Adding upstream version 8.4.4.upstream/8.4.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 695 insertions, 0 deletions

diff --git a/lib/sockopt.c b/lib/sockopt.c
new file mode 100644
index 0000000..7a2b8a1
--- /dev/null
+++ b/lib/sockopt.c
@@ -0,0 +1,695 @@
+/* setsockopt functions
+ * Copyright (C) 1999 Kunihiro Ishiguro
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * GNU Zebra is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "log.h"
+#include "sockopt.h"
+#include "sockunion.h"
+#include "lib_errors.h"
+
+#if (defined(__FreeBSD__)                                                      \
+     && ((__FreeBSD_version >= 500022 && __FreeBSD_version < 700000)           \
+	 || (__FreeBSD_version < 500000 && __FreeBSD_version >= 440000)))      \
+	|| (defined(__NetBSD__) && defined(__NetBSD_Version__)                 \
+	    && __NetBSD_Version__ >= 106010000)                                \
+	|| defined(__OpenBSD__) || defined(__APPLE__)                          \
+	|| defined(__DragonFly__) || defined(__sun)
+#define HAVE_BSD_STRUCT_IP_MREQ_HACK
+#endif
+
+void setsockopt_so_recvbuf(int sock, int size)
+{
+	int orig_req = size;
+
+	while (setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size))
+	       == -1)
+		size /= 2;
+
+	if (size != orig_req)
+		flog_err(EC_LIB_SOCKET,
+			 "%s: fd %d: SO_RCVBUF set to %d (requested %d)",
+			 __func__, sock, size, orig_req);
+}
+
+void setsockopt_so_sendbuf(const int sock, int size)
+{
+	int orig_req = size;
+
+	while (setsockopt(sock, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size))
+	       == -1)
+		size /= 2;
+
+	if (size != orig_req)
+		flog_err(EC_LIB_SOCKET,
+			 "%s: fd %d: SO_SNDBUF set to %d (requested %d)",
+			 __func__, sock, size, orig_req);
+}
+
+int getsockopt_so_sendbuf(const int sock)
+{
+	uint32_t optval;
+	socklen_t optlen = sizeof(optval);
+	int ret = getsockopt(sock, SOL_SOCKET, SO_SNDBUF, (char *)&optval,
+			     &optlen);
+	if (ret < 0) {
+		flog_err_sys(EC_LIB_SYSTEM_CALL,
+			     "fd %d: can't getsockopt SO_SNDBUF: %d (%s)", sock,
+			     errno, safe_strerror(errno));
+		return ret;
+	}
+	return optval;
+}
+
+int getsockopt_so_recvbuf(const int sock)
+{
+	uint32_t optval;
+	socklen_t optlen = sizeof(optval);
+	int ret = getsockopt(sock, SOL_SOCKET, SO_RCVBUF, (char *)&optval,
+			     &optlen);
+	if (ret < 0) {
+		flog_err_sys(EC_LIB_SYSTEM_CALL,
+			     "fd %d: can't getsockopt SO_RCVBUF: %d (%s)", sock,
+			     errno, safe_strerror(errno));
+		return ret;
+	}
+	return optval;
+}
+
+static void *getsockopt_cmsg_data(struct msghdr *msgh, int level, int type)
+{
+	struct cmsghdr *cmsg;
+
+	for (cmsg = CMSG_FIRSTHDR(msgh); cmsg != NULL;
+	     cmsg = CMSG_NXTHDR(msgh, cmsg))
+		if (cmsg->cmsg_level == level && cmsg->cmsg_type == type)
+			return CMSG_DATA(cmsg);
+
+	return NULL;
+}
+
+/* Set IPv6 packet info to the socket. */
+int setsockopt_ipv6_pktinfo(int sock, int val)
+{
+	int ret;
+
+#ifdef IPV6_RECVPKTINFO /*2292bis-01*/
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &val,
+			 sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "can't setsockopt IPV6_RECVPKTINFO : %s",
+			 safe_strerror(errno));
+#else  /*RFC2292*/
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &val, sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IPV6_PKTINFO : %s",
+			 safe_strerror(errno));
+#endif /* IANA_IPV6 */
+	return ret;
+}
+
+/* Set multicast hops val to the socket. */
+int setsockopt_ipv6_multicast_hops(int sock, int val)
+{
+	int ret;
+
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &val,
+			 sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IPV6_MULTICAST_HOPS");
+	return ret;
+}
+
+/* Set multicast hops val to the socket. */
+int setsockopt_ipv6_unicast_hops(int sock, int val)
+{
+	int ret;
+
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &val,
+			 sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IPV6_UNICAST_HOPS");
+	return ret;
+}
+
+int setsockopt_ipv6_hoplimit(int sock, int val)
+{
+	int ret;
+
+#ifdef IPV6_RECVHOPLIMIT /*2292bis-01*/
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &val,
+			 sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IPV6_RECVHOPLIMIT");
+#else /*RFC2292*/
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_HOPLIMIT, &val, sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IPV6_HOPLIMIT");
+#endif
+	return ret;
+}
+
+/* Set multicast loop zero to the socket. */
+int setsockopt_ipv6_multicast_loop(int sock, int val)
+{
+	int ret;
+
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &val,
+			 sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IPV6_MULTICAST_LOOP");
+	return ret;
+}
+
+static int getsockopt_ipv6_ifindex(struct msghdr *msgh)
+{
+	struct in6_pktinfo *pktinfo;
+
+	pktinfo = getsockopt_cmsg_data(msgh, IPPROTO_IPV6, IPV6_PKTINFO);
+
+	return pktinfo->ipi6_ifindex;
+}
+
+int setsockopt_ipv6_tclass(int sock, int tclass)
+{
+	int ret = 0;
+
+#ifdef IPV6_TCLASS /* RFC3542 */
+	ret = setsockopt(sock, IPPROTO_IPV6, IPV6_TCLASS, &tclass,
+			 sizeof(tclass));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "Can't set IPV6_TCLASS option for fd %d to %#x: %s",
+			 sock, tclass, safe_strerror(errno));
+#endif
+	return ret;
+}
+
+/*
+ * Process multicast socket options for IPv4 in an OS-dependent manner.
+ * Supported options are IP_{ADD,DROP}_MEMBERSHIP.
+ *
+ * Many operating systems have a limit on the number of groups that
+ * can be joined per socket (where each group and local address
+ * counts).  This impacts OSPF, which joins groups on each interface
+ * using a single socket.  The limit is typically 20, derived from the
+ * original BSD multicast implementation.  Some systems have
+ * mechanisms for increasing this limit.
+ *
+ * In many 4.4BSD-derived systems, multicast group operations are not
+ * allowed on interfaces that are not UP.  Thus, a previous attempt to
+ * leave the group may have failed, leaving it still joined, and we
+ * drop/join quietly to recover.  This may not be necessary, but aims to
+ * defend against unknown behavior in that we will still return an error
+ * if the second join fails.  It is not clear how other systems
+ * (e.g. Linux, Solaris) behave when leaving groups on down interfaces,
+ * but this behavior should not be harmful if they behave the same way,
+ * allow leaves, or implicitly leave all groups joined to down interfaces.
+ */
+int setsockopt_ipv4_multicast(int sock, int optname, struct in_addr if_addr,
+			      unsigned int mcast_addr, ifindex_t ifindex)
+{
+#ifdef HAVE_RFC3678
+	struct group_req gr;
+	struct sockaddr_in *si;
+	int ret;
+	memset(&gr, 0, sizeof(gr));
+	si = (struct sockaddr_in *)&gr.gr_group;
+	gr.gr_interface = ifindex;
+	si->sin_family = AF_INET;
+#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
+	si->sin_len = sizeof(struct sockaddr_in);
+#endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
+	si->sin_addr.s_addr = mcast_addr;
+	ret = setsockopt(sock, IPPROTO_IP,
+			 (optname == IP_ADD_MEMBERSHIP) ? MCAST_JOIN_GROUP
+							: MCAST_LEAVE_GROUP,
+			 (void *)&gr, sizeof(gr));
+	if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP)
+	    && (errno == EADDRINUSE)) {
+		setsockopt(sock, IPPROTO_IP, MCAST_LEAVE_GROUP, (void *)&gr,
+			   sizeof(gr));
+		ret = setsockopt(sock, IPPROTO_IP, MCAST_JOIN_GROUP,
+				 (void *)&gr, sizeof(gr));
+	}
+	return ret;
+
+#elif defined(HAVE_STRUCT_IP_MREQN_IMR_IFINDEX) && !defined(__FreeBSD__)
+	struct ip_mreqn mreqn;
+	int ret;
+
+	assert(optname == IP_ADD_MEMBERSHIP || optname == IP_DROP_MEMBERSHIP);
+	memset(&mreqn, 0, sizeof(mreqn));
+
+	mreqn.imr_multiaddr.s_addr = mcast_addr;
+	mreqn.imr_ifindex = ifindex;
+
+	ret = setsockopt(sock, IPPROTO_IP, optname, (void *)&mreqn,
+			 sizeof(mreqn));
+	if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP)
+	    && (errno == EADDRINUSE)) {
+		/* see above: handle possible problem when interface comes back
+		 * up */
+		zlog_info(
+			"setsockopt_ipv4_multicast attempting to drop and re-add (fd %d, mcast %pI4, ifindex %u)",
+			sock, &mreqn.imr_multiaddr, ifindex);
+		setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP, (void *)&mreqn,
+			   sizeof(mreqn));
+		ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+				 (void *)&mreqn, sizeof(mreqn));
+	}
+	return ret;
+
+/* Example defines for another OS, boilerplate off other code in this
+   function, AND handle optname as per other sections for consistency !! */
+/* #elif  defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
+/* Add your favourite OS here! */
+
+#elif defined(HAVE_BSD_STRUCT_IP_MREQ_HACK) /* #if OS_TYPE */
+	/* standard BSD API */
+
+	struct ip_mreq mreq;
+	int ret;
+
+	assert(optname == IP_ADD_MEMBERSHIP || optname == IP_DROP_MEMBERSHIP);
+
+
+	memset(&mreq, 0, sizeof(mreq));
+	mreq.imr_multiaddr.s_addr = mcast_addr;
+#if !defined __OpenBSD__
+	mreq.imr_interface.s_addr = htonl(ifindex);
+#else
+	mreq.imr_interface.s_addr = if_addr.s_addr;
+#endif
+
+	ret = setsockopt(sock, IPPROTO_IP, optname, (void *)&mreq,
+			 sizeof(mreq));
+	if ((ret < 0) && (optname == IP_ADD_MEMBERSHIP)
+	    && (errno == EADDRINUSE)) {
+		/* see above: handle possible problem when interface comes back
+		 * up */
+		zlog_info(
+			"setsockopt_ipv4_multicast attempting to drop and re-add (fd %d, mcast %pI4, ifindex %u)",
+			sock, &mreq.imr_multiaddr, ifindex);
+		setsockopt(sock, IPPROTO_IP, IP_DROP_MEMBERSHIP, (void *)&mreq,
+			   sizeof(mreq));
+		ret = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
+				 (void *)&mreq, sizeof(mreq));
+	}
+	return ret;
+
+#else
+#error "Unsupported multicast API"
+#endif /* #if OS_TYPE */
+}
+
+/*
+ * Set IP_MULTICAST_IF socket option in an OS-dependent manner.
+ */
+int setsockopt_ipv4_multicast_if(int sock, struct in_addr if_addr,
+				 ifindex_t ifindex)
+{
+
+#ifdef HAVE_STRUCT_IP_MREQN_IMR_IFINDEX
+	struct ip_mreqn mreqn;
+	memset(&mreqn, 0, sizeof(mreqn));
+
+	mreqn.imr_ifindex = ifindex;
+	return setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&mreqn,
+			  sizeof(mreqn));
+
+/* Example defines for another OS, boilerplate off other code in this
+   function */
+/* #elif  defined(BOGON_NIX) && EXAMPLE_VERSION_CODE > -100000 */
+/* Add your favourite OS here! */
+#elif defined(HAVE_BSD_STRUCT_IP_MREQ_HACK)
+	struct in_addr m;
+
+#if !defined __OpenBSD__
+	m.s_addr = htonl(ifindex);
+#else
+	m.s_addr = if_addr.s_addr;
+#endif
+
+	return setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, (void *)&m,
+			  sizeof(m));
+#else
+#error "Unsupported multicast API"
+#endif
+}
+
+int setsockopt_ipv4_multicast_loop(int sock, uint8_t val)
+{
+	int ret;
+
+	ret = setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP, (void *)&val,
+			 sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET, "can't setsockopt IP_MULTICAST_LOOP");
+
+	return ret;
+}
+
+static int setsockopt_ipv4_ifindex(int sock, ifindex_t val)
+{
+	int ret;
+
+#if defined(IP_PKTINFO)
+	ret = setsockopt(sock, IPPROTO_IP, IP_PKTINFO, &val, sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "Can't set IP_PKTINFO option for fd %d to %d: %s",
+			 sock, val, safe_strerror(errno));
+#elif defined(IP_RECVIF)
+	ret = setsockopt(sock, IPPROTO_IP, IP_RECVIF, &val, sizeof(val));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "Can't set IP_RECVIF option for fd %d to %d: %s", sock,
+			 val, safe_strerror(errno));
+#else
+#warning "Neither IP_PKTINFO nor IP_RECVIF is available."
+#warning "Will not be able to receive link info."
+#warning "Things might be seriously broken.."
+	/* XXX Does this ever happen?  Should there be a zlog_warn message here?
+	 */
+	ret = -1;
+#endif
+	return ret;
+}
+
+int setsockopt_ipv4_tos(int sock, int tos)
+{
+	int ret;
+
+	ret = setsockopt(sock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
+	if (ret < 0)
+		flog_err(EC_LIB_SOCKET,
+			 "Can't set IP_TOS option for fd %d to %#x: %s", sock,
+			 tos, safe_strerror(errno));
+	return ret;
+}
+
+
+int setsockopt_ifindex(int af, int sock, ifindex_t val)
+{
+	int ret = -1;
+
+	switch (af) {
+	case AF_INET:
+		ret = setsockopt_ipv4_ifindex(sock, val);
+		break;
+	case AF_INET6:
+		ret = setsockopt_ipv6_pktinfo(sock, val);
+		break;
+	default:
+		flog_err(EC_LIB_DEVELOPMENT,
+			 "setsockopt_ifindex: unknown address family %d", af);
+	}
+	return ret;
+}
+
+/*
+ * Requires: msgh is not NULL and points to a valid struct msghdr, which
+ * may or may not have control data about the incoming interface.
+ *
+ * Returns the interface index (small integer >= 1) if it can be
+ * determined, or else 0.
+ */
+static ifindex_t getsockopt_ipv4_ifindex(struct msghdr *msgh)
+{
+	ifindex_t ifindex;
+
+#if defined(IP_PKTINFO)
+	/* Linux pktinfo based ifindex retrieval */
+	struct in_pktinfo *pktinfo;
+
+	pktinfo = (struct in_pktinfo *)getsockopt_cmsg_data(msgh, IPPROTO_IP,
+							    IP_PKTINFO);
+
+	/* getsockopt_ifindex() will forward this, being 0 "not found" */
+	if (pktinfo == NULL)
+		return 0;
+
+	ifindex = pktinfo->ipi_ifindex;
+
+#elif defined(IP_RECVIF)
+
+/* retrieval based on IP_RECVIF */
+
+	/* BSD systems use a sockaddr_dl as the control message payload. */
+	struct sockaddr_dl *sdl;
+
+	/* BSD */
+	sdl = (struct sockaddr_dl *)getsockopt_cmsg_data(msgh, IPPROTO_IP,
+							 IP_RECVIF);
+	if (sdl != NULL)
+		ifindex = sdl->sdl_index;
+	else
+		ifindex = 0;
+
+#else
+/*
+ * Neither IP_PKTINFO nor IP_RECVIF defined - warn at compile time.
+ * XXX Decide if this is a core service, or if daemons have to cope.
+ * Since Solaris 8 and OpenBSD seem not to provide it, it seems that
+ * daemons have to cope.
+ */
+#warning "getsockopt_ipv4_ifindex: Neither IP_PKTINFO nor IP_RECVIF defined."
+#warning "Some daemons may fail to operate correctly!"
+	ifindex = 0;
+
+#endif /* IP_PKTINFO */
+
+	return ifindex;
+}
+
+/* return ifindex, 0 if none found */
+ifindex_t getsockopt_ifindex(int af, struct msghdr *msgh)
+{
+	switch (af) {
+	case AF_INET:
+		return (getsockopt_ipv4_ifindex(msgh));
+	case AF_INET6:
+		return (getsockopt_ipv6_ifindex(msgh));
+	default:
+		flog_err(EC_LIB_DEVELOPMENT,
+			 "getsockopt_ifindex: unknown address family %d", af);
+		return 0;
+	}
+}
+
+/* swab iph between order system uses for IP_HDRINCL and host order */
+void sockopt_iphdrincl_swab_htosys(struct ip *iph)
+{
+/* BSD and derived take iph in network order, except for
+ * ip_len and ip_off
+ */
+#ifndef HAVE_IP_HDRINCL_BSD_ORDER
+	iph->ip_len = htons(iph->ip_len);
+	iph->ip_off = htons(iph->ip_off);
+#endif /* HAVE_IP_HDRINCL_BSD_ORDER */
+
+	iph->ip_id = htons(iph->ip_id);
+}
+
+void sockopt_iphdrincl_swab_systoh(struct ip *iph)
+{
+#ifndef HAVE_IP_HDRINCL_BSD_ORDER
+	iph->ip_len = ntohs(iph->ip_len);
+	iph->ip_off = ntohs(iph->ip_off);
+#endif /* HAVE_IP_HDRINCL_BSD_ORDER */
+
+	iph->ip_id = ntohs(iph->ip_id);
+}
+
+int sockopt_tcp_rtt(int sock)
+{
+#ifdef TCP_INFO
+	struct tcp_info ti;
+	socklen_t len = sizeof(ti);
+
+	if (getsockopt(sock, IPPROTO_TCP, TCP_INFO, &ti, &len) != 0)
+		return 0;
+
+	return ti.tcpi_rtt / 1000;
+#else
+	return 0;
+#endif
+}
+
+int sockopt_tcp_signature_ext(int sock, union sockunion *su, uint16_t prefixlen,
+			      const char *password)
+{
+#ifndef HAVE_DECL_TCP_MD5SIG
+	/*
+	 * We have been asked to enable MD5 auth for an address, but our
+	 * platform doesn't support that
+	 */
+	return -2;
+#endif
+
+#ifndef TCP_MD5SIG_EXT
+	/*
+	 * We have been asked to enable MD5 auth for a prefix, but our platform
+	 * doesn't support that
+	 */
+	if (prefixlen > 0)
+		return -2;
+#endif
+
+#if HAVE_DECL_TCP_MD5SIG
+	int ret;
+
+	int optname = TCP_MD5SIG;
+#ifndef GNU_LINUX
+	/*
+	 * XXX Need to do PF_KEY operation here to add/remove an SA entry,
+	 * and add/remove an SP entry for this peer's packet flows also.
+	 */
+	int md5sig = password && *password ? 1 : 0;
+#else
+	int keylen = password ? strlen(password) : 0;
+	struct tcp_md5sig md5sig;
+	union sockunion *su2, *susock;
+
+	/* Figure out whether the socket and the sockunion are the same family..
+	 * adding AF_INET to AF_INET6 needs to be v4 mapped, you'd think..
+	 */
+	if (!(susock = sockunion_getsockname(sock)))
+		return -1;
+
+	if (susock->sa.sa_family == su->sa.sa_family)
+		su2 = su;
+	else {
+		/* oops.. */
+		su2 = susock;
+
+		if (su2->sa.sa_family == AF_INET) {
+			sockunion_free(susock);
+			return 0;
+		}
+
+		/* If this does not work, then all users of this sockopt will
+		 * need to
+		 * differentiate between IPv4 and IPv6, and keep separate
+		 * sockets for
+		 * each.
+		 *
+		 * Sadly, it doesn't seem to work at present. It's unknown
+		 * whether
+		 * this is a bug or not.
+		 */
+		if (su2->sa.sa_family == AF_INET6
+		    && su->sa.sa_family == AF_INET) {
+			su2->sin6.sin6_family = AF_INET6;
+			/* V4Map the address */
+			memset(&su2->sin6.sin6_addr, 0,
+			       sizeof(struct in6_addr));
+			su2->sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
+			memcpy(&su2->sin6.sin6_addr.s6_addr32[3],
+			       &su->sin.sin_addr, 4);
+		}
+	}
+
+	memset(&md5sig, 0, sizeof(md5sig));
+	memcpy(&md5sig.tcpm_addr, su2, sizeof(*su2));
+
+	md5sig.tcpm_keylen = keylen;
+	if (keylen)
+		memcpy(md5sig.tcpm_key, password, keylen);
+	sockunion_free(susock);
+
+	/*
+	 * Handle support for MD5 signatures on prefixes, if available and
+	 * requested. Technically the #ifdef check below is not needed because
+	 * if prefixlen > 0 and we don't have support for this feature we would
+	 * have already returned by now, but leaving it there to be explicit.
+	 */
+#ifdef TCP_MD5SIG_EXT
+	if (prefixlen > 0) {
+		md5sig.tcpm_prefixlen = prefixlen;
+		md5sig.tcpm_flags = TCP_MD5SIG_FLAG_PREFIX;
+		optname = TCP_MD5SIG_EXT;
+	}
+#endif /* TCP_MD5SIG_EXT */
+
+#endif /* GNU_LINUX */
+
+	ret = setsockopt(sock, IPPROTO_TCP, optname, &md5sig, sizeof(md5sig));
+	if (ret < 0) {
+		if (ENOENT == errno)
+			ret = 0;
+		else
+			flog_err_sys(
+				EC_LIB_SYSTEM_CALL,
+				"sockopt_tcp_signature: setsockopt(%d): %s",
+				sock, safe_strerror(errno));
+	}
+	return ret;
+#endif /* HAVE_TCP_MD5SIG */
+
+	/*
+	 * Making compiler happy.  If we get to this point we probably
+	 * have done something really really wrong.
+	 */
+	return -2;
+}
+
+int sockopt_tcp_signature(int sock, union sockunion *su, const char *password)
+{
+	return sockopt_tcp_signature_ext(sock, su, 0, password);
+}
+
+/* set TCP mss value to socket */
+int sockopt_tcp_mss_set(int sock, int tcp_maxseg)
+{
+	int ret = 0;
+	socklen_t tcp_maxseg_len = sizeof(tcp_maxseg);
+
+	ret = setsockopt(sock, IPPROTO_TCP, TCP_MAXSEG, &tcp_maxseg,
+			 tcp_maxseg_len);
+	if (ret != 0) {
+		flog_err_sys(EC_LIB_SYSTEM_CALL,
+			     "%s failed: setsockopt(%d): %s", __func__, sock,
+			     safe_strerror(errno));
+	}
+
+	return ret;
+}
+
+/* get TCP mss value synced by socket */
+int sockopt_tcp_mss_get(int sock)
+{
+	int ret = 0;
+	int tcp_maxseg = 0;
+	socklen_t tcp_maxseg_len = sizeof(tcp_maxseg);
+
+	ret = getsockopt(sock, IPPROTO_TCP, TCP_MAXSEG, &tcp_maxseg,
+			 &tcp_maxseg_len);
+	if (ret != 0) {
+		flog_err_sys(EC_LIB_SYSTEM_CALL,
+			     "%s failed: getsockopt(%d): %s", __func__, sock,
+			     safe_strerror(errno));
+		return 0;
+	}
+
+	return tcp_maxseg;
+}