ipcp.c

vxworks的tcpip协议栈源码

/* ipcp.c - PPP IP Control Protocol */

/* Copyright 1995 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
modification history
--------------------
01e,16jun95,dzb  header file consolidation.
01d,08jun95,dzb  made LOG_NOTICE message printed even w/o debug option.
01c,07feb95,dab  die() if IP address reject (SPR #4038).
01b,16jan95,dab  removed ipcp_script call.  removed pathname.h inclusion.
01a,21dec94,dab  VxWorks port - first WRS version.
	   +dzb  added: path for ppp header files, WRS copyright.
*/

#include <vxWorks.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "pppLib.h"

/*
 * Callbacks for fsm code.  (CI = Configuration Information)
 */
static void ipcp_resetci __ARGS((fsm *));	/* Reset our CI */
static int  ipcp_cilen __ARGS((fsm *));	        /* Return length of our CI */
static void ipcp_addci __ARGS((fsm *, u_char *, int *)); /* Add our CI */
static int  ipcp_ackci __ARGS((fsm *, u_char *, int));	/* Peer ack'd our CI */
static int  ipcp_nakci __ARGS((fsm *, u_char *, int));	/* Peer nak'd our CI */
static int  ipcp_rejci __ARGS((fsm *, u_char *, int));	/* Peer rej'd our CI */
static int  ipcp_reqci __ARGS((fsm *, u_char *, int *, int)); /* Rcv CI */
static void ipcp_up __ARGS((fsm *));		/* We're UP */
static void ipcp_down __ARGS((fsm *));		/* We're DOWN */

static fsm_callbacks ipcp_callbacks = { /* IPCP callback routines */
    ipcp_resetci,		/* Reset our Configuration Information */
    ipcp_cilen,			/* Length of our Configuration Information */
    ipcp_addci,			/* Add our Configuration Information */
    ipcp_ackci,			/* ACK our Configuration Information */
    ipcp_nakci,			/* NAK our Configuration Information */
    ipcp_rejci,			/* Reject our Configuration Information */
    ipcp_reqci,			/* Request peer's Configuration Information */
    ipcp_up,			/* Called when fsm reaches OPENED state */
    ipcp_down,			/* Called when fsm leaves OPENED state */
    NULL,			/* Called when we want the lower layer up */
    NULL,			/* Called when we want the lower layer down */
    NULL,			/* Called when Protocol-Reject received */
    NULL,			/* Retransmission is necessary */
    NULL,			/* Called to handle protocol-specific codes */
    "IPCP"			/* String name of protocol */
};

/*
 * Lengths of configuration options.
 */
#define CILEN_VOID	2
#define CILEN_COMPRESS	4	/* min length for compression protocol opt. */
#define CILEN_VJ	6	/* length for RFC1332 Van-Jacobson opt. */
#define CILEN_ADDR	6	/* new-style single address option */
#define CILEN_ADDRS	10	/* old-style dual address option */


#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
			 (x) == CONFNAK ? "NAK" : "REJ")


/*
 * Make a string representation of a network IP address.
 */
char *
ip_ntoa(ipaddr)
    u_long ipaddr;
{
    static char b[64];

    ipaddr = ntohl(ipaddr);

    sprintf(b, "%d.%d.%d.%d",
	    (u_char)(ipaddr >> 24),
	    (u_char)(ipaddr >> 16),
	    (u_char)(ipaddr >> 8),
	    (u_char)(ipaddr));
    return b;
}


/*
 * ipcp_init - Initialize IPCP.
 */
void
ipcp_init(unit)
    int unit;
{
    fsm *f = &ppp_if[unit]->ipcp_fsm;
    ipcp_options *wo = &ppp_if[unit]->ipcp_wantoptions;
    ipcp_options *ao = &ppp_if[unit]->ipcp_allowoptions;

    f->unit = unit;
    f->protocol = IPCP;
    f->callbacks = &ipcp_callbacks;
    fsm_init(&ppp_if[unit]->ipcp_fsm);

    wo->neg_addr = 1;
    wo->old_addrs = 0;
    wo->ouraddr = 0;
    wo->hisaddr = 0;

    wo->neg_vj = 1;
    wo->old_vj = 0;
    wo->vj_protocol = IPCP_VJ_COMP;
    wo->maxslotindex = MAX_STATES - 1; /* really max index */
    wo->cflag = 1;

    /* max slots and slot-id compression are currently hardwired in */
    /* ppp_if.c to 16 and 1, this needs to be changed (among other */
    /* things) gmc */

    ao->neg_addr = 1;
    ao->neg_vj = 1;
    ao->maxslotindex = MAX_STATES - 1;
    ao->cflag = 1;
}


/*
 * ipcp_open - IPCP is allowed to come up.
 */
void
ipcp_open(unit)
    int unit;
{
    fsm_open(&ppp_if[unit]->ipcp_fsm);
}


/*
 * ipcp_close - Take IPCP down.
 */
void
ipcp_close(unit)
    int unit;
{
    fsm_close(&ppp_if[unit]->ipcp_fsm);

    /*
     * NB
     * Since the only NCP supported by VxWorks is IPCP, this routine should
     * also take down the entire link if IPCP is going down... Thus,
     * an LCP should occur so that an LCP terminate request is sent to the
     * peer.  This is *not* usual behavior, especially in regard to the
     * RFC's protocol specification, but it makes sense for VxWorks.
     * Users should not mind, since the link is useless without IPCP.
     * -dzb
     */

     die(unit, 1);
}


/*
 * ipcp_lowerup - The lower layer is up.
 */
void
ipcp_lowerup(unit)
    int unit;
{
    fsm_lowerup(&ppp_if[unit]->ipcp_fsm);
}


/*
 * ipcp_lowerdown - The lower layer is down.
 */
void
ipcp_lowerdown(unit)
    int unit;
{
    fsm_lowerdown(&ppp_if[unit]->ipcp_fsm);
}


/*
 * ipcp_input - Input IPCP packet.
 */
void
ipcp_input(unit, p, len)
    int unit;
    u_char *p;
    int len;
{
    fsm_input(&ppp_if[unit]->ipcp_fsm, p, len);
}


/*
 * ipcp_protrej - A Protocol-Reject was received for IPCP.
 *
 * Pretend the lower layer went down, so we shut up.
 */
void
ipcp_protrej(unit)
    int unit;
{
    fsm_lowerdown(&ppp_if[unit]->ipcp_fsm);
}


/*
 * ipcp_resetci - Reset our CI.
 */
static void
ipcp_resetci(f)
    fsm *f;
{
    ipcp_options *wo = &ppp_if[f->unit]->ipcp_wantoptions;

    wo->req_addr = wo->neg_addr && ppp_if[f->unit]->ipcp_allowoptions.neg_addr;
    if (wo->ouraddr == 0)
        wo->accept_local = 1;
    if (wo->hisaddr == 0)
        wo->accept_remote = 1;
    ppp_if[f->unit]->ipcp_gotoptions = *wo;
    ppp_if[f->unit]->cis_received = 0;
}


/*
 * ipcp_cilen - Return length of our CI.
 */
static int
ipcp_cilen(f)
    fsm *f;
{
    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;

#define LENCIVJ(neg, old)	(neg ? (old? CILEN_COMPRESS : CILEN_VJ) : 0)
#define LENCIADDR(neg, old)	(neg ? (old? CILEN_ADDRS : CILEN_ADDR) : 0)

    return (LENCIADDR(go->neg_addr, go->old_addrs) +
	    LENCIVJ(go->neg_vj, go->old_vj));
}


/*
 * ipcp_addci - Add our desired CIs to a packet.
 */
static void
ipcp_addci(f, ucp, lenp)
    fsm *f;
    u_char *ucp;
    int *lenp;
{
    ipcp_options *wo = &ppp_if[f->unit]->ipcp_wantoptions;
    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;
    ipcp_options *ho = &ppp_if[f->unit]->ipcp_hisoptions;
    int len = *lenp;

#define ADDCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    if (neg) { \
	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
	if (len >= vjlen) { \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(vjlen, ucp); \
	    PUTSHORT(val, ucp); \
	    if (!old) { \
		PUTCHAR(maxslotindex, ucp); \
		PUTCHAR(cflag, ucp); \
	    } \
	    len -= vjlen; \
	} else \
	    neg = 0; \
    }

#define ADDCIADDR(opt, neg, old, val1, val2) \
    if (neg) { \
	int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
	if (len >= addrlen) { \
	    u_long l; \
	    PUTCHAR(opt, ucp); \
	    PUTCHAR(addrlen, ucp); \
	    l = ntohl(val1); \
	    PUTLONG(l, ucp); \
	    if (old) { \
		l = ntohl(val2); \
		PUTLONG(l, ucp); \
	    } \
	    len -= addrlen; \
	} else \
	    neg = 0; \
    }

    /*
     * First see if we want to change our options to the old
     * forms because we have received old forms from the peer.
     */
    if (wo->neg_addr && !go->neg_addr && !go->old_addrs) {
	/* use the old style of address negotiation */
	go->neg_addr = 1;
	go->old_addrs = 1;
    }
    if (wo->neg_vj && !go->neg_vj && !go->old_vj) {
	/* try an older style of VJ negotiation */
	if (ppp_if[f->unit]->cis_received == 0) {
	    /* keep trying the new style until we see some CI from the peer */
	    go->neg_vj = 1;
	} else {
	    /* use the old style only if the peer did */
	    if (ho->neg_vj && ho->old_vj) {
		go->neg_vj = 1;
		go->old_vj = 1;
		go->vj_protocol = ho->vj_protocol;
	    }
	}
    }

    ADDCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,
	      go->old_addrs, go->ouraddr, go->hisaddr);

    ADDCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,
	    go->maxslotindex, go->cflag);

    *lenp -= len;
}


/*
 * ipcp_ackci - Ack our CIs.
 *
 * Returns:
 *	0 - Ack was bad.
 *	1 - Ack was good.
 */
static int
ipcp_ackci(f, p, len)
    fsm *f;
    u_char *p;
    int len;
{
    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;
    u_short cilen, citype, cishort;
    u_long cilong;
    u_char cimaxslotindex, cicflag;

    /*
     * CIs must be in exactly the same order that we sent...
     * Check packet length and CI length at each step.
     * If we find any deviations, then this packet is bad.
     */

#define ACKCIVJ(opt, neg, val, old, maxslotindex, cflag) \
    if (neg) { \
	int vjlen = old? CILEN_COMPRESS : CILEN_VJ; \
	if ((len -= vjlen) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != vjlen || \
	    citype != opt)  \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != val) \
	    goto bad; \
	if (!old) { \
	    GETCHAR(cimaxslotindex, p); \
	    if (cimaxslotindex != maxslotindex) \
		goto bad; \
	    GETCHAR(cicflag, p); \
	    if (cicflag != cflag) \
		goto bad; \
	} \
    }

#define ACKCIADDR(opt, neg, old, val1, val2) \
    if (neg) { \
	int addrlen = (old? CILEN_ADDRS: CILEN_ADDR); \
	u_long l; \
	if ((len -= addrlen) < 0) \
	    goto bad; \