ref: 7628681f83b663609eace87a50f8fbf68c31f40b
dir: /sys/src/9/ip/iproute.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "ip.h" static void walkadd(Fs*, Route**, Route*); static void addnode(Fs*, Route**, Route*); static void calcd(Route*); /* these are used for all instances of IP */ static Route* v4freelist; static Route* v6freelist; static RWlock routelock; static ulong v4routegeneration, v6routegeneration; static void freeroute(Route *r) { Route **l; r->ref = 0; r->left = nil; r->right = nil; if(r->type & Rv4) l = &v4freelist; else l = &v6freelist; r->mid = *l; *l = r; } static Route* allocroute(int type) { Route *r, **l; int n; if(type & Rv4){ n = sizeof(RouteTree) + sizeof(V4route); l = &v4freelist; } else { n = sizeof(RouteTree) + sizeof(V6route); l = &v6freelist; } if((r = *l) != nil) *l = r->mid; else r = smalloc(n); memset(r, 0, n); r->type = type; r->ifc = nil; r->ref = 1; return r; } static void addqueue(Route **q, Route *r) { Route *l; if(r == nil) return; l = allocroute(r->type); l->left = r; l->mid = *q; *q = l; } /* * compare 2 v6 addresses */ static int lcmp(ulong *a, ulong *b) { int i; for(i = 0; i < IPllen; i++){ if(a[i] > b[i]) return 1; if(a[i] < b[i]) return -1; } return 0; } /* * compare 2 v4 or v6 ranges */ enum { Rpreceeds, /* a left of b */ Rfollows, /* a right of b */ Requals, /* a equals b */ Rcontains, /* a contians b */ Roverlaps, /* a overlaps b */ }; static int rangecompare(Route *a, Route *b) { if(a->type & Rv4){ if(a->v4.endaddress < b->v4.address) return Rpreceeds; if(a->v4.address > b->v4.endaddress) return Rfollows; if(a->v4.address <= b->v4.address && a->v4.endaddress >= b->v4.endaddress){ if(a->v4.address == b->v4.address && a->v4.endaddress == b->v4.endaddress){ if(a->v4.source <= b->v4.source && a->v4.endsource >= b->v4.endsource){ if(a->v4.source == b->v4.source && a->v4.endsource == b->v4.endsource) return Requals; return Rcontains; } return Roverlaps; } return Rcontains; } return Roverlaps; } if(lcmp(a->v6.endaddress, b->v6.address) < 0) return Rpreceeds; if(lcmp(a->v6.address, b->v6.endaddress) > 0) return Rfollows; if(lcmp(a->v6.address, b->v6.address) <= 0 && lcmp(a->v6.endaddress, b->v6.endaddress) >= 0){ if(lcmp(a->v6.address, b->v6.address) == 0 && lcmp(a->v6.endaddress, b->v6.endaddress) == 0){ if(lcmp(a->v6.source, b->v6.source) <= 0 && lcmp(a->v6.endsource, b->v6.endsource) >= 0){ if(lcmp(a->v6.source, b->v6.source) == 0 && lcmp(a->v6.endsource, b->v6.endsource) == 0) return Requals; return Rcontains; } return Roverlaps; } return Rcontains; } return Roverlaps; } /* return 1 if a matches b, otherwise 0 */ static int matchroute(Route *a, Route *b) { if(a == b) return 1; if((a->type^b->type) & (Rifc|Runi|Rmulti|Rbcast)) return 0; if(a->type & Rv4){ if(memcmp(a->v4.gate, IPnoaddr+IPv4off, IPv4addrlen) != 0 && memcmp(a->v4.gate, b->v4.gate, IPv4addrlen) != 0) return 0; } else { if(ipcmp(a->v6.gate, IPnoaddr) != 0 && ipcmp(a->v6.gate, b->v6.gate) != 0) return 0; } if(a->ifc != b->ifc) return 0; if(*a->tag != 0 && strncmp(a->tag, b->tag, sizeof(a->tag)) != 0) return 0; return 1; } static void copygate(Route *old, Route *new) { old->type = new->type; old->ifc = new->ifc; old->ifcid = new->ifcid; if(new->type & Rv4) memmove(old->v4.gate, new->v4.gate, IPv4addrlen); else ipmove(old->v6.gate, new->v6.gate); strncpy(old->tag, new->tag, sizeof(new->tag)); } /* * walk down a tree adding nodes back in */ static void walkadd(Fs *f, Route **root, Route *p) { Route *l, *r; l = p->left; r = p->right; p->left = nil; p->right = nil; addnode(f, root, p); if(l != nil) walkadd(f, root, l); if(r != nil) walkadd(f, root, r); } /* * calculate depth */ static void calcd(Route *p) { Route *q; int d; if(p != nil) { d = 0; q = p->left; if(q != nil) d = q->depth; q = p->right; if(q != nil && q->depth > d) d = q->depth; q = p->mid; if(q != nil && q->depth > d) d = q->depth; p->depth = d+1; } } /* * balance the tree at the current node */ static void balancetree(Route **cur) { Route *p, *l, *r; int dl, dr; /* * if left and right are * too out of balance, * rotate tree node */ p = *cur; dl = 0; if((l = p->left) != nil) dl = l->depth; dr = 0; if((r = p->right) != nil) dr = r->depth; if(dl > dr+1) { p->left = l->right; l->right = p; *cur = l; calcd(p); calcd(l); } else if(dr > dl+1) { p->right = r->left; r->left = p; *cur = r; calcd(p); calcd(r); } else calcd(p); } /* * add a new node to the tree */ static void addnode(Fs *f, Route **cur, Route *new) { Route *p; p = *cur; if(p == nil) { *cur = new; new->depth = 1; return; } switch(rangecompare(new, p)){ case Rpreceeds: addnode(f, &p->left, new); break; case Rfollows: addnode(f, &p->right, new); break; case Rcontains: /* * if new node is superset * of tree node, * replace tree node and * queue tree node to be * merged into root. */ *cur = new; new->depth = 1; addqueue(&f->queue, p); break; case Requals: /* * supercede the old entry if the old one isn't * a local interface. */ if((p->type & Rifc) == 0) copygate(p, new); else if(new->type & Rifc){ p->type = (p->type & ~(Rproxy|Rtrans)) | (new->type & (Rproxy|Rtrans)); p->ref++; } freeroute(new); break; case Roverlaps: addnode(f, &p->mid, new); break; } balancetree(cur); } /* * find node matching r */ static Route** looknode(Route **cur, Route *r) { Route *p; for(;;){ p = *cur; if(p == nil) return nil; switch(rangecompare(r, p)){ case Rcontains: return nil; case Rpreceeds: cur = &p->left; break; case Rfollows: cur = &p->right; break; case Roverlaps: cur = &p->mid; break; case Requals: if((p->type & Rifc) == 0 && !matchroute(r, p)) return nil; return cur; } } } static Route* looknodematch(Route *r, int (*match)(Route*, void*), void *arg) { Route *x; if(r == nil) return nil; if((x = looknodematch(r->mid, match, arg)) != nil) return x; if((x = looknodematch(r->left, match, arg)) != nil) return x; if((x = looknodematch(r->right, match, arg)) != nil) return x; if((*match)(r, arg)) return r; return nil; } static int matchtag(Route *r, void *arg) { char *tag = (char*)arg; if(r->type & Rifc) return 0; return tag == nil || strncmp(tag, r->tag, sizeof(r->tag)) == 0; } static int matchifc(Route *r, void *arg) { Ipifc *ifc = (Ipifc*)arg; return r->ifc == ifc; } #define V4H(a) ((a&0x07ffffff)>>(32-Lroot-5)) #define V6H(a) (((a)[0]&0x80000000)>>(32-Lroot) | ((a)[(IPllen/2)-1]&(0xffff>>(16-Lroot)))) static void routeadd(Fs *f, Route *r) { Route **h, **e, *p, *q; if(r->type & Rv4){ h = &f->v4root[V4H(r->v4.address)]; e = &f->v4root[V4H(r->v4.endaddress)]; } else { h = &f->v6root[V6H(r->v6.address)]; e = &f->v6root[V6H(r->v6.endaddress)]; } for(; h <= e; h++) { p = allocroute(r->type); p->ifc = r->ifc; p->ifcid = r->ifcid; if(r->type & Rv4) memmove(&p->v4, &r->v4, sizeof(r->v4)); else memmove(&p->v6, &r->v6, sizeof(r->v6)); memmove(p->tag, r->tag, sizeof(r->tag)); addnode(f, h, p); while((p = f->queue) != nil) { f->queue = p->mid; q = p->left; freeroute(p); walkadd(f, h, q); } } if(r->type & Rv4) v4routegeneration++; else v6routegeneration++; } static void routedel(Fs *f, Route *r) { Route **h, **e, **l, *p, *q; if(r->type & Rv4){ h = &f->v4root[V4H(r->v4.address)]; e = &f->v4root[V4H(r->v4.endaddress)]; } else { h = &f->v6root[V6H(r->v6.address)]; e = &f->v6root[V6H(r->v6.endaddress)]; } for(; h <= e; h++) { if((l = looknode(h, r)) == nil) continue; p = *l; if(--(p->ref) != 0) continue; *l = nil; addqueue(&f->queue, p->left); addqueue(&f->queue, p->mid); addqueue(&f->queue, p->right); freeroute(p); while((p = f->queue) != nil) { f->queue = p->mid; q = p->left; freeroute(p); walkadd(f, h, q); } } if(r->type & Rv4) v4routegeneration++; else v6routegeneration++; } static Route mkroute(uchar *a, uchar *mask, uchar *s, uchar *smask, uchar *gate, int type, Ipifc *ifc, uchar ifcid, char *tag) { ulong x, y; Route r; int h; assert(ifc != nil); memset(&r, 0, sizeof(r)); r.type = type; r.ifc = ifc; r.ifcid = ifcid; if(type & Rv4){ x = nhgetl(a+IPv4off); y = nhgetl(mask+IPv4off); r.v4.address = x & y; r.v4.endaddress = x | ~y; x = nhgetl(s+IPv4off); y = nhgetl(smask+IPv4off); if(y != 0) r.type |= Rsrc; r.v4.source = x & y; r.v4.endsource = x | ~y; memmove(r.v4.gate, gate+IPv4off, IPv4addrlen); } else { for(h = 0; h < IPllen; h++){ x = nhgetl(a+4*h); y = nhgetl(mask+4*h); r.v6.address[h] = x & y; r.v6.endaddress[h] = x | ~y; x = nhgetl(s+4*h); y = nhgetl(smask+4*h); if(y != 0) r.type |= Rsrc; r.v6.source[h] = x & y; r.v6.endsource[h] = x | ~y; } memmove(r.v6.gate, gate, IPaddrlen); } if(tag != nil) strncpy(r.tag, tag, sizeof(r.tag)); return r; } void addroute(Fs *f, uchar *a, uchar *mask, uchar *s, uchar *smask, uchar *gate, int type, Ipifc *ifc, char *tag) { Route r = mkroute(a, mask, s, smask, gate, type, ifc, ifc->ifcid, tag); wlock(&routelock); routeadd(f, &r); wunlock(&routelock); } void delroute(Fs *f, uchar *a, uchar *mask, uchar *s, uchar *smask, uchar *gate, int type, Ipifc *ifc, char *tag) { Route r = mkroute(a, mask, s, smask, gate, type, ifc, ifc->ifcid, tag); wlock(&routelock); routedel(f, &r); wunlock(&routelock); } static void flushroutematch(Fs *f, int (*match)(Route*, void*), void *arg) { Route r, *x; int h; wlock(&routelock); for(h = 0; h < nelem(f->v4root); h++) while((x = looknodematch(f->v4root[h], match, arg)) != nil){ memmove(&r, x, sizeof(RouteTree) + sizeof(V4route)); routedel(f, &r); } for(h = 0; h < nelem(f->v6root); h++) while((x = looknodematch(f->v6root[h], match, arg)) != nil){ memmove(&r, x, sizeof(RouteTree) + sizeof(V6route)); routedel(f, &r); } wunlock(&routelock); } /* * flushrouteifc: * remove all routes associated with ifc (wlock()'ed). */ void flushrouteifc(Fs *f, Ipifc *ifc) { flushroutematch(f, matchifc, ifc); ifc->ifcid++; /* invalidate all routes */ } /* * v4lookup, v6lookup: * lookup a route to destination address a from source address s * and return the route. returns nil if no route was found. * an optional Routehint can be passed in rh to cache the lookup. * * for v4lookup, addresses are in 4 byte format. */ Route* v4lookup(Fs *f, uchar *a, uchar *s, Routehint *rh) { ulong la, ls; Route *p, *q; Ipifc *ifc; if(rh != nil && rh->rgen == v4routegeneration && (q = rh->r) != nil && (ifc = q->ifc) != nil && q->ifcid == ifc->ifcid && q->ref > 0) return q; q = nil; la = nhgetl(a); ls = nhgetl(s); rlock(&routelock); for(p = f->v4root[V4H(la)]; p != nil;){ if(la < p->v4.address){ p = p->left; continue; } if(la > p->v4.endaddress){ p = p->right; continue; } if(p->type & Rsrc){ if(ls < p->v4.source){ p = p->mid; continue; } if(ls > p->v4.endsource){ p = p->mid; continue; } } q = p; p = p->mid; } if(rh != nil){ rh->r = q; rh->rgen = v4routegeneration; } runlock(&routelock); return q; } Route* v6lookup(Fs *f, uchar *a, uchar *s, Routehint *rh) { ulong la[IPllen], ls[IPllen]; ulong x, y; Route *p, *q; Ipifc *ifc; int h; if(isv4(s)){ if(isv4(a)) return v4lookup(f, a+IPv4off, s+IPv4off, rh); return nil; } if(rh != nil && rh->rgen == v6routegeneration && (q = rh->r) != nil && (ifc = q->ifc) != nil && q->ifcid == ifc->ifcid && q->ref > 0) return q; q = nil; for(h = 0; h < IPllen; h++){ la[h] = nhgetl(a+4*h); ls[h] = nhgetl(s+4*h); } rlock(&routelock); for(p = f->v6root[V6H(la)]; p != nil;){ for(h = 0; h < IPllen; h++){ x = la[h]; y = p->v6.address[h]; if(x == y) continue; if(x < y){ p = p->left; goto next; } break; } for(h = 0; h < IPllen; h++){ x = la[h]; y = p->v6.endaddress[h]; if(x == y) continue; if(x > y){ p = p->right; goto next; } break; } if(p->type & Rsrc){ for(h = 0; h < IPllen; h++){ x = ls[h]; y = p->v6.source[h]; if(x == y) continue; if(x < y){ p = p->mid; goto next; } break; } for(h = 0; h < IPllen; h++){ x = ls[h]; y = p->v6.endsource[h]; if(x == y) continue; if(x > y){ p = p->mid; goto next; } break; } } q = p; p = p->mid; next: ; } if(rh != nil){ rh->r = q; rh->rgen = v6routegeneration; } runlock(&routelock); return q; } /* * v4source, v6source: * lookup a route to destination address a and also find * a suitable source address s on the outgoing interface. * return the route on success or nil when no route * was found. * * for v4source, addresses are in 4 byte format. */ Route* v4source(Fs *f, uchar *a, uchar *s) { uchar src[IPv4addrlen]; int splen; ulong x, la; Route *p, *q; Ipifc *ifc; la = nhgetl(a); again: q = nil; rlock(&routelock); for(p = f->v4root[V4H(la)]; p != nil;){ if(la < p->v4.address){ p = p->left; continue; } if(la > p->v4.endaddress){ p = p->right; continue; } ifc = p->ifc; if(!canrlock(ifc)){ int gen = v4routegeneration; runlock(&routelock); rlock(ifc); rlock(&routelock); if(v4routegeneration != gen){ runlock(&routelock); runlock(ifc); goto again; } } splen = 0; if(p->type & Rsrc){ /* calculate local prefix length for source specific routes */ for(x = ~(p->v4.endsource ^ p->v4.source); x & 0x80000000UL; x <<= 1) splen++; hnputl(src, p->v4.source); } if(!ipv4local(ifc, src, splen, (p->type & (Rifc|Rbcast|Rmulti|Rv4))==Rv4? p->v4.gate: a)){ runlock(ifc); p = p->mid; continue; } memmove(s, src, IPv4addrlen); runlock(ifc); q = p; p = p->mid; } runlock(&routelock); return q; } Route* v6source(Fs *f, uchar *a, uchar *s) { uchar src[IPaddrlen]; int splen, h; ulong x, y, la[IPllen]; Route *p, *q; Ipifc *ifc; for(h = 0; h < IPllen; h++) la[h] = nhgetl(a+4*h); again: q = nil; rlock(&routelock); for(p = f->v6root[V6H(la)]; p != nil;){ for(h = 0; h < IPllen; h++){ x = la[h]; y = p->v6.address[h]; if(x == y) continue; if(x < y){ p = p->left; goto next; } break; } for(h = 0; h < IPllen; h++){ x = la[h]; y = p->v6.endaddress[h]; if(x == y) continue; if(x > y){ p = p->right; goto next; } break; } ifc = p->ifc; if(!canrlock(ifc)){ int gen = v6routegeneration; runlock(&routelock); rlock(ifc); rlock(&routelock); if(v6routegeneration != gen){ runlock(&routelock); runlock(ifc); goto again; } } splen = 0; if(p->type & Rsrc){ /* calculate local prefix length for source specific routes */ for(h = 0; h < IPllen; h++){ hnputl(src+4*h, p->v6.source[h]); if((x = ~(p->v6.endsource[h] ^ p->v6.source[h])) != ~0UL){ for(; x & 0x80000000UL; x <<= 1) splen++; break; } splen += 32; } } if(!ipv6local(ifc, src, splen, a)){ runlock(ifc); p = p->mid; continue; } ipmove(s, src); runlock(ifc); q = p; p = p->mid; next: ; } runlock(&routelock); return q; } static int parseroutetype(char *p) { int type = 0; switch(*p++){ default: return -1; case '4': type |= Rv4; case '6': break; } for(;;) switch(*p++){ default: return -1; case 'i': if(((type ^= Rifc) & Rifc) != Rifc) return -1; break; case 'u': if(((type ^= Runi) & (Runi|Rbcast|Rmulti)) != Runi) return -1; break; case 'b': if(((type ^= Rbcast) & (Runi|Rbcast|Rmulti)) != Rbcast) return -1; break; case 'm': if(((type ^= Rmulti) & (Runi|Rbcast|Rmulti)) != Rmulti) return -1; break; case 'p': if(((type ^= Rptpt) & Rptpt) != Rptpt) return -1; break; case 'y': if(((type ^= Rproxy) & Rproxy) != Rproxy) return -1; break; case 't': if(((type ^= Rtrans) & Rtrans) != Rtrans) return -1; break; case '\0': return type; } } void routetype(int type, char p[8]) { if(type & Rv4) *p++ = '4'; else *p++ = '6'; if(type & Rifc) *p++ = 'i'; if(type & Runi) *p++ = 'u'; else if(type & Rbcast) *p++ = 'b'; else if(type & Rmulti) *p++ = 'm'; if(type & Rptpt) *p++ = 'p'; if(type & Rproxy) *p++ = 'y'; if(type & Rtrans) *p++ = 't'; *p = 0; } static void convroute(Route *r, uchar *addr, uchar *mask, uchar *src, uchar *smask, uchar *gate) { int i; if(r->type & Rv4){ memmove(addr, v4prefix, IPv4off); hnputl(addr+IPv4off, r->v4.address); memset(mask, 0xff, IPv4off); hnputl(mask+IPv4off, ~(r->v4.endaddress ^ r->v4.address)); memmove(src, v4prefix, IPv4off); hnputl(src+IPv4off, r->v4.source); memset(smask, 0xff, IPv4off); hnputl(smask+IPv4off, ~(r->v4.endsource ^ r->v4.source)); memmove(gate, v4prefix, IPv4off); memmove(gate+IPv4off, r->v4.gate, IPv4addrlen); } else { for(i = 0; i < IPllen; i++){ hnputl(addr + 4*i, r->v6.address[i]); hnputl(mask + 4*i, ~(r->v6.endaddress[i] ^ r->v6.address[i])); hnputl(src + 4*i, r->v6.source[i]); hnputl(smask + 4*i, ~(r->v6.endsource[i] ^ r->v6.source[i])); } memmove(gate, r->v6.gate, IPaddrlen); } } static char* seprintroute(char *p, char *e, Route *r) { uchar addr[IPaddrlen], mask[IPaddrlen], src[IPaddrlen], smask[IPaddrlen], gate[IPaddrlen]; char type[8], ifbuf[4]; convroute(r, addr, mask, src, smask, gate); routetype(r->type, type); snprint(ifbuf, sizeof ifbuf, "%d", r->ifc->conv->x); return seprint(p, e, "%-15I %-4M %-15I %-4s %4.4s %3s %-15I %-4M\n", addr, mask, gate, type, r->tag, ifbuf, src, smask); } typedef struct Routewalk Routewalk; struct Routewalk { int o; int h; char* p; char* e; }; static int rr1(Routewalk *rw, Route *r) { int n = seprintroute(rw->p, rw->e, r) - rw->p; if(rw->o < 0){ if(n > -rw->o){ memmove(rw->p, rw->p - rw->o, n + rw->o); rw->p += n + rw->o; } rw->o += n; } else rw->p += n; return rw->p < rw->e; } static int rr(Route *r, Routewalk *rw) { int h; if(r == nil) return 1; if(rr(r->left, rw) == 0) return 0; if(r->type & Rv4) h = V4H(r->v4.address); else h = V6H(r->v6.address); if(h == rw->h){ if(rr1(rw, r) == 0) return 0; } if(rr(r->mid, rw) == 0) return 0; return rr(r->right, rw); } long routeread(Fs *f, char *p, ulong offset, int n) { Routewalk rw[1]; rw->p = p; rw->e = p+n; rw->o = -offset; if(rw->o > 0) return 0; rlock(&routelock); if(rw->p < rw->e) { for(rw->h = 0; rw->h < nelem(f->v4root); rw->h++) if(rr(f->v4root[rw->h], rw) == 0) break; } if(rw->p < rw->e) { for(rw->h = 0; rw->h < nelem(f->v6root); rw->h++) if(rr(f->v6root[rw->h], rw) == 0) break; } runlock(&routelock); return rw->p - p; } /* * 4 add addr mask gate * 5 add addr mask gate ifc * 6 add addr mask gate src smask * 7 add addr mask gate ifc src smask * 8 add addr mask gate type ifc src smask * 9 add addr mask gate type tag ifc src smask * * 3 del addr mask * 4 del addr mask gate * 5 del addr mask src smask * 6 del addr mask gate src smask * 7 del addr mask gate ifc src smask * 8 del addr mask gate type ifc src smask * 9 del addr mask gate type tag ifc src smask */ static Route parseroute(Fs *f, char **argv, int argc) { uchar addr[IPaddrlen], mask[IPaddrlen]; uchar src[IPaddrlen], smask[IPaddrlen]; uchar gate[IPaddrlen]; char *ifcstr, *tag; Ipifc *ifc; uchar ifcid; int type; type = 0; tag = nil; ifcstr = nil; ipmove(gate, IPnoaddr); ipmove(src, IPnoaddr); ipmove(smask, IPnoaddr); if(argc < 3) error(Ebadctl); if(parseipandmask(addr, mask, argv[1], argv[2]) == -1) error(Ebadip); if(strcmp(argv[0], "add") == 0 || (argc > 3 && argc != 5)){ if(argc < 4) error(Ebadctl); if(parseip(gate, argv[3]) == -1) error(Ebadip); } if(argc > 4 && (strcmp(argv[0], "add") != 0 || argc != 5)){ if(parseipandmask(src, smask, argv[argc-2], argv[argc-1]) == -1) error(Ebadip); } if(argc == 5 && strcmp(argv[0], "add") == 0) ifcstr = argv[4]; else if(argc > 6) ifcstr = argv[argc-3]; if(argc > 7 && (type = parseroutetype(argv[4])) < 0) error(Ebadctl); if(isv4(addr)) type |= Rv4; if(argc > 8) tag = argv[5]; if(argc > 9) error(Ebadctl); if(type & Rv4){ if(ipcmp(smask, IPnoaddr) != 0 && !isv4(src)) error(Ebadip); if(ipcmp(gate, IPnoaddr) != 0 && !isv4(gate)) error(Ebadip); } else { if(isv4(addr)) error(Ebadip); } if(ifcstr != nil && strcmp(ifcstr, "-") != 0) ifc = findipifcstr(f, ifcstr); else ifc = findipifc(f, src, gate, type); if(ifc == nil) error("interface not found"); ifcid = ifc->ifcid; runlock(ifc); return mkroute(addr, mask, src, smask, gate, type, ifc, ifcid, tag); } long routewrite(Fs *f, Chan *c, char *p, int n) { Cmdbuf *cb; IPaux *a; cb = parsecmd(p, n); if(waserror()){ free(cb); nexterror(); } if(cb->nf < 1) error("short control request"); if(strcmp(cb->f[0], "flush") == 0){ flushroutematch(f, matchtag, cb->nf < 2 ? nil : cb->f[1]); } else if(strcmp(cb->f[0], "add") == 0 ||strcmp(cb->f[0], "del") == 0 ||strcmp(cb->f[0], "remove") == 0){ Route r = parseroute(f, cb->f, cb->nf); if(*r.tag == 0){ a = c->aux; strncpy(r.tag, a->tag, sizeof(r.tag)); } wlock(&routelock); if(strcmp(cb->f[0], "add") == 0) routeadd(f, &r); else routedel(f, &r); wunlock(&routelock); } else if(strcmp(cb->f[0], "tag") == 0) { if(cb->nf < 2) error(Ebadarg); a = c->aux; c->aux = newipaux(a->owner, cb->f[1]); free(a); } else error(Ebadctl); poperror(); free(cb); return n; }