diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c index 972701369d13..e09ad3d47382 100644 --- a/sys/netinet/if_ether.c +++ b/sys/netinet/if_ether.c @@ -1,1519 +1,1519 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1988, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)if_ether.c 8.1 (Berkeley) 6/10/93 */ /* * Ethernet address resolution protocol. * TODO: * add "inuse/lock" bit (or ref. count) along with valid bit */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #endif #include #define SIN(s) ((const struct sockaddr_in *)(s)) static struct timeval arp_lastlog; static int arp_curpps; static int arp_maxpps = 1; /* Simple ARP state machine */ enum arp_llinfo_state { ARP_LLINFO_INCOMPLETE = 0, /* No LLE data */ ARP_LLINFO_REACHABLE, /* LLE is valid */ ARP_LLINFO_VERIFY, /* LLE is valid, need refresh */ ARP_LLINFO_DELETED, /* LLE is deleted */ }; SYSCTL_DECL(_net_link_ether); static SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, ""); static SYSCTL_NODE(_net_link_ether, PF_ARP, arp, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, ""); /* timer values */ VNET_DEFINE_STATIC(int, arpt_keep) = (20*60); /* once resolved, good for 20 * minutes */ VNET_DEFINE_STATIC(int, arp_maxtries) = 5; VNET_DEFINE_STATIC(int, arp_proxyall) = 0; VNET_DEFINE_STATIC(int, arpt_down) = 20; /* keep incomplete entries for * 20 seconds */ VNET_DEFINE_STATIC(int, arpt_rexmit) = 1; /* retransmit arp entries, sec*/ VNET_PCPUSTAT_DEFINE(struct arpstat, arpstat); /* ARP statistics, see if_arp.h */ VNET_PCPUSTAT_SYSINIT(arpstat); #ifdef VIMAGE VNET_PCPUSTAT_SYSUNINIT(arpstat); #endif /* VIMAGE */ -VNET_DEFINE_STATIC(int, arp_maxhold) = 1; +VNET_DEFINE_STATIC(int, arp_maxhold) = 16; #define V_arpt_keep VNET(arpt_keep) #define V_arpt_down VNET(arpt_down) #define V_arpt_rexmit VNET(arpt_rexmit) #define V_arp_maxtries VNET(arp_maxtries) #define V_arp_proxyall VNET(arp_proxyall) #define V_arp_maxhold VNET(arp_maxhold) SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(arpt_keep), 0, "ARP entry lifetime in seconds"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(arp_maxtries), 0, "ARP resolution attempts before returning error"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(arp_proxyall), 0, "Enable proxy ARP for all suitable requests"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, wait, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(arpt_down), 0, "Incomplete ARP entry lifetime in seconds"); SYSCTL_VNET_PCPUSTAT(_net_link_ether_arp, OID_AUTO, stats, struct arpstat, arpstat, "ARP statistics (struct arpstat, net/if_arp.h)"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxhold, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(arp_maxhold), 0, "Number of packets to hold per ARP entry"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_log_per_second, CTLFLAG_RW, &arp_maxpps, 0, "Maximum number of remotely triggered ARP messages that can be " "logged per second"); /* * Due to the exponential backoff algorithm used for the interval between GARP * retransmissions, the maximum number of retransmissions is limited for * sanity. This limit corresponds to a maximum interval between retransmissions * of 2^16 seconds ~= 18 hours. * * Making this limit more dynamic is more complicated than worthwhile, * especially since sending out GARPs spaced days apart would be of little * use. A maximum dynamic limit would look something like: * * const int max = fls(INT_MAX / hz) - 1; */ #define MAX_GARP_RETRANSMITS 16 static int sysctl_garp_rexmit(SYSCTL_HANDLER_ARGS); static int garp_rexmit_count = 0; /* GARP retransmission setting. */ SYSCTL_PROC(_net_link_ether_inet, OID_AUTO, garp_rexmit_count, CTLTYPE_INT|CTLFLAG_RW|CTLFLAG_MPSAFE, &garp_rexmit_count, 0, sysctl_garp_rexmit, "I", "Number of times to retransmit GARP packets;" " 0 to disable, maximum of 16"); VNET_DEFINE_STATIC(int, arp_log_level) = LOG_INFO; /* Min. log(9) level. */ #define V_arp_log_level VNET(arp_log_level) SYSCTL_INT(_net_link_ether_arp, OID_AUTO, log_level, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(arp_log_level), 0, "Minimum log(9) level for recording rate limited arp log messages. " "The higher will be log more (emerg=0, info=6 (default), debug=7)."); #define ARP_LOG(pri, ...) do { \ if ((pri) <= V_arp_log_level && \ ppsratecheck(&arp_lastlog, &arp_curpps, arp_maxpps)) \ log((pri), "arp: " __VA_ARGS__); \ } while (0) static void arpintr(struct mbuf *); static void arptimer(void *); #ifdef INET static void in_arpinput(struct mbuf *); #endif static void arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr, struct ifnet *ifp, int bridged, struct llentry *la); static void arp_mark_lle_reachable(struct llentry *la); static void arp_iflladdr(void *arg __unused, struct ifnet *ifp); static eventhandler_tag iflladdr_tag; static const struct netisr_handler arp_nh = { .nh_name = "arp", .nh_handler = arpintr, .nh_proto = NETISR_ARP, .nh_policy = NETISR_POLICY_SOURCE, }; /* * Timeout routine. Age arp_tab entries periodically. */ static void arptimer(void *arg) { struct llentry *lle = (struct llentry *)arg; struct ifnet *ifp; int r_skip_req; if (lle->la_flags & LLE_STATIC) { return; } LLE_WLOCK(lle); if (callout_pending(&lle->lle_timer)) { /* * Here we are a bit odd here in the treatment of * active/pending. If the pending bit is set, it got * rescheduled before I ran. The active * bit we ignore, since if it was stopped * in ll_tablefree() and was currently running * it would have return 0 so the code would * not have deleted it since the callout could * not be stopped so we want to go through * with the delete here now. If the callout * was restarted, the pending bit will be back on and * we just want to bail since the callout_reset would * return 1 and our reference would have been removed * by arpresolve() below. */ LLE_WUNLOCK(lle); return; } ifp = lle->lle_tbl->llt_ifp; CURVNET_SET(ifp->if_vnet); switch (lle->ln_state) { case ARP_LLINFO_REACHABLE: /* * Expiration time is approaching. * Let's try to refresh entry if it is still * in use. * * Set r_skip_req to get feedback from * fast path. Change state and re-schedule * ourselves. */ LLE_REQ_LOCK(lle); lle->r_skip_req = 1; LLE_REQ_UNLOCK(lle); lle->ln_state = ARP_LLINFO_VERIFY; callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit); LLE_WUNLOCK(lle); CURVNET_RESTORE(); return; case ARP_LLINFO_VERIFY: LLE_REQ_LOCK(lle); r_skip_req = lle->r_skip_req; LLE_REQ_UNLOCK(lle); if (r_skip_req == 0 && lle->la_preempt > 0) { /* Entry was used, issue refresh request */ struct epoch_tracker et; struct in_addr dst; dst = lle->r_l3addr.addr4; lle->la_preempt--; callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit); LLE_WUNLOCK(lle); NET_EPOCH_ENTER(et); arprequest(ifp, NULL, &dst, NULL); NET_EPOCH_EXIT(et); CURVNET_RESTORE(); return; } /* Nothing happened. Reschedule if not too late */ if (lle->la_expire > time_uptime) { callout_schedule(&lle->lle_timer, hz * V_arpt_rexmit); LLE_WUNLOCK(lle); CURVNET_RESTORE(); return; } break; case ARP_LLINFO_INCOMPLETE: case ARP_LLINFO_DELETED: break; } if ((lle->la_flags & LLE_DELETED) == 0) { int evt; if (lle->la_flags & LLE_VALID) evt = LLENTRY_EXPIRED; else evt = LLENTRY_TIMEDOUT; EVENTHANDLER_INVOKE(lle_event, lle, evt); } callout_stop(&lle->lle_timer); /* XXX: LOR avoidance. We still have ref on lle. */ LLE_WUNLOCK(lle); IF_AFDATA_LOCK(ifp); LLE_WLOCK(lle); /* Guard against race with other llentry_free(). */ if (lle->la_flags & LLE_LINKED) { LLE_REMREF(lle); lltable_unlink_entry(lle->lle_tbl, lle); } IF_AFDATA_UNLOCK(ifp); size_t pkts_dropped = llentry_free(lle); ARPSTAT_ADD(dropped, pkts_dropped); ARPSTAT_INC(timeouts); CURVNET_RESTORE(); } /* * Stores link-layer header for @ifp in format suitable for if_output() * into buffer @buf. Resulting header length is stored in @bufsize. * * Returns 0 on success. */ static int arp_fillheader(struct ifnet *ifp, struct arphdr *ah, int bcast, u_char *buf, size_t *bufsize) { struct if_encap_req ereq; int error; bzero(buf, *bufsize); bzero(&ereq, sizeof(ereq)); ereq.buf = buf; ereq.bufsize = *bufsize; ereq.rtype = IFENCAP_LL; ereq.family = AF_ARP; ereq.lladdr = ar_tha(ah); ereq.hdata = (u_char *)ah; if (bcast) ereq.flags = IFENCAP_FLAG_BROADCAST; error = ifp->if_requestencap(ifp, &ereq); if (error == 0) *bufsize = ereq.bufsize; return (error); } /* * Broadcast an ARP request. Caller specifies: * - arp header source ip address * - arp header target ip address * - arp header source ethernet address */ static int arprequest_internal(struct ifnet *ifp, const struct in_addr *sip, const struct in_addr *tip, u_char *enaddr) { struct mbuf *m; struct arphdr *ah; struct sockaddr sa; u_char *carpaddr = NULL; uint8_t linkhdr[LLE_MAX_LINKHDR]; size_t linkhdrsize; struct route ro; int error; NET_EPOCH_ASSERT(); if (sip == NULL) { /* * The caller did not supply a source address, try to find * a compatible one among those assigned to this interface. */ struct ifaddr *ifa; CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET) continue; if (ifa->ifa_carp) { if ((*carp_iamatch_p)(ifa, &carpaddr) == 0) continue; sip = &IA_SIN(ifa)->sin_addr; } else { carpaddr = NULL; sip = &IA_SIN(ifa)->sin_addr; } if (0 == ((sip->s_addr ^ tip->s_addr) & IA_MASKSIN(ifa)->sin_addr.s_addr)) break; /* found it. */ } if (sip == NULL) { printf("%s: cannot find matching address\n", __func__); return (EADDRNOTAVAIL); } } if (enaddr == NULL) enaddr = carpaddr ? carpaddr : (u_char *)IF_LLADDR(ifp); if ((m = m_gethdr(M_NOWAIT, MT_DATA)) == NULL) return (ENOMEM); m->m_len = sizeof(*ah) + 2 * sizeof(struct in_addr) + 2 * ifp->if_addrlen; m->m_pkthdr.len = m->m_len; M_ALIGN(m, m->m_len); ah = mtod(m, struct arphdr *); bzero((caddr_t)ah, m->m_len); #ifdef MAC mac_netinet_arp_send(ifp, m); #endif ah->ar_pro = htons(ETHERTYPE_IP); ah->ar_hln = ifp->if_addrlen; /* hardware address length */ ah->ar_pln = sizeof(struct in_addr); /* protocol address length */ ah->ar_op = htons(ARPOP_REQUEST); bcopy(enaddr, ar_sha(ah), ah->ar_hln); bcopy(sip, ar_spa(ah), ah->ar_pln); bcopy(tip, ar_tpa(ah), ah->ar_pln); sa.sa_family = AF_ARP; sa.sa_len = 2; /* Calculate link header for sending frame */ bzero(&ro, sizeof(ro)); linkhdrsize = sizeof(linkhdr); error = arp_fillheader(ifp, ah, 1, linkhdr, &linkhdrsize); if (error != 0 && error != EAFNOSUPPORT) { ARP_LOG(LOG_ERR, "Failed to calculate ARP header on %s: %d\n", if_name(ifp), error); return (error); } ro.ro_prepend = linkhdr; ro.ro_plen = linkhdrsize; ro.ro_flags = 0; m->m_flags |= M_BCAST; m_clrprotoflags(m); /* Avoid confusing lower layers. */ error = (*ifp->if_output)(ifp, m, &sa, &ro); ARPSTAT_INC(txrequests); if (error) { ARPSTAT_INC(txerrors); ARP_LOG(LOG_DEBUG, "Failed to send ARP packet on %s: %d\n", if_name(ifp), error); } return (error); } void arprequest(struct ifnet *ifp, const struct in_addr *sip, const struct in_addr *tip, u_char *enaddr) { (void) arprequest_internal(ifp, sip, tip, enaddr); } /* * Resolve an IP address into an ethernet address - heavy version. * Used internally by arpresolve(). * We have already checked that we can't use an existing lle without * modification so we have to acquire an LLE_EXCLUSIVE lle lock. * * On success, desten and pflags are filled in and the function returns 0; * If the packet must be held pending resolution, we return EWOULDBLOCK * On other errors, we return the corresponding error code. * Note that m_freem() handles NULL. */ static int arpresolve_full(struct ifnet *ifp, int is_gw, int flags, struct mbuf *m, const struct sockaddr *dst, u_char *desten, uint32_t *pflags, struct llentry **plle) { struct llentry *la = NULL, *la_tmp; struct mbuf *curr = NULL; struct mbuf *next = NULL; int error, renew; char *lladdr; int ll_len; NET_EPOCH_ASSERT(); if (pflags != NULL) *pflags = 0; if (plle != NULL) *plle = NULL; if ((flags & LLE_CREATE) == 0) la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); if (la == NULL && (ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) { la = lltable_alloc_entry(LLTABLE(ifp), 0, dst); if (la == NULL) { char addrbuf[INET_ADDRSTRLEN]; log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s on %s\n", inet_ntoa_r(SIN(dst)->sin_addr, addrbuf), if_name(ifp)); m_freem(m); return (EINVAL); } IF_AFDATA_WLOCK(ifp); LLE_WLOCK(la); la_tmp = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); /* Prefer ANY existing lle over newly-created one */ if (la_tmp == NULL) lltable_link_entry(LLTABLE(ifp), la); IF_AFDATA_WUNLOCK(ifp); if (la_tmp != NULL) { lltable_free_entry(LLTABLE(ifp), la); la = la_tmp; } } if (la == NULL) { m_freem(m); return (EINVAL); } if ((la->la_flags & LLE_VALID) && ((la->la_flags & LLE_STATIC) || la->la_expire > time_uptime)) { if (flags & LLE_ADDRONLY) { lladdr = la->ll_addr; ll_len = ifp->if_addrlen; } else { lladdr = la->r_linkdata; ll_len = la->r_hdrlen; } bcopy(lladdr, desten, ll_len); /* Notify LLE code that the entry was used by datapath */ llentry_mark_used(la); if (pflags != NULL) *pflags = la->la_flags & (LLE_VALID|LLE_IFADDR); if (plle) { LLE_ADDREF(la); *plle = la; } LLE_WUNLOCK(la); return (0); } renew = (la->la_asked == 0 || la->la_expire != time_uptime); /* * There is an arptab entry, but no ethernet address * response yet. Add the mbuf to the list, dropping * the oldest packet if we have exceeded the system * setting. */ if (m != NULL) { if (la->la_numheld >= V_arp_maxhold) { if (la->la_hold != NULL) { next = la->la_hold->m_nextpkt; m_freem(la->la_hold); la->la_hold = next; la->la_numheld--; ARPSTAT_INC(dropped); } } if (la->la_hold != NULL) { curr = la->la_hold; while (curr->m_nextpkt != NULL) curr = curr->m_nextpkt; curr->m_nextpkt = m; } else la->la_hold = m; la->la_numheld++; } /* * Return EWOULDBLOCK if we have tried less than arp_maxtries. It * will be masked by ether_output(). Return EHOSTDOWN/EHOSTUNREACH * if we have already sent arp_maxtries ARP requests. Retransmit the * ARP request, but not faster than one request per second. */ if (la->la_asked < V_arp_maxtries) error = EWOULDBLOCK; /* First request. */ else error = is_gw != 0 ? EHOSTUNREACH : EHOSTDOWN; if (renew) { int canceled, e; LLE_ADDREF(la); la->la_expire = time_uptime; canceled = callout_reset(&la->lle_timer, hz * V_arpt_down, arptimer, la); if (canceled) LLE_REMREF(la); la->la_asked++; LLE_WUNLOCK(la); e = arprequest_internal(ifp, NULL, &SIN(dst)->sin_addr, NULL); /* * Only overwrite 'error' in case of error; in case of success * the proper return value was already set above. */ if (e != 0) return (e); return (error); } LLE_WUNLOCK(la); return (error); } /* * Lookups link header based on an IP address. * On input: * ifp is the interface we use * is_gw != 0 if @dst represents gateway to some destination * m is the mbuf. May be NULL if we don't have a packet. * dst is the next hop, * desten is the storage to put LL header. * flags returns subset of lle flags: LLE_VALID | LLE_IFADDR * * On success, full/partial link header and flags are filled in and * the function returns 0. * If the packet must be held pending resolution, we return EWOULDBLOCK * On other errors, we return the corresponding error code. * Note that m_freem() handles NULL. */ int arpresolve(struct ifnet *ifp, int is_gw, struct mbuf *m, const struct sockaddr *dst, u_char *desten, uint32_t *pflags, struct llentry **plle) { struct llentry *la = NULL; NET_EPOCH_ASSERT(); if (pflags != NULL) *pflags = 0; if (plle != NULL) *plle = NULL; if (m != NULL) { if (m->m_flags & M_BCAST) { /* broadcast */ (void)memcpy(desten, ifp->if_broadcastaddr, ifp->if_addrlen); return (0); } if (m->m_flags & M_MCAST) { /* multicast */ ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); return (0); } } la = lla_lookup(LLTABLE(ifp), plle ? LLE_EXCLUSIVE : LLE_UNLOCKED, dst); if (la != NULL && (la->r_flags & RLLE_VALID) != 0) { /* Entry found, let's copy lle info */ bcopy(la->r_linkdata, desten, la->r_hdrlen); if (pflags != NULL) *pflags = LLE_VALID | (la->r_flags & RLLE_IFADDR); /* Notify the LLE handling code that the entry was used. */ llentry_mark_used(la); if (plle) { LLE_ADDREF(la); *plle = la; LLE_WUNLOCK(la); } return (0); } if (plle && la) LLE_WUNLOCK(la); return (arpresolve_full(ifp, is_gw, la == NULL ? LLE_CREATE : 0, m, dst, desten, pflags, plle)); } /* * Common length and type checks are done here, * then the protocol-specific routine is called. */ static void arpintr(struct mbuf *m) { struct arphdr *ar; struct ifnet *ifp; char *layer; int hlen; ifp = m->m_pkthdr.rcvif; if (m->m_len < sizeof(struct arphdr) && ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { ARP_LOG(LOG_NOTICE, "packet with short header received on %s\n", if_name(ifp)); return; } ar = mtod(m, struct arphdr *); /* Check if length is sufficient */ if (m->m_len < arphdr_len(ar)) { m = m_pullup(m, arphdr_len(ar)); if (m == NULL) { ARP_LOG(LOG_NOTICE, "short packet received on %s\n", if_name(ifp)); return; } ar = mtod(m, struct arphdr *); } hlen = 0; layer = ""; switch (ntohs(ar->ar_hrd)) { case ARPHRD_ETHER: hlen = ETHER_ADDR_LEN; /* RFC 826 */ layer = "ethernet"; break; case ARPHRD_INFINIBAND: hlen = 20; /* RFC 4391, INFINIBAND_ALEN */ layer = "infiniband"; break; case ARPHRD_IEEE1394: hlen = 0; /* SHALL be 16 */ /* RFC 2734 */ layer = "firewire"; /* * Restrict too long hardware addresses. * Currently we are capable of handling 20-byte * addresses ( sizeof(lle->ll_addr) ) */ if (ar->ar_hln >= 20) hlen = 16; break; default: ARP_LOG(LOG_NOTICE, "packet with unknown hardware format 0x%02d received on " "%s\n", ntohs(ar->ar_hrd), if_name(ifp)); m_freem(m); return; } if (hlen != 0 && hlen != ar->ar_hln) { ARP_LOG(LOG_NOTICE, "packet with invalid %s address length %d received on %s\n", layer, ar->ar_hln, if_name(ifp)); m_freem(m); return; } ARPSTAT_INC(received); switch (ntohs(ar->ar_pro)) { #ifdef INET case ETHERTYPE_IP: in_arpinput(m); return; #endif } m_freem(m); } #ifdef INET /* * ARP for Internet protocols on 10 Mb/s Ethernet. * Algorithm is that given in RFC 826. * In addition, a sanity check is performed on the sender * protocol address, to catch impersonators. * We no longer handle negotiations for use of trailer protocol: * Formerly, ARP replied for protocol type ETHERTYPE_TRAIL sent * along with IP replies if we wanted trailers sent to us, * and also sent them in response to IP replies. * This allowed either end to announce the desire to receive * trailer packets. * We no longer reply to requests for ETHERTYPE_TRAIL protocol either, * but formerly didn't normally send requests. */ static int log_arp_wrong_iface = 1; static int log_arp_movements = 1; static int log_arp_permanent_modify = 1; static int allow_multicast = 0; SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_wrong_iface, CTLFLAG_RW, &log_arp_wrong_iface, 0, "log arp packets arriving on the wrong interface"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_movements, CTLFLAG_RW, &log_arp_movements, 0, "log arp replies from MACs different than the one in the cache"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, log_arp_permanent_modify, CTLFLAG_RW, &log_arp_permanent_modify, 0, "log arp replies from MACs different than the one in the permanent arp entry"); SYSCTL_INT(_net_link_ether_inet, OID_AUTO, allow_multicast, CTLFLAG_RW, &allow_multicast, 0, "accept multicast addresses"); static void in_arpinput(struct mbuf *m) { struct rm_priotracker in_ifa_tracker; struct arphdr *ah; struct ifnet *ifp = m->m_pkthdr.rcvif; struct llentry *la = NULL, *la_tmp; struct ifaddr *ifa; struct in_ifaddr *ia; struct sockaddr sa; struct in_addr isaddr, itaddr, myaddr; u_int8_t *enaddr = NULL; int op; int bridged = 0, is_bridge = 0; int carped; struct sockaddr_in sin; struct sockaddr *dst; struct nhop_object *nh; uint8_t linkhdr[LLE_MAX_LINKHDR]; struct route ro; size_t linkhdrsize; int lladdr_off; int error; char addrbuf[INET_ADDRSTRLEN]; NET_EPOCH_ASSERT(); sin.sin_len = sizeof(struct sockaddr_in); sin.sin_family = AF_INET; sin.sin_addr.s_addr = 0; if (ifp->if_bridge) bridged = 1; if (ifp->if_type == IFT_BRIDGE) is_bridge = 1; /* * We already have checked that mbuf contains enough contiguous data * to hold entire arp message according to the arp header. */ ah = mtod(m, struct arphdr *); /* * ARP is only for IPv4 so we can reject packets with * a protocol length not equal to an IPv4 address. */ if (ah->ar_pln != sizeof(struct in_addr)) { ARP_LOG(LOG_NOTICE, "requested protocol length != %zu\n", sizeof(struct in_addr)); goto drop; } if (allow_multicast == 0 && ETHER_IS_MULTICAST(ar_sha(ah))) { ARP_LOG(LOG_NOTICE, "%*D is multicast\n", ifp->if_addrlen, (u_char *)ar_sha(ah), ":"); goto drop; } op = ntohs(ah->ar_op); (void)memcpy(&isaddr, ar_spa(ah), sizeof (isaddr)); (void)memcpy(&itaddr, ar_tpa(ah), sizeof (itaddr)); if (op == ARPOP_REPLY) ARPSTAT_INC(rxreplies); /* * For a bridge, we want to check the address irrespective * of the receive interface. (This will change slightly * when we have clusters of interfaces). */ IN_IFADDR_RLOCK(&in_ifa_tracker); LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) || ia->ia_ifp == ifp) && itaddr.s_addr == ia->ia_addr.sin_addr.s_addr && (ia->ia_ifa.ifa_carp == NULL || (*carp_iamatch_p)(&ia->ia_ifa, &enaddr))) { ifa_ref(&ia->ia_ifa); IN_IFADDR_RUNLOCK(&in_ifa_tracker); goto match; } } LIST_FOREACH(ia, INADDR_HASH(isaddr.s_addr), ia_hash) if (((bridged && ia->ia_ifp->if_bridge == ifp->if_bridge) || ia->ia_ifp == ifp) && isaddr.s_addr == ia->ia_addr.sin_addr.s_addr) { ifa_ref(&ia->ia_ifa); IN_IFADDR_RUNLOCK(&in_ifa_tracker); goto match; } #define BDG_MEMBER_MATCHES_ARP(addr, ifp, ia) \ (ia->ia_ifp->if_bridge == ifp->if_softc && \ !bcmp(IF_LLADDR(ia->ia_ifp), IF_LLADDR(ifp), ifp->if_addrlen) && \ addr == ia->ia_addr.sin_addr.s_addr) /* * Check the case when bridge shares its MAC address with * some of its children, so packets are claimed by bridge * itself (bridge_input() does it first), but they are really * meant to be destined to the bridge member. */ if (is_bridge) { LIST_FOREACH(ia, INADDR_HASH(itaddr.s_addr), ia_hash) { if (BDG_MEMBER_MATCHES_ARP(itaddr.s_addr, ifp, ia)) { ifa_ref(&ia->ia_ifa); ifp = ia->ia_ifp; IN_IFADDR_RUNLOCK(&in_ifa_tracker); goto match; } } } #undef BDG_MEMBER_MATCHES_ARP IN_IFADDR_RUNLOCK(&in_ifa_tracker); /* * No match, use the first inet address on the receive interface * as a dummy address for the rest of the function. */ CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) if (ifa->ifa_addr->sa_family == AF_INET && (ifa->ifa_carp == NULL || (*carp_iamatch_p)(ifa, &enaddr))) { ia = ifatoia(ifa); ifa_ref(ifa); goto match; } /* * If bridging, fall back to using any inet address. */ IN_IFADDR_RLOCK(&in_ifa_tracker); if (!bridged || (ia = CK_STAILQ_FIRST(&V_in_ifaddrhead)) == NULL) { IN_IFADDR_RUNLOCK(&in_ifa_tracker); goto drop; } ifa_ref(&ia->ia_ifa); IN_IFADDR_RUNLOCK(&in_ifa_tracker); match: if (!enaddr) enaddr = (u_int8_t *)IF_LLADDR(ifp); carped = (ia->ia_ifa.ifa_carp != NULL); myaddr = ia->ia_addr.sin_addr; ifa_free(&ia->ia_ifa); if (!bcmp(ar_sha(ah), enaddr, ifp->if_addrlen)) goto drop; /* it's from me, ignore it. */ if (!bcmp(ar_sha(ah), ifp->if_broadcastaddr, ifp->if_addrlen)) { ARP_LOG(LOG_NOTICE, "link address is broadcast for IP address " "%s!\n", inet_ntoa_r(isaddr, addrbuf)); goto drop; } if (ifp->if_addrlen != ah->ar_hln) { ARP_LOG(LOG_WARNING, "from %*D: addr len: new %d, " "i/f %d (ignored)\n", ifp->if_addrlen, (u_char *) ar_sha(ah), ":", ah->ar_hln, ifp->if_addrlen); goto drop; } /* * Warn if another host is using the same IP address, but only if the * IP address isn't 0.0.0.0, which is used for DHCP only, in which * case we suppress the warning to avoid false positive complaints of * potential misconfiguration. */ if (!bridged && !carped && isaddr.s_addr == myaddr.s_addr && myaddr.s_addr != 0) { ARP_LOG(LOG_ERR, "%*D is using my IP address %s on %s!\n", ifp->if_addrlen, (u_char *)ar_sha(ah), ":", inet_ntoa_r(isaddr, addrbuf), ifp->if_xname); itaddr = myaddr; ARPSTAT_INC(dupips); goto reply; } if (ifp->if_flags & IFF_STATICARP) goto reply; bzero(&sin, sizeof(sin)); sin.sin_len = sizeof(struct sockaddr_in); sin.sin_family = AF_INET; sin.sin_addr = isaddr; dst = (struct sockaddr *)&sin; la = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); if (la != NULL) arp_check_update_lle(ah, isaddr, ifp, bridged, la); else if (itaddr.s_addr == myaddr.s_addr) { /* * Request/reply to our address, but no lle exists yet. * Calculate full link prepend to use in lle. */ linkhdrsize = sizeof(linkhdr); if (lltable_calc_llheader(ifp, AF_INET, ar_sha(ah), linkhdr, &linkhdrsize, &lladdr_off) != 0) goto reply; /* Allocate new entry */ la = lltable_alloc_entry(LLTABLE(ifp), 0, dst); if (la == NULL) { /* * lle creation may fail if source address belongs * to non-directly connected subnet. However, we * will try to answer the request instead of dropping * frame. */ goto reply; } lltable_set_entry_addr(ifp, la, linkhdr, linkhdrsize, lladdr_off); IF_AFDATA_WLOCK(ifp); LLE_WLOCK(la); la_tmp = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); /* * Check if lle still does not exists. * If it does, that means that we either * 1) have configured it explicitly, via * 1a) 'arp -s' static entry or * 1b) interface address static record * or * 2) it was the result of sending first packet to-host * or * 3) it was another arp reply packet we handled in * different thread. * * In all cases except 3) we definitely need to prefer * existing lle. For the sake of simplicity, prefer any * existing lle over newly-create one. */ if (la_tmp == NULL) lltable_link_entry(LLTABLE(ifp), la); IF_AFDATA_WUNLOCK(ifp); if (la_tmp == NULL) { arp_mark_lle_reachable(la); LLE_WUNLOCK(la); } else { /* Free newly-create entry and handle packet */ lltable_free_entry(LLTABLE(ifp), la); la = la_tmp; la_tmp = NULL; arp_check_update_lle(ah, isaddr, ifp, bridged, la); /* arp_check_update_lle() returns @la unlocked */ } la = NULL; } reply: if (op != ARPOP_REQUEST) goto drop; ARPSTAT_INC(rxrequests); if (itaddr.s_addr == myaddr.s_addr) { /* Shortcut.. the receiving interface is the target. */ (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln); } else { /* * Destination address is not ours. Check if * proxyarp entry exists or proxyarp is turned on globally. */ struct llentry *lle; sin.sin_addr = itaddr; lle = lla_lookup(LLTABLE(ifp), 0, (struct sockaddr *)&sin); if ((lle != NULL) && (lle->la_flags & LLE_PUB)) { (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); (void)memcpy(ar_sha(ah), lle->ll_addr, ah->ar_hln); LLE_RUNLOCK(lle); } else { if (lle != NULL) LLE_RUNLOCK(lle); if (!V_arp_proxyall) goto drop; NET_EPOCH_ASSERT(); nh = fib4_lookup(ifp->if_fib, itaddr, 0, 0, 0); if (nh == NULL) goto drop; /* * Don't send proxies for nodes on the same interface * as this one came out of, or we'll get into a fight * over who claims what Ether address. */ if (nh->nh_ifp == ifp) goto drop; (void)memcpy(ar_tha(ah), ar_sha(ah), ah->ar_hln); (void)memcpy(ar_sha(ah), enaddr, ah->ar_hln); /* * Also check that the node which sent the ARP packet * is on the interface we expect it to be on. This * avoids ARP chaos if an interface is connected to the * wrong network. */ nh = fib4_lookup(ifp->if_fib, isaddr, 0, 0, 0); if (nh == NULL) goto drop; if (nh->nh_ifp != ifp) { ARP_LOG(LOG_INFO, "proxy: ignoring request" " from %s via %s\n", inet_ntoa_r(isaddr, addrbuf), ifp->if_xname); goto drop; } #ifdef DEBUG_PROXY printf("arp: proxying for %s\n", inet_ntoa_r(itaddr, addrbuf)); #endif } } if (itaddr.s_addr == myaddr.s_addr && IN_LINKLOCAL(ntohl(itaddr.s_addr))) { /* RFC 3927 link-local IPv4; always reply by broadcast. */ #ifdef DEBUG_LINKLOCAL printf("arp: sending reply for link-local addr %s\n", inet_ntoa_r(itaddr, addrbuf)); #endif m->m_flags |= M_BCAST; m->m_flags &= ~M_MCAST; } else { /* default behaviour; never reply by broadcast. */ m->m_flags &= ~(M_BCAST|M_MCAST); } (void)memcpy(ar_tpa(ah), ar_spa(ah), ah->ar_pln); (void)memcpy(ar_spa(ah), &itaddr, ah->ar_pln); ah->ar_op = htons(ARPOP_REPLY); ah->ar_pro = htons(ETHERTYPE_IP); /* let's be sure! */ m->m_len = sizeof(*ah) + (2 * ah->ar_pln) + (2 * ah->ar_hln); m->m_pkthdr.len = m->m_len; m->m_pkthdr.rcvif = NULL; sa.sa_family = AF_ARP; sa.sa_len = 2; /* Calculate link header for sending frame */ bzero(&ro, sizeof(ro)); linkhdrsize = sizeof(linkhdr); error = arp_fillheader(ifp, ah, 0, linkhdr, &linkhdrsize); /* * arp_fillheader() may fail due to lack of support inside encap request * routing. This is not necessary an error, AF_ARP can/should be handled * by if_output(). */ if (error != 0 && error != EAFNOSUPPORT) { ARP_LOG(LOG_ERR, "Failed to calculate ARP header on %s: %d\n", if_name(ifp), error); return; } ro.ro_prepend = linkhdr; ro.ro_plen = linkhdrsize; ro.ro_flags = 0; m_clrprotoflags(m); /* Avoid confusing lower layers. */ (*ifp->if_output)(ifp, m, &sa, &ro); ARPSTAT_INC(txreplies); return; drop: m_freem(m); } #endif /* * Checks received arp data against existing @la. * Updates lle state/performs notification if necessary. */ static void arp_check_update_lle(struct arphdr *ah, struct in_addr isaddr, struct ifnet *ifp, int bridged, struct llentry *la) { struct sockaddr sa; struct mbuf *m_hold, *m_hold_next; uint8_t linkhdr[LLE_MAX_LINKHDR]; size_t linkhdrsize; int lladdr_off; char addrbuf[INET_ADDRSTRLEN]; LLE_WLOCK_ASSERT(la); /* the following is not an error when doing bridging */ if (!bridged && la->lle_tbl->llt_ifp != ifp) { if (log_arp_wrong_iface) ARP_LOG(LOG_WARNING, "%s is on %s " "but got reply from %*D on %s\n", inet_ntoa_r(isaddr, addrbuf), la->lle_tbl->llt_ifp->if_xname, ifp->if_addrlen, (u_char *)ar_sha(ah), ":", ifp->if_xname); LLE_WUNLOCK(la); return; } if ((la->la_flags & LLE_VALID) && bcmp(ar_sha(ah), la->ll_addr, ifp->if_addrlen)) { if (la->la_flags & LLE_STATIC) { LLE_WUNLOCK(la); if (log_arp_permanent_modify) ARP_LOG(LOG_ERR, "%*D attempts to modify " "permanent entry for %s on %s\n", ifp->if_addrlen, (u_char *)ar_sha(ah), ":", inet_ntoa_r(isaddr, addrbuf), ifp->if_xname); return; } if (log_arp_movements) { ARP_LOG(LOG_INFO, "%s moved from %*D " "to %*D on %s\n", inet_ntoa_r(isaddr, addrbuf), ifp->if_addrlen, (u_char *)la->ll_addr, ":", ifp->if_addrlen, (u_char *)ar_sha(ah), ":", ifp->if_xname); } } /* Calculate full link prepend to use in lle */ linkhdrsize = sizeof(linkhdr); if (lltable_calc_llheader(ifp, AF_INET, ar_sha(ah), linkhdr, &linkhdrsize, &lladdr_off) != 0) return; /* Check if something has changed */ if (memcmp(la->r_linkdata, linkhdr, linkhdrsize) != 0 || (la->la_flags & LLE_VALID) == 0) { /* Try to perform LLE update */ if (lltable_try_set_entry_addr(ifp, la, linkhdr, linkhdrsize, lladdr_off) == 0) return; /* Clear fast path feedback request if set */ la->r_skip_req = 0; } arp_mark_lle_reachable(la); /* * The packets are all freed within the call to the output * routine. * * NB: The lock MUST be released before the call to the * output routine. */ if (la->la_hold != NULL) { m_hold = la->la_hold; la->la_hold = NULL; la->la_numheld = 0; lltable_fill_sa_entry(la, &sa); LLE_WUNLOCK(la); for (; m_hold != NULL; m_hold = m_hold_next) { m_hold_next = m_hold->m_nextpkt; m_hold->m_nextpkt = NULL; /* Avoid confusing lower layers. */ m_clrprotoflags(m_hold); (*ifp->if_output)(ifp, m_hold, &sa, NULL); } } else LLE_WUNLOCK(la); } static void arp_mark_lle_reachable(struct llentry *la) { int canceled, wtime; LLE_WLOCK_ASSERT(la); la->ln_state = ARP_LLINFO_REACHABLE; EVENTHANDLER_INVOKE(lle_event, la, LLENTRY_RESOLVED); if (!(la->la_flags & LLE_STATIC)) { LLE_ADDREF(la); la->la_expire = time_uptime + V_arpt_keep; wtime = V_arpt_keep - V_arp_maxtries * V_arpt_rexmit; if (wtime < 0) wtime = V_arpt_keep; canceled = callout_reset(&la->lle_timer, hz * wtime, arptimer, la); if (canceled) LLE_REMREF(la); } la->la_asked = 0; la->la_preempt = V_arp_maxtries; } /* * Add permanent link-layer record for given interface address. */ static __noinline void arp_add_ifa_lle(struct ifnet *ifp, const struct sockaddr *dst) { struct llentry *lle, *lle_tmp; /* * Interface address LLE record is considered static * because kernel code relies on LLE_STATIC flag to check * if these entries can be rewriten by arp updates. */ lle = lltable_alloc_entry(LLTABLE(ifp), LLE_IFADDR | LLE_STATIC, dst); if (lle == NULL) { log(LOG_INFO, "arp_ifinit: cannot create arp " "entry for interface address\n"); return; } IF_AFDATA_WLOCK(ifp); LLE_WLOCK(lle); /* Unlink any entry if exists */ lle_tmp = lla_lookup(LLTABLE(ifp), LLE_EXCLUSIVE, dst); if (lle_tmp != NULL) lltable_unlink_entry(LLTABLE(ifp), lle_tmp); lltable_link_entry(LLTABLE(ifp), lle); IF_AFDATA_WUNLOCK(ifp); if (lle_tmp != NULL) EVENTHANDLER_INVOKE(lle_event, lle_tmp, LLENTRY_EXPIRED); EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_RESOLVED); LLE_WUNLOCK(lle); if (lle_tmp != NULL) lltable_free_entry(LLTABLE(ifp), lle_tmp); } /* * Handle the garp_rexmit_count. Like sysctl_handle_int(), but limits the range * of valid values. */ static int sysctl_garp_rexmit(SYSCTL_HANDLER_ARGS) { int error; int rexmit_count = *(int *)arg1; error = sysctl_handle_int(oidp, &rexmit_count, 0, req); /* Enforce limits on any new value that may have been set. */ if (!error && req->newptr) { /* A new value was set. */ if (rexmit_count < 0) { rexmit_count = 0; } else if (rexmit_count > MAX_GARP_RETRANSMITS) { rexmit_count = MAX_GARP_RETRANSMITS; } *(int *)arg1 = rexmit_count; } return (error); } /* * Retransmit a Gratuitous ARP (GARP) and, if necessary, schedule a callout to * retransmit it again. A pending callout owns a reference to the ifa. */ static void garp_rexmit(void *arg) { struct in_ifaddr *ia = arg; if (callout_pending(&ia->ia_garp_timer) || !callout_active(&ia->ia_garp_timer)) { IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp); ifa_free(&ia->ia_ifa); return; } CURVNET_SET(ia->ia_ifa.ifa_ifp->if_vnet); /* * Drop lock while the ARP request is generated. */ IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp); arprequest(ia->ia_ifa.ifa_ifp, &IA_SIN(ia)->sin_addr, &IA_SIN(ia)->sin_addr, IF_LLADDR(ia->ia_ifa.ifa_ifp)); /* * Increment the count of retransmissions. If the count has reached the * maximum value, stop sending the GARP packets. Otherwise, schedule * the callout to retransmit another GARP packet. */ ++ia->ia_garp_count; if (ia->ia_garp_count >= garp_rexmit_count) { ifa_free(&ia->ia_ifa); } else { int rescheduled; IF_ADDR_WLOCK(ia->ia_ifa.ifa_ifp); rescheduled = callout_reset(&ia->ia_garp_timer, (1 << ia->ia_garp_count) * hz, garp_rexmit, ia); IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp); if (rescheduled) { ifa_free(&ia->ia_ifa); } } CURVNET_RESTORE(); } /* * Start the GARP retransmit timer. * * A single GARP is always transmitted when an IPv4 address is added * to an interface and that is usually sufficient. However, in some * circumstances, such as when a shared address is passed between * cluster nodes, this single GARP may occasionally be dropped or * lost. This can lead to neighbors on the network link working with a * stale ARP cache and sending packets destined for that address to * the node that previously owned the address, which may not respond. * * To avoid this situation, GARP retransmits can be enabled by setting * the net.link.ether.inet.garp_rexmit_count sysctl to a value greater * than zero. The setting represents the maximum number of * retransmissions. The interval between retransmissions is calculated * using an exponential backoff algorithm, doubling each time, so the * retransmission intervals are: {1, 2, 4, 8, 16, ...} (seconds). */ static void garp_timer_start(struct ifaddr *ifa) { struct in_ifaddr *ia = (struct in_ifaddr *) ifa; IF_ADDR_WLOCK(ia->ia_ifa.ifa_ifp); ia->ia_garp_count = 0; if (callout_reset(&ia->ia_garp_timer, (1 << ia->ia_garp_count) * hz, garp_rexmit, ia) == 0) { ifa_ref(ifa); } IF_ADDR_WUNLOCK(ia->ia_ifa.ifa_ifp); } void arp_ifinit(struct ifnet *ifp, struct ifaddr *ifa) { struct epoch_tracker et; const struct sockaddr_in *dst_in; const struct sockaddr *dst; if (ifa->ifa_carp != NULL) return; dst = ifa->ifa_addr; dst_in = (const struct sockaddr_in *)dst; if (ntohl(dst_in->sin_addr.s_addr) == INADDR_ANY) return; NET_EPOCH_ENTER(et); arp_announce_ifaddr(ifp, dst_in->sin_addr, IF_LLADDR(ifp)); NET_EPOCH_EXIT(et); if (garp_rexmit_count > 0) { garp_timer_start(ifa); } arp_add_ifa_lle(ifp, dst); } void arp_announce_ifaddr(struct ifnet *ifp, struct in_addr addr, u_char *enaddr) { if (ntohl(addr.s_addr) != INADDR_ANY) arprequest(ifp, &addr, &addr, enaddr); } /* * Sends gratuitous ARPs for each ifaddr to notify other * nodes about the address change. */ static __noinline void arp_handle_ifllchange(struct ifnet *ifp) { struct ifaddr *ifa; CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family == AF_INET) arp_ifinit(ifp, ifa); } } /* * A handler for interface link layer address change event. */ static void arp_iflladdr(void *arg __unused, struct ifnet *ifp) { lltable_update_ifaddr(LLTABLE(ifp)); if ((ifp->if_flags & IFF_UP) != 0) arp_handle_ifllchange(ifp); } static void vnet_arp_init(void) { if (IS_DEFAULT_VNET(curvnet)) { netisr_register(&arp_nh); iflladdr_tag = EVENTHANDLER_REGISTER(iflladdr_event, arp_iflladdr, NULL, EVENTHANDLER_PRI_ANY); } #ifdef VIMAGE else netisr_register_vnet(&arp_nh); #endif } VNET_SYSINIT(vnet_arp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_SECOND, vnet_arp_init, 0); #ifdef VIMAGE /* * We have to unregister ARP along with IP otherwise we risk doing INADDR_HASH * lookups after destroying the hash. Ideally this would go on SI_ORDER_3.5. */ static void vnet_arp_destroy(__unused void *arg) { netisr_unregister_vnet(&arp_nh); } VNET_SYSUNINIT(vnet_arp_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, vnet_arp_destroy, NULL); #endif diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c index 5b66375e6613..386eb7cca922 100644 --- a/sys/netinet6/nd6.c +++ b/sys/netinet6/nd6.c @@ -1,2659 +1,2659 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $KAME: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $ */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include "opt_route.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */ #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */ #define SIN6(s) ((const struct sockaddr_in6 *)(s)) MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery"); /* timer values */ VNET_DEFINE(int, nd6_prune) = 1; /* walk list every 1 seconds */ VNET_DEFINE(int, nd6_delay) = 5; /* delay first probe time 5 second */ VNET_DEFINE(int, nd6_umaxtries) = 3; /* maximum unicast query */ VNET_DEFINE(int, nd6_mmaxtries) = 3; /* maximum multicast query */ VNET_DEFINE(int, nd6_useloopback) = 1; /* use loopback interface for * local traffic */ VNET_DEFINE(int, nd6_gctimer) = (60 * 60 * 24); /* 1 day: garbage * collection timer */ /* preventing too many loops in ND option parsing */ VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */ VNET_DEFINE(int, nd6_maxnudhint) = 0; /* max # of subsequent upper * layer hints */ -VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 1; /* max pkts cached in unresolved +VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 16; /* max pkts cached in unresolved * ND entries */ #define V_nd6_maxndopt VNET(nd6_maxndopt) #define V_nd6_maxqueuelen VNET(nd6_maxqueuelen) #ifdef ND6_DEBUG VNET_DEFINE(int, nd6_debug) = 1; #else VNET_DEFINE(int, nd6_debug) = 0; #endif static eventhandler_tag lle_event_eh, iflladdr_event_eh, ifnet_link_event_eh; VNET_DEFINE(struct nd_prhead, nd_prefix); VNET_DEFINE(struct rwlock, nd6_lock); VNET_DEFINE(uint64_t, nd6_list_genid); VNET_DEFINE(struct mtx, nd6_onlink_mtx); VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL; #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval) int (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int); static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *, struct ifnet *); static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *); static void nd6_slowtimo(void *); static int regen_tmpaddr(struct in6_ifaddr *); static void nd6_free(struct llentry **, int); static void nd6_free_redirect(const struct llentry *); static void nd6_llinfo_timer(void *); static void nd6_llinfo_settimer_locked(struct llentry *, long); static void clear_llinfo_pqueue(struct llentry *); static int nd6_resolve_slow(struct ifnet *, int, struct mbuf *, const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **); static int nd6_need_cache(struct ifnet *); VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch); #define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch) VNET_DEFINE_STATIC(struct callout, nd6_timer_ch); #define V_nd6_timer_ch VNET(nd6_timer_ch) SYSCTL_DECL(_net_inet6_icmp6); static void nd6_lle_event(void *arg __unused, struct llentry *lle, int evt) { struct rt_addrinfo rtinfo; struct sockaddr_in6 dst; struct sockaddr_dl gw; struct ifnet *ifp; int type; int fibnum; LLE_WLOCK_ASSERT(lle); if (lltable_get_af(lle->lle_tbl) != AF_INET6) return; switch (evt) { case LLENTRY_RESOLVED: type = RTM_ADD; KASSERT(lle->la_flags & LLE_VALID, ("%s: %p resolved but not valid?", __func__, lle)); break; case LLENTRY_EXPIRED: type = RTM_DELETE; break; default: return; } ifp = lltable_get_ifp(lle->lle_tbl); bzero(&dst, sizeof(dst)); bzero(&gw, sizeof(gw)); bzero(&rtinfo, sizeof(rtinfo)); lltable_fill_sa_entry(lle, (struct sockaddr *)&dst); dst.sin6_scope_id = in6_getscopezone(ifp, in6_addrscope(&dst.sin6_addr)); gw.sdl_len = sizeof(struct sockaddr_dl); gw.sdl_family = AF_LINK; gw.sdl_alen = ifp->if_addrlen; gw.sdl_index = ifp->if_index; gw.sdl_type = ifp->if_type; if (evt == LLENTRY_RESOLVED) bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen); rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst; rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw; rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY; fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib; rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | ( type == RTM_ADD ? RTF_UP: 0), 0, fibnum); } /* * A handler for interface link layer address change event. */ static void nd6_iflladdr(void *arg __unused, struct ifnet *ifp) { lltable_update_ifaddr(LLTABLE6(ifp)); } void nd6_init(void) { mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF); rw_init(&V_nd6_lock, "nd6 list"); LIST_INIT(&V_nd_prefix); nd6_defrouter_init(); /* Start timers. */ callout_init(&V_nd6_slowtimo_ch, 0); callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, nd6_slowtimo, curvnet); callout_init(&V_nd6_timer_ch, 0); callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet); nd6_dad_init(); if (IS_DEFAULT_VNET(curvnet)) { lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event, NULL, EVENTHANDLER_PRI_ANY); iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event, nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY); ifnet_link_event_eh = EVENTHANDLER_REGISTER(ifnet_link_event, nd6_ifnet_link_event, NULL, EVENTHANDLER_PRI_ANY); } } #ifdef VIMAGE void nd6_destroy() { callout_drain(&V_nd6_slowtimo_ch); callout_drain(&V_nd6_timer_ch); if (IS_DEFAULT_VNET(curvnet)) { EVENTHANDLER_DEREGISTER(ifnet_link_event, ifnet_link_event_eh); EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh); EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh); } rw_destroy(&V_nd6_lock); mtx_destroy(&V_nd6_onlink_mtx); } #endif struct nd_ifinfo * nd6_ifattach(struct ifnet *ifp) { struct nd_ifinfo *nd; nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO); nd->initialized = 1; nd->chlim = IPV6_DEFHLIM; nd->basereachable = REACHABLE_TIME; nd->reachable = ND_COMPUTE_RTIME(nd->basereachable); nd->retrans = RETRANS_TIMER; nd->flags = ND6_IFF_PERFORMNUD; /* Set IPv6 disabled on all interfaces but loopback by default. */ if ((ifp->if_flags & IFF_LOOPBACK) == 0) nd->flags |= ND6_IFF_IFDISABLED; /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL. * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by * default regardless of the V_ip6_auto_linklocal configuration to * give a reasonable default behavior. */ if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) || (ifp->if_flags & IFF_LOOPBACK)) nd->flags |= ND6_IFF_AUTO_LINKLOCAL; /* * A loopback interface does not need to accept RTADV. * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by * default regardless of the V_ip6_accept_rtadv configuration to * prevent the interface from accepting RA messages arrived * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV. */ if (V_ip6_accept_rtadv && !(ifp->if_flags & IFF_LOOPBACK) && (ifp->if_type != IFT_BRIDGE)) { nd->flags |= ND6_IFF_ACCEPT_RTADV; /* If we globally accept rtadv, assume IPv6 on. */ nd->flags &= ~ND6_IFF_IFDISABLED; } if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK)) nd->flags |= ND6_IFF_NO_RADR; /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */ nd6_setmtu0(ifp, nd); return nd; } void nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd) { struct epoch_tracker et; struct ifaddr *ifa, *next; NET_EPOCH_ENTER(et); CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; /* stop DAD processing */ nd6_dad_stop(ifa); } NET_EPOCH_EXIT(et); free(nd, M_IP6NDP); } /* * Reset ND level link MTU. This function is called when the physical MTU * changes, which means we might have to adjust the ND level MTU. */ void nd6_setmtu(struct ifnet *ifp) { if (ifp->if_afdata[AF_INET6] == NULL) return; nd6_setmtu0(ifp, ND_IFINFO(ifp)); } /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */ void nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi) { u_int32_t omaxmtu; omaxmtu = ndi->maxmtu; ndi->maxmtu = ifp->if_mtu; /* * Decreasing the interface MTU under IPV6 minimum MTU may cause * undesirable situation. We thus notify the operator of the change * explicitly. The check for omaxmtu is necessary to restrict the * log to the case of changing the MTU, not initializing it. */ if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) { log(LOG_NOTICE, "nd6_setmtu0: " "new link MTU on %s (%lu) is too small for IPv6\n", if_name(ifp), (unsigned long)ndi->maxmtu); } if (ndi->maxmtu > V_in6_maxmtu) in6_setmaxmtu(); /* check all interfaces just in case */ } void nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts) { bzero(ndopts, sizeof(*ndopts)); ndopts->nd_opts_search = (struct nd_opt_hdr *)opt; ndopts->nd_opts_last = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len); if (icmp6len == 0) { ndopts->nd_opts_done = 1; ndopts->nd_opts_search = NULL; } } /* * Take one ND option. */ struct nd_opt_hdr * nd6_option(union nd_opts *ndopts) { struct nd_opt_hdr *nd_opt; int olen; KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__)); KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts", __func__)); if (ndopts->nd_opts_search == NULL) return NULL; if (ndopts->nd_opts_done) return NULL; nd_opt = ndopts->nd_opts_search; /* make sure nd_opt_len is inside the buffer */ if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) { bzero(ndopts, sizeof(*ndopts)); return NULL; } olen = nd_opt->nd_opt_len << 3; if (olen == 0) { /* * Message validation requires that all included * options have a length that is greater than zero. */ bzero(ndopts, sizeof(*ndopts)); return NULL; } ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen); if (ndopts->nd_opts_search > ndopts->nd_opts_last) { /* option overruns the end of buffer, invalid */ bzero(ndopts, sizeof(*ndopts)); return NULL; } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) { /* reached the end of options chain */ ndopts->nd_opts_done = 1; ndopts->nd_opts_search = NULL; } return nd_opt; } /* * Parse multiple ND options. * This function is much easier to use, for ND routines that do not need * multiple options of the same type. */ int nd6_options(union nd_opts *ndopts) { struct nd_opt_hdr *nd_opt; int i = 0; KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__)); KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts", __func__)); if (ndopts->nd_opts_search == NULL) return 0; while (1) { nd_opt = nd6_option(ndopts); if (nd_opt == NULL && ndopts->nd_opts_last == NULL) { /* * Message validation requires that all included * options have a length that is greater than zero. */ ICMP6STAT_INC(icp6s_nd_badopt); bzero(ndopts, sizeof(*ndopts)); return -1; } if (nd_opt == NULL) goto skip1; switch (nd_opt->nd_opt_type) { case ND_OPT_SOURCE_LINKADDR: case ND_OPT_TARGET_LINKADDR: case ND_OPT_MTU: case ND_OPT_REDIRECTED_HEADER: case ND_OPT_NONCE: if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { nd6log((LOG_INFO, "duplicated ND6 option found (type=%d)\n", nd_opt->nd_opt_type)); /* XXX bark? */ } else { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } break; case ND_OPT_PREFIX_INFORMATION: if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) { ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; } ndopts->nd_opts_pi_end = (struct nd_opt_prefix_info *)nd_opt; break; /* What about ND_OPT_ROUTE_INFO? RFC 4191 */ case ND_OPT_RDNSS: /* RFC 6106 */ case ND_OPT_DNSSL: /* RFC 6106 */ /* * Silently ignore options we know and do not care about * in the kernel. */ break; default: /* * Unknown options must be silently ignored, * to accommodate future extension to the protocol. */ nd6log((LOG_DEBUG, "nd6_options: unsupported option %d - " "option ignored\n", nd_opt->nd_opt_type)); } skip1: i++; if (i > V_nd6_maxndopt) { ICMP6STAT_INC(icp6s_nd_toomanyopt); nd6log((LOG_INFO, "too many loop in nd opt\n")); break; } if (ndopts->nd_opts_done) break; } return 0; } /* * ND6 timer routine to handle ND6 entries */ static void nd6_llinfo_settimer_locked(struct llentry *ln, long tick) { int canceled; LLE_WLOCK_ASSERT(ln); if (tick < 0) { ln->la_expire = 0; ln->ln_ntick = 0; canceled = callout_stop(&ln->lle_timer); } else { ln->la_expire = time_uptime + tick / hz; LLE_ADDREF(ln); if (tick > INT_MAX) { ln->ln_ntick = tick - INT_MAX; canceled = callout_reset(&ln->lle_timer, INT_MAX, nd6_llinfo_timer, ln); } else { ln->ln_ntick = 0; canceled = callout_reset(&ln->lle_timer, tick, nd6_llinfo_timer, ln); } } if (canceled > 0) LLE_REMREF(ln); } /* * Gets source address of the first packet in hold queue * and stores it in @src. * Returns pointer to @src (if hold queue is not empty) or NULL. * * Set noinline to be dtrace-friendly */ static __noinline struct in6_addr * nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src) { struct ip6_hdr hdr; struct mbuf *m; if (ln->la_hold == NULL) return (NULL); /* * assume every packet in la_hold has the same IP header */ m = ln->la_hold; if (sizeof(hdr) > m->m_len) return (NULL); m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr); *src = hdr.ip6_src; return (src); } /* * Checks if we need to switch from STALE state. * * RFC 4861 requires switching from STALE to DELAY state * on first packet matching entry, waiting V_nd6_delay and * transition to PROBE state (if upper layer confirmation was * not received). * * This code performs a bit differently: * On packet hit we don't change state (but desired state * can be guessed by control plane). However, after V_nd6_delay * seconds code will transition to PROBE state (so DELAY state * is kinda skipped in most situations). * * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so * we perform the following upon entering STALE state: * * 1) Arm timer to run each V_nd6_delay seconds to make sure that * if packet was transmitted at the start of given interval, we * would be able to switch to PROBE state in V_nd6_delay seconds * as user expects. * * 2) Reschedule timer until original V_nd6_gctimer expires keeping * lle in STALE state (remaining timer value stored in lle_remtime). * * 3) Reschedule timer if packet was transmitted less that V_nd6_delay * seconds ago. * * Returns non-zero value if the entry is still STALE (storing * the next timer interval in @pdelay). * * Returns zero value if original timer expired or we need to switch to * PROBE (store that in @do_switch variable). */ static int nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch) { int nd_delay, nd_gctimer, r_skip_req; time_t lle_hittime; long delay; *do_switch = 0; nd_gctimer = V_nd6_gctimer; nd_delay = V_nd6_delay; LLE_REQ_LOCK(lle); r_skip_req = lle->r_skip_req; lle_hittime = lle->lle_hittime; LLE_REQ_UNLOCK(lle); if (r_skip_req > 0) { /* * Nonzero r_skip_req value was set upon entering * STALE state. Since value was not changed, no * packets were passed using this lle. Ask for * timer reschedule and keep STALE state. */ delay = (long)(MIN(nd_gctimer, nd_delay)); delay *= hz; if (lle->lle_remtime > delay) lle->lle_remtime -= delay; else { delay = lle->lle_remtime; lle->lle_remtime = 0; } if (delay == 0) { /* * The original ng6_gctime timeout ended, * no more rescheduling. */ return (0); } *pdelay = delay; return (1); } /* * Packet received. Verify timestamp */ delay = (long)(time_uptime - lle_hittime); if (delay < nd_delay) { /* * V_nd6_delay still not passed since the first * hit in STALE state. * Reshedule timer and return. */ *pdelay = (long)(nd_delay - delay) * hz; return (1); } /* Request switching to probe */ *do_switch = 1; return (0); } /* * Switch @lle state to new state optionally arming timers. * * Set noinline to be dtrace-friendly */ __noinline void nd6_llinfo_setstate(struct llentry *lle, int newstate) { struct ifnet *ifp; int nd_gctimer, nd_delay; long delay, remtime; delay = 0; remtime = 0; switch (newstate) { case ND6_LLINFO_INCOMPLETE: ifp = lle->lle_tbl->llt_ifp; delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000; break; case ND6_LLINFO_REACHABLE: if (!ND6_LLINFO_PERMANENT(lle)) { ifp = lle->lle_tbl->llt_ifp; delay = (long)ND_IFINFO(ifp)->reachable * hz; } break; case ND6_LLINFO_STALE: /* * Notify fast path that we want to know if any packet * is transmitted by setting r_skip_req. */ LLE_REQ_LOCK(lle); lle->r_skip_req = 1; LLE_REQ_UNLOCK(lle); nd_delay = V_nd6_delay; nd_gctimer = V_nd6_gctimer; delay = (long)(MIN(nd_gctimer, nd_delay)) * hz; remtime = (long)nd_gctimer * hz - delay; break; case ND6_LLINFO_DELAY: lle->la_asked = 0; delay = (long)V_nd6_delay * hz; break; } if (delay > 0) nd6_llinfo_settimer_locked(lle, delay); lle->lle_remtime = remtime; lle->ln_state = newstate; } /* * Timer-dependent part of nd state machine. * * Set noinline to be dtrace-friendly */ static __noinline void nd6_llinfo_timer(void *arg) { struct epoch_tracker et; struct llentry *ln; struct in6_addr *dst, *pdst, *psrc, src; struct ifnet *ifp; struct nd_ifinfo *ndi; int do_switch, send_ns; long delay; KASSERT(arg != NULL, ("%s: arg NULL", __func__)); ln = (struct llentry *)arg; ifp = lltable_get_ifp(ln->lle_tbl); CURVNET_SET(ifp->if_vnet); ND6_RLOCK(); LLE_WLOCK(ln); if (callout_pending(&ln->lle_timer)) { /* * Here we are a bit odd here in the treatment of * active/pending. If the pending bit is set, it got * rescheduled before I ran. The active * bit we ignore, since if it was stopped * in ll_tablefree() and was currently running * it would have return 0 so the code would * not have deleted it since the callout could * not be stopped so we want to go through * with the delete here now. If the callout * was restarted, the pending bit will be back on and * we just want to bail since the callout_reset would * return 1 and our reference would have been removed * by nd6_llinfo_settimer_locked above since canceled * would have been 1. */ LLE_WUNLOCK(ln); ND6_RUNLOCK(); CURVNET_RESTORE(); return; } NET_EPOCH_ENTER(et); ndi = ND_IFINFO(ifp); send_ns = 0; dst = &ln->r_l3addr.addr6; pdst = dst; if (ln->ln_ntick > 0) { if (ln->ln_ntick > INT_MAX) { ln->ln_ntick -= INT_MAX; nd6_llinfo_settimer_locked(ln, INT_MAX); } else { ln->ln_ntick = 0; nd6_llinfo_settimer_locked(ln, ln->ln_ntick); } goto done; } if (ln->la_flags & LLE_STATIC) { goto done; } if (ln->la_flags & LLE_DELETED) { nd6_free(&ln, 0); goto done; } switch (ln->ln_state) { case ND6_LLINFO_INCOMPLETE: if (ln->la_asked < V_nd6_mmaxtries) { ln->la_asked++; send_ns = 1; /* Send NS to multicast address */ pdst = NULL; } else { struct mbuf *m = ln->la_hold; if (m) { struct mbuf *m0; /* * assuming every packet in la_hold has the * same IP header. Send error after unlock. */ m0 = m->m_nextpkt; m->m_nextpkt = NULL; ln->la_hold = m0; clear_llinfo_pqueue(ln); } nd6_free(&ln, 0); if (m != NULL) { struct mbuf *n = m; /* * if there are any ummapped mbufs, we * must free them, rather than using * them for an ICMP, as they cannot be * checksummed. */ while ((n = n->m_next) != NULL) { if (n->m_flags & M_EXTPG) break; } if (n != NULL) { m_freem(m); m = NULL; } else { icmp6_error2(m, ICMP6_DST_UNREACH, ICMP6_DST_UNREACH_ADDR, 0, ifp); } } } break; case ND6_LLINFO_REACHABLE: if (!ND6_LLINFO_PERMANENT(ln)) nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); break; case ND6_LLINFO_STALE: if (nd6_is_stale(ln, &delay, &do_switch) != 0) { /* * No packet has used this entry and GC timeout * has not been passed. Reshedule timer and * return. */ nd6_llinfo_settimer_locked(ln, delay); break; } if (do_switch == 0) { /* * GC timer has ended and entry hasn't been used. * Run Garbage collector (RFC 4861, 5.3) */ if (!ND6_LLINFO_PERMANENT(ln)) nd6_free(&ln, 1); break; } /* Entry has been used AND delay timer has ended. */ /* FALLTHROUGH */ case ND6_LLINFO_DELAY: if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) { /* We need NUD */ ln->la_asked = 1; nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE); send_ns = 1; } else nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */ break; case ND6_LLINFO_PROBE: if (ln->la_asked < V_nd6_umaxtries) { ln->la_asked++; send_ns = 1; } else { nd6_free(&ln, 0); } break; default: panic("%s: paths in a dark night can be confusing: %d", __func__, ln->ln_state); } done: if (ln != NULL) ND6_RUNLOCK(); if (send_ns != 0) { nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000); psrc = nd6_llinfo_get_holdsrc(ln, &src); LLE_FREE_LOCKED(ln); ln = NULL; nd6_ns_output(ifp, psrc, pdst, dst, NULL); } if (ln != NULL) LLE_FREE_LOCKED(ln); NET_EPOCH_EXIT(et); CURVNET_RESTORE(); } /* * ND6 timer routine to expire default route list and prefix list */ void nd6_timer(void *arg) { CURVNET_SET((struct vnet *) arg); struct epoch_tracker et; struct nd_prhead prl; struct nd_prefix *pr, *npr; struct ifnet *ifp; struct in6_ifaddr *ia6, *nia6; uint64_t genid; LIST_INIT(&prl); NET_EPOCH_ENTER(et); nd6_defrouter_timer(); /* * expire interface addresses. * in the past the loop was inside prefix expiry processing. * However, from a stricter speci-confrmance standpoint, we should * rather separate address lifetimes and prefix lifetimes. * * XXXRW: in6_ifaddrhead locking. */ addrloop: CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) { /* check address lifetime */ if (IFA6_IS_INVALID(ia6)) { int regen = 0; /* * If the expiring address is temporary, try * regenerating a new one. This would be useful when * we suspended a laptop PC, then turned it on after a * period that could invalidate all temporary * addresses. Although we may have to restart the * loop (see below), it must be after purging the * address. Otherwise, we'd see an infinite loop of * regeneration. */ if (V_ip6_use_tempaddr && (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) { if (regen_tmpaddr(ia6) == 0) regen = 1; } in6_purgeaddr(&ia6->ia_ifa); if (regen) goto addrloop; /* XXX: see below */ } else if (IFA6_IS_DEPRECATED(ia6)) { int oldflags = ia6->ia6_flags; ia6->ia6_flags |= IN6_IFF_DEPRECATED; /* * If a temporary address has just become deprecated, * regenerate a new one if possible. */ if (V_ip6_use_tempaddr && (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && (oldflags & IN6_IFF_DEPRECATED) == 0) { if (regen_tmpaddr(ia6) == 0) { /* * A new temporary address is * generated. * XXX: this means the address chain * has changed while we are still in * the loop. Although the change * would not cause disaster (because * it's not a deletion, but an * addition,) we'd rather restart the * loop just for safety. Or does this * significantly reduce performance?? */ goto addrloop; } } } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) { /* * Schedule DAD for a tentative address. This happens * if the interface was down or not running * when the address was configured. */ int delay; delay = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz); nd6_dad_start((struct ifaddr *)ia6, delay); } else { /* * Check status of the interface. If it is down, * mark the address as tentative for future DAD. */ ifp = ia6->ia_ifp; if ((ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0 && ((ifp->if_flags & IFF_UP) == 0 || (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 || (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0)){ ia6->ia6_flags &= ~IN6_IFF_DUPLICATED; ia6->ia6_flags |= IN6_IFF_TENTATIVE; } /* * A new RA might have made a deprecated address * preferred. */ ia6->ia6_flags &= ~IN6_IFF_DEPRECATED; } } NET_EPOCH_EXIT(et); ND6_WLOCK(); restart: LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) { /* * Expire prefixes. Since the pltime is only used for * autoconfigured addresses, pltime processing for prefixes is * not necessary. * * Only unlink after all derived addresses have expired. This * may not occur until two hours after the prefix has expired * per RFC 4862. If the prefix expires before its derived * addresses, mark it off-link. This will be done automatically * after unlinking if no address references remain. */ if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME || time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime) continue; if (pr->ndpr_addrcnt == 0) { nd6_prefix_unlink(pr, &prl); continue; } if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) { genid = V_nd6_list_genid; nd6_prefix_ref(pr); ND6_WUNLOCK(); ND6_ONLINK_LOCK(); (void)nd6_prefix_offlink(pr); ND6_ONLINK_UNLOCK(); ND6_WLOCK(); nd6_prefix_rele(pr); if (genid != V_nd6_list_genid) goto restart; } } ND6_WUNLOCK(); while ((pr = LIST_FIRST(&prl)) != NULL) { LIST_REMOVE(pr, ndpr_entry); nd6_prefix_del(pr); } callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz, nd6_timer, curvnet); CURVNET_RESTORE(); } /* * ia6 - deprecated/invalidated temporary address */ static int regen_tmpaddr(struct in6_ifaddr *ia6) { struct ifaddr *ifa; struct ifnet *ifp; struct in6_ifaddr *public_ifa6 = NULL; NET_EPOCH_ASSERT(); ifp = ia6->ia_ifa.ifa_ifp; CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { struct in6_ifaddr *it6; if (ifa->ifa_addr->sa_family != AF_INET6) continue; it6 = (struct in6_ifaddr *)ifa; /* ignore no autoconf addresses. */ if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; /* ignore autoconf addresses with different prefixes. */ if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr) continue; /* * Now we are looking at an autoconf address with the same * prefix as ours. If the address is temporary and is still * preferred, do not create another one. It would be rare, but * could happen, for example, when we resume a laptop PC after * a long period. */ if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 && !IFA6_IS_DEPRECATED(it6)) { public_ifa6 = NULL; break; } /* * This is a public autoconf address that has the same prefix * as ours. If it is preferred, keep it. We can't break the * loop here, because there may be a still-preferred temporary * address with the prefix. */ if (!IFA6_IS_DEPRECATED(it6)) public_ifa6 = it6; } if (public_ifa6 != NULL) ifa_ref(&public_ifa6->ia_ifa); if (public_ifa6 != NULL) { int e; if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) { ifa_free(&public_ifa6->ia_ifa); log(LOG_NOTICE, "regen_tmpaddr: failed to create a new" " tmp addr,errno=%d\n", e); return (-1); } ifa_free(&public_ifa6->ia_ifa); return (0); } return (-1); } /* * Remove prefix and default router list entries corresponding to ifp. Neighbor * cache entries are freed in in6_domifdetach(). */ void nd6_purge(struct ifnet *ifp) { struct nd_prhead prl; struct nd_prefix *pr, *npr; LIST_INIT(&prl); /* Purge default router list entries toward ifp. */ nd6_defrouter_purge(ifp); ND6_WLOCK(); /* * Remove prefixes on ifp. We should have already removed addresses on * this interface, so no addresses should be referencing these prefixes. */ LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) { if (pr->ndpr_ifp == ifp) nd6_prefix_unlink(pr, &prl); } ND6_WUNLOCK(); /* Delete the unlinked prefix objects. */ while ((pr = LIST_FIRST(&prl)) != NULL) { LIST_REMOVE(pr, ndpr_entry); nd6_prefix_del(pr); } /* cancel default outgoing interface setting */ if (V_nd6_defifindex == ifp->if_index) nd6_setdefaultiface(0); if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) { /* Refresh default router list. */ defrouter_select_fib(ifp->if_fib); } } /* * the caller acquires and releases the lock on the lltbls * Returns the llentry locked */ struct llentry * nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp) { struct sockaddr_in6 sin6; struct llentry *ln; bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = *addr6; IF_AFDATA_LOCK_ASSERT(ifp); ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6); return (ln); } static struct llentry * nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp) { struct sockaddr_in6 sin6; struct llentry *ln; bzero(&sin6, sizeof(sin6)); sin6.sin6_len = sizeof(struct sockaddr_in6); sin6.sin6_family = AF_INET6; sin6.sin6_addr = *addr6; ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6); if (ln != NULL) ln->ln_state = ND6_LLINFO_NOSTATE; return (ln); } /* * Test whether a given IPv6 address is a neighbor or not, ignoring * the actual neighbor cache. The neighbor cache is ignored in order * to not reenter the routing code from within itself. */ static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) { struct nd_prefix *pr; struct ifaddr *ifa; struct rt_addrinfo info; struct sockaddr_in6 rt_key; const struct sockaddr *dst6; uint64_t genid; int error, fibnum; /* * A link-local address is always a neighbor. * XXX: a link does not necessarily specify a single interface. */ if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) { struct sockaddr_in6 sin6_copy; u_int32_t zone; /* * We need sin6_copy since sa6_recoverscope() may modify the * content (XXX). */ sin6_copy = *addr; if (sa6_recoverscope(&sin6_copy)) return (0); /* XXX: should be impossible */ if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone)) return (0); if (sin6_copy.sin6_scope_id == zone) return (1); else return (0); } bzero(&rt_key, sizeof(rt_key)); bzero(&info, sizeof(info)); info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key; /* * If the address matches one of our addresses, * it should be a neighbor. * If the address matches one of our on-link prefixes, it should be a * neighbor. */ ND6_RLOCK(); restart: LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) { if (pr->ndpr_ifp != ifp) continue; if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) { dst6 = (const struct sockaddr *)&pr->ndpr_prefix; /* * We only need to check all FIBs if add_addr_allfibs * is unset. If set, checking any FIB will suffice. */ fibnum = V_rt_add_addr_allfibs ? rt_numfibs - 1 : 0; for (; fibnum < rt_numfibs; fibnum++) { genid = V_nd6_list_genid; ND6_RUNLOCK(); /* * Restore length field before * retrying lookup */ rt_key.sin6_len = sizeof(rt_key); error = rib_lookup_info(fibnum, dst6, 0, 0, &info); ND6_RLOCK(); if (genid != V_nd6_list_genid) goto restart; if (error == 0) break; } if (error != 0) continue; /* * This is the case where multiple interfaces * have the same prefix, but only one is installed * into the routing table and that prefix entry * is not the one being examined here. */ if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr, &rt_key.sin6_addr)) continue; } if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr, &addr->sin6_addr, &pr->ndpr_mask)) { ND6_RUNLOCK(); return (1); } } ND6_RUNLOCK(); /* * If the address is assigned on the node of the other side of * a p2p interface, the address should be a neighbor. */ if (ifp->if_flags & IFF_POINTOPOINT) { struct epoch_tracker et; NET_EPOCH_ENTER(et); CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != addr->sin6_family) continue; if (ifa->ifa_dstaddr != NULL && sa_equal(addr, ifa->ifa_dstaddr)) { NET_EPOCH_EXIT(et); return 1; } } NET_EPOCH_EXIT(et); } /* * If the default router list is empty, all addresses are regarded * as on-link, and thus, as a neighbor. */ if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && nd6_defrouter_list_empty() && V_nd6_defifindex == ifp->if_index) { return (1); } return (0); } /* * Detect if a given IPv6 address identifies a neighbor on a given link. * XXX: should take care of the destination of a p2p link? */ int nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp) { struct llentry *lle; int rc = 0; NET_EPOCH_ASSERT(); IF_AFDATA_UNLOCK_ASSERT(ifp); if (nd6_is_new_addr_neighbor(addr, ifp)) return (1); /* * Even if the address matches none of our addresses, it might be * in the neighbor cache. */ if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) { LLE_RUNLOCK(lle); rc = 1; } return (rc); } /* * Free an nd6 llinfo entry. * Since the function would cause significant changes in the kernel, DO NOT * make it global, unless you have a strong reason for the change, and are sure * that the change is safe. * * Set noinline to be dtrace-friendly */ static __noinline void nd6_free(struct llentry **lnp, int gc) { struct ifnet *ifp; struct llentry *ln; struct nd_defrouter *dr; ln = *lnp; *lnp = NULL; LLE_WLOCK_ASSERT(ln); ND6_RLOCK_ASSERT(); ifp = lltable_get_ifp(ln->lle_tbl); if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0) dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp); else dr = NULL; ND6_RUNLOCK(); if ((ln->la_flags & LLE_DELETED) == 0) EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED); /* * we used to have pfctlinput(PRC_HOSTDEAD) here. * even though it is not harmful, it was not really necessary. */ /* cancel timer */ nd6_llinfo_settimer_locked(ln, -1); if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) { if (dr != NULL && dr->expire && ln->ln_state == ND6_LLINFO_STALE && gc) { /* * If the reason for the deletion is just garbage * collection, and the neighbor is an active default * router, do not delete it. Instead, reset the GC * timer using the router's lifetime. * Simply deleting the entry would affect default * router selection, which is not necessarily a good * thing, especially when we're using router preference * values. * XXX: the check for ln_state would be redundant, * but we intentionally keep it just in case. */ if (dr->expire > time_uptime) nd6_llinfo_settimer_locked(ln, (dr->expire - time_uptime) * hz); else nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz); LLE_REMREF(ln); LLE_WUNLOCK(ln); defrouter_rele(dr); return; } if (dr) { /* * Unreachablity of a router might affect the default * router selection and on-link detection of advertised * prefixes. */ /* * Temporarily fake the state to choose a new default * router and to perform on-link determination of * prefixes correctly. * Below the state will be set correctly, * or the entry itself will be deleted. */ ln->ln_state = ND6_LLINFO_INCOMPLETE; } if (ln->ln_router || dr) { /* * We need to unlock to avoid a LOR with rt6_flush() with the * rnh and for the calls to pfxlist_onlink_check() and * defrouter_select_fib() in the block further down for calls * into nd6_lookup(). We still hold a ref. */ LLE_WUNLOCK(ln); /* * rt6_flush must be called whether or not the neighbor * is in the Default Router List. * See a corresponding comment in nd6_na_input(). */ rt6_flush(&ln->r_l3addr.addr6, ifp); } if (dr) { /* * Since defrouter_select_fib() does not affect the * on-link determination and MIP6 needs the check * before the default router selection, we perform * the check now. */ pfxlist_onlink_check(); /* * Refresh default router list. */ defrouter_select_fib(dr->ifp->if_fib); } /* * If this entry was added by an on-link redirect, remove the * corresponding host route. */ if (ln->la_flags & LLE_REDIRECT) nd6_free_redirect(ln); if (ln->ln_router || dr) LLE_WLOCK(ln); } /* * Save to unlock. We still hold an extra reference and will not * free(9) in llentry_free() if someone else holds one as well. */ LLE_WUNLOCK(ln); IF_AFDATA_LOCK(ifp); LLE_WLOCK(ln); /* Guard against race with other llentry_free(). */ if (ln->la_flags & LLE_LINKED) { /* Remove callout reference */ LLE_REMREF(ln); lltable_unlink_entry(ln->lle_tbl, ln); } IF_AFDATA_UNLOCK(ifp); llentry_free(ln); if (dr != NULL) defrouter_rele(dr); } static int nd6_isdynrte(const struct rtentry *rt, const struct nhop_object *nh, void *xap) { if (nh->nh_flags & NHF_REDIRECT) return (1); return (0); } /* * Remove the rtentry for the given llentry, * both of which were installed by a redirect. */ static void nd6_free_redirect(const struct llentry *ln) { int fibnum; struct sockaddr_in6 sin6; struct rt_addrinfo info; struct rib_cmd_info rc; struct epoch_tracker et; lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6); memset(&info, 0, sizeof(info)); info.rti_info[RTAX_DST] = (struct sockaddr *)&sin6; info.rti_filter = nd6_isdynrte; NET_EPOCH_ENTER(et); for (fibnum = 0; fibnum < rt_numfibs; fibnum++) rib_action(fibnum, RTM_DELETE, &info, &rc); NET_EPOCH_EXIT(et); } /* * Updates status of the default router route. */ static void check_release_defrouter(struct rib_cmd_info *rc, void *_cbdata) { struct nd_defrouter *dr; struct nhop_object *nh; nh = rc->rc_nh_old; if ((nh != NULL) && (nh->nh_flags & NHF_DEFAULT)) { dr = defrouter_lookup(&nh->gw6_sa.sin6_addr, nh->nh_ifp); if (dr != NULL) { dr->installed = 0; defrouter_rele(dr); } } } void nd6_subscription_cb(struct rib_head *rnh, struct rib_cmd_info *rc, void *arg) { #ifdef ROUTE_MPATH rib_decompose_notification(rc, check_release_defrouter, NULL); #else check_release_defrouter(rc, NULL); #endif } int nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp) { struct in6_ndireq *ndi = (struct in6_ndireq *)data; struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data; struct in6_ndifreq *ndif = (struct in6_ndifreq *)data; struct epoch_tracker et; int error = 0; if (ifp->if_afdata[AF_INET6] == NULL) return (EPFNOSUPPORT); switch (cmd) { case OSIOCGIFINFO_IN6: #define ND ndi->ndi /* XXX: old ndp(8) assumes a positive value for linkmtu. */ bzero(&ND, sizeof(ND)); ND.linkmtu = IN6_LINKMTU(ifp); ND.maxmtu = ND_IFINFO(ifp)->maxmtu; ND.basereachable = ND_IFINFO(ifp)->basereachable; ND.reachable = ND_IFINFO(ifp)->reachable; ND.retrans = ND_IFINFO(ifp)->retrans; ND.flags = ND_IFINFO(ifp)->flags; ND.recalctm = ND_IFINFO(ifp)->recalctm; ND.chlim = ND_IFINFO(ifp)->chlim; break; case SIOCGIFINFO_IN6: ND = *ND_IFINFO(ifp); break; case SIOCSIFINFO_IN6: /* * used to change host variables from userland. * intended for a use on router to reflect RA configurations. */ /* 0 means 'unspecified' */ if (ND.linkmtu != 0) { if (ND.linkmtu < IPV6_MMTU || ND.linkmtu > IN6_LINKMTU(ifp)) { error = EINVAL; break; } ND_IFINFO(ifp)->linkmtu = ND.linkmtu; } if (ND.basereachable != 0) { int obasereachable = ND_IFINFO(ifp)->basereachable; ND_IFINFO(ifp)->basereachable = ND.basereachable; if (ND.basereachable != obasereachable) ND_IFINFO(ifp)->reachable = ND_COMPUTE_RTIME(ND.basereachable); } if (ND.retrans != 0) ND_IFINFO(ifp)->retrans = ND.retrans; if (ND.chlim != 0) ND_IFINFO(ifp)->chlim = ND.chlim; /* FALLTHROUGH */ case SIOCSIFINFO_FLAGS: { struct ifaddr *ifa; struct in6_ifaddr *ia; if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) && !(ND.flags & ND6_IFF_IFDISABLED)) { /* ifdisabled 1->0 transision */ /* * If the interface is marked as ND6_IFF_IFDISABLED and * has an link-local address with IN6_IFF_DUPLICATED, * do not clear ND6_IFF_IFDISABLED. * See RFC 4862, Section 5.4.5. */ NET_EPOCH_ENTER(et); CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia = (struct in6_ifaddr *)ifa; if ((ia->ia6_flags & IN6_IFF_DUPLICATED) && IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))) break; } NET_EPOCH_EXIT(et); if (ifa != NULL) { /* LLA is duplicated. */ ND.flags |= ND6_IFF_IFDISABLED; log(LOG_ERR, "Cannot enable an interface" " with a link-local address marked" " duplicate.\n"); } else { ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED; if (ifp->if_flags & IFF_UP) in6_if_up(ifp); } } else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) && (ND.flags & ND6_IFF_IFDISABLED)) { /* ifdisabled 0->1 transision */ /* Mark all IPv6 address as tentative. */ ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED; if (V_ip6_dad_count > 0 && (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) { NET_EPOCH_ENTER(et); CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia = (struct in6_ifaddr *)ifa; ia->ia6_flags |= IN6_IFF_TENTATIVE; } NET_EPOCH_EXIT(et); } } if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) { if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) { /* auto_linklocal 0->1 transision */ /* If no link-local address on ifp, configure */ ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL; in6_ifattach(ifp, NULL); } else if (!(ND.flags & ND6_IFF_IFDISABLED) && ifp->if_flags & IFF_UP) { /* * When the IF already has * ND6_IFF_AUTO_LINKLOCAL, no link-local * address is assigned, and IFF_UP, try to * assign one. */ NET_EPOCH_ENTER(et); CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) { if (ifa->ifa_addr->sa_family != AF_INET6) continue; ia = (struct in6_ifaddr *)ifa; if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia))) break; } NET_EPOCH_EXIT(et); if (ifa != NULL) /* No LLA is configured. */ in6_ifattach(ifp, NULL); } } ND_IFINFO(ifp)->flags = ND.flags; break; } #undef ND case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */ /* sync kernel routing table with the default router list */ defrouter_reset(); defrouter_select_fib(RT_ALL_FIBS); break; case SIOCSPFXFLUSH_IN6: { /* flush all the prefix advertised by routers */ struct in6_ifaddr *ia, *ia_next; struct nd_prefix *pr, *next; struct nd_prhead prl; LIST_INIT(&prl); ND6_WLOCK(); LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) { if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr)) continue; /* XXX */ nd6_prefix_unlink(pr, &prl); } ND6_WUNLOCK(); while ((pr = LIST_FIRST(&prl)) != NULL) { LIST_REMOVE(pr, ndpr_entry); /* XXXRW: in6_ifaddrhead locking. */ CK_STAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link, ia_next) { if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0) continue; if (ia->ia6_ndpr == pr) in6_purgeaddr(&ia->ia_ifa); } nd6_prefix_del(pr); } break; } case SIOCSRTRFLUSH_IN6: { /* flush all the default routers */ defrouter_reset(); nd6_defrouter_flush_all(); defrouter_select_fib(RT_ALL_FIBS); break; } case SIOCGNBRINFO_IN6: { struct llentry *ln; struct in6_addr nb_addr = nbi->addr; /* make local for safety */ if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0) return (error); NET_EPOCH_ENTER(et); ln = nd6_lookup(&nb_addr, 0, ifp); NET_EPOCH_EXIT(et); if (ln == NULL) { error = EINVAL; break; } nbi->state = ln->ln_state; nbi->asked = ln->la_asked; nbi->isrouter = ln->ln_router; if (ln->la_expire == 0) nbi->expire = 0; else nbi->expire = ln->la_expire + ln->lle_remtime / hz + (time_second - time_uptime); LLE_RUNLOCK(ln); break; } case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */ ndif->ifindex = V_nd6_defifindex; break; case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */ return (nd6_setdefaultiface(ndif->ifindex)); } return (error); } /* * Calculates new isRouter value based on provided parameters and * returns it. */ static int nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr, int ln_router) { /* * ICMP6 type dependent behavior. * * NS: clear IsRouter if new entry * RS: clear IsRouter * RA: set IsRouter if there's lladdr * redir: clear IsRouter if new entry * * RA case, (1): * The spec says that we must set IsRouter in the following cases: * - If lladdr exist, set IsRouter. This means (1-5). * - If it is old entry (!newentry), set IsRouter. This means (7). * So, based on the spec, in (1-5) and (7) cases we must set IsRouter. * A quetion arises for (1) case. (1) case has no lladdr in the * neighbor cache, this is similar to (6). * This case is rare but we figured that we MUST NOT set IsRouter. * * is_new old_addr new_addr NS RS RA redir * D R * 0 n n (1) c ? s * 0 y n (2) c s s * 0 n y (3) c s s * 0 y y (4) c s s * 0 y y (5) c s s * 1 -- n (6) c c c s * 1 -- y (7) c c s c s * * (c=clear s=set) */ switch (type & 0xff) { case ND_NEIGHBOR_SOLICIT: /* * New entry must have is_router flag cleared. */ if (is_new) /* (6-7) */ ln_router = 0; break; case ND_REDIRECT: /* * If the icmp is a redirect to a better router, always set the * is_router flag. Otherwise, if the entry is newly created, * clear the flag. [RFC 2461, sec 8.3] */ if (code == ND_REDIRECT_ROUTER) ln_router = 1; else { if (is_new) /* (6-7) */ ln_router = 0; } break; case ND_ROUTER_SOLICIT: /* * is_router flag must always be cleared. */ ln_router = 0; break; case ND_ROUTER_ADVERT: /* * Mark an entry with lladdr as a router. */ if ((!is_new && (old_addr || new_addr)) || /* (2-5) */ (is_new && new_addr)) { /* (7) */ ln_router = 1; } break; } return (ln_router); } /* * Create neighbor cache entry and cache link-layer address, * on reception of inbound ND6 packets. (RS/RA/NS/redirect) * * type - ICMP6 type * code - type dependent information * */ void nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr, int lladdrlen, int type, int code) { struct llentry *ln = NULL, *ln_tmp; int is_newentry; int do_update; int olladdr; int llchange; int flags; uint16_t router = 0; struct sockaddr_in6 sin6; struct mbuf *chain = NULL; u_char linkhdr[LLE_MAX_LINKHDR]; size_t linkhdrsize; int lladdr_off; NET_EPOCH_ASSERT(); IF_AFDATA_UNLOCK_ASSERT(ifp); KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__)); KASSERT(from != NULL, ("%s: from == NULL", __func__)); /* nothing must be updated for unspecified address */ if (IN6_IS_ADDR_UNSPECIFIED(from)) return; /* * Validation about ifp->if_addrlen and lladdrlen must be done in * the caller. * * XXX If the link does not have link-layer adderss, what should * we do? (ifp->if_addrlen == 0) * Spec says nothing in sections for RA, RS and NA. There's small * description on it in NS section (RFC 2461 7.2.3). */ flags = lladdr ? LLE_EXCLUSIVE : 0; ln = nd6_lookup(from, flags, ifp); is_newentry = 0; if (ln == NULL) { flags |= LLE_EXCLUSIVE; ln = nd6_alloc(from, 0, ifp); if (ln == NULL) return; /* * Since we already know all the data for the new entry, * fill it before insertion. */ if (lladdr != NULL) { linkhdrsize = sizeof(linkhdr); if (lltable_calc_llheader(ifp, AF_INET6, lladdr, linkhdr, &linkhdrsize, &lladdr_off) != 0) return; lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, lladdr_off); } IF_AFDATA_WLOCK(ifp); LLE_WLOCK(ln); /* Prefer any existing lle over newly-created one */ ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp); if (ln_tmp == NULL) lltable_link_entry(LLTABLE6(ifp), ln); IF_AFDATA_WUNLOCK(ifp); if (ln_tmp == NULL) { /* No existing lle, mark as new entry (6,7) */ is_newentry = 1; if (lladdr != NULL) { /* (7) */ nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); } } else { lltable_free_entry(LLTABLE6(ifp), ln); ln = ln_tmp; ln_tmp = NULL; } } /* do nothing if static ndp is set */ if ((ln->la_flags & LLE_STATIC)) { if (flags & LLE_EXCLUSIVE) LLE_WUNLOCK(ln); else LLE_RUNLOCK(ln); return; } olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0; if (olladdr && lladdr) { llchange = bcmp(lladdr, ln->ll_addr, ifp->if_addrlen); } else if (!olladdr && lladdr) llchange = 1; else llchange = 0; /* * newentry olladdr lladdr llchange (*=record) * 0 n n -- (1) * 0 y n -- (2) * 0 n y y (3) * STALE * 0 y y n (4) * * 0 y y y (5) * STALE * 1 -- n -- (6) NOSTATE(= PASSIVE) * 1 -- y -- (7) * STALE */ do_update = 0; if (is_newentry == 0 && llchange != 0) { do_update = 1; /* (3,5) */ /* * Record source link-layer address * XXX is it dependent to ifp->if_type? */ linkhdrsize = sizeof(linkhdr); if (lltable_calc_llheader(ifp, AF_INET6, lladdr, linkhdr, &linkhdrsize, &lladdr_off) != 0) return; if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize, lladdr_off) == 0) { /* Entry was deleted */ return; } nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); if (ln->la_hold != NULL) nd6_grab_holdchain(ln, &chain, &sin6); } /* Calculates new router status */ router = nd6_is_router(type, code, is_newentry, olladdr, lladdr != NULL ? 1 : 0, ln->ln_router); ln->ln_router = router; /* Mark non-router redirects with special flag */ if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER) ln->la_flags |= LLE_REDIRECT; if (flags & LLE_EXCLUSIVE) LLE_WUNLOCK(ln); else LLE_RUNLOCK(ln); if (chain != NULL) nd6_flush_holdchain(ifp, chain, &sin6); /* * When the link-layer address of a router changes, select the * best router again. In particular, when the neighbor entry is newly * created, it might affect the selection policy. * Question: can we restrict the first condition to the "is_newentry" * case? * XXX: when we hear an RA from a new router with the link-layer * address option, defrouter_select_fib() is called twice, since * defrtrlist_update called the function as well. However, I believe * we can compromise the overhead, since it only happens the first * time. * XXX: although defrouter_select_fib() should not have a bad effect * for those are not autoconfigured hosts, we explicitly avoid such * cases for safety. */ if ((do_update || is_newentry) && router && ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) { /* * guaranteed recursion */ defrouter_select_fib(ifp->if_fib); } } static void nd6_slowtimo(void *arg) { struct epoch_tracker et; CURVNET_SET((struct vnet *) arg); struct nd_ifinfo *nd6if; struct ifnet *ifp; callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz, nd6_slowtimo, curvnet); NET_EPOCH_ENTER(et); CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { if (ifp->if_afdata[AF_INET6] == NULL) continue; nd6if = ND_IFINFO(ifp); if (nd6if->basereachable && /* already initialized */ (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) { /* * Since reachable time rarely changes by router * advertisements, we SHOULD insure that a new random * value gets recomputed at least once every few hours. * (RFC 2461, 6.3.4) */ nd6if->recalctm = V_nd6_recalc_reachtm_interval; nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable); } } NET_EPOCH_EXIT(et); CURVNET_RESTORE(); } void nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain, struct sockaddr_in6 *sin6) { LLE_WLOCK_ASSERT(ln); *chain = ln->la_hold; ln->la_hold = NULL; lltable_fill_sa_entry(ln, (struct sockaddr *)sin6); if (ln->ln_state == ND6_LLINFO_STALE) { /* * The first time we send a packet to a * neighbor whose entry is STALE, we have * to change the state to DELAY and a sets * a timer to expire in DELAY_FIRST_PROBE_TIME * seconds to ensure do neighbor unreachability * detection on expiration. * (RFC 2461 7.3.3) */ nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY); } } int nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m, struct sockaddr_in6 *dst, struct route *ro) { int error; int ip6len; struct ip6_hdr *ip6; struct m_tag *mtag; #ifdef MAC mac_netinet6_nd6_send(ifp, m); #endif /* * If called from nd6_ns_output() (NS), nd6_na_output() (NA), * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA * as handled by rtsol and rtadvd), mbufs will be tagged for SeND * to be diverted to user space. When re-injected into the kernel, * send_output() will directly dispatch them to the outgoing interface. */ if (send_sendso_input_hook != NULL) { mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL); if (mtag != NULL) { ip6 = mtod(m, struct ip6_hdr *); ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen); /* Use the SEND socket */ error = send_sendso_input_hook(m, ifp, SND_OUT, ip6len); /* -1 == no app on SEND socket */ if (error == 0 || error != -1) return (error); } } m_clrprotoflags(m); /* Avoid confusing lower layers. */ IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL, mtod(m, struct ip6_hdr *)); if ((ifp->if_flags & IFF_LOOPBACK) == 0) origifp = ifp; error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro); return (error); } /* * Lookup link headerfor @sa_dst address. Stores found * data in @desten buffer. Copy of lle ln_flags can be also * saved in @pflags if @pflags is non-NULL. * * If destination LLE does not exists or lle state modification * is required, call "slow" version. * * Return values: * - 0 on success (address copied to buffer). * - EWOULDBLOCK (no local error, but address is still unresolved) * - other errors (alloc failure, etc) */ int nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m, const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags, struct llentry **plle) { struct llentry *ln = NULL; const struct sockaddr_in6 *dst6; NET_EPOCH_ASSERT(); if (pflags != NULL) *pflags = 0; dst6 = (const struct sockaddr_in6 *)sa_dst; /* discard the packet if IPv6 operation is disabled on the interface */ if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) { m_freem(m); return (ENETDOWN); /* better error? */ } if (m != NULL && m->m_flags & M_MCAST) { switch (ifp->if_type) { case IFT_ETHER: case IFT_L2VLAN: case IFT_BRIDGE: ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr, desten); return (0); default: m_freem(m); return (EAFNOSUPPORT); } } ln = nd6_lookup(&dst6->sin6_addr, plle ? LLE_EXCLUSIVE : LLE_UNLOCKED, ifp); if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) { /* Entry found, let's copy lle info */ bcopy(ln->r_linkdata, desten, ln->r_hdrlen); if (pflags != NULL) *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR); /* Check if we have feedback request from nd6 timer */ if (ln->r_skip_req != 0) { LLE_REQ_LOCK(ln); ln->r_skip_req = 0; /* Notify that entry was used */ ln->lle_hittime = time_uptime; LLE_REQ_UNLOCK(ln); } if (plle) { LLE_ADDREF(ln); *plle = ln; LLE_WUNLOCK(ln); } return (0); } else if (plle && ln) LLE_WUNLOCK(ln); return (nd6_resolve_slow(ifp, 0, m, dst6, desten, pflags, plle)); } /* * Do L2 address resolution for @sa_dst address. Stores found * address in @desten buffer. Copy of lle ln_flags can be also * saved in @pflags if @pflags is non-NULL. * * Heavy version. * Function assume that destination LLE does not exist, * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired. * * Set noinline to be dtrace-friendly */ static __noinline int nd6_resolve_slow(struct ifnet *ifp, int flags, struct mbuf *m, const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags, struct llentry **plle) { struct llentry *lle = NULL, *lle_tmp; struct in6_addr *psrc, src; int send_ns, ll_len; char *lladdr; NET_EPOCH_ASSERT(); /* * Address resolution or Neighbor Unreachability Detection * for the next hop. * At this point, the destination of the packet must be a unicast * or an anycast address(i.e. not a multicast). */ if (lle == NULL) { lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp); if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp)) { /* * Since nd6_is_addr_neighbor() internally calls nd6_lookup(), * the condition below is not very efficient. But we believe * it is tolerable, because this should be a rare case. */ lle = nd6_alloc(&dst->sin6_addr, 0, ifp); if (lle == NULL) { char ip6buf[INET6_ADDRSTRLEN]; log(LOG_DEBUG, "nd6_output: can't allocate llinfo for %s " "(ln=%p)\n", ip6_sprintf(ip6buf, &dst->sin6_addr), lle); m_freem(m); return (ENOBUFS); } IF_AFDATA_WLOCK(ifp); LLE_WLOCK(lle); /* Prefer any existing entry over newly-created one */ lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp); if (lle_tmp == NULL) lltable_link_entry(LLTABLE6(ifp), lle); IF_AFDATA_WUNLOCK(ifp); if (lle_tmp != NULL) { lltable_free_entry(LLTABLE6(ifp), lle); lle = lle_tmp; lle_tmp = NULL; } } } if (lle == NULL) { m_freem(m); return (ENOBUFS); } LLE_WLOCK_ASSERT(lle); /* * The first time we send a packet to a neighbor whose entry is * STALE, we have to change the state to DELAY and a sets a timer to * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do * neighbor unreachability detection on expiration. * (RFC 2461 7.3.3) */ if (lle->ln_state == ND6_LLINFO_STALE) nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY); /* * If the neighbor cache entry has a state other than INCOMPLETE * (i.e. its link-layer address is already resolved), just * send the packet. */ if (lle->ln_state > ND6_LLINFO_INCOMPLETE) { if (flags & LLE_ADDRONLY) { lladdr = lle->ll_addr; ll_len = ifp->if_addrlen; } else { lladdr = lle->r_linkdata; ll_len = lle->r_hdrlen; } bcopy(lladdr, desten, ll_len); if (pflags != NULL) *pflags = lle->la_flags; if (plle) { LLE_ADDREF(lle); *plle = lle; } LLE_WUNLOCK(lle); return (0); } /* * There is a neighbor cache entry, but no ethernet address * response yet. Append this latest packet to the end of the * packet queue in the mbuf. When it exceeds nd6_maxqueuelen, * the oldest packet in the queue will be removed. */ if (lle->la_hold != NULL) { struct mbuf *m_hold; int i; i = 0; for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){ i++; if (m_hold->m_nextpkt == NULL) { m_hold->m_nextpkt = m; break; } } while (i >= V_nd6_maxqueuelen) { m_hold = lle->la_hold; lle->la_hold = lle->la_hold->m_nextpkt; m_freem(m_hold); i--; } } else { lle->la_hold = m; } /* * If there has been no NS for the neighbor after entering the * INCOMPLETE state, send the first solicitation. * Note that for newly-created lle la_asked will be 0, * so we will transition from ND6_LLINFO_NOSTATE to * ND6_LLINFO_INCOMPLETE state here. */ psrc = NULL; send_ns = 0; if (lle->la_asked == 0) { lle->la_asked++; send_ns = 1; psrc = nd6_llinfo_get_holdsrc(lle, &src); nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE); } LLE_WUNLOCK(lle); if (send_ns != 0) nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL); return (EWOULDBLOCK); } /* * Do L2 address resolution for @sa_dst address. Stores found * address in @desten buffer. Copy of lle ln_flags can be also * saved in @pflags if @pflags is non-NULL. * * Return values: * - 0 on success (address copied to buffer). * - EWOULDBLOCK (no local error, but address is still unresolved) * - other errors (alloc failure, etc) */ int nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst, char *desten, uint32_t *pflags) { int error; flags |= LLE_ADDRONLY; error = nd6_resolve_slow(ifp, flags, NULL, (const struct sockaddr_in6 *)dst, desten, pflags, NULL); return (error); } int nd6_flush_holdchain(struct ifnet *ifp, struct mbuf *chain, struct sockaddr_in6 *dst) { struct mbuf *m, *m_head; int error = 0; m_head = chain; while (m_head) { m = m_head; m_head = m_head->m_nextpkt; error = nd6_output_ifp(ifp, ifp, m, dst, NULL); } /* * XXX * note that intermediate errors are blindly ignored */ return (error); } static int nd6_need_cache(struct ifnet *ifp) { /* * XXX: we currently do not make neighbor cache on any interface * other than Ethernet and GIF. * * RFC2893 says: * - unidirectional tunnels needs no ND */ switch (ifp->if_type) { case IFT_ETHER: case IFT_IEEE1394: case IFT_L2VLAN: case IFT_INFINIBAND: case IFT_BRIDGE: case IFT_PROPVIRTUAL: return (1); default: return (0); } } /* * Add pernament ND6 link-layer record for given * interface address. * * Very similar to IPv4 arp_ifinit(), but: * 1) IPv6 DAD is performed in different place * 2) It is called by IPv6 protocol stack in contrast to * arp_ifinit() which is typically called in SIOCSIFADDR * driver ioctl handler. * */ int nd6_add_ifa_lle(struct in6_ifaddr *ia) { struct ifnet *ifp; struct llentry *ln, *ln_tmp; struct sockaddr *dst; ifp = ia->ia_ifa.ifa_ifp; if (nd6_need_cache(ifp) == 0) return (0); dst = (struct sockaddr *)&ia->ia_addr; ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst); if (ln == NULL) return (ENOBUFS); IF_AFDATA_WLOCK(ifp); LLE_WLOCK(ln); /* Unlink any entry if exists */ ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst); if (ln_tmp != NULL) lltable_unlink_entry(LLTABLE6(ifp), ln_tmp); lltable_link_entry(LLTABLE6(ifp), ln); IF_AFDATA_WUNLOCK(ifp); if (ln_tmp != NULL) EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED); EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED); LLE_WUNLOCK(ln); if (ln_tmp != NULL) llentry_free(ln_tmp); return (0); } /* * Removes either all lle entries for given @ia, or lle * corresponding to @ia address. */ void nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all) { struct sockaddr_in6 mask, addr; struct sockaddr *saddr, *smask; struct ifnet *ifp; ifp = ia->ia_ifa.ifa_ifp; memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr)); memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask)); saddr = (struct sockaddr *)&addr; smask = (struct sockaddr *)&mask; if (all != 0) lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC); else lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr); } static void clear_llinfo_pqueue(struct llentry *ln) { struct mbuf *m_hold, *m_hold_next; for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) { m_hold_next = m_hold->m_nextpkt; m_freem(m_hold); } ln->la_hold = NULL; } static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS) { struct in6_prefix p; struct sockaddr_in6 s6; struct nd_prefix *pr; struct nd_pfxrouter *pfr; time_t maxexpire; int error; char ip6buf[INET6_ADDRSTRLEN]; if (req->newptr) return (EPERM); error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); bzero(&p, sizeof(p)); p.origin = PR_ORIG_RA; bzero(&s6, sizeof(s6)); s6.sin6_family = AF_INET6; s6.sin6_len = sizeof(s6); ND6_RLOCK(); LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) { p.prefix = pr->ndpr_prefix; if (sa6_recoverscope(&p.prefix)) { log(LOG_ERR, "scope error in prefix list (%s)\n", ip6_sprintf(ip6buf, &p.prefix.sin6_addr)); /* XXX: press on... */ } p.raflags = pr->ndpr_raf; p.prefixlen = pr->ndpr_plen; p.vltime = pr->ndpr_vltime; p.pltime = pr->ndpr_pltime; p.if_index = pr->ndpr_ifp->if_index; if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME) p.expire = 0; else { /* XXX: we assume time_t is signed. */ maxexpire = (-1) & ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1)); if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate) p.expire = pr->ndpr_lastupdate + pr->ndpr_vltime + (time_second - time_uptime); else p.expire = maxexpire; } p.refcnt = pr->ndpr_addrcnt; p.flags = pr->ndpr_stateflags; p.advrtrs = 0; LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) p.advrtrs++; error = SYSCTL_OUT(req, &p, sizeof(p)); if (error != 0) break; LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) { s6.sin6_addr = pfr->router->rtaddr; if (sa6_recoverscope(&s6)) log(LOG_ERR, "scope error in prefix list (%s)\n", ip6_sprintf(ip6buf, &pfr->router->rtaddr)); error = SYSCTL_OUT(req, &s6, sizeof(s6)); if (error != 0) goto out; } } out: ND6_RUNLOCK(); return (error); } SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist, CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, nd6_sysctl_prlist, "S,in6_prefix", "NDP prefix list"); SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, ""); SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), ""); diff --git a/usr.sbin/arp/arp.4 b/usr.sbin/arp/arp.4 index f13af95778a8..c9c9002cf908 100644 --- a/usr.sbin/arp/arp.4 +++ b/usr.sbin/arp/arp.4 @@ -1,251 +1,240 @@ .\" Copyright (c) 1985, 1986, 1988, 1994 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)arp4.4 6.5 (Berkeley) 4/18/94 .\" $FreeBSD$ .\" .Dd October 7, 2016 .Dt ARP 4 .Os .Sh NAME .Nm arp .Nd Address Resolution Protocol .Sh SYNOPSIS .Cd "device ether" .Sh DESCRIPTION The Address Resolution Protocol (ARP) is used to dynamically map between Protocol Addresses (such as IP addresses) and Local Network Addresses (such as Ethernet addresses). -This implementation maps IP addresses to Ethernet, -ARCnet, -or Token Ring addresses. +This implementation maps IP addresses to Ethernet addresses. It is used by all the Ethernet interface drivers. .Pp ARP caches Internet-Ethernet address mappings. When an interface requests a mapping for an address not in the cache, ARP queues the message which requires the mapping and broadcasts a message on the associated network requesting the address mapping. If a response is provided, the new mapping is cached and any pending message is transmitted. -ARP will queue at most one packet while waiting for a response to a -mapping request; -only the most recently ``transmitted'' packet is kept. +ARP will queue at most +.Va net.link.ether.inet.maxhold +packets while waiting for a response to a mapping request; +only the most recently ``transmitted'' packets are kept. If the target host does not respond after several requests, the host is considered to be down allowing an error to be returned to transmission attempts. Further demand for this mapping causes ARP request retransmissions, that are ratelimited to one packet per second. The error is .Er EHOSTDOWN for a non-responding destination host, and .Er EHOSTUNREACH for a non-responding router. .Pp -The ARP cache is stored in the system routing table as -dynamically-created host routes. -The route to a directly-attached Ethernet network is installed as a -.Dq cloning -route (one with the -.Li RTF_CLONING -flag set), -causing routes to individual hosts on that network to be created on -demand. -These routes time out periodically (normally 20 minutes after validated; -entries are not validated when not in use). +The ARP cache is stored in per-interface link-level table. .Pp ARP entries may be added, deleted or changed with the .Xr arp 8 utility. Manually-added entries may be temporary or permanent, and may be .Dq published , in which case the system will respond to ARP requests for that host as if it were the target of the request. .Pp In the past, ARP was used to negotiate the use of a trailer encapsulation. This is no longer supported. .Pp ARP watches passively for hosts impersonating the local host (i.e., a host which responds to an ARP mapping request for the local host's address). .Pp Proxy ARP is a feature whereby the local host will respond to requests for addresses other than itself, with its own address. Normally, proxy ARP in .Fx is set up on a host-by-host basis using the .Xr arp 8 utility, by adding an entry for each host inside a given subnet for which proxying of ARP requests is desired. However, the .Dq "proxy all" feature causes the local host to act as a proxy for .Em all hosts reachable through some other network interface, different from the one the request came in from. It may be enabled by setting the .Xr sysctl 8 MIB variable .Va net.link.ether.inet.proxyall to 1. .Sh MIB Variables The ARP protocol implements a number of configurable variables in .Va net.link.ether.inet branch of the .Xr sysctl 3 MIB. .Bl -tag -width "log_arp_permanent_modify" .It Va allow_multicast Install ARP entries with the multicast bit set in the hardware address. Installing such entries is an RFC 1812 violation, but some proprietary load balancing techniques require routers to do so. Turned off by default. .It Va garp_rexmit_count Retransmit gratuitous ARP (GARP) packets when an IPv4 address is added to an interface. A GARP is always transmitted when an IPv4 address is added to an interface. A non-zero value causes the GARP packet to be retransmitted the stated number of times. The interval between retransmissions is doubled each time, so the retransmission intervals are: {1, 2, 4, 8, 16, ...} (seconds). The default value of zero means only the initial GARP is sent; no additional GARP packets are retransmitted. The maximum value is sixteen. .Pp The default behavior of a single GARP packet is usually sufficient. However, a single GARP might be dropped or lost in some circumstances. This is particularly harmful when a shared address is passed between cluster nodes. Neighbors on the network link might then work with a stale ARP cache and send packets destined for that address to the node that previously owned the address, which might not respond. .It Va log_arp_movements Log movements of IP addresses from one hardware address to another. See .Sx DIAGNOSTICS below. Turned on by default. .It Va log_arp_permanent_modify Log attempts by a remote host to modify a permanent ARP entry. See .Sx DIAGNOSTICS below. Turned on by default. .It Va log_arp_wrong_iface Log attempts to insert an ARP entry on an interface when the IP network to which the address belongs is connected to another interface. See .Sx DIAGNOSTICS below. Turned on by default. .It Va max_log_per_second Limit the number of remotely triggered logging events to a configured value per second. Default is 1 log message per second. .It Va max_age How long an ARP entry is held in the cache until it needs to be refreshed. Default is 1200 seconds. .It Va maxhold How many packets to hold in the per-entry output queue while the entry is being resolved. -Default is one packet. +Default is 16 packets. .It Va maxtries Number of retransmits before a host is considered down and an error is returned. Default is 5 tries. .It Va proxyall Enables ARP proxying. Turned off by default. .It Va wait Lifetime of an incomplete ARP entry. Default is 20 seconds. .El .Sh DIAGNOSTICS .Bl -diag .It "arp: %x:%x:%x:%x:%x:%x is using my IP address %d.%d.%d.%d on %s!" ARP has discovered another host on the local network which responds to mapping requests for its own Internet address with a different Ethernet address, generally indicating that two hosts are attempting to use the same Internet address. .It "arp: link address is broadcast for IP address %d.%d.%d.%d!" ARP requested information for a host, and received an answer indicating that the host's ethernet address is the ethernet broadcast address. This indicates a misconfigured or broken device. .It "arp: %d.%d.%d.%d moved from %x:%x:%x:%x:%x:%x to %x:%x:%x:%x:%x:%x on %s" ARP had a cached value for the ethernet address of the referenced host, but received a reply indicating that the host is at a new address. This can happen normally when host hardware addresses change, or when a mobile node arrives or leaves the local subnet. It can also indicate a problem with proxy ARP. This message can only be issued if the sysctl .Va net.link.ether.inet.log_arp_movements is set to 1, which is the system's default behaviour. .It "arpresolve: can't allocate llinfo for %d.%d.%d.%d" The route for the referenced host points to a device upon which ARP is required, but ARP was unable to allocate a routing table entry in which to store the host's MAC address. This usually points to a misconfigured routing table. It can also occur if the kernel cannot allocate memory. .It "arp: %d.%d.%d.%d is on if0 but got reply from %x:%x:%x:%x:%x:%x on if1" Physical connections exist to the same logical IP network on both if0 and if1. It can also occur if an entry already exists in the ARP cache for the IP address above, and the cable has been disconnected from if0, then reconnected to if1. This message can only be issued if the sysctl .Va net.link.ether.inet.log_arp_wrong_iface is set to 1, which is the system's default behaviour. .It "arp: %x:%x:%x:%x:%x:%x attempts to modify permanent entry for %d.%d.%d.%d on %s" ARP has received an ARP reply that attempts to overwrite a permanent entry in the local ARP table. This error will only be logged if the sysctl .Va net.link.ether.inet.log_arp_permanent_modify is set to 1, which is the system's default behaviour. .It "arp: %x:%x:%x:%x:%x:%x is multicast" Kernel refused to install an entry with multicast hardware address. If you really want such addresses being installed, set the sysctl .Va net.link.ether.inet.allow_multicast to a positive value. .El .Sh SEE ALSO .Xr inet 4 , .Xr route 4 , .Xr arp 8 , .Xr ifconfig 8 , .Xr route 8 , .Xr sysctl 8 .Rs .%A Plummer, D. .%B "An Ethernet Address Resolution Protocol" .%T RFC826 .Re .Rs .%A Leffler, S.J. .%A Karels, M.J. .%B "Trailer Encapsulations" .%T RFC893 .Re