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File libibverbs-Use-neighbour-lookup-for-RoCE-UD-QPs-Eth-L2-resoluti.patch of Package libibverbs (Revision c2a71f5fc68920afd459c7e729cc38c0)

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From 66fe5611a71bf83d2d77f33971793630fa37ada6 Mon Sep 17 00:00:00 2001
From: Matan Barak <matanb@mellanox.com>
Date: Thu, 16 Jan 2014 18:11:57 +0200
Subject: [PATCH 4/6] Use neighbour lookup for RoCE UD QPs Eth L2 resolution

In order to implement RoCE IP based addressing for UD QPs, without introducing
uverbs changes, we need a way to resolve the L2 Ethernet addresses from user-space.

This is done with netlink through libnl, and in libibverbs such that multiple
vendor provider libraries can use the code.

The Ethernet L2 params are passed to the provider driver using an extension
verb drv_ibv_create_ah_ex call. This resolution is done only for providers
that support this extension verb, otherwise, there's not real reason to do that.

The steps for resolution:

1. get sgid

2. from sgid, get the interface

3. query route from interface to the destination

4. query the neigh table, if the MAC for the destination is already known, done.

5. if not, loop until timeout:
    a. send a UDP packet to that IP targeted to the "discard" port
    b. listen to events from the neigh table
    c. query neigh table in order to know if the neigh has shown up between
       query until we started monitoring it

6. query vlan id from the interface

This solution depends on libnl-3 with backports to libnl-1.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
---
 Makefile.am                |   24 -
 configure.ac               |   31 +
 include/infiniband/verbs.h |   35 +
 src/neigh.c                | 1003 +++++++++++++++++++++++++++++++++++++++++++++
 src/neigh.h                |   53 ++
 src/verbs.c                |  161 +++++++
 6 files changed, 1294 insertions(+), 13 deletions(-)
 create mode 100644 src/neigh.c
 create mode 100644 src/neigh.h

Index: libibverbs-1.1.7/Makefile.am
===================================================================
--- libibverbs-1.1.7.orig/Makefile.am	2014-03-05 10:36:36.000000000 +0100
+++ libibverbs-1.1.7/Makefile.am	2014-04-03 17:28:59.192327221 +0200
@@ -5,13 +5,17 @@ lib_LTLIBRARIES = src/libibverbs.la
 ACLOCAL_AMFLAGS = -I config
 AM_CFLAGS = -g -Wall
 
-src_libibverbs_la_CFLAGS = $(AM_CFLAGS) -DIBV_CONFIG_DIR=\"$(sysconfdir)/libibverbs.d\"
-
+src_libibverbs_la_CFLAGS = $(AM_CFLAGS) -DIBV_CONFIG_DIR=\"$(sysconfdir)/libibverbs.d\" \
+			   $(LIBNL_CFLAGS)
 libibverbs_version_script = @LIBIBVERBS_VERSION_SCRIPT@
+src_libibverbs_la_LIBADD = $(LIBNL_LIBS)
 
 src_libibverbs_la_SOURCES = src/cmd.c src/compat-1_0.c src/device.c src/init.c \
 			    src/marshall.c src/memory.c src/sysfs.c src/verbs.c \
 			    src/enum_strs.c
+if ! NO_RESOLVE_NEIGH
+src_libibverbs_la_SOURCES += src/neigh.c
+endif
 src_libibverbs_la_LDFLAGS = -version-info 1 -export-dynamic \
     $(libibverbs_version_script)
 src_libibverbs_la_DEPENDENCIES = $(srcdir)/src/libibverbs.map
@@ -20,21 +24,21 @@ bin_PROGRAMS = examples/ibv_devices exam
     examples/ibv_asyncwatch examples/ibv_rc_pingpong examples/ibv_uc_pingpong \
     examples/ibv_ud_pingpong examples/ibv_srq_pingpong examples/ibv_xsrq_pingpong
 examples_ibv_devices_SOURCES = examples/device_list.c
-examples_ibv_devices_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_devices_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_devinfo_SOURCES = examples/devinfo.c
-examples_ibv_devinfo_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_devinfo_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_rc_pingpong_SOURCES = examples/rc_pingpong.c examples/pingpong.c
-examples_ibv_rc_pingpong_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_rc_pingpong_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_uc_pingpong_SOURCES = examples/uc_pingpong.c examples/pingpong.c
-examples_ibv_uc_pingpong_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_uc_pingpong_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_ud_pingpong_SOURCES = examples/ud_pingpong.c examples/pingpong.c
-examples_ibv_ud_pingpong_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_ud_pingpong_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_srq_pingpong_SOURCES = examples/srq_pingpong.c examples/pingpong.c
-examples_ibv_srq_pingpong_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_srq_pingpong_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_xsrq_pingpong_SOURCES = examples/xsrq_pingpong.c examples/pingpong.c
-examples_ibv_xsrq_pingpong_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_xsrq_pingpong_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 examples_ibv_asyncwatch_SOURCES = examples/asyncwatch.c
-examples_ibv_asyncwatch_LDADD = $(top_builddir)/src/libibverbs.la
+examples_ibv_asyncwatch_LDADD = $(top_builddir)/src/libibverbs.la $(LIBNL_LIBS)
 
 libibverbsincludedir = $(includedir)/infiniband
 
Index: libibverbs-1.1.7/configure.ac
===================================================================
--- libibverbs-1.1.7.orig/configure.ac	2014-03-05 10:36:36.000000000 +0100
+++ libibverbs-1.1.7/configure.ac	2014-04-03 17:47:33.757755419 +0200
@@ -28,6 +28,37 @@ else
     fi
 fi
 
+AC_ARG_WITH([resolve-neigh],
+    [AS_HELP_STRING([--with-resolve-neigh],
+        [Enable neighbour resolution in Ethernet (default YES)])])
+have_libnl=no
+if  test x$with_resolve_neigh = x || test x$with_resolve_neigh = xyes; then
+	PKG_CHECK_MODULES([LIBNL],[libnl-3.0],
+			  [have_libnl=yes
+			   AC_DEFINE([HAVE_LIBNL3], [1], [Use libnl-3.0])
+			   AC_DEFINE([HAVE_LIBNL], [1],  [Use libnl])
+			   PKG_CHECK_MODULES([LIBNL_ROUTE3], [libnl-route-3.0])
+			   LIBNL_CFLAGS="$LIBNL_CFLAGS $LIBNL_ROUTE3_CFLAGS"
+			   LIBNL_LIBS="$LIBNL_LIBS $LIBNL_ROUTE3_LIBS"], [:]
+			  )
+	if test "$have_libnl" = no; then
+		PKG_CHECK_MODULES([LIBNL], [libnl-1], [have_libnl=yes
+				  AC_DEFINE([HAVE_LIBNL1], [1], [Use libnl-1])
+				  AC_DEFINE([HAVE_LIBNL], [1],  [Use libnl])
+				  AC_CHECK_LIB([nl], [rtnl_link_vlan_get_id], [],
+					[AC_MSG_ERROR([rtnl_link_vlan_get_id not found.  libibverbs requires libnl.])])
+				 ],[
+					AC_MSG_ERROR([libibverbs requires libnl.])
+				 ])
+	fi
+else
+    AC_DEFINE([NRESOLVE_NEIGH], 1, [Define to 1 to disable resovle neigh annotations.])
+fi
+AM_CONDITIONAL([HAVE_LIBNL], [test "$have_libnl" = "yes"])
+AC_SUBST([LIBNL_CFLAGS])
+AC_SUBST([LIBNL_LIBS])
+AM_CONDITIONAL(NO_RESOLVE_NEIGH, test x$with_resolve_neigh = xno)
+
 dnl Checks for libraries
 AC_CHECK_LIB(dl, dlsym, [],
     AC_MSG_ERROR([dlsym() not found.  libibverbs requires libdl.]))
Index: libibverbs-1.1.7/include/infiniband/verbs.h
===================================================================
--- libibverbs-1.1.7.orig/include/infiniband/verbs.h	2014-04-03 17:28:59.179327520 +0200
+++ libibverbs-1.1.7/include/infiniband/verbs.h	2014-04-03 17:46:43.653905574 +0200
@@ -462,6 +462,36 @@ struct ibv_ah_attr {
 	uint8_t			port_num;
 };
 
+enum ibv_ah_attr_ex_attr_mask {
+	IBV_AH_ATTR_EX_LL = 1UL << 0,
+	IBV_AH_ATTR_EX_VID = 1UL << 1,
+};
+
+enum ll_address_type {
+	LL_ADDRESS_UNKNOWN,
+	LL_ADDRESS_IB,
+	LL_ADDRESS_ETH,
+	LL_ADDRESS_SIZE
+};
+
+struct ibv_ah_attr_ex {
+	struct ibv_global_route	grh;
+	uint16_t		dlid;
+	uint8_t			sl;
+	uint8_t			src_path_bits;
+	uint8_t			static_rate;
+	uint8_t			is_global;
+	uint8_t			port_num;
+	uint32_t		comp_mask;
+	struct {
+		enum ll_address_type type;
+		uint32_t	len;
+		char		*address;
+	} ll_address;
+	uint16_t		vid;
+};
+
+
 enum ibv_srq_attr_mask {
 	IBV_SRQ_MAX_WR	= 1 << 0,
 	IBV_SRQ_LIMIT	= 1 << 1
@@ -868,11 +898,14 @@ enum verbs_context_mask {
 	VERBS_CONTEXT_XRCD	= 1 << 0,
 	VERBS_CONTEXT_SRQ	= 1 << 1,
 	VERBS_CONTEXT_QP	= 1 << 2,
-	VERBS_CONTEXT_RESERVED	= 1 << 3
+	VERBS_CONTEXT_CREATE_AH = 1 << 3,
+	VERBS_CONTEXT_RESERVED  = 1 << 4
 };
 
 struct verbs_context {
 	/*  "grows up" - new fields go here */
+	struct ibv_ah * (*drv_ibv_create_ah_ex)(struct ibv_pd *pd,
+						struct ibv_ah_attr_ex *attr);
 	struct ibv_qp *(*open_qp)(struct ibv_context *context,
 			struct ibv_qp_open_attr *attr);
 	struct ibv_qp *(*create_qp_ex)(struct ibv_context *context,
Index: libibverbs-1.1.7/src/neigh.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ libibverbs-1.1.7/src/neigh.c	2014-04-03 17:28:59.194327176 +0200
@@ -0,0 +1,1003 @@
+
+#include "config.h"
+#include <net/if_packet.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <netlink/route/rtnl.h>
+#include <netlink/route/link.h>
+#include <netlink/route/route.h>
+#include <netlink/route/neighbour.h>
+#ifndef HAVE_LIBNL1
+#include <netlink/route/link/vlan.h>
+#endif
+
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/timerfd.h>
+#include <netinet/in.h>
+#include <errno.h>
+#include <unistd.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+#ifndef _LINUX_IF_H
+#include <net/if.h>
+#else
+/*Workaround when there's a collision between the includes */
+extern unsigned int if_nametoindex(__const char *__ifname) __THROW;
+#endif
+
+/* for PFX */
+#include "ibverbs.h"
+
+#include "neigh.h"
+
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define print_hdr PFX "resolver: "
+#define print_err(...) fprintf(stderr, print_hdr __VA_ARGS__)
+#ifdef _DEBUG_
+#define print_dbg_s(stream, ...) fprintf((stream), __VA_ARGS__)
+#define print_address(stream, msg, addr) \
+	{							      \
+		char buff[100];					      \
+		print_dbg_s((stream), (msg), nl_addr2str((addr), buff,\
+			    sizeof(buff)));			      \
+	}
+#else
+#define print_dbg_s(stream, args...)
+#define print_address(stream, msg, ...)
+#endif
+#define print_dbg(...) print_dbg_s(stderr, print_hdr __VA_ARGS__)
+
+#ifdef HAVE_LIBNL1
+#define nl_geterror(x) nl_geterror()
+#endif
+
+/* Workaround - declaration missing */
+extern int		rtnl_link_vlan_get_id(struct rtnl_link *);
+
+static pthread_once_t device_neigh_alloc = PTHREAD_ONCE_INIT;
+#ifdef HAVE_LIBNL1
+static struct nl_handle *zero_socket;
+#else
+static struct nl_sock *zero_socket;
+#endif
+
+union sktaddr {
+	struct sockaddr s;
+	struct sockaddr_in s4;
+	struct sockaddr_in6 s6;
+};
+
+struct skt {
+	union sktaddr sktaddr;
+	socklen_t len;
+};
+
+
+static int set_link_port(union sktaddr *s, int port, int oif)
+{
+	switch (s->s.sa_family) {
+	case AF_INET:
+		s->s4.sin_port = port;
+		break;
+	case AF_INET6:
+		s->s6.sin6_port = port;
+		s->s6.sin6_scope_id = oif;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cmp_address(const struct sockaddr *s1,
+		       const struct sockaddr *s2) {
+	if (s1->sa_family != s2->sa_family)
+		return s1->sa_family ^ s2->sa_family;
+
+	switch (s1->sa_family) {
+	case AF_INET:
+		return ((struct sockaddr_in *)s1)->sin_addr.s_addr ^
+		       ((struct sockaddr_in *)s2)->sin_addr.s_addr;
+	case AF_INET6:
+		return memcmp(
+			((struct sockaddr_in6 *)s1)->sin6_addr.s6_addr,
+			((struct sockaddr_in6 *)s2)->sin6_addr.s6_addr,
+			sizeof(((struct sockaddr_in6 *)s1)->sin6_addr.s6_addr));
+	default:
+		return -ENOTSUP;
+	}
+}
+
+
+static int get_ifindex(const struct sockaddr *s)
+{
+	struct ifaddrs *ifaddr, *ifa;
+	int name2index = -ENODEV;
+
+	if (-1 == getifaddrs(&ifaddr))
+		return errno;
+
+	for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
+		if (NULL == ifa->ifa_addr)
+			continue;
+
+		if (!cmp_address(ifa->ifa_addr, s)) {
+			name2index = if_nametoindex(ifa->ifa_name);
+			break;
+		}
+	}
+
+	freeifaddrs(ifaddr);
+
+	return name2index;
+}
+
+static struct nl_addr *get_neigh_mac(struct get_neigh_handler *neigh_handler)
+{
+	struct rtnl_neigh *neigh;
+	struct nl_addr *ll_addr = NULL;
+
+	/* future optimization - if link local address - parse address and
+	 * return mac */
+	neigh = rtnl_neigh_get(neigh_handler->neigh_cache,
+			       neigh_handler->oif,
+			       neigh_handler->dst);
+	if (NULL == neigh) {
+		print_dbg("Neigh isn't at cache\n");
+		return NULL;
+	}
+
+	ll_addr = rtnl_neigh_get_lladdr(neigh);
+	if (NULL == ll_addr)
+		print_err("Failed to get hw address from neighbour\n");
+	else
+		ll_addr = nl_addr_clone(ll_addr);
+
+	rtnl_neigh_put(neigh);
+	return ll_addr;
+}
+
+static void get_neigh_cb_event(struct nl_object *obj, void *arg)
+{
+	struct get_neigh_handler *neigh_handler =
+		(struct get_neigh_handler *)arg;
+	/* assumed serilized callback (no parallel execution of function) */
+	if (nl_object_match_filter(
+		obj,
+		(struct nl_object *)neigh_handler->filter_neigh)) {
+		struct rtnl_neigh *neigh = (struct rtnl_neigh *)obj;
+		print_dbg("Found a match for neighbour\n");
+		/* check that we didn't set it already */
+		if (NULL == neigh_handler->found_ll_addr) {
+			if (NULL == rtnl_neigh_get_lladdr(neigh)) {
+				print_err("Neighbour doesn't have a hw addr\n");
+				return;
+			}
+			neigh_handler->found_ll_addr =
+				nl_addr_clone(rtnl_neigh_get_lladdr(neigh));
+			if (NULL == neigh_handler->found_ll_addr)
+				print_err("Couldn't copy neighbour hw addr\n");
+		}
+	}
+}
+
+static int get_neigh_cb(struct nl_msg *msg, void *arg)
+{
+	struct get_neigh_handler *neigh_handler =
+		(struct get_neigh_handler *)arg;
+
+	if (nl_msg_parse(msg, &get_neigh_cb_event, neigh_handler) < 0)
+		print_err("Unknown event\n");
+
+	return NL_OK;
+}
+
+static void set_neigh_filter(struct get_neigh_handler *neigh_handler,
+			     struct rtnl_neigh *filter) {
+	neigh_handler->filter_neigh = filter;
+}
+
+static struct rtnl_neigh *create_filter_neigh_for_dst(struct nl_addr *dst_addr,
+						      int oif)
+{
+	struct rtnl_neigh *filter_neigh;
+
+	filter_neigh = rtnl_neigh_alloc();
+	if (NULL == filter_neigh) {
+		print_err("Couldn't allocate filter neigh\n");
+		return NULL;
+	}
+	rtnl_neigh_set_ifindex(filter_neigh, oif);
+	rtnl_neigh_set_dst(filter_neigh, dst_addr);
+
+	return filter_neigh;
+}
+
+#define PORT_DISCARD htons(9)
+#define SEND_PAYLOAD "H"
+
+static int create_socket(struct get_neigh_handler *neigh_handler,
+			 struct skt *addr_dst, int *psock_fd)
+{
+	int err;
+	struct skt addr_src;
+	int sock_fd;
+
+	memset(addr_dst, 0, sizeof(*addr_dst));
+	memset(&addr_src, 0, sizeof(addr_src));
+	addr_src.len = sizeof(addr_src.sktaddr);
+
+	err = nl_addr_fill_sockaddr(neigh_handler->src,
+				    &addr_src.sktaddr.s,
+				    &addr_src.len);
+	if (err) {
+		print_err("couldn't convert src to sockaddr\n");
+		return err;
+	}
+
+	addr_dst->len = sizeof(addr_dst->sktaddr);
+	err = nl_addr_fill_sockaddr(neigh_handler->dst,
+				    &addr_dst->sktaddr.s,
+				    &addr_dst->len);
+	if (err) {
+		print_err("couldn't convert dst to sockaddr\n");
+		return err;
+	}
+
+	err = set_link_port(&addr_dst->sktaddr, PORT_DISCARD,
+			    neigh_handler->oif);
+	if (err)
+		return err;
+
+	sock_fd = socket(addr_dst->sktaddr.s.sa_family,
+			SOCK_DGRAM | SOCK_CLOEXEC, 0);
+	if (sock_fd == -1)
+		return errno ? -errno : -1;
+	err = bind(sock_fd, &addr_src.sktaddr.s, addr_src.len);
+	if (err) {
+		int bind_err = -errno;
+		print_err("Couldn't bind socket\n");
+		close(sock_fd);
+		return bind_err ?: err;
+	}
+
+	*psock_fd = sock_fd;
+
+	return 0;
+}
+
+#define NUM_OF_RETRIES 10
+#define NUM_OF_TRIES ((NUM_OF_RETRIES) + 1)
+#if NUM_OF_TRIES < 1
+#error "neigh: invalid value of NUM_OF_RETRIES"
+#endif
+static int create_timer(struct get_neigh_handler *neigh_handler)
+{
+	int user_timeout = neigh_handler->timeout/NUM_OF_TRIES;
+	struct timespec timeout = {
+		.tv_sec = user_timeout / 1000,
+		.tv_nsec = (user_timeout % 1000) * 1000000
+	};
+	struct itimerspec timer_time = {.it_value = timeout};
+	int timer_fd;
+
+	timer_fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
+	if (-1 == timer_fd) {
+		print_err("Couldn't create timer\n");
+		return timer_fd;
+	}
+
+	if (neigh_handler->timeout) {
+		if (NUM_OF_TRIES <= 1)
+			bzero(&timer_time.it_interval,
+			      sizeof(timer_time.it_interval));
+		else
+			timer_time.it_interval = timeout;
+		if (timerfd_settime(timer_fd, 0, &timer_time, NULL)) {
+			print_err("Couldn't set timer\n");
+			return -1;
+		}
+	}
+
+	return timer_fd;
+}
+
+#define UDP_SOCKET_MAX_SENDTO 100000ULL
+
+static struct nl_addr *process_get_neigh_mac(
+		struct get_neigh_handler *neigh_handler)
+{
+	int err;
+	struct nl_addr *ll_addr = get_neigh_mac(neigh_handler);
+	struct rtnl_neigh *neigh_filter;
+	fd_set fdset;
+	int sock_fd;
+	int fd;
+	int nfds;
+	int timer_fd;
+	int ret;
+	struct skt addr_dst;
+	char buff[sizeof(SEND_PAYLOAD)] = SEND_PAYLOAD;
+	int retries = 0;
+	uint64_t max_count = UDP_SOCKET_MAX_SENDTO;
+
+	if (NULL != ll_addr)
+		return ll_addr;
+
+	err = nl_socket_add_membership(neigh_handler->sock,
+				       RTNLGRP_NEIGH);
+	if (err < 0) {
+		print_err("%s\n", nl_geterror(err));
+		return NULL;
+	}
+
+	neigh_filter = create_filter_neigh_for_dst(neigh_handler->dst,
+						   neigh_handler->oif);
+	if (NULL == neigh_filter)
+		return NULL;
+
+	set_neigh_filter(neigh_handler, neigh_filter);
+
+#ifdef HAVE_LIBNL1
+	nl_disable_sequence_check(neigh_handler->sock);
+#else
+	nl_socket_disable_seq_check(neigh_handler->sock);
+#endif
+	nl_socket_modify_cb(neigh_handler->sock, NL_CB_VALID, NL_CB_CUSTOM,
+			    &get_neigh_cb, neigh_handler);
+
+	fd = nl_socket_get_fd(neigh_handler->sock);
+
+	err = create_socket(neigh_handler, &addr_dst, &sock_fd);
+
+	if (err)
+		return NULL;
+
+	do {
+		err = sendto(sock_fd, buff, sizeof(buff), 0,
+				 &addr_dst.sktaddr.s,
+				 addr_dst.len);
+		if (err > 0)
+			err = 0;
+	} while (-1 == err && EADDRNOTAVAIL == errno && --max_count);
+
+	if (err) {
+		print_err("Failed to send packet %d", err);
+		goto close_socket;
+	}
+	timer_fd = create_timer(neigh_handler);
+	if (timer_fd < 0)
+		goto close_socket;
+
+	nfds = MAX(fd, timer_fd) + 1;
+
+
+	while (1) {
+		FD_ZERO(&fdset);
+		FD_SET(fd, &fdset);
+		FD_SET(timer_fd, &fdset);
+
+		/* wait for an incoming message on the netlink socket */
+		ret = select(nfds, &fdset, NULL, NULL, NULL);
+
+		if (ret) {
+			if (FD_ISSET(fd, &fdset)) {
+				nl_recvmsgs_default(neigh_handler->sock);
+				if (neigh_handler->found_ll_addr)
+					break;
+			} else {
+				nl_cache_refill(neigh_handler->sock,
+						neigh_handler->neigh_cache);
+				ll_addr = get_neigh_mac(neigh_handler);
+				if (NULL != ll_addr) {
+					break;
+				} else if (FD_ISSET(timer_fd, &fdset) &&
+					   retries < NUM_OF_RETRIES) {
+					if (sendto(sock_fd, buff, sizeof(buff),
+						   0, &addr_dst.sktaddr.s,
+						   addr_dst.len) < 0)
+						print_err("Failed to send "
+							  "packet while waiting"
+							  " for events\n");
+				}
+			}
+
+			if (FD_ISSET(timer_fd, &fdset)) {
+				uint64_t read_val;
+				if (read(timer_fd, &read_val, sizeof(read_val))
+				    < 0)
+					print_dbg("Read timer_fd failed\n");
+				if (++retries >=  NUM_OF_TRIES) {
+					print_dbg("Timeout while trying to fetch "
+						  "neighbours\n");
+					break;
+				}
+			}
+		}
+	}
+	close(timer_fd);
+close_socket:
+	close(sock_fd);
+	return ll_addr ? ll_addr : neigh_handler->found_ll_addr;
+}
+
+
+static int get_mcast_mac_ipv4(struct nl_addr *dst, struct nl_addr **ll_addr)
+{
+	char mac_addr[6] = {0x01, 0x00, 0x5E};
+	uint32_t addr = ntohl(*(uint32_t *)nl_addr_get_binary_addr(dst));
+	mac_addr[5] = addr & 0xFF;
+	addr >>= 8;
+	mac_addr[4] = addr & 0xFF;
+	addr >>= 8;
+	mac_addr[3] = addr & 0x7F;
+
+	*ll_addr = nl_addr_build(AF_LLC, mac_addr, sizeof(mac_addr));
+
+	return *ll_addr == NULL ? -EINVAL : 0;
+}
+
+static int get_mcast_mac_ipv6(struct nl_addr *dst, struct nl_addr **ll_addr)
+{
+	char mac_addr[6] = {0x33, 0x33};
+	memcpy(mac_addr + 2, (char *)nl_addr_get_binary_addr(dst) + 12, 4);
+
+	*ll_addr = nl_addr_build(AF_LLC, mac_addr, sizeof(mac_addr));
+
+	return *ll_addr == NULL ? -EINVAL : 0;
+}
+
+static int get_link_local_mac_ipv6(struct nl_addr *dst,
+				   struct nl_addr **ll_addr)
+{
+	char mac_addr[6];
+
+	memcpy(mac_addr + 3, (char *)nl_addr_get_binary_addr(dst) + 13, 3);
+	memcpy(mac_addr, (char *)nl_addr_get_binary_addr(dst) + 8, 3);
+	mac_addr[0] ^= 2;
+
+	*ll_addr = nl_addr_build(AF_LLC, mac_addr, sizeof(mac_addr));
+	return *ll_addr == NULL ? -EINVAL : 0;
+}
+
+const struct encoded_l3_addr {
+	short family;
+	uint8_t prefix_bits;
+	const char data[16];
+	int (*getter)(struct nl_addr *dst, struct nl_addr **ll_addr);
+} encoded_prefixes[] = {
+	{.family = AF_INET,
+	 .prefix_bits = 4,
+	 .data = {0xe0},
+	 .getter = &get_mcast_mac_ipv4},
+	{.family = AF_INET6,
+	 .prefix_bits = 8,
+	 .data = {0xff},
+	 .getter = &get_mcast_mac_ipv6},
+	{.family = AF_INET6,
+	 .prefix_bits = 64,
+	 .data = {0xfe, 0x80},
+	 .getter = get_link_local_mac_ipv6},
+};
+
+int nl_addr_cmp_prefix_msb(void *addr1, int len1, void *addr2, int len2)
+{
+	int len = MIN(len1, len2);
+	int bytes = len / 8;
+	int d = memcmp(addr1, addr2, bytes);
+
+	if (d == 0) {
+		int mask = ((1UL << (len % 8)) - 1UL) << (8 - len);
+
+		d = (((char *)addr1)[bytes] & mask) -
+		    (((char *)addr2)[bytes] & mask);
+	}
+
+	return d;
+}
+static int handle_encoded_mac(struct nl_addr *dst, struct nl_addr **ll_addr)
+{
+	uint32_t family = nl_addr_get_family(dst);
+	struct nl_addr *prefix = NULL;
+	int i;
+	int ret = 1;
+
+	for (i = 0;
+	     i < sizeof(encoded_prefixes)/sizeof(encoded_prefixes[0]) &&
+	     ret; prefix = NULL, i++) {
+		if (encoded_prefixes[i].family != family)
+			continue;
+
+		prefix = nl_addr_build(
+				family,
+				(void *)encoded_prefixes[i].data,
+				MIN(encoded_prefixes[i].prefix_bits/8 +
+				    !!(encoded_prefixes[i].prefix_bits % 8),
+				    sizeof(encoded_prefixes[i].data)));
+
+		if (NULL == prefix)
+			return -ENOMEM;
+		nl_addr_set_prefixlen(prefix,
+				      encoded_prefixes[i].prefix_bits);
+
+		if (nl_addr_cmp_prefix_msb(nl_addr_get_binary_addr(dst),
+					   nl_addr_get_prefixlen(dst),
+					   nl_addr_get_binary_addr(prefix),
+					   nl_addr_get_prefixlen(prefix)))
+			continue;
+
+		ret = encoded_prefixes[i].getter(dst, ll_addr);
+#ifdef HAVE_LIBNL1
+		nl_addr_destroy(prefix);
+#else
+		nl_addr_put(prefix);
+#endif
+	}
+
+	return ret;
+}
+
+static void get_route_cb_parser(struct nl_object *obj, void *arg)
+{
+	struct get_neigh_handler *neigh_handler =
+		(struct get_neigh_handler *)arg;
+
+	struct rtnl_route *route = (struct rtnl_route *)obj;
+	struct nl_addr *gateway;
+	struct nl_addr *src = rtnl_route_get_pref_src(route);
+	int oif;
+	int type = rtnl_route_get_type(route);
+	struct rtnl_link *link;
+
+#ifdef HAVE_LIBNL1
+	gateway = rtnl_route_get_gateway(route);
+	oif = rtnl_route_get_oif(route);
+#else
+	struct rtnl_nexthop *nh = rtnl_route_nexthop_n(route, 0);
+	if (!nh)
+		print_err("Out of memory\n");
+	gateway = rtnl_route_nh_get_gateway(nh);
+	oif = rtnl_route_nh_get_ifindex(nh);
+#endif
+
+	if (gateway) {
+#ifdef HAVE_LIBNL1
+		nl_addr_destroy(neigh_handler->dst);
+#else
+		nl_addr_put(neigh_handler->dst);
+#endif
+		neigh_handler->dst = nl_addr_clone(gateway);
+		print_dbg("Found gateway\n");
+	}
+
+	if (RTN_BLACKHOLE == type ||
+	    RTN_UNREACHABLE == type ||
+	    RTN_PROHIBIT == type ||
+	    RTN_THROW == type) {
+		print_err("Destination unrechable (type %d)\n", type);
+		goto err;
+	}
+
+	if (!neigh_handler->src && src)
+		neigh_handler->src = nl_addr_clone(src);
+
+	if (neigh_handler->oif < 0 && oif > 0)
+		neigh_handler->oif = oif;
+
+	/* Link Local */
+	if (RTN_LOCAL == type) {
+		struct nl_addr *lladdr;
+
+		link = rtnl_link_get(neigh_handler->link_cache,
+				     neigh_handler->oif);
+
+		if (NULL == link)
+			goto err;
+
+		lladdr = rtnl_link_get_addr(link);
+
+		if (NULL == lladdr)
+			goto err_link;
+
+		neigh_handler->found_ll_addr = nl_addr_clone(lladdr);
+		rtnl_link_put(link);
+	} else {
+		if (!handle_encoded_mac(
+				neigh_handler->dst,
+				&neigh_handler->found_ll_addr))
+			print_address(stderr, "calculated address %s\n",
+				      neigh_handler->found_ll_addr);
+	}
+
+	print_address(stderr, "Current dst %s\n", neigh_handler->dst);
+	return;
+
+err_link:
+	rtnl_link_put(link);
+err:
+	if (neigh_handler->src) {
+#ifdef HAVE_LIBNL1
+		nl_addr_put(neigh_handler->src);
+#else
+		nl_addr_put(neigh_handler->src);
+#endif
+		neigh_handler->src = NULL;
+	}
+}
+
+static int get_route_cb(struct nl_msg *msg, void *arg)
+{
+	struct get_neigh_handler *neigh_handler =
+		(struct get_neigh_handler *)arg;
+	int err;
+
+	err = nl_msg_parse(msg, &get_route_cb_parser, neigh_handler);
+	if (err < 0) {
+		print_err("Unable to parse object: %s", nl_geterror(err));
+		return err;
+	}
+
+	if (!neigh_handler->dst || !neigh_handler->src ||
+	    neigh_handler->oif <= 0) {
+		print_err("Missing params\n");
+		return -1;
+	}
+
+	if (NULL != neigh_handler->found_ll_addr)
+		goto found;
+
+	neigh_handler->found_ll_addr =
+		process_get_neigh_mac(neigh_handler);
+	if (neigh_handler->found_ll_addr)
+		print_address(stderr, "Neigh is %s\n",
+			      neigh_handler->found_ll_addr);
+
+found:
+	return neigh_handler->found_ll_addr ? 0 : -1;
+}
+
+int neigh_get_oif_from_src(struct get_neigh_handler *neigh_handler)
+{
+	int oif = -ENODEV;
+	struct addrinfo *src_info;
+
+#ifdef HAVE_LIBNL1
+	src_info = nl_addr_info(neigh_handler->src);
+	if (NULL == src_info) {
+#else
+	int err;
+	err = nl_addr_info(neigh_handler->src, &src_info);
+	if (err) {
+#endif
+		print_err("Unable to get address info %s\n",
+			  nl_geterror(err));
+		return oif;
+	}
+
+	oif = get_ifindex(src_info->ai_addr);
+	if (oif <= 0)
+		goto free;
+
+	print_dbg("IF index is %d\n", oif);
+
+free:
+	freeaddrinfo(src_info);
+	return oif;
+}
+
+static void destroy_zero_based_socket(void)
+{
+	if (NULL != zero_socket) {
+		print_dbg("destroying zero based socket\n");
+#ifdef HAVE_LIBNL1
+		nl_handle_destroy(zero_socket);
+#else
+		nl_socket_free(zero_socket);
+#endif
+	}
+}
+
+static void alloc_zero_based_socket(void)
+{
+#ifdef HAVE_LIBNL1
+	zero_socket = nl_handle_alloc();
+#else
+	zero_socket = nl_socket_alloc();
+#endif
+	print_dbg("creating zero based socket\n");
+	atexit(&destroy_zero_based_socket);
+}
+
+int neigh_init_resources(struct get_neigh_handler *neigh_handler, int timeout)
+{
+	int err;
+
+	pthread_once(&device_neigh_alloc, &alloc_zero_based_socket);
+#ifdef HAVE_LIBNL1
+	neigh_handler->sock = nl_handle_alloc();
+#else
+	neigh_handler->sock = nl_socket_alloc();
+#endif
+	if (NULL == neigh_handler->sock) {
+		print_err("Unable to allocate netlink socket\n");
+		return -ENOMEM;
+	}
+
+	err = nl_connect(neigh_handler->sock, NETLINK_ROUTE);
+	if (err < 0) {
+		print_err("Unable to connect netlink socket: %s\n",
+			  nl_geterror(err));
+		goto free_socket;
+	}
+
+#ifdef HAVE_LIBNL1
+	neigh_handler->link_cache =
+		rtnl_link_alloc_cache(neigh_handler->sock);
+	if (NULL == neigh_handler->link_cache) {
+		err = -ENOMEM;
+#else
+
+	err = rtnl_link_alloc_cache(neigh_handler->sock, AF_UNSPEC,
+				    &neigh_handler->link_cache);
+	if (err) {
+#endif
+		print_err("Unable to allocate link cache: %s\n",
+			  nl_geterror(err));
+		err = -ENOMEM;
+		goto close_connection;
+	}
+
+	nl_cache_mngt_provide(neigh_handler->link_cache);
+
+#ifdef HAVE_LIBNL1
+	neigh_handler->route_cache =
+		rtnl_route_alloc_cache(neigh_handler->sock);
+	if (NULL == neigh_handler->route_cache) {
+		err = -ENOMEM;
+#else
+	err = rtnl_route_alloc_cache(neigh_handler->sock, AF_UNSPEC, 0,
+				     &neigh_handler->route_cache);
+	if (err) {
+#endif
+		print_err("Unable to allocate route cache: %s\n",
+			  nl_geterror(err));
+		goto free_link_cache;
+	}
+
+	nl_cache_mngt_provide(neigh_handler->route_cache);
+
+#ifdef HAVE_LIBNL1
+	neigh_handler->neigh_cache =
+		rtnl_neigh_alloc_cache(neigh_handler->sock);
+	if (NULL == neigh_handler->neigh_cache) {
+		err = -ENOMEM;
+#else
+	err = rtnl_neigh_alloc_cache(neigh_handler->sock,
+				     &neigh_handler->neigh_cache);
+	if (err) {
+#endif
+		print_err("Couldn't allocate neigh cache %s\n",
+			  nl_geterror(err));
+		goto free_route_cache;
+	}
+
+	nl_cache_mngt_provide(neigh_handler->neigh_cache);
+
+	/* init structure */
+	neigh_handler->timeout = timeout;
+	neigh_handler->oif = -1;
+	neigh_handler->filter_neigh = NULL;
+	neigh_handler->found_ll_addr = NULL;
+	neigh_handler->dst = NULL;
+	neigh_handler->src = NULL;
+	neigh_handler->vid = -1;
+	neigh_handler->neigh_status = GET_NEIGH_STATUS_OK;
+
+	return 0;
+
+free_route_cache:
+	nl_cache_mngt_unprovide(neigh_handler->route_cache);
+	nl_cache_free(neigh_handler->route_cache);
+	neigh_handler->route_cache = NULL;
+free_link_cache:
+	nl_cache_mngt_unprovide(neigh_handler->link_cache);
+	nl_cache_free(neigh_handler->link_cache);
+	neigh_handler->link_cache = NULL;
+close_connection:
+	nl_close(neigh_handler->sock);
+free_socket:
+#ifdef HAVE_LIBNL1
+	nl_handle_destroy(neigh_handler->sock);
+		nl_handle_destroy(zero_socket);
+#else
+	nl_socket_free(neigh_handler->sock);
+#endif
+	neigh_handler->sock = NULL;
+	return err;
+}
+
+uint16_t neigh_get_vlan_id_from_dev(struct get_neigh_handler *neigh_handler)
+{
+	struct rtnl_link *link;
+	int vid = 0xffff;
+
+	link = rtnl_link_get(neigh_handler->link_cache, neigh_handler->oif);
+	if (NULL == link) {
+		print_err("Can't find link in cache\n");
+		return -EINVAL;
+	}
+
+#ifndef HAVE_LIBNL1
+	if (rtnl_link_is_vlan(link))
+#endif
+		vid = rtnl_link_vlan_get_id(link);
+	rtnl_link_put(link);
+	return vid >= 0 && vid <= 0xfff ? vid : 0xffff;
+}
+
+void neigh_set_vlan_id(struct get_neigh_handler *neigh_handler, uint16_t vid)
+{
+	if (vid >= 0 && vid <= 0xfff)
+		neigh_handler->vid = vid;
+}
+
+int neigh_set_dst(struct get_neigh_handler *neigh_handler,
+		  int family, void *buf, size_t size)
+{
+	neigh_handler->dst = nl_addr_build(family, buf, size);
+	return NULL == neigh_handler->dst;
+}
+
+int neigh_set_src(struct get_neigh_handler *neigh_handler,
+		  int family, void *buf, size_t size)
+{
+	neigh_handler->src = nl_addr_build(family, buf, size);
+	return NULL == neigh_handler->src;
+}
+
+void neigh_set_oif(struct get_neigh_handler *neigh_handler, int oif)
+{
+	neigh_handler->oif = oif;
+}
+
+int neigh_get_ll(struct get_neigh_handler *neigh_handler, void *addr_buff,
+		 int addr_size) {
+	int neigh_len;
+
+	if (NULL == neigh_handler->found_ll_addr)
+		return -EINVAL;
+
+	 neigh_len = nl_addr_get_len(neigh_handler->found_ll_addr);
+
+	if (neigh_len > addr_size)
+		return -EINVAL;
+
+	memcpy(addr_buff, nl_addr_get_binary_addr(neigh_handler->found_ll_addr),
+	       neigh_len);
+
+	return neigh_len;
+}
+
+void neigh_free_resources(struct get_neigh_handler *neigh_handler)
+{
+	/* Should be released first because it's holding a reference to dst */
+	if (NULL != neigh_handler->filter_neigh) {
+		rtnl_neigh_put(neigh_handler->filter_neigh);
+		neigh_handler->filter_neigh = NULL;
+	}
+
+	if (NULL != neigh_handler->src) {
+#ifdef HAVE_LIBNL1
+		nl_addr_put(neigh_handler->src);
+#else
+		nl_addr_put(neigh_handler->src);
+#endif
+		neigh_handler->src = NULL;
+	}
+
+	if (NULL != neigh_handler->dst) {
+#ifdef HAVE_LIBNL1
+		nl_addr_destroy(neigh_handler->dst);
+#else
+		nl_addr_put(neigh_handler->dst);
+#endif
+		neigh_handler->dst = NULL;
+	}
+
+	if (NULL != neigh_handler->found_ll_addr) {
+#ifdef HAVE_LIBNL1
+		nl_addr_destroy(neigh_handler->found_ll_addr);
+#else
+		nl_addr_put(neigh_handler->found_ll_addr);
+#endif
+		neigh_handler->found_ll_addr = NULL;
+	}
+
+	if (NULL != neigh_handler->neigh_cache) {
+		nl_cache_mngt_unprovide(neigh_handler->neigh_cache);
+		nl_cache_free(neigh_handler->neigh_cache);
+		neigh_handler->neigh_cache = NULL;
+	}
+
+	if (NULL != neigh_handler->route_cache) {
+		nl_cache_mngt_unprovide(neigh_handler->route_cache);
+		nl_cache_free(neigh_handler->route_cache);
+		neigh_handler->route_cache = NULL;
+	}
+
+	if (NULL != neigh_handler->link_cache) {
+		nl_cache_mngt_unprovide(neigh_handler->link_cache);
+		nl_cache_free(neigh_handler->link_cache);
+		neigh_handler->link_cache = NULL;
+	}
+
+	if (NULL != neigh_handler->sock) {
+		nl_close(neigh_handler->sock);
+#ifdef HAVE_LIBNL1
+		nl_handle_destroy(neigh_handler->sock);
+#else
+		nl_socket_free(neigh_handler->sock);
+#endif
+		neigh_handler->sock = NULL;
+	}
+}
+
+int process_get_neigh(struct get_neigh_handler *neigh_handler)
+{
+	struct nl_msg *m;
+	struct rtmsg rmsg = {
+		.rtm_family = nl_addr_get_family(neigh_handler->dst),
+		.rtm_dst_len = nl_addr_get_prefixlen(neigh_handler->dst),
+	};
+	int err;
+	int last_status;
+
+	last_status = __sync_fetch_and_or(
+			&neigh_handler->neigh_status,
+			GET_NEIGH_STATUS_IN_PROCESS);
+
+	if (last_status != GET_NEIGH_STATUS_OK)
+		return -EINPROGRESS;
+
+	m = nlmsg_alloc_simple(RTM_GETROUTE, 0);
+
+	if (NULL == m)
+		return -ENOMEM;
+
+	nlmsg_append(m, &rmsg, sizeof(rmsg), NLMSG_ALIGNTO);
+
+	nla_put_addr(m, RTA_DST, neigh_handler->dst);
+
+	if (neigh_handler->oif > 0)
+		nla_put_u32(m, RTA_OIF, neigh_handler->oif);
+
+	err = nl_send_auto_complete(neigh_handler->sock, m);
+	nlmsg_free(m);
+	if (err < 0) {
+		print_err("%s", nl_geterror(err));
+		return err;
+	}
+
+	nl_socket_modify_cb(neigh_handler->sock, NL_CB_VALID,
+			    NL_CB_CUSTOM, &get_route_cb, neigh_handler);
+
+	err = nl_recvmsgs_default(neigh_handler->sock);
+	if (err < 0) {
+		print_err("%s", nl_geterror(err));
+		__sync_fetch_and_or(
+			&neigh_handler->neigh_status,
+			GET_NEIGH_STATUS_ERR);
+	}
+
+	__sync_fetch_and_and(
+		&neigh_handler->neigh_status,
+		~GET_NEIGH_STATUS_IN_PROCESS);
+
+	return err;
+}
Index: libibverbs-1.1.7/src/neigh.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ libibverbs-1.1.7/src/neigh.h	2014-04-03 17:28:59.194327176 +0200
@@ -0,0 +1,53 @@
+#ifndef _GET_NEIGH_
+#define _GET_NEIGH_
+
+#include <stddef.h>
+#include <stdint.h>
+#include "config.h"
+#ifdef HAVE_LIBNL1
+#include <netlink/object.h>
+#else
+#include <netlink/object-api.h>
+#endif
+
+enum get_neigh_status {
+	GET_NEIGH_STATUS_OK = 0,
+	GET_NEIGH_STATUS_IN_PROCESS = 1 << 0,
+	GET_NEIGH_STATUS_ERR = 1 << 1,
+};
+
+struct get_neigh_handler {
+#ifdef HAVE_LIBNL1
+	struct nl_handle *sock;
+#else
+	struct nl_sock *sock;
+#endif
+	struct nl_cache *link_cache;
+	struct nl_cache	*neigh_cache;
+	struct nl_cache *route_cache;
+	int32_t oif;
+	int vid;
+	struct rtnl_neigh *filter_neigh;
+	struct nl_addr *found_ll_addr;
+	struct nl_addr *dst;
+	struct nl_addr *src;
+	enum get_neigh_status neigh_status;
+	uint64_t timeout;
+};
+
+int process_get_neigh(struct get_neigh_handler *neigh_handler);
+void neigh_free_resources(struct get_neigh_handler *neigh_handler);
+void neigh_set_vlan_id(struct get_neigh_handler *neigh_handler, uint16_t vid);
+uint16_t neigh_get_vlan_id_from_dev(struct get_neigh_handler *neigh_handler);
+int neigh_init_resources(struct get_neigh_handler *neigh_handler, int timeout);
+
+int neigh_set_src(struct get_neigh_handler *neigh_handler,
+		  int family, void *buf, size_t size);
+void neigh_set_oif(struct get_neigh_handler *neigh_handler, int oif);
+int neigh_set_dst(struct get_neigh_handler *neigh_handler,
+		  int family, void *buf, size_t size);
+int neigh_get_oif_from_src(struct get_neigh_handler *neigh_handler);
+int neigh_get_ll(struct get_neigh_handler *neigh_handler, void *addr_buf,
+		 int addr_size);
+
+#endif
Index: libibverbs-1.1.7/src/verbs.c
===================================================================
--- libibverbs-1.1.7.orig/src/verbs.c	2014-03-05 10:36:36.000000000 +0100
+++ libibverbs-1.1.7/src/verbs.c	2014-04-03 17:46:43.653905574 +0200
@@ -43,6 +43,9 @@
 #include <string.h>
 
 #include "ibverbs.h"
+#ifndef NRESOLVE_NEIGH
+#include "neigh.h"
+#endif
 
 int ibv_rate_to_mult(enum ibv_rate rate)
 {
@@ -505,15 +508,169 @@ int __ibv_destroy_qp(struct ibv_qp *qp)
 }
 default_symver(__ibv_destroy_qp, ibv_destroy_qp);
 
+static inline int ipv6_addr_v4mapped(const struct in6_addr *a)
+{
+	return ((a->s6_addr32[0] | a->s6_addr32[1]) |
+		(a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL ||
+		/* IPv4 encoded multicast addresses */
+	       (a->s6_addr32[0]  == htonl(0xff0e0000) &&
+		((a->s6_addr32[1] |
+		  (a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0UL));
+}
+
+
+struct peer_address {
+	void *address;
+	uint32_t size;
+};
+
+static inline int create_peer_from_gid(int family, void *raw_gid,
+				       struct peer_address *peer_address)
+{
+	switch (family) {
+	case AF_INET:
+		peer_address->address = raw_gid + 12;
+		peer_address->size = 4;
+		break;
+	case AF_INET6:
+		peer_address->address = raw_gid;
+		peer_address->size = 16;
+		break;
+	default:
+		return -1;
+	}
+
+	return 0;
+}
+
+#define ETHERNET_LL_SIZE 6
+#define NEIGH_GET_DEFAULT_TIMEOUT_MS 3000
 struct ibv_ah *__ibv_create_ah(struct ibv_pd *pd, struct ibv_ah_attr *attr)
 {
-	struct ibv_ah *ah = pd->context->ops.create_ah(pd, attr);
+	int err;
+	struct ibv_ah *ah = NULL;
+#ifndef NRESOLVE_NEIGH
+	struct ibv_port_attr port_attr;
+	int dst_family;
+	int src_family;
+	int oif;
+	struct get_neigh_handler neigh_handler;
+	union ibv_gid sgid;
+	struct ibv_ah_attr_ex attr_ex;
+	char ethernet_ll[ETHERNET_LL_SIZE];
+	struct verbs_context *vctx = verbs_get_ctx_op(pd->context,
+						      drv_ibv_create_ah_ex);
+	struct peer_address src;
+	struct peer_address dst;
+
+	if (!vctx) {
+#endif
+		ah = pd->context->ops.create_ah(pd, attr);
+#ifndef NRESOLVE_NEIGH
+		goto return_ah;
+	}
+
+	err = ibv_query_port(pd->context, attr->port_num, &port_attr);
 
+	if (err) {
+		fprintf(stderr, PFX "ibv_create_ah failed to query port.\n");
+		return NULL;
+	}
+
+	if (IBV_LINK_LAYER_ETHERNET != port_attr.link_layer ||
+	    !(port_attr.port_cap_flags & IBV_PORT_IP_BASED_GIDS)) {
+		ah = pd->context->ops.create_ah(pd, attr);
+		goto return_ah;
+	}
+
+	memcpy(&attr_ex, attr, sizeof(*attr));
+	memset((void *)&attr_ex + sizeof(*attr), 0,
+	       sizeof(attr_ex) - sizeof(*attr));
+
+	err = ibv_query_gid(pd->context, attr->port_num,
+			    attr->grh.sgid_index, &sgid);
+
+	if (err) {
+		fprintf(stderr, PFX "ibv_create_ah failed to query sgid.\n");
+		return NULL;
+	}
+
+	if (neigh_init_resources(&neigh_handler, NEIGH_GET_DEFAULT_TIMEOUT_MS))
+		return NULL;
+
+	dst_family = ipv6_addr_v4mapped((struct in6_addr *)attr->grh.dgid.raw) ?
+			AF_INET : AF_INET6;
+	src_family = ipv6_addr_v4mapped((struct in6_addr *)sgid.raw) ?
+			AF_INET : AF_INET6;
+
+	if (create_peer_from_gid(dst_family, attr->grh.dgid.raw, &dst)) {
+		fprintf(stderr, PFX
+			"ibv_create_ah failed to create dst peer\n");
+		goto free_resources;
+	}
+	if (create_peer_from_gid(src_family, &sgid.raw, &src)) {
+		fprintf(stderr, PFX
+			"ibv_create_ah failed to create src peer\n");
+		goto free_resources;
+	}
+	if (neigh_set_dst(&neigh_handler, dst_family, dst.address,
+			  dst.size)) {
+		fprintf(stderr, PFX
+			"ibv_create_ah failed to create dst addr\n");
+		goto free_resources;
+	}
+
+	if (neigh_set_src(&neigh_handler, src_family, src.address,
+			  src.size)) {
+		fprintf(stderr, PFX
+			"ibv_create_ah failed to create src addr\n");
+		goto free_resources;
+	}
+
+	oif = neigh_get_oif_from_src(&neigh_handler);
+
+	if (oif > 0) {
+		neigh_set_oif(&neigh_handler, oif);
+	} else {
+		fprintf(stderr, PFX "ibv_create_ah failed to get output IF\n");
+		goto free_resources;
+	}
+
+	/* blocking call */
+	if (process_get_neigh(&neigh_handler)) {
+		fprintf(stderr, PFX "Neigh resolution process failed\n");
+		goto free_resources;
+	}
+
+	attr_ex.vid = neigh_get_vlan_id_from_dev(&neigh_handler);
+
+	if (attr_ex.vid <= 0xfff) {
+		neigh_set_vlan_id(&neigh_handler, attr_ex.vid);
+		attr_ex.comp_mask |= IBV_AH_ATTR_EX_VID;
+	}
+	/* We are using only Ethernet here */
+	attr_ex.ll_address.len = neigh_get_ll(&neigh_handler, ethernet_ll,
+					      sizeof(ethernet_ll));
+
+	if (attr_ex.ll_address.len <= 0)
+		goto free_resources;
+
+	attr_ex.comp_mask |= IBV_AH_ATTR_EX_LL;
+	attr_ex.ll_address.type = LL_ADDRESS_ETH;
+	attr_ex.ll_address.address = ethernet_ll;
+
+
+	ah = vctx->drv_ibv_create_ah_ex(pd, &attr_ex);
+
+free_resources:
+	neigh_free_resources(&neigh_handler);
+
+return_ah:
+#endif
 	if (ah) {
 		ah->context = pd->context;
 		ah->pd      = pd;
 	}
-
 	return ah;
 }
 default_symver(__ibv_create_ah, ibv_create_ah);

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File libibverbs-Use-neighbour-lookup-for-RoCE-UD-QPs-Eth-L2-resoluti.patch of Package libibverbs (Revision c2a71f5fc68920afd459c7e729cc38c0)

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