ip.h

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

	int	np;
	Proto*	p[Maxproto+1];		/* list of supported protocols */
	Proto*	t2p[256];		/* vector of all protocols */
	Proto*	ipifc;			/* kludge for ipifcremroute & ipifcaddroute */
	Proto*	ipmux;			/* kludge for finding an ip multiplexor */

	IP	*ip;
	Ipselftab	*self;
	Arp	*arp;
	v6params	*v6p;

	Route	*v4root[1<<Lroot];	/* v4 routing forest */
	Route	*v6root[1<<Lroot];	/* v6 routing forest */
	Route	*queue;			/* used as temp when reinjecting routes */

	Netlog	*alog;

	char	ndb[1024];		/* an ndb entry for this interface */
	int	ndbvers;
	long	ndbmtime;
};

/* one per default router known to host */
struct v6router {
	uchar	inuse;
	Ipifc	*ifc;
	int	ifcid;
	uchar	routeraddr[IPaddrlen];
	long	ltorigin;
	Routerparams	rp;
};

struct v6params
{
	Routerparams	rp;		/* v6 params, one copy per node now */
	Hostparams	hp;
	v6router	v6rlist[3];	/* max 3 default routers, currently */
	int		cdrouter;	/* uses only v6rlist[cdrouter] if   */ 
					/* cdrouter >= 0. */
};


int	Fsconnected(Conv*, char*);
Conv*	Fsnewcall(Conv*, uchar*, ushort, uchar*, ushort, uchar);
int	Fspcolstats(char*, int);
int	Fsproto(Fs*, Proto*);
int	Fsbuiltinproto(Fs*, uchar);
Conv*	Fsprotoclone(Proto*, char*);
Proto*	Fsrcvpcol(Fs*, uchar);
Proto*	Fsrcvpcolx(Fs*, uchar);
char*	Fsstdconnect(Conv*, char**, int);
char*	Fsstdannounce(Conv*, char**, int);
char*	Fsstdbind(Conv*, char**, int);
ulong	scalednconv(void);
void	closeconv(Conv*);
/* 
 *  logging
 */
enum
{
	Logip=		1<<1,
	Logtcp=		1<<2,
	Logfs=		1<<3,
	Logil=		1<<4,
	Logicmp=	1<<5,
	Logudp=		1<<6,
	Logcompress=	1<<7,
	Logilmsg=	1<<8,
	Loggre=		1<<9,
	Logppp=		1<<10,
	Logtcprxmt=	1<<11,
	Logigmp=	1<<12,
	Logudpmsg=	1<<13,
	Logipmsg=	1<<14,
	Logrudp=	1<<15,
	Logrudpmsg=	1<<16,
	Logesp=		1<<17,
	Logtcpwin=	1<<18,
};

void	netloginit(Fs*);
void	netlogopen(Fs*);
void	netlogclose(Fs*);
void	netlogctl(Fs*, char*, int);
long	netlogread(Fs*, void*, ulong, long);
void	netlog(Fs*, int, char*, ...);
void	ifcloginit(Fs*);
long	ifclogread(Fs*, Chan *,void*, ulong, long);
void	ifclog(Fs*, uchar *, int);
void	ifclogopen(Fs*, Chan*);
void	ifclogclose(Fs*, Chan*);

/*
 *  iproute.c
 */
typedef	struct RouteTree RouteTree;
typedef struct Routewalk Routewalk;
typedef struct V4route V4route;
typedef struct V6route V6route;

enum
{

	/* type bits */
	Rv4=		(1<<0),		/* this is a version 4 route */
	Rifc=		(1<<1),		/* this route is a directly connected interface */
	Rptpt=		(1<<2),		/* this route is a pt to pt interface */
	Runi=		(1<<3),		/* a unicast self address */
	Rbcast=		(1<<4),		/* a broadcast self address */
	Rmulti=		(1<<5),		/* a multicast self address */
	Rproxy=		(1<<6),		/* this route should be proxied */
};

struct Routewalk
{
	int	o;
	int	h;
	char*	p;
	char*	e;
	void*	state;
	void	(*walk)(Route*, Routewalk*);
};

struct	RouteTree
{
	Route*	right;
	Route*	left;
	Route*	mid;
	uchar	depth;
	uchar	type;
	uchar	ifcid;		/* must match ifc->id */
	Ipifc	*ifc;
	char	tag[4];
	int	ref;
};

struct V4route
{
	ulong	address;
	ulong	endaddress;
	uchar	gate[IPv4addrlen];
};

struct V6route
{
	ulong	address[IPllen];
	ulong	endaddress[IPllen];
	uchar	gate[IPaddrlen];
};

struct Route
{
	RouteTree;

	union {
		V6route	v6;
		V4route v4;
	};
};
extern void	v4addroute(Fs *f, char *tag, uchar *a, uchar *mask, uchar *gate, int type);
extern void	v6addroute(Fs *f, char *tag, uchar *a, uchar *mask, uchar *gate, int type);
extern void	v4delroute(Fs *f, uchar *a, uchar *mask, int dolock);
extern void	v6delroute(Fs *f, uchar *a, uchar *mask, int dolock);
extern Route*	v4lookup(Fs *f, uchar *a, Conv *c);
extern Route*	v6lookup(Fs *f, uchar *a, Conv *c);
extern long	routeread(Fs *f, char*, ulong, int);
extern long	routewrite(Fs *f, Chan*, char*, int);
extern void	routetype(int, char*);
extern void	ipwalkroutes(Fs*, Routewalk*);
extern void	convroute(Route*, uchar*, uchar*, uchar*, char*, int*);

/*
 *  devip.c
 */

/*
 *  Hanging off every ip channel's ->aux is the following structure.
 *  It maintains the state used by devip and iproute.
 */
struct IPaux
{
	char	*owner;		/* the user that did the attach */
	char	tag[4];
};

extern IPaux*	newipaux(char*, char*);

/*
 *  arp.c
 */
struct Arpent
{
	uchar	ip[IPaddrlen];
	uchar	mac[MAClen];
	Medium	*type;			/* media type */
	Arpent*	hash;
	Block*	hold;
	Block*	last;
	uint	ctime;			/* time entry was created or refreshed */
	uint	utime;			/* time entry was last used */
	uchar	state;
	Arpent	*nextrxt;		/* re-transmit chain */
	uint	rtime;			/* time for next retransmission */
	uchar	rxtsrem;
	Ipifc	*ifc;
	uchar	ifcid;			/* must match ifc->id */
};

extern void	arpinit(Fs*);
extern int	arpread(Arp*, char*, ulong, int);
extern int	arpwrite(Fs*, char*, int);
extern Arpent*	arpget(Arp*, Block *bp, int version, Ipifc *ifc, uchar *ip, uchar *h);
extern void	arprelease(Arp*, Arpent *a);
extern Block*	arpresolve(Arp*, Arpent *a, Medium *type, uchar *mac);
extern void	arpenter(Fs*, int version, uchar *ip, uchar *mac, int len, int norefresh);

/*
 * ipaux.c
 */

extern int	myetheraddr(uchar*, char*);
extern ulong	parseip(uchar*, char*);
extern ulong	parseipmask(uchar*, char*);
extern char*	v4parseip(uchar*, char*);
extern void	maskip(uchar *from, uchar *mask, uchar *to);
extern int	parsemac(uchar *to, char *from, int len);
extern uchar*	defmask(uchar*);
extern int	isv4(uchar*);
extern void	v4tov6(uchar *v6, uchar *v4);
extern int	v6tov4(uchar *v4, uchar *v6);
extern int	eipfmt(Fmt*);

#define	ipmove(x, y) memmove(x, y, IPaddrlen)
#define	ipcmp(x, y) ( (x)[IPaddrlen-1] != (y)[IPaddrlen-1] || memcmp(x, y, IPaddrlen) )

extern uchar IPv4bcast[IPaddrlen];
extern uchar IPv4bcastobs[IPaddrlen];
extern uchar IPv4allsys[IPaddrlen];
extern uchar IPv4allrouter[IPaddrlen];
extern uchar IPnoaddr[IPaddrlen];
extern uchar v4prefix[IPaddrlen];
extern uchar IPallbits[IPaddrlen];

#define	NOW	TK2MS(MACHP(0)->ticks)

/*
 *  media
 */
extern Medium	ethermedium;
extern Medium	nullmedium;
extern Medium	pktmedium;
extern Medium	tripmedium;

/*
 *  ipifc.c
 */
extern Medium*	ipfindmedium(char *name);
extern void	addipmedium(Medium *med);
extern int	ipforme(Fs*, uchar *addr);
extern int	iptentative(Fs*, uchar *addr);
extern int	ipisbm(uchar *);
extern int	ipismulticast(uchar *);
extern Ipifc*	findipifc(Fs*, uchar *remote, int type);
extern void	findlocalip(Fs*, uchar *local, uchar *remote);
extern int	ipv4local(Ipifc *ifc, uchar *addr);
extern int	ipv6local(Ipifc *ifc, uchar *addr);
extern int	ipv6anylocal(Ipifc *ifc, uchar *addr);
extern Iplifc*	iplocalonifc(Ipifc *ifc, uchar *ip);
extern int	ipproxyifc(Fs *f, Ipifc *ifc, uchar *ip);
extern int	ipismulticast(uchar *ip);
extern int	ipisbooting(void);
extern int	ipifccheckin(Ipifc *ifc, Medium *med);
extern void	ipifccheckout(Ipifc *ifc);
extern int	ipifcgrab(Ipifc *ifc);
extern void	ipifcaddroute(Fs*, int, uchar*, uchar*, uchar*, int);
extern void	ipifcremroute(Fs*, int, uchar*, uchar*);
extern void	ipifcremmulti(Conv *c, uchar *ma, uchar *ia);
extern void	ipifcaddmulti(Conv *c, uchar *ma, uchar *ia);
extern char*	ipifcrem(Ipifc *ifc, char **argv, int argc);
extern char*	ipifcadd(Ipifc *ifc, char **argv, int argc, int tentative, Iplifc *lifcp);
extern long	ipselftabread(Fs*, char *a, ulong offset, int n);
extern char*	ipifcaddpref6(Ipifc *ifc, char**argv, int argc);
extern void	ipsendra6(Fs *f, int on);
/*
 *  ip.c
 */
extern void	iprouting(Fs*, int);
extern void	icmpnoconv(Fs*, Block*);
extern void	icmpcantfrag(Fs*, Block*, int);
extern void	icmpttlexceeded(Fs*, uchar*, Block*);
extern ushort	ipcsum(uchar*);
extern void	ipiput4(Fs*, Ipifc*, Block*);
extern void	ipiput6(Fs*, Ipifc*, Block*);
extern int	ipoput4(Fs*, Block*, int, int, int, Conv*);
extern int	ipoput6(Fs*, Block*, int, int, int, Conv*);
extern int	ipstats(Fs*, char*, int);
extern ushort	ptclbsum(uchar*, int);
extern ushort	ptclcsum(Block*, int, int);
extern void	ip_init(Fs*);
extern void	update_mtucache(uchar*, ulong);
extern ulong	restrict_mtu(uchar*, ulong);
/*
 * bootp.c
 */
extern char*	bootp(Ipifc*);
extern int	bootpread(char*, ulong, int);

/*
 *  resolving inferno/plan9 differences
 */
Chan*		commonfdtochan(int, int, int, int);
char*		commonuser(void);
char*		commonerror(void);

/*
 * chandial.c
 */
extern Chan*	chandial(char*, char*, char*, Chan**);

/*
 *  global to all of the stack
 */
extern void	(*igmpreportfn)(Ipifc*, uchar*);