Adding upstream version 6.1.0.upstream/6.1.0upstream

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

1 files changed, 1657 insertions, 0 deletions

diff --git a/lib/libnetlink.c b/lib/libnetlink.c
new file mode 100644
index 0000000..001efc1
--- /dev/null
+++ b/lib/libnetlink.c
@@ -0,0 +1,1657 @@
+/*
+ * libnetlink.c	RTnetlink service routines.
+ *
+ *		This program 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 of the License, or (at your option) any later version.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <net/if_arp.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/uio.h>
+#include <linux/fib_rules.h>
+#include <linux/if_addrlabel.h>
+#include <linux/if_bridge.h>
+#include <linux/nexthop.h>
+
+#include "libnetlink.h"
+#include "utils.h"
+
+#ifndef __aligned
+#define __aligned(x)		__attribute__((aligned(x)))
+#endif
+
+#ifndef SOL_NETLINK
+#define SOL_NETLINK 270
+#endif
+
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
+int rcvbuf = 1024 * 1024;
+
+#ifdef HAVE_LIBMNL
+#include <libmnl/libmnl.h>
+
+static const enum mnl_attr_data_type extack_policy[NLMSGERR_ATTR_MAX + 1] = {
+	[NLMSGERR_ATTR_MSG]	= MNL_TYPE_NUL_STRING,
+	[NLMSGERR_ATTR_OFFS]	= MNL_TYPE_U32,
+};
+
+static int err_attr_cb(const struct nlattr *attr, void *data)
+{
+	const struct nlattr **tb = data;
+	uint16_t type;
+
+	if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0) {
+		fprintf(stderr, "Invalid extack attribute\n");
+		return MNL_CB_ERROR;
+	}
+
+	type = mnl_attr_get_type(attr);
+	if (mnl_attr_validate(attr, extack_policy[type]) < 0) {
+		fprintf(stderr, "extack attribute %d failed validation\n",
+			type);
+		return MNL_CB_ERROR;
+	}
+
+	tb[type] = attr;
+	return MNL_CB_OK;
+}
+
+static void print_ext_ack_msg(bool is_err, const char *msg)
+{
+	fprintf(stderr, "%s: %s", is_err ? "Error" : "Warning", msg);
+	if (msg[strlen(msg) - 1] != '.')
+		fprintf(stderr, ".");
+	fprintf(stderr, "\n");
+}
+
+/* dump netlink extended ack error message */
+int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
+{
+	struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
+	const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
+	const struct nlmsghdr *err_nlh = NULL;
+	unsigned int hlen = sizeof(*err);
+	const char *msg = NULL;
+	uint32_t off = 0;
+
+	/* no TLVs, nothing to do here */
+	if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
+		return 0;
+
+	/* if NLM_F_CAPPED is set then the inner err msg was capped */
+	if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
+		hlen += mnl_nlmsg_get_payload_len(&err->msg);
+
+	if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK)
+		return 0;
+
+	if (tb[NLMSGERR_ATTR_MSG])
+		msg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
+
+	if (tb[NLMSGERR_ATTR_OFFS]) {
+		off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]);
+
+		if (off > nlh->nlmsg_len) {
+			fprintf(stderr,
+				"Invalid offset for NLMSGERR_ATTR_OFFS\n");
+			off = 0;
+		} else if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
+			err_nlh = &err->msg;
+	}
+
+	if (errfn)
+		return errfn(msg, off, err_nlh);
+
+	if (msg && *msg != '\0') {
+		bool is_err = !!err->error;
+
+		print_ext_ack_msg(is_err, msg);
+		return is_err ? 1 : 0;
+	}
+
+	return 0;
+}
+
+int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, unsigned int offset, int error)
+{
+	struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
+	const char *msg = NULL;
+
+	if (mnl_attr_parse(nlh, offset, err_attr_cb, tb) != MNL_CB_OK)
+		return 0;
+
+	if (tb[NLMSGERR_ATTR_MSG])
+		msg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
+
+	if (msg && *msg != '\0') {
+		bool is_err = !!error;
+
+		print_ext_ack_msg(is_err, msg);
+		return is_err ? 1 : 0;
+	}
+
+	return 0;
+}
+#else
+#warning "libmnl required for error support"
+
+/* No extended error ack without libmnl */
+int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
+{
+	return 0;
+}
+
+int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, unsigned int offset, int error)
+{
+	return 0;
+}
+#endif
+
+/* Older kernels may not support strict dump and filtering */
+void rtnl_set_strict_dump(struct rtnl_handle *rth)
+{
+	int one = 1;
+
+	if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK,
+		       &one, sizeof(one)) < 0)
+		return;
+
+	rth->flags |= RTNL_HANDLE_F_STRICT_CHK;
+}
+
+int rtnl_add_nl_group(struct rtnl_handle *rth, unsigned int group)
+{
+	return setsockopt(rth->fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP,
+			  &group, sizeof(group));
+}
+
+void rtnl_close(struct rtnl_handle *rth)
+{
+	if (rth->fd >= 0) {
+		close(rth->fd);
+		rth->fd = -1;
+	}
+}
+
+int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
+		      int protocol)
+{
+	socklen_t addr_len;
+	int sndbuf = 32768;
+	int one = 1;
+
+	memset(rth, 0, sizeof(*rth));
+
+	rth->proto = protocol;
+	rth->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
+	if (rth->fd < 0) {
+		perror("Cannot open netlink socket");
+		return -1;
+	}
+
+	if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF,
+		       &sndbuf, sizeof(sndbuf)) < 0) {
+		perror("SO_SNDBUF");
+		goto err;
+	}
+
+	if (setsockopt(rth->fd, SOL_SOCKET, SO_RCVBUF,
+		       &rcvbuf, sizeof(rcvbuf)) < 0) {
+		perror("SO_RCVBUF");
+		goto err;
+	}
+
+	/* Older kernels may no support extended ACK reporting */
+	setsockopt(rth->fd, SOL_NETLINK, NETLINK_EXT_ACK,
+		   &one, sizeof(one));
+
+	memset(&rth->local, 0, sizeof(rth->local));
+	rth->local.nl_family = AF_NETLINK;
+	rth->local.nl_groups = subscriptions;
+
+	if (bind(rth->fd, (struct sockaddr *)&rth->local,
+		 sizeof(rth->local)) < 0) {
+		perror("Cannot bind netlink socket");
+		goto err;
+	}
+	addr_len = sizeof(rth->local);
+	if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
+			&addr_len) < 0) {
+		perror("Cannot getsockname");
+		goto err;
+	}
+	if (addr_len != sizeof(rth->local)) {
+		fprintf(stderr, "Wrong address length %d\n", addr_len);
+		goto err;
+	}
+	if (rth->local.nl_family != AF_NETLINK) {
+		fprintf(stderr, "Wrong address family %d\n",
+			rth->local.nl_family);
+		goto err;
+	}
+	rth->seq = time(NULL);
+	return 0;
+err:
+	rtnl_close(rth);
+	return -1;
+}
+
+int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
+{
+	return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
+}
+
+int rtnl_nexthopdump_req(struct rtnl_handle *rth, int family,
+			 req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct nhmsg nhm;
+		char buf[128];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg)),
+		.nlh.nlmsg_type = RTM_GETNEXTHOP,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.nhm.nh_family = family,
+	};
+
+	if (filter_fn) {
+		int err;
+
+		err = filter_fn(&req.nlh, sizeof(req));
+		if (err)
+			return err;
+	}
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_nexthop_bucket_dump_req(struct rtnl_handle *rth, int family,
+				 req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct nhmsg nhm;
+		char buf[128];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct nhmsg)),
+		.nlh.nlmsg_type = RTM_GETNEXTHOPBUCKET,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.nhm.nh_family = family,
+	};
+
+	if (filter_fn) {
+		int err;
+
+		err = filter_fn(&req.nlh, sizeof(req));
+		if (err)
+			return err;
+	}
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_addrdump_req(struct rtnl_handle *rth, int family,
+		      req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct ifaddrmsg ifm;
+		char buf[128];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
+		.nlh.nlmsg_type = RTM_GETADDR,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ifm.ifa_family = family,
+	};
+
+	if (filter_fn) {
+		int err;
+
+		err = filter_fn(&req.nlh, sizeof(req));
+		if (err)
+			return err;
+	}
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_addrlbldump_req(struct rtnl_handle *rth, int family)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct ifaddrlblmsg ifal;
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrlblmsg)),
+		.nlh.nlmsg_type = RTM_GETADDRLABEL,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ifal.ifal_family = family,
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_routedump_req(struct rtnl_handle *rth, int family,
+		       req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct rtmsg rtm;
+		char buf[128];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
+		.nlh.nlmsg_type = RTM_GETROUTE,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.rtm.rtm_family = family,
+	};
+
+	if (filter_fn) {
+		int err;
+
+		err = filter_fn(&req.nlh, sizeof(req));
+		if (err)
+			return err;
+	}
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_ruledump_req(struct rtnl_handle *rth, int family)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct fib_rule_hdr frh;
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
+		.nlh.nlmsg_type = RTM_GETRULE,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.frh.family = family
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_neighdump_req(struct rtnl_handle *rth, int family,
+		       req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct ndmsg ndm;
+		char buf[256];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
+		.nlh.nlmsg_type = RTM_GETNEIGH,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ndm.ndm_family = family,
+	};
+
+	if (filter_fn) {
+		int err;
+
+		err = filter_fn(&req.nlh, sizeof(req));
+		if (err)
+			return err;
+	}
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_neightbldump_req(struct rtnl_handle *rth, int family)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct ndtmsg ndtmsg;
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndtmsg)),
+		.nlh.nlmsg_type = RTM_GETNEIGHTBL,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ndtmsg.ndtm_family = family,
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_mdbdump_req(struct rtnl_handle *rth, int family)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct br_port_msg bpm;
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct br_port_msg)),
+		.nlh.nlmsg_type = RTM_GETMDB,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.bpm.family = family,
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_brvlandump_req(struct rtnl_handle *rth, int family, __u32 dump_flags)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct br_vlan_msg bvm;
+		char buf[256];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct br_vlan_msg)),
+		.nlh.nlmsg_type = RTM_GETVLAN,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.bvm.family = family,
+	};
+
+	addattr32(&req.nlh, sizeof(req), BRIDGE_VLANDB_DUMP_FLAGS, dump_flags);
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_netconfdump_req(struct rtnl_handle *rth, int family)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct netconfmsg ncm;
+		char buf[0] __aligned(NLMSG_ALIGNTO);
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct netconfmsg))),
+		.nlh.nlmsg_type = RTM_GETNETCONF,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ncm.ncm_family = family,
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_nsiddump_req_filter_fn(struct rtnl_handle *rth, int family,
+				req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct rtgenmsg rtm;
+		char buf[1024];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct rtgenmsg))),
+		.nlh.nlmsg_type = RTM_GETNSID,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.rtm.rtgen_family = family,
+	};
+	int err;
+
+	if (!filter_fn)
+		return -EINVAL;
+
+	err = filter_fn(&req.nlh, sizeof(req));
+	if (err)
+		return err;
+
+	return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
+}
+
+static int __rtnl_linkdump_req(struct rtnl_handle *rth, int family)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct ifinfomsg ifm;
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+		.nlh.nlmsg_type = RTM_GETLINK,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ifm.ifi_family = family,
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_linkdump_req(struct rtnl_handle *rth, int family)
+{
+	if (family == AF_UNSPEC)
+		return rtnl_linkdump_req_filter(rth, family, RTEXT_FILTER_VF);
+
+	return __rtnl_linkdump_req(rth, family);
+}
+
+int rtnl_linkdump_req_filter(struct rtnl_handle *rth, int family,
+			    __u32 filt_mask)
+{
+	if (family == AF_UNSPEC || family == AF_BRIDGE) {
+		struct {
+			struct nlmsghdr nlh;
+			struct ifinfomsg ifm;
+			/* attribute has to be NLMSG aligned */
+			struct rtattr ext_req __aligned(NLMSG_ALIGNTO);
+			__u32 ext_filter_mask;
+		} req = {
+			.nlh.nlmsg_len = sizeof(req),
+			.nlh.nlmsg_type = RTM_GETLINK,
+			.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+			.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+			.ifm.ifi_family = family,
+			.ext_req.rta_type = IFLA_EXT_MASK,
+			.ext_req.rta_len = RTA_LENGTH(sizeof(__u32)),
+			.ext_filter_mask = filt_mask,
+		};
+
+		return send(rth->fd, &req, sizeof(req), 0);
+	}
+
+	return __rtnl_linkdump_req(rth, family);
+}
+
+int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int family,
+				req_filter_fn_t filter_fn)
+{
+	if (family == AF_UNSPEC || family == AF_PACKET) {
+		struct {
+			struct nlmsghdr nlh;
+			struct ifinfomsg ifm;
+			char buf[1024];
+		} req = {
+			.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+			.nlh.nlmsg_type = RTM_GETLINK,
+			.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+			.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+			.ifm.ifi_family = family,
+		};
+		int err;
+
+		if (!filter_fn)
+			return -EINVAL;
+
+		err = filter_fn(&req.nlh, sizeof(req));
+		if (err)
+			return err;
+
+		return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
+	}
+
+	return __rtnl_linkdump_req(rth, family);
+}
+
+int rtnl_fdb_linkdump_req_filter_fn(struct rtnl_handle *rth,
+				    req_filter_fn_t filter_fn)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct ifinfomsg ifm;
+		char buf[128];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
+		.nlh.nlmsg_type = RTM_GETNEIGH,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.ifm.ifi_family = PF_BRIDGE,
+	};
+	int err;
+
+	err = filter_fn(&req.nlh, sizeof(req));
+	if (err)
+		return err;
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam,
+			      __u32 filt_mask,
+			      int (*filter_fn)(struct ipstats_req *req,
+					       void *data),
+			      void *filter_data)
+{
+	struct ipstats_req req;
+
+	memset(&req, 0, sizeof(req));
+	req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct if_stats_msg));
+	req.nlh.nlmsg_type = RTM_GETSTATS;
+	req.nlh.nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
+	req.nlh.nlmsg_pid = 0;
+	req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
+	req.ifsm.family = fam;
+	req.ifsm.filter_mask = filt_mask;
+
+	if (filter_fn) {
+		int err;
+
+		err = filter_fn(&req, filter_data);
+		if (err)
+			return err;
+	}
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}
+
+int rtnl_send(struct rtnl_handle *rth, const void *buf, int len)
+{
+	return send(rth->fd, buf, len, 0);
+}
+
+int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
+{
+	struct nlmsghdr *h;
+	int status;
+	char resp[1024];
+
+	status = send(rth->fd, buf, len, 0);
+	if (status < 0)
+		return status;
+
+	/* Check for immediate errors */
+	status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
+	if (status < 0) {
+		if (errno == EAGAIN)
+			return 0;
+		return -1;
+	}
+
+	for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
+	     h = NLMSG_NEXT(h, status)) {
+		if (h->nlmsg_type == NLMSG_ERROR) {
+			struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
+
+			if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
+				fprintf(stderr, "ERROR truncated\n");
+			else
+				errno = -err->error;
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
+{
+	struct nlmsghdr nlh = {
+		.nlmsg_len = NLMSG_LENGTH(len),
+		.nlmsg_type = type,
+		.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlmsg_seq = rth->dump = ++rth->seq,
+	};
+	struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
+	struct iovec iov[2] = {
+		{ .iov_base = &nlh, .iov_len = sizeof(nlh) },
+		{ .iov_base = req, .iov_len = len }
+	};
+	struct msghdr msg = {
+		.msg_name = &nladdr,
+		.msg_namelen = sizeof(nladdr),
+		.msg_iov = iov,
+		.msg_iovlen = 2,
+	};
+
+	return sendmsg(rth->fd, &msg, 0);
+}
+
+int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
+{
+	struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
+	struct iovec iov = {
+		.iov_base = n,
+		.iov_len = n->nlmsg_len
+	};
+	struct msghdr msg = {
+		.msg_name = &nladdr,
+		.msg_namelen = sizeof(nladdr),
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+	};
+
+	n->nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
+	n->nlmsg_pid = 0;
+	n->nlmsg_seq = rth->dump = ++rth->seq;
+
+	return sendmsg(rth->fd, &msg, 0);
+}
+
+static int rtnl_dump_done(struct nlmsghdr *h,
+			  const struct rtnl_dump_filter_arg *a)
+{
+	int len = *(int *)NLMSG_DATA(h);
+
+	if (h->nlmsg_len < NLMSG_LENGTH(sizeof(int))) {
+		fprintf(stderr, "DONE truncated\n");
+		return -1;
+	}
+
+	if (len < 0) {
+		errno = -len;
+
+		if (a->errhndlr && (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_DONE_NLERR))
+			return 0;
+
+		/* check for any messages returned from kernel */
+		if (nl_dump_ext_ack_done(h, sizeof(int), len))
+			return len;
+
+		switch (errno) {
+		case ENOENT:
+		case EOPNOTSUPP:
+			return -1;
+		case EMSGSIZE:
+			fprintf(stderr,
+				"Error: Buffer too small for object.\n");
+			break;
+		default:
+			perror("RTNETLINK answers");
+		}
+		return len;
+	}
+
+	/* check for any messages returned from kernel */
+	nl_dump_ext_ack(h, NULL);
+
+	return 0;
+}
+
+static int rtnl_dump_error(const struct rtnl_handle *rth,
+			    struct nlmsghdr *h,
+			    const struct rtnl_dump_filter_arg *a)
+{
+
+	if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
+		fprintf(stderr, "ERROR truncated\n");
+	} else {
+		const struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
+
+		errno = -err->error;
+		if (rth->proto == NETLINK_SOCK_DIAG &&
+		    (errno == ENOENT ||
+		     errno == EOPNOTSUPP))
+			return -1;
+
+		if (a->errhndlr && (a->errhndlr(h, a->arg2) & RTNL_SUPPRESS_NLMSG_ERROR_NLERR))
+			return 0;
+
+		if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
+			perror("RTNETLINK answers");
+	}
+
+	return -1;
+}
+
+static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
+{
+	int len;
+
+	do {
+		len = recvmsg(fd, msg, flags);
+	} while (len < 0 && (errno == EINTR || errno == EAGAIN));
+
+	if (len < 0) {
+		fprintf(stderr, "netlink receive error %s (%d)\n",
+			strerror(errno), errno);
+		return -errno;
+	}
+
+	if (len == 0) {
+		fprintf(stderr, "EOF on netlink\n");
+		return -ENODATA;
+	}
+
+	return len;
+}
+
+static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
+{
+	struct iovec *iov = msg->msg_iov;
+	char *buf;
+	int len;
+
+	iov->iov_base = NULL;
+	iov->iov_len = 0;
+
+	len = __rtnl_recvmsg(fd, msg, MSG_PEEK | MSG_TRUNC);
+	if (len < 0)
+		return len;
+
+	if (len < 32768)
+		len = 32768;
+	buf = malloc(len);
+	if (!buf) {
+		fprintf(stderr, "malloc error: not enough buffer\n");
+		return -ENOMEM;
+	}
+
+	iov->iov_base = buf;
+	iov->iov_len = len;
+
+	len = __rtnl_recvmsg(fd, msg, 0);
+	if (len < 0) {
+		free(buf);
+		return len;
+	}
+
+	if (answer)
+		*answer = buf;
+	else
+		free(buf);
+
+	return len;
+}
+
+static int rtnl_dump_filter_l(struct rtnl_handle *rth,
+			      const struct rtnl_dump_filter_arg *arg)
+{
+	struct sockaddr_nl nladdr;
+	struct iovec iov;
+	struct msghdr msg = {
+		.msg_name = &nladdr,
+		.msg_namelen = sizeof(nladdr),
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+	};
+	char *buf;
+	int dump_intr = 0;
+
+	while (1) {
+		int status;
+		const struct rtnl_dump_filter_arg *a;
+		int found_done = 0;
+		int msglen = 0;
+
+		status = rtnl_recvmsg(rth->fd, &msg, &buf);
+		if (status < 0)
+			return status;
+
+		if (rth->dump_fp)
+			fwrite(buf, 1, NLMSG_ALIGN(status), rth->dump_fp);
+
+		for (a = arg; a->filter; a++) {
+			struct nlmsghdr *h = (struct nlmsghdr *)buf;
+
+			msglen = status;
+
+			while (NLMSG_OK(h, msglen)) {
+				int err = 0;
+
+				h->nlmsg_flags &= ~a->nc_flags;
+
+				if (nladdr.nl_pid != 0 ||
+				    h->nlmsg_pid != rth->local.nl_pid ||
+				    h->nlmsg_seq != rth->dump)
+					goto skip_it;
+
+				if (h->nlmsg_flags & NLM_F_DUMP_INTR)
+					dump_intr = 1;
+
+				if (h->nlmsg_type == NLMSG_DONE) {
+					err = rtnl_dump_done(h, a);
+					if (err < 0) {
+						free(buf);
+						return -1;
+					}
+
+					found_done = 1;
+					break; /* process next filter */
+				}
+
+				if (h->nlmsg_type == NLMSG_ERROR) {
+					err = rtnl_dump_error(rth, h, a);
+					if (err < 0) {
+						free(buf);
+						return -1;
+					}
+
+					goto skip_it;
+				}
+
+				if (!rth->dump_fp) {
+					err = a->filter(h, a->arg1);
+					if (err < 0) {
+						free(buf);
+						return err;
+					}
+				}
+
+skip_it:
+				h = NLMSG_NEXT(h, msglen);
+			}
+		}
+		free(buf);
+
+		if (found_done) {
+			if (dump_intr)
+				fprintf(stderr,
+					"Dump was interrupted and may be inconsistent.\n");
+			return 0;
+		}
+
+		if (msg.msg_flags & MSG_TRUNC) {
+			fprintf(stderr, "Message truncated\n");
+			continue;
+		}
+		if (msglen) {
+			fprintf(stderr, "!!!Remnant of size %d\n", msglen);
+			exit(1);
+		}
+	}
+}
+
+int rtnl_dump_filter_nc(struct rtnl_handle *rth,
+			rtnl_filter_t filter,
+			void *arg1, __u16 nc_flags)
+{
+	const struct rtnl_dump_filter_arg a[] = {
+		{
+			.filter = filter, .arg1 = arg1,
+			.nc_flags = nc_flags,
+		},
+		{ },
+	};
+
+	return rtnl_dump_filter_l(rth, a);
+}
+
+int rtnl_dump_filter_errhndlr_nc(struct rtnl_handle *rth,
+		     rtnl_filter_t filter,
+		     void *arg1,
+		     rtnl_err_hndlr_t errhndlr,
+		     void *arg2,
+		     __u16 nc_flags)
+{
+	const struct rtnl_dump_filter_arg a[] = {
+		{
+			.filter = filter, .arg1 = arg1,
+			.errhndlr = errhndlr, .arg2 = arg2,
+			.nc_flags = nc_flags,
+		},
+		{ },
+	};
+
+	return rtnl_dump_filter_l(rth, a);
+}
+
+static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
+			    nl_ext_ack_fn_t errfn)
+{
+	if (nl_dump_ext_ack(h, errfn))
+		return;
+
+	fprintf(stderr, "RTNETLINK answers: %s\n",
+		strerror(-err->error));
+}
+
+
+static int __rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iov,
+			   size_t iovlen, struct nlmsghdr **answer,
+			   bool show_rtnl_err, nl_ext_ack_fn_t errfn)
+{
+	struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
+	struct iovec riov;
+	struct msghdr msg = {
+		.msg_name = &nladdr,
+		.msg_namelen = sizeof(nladdr),
+		.msg_iov = iov,
+		.msg_iovlen = iovlen,
+	};
+	unsigned int seq = 0;
+	struct nlmsghdr *h;
+	int i, status;
+	char *buf;
+
+	for (i = 0; i < iovlen; i++) {
+		h = iov[i].iov_base;
+		h->nlmsg_seq = seq = ++rtnl->seq;
+		if (answer == NULL)
+			h->nlmsg_flags |= NLM_F_ACK;
+	}
+
+	status = sendmsg(rtnl->fd, &msg, 0);
+	if (status < 0) {
+		perror("Cannot talk to rtnetlink");
+		return -1;
+	}
+
+	/* change msg to use the response iov */
+	msg.msg_iov = &riov;
+	msg.msg_iovlen = 1;
+	i = 0;
+	while (1) {
+next:
+		status = rtnl_recvmsg(rtnl->fd, &msg, &buf);
+		++i;
+
+		if (status < 0)
+			return status;
+
+		if (msg.msg_namelen != sizeof(nladdr)) {
+			fprintf(stderr,
+				"sender address length == %d\n",
+				msg.msg_namelen);
+			exit(1);
+		}
+		for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
+			int len = h->nlmsg_len;
+			int l = len - sizeof(*h);
+
+			if (l < 0 || len > status) {
+				if (msg.msg_flags & MSG_TRUNC) {
+					fprintf(stderr, "Truncated message\n");
+					free(buf);
+					return -1;
+				}
+				fprintf(stderr,
+					"!!!malformed message: len=%d\n",
+					len);
+				exit(1);
+			}
+
+			if (nladdr.nl_pid != 0 ||
+			    h->nlmsg_pid != rtnl->local.nl_pid ||
+			    h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen) {
+				/* Don't forget to skip that message. */
+				status -= NLMSG_ALIGN(len);
+				h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
+				continue;
+			}
+
+			if (h->nlmsg_type == NLMSG_ERROR) {
+				struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
+				int error = err->error;
+
+				if (l < sizeof(struct nlmsgerr)) {
+					fprintf(stderr, "ERROR truncated\n");
+					free(buf);
+					return -1;
+				}
+
+				if (!error) {
+					/* check messages from kernel */
+					nl_dump_ext_ack(h, errfn);
+				} else {
+					errno = -error;
+
+					if (rtnl->proto != NETLINK_SOCK_DIAG &&
+					    show_rtnl_err)
+						rtnl_talk_error(h, err, errfn);
+				}
+
+				if (i < iovlen) {
+					free(buf);
+					goto next;
+				}
+
+				if (error) {
+					free(buf);
+					return -i;
+				}
+
+				if (answer)
+					*answer = (struct nlmsghdr *)buf;
+				return 0;
+			}
+
+			if (answer) {
+				*answer = (struct nlmsghdr *)buf;
+				return 0;
+			}
+
+			fprintf(stderr, "Unexpected reply!!!\n");
+
+			status -= NLMSG_ALIGN(len);
+			h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
+		}
+		free(buf);
+
+		if (msg.msg_flags & MSG_TRUNC) {
+			fprintf(stderr, "Message truncated\n");
+			continue;
+		}
+
+		if (status) {
+			fprintf(stderr, "!!!Remnant of size %d\n", status);
+			exit(1);
+		}
+	}
+}
+
+static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
+		       struct nlmsghdr **answer,
+		       bool show_rtnl_err, nl_ext_ack_fn_t errfn)
+{
+	struct iovec iov = {
+		.iov_base = n,
+		.iov_len = n->nlmsg_len
+	};
+
+	return __rtnl_talk_iov(rtnl, &iov, 1, answer, show_rtnl_err, errfn);
+}
+
+int rtnl_echo_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, int json,
+		   int (*print_info)(struct nlmsghdr *n, void *arg))
+{
+	struct nlmsghdr *answer;
+	int ret;
+
+	n->nlmsg_flags |= NLM_F_ECHO | NLM_F_ACK;
+
+	ret = rtnl_talk(rtnl, n, &answer);
+	if (ret)
+		return ret;
+
+	new_json_obj(json);
+	open_json_object(NULL);
+	print_info(answer, stdout);
+	close_json_object();
+	delete_json_obj();
+	free(answer);
+
+	return 0;
+}
+
+int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
+	      struct nlmsghdr **answer)
+{
+	return __rtnl_talk(rtnl, n, answer, true, NULL);
+}
+
+int rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iovec, size_t iovlen,
+		  struct nlmsghdr **answer)
+{
+	return __rtnl_talk_iov(rtnl, iovec, iovlen, answer, true, NULL);
+}
+
+int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
+				   struct nlmsghdr **answer)
+{
+	return __rtnl_talk(rtnl, n, answer, false, NULL);
+}
+
+int rtnl_listen_all_nsid(struct rtnl_handle *rth)
+{
+	unsigned int on = 1;
+
+	if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, &on,
+		       sizeof(on)) < 0) {
+		perror("NETLINK_LISTEN_ALL_NSID");
+		return -1;
+	}
+	rth->flags |= RTNL_HANDLE_F_LISTEN_ALL_NSID;
+	return 0;
+}
+
+int rtnl_listen(struct rtnl_handle *rtnl,
+		rtnl_listen_filter_t handler,
+		void *jarg)
+{
+	int status;
+	struct nlmsghdr *h;
+	struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
+	struct iovec iov;
+	struct msghdr msg = {
+		.msg_name = &nladdr,
+		.msg_namelen = sizeof(nladdr),
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+	};
+	char   buf[16384];
+	char   cmsgbuf[BUFSIZ];
+
+	iov.iov_base = buf;
+	while (1) {
+		struct rtnl_ctrl_data ctrl;
+		struct cmsghdr *cmsg;
+
+		if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
+			msg.msg_control = &cmsgbuf;
+			msg.msg_controllen = sizeof(cmsgbuf);
+		}
+
+		iov.iov_len = sizeof(buf);
+		status = recvmsg(rtnl->fd, &msg, 0);
+
+		if (status < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			fprintf(stderr, "netlink receive error %s (%d)\n",
+				strerror(errno), errno);
+			if (errno == ENOBUFS)
+				continue;
+			return -1;
+		}
+		if (status == 0) {
+			fprintf(stderr, "EOF on netlink\n");
+			return -1;
+		}
+		if (msg.msg_namelen != sizeof(nladdr)) {
+			fprintf(stderr,
+				"Sender address length == %d\n",
+				msg.msg_namelen);
+			exit(1);
+		}
+
+		if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
+			memset(&ctrl, 0, sizeof(ctrl));
+			ctrl.nsid = -1;
+			for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
+			     cmsg = CMSG_NXTHDR(&msg, cmsg))
+				if (cmsg->cmsg_level == SOL_NETLINK &&
+				    cmsg->cmsg_type == NETLINK_LISTEN_ALL_NSID &&
+				    cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
+					int *data = (int *)CMSG_DATA(cmsg);
+
+					ctrl.nsid = *data;
+				}
+		}
+
+		for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
+			int err;
+			int len = h->nlmsg_len;
+			int l = len - sizeof(*h);
+
+			if (l < 0 || len > status) {
+				if (msg.msg_flags & MSG_TRUNC) {
+					fprintf(stderr, "Truncated message\n");
+					return -1;
+				}
+				fprintf(stderr,
+					"!!!malformed message: len=%d\n",
+					len);
+				exit(1);
+			}
+
+			err = handler(&ctrl, h, jarg);
+			if (err < 0)
+				return err;
+
+			status -= NLMSG_ALIGN(len);
+			h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
+		}
+		if (msg.msg_flags & MSG_TRUNC) {
+			fprintf(stderr, "Message truncated\n");
+			continue;
+		}
+		if (status) {
+			fprintf(stderr, "!!!Remnant of size %d\n", status);
+			exit(1);
+		}
+	}
+}
+
+int rtnl_from_file(FILE *rtnl, rtnl_listen_filter_t handler,
+		   void *jarg)
+{
+	size_t status;
+	char buf[16384];
+	struct nlmsghdr *h = (struct nlmsghdr *)buf;
+
+	while (1) {
+		int err, len;
+		int l;
+
+		status = fread(&buf, 1, sizeof(*h), rtnl);
+
+		if (status == 0 && feof(rtnl))
+			return 0;
+		if (status != sizeof(*h)) {
+			if (ferror(rtnl))
+				perror("rtnl_from_file: fread");
+			if (feof(rtnl))
+				fprintf(stderr, "rtnl-from_file: truncated message\n");
+			return -1;
+		}
+
+		len = h->nlmsg_len;
+		l = len - sizeof(*h);
+
+		if (l < 0 || len > sizeof(buf)) {
+			fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
+				len, ftell(rtnl));
+			return -1;
+		}
+
+		status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
+
+		if (status != NLMSG_ALIGN(l)) {
+			if (ferror(rtnl))
+				perror("rtnl_from_file: fread");
+			if (feof(rtnl))
+				fprintf(stderr, "rtnl-from_file: truncated message\n");
+			return -1;
+		}
+
+		err = handler(NULL, h, jarg);
+		if (err < 0)
+			return err;
+	}
+}
+
+int addattr(struct nlmsghdr *n, int maxlen, int type)
+{
+	return addattr_l(n, maxlen, type, NULL, 0);
+}
+
+int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data)
+{
+	return addattr_l(n, maxlen, type, &data, sizeof(__u8));
+}
+
+int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data)
+{
+	return addattr_l(n, maxlen, type, &data, sizeof(__u16));
+}
+
+int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
+{
+	return addattr_l(n, maxlen, type, &data, sizeof(__u32));
+}
+
+int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data)
+{
+	return addattr_l(n, maxlen, type, &data, sizeof(__u64));
+}
+
+int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *str)
+{
+	return addattr_l(n, maxlen, type, str, strlen(str)+1);
+}
+
+int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
+	      int alen)
+{
+	int len = RTA_LENGTH(alen);
+	struct rtattr *rta;
+
+	if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
+		fprintf(stderr,
+			"addattr_l ERROR: message exceeded bound of %d\n",
+			maxlen);
+		return -1;
+	}
+	rta = NLMSG_TAIL(n);
+	rta->rta_type = type;
+	rta->rta_len = len;
+	if (alen)
+		memcpy(RTA_DATA(rta), data, alen);
+	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
+	return 0;
+}
+
+int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
+{
+	if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
+		fprintf(stderr,
+			"addraw_l ERROR: message exceeded bound of %d\n",
+			maxlen);
+		return -1;
+	}
+
+	memcpy(NLMSG_TAIL(n), data, len);
+	memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
+	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
+	return 0;
+}
+
+struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
+{
+	struct rtattr *nest = NLMSG_TAIL(n);
+
+	addattr_l(n, maxlen, type, NULL, 0);
+	return nest;
+}
+
+int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
+{
+	nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
+	return n->nlmsg_len;
+}
+
+struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
+				   const void *data, int len)
+{
+	struct rtattr *start = NLMSG_TAIL(n);
+
+	addattr_l(n, maxlen, type, data, len);
+	addattr_nest(n, maxlen, type);
+	return start;
+}
+
+int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
+{
+	struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
+
+	start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
+	addattr_nest_end(n, nest);
+	return n->nlmsg_len;
+}
+
+int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
+{
+	int len = RTA_LENGTH(4);
+	struct rtattr *subrta;
+
+	if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
+		fprintf(stderr,
+			"rta_addattr32: Error! max allowed bound %d exceeded\n",
+			maxlen);
+		return -1;
+	}
+	subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
+	subrta->rta_type = type;
+	subrta->rta_len = len;
+	memcpy(RTA_DATA(subrta), &data, 4);
+	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
+	return 0;
+}
+
+int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
+		  const void *data, int alen)
+{
+	struct rtattr *subrta;
+	int len = RTA_LENGTH(alen);
+
+	if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
+		fprintf(stderr,
+			"rta_addattr_l: Error! max allowed bound %d exceeded\n",
+			maxlen);
+		return -1;
+	}
+	subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
+	subrta->rta_type = type;
+	subrta->rta_len = len;
+	if (alen)
+		memcpy(RTA_DATA(subrta), data, alen);
+	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
+	return 0;
+}
+
+int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data)
+{
+	return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u8));
+}
+
+int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data)
+{
+	return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u16));
+}
+
+int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data)
+{
+	return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u64));
+}
+
+struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type)
+{
+	struct rtattr *nest = RTA_TAIL(rta);
+
+	rta_addattr_l(rta, maxlen, type, NULL, 0);
+	nest->rta_type |= NLA_F_NESTED;
+
+	return nest;
+}
+
+int rta_nest_end(struct rtattr *rta, struct rtattr *nest)
+{
+	nest->rta_len = (void *)RTA_TAIL(rta) - (void *)nest;
+
+	return rta->rta_len;
+}
+
+int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
+{
+	return parse_rtattr_flags(tb, max, rta, len, 0);
+}
+
+int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
+		       int len, unsigned short flags)
+{
+	unsigned short type;
+
+	memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
+	while (RTA_OK(rta, len)) {
+		type = rta->rta_type & ~flags;
+		if ((type <= max) && (!tb[type]))
+			tb[type] = rta;
+		rta = RTA_NEXT(rta, len);
+	}
+	if (len)
+		fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
+			len, rta->rta_len);
+	return 0;
+}
+
+struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len)
+{
+	while (RTA_OK(rta, len)) {
+		if (rta->rta_type == type)
+			return rta;
+		rta = RTA_NEXT(rta, len);
+	}
+
+	if (len)
+		fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
+			len, rta->rta_len);
+	return NULL;
+}
+
+int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
+				 struct rtattr *rta,
+				 int len)
+{
+	if (RTA_PAYLOAD(rta) < len)
+		return -1;
+	if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
+		rta = RTA_DATA(rta) + RTA_ALIGN(len);
+		return parse_rtattr_nested(tb, max, rta);
+	}
+	memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
+	return 0;
+}
+
+static const char *get_nla_type_str(unsigned int attr)
+{
+	switch (attr) {
+#define C(x) case NL_ATTR_TYPE_ ## x: return #x
+	C(U8);
+	C(U16);
+	C(U32);
+	C(U64);
+	C(STRING);
+	C(FLAG);
+	C(NESTED);
+	C(NESTED_ARRAY);
+	C(NUL_STRING);
+	C(BINARY);
+	C(S8);
+	C(S16);
+	C(S32);
+	C(S64);
+	C(BITFIELD32);
+	default:
+		return "unknown";
+	}
+}
+
+void nl_print_policy(const struct rtattr *attr, FILE *fp)
+{
+	const struct rtattr *pos;
+
+	rtattr_for_each_nested(pos, attr) {
+		const struct rtattr *attr;
+
+		fprintf(fp, " policy[%u]:", pos->rta_type & ~NLA_F_NESTED);
+
+		rtattr_for_each_nested(attr, pos) {
+			struct rtattr *tp[NL_POLICY_TYPE_ATTR_MAX + 1];
+
+			parse_rtattr_nested(tp, ARRAY_SIZE(tp) - 1, attr);
+
+			if (tp[NL_POLICY_TYPE_ATTR_TYPE])
+				fprintf(fp, "attr[%u]: type=%s",
+					attr->rta_type & ~NLA_F_NESTED,
+					get_nla_type_str(rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_TYPE])));
+
+			if (tp[NL_POLICY_TYPE_ATTR_POLICY_IDX])
+				fprintf(fp, " policy:%u",
+					rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_POLICY_IDX]));
+
+			if (tp[NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE])
+				fprintf(fp, " maxattr:%u",
+					rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_POLICY_MAXTYPE]));
+
+			if (tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_S] && tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_S])
+				fprintf(fp, " range:[%lld,%lld]",
+					(signed long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_S]),
+					(signed long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_S]));
+
+			if (tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_U] && tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_U])
+				fprintf(fp, " range:[%llu,%llu]",
+					(unsigned long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MIN_VALUE_U]),
+					(unsigned long long)rta_getattr_u64(tp[NL_POLICY_TYPE_ATTR_MAX_VALUE_U]));
+
+			if (tp[NL_POLICY_TYPE_ATTR_MIN_LENGTH])
+				fprintf(fp, " min len:%u",
+					rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_MIN_LENGTH]));
+
+			if (tp[NL_POLICY_TYPE_ATTR_MAX_LENGTH])
+				fprintf(fp, " max len:%u",
+					rta_getattr_u32(tp[NL_POLICY_TYPE_ATTR_MAX_LENGTH]));
+		}
+	}
+}
+
+int rtnl_tunneldump_req(struct rtnl_handle *rth, int family, int ifindex,
+			__u8 flags)
+{
+	struct {
+		struct nlmsghdr nlh;
+		struct tunnel_msg tmsg;
+		char buf[256];
+	} req = {
+		.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct tunnel_msg)),
+		.nlh.nlmsg_type = RTM_GETTUNNEL,
+		.nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
+		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
+		.tmsg.family = family,
+		.tmsg.flags = flags,
+		.tmsg.ifindex = ifindex,
+	};
+
+	return send(rth->fd, &req, sizeof(req), 0);
+}