drivers/infiniband/core/nldev.c - linux - Git at Google

 /*
  * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the names of the copyright holders nor the names of its
  *    contributors may be used to endorse or promote products derived from
  *    this software without specific prior written permission.
  *
  * Alternatively, this software may be distributed under the terms of the
  * GNU General Public License ("GPL") version 2 as published by the Free
  * Software Foundation.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */

 #include <linux/module.h>
 #include <net/netlink.h>
 #include <rdma/rdma_netlink.h>

 #include "core_priv.h"

 static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
 	[RDMA_NLDEV_ATTR_DEV_INDEX]     = { .type = NLA_U32 },
 	[RDMA_NLDEV_ATTR_DEV_NAME]	= { .type = NLA_NUL_STRING,
 					    .len = IB_DEVICE_NAME_MAX - 1},
 	[RDMA_NLDEV_ATTR_PORT_INDEX]	= { .type = NLA_U32 },
 	[RDMA_NLDEV_ATTR_FW_VERSION]	= { .type = NLA_NUL_STRING,
 					    .len = IB_FW_VERSION_NAME_MAX - 1},
 	[RDMA_NLDEV_ATTR_NODE_GUID]	= { .type = NLA_U64 },
 	[RDMA_NLDEV_ATTR_SYS_IMAGE_GUID] = { .type = NLA_U64 },
 	[RDMA_NLDEV_ATTR_SUBNET_PREFIX]	= { .type = NLA_U64 },
 	[RDMA_NLDEV_ATTR_LID]		= { .type = NLA_U32 },
 	[RDMA_NLDEV_ATTR_SM_LID]	= { .type = NLA_U32 },
 	[RDMA_NLDEV_ATTR_LMC]		= { .type = NLA_U8 },
 	[RDMA_NLDEV_ATTR_PORT_STATE]	= { .type = NLA_U8 },
 	[RDMA_NLDEV_ATTR_PORT_PHYS_STATE] = { .type = NLA_U8 },
 	[RDMA_NLDEV_ATTR_DEV_NODE_TYPE] = { .type = NLA_U8 },
 };

 static int fill_dev_info(struct sk_buff *msg, struct ib_device *device)
 {
 	char fw[IB_FW_VERSION_NAME_MAX];

 	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_DEV_INDEX, device->index))
 		return -EMSGSIZE;
 	if (nla_put_string(msg, RDMA_NLDEV_ATTR_DEV_NAME, device->name))
 		return -EMSGSIZE;
 	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, rdma_end_port(device)))
 		return -EMSGSIZE;

 	BUILD_BUG_ON(sizeof(device->attrs.device_cap_flags) != sizeof(u64));
 	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CAP_FLAGS,
 			      device->attrs.device_cap_flags, 0))
 		return -EMSGSIZE;

 	ib_get_device_fw_str(device, fw);
 	/* Device without FW has strlen(fw) */
 	if (strlen(fw) && nla_put_string(msg, RDMA_NLDEV_ATTR_FW_VERSION, fw))
 		return -EMSGSIZE;

 	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_NODE_GUID,
 			      be64_to_cpu(device->node_guid), 0))
 		return -EMSGSIZE;
 	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_SYS_IMAGE_GUID,
 			      be64_to_cpu(device->attrs.sys_image_guid), 0))
 		return -EMSGSIZE;
 	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_DEV_NODE_TYPE, device->node_type))
 		return -EMSGSIZE;
 	return 0;
 }

 static int fill_port_info(struct sk_buff *msg,
 			  struct ib_device *device, u32 port)
 {
 	struct ib_port_attr attr;
 	int ret;

 	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_DEV_INDEX, device->index))
 		return -EMSGSIZE;
 	if (nla_put_string(msg, RDMA_NLDEV_ATTR_DEV_NAME, device->name))
 		return -EMSGSIZE;
 	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, port))
 		return -EMSGSIZE;

 	ret = ib_query_port(device, port, &attr);
 	if (ret)
 		return ret;

 	BUILD_BUG_ON(sizeof(attr.port_cap_flags) > sizeof(u64));
 	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CAP_FLAGS,
 			      (u64)attr.port_cap_flags, 0))
 		return -EMSGSIZE;
 	if (rdma_protocol_ib(device, port) &&
 	    nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_SUBNET_PREFIX,
 			      attr.subnet_prefix, 0))
 		return -EMSGSIZE;
 	if (rdma_protocol_ib(device, port)) {
 		if (nla_put_u32(msg, RDMA_NLDEV_ATTR_LID, attr.lid))
 			return -EMSGSIZE;
 		if (nla_put_u32(msg, RDMA_NLDEV_ATTR_SM_LID, attr.sm_lid))
 			return -EMSGSIZE;
 		if (nla_put_u8(msg, RDMA_NLDEV_ATTR_LMC, attr.lmc))
 			return -EMSGSIZE;
 	}
 	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_PORT_STATE, attr.state))
 		return -EMSGSIZE;
 	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_PORT_PHYS_STATE, attr.phys_state))
 		return -EMSGSIZE;
 	return 0;
 }

 static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 			  struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
 	struct ib_device *device;
 	struct sk_buff *msg;
 	u32 index;
 	int err;

 	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
 			  nldev_policy, extack);
 	if (err || !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
 		return -EINVAL;

 	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);

 	device = __ib_device_get_by_index(index);
 	if (!device)
 		return -EINVAL;

 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
 			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
 			0, 0);

 	err = fill_dev_info(msg, device);
 	if (err) {
 		nlmsg_free(msg);
 		return err;
 	}

 	nlmsg_end(msg, nlh);

 	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
 }

 static int _nldev_get_dumpit(struct ib_device *device,
 			     struct sk_buff *skb,
 			     struct netlink_callback *cb,
 			     unsigned int idx)
 {
 	int start = cb->args[0];
 	struct nlmsghdr *nlh;

 	if (idx < start)
 		return 0;

 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
 			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
 			0, NLM_F_MULTI);

 	if (fill_dev_info(skb, device)) {
 		nlmsg_cancel(skb, nlh);
 		goto out;
 	}

 	nlmsg_end(skb, nlh);

 	idx++;

 out:	cb->args[0] = idx;
 	return skb->len;
 }

 static int nldev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	/*
 	 * There is no need to take lock, because
 	 * we are relying on ib_core's lists_rwsem
 	 */
 	return ib_enum_all_devs(_nldev_get_dumpit, skb, cb);
 }

 static int nldev_port_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 			       struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
 	struct ib_device *device;
 	struct sk_buff *msg;
 	u32 index;
 	u32 port;
 	int err;

 	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
 			  nldev_policy, extack);
 	if (err ||
 	    !tb[RDMA_NLDEV_ATTR_DEV_INDEX] ||
 	    !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
 		return -EINVAL;

 	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
 	device = __ib_device_get_by_index(index);
 	if (!device)
 		return -EINVAL;

 	port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
 	if (!rdma_is_port_valid(device, port))
 		return -EINVAL;

 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;

 	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
 			RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
 			0, 0);

 	err = fill_port_info(msg, device, port);
 	if (err) {
 		nlmsg_free(msg);
 		return err;
 	}

 	nlmsg_end(msg, nlh);

 	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
 }

 static int nldev_port_get_dumpit(struct sk_buff *skb,
 				 struct netlink_callback *cb)
 {
 	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
 	struct ib_device *device;
 	int start = cb->args[0];
 	struct nlmsghdr *nlh;
 	u32 idx = 0;
 	u32 ifindex;
 	int err;
 	u32 p;

 	err = nlmsg_parse(cb->nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
 			  nldev_policy, NULL);
 	if (err || !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
 		return -EINVAL;

 	ifindex = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
 	device = __ib_device_get_by_index(ifindex);
 	if (!device)
 		return -EINVAL;

 	for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {
 		/*
 		 * The dumpit function returns all information from specific
 		 * index. This specific index is taken from the netlink
 		 * messages request sent by user and it is available
 		 * in cb->args[0].
 		 *
 		 * Usually, the user doesn't fill this field and it causes
 		 * to return everything.
 		 *
 		 */
 		if (idx < start) {
 			idx++;
 			continue;
 		}

 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
 				cb->nlh->nlmsg_seq,
 				RDMA_NL_GET_TYPE(RDMA_NL_NLDEV,
 						 RDMA_NLDEV_CMD_PORT_GET),
 				0, NLM_F_MULTI);

 		if (fill_port_info(skb, device, p)) {
 			nlmsg_cancel(skb, nlh);
 			goto out;
 		}
 		idx++;
 		nlmsg_end(skb, nlh);
 	}

 out:	cb->args[0] = idx;
 	return skb->len;
 }

 static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
 	[RDMA_NLDEV_CMD_GET] = {
 		.doit = nldev_get_doit,
 		.dump = nldev_get_dumpit,
 	},
 	[RDMA_NLDEV_CMD_PORT_GET] = {
 		.doit = nldev_port_get_doit,
 		.dump = nldev_port_get_dumpit,
 	},
 };

 void __init nldev_init(void)
 {
 	rdma_nl_register(RDMA_NL_NLDEV, nldev_cb_table);
 }

 void __exit nldev_exit(void)
 {
 	rdma_nl_unregister(RDMA_NL_NLDEV);
 }

 MODULE_ALIAS_RDMA_NETLINK(RDMA_NL_NLDEV, 5);
	/*
	* Copyright (c) 2017 Mellanox Technologies. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the names of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* Alternatively, this software may be distributed under the terms of the
	* GNU General Public License ("GPL") version 2 as published by the Free
	* Software Foundation.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGE.
	*/

	#include <linux/module.h>
	#include <net/netlink.h>
	#include <rdma/rdma_netlink.h>

	#include "core_priv.h"

	static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
	[RDMA_NLDEV_ATTR_DEV_INDEX] = { .type = NLA_U32 },
	[RDMA_NLDEV_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING,
	.len = IB_DEVICE_NAME_MAX - 1},
	[RDMA_NLDEV_ATTR_PORT_INDEX] = { .type = NLA_U32 },
	[RDMA_NLDEV_ATTR_FW_VERSION] = { .type = NLA_NUL_STRING,
	.len = IB_FW_VERSION_NAME_MAX - 1},
	[RDMA_NLDEV_ATTR_NODE_GUID] = { .type = NLA_U64 },
	[RDMA_NLDEV_ATTR_SYS_IMAGE_GUID] = { .type = NLA_U64 },
	[RDMA_NLDEV_ATTR_SUBNET_PREFIX] = { .type = NLA_U64 },
	[RDMA_NLDEV_ATTR_LID] = { .type = NLA_U32 },
	[RDMA_NLDEV_ATTR_SM_LID] = { .type = NLA_U32 },
	[RDMA_NLDEV_ATTR_LMC] = { .type = NLA_U8 },
	[RDMA_NLDEV_ATTR_PORT_STATE] = { .type = NLA_U8 },
	[RDMA_NLDEV_ATTR_PORT_PHYS_STATE] = { .type = NLA_U8 },
	[RDMA_NLDEV_ATTR_DEV_NODE_TYPE] = { .type = NLA_U8 },
	};

	static int fill_dev_info(struct sk_buff msg, struct ib_device device)
	{
	char fw[IB_FW_VERSION_NAME_MAX];

	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_DEV_INDEX, device->index))
	return -EMSGSIZE;
	if (nla_put_string(msg, RDMA_NLDEV_ATTR_DEV_NAME, device->name))
	return -EMSGSIZE;
	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, rdma_end_port(device)))
	return -EMSGSIZE;

	BUILD_BUG_ON(sizeof(device->attrs.device_cap_flags) != sizeof(u64));
	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CAP_FLAGS,
	device->attrs.device_cap_flags, 0))
	return -EMSGSIZE;

	ib_get_device_fw_str(device, fw);
	/* Device without FW has strlen(fw) */
	if (strlen(fw) && nla_put_string(msg, RDMA_NLDEV_ATTR_FW_VERSION, fw))
	return -EMSGSIZE;

	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_NODE_GUID,
	be64_to_cpu(device->node_guid), 0))
	return -EMSGSIZE;
	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_SYS_IMAGE_GUID,
	be64_to_cpu(device->attrs.sys_image_guid), 0))
	return -EMSGSIZE;
	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_DEV_NODE_TYPE, device->node_type))
	return -EMSGSIZE;
	return 0;
	}

	static int fill_port_info(struct sk_buff *msg,
	struct ib_device *device, u32 port)
	{
	struct ib_port_attr attr;
	int ret;

	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_DEV_INDEX, device->index))
	return -EMSGSIZE;
	if (nla_put_string(msg, RDMA_NLDEV_ATTR_DEV_NAME, device->name))
	return -EMSGSIZE;
	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, port))
	return -EMSGSIZE;

	ret = ib_query_port(device, port, &attr);
	if (ret)
	return ret;

	BUILD_BUG_ON(sizeof(attr.port_cap_flags) > sizeof(u64));
	if (nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_CAP_FLAGS,
	(u64)attr.port_cap_flags, 0))
	return -EMSGSIZE;
	if (rdma_protocol_ib(device, port) &&
	nla_put_u64_64bit(msg, RDMA_NLDEV_ATTR_SUBNET_PREFIX,
	attr.subnet_prefix, 0))
	return -EMSGSIZE;
	if (rdma_protocol_ib(device, port)) {
	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_LID, attr.lid))
	return -EMSGSIZE;
	if (nla_put_u32(msg, RDMA_NLDEV_ATTR_SM_LID, attr.sm_lid))
	return -EMSGSIZE;
	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_LMC, attr.lmc))
	return -EMSGSIZE;
	}
	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_PORT_STATE, attr.state))
	return -EMSGSIZE;
	if (nla_put_u8(msg, RDMA_NLDEV_ATTR_PORT_PHYS_STATE, attr.phys_state))
	return -EMSGSIZE;
	return 0;
	}

	static int nldev_get_doit(struct sk_buff skb, struct nlmsghdr nlh,
	struct netlink_ext_ack *extack)
	{
	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
	struct ib_device *device;
	struct sk_buff *msg;
	u32 index;
	int err;

	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
	nldev_policy, extack);
	if (err \|\| !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
	return -EINVAL;

	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);

	device = __ib_device_get_by_index(index);
	if (!device)
	return -EINVAL;

	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
	RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
	0, 0);

	err = fill_dev_info(msg, device);
	if (err) {
	nlmsg_free(msg);
	return err;
	}

	nlmsg_end(msg, nlh);

	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
	}

	static int _nldev_get_dumpit(struct ib_device *device,
	struct sk_buff *skb,
	struct netlink_callback *cb,
	unsigned int idx)
	{
	int start = cb->args[0];
	struct nlmsghdr *nlh;

	if (idx < start)
	return 0;

	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
	RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
	0, NLM_F_MULTI);

	if (fill_dev_info(skb, device)) {
	nlmsg_cancel(skb, nlh);
	goto out;
	}

	nlmsg_end(skb, nlh);

	idx++;

	out: cb->args[0] = idx;
	return skb->len;
	}

	static int nldev_get_dumpit(struct sk_buff skb, struct netlink_callback cb)
	{
	/*
	* There is no need to take lock, because
	* we are relying on ib_core's lists_rwsem
	*/
	return ib_enum_all_devs(_nldev_get_dumpit, skb, cb);
	}

	static int nldev_port_get_doit(struct sk_buff skb, struct nlmsghdr nlh,
	struct netlink_ext_ack *extack)
	{
	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
	struct ib_device *device;
	struct sk_buff *msg;
	u32 index;
	u32 port;
	int err;

	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
	nldev_policy, extack);
	if (err \|\|
	!tb[RDMA_NLDEV_ATTR_DEV_INDEX] \|\|
	!tb[RDMA_NLDEV_ATTR_PORT_INDEX])
	return -EINVAL;

	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
	device = __ib_device_get_by_index(index);
	if (!device)
	return -EINVAL;

	port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
	if (!rdma_is_port_valid(device, port))
	return -EINVAL;

	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
	RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_GET),
	0, 0);

	err = fill_port_info(msg, device, port);
	if (err) {
	nlmsg_free(msg);
	return err;
	}

	nlmsg_end(msg, nlh);

	return rdma_nl_unicast(msg, NETLINK_CB(skb).portid);
	}

	static int nldev_port_get_dumpit(struct sk_buff *skb,
	struct netlink_callback *cb)
	{
	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
	struct ib_device *device;
	int start = cb->args[0];
	struct nlmsghdr *nlh;
	u32 idx = 0;
	u32 ifindex;
	int err;
	u32 p;

	err = nlmsg_parse(cb->nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
	nldev_policy, NULL);
	if (err \|\| !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
	return -EINVAL;

	ifindex = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
	device = __ib_device_get_by_index(ifindex);
	if (!device)
	return -EINVAL;

	for (p = rdma_start_port(device); p <= rdma_end_port(device); ++p) {
	/*
	* The dumpit function returns all information from specific
	* index. This specific index is taken from the netlink
	* messages request sent by user and it is available
	* in cb->args[0].
	*
	* Usually, the user doesn't fill this field and it causes
	* to return everything.
	*
	*/
	if (idx < start) {
	idx++;
	continue;
	}

	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
	cb->nlh->nlmsg_seq,
	RDMA_NL_GET_TYPE(RDMA_NL_NLDEV,
	RDMA_NLDEV_CMD_PORT_GET),
	0, NLM_F_MULTI);

	if (fill_port_info(skb, device, p)) {
	nlmsg_cancel(skb, nlh);
	goto out;
	}
	idx++;
	nlmsg_end(skb, nlh);
	}

	out: cb->args[0] = idx;
	return skb->len;
	}

	static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
	[RDMA_NLDEV_CMD_GET] = {
	.doit = nldev_get_doit,
	.dump = nldev_get_dumpit,
	},
	[RDMA_NLDEV_CMD_PORT_GET] = {
	.doit = nldev_port_get_doit,
	.dump = nldev_port_get_dumpit,
	},
	};

	void __init nldev_init(void)
	{
	rdma_nl_register(RDMA_NL_NLDEV, nldev_cb_table);
	}

	void __exit nldev_exit(void)
	{
	rdma_nl_unregister(RDMA_NL_NLDEV);
	}

	MODULE_ALIAS_RDMA_NETLINK(RDMA_NL_NLDEV, 5);