In recent versions Arylic has fixed several vulnerabilities and I have not found a way to "hack" into the CLI anymore. Telnet acces was still possible with version 4.2.8020 from 2020/02/20 (20th of Feb 2020) that was installed when I had bought the first devices.
The following information is specific for Arylic Up2Stream Amp v2 and Up2Stream Pro v3, but might also helpful for other devices, especially if they are also based on the Linkplay A31 module.
With Wireshark I have sniffed how the upgrade process is working and which files are required. At first the device gets a list of all (or at least many) Linkplay products
The XML file contains a list of products with their ID and more, including an URL for specific information. The example contains the two devices listed above (list was retrieved in Oct 2020):
> In previous versions the **_product.xml_** was also retrieved from silenceota.linkplay.com/wifi_audio_image and stored in the same directory as the images below.
The URLs include a "random" ID that might be mapped to the product ID and a subdirectory with the version (date) for some files. The MCU files follow a different structure with the product ID used as a subdirectory and a version number that is included in the name of the image.
I'm not sure if the **<sign>** tag is used. I've modified the URLs (different FQDN and path) and got no error. Only the following files are downloaded during an upgrade (verified with Up2Stream Amp v2.0):
| URL | Description |
| --------------- | ------------- |
| http://silenceota.linkplay.com/wifi_audio_image/products.xml | List of all Linkplay products in XML format with infos and URL |
| http://ota.rakoit.com/release/RP0011_WB60/product.xml | Infos and URLs for images for a specific Linkplay product |
| http://silenceota.linkplay.com/wifi_audio_image/2ANRu7eyAEYtoo4NZPy9dL/20201026/MVver_20201026 | Version information |
| http://silenceota.linkplay.com/wifi_audio_image/2ANRu7eyAEYtoo4NZPy9dL/20201026/layout | Layout of file system in flash |
| http://silenceota.linkplay.com/wifi_audio_image/2ANRu7eyAEYtoo4NZPy9dL/20201026/a31rakoit_new_uImage_20201026 | main image |
The other images, e.g. uBoot loader (was already installed), user and user2 images were not downloaded.
> **Note:**
> If an upgrade is available, it may be installed automatically without any notice! In the 4Stream app you might see that a new version is highlighted with "new" and you might get a popup with a notification. I have not found out, when an update is installed automatically.
To be able to downgrade the firmware you need to modify DNS names, e.g. you may install dnsmasq on your local network and point to that DNS server from your DHCP server. To redirect the firmware up-/downgrade process to your own webserver, you can create a simple file in the /etc/dnsmasq.d directory with the following content (10.1.1.22 is the IP address of my webserver located on my MacMini)
You may modify the configuration file on your webserver to use different folders for different FQDNs. Be sure to verify any URLs from a web browser or curl. On your PC you may manually point to a public DNS server to be able to download XML files and images from the Internet.
> **Note:**
> The modification of the two FQDNs will prevent any further updates!
Here it is documented from v4.2.8826 to v4.2.8026. To get information about the product ID (project), the current version and release date you can use the "getStatusEx" command. The following output is "enhanced" / beautified with the tool "jq" (JSON processor):
At first you have to download the following XML files, install them in the appropriate directory on your webserver (you may keep the path and create the directories as required).
> **Important:**
> There is no link to older version available. The **_products.xml_** file only contains URLs for the latest version, so you need to know (or guess) the URL for the specific **_product.xml_** file. The following URL is working for the Up2Stream Amp v2 and partially also for the Up2Stream Pro v3 (without MCU). I've added the URL for the **_products.xml_** file to the Wayback archive (https://web.archive.org) on Dec 31th 2023, so it does not work for older versions.
The **_products.xml_** file that has been archived on 20231231 can be retrieved here:
At first you can download the actual **_products.xml_** file, remove everything except your products, adjust the URLs (optionally) and install it on your web server:
Next you download the specific **_product.xml_** file. The following URL is for the RP0011_WB60_S product ID, but except for the MCU all images look to be the same as for product ID RP0011_WB60, UP2STREAM_PRO_V3, and others. I'm not sure, but all devices with the Linkplay A31 module might use the same firmware. You may download and compare the RP0011_WB60_S product below with your device (including MD5 checksums) and replace MCU part show below with the one from your device. It looks that older versions of the **_product.xml_** files and images are still available for download - you just need to know (or guess) the URLs.
> **Important:**
> I do not take responsibilities for results or consequences. You might damage your device! Do not try to downgrade your device if you are unsure!
The following URL is for product ID RP0011_WB60_S:
Modify the <major-version> in the **_product.xml_** file to be one day ahead of your current release date, e.g. 20201027 if your current release date is 20201026. You may also combine the content with a different MCU (project). Be sure that the project name is exactly matching your device!
Download and install all files from the list above on your web server.
Modifiy the version number in the **_MVver_** file (first line) to be higher than your current version number, e.g. WiiMu.4.2.8027 if your current version is 4.2.8826.
Modify the release date in the **_MVver_** file (6th line) with the same date used in the previous step.
Here is an example of the modified **_MVver_** file:
```
WiiMu.4.2.8827
WiiMu
WiiMu-A31
a31rakoit
release
20201027
customuuid=FF31F09E
```
Modify the version (ver, 4th column) in the **_layout_** file (4th line) with the same date used in the previous step (here 8827):
Trigger an update with the following commands and verify the progress with Wireshark running on your web server. You may use "http" as a filter to see the downgrade process:
In newer versions it does not work to modifiy your DNS server to add a spoofed (local) IP address like 10.1.1.22 for silenceota.linkplay.com anymore. I'm not sure if that's due to the fact that this is a local IP address or spoofing is not allowed for silenceota.linkplay.com anymore. The following procedure has been tested with v4.6.415145, release date 2022/04/27.
To be able to downgrade the firmware and prevent an automatic upgrade afterwards you need to modify DNS names, e.g. you may install dnsmasq on your local network and point to that DNS server from your DHCP server. To redirect the firmware up-/downgrade process to your own webserver, you can create a simple file in the /etc/dnsmasq.d directory with the following content (10.1.1.22 is the IP address of my webserver located on my MacMini)
I've used the FQDN **_ota.tatooine.org_** (that I do not have registered) to be independent of a specific IP address. The downgrade has been tested with plain IP addresses as well (in all config files and SetUpdateServer command), so you may not need to run your own dnsmasq server, but you need to block Internet requests from the Linkplay devices to prevent automatic upgrades afterwards.
The following records were created on the DNS server:
```
cat /etc/dnsmasq.d/linkplay.conf
address=/silenceota.linkplay.com/10.1.1.22
address=/ota.rakoit.com/10.1.1.22
address=/api.linkplay.com/10.1.1.22
address=/ota.tatooine.org/10.1.1.22
```
Restart dnsmasq after any changes:
```
/etc/init.d/dnsmasq restart
```
You may modify the configuration file on your webserver to use different folders for different FQDNs. Be sure to verify any URLs from a web browser or curl. On your PC you may manually point to a public DNS server to be able to download XML files and images from the Internet.
> **Note:**
> Beside of your own DNS server (typically set by DHCP), the Linkplay devices also send DNS requests to 8.8.8.8 and 8.8.4.4 (the two Google DNS servers). The device also sends requests to firehose.eu-central-1.amazonaws.com, api.linkplay.com
The modification of the two FQDNs will prevent any further updates!
Here it is documented from v4.2.8826 to v4.2.8026. To get information about the product ID (project), the current version and release date you can use the "getStatusEx" command. The following output is "enhanced" / beautified with the tool "jq" (JSON processor):
At first you have to download the following XML files, install them in the appropriate directory on your webserver (you may keep the path and create the directories as required).
> **Important:**
> There is no link to older version available. The **_products.xml_** file only contains URLs for the latest version, so you need to know (or guess) the URL for the specific **_product.xml_** file. The following URL is working for the Up2Stream Amp v2 and partially also for the Up2Stream Pro v3 (without MCU). I've added the URL for the **_products.xml_** file to the Wayback archive (https://web.archive.org) on Dec 31th 2023, so it does not work for older versions.
The **_products.xml_** file that has been archived on 20231231 can be retrieved here:
At first you can download the actual **_products.xml_** file, remove everything except your products, adjust the URLs (optionally) and install it on your web server:
Next you download the specific **_product.xml_** file. The following URL is for the RP0011_WB60_S product ID, but except for the MCU all images look to be the same as for product ID RP0011_WB60, UP2STREAM_PRO_V3, and others. I'm not sure, but all devices with the Linkplay A31 module might use the same firmware. You may download and compare the RP0011_WB60_S product below with your device (including MD5 checksums) and replace MCU part show below with the one from your device. It looks that older versions of the **_product.xml_** files and images are still available for download - you just need to know (or guess) the URLs.
> **Important:**
> I do not take responsibilities for results or consequences. You might damage your device! Do not try to downgrade your device if you are unsure!
Modify the <major-version> in the **_product.xml_** file to be one day ahead of your current release date, e.g. 20201027 if your current release date is 20201026. You may also combine the content with a different MCU (project). Be sure that the project name is exactly matching your device!
Modifiy the version number in the **_MVver_** file (first line) to be higher than your current version number, e.g. WiiMu.4.2.8027 if your current version is 4.2.8826.
Trigger an update with the following commands and verify the progress with Wireshark running on your web server. You may use "http" as a filter to see the downgrade process:
