So far received packets were parsed (at AT command level) and allocated
in [esp_rx] thread. Then they were submitted to [esp_workq] thread for
processing (calling application callback).
This flow results in following deadlock when esp_workq thread waits on
response to some AT command:
- [esp_rx] waits on allocation of new RX packet
- [esp_workq] waits for [esp_rx] to process response to AT command
that was just sent
- blocked [esp_workq] prevents processing and deallocating RX packets
- [esp_rx] times out on allocation and closes socket
Process RX packets directly from [esp_rx] thread to prevent above
deadlock.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
ESP fetches DNS servers from local network by using DHCP. There is an AT
command to get those DNS addresses. Use that to provide DNS addresses
for Zephyr's DNS resolver.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
net_context contains both net_sock_type and net_ip_protocol, which are
static during the lifetime of net_context. net_context has basically the
ownership of esp_socket, so we can be sure 'type' and 'ip_proto' are
always accessible through net_context API.
Remove 'type' and 'ip_proto' members from 'esp_socket' structure, as
those are already accessible by net_context API.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Change type of esp_socket->flags from uint8_t to atomic_t, so that read
and write access to those flags is done in atomic (thread-safe) manner.
Introduce esp_socket_ref() and esp_socket_unref() functions, which
operate on atomic refcount variable. esp_socket_ref() role is to
increase refcount if it was already non-zero. If it was zero then NULL
is returned, which means that socket is not used by net_context at the
moment.
Role of refcount:
* socket instance is assured to be between net_offload->get() and
net_offload->put() when refcount > 0,
* makes sure that socket instance can be used (its members can be
dereferenced) when refcount > 0,
* 'context' member is always valid and its members can be dereferenced
when refcount > 0.
esp_socket_get() gets unused socket, as previously. Additionally it sets
refcount to 1 at the end of call, which basically means that from that
point such socket can be referenced by other parts of the driver. Each
esp_socket_get() call should be followed by esp_socket_unref() and
esp_socket_put() to properly invalidate socket and prevent other parts
of driver from using it.
Add ESP_SOCK_WORKQ_STOPPED flag, which is now used to prevent scheduling
more work into driver workqueue. This flag is set in net_offload->put()
callback, so that no more socket work (such as processing RX/TX packets
or closing socket because of errors) is submitted after that.
Introduce mutex lock, which has following role:
* protects dst, connect_cb + conn_user_data, recv_cb + recv_user_data,
* assures that checking ESP_SOCK_WORKQ_STOPPED flag and actually
submitting (or not if net_offload->put was already called) new socket
work to workqueue is done in atomic way.
As there is a mechanism to prevent submitting new work items to
workqueue when net_offload->put() has been executed, then there is no
need to explicitly call esp_socket_ref() in esp_workq thread. This is
because one reference is being held by net_context (after calling
net_context->get()). This is why all the esp_socket_in_use() were simply
dropped. Code running from esp_rx thread on the other hand always uses
esp_socket_ref_from_link_id() helper function (which is backed by
esp_socket_ref()), so that it replaces previous esp_socket_in_use()
calls and additionally makes sure that socket stays valid ("in use")
until esp_socket_unref() is called.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
So far a dedicated FIFO was used for all RX packets, which was consumed
in single submitted work. This work was also responsible for closing
socket and notifying uppper network layers if some errors occurred
previously or socket was simply closed by peer. There is however a
potential race condition in scenario described below:
esp_rx thread | esp_workq thread
--------------------------|-----------------------------
| ---- esp_recv_work ----
| handle RX packets from FIFO
|
---- on_cmd_ipd ---- |
put new RX packet to FIFO |
---- on_cmd_ipd ---- |
|
---- on_cmd_closed ---- |
mark socket as closed |
---- on_cmd_closed ---- |
|
| handle close
| ---- esp_recv_work ----
In this case we assume that esp_workq was preempted just after
processing all RX packets from FIFO and before checking if socket was
closed. In such scenario RX packet put to FIFO just before doing close
is going to be unhandled, so application layer will miss part of the
data.
Change the way RX packets are scheduled to workqueue, by using the
already available net_pkt->work objects (used for example in native TCP
stack). Create a separate work for closing connection. As a result all
RX packets and close handlers are on the same queue and there is no risk
of handling close events before handling all previously received data.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
There might be some scheduled work related to socket currently requested
to be destroyed/closed. Schedule a dummy work to make sure all
previously running work items in workqueue are finished.
When talking about TX packets, this makes sure that all previously
scheduled data is actually sent (flushed) before closing socket.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
It is enough to initialize work structures once during driver init,
because work handlers do not change during driver lifetime.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Currently there are two code paths when sending packets:
asynchronous (using workqueue) when zero timeout was specified and
synchronous in other cases. This doesn't seem to be justified, so
convert code to always schedule packet sending using workqueue.
Each net_pkt has an embedded work item, so use it instead of esp socket
specific work that was shared across all sent packets. This gives a
possibility to schedule multiple packets for sending.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Callback and user data are saved in net_context structure. Those members
are used by native networking stack (net_if), so simply follow the same
pattern.
First of all this allows to reduce runtime information for driver socket
instance. Second and most important benefit is that it allows to move
send handling entirely to workqueue thread.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
ESP chip send number of available RX data using
+IPD=<sock>,<avail_bytes> command. This exact number (truncated to MRU)
was used to read data with AT+CIPRECVDATA=<sock>,<num_of_bytes>.
Use always MRU when sending AT+CIPRECVDATA=<sock>,<mru> request. When
there are less bytes available, then +CIPRECVDATA will just return less
bytes, which is fine for the driver.
There are two advantages to this new behavior:
* there is no need to follow how many bytes were notified by +IPD
message, thus reducing implementation size,
* when data is constantly received by ESP chip, then the last number of
bytes notified by +IPD is no longer up-to-date when sending a
AT+CIPRECVDATA; always requesting MRU number of bytes allows to
always receive maximum currently available number of bytes buffered
by ESP chip.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Deduplicate final part of RX data processing for two supported cases:
passive (+CIPRECVDATA) and non-passive (+IPD). Move implementation to
esp_socket module, as this is strictly related to socket.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
So far ESP chip was configured directly into STA mode. This works fine,
but consumes lots of power because of enabled WiFi radio, even when it
is not actively used.
Enter NONE mode during initialization, so WiFi radio will be
disabled. Switch between NONE, STA, AP and STA+AP modes depending on
what driver is currently doing (e.g. enable STA only when scanning,
connecting and being connected to AP).
AT+CWAUTOCONN=0 command fails when in NONE mode, so workaround that by
entering temporarily into STA and then switching back to NONE.
Add also a warning log when switching mode was not successful, to ease
debugging possible issues.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
AT+CWMODE command controls in which mode (NONE, STA, AP, STA+AP) ESP
chip is operating. Add helper macros to replace usage of magic
numbers (0-3), hence improve readability. Add also a esp_mode_switch()
helper function, which allows to conveniently switch to chosen mode.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Change internal API operating on ESP driver flags to support multiple
bitwise ORed flags at once. This allows to improve resulting code when
multiple flags are read or modified at once.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
All except one invocations of modem_cmd_send() pass the same interface,
command handler and semaphore. Create a helper function in order to make
invocations slightly more readable.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
- Add ESP DHCP Support
- Add ESP Static IP Support including
KConfig entries for configuring IP,Gateway and netMask
Signed-off-by: Mohamed ElShahawi <ExtremeGTX@hotmail.com>
There is no reason to keep active stream socket when there was some data
loss. Mark such socket for closing and close it when all (so far)
received packets have been processed.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
All net_bufs allocated to modem_cmd_handler's data->rx_buf are consumed
synchronously in esp.c in the same thread. This means that allocating
them with timeout makes no sense, because timeout will *always* be hit
when there are no more buffers in net_buf_pool.
Get rid of the unnecessary timeout, as it doesn't help and just slows
down processing of incoming data, increasing possibility of data
overrun.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
So far a dedicated buffer was used for data read from modem
interface. New net_bufs were allocated and filled later, which means
that data was lost when no more net_bufs were available in the pool.
Prevent data loss by allocating net_buf before attempting any read on
modem interface. Process incoming data in a loop as long as reading from
interface results in new data. Also remove dedicated buffer
(data->read_buf) and directly fill net_buf content instead. As a side
effect there are less memory copy operations and RAM usage is reduced.
Pre-allocated net_buf is now always appended to data->rx_buf. When there
was no (more) data read from interface to such net_buf, then this empty
net_buf will be on the end of data->rx_buf fragment list. Update
skipcrlf() and findcrlf() implementations to explicitly check for each
net_buf length, instead of blindly assuming them to have at least single
byte.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
This API allows to drop use of preallocated isr_buf. Most importantly as
a result RAM usage is reduced for each driver utilizing modem_context
framework. Additionally there is less copying done in ISR context, as
data is direcly read from UART FIFO to ring_buf.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Allow to reconfigure UART baudrate on ESP and on host MCU, so a
non-default baudrate can be used for communication. This option helps
for example to increase network bandwidth without touching ESP chip
firmware.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Add Kconfig options to configure modem command handler buffer size and
count. This will allow to fine tune those based on UART baudrate, system
load and available memory.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Add new Kconfig option to configure modem UART interface handler ring
buffer size. This will allow to lower ring buffer to save some resources
or increase it in case high network bandwidth is utilized (with high
UART baudrate).
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
- Fix passive mode protocol selection depending on AT versions
- Use Kconfig value for reset timeout
- Fix bug with parsing security from scan result
- Re-order some AT commands during init due to some commands having
dependency on other commands
Signed-off-by: Tobias Svehagen <tobias.svehagen@gmail.com>
With the introduction of the new device-tree macros it is now possible
to use the settings for speed and flow-control from the bus node instead
of having the same properties on the esp node itself.
Signed-off-by: Tobias Svehagen <tobias.svehagen@gmail.com>
This adds support for the Espressif ESP8266 and ESP32 devices to be used
as peripherals on a UART.
There are two main AT command versions that can be selected, 1.7 and
2.0. Since they behave a bit different it is important to select the
one that matches the used in the firmware on your device.
When downloading large amounts of data it is highly recommended to
enable CONFIG_ESP_PASSIVE_TCP and flow control on the UART so that
data is not lost due to UART speed or receive buffer size.
Currently unsupported:
- Changing UDP endpoint with a sendto()
- Bind to a specific local port
- Server socket operations, ie listen() and accept()
Official AT firmware for ESP8266 and ESP32 can be found at:
https://github.com/espressif/esp-at
Signed-off-by: Tobias Svehagen <tobias.svehagen@gmail.com>
