CA C API

CA API

Cirrent's CA API gives your device code the ability to:

Initialize the API
Check on the status and capabilities of the currently connected network
Retrieve a list of private networks configured for this device
Add or delete private networks from this device
Get the Wi-Fi scan list
Get device info
Set device location
Set user action (tell Cirrent cloud that user took an action on the device)
Upload product data to the Cirrent cloud
Reset the device status in the Cirrent cloud
Wake or sleep the CA
Start WPS
Make device discoverable (turn on SoftAP, tell Cirrent cloud to make discoverable)
Revert to last known good CA configuration
Get notified when there is a change in the connectivity status.
Get notified when the device should perform its identifying action (e.g. play a sound, turn on a light)
Get notified when the device should perform some product-specific action

Note that the CA must be running for the API methods to be executed.

The API provides programmatic interfaces to do this directly from your code with the following commands:

Init

Command: cac_init

Description: When the API is no longer needed, this method should be called to disable all notifications and free the API internals.

Inputs: Initializes the API. Must be called before any other API calls are made.

stack-size: the size of the stack. The function takes a stack size as an argument and creates a worker thread with the given stack size. The status/action callbacks will be called from the worker thread context.

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Cleanup

Command: cac_cleanup

Description:When the API is no longer needed, this method should be called to disable all notifications and free the API internals.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Get Network Status

Command: cac_get_network_status

Description: Retrieves the current network status and the network capabilities. Your device code should use this information to determine which services can be started on the device. For example, with a 20kbps bandwidth limitation you will not want to start video streaming.

Inputs: none

Outputs:

Connection Status: Connected, Disconnected, Ready-for-onboarding, onboarding-disabled, Failed-to-join-private-network
Network Type: Specifies whether the network is a ZipKey network or a private network
Network Security: the security type of the network (none, WPA, WPA2-Enterprise, WISPr)
Domains: what domains are reachable by the device on this network (none, any, or a semicolon-delimited list of domains)
Priority: The priority that was assigned to this network
Bandwidth: bandwidth limit for this network, or 0 if unlimited If the device is connected to a private network it also passes back
SSID: the SSID of the connected network as printable ASCII string
HEX_SSID: SSID as hexdump string
BSSID: the BSSID of the router the devices is connected to
Roaming Id: If a Hotspot 2.0 network, the hotspot 2.0 roaming consortium id of the connected network
Credential Id: The credential id that was used to define this network

Returns: returns 0 on success, a non-zero error code on failure

Note that when the device is in “ready for onboarding state”, then connection_status is READY_FOR_ONBOARDING at each call. A user can obtain connection information from other CAC_NETWORK_STATUS_T fields for information about what type of network (if any) the CA is on.

Get Private Networks

Command: cac_get_private_networks

Description: Retrieves a null-terminated list of user-configured networks for this device.

Inputs: none

Outputs: List of user networks, each of which contains

Source: where the user network was configured. This can be either "Cirrent" if the network was configured via the Cirrent cloud, or "Device" if the credentials were passed to the CA with the cac_add_private_network function, or "SoftAP" if the credentials were passed through the SoftAP process
SSID: the SSID of the network
HEX_SSID: SSID as hexdump string
Roaming Id: The hotspot 2.0 roaming consortium id of the connected network (if a Hotspot 2.0 network)
Security: The security type of the network (none, WPA, WPA2-Enterprise, WISPr)
Priority: The priority that was assigned to this network
Credential Id: The credential id that was used to define this network
Status: status of the network (unused, joining, joined, failed, not_found, disconnected, confirmed)
Disconnect reason: reason of last disconnection (disconnect_request, connection_lost, not_found, assiciation error, incorrect_password, dhcp_timeout, internet_not_reachable, rsa_decryption_error)

Returns: returns 0 on success, a non-zero error code on failure

cac_free_private_networks should be called to free the list of networks that was returned by cac_get_private_networks.

Add Private Network

Command: cac_add_private_network

Description: Adds a private network for this device.

Inputs:

SSID: the SSID of the network to add.
Roaming Id: the Hotspot 2.0 roaming consortium id (if a Hotspot 2.0 network)
Security: the type of security for this network (none, WPA, WPA2-Enterprise, WISPr)
Hidden: Whether the SSID is hidden or broadcast
Pre-Shared Key: If a WPA network, the pre-shared key to use to authenticate
Username: If a WPA2-Enterprise or WISPr network, the username to use to authenticate
Password: If a WPA2-Enterprise or WISPr network, the password to use to authenticate
Priority: The priority to assign to this network. Priorities are in the range of 0-255, with ZipKey networks in the range of 1-150, and private networks in the range of 150-250. Higher priority networks will be chosen before lower priority networks.
Certificate validation: If the CA should validate the server certificate for this network, this is the expected server certificate.
Credential id: A unique id for this credential (a string, used for report status).

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Delete Private Network

Command: cac_delete_private_network

Description: Deletes a private network for this device by matching the SSID or HEX_SSID or Roaming Consortium Id.

Inputs:

SSID: the SSID of the network to delete
HEX_SSID: SSID as hexdump string
Roaming Id: For Hotspot 2.0 network, the Hotspot 2.0 roaming consortium id for the network to delete

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Set Location

Command: cac_set_location

Description: Sets the location (GPS coordinates) for this device.

Inputs:

Latitude: the current device latitude
Longitude: the current device longitude
Accuracy: the accuracy of the measurement in meters.

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Get WiFi Scan

Command: cac_get_wifi_scan

Description: Retrieves the most recent Wi-Fi scan. Typically the CA takes care of the WiFi connection so the device should not need visibility to the Wi-Fi scan. This is in case the device supports some alternative local onboarding (e.g. via BLE) and needs access to the Wi-Fi scan list.

Inputs: none

Outputs: A list of networks, each of which contains -

SSID: the SSID of the network
HEX_SSID: SSID as hexdump string
BSSID: the BSSID of the network
Roaming Id: If a Hotspot 2.0 network, the hotspot 2.0 roaming consortium id of the network
Security: the type of security for the network (none, WPA, WPA2-Enterprise, WISPr)
Flags: The flags, as returned by the wpa_supplicant - e.g. [WPA2-PSK-CCMP][ESS]
Signal level: The signal level for this network
Frequency: The frequency in MHz (e.g. 2412 = channel 1)

Returns: returns 0 on success, a non-zero error code on failure

cac_free_wifi_scan should be called to free the network list that was returned by cac_get_wifi_scan.

Get Device Info

Command: cac_get_device_info

Description: Retrieves identifying info about this device, in case it is needed for some alternative on boarding process.

Inputs: none

Outputs:

Device id: The unique identifier for this device
DUB key: The Product User Binding key (an additional key to differentiate the device)
SCD key: Public key used to encrypt private network credentials

Returns: returns 0 on success, a non-zero error code on failure

Set User Action

Command: cac_set_user_action

Description: Tells the CA that the user has taken some action on the device. This can be used as an extra precaution during the on boarding process to confirm that the user is on boarding the correct device. The CA will send a status update to the Cirrent cloud so that the app knows that the user took an action.

Inputs:

Action name: the name of the action the user took (in case there is more than one possible user action).

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Revert CA

Command: cac_revert

Description: Revert the CA configuration to the last known good configuration.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Reset Device

Command: cac_reset_device

Description: Clears the device settings and history from the Cirrent cloud.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Upload Data

Command: cac_upload_data

Description: Upload data to Cirrent's cloud

Inputs:

key: an identifier for this data
*value: the data to upload

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Wake CA

Command: cac_wake

Description: Triggers the CA to start normal operation (looking for networks, checking for private wi-fi credentials, updating network configuration, uploading log files etc.)

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Sleep CA

Command: cac_sleep

Description: Triggers the CA to stop actively managing the connection, or interacting with the Cirrent cloud. This can be done to conserve power, as the CA moves into a dormant mode, where it only responds to a command from the API to start.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Start WPS

Command: cac_start_wps

Description: Triggers the CA to start WPS (Wi-Fi Protected Setup) protocol between the device and the router.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Make Device Discoverable

Command: cac_make_discoverable

Description: Triggers the CA to bring up the SoftAP so that the user has the option to locally configure the private network credentials. When the device is first powered up, and has no private networks, the CA will take care of starting/stopping SoftAP. This call is for the case where the user wants to re-provision their device, and has pressed a button to put the device back into on-boarding mode. If the CA is connected to the Cirrent cloud, it will also tell the cloud to make the device discoverable (no longer consider it bound to a user account).

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Getting notified on connection status changes

Command: cac_register_network_status_handler

Description: For both Linux and Embedded implementations, Cirrent also provides a way to register a callback function so your code receives a notification when the network connection status changes. This makes it unnecessary to run a timer and periodically check the network status. In many devices, this will replace any hooks you have to wpa_supplicant, dhclient, or the underlying radio drivers. You register a callback via the function cac_register_network_status_handler. Your cac_network_status_handler will be called whenever the network status changes. Your application can then call cac_get_network_status to get detailed information about the connection.

Your callback will be called once with READY_FOR_ONBOARDING connection_status when the device enters “ready for onboarding” state. When the device exits “ready for onboarding” status, then it calls the callback with ONBOARDING_DISABLED connection_status.

Your callback will get called with CONNECTED when the device joins a network. You can then call cac_get_network_status to determine if it was a ZipKey or a private network. Your callback will get called with DISCONNECTED when the device falls off a network. Your callback will get called with FAILED_TO_JOIN_PRIVATE_NETWORK connection_status whenever the device fails its attempt to join a private network.

Inputs: handler to be called when network status changes

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Getting notified on action changes

Command: cac_register_action_handler

Description:Some products will have an option for the user to get some confirmation that the right device is being onboarded (e.g. a light flashes or a sound plays). To implement this, you register a callback function so your code receives a notification that the action is to be performed. You register a callback via the function cac_register_action_handler. Your cac_action_handler will be called whenever the app requests that the identifying action occur.

Inputs: handler to be called when network status changes

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Enable notifications

Command: cac_enable_notifications

Description: Enable all notifications (network status updates, action handlers) from ca_agent.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Disable notifications

Command: cac_disable_notifications

Description: Disable all notifications (network status updates, action handlers) from ca_agent.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

Get version of CA

Command: cac_get_ca_version

Description: Get the version of the CA.

Inputs: none

Outputs: none

Returns: returns 0 on success, a non-zero error code on failure

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