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-rw-r--r--sys/netinet/if_ether.c554
1 files changed, 554 insertions, 0 deletions
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
new file mode 100644
index 0000000..41f07c0
--- /dev/null
+++ b/sys/netinet/if_ether.c
@@ -0,0 +1,554 @@
+/*
+ * 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
+ */
+
+/*
+ * Ethernet address resolution protocol.
+ * TODO:
+ * add "inuse/lock" bit (or ref. count) along with valid bit
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/syslog.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/route.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/in_var.h>
+#include <netinet/ip.h>
+#include <netinet/if_ether.h>
+
+#define SIN(s) ((struct sockaddr_in *)s)
+#define SDL(s) ((struct sockaddr_dl *)s)
+#define SRP(s) ((struct sockaddr_inarp *)s)
+
+/*
+ * ARP trailer negotiation. Trailer protocol is not IP specific,
+ * but ARP request/response use IP addresses.
+ */
+#define ETHERTYPE_IPTRAILERS ETHERTYPE_TRAIL
+
+
+/* timer values */
+int arpt_prune = (5*60*1); /* walk list every 5 minutes */
+int arpt_keep = (20*60); /* once resolved, good for 20 more minutes */
+int arpt_down = 20; /* once declared down, don't send for 20 secs */
+#define rt_expire rt_rmx.rmx_expire
+
+static void arprequest __P((struct arpcom *, u_long *, u_long *, u_char *));
+static void arptfree __P((struct llinfo_arp *));
+static void arptimer __P((void *));
+static struct llinfo_arp *arplookup __P((u_long, int, int));
+static void in_arpinput __P((struct mbuf *));
+
+extern struct ifnet loif;
+extern struct timeval time;
+struct llinfo_arp llinfo_arp = {&llinfo_arp, &llinfo_arp};
+struct ifqueue arpintrq = {0, 0, 0, 50};
+int arp_inuse, arp_allocated, arp_intimer;
+int arp_maxtries = 5;
+int useloopback = 1; /* use loopback interface for local traffic */
+int arpinit_done = 0;
+
+/*
+ * Timeout routine. Age arp_tab entries periodically.
+ */
+/* ARGSUSED */
+static void
+arptimer(ignored_arg)
+ void *ignored_arg;
+{
+ int s = splnet();
+ register struct llinfo_arp *la = llinfo_arp.la_next;
+
+ timeout(arptimer, (caddr_t)0, arpt_prune * hz);
+ while (la != &llinfo_arp) {
+ register struct rtentry *rt = la->la_rt;
+ la = la->la_next;
+ if (rt->rt_expire && rt->rt_expire <= time.tv_sec)
+ arptfree(la->la_prev); /* timer has expired, clear */
+ }
+ splx(s);
+}
+
+/*
+ * Parallel to llc_rtrequest.
+ */
+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};
+
+ if (!arpinit_done) {
+ arpinit_done = 1;
+ timeout(arptimer, (caddr_t)0, hz);
+ }
+ 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.tv_sec;
+ 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.s_addr,
+ &SIN(rt_key(rt))->sin_addr.s_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");
+ 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;
+ insque(la, &llinfo_arp);
+ 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--;
+ remque(la);
+ 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 packet, asking who has addr on interface ac.
+ */
+void
+arpwhohas(ac, addr)
+ register struct arpcom *ac;
+ register struct in_addr *addr;
+{
+ arprequest(ac, &ac->ac_ipaddr.s_addr, &addr->s_addr, ac->ac_enaddr);
+}
+
+/*
+ * 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 u_long *sip, *tip;
+ register u_char *enaddr;
+{
+ register struct mbuf *m;
+ register struct ether_header *eh;
+ register struct ether_arp *ea;
+ struct sockaddr sa;
+
+ if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
+ return;
+ 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));
+ bcopy((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
+ sizeof(eh->ether_dhost));
+ eh->ether_type = ETHERTYPE_ARP; /* if_output will swap */
+ ea->arp_hrd = htons(ARPHRD_ETHER);
+ 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);
+ bcopy((caddr_t)enaddr, (caddr_t)ea->arp_sha, sizeof(ea->arp_sha));
+ bcopy((caddr_t)sip, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa));
+ bcopy((caddr_t)tip, (caddr_t)ea->arp_tpa, 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)
+ register struct arpcom *ac;
+ register struct rtentry *rt;
+ struct mbuf *m;
+ register struct sockaddr *dst;
+ register u_char *desten;
+{
+ register struct llinfo_arp *la;
+ struct sockaddr_dl *sdl;
+
+ if (m->m_flags & M_BCAST) { /* broadcast */
+ bcopy((caddr_t)etherbroadcastaddr, (caddr_t)desten,
+ 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;
+ else {
+ if (la = arplookup(SIN(dst)->sin_addr.s_addr, 1, 0))
+ rt = la->la_rt;
+ }
+ if (la == 0 || rt == 0) {
+ log(LOG_DEBUG, "arpresolve: can't allocate llinfo");
+ 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.tv_sec) &&
+ 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.tv_sec) {
+ rt->rt_expire = time.tv_sec;
+ if (la->la_asked++ < arp_maxtries)
+ arpwhohas(ac, &(SIN(dst)->sin_addr));
+ 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.
+ */
+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) &&
+ (ar = mtod(m, struct arphdr *)) &&
+ ntohs(ar->ar_hrd) == ARPHRD_ETHER &&
+ m->m_len >=
+ sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
+
+ switch (ntohs(ar->ar_pro)) {
+
+ case ETHERTYPE_IP:
+ case ETHERTYPE_IPTRAILERS:
+ in_arpinput(m);
+ continue;
+ }
+ m_freem(m);
+ }
+}
+
+/*
+ * 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 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;
+ 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;
+
+ ea = mtod(m, struct ether_arp *);
+ op = ntohs(ea->arp_op);
+ bcopy((caddr_t)ea->arp_spa, (caddr_t)&isaddr, sizeof (isaddr));
+ bcopy((caddr_t)ea->arp_tpa, (caddr_t)&itaddr, sizeof (itaddr));
+ for (ia = in_ifaddr; ia; ia = ia->ia_next)
+ if (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)
+ goto out;
+ 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)))
+ goto out; /* it's from me, ignore it. */
+ 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 %x!\n",
+ ntohl(isaddr.s_addr));
+ goto out;
+ }
+ if (isaddr.s_addr == myaddr.s_addr) {
+ log(LOG_ERR,
+ "duplicate IP address %x!! sent from ethernet address: %s\n",
+ ntohl(isaddr.s_addr), ether_sprintf(ea->arp_sha));
+ 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))) {
+ if (sdl->sdl_alen &&
+ bcmp((caddr_t)ea->arp_sha, LLADDR(sdl), sdl->sdl_alen))
+ log(LOG_INFO, "arp info overwritten for %x by %s\n",
+ isaddr.s_addr, ether_sprintf(ea->arp_sha));
+ bcopy((caddr_t)ea->arp_sha, LLADDR(sdl),
+ sdl->sdl_alen = sizeof(ea->arp_sha));
+ if (rt->rt_expire)
+ rt->rt_expire = time.tv_sec + 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) {
+ out:
+ m_freem(m);
+ return;
+ }
+ if (itaddr.s_addr == myaddr.s_addr) {
+ /* I am the target */
+ bcopy((caddr_t)ea->arp_sha, (caddr_t)ea->arp_tha,
+ sizeof(ea->arp_sha));
+ bcopy((caddr_t)ac->ac_enaddr, (caddr_t)ea->arp_sha,
+ sizeof(ea->arp_sha));
+ } else {
+ la = arplookup(itaddr.s_addr, 0, SIN_PROXY);
+ if (la == NULL)
+ goto out;
+ rt = la->la_rt;
+ bcopy((caddr_t)ea->arp_sha, (caddr_t)ea->arp_tha,
+ sizeof(ea->arp_sha));
+ sdl = SDL(rt->rt_gateway);
+ bcopy(LLADDR(sdl), (caddr_t)ea->arp_sha, sizeof(ea->arp_sha));
+ }
+
+ bcopy((caddr_t)ea->arp_spa, (caddr_t)ea->arp_tpa, sizeof(ea->arp_spa));
+ bcopy((caddr_t)&itaddr, (caddr_t)ea->arp_spa, sizeof(ea->arp_spa));
+ ea->arp_op = htons(ARPOP_REPLY);
+ ea->arp_pro = htons(ETHERTYPE_IP); /* let's be sure! */
+ eh = (struct ether_header *)sa.sa_data;
+ bcopy((caddr_t)ea->arp_tha, (caddr_t)eh->ether_dhost,
+ sizeof(eh->ether_dhost));
+ eh->ether_type = ETHERTYPE_ARP;
+ sa.sa_family = AF_UNSPEC;
+ sa.sa_len = sizeof(sa);
+ (*ac->ac_if.if_output)(&ac->ac_if, m, &sa, (struct rtentry *)0);
+ return;
+}
+
+/*
+ * 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 };
+
+ sin.sin_addr.s_addr = addr;
+ sin.sin_other = proxy ? SIN_PROXY : 0;
+ rt = rtalloc1((struct sockaddr *)&sin, create);
+ if (rt == 0)
+ return (0);
+ rt->rt_refcnt--;
+ if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
+ rt->rt_gateway->sa_family != AF_LINK) {
+ if (create)
+ log(LOG_DEBUG, "arptnew failed on %x\n", ntohl(addr));
+ return (0);
+ }
+ return ((struct llinfo_arp *)rt->rt_llinfo);
+}
+
+int
+arpioctl(cmd, data)
+ int cmd;
+ caddr_t data;
+{
+ return (EOPNOTSUPP);
+}
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