2003/0220/ip/gre.c (diff list | history)

ip/gre.c on 1997/0327
1997/0327		#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "ip.h" #define DPRINT if(0)print enum {
1997/0530		GRE_IPONLY = 12, /* size of ip header */ GRE_IPPLUSGRE = 12, /* minimum size of GRE header */
1997/0327		IP_GREPROTO = 47, GRErxms = 200, GREtickms = 100, GREmaxxmit = 10, }; typedef struct GREhdr { /* ip header */
1998/0306		uchar vihl; /* Version and header length */ uchar tos; /* Type of service */ uchar len[2]; /* packet length (including headers) */ uchar id[2]; /* Identification */ uchar frag[2]; /* Fragment information */ uchar Unused; uchar proto; /* Protocol */ uchar cksum[2]; /* checksum */ uchar src[4]; /* Ip source */ uchar dst[4]; /* Ip destination */
1997/0327		/* gre header */
1998/0306		uchar flags[2]; uchar eproto[2]; /* encapsulation protocol */
1997/0327		} GREhdr;
1998/0313		typedef struct GREpriv GREpriv; struct GREpriv { /* non-MIB stats */ ulong csumerr; /* checksum errors */ ulong lenerr; /* short packet */ };
1997/0327
2003/0220		static void grekick(void *x, Block *bp);
2002/0712
1997/0327		static char* greconnect(Conv *c, char **argv, int argc) { Proto *p; char *err; Conv *tc, **cp, **ecp; err = Fsstdconnect(c, argv, argc); if(err != nil) return err; /* make sure noone's already connected to this other sys */ p = c->p;
1998/0306		qlock(p);
1997/0327		ecp = &p->conv[p->nc]; for(cp = p->conv; cp < ecp; cp++){ tc = *cp; if(tc == nil) break; if(tc == c) continue;
1998/0401		if(tc->rport == c->rport && ipcmp(tc->raddr, c->raddr) == 0){
1997/0327		err = "already connected to that addr/proto";
1998/0306		ipmove(c->laddr, IPnoaddr); ipmove(c->raddr, IPnoaddr);
1997/0327		break; } }
1998/0306		qunlock(p);
1997/0327
1997/0403		if(err != nil) return err;
1998/0313		Fsconnected(c, nil);
1997/0327
1997/0403		return nil;
1997/0327		}
2002/0712		static void grecreate(Conv *c) { c->rq = qopen(64*1024, Qmsg, 0, c);
2003/0220		c->wq = qbypass(grekick, c);
2002/0712		}
1997/0327		static int
1998/0306		grestate(Conv *c, char *state, int n)
1997/0327		{ USED(c);
1998/0306		return snprint(state, n, "%s", "Datagram");
1997/0327		}
1997/0403		static char* greannounce(Conv*, char**, int)
1997/0327		{
1997/0403		return "pktifc does not support announce";
1997/0327		} static void greclose(Conv *c) { qclose(c->rq); qclose(c->wq); qclose(c->eq);
1998/0306		ipmove(c->laddr, IPnoaddr); ipmove(c->raddr, IPnoaddr);
1997/0327		c->lport = 0; c->rport = 0; } int drop; static void
2003/0220		grekick(void *x, Block *bp)
1997/0327		{
2002/0712		Conv *c = x;
1997/0327		GREhdr *ghp;
1998/0306		uchar laddr[IPaddrlen], raddr[IPaddrlen];
1997/0327		if(bp == nil) return; /* Make space to fit ip header (gre header already there) */
1997/0530		bp = padblock(bp, GRE_IPONLY);
1997/0327		if(bp == nil) return; /* make sure the message has a GRE header */
1997/0530		bp = pullupblock(bp, GRE_IPONLY+GRE_IPPLUSGRE);
1997/0327		if(bp == nil) return; ghp = (GREhdr *)(bp->rp);
2002/0507		ghp->vihl = IP_VER4;
1997/0327
1998/0306		v4tov6(raddr, ghp->dst); if(ipcmp(raddr, v4prefix) == 0) memmove(ghp->dst, c->raddr + IPv4off, IPv4addrlen); v4tov6(laddr, ghp->src); if(ipcmp(laddr, v4prefix) == 0){ if(ipcmp(c->laddr, IPnoaddr) == 0)
1998/0313		findlocalip(c->p->f, c->laddr, raddr); /* pick interface closest to dest */
1998/0306		memmove(ghp->src, c->laddr + IPv4off, IPv4addrlen); }
1997/0530
1997/0327		ghp->proto = IP_GREPROTO; hnputs(ghp->eproto, c->rport);
1997/0522		ghp->frag[0] = 0; ghp->frag[1] = 0;
1997/0327
2002/0507		ipoput4(c->p->f, bp, 0, c->ttl, c->tos);
1997/0327		} static void
2001/0623		greiput(Proto *gre, Ipifc*, Block *bp)
1997/0327		{ int len; GREhdr *ghp; Conv *c, **p; ushort eproto;
1998/0306		uchar raddr[IPaddrlen];
1998/0313		GREpriv *gpriv;
1997/0327
1998/0313		gpriv = gre->priv;
1997/0327		ghp = (GREhdr*)(bp->rp);
1998/0306		v4tov6(raddr, ghp->src);
1997/0327		eproto = nhgets(ghp->eproto);
1999/0302		qlock(gre);
1997/0327		/* Look for a conversation structure for this port and address */ c = nil;
1998/0313		for(p = gre->conv; *p; p++) {
1997/0327		c = *p; if(c->inuse == 0) continue;
1998/0306		if(c->rport == eproto && ipcmp(c->raddr, raddr) == 0)
1997/0327		break; } if(*p == nil) {
1999/0302		qunlock(gre);
1997/0327		freeblist(bp); return; }
1999/0302		qunlock(gre);
1997/0327		/* * Trim the packet down to data size */
1997/0530		len = nhgets(ghp->len) - GRE_IPONLY; if(len < GRE_IPPLUSGRE){
1997/0327		freeblist(bp); return; }
1997/0530		bp = trimblock(bp, GRE_IPONLY, len);
1997/0327		if(bp == nil){
1998/0313		gpriv->lenerr++;
1997/0327		return; } /* * Can't delimit packet so pull it all into one block. */ if(qlen(c->rq) > 64*1024) freeblist(bp); else{ bp = concatblock(bp); if(bp == 0) panic("greiput"); qpass(c->rq, bp); } }
1998/0306		int
1998/0313		grestats(Proto *gre, char *buf, int len)
1998/0306		{
1998/0313		GREpriv *gpriv; gpriv = gre->priv;
1998/0825		return snprint(buf, len, "gre: len %lud\n", gpriv->lenerr);
1998/0306		}
1997/0327		void greinit(Fs *fs) {
1998/0313		Proto *gre;
1997/0327
1998/0313		gre = smalloc(sizeof(Proto)); gre->priv = smalloc(sizeof(GREpriv)); gre->name = "gre"; gre->connect = greconnect; gre->announce = greannounce; gre->state = grestate; gre->create = grecreate; gre->close = greclose; gre->rcv = greiput; gre->ctl = nil; gre->advise = nil; gre->stats = grestats; gre->ipproto = IP_GREPROTO; gre->nc = 64; gre->ptclsize = 0; Fsproto(fs, gre);
1997/0327		}