Support option to resolve hostname as IPv6 with esp_tls_conn_new_xxxx() (IDFGH-8458)

[hideakitai]

Is your feature request related to a problem?

esp_tls_conn_new_xxxx() cannot resolve hostname as IPv6 now. Because esp_tls_hostname_to_fd() that is called inside of it calls getaddrinfo() with fixed option: hints.ai_family = AF_UNSPEC. getaddrinfo() with AF_UNSPEC try to resolve hostname as IPv4 even when IPv4 address is not acquired (e.g. even on IPv6 only network).

esp-idf/components/esp-tls/esp_tls.c

Lines 142 to 156 in 495d359

	static esp_err_t esp_tls_hostname_to_fd(const char *host, size_t hostlen, int port, struct sockaddr_storage *address, int* fd)
	{
	struct addrinfo *address_info;
	struct addrinfo hints;
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	char *use_host = strndup(host, hostlen);
	if (!use_host) {
	return ESP_ERR_NO_MEM;
	}
	ESP_LOGD(TAG, "host:%s: strlen %lu", use_host, (unsigned long)hostlen);
	int res = getaddrinfo(use_host, NULL, &hints, &address_info);

Describe the solution you'd like.

Could you support an option to esp_tls_conn_new_xxxx() to set how to resolve hostname (e.g. AF_UNSPEC, AF_INET, AF_INET6, etc.) ?

Describe alternatives you've considered.

No response

Additional context.

• IPv6 SLAAC is enabled
• DHCPv6 is disabled

CONFIG_LWIP_IPV6=y
CONFIG_LWIP_IPV6_AUTOCONFIG=y
CONFIG_LWIP_IPV6_RDNSS_MAX_DNS_SERVERS=16

[Harshal5]

Hello, @hideakitai!

Thank you for the issue report. Could you please provide the following info -

• Target chip or module (ESP32, ESP32-S2, ESP32-S3, etc.)
• ESP-IDF version (run git describe --tags) / commit ID
• Example to reproduce the issue (or a minimal code snippet)
• Debug logs
• build sdkconfig

[Alvin1Zhang]

Thanks for reporting, will close due to short of feedback, feel free to reopen with more updates. Thanks.