diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
index 1b24e36b404781207c43cac6e4c759e65354c006..ba9ee36c9e9462a97c6993cc8eef5e2223a423d9 100644
--- a/tools/testing/selftests/net/Makefile
+++ b/tools/testing/selftests/net/Makefile
@@ -12,7 +12,7 @@ TEST_PROGS += udpgro_bench.sh udpgro.sh test_vxlan_under_vrf.sh reuseport_addr_a
 TEST_PROGS += test_vxlan_fdb_changelink.sh so_txtime.sh ipv6_flowlabel.sh
 TEST_PROGS += tcp_fastopen_backup_key.sh
 TEST_PROGS_EXTENDED := in_netns.sh
-TEST_GEN_FILES =  socket
+TEST_GEN_FILES =  socket nettest
 TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any
 TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd txring_overwrite
 TEST_GEN_FILES += udpgso udpgso_bench_tx udpgso_bench_rx ip_defrag
diff --git a/tools/testing/selftests/net/nettest.c b/tools/testing/selftests/net/nettest.c
new file mode 100644
index 0000000000000000000000000000000000000000..9278f8460d75accad8fb3eb32ff73ec3b37374e0
--- /dev/null
+++ b/tools/testing/selftests/net/nettest.c
@@ -0,0 +1,1756 @@
+// SPDX-License-Identifier: GPL-2.0
+/* nettest - used for functional tests of networking APIs
+ *
+ * Copyright (c) 2013-2019 David Ahern <dsahern@gmail.com>. All rights reserved.
+ */
+
+#define _GNU_SOURCE
+#include <features.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <linux/tcp.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+#include <errno.h>
+
+#ifndef IPV6_UNICAST_IF
+#define IPV6_UNICAST_IF         76
+#endif
+#ifndef IPV6_MULTICAST_IF
+#define IPV6_MULTICAST_IF       17
+#endif
+
+#define DEFAULT_PORT 12345
+
+#ifndef MAX
+#define MAX(a, b)  ((a) > (b) ? (a) : (b))
+#endif
+#ifndef MIN
+#define MIN(a, b)  ((a) < (b) ? (a) : (b))
+#endif
+
+struct sock_args {
+	/* local address */
+	union {
+		struct in_addr  in;
+		struct in6_addr in6;
+	} local_addr;
+
+	/* remote address */
+	union {
+		struct in_addr  in;
+		struct in6_addr in6;
+	} remote_addr;
+	int scope_id;  /* remote scope; v6 send only */
+
+	struct in_addr grp;     /* multicast group */
+
+	unsigned int has_local_ip:1,
+		     has_remote_ip:1,
+		     has_grp:1,
+		     has_expected_laddr:1,
+		     has_expected_raddr:1,
+		     bind_test_only:1;
+
+	unsigned short port;
+
+	int type;      /* DGRAM, STREAM, RAW */
+	int protocol;
+	int version;   /* AF_INET/AF_INET6 */
+
+	int use_setsockopt;
+	int use_cmsg;
+	const char *dev;
+	int ifindex;
+	const char *password;
+
+	/* expected addresses and device index for connection */
+	int expected_ifindex;
+
+	/* local address */
+	union {
+		struct in_addr  in;
+		struct in6_addr in6;
+	} expected_laddr;
+
+	/* remote address */
+	union {
+		struct in_addr  in;
+		struct in6_addr in6;
+	} expected_raddr;
+};
+
+static int server_mode;
+static unsigned int prog_timeout = 5;
+static unsigned int interactive;
+static int iter = 1;
+static char *msg = "Hello world!";
+static int msglen;
+static int quiet;
+static int try_broadcast = 1;
+
+static char *timestamp(char *timebuf, int buflen)
+{
+	time_t now;
+
+	now = time(NULL);
+	if (strftime(timebuf, buflen, "%T", localtime(&now)) == 0) {
+		memset(timebuf, 0, buflen);
+		strncpy(timebuf, "00:00:00", buflen-1);
+	}
+
+	return timebuf;
+}
+
+static void log_msg(const char *format, ...)
+{
+	char timebuf[64];
+	va_list args;
+
+	if (quiet)
+		return;
+
+	fprintf(stdout, "%s %s:",
+		timestamp(timebuf, sizeof(timebuf)),
+		server_mode ? "server" : "client");
+	va_start(args, format);
+	vfprintf(stdout, format, args);
+	va_end(args);
+
+	fflush(stdout);
+}
+
+static void log_error(const char *format, ...)
+{
+	char timebuf[64];
+	va_list args;
+
+	if (quiet)
+		return;
+
+	fprintf(stderr, "%s %s:",
+		timestamp(timebuf, sizeof(timebuf)),
+		server_mode ? "server" : "client");
+	va_start(args, format);
+	vfprintf(stderr, format, args);
+	va_end(args);
+
+	fflush(stderr);
+}
+
+static void log_err_errno(const char *fmt, ...)
+{
+	char timebuf[64];
+	va_list args;
+
+	if (quiet)
+		return;
+
+	fprintf(stderr, "%s %s: ",
+		timestamp(timebuf, sizeof(timebuf)),
+		server_mode ? "server" : "client");
+	va_start(args, fmt);
+	vfprintf(stderr, fmt, args);
+	va_end(args);
+
+	fprintf(stderr, ": %d: %s\n", errno, strerror(errno));
+	fflush(stderr);
+}
+
+static void log_address(const char *desc, struct sockaddr *sa)
+{
+	char addrstr[64];
+
+	if (quiet)
+		return;
+
+	if (sa->sa_family == AF_INET) {
+		struct sockaddr_in *s = (struct sockaddr_in *) sa;
+
+		log_msg("%s %s:%d",
+			desc,
+			inet_ntop(AF_INET, &s->sin_addr, addrstr,
+				  sizeof(addrstr)),
+			ntohs(s->sin_port));
+
+	} else if (sa->sa_family == AF_INET6) {
+		struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) sa;
+
+		log_msg("%s [%s]:%d",
+			desc,
+			inet_ntop(AF_INET6, &s6->sin6_addr, addrstr,
+				  sizeof(addrstr)),
+			ntohs(s6->sin6_port));
+	}
+
+	printf("\n");
+
+	fflush(stdout);
+}
+
+static int tcp_md5sig(int sd, void *addr, socklen_t alen, const char *password)
+{
+	struct tcp_md5sig md5sig;
+	int keylen = password ? strlen(password) : 0;
+	int rc;
+
+	memset(&md5sig, 0, sizeof(md5sig));
+	memcpy(&md5sig.tcpm_addr, addr, alen);
+	md5sig.tcpm_keylen = keylen;
+
+	if (keylen)
+		memcpy(md5sig.tcpm_key, password, keylen);
+
+	rc = setsockopt(sd, IPPROTO_TCP, TCP_MD5SIG, &md5sig, sizeof(md5sig));
+	if (rc < 0) {
+		/* ENOENT is harmless. Returned when a password is cleared */
+		if (errno == ENOENT)
+			rc = 0;
+		else
+			log_err_errno("setsockopt(TCP_MD5SIG)");
+	}
+
+	return rc;
+}
+
+static int tcp_md5_remote(int sd, struct sock_args *args)
+{
+	struct sockaddr_in sin = {
+		.sin_family = AF_INET,
+	};
+	struct sockaddr_in6 sin6 = {
+		.sin6_family = AF_INET6,
+	};
+	void *addr;
+	int alen;
+
+	switch (args->version) {
+	case AF_INET:
+		sin.sin_port = htons(args->port);
+		sin.sin_addr = args->remote_addr.in;
+		addr = &sin;
+		alen = sizeof(sin);
+		break;
+	case AF_INET6:
+		sin6.sin6_port = htons(args->port);
+		sin6.sin6_addr = args->remote_addr.in6;
+		addr = &sin6;
+		alen = sizeof(sin6);
+		break;
+	default:
+		log_error("unknown address family\n");
+		exit(1);
+	}
+
+	if (tcp_md5sig(sd, addr, alen, args->password))
+		return -1;
+
+	return 0;
+}
+
+static int get_ifidx(const char *ifname)
+{
+	struct ifreq ifdata;
+	int sd, rc;
+
+	if (!ifname || *ifname == '\0')
+		return 0;
+
+	memset(&ifdata, 0, sizeof(ifdata));
+
+	strcpy(ifdata.ifr_name, ifname);
+
+	sd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
+	if (sd < 0) {
+		log_err_errno("socket failed");
+		return 0;
+	}
+
+	rc = ioctl(sd, SIOCGIFINDEX, (char *)&ifdata);
+	close(sd);
+	if (rc != 0) {
+		log_err_errno("ioctl(SIOCGIFINDEX) failed");
+		return 0;
+	}
+
+	return ifdata.ifr_ifindex;
+}
+
+static int bind_to_device(int sd, const char *name)
+{
+	int rc;
+
+	rc = setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, name, strlen(name)+1);
+	if (rc < 0)
+		log_err_errno("setsockopt(SO_BINDTODEVICE)");
+
+	return rc;
+}
+
+static int get_bind_to_device(int sd, char *name, size_t len)
+{
+	int rc;
+	socklen_t optlen = len;
+
+	name[0] = '\0';
+	rc = getsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, name, &optlen);
+	if (rc < 0)
+		log_err_errno("setsockopt(SO_BINDTODEVICE)");
+
+	return rc;
+}
+
+static int check_device(int sd, struct sock_args *args)
+{
+	int ifindex = 0;
+	char name[32];
+
+	if (get_bind_to_device(sd, name, sizeof(name)))
+		*name = '\0';
+	else
+		ifindex = get_ifidx(name);
+
+	log_msg("    bound to device %s/%d\n",
+		*name ? name : "<none>", ifindex);
+
+	if (!args->expected_ifindex)
+		return 0;
+
+	if (args->expected_ifindex != ifindex) {
+		log_error("Device index mismatch: expected %d have %d\n",
+			  args->expected_ifindex, ifindex);
+		return 1;
+	}
+
+	log_msg("Device index matches: expected %d have %d\n",
+		args->expected_ifindex, ifindex);
+
+	return 0;
+}
+
+static int set_pktinfo_v4(int sd)
+{
+	int one = 1;
+	int rc;
+
+	rc = setsockopt(sd, SOL_IP, IP_PKTINFO, &one, sizeof(one));
+	if (rc < 0 && rc != -ENOTSUP)
+		log_err_errno("setsockopt(IP_PKTINFO)");
+
+	return rc;
+}
+
+static int set_recvpktinfo_v6(int sd)
+{
+	int one = 1;
+	int rc;
+
+	rc = setsockopt(sd, SOL_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));
+	if (rc < 0 && rc != -ENOTSUP)
+		log_err_errno("setsockopt(IPV6_RECVPKTINFO)");
+
+	return rc;
+}
+
+static int set_recverr_v4(int sd)
+{
+	int one = 1;
+	int rc;
+
+	rc = setsockopt(sd, SOL_IP, IP_RECVERR, &one, sizeof(one));
+	if (rc < 0 && rc != -ENOTSUP)
+		log_err_errno("setsockopt(IP_RECVERR)");
+
+	return rc;
+}
+
+static int set_recverr_v6(int sd)
+{
+	int one = 1;
+	int rc;
+
+	rc = setsockopt(sd, SOL_IPV6, IPV6_RECVERR, &one, sizeof(one));
+	if (rc < 0 && rc != -ENOTSUP)
+		log_err_errno("setsockopt(IPV6_RECVERR)");
+
+	return rc;
+}
+
+static int set_unicast_if(int sd, int ifindex, int version)
+{
+	int opt = IP_UNICAST_IF;
+	int level = SOL_IP;
+	int rc;
+
+	ifindex = htonl(ifindex);
+
+	if (version == AF_INET6) {
+		opt = IPV6_UNICAST_IF;
+		level = SOL_IPV6;
+	}
+	rc = setsockopt(sd, level, opt, &ifindex, sizeof(ifindex));
+	if (rc < 0)
+		log_err_errno("setsockopt(IP_UNICAST_IF)");
+
+	return rc;
+}
+
+static int set_multicast_if(int sd, int ifindex)
+{
+	struct ip_mreqn mreq = { .imr_ifindex = ifindex };
+	int rc;
+
+	rc = setsockopt(sd, SOL_IP, IP_MULTICAST_IF, &mreq, sizeof(mreq));
+	if (rc < 0)
+		log_err_errno("setsockopt(IP_MULTICAST_IF)");
+
+	return rc;
+}
+
+static int set_membership(int sd, uint32_t grp, uint32_t addr, const char *dev)
+{
+	uint32_t if_addr = addr;
+	struct ip_mreqn mreq;
+	int rc;
+
+	if (addr == htonl(INADDR_ANY) && !dev) {
+		log_error("Either local address or device needs to be given for multicast membership\n");
+		return -1;
+	}
+
+	mreq.imr_multiaddr.s_addr = grp;
+	mreq.imr_address.s_addr = if_addr;
+	mreq.imr_ifindex = dev ? get_ifidx(dev) : 0;
+
+	rc = setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
+	if (rc < 0) {
+		log_err_errno("setsockopt(IP_ADD_MEMBERSHIP)");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int set_broadcast(int sd)
+{
+	unsigned int one = 1;
+	int rc = 0;
+
+	if (setsockopt(sd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)) != 0) {
+		log_err_errno("setsockopt(SO_BROADCAST)");
+		rc = -1;
+	}
+
+	return rc;
+}
+
+static int set_reuseport(int sd)
+{
+	unsigned int one = 1;
+	int rc = 0;
+
+	if (setsockopt(sd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) != 0) {
+		log_err_errno("setsockopt(SO_REUSEPORT)");
+		rc = -1;
+	}
+
+	return rc;
+}
+
+static int set_reuseaddr(int sd)
+{
+	unsigned int one = 1;
+	int rc = 0;
+
+	if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) != 0) {
+		log_err_errno("setsockopt(SO_REUSEADDR)");
+		rc = -1;
+	}
+
+	return rc;
+}
+
+static int str_to_uint(const char *str, int min, int max, unsigned int *value)
+{
+	int number;
+	char *end;
+
+	errno = 0;
+	number = (unsigned int) strtoul(str, &end, 0);
+
+	/* entire string should be consumed by conversion
+	 * and value should be between min and max
+	 */
+	if (((*end == '\0') || (*end == '\n')) && (end != str) &&
+	    (errno != ERANGE) && (min <= number) && (number <= max)) {
+		*value = number;
+		return 0;
+	}
+
+	return -1;
+}
+
+static int expected_addr_match(struct sockaddr *sa, void *expected,
+			       const char *desc)
+{
+	char addrstr[64];
+	int rc = 0;
+
+	if (sa->sa_family == AF_INET) {
+		struct sockaddr_in *s = (struct sockaddr_in *) sa;
+		struct in_addr *exp_in = (struct in_addr *) expected;
+
+		if (s->sin_addr.s_addr != exp_in->s_addr) {
+			log_error("%s address does not match expected %s",
+				  desc,
+				  inet_ntop(AF_INET, exp_in,
+					    addrstr, sizeof(addrstr)));
+			rc = 1;
+		}
+	} else if (sa->sa_family == AF_INET6) {
+		struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) sa;
+		struct in6_addr *exp_in = (struct in6_addr *) expected;
+
+		if (memcmp(&s6->sin6_addr, exp_in, sizeof(*exp_in))) {
+			log_error("%s address does not match expected %s",
+				  desc,
+				  inet_ntop(AF_INET6, exp_in,
+					    addrstr, sizeof(addrstr)));
+			rc = 1;
+		}
+	} else {
+		log_error("%s address does not match expected - unknown family",
+			  desc);
+		rc = 1;
+	}
+
+	if (!rc)
+		log_msg("%s address matches expected\n", desc);
+
+	return rc;
+}
+
+static int show_sockstat(int sd, struct sock_args *args)
+{
+	struct sockaddr_in6 local_addr, remote_addr;
+	socklen_t alen = sizeof(local_addr);
+	struct sockaddr *sa;
+	const char *desc;
+	int rc = 0;
+
+	desc = server_mode ? "server local:" : "client local:";
+	sa = (struct sockaddr *) &local_addr;
+	if (getsockname(sd, sa, &alen) == 0) {
+		log_address(desc, sa);
+
+		if (args->has_expected_laddr) {
+			rc = expected_addr_match(sa, &args->expected_laddr,
+						 "local");
+		}
+	} else {
+		log_err_errno("getsockname failed");
+	}
+
+	sa = (struct sockaddr *) &remote_addr;
+	desc = server_mode ? "server peer:" : "client peer:";
+	if (getpeername(sd, sa, &alen) == 0) {
+		log_address(desc, sa);
+
+		if (args->has_expected_raddr) {
+			rc |= expected_addr_match(sa, &args->expected_raddr,
+						 "remote");
+		}
+	} else {
+		log_err_errno("getpeername failed");
+	}
+
+	return rc;
+}
+
+static int get_index_from_cmsg(struct msghdr *m)
+{
+	struct cmsghdr *cm;
+	int ifindex = 0;
+	char buf[64];
+
+	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(m);
+	     m->msg_controllen != 0 && cm;
+	     cm = (struct cmsghdr *)CMSG_NXTHDR(m, cm)) {
+
+		if (cm->cmsg_level == SOL_IP &&
+		    cm->cmsg_type == IP_PKTINFO) {
+			struct in_pktinfo *pi;
+
+			pi = (struct in_pktinfo *)(CMSG_DATA(cm));
+			inet_ntop(AF_INET, &pi->ipi_addr, buf, sizeof(buf));
+			ifindex = pi->ipi_ifindex;
+		} else if (cm->cmsg_level == SOL_IPV6 &&
+			   cm->cmsg_type == IPV6_PKTINFO) {
+			struct in6_pktinfo *pi6;
+
+			pi6 = (struct in6_pktinfo *)(CMSG_DATA(cm));
+			inet_ntop(AF_INET6, &pi6->ipi6_addr, buf, sizeof(buf));
+			ifindex = pi6->ipi6_ifindex;
+		}
+	}
+
+	if (ifindex) {
+		log_msg("    pktinfo: ifindex %d dest addr %s\n",
+			ifindex, buf);
+	}
+	return ifindex;
+}
+
+static int send_msg_no_cmsg(int sd, void *addr, socklen_t alen)
+{
+	int err;
+
+again:
+	err = sendto(sd, msg, msglen, 0, addr, alen);
+	if (err < 0) {
+		if (errno == EACCES && try_broadcast) {
+			try_broadcast = 0;
+			if (!set_broadcast(sd))
+				goto again;
+			errno = EACCES;
+		}
+
+		log_err_errno("sendto failed");
+		return 1;
+	}
+
+	return 0;
+}
+
+static int send_msg_cmsg(int sd, void *addr, socklen_t alen,
+			 int ifindex, int version)
+{
+	unsigned char cmsgbuf[64];
+	struct iovec iov[2];
+	struct cmsghdr *cm;
+	struct msghdr m;
+	int err;
+
+	iov[0].iov_base = msg;
+	iov[0].iov_len = msglen;
+	m.msg_iov = iov;
+	m.msg_iovlen = 1;
+	m.msg_name = (caddr_t)addr;
+	m.msg_namelen = alen;
+
+	memset(cmsgbuf, 0, sizeof(cmsgbuf));
+	cm = (struct cmsghdr *)cmsgbuf;
+	m.msg_control = (caddr_t)cm;
+
+	if (version == AF_INET) {
+		struct in_pktinfo *pi;
+
+		cm->cmsg_level = SOL_IP;
+		cm->cmsg_type = IP_PKTINFO;
+		cm->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
+		pi = (struct in_pktinfo *)(CMSG_DATA(cm));
+		pi->ipi_ifindex = ifindex;
+
+		m.msg_controllen = cm->cmsg_len;
+
+	} else if (version == AF_INET6) {
+		struct in6_pktinfo *pi6;
+
+		cm->cmsg_level = SOL_IPV6;
+		cm->cmsg_type = IPV6_PKTINFO;
+		cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
+
+		pi6 = (struct in6_pktinfo *)(CMSG_DATA(cm));
+		pi6->ipi6_ifindex = ifindex;
+
+		m.msg_controllen = cm->cmsg_len;
+	}
+
+again:
+	err = sendmsg(sd, &m, 0);
+	if (err < 0) {
+		if (errno == EACCES && try_broadcast) {
+			try_broadcast = 0;
+			if (!set_broadcast(sd))
+				goto again;
+			errno = EACCES;
+		}
+
+		log_err_errno("sendmsg failed");
+		return 1;
+	}
+
+	return 0;
+}
+
+
+static int send_msg(int sd, void *addr, socklen_t alen, struct sock_args *args)
+{
+	if (args->type == SOCK_STREAM) {
+		if (write(sd, msg, msglen) < 0) {
+			log_err_errno("write failed sending msg to peer");
+			return 1;
+		}
+	} else if (args->ifindex && args->use_cmsg) {
+		if (send_msg_cmsg(sd, addr, alen, args->ifindex, args->version))
+			return 1;
+	} else {
+		if (send_msg_no_cmsg(sd, addr, alen))
+			return 1;
+	}
+
+	log_msg("Sent message:\n");
+	log_msg("    %.24s%s\n", msg, msglen > 24 ? " ..." : "");
+
+	return 0;
+}
+
+static int socket_read_dgram(int sd, struct sock_args *args)
+{
+	unsigned char addr[sizeof(struct sockaddr_in6)];
+	struct sockaddr *sa = (struct sockaddr *) addr;
+	socklen_t alen = sizeof(addr);
+	struct iovec iov[2];
+	struct msghdr m = {
+		.msg_name = (caddr_t)addr,
+		.msg_namelen = alen,
+		.msg_iov = iov,
+		.msg_iovlen = 1,
+	};
+	unsigned char cmsgbuf[256];
+	struct cmsghdr *cm = (struct cmsghdr *)cmsgbuf;
+	char buf[16*1024];
+	int ifindex;
+	int len;
+
+	iov[0].iov_base = (caddr_t)buf;
+	iov[0].iov_len = sizeof(buf);
+
+	memset(cmsgbuf, 0, sizeof(cmsgbuf));
+	m.msg_control = (caddr_t)cm;
+	m.msg_controllen = sizeof(cmsgbuf);
+
+	len = recvmsg(sd, &m, 0);
+	if (len == 0) {
+		log_msg("peer closed connection.\n");
+		return 0;
+	} else if (len < 0) {
+		log_msg("failed to read message: %d: %s\n",
+			errno, strerror(errno));
+		return -1;
+	}
+
+	buf[len] = '\0';
+
+	log_address("Message from:", sa);
+	log_msg("    %.24s%s\n", buf, len > 24 ? " ..." : "");
+
+	ifindex = get_index_from_cmsg(&m);
+	if (args->expected_ifindex) {
+		if (args->expected_ifindex != ifindex) {
+			log_error("Device index mismatch: expected %d have %d\n",
+				  args->expected_ifindex, ifindex);
+			return -1;
+		}
+		log_msg("Device index matches: expected %d have %d\n",
+			args->expected_ifindex, ifindex);
+	}
+
+	if (!interactive && server_mode) {
+		if (sa->sa_family == AF_INET6) {
+			struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) sa;
+			struct in6_addr *in6 = &s6->sin6_addr;
+
+			if (IN6_IS_ADDR_V4MAPPED(in6)) {
+				const uint32_t *pa = (uint32_t *) &in6->s6_addr;
+				struct in_addr in4;
+				struct sockaddr_in *sin;
+
+				sin = (struct sockaddr_in *) addr;
+				pa += 3;
+				in4.s_addr = *pa;
+				sin->sin_addr = in4;
+				sin->sin_family = AF_INET;
+				if (send_msg_cmsg(sd, addr, alen,
+						  ifindex, AF_INET) < 0)
+					goto out_err;
+			}
+		}
+again:
+		iov[0].iov_len = len;
+
+		if (args->version == AF_INET6) {
+			struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) sa;
+
+			if (args->dev) {
+				/* avoid PKTINFO conflicts with bindtodev */
+				if (sendto(sd, buf, len, 0,
+					   (void *) addr, alen) < 0)
+					goto out_err;
+			} else {
+				/* kernel is allowing scope_id to be set to VRF
+				 * index for LLA. for sends to global address
+				 * reset scope id
+				 */
+				s6->sin6_scope_id = ifindex;
+				if (sendmsg(sd, &m, 0) < 0)
+					goto out_err;
+			}
+		} else {
+			int err;
+
+			err = sendmsg(sd, &m, 0);
+			if (err < 0) {
+				if (errno == EACCES && try_broadcast) {
+					try_broadcast = 0;
+					if (!set_broadcast(sd))
+						goto again;
+					errno = EACCES;
+				}
+				goto out_err;
+			}
+		}
+		log_msg("Sent message:\n");
+		log_msg("    %.24s%s\n", buf, len > 24 ? " ..." : "");
+	}
+
+	return 1;
+out_err:
+	log_err_errno("failed to send msg to peer");
+	return -1;
+}
+
+static int socket_read_stream(int sd)
+{
+	char buf[1024];
+	int len;
+
+	len = read(sd, buf, sizeof(buf)-1);
+	if (len == 0) {
+		log_msg("client closed connection.\n");
+		return 0;
+	} else if (len < 0) {
+		log_msg("failed to read message\n");
+		return -1;
+	}
+
+	buf[len] = '\0';
+	log_msg("Incoming message:\n");
+	log_msg("    %.24s%s\n", buf, len > 24 ? " ..." : "");
+
+	if (!interactive && server_mode) {
+		if (write(sd, buf, len) < 0) {
+			log_err_errno("failed to send buf");
+			return -1;
+		}
+		log_msg("Sent message:\n");
+		log_msg("     %.24s%s\n", buf, len > 24 ? " ..." : "");
+	}
+
+	return 1;
+}
+
+static int socket_read(int sd, struct sock_args *args)
+{
+	if (args->type == SOCK_STREAM)
+		return socket_read_stream(sd);
+
+	return socket_read_dgram(sd, args);
+}
+
+static int stdin_to_socket(int sd, int type, void *addr, socklen_t alen)
+{
+	char buf[1024];
+	int len;
+
+	if (fgets(buf, sizeof(buf), stdin) == NULL)
+		return 0;
+
+	len = strlen(buf);
+	if (type == SOCK_STREAM) {
+		if (write(sd, buf, len) < 0) {
+			log_err_errno("failed to send buf");
+			return -1;
+		}
+	} else {
+		int err;
+
+again:
+		err = sendto(sd, buf, len, 0, addr, alen);
+		if (err < 0) {
+			if (errno == EACCES && try_broadcast) {
+				try_broadcast = 0;
+				if (!set_broadcast(sd))
+					goto again;
+				errno = EACCES;
+			}
+			log_err_errno("failed to send msg to peer");
+			return -1;
+		}
+	}
+	log_msg("Sent message:\n");
+	log_msg("    %.24s%s\n", buf, len > 24 ? " ..." : "");
+
+	return 1;
+}
+
+static void set_recv_attr(int sd, int version)
+{
+	if (version == AF_INET6) {
+		set_recvpktinfo_v6(sd);
+		set_recverr_v6(sd);
+	} else {
+		set_pktinfo_v4(sd);
+		set_recverr_v4(sd);
+	}
+}
+
+static int msg_loop(int client, int sd, void *addr, socklen_t alen,
+		    struct sock_args *args)
+{
+	struct timeval timeout = { .tv_sec = prog_timeout }, *ptval = NULL;
+	fd_set rfds;
+	int nfds;
+	int rc;
+
+	if (args->type != SOCK_STREAM)
+		set_recv_attr(sd, args->version);
+
+	if (msg) {
+		msglen = strlen(msg);
+
+		/* client sends first message */
+		if (client) {
+			if (send_msg(sd, addr, alen, args))
+				return 1;
+		}
+		if (!interactive) {
+			ptval = &timeout;
+			if (!prog_timeout)
+				timeout.tv_sec = 5;
+		}
+	}
+
+	nfds = interactive ? MAX(fileno(stdin), sd)  + 1 : sd + 1;
+	while (1) {
+		FD_ZERO(&rfds);
+		FD_SET(sd, &rfds);
+		if (interactive)
+			FD_SET(fileno(stdin), &rfds);
+
+		rc = select(nfds, &rfds, NULL, NULL, ptval);
+		if (rc < 0) {
+			if (errno == EINTR)
+				continue;
+
+			rc = 1;
+			log_err_errno("select failed");
+			break;
+		} else if (rc == 0) {
+			log_error("Timed out waiting for response\n");
+			rc = 2;
+			break;
+		}
+
+		if (FD_ISSET(sd, &rfds)) {
+			rc = socket_read(sd, args);
+			if (rc < 0) {
+				rc = 1;
+				break;
+			}
+			if (rc == 0)
+				break;
+		}
+
+		rc = 0;
+
+		if (FD_ISSET(fileno(stdin), &rfds)) {
+			if (stdin_to_socket(sd, args->type, addr, alen) <= 0)
+				break;
+		}
+
+		if (interactive)
+			continue;
+
+		if (iter != -1) {
+			--iter;
+			if (iter == 0)
+				break;
+		}
+
+		log_msg("Going into quiet mode\n");
+		quiet = 1;
+
+		if (client) {
+			if (send_msg(sd, addr, alen, args)) {
+				rc = 1;
+				break;
+			}
+		}
+	}
+
+	return rc;
+}
+
+static int msock_init(struct sock_args *args, int server)
+{
+	uint32_t if_addr = htonl(INADDR_ANY);
+	struct sockaddr_in laddr = {
+		.sin_family = AF_INET,
+		.sin_port = htons(args->port),
+	};
+	int one = 1;
+	int sd;
+
+	if (!server && args->has_local_ip)
+		if_addr = args->local_addr.in.s_addr;
+
+	sd = socket(PF_INET, SOCK_DGRAM, 0);
+	if (sd < 0) {
+		log_err_errno("socket");
+		return -1;
+	}
+
+	if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR,
+		       (char *)&one, sizeof(one)) < 0) {
+		log_err_errno("Setting SO_REUSEADDR error");
+		goto out_err;
+	}
+
+	if (setsockopt(sd, SOL_SOCKET, SO_BROADCAST,
+		       (char *)&one, sizeof(one)) < 0)
+		log_err_errno("Setting SO_BROADCAST error");
+
+	if (args->dev && bind_to_device(sd, args->dev) != 0)
+		goto out_err;
+	else if (args->use_setsockopt &&
+		 set_multicast_if(sd, args->ifindex))
+		goto out_err;
+
+	laddr.sin_addr.s_addr = if_addr;
+
+	if (bind(sd, (struct sockaddr *) &laddr, sizeof(laddr)) < 0) {
+		log_err_errno("bind failed");
+		goto out_err;
+	}
+
+	if (server &&
+	    set_membership(sd, args->grp.s_addr,
+			   args->local_addr.in.s_addr, args->dev))
+		goto out_err;
+
+	return sd;
+out_err:
+	close(sd);
+	return -1;
+}
+
+static int msock_server(struct sock_args *args)
+{
+	return msock_init(args, 1);
+}
+
+static int msock_client(struct sock_args *args)
+{
+	return msock_init(args, 0);
+}
+
+static int bind_socket(int sd, struct sock_args *args)
+{
+	struct sockaddr_in serv_addr = {
+		.sin_family = AF_INET,
+	};
+	struct sockaddr_in6 serv6_addr = {
+		.sin6_family = AF_INET6,
+	};
+	void *addr;
+	socklen_t alen;
+
+	if (!args->has_local_ip && args->type == SOCK_RAW)
+		return 0;
+
+	switch (args->version) {
+	case AF_INET:
+		serv_addr.sin_port = htons(args->port);
+		serv_addr.sin_addr = args->local_addr.in;
+		addr = &serv_addr;
+		alen = sizeof(serv_addr);
+		break;
+
+	case AF_INET6:
+		serv6_addr.sin6_port = htons(args->port);
+		serv6_addr.sin6_addr = args->local_addr.in6;
+		addr = &serv6_addr;
+		alen = sizeof(serv6_addr);
+		break;
+
+	default:
+		log_error("Invalid address family\n");
+		return -1;
+	}
+
+	if (bind(sd, addr, alen) < 0) {
+		log_err_errno("error binding socket");
+		return -1;
+	}
+
+	return 0;
+}
+
+static int lsock_init(struct sock_args *args)
+{
+	long flags;
+	int sd;
+
+	sd = socket(args->version, args->type, args->protocol);
+	if (sd < 0) {
+		log_err_errno("Error opening socket");
+		return  -1;
+	}
+
+	if (set_reuseaddr(sd) != 0)
+		goto err;
+
+	if (set_reuseport(sd) != 0)
+		goto err;
+
+	if (args->dev && bind_to_device(sd, args->dev) != 0)
+		goto err;
+	else if (args->use_setsockopt &&
+		 set_unicast_if(sd, args->ifindex, args->version))
+		goto err;
+
+	if (bind_socket(sd, args))
+		goto err;
+
+	if (args->bind_test_only)
+		goto out;
+
+	if (args->type == SOCK_STREAM && listen(sd, 1) < 0) {
+		log_err_errno("listen failed");
+		goto err;
+	}
+
+	flags = fcntl(sd, F_GETFL);
+	if ((flags < 0) || (fcntl(sd, F_SETFL, flags|O_NONBLOCK) < 0)) {
+		log_err_errno("Failed to set non-blocking option");
+		goto err;
+	}
+
+	if (fcntl(sd, F_SETFD, FD_CLOEXEC) < 0)
+		log_err_errno("Failed to set close-on-exec flag");
+
+out:
+	return sd;
+
+err:
+	close(sd);
+	return -1;
+}
+
+static int do_server(struct sock_args *args)
+{
+	struct timeval timeout = { .tv_sec = prog_timeout }, *ptval = NULL;
+	unsigned char addr[sizeof(struct sockaddr_in6)] = {};
+	socklen_t alen = sizeof(addr);
+	int lsd, csd = -1;
+
+	fd_set rfds;
+	int rc;
+
+	if (prog_timeout)
+		ptval = &timeout;
+
+	if (args->has_grp)
+		lsd = msock_server(args);
+	else
+		lsd = lsock_init(args);
+
+	if (lsd < 0)
+		return 1;
+
+	if (args->bind_test_only) {
+		close(lsd);
+		return 0;
+	}
+
+	if (args->type != SOCK_STREAM) {
+		rc = msg_loop(0, lsd, (void *) addr, alen, args);
+		close(lsd);
+		return rc;
+	}
+
+	if (args->password && tcp_md5_remote(lsd, args)) {
+		close(lsd);
+		return -1;
+	}
+
+	while (1) {
+		log_msg("\n");
+		log_msg("waiting for client connection.\n");
+		FD_ZERO(&rfds);
+		FD_SET(lsd, &rfds);
+
+		rc = select(lsd+1, &rfds, NULL, NULL, ptval);
+		if (rc == 0) {
+			rc = 2;
+			break;
+		}
+
+		if (rc < 0) {
+			if (errno == EINTR)
+				continue;
+
+			log_err_errno("select failed");
+			break;
+		}
+
+		if (FD_ISSET(lsd, &rfds)) {
+
+			csd = accept(lsd, (void *) addr, &alen);
+			if (csd < 0) {
+				log_err_errno("accept failed");
+				break;
+			}
+
+			rc = show_sockstat(csd, args);
+			if (rc)
+				break;
+
+			rc = check_device(csd, args);
+			if (rc)
+				break;
+		}
+
+		rc = msg_loop(0, csd, (void *) addr, alen, args);
+		close(csd);
+
+		if (!interactive)
+			break;
+	}
+
+	close(lsd);
+
+	return rc;
+}
+
+static int wait_for_connect(int sd)
+{
+	struct timeval _tv = { .tv_sec = prog_timeout }, *tv = NULL;
+	fd_set wfd;
+	int val = 0, sz = sizeof(val);
+	int rc;
+
+	FD_ZERO(&wfd);
+	FD_SET(sd, &wfd);
+
+	if (prog_timeout)
+		tv = &_tv;
+
+	rc = select(FD_SETSIZE, NULL, &wfd, NULL, tv);
+	if (rc == 0) {
+		log_error("connect timed out\n");
+		return -2;
+	} else if (rc < 0) {
+		log_err_errno("select failed");
+		return -3;
+	}
+
+	if (getsockopt(sd, SOL_SOCKET, SO_ERROR, &val, (socklen_t *)&sz) < 0) {
+		log_err_errno("getsockopt(SO_ERROR) failed");
+		return -4;
+	}
+
+	if (val != 0) {
+		log_error("connect failed: %d: %s\n", val, strerror(val));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int connectsock(void *addr, socklen_t alen, struct sock_args *args)
+{
+	int sd, rc = -1;
+	long flags;
+
+	sd = socket(args->version, args->type, args->protocol);
+	if (sd < 0) {
+		log_err_errno("Failed to create socket");
+		return -1;
+	}
+
+	flags = fcntl(sd, F_GETFL);
+	if ((flags < 0) || (fcntl(sd, F_SETFL, flags|O_NONBLOCK) < 0)) {
+		log_err_errno("Failed to set non-blocking option");
+		goto err;
+	}
+
+	if (set_reuseport(sd) != 0)
+		goto err;
+
+	if (args->dev && bind_to_device(sd, args->dev) != 0)
+		goto err;
+	else if (args->use_setsockopt &&
+		 set_unicast_if(sd, args->ifindex, args->version))
+		goto err;
+
+	if (args->has_local_ip && bind_socket(sd, args))
+		goto err;
+
+	if (args->type != SOCK_STREAM)
+		goto out;
+
+	if (args->password && tcp_md5sig(sd, addr, alen, args->password))
+		goto err;
+
+	if (args->bind_test_only)
+		goto out;
+
+	if (connect(sd, addr, alen) < 0) {
+		if (errno != EINPROGRESS) {
+			log_err_errno("Failed to connect to remote host");
+			rc = -1;
+			goto err;
+		}
+		rc = wait_for_connect(sd);
+		if (rc < 0)
+			goto err;
+	}
+out:
+	return sd;
+
+err:
+	close(sd);
+	return rc;
+}
+
+static int do_client(struct sock_args *args)
+{
+	struct sockaddr_in sin = {
+		.sin_family = AF_INET,
+	};
+	struct sockaddr_in6 sin6 = {
+		.sin6_family = AF_INET6,
+	};
+	void *addr;
+	int alen;
+	int rc = 0;
+	int sd;
+
+	if (!args->has_remote_ip && !args->has_grp) {
+		fprintf(stderr, "remote IP or multicast group not given\n");
+		return 1;
+	}
+
+	switch (args->version) {
+	case AF_INET:
+		sin.sin_port = htons(args->port);
+		if (args->has_grp)
+			sin.sin_addr = args->grp;
+		else
+			sin.sin_addr = args->remote_addr.in;
+		addr = &sin;
+		alen = sizeof(sin);
+		break;
+	case AF_INET6:
+		sin6.sin6_port = htons(args->port);
+		sin6.sin6_addr = args->remote_addr.in6;
+		sin6.sin6_scope_id = args->scope_id;
+		addr = &sin6;
+		alen = sizeof(sin6);
+		break;
+	}
+
+	if (args->has_grp)
+		sd = msock_client(args);
+	else
+		sd = connectsock(addr, alen, args);
+
+	if (sd < 0)
+		return -sd;
+
+	if (args->bind_test_only)
+		goto out;
+
+	if (args->type == SOCK_STREAM) {
+		rc = show_sockstat(sd, args);
+		if (rc != 0)
+			goto out;
+	}
+
+	rc = msg_loop(1, sd, addr, alen, args);
+
+out:
+	close(sd);
+
+	return rc;
+}
+
+enum addr_type {
+	ADDR_TYPE_LOCAL,
+	ADDR_TYPE_REMOTE,
+	ADDR_TYPE_MCAST,
+	ADDR_TYPE_EXPECTED_LOCAL,
+	ADDR_TYPE_EXPECTED_REMOTE,
+};
+
+static int convert_addr(struct sock_args *args, const char *_str,
+			enum addr_type atype)
+{
+	int family = args->version;
+	struct in6_addr *in6;
+	struct in_addr  *in;
+	const char *desc;
+	char *str, *dev;
+	void *addr;
+	int rc = 0;
+
+	str = strdup(_str);
+	if (!str)
+		return -ENOMEM;
+
+	switch (atype) {
+	case ADDR_TYPE_LOCAL:
+		desc = "local";
+		addr = &args->local_addr;
+		break;
+	case ADDR_TYPE_REMOTE:
+		desc = "remote";
+		addr = &args->remote_addr;
+		break;
+	case ADDR_TYPE_MCAST:
+		desc = "mcast grp";
+		addr = &args->grp;
+		break;
+	case ADDR_TYPE_EXPECTED_LOCAL:
+		desc = "expected local";
+		addr = &args->expected_laddr;
+		break;
+	case ADDR_TYPE_EXPECTED_REMOTE:
+		desc = "expected remote";
+		addr = &args->expected_raddr;
+		break;
+	default:
+		log_error("unknown address type");
+		exit(1);
+	}
+
+	switch (family) {
+	case AF_INET:
+		in  = (struct in_addr *) addr;
+		if (str) {
+			if (inet_pton(AF_INET, str, in) == 0) {
+				log_error("Invalid %s IP address\n", desc);
+				rc = -1;
+				goto out;
+			}
+		} else {
+			in->s_addr = htonl(INADDR_ANY);
+		}
+		break;
+
+	case AF_INET6:
+		dev = strchr(str, '%');
+		if (dev) {
+			*dev = '\0';
+			dev++;
+		}
+
+		in6 = (struct in6_addr *) addr;
+		if (str) {
+			if (inet_pton(AF_INET6, str, in6) == 0) {
+				log_error("Invalid %s IPv6 address\n", desc);
+				rc = -1;
+				goto out;
+			}
+		} else {
+			*in6 = in6addr_any;
+		}
+		if (dev) {
+			args->scope_id = get_ifidx(dev);
+			if (args->scope_id < 0) {
+				log_error("Invalid scope on %s IPv6 address\n",
+					  desc);
+				rc = -1;
+				goto out;
+			}
+		}
+		break;
+
+	default:
+		log_error("Invalid address family\n");
+	}
+
+out:
+	free(str);
+	return rc;
+}
+
+static char *random_msg(int len)
+{
+	int i, n = 0, olen = len + 1;
+	char *m;
+
+	if (len <= 0)
+		return NULL;
+
+	m = malloc(olen);
+	if (!m)
+		return NULL;
+
+	while (len > 26) {
+		i = snprintf(m + n, olen - n, "%.26s",
+			     "abcdefghijklmnopqrstuvwxyz");
+		n += i;
+		len -= i;
+	}
+	i = snprintf(m + n, olen - n, "%.*s", len,
+		     "abcdefghijklmnopqrstuvwxyz");
+	return m;
+}
+
+#define GETOPT_STR  "sr:l:p:t:g:P:DRn:M:d:SCi6L:0:1:2:Fbq"
+
+static void print_usage(char *prog)
+{
+	printf(
+	"usage: %s OPTS\n"
+	"Required:\n"
+	"    -r addr       remote address to connect to (client mode only)\n"
+	"    -p port       port to connect to (client mode)/listen on (server mode)\n"
+	"                  (default: %d)\n"
+	"    -s            server mode (default: client mode)\n"
+	"    -t            timeout seconds (default: none)\n"
+	"\n"
+	"Optional:\n"
+	"    -F            Restart server loop\n"
+	"    -6            IPv6 (default is IPv4)\n"
+	"    -P proto      protocol for socket: icmp, ospf (default: none)\n"
+	"    -D|R          datagram (D) / raw (R) socket (default stream)\n"
+	"    -l addr       local address to bind to\n"
+	"\n"
+	"    -d dev        bind socket to given device name\n"
+	"    -S            use setsockopt (IP_UNICAST_IF or IP_MULTICAST_IF)\n"
+	"                  to set device binding\n"
+	"    -C            use cmsg and IP_PKTINFO to specify device binding\n"
+	"\n"
+	"    -L len        send random message of given length\n"
+	"    -n num        number of times to send message\n"
+	"\n"
+	"    -M password   use MD5 sum protection\n"
+	"    -g grp        multicast group (e.g., 239.1.1.1)\n"
+	"    -i            interactive mode (default is echo and terminate)\n"
+	"\n"
+	"    -0 addr       Expected local address\n"
+	"    -1 addr       Expected remote address\n"
+	"    -2 dev        Expected device name (or index) to receive packet\n"
+	"\n"
+	"    -b            Bind test only.\n"
+	"    -q            Be quiet. Run test without printing anything.\n"
+	, prog, DEFAULT_PORT);
+}
+
+int main(int argc, char *argv[])
+{
+	struct sock_args args = {
+		.version = AF_INET,
+		.type    = SOCK_STREAM,
+		.port    = DEFAULT_PORT,
+	};
+	struct protoent *pe;
+	unsigned int tmp;
+	int forever = 0;
+
+	/* process inputs */
+	extern char *optarg;
+	int rc = 0;
+
+	/*
+	 * process input args
+	 */
+
+	while ((rc = getopt(argc, argv, GETOPT_STR)) != -1) {
+		switch (rc) {
+		case 's':
+			server_mode = 1;
+			break;
+		case 'F':
+			forever = 1;
+			break;
+		case 'l':
+			args.has_local_ip = 1;
+			if (convert_addr(&args, optarg, ADDR_TYPE_LOCAL) < 0)
+				return 1;
+			break;
+		case 'r':
+			args.has_remote_ip = 1;
+			if (convert_addr(&args, optarg, ADDR_TYPE_REMOTE) < 0)
+				return 1;
+			break;
+		case 'p':
+			if (str_to_uint(optarg, 1, 65535, &tmp) != 0) {
+				fprintf(stderr, "Invalid port\n");
+				return 1;
+			}
+			args.port = (unsigned short) tmp;
+			break;
+		case 't':
+			if (str_to_uint(optarg, 0, INT_MAX,
+					&prog_timeout) != 0) {
+				fprintf(stderr, "Invalid timeout\n");
+				return 1;
+			}
+			break;
+		case 'D':
+			args.type = SOCK_DGRAM;
+			break;
+		case 'R':
+			args.type = SOCK_RAW;
+			args.port = 0;
+			break;
+		case 'P':
+			pe = getprotobyname(optarg);
+			if (pe) {
+				args.protocol = pe->p_proto;
+			} else {
+				if (str_to_uint(optarg, 0, 0xffff, &tmp) != 0) {
+					fprintf(stderr, "Invalid potocol\n");
+					return 1;
+				}
+				args.protocol = tmp;
+			}
+			break;
+		case 'n':
+			iter = atoi(optarg);
+			break;
+		case 'L':
+			msg = random_msg(atoi(optarg));
+			break;
+		case 'M':
+			args.password = optarg;
+			break;
+		case 'S':
+			args.use_setsockopt = 1;
+			break;
+		case 'C':
+			args.use_cmsg = 1;
+			break;
+		case 'd':
+			args.dev = optarg;
+			args.ifindex = get_ifidx(optarg);
+			if (args.ifindex < 0) {
+				fprintf(stderr, "Invalid device name\n");
+				return 1;
+			}
+			break;
+		case 'i':
+			interactive = 1;
+			break;
+		case 'g':
+			args.has_grp = 1;
+			if (convert_addr(&args, optarg, ADDR_TYPE_MCAST) < 0)
+				return 1;
+			args.type = SOCK_DGRAM;
+			break;
+		case '6':
+			args.version = AF_INET6;
+			break;
+		case 'b':
+			args.bind_test_only = 1;
+			break;
+		case '0':
+			args.has_expected_laddr = 1;
+			if (convert_addr(&args, optarg,
+					 ADDR_TYPE_EXPECTED_LOCAL))
+				return 1;
+			break;
+		case '1':
+			args.has_expected_raddr = 1;
+			if (convert_addr(&args, optarg,
+					 ADDR_TYPE_EXPECTED_REMOTE))
+				return 1;
+
+			break;
+		case '2':
+			if (str_to_uint(optarg, 0, 0x7ffffff, &tmp) != 0) {
+				tmp = get_ifidx(optarg);
+				if (tmp < 0) {
+					fprintf(stderr,
+						"Invalid device index\n");
+					return 1;
+				}
+			}
+			args.expected_ifindex = (int)tmp;
+			break;
+		case 'q':
+			quiet = 1;
+			break;
+		default:
+			print_usage(argv[0]);
+			return 1;
+		}
+	}
+
+	if (args.password &&
+	    (!args.has_remote_ip || args.type != SOCK_STREAM)) {
+		log_error("MD5 passwords apply to TCP only and require a remote ip for the password\n");
+		return 1;
+	}
+
+	if ((args.use_setsockopt || args.use_cmsg) && !args.ifindex) {
+		fprintf(stderr, "Device binding not specified\n");
+		return 1;
+	}
+	if (args.use_setsockopt || args.use_cmsg)
+		args.dev = NULL;
+
+	if (iter == 0) {
+		fprintf(stderr, "Invalid number of messages to send\n");
+		return 1;
+	}
+
+	if (args.type == SOCK_STREAM && !args.protocol)
+		args.protocol = IPPROTO_TCP;
+	if (args.type == SOCK_DGRAM && !args.protocol)
+		args.protocol = IPPROTO_UDP;
+
+	if ((args.type == SOCK_STREAM || args.type == SOCK_DGRAM) &&
+	     args.port == 0) {
+		fprintf(stderr, "Invalid port number\n");
+		return 1;
+	}
+
+	if (!server_mode && !args.has_grp &&
+	    !args.has_remote_ip && !args.has_local_ip) {
+		fprintf(stderr,
+			"Local (server mode) or remote IP (client IP) required\n");
+		return 1;
+	}
+
+	if (interactive) {
+		prog_timeout = 0;
+		msg = NULL;
+	}
+
+	if (server_mode) {
+		do {
+			rc = do_server(&args);
+		} while (forever);
+
+		return rc;
+	}
+	return do_client(&args);
+}