usr/src/cmd/cmd-inet/sbin/dhcpagent/inform.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
  23  *
  24  * INFORM_SENT state of the client state machine.
  25  */
  26
  27 #include <sys/types.h>
  28 #include <time.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <netinet/udp.h>
  32 #include <netinet/ip_var.h>
  33 #include <netinet/udp_var.h>
  34 #include <dhcpmsg.h>
  35
  36 #include "agent.h"
  37 #include "states.h"
  38 #include "interface.h"
  39 #include "packet.h"
  40
  41 static boolean_t stop_informing(dhcp_smach_t *, unsigned int);
  42
  43 /*
  44  * dhcp_inform(): sends an INFORM packet and sets up reception for an ACK
  45  *
  46  *   input: dhcp_smach_t *: the state machine to use
  47  *  output: void
  48  *    note: the INFORM cannot be sent successfully if the interface
  49  *          does not have an IP address (this is mostly an issue for IPv4).
  50  *          We switch into INFORM_SENT state before sending the packet so
  51  *          that the packet-sending subsystem uses regular sockets and sets
  52  *          the source address.  (See set_smach_state.)
  53  */
  54
  55 void
  56 dhcp_inform(dhcp_smach_t *dsmp)
  57 {
  58         dhcp_pkt_t              *dpkt;
  59
  60         if (!set_smach_state(dsmp, INFORM_SENT))
  61                 goto failed;
  62
  63         if (dsmp->dsm_isv6) {
  64                 dpkt = init_pkt(dsmp, DHCPV6_MSG_INFO_REQ);
  65
  66                 /* Add required Option Request option */
  67                 (void) add_pkt_prl(dpkt, dsmp);
  68                 dsmp->dsm_server = ipv6_all_dhcp_relay_and_servers;
  69                 (void) send_pkt_v6(dsmp, dpkt, dsmp->dsm_server,
  70                     stop_informing, DHCPV6_INF_TIMEOUT, DHCPV6_INF_MAX_RT);
  71         } else {
  72                 ipaddr_t server;
  73
  74                 /*
  75                  * Assemble a DHCPREQUEST packet, without the Server ID option.
  76                  * Fill in ciaddr, since we know this.  dsm_server will be set
  77                  * to the server's IP address, which will be the broadcast
  78                  * address if we don't know it.  The max DHCP message size
  79                  * option is set to the interface max, minus the size of the
  80                  * UDP and IP headers.
  81                  */
  82
  83                 dpkt = init_pkt(dsmp, INFORM);
  84                 IN6_V4MAPPED_TO_INADDR(&dsmp->dsm_lif->lif_v6addr,
  85                     &dpkt->pkt->ciaddr);
  86
  87                 (void) add_pkt_opt16(dpkt, CD_MAX_DHCP_SIZE,
  88                     htons(dsmp->dsm_lif->lif_pif->pif_max -
  89                     sizeof (struct udpiphdr)));
  90                 if (class_id_len != 0) {
  91                         (void) add_pkt_opt(dpkt, CD_CLASS_ID, class_id,
  92                             class_id_len);
  93                 }
  94                 (void) add_pkt_prl(dpkt, dsmp);
  95                 (void) add_pkt_opt(dpkt, CD_END, NULL, 0);
  96
  97                 IN6_V4MAPPED_TO_IPADDR(&dsmp->dsm_server, server);
  98                 if (!send_pkt(dsmp, dpkt, server, stop_informing)) {
  99                         dhcpmsg(MSG_ERROR, "dhcp_inform: send_pkt failed");
 100                         goto failed;
 101                 }
 102         }
 103
 104         return;
 105
 106 failed:
 107         dsmp->dsm_dflags |= DHCP_IF_FAILED;
 108         ipc_action_finish(dsmp, DHCP_IPC_E_INT);
 109         (void) set_smach_state(dsmp, INIT);
 110 }
 111
 112 /*
 113  * stop_informing(): decides when to stop retransmitting Information-Requests
 114  *
 115  *   input: dhcp_smach_t *: the state machine Info-Reqs are being sent from
 116  *          unsigned int: the number of requests sent so far
 117  *  output: boolean_t: B_TRUE if retransmissions should stop
 118  */
 119
 120 /* ARGSUSED */
 121 static boolean_t
 122 stop_informing(dhcp_smach_t *dsmp, unsigned int n_requests)
 123 {
 124         return (B_FALSE);
 125 }