/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

typedef struct Conv Conv;
typedef struct Fragment4 Fragment4;
typedef struct Fragment6 Fragment6;
typedef struct Fs Fs;
typedef union Hwaddr Hwaddr;
typedef struct IP IP;
typedef struct IPaux IPaux;
typedef struct Ip4hdr Ip4hdr;
typedef struct Ipfrag Ipfrag;
typedef struct Ipself Ipself;
typedef struct Ipselftab Ipselftab;
typedef struct Iplink Iplink;
typedef struct Iplifc Iplifc;
typedef struct Ipmulti Ipmulti;
typedef struct Ipifc Ipifc;
typedef struct Iphash Iphash;
typedef struct Ipht Ipht;
typedef struct Netlog Netlog;
typedef struct Medium Medium;
typedef struct Proto Proto;
typedef struct Arpent Arpent;
typedef struct Arp Arp;
typedef struct Route Route;

typedef struct Routerparams Routerparams;
typedef struct Hostparams Hostparams;
typedef struct v6router v6router;
typedef struct v6params v6params;

//#pragma incomplete Arp
//#pragma incomplete Ipself
//#pragma incomplete Ipselftab
//#pragma incomplete IP
//#pragma incomplete Netlog

enum {
	Addrlen = 64,
	Maxproto = 20,
	Nhash = 64,
	Maxincall = 64, /* max. conn.s in listen q not accepted yet */
	Nchans = 1024,
	MAClen = 16, /* int32_test mac address */

	MAXTTL = 255,
	DFLTTOS = 0,

	IPaddrlen = 16,
	IPv4addrlen = 4,
	IPv4off = 12,
	IPllen = 4,

	/* ip versions */
	V4 = 4,
	V6 = 6,
	IP_VER4 = 0x40,
	IP_VER6 = 0x60,
	IP_HLEN4 = 5,	    /* v4: Header length in words */
	IP_DF = 0x4000,	    /* v4: Don't fragment */
	IP_MF = 0x2000,	    /* v4: More fragments */
	IP4HDR = 20,	    /* sizeof(Ip4hdr) */
	IP_MAX = 64 * 1024, /* Max. Internet packet size, v4 & v6 */

	/* 2^Lroot trees in the root table */
	Lroot = 10,

	Maxpath = 64,
};

enum {
	Idle = 0,
	Announcing = 1,
	Announced = 2,
	Connecting = 3,
	Connected = 4,
};

/* MIB II counters */
enum {
	Forwarding,
	DefaultTTL,
	InReceives,
	InHdrErrors,
	InAddrErrors,
	ForwDatagrams,
	InUnknownProtos,
	InDiscards,
	InDelivers,
	OutRequests,
	OutDiscards,
	OutNoRoutes,
	ReasmTimeout,
	ReasmReqds,
	ReasmOKs,
	ReasmFails,
	FragOKs,
	FragFails,
	FragCreates,

	Nipstats,
};

struct Fragment4 {
	Block *blist;
	Fragment4 *next;
	uint32_t src;
	uint32_t dst;
	uint16_t id;
	uint32_t age;
};

struct Fragment6 {
	Block *blist;
	Fragment6 *next;
	uint8_t src[IPaddrlen];
	uint8_t dst[IPaddrlen];
	uint id;
	uint32_t age;
};

struct Ipfrag {
	uint16_t foff;
	uint16_t flen;

	uint8_t payload[];
};

#define IPFRAGSZ offsetof(Ipfrag, payload[0])

/* an instance of IP */
struct IP {
	uint64_t stats[Nipstats];

	QLock fraglock4;
	Fragment4 *flisthead4;
	Fragment4 *fragfree4;
	Ref id4;

	QLock fraglock6;
	Fragment6 *flisthead6;
	Fragment6 *fragfree6;
	Ref id6;

	int iprouting; /* true if we route like a gateway */
};

/* on the wire packet header */
struct Ip4hdr {
	uint8_t vihl;	   /* Version and header length */
	uint8_t tos;	   /* Type of service */
	uint8_t length[2]; /* packet length */
	uint8_t id[2];	   /* ip->identification */
	uint8_t frag[2];   /* Fragment information */
	uint8_t ttl;	   /* Time to live */
	uint8_t proto;	   /* Protocol */
	uint8_t cksum[2];  /* Header checksum */
	uint8_t src[4];	   /* IP source */
	uint8_t dst[4];	   /* IP destination */
};

/*
 *  one per conversation directory
 */
struct Conv {
	QLock ql;

	int x; /* conversation index */
	Proto *p;

	int restricted;	  /* remote port is restricted */
	uint ttl;	  /* max time to live */
	uint tos;	  /* type of service */
	int ignoreadvice; /* don't terminate connection on icmp errors */

	uint8_t ipversion;
	uint8_t laddr[IPaddrlen]; /* local IP address */
	uint8_t raddr[IPaddrlen]; /* remote IP address */
	uint16_t lport;		  /* local port number */
	uint16_t rport;		  /* remote port number */

	char *owner; /* protections */
	int perm;
	int inuse; /* opens of listen/data/ctl */
	int length;
	int state;

	int maxfragsize; /* If set, used for fragmentation */

	/* udp specific */
	int headers;  /* data src/dst headers in udp */
	int reliable; /* true if reliable udp */

	Conv *incall; /* calls waiting to be listened for */
	Conv *next;

	Queue *rq;    /* queued data waiting to be read */
	Queue *wq;    /* queued data waiting to be written */
	Queue *eq;    /* returned error packets */
	Queue *sq;    /* snooping queue */
	Ref snoopers; /* number of processes with snoop open */

	QLock car;
	Rendez cr;
	char cerr[ERRMAX];

	QLock listenq;
	Rendez listenr;

	Ipmulti *multi; /* multicast bindings for this interface */

	void *ptcl; /* protocol specific stuff */

	Route *r;      /* last route used */
	uint32_t rgen; /* routetable generation for *r */
};

struct Medium {
	char *name;
	int hsize;  /* medium header size */
	int mintu;  /* default min mtu */
	int maxtu;  /* default max mtu */
	int maclen; /* mac address length  */
	void (*bind)(Ipifc *, int, char **);
	void (*unbind)(Ipifc *);
	void (*bwrite)(Ipifc *ifc, Block *b, int version, uint8_t *ip);

	/* for arming interfaces to receive multicast */
	void (*addmulti)(Ipifc *ifc, uint8_t *a, uint8_t *ia);
	void (*remmulti)(Ipifc *ifc, uint8_t *a, uint8_t *ia);

	/* process packets written to 'data' */
	void (*pktin)(Fs *f, Ipifc *ifc, Block *bp);

	/* routes for router boards */
	void (*addroute)(Ipifc *ifc, int, uint8_t *, uint8_t *, uint8_t *, int);
	void (*remroute)(Ipifc *ifc, int, uint8_t *, uint8_t *);
	void (*flushroutes)(Ipifc *ifc);

	/* for routing multicast groups */
	void (*joinmulti)(Ipifc *ifc, uint8_t *a, uint8_t *ia);
	void (*leavemulti)(Ipifc *ifc, uint8_t *a, uint8_t *ia);

	/* address resolution */
	void (*ares)(Fs *, int, uint8_t *, uint8_t *, int, int); /* resolve */
	void (*areg)(Ipifc *, uint8_t *);			 /* register */

	/* v6 address generation */
	void (*pref2addr)(uint8_t *pref, uint8_t *ea);

	int unbindonclose; /* if non-zero, unbind on last close */
};

/* logical interface associated with a physical one */
struct Iplifc {
	uint8_t local[IPaddrlen];
	uint8_t mask[IPaddrlen];
	uint8_t remote[IPaddrlen];
	uint8_t net[IPaddrlen];
	uint8_t tentative; /* =1 => v6 dup disc on, =0 => confirmed unique */
	uint8_t onlink;	   /* =1 => onlink, =0 offlink. */
	uint8_t autoflag;  /* v6 autonomous flag */
	int32_t validlt;   /* v6 valid lifetime */
	int32_t preflt;	   /* v6 preferred lifetime */
	int32_t origint;   /* time when addr was added */
	Iplink *link;	   /* addresses linked to this lifc */
	Iplifc *next;
};

/* binding twixt Ipself and Iplifc */
struct Iplink {
	Ipself *self;
	Iplifc *lifc;
	Iplink *selflink; /* next link for this local address */
	Iplink *lifclink; /* next link for this ifc */
	uint32_t expire;
	Iplink *next; /* free list */
	int ref;
};

/* rfc 2461, pp.40—43. */

/* default values, one per stack */
struct Routerparams {
	int mflag;     /* flag: managed address configuration */
	int oflag;     /* flag: other stateful configuration */
	int maxraint;  /* max. router adv interval (ms) */
	int minraint;  /* min. router adv interval (ms) */
	int linkmtu;   /* mtu options */
	int reachtime; /* reachable time */
	int rxmitra;   /* retransmit interval */
	int ttl;       /* cur hop count limit */
	int routerlt;  /* router lifetime */
};

struct Hostparams {
	int rxmithost;
};

struct Ipifc {
	RWlock rwl;

	Conv *conv;	/* link to its conversation structure */
	char dev[64];	/* device we're attached to */
	Medium *medium; /* Media pointer */
	int maxtu;	/* Maximum transfer unit */
	int mintu;	/* Minumum tranfer unit */
	int mbps;	/* megabits per second */
	void *arg;	/* medium specific */
	int reassemble; /* reassemble IP packets before forwarding */

	/* these are used so that we can unbind on the fly */
	Lock idlock;
	uint8_t ifcid; /* incremented each 'bind/unbind/add/remove' */
	int ref;       /* number of proc's using this ipifc */
	Rendez wait;   /* where unbinder waits for ref == 0 */
	int unbinding;

	uint8_t mac[MAClen]; /* MAC address */

	Iplifc *lifc; /* logical interfaces on this physical one */

	uint32_t in, out;	/* message statistics */
	uint32_t inerr, outerr; /* ... */

	uint8_t sendra6; /* flag: send router advs on this ifc */
	uint8_t recvra6; /* flag: recv router advs on this ifc */
	Routerparams rp; /* router parameters as in RFC 2461, pp.40—43.
					used only if node is router */
};

/*
 *  one per multicast-lifc pair used by a Conv
 */
struct Ipmulti {
	uint8_t ma[IPaddrlen];
	uint8_t ia[IPaddrlen];
	Ipmulti *next;
};

/*
 *  hash table for 2 ip addresses + 2 ports
 */
enum {
	Nipht = 521, /* convenient prime */

	IPmatchexact = 0, /* match on 4 tuple */
	IPmatchany,	  /* *!* */
	IPmatchport,	  /* *!port */
	IPmatchaddr,	  /* addr!* */
	IPmatchpa,	  /* addr!port */
};
struct Iphash {
	Iphash *next;
	Conv *c;
	int match;
};
struct Ipht {
	Lock l;
	Iphash *tab[Nipht];
};
void iphtadd(Ipht *, Conv *);
void iphtrem(Ipht *, Conv *);
Conv *iphtlook(Ipht *ht, uint8_t *sa, uint16_t sp, uint8_t *da, uint16_t dp);

/*
 *  one per multiplexed protocol
 */
struct Proto {
	QLock ql;
	char *name;  /* protocol name */
	int x;	     /* protocol index */
	int ipproto; /* ip protocol type */

	char *(*connect)(Conv *, char **, int);
	char *(*announce)(Conv *, char **, int);
	char *(*bind)(Conv *, char **, int);
	int (*state)(Conv *, char *, int);
	void (*create)(Conv *);
	void (*close)(Conv *);
	void (*rcv)(Proto *, Ipifc *, Block *);
	char *(*ctl)(Conv *, char **, int);
	void (*advise)(Proto *, Block *, char *);
	int (*stats)(Proto *, char *, int);
	int (*local)(Conv *, char *, int);
	int (*remote)(Conv *, char *, int);
	int (*inuse)(Conv *);
	int (*gc)(Proto *); /* returns true if any conversations are freed */

	Fs *f;	      /* file system this proto is part of */
	Conv **conv;  /* array of conversations */
	int ptclsize; /* size of per protocol ctl block */
	int nc;	      /* number of conversations */
	int ac;
	Qid qid; /* qid for protocol directory */
	uint16_t nextrport;

	void *priv;
};

/*
 *  one per IP protocol stack
 */
struct Fs {
	RWlock rwl;
	int dev;

	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;
	int32_t ndbmtime;
};

/* one per default router known to host */
struct v6router {
	uint8_t inuse;
	Ipifc *ifc;
	int ifcid;
	uint8_t routeraddr[IPaddrlen];
	int32_t 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 *, uint8_t *, uint16_t, uint8_t *, uint16_t, uint8_t);
int Fspcolstats(char *, int);
int Fsproto(Fs *, Proto *);
int Fsbuiltinproto(Fs *, uint8_t);
Conv *Fsprotoclone(Proto *, char *);
Proto *Fsrcvpcol(Fs *, uint8_t);
Proto *Fsrcvpcolx(Fs *, uint8_t);
char *Fsstdconnect(Conv *, char **, int);
char *Fsstdannounce(Conv *, char **, int);
char *Fsstdbind(Conv *, char **, int);
uint32_t scalednconv(void);
void closeconv(Conv *);
/*
 *  logging
 */
enum {
	Logip = 1 << 1,
	Logtcp = 1 << 2,
	Logfs = 1 << 3,
	Logicmp = 1 << 5,
	Logudp = 1 << 6,
	Logcompress = 1 << 7,
	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);
int32_t netlogread(Fs *, void *, uint32_t, int32_t);
void netlog(Fs *, int, char *, ...);
void ifcloginit(Fs *);
int32_t ifclogread(Fs *, Chan *, void *, uint32_t, int32_t);
void ifclog(Fs *, uint8_t *, int);
void ifclogopen(Fs *, Chan *);
void ifclogclose(Fs *, Chan *);

//#pragma varargck argpos netlog	3

/*
 *  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;
	uint8_t depth;
	uint8_t type;
	uint8_t ifcid; /* must match ifc->id */
	Ipifc *ifc;
	char tag[4];
	int ref;
};

struct V4route {
	uint32_t address;
	uint32_t endaddress;
	uint8_t gate[IPv4addrlen];
};

struct V6route {
	uint32_t address[IPllen];
	uint32_t endaddress[IPllen];
	uint8_t gate[IPaddrlen];
};

struct Route {
	RouteTree RouteTree;

	union {
		V6route v6;
		V4route v4;
	};
};
extern void v4addroute(Fs *f, char *tag, uint8_t *a, uint8_t *mask, uint8_t *gate, int type);
extern void v6addroute(Fs *f, char *tag, uint8_t *a, uint8_t *mask, uint8_t *gate, int type);
extern void v4delroute(Fs *f, uint8_t *a, uint8_t *mask, int dolock);
extern void v6delroute(Fs *f, uint8_t *a, uint8_t *mask, int dolock);
extern Route *v4lookup(Fs *f, uint8_t *a, Conv *c);
extern Route *v6lookup(Fs *f, uint8_t *a, Conv *c);
extern int32_t routeread(Fs *f, char *, uint32_t, int);
extern int32_t routewrite(Fs *f, Chan *, char *, int);
extern void routetype(int, char *);
extern void ipwalkroutes(Fs *, Routewalk *);
extern void convroute(Route *, uint8_t *, uint8_t *, uint8_t *, 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 {
	uint8_t ip[IPaddrlen];
	uint8_t 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 */
	uint8_t state;
	Arpent *nextrxt; /* re-transmit chain */
	uint rtime;	 /* time for next retransmission */
	uint8_t rxtsrem;
	Ipifc *ifc;
	uint8_t ifcid; /* must match ifc->id */
};

extern void arpinit(Fs *);
extern int arpread(Arp *, char *, uint32_t, int);
extern int arpwrite(Fs *, char *, int);
extern Arpent *arpget(Arp *, Block *bp, int version, Ipifc *ifc, uint8_t *ip, uint8_t *h);
extern void arprelease(Arp *, Arpent *a);
extern Block *arpresolve(Arp *, Arpent *a, Medium *type, uint8_t *mac);
extern void arpenter(Fs *, int version, uint8_t *ip, uint8_t *mac, int len, int norefresh);

/*
 * ipaux.c
 */

extern int myetheraddr(uint8_t *, char *);
extern int64_t parseip(uint8_t *, char *);
extern int64_t parseipmask(uint8_t *, char *);
extern char *v4parseip(uint8_t *, char *);
extern void maskip(uint8_t *from, uint8_t *mask, uint8_t *to);
extern int parsemac(uint8_t *to, char *from, int len);
extern uint8_t *defmask(uint8_t *);
extern int isv4(uint8_t *);
extern void v4tov6(uint8_t *v6, uint8_t *v4);
extern int v6tov4(uint8_t *v4, uint8_t *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 uint8_t IPv4bcast[IPaddrlen];
extern uint8_t IPv4bcastobs[IPaddrlen];
extern uint8_t IPv4allsys[IPaddrlen];
extern uint8_t IPv4allrouter[IPaddrlen];
extern uint8_t IPnoaddr[IPaddrlen];
extern uint8_t v4prefix[IPaddrlen];
extern uint8_t IPallbits[IPaddrlen];

#define NOW TK2MS(sys->machptr[0]->ticks)

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

/*
 *  ipifc.c
 */
extern Medium *ipfindmedium(char *name);
extern void addipmedium(Medium *med);
extern int ipforme(Fs *, uint8_t *addr);
extern int iptentative(Fs *, uint8_t *addr);
extern int ipisbm(uint8_t *);
extern int ipismulticast(uint8_t *);
extern Ipifc *findipifc(Fs *, uint8_t *remote, int type);
extern void findlocalip(Fs *, uint8_t *local, uint8_t *remote);
extern int ipv4local(Ipifc *ifc, uint8_t *addr);
extern int ipv6local(Ipifc *ifc, uint8_t *addr);
extern int ipv6anylocal(Ipifc *ifc, uint8_t *addr);
extern Iplifc *iplocalonifc(Ipifc *ifc, uint8_t *ip);
extern int ipproxyifc(Fs *f, Ipifc *ifc, uint8_t *ip);
extern int ipismulticast(uint8_t *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, uint8_t *, uint8_t *, uint8_t *, int);
extern void ipifcremroute(Fs *, int, uint8_t *, uint8_t *);
extern void ipifcremmulti(Conv *c, uint8_t *ma, uint8_t *ia);
extern void ipifcaddmulti(Conv *c, uint8_t *ma, uint8_t *ia);
extern char *ipifcrem(Ipifc *ifc, char **argv, int argc);
extern char *ipifcadd(Ipifc *ifc, char **argv, int argc, int tentative, Iplifc *lifcp);
extern int32_t ipselftabread(Fs *, char *a, uint32_t offset, int n);
extern char *ipifcadd6(Ipifc *ifc, char **argv, int argc);
/*
 *  ip.c
 */
extern void iprouting(Fs *, int);
extern void icmpnoconv(Fs *, Block *);
extern void icmpcantfrag(Fs *, Block *, int);
extern void icmpttlexceeded(Fs *, uint8_t *, Block *);
extern uint16_t ipcsum(uint8_t *);
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 uint16_t ptclbsum(uint8_t *, int);
extern uint16_t ptclcsum(Block *, int, int);
extern void ip_init(Fs *);
extern void update_mtucache(uint8_t *, uint32_t);
extern uint32_t restrict_mtu(uint8_t *, uint32_t);
/*
 * bootp.c
 */
extern int bootpread(char *, uint32_t, int);

/*
 *  resolving inferno/plan9 differences
 */
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 *, uint8_t *);