1 files changed, 288 insertions, 0 deletions
diff --git a/usr.sbin/dvmrpd/packet.c b/usr.sbin/dvmrpd/packet.c
new file mode 100644
index 00000000000..f81a1614308
--- /dev/null
+++ b/usr.sbin/dvmrpd/packet.c
@@ -0,0 +1,288 @@
+/*	$OpenBSD: packet.c,v 1.1 2006/06/01 14:12:20 norby Exp $ */
+
+/*
+ * Copyright (c) 2004, 2005, 2006 Esben Norby <norby@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_mroute.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <event.h>
+#include <stdlib.h>
+#include <strings.h>
+
+#include "igmp.h"
+#include "dvmrpd.h"
+#include "dvmrp.h"
+#include "log.h"
+#include "dvmrpe.h"
+
+int		 ip_hdr_sanity_check(const struct ip *, u_int16_t);
+int		 dvmrp_hdr_sanity_check(const struct ip *, struct dvmrp_hdr *,
+		     u_int16_t, const struct iface *);
+struct iface	*find_iface(struct dvmrpd_conf *, struct in_addr);
+
+extern struct dvmrpd_conf	*deconf;
+
+int
+gen_dvmrp_hdr(struct buf *buf, struct iface *iface, u_int8_t code)
+{
+	struct dvmrp_hdr	dvmrp_hdr;
+
+	bzero(&dvmrp_hdr, sizeof(dvmrp_hdr));
+	dvmrp_hdr.type = PKT_TYPE_DVMRP;
+	dvmrp_hdr.code = code;
+	dvmrp_hdr.chksum = 0;				/* updated later */
+	dvmrp_hdr.capabilities = DVMRP_CAP_DEFAULT;	/* XXX update */
+	dvmrp_hdr.minor_version = DVMRP_MINOR_VERSION;
+	dvmrp_hdr.major_version = DVMRP_MAJOR_VERSION;
+
+	return (buf_add(buf, &dvmrp_hdr, sizeof(dvmrp_hdr)));
+}
+
+/* send and receive packets */
+int
+send_packet(struct iface *iface, void *pkt, size_t len, struct sockaddr_in *dst)
+{
+	if (iface->passive) {
+		log_warnx("send_packet: cannot send packet on passive "
+		    "interface %s", iface->name);
+		return (-1);
+	}
+
+	/* set outgoing interface for multicast traffic */
+	if (IN_MULTICAST(ntohl(dst->sin_addr.s_addr)))
+		if (if_set_mcast(iface) == -1) {
+			log_warn("send_packet: error setting multicast "
+			    "interface, %s", iface->name);
+			return (-1);
+		}
+
+	if (sendto(iface->fd, pkt, len, 0,
+	    (struct sockaddr *)dst, sizeof(*dst)) == -1 ) {
+		log_warn("send_packet: error sending packet on interface %s",
+		    iface->name);
+		return (-1);
+	}
+
+	return (0);
+}
+
+void
+recv_packet(int fd, short event, void *bula)
+{
+	struct dvmrpd_conf	*xconf = bula;
+	struct ip		 ip_hdr;
+	struct dvmrp_hdr	*dvmrp_hdr;
+	struct iface		*iface;
+	struct nbr		*nbr = NULL;
+	struct in_addr		 addr;
+	char			*buf;
+	ssize_t			 r;
+	u_int16_t		 len;
+	int			 l;
+
+	if (event != EV_READ)
+		return;
+
+	/* setup buffer */
+	buf = pkt_ptr;
+
+	if ((r = recvfrom(fd, buf, READ_BUF_SIZE, 0, NULL, NULL)) == -1) {
+		if (errno != EAGAIN && errno != EINTR)
+			log_debug("recv_packet: error receiving packet");
+		return;
+	}
+
+	len = (u_int16_t)r;
+
+	/* IP header sanity checks */
+	if (len < sizeof(ip_hdr)) {
+		log_warnx("recv_packet: bad packet size");
+		return;
+	}
+
+	memcpy(&ip_hdr, buf, sizeof(ip_hdr));
+	if ((l = ip_hdr_sanity_check(&ip_hdr, len)) == -1)
+		return;
+	buf += l;
+	len -= l;
+
+	/* find a matching interface */
+	if ((iface = find_iface(xconf, ip_hdr.ip_src)) == NULL) {
+		log_debug("recv_packet: cannot find valid interface, ip src %s",
+		    inet_ntoa(ip_hdr.ip_src));
+		return;
+	}
+
+	/* header sanity checks */
+	if (len < sizeof(*dvmrp_hdr)) {
+		log_warnx("recv_packet: bad packet size");
+		return;
+	}
+	dvmrp_hdr = (struct dvmrp_hdr *)buf;
+
+	switch (dvmrp_hdr->type) {
+	/* DVMRP */
+	case PKT_TYPE_DVMRP:
+		if ((l = dvmrp_hdr_sanity_check(&ip_hdr, dvmrp_hdr, len,
+		    iface)) == -1)
+			return;
+
+		/*
+		 * mrouted compat
+		 *
+		 * Old mrouted versions, send route reports before establishing
+		 * 2-WAY neighbor relationships.
+		 */
+		if ((nbr_find_ip(iface, ip_hdr.ip_src.s_addr) == NULL) &&
+		    (dvmrp_hdr->code == DVMRP_CODE_REPORT)) {
+			log_debug("recv_packet: route report from neighbor"
+			    " ID %s, compat", inet_ntoa(ip_hdr.ip_src));
+			nbr = nbr_new(ip_hdr.ip_src.s_addr, iface, 0);
+			nbr_fsm(nbr, NBR_EVT_PROBE_RCVD);
+			nbr->compat = 1;
+			nbr->addr = ip_hdr.ip_src;
+		}
+
+		if ((dvmrp_hdr->type == PKT_TYPE_DVMRP) &&
+		    (dvmrp_hdr->code != DVMRP_CODE_PROBE))
+			/* find neighbor */
+			if ((nbr = nbr_find_ip(iface, ip_hdr.ip_src.s_addr))
+			    == NULL) {
+				log_debug("recv_packet: unknown neighbor ID");
+				return;
+			}
+
+		buf += sizeof(*dvmrp_hdr);
+		len = l - sizeof(*dvmrp_hdr);
+
+		inet_aton(AllDVMRPRouters, &addr);
+		if ((ip_hdr.ip_dst.s_addr != addr.s_addr) &&
+		    (ip_hdr.ip_dst.s_addr != iface->addr.s_addr)) {
+			log_debug("recv_packet: interface %s, invalid"
+			    " destination IP address %s", iface->name,
+			    inet_ntoa(ip_hdr.ip_dst));
+			break;
+		}
+
+		switch (dvmrp_hdr->code) {
+		case DVMRP_CODE_PROBE:
+			recv_probe(iface, ip_hdr.ip_src, ip_hdr.ip_src.s_addr,
+			    dvmrp_hdr->capabilities, buf, len);
+			break;
+		case DVMRP_CODE_REPORT:
+			recv_report(nbr, buf, len);
+			break;
+		case DVMRP_CODE_ASK_NBRS2:
+			recv_ask_nbrs2(nbr, buf,len);
+			break;
+		case DVMRP_CODE_NBRS2:
+			recv_nbrs2(nbr, buf,len);
+			break;
+		case DVMRP_CODE_PRUNE:
+			recv_prune(nbr, buf, len);
+			break;
+		case DVMRP_CODE_GRAFT:
+			recv_graft(nbr, buf,len);
+			break;
+		case DVMRP_CODE_GRAFT_ACK:
+			recv_graft_ack(nbr, buf,len);
+			break;
+		default:
+			log_debug("recv_packet: unknown DVMRP packet type, "
+			    "interface %s", iface->name);
+		}
+		break;
+	/* IGMP */
+	case PKT_TYPE_MEMBER_QUERY:
+		recv_igmp_query(iface, ip_hdr.ip_src, buf, len);
+		break;
+	case PKT_TYPE_MEMBER_REPORTv1:
+	case PKT_TYPE_MEMBER_REPORTv2:
+		recv_igmp_report(iface, ip_hdr.ip_src, buf, len,
+		    dvmrp_hdr->type);
+		break;
+	case PKT_TYPE_LEAVE_GROUPv2:
+		recv_igmp_leave(iface, ip_hdr.ip_src, buf, len);
+		break;
+	default:
+		log_debug("recv_packet: unknown IGMP packet type, interface %s",
+		    iface->name);
+	}
+}
+
+int
+ip_hdr_sanity_check(const struct ip *ip_hdr, u_int16_t len)
+{
+	if (ntohs(ip_hdr->ip_len) != len) {
+		log_debug("recv_packet: invalid IP packet length %u",
+		    ntohs(ip_hdr->ip_len));
+		return (-1);
+	}
+
+	if (ip_hdr->ip_p != IPPROTO_IGMP)
+		/* this is enforced by the socket itself */
+		fatalx("recv_packet: invalid IP proto");
+
+	return (ip_hdr->ip_hl << 2);
+}
+
+int
+dvmrp_hdr_sanity_check(const struct ip *ip_hdr, struct dvmrp_hdr *dvmrp_hdr,
+    u_int16_t len, const struct iface *iface)
+{
+	/* we only support DVMRPv3 */
+	if (dvmrp_hdr->major_version != DVMRP_MAJOR_VERSION) {
+		log_debug("recv_packet: invalid DVMRP version");
+		return (-1);
+	}
+
+	/* XXX enforce minor version as well, but not yet */
+
+	/* XXX chksum */
+
+	return (len);
+}
+
+struct iface *
+find_iface(struct dvmrpd_conf *xconf, struct in_addr src)
+{
+	struct iface	*iface = NULL;
+
+	/* returned interface needs to be active */
+	LIST_FOREACH(iface, &xconf->iface_list, entry) {
+		if (iface->fd > 0 &&
+		    (iface->type == IF_TYPE_POINTOPOINT) &&
+		    (iface->dst.s_addr == src.s_addr) &&
+		    !iface->passive)
+			return (iface);
+
+		if (iface->fd > 0 && (iface->addr.s_addr &
+		    iface->mask.s_addr) == (src.s_addr &
+		    iface->mask.s_addr) && !iface->passive)
+			return (iface);
+	}
+
+	return (NULL);
+}