subsys/net/lib/shell/dns.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /*
  * Copyright (c) 2016 Intel Corporation
  * Copyright (c) 2023 Nordic Semiconductor ASA
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #include <stdio.h>
 #include <strings.h>

 #include <zephyr/logging/log.h>
 LOG_MODULE_DECLARE(net_shell);

 #include <zephyr/net/socket.h>
 #include <zephyr/net/dns_resolve.h>
 #include <zephyr/net/dns_sd.h>
 #include "dns/dns_sd.h"

 #include "net_shell_private.h"

 #if defined(CONFIG_DNS_RESOLVER)
 static void dns_result_cb(enum dns_resolve_status status,
 			  struct dns_addrinfo *info,
 			  void *user_data)
 {
 	const struct shell *sh = user_data;

 	if (status == DNS_EAI_CANCELED) {
 		PR_WARNING("dns: Timeout while resolving name.\n");
 		return;
 	}

 	if (status == DNS_EAI_INPROGRESS && info) {
 #define MAX_STR_LEN CONFIG_DNS_RESOLVER_MAX_NAME_LEN
 		char str[MAX_STR_LEN + 1];

 		switch (info->ai_family) {
 		case AF_INET:
 			net_addr_ntop(AF_INET,
 				      &net_sin(&info->ai_addr)->sin_addr,
 				      str, sizeof(str));
 			break;

 		case AF_INET6:
 			net_addr_ntop(AF_INET6,
 				      &net_sin6(&info->ai_addr)->sin6_addr,
 				      str, sizeof(str));
 			break;

 		case AF_LOCAL:
 			/* service discovery */
 			memset(str, 0, MAX_STR_LEN);
 			memcpy(str, info->ai_canonname,
 			       MIN(info->ai_addrlen, MAX_STR_LEN));
 			break;

 		case AF_UNSPEC:
 			if (info->ai_extension == DNS_RESOLVE_TXT) {
 				memset(str, 0, MAX_STR_LEN);
 				memcpy(str, info->ai_txt.text,
 				       MIN(info->ai_txt.textlen, MAX_STR_LEN));
 				break;
 			} else if (info->ai_extension == DNS_RESOLVE_SRV) {
 				snprintf(str, sizeof(str), "%d %d %d %.*s",
 					 info->ai_srv.priority,
 					 info->ai_srv.weight,
 					 info->ai_srv.port,
 					 (int)info->ai_srv.targetlen,
 					 info->ai_srv.target);
 				break;
 			}

 			/* fallthru */
 		default:
 			strncpy(str, "Invalid proto family", MAX_STR_LEN + 1);
 			break;
 		}

 		str[MAX_STR_LEN] = '\0';

 		PR("dns: %s\n", str);
 		return;
 	}

 	if (status == DNS_EAI_ALLDONE) {
 		PR("dns: All results received\n");
 		return;
 	}

 	if (status == DNS_EAI_FAIL) {
 		PR_WARNING("dns: No such name found.\n");
 		return;
 	}

 	PR_WARNING("dns: Unhandled status %d received (errno %d)\n", status, errno);
 }

 static const char *printable_iface(const char *iface_name,
 				   const char *found,
 				   const char *not_found)
 {
 	if (iface_name[0] != '\0') {
 		return found;
 	}

 	return not_found;
 }

 static void print_dns_info(const struct shell *sh,
 			   struct dns_resolve_context *ctx)
 {
 	int i, ret;

 	PR("DNS servers:\n");

 	for (i = 0; i < CONFIG_DNS_RESOLVER_MAX_SERVERS +
 		     DNS_MAX_MCAST_SERVERS; i++) {
 		char iface_name[IFNAMSIZ] = { 0 };

 		if (ctx->servers[i].if_index > 0) {
 			ret = net_if_get_name(
 				net_if_get_by_index(ctx->servers[i].if_index),
 				iface_name, sizeof(iface_name));
 			if (ret < 0) {
 				snprintk(iface_name, sizeof(iface_name), "%d",
 					 ctx->servers[i].if_index);
 			}
 		}

 		if (ctx->servers[i].dns_server.sa_family == AF_INET) {
 			PR("\t%s:%u%s%s%s%s%s\n",
 			   net_sprint_ipv4_addr(
 				   &net_sin(&ctx->servers[i].dns_server)->
 				   sin_addr),
 			   ntohs(net_sin(&ctx->servers[i].dns_server)->sin_port),
 			   printable_iface(iface_name, " via ", ""),
 			   printable_iface(iface_name, iface_name, ""),
 			   ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? " (" : "",
 			   ctx->servers[i].source != DNS_SOURCE_UNKNOWN ?
 					dns_get_source_str(ctx->servers[i].source) : "",
 			   ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? ")" : "");

 		} else if (ctx->servers[i].dns_server.sa_family == AF_INET6) {
 			PR("\t[%s]:%u%s%s%s%s%s\n",
 			   net_sprint_ipv6_addr(
 				   &net_sin6(&ctx->servers[i].dns_server)->
 				   sin6_addr),
 			   ntohs(net_sin6(&ctx->servers[i].dns_server)->sin6_port),
 			   printable_iface(iface_name, " via ", ""),
 			   printable_iface(iface_name, iface_name, ""),
 			   ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? " (" : "",
 			   ctx->servers[i].source != DNS_SOURCE_UNKNOWN ?
 					dns_get_source_str(ctx->servers[i].source) : "",
 			   ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? ")" : "");
 		}
 	}

 	PR("Pending queries:\n");

 	for (i = 0; i < CONFIG_DNS_NUM_CONCUR_QUERIES; i++) {
 		int32_t remaining;

 		if (!ctx->queries[i].cb || !ctx->queries[i].query) {
 			continue;
 		}

 		remaining = k_ticks_to_ms_ceil32(
 			k_work_delayable_remaining_get(&ctx->queries[i].timer));

 		if (ctx->queries[i].query_type == DNS_QUERY_TYPE_A) {
 			PR("\t%s[%u]: %s remaining %d\n", "IPv4",
 			   ctx->queries[i].id,
 			   ctx->queries[i].query,
 			   remaining);
 		} else if (ctx->queries[i].query_type == DNS_QUERY_TYPE_AAAA) {
 			PR("\t%s[%u]: %s remaining %d\n", "IPv6",
 			   ctx->queries[i].id,
 			   ctx->queries[i].query,
 			   remaining);
 		} else if (ctx->queries[i].query_type == DNS_QUERY_TYPE_PTR) {
 			PR("\t%s[%u]: %s remaining %d\n", "PTR",
 			   ctx->queries[i].id,
 			   ctx->queries[i].query,
 			   remaining);
 		} else {
 			PR_WARNING("\tUnknown query type %d for query %s[%u] "
 				   "remaining %d\n",
 				   ctx->queries[i].query_type,
 				   ctx->queries[i].query, ctx->queries[i].id,
 				   remaining);
 		}
 	}
 }
 #endif

 static int cmd_net_dns_cancel(const struct shell *sh, size_t argc, char *argv[])
 {
 #if defined(CONFIG_DNS_RESOLVER)
 	struct dns_resolve_context *ctx;
 	int ret, i;
 #endif

 	ARG_UNUSED(argc);
 	ARG_UNUSED(argv);

 #if defined(CONFIG_DNS_RESOLVER)
 	ctx = dns_resolve_get_default();
 	if (!ctx) {
 		PR_WARNING("No default DNS context found.\n");
 		return -ENOEXEC;
 	}

 	for (ret = 0, i = 0; i < CONFIG_DNS_NUM_CONCUR_QUERIES; i++) {
 		if (!ctx->queries[i].cb) {
 			continue;
 		}

 		if (!dns_resolve_cancel(ctx, ctx->queries[i].id)) {
 			ret++;
 		}
 	}

 	if (ret) {
 		PR("Cancelled %d pending requests.\n", ret);
 	} else {
 		PR("No pending DNS requests.\n");
 	}
 #else
 	PR_INFO("Set %s to enable %s support.\n", "CONFIG_DNS_RESOLVER",
 		"DNS resolver");
 #endif

 	return 0;
 }

 static int cmd_net_dns_query(const struct shell *sh, size_t argc, char *argv[])
 {

 #if defined(CONFIG_DNS_RESOLVER)
 #define DNS_TIMEOUT (MSEC_PER_SEC * 2) /* ms */
 	struct dns_resolve_context *ctx;
 	enum dns_query_type qtype = DNS_QUERY_TYPE_A;
 	char *host, *type = NULL;
 	int ret, arg = 1;

 	host = argv[arg++];
 	if (!host) {
 		PR_WARNING("Hostname not specified.\n");
 		return -ENOEXEC;
 	}

 	if (argv[arg]) {
 		type = argv[arg];
 	}

 	if (type) {
 		if (strcasecmp(type, "A") == 0) {
 			qtype = DNS_QUERY_TYPE_A;
 			PR("IPv4 address query type\n");
 		} else if (strcasecmp(type, "CNAME") == 0) {
 			qtype = DNS_QUERY_TYPE_CNAME;
 			PR("CNAME query type\n");
 		} else if (strcasecmp(type, "PTR") == 0) {
 			qtype = DNS_QUERY_TYPE_PTR;
 			PR("Pointer query type\n");
 		} else if (strcasecmp(type, "TXT") == 0) {
 			qtype = DNS_QUERY_TYPE_TXT;
 			PR("Text query type\n");
 		} else if (strcasecmp(type, "AAAA") == 0) {
 			qtype = DNS_QUERY_TYPE_AAAA;
 			PR("IPv6 address query type\n");
 		} else if (strcasecmp(type, "SRV") == 0) {
 			qtype = DNS_QUERY_TYPE_SRV;
 			PR("Service query type\n");
 		} else {
 			PR_WARNING("Unknown query type, specify either "
 				   "A, CNAME, PTR, TXT, AAAA, or SRV\n");
 			return -ENOEXEC;
 		}
 	}

 	ctx = dns_resolve_get_default();
 	if (!ctx) {
 		PR_WARNING("No default DNS context found.\n");
 		return -ENOEXEC;
 	}

 	ret = dns_resolve_name(ctx, host, qtype, NULL, dns_result_cb,
 				(void *)sh, DNS_TIMEOUT);
 	if (ret < 0) {
 		PR_WARNING("Cannot resolve '%s' (%d)\n", host, ret);
 	} else {
 		PR("Query for '%s' sent.\n", host);
 	}
 #else
 	PR_INFO("DNS resolver not supported. Set CONFIG_DNS_RESOLVER to "
 		"enable it.\n");
 #endif

 	return 0;
 }

 static int cmd_net_dns(const struct shell *sh, size_t argc, char *argv[])
 {
 #if defined(CONFIG_DNS_RESOLVER)
 	struct dns_resolve_context *ctx;
 #endif

 #if defined(CONFIG_DNS_RESOLVER)
 	if (argv[1]) {
 		/* So this is a query then */
 		cmd_net_dns_query(sh, argc, argv);
 		return 0;
 	}

 	/* DNS status */
 	ctx = dns_resolve_get_default();
 	if (!ctx) {
 		PR_WARNING("No default DNS context found.\n");
 		return -ENOEXEC;
 	}

 	print_dns_info(sh, ctx);
 #else
 	PR_INFO("DNS resolver not supported. Set CONFIG_DNS_RESOLVER to "
 		"enable it.\n");
 #endif

 	return 0;
 }

 static int cmd_net_dns_list(const struct shell *sh, size_t argc, char *argv[])
 {
 #if defined(CONFIG_DNS_SD)
 #define MAX_PORT_LEN 6
 	char buf[MAX_PORT_LEN];
 	int n_records = 0;

 	DNS_SD_FOREACH(record) {
 		if (!dns_sd_rec_is_valid(record)) {
 			continue;
 		}

 		if (n_records == 0) {
 			PR("     DNS service records\n");
 		}

 		++n_records;

 		if (record->port != NULL) {
 			snprintk(buf, sizeof(buf), "%u", ntohs(*record->port));
 		}

 		PR("[%2d] %s.%s%s%s%s%s%s%s\n",
 		   n_records,
 		   record->instance != NULL ? record->instance : "",
 		   record->service != NULL ? record->service : "",
 		   record->proto != NULL ? "." : "",
 		   record->proto != NULL ? record->proto : "",
 		   record->domain != NULL ? "." : "",
 		   record->domain != NULL ? record->domain : "",
 		   record->port != NULL ? ":" : "",
 		   record->port != NULL ? buf : "");
 	}

 	if (n_records == 0) {
 		PR("No DNS service records found.\n");
 		return 0;
 	}
 #else
 	PR_INFO("DNS service discovery not supported. Set CONFIG_DNS_SD to "
 		"enable it.\n");
 #endif

 	return 0;
 }

 static int cmd_net_dns_service(const struct shell *sh, size_t argc, char *argv[])
 {
 #if defined(CONFIG_DNS_RESOLVER)
 #define DNS_TIMEOUT (MSEC_PER_SEC * 2) /* ms */
 	struct dns_resolve_context *ctx;
 	char *service;
 	uint16_t dns_id;
 	int ret, arg = 1;

 	service = argv[arg++];
 	if (service == NULL) {
 		PR_WARNING("Service not specified.\n");
 		return -ENOEXEC;
 	}

 	ctx = dns_resolve_get_default();
 	if (ctx == NULL) {
 		PR_WARNING("No default DNS context found.\n");
 		return -ENOEXEC;
 	}

 	ret = dns_resolve_service(ctx, service, &dns_id, dns_result_cb,
 				(void *)sh, DNS_TIMEOUT);
 	if (ret < 0) {
 		PR_WARNING("Cannot resolve '%s' (%d)\n", service, ret);
 	} else {
 		PR("Query for '%s' sent.\n", service);
 	}
 #else
 	PR_INFO("DNS resolver not supported. Set CONFIG_DNS_RESOLVER to "
 		"enable it.\n");
 #endif

 	return 0;
 }

 SHELL_STATIC_SUBCMD_SET_CREATE(net_cmd_dns,
 	SHELL_CMD(cancel, NULL, "Cancel all pending requests.",
 		  cmd_net_dns_cancel),
 	SHELL_CMD(query, NULL,
 		  "'net dns <hostname> [A or AAAA]' queries IPv4 address "
 		  "(default) or IPv6 address for a host name.",
 		  cmd_net_dns_query),
 	SHELL_CMD(list, NULL,
 		  "List local DNS service records.",
 		  cmd_net_dns_list),
 	SHELL_CMD(service, NULL,
 		  "'net dns service <service-description>\n"
 		  "Execute DNS service discovery query.",
 		  cmd_net_dns_service),
 	SHELL_SUBCMD_SET_END
 );

 SHELL_SUBCMD_ADD((net), dns, &net_cmd_dns,
 		 "Show how DNS is configured. Optionally do a query using a given name.",
 		 cmd_net_dns, 1, 2);
	/*
	* Copyright (c) 2016 Intel Corporation
	* Copyright (c) 2023 Nordic Semiconductor ASA
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#include <stdio.h>
	#include <strings.h>

	#include <zephyr/logging/log.h>
	LOG_MODULE_DECLARE(net_shell);

	#include <zephyr/net/socket.h>
	#include <zephyr/net/dns_resolve.h>
	#include <zephyr/net/dns_sd.h>
	#include "dns/dns_sd.h"

	#include "net_shell_private.h"

	#if defined(CONFIG_DNS_RESOLVER)
	static void dns_result_cb(enum dns_resolve_status status,
	struct dns_addrinfo *info,
	void *user_data)
	{
	const struct shell *sh = user_data;

	if (status == DNS_EAI_CANCELED) {
	PR_WARNING("dns: Timeout while resolving name.\n");
	return;
	}

	if (status == DNS_EAI_INPROGRESS && info) {
	#define MAX_STR_LEN CONFIG_DNS_RESOLVER_MAX_NAME_LEN
	char str[MAX_STR_LEN + 1];

	switch (info->ai_family) {
	case AF_INET:
	net_addr_ntop(AF_INET,
	&net_sin(&info->ai_addr)->sin_addr,
	str, sizeof(str));
	break;

	case AF_INET6:
	net_addr_ntop(AF_INET6,
	&net_sin6(&info->ai_addr)->sin6_addr,
	str, sizeof(str));
	break;

	case AF_LOCAL:
	/* service discovery */
	memset(str, 0, MAX_STR_LEN);
	memcpy(str, info->ai_canonname,
	MIN(info->ai_addrlen, MAX_STR_LEN));
	break;

	case AF_UNSPEC:
	if (info->ai_extension == DNS_RESOLVE_TXT) {
	memset(str, 0, MAX_STR_LEN);
	memcpy(str, info->ai_txt.text,
	MIN(info->ai_txt.textlen, MAX_STR_LEN));
	break;
	} else if (info->ai_extension == DNS_RESOLVE_SRV) {
	snprintf(str, sizeof(str), "%d %d %d %.*s",
	info->ai_srv.priority,
	info->ai_srv.weight,
	info->ai_srv.port,
	(int)info->ai_srv.targetlen,
	info->ai_srv.target);
	break;
	}

	/* fallthru */
	default:
	strncpy(str, "Invalid proto family", MAX_STR_LEN + 1);
	break;
	}

	str[MAX_STR_LEN] = '\0';

	PR("dns: %s\n", str);
	return;
	}

	if (status == DNS_EAI_ALLDONE) {
	PR("dns: All results received\n");
	return;
	}

	if (status == DNS_EAI_FAIL) {
	PR_WARNING("dns: No such name found.\n");
	return;
	}

	PR_WARNING("dns: Unhandled status %d received (errno %d)\n", status, errno);
	}

	static const char printable_iface(const char iface_name,
	const char *found,
	const char *not_found)
	{
	if (iface_name[0] != '\0') {
	return found;
	}

	return not_found;
	}

	static void print_dns_info(const struct shell *sh,
	struct dns_resolve_context *ctx)
	{
	int i, ret;

	PR("DNS servers:\n");

	for (i = 0; i < CONFIG_DNS_RESOLVER_MAX_SERVERS +
	DNS_MAX_MCAST_SERVERS; i++) {
	char iface_name[IFNAMSIZ] = { 0 };

	if (ctx->servers[i].if_index > 0) {
	ret = net_if_get_name(
	net_if_get_by_index(ctx->servers[i].if_index),
	iface_name, sizeof(iface_name));
	if (ret < 0) {
	snprintk(iface_name, sizeof(iface_name), "%d",
	ctx->servers[i].if_index);
	}
	}

	if (ctx->servers[i].dns_server.sa_family == AF_INET) {
	PR("\t%s:%u%s%s%s%s%s\n",
	net_sprint_ipv4_addr(
	&net_sin(&ctx->servers[i].dns_server)->
	sin_addr),
	ntohs(net_sin(&ctx->servers[i].dns_server)->sin_port),
	printable_iface(iface_name, " via ", ""),
	printable_iface(iface_name, iface_name, ""),
	ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? " (" : "",
	ctx->servers[i].source != DNS_SOURCE_UNKNOWN ?
	dns_get_source_str(ctx->servers[i].source) : "",
	ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? ")" : "");

	} else if (ctx->servers[i].dns_server.sa_family == AF_INET6) {
	PR("\t[%s]:%u%s%s%s%s%s\n",
	net_sprint_ipv6_addr(
	&net_sin6(&ctx->servers[i].dns_server)->
	sin6_addr),
	ntohs(net_sin6(&ctx->servers[i].dns_server)->sin6_port),
	printable_iface(iface_name, " via ", ""),
	printable_iface(iface_name, iface_name, ""),
	ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? " (" : "",
	ctx->servers[i].source != DNS_SOURCE_UNKNOWN ?
	dns_get_source_str(ctx->servers[i].source) : "",
	ctx->servers[i].source != DNS_SOURCE_UNKNOWN ? ")" : "");
	}
	}

	PR("Pending queries:\n");

	for (i = 0; i < CONFIG_DNS_NUM_CONCUR_QUERIES; i++) {
	int32_t remaining;

	if (!ctx->queries[i].cb \|\| !ctx->queries[i].query) {
	continue;
	}

	remaining = k_ticks_to_ms_ceil32(
	k_work_delayable_remaining_get(&ctx->queries[i].timer));

	if (ctx->queries[i].query_type == DNS_QUERY_TYPE_A) {
	PR("\t%s[%u]: %s remaining %d\n", "IPv4",
	ctx->queries[i].id,
	ctx->queries[i].query,
	remaining);
	} else if (ctx->queries[i].query_type == DNS_QUERY_TYPE_AAAA) {
	PR("\t%s[%u]: %s remaining %d\n", "IPv6",
	ctx->queries[i].id,
	ctx->queries[i].query,
	remaining);
	} else if (ctx->queries[i].query_type == DNS_QUERY_TYPE_PTR) {
	PR("\t%s[%u]: %s remaining %d\n", "PTR",
	ctx->queries[i].id,
	ctx->queries[i].query,
	remaining);
	} else {
	PR_WARNING("\tUnknown query type %d for query %s[%u] "
	"remaining %d\n",
	ctx->queries[i].query_type,
	ctx->queries[i].query, ctx->queries[i].id,
	remaining);
	}
	}
	}
	#endif

	static int cmd_net_dns_cancel(const struct shell sh, size_t argc, char argv[])
	{
	#if defined(CONFIG_DNS_RESOLVER)
	struct dns_resolve_context *ctx;
	int ret, i;
	#endif

	ARG_UNUSED(argc);
	ARG_UNUSED(argv);

	#if defined(CONFIG_DNS_RESOLVER)
	ctx = dns_resolve_get_default();
	if (!ctx) {
	PR_WARNING("No default DNS context found.\n");
	return -ENOEXEC;
	}

	for (ret = 0, i = 0; i < CONFIG_DNS_NUM_CONCUR_QUERIES; i++) {
	if (!ctx->queries[i].cb) {
	continue;
	}

	if (!dns_resolve_cancel(ctx, ctx->queries[i].id)) {
	ret++;
	}
	}

	if (ret) {
	PR("Cancelled %d pending requests.\n", ret);
	} else {
	PR("No pending DNS requests.\n");
	}
	#else
	PR_INFO("Set %s to enable %s support.\n", "CONFIG_DNS_RESOLVER",
	"DNS resolver");
	#endif

	return 0;
	}

	static int cmd_net_dns_query(const struct shell sh, size_t argc, char argv[])
	{

	#if defined(CONFIG_DNS_RESOLVER)
	#define DNS_TIMEOUT (MSEC_PER_SEC * 2) /* ms */
	struct dns_resolve_context *ctx;
	enum dns_query_type qtype = DNS_QUERY_TYPE_A;
	char host, type = NULL;
	int ret, arg = 1;

	host = argv[arg++];
	if (!host) {
	PR_WARNING("Hostname not specified.\n");
	return -ENOEXEC;
	}

	if (argv[arg]) {
	type = argv[arg];
	}

	if (type) {
	if (strcasecmp(type, "A") == 0) {
	qtype = DNS_QUERY_TYPE_A;
	PR("IPv4 address query type\n");
	} else if (strcasecmp(type, "CNAME") == 0) {
	qtype = DNS_QUERY_TYPE_CNAME;
	PR("CNAME query type\n");
	} else if (strcasecmp(type, "PTR") == 0) {
	qtype = DNS_QUERY_TYPE_PTR;
	PR("Pointer query type\n");
	} else if (strcasecmp(type, "TXT") == 0) {
	qtype = DNS_QUERY_TYPE_TXT;
	PR("Text query type\n");
	} else if (strcasecmp(type, "AAAA") == 0) {
	qtype = DNS_QUERY_TYPE_AAAA;
	PR("IPv6 address query type\n");
	} else if (strcasecmp(type, "SRV") == 0) {
	qtype = DNS_QUERY_TYPE_SRV;
	PR("Service query type\n");
	} else {
	PR_WARNING("Unknown query type, specify either "
	"A, CNAME, PTR, TXT, AAAA, or SRV\n");
	return -ENOEXEC;
	}
	}

	ctx = dns_resolve_get_default();
	if (!ctx) {
	PR_WARNING("No default DNS context found.\n");
	return -ENOEXEC;
	}

	ret = dns_resolve_name(ctx, host, qtype, NULL, dns_result_cb,
	(void *)sh, DNS_TIMEOUT);
	if (ret < 0) {
	PR_WARNING("Cannot resolve '%s' (%d)\n", host, ret);
	} else {
	PR("Query for '%s' sent.\n", host);
	}
	#else
	PR_INFO("DNS resolver not supported. Set CONFIG_DNS_RESOLVER to "
	"enable it.\n");
	#endif

	return 0;
	}

	static int cmd_net_dns(const struct shell sh, size_t argc, char argv[])
	{
	#if defined(CONFIG_DNS_RESOLVER)
	struct dns_resolve_context *ctx;
	#endif

	#if defined(CONFIG_DNS_RESOLVER)
	if (argv[1]) {
	/* So this is a query then */
	cmd_net_dns_query(sh, argc, argv);
	return 0;
	}

	/* DNS status */
	ctx = dns_resolve_get_default();
	if (!ctx) {
	PR_WARNING("No default DNS context found.\n");
	return -ENOEXEC;
	}

	print_dns_info(sh, ctx);
	#else
	PR_INFO("DNS resolver not supported. Set CONFIG_DNS_RESOLVER to "
	"enable it.\n");
	#endif

	return 0;
	}

	static int cmd_net_dns_list(const struct shell sh, size_t argc, char argv[])
	{
	#if defined(CONFIG_DNS_SD)
	#define MAX_PORT_LEN 6
	char buf[MAX_PORT_LEN];
	int n_records = 0;

	DNS_SD_FOREACH(record) {
	if (!dns_sd_rec_is_valid(record)) {
	continue;
	}

	if (n_records == 0) {
	PR(" DNS service records\n");
	}

	++n_records;

	if (record->port != NULL) {
	snprintk(buf, sizeof(buf), "%u", ntohs(*record->port));
	}

	PR("[%2d] %s.%s%s%s%s%s%s%s\n",
	n_records,
	record->instance != NULL ? record->instance : "",
	record->service != NULL ? record->service : "",
	record->proto != NULL ? "." : "",
	record->proto != NULL ? record->proto : "",
	record->domain != NULL ? "." : "",
	record->domain != NULL ? record->domain : "",
	record->port != NULL ? ":" : "",
	record->port != NULL ? buf : "");
	}

	if (n_records == 0) {
	PR("No DNS service records found.\n");
	return 0;
	}
	#else
	PR_INFO("DNS service discovery not supported. Set CONFIG_DNS_SD to "
	"enable it.\n");
	#endif

	return 0;
	}

	static int cmd_net_dns_service(const struct shell sh, size_t argc, char argv[])
	{
	#if defined(CONFIG_DNS_RESOLVER)
	#define DNS_TIMEOUT (MSEC_PER_SEC * 2) /* ms */
	struct dns_resolve_context *ctx;
	char *service;
	uint16_t dns_id;
	int ret, arg = 1;

	service = argv[arg++];
	if (service == NULL) {
	PR_WARNING("Service not specified.\n");
	return -ENOEXEC;
	}

	ctx = dns_resolve_get_default();
	if (ctx == NULL) {
	PR_WARNING("No default DNS context found.\n");
	return -ENOEXEC;
	}

	ret = dns_resolve_service(ctx, service, &dns_id, dns_result_cb,
	(void *)sh, DNS_TIMEOUT);
	if (ret < 0) {
	PR_WARNING("Cannot resolve '%s' (%d)\n", service, ret);
	} else {
	PR("Query for '%s' sent.\n", service);
	}
	#else
	PR_INFO("DNS resolver not supported. Set CONFIG_DNS_RESOLVER to "
	"enable it.\n");
	#endif

	return 0;
	}

	SHELL_STATIC_SUBCMD_SET_CREATE(net_cmd_dns,
	SHELL_CMD(cancel, NULL, "Cancel all pending requests.",
	cmd_net_dns_cancel),
	SHELL_CMD(query, NULL,
	"'net dns <hostname> [A or AAAA]' queries IPv4 address "
	"(default) or IPv6 address for a host name.",
	cmd_net_dns_query),
	SHELL_CMD(list, NULL,
	"List local DNS service records.",
	cmd_net_dns_list),
	SHELL_CMD(service, NULL,
	"'net dns service <service-description>\n"
	"Execute DNS service discovery query.",
	cmd_net_dns_service),
	SHELL_SUBCMD_SET_END
	);

	SHELL_SUBCMD_ADD((net), dns, &net_cmd_dns,
	"Show how DNS is configured. Optionally do a query using a given name.",
	cmd_net_dns, 1, 2);