rdma/link.c - manifest_repos/iproute2 - Git at Google

 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
 /*
  * link.c	RDMA tool
  * Authors:     Leon Romanovsky <leonro@mellanox.com>
  */

 #include "rdma.h"

 static int link_help(struct rd *rd)
 {
 	pr_out("Usage: %s link show [DEV/PORT_INDEX]\n", rd->filename);
 	pr_out("Usage: %s link add NAME type TYPE netdev NETDEV\n",
 	       rd->filename);
 	pr_out("Usage: %s link delete NAME\n", rd->filename);
 	return 0;
 }

 static const char *caps_to_str(uint32_t idx)
 {
 #define RDMA_PORT_FLAGS_LOW(x) \
 	x(RESERVED, 0) \
 	x(SM, 1) \
 	x(NOTICE, 2) \
 	x(TRAP, 3) \
 	x(OPT_IPD, 4) \
 	x(AUTO_MIGR, 5) \
 	x(SL_MAP, 6) \
 	x(MKEY_NVRAM, 7) \
 	x(PKEY_NVRAM, 8) \
 	x(LED_INFO, 9) \
 	x(SM_DISABLED, 10) \
 	x(SYS_IMAGE_GUID, 11) \
 	x(PKEY_SW_EXT_PORT_TRAP, 12) \
 	x(CABLE_INFO, 13) \
 	x(EXTENDED_SPEEDS, 14) \
 	x(CAP_MASK2, 15) \
 	x(CM, 16) \
 	x(SNMP_TUNNEL, 17) \
 	x(REINIT, 18) \
 	x(DEVICE_MGMT, 19) \
 	x(VENDOR_CLASS, 20) \
 	x(DR_NOTICE, 21) \
 	x(CAP_MASK_NOTICE, 22) \
 	x(BOOT_MGMT, 23) \
 	x(LINK_LATENCY, 24) \
 	x(CLIENT_REG, 25) \
 	x(OTHER_LOCAL_CHANGES, 26) \
 	x(LINK_SPPED_WIDTH, 27) \
 	x(VENDOR_SPECIFIC_MADS, 28) \
 	x(MULT_PKER_TRAP, 29) \
 	x(MULT_FDB, 30) \
 	x(HIERARCHY_INFO, 31)

 #define RDMA_PORT_FLAGS_HIGH(x) \
 	x(SET_NODE_DESC, 0) \
 	x(EXT_INFO, 1) \
 	x(VIRT, 2) \
 	x(SWITCH_POR_STATE_TABLE, 3) \
 	x(LINK_WIDTH_2X, 4) \
 	x(LINK_SPEED_HDR, 5)

 	/*
 	 * Separation below is needed to allow compilation of rdmatool
 	 * on 32bits systems. On such systems, C-enum is limited to be
 	 * int and can't hold more than 32 bits.
 	 */
 	enum { RDMA_PORT_FLAGS_LOW(RDMA_BITMAP_ENUM) };
 	enum { RDMA_PORT_FLAGS_HIGH(RDMA_BITMAP_ENUM) };

 	static const char * const
 		rdma_port_names_low[] = { RDMA_PORT_FLAGS_LOW(RDMA_BITMAP_NAMES) };
 	static const char * const
 		rdma_port_names_high[] = { RDMA_PORT_FLAGS_HIGH(RDMA_BITMAP_NAMES) };
 	uint32_t high_idx;
 	#undef RDMA_PORT_FLAGS_LOW
 	#undef RDMA_PORT_FLAGS_HIGH

 	if (idx < ARRAY_SIZE(rdma_port_names_low) && rdma_port_names_low[idx])
 		return rdma_port_names_low[idx];

 	high_idx = idx - ARRAY_SIZE(rdma_port_names_low);
 	if (high_idx < ARRAY_SIZE(rdma_port_names_high) &&
 	    rdma_port_names_high[high_idx])
 		return rdma_port_names_high[high_idx];

 	return "UNKNOWN";
 }

 static void link_print_caps(struct rd *rd, struct nlattr **tb)
 {
 	uint64_t caps;
 	uint32_t idx;

 	if (!tb[RDMA_NLDEV_ATTR_CAP_FLAGS])
 		return;

 	caps = mnl_attr_get_u64(tb[RDMA_NLDEV_ATTR_CAP_FLAGS]);

 	if (rd->json_output) {
 		jsonw_name(rd->jw, "caps");
 		jsonw_start_array(rd->jw);
 	} else {
 		pr_out("\n    caps: <");
 	}
 	for (idx = 0; caps; idx++) {
 		if (caps & 0x1) {
 			if (rd->json_output) {
 				jsonw_string(rd->jw, caps_to_str(idx));
 			} else {
 				pr_out("%s", caps_to_str(idx));
 				if (caps >> 0x1)
 					pr_out(", ");
 			}
 		}
 		caps >>= 0x1;
 	}

 	if (rd->json_output)
 		jsonw_end_array(rd->jw);
 	else
 		pr_out(">");
 }

 static void link_print_subnet_prefix(struct rd *rd, struct nlattr **tb)
 {
 	uint64_t subnet_prefix;
 	uint16_t vp[4];
 	char str[32];

 	if (!tb[RDMA_NLDEV_ATTR_SUBNET_PREFIX])
 		return;

 	subnet_prefix = mnl_attr_get_u64(tb[RDMA_NLDEV_ATTR_SUBNET_PREFIX]);
 	memcpy(vp, &subnet_prefix, sizeof(uint64_t));
 	snprintf(str, 32, "%04x:%04x:%04x:%04x", vp[3], vp[2], vp[1], vp[0]);
 	if (rd->json_output)
 		jsonw_string_field(rd->jw, "subnet_prefix", str);
 	else
 		pr_out("subnet_prefix %s ", str);
 }

 static void link_print_lid(struct rd *rd, struct nlattr **tb)
 {
 	uint32_t lid;

 	if (!tb[RDMA_NLDEV_ATTR_LID])
 		return;

 	lid = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_LID]);
 	if (rd->json_output)
 		jsonw_uint_field(rd->jw, "lid", lid);
 	else
 		pr_out("lid %u ", lid);
 }

 static void link_print_sm_lid(struct rd *rd, struct nlattr **tb)
 {
 	uint32_t sm_lid;

 	if (!tb[RDMA_NLDEV_ATTR_SM_LID])
 		return;

 	sm_lid = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_SM_LID]);
 	if (rd->json_output)
 		jsonw_uint_field(rd->jw, "sm_lid", sm_lid);
 	else
 		pr_out("sm_lid %u ", sm_lid);
 }

 static void link_print_lmc(struct rd *rd, struct nlattr **tb)
 {
 	uint8_t lmc;

 	if (!tb[RDMA_NLDEV_ATTR_LMC])
 		return;

 	lmc = mnl_attr_get_u8(tb[RDMA_NLDEV_ATTR_LMC]);
 	if (rd->json_output)
 		jsonw_uint_field(rd->jw, "lmc", lmc);
 	else
 		pr_out("lmc %u ", lmc);
 }

 static const char *link_state_to_str(uint8_t link_state)
 {
 	static const char * const link_state_str[] = { "NOP", "DOWN",
 						       "INIT", "ARMED",
 						       "ACTIVE",
 						       "ACTIVE_DEFER" };
 	if (link_state < ARRAY_SIZE(link_state_str))
 		return link_state_str[link_state];
 	return "UNKNOWN";
 }

 static void link_print_state(struct rd *rd, struct nlattr **tb)
 {
 	uint8_t state;

 	if (!tb[RDMA_NLDEV_ATTR_PORT_STATE])
 		return;

 	state = mnl_attr_get_u8(tb[RDMA_NLDEV_ATTR_PORT_STATE]);
 	if (rd->json_output)
 		jsonw_string_field(rd->jw, "state", link_state_to_str(state));
 	else
 		pr_out("state %s ", link_state_to_str(state));
 }

 static const char *phys_state_to_str(uint8_t phys_state)
 {
 	static const char * const phys_state_str[] = { "NOP", "SLEEP",
 						       "POLLING", "DISABLED",
 						       "ARMED", "LINK_UP",
 						       "LINK_ERROR_RECOVER",
 						       "PHY_TEST", "UNKNOWN",
 						       "OPA_OFFLINE",
 						       "UNKNOWN", "OPA_TEST" };
 	if (phys_state < ARRAY_SIZE(phys_state_str))
 		return phys_state_str[phys_state];
 	return "UNKNOWN";
 };

 static void link_print_phys_state(struct rd *rd, struct nlattr **tb)
 {
 	uint8_t phys_state;

 	if (!tb[RDMA_NLDEV_ATTR_PORT_PHYS_STATE])
 		return;

 	phys_state = mnl_attr_get_u8(tb[RDMA_NLDEV_ATTR_PORT_PHYS_STATE]);
 	if (rd->json_output)
 		jsonw_string_field(rd->jw, "physical_state",
 				   phys_state_to_str(phys_state));
 	else
 		pr_out("physical_state %s ", phys_state_to_str(phys_state));
 }

 static void link_print_netdev(struct rd *rd, struct nlattr **tb)
 {
 	const char *netdev_name;
 	uint32_t idx;

 	if (!tb[RDMA_NLDEV_ATTR_NDEV_NAME] || !tb[RDMA_NLDEV_ATTR_NDEV_INDEX])
 		return;

 	netdev_name = mnl_attr_get_str(tb[RDMA_NLDEV_ATTR_NDEV_NAME]);
 	idx = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_NDEV_INDEX]);
 	if (rd->json_output) {
 		jsonw_string_field(rd->jw, "netdev", netdev_name);
 		jsonw_uint_field(rd->jw, "netdev_index", idx);
 	} else {
 		pr_out("netdev %s ", netdev_name);
 		if (rd->show_details)
 			pr_out("netdev_index %u ", idx);
 	}
 }

 static int link_parse_cb(const struct nlmsghdr *nlh, void *data)
 {
 	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX] = {};
 	struct rd *rd = data;
 	uint32_t port, idx;
 	char name[32];

 	mnl_attr_parse(nlh, 0, rd_attr_cb, tb);
 	if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_DEV_NAME])
 		return MNL_CB_ERROR;

 	if (!tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {
 		pr_err("This tool doesn't support switches yet\n");
 		return MNL_CB_ERROR;
 	}

 	idx = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
 	port = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
 	snprintf(name, 32, "%s/%u",
 		 mnl_attr_get_str(tb[RDMA_NLDEV_ATTR_DEV_NAME]), port);

 	if (rd->json_output) {
 		jsonw_uint_field(rd->jw, "ifindex", idx);
 		jsonw_uint_field(rd->jw, "port", port);
 		jsonw_string_field(rd->jw, "ifname", name);

 	} else {
 		pr_out("%u/%u: %s: ", idx, port, name);
 	}

 	link_print_subnet_prefix(rd, tb);
 	link_print_lid(rd, tb);
 	link_print_sm_lid(rd, tb);
 	link_print_lmc(rd, tb);
 	link_print_state(rd, tb);
 	link_print_phys_state(rd, tb);
 	link_print_netdev(rd, tb);
 	if (rd->show_details)
 		link_print_caps(rd, tb);

 	if (!rd->json_output)
 		pr_out("\n");
 	return MNL_CB_OK;
 }

 static int link_no_args(struct rd *rd)
 {
 	uint32_t seq;
 	int ret;

 	rd_prepare_msg(rd, RDMA_NLDEV_CMD_PORT_GET, &seq,
 		       (NLM_F_REQUEST | NLM_F_ACK));
 	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_DEV_INDEX, rd->dev_idx);
 	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_PORT_INDEX, rd->port_idx);
 	ret = rd_send_msg(rd);
 	if (ret)
 		return ret;

 	if (rd->json_output)
 		jsonw_start_object(rd->jw);
 	ret = rd_recv_msg(rd, link_parse_cb, rd, seq);
 	if (rd->json_output)
 		jsonw_end_object(rd->jw);
 	return ret;
 }

 static int link_one_show(struct rd *rd)
 {
 	const struct rd_cmd cmds[] = {
 		{ NULL,		link_no_args},
 		{ 0 }
 	};

 	if (!rd->port_idx)
 		return 0;

 	return rd_exec_cmd(rd, cmds, "parameter");
 }

 static int link_show(struct rd *rd)
 {
 	return rd_exec_link(rd, link_one_show, true);
 }

 static int link_add_netdev(struct rd *rd)
 {
 	char *link_netdev;
 	uint32_t seq;

 	if (rd_no_arg(rd)) {
 		pr_err("Please provide a net device name.\n");
 		return -EINVAL;
 	}

 	link_netdev = rd_argv(rd);
 	rd_prepare_msg(rd, RDMA_NLDEV_CMD_NEWLINK, &seq,
 		       (NLM_F_REQUEST | NLM_F_ACK));
 	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_DEV_NAME, rd->link_name);
 	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_LINK_TYPE, rd->link_type);
 	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_NDEV_NAME, link_netdev);
 	return rd_sendrecv_msg(rd, seq);
 }

 static int link_add_type(struct rd *rd)
 {
 	const struct rd_cmd cmds[] = {
 		{ NULL,		link_help},
 		{ "netdev",	link_add_netdev},
 		{ 0 }
 	};

 	if (rd_no_arg(rd)) {
 		pr_err("Please provide a link type name.\n");
 		return -EINVAL;
 	}
 	rd->link_type = rd_argv(rd);
 	rd_arg_inc(rd);
 	return rd_exec_cmd(rd, cmds, "parameter");
 }

 static int link_add(struct rd *rd)
 {
 	const struct rd_cmd cmds[] = {
 		{ NULL,		link_help},
 		{ "type",	link_add_type},
 		{ 0 }
 	};

 	if (rd_no_arg(rd)) {
 		pr_err("Please provide a link name to add.\n");
 		return -EINVAL;
 	}
 	rd->link_name = rd_argv(rd);
 	rd_arg_inc(rd);

 	return rd_exec_cmd(rd, cmds, "parameter");
 }

 static int _link_del(struct rd *rd)
 {
 	uint32_t seq;

 	if (!rd_no_arg(rd)) {
 		pr_err("Unknown parameter %s\n", rd_argv(rd));
 		return -EINVAL;
 	}
 	rd_prepare_msg(rd, RDMA_NLDEV_CMD_DELLINK, &seq,
 		       (NLM_F_REQUEST | NLM_F_ACK));
 	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_DEV_INDEX, rd->dev_idx);
 	return rd_sendrecv_msg(rd, seq);
 }

 static int link_del(struct rd *rd)
 {
 	return rd_exec_require_dev(rd, _link_del);
 }

 int cmd_link(struct rd *rd)
 {
 	const struct rd_cmd cmds[] = {
 		{ NULL,		link_show },
 		{ "add",	link_add },
 		{ "delete",	link_del },
 		{ "show",	link_show },
 		{ "list",	link_show },
 		{ "help",	link_help },
 		{ 0 }
 	};

 	return rd_exec_cmd(rd, cmds, "link command");
 }
	// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
	/*
	* link.c RDMA tool
	* Authors: Leon Romanovsky <leonro@mellanox.com>
	*/

	#include "rdma.h"

	static int link_help(struct rd *rd)
	{
	pr_out("Usage: %s link show [DEV/PORT_INDEX]\n", rd->filename);
	pr_out("Usage: %s link add NAME type TYPE netdev NETDEV\n",
	rd->filename);
	pr_out("Usage: %s link delete NAME\n", rd->filename);
	return 0;
	}

	static const char *caps_to_str(uint32_t idx)
	{
	#define RDMA_PORT_FLAGS_LOW(x) \
	x(RESERVED, 0) \
	x(SM, 1) \
	x(NOTICE, 2) \
	x(TRAP, 3) \
	x(OPT_IPD, 4) \
	x(AUTO_MIGR, 5) \
	x(SL_MAP, 6) \
	x(MKEY_NVRAM, 7) \
	x(PKEY_NVRAM, 8) \
	x(LED_INFO, 9) \
	x(SM_DISABLED, 10) \
	x(SYS_IMAGE_GUID, 11) \
	x(PKEY_SW_EXT_PORT_TRAP, 12) \
	x(CABLE_INFO, 13) \
	x(EXTENDED_SPEEDS, 14) \
	x(CAP_MASK2, 15) \
	x(CM, 16) \
	x(SNMP_TUNNEL, 17) \
	x(REINIT, 18) \
	x(DEVICE_MGMT, 19) \
	x(VENDOR_CLASS, 20) \
	x(DR_NOTICE, 21) \
	x(CAP_MASK_NOTICE, 22) \
	x(BOOT_MGMT, 23) \
	x(LINK_LATENCY, 24) \
	x(CLIENT_REG, 25) \
	x(OTHER_LOCAL_CHANGES, 26) \
	x(LINK_SPPED_WIDTH, 27) \
	x(VENDOR_SPECIFIC_MADS, 28) \
	x(MULT_PKER_TRAP, 29) \
	x(MULT_FDB, 30) \
	x(HIERARCHY_INFO, 31)

	#define RDMA_PORT_FLAGS_HIGH(x) \
	x(SET_NODE_DESC, 0) \
	x(EXT_INFO, 1) \
	x(VIRT, 2) \
	x(SWITCH_POR_STATE_TABLE, 3) \
	x(LINK_WIDTH_2X, 4) \
	x(LINK_SPEED_HDR, 5)

	/*
	* Separation below is needed to allow compilation of rdmatool
	* on 32bits systems. On such systems, C-enum is limited to be
	* int and can't hold more than 32 bits.
	*/
	enum { RDMA_PORT_FLAGS_LOW(RDMA_BITMAP_ENUM) };
	enum { RDMA_PORT_FLAGS_HIGH(RDMA_BITMAP_ENUM) };

	static const char * const
	rdma_port_names_low[] = { RDMA_PORT_FLAGS_LOW(RDMA_BITMAP_NAMES) };
	static const char * const
	rdma_port_names_high[] = { RDMA_PORT_FLAGS_HIGH(RDMA_BITMAP_NAMES) };
	uint32_t high_idx;
	#undef RDMA_PORT_FLAGS_LOW
	#undef RDMA_PORT_FLAGS_HIGH

	if (idx < ARRAY_SIZE(rdma_port_names_low) && rdma_port_names_low[idx])
	return rdma_port_names_low[idx];

	high_idx = idx - ARRAY_SIZE(rdma_port_names_low);
	if (high_idx < ARRAY_SIZE(rdma_port_names_high) &&
	rdma_port_names_high[high_idx])
	return rdma_port_names_high[high_idx];

	return "UNKNOWN";
	}

	static void link_print_caps(struct rd rd, struct nlattr *tb)
	{
	uint64_t caps;
	uint32_t idx;

	if (!tb[RDMA_NLDEV_ATTR_CAP_FLAGS])
	return;

	caps = mnl_attr_get_u64(tb[RDMA_NLDEV_ATTR_CAP_FLAGS]);

	if (rd->json_output) {
	jsonw_name(rd->jw, "caps");
	jsonw_start_array(rd->jw);
	} else {
	pr_out("\n caps: <");
	}
	for (idx = 0; caps; idx++) {
	if (caps & 0x1) {
	if (rd->json_output) {
	jsonw_string(rd->jw, caps_to_str(idx));
	} else {
	pr_out("%s", caps_to_str(idx));
	if (caps >> 0x1)
	pr_out(", ");
	}
	}
	caps >>= 0x1;
	}

	if (rd->json_output)
	jsonw_end_array(rd->jw);
	else
	pr_out(">");
	}

	static void link_print_subnet_prefix(struct rd rd, struct nlattr *tb)
	{
	uint64_t subnet_prefix;
	uint16_t vp[4];
	char str[32];

	if (!tb[RDMA_NLDEV_ATTR_SUBNET_PREFIX])
	return;

	subnet_prefix = mnl_attr_get_u64(tb[RDMA_NLDEV_ATTR_SUBNET_PREFIX]);
	memcpy(vp, &subnet_prefix, sizeof(uint64_t));
	snprintf(str, 32, "%04x:%04x:%04x:%04x", vp[3], vp[2], vp[1], vp[0]);
	if (rd->json_output)
	jsonw_string_field(rd->jw, "subnet_prefix", str);
	else
	pr_out("subnet_prefix %s ", str);
	}

	static void link_print_lid(struct rd rd, struct nlattr *tb)
	{
	uint32_t lid;

	if (!tb[RDMA_NLDEV_ATTR_LID])
	return;

	lid = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_LID]);
	if (rd->json_output)
	jsonw_uint_field(rd->jw, "lid", lid);
	else
	pr_out("lid %u ", lid);
	}

	static void link_print_sm_lid(struct rd rd, struct nlattr *tb)
	{
	uint32_t sm_lid;

	if (!tb[RDMA_NLDEV_ATTR_SM_LID])
	return;

	sm_lid = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_SM_LID]);
	if (rd->json_output)
	jsonw_uint_field(rd->jw, "sm_lid", sm_lid);
	else
	pr_out("sm_lid %u ", sm_lid);
	}

	static void link_print_lmc(struct rd rd, struct nlattr *tb)
	{
	uint8_t lmc;

	if (!tb[RDMA_NLDEV_ATTR_LMC])
	return;

	lmc = mnl_attr_get_u8(tb[RDMA_NLDEV_ATTR_LMC]);
	if (rd->json_output)
	jsonw_uint_field(rd->jw, "lmc", lmc);
	else
	pr_out("lmc %u ", lmc);
	}

	static const char *link_state_to_str(uint8_t link_state)
	{
	static const char * const link_state_str[] = { "NOP", "DOWN",
	"INIT", "ARMED",
	"ACTIVE",
	"ACTIVE_DEFER" };
	if (link_state < ARRAY_SIZE(link_state_str))
	return link_state_str[link_state];
	return "UNKNOWN";
	}

	static void link_print_state(struct rd rd, struct nlattr *tb)
	{
	uint8_t state;

	if (!tb[RDMA_NLDEV_ATTR_PORT_STATE])
	return;

	state = mnl_attr_get_u8(tb[RDMA_NLDEV_ATTR_PORT_STATE]);
	if (rd->json_output)
	jsonw_string_field(rd->jw, "state", link_state_to_str(state));
	else
	pr_out("state %s ", link_state_to_str(state));
	}

	static const char *phys_state_to_str(uint8_t phys_state)
	{
	static const char * const phys_state_str[] = { "NOP", "SLEEP",
	"POLLING", "DISABLED",
	"ARMED", "LINK_UP",
	"LINK_ERROR_RECOVER",
	"PHY_TEST", "UNKNOWN",
	"OPA_OFFLINE",
	"UNKNOWN", "OPA_TEST" };
	if (phys_state < ARRAY_SIZE(phys_state_str))
	return phys_state_str[phys_state];
	return "UNKNOWN";
	};

	static void link_print_phys_state(struct rd rd, struct nlattr *tb)
	{
	uint8_t phys_state;

	if (!tb[RDMA_NLDEV_ATTR_PORT_PHYS_STATE])
	return;

	phys_state = mnl_attr_get_u8(tb[RDMA_NLDEV_ATTR_PORT_PHYS_STATE]);
	if (rd->json_output)
	jsonw_string_field(rd->jw, "physical_state",
	phys_state_to_str(phys_state));
	else
	pr_out("physical_state %s ", phys_state_to_str(phys_state));
	}

	static void link_print_netdev(struct rd rd, struct nlattr *tb)
	{
	const char *netdev_name;
	uint32_t idx;

	if (!tb[RDMA_NLDEV_ATTR_NDEV_NAME] \|\| !tb[RDMA_NLDEV_ATTR_NDEV_INDEX])
	return;

	netdev_name = mnl_attr_get_str(tb[RDMA_NLDEV_ATTR_NDEV_NAME]);
	idx = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_NDEV_INDEX]);
	if (rd->json_output) {
	jsonw_string_field(rd->jw, "netdev", netdev_name);
	jsonw_uint_field(rd->jw, "netdev_index", idx);
	} else {
	pr_out("netdev %s ", netdev_name);
	if (rd->show_details)
	pr_out("netdev_index %u ", idx);
	}
	}

	static int link_parse_cb(const struct nlmsghdr nlh, void data)
	{
	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX] = {};
	struct rd *rd = data;
	uint32_t port, idx;
	char name[32];

	mnl_attr_parse(nlh, 0, rd_attr_cb, tb);
	if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] \|\| !tb[RDMA_NLDEV_ATTR_DEV_NAME])
	return MNL_CB_ERROR;

	if (!tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {
	pr_err("This tool doesn't support switches yet\n");
	return MNL_CB_ERROR;
	}

	idx = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
	port = mnl_attr_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
	snprintf(name, 32, "%s/%u",
	mnl_attr_get_str(tb[RDMA_NLDEV_ATTR_DEV_NAME]), port);

	if (rd->json_output) {
	jsonw_uint_field(rd->jw, "ifindex", idx);
	jsonw_uint_field(rd->jw, "port", port);
	jsonw_string_field(rd->jw, "ifname", name);

	} else {
	pr_out("%u/%u: %s: ", idx, port, name);
	}

	link_print_subnet_prefix(rd, tb);
	link_print_lid(rd, tb);
	link_print_sm_lid(rd, tb);
	link_print_lmc(rd, tb);
	link_print_state(rd, tb);
	link_print_phys_state(rd, tb);
	link_print_netdev(rd, tb);
	if (rd->show_details)
	link_print_caps(rd, tb);

	if (!rd->json_output)
	pr_out("\n");
	return MNL_CB_OK;
	}

	static int link_no_args(struct rd *rd)
	{
	uint32_t seq;
	int ret;

	rd_prepare_msg(rd, RDMA_NLDEV_CMD_PORT_GET, &seq,
	(NLM_F_REQUEST \| NLM_F_ACK));
	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_DEV_INDEX, rd->dev_idx);
	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_PORT_INDEX, rd->port_idx);
	ret = rd_send_msg(rd);
	if (ret)
	return ret;

	if (rd->json_output)
	jsonw_start_object(rd->jw);
	ret = rd_recv_msg(rd, link_parse_cb, rd, seq);
	if (rd->json_output)
	jsonw_end_object(rd->jw);
	return ret;
	}

	static int link_one_show(struct rd *rd)
	{
	const struct rd_cmd cmds[] = {
	{ NULL, link_no_args},
	{ 0 }
	};

	if (!rd->port_idx)
	return 0;

	return rd_exec_cmd(rd, cmds, "parameter");
	}

	static int link_show(struct rd *rd)
	{
	return rd_exec_link(rd, link_one_show, true);
	}

	static int link_add_netdev(struct rd *rd)
	{
	char *link_netdev;
	uint32_t seq;

	if (rd_no_arg(rd)) {
	pr_err("Please provide a net device name.\n");
	return -EINVAL;
	}

	link_netdev = rd_argv(rd);
	rd_prepare_msg(rd, RDMA_NLDEV_CMD_NEWLINK, &seq,
	(NLM_F_REQUEST \| NLM_F_ACK));
	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_DEV_NAME, rd->link_name);
	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_LINK_TYPE, rd->link_type);
	mnl_attr_put_strz(rd->nlh, RDMA_NLDEV_ATTR_NDEV_NAME, link_netdev);
	return rd_sendrecv_msg(rd, seq);
	}

	static int link_add_type(struct rd *rd)
	{
	const struct rd_cmd cmds[] = {
	{ NULL, link_help},
	{ "netdev", link_add_netdev},
	{ 0 }
	};

	if (rd_no_arg(rd)) {
	pr_err("Please provide a link type name.\n");
	return -EINVAL;
	}
	rd->link_type = rd_argv(rd);
	rd_arg_inc(rd);
	return rd_exec_cmd(rd, cmds, "parameter");
	}

	static int link_add(struct rd *rd)
	{
	const struct rd_cmd cmds[] = {
	{ NULL, link_help},
	{ "type", link_add_type},
	{ 0 }
	};

	if (rd_no_arg(rd)) {
	pr_err("Please provide a link name to add.\n");
	return -EINVAL;
	}
	rd->link_name = rd_argv(rd);
	rd_arg_inc(rd);

	return rd_exec_cmd(rd, cmds, "parameter");
	}

	static int _link_del(struct rd *rd)
	{
	uint32_t seq;

	if (!rd_no_arg(rd)) {
	pr_err("Unknown parameter %s\n", rd_argv(rd));
	return -EINVAL;
	}
	rd_prepare_msg(rd, RDMA_NLDEV_CMD_DELLINK, &seq,
	(NLM_F_REQUEST \| NLM_F_ACK));
	mnl_attr_put_u32(rd->nlh, RDMA_NLDEV_ATTR_DEV_INDEX, rd->dev_idx);
	return rd_sendrecv_msg(rd, seq);
	}

	static int link_del(struct rd *rd)
	{
	return rd_exec_require_dev(rd, _link_del);
	}

	int cmd_link(struct rd *rd)
	{
	const struct rd_cmd cmds[] = {
	{ NULL, link_show },
	{ "add", link_add },
	{ "delete", link_del },
	{ "show", link_show },
	{ "list", link_show },
	{ "help", link_help },
	{ 0 }
	};

	return rd_exec_cmd(rd, cmds, "link command");
	}