sbin/dhcpagent/inform.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * INFORM_SENT state of the client state machine.
 */

#include <sys/types.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/udp.h>
#include <netinet/ip_var.h>
#include <netinet/udp_var.h>
#include <dhcpmsg.h>

#include "agent.h"
#include "states.h"
#include "interface.h"
#include "packet.h"

static boolean_t stop_informing(dhcp_smach_t *, unsigned int);

/*
 * dhcp_inform(): sends an INFORM packet and sets up reception for an ACK
 *
 *   input: dhcp_smach_t *: the state machine to use
 *  output: void
 *    note: the INFORM cannot be sent successfully if the interface
 *      does not have an IP address (this is mostly an issue for IPv4).
 *      We switch into INFORM_SENT state before sending the packet so
 *      that the packet-sending subsystem uses regular sockets and sets
 *      the source address.  (See set_smach_state.)
 */

void
dhcp_inform(dhcp_smach_t *dsmp)
{
    dhcp_pkt_t      *dpkt;

    if (!set_smach_state(dsmp, INFORM_SENT))
        goto failed;

    if (dsmp->dsm_isv6) {
        dpkt = init_pkt(dsmp, DHCPV6_MSG_INFO_REQ);

        /* Add required Option Request option */
        (void) add_pkt_prl(dpkt, dsmp);
        dsmp->dsm_server = ipv6_all_dhcp_relay_and_servers;
        (void) send_pkt_v6(dsmp, dpkt, dsmp->dsm_server,
            stop_informing, DHCPV6_INF_TIMEOUT, DHCPV6_INF_MAX_RT);
    } else {
        ipaddr_t server;

        /*
         * Assemble a DHCPREQUEST packet, without the Server ID option.
         * Fill in ciaddr, since we know this.  dsm_server will be set
         * to the server's IP address, which will be the broadcast
         * address if we don't know it.  The max DHCP message size
         * option is set to the interface max, minus the size of the
         * UDP and IP headers.
         */

        dpkt = init_pkt(dsmp, INFORM);
        IN6_V4MAPPED_TO_INADDR(&dsmp->dsm_lif->lif_v6addr,
            &dpkt->pkt->ciaddr);

        (void) add_pkt_opt16(dpkt, CD_MAX_DHCP_SIZE,
            htons(dsmp->dsm_lif->lif_pif->pif_max -
            sizeof (struct udpiphdr)));
        if (class_id_len != 0) {
            (void) add_pkt_opt(dpkt, CD_CLASS_ID, class_id,
                class_id_len);
        }
        (void) add_pkt_prl(dpkt, dsmp);
        (void) add_pkt_opt(dpkt, CD_END, NULL, 0);

        IN6_V4MAPPED_TO_IPADDR(&dsmp->dsm_server, server);
        if (!send_pkt(dsmp, dpkt, server, stop_informing)) {
            dhcpmsg(MSG_ERROR, "dhcp_inform: send_pkt failed");
            goto failed;
        }
    }

    return;

failed:
    dsmp->dsm_dflags |= DHCP_IF_FAILED;
    ipc_action_finish(dsmp, DHCP_IPC_E_INT);
    (void) set_smach_state(dsmp, INIT);
}

/*
 * stop_informing(): decides when to stop retransmitting Information-Requests
 *
 *   input: dhcp_smach_t *: the state machine Info-Reqs are being sent from
 *      unsigned int: the number of requests sent so far
 *  output: boolean_t: B_TRUE if retransmissions should stop
 */

/* ARGSUSED */
static boolean_t
stop_informing(dhcp_smach_t *dsmp, unsigned int n_requests)
{
    return (B_FALSE);
}