af58b0c058
Replace howsmyssl.com with letsencrypt.org in the https_x509_bundle example. howsmyssl.com is a third-party server that is frequently unreachable from CI, causing flaky test failures. letsencrypt.org chains to the same ISRG Root X1 CA, so the custom certificate bundle validation coverage is identical. Since letsencrypt.org was already present in the full bundle URL list, remove the duplicate entry and reduce MAX_URLS from 9 to 8. All 6 unique root CAs in the stress test are still covered. For the QEMU stress test, increase per-connection timeout from 30s to 60s and final completion timeout from 60s to 180s. QEMU emulated network is 3-5x slower than real hardware for TLS handshakes. (cherry picked from commitd6596eff3a) (squashed with commit995c0f129e)
Protocols Examples
Implementation of internet communication protocols and services.
See the README.md file in the upper level examples directory for more information about examples.
Establishing Wi-Fi or Ethernet Connection
About the example_connect() Function
Protocols examples use a simple helper function, example_connect(), to establish Wi-Fi and/or Ethernet connection. This function is implemented in examples/common_components/protocol_examples_common/include/protocol_examples_common.h, and has a very simple behavior: block until connection is established and IP address is obtained, then return. This function is used to reduce the amount of boilerplate and to keep the example code focused on the protocol or library being demonstrated.
The simple example_connect() function does not handle timeouts, does not gracefully handle various error conditions, and is only suited for use in examples. When developing real applications, this helper function needs to be replaced with full Wi-Fi / Ethernet connection handling code. Such code can be found in examples/wifi/getting_started/ and examples/ethernet/basic/ examples.
Configuring the Example
To configure the example to use Wi-Fi, Ethernet or both connections, open the project configuration menu (idf.py menuconfig) and navigate to "Example Connection Configuration" menu. Select either "Wi-Fi" or "Ethernet" or both in the "Connect using" choice.
When connecting using Wi-Fi, enter SSID and password of your Wi-Fi access point into the corresponding fields. If connecting to an open Wi-Fi network, keep the password field empty.
When connecting using Ethernet, set up PHY type and configuration in the provided fields. If using Ethernet for the first time, it is recommended to start with the Ethernet example readme, which contains instructions for connecting and configuring the PHY. Once Ethernet example obtains IP address successfully, proceed to the protocols example and set the same configuration options.
Disabling IPv6
By default, example_connect() function waits until Wi-Fi or Ethernet connection is established, and IPv4 address and IPv6 link-local address are obtained. In network environments where IPv6 link-local address cannot be obtained, disable "Obtain IPv6 link-local address" option found in "Example Connection Configuration" menu.