/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Licensed under the Academic Free License version 2.1
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <glib.h>

#include <libhal.h>
#include <logger.h>

#undef PACKAGE_STRING
#undef PACKAGE_VERSION

#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>

#include "network-discovery.h"
#include "printer.h"

#define NP(x)   (x?x:"NULL")

static GList *new_addrs = NULL;

static void
add_snmp_device(LibHalContext *ctx, char *parent, char *name, char *community)
{
        /* most printers listen on the appsocket port (9100) */
        if (is_listening(name, 9100) == 0) {
                char device[128];

                snprintf(device, sizeof (device), "socket://%s:9100", name);

                add_network_printer(ctx, parent, name, device, community);
        }

        /*
         * This would be a good place to detect other types of devices or other
         * device capabilities.  scanners, removable media, storage, ...
         */
}

static int
snmp_response_cb(int operation, struct snmp_session *sp, int reqid,
                struct snmp_pdu *pdu, void *data)
{
        struct sockaddr_in *addr = pdu->transport_data;
        char *name;

        name = inet_ntoa(addr->sin_addr);

        /* have we already seen this network device */
        if (device_seen(name) == FALSE)
                new_addrs = g_list_append(new_addrs, strdup(name));

        return (0);
}

gboolean
scan_for_devices_using_snmp(LibHalContext *ctx, char *parent, char *community,
                char *network)
{
        struct snmp_session session, *ss;
        struct snmp_pdu *request = NULL, *response = NULL;
        oid Oid[MAX_OID_LEN];
        unsigned int oid_len = MAX_OID_LEN;
        GList *elem;

        HAL_DEBUG(("scan_for_devices_using_snmp(0x%8.8x, %s, %s, %s)",
            ctx, NP(parent), NP(community), NP(network)));

        init_snmp("snmp-scan");
        init_mib();

        /* initialize the SNMP session */
        snmp_sess_init(&session);
        session.peername = network;
        session.community = (uchar_t *)community;
        session.community_len = strlen((const char *)session.community);
        session.version = SNMP_VERSION_1;

        if ((ss = snmp_open(&session)) == NULL)
                return (FALSE);

        /* initialize the request PDU */
        request = snmp_pdu_create(SNMP_MSG_GET);

        /* add the requested data (everyone should have a sysDescr.0) */
        if (!read_objid("SNMPv2-MIB::sysDescr.0", Oid, &oid_len))
                snmp_perror("sysDescr.0");
        snmp_add_null_var(request, Oid, oid_len);

        snmp_async_send(ss, request, snmp_response_cb, NULL);

        /* detect any new devices */
        while (1) {
                int fds = 0, block = 0;
                fd_set fdset;
                struct timeval timeout;

                FD_ZERO(&fdset);
                snmp_select_info(&fds, &fdset, &timeout, &block);
                fds = select(fds, &fdset, NULL, NULL, block ? NULL : &timeout);
                if (fds < 0) {
                        perror("select failed");
                        break;
                } if (fds == 0) {
                        break;
                } else {
                        snmp_read(&fdset);
                }
        }

        snmp_close(ss);

        /* add the newly detected devices */
        for (elem = new_addrs; elem != NULL; elem = g_list_next(elem)) {
                add_snmp_device(ctx, parent, (char *)elem->data, community);
                free(elem->data);
        }
        g_list_free(new_addrs);
        new_addrs = NULL;

        return (TRUE);
}