1991/0418/port/deviproute.c (diff list | history)

port/deviproute.c on 1991/0331
1991/0331		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "errno.h"
1991/0401		#include "arp.h" #include "ipdat.h"
1991/0330
1991/0331		#include "devtab.h"
1991/0401		/* * All ip numbers and masks are stored as ulongs. * All interfaces to this code uses the standard byte * string representation. */
1991/0330		typedef struct Iproute Iproute; typedef struct Iprtab Iprtab; enum { Nroutes= 256, }; /* * routes */ struct Iproute {
1991/0401		ulong dst; ulong gate; ulong mask;
1991/0330		Iproute *next; int inuse; }; struct Iprtab {
1991/0331		Lock; int n; /* number of valid routes */ Iproute *first; /* list of valid routes */ Iproute r[Nroutes]; /* all routes */
1991/0330		}; Iprtab iprtab;
1991/0331		/*
1991/0330		* The chosen route is the one obeys the constraint
1991/0401		* r->mask & dst == r->dst
1991/0330		* * If there are several matches, the one whose mask has the most
1991/0401		* leading ones (and hence is the most specific) wins. This is * forced by storing the routes in decreasing number of ones order * and returning the first match. The default gateway has no ones * in the mask and is thus the last matched.
1991/0330		*/ void iproute(uchar *dst, uchar *gate) { Iproute *r;
1991/0401		ulong udst;
1991/0330
1991/0401		udst = nhgetl(dst); if((udst&Mymask) == (Myip&Mymask)){ memmove(gate, dst, 4); return; }
1991/0330		/* * first check routes */ for(r = iprtab.first; r; r = r->next){
1991/0401		if((r->mask&udst) == r->dst){ hnputl(gate, r->gate);
1991/0330		return; } } /*
1991/0401		* else just return the same address
1991/0330		*/ memmove(gate, dst, 4); } /* * Add a route, create a mask if the first mask is 0. * * All routes are stored sorted by the length of leading * ones in the mask. * * NOTE: A default route has an all zeroes mask and dst. */ void
1991/0401		ipaddroute(ulong dst, ulong mask, ulong gate)
1991/0330		{ Iproute *r, *e, *free; int i; /* * filter out impossible requests */
1991/0401		if((dst&mask) != dst) errors("bad ip route");
1991/0330		/* * see if we already have a route for * the destination */ lock(&iprtab); free = 0; for(r = iprtab.r; r < &iprtab.r[Nroutes]; r++){ if(r->inuse == 0){ free = r; continue; }
1991/0401		if(dst==r->dst && mask==r->mask){ r->gate = gate;
1991/0330		unlock(&iprtab); return; } }
1991/0401		if(free == 0){ unlock(&iprtab);
1991/0331		errors("no free ip routes");
1991/0401		}
1991/0330		/* * add the new route in sorted order */
1991/0401		free->dst = dst; free->mask = mask; free->gate = gate;
1991/0330		free->inuse = 1;
1991/0401		for(r = e = iprtab.first; r; r = r->next){ if(mask > r->mask)
1991/0330		break; e = r; } free->next = r; if(r == iprtab.first) iprtab.first = free; else e->next = free;
1991/0331		iprtab.n++;
1991/0330		unlock(&iprtab); } /* * remove a route */ void
1991/0401		ipremroute(ulong dst, ulong mask)
1991/0330		{ Iproute *r, *e; lock(&iprtab);
1991/0401		for(r = e = iprtab.first; r; r = r->next){ if(dst==r->dst && mask==r->mask){
1991/0330		if(r == iprtab.first) iprtab.first = r->next; else e->next = r->next; r->inuse = 0;
1991/0331		iprtab.n--;
1991/0330		break; } e = r; } unlock(&iprtab); } /* * remove all routes */ void ipflushroute(void) { Iproute *r; lock(&iprtab); for(r = iprtab.first; r; r = r->next) r->inuse = 0; iprtab.first = 0;
1991/0331		iprtab.n = 0;
1991/0330		unlock(&iprtab);
1991/0331		} /* * device interface */ enum{ Qdir, Qdata, }; Dirtab iproutetab[]={ "iproute", Qdata, 0, 0600, }; #define Niproutetab (sizeof(iproutetab)/sizeof(Dirtab)) void iproutereset(void) { } void iprouteinit(void) { } Chan * iprouteattach(char *spec) {
1991/0418		return devattach('P', spec);
1991/0331		} Chan * iprouteclone(Chan *c, Chan *nc) { return devclone(c, nc); } int iproutewalk(Chan *c, char *name) { return devwalk(c, name, iproutetab, (long)Niproutetab, devgen); } void iproutestat(Chan *c, char *db) { devstat(c, db, iproutetab, (long)Niproutetab, devgen); } Chan * iprouteopen(Chan *c, int omode) { if(c->qid.path == CHDIR){ if(omode != OREAD) error(Eperm); } c->mode = openmode(omode); c->flag |= COPEN; c->offset = 0; return c; } void iproutecreate(Chan *c, char *name, int omode, ulong perm) { error(Eperm); } void iprouteremove(Chan *c) { error(Eperm); } void iproutewstat(Chan *c, char *dp) { error(Eperm); } void iprouteclose(Chan *c) { } #define IPR_ENTRYLEN 54 #define PAD " " long
1991/0411		iprouteread(Chan *c, void *a, long n, ulong offset)
1991/0331		{
1991/0401		char buf[IPR_ENTRYLEN*3];
1991/0331		Iproute *r; int part, bytes, size;
1991/0401		uchar dst[4], mask[4], gate[4];
1991/0331		switch((int)(c->qid.path&~CHDIR)){ case Qdir: return devdirread(c, a, n, iproutetab, Niproutetab, devgen); case Qdata: lock(&iprtab);
1991/0411		part = offset/IPR_ENTRYLEN;
1991/0331		for(r = iprtab.first; part && r; r = r->next)
1991/0401		part--;
1991/0411		bytes = offset;
1991/0401		while(r && bytes < iprtab.n*IPR_ENTRYLEN && n){
1991/0331		part = bytes%IPR_ENTRYLEN;
1991/0401		hnputl(dst, r->dst); hnputl(mask, r->mask); hnputl(gate, r->gate);
1991/0331		sprint(buf,"%d.%d.%d.%d & %d.%d.%d.%d -> %d.%d.%d.%d%s",
1991/0401		dst[0], dst[1], dst[2], dst[3], mask[0], mask[1], mask[2], mask[3], gate[0], gate[1], gate[2], gate[3],
1991/0331		PAD); buf[IPR_ENTRYLEN-1] = '\n'; size = IPR_ENTRYLEN - part;
1991/0401		if(size > n) size = n;
1991/0331		memmove(a, buf+part, size); a = (void *)((int)a + size); n -= size; bytes += size;
1991/0401		r = r->next;
1991/0331		} unlock(&iprtab);
1991/0411		return bytes - offset;
1991/0331		break; default: n=0; break; } return n; } long
1991/0411		iproutewrite(Chan *c, char *a, long n, ulong offset)
1991/0331		{ char buf[IPR_ENTRYLEN]; char *field[4];
1991/0401		Ipaddr mask, dst, gate;
1991/0331		int m; switch((int)(c->qid.path&~CHDIR)){ case Qdata: strncpy(buf, a, sizeof buf); m = getfields(buf, field, 4, ' '); if(strncmp(field[0], "flush", 5) == 0) ipflushroute(); else if(strcmp(field[0], "add") == 0){ switch(m){ case 4:
1991/0401		dst = ipparse(field[1]); mask = ipparse(field[2]); gate = ipparse(field[3]);
1991/0331		ipaddroute(dst, mask, gate); break; case 3:
1991/0401		dst = ipparse(field[1]); gate = ipparse(field[2]); ipaddroute(dst, classmask[dst>>30], gate);
1991/0331		break; default: error(Ebadarg); } } else if(strcmp(field[0], "delete") == 0){ switch(m){ case 3:
1991/0401		dst = ipparse(field[1]); mask = ipparse(field[2]);
1991/0331		ipremroute(dst, mask); break; case 2:
1991/0401		dst = ipparse(field[1]); ipremroute(dst, classmask[dst>>30]);
1991/0331		break; default: error(Ebadarg); } } break; default: error(Ebadusefd); } return n;
1991/0330		}