dhcpcstate1.c

VXWORKS源代码

/* dhcpcState1.c - DHCP client runtime state machine (lease acquisition) */

/* Copyright 1984 - 2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01r,25apr02,wap  Only do arp_check() once so DHCPDECLINE messages are sent
                 (SPR #76315)
01q,23apr02,wap  use dhcpTime() instead of time() (SPR #68900)
01p,05nov01,wap  Fix memory leak in selecting() (SPR #68981)
01o,12oct01,rae  merge from truestack (modhist update)
                 note: SPRs 29555 30344 fixed here
01n,24oct00,spm  fixed modification history after tor3_x merge
01m,23oct00,niq  merged from version 01p of tor3_x branch (base version 01l);
                 upgrade to BPF replaces tagged frame support
01l,04dec97,spm  added code review modifications
01k,06oct97,spm  removed reference to deleted endDriver global
01j,02sep97,spm  moved data retrieval to prevent dereferenced NULL (SPR #9243);
                 removed excess IMPORT statement
01i,26aug97,spm  major overhaul: reorganized code and changed user interface
                 to support multiple leases at runtime
01h,06aug97,spm  removed parameters linked list to reduce memory required
01g,10jun97,spm  isolated incoming messages in state machine from input hooks
01f,02jun97,spm  changed DHCP option tags to prevent name conflicts (SPR #8667)
01e,06may97,spm  changed memory access to align IP header on four byte boundary
01d,28apr97,spm  corrected placement of conditional include to prevent failure
01c,18apr97,spm  added conditional include DHCPC_DEBUG for displayed output
01b,07apr97,spm  added code to use Host Requirements defaults, rewrote docs
01a,27jan97,spm  extracted from dhcpc.c to reduce object size
*/

/*
DESCRIPTION
This library contains a portion of the finite state machine for the WIDE 
project DHCP client, modified for vxWorks compatibility.

INTERNAL
This module contains the functions used prior to the BOUND state. It was
created to isolate those functions and reduce the size of the boot ROM image 
so that the DHCP client could be used with targets like the MV147 which have 
limited ROM capacity. When executing at boot time, the DHCP client's state
machine only used the states defined in this module. After the initial port 
was completed, the WIDE project implementation was greatly modified to allow 
the DHCP client library to establish and maintain multiple leases unassociated 
with the network interface used for message transfer. That capability is
completely unnecessary for the boot time client, so it no longer shares any 
code with this module.

INCLUDE_FILES: dhcpcLib.h
*/

/*
 * WIDE Project DHCP Implementation
 * Copyright (c) 1995 Akihiro Tominaga
 * Copyright (c) 1995 WIDE Project
 * All rights reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided only with the following
 * conditions are satisfied:
 *
 * 1. Both the copyright notice and this permission notice appear in
 *    all copies of the software, derivative works or modified versions,
 *    and any portions thereof, and that both notices appear in
 *    supporting documentation.
 * 2. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by WIDE Project and
 *      its contributors.
 * 3. Neither the name of WIDE Project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND WIDE
 * PROJECT DISCLAIMS ANY LIABILITY OF ANY KIND FOR ANY DAMAGES
 * WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. ALSO, THERE
 * IS NO WARRANTY IMPLIED OR OTHERWISE, NOR IS SUPPORT PROVIDED.
 *
 * Feedback of the results generated from any improvements or
 * extensions made to this software would be much appreciated.
 * Any such feedback should be sent to:
 * 
 *  Akihiro Tominaga
 *  WIDE Project
 *  Keio University, Endo 5322, Kanagawa, Japan
 *  (E-mail: [e-mail])
 *
 * WIDE project has the rights to redistribute these changes.
 */

/* includes */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/if_ether.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <arpa/inet.h>

#include "vxWorks.h"
#include "rngLib.h"
#include "wdLib.h"
#include "time.h"
#include "inetLib.h"
#include "logLib.h"
#include "taskLib.h"
#include "sysLib.h"
#include "vxLib.h"
#include "netLib.h"

#include "dhcp/dhcpcStateLib.h"
#include "dhcp/dhcpcInternal.h"
#include "dhcp/dhcpcCommonLib.h"

/* defines */

/* Retransmission delay is timer value plus/minus one second (RFC 1541). */

#define	SLEEP_RANDOM(timer) ( (timer - 1) + (rand () % 2) )
#define REQUEST_RETRANS   4  /* Max number of retransmissions (RFC 1541). */

/* globals */

IMPORT int 	dhcpcMinLease; 	/* Minimum accepted lease length. */
IMPORT SEM_ID 	dhcpcMutexSem;	/* Protects status indicator */
 
unsigned char		dhcpCookie [MAGIC_LEN] = RFC1048_MAGIC;
struct buffer		sbuf;

int (*fsm [MAX_STATES]) ();

int (*handle_param [MAXTAGNUM]) () = 
    {
    NULL,           /* PAD */
    handle_ip,      /* SUBNET_MASK */
    handle_num,     /* TIME_OFFSET */
    handle_ips,     /* ROUTER */
    handle_ips,     /* TIME_SERVER */
    handle_ips,     /* NAME_SERVER */
    handle_ips,     /* DNS_SERVER */
    handle_ips,     /* LOG_SERVER */
    handle_ips,     /* COOKIE_SERVER */
    handle_ips,     /* LPR_SERVER */
    handle_ips,     /* IMPRESS_SERVER */
    handle_ips,     /* RLS_SERVER */
    handle_str,     /* HOSTNAME */
    handle_num,     /* BOOTSIZE */
    handle_str,     /* MERIT_DUMP */
    handle_str,     /* DNS_DOMAIN */
    handle_ip,      /* SWAP_SERVER */
    handle_str,     /* ROOT_PATH */
    handle_str,     /* EXTENSIONS_PATH */
    handle_bool,    /* IP_FORWARD */
    handle_bool,    /* NONLOCAL_SRCROUTE */
    handle_ippairs, /* POLICY_FILTER */
    handle_num,     /* MAX_DGRAM_SIZE */
    handle_num,     /* DEFAULT_IP_TTL */
    handle_num,     /* MTU_AGING_TIMEOUT */
    handle_nums,    /* MTU_PLATEAU_TABLE */
    handle_num,     /* IF_MTU */
    handle_bool,    /* ALL_SUBNET_LOCAL */
    handle_ip,      /* BRDCAST_ADDR */
    handle_bool,    /* MASK_DISCOVER */
    handle_bool,    /* MASK_SUPPLIER */
    handle_bool,    /* ROUTER_DISCOVER */
    handle_ip,      /* ROUTER_SOLICIT */
    handle_ippairs, /* STATIC_ROUTE */
    handle_bool,    /* TRAILER */
    handle_num,     /* ARP_CACHE_TIMEOUT */
    handle_bool,    /* ETHER_ENCAP */
    handle_num,     /* DEFAULT_TCP_TTL */
    handle_num,     /* KEEPALIVE_INTER */
    handle_bool,    /* KEEPALIVE_GARBA */
    handle_str,     /* NIS_DOMAIN */
    handle_ips,     /* NIS_SERVER */
    handle_ips,     /* NTP_SERVER */
    handle_list,    /* VENDOR_SPEC */
    handle_ips,     /* NBN_SERVER */
    handle_ips,     /* NBDD_SERVER */
    handle_num,     /* NB_NODETYPE */
    handle_str,     /* NB_SCOPE */
    handle_ips,     /* XFONT_SERVER */
    handle_ips,     /* XDISPLAY_MANAGER */
    NULL,           /* REQUEST_IPADDR */
    handle_num,     /* LEASE_TIME */
    NULL,           /* OPT_OVERLOAD */
    NULL,           /* DHCP_MSGTYPE */
    handle_ip,      /* SERVER_ID */
    NULL,           /* REQ_LIST */
    handle_str,     /* DHCP_ERRMSG */
    NULL,           /* DHCP_MAXMSGSIZE */
    handle_num,     /* DHCP_T1 */
    handle_num,     /* DHCP_T2  */
    NULL,           /* CLASS_ID */
    NULL,           /* CLIENT_ID */
    NULL,
    NULL,
    handle_str,     /* NISP_DOMAIN */
    handle_ips,     /* NISP_SERVER */
    handle_str,     /* TFTP_SERVERNAME */
    handle_str,     /* BOOTFILE */
    handle_ips,     /* MOBILEIP_HA */
    handle_ips,     /* SMTP_SERVER */
    handle_ips,     /* POP3_SERVER */
    handle_ips,     /* NNTP_SERVER */
    handle_ips,     /* DFLT_WWW_SERVER */
    handle_ips,     /* DFLT_FINGER_SERVER */
    handle_ips,     /* DFLT_IRC_SERVER */
    handle_ips,     /* STREETTALK_SERVER */
    handle_ips      /* STDA_SERVER */
    };

/*******************************************************************************
*
* gen_retransmit - generic retransmission after timeout
*
* This routine retransmits the current DHCP client message (a discover or
* a request message) after the appropriate timeout interval expires.
* It is called from multiple locations in the finite state machine.
*
* RETURNS: 0 if transmission completed, or negative value on error.
*
* ERRNO: N/A
*
* NOMANUAL
*/

int gen_retransmit
    (
    LEASE_DATA * 	pLeaseData, 	/* lease-specific data structures */
    int 		length 		/* length of DHCP message */
    )
    {
    time_t	curr_epoch = 0;
    struct ifnet * 	pIf; 	/* interface used for retransmission */
    struct sockaddr_in  dest;
    BOOL bcastFlag;

    pIf = pLeaseData->ifData.iface;

    if (dhcpTime (&curr_epoch) == -1)
        return (-1);

    /* Update the appropriate fields in the current DHCP message. */

    if (pLeaseData->currState != REQUESTING)
        dhcpcMsgOut.dhcp->secs = htons (curr_epoch - pLeaseData->initEpoch);

    dhcpcMsgOut.udp->uh_sum = 0;
    dhcpcMsgOut.udp->uh_sum = udp_cksum (&spudph, (char *)dhcpcMsgOut.udp, 
                                         ntohs (spudph.ulen));

    /*
     * Retransmit the message. Set the flag to use a link-level broadcast
     * address if needed (prevents ARP messages if using Ethernet devices).
     */

    bzero ( (char *)&dest, sizeof (struct sockaddr_in));

    dest.sin_len = sizeof (struct sockaddr_in);
    dest.sin_family = AF_INET;
    dest.sin_addr.s_addr = dhcpcMsgOut.ip->ip_dst.s_addr;

    if (dest.sin_addr.s_addr == 0xffffffff)
        bcastFlag = TRUE;
    else
        bcastFlag = FALSE;

    pIf = pLeaseData->ifData.iface;

    if (dhcpSend (pIf, &dest, sbuf.buf, length, bcastFlag) == ERROR)
        return (-2);
    return(0);
    }

/*******************************************************************************
*
* retrans_wait_offer - signal reception interval for initial offer expires
*
* This routine sends a timeout notification to the client monitor task when
* the interval for receiving an initial lease offer expires. It is called at 
* interrupt level by a watchdog timer. The monitor task will eventually execute
* the WAIT_OFFER state to process the timeout event and retransmit the
* DHCP discover message.
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/

void retrans_wait_offer
    (
    LEASE_DATA * 	pLeaseData 	/* lease-specific status information */
    )
    { 
    /* 
     * Ignore the timeout if a state transition occurred during 
     * the scheduled timer interval.
     */

    if (pLeaseData->currState != WAIT_OFFER)
        return;

    /* Construct and send a timeout message to the lease monitor task. */

    dhcpcEventAdd (DHCP_AUTO_EVENT, DHCP_TIMEOUT, pLeaseData, TRUE);

    return;
    }

/*******************************************************************************
*
* alarm_selecting - signal when collection time expires 
*
* This routine sends a timeout notification to the client monitor task so
* that the corresponding lease will stop collecting DHCP offers. It is called 
* at interrupt level by a watchdog timer. The monitor task will eventually 
* advance the lease from the SELECTING to the REQUESTING state.
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/

void alarm_selecting
    (
    LEASE_DATA * 	pLeaseData 	/* lease-specific status information */
    )
    {
    STATUS result;

    /* 
     * Ignore the timeout if a state transition occurred during 
     * the scheduled timer interval.
     */

    if (pLeaseData->currState != SELECTING)
        return;

    /* Construct and send a timeout message to the lease monitor task. */

    result = dhcpcEventAdd (DHCP_AUTO_EVENT, DHCP_TIMEOUT, pLeaseData, TRUE);

#ifdef DHCPC_DEBUG
    if (result == ERROR)
        logMsg ("Warning: couldn't add timeout event for SELECTING state.\n", 
                0, 0, 0, 0, 0, 0);
#endif
    return;
    }

/*******************************************************************************
*
* retrans_requesting - signal when reception interval for initial reply expires
*
* This routine sends a timeout notification to the client monitor task when
* the interval for receiving a server reply to a lease request expires. It
* is called at interrupt level by a watchdog timer. The monitor task will 
* eventually execute the REQUESTING state to process the timeout event and 
* retransmit the DHCP request message.
*
* RETURNS: N/A
*
* ERRNO: N/A
*
* NOMANUAL
*/