netppp.c

ucos操作系统下TCPIP实现代码

/*****************************************************************************
* netppp.c - Network Point to Point Protocol program file.
*
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 97-11-05 Guy Lancaster <[e-mail]>, Global Election Systems Inc.
*	Original.
*****************************************************************************/

/*
 * ppp_defs.h - PPP definitions.
 *
 * if_pppvar.h - private structures and declarations for PPP.
 *
 * Copyright (c) 1994 The Australian National University.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation is hereby granted, provided that the above copyright
 * notice appears in all copies.  This software is provided without any
 * warranty, express or implied. The Australian National University
 * makes no representations about the suitability of this software for
 * any purpose.
 *
 * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
 * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
 * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
 * OR MODIFICATIONS.
 */

/*
 * if_ppp.h - Point-to-Point Protocol definitions.
 *
 * 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 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "typedefs.h"
#include "v25.h"
#include "avconfig.h"
#include "avos.h"
#include <string.h>
#include "stdio.h"
#include "butctrl.h"
#include "rand.h"
#include "netbuf.h"

#include "net.h"
#include "netfsm.h"
#if PAP_SUPPORT > 0
#include "netpap.h"
#endif
#if CHAP_SUPPORT > 0
#include "netchap.h"
#endif
#include "netipcp.h"
#include "netlcp.h"
#include "netiphdr.h"		/* Required for netvj.h. */
#if VJ_SUPPORT > 0
#include "netvj.h"
#endif
#include "netppp.h"

/* Upper layer protocols. */
#include "netip.h"

/* Lower layer interfaces. */
#include "devio.h"

#include "debug.h"


/*************************/
/*** LOCAL DEFINITIONS ***/
/*************************/
/*
 *	Configuration parameters.
 */
#define MAXIDLEFLAG	500					/* Max Xmit idle time before resend flag char. */
#define MAXKILLDELAY TICKSPERSEC		/* Max delay jiffys before PPP task checks kill. */
#define STACK_SIZE NETSTACK+512		/* Enough to handle printf's. */

#define MAX_IFS		32


/*
 * The basic PPP frame.
 */
#define PPP_HDRLEN	4			/* octets for standard ppp header */
#define PPP_FCSLEN	2			/* octets for FCS */
#define PPP_ADDRESS(p)	(((u_char *)(p))[0])
#define PPP_CONTROL(p)	(((u_char *)(p))[1])
#define PPP_PROTOCOL(p)	((((u_char *)(p))[2] << 8) + ((u_char *)(p))[3])

/* PPP packet parser states.  Current state indicates operation yet to be
 * completed. */
typedef enum {
	PDIDLE = 0,					/* Idle state - waiting. */
	PDSTART,					/* Process start flag. */
	PDADDRESS,					/* Process address field. */
	PDCONTROL,					/* Process control field. */
	PDPROTOCOL1,				/* Process protocol field 1. */
	PDPROTOCOL2,				/* Process protocol field 2. */
	PDDATA						/* Process data byte. */
} PPPDevStates;

/* Special character codes. */
#define PPPFLAG 0x7e			/* Flag character. */
#define PPPESCAPE 0x7d			/* Escape character. */
#define PPPESCMASK 0x20			/* Mask to x-or with escaped character. */
#define PPPADDRESS 0xff			/* All-stations address. */
#define PPPCONTROL 0x03			/* Unnumbered info. */
/*
 * Significant octet values.
 */
#define	PPP_ALLSTATIONS	0xff	/* All-Stations broadcast address */
#define	PPP_UI		0x03		/* Unnumbered Information */
#define	PPP_FLAG	0x7e		/* Flag Sequence */
#define	PPP_ESCAPE	0x7d		/* Asynchronous Control Escape */
#define	PPP_TRANS	0x20		/* Asynchronous transparency modifier */

/*
 * Protocol field values.
 */
#define PPP_IP		0x21		/* Internet Protocol */
#define	PPP_XNS		0x25		/* Xerox NS */
#define PPP_AT		0x29		/* AppleTalk Protocol */
#define PPP_IPX		0x2b		/* IPX Datagram (RFC1552) */
#define	PPP_VJC_COMP	0x2d	/* VJ compressed TCP */
#define	PPP_VJC_UNCOMP	0x2f	/* VJ uncompressed TCP */
#define PPP_COMP	0xfd		/* compressed packet */
#define PPP_IPCP	0x8021		/* IP Control Protocol */
#define PPP_ATCP	0x8029		/* AppleTalk Control Protocol */
#define PPP_IPXCP	0x802b		/* IPX Control Protocol (RFC1552) */
#define PPP_CCP		0x80fd		/* Compression Control Protocol */
#define PPP_LCP		0xc021		/* Link Control Protocol */
#define PPP_PAP		0xc023		/* Password Authentication Protocol */
#define PPP_LQR		0xc025		/* Link Quality Report protocol */
#define PPP_CHAP	0xc223		/* Cryptographic Handshake Auth. Protocol */
#define PPP_CBCP	0xc029		/* Callback Control Protocol */

/*
 * Values for FCS calculations.
 */
#define PPP_INITFCS	0xffff		/* Initial FCS value */
#define PPP_GOODFCS	0xf0b8		/* Good final FCS value */
#define PPP_FCS(fcs, c)	(((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])

/*
 * Bit definitions for flags.
 */
#define SC_COMP_PROT	0x00000001	/* protocol compression (output) */
#define SC_COMP_AC		0x00000002	/* header compression (output) */
#define	SC_COMP_TCP		0x00000004	/* TCP (VJ) compression (output) */
#define SC_NO_TCP_CCID	0x00000008	/* disable VJ connection-id comp. */
#define SC_REJ_COMP_AC	0x00000010	/* reject adrs/ctrl comp. on input */
#define SC_REJ_COMP_TCP	0x00000020	/* reject TCP (VJ) comp. on input */
#define SC_CCP_OPEN		0x00000040	/* Look at CCP packets */
#define SC_CCP_UP		0x00000080	/* May send/recv compressed packets */
#define SC_DEBUG		0x00010000	/* enable debug messages */
#define SC_LOG_INPKT	0x00020000	/* log contents of good pkts recvd */
#define SC_LOG_OUTPKT	0x00040000	/* log contents of pkts sent */
#define SC_LOG_RAWIN	0x00080000	/* log all chars received */
#define SC_LOG_FLUSH	0x00100000	/* log all chars flushed */
#define SC_RCV_B7_0		0x01000000	/* have rcvd char with bit 7 = 0 */
#define SC_RCV_B7_1		0x02000000	/* have rcvd char with bit 7 = 1 */
#define SC_RCV_EVNP		0x04000000	/* have rcvd char with even parity */
#define SC_RCV_ODDP		0x08000000	/* have rcvd char with odd parity */
#define	SC_MASK			0x0fff00ff	/* bits that user can change */

/*
 * State bits in sc_flags, not changeable by user.
 */
#define SC_TIMEOUT		0x00000400	/* timeout is currently pending */
#define SC_VJ_RESET		0x00000800	/* need to reset VJ decomp */
#define SC_COMP_RUN		0x00001000	/* compressor has been initiated */
#define SC_DECOMP_RUN	0x00002000	/* decompressor has been initiated */
#define SC_DC_ERROR		0x00004000	/* non-fatal decomp error detected */
#define SC_DC_FERROR	0x00008000	/* fatal decomp error detected */
#define SC_TBUSY		0x10000000	/* xmitter doesn't need a packet yet */
#define SC_PKTLOST		0x20000000	/* have lost or dropped a packet */
#define	SC_FLUSH		0x40000000	/* flush input until next PPP_FLAG */
#define	SC_ESCAPED		0x80000000	/* saw a PPP_ESCAPE */


                                                                                                                                        
/************************/
/*** LOCAL DATA TYPES ***/
/************************/
/*
 * PPP interface control block.
 */
typedef struct PPPControl_s {
	char ifname[IFNAMSIZ];				/* Interface name */
	char openFlag;						/* True when in use. */
	char oldFrame;						/* Old framing character for fd. */
	int  fd;							/* File device ID of port. */
	int  kill_link;						/* Shut the link down. */
	int  if_up;							/* True when the interface is up. */
	int  errCode;						/* Code indicating why interface is down. */
	char pppStack[STACK_SIZE];			/* The ppp task stack. */
	NBuf *inHead, *inTail;				/* The input packet. */
	PPPDevStates inState;				/* The input process state. */
	char inEscaped;						/* Escape next character. */
	u_int inProtocol;					/* The input protocol code. */
	u_int inFCS;						/* Input Frame Check Sequence value. */
	u_int inLen;						/* Input packet length. */
	int  mtu;							/* Peer's mru */
	int  pcomp;							/* Does peer accept protocol compression? */
	int  accomp;						/* Does peer accept addr/ctl compression? */
	u_long lastXMit;					/* Time of last transmission. */
	ext_accm inACCM;					/* Async-Ctl-Char-Map for input. */
	ext_accm outACCM;					/* Async-Ctl-Char-Map for output. */
#if VJ_SUPPORT > 0
	int  vjEnabled;						/* Flag indicating VJ compression enabled. */
	struct vjcompress vjComp;			/* Van Jabobsen compression header. */
#endif
	int traceOffset;					/* Trace level offset. */
} PPPControl;


/*
 * Ioctl definitions.
 */

struct npioctl {
    int		protocol;			/* PPP procotol, e.g. PPP_IP */
    enum NPmode	mode;
};



/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
static void pppMain(void *pd);
static void pppDispatch(int pd, NBuf *nb, u_int protocol);
static void pppDrop(PPPControl *pc);
static void pppInProc(int pd, u_char *s, int l);
static NBuf *pppMPutC(u_char c, ext_accm *outACCM, NBuf *nb);
static NBuf *pppMPutRaw(u_char c, NBuf *nb);

#define ESCAPE_P(accm, c) ((accm)[(c) >> 3] & pppACCMMask[c & 0x07])

/* For development use only. */

/******************************/
/*** PUBLIC DATA STRUCTURES ***/
/******************************/
int	auth_required = 0;			/* Peer is required to authenticate */
PPPControl pppControl[NUM_PPP];	/* The PPP interface control blocks. */
#if STATS_SUPPORT > 0
PPPStats pppStats;				/* Statistics. */
#endif

/*
 * PPP Data Link Layer "protocol" table.
 * One entry per supported protocol.
 * The last entry must be NULL.
 */
struct protent *protocols[] = {
	&lcp_protent,
#if PAP_SUPPORT > 0
	&pap_protent,
#endif
#if CHAP_SUPPORT > 0
	&chap_protent,
#endif
#if CBCP_SUPPORT > 0
	&cbcp_protent,
#endif
	&ipcp_protent,
#if CCP_SUPPORT	> 0
	&ccp_protent,
#endif
    NULL
};

/*
 * Buffers for outgoing packets.  This must be accessed only from the appropriate
 * PPP task so that it doesn't need to be protected to avoid collisions.
 */
u_char outpacket_buf[NUM_PPP][PPP_MRU+PPP_HDRLEN];	



/*****************************/
/*** LOCAL DATA STRUCTURES ***/
/*****************************/

/*
 * FCS lookup table as calculated by genfcstab.
 */
const u_short fcstab[256] = {
	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

/* PPP's Asynchronous-Control-Character-Map.  The mask array is used
 * to select the specific bit for a character. */
static u_char pppACCMMask[] = {
	0x01,
	0x02,
	0x04,
	0x08,
	0x10,
	0x20,
	0x40,
	0x80
};


/***********************************/
/*** PUBLIC FUNCTION DEFINITIONS ***/
/***********************************/
/* Initialize the PPP subsystem. */
void pppInit(void)
{
	struct protent *protp;
	int i, j;
	
	for (i = 0; i < NUM_PPP; i++) {
		pppControl[i].openFlag = 0;
		sprintf(pppControl[i].ifname, "ppp%d", i);
	
		/*
		 * Initialize to the standard option set.
		 */
		for (j = 0; (protp = protocols[j]) != NULL; ++j)
			(*protp->init)(i);
	}
	
#if STATS_SUPPORT > 0
	/* Clear the statistics. */
	memset(&pppStats, 0, sizeof(pppStats));
	pppStats.headLine.fmtStr		= "\t\tPPP STATISTICS\r\n";
	pppStats.ppp_ibytes.fmtStr		= "\tBYTES IN    : %5lu\r\n";
	pppStats.ppp_ipackets.fmtStr	= "\tPACKETS IN  : %5lu\r\n";
	pppStats.ppp_ierrors.fmtStr		= "\tIN ERRORS   : %5lu\r\n";
	pppStats.ppp_derrors.fmtStr		= "\tDISPATCH ERR: %5lu\r\n";
	pppStats.ppp_obytes.fmtStr		= "\tBYTES OUT   : %5lu\r\n";
	pppStats.ppp_opackets.fmtStr	= "\tPACKETS OUT : %5lu\r\n";
	pppStats.ppp_oerrors.fmtStr		= "\tOUT ERRORS  : %5lu\r\n";
#endif
}

/* Open a new PPP connection using the given I/O device.
 * This initializes the PPP control block but does not
 * attempt to negotiate the LCP session.  If this port
 * connects to a modem, the modem connection must be
 * established before calling this.
 * Return a new PPP connection descriptor on success or
 * an error code (negative) on failure. */
int pppOpen(int fd)
{
	PPPControl *pc;
	char c;
	int pd;
	
	/* XXX
	 * Ensure that fd is not already used for PPP
	 */

	/* Find a free PPP session descriptor. */
	OS_ENTER_CRITICAL();
	for (pd = 0; pd < NUM_PPP && pppControl[pd].openFlag != 0; pd++);
	if (pd >= NUM_PPP)
		pd = PPPERR_OPEN;
	else
		pppControl[pd].openFlag = !0;
	OS_EXIT_CRITICAL();

	/*
	 * Save the old line discipline of fd, and set it to PPP.
	 *	(For the Accu-Vote, save and set the framing character).
	 *	Set the user name and password in case we need PAP
	 *	authentication.
	 */
	if (pd >= 0) {
		c = PPP_FLAG;
		if (ioctl(fd, GETFRAME, &pppControl[pd].oldFrame) < 0
				|| ioctl(fd, SETFRAME, &c) < 0) {
			pd = PPPERR_DEVICE;
			pppControl[pd].openFlag = 0;
		}
		upap_setloginpasswd(pd, user, passwd);
	}
	
	/* Launch a deamon thread. */
	if (pd >= 0) {
		lcp_init(pd);
		pc = &pppControl[pd];
		pc->fd = fd;
		pc->kill_link = 0;
		pc->if_up = 0;
		pc->errCode = 0;
		pc->inState = PDIDLE;
		pc->inHead = NULL;
		pc->inTail = NULL;
		pc->inEscaped = 0;
		pc->lastXMit = mtime() - MAXIDLEFLAG;
		pc->traceOffset = 0;
		
#if VJ_SUPPORT > 0
		pc->vjEnabled = 0;
		vj_compress_init(&pc->vjComp);
#endif

		/* 
		 * Default the in and out accm so that escape and flag characters
		 * are always escaped. 
		 */
		memset(pc->inACCM, 0, sizeof(ext_accm));
		pc->inACCM[15] = 0x60;
		memset(pc->outACCM, 0, sizeof(ext_accm));
		pc->outACCM[15] = 0x60;
		
		OSTaskCreate(pppMain, (void *)pd, pc->pppStack + STACK_SIZE, PRI_PPP0 + pd);
	
		while(pd >= 0 && !pc->if_up) {
			msleep(500);
			if (lcp_phase[pd] == PHASE_DEAD) {
				pppClose(pd);
				if (pc->errCode)
					pd = pc->errCode;
				else
					pd = PPPERR_CONNECT;
			} else if (buttonStatus() == YESNOBUTTON) {
				pppClose(pd);
				pd = PPPERR_USER;
			}
		}
		pc->traceOffset = 2;
	}

	return pd;