ax25.h

网友张巍提供的tcpip协议栈,是一个成功稳定的以太网接口上的TCP/IP协议程序。里面包括有说明

#ifndef	_AX25_H
#define	_AX25_H

#ifndef	_GLOBAL_H
#include "global.h"
#endif

#ifndef	_MBUF_H
#include "mbuf.h"
#endif

#ifndef	_IFACE_H
#include "iface.h"
#endif

#ifndef _SOCKADDR_H
#include "sockaddr.h"
#endif

extern char Ax25_eol[];

/* AX.25 datagram (address) sub-layer definitions */

#define	MAXDIGIS	7	/* Maximum number of digipeaters */
#define	ALEN		6	/* Number of chars in callsign field */
#define	AXALEN		7	/* Total AX.25 address length, including SSID */
#define	AXBUF		10	/* Buffer size for maximum-length ascii call */

/* Bits within SSID field of AX.25 address */
#define	SSID		0x1e	/* Sub station ID */
#define	REPEATED	0x80	/* Has-been-repeated bit in repeater field */
#define	E		0x01	/* Address extension bit */
#define	C		0x80	/* Command/response designation */

/* Our AX.25 address */
extern uint8 Mycall[AXALEN];

/* List of AX.25 multicast addresses, e.g., "QST   -0" in shifted ASCII */
extern uint8 Ax25multi[][AXALEN];

extern int Digipeat;
extern int Ax25mbox;

/* Number of chars in interface field. The involved definition takes possible
 * alignment requirements into account, since ax25_addr is of an odd size.
 */
#define	ILEN	(sizeof(struct sockaddr) - sizeof(short) - AXALEN)

/* Socket address, AX.25 style */
struct sockaddr_ax {
	short sax_family;		/* 2 bytes */
	uint8 ax25_addr[AXALEN];
	char iface[ILEN];		/* Interface name */
};

/* Internal representation of an AX.25 header */
struct ax25 {
	uint8 dest[AXALEN];		/* Destination address */
	uint8 source[AXALEN];		/* Source address */
	uint8 digis[MAXDIGIS][AXALEN];	/* Digi string */
	int ndigis;			/* Number of digipeaters */
	int nextdigi;			/* Index to next digi in chain */
	enum {
		LAPB_UNKNOWN,
		LAPB_COMMAND,
		LAPB_RESPONSE
	} cmdrsp;			/* Command/response */
};

/* AX.25 routing table entry */
struct ax_route {
	struct ax_route *next;		/* Linked list pointer */
	uint8 target[AXALEN];
	uint8 digis[MAXDIGIS][AXALEN];
	int ndigis;
	enum {
		AX_LOCAL,		/* Set by local ax25 route command */
		AX_AUTO			/* Set by incoming packet */
	} type;
};

extern struct ax_route *Ax_routes;
extern struct ax_route Ax_default;

/* AX.25 Level 3 Protocol IDs (PIDs) */
#define PID_X25		0x01	/* CCITT X.25 PLP */
#define	PID_SEGMENT	0x08	/* Segmentation fragment */
#define PID_TEXNET	0xc3	/* TEXNET datagram protocol */
#define	PID_LQ		0xc4	/* Link quality protocol */
#define	PID_APPLETALK	0xca	/* Appletalk */
#define	PID_APPLEARP	0xcb	/* Appletalk ARP */
#define	PID_IP		0xcc	/* ARPA Internet Protocol */
#define	PID_ARP		0xcd	/* ARPA Address Resolution Protocol */
#define	PID_NETROM	0xcf	/* NET/ROM */
#define	PID_NO_L3	0xf0	/* No level 3 protocol */

/* Link quality report packet header, internal format */
struct lqhdr {
	uint16 version;		/* Version number of protocol */
#define	LINKVERS	1
	int32	ip_addr;	/* Sending station's IP address */
};
#define	LQHDR	6
/* Link quality entry, internal format */
struct lqentry {
	uint8 addr[AXALEN];	/* Address of heard station */
	int32 count;		/* Count of packets heard from that station */
};
#define	LQENTRY	11

/* Link quality database record format
 * Currently used only by AX.25 interfaces
 */
struct lq {
	struct lq *next;
	uint8 addr[AXALEN];	/* Hardware address of station heard */
	struct iface *iface;	/* Interface address was heard on */
	int32 time;		/* Time station was last heard */
	int32 currxcnt;	/* Current # of packets heard from this station */

#ifdef	notdef		/* Not yet implemented */
	/* # of packets heard from this station as of his last update */
	int32 lastrxcnt;

	/* # packets reported as transmitted by station as of his last update */
	int32 lasttxcnt;

	uint16 hisqual;	/* Fraction (0-1000) of station's packets heard
			 * as of last update
			 */
	uint16 myqual;	/* Fraction (0-1000) of our packets heard by station
			 * as of last update
			 */
#endif
};

extern struct lq *Lq;	/* Link quality record headers */

/* Structure used to keep track of monitored destination addresses */
struct ld {
	struct ld *next;	/* Linked list pointers */
	uint8 addr[AXALEN];/* Hardware address of destination overheard */
	struct iface *iface;	/* Interface address was heard on */
	int32 time;		/* Time station was last mentioned */
	int32 currxcnt;	/* Current # of packets destined to this station */
};

extern struct ld *Ld;	/* Destination address record headers */

/* In ax25.c: */
struct ax_route *ax_add(uint8 *,int,uint8 digis[][AXALEN],int);
int ax_drop(uint8 *);
struct ax_route *ax_lookup(uint8 *);
void ax_recv(struct iface *,struct mbuf **);
int axui_send(struct mbuf **bp,struct iface *iface,int32 gateway,uint8 tos);
int axi_send(struct mbuf **bp,struct iface *iface,int32 gateway,uint8 tos);
int ax_output(struct iface *iface,uint8 *dest,uint8 *source,uint16 pid,
	struct mbuf **data);
int axsend(struct iface *iface,uint8 *dest,uint8 *source,
	int cmdrsp,int ctl,struct mbuf **data);

/* In axhdr.c: */
void htonax25(struct ax25 *hdr,struct mbuf **data);
int ntohax25(struct ax25 *hdr,struct mbuf **bpp);

/* In axlink.c: */
void getlqentry(struct lqentry *ep,struct mbuf **bpp);
void getlqhdr(struct lqhdr *hp,struct mbuf **bpp);
void logsrc(struct iface *iface,uint8 *addr);
void logdest(struct iface *iface,uint8 *addr);
char *putlqentry(char *cp,uint8 *addr,int32 count);
char *putlqhdr(char *cp,uint16 version,int32 ip_addr);
struct lq *al_lookup(struct iface *ifp,uint8 *addr,int sort);

/* In ax25subr.c: */
int addreq(uint8 *a,uint8 *b);
char *pax25(char *e,uint8 *addr);
int setcall(uint8 *out,char *call);

void beac_input(struct iface *iface,uint8 *src,struct mbuf **bpp);

#endif  /* _AX25_H */