1998/0306/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; Proto gre; extern Fs fs; int gredebug; 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; if(tc->rport == c->rport && tc->raddr == c->raddr){ 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; Fsconnected(&fs, c, nil);
1997/0327
1997/0403		return nil;
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		} static void grecreate(Conv *c) { c->rq = qopen(64*1024, 0, 0, c); c->wq = qopen(64*1024, 0, 0, 0); }
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; unlock(c); } int drop; static void grekick(Conv *c, int l) { GREhdr *ghp;
1997/0524		Block *bp;
1998/0306		uchar laddr[IPaddrlen], raddr[IPaddrlen];
1997/0327		USED(l); bp = qget(c->wq); 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);
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) findlocalip(c->laddr, raddr); /* pick interface closest to dest */ 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		ipoput(bp, 0, c->ttl); } static void
1998/0306		greiput(uchar*, Block *bp)
1997/0327		{ int len; GREhdr *ghp; Conv *c, **p; ushort eproto;
1998/0306		uchar raddr[IPaddrlen];
1997/0327		ghp = (GREhdr*)(bp->rp);
1998/0306		v4tov6(raddr, ghp->src);
1997/0327		eproto = nhgets(ghp->eproto); /* Look for a conversation structure for this port and address */ c = nil; for(p = gre.conv; *p; p++) { c = *p; if(c->inuse == 0) continue;
1998/0306		if(c->rport == eproto && ipcmp(c->raddr, raddr) == 0)
1997/0327		break; } if(*p == nil) { freeblist(bp); return; } /* * 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){ gre.lenerr++; 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 grestats(char *buf, int len) { return snprint(buf, len, "gre: csum %d hlen %d len %d order %d rexmit %d\n", gre.csumerr, gre.hlenerr, gre.lenerr, gre.order, gre.rexmit); }
1997/0327		void greinit(Fs *fs) { gre.name = "gre"; gre.kick = grekick; gre.connect = greconnect; gre.announce = greannounce; gre.state = grestate; gre.create = grecreate; gre.close = greclose; gre.rcv = greiput; gre.ctl = nil; gre.advise = nil;
1998/0306		gre.stats = grestats;
1997/0327		gre.ipproto = IP_GREPROTO; gre.nc = 64; gre.ptclsize = 0; Fsproto(fs, &gre); }