/* * BIRD -- Linux Routing Table Scanning * * (c) 1998--2000 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ #include <stdio.h> #include <ctype.h> #include <fcntl.h> #include <unistd.h> #include <net/route.h> #undef LOCAL_DEBUG #include "nest/bird.h" #include "nest/route.h" #include "nest/protocol.h" #include "nest/iface.h" #include "lib/timer.h" #include "lib/unix.h" #include "lib/krt.h" #include "lib/string.h" static int krt_scan_fd = -1; struct iface * krt_temp_iface(struct krt_proto *p, char *name) { struct iface *i; WALK_LIST(i, p->scan.temp_ifs) if (!strcmp(i->name, name)) return i; i = mb_allocz(p->p.pool, sizeof(struct iface)); strcpy(i->name, name); add_tail(&p->scan.temp_ifs, &i->n); return i; } static void krt_parse_entry(byte *ent, struct krt_proto *p) { u32 dest0, gw0, mask0; ip_addr dest, gw, mask; unsigned int flags; int masklen; net *net; byte *iface = ent; rta a; rte *e; if (sscanf(ent, "%*s\t%x\t%x\t%x\t%*d\t%*d\t%*d\t%x\t", &dest0, &gw0, &flags, &mask0) != 4) { log(L_ERR "krt read: unable to parse `%s'", ent); return; } while (*ent != '\t') ent++; *ent = 0; dest = ipa_from_u32(dest0); ipa_ntoh(dest); gw = ipa_from_u32(gw0); ipa_ntoh(gw); mask = ipa_from_u32(mask0); ipa_ntoh(mask); if ((masklen = ipa_mklen(mask)) < 0) { log(L_ERR "krt read: invalid netmask %08x", mask0); return; } DBG("Got %I/%d via %I flags %x\n", dest, masklen, gw, flags); if (!(flags & RTF_UP)) { DBG("Down.\n"); return; } if (flags & RTF_HOST) masklen = 32; if (flags & (RTF_DYNAMIC | RTF_MODIFIED)) /* Redirect route */ { log(L_WARN "krt: Ignoring redirect to %I/%d via %I", dest, masklen, gw); return; } net = net_get(p->p.table, dest, masklen); a.proto = &p->p; a.source = RTS_INHERIT; a.scope = SCOPE_UNIVERSE; a.cast = RTC_UNICAST; a.flags = a.aflags = 0; a.from = IPA_NONE; a.iface = NULL; a.eattrs = NULL; if (flags & RTF_GATEWAY) { neighbor *ng = neigh_find(&p->p, &gw, 0); if (ng && ng->scope) a.iface = ng->iface; else /* FIXME: Remove this warning? Handle it somehow... */ log(L_WARN "Kernel told us to use non-neighbor %I for %I/%d", gw, net->n.prefix, net->n.pxlen); a.dest = RTD_ROUTER; a.gw = gw; } else if (flags & RTF_REJECT) { a.dest = RTD_UNREACHABLE; a.gw = IPA_NONE; } else if (isalpha(iface[0])) { a.dest = RTD_DEVICE; a.gw = IPA_NONE; a.iface = krt_temp_iface(p, iface); } else { log(L_WARN "Kernel reporting unknown route type to %I/%d", net->n.prefix, net->n.pxlen); return; } e = rte_get_temp(&a); e->net = net; e->u.krt.src = KRT_SRC_UNKNOWN; krt_got_route(p, e); } void krt_scan_fire(struct krt_proto *p) { byte buf[32768]; int l, seen_hdr; if (krt_scan_fd < 0) { krt_scan_fd = open("/proc/net/route", O_RDONLY); if (krt_scan_fd < 0) die("/proc/net/route: %m"); } else if (lseek(krt_scan_fd, 0, SEEK_SET) < 0) { log(L_ERR "krt seek: %m"); return; } seen_hdr = 0; while ((l = read(krt_scan_fd, buf, sizeof(buf))) > 0) { byte *z = buf; if (l & 127) { log(L_ERR "krt read: misaligned entry: l=%d", l); return; } while (l >= 128) { if (seen_hdr++) krt_parse_entry(z, p); z += 128; l -= 128; } } if (l < 0) { log(L_ERR "krt read: %m"); return; } DBG("KRT scan done, seen %d lines\n", seen_hdr); } void krt_scan_construct(struct krt_config *c) { } void krt_scan_preconfig(struct config *c) { } void krt_scan_postconfig(struct krt_config *c) { } void krt_scan_start(struct krt_proto *x, int first) { init_list(&x->scan.temp_ifs); } void krt_scan_shutdown(struct krt_proto *x, int last) { }