/* * BIRD -- Linux Netlink Interface * * (c) 1999--2000 Martin Mares * * Can be freely distributed and used under the terms of the GNU GPL. */ #include #include #include #include #include #undef LOCAL_DEBUG #include "nest/bird.h" #include "nest/route.h" #include "nest/protocol.h" #include "nest/iface.h" #include "lib/alloca.h" #include "lib/timer.h" #include "lib/unix.h" #include "lib/krt.h" #include "lib/socket.h" #include "lib/string.h" #include "conf/conf.h" #include #include #include #include #ifndef MSG_TRUNC /* Hack: Several versions of glibc miss this one :( */ #define MSG_TRUNC 0x20 #endif #ifndef IFF_LOWER_UP #define IFF_LOWER_UP 0x10000 #endif /* * Synchronous Netlink interface */ struct nl_sock { int fd; u32 seq; byte *rx_buffer; /* Receive buffer */ struct nlmsghdr *last_hdr; /* Recently received packet */ unsigned int last_size; }; #define NL_RX_SIZE 8192 static struct nl_sock nl_scan = {.fd = -1}; /* Netlink socket for synchronous scan */ static struct nl_sock nl_req = {.fd = -1}; /* Netlink socket for requests */ static void nl_open_sock(struct nl_sock *nl) { if (nl->fd < 0) { nl->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (nl->fd < 0) die("Unable to open rtnetlink socket: %m"); nl->seq = now; nl->rx_buffer = xmalloc(NL_RX_SIZE); nl->last_hdr = NULL; nl->last_size = 0; } } static void nl_open(void) { nl_open_sock(&nl_scan); nl_open_sock(&nl_req); } static void nl_send(struct nl_sock *nl, struct nlmsghdr *nh) { struct sockaddr_nl sa; memset(&sa, 0, sizeof(sa)); sa.nl_family = AF_NETLINK; nh->nlmsg_pid = 0; nh->nlmsg_seq = ++(nl->seq); if (sendto(nl->fd, nh, nh->nlmsg_len, 0, (struct sockaddr *)&sa, sizeof(sa)) < 0) die("rtnetlink sendto: %m"); nl->last_hdr = NULL; } static void nl_request_dump(int cmd) { struct { struct nlmsghdr nh; struct rtgenmsg g; } req; req.nh.nlmsg_type = cmd; req.nh.nlmsg_len = sizeof(req); req.nh.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; /* Is it important which PF_* is used for link-level interface scan? It seems that some information is available only when PF_INET is used. */ req.g.rtgen_family = (cmd == RTM_GETLINK) ? PF_INET : BIRD_PF; nl_send(&nl_scan, &req.nh); } static struct nlmsghdr * nl_get_reply(struct nl_sock *nl) { for(;;) { if (!nl->last_hdr) { struct iovec iov = { nl->rx_buffer, NL_RX_SIZE }; struct sockaddr_nl sa; struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 }; int x = recvmsg(nl->fd, &m, 0); if (x < 0) die("nl_get_reply: %m"); if (sa.nl_pid) /* It isn't from the kernel */ { DBG("Non-kernel packet\n"); continue; } nl->last_size = x; nl->last_hdr = (void *) nl->rx_buffer; if (m.msg_flags & MSG_TRUNC) bug("nl_get_reply: got truncated reply which should be impossible"); } if (NLMSG_OK(nl->last_hdr, nl->last_size)) { struct nlmsghdr *h = nl->last_hdr; nl->last_hdr = NLMSG_NEXT(h, nl->last_size); if (h->nlmsg_seq != nl->seq) { log(L_WARN "nl_get_reply: Ignoring out of sequence netlink packet (%x != %x)", h->nlmsg_seq, nl->seq); continue; } return h; } if (nl->last_size) log(L_WARN "nl_get_reply: Found packet remnant of size %d", nl->last_size); nl->last_hdr = NULL; } } static struct rate_limit rl_netlink_err; static int nl_error(struct nlmsghdr *h) { struct nlmsgerr *e; int ec; if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) { log(L_WARN "Netlink: Truncated error message received"); return ENOBUFS; } e = (struct nlmsgerr *) NLMSG_DATA(h); ec = -e->error; if (ec) log_rl(&rl_netlink_err, L_WARN "Netlink: %s", strerror(ec)); return ec; } static struct nlmsghdr * nl_get_scan(void) { struct nlmsghdr *h = nl_get_reply(&nl_scan); if (h->nlmsg_type == NLMSG_DONE) return NULL; if (h->nlmsg_type == NLMSG_ERROR) { nl_error(h); return NULL; } return h; } static int nl_exchange(struct nlmsghdr *pkt) { struct nlmsghdr *h; nl_send(&nl_req, pkt); for(;;) { h = nl_get_reply(&nl_req); if (h->nlmsg_type == NLMSG_ERROR) break; log(L_WARN "nl_exchange: Unexpected reply received"); } return nl_error(h) ? -1 : 0; } /* * Netlink attributes */ static int nl_attr_len; static void * nl_checkin(struct nlmsghdr *h, int lsize) { nl_attr_len = h->nlmsg_len - NLMSG_LENGTH(lsize); if (nl_attr_len < 0) { log(L_ERR "nl_checkin: underrun by %d bytes", -nl_attr_len); return NULL; } return NLMSG_DATA(h); } static int nl_parse_attrs(struct rtattr *a, struct rtattr **k, int ksize) { int max = ksize / sizeof(struct rtattr *); bzero(k, ksize); while (RTA_OK(a, nl_attr_len)) { if (a->rta_type < max) k[a->rta_type] = a; a = RTA_NEXT(a, nl_attr_len); } if (nl_attr_len) { log(L_ERR "nl_parse_attrs: remnant of size %d", nl_attr_len); return 0; } else return 1; } void nl_add_attr(struct nlmsghdr *h, unsigned bufsize, unsigned code, void *data, unsigned dlen) { unsigned len = RTA_LENGTH(dlen); unsigned pos = NLMSG_ALIGN(h->nlmsg_len); struct rtattr *a; if (pos + len > bufsize) bug("nl_add_attr: packet buffer overflow"); a = (struct rtattr *)((char *)h + pos); a->rta_type = code; a->rta_len = len; h->nlmsg_len = pos + len; memcpy(RTA_DATA(a), data, dlen); } static inline void nl_add_attr_u32(struct nlmsghdr *h, unsigned bufsize, int code, u32 data) { nl_add_attr(h, bufsize, code, &data, 4); } static inline void nl_add_attr_ipa(struct nlmsghdr *h, unsigned bufsize, int code, ip_addr ipa) { ipa_hton(ipa); nl_add_attr(h, bufsize, code, &ipa, sizeof(ipa)); } #define RTNH_SIZE (sizeof(struct rtnexthop) + sizeof(struct rtattr) + sizeof(ip_addr)) static inline void add_mpnexthop(char *buf, ip_addr ipa, unsigned iface, unsigned char weight) { struct rtnexthop *nh = (void *) buf; struct rtattr *rt = (void *) (buf + sizeof(*nh)); nh->rtnh_len = RTNH_SIZE; nh->rtnh_flags = 0; nh->rtnh_hops = weight; nh->rtnh_ifindex = iface; rt->rta_len = sizeof(*rt) + sizeof(ipa); rt->rta_type = RTA_GATEWAY; ipa_hton(ipa); memcpy(buf + sizeof(*nh) + sizeof(*rt), &ipa, sizeof(ipa)); } static void nl_add_multipath(struct nlmsghdr *h, unsigned bufsize, struct mpnh *nh) { unsigned len = sizeof(struct rtattr); unsigned pos = NLMSG_ALIGN(h->nlmsg_len); char *buf = (char *)h + pos; struct rtattr *rt = (void *) buf; buf += len; for (; nh; nh = nh->next) { len += RTNH_SIZE; if (pos + len > bufsize) bug("nl_add_multipath: packet buffer overflow"); add_mpnexthop(buf, nh->gw, nh->iface->index, nh->weight); buf += RTNH_SIZE; } rt->rta_type = RTA_MULTIPATH; rt->rta_len = len; h->nlmsg_len = pos + len; } static struct mpnh * nl_parse_multipath(struct krt_proto *p, struct rtattr *ra) { /* Temporary buffer for multicast nexthops */ static struct mpnh *nh_buffer; static int nh_buf_size; /* in number of structures */ static int nh_buf_used; struct rtattr *a[RTA_CACHEINFO+1]; struct rtnexthop *nh = RTA_DATA(ra); struct mpnh *rv, *first, **last; int len = RTA_PAYLOAD(ra); first = NULL; last = &first; nh_buf_used = 0; while (len) { /* Use RTNH_OK(nh,len) ?? */ if ((len < sizeof(*nh)) || (len < nh->rtnh_len)) return NULL; if (nh_buf_used == nh_buf_size) { nh_buf_size = nh_buf_size ? (nh_buf_size * 2) : 4; nh_buffer = xrealloc(nh_buffer, nh_buf_size * sizeof(struct mpnh)); } *last = rv = nh_buffer + nh_buf_used++; rv->next = NULL; last = &(rv->next); rv->weight = nh->rtnh_hops; rv->iface = if_find_by_index(nh->rtnh_ifindex); if (!rv->iface) return NULL; /* Nonexistent RTNH_PAYLOAD ?? */ nl_attr_len = nh->rtnh_len - RTNH_LENGTH(0); nl_parse_attrs(RTNH_DATA(nh), a, sizeof(a)); if (a[RTA_GATEWAY]) { if (RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)) return NULL; memcpy(&rv->gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ip_addr)); ipa_ntoh(rv->gw); neighbor *ng = neigh_find2(&p->p, &rv->gw, rv->iface, (nh->rtnh_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0); if (!ng || (ng->scope == SCOPE_HOST)) return NULL; } else return NULL; len -= NLMSG_ALIGN(nh->rtnh_len); nh = RTNH_NEXT(nh); } return first; } /* * Scanning of interfaces */ static void nl_parse_link(struct nlmsghdr *h, int scan) { struct ifinfomsg *i; struct rtattr *a[IFLA_WIRELESS+1]; int new = h->nlmsg_type == RTM_NEWLINK; struct iface f = {}; struct iface *ifi; char *name; u32 mtu; unsigned int fl; if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFLA_RTA(i), a, sizeof(a))) return; if (!a[IFLA_IFNAME] || RTA_PAYLOAD(a[IFLA_IFNAME]) < 2 || !a[IFLA_MTU] || RTA_PAYLOAD(a[IFLA_MTU]) != 4) { if (scan || !a[IFLA_WIRELESS]) log(L_ERR "nl_parse_link: Malformed message received"); return; } name = RTA_DATA(a[IFLA_IFNAME]); memcpy(&mtu, RTA_DATA(a[IFLA_MTU]), sizeof(u32)); ifi = if_find_by_index(i->ifi_index); if (!new) { DBG("KIF: IF%d(%s) goes down\n", i->ifi_index, name); if (!ifi) return; if_delete(ifi); } else { DBG("KIF: IF%d(%s) goes up (mtu=%d,flg=%x)\n", i->ifi_index, name, mtu, i->ifi_flags); if (ifi && strncmp(ifi->name, name, sizeof(ifi->name)-1)) if_delete(ifi); strncpy(f.name, name, sizeof(f.name)-1); f.index = i->ifi_index; f.mtu = mtu; fl = i->ifi_flags; if (fl & IFF_UP) f.flags |= IF_ADMIN_UP; if (fl & IFF_LOWER_UP) f.flags |= IF_LINK_UP; if (fl & IFF_LOOPBACK) /* Loopback */ f.flags |= IF_MULTIACCESS | IF_LOOPBACK | IF_IGNORE; else if (fl & IFF_POINTOPOINT) /* PtP */ f.flags |= IF_MULTICAST; else if (fl & IFF_BROADCAST) /* Broadcast */ f.flags |= IF_MULTIACCESS | IF_BROADCAST | IF_MULTICAST; else f.flags |= IF_MULTIACCESS; /* NBMA */ if_update(&f); } } static void nl_parse_addr(struct nlmsghdr *h) { struct ifaddrmsg *i; struct rtattr *a[IFA_ANYCAST+1]; int new = h->nlmsg_type == RTM_NEWADDR; struct ifa ifa; struct iface *ifi; int scope; if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(IFA_RTA(i), a, sizeof(a))) return; if (i->ifa_family != BIRD_AF) return; if (!a[IFA_ADDRESS] || RTA_PAYLOAD(a[IFA_ADDRESS]) != sizeof(ip_addr) #ifdef IPV6 || a[IFA_LOCAL] && RTA_PAYLOAD(a[IFA_LOCAL]) != sizeof(ip_addr) #else || !a[IFA_LOCAL] || RTA_PAYLOAD(a[IFA_LOCAL]) != sizeof(ip_addr) || (a[IFA_BROADCAST] && RTA_PAYLOAD(a[IFA_BROADCAST]) != sizeof(ip_addr)) #endif ) { log(L_ERR "nl_parse_addr: Malformed message received"); return; } ifi = if_find_by_index(i->ifa_index); if (!ifi) { log(L_ERR "KIF: Received address message for unknown interface %d", i->ifa_index); return; } bzero(&ifa, sizeof(ifa)); ifa.iface = ifi; if (i->ifa_flags & IFA_F_SECONDARY) ifa.flags |= IA_SECONDARY; /* IFA_LOCAL can be unset for IPv6 interfaces */ memcpy(&ifa.ip, RTA_DATA(a[IFA_LOCAL] ? : a[IFA_ADDRESS]), sizeof(ifa.ip)); ipa_ntoh(ifa.ip); ifa.pxlen = i->ifa_prefixlen; if (i->ifa_prefixlen > BITS_PER_IP_ADDRESS) { log(L_ERR "KIF: Invalid prefix length for interface %s: %d", ifi->name, i->ifa_prefixlen); new = 0; } if (i->ifa_prefixlen == BITS_PER_IP_ADDRESS) { ip_addr addr; memcpy(&addr, RTA_DATA(a[IFA_ADDRESS]), sizeof(addr)); ipa_ntoh(addr); ifa.prefix = ifa.brd = addr; /* It is either a host address or a peer address */ if (ipa_equal(ifa.ip, addr)) ifa.flags |= IA_HOST; else { ifa.flags |= IA_PEER; ifa.opposite = addr; } } else { ip_addr netmask = ipa_mkmask(ifa.pxlen); ifa.prefix = ipa_and(ifa.ip, netmask); ifa.brd = ipa_or(ifa.ip, ipa_not(netmask)); if (i->ifa_prefixlen == BITS_PER_IP_ADDRESS - 1) ifa.opposite = ipa_opposite_m1(ifa.ip); #ifndef IPV6 if (i->ifa_prefixlen == BITS_PER_IP_ADDRESS - 2) ifa.opposite = ipa_opposite_m2(ifa.ip); if ((ifi->flags & IF_BROADCAST) && a[IFA_BROADCAST]) { ip_addr xbrd; memcpy(&xbrd, RTA_DATA(a[IFA_BROADCAST]), sizeof(xbrd)); ipa_ntoh(xbrd); if (ipa_equal(xbrd, ifa.prefix) || ipa_equal(xbrd, ifa.brd)) ifa.brd = xbrd; else if (ifi->flags & IF_TMP_DOWN) /* Complain only during the first scan */ log(L_ERR "KIF: Invalid broadcast address %I for %s", xbrd, ifi->name); } #endif } scope = ipa_classify(ifa.ip); if (scope < 0) { log(L_ERR "KIF: Invalid interface address %I for %s", ifa.ip, ifi->name); return; } ifa.scope = scope & IADDR_SCOPE_MASK; DBG("KIF: IF%d(%s): %s IPA %I, flg %x, net %I/%d, brd %I, opp %I\n", ifi->index, ifi->name, new ? "added" : "removed", ifa.ip, ifa.flags, ifa.prefix, ifa.pxlen, ifa.brd, ifa.opposite); if (new) ifa_update(&ifa); else ifa_delete(&ifa); } void kif_do_scan(struct kif_proto *p UNUSED) { struct nlmsghdr *h; if_start_update(); nl_request_dump(RTM_GETLINK); while (h = nl_get_scan()) if (h->nlmsg_type == RTM_NEWLINK || h->nlmsg_type == RTM_DELLINK) nl_parse_link(h, 1); else log(L_DEBUG "nl_scan_ifaces: Unknown packet received (type=%d)", h->nlmsg_type); nl_request_dump(RTM_GETADDR); while (h = nl_get_scan()) if (h->nlmsg_type == RTM_NEWADDR || h->nlmsg_type == RTM_DELADDR) nl_parse_addr(h); else log(L_DEBUG "nl_scan_ifaces: Unknown packet received (type=%d)", h->nlmsg_type); if_end_update(); } /* * Routes */ static struct krt_proto *nl_table_map[NL_NUM_TABLES]; int krt_capable(rte *e) { rta *a = e->attrs; if (a->cast != RTC_UNICAST) return 0; switch (a->dest) { case RTD_ROUTER: case RTD_DEVICE: if (a->iface == NULL) return 0; case RTD_BLACKHOLE: case RTD_UNREACHABLE: case RTD_PROHIBIT: case RTD_MULTIPATH: break; default: return 0; } return 1; } static inline int nh_bufsize(struct mpnh *nh) { int rv = 0; for (; nh != NULL; nh = nh->next) rv += RTNH_SIZE; return rv; } static int nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new) { eattr *ea; net *net = e->net; rta *a = e->attrs; struct { struct nlmsghdr h; struct rtmsg r; char buf[128 + nh_bufsize(a->nexthops)]; } r; DBG("nl_send_route(%I/%d,new=%d)\n", net->n.prefix, net->n.pxlen, new); bzero(&r.h, sizeof(r.h)); bzero(&r.r, sizeof(r.r)); r.h.nlmsg_type = new ? RTM_NEWROUTE : RTM_DELROUTE; r.h.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); r.h.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | (new ? NLM_F_CREATE|NLM_F_EXCL : 0); r.r.rtm_family = BIRD_AF; r.r.rtm_dst_len = net->n.pxlen; r.r.rtm_tos = 0; r.r.rtm_table = KRT_CF->sys.table_id; r.r.rtm_protocol = RTPROT_BIRD; r.r.rtm_scope = RT_SCOPE_UNIVERSE; nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net->n.prefix); u32 metric = 0; if (new && e->attrs->source == RTS_INHERIT) metric = e->u.krt.metric; if (ea = ea_find(eattrs, EA_KRT_METRIC)) metric = ea->u.data; if (metric != 0) nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, metric); if (ea = ea_find(eattrs, EA_KRT_PREFSRC)) nl_add_attr_ipa(&r.h, sizeof(r), RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data); if (ea = ea_find(eattrs, EA_KRT_REALM)) nl_add_attr_u32(&r.h, sizeof(r), RTA_FLOW, ea->u.data); /* a->iface != NULL checked in krt_capable() for router and device routes */ switch (a->dest) { case RTD_ROUTER: r.r.rtm_type = RTN_UNICAST; nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index); nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw); break; case RTD_DEVICE: r.r.rtm_type = RTN_UNICAST; nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index); break; case RTD_BLACKHOLE: r.r.rtm_type = RTN_BLACKHOLE; break; case RTD_UNREACHABLE: r.r.rtm_type = RTN_UNREACHABLE; break; case RTD_PROHIBIT: r.r.rtm_type = RTN_PROHIBIT; break; case RTD_MULTIPATH: r.r.rtm_type = RTN_UNICAST; nl_add_multipath(&r.h, sizeof(r), a->nexthops); break; default: bug("krt_capable inconsistent with nl_send_route"); } return nl_exchange(&r.h); } void krt_do_notify(struct krt_proto *p, net *n, rte *new, rte *old, struct ea_list *eattrs) { int err = 0; /* * NULL for eattr of the old route is a little hack, but we don't * get proper eattrs for old in rt_notify() anyway. NULL means no * extended route attributes and therefore matches if the kernel * route has any of them. */ if (old) nl_send_route(p, old, NULL, 0); if (new) err = nl_send_route(p, new, eattrs, 1); if (err < 0) n->n.flags |= KRF_SYNC_ERROR; else n->n.flags &= ~KRF_SYNC_ERROR; } #define SKIP(ARG...) do { DBG("KRT: Ignoring route - " ARG); return; } while(0) static void nl_parse_route(struct nlmsghdr *h, int scan) { struct krt_proto *p; struct rtmsg *i; struct rtattr *a[RTA_CACHEINFO+1]; int new = h->nlmsg_type == RTM_NEWROUTE; ip_addr dst = IPA_NONE; u32 oif = ~0; int src; if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(RTM_RTA(i), a, sizeof(a))) return; if (i->rtm_family != BIRD_AF) return; if ((a[RTA_DST] && RTA_PAYLOAD(a[RTA_DST]) != sizeof(ip_addr)) || #ifdef IPV6 (a[RTA_IIF] && RTA_PAYLOAD(a[RTA_IIF]) != 4) || #endif (a[RTA_OIF] && RTA_PAYLOAD(a[RTA_OIF]) != 4) || (a[RTA_GATEWAY] && RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)) || (a[RTA_PRIORITY] && RTA_PAYLOAD(a[RTA_PRIORITY]) != 4) || (a[RTA_PREFSRC] && RTA_PAYLOAD(a[RTA_PREFSRC]) != sizeof(ip_addr)) || (a[RTA_FLOW] && RTA_PAYLOAD(a[RTA_OIF]) != 4)) { log(L_ERR "KRT: Malformed message received"); return; } if (a[RTA_DST]) { memcpy(&dst, RTA_DATA(a[RTA_DST]), sizeof(dst)); ipa_ntoh(dst); } if (a[RTA_OIF]) memcpy(&oif, RTA_DATA(a[RTA_OIF]), sizeof(oif)); p = nl_table_map[i->rtm_table]; /* Do we know this table? */ DBG("KRT: Got %I/%d, type=%d, oif=%d, table=%d, prid=%d, proto=%s\n", dst, i->rtm_dst_len, i->rtm_type, oif, i->rtm_table, i->rtm_protocol, p ? p->p.name : "(none)"); if (!p) SKIP("unknown table %d\n", i->rtm_table); #ifdef IPV6 if (a[RTA_IIF]) SKIP("IIF set\n"); #else if (i->rtm_tos != 0) /* We don't support TOS */ SKIP("TOS %02x\n", i->rtm_tos); #endif if (scan && !new) SKIP("RTM_DELROUTE in scan\n"); int c = ipa_classify_net(dst); if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK)) SKIP("strange class/scope\n"); // ignore rtm_scope, it is not a real scope // if (i->rtm_scope != RT_SCOPE_UNIVERSE) // SKIP("scope %u\n", i->rtm_scope); switch (i->rtm_protocol) { case RTPROT_UNSPEC: SKIP("proto unspec\n"); case RTPROT_REDIRECT: src = KRT_SRC_REDIRECT; break; case RTPROT_KERNEL: src = KRT_SRC_KERNEL; return; case RTPROT_BIRD: if (!scan) SKIP("echo\n"); src = KRT_SRC_BIRD; break; case RTPROT_BOOT: default: src = KRT_SRC_ALIEN; } net *net = net_get(p->p.table, dst, i->rtm_dst_len); rta ra = { .proto = &p->p, .source = RTS_INHERIT, .scope = SCOPE_UNIVERSE, .cast = RTC_UNICAST }; switch (i->rtm_type) { case RTN_UNICAST: if (a[RTA_MULTIPATH]) { ra.dest = RTD_MULTIPATH; ra.nexthops = nl_parse_multipath(p, a[RTA_MULTIPATH]); if (!ra.nexthops) { log(L_ERR "KRT: Received strange multipath route %I/%d", net->n.prefix, net->n.pxlen); return; } break; } ra.iface = if_find_by_index(oif); if (!ra.iface) { log(L_ERR "KRT: Received route %I/%d with unknown ifindex %u", net->n.prefix, net->n.pxlen, oif); return; } if (a[RTA_GATEWAY]) { neighbor *ng; ra.dest = RTD_ROUTER; memcpy(&ra.gw, RTA_DATA(a[RTA_GATEWAY]), sizeof(ra.gw)); ipa_ntoh(ra.gw); /* Silently skip strange 6to4 routes */ if (ipa_in_net(ra.gw, IPA_NONE, 96)) return; ng = neigh_find2(&p->p, &ra.gw, ra.iface, (i->rtm_flags & RTNH_F_ONLINK) ? NEF_ONLINK : 0); if (!ng || (ng->scope == SCOPE_HOST)) { log(L_ERR "KRT: Received route %I/%d with strange next-hop %I", net->n.prefix, net->n.pxlen, ra.gw); return; } } else { ra.dest = RTD_DEVICE; /* * In Linux IPv6, 'native' device routes have proto * RTPROT_BOOT and not RTPROT_KERNEL (which they have in * IPv4 and which is expected). We cannot distinguish * 'native' and user defined device routes, so we ignore all * such device routes and for consistency, we have the same * behavior in IPv4. Anyway, users should use RTPROT_STATIC * for their 'alien' routes. */ if (i->rtm_protocol == RTPROT_BOOT) src = KRT_SRC_KERNEL; } break; case RTN_BLACKHOLE: ra.dest = RTD_BLACKHOLE; break; case RTN_UNREACHABLE: ra.dest = RTD_UNREACHABLE; break; case RTN_PROHIBIT: ra.dest = RTD_PROHIBIT; break; /* FIXME: What about RTN_THROW? */ default: SKIP("type %d\n", i->rtm_type); return; } rte *e = rte_get_temp(&ra); e->net = net; e->u.krt.src = src; e->u.krt.proto = i->rtm_protocol; e->u.krt.type = i->rtm_type; if (a[RTA_PRIORITY]) memcpy(&e->u.krt.metric, RTA_DATA(a[RTA_PRIORITY]), sizeof(e->u.krt.metric)); else e->u.krt.metric = 0; if (a[RTA_PREFSRC]) { ip_addr ps; memcpy(&ps, RTA_DATA(a[RTA_PREFSRC]), sizeof(ps)); ipa_ntoh(ps); ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr)); ea->next = ra.eattrs; ra.eattrs = ea; ea->flags = EALF_SORTED; ea->count = 1; ea->attrs[0].id = EA_KRT_PREFSRC; ea->attrs[0].flags = 0; ea->attrs[0].type = EAF_TYPE_IP_ADDRESS; ea->attrs[0].u.ptr = alloca(sizeof(struct adata) + sizeof(ps)); ea->attrs[0].u.ptr->length = sizeof(ps); memcpy(ea->attrs[0].u.ptr->data, &ps, sizeof(ps)); } if (a[RTA_FLOW]) { ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr)); ea->next = ra.eattrs; ra.eattrs = ea; ea->flags = EALF_SORTED; ea->count = 1; ea->attrs[0].id = EA_KRT_REALM; ea->attrs[0].flags = 0; ea->attrs[0].type = EAF_TYPE_INT; memcpy(&ea->attrs[0].u.data, RTA_DATA(a[RTA_FLOW]), 4); } if (scan) krt_got_route(p, e); else krt_got_route_async(p, e, new); } void krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */ { struct nlmsghdr *h; nl_request_dump(RTM_GETROUTE); while (h = nl_get_scan()) if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE) nl_parse_route(h, 1); else log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type); } /* * Asynchronous Netlink interface */ static sock *nl_async_sk; /* BIRD socket for asynchronous notifications */ static byte *nl_async_rx_buffer; /* Receive buffer */ static void nl_async_msg(struct nlmsghdr *h) { switch (h->nlmsg_type) { case RTM_NEWROUTE: case RTM_DELROUTE: DBG("KRT: Received async route notification (%d)\n", h->nlmsg_type); nl_parse_route(h, 0); break; case RTM_NEWLINK: case RTM_DELLINK: DBG("KRT: Received async link notification (%d)\n", h->nlmsg_type); nl_parse_link(h, 0); break; case RTM_NEWADDR: case RTM_DELADDR: DBG("KRT: Received async address notification (%d)\n", h->nlmsg_type); nl_parse_addr(h); break; default: DBG("KRT: Received unknown async notification (%d)\n", h->nlmsg_type); } } static int nl_async_hook(sock *sk, int size UNUSED) { struct iovec iov = { nl_async_rx_buffer, NL_RX_SIZE }; struct sockaddr_nl sa; struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 }; struct nlmsghdr *h; int x; unsigned int len; x = recvmsg(sk->fd, &m, 0); if (x < 0) { if (errno == ENOBUFS) { /* * Netlink reports some packets have been thrown away. * One day we might react to it by asking for route table * scan in near future. */ return 1; /* More data are likely to be ready */ } else if (errno != EWOULDBLOCK) log(L_ERR "Netlink recvmsg: %m"); return 0; } if (sa.nl_pid) /* It isn't from the kernel */ { DBG("Non-kernel packet\n"); return 1; } h = (void *) nl_async_rx_buffer; len = x; if (m.msg_flags & MSG_TRUNC) { log(L_WARN "Netlink got truncated asynchronous message"); return 1; } while (NLMSG_OK(h, len)) { nl_async_msg(h); h = NLMSG_NEXT(h, len); } if (len) log(L_WARN "nl_async_hook: Found packet remnant of size %d", len); return 1; } static void nl_open_async(void) { sock *sk; struct sockaddr_nl sa; int fd; static int nl_open_tried = 0; if (nl_open_tried) return; nl_open_tried = 1; DBG("KRT: Opening async netlink socket\n"); fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (fd < 0) { log(L_ERR "Unable to open asynchronous rtnetlink socket: %m"); return; } bzero(&sa, sizeof(sa)); sa.nl_family = AF_NETLINK; #ifdef IPV6 sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV6_IFADDR | RTMGRP_IPV6_ROUTE; #else sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV4_ROUTE; #endif if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) { log(L_ERR "Unable to bind asynchronous rtnetlink socket: %m"); return; } sk = nl_async_sk = sk_new(krt_pool); sk->type = SK_MAGIC; sk->rx_hook = nl_async_hook; sk->fd = fd; if (sk_open(sk)) bug("Netlink: sk_open failed"); if (!nl_async_rx_buffer) nl_async_rx_buffer = xmalloc(NL_RX_SIZE); } /* * Interface to the UNIX krt module */ static u8 nl_cf_table[(NL_NUM_TABLES+7) / 8]; void krt_sys_start(struct krt_proto *p, int first) { nl_table_map[KRT_CF->sys.table_id] = p; if (first) { nl_open(); nl_open_async(); } } void krt_sys_shutdown(struct krt_proto *p UNUSED, int last UNUSED) { } int krt_sys_reconfigure(struct krt_proto *p UNUSED, struct krt_config *n, struct krt_config *o) { return n->sys.table_id == o->sys.table_id; } void krt_sys_preconfig(struct config *c UNUSED) { bzero(&nl_cf_table, sizeof(nl_cf_table)); } void krt_sys_postconfig(struct krt_config *x) { int id = x->sys.table_id; if (nl_cf_table[id/8] & (1 << (id%8))) cf_error("Multiple kernel syncers defined for table #%d", id); nl_cf_table[id/8] |= (1 << (id%8)); } void krt_sys_init_config(struct krt_config *cf) { cf->sys.table_id = RT_TABLE_MAIN; } void krt_sys_copy_config(struct krt_config *d, struct krt_config *s) { d->sys.table_id = s->sys.table_id; } void kif_sys_start(struct kif_proto *p UNUSED) { nl_open(); nl_open_async(); } void kif_sys_shutdown(struct kif_proto *p UNUSED) { }