diff options
Diffstat (limited to 'sys/netinet/if_ether.c')
| -rw-r--r-- | sys/netinet/if_ether.c | 847 |
1 files changed, 847 insertions, 0 deletions
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c new file mode 100644 index 0000000..de5d906 --- /dev/null +++ b/sys/netinet/if_ether.c @@ -0,0 +1,847 @@ +/* + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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 + * $FreeBSD$ + */ + +/* + * Ethernet address resolution protocol. + * TODO: + * add "inuse/lock" bit (or ref. count) along with valid bit + */ + +#include "opt_inet.h" +#include "opt_bdg.h" + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/queue.h> +#include <sys/sysctl.h> +#include <sys/systm.h> +#include <sys/mbuf.h> +#include <sys/malloc.h> +#include <sys/socket.h> +#include <sys/syslog.h> + +#include <net/if.h> +#include <net/if_dl.h> +#include <net/if_types.h> +#include <net/route.h> +#include <net/netisr.h> +#include <net/if_llc.h> +#ifdef BRIDGE +#include <net/ethernet.h> +#include <net/bridge.h> +#endif + +#include <netinet/in.h> +#include <netinet/in_var.h> +#include <netinet/if_ether.h> + +#include <net/iso88025.h> + +#define SIN(s) ((struct sockaddr_in *)s) +#define SDL(s) ((struct sockaddr_dl *)s) + +SYSCTL_DECL(_net_link_ether); +SYSCTL_NODE(_net_link_ether, PF_INET, inet, CTLFLAG_RW, 0, ""); + +/* timer values */ +static int arpt_prune = (5*60*1); /* walk list every 5 minutes */ +static int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */ +static int arpt_down = 20; /* once declared down, don't send for 20 sec */ + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, prune_intvl, CTLFLAG_RW, + &arpt_prune, 0, ""); +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, max_age, CTLFLAG_RW, + &arpt_keep, 0, ""); +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, host_down_time, CTLFLAG_RW, + &arpt_down, 0, ""); + +#define rt_expire rt_rmx.rmx_expire + +struct llinfo_arp { + LIST_ENTRY(llinfo_arp) la_le; + struct rtentry *la_rt; + struct mbuf *la_hold; /* last packet until resolved/timeout */ + long la_asked; /* last time we QUERIED for this addr */ +#define la_timer la_rt->rt_rmx.rmx_expire /* deletion time in seconds */ +}; + +static LIST_HEAD(, llinfo_arp) llinfo_arp; + +struct ifqueue arpintrq; +static int arp_inuse, arp_allocated; + +static int arp_maxtries = 5; +static int useloopback = 1; /* use loopback interface for local traffic */ +static int arp_proxyall = 0; + +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, maxtries, CTLFLAG_RW, + &arp_maxtries, 0, ""); +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, useloopback, CTLFLAG_RW, + &useloopback, 0, ""); +SYSCTL_INT(_net_link_ether_inet, OID_AUTO, proxyall, CTLFLAG_RW, + &arp_proxyall, 0, ""); + +static void arp_init __P((void)); +static void arp_rtrequest __P((int, struct rtentry *, struct sockaddr *)); +static void arprequest __P((struct arpcom *, + struct in_addr *, struct in_addr *, u_char *)); +static void arpintr __P((void)); +static void arptfree __P((struct llinfo_arp *)); +static void arptimer __P((void *)); +static struct llinfo_arp + *arplookup __P((u_long, int, int)); +#ifdef INET +static void in_arpinput __P((struct mbuf *)); +#endif + +/* + * Timeout routine. Age arp_tab entries periodically. + */ +/* ARGSUSED */ +static void +arptimer(ignored_arg) + void *ignored_arg; +{ + int s = splnet(); + register struct llinfo_arp *la = LIST_FIRST(&llinfo_arp); + struct llinfo_arp *ola; + + timeout(arptimer, (caddr_t)0, arpt_prune * hz); + while ((ola = la) != 0) { + register struct rtentry *rt = la->la_rt; + la = LIST_NEXT(la, la_le); + if (rt->rt_expire && rt->rt_expire <= time_second) + arptfree(ola); /* timer has expired, clear */ + } + splx(s); +} + +/* + * Parallel to llc_rtrequest. + */ +static void +arp_rtrequest(req, rt, sa) + int req; + register struct rtentry *rt; + struct sockaddr *sa; +{ + register struct sockaddr *gate = rt->rt_gateway; + register struct llinfo_arp *la = (struct llinfo_arp *)rt->rt_llinfo; + static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK}; + static int arpinit_done; + + if (!arpinit_done) { + arpinit_done = 1; + LIST_INIT(&llinfo_arp); + timeout(arptimer, (caddr_t)0, hz); + register_netisr(NETISR_ARP, arpintr); + } + if (rt->rt_flags & RTF_GATEWAY) + return; + switch (req) { + + case RTM_ADD: + /* + * XXX: If this is a manually added route to interface + * such as older version of routed or gated might provide, + * restore cloning bit. + */ + if ((rt->rt_flags & RTF_HOST) == 0 && + SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff) + rt->rt_flags |= RTF_CLONING; + if (rt->rt_flags & RTF_CLONING) { + /* + * Case 1: This route should come from a route to iface. + */ + rt_setgate(rt, rt_key(rt), + (struct sockaddr *)&null_sdl); + gate = rt->rt_gateway; + SDL(gate)->sdl_type = rt->rt_ifp->if_type; + SDL(gate)->sdl_index = rt->rt_ifp->if_index; + rt->rt_expire = time_second; + break; + } + /* Announce a new entry if requested. */ + if (rt->rt_flags & RTF_ANNOUNCE) + arprequest((struct arpcom *)rt->rt_ifp, + &SIN(rt_key(rt))->sin_addr, + &SIN(rt_key(rt))->sin_addr, + (u_char *)LLADDR(SDL(gate))); + /*FALLTHROUGH*/ + case RTM_RESOLVE: + if (gate->sa_family != AF_LINK || + gate->sa_len < sizeof(null_sdl)) { + log(LOG_DEBUG, "arp_rtrequest: bad gateway value\n"); + break; + } + SDL(gate)->sdl_type = rt->rt_ifp->if_type; + SDL(gate)->sdl_index = rt->rt_ifp->if_index; + if (la != 0) + break; /* This happens on a route change */ + /* + * Case 2: This route may come from cloning, or a manual route + * add with a LL address. + */ + R_Malloc(la, struct llinfo_arp *, sizeof(*la)); + rt->rt_llinfo = (caddr_t)la; + if (la == 0) { + log(LOG_DEBUG, "arp_rtrequest: malloc failed\n"); + break; + } + arp_inuse++, arp_allocated++; + Bzero(la, sizeof(*la)); + la->la_rt = rt; + rt->rt_flags |= RTF_LLINFO; + LIST_INSERT_HEAD(&llinfo_arp, la, la_le); + +#ifdef INET + /* + * This keeps the multicast addresses from showing up + * in `arp -a' listings as unresolved. It's not actually + * functional. Then the same for broadcast. + */ + if (IN_MULTICAST(ntohl(SIN(rt_key(rt))->sin_addr.s_addr))) { + ETHER_MAP_IP_MULTICAST(&SIN(rt_key(rt))->sin_addr, + LLADDR(SDL(gate))); + SDL(gate)->sdl_alen = 6; + rt->rt_expire = 0; + } + if (in_broadcast(SIN(rt_key(rt))->sin_addr, rt->rt_ifp)) { + memcpy(LLADDR(SDL(gate)), etherbroadcastaddr, 6); + SDL(gate)->sdl_alen = 6; + rt->rt_expire = 0; + } +#endif + + if (SIN(rt_key(rt))->sin_addr.s_addr == + (IA_SIN(rt->rt_ifa))->sin_addr.s_addr) { + /* + * This test used to be + * if (loif.if_flags & IFF_UP) + * It allowed local traffic to be forced + * through the hardware by configuring the loopback down. + * However, it causes problems during network configuration + * for boards that can't receive packets they send. + * It is now necessary to clear "useloopback" and remove + * the route to force traffic out to the hardware. + */ + rt->rt_expire = 0; + Bcopy(((struct arpcom *)rt->rt_ifp)->ac_enaddr, + LLADDR(SDL(gate)), SDL(gate)->sdl_alen = 6); + if (useloopback) + rt->rt_ifp = loif; + + } + break; + + case RTM_DELETE: + if (la == 0) + break; + arp_inuse--; + LIST_REMOVE(la, la_le); + rt->rt_llinfo = 0; + rt->rt_flags &= ~RTF_LLINFO; + if (la->la_hold) + m_freem(la->la_hold); + Free((caddr_t)la); + } +} + +/* + * Broadcast an ARP request. Caller specifies: + * - arp header source ip address + * - arp header target ip address + * - arp header source ethernet address + */ +static void +arprequest(ac, sip, tip, enaddr) + register struct arpcom *ac; + register struct in_addr *sip, *tip; + register u_char *enaddr; +{ + register struct mbuf *m; + register struct ether_header *eh; + register struct ether_arp *ea; + struct sockaddr sa; + static u_char llcx[] = { 0x82, 0x40, LLC_SNAP_LSAP, LLC_SNAP_LSAP, + LLC_UI, 0x00, 0x00, 0x00, 0x08, 0x06 }; + + if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) + return; + m->m_pkthdr.rcvif = (struct ifnet *)0; + switch (ac->ac_if.if_type) { + case IFT_ISO88025: + m->m_len = sizeof(*ea) + sizeof(llcx); + m->m_pkthdr.len = sizeof(*ea) + sizeof(llcx); + MH_ALIGN(m, sizeof(*ea) + sizeof(llcx)); + (void)memcpy(mtod(m, caddr_t), llcx, sizeof(llcx)); + (void)memcpy(sa.sa_data, etherbroadcastaddr, 6); + (void)memcpy(sa.sa_data + 6, enaddr, 6); + sa.sa_data[6] |= TR_RII; + sa.sa_data[12] = TR_AC; + sa.sa_data[13] = TR_LLC_FRAME; + ea = (struct ether_arp *)(mtod(m, char *) + sizeof(llcx)); + bzero((caddr_t)ea, sizeof (*ea)); + ea->arp_hrd = htons(ARPHRD_IEEE802); + break; + case IFT_FDDI: + case IFT_ETHER: + /* + * This may not be correct for types not explicitly + * listed, but this is our best guess + */ + default: + m->m_len = sizeof(*ea); + m->m_pkthdr.len = sizeof(*ea); + MH_ALIGN(m, sizeof(*ea)); + ea = mtod(m, struct ether_arp *); + eh = (struct ether_header *)sa.sa_data; + bzero((caddr_t)ea, sizeof (*ea)); + /* if_output will not swap */ + eh->ether_type = htons(ETHERTYPE_ARP); + (void)memcpy(eh->ether_dhost, etherbroadcastaddr, + sizeof(eh->ether_dhost)); + ea->arp_hrd = htons(ARPHRD_ETHER); + break; + } + ea->arp_pro = htons(ETHERTYPE_IP); + ea->arp_hln = sizeof(ea->arp_sha); /* hardware address length */ + ea->arp_pln = sizeof(ea->arp_spa); /* protocol address length */ + ea->arp_op = htons(ARPOP_REQUEST); + (void)memcpy(ea->arp_sha, enaddr, sizeof(ea->arp_sha)); + (void)memcpy(ea->arp_spa, sip, sizeof(ea->arp_spa)); + (void)memcpy(ea->arp_tpa, tip, sizeof(ea->arp_tpa)); + sa.sa_family = AF_UNSPEC; + sa.sa_len = sizeof(sa); + (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); +} + +/* + * Resolve an IP address into an ethernet address. If success, + * desten is filled in. If there is no entry in arptab, + * set one up and broadcast a request for the IP address. + * Hold onto this mbuf and resend it once the address + * is finally resolved. A return value of 1 indicates + * that desten has been filled in and the packet should be sent + * normally; a 0 return indicates that the packet has been + * taken over here, either now or for later transmission. + */ +int +arpresolve(ac, rt, m, dst, desten, rt0) + register struct arpcom *ac; + register struct rtentry *rt; + struct mbuf *m; + register struct sockaddr *dst; + register u_char *desten; + struct rtentry *rt0; +{ + register struct llinfo_arp *la = 0; + struct sockaddr_dl *sdl; + + if (m->m_flags & M_BCAST) { /* broadcast */ + (void)memcpy(desten, etherbroadcastaddr, sizeof(etherbroadcastaddr)); + return (1); + } + if (m->m_flags & M_MCAST) { /* multicast */ + ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr, desten); + return(1); + } + if (rt) + la = (struct llinfo_arp *)rt->rt_llinfo; + if (la == 0) { + la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0); + if (la) + rt = la->la_rt; + } + if (la == 0 || rt == 0) { + log(LOG_DEBUG, "arpresolve: can't allocate llinfo for %s%s%s\n", + inet_ntoa(SIN(dst)->sin_addr), la ? "la" : "", + rt ? "rt" : ""); + m_freem(m); + return (0); + } + sdl = SDL(rt->rt_gateway); + /* + * Check the address family and length is valid, the address + * is resolved; otherwise, try to resolve. + */ + if ((rt->rt_expire == 0 || rt->rt_expire > time_second) && + sdl->sdl_family == AF_LINK && sdl->sdl_alen != 0) { + bcopy(LLADDR(sdl), desten, sdl->sdl_alen); + return 1; + } + /* + * There is an arptab entry, but no ethernet address + * response yet. Replace the held mbuf with this + * latest one. + */ + if (la->la_hold) + m_freem(la->la_hold); + la->la_hold = m; + if (rt->rt_expire) { + rt->rt_flags &= ~RTF_REJECT; + if (la->la_asked == 0 || rt->rt_expire != time_second) { + rt->rt_expire = time_second; + if (la->la_asked++ < arp_maxtries) + arprequest(ac, + &SIN(rt->rt_ifa->ifa_addr)->sin_addr, + &SIN(dst)->sin_addr, ac->ac_enaddr); + else { + rt->rt_flags |= RTF_REJECT; + rt->rt_expire += arpt_down; + la->la_asked = 0; + } + + } + } + return (0); +} + +/* + * Common length and type checks are done here, + * then the protocol-specific routine is called. + */ +static void +arpintr() +{ + register struct mbuf *m; + register struct arphdr *ar; + int s; + + while (arpintrq.ifq_head) { + s = splimp(); + IF_DEQUEUE(&arpintrq, m); + splx(s); + if (m == 0 || (m->m_flags & M_PKTHDR) == 0) + panic("arpintr"); + + if (m->m_len < sizeof(struct arphdr) && + ((m = m_pullup(m, sizeof(struct arphdr))) == NULL)) { + log(LOG_ERR, "arp: runt packet -- m_pullup failed\n"); + continue; + } + ar = mtod(m, struct arphdr *); + + if (ntohs(ar->ar_hrd) != ARPHRD_ETHER + && ntohs(ar->ar_hrd) != ARPHRD_IEEE802) { + log(LOG_ERR, + "arp: unknown hardware address format (0x%2D)\n", + (unsigned char *)&ar->ar_hrd, ""); + m_freem(m); + continue; + } + + if (m->m_pkthdr.len < sizeof(struct arphdr) + 2 * ar->ar_hln + + 2 * ar->ar_pln) { + log(LOG_ERR, "arp: runt packet\n"); + m_freem(m); + continue; + } + + switch (ntohs(ar->ar_pro)) { +#ifdef INET + case ETHERTYPE_IP: + in_arpinput(m); + continue; +#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; + +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"); + +static void +in_arpinput(m) + struct mbuf *m; +{ + register struct ether_arp *ea; + register struct arpcom *ac = (struct arpcom *)m->m_pkthdr.rcvif; + struct ether_header *eh; + struct iso88025_header *th = (struct iso88025_header *)0; + register struct llinfo_arp *la = 0; + register struct rtentry *rt; + struct in_ifaddr *ia, *maybe_ia = 0; + struct sockaddr_dl *sdl; + struct sockaddr sa; + struct in_addr isaddr, itaddr, myaddr; + int op, rif_len; + + if (m->m_len < sizeof(struct ether_arp) && + (m = m_pullup(m, sizeof(struct ether_arp))) == NULL) { + log(LOG_ERR, "in_arp: runt packet -- m_pullup failed\n"); + return; + } + + ea = mtod(m, struct ether_arp *); + op = ntohs(ea->arp_op); + (void)memcpy(&isaddr, ea->arp_spa, sizeof (isaddr)); + (void)memcpy(&itaddr, ea->arp_tpa, sizeof (itaddr)); + TAILQ_FOREACH(ia, &in_ifaddrhead, ia_link) { + /* + * For a bridge, we want to check the address irrespective + * of the receive interface. (This will change slightly + * when we have clusters of interfaces). + */ +#ifdef BRIDGE +#define BRIDGE_TEST (do_bridge) +#else +#define BRIDGE_TEST (0) /* cc will optimise the test away */ +#endif + if ((BRIDGE_TEST) || (ia->ia_ifp == &ac->ac_if)) { + maybe_ia = ia; + if ((itaddr.s_addr == ia->ia_addr.sin_addr.s_addr) || + (isaddr.s_addr == ia->ia_addr.sin_addr.s_addr)) { + break; + } + } + } + if (maybe_ia == 0) { + m_freem(m); + return; + } + myaddr = ia ? ia->ia_addr.sin_addr : maybe_ia->ia_addr.sin_addr; + if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)ac->ac_enaddr, + sizeof (ea->arp_sha))) { + m_freem(m); /* it's from me, ignore it. */ + return; + } + if (!bcmp((caddr_t)ea->arp_sha, (caddr_t)etherbroadcastaddr, + sizeof (ea->arp_sha))) { + log(LOG_ERR, + "arp: ether address is broadcast for IP address %s!\n", + inet_ntoa(isaddr)); + m_freem(m); + return; + } + if (isaddr.s_addr == myaddr.s_addr) { + log(LOG_ERR, + "arp: %6D is using my IP address %s!\n", + ea->arp_sha, ":", inet_ntoa(isaddr)); + itaddr = myaddr; + goto reply; + } + la = arplookup(isaddr.s_addr, itaddr.s_addr == myaddr.s_addr, 0); + if (la && (rt = la->la_rt) && (sdl = SDL(rt->rt_gateway))) { + /* the following is not an error when doing bridging */ + if (!BRIDGE_TEST && rt->rt_ifp != &ac->ac_if) { + if (log_arp_wrong_iface) + log(LOG_ERR, "arp: %s is on %s%d but got reply from %6D on %s%d\n", + inet_ntoa(isaddr), + rt->rt_ifp->if_name, rt->rt_ifp->if_unit, + ea->arp_sha, ":", + ac->ac_if.if_name, ac->ac_if.if_unit); + goto reply; + } + if (sdl->sdl_alen && + bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen)) { + if (rt->rt_expire) + log(LOG_INFO, "arp: %s moved from %6D to %6D on %s%d\n", + inet_ntoa(isaddr), (u_char *)LLADDR(sdl), ":", + ea->arp_sha, ":", + ac->ac_if.if_name, ac->ac_if.if_unit); + else { + log(LOG_ERR, + "arp: %6D attempts to modify permanent entry for %s on %s%d\n", + ea->arp_sha, ":", inet_ntoa(isaddr), + ac->ac_if.if_name, ac->ac_if.if_unit); + goto reply; + } + } + (void)memcpy(LLADDR(sdl), ea->arp_sha, sizeof(ea->arp_sha)); + sdl->sdl_alen = sizeof(ea->arp_sha); + sdl->sdl_rcf = (u_short)0; + /* + * If we receive an arp from a token-ring station over + * a token-ring nic then try to save the source + * routing info. + */ + if (ac->ac_if.if_type == IFT_ISO88025) { + th = (struct iso88025_header *)m->m_pkthdr.header; + rif_len = TR_RCF_RIFLEN(th->rcf); + if ((th->iso88025_shost[0] & TR_RII) && + (rif_len > 2)) { + sdl->sdl_rcf = th->rcf; + sdl->sdl_rcf ^= htons(TR_RCF_DIR); + memcpy(sdl->sdl_route, th->rd, rif_len - 2); + sdl->sdl_rcf &= ~htons(TR_RCF_BCST_MASK); + /* + * Set up source routing information for + * reply packet (XXX) + */ + m->m_data -= rif_len; + m->m_len += rif_len; + m->m_pkthdr.len += rif_len; + } else { + th->iso88025_shost[0] &= ~TR_RII; + } + m->m_data -= 8; + m->m_len += 8; + m->m_pkthdr.len += 8; + th->rcf = sdl->sdl_rcf; + } else { + sdl->sdl_rcf = (u_short)0; + } + if (rt->rt_expire) + rt->rt_expire = time_second + arpt_keep; + rt->rt_flags &= ~RTF_REJECT; + la->la_asked = 0; + if (la->la_hold) { + (*ac->ac_if.if_output)(&ac->ac_if, la->la_hold, + rt_key(rt), rt); + la->la_hold = 0; + } + } +reply: + if (op != ARPOP_REQUEST) { + m_freem(m); + return; + } + if (itaddr.s_addr == myaddr.s_addr) { + /* I am the target */ + (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); + (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha)); + } else { + la = arplookup(itaddr.s_addr, 0, SIN_PROXY); + if (la == NULL) { + struct sockaddr_in sin; + + if (!arp_proxyall) { + m_freem(m); + return; + } + + bzero(&sin, sizeof sin); + sin.sin_family = AF_INET; + sin.sin_len = sizeof sin; + sin.sin_addr = itaddr; + + rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); + if (!rt) { + m_freem(m); + return; + } + /* + * 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 (rt->rt_ifp == &ac->ac_if) { + rtfree(rt); + m_freem(m); + return; + } + (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); + (void)memcpy(ea->arp_sha, ac->ac_enaddr, sizeof(ea->arp_sha)); + rtfree(rt); + + /* + * Also check that the node which sent the ARP packet + * is on the the interface we expect it to be on. This + * avoids ARP chaos if an interface is connected to the + * wrong network. + */ + sin.sin_addr = isaddr; + + rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL); + if (!rt) { + m_freem(m); + return; + } + if (rt->rt_ifp != &ac->ac_if) { + log(LOG_INFO, "arp_proxy: ignoring request" + " from %s via %s%d, expecting %s%d\n", + inet_ntoa(isaddr), ac->ac_if.if_name, + ac->ac_if.if_unit, rt->rt_ifp->if_name, + rt->rt_ifp->if_unit); + rtfree(rt); + m_freem(m); + return; + } + rtfree(rt); + +#ifdef DEBUG_PROXY + printf("arp: proxying for %s\n", + inet_ntoa(itaddr)); +#endif + } else { + rt = la->la_rt; + (void)memcpy(ea->arp_tha, ea->arp_sha, sizeof(ea->arp_sha)); + sdl = SDL(rt->rt_gateway); + (void)memcpy(ea->arp_sha, LLADDR(sdl), sizeof(ea->arp_sha)); + } + } + + (void)memcpy(ea->arp_tpa, ea->arp_spa, sizeof(ea->arp_spa)); + (void)memcpy(ea->arp_spa, &itaddr, sizeof(ea->arp_spa)); + ea->arp_op = htons(ARPOP_REPLY); + ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */ + switch (ac->ac_if.if_type) { + case IFT_ISO88025: + /* Re-arrange the source/dest address */ + memcpy(th->iso88025_dhost, th->iso88025_shost, + sizeof(th->iso88025_dhost)); + memcpy(th->iso88025_shost, ac->ac_enaddr, + sizeof(th->iso88025_shost)); + /* Set the source routing bit if neccesary */ + if (th->iso88025_dhost[0] & TR_RII) { + th->iso88025_dhost[0] &= ~TR_RII; + if (TR_RCF_RIFLEN(th->rcf) > 2) + th->iso88025_shost[0] |= TR_RII; + } + /* Copy the addresses, ac and fc into sa_data */ + memcpy(sa.sa_data, th->iso88025_dhost, + sizeof(th->iso88025_dhost) * 2); + sa.sa_data[(sizeof(th->iso88025_dhost) * 2)] = TR_AC; + sa.sa_data[(sizeof(th->iso88025_dhost) * 2) + 1] = TR_LLC_FRAME; + break; + case IFT_ETHER: + case IFT_FDDI: + /* + * May not be correct for types not explictly + * listed, but it is our best guess. + */ + default: + eh = (struct ether_header *)sa.sa_data; + (void)memcpy(eh->ether_dhost, ea->arp_tha, + sizeof(eh->ether_dhost)); + eh->ether_type = htons(ETHERTYPE_ARP); + break; + } + sa.sa_family = AF_UNSPEC; + sa.sa_len = sizeof(sa); + (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0); + return; +} +#endif + +/* + * Free an arp entry. + */ +static void +arptfree(la) + register struct llinfo_arp *la; +{ + register struct rtentry *rt = la->la_rt; + register struct sockaddr_dl *sdl; + if (rt == 0) + panic("arptfree"); + if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) && + sdl->sdl_family == AF_LINK) { + sdl->sdl_alen = 0; + la->la_asked = 0; + rt->rt_flags &= ~RTF_REJECT; + return; + } + rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt), + 0, (struct rtentry **)0); +} +/* + * Lookup or enter a new address in arptab. + */ +static struct llinfo_arp * +arplookup(addr, create, proxy) + u_long addr; + int create, proxy; +{ + register struct rtentry *rt; + static struct sockaddr_inarp sin = {sizeof(sin), AF_INET }; + const char *why = 0; + + sin.sin_addr.s_addr = addr; + sin.sin_other = proxy ? SIN_PROXY : 0; + rt = rtalloc1((struct sockaddr *)&sin, create, 0UL); + if (rt == 0) + return (0); + rt->rt_refcnt--; + + if (rt->rt_flags & RTF_GATEWAY) + why = "host is not on local network"; + else if ((rt->rt_flags & RTF_LLINFO) == 0) + why = "could not allocate llinfo"; + else if (rt->rt_gateway->sa_family != AF_LINK) + why = "gateway route is not ours"; + + if (why && create) { + log(LOG_DEBUG, "arplookup %s failed: %s\n", + inet_ntoa(sin.sin_addr), why); + return 0; + } else if (why) { + return 0; + } + return ((struct llinfo_arp *)rt->rt_llinfo); +} + +void +arp_ifinit(ac, ifa) + struct arpcom *ac; + struct ifaddr *ifa; +{ + if (ntohl(IA_SIN(ifa)->sin_addr.s_addr) != INADDR_ANY) + arprequest(ac, &IA_SIN(ifa)->sin_addr, + &IA_SIN(ifa)->sin_addr, ac->ac_enaddr); + ifa->ifa_rtrequest = arp_rtrequest; + ifa->ifa_flags |= RTF_CLONING; +} + +static void +arp_init(void) +{ + + arpintrq.ifq_maxlen = 50; + mtx_init(&arpintrq.ifq_mtx, "arp_inq", MTX_DEF); +} + +SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, arp_init, 0); |
