "Version %s\n", PGSNMP_DAEMON);
    fprintf(stderr, "usage: pgsnmpd [-s] [-b] [-c FILE ] [-x address ] [-g] [-C \"Connect String\"]\n");
    fprintf(stderr, "   -s : run as AgentX sub-agent of an existing snmpd process\n");
    fprintf(stderr, "   -b : run in the background\n");
    fprintf(stderr, "   -c : configuration file name\n");
    fprintf(stderr, "   -g : use syslog\n");
    fprintf(stderr, "   -C : libpq connect strings\n");
    fprintf(stderr, "   -Q : custom query configuration file\n");
    fprintf(stderr, "   -x : address:port of a network interface\n");
/*    fprintf(stderr, "   -n : database search_path to use for pgsnmpd-specific tables (default: $user, public)\n"); */
    fprintf(stderr, "   -V : display version strings\n");
}

int
main(int argc, char *argv[]) 
{
    int agentx_subagent=0;    /* SNMP master agent */
    int background = 0;    /* run the background */
    int syslog = 0;        /* use syslog */

    int    arg;
/*    char *set_search_path, *escaped_search_path; 
    int errorval;*/

#ifdef DEBUG
    char *strv;
#endif

    char     options[128] = "sbc:gC:x:V-:Q:";
    /*char     options[128] = "sbc:gC:x:V-:n:"; */
    PGresult *qryRes;

    while ((arg = getopt(argc, argv, options)) != EOF)
    {
        switch (arg)
        {
        case 'V':
        case '?':
            usage();
            exit(0);
        case 'Q':
            if (optarg != NULL)
                custom_query_config_file = optarg;
            else {
                usage();
                exit(-1);
            }
        case 'c':
            if (optarg != NULL) {
                        netsnmp_ds_set_string(NETSNMP_DS_LIBRARY_ID,
                                      NETSNMP_DS_LIB_OPTIONALCONFIG, optarg);
            } else {
                usage();
                exit(-1);
            }
            break;
        case 'g':
            syslog = 1;
            break;
        case 'b':
            background = 1;
            break;
        case 's':
            agentx_subagent = 1;
            break;
        case 'x':
            if (optarg != NULL) {
                printf("-x option: %s\n", optarg);
                netsnmp_ds_set_string(NETSNMP_DS_APPLICATION_ID,
                                    NETSNMP_DS_AGENT_X_SOCKET, optarg);
            } else {
                usage();
                exit(-1);
            }
            break;
/*        case 'n':
            if (optarg != NULL) search_path = optarg;
            else {
                usage();
                exit(1);
            } */
        case 'C':
            if (optarg != NULL) {
                conninfo = optarg;
            } else {
                usage();
                exit(1);
            }
            break;
/*            default:
                    usage(); 
                    exit(1); */
        }
    }

      gettimeofday(&snmp_boottime, (struct timezone *)0);

      if (syslog)
        /* Some problems are contained.
            snmp_enable_calllog(); */
            snmp_enable_syslog();
      else
            snmp_enable_stderrlog();

        if (getuid() !=0)
              netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
             NETSNMP_DS_AGENT_NO_ROOT_ACCESS, 1);

      if ((dbconn = db_connect(conninfo))) {
             pgsqlState = 1;
        qryRes = PQexec(dbconn, SEARCH_PATH);
        if (PQresultStatus(qryRes) != PGRES_COMMAND_OK) snmp_log(LOG_ERR, "Could not set search path because of some problem with the set query\n");
#if 0
        if (strncmp(search_path, "$user, public", 13) != 0) {;
            escaped_search_path = calloc(sizeof(*search_path) * 2 + 1, sizeof(char*));
            if (escaped_search_path == NULL) {
                snmp_log(LOG_ERR, "Could not allocate memory to escape search_path value\n");
                exit(1);
            }
            PQescapeStringConn(dbconn, escaped_search_path, search_path, strlen(search_path), &errorval); */
            /* This initialization is to avoid a compiler warning */
            set_search_path = NULL;
            if (errorval != 0)
                snmp_log(LOG_ERR, "Could not escape search path string\n"); 
                /* Note: I'm not exiting after this error. The only problem with not setting the 
                 * search_path is not having the database tables available, which right now isn't
                 * a really big deal */
            else {
                set_search_path = calloc(sizeof(*escaped_search_path) + sizeof("SET search_path TO "), sizeof(char*));
                if (set_search_path == NULL) 
                    snmp_log(LOG_ERR, "Could not allocate memory to set search_path\n");
                else {
                    snmp_log(LOG_INFO, set_search_path);
                    sprintf(set_search_path, "SET search_path TO %s", escaped_search_path);
                    qryRes = PQexec(dbconn, set_search_path);
                    if (PQresultStatus(qryRes) != PGRES_COMMAND_OK) snmp_log(LOG_ERR, "Could not set search path because of some problem with the set query\n");
                    PQclear(qryRes);
                }
            }
            free(escaped_search_path); free(set_search_path);
        } 
#endif
    }
    else {
        printf("Failure connecting to PostgreSQL. pgsnmpd will exit\n");
        exit(1);
    }

      if (agentx_subagent)
      {
            /* make us a agentx client. */
            netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID,
                           NETSNMP_DS_AGENT_ROLE, SUB_AGENT);

#if 0
            netsnmp_ds_set_boolean(NETSNMP_DS_APPLICATION_ID, 
               NETSNMP_DS_AGENT_AGENTX_MASTER, 0);

#endif
#ifdef DEBUG
            if (netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID, 
                               NETSNMP_DS_AGENT_ROLE)) 
              snmp_log(LOG_INFO,"SUB_AGENT running.\n");
#endif

    }
#if 0
      netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID,
                       NETSNMP_DS_AGENT_AGENTX_TIMEOUT, -1);
      netsnmp_ds_set_int(NETSNMP_DS_APPLICATION_ID,
                       NETSNMP_DS_AGENT_AGENTX_RETRIES, -1);

      netsnmp_ds_register_config(ASN_OCTET_STR, "snmp", "public",
               NETSNMP_DS_LIBRARY_ID, NETSNMP_DS_LIB_COMMUNITY);

#endif
#ifdef DEBUG
    if(netsnmp_ds_get_string(NETSNMP_DS_APPLICATION_ID, 
            NETSNMP_DS_AGENT_X_SOCKET))

        snmp_log(LOG_INFO,"AGENT_X_SOCKET:%s\n",
            netsnmp_ds_get_string(NETSNMP_DS_APPLICATION_ID, 
                        NETSNMP_DS_AGENT_X_SOCKET));
     if(netsnmp_ds_get_string(NETSNMP_DS_APPLICATION_ID, 
            NETSNMP_DS_AGENT_PORTS))
            snmp_log(LOG_INFO,"AGENT_PORTS:%s\n",
            netsnmp_ds_get_string(NETSNMP_DS_APPLICATION_ID, 
                        NETSNMP_DS_AGENT_PORTS));
#endif

    /* run in background */
    if (background && netsnmp_daemonize(1, !syslog))
        exit(1);

/* initialize tcpip */
SOCK_STARTUP;

    init_agent(PGSNMP_DAEMON);

    init_mibs();

    init_snmp(PGSNMP_DAEMON);

    if (!agentx_subagent)
        init_master_agent();

    keep_running = 1;

    signal(SIGTERM, stop_server);
    signal(SIGINT, stop_server);

    snmp_log(LOG_INFO,"%s is running.\n", PGSNMP_DAEMON);

    while(keep_running)
    {

        agent_check_and_process(1);
#ifdef DEBUG
        strv = netsnmp_ds_get_string(NETSNMP_DS_LIBRARY_ID,
                NETSNMP_DS_LIB_COMMUNITY );
        if (strv)
            snmp_log(LOG_INFO, strv);
#endif

    }

    /* shutdown */
    if (!agentx_subagent)
        snmp_shutdown(PGSNMP_DAEMON);

SOCK_CLEANUP;

    return 0;

}