1 files changed, 352 insertions, 0 deletions
diff --git a/zebra/irdp_packet.c b/zebra/irdp_packet.c
new file mode 100644
index 0000000..2dfc027
--- /dev/null
+++ b/zebra/irdp_packet.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ * Copyright (C) 2000  Robert Olsson.
+ * Swedish University of Agricultural Sciences
+ */
+
+/*
+ * This work includes work with the following copywrite:
+ *
+ * Copyright (C) 1997, 2000 Kunihiro Ishiguro
+ *
+ */
+
+/*
+ * Thanks to Jens Laas at Swedish University of Agricultural Sciences
+ * for reviewing and tests.
+ */
+
+
+#include <zebra.h>
+#include <netinet/ip_icmp.h>
+
+#include "checksum.h"
+#include "command.h"
+#include "connected.h"
+#include "if.h"
+#include "ioctl.h"
+#include "log.h"
+#include "log.h"
+#include "memory.h"
+#include "prefix.h"
+#include "sockopt.h"
+#include "sockunion.h"
+#include "sockunion.h"
+#include "stream.h"
+#include "frrevent.h"
+#include "vty.h"
+#include "zclient.h"
+#include "lib_errors.h"
+
+#include "zebra/interface.h"
+#include "zebra/rtadv.h"
+#include "zebra/rib.h"
+#include "zebra/zebra_router.h"
+#include "zebra/redistribute.h"
+#include "zebra/irdp.h"
+#include "zebra/zebra_errors.h"
+
+
+/* GLOBAL VARS */
+
+int irdp_sock = -1;
+
+extern struct event *t_irdp_raw;
+
+static void parse_irdp_packet(char *p, int len, struct interface *ifp)
+{
+	struct ip *ip = (struct ip *)p;
+	struct icmphdr *icmp;
+	struct in_addr src;
+	int ip_hlen, iplen, datalen;
+	struct zebra_if *zi;
+	struct irdp_interface *irdp;
+	uint16_t saved_chksum;
+	char buf[PREFIX_STRLEN];
+
+	zi = ifp->info;
+	if (!zi)
+		return;
+
+	irdp = zi->irdp;
+	if (!irdp)
+		return;
+
+	ip_hlen = ip->ip_hl << 2;
+
+	sockopt_iphdrincl_swab_systoh(ip);
+
+	iplen = ip->ip_len;
+	datalen = len - ip_hlen;
+	src = ip->ip_src;
+
+	if (len != iplen) {
+		flog_err(EC_ZEBRA_IRDP_LEN_MISMATCH,
+			 "IRDP: RX length doesn't match IP length");
+		return;
+	}
+
+	if (iplen < ICMP_MINLEN) {
+		flog_err(EC_ZEBRA_IRDP_LEN_MISMATCH,
+			 "IRDP: RX ICMP packet too short from %pI4",
+			 &src);
+		return;
+	}
+
+	/* XXX: RAW doesn't receive link-layer, surely? ??? */
+	/* Check so we don't checksum packets longer than oure RX_BUF - (ethlen
+	 +
+	 len of IP-header) 14+20 */
+	if (iplen > IRDP_RX_BUF - 34) {
+		flog_err(EC_ZEBRA_IRDP_LEN_MISMATCH,
+			 "IRDP: RX ICMP packet too long from %pI4",
+			 &src);
+		return;
+	}
+
+	icmp = (struct icmphdr *)(p + ip_hlen);
+
+	saved_chksum = icmp->checksum;
+	icmp->checksum = 0;
+	/* check icmp checksum */
+	if (in_cksum(icmp, datalen) != saved_chksum) {
+		flog_warn(
+			EC_ZEBRA_IRDP_BAD_CHECKSUM,
+			"IRDP: RX ICMP packet from %pI4 Bad checksum, silently ignored",
+			&src);
+		return;
+	}
+
+	/* Handle just only IRDP */
+	if (!(icmp->type == ICMP_ROUTERADVERT
+	      || icmp->type == ICMP_ROUTERSOLICIT))
+		return;
+
+	if (icmp->code != 0) {
+		flog_warn(
+			EC_ZEBRA_IRDP_BAD_TYPE_CODE,
+			"IRDP: RX packet type %d from %pI4 Bad ICMP type code, silently ignored",
+			icmp->type, &src);
+		return;
+	}
+
+	if (!((ntohl(ip->ip_dst.s_addr) == INADDR_BROADCAST)
+	      && (irdp->flags & IF_BROADCAST))
+	    || (ntohl(ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP
+		&& !(irdp->flags & IF_BROADCAST))) {
+		flog_warn(
+			EC_ZEBRA_IRDP_BAD_RX_FLAGS,
+			"IRDP: RX illegal from %pI4 to %s while %s operates in %s; Please correct settings",
+			&src,
+			ntohl(ip->ip_dst.s_addr) == INADDR_ALLRTRS_GROUP
+				? "multicast"
+				: inet_ntop(AF_INET, &ip->ip_dst,
+					    buf, sizeof(buf)),
+			ifp->name,
+			irdp->flags & IF_BROADCAST ? "broadcast" : "multicast");
+		return;
+	}
+
+	switch (icmp->type) {
+	case ICMP_ROUTERADVERT:
+		break;
+
+	case ICMP_ROUTERSOLICIT:
+
+		if (irdp->flags & IF_DEBUG_MESSAGES)
+			zlog_debug("IRDP: RX Solicit on %s from %pI4",
+				   ifp->name, &src);
+
+		process_solicit(ifp);
+		break;
+
+	default:
+		flog_warn(
+			EC_ZEBRA_IRDP_BAD_TYPE_CODE,
+			"IRDP: RX packet type %d from %pI4 Bad ICMP type code, silently ignored",
+			icmp->type, &src);
+	}
+}
+
+static int irdp_recvmsg(int sock, uint8_t *buf, int size, int *ifindex)
+{
+	struct msghdr msg;
+	struct iovec iov;
+	char adata[CMSG_SPACE(SOPT_SIZE_CMSG_PKTINFO_IPV4())];
+	int ret;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_name = (void *)0;
+	msg.msg_namelen = 0;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = (void *)adata;
+	msg.msg_controllen = sizeof(adata);
+
+	iov.iov_base = buf;
+	iov.iov_len = size;
+
+	ret = recvmsg(sock, &msg, 0);
+	if (ret < 0) {
+		flog_warn(EC_LIB_SOCKET, "IRDP: recvmsg: read error %s",
+			  safe_strerror(errno));
+		return ret;
+	}
+
+	if (msg.msg_flags & MSG_TRUNC) {
+		flog_warn(EC_LIB_SOCKET, "IRDP: recvmsg: truncated message");
+		return ret;
+	}
+	if (msg.msg_flags & MSG_CTRUNC) {
+		flog_warn(EC_LIB_SOCKET,
+			  "IRDP: recvmsg: truncated control message");
+		return ret;
+	}
+
+	*ifindex = getsockopt_ifindex(AF_INET, &msg);
+
+	return ret;
+}
+
+void irdp_read_raw(struct event *r)
+{
+	struct interface *ifp;
+	struct zebra_if *zi;
+	struct irdp_interface *irdp;
+	char buf[IRDP_RX_BUF];
+	int ret, ifindex = 0;
+
+	int irdp_sock = EVENT_FD(r);
+	event_add_read(zrouter.master, irdp_read_raw, NULL, irdp_sock,
+		       &t_irdp_raw);
+
+	ret = irdp_recvmsg(irdp_sock, (uint8_t *)buf, IRDP_RX_BUF, &ifindex);
+
+	if (ret < 0)
+		flog_warn(EC_LIB_SOCKET, "IRDP: RX Error length = %d", ret);
+
+	ifp = if_lookup_by_index(ifindex, VRF_DEFAULT);
+	if (!ifp)
+		return;
+
+	zi = ifp->info;
+	if (!zi)
+		return;
+
+	irdp = zi->irdp;
+	if (!irdp)
+		return;
+
+	if (!(irdp->flags & IF_ACTIVE)) {
+
+		if (irdp->flags & IF_DEBUG_MISC)
+			zlog_debug("IRDP: RX ICMP for disabled interface %s",
+				   ifp->name);
+		return;
+	}
+
+	if (irdp->flags & IF_DEBUG_PACKET) {
+		int i;
+		zlog_debug("IRDP: RX (idx %d) ", ifindex);
+		for (i = 0; i < ret; i++)
+			zlog_debug("IRDP: RX %x ", buf[i] & 0xFF);
+	}
+
+	parse_irdp_packet(buf, ret, ifp);
+}
+
+void send_packet(struct interface *ifp, struct stream *s, uint32_t dst,
+		 struct prefix *p, uint32_t ttl)
+{
+	static struct sockaddr_in sockdst = {AF_INET};
+	struct ip *ip;
+	struct icmphdr *icmp;
+	struct msghdr *msg;
+	struct cmsghdr *cmsg;
+	struct iovec iovector;
+	char msgbuf[256];
+	char buf[256];
+	struct in_pktinfo *pktinfo;
+	unsigned long src;
+	uint8_t on;
+
+	if (!(ifp->flags & IFF_UP))
+		return;
+
+	if (p)
+		src = ntohl(p->u.prefix4.s_addr);
+	else
+		src = 0; /* Is filled in */
+
+	ip = (struct ip *)buf;
+	ip->ip_hl = sizeof(struct ip) >> 2;
+	ip->ip_v = IPVERSION;
+	ip->ip_tos = 0xC0;
+	ip->ip_off = 0L;
+	ip->ip_p = 1; /* IP_ICMP */
+	ip->ip_ttl = ttl;
+	ip->ip_src.s_addr = src;
+	ip->ip_dst.s_addr = dst;
+	icmp = (struct icmphdr *)(buf + sizeof(struct ip));
+
+	/* Merge IP header with icmp packet */
+	assert(stream_get_endp(s) < (sizeof(buf) - sizeof(struct ip)));
+	stream_get(icmp, s, stream_get_endp(s));
+
+	/* icmp->checksum is already calculated */
+	ip->ip_len = sizeof(struct ip) + stream_get_endp(s);
+
+	on = 1;
+	if (setsockopt(irdp_sock, IPPROTO_IP, IP_HDRINCL, (char *)&on,
+		       sizeof(on))
+	    < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "IRDP: Cannot set IP_HDRINCLU %s(%d) on %s",
+			 safe_strerror(errno), errno, ifp->name);
+
+
+	if (dst == INADDR_BROADCAST) {
+		uint32_t bon = 1;
+
+		if (setsockopt(irdp_sock, SOL_SOCKET, SO_BROADCAST, &bon,
+			       sizeof(bon))
+		    < 0)
+			flog_err(EC_LIB_SOCKET,
+				 "IRDP: Cannot set SO_BROADCAST %s(%d) on %s",
+				 safe_strerror(errno), errno, ifp->name);
+	}
+
+	if (dst != INADDR_BROADCAST)
+		setsockopt_ipv4_multicast_loop(irdp_sock, 0);
+
+	memset(&sockdst, 0, sizeof(sockdst));
+	sockdst.sin_family = AF_INET;
+	sockdst.sin_addr.s_addr = dst;
+
+	cmsg = (struct cmsghdr *)(msgbuf + sizeof(struct msghdr));
+	cmsg->cmsg_len = sizeof(struct cmsghdr) + sizeof(struct in_pktinfo);
+	cmsg->cmsg_level = SOL_IP;
+	cmsg->cmsg_type = IP_PKTINFO;
+	pktinfo = (struct in_pktinfo *)CMSG_DATA(cmsg);
+	pktinfo->ipi_ifindex = ifp->ifindex;
+	pktinfo->ipi_spec_dst.s_addr = src;
+	pktinfo->ipi_addr.s_addr = src;
+
+	iovector.iov_base = (void *)buf;
+	iovector.iov_len = ip->ip_len;
+	msg = (struct msghdr *)msgbuf;
+	msg->msg_name = &sockdst;
+	msg->msg_namelen = sizeof(sockdst);
+	msg->msg_iov = &iovector;
+	msg->msg_iovlen = 1;
+	msg->msg_control = cmsg;
+	msg->msg_controllen = cmsg->cmsg_len;
+
+	sockopt_iphdrincl_swab_htosys(ip);
+
+	if (sendmsg(irdp_sock, msg, 0) < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "IRDP: sendmsg send failure %s(%d) on %s",
+			 safe_strerror(errno), errno, ifp->name);
+}