This adds the new `nanocoap_server_observe` module that implements the
server side of the CoAP Observe option. It does require cooperation
from the resource handler to work, though.
Co-Authored-By: mguetschow <mikolai.guetschow@tu-dresden.de>
Co-authored-by: benpicco <benpicco@googlemail.com>
This allows sending a separate response with CoAP Options and adds a
helper to detect duplicate requests, so that resource handlers can
repeat their empty ACK on duplicates.
When module `nanocoap_server_separate` is not used, the functions to
send separate responses are still provided, just in a broken version:
They will send the separate replies from a different endpoint than the
request was received at (even on machines with only one IP address, as
also the source port is randomized).
This changes the behavior to only provide the functions for separate
response when the do work, so that others will detect an invalid
configuration at compile time rather than at run time.
The documentation is duly updated.
When RFC 8974 support (module `nanocoap_token_ext`) is in use, the
request token may be longer than the buffer in the separate response
context is large. This adds a check to not overflow the buffer.
Sadly, this is an API change: Preparing the separate response context
can actually fail, so we need to report this with a return value.
The example application has been adapted to only proceed if the separate
reply context could have been prepared, and rather directly emit a
reset message if the token exceeds the static buffer.
Co-authored-by: benpicco <benpicco@googlemail.com>
Before, handlers writing blockwise transfer assumed that the response
header length will match the request header length. This is true for
UDP, but not for TCP: The CoAP over TCP header contains a Len field,
that gets extended for larger messages. Since the reply often is indeed
larger than the request, this is indeed often the case for CoAP over
TCP.
Note: Right now, no CoAP over TCP implementation is upstream. However,
getting rid of incorrect assumptions now will make life easier
later on.
18752: nanocoap_sock: deprecate nanocoap_get() r=benpicco a=benpicco
19100: cpu/esp_common: allow configuration of UART0 r=benpicco a=gschorcht
### Contribution description
This PR
- fixes the issue for ESP32 SoCs that UART0 signals can't be routed to arbitrary GPIOs and
- allows the configuration of the UART device used by the bootloader.
The UART interface and its configuration used by the STDIO are defined in RIOT using the define `STDIO_UART_DEV` and the configuration of the corresponding UART device in `periph_conf.h`.
However, the bootloader compiled directly in ESP-IDF uses its own definitions `CONFIG_ESP_CONSOLE_UART_*` for the UART configuration. To be able to use a consistent UART configuration in RIOT and the bootloader, e.g. to see the output of the 2nd stage bootloader, these `CONFIG_ESP_CONSOLE_UART_*` can be defined via a set of KConfig variables in RIOT (not yet implemented in Kconfig):
- `CONSOLE_CONFIG_UART_NUM` defines the UART device to be used by the bootloader and by `STDIO_UART_DEV`
- `CONSOLE_CONFIG_UART_RX` and `CONSOLE_CONFIG_UART_TX` define the GPIOs to be used by the bootloader and should be the GPIOs as defined in `periph_conf.h` for the corresponding UART device.
### Testing procedure
Any ESP32 node should still work with `stdio_uart` and the default configuration. To test an alternative configuration, use
```
CFLAGS='-DUART1_TXD=5 -DUART1_RXD=4 -DCONFIG_CONSOLE_UART_NUM=1 -DCONFIG_CONSOLE_UART_TX=5 -DCONFIG_CONSOLE_UART_RX=4' USEMODULE=esp_log_startup BOARD=esp32-wroom-32 make -C tests/shell flash
```
The bootloader output and the STDIO should be routed to UART1 at GPIO4 and GPIO5.
### Issues/PRs references
Prerequisite for PR ##18863
19104: tests/periph_uart: only exclude STDIO_UART_DEV if stdio_uart is used r=benpicco a=benpicco
Co-authored-by: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Co-authored-by: Gunar Schorcht <gunar@schorcht.net>
Co-authored-by: Benjamin Valentin <benjamin.valentin@bht-berlin.de>
This removes the need for a user provied work buffer from nanocoap.
Instead we let the user operate directly on network stack internal
memory and provide a callback mechanism to make sure the memory is
properly freed again.
