Commit 0f71a130 authored by Stig Bjørlykke's avatar Stig Bjørlykke Committed by Carles Cufi
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net: sockets: getaddrinfo: Minor refactoring 



Minor refactoring in getaddrinfo() to make the code easier to
read and to make handling IPv4 and IPv6 support more equal.

- Move common wait and error handling code to exec_query()
- Use the same check for CONFIG_NET_IPV4 and CONFIG_NET_IPV6
- Add extra sanity check for family before exec_query()
- Do not set errno when return DNS_EAI_ADDRFAMILY

Fix issue with setting port number for all DNS servers.

Signed-off-by: default avatarStig Bjørlykke <stig.bjorlykke@nordicsemi.no>
parent d92aaba3

subsys/net/lib/sockets/getaddrinfo.c

+48 −56
Original line number Diff line number Diff line
@@ -107,14 +107,41 @@ static int exec_query(const char *host, int family, 
		      struct getaddrinfo_state *ai_state)

{

	enum dns_query_type qtype = DNS_QUERY_TYPE_A;

	int st, ret;



	if (IS_ENABLED(CONFIG_NET_IPV6) && family == AF_INET6) {

	if (family == AF_INET6) {

		qtype = DNS_QUERY_TYPE_AAAA;

	}



	return dns_get_addr_info(host, qtype, &ai_state->dns_id,

	ret = dns_get_addr_info(host, qtype, &ai_state->dns_id,

				dns_resolve_cb, ai_state,

				CONFIG_NET_SOCKETS_DNS_TIMEOUT);

	if (ret == 0) {

		/* If the DNS query for reason fails so that the

		 * dns_resolve_cb() would not be called, then we want the

		 * semaphore to timeout so that we will not hang forever.

		 * So make the sem timeout longer than the DNS timeout so that

		 * we do not need to start to cancel any pending DNS queries.

		 */

		ret = k_sem_take(&ai_state->sem, K_MSEC(CONFIG_NET_SOCKETS_DNS_TIMEOUT + 100));

		if (ret == -EAGAIN) {

			(void)dns_cancel_addr_info(ai_state->dns_id);

			st = DNS_EAI_AGAIN;

		} else {

			st = ai_state->status;

		}

	} else if (ret == -EPFNOSUPPORT) {

		/* If we are returned -EPFNOSUPPORT then that will indicate

		 * wrong address family type queried. Check that and return

		 * DNS_EAI_ADDRFAMILY.

		 */

		st = DNS_EAI_ADDRFAMILY;

	} else {

		errno = -ret;

		st = DNS_EAI_SYSTEM;

	}



	return st;

}



static int getaddrinfo_null_host(int port, const struct zsock_addrinfo *hints,
@@ -162,12 +189,15 @@ int z_impl_z_zsock_getaddrinfo_internal(const char *host, const char *service, 
	long int port = 0;

	int st1 = DNS_EAI_ADDRFAMILY, st2 = DNS_EAI_ADDRFAMILY;

	struct sockaddr *ai_addr;

	int ret;

	struct getaddrinfo_state ai_state;



	if (hints) {

		family = hints->ai_family;

		ai_flags = hints->ai_flags;



		if ((family != AF_UNSPEC) && (family != AF_INET) && (family != AF_INET6)) {

			return DNS_EAI_ADDRFAMILY;

		}

	}



	if (ai_flags & AI_NUMERICHOST) {
@@ -201,66 +231,28 @@ int z_impl_z_zsock_getaddrinfo_internal(const char *host, const char *service, 
	ai_state.dns_id = 0;

	k_sem_init(&ai_state.sem, 0, K_SEM_MAX_LIMIT);



	/* In case IPv4 is not supported, force to check only for IPv6 */

	if (family == AF_UNSPEC && !IS_ENABLED(CONFIG_NET_IPV4)) {

		family = AF_INET6;

	}



	/* If the family is AF_UNSPEC, then we query IPv4 address first */

	ret = exec_query(host, family, &ai_state);

	if (ret == 0) {

		/* If the DNS query for reason fails so that the

		 * dns_resolve_cb() would not be called, then we want the

		 * semaphore to timeout so that we will not hang forever.

		 * So make the sem timeout longer than the DNS timeout so that

		 * we do not need to start to cancel any pending DNS queries.

		 */

		int ret = k_sem_take(&ai_state.sem,

				     K_MSEC(CONFIG_NET_SOCKETS_DNS_TIMEOUT +

					    100));

		if (ret == -EAGAIN) {

			(void)dns_cancel_addr_info(ai_state.dns_id);

			return DNS_EAI_AGAIN;

		}



		st1 = ai_state.status;

	} else {

		/* If we are returned -EPFNOSUPPORT then that will indicate

		 * wrong address family type queried. Check that and return

		 * DNS_EAI_ADDRFAMILY and set errno to EINVAL.

	/* If family is AF_UNSPEC, then we query IPv4 address first

	 * if IPv4 is enabled in the config.

	 */

		if (ret == -EPFNOSUPPORT) {

			errno = EINVAL;

			st1 = DNS_EAI_ADDRFAMILY;

		} else {

			errno = -ret;

			st1 = DNS_EAI_SYSTEM;

	if ((family != AF_INET6) && IS_ENABLED(CONFIG_NET_IPV4)) {

		st1 = exec_query(host, AF_INET, &ai_state);

		if (st1 == DNS_EAI_AGAIN) {

			return st1;

		}

	}



	/* If family is AF_UNSPEC, the IPv4 query has been already done

	 * so we can do IPv6 query next if IPv6 is enabled in the config.

	 */

	if (family == AF_UNSPEC && IS_ENABLED(CONFIG_NET_IPV6)) {

		ret = exec_query(host, AF_INET6, &ai_state);

		if (ret == 0) {

			int ret = k_sem_take(

				&ai_state.sem,

				K_MSEC(CONFIG_NET_SOCKETS_DNS_TIMEOUT + 100));

			if (ret == -EAGAIN) {

				(void)dns_cancel_addr_info(ai_state.dns_id);

				return DNS_EAI_AGAIN;

			}



			st2 = ai_state.status;

		} else {

			errno = -ret;

			st2 = DNS_EAI_SYSTEM;

	if ((family != AF_INET) && IS_ENABLED(CONFIG_NET_IPV6)) {

		st2 = exec_query(host, AF_INET6, &ai_state);

		if (st2 == DNS_EAI_AGAIN) {

			return st2;

		}

	}



	if (ai_state.idx > 0) {

		ai_addr = &ai_state.ai_arr[ai_state.idx - 1]._ai_addr;

	for (uint16_t idx = 0; idx < ai_state.idx; idx++) {

		ai_addr = &ai_state.ai_arr[idx]._ai_addr;

		net_sin(ai_addr)->sin_port = htons(port);

	}

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