OpenBMC webserver

This component attempts to be a "do everything" embedded webserver for OpenBMC.

Features

The webserver implements a few distinct interfaces:

• DBus event websocket. Allows registering on changes to specific dbus paths, properties, and will send an event from the websocket if those filters match.
• OpenBMC DBus REST api. Allows direct, low interference, high fidelity access to dbus and the objects it represents.
• Serial: A serial websocket for interacting with the host serial console through websockets.
• Redfish: A protocol compliant, (Redfish.md)[DBus to Redfish translator].
• KVM: A websocket based implementation of the RFB (VNC) frame buffer protocol intended to mate to webui-vue to provide a complete KVM implementation.

Protocols

bmcweb at a protocol level supports http and https. TLS is supported through OpenSSL.

AuthX

Authentication

Bmcweb supports multiple authentication protocols:

• Basic authentication per RFC7617
• Cookie based authentication for authenticating against webui-vue
• Mutual TLS authentication based on OpenSSL
• Session authentication through webui-vue
• XToken based authentication conformant to Redfish DSP0266

Each of these types of authentication is able to be enabled or disabled both via runtime policy changes (through the relevant Redfish APIs) or via configure time options. All authentication mechanisms supporting username/password are routed to libpam, to allow for customization in authentication implementations.

Authorization

All authorization in bmcweb is determined at routing time, and per route, and conform to the Redfish PrivilegeRegistry.

*Note: Non-Redfish functions are mapped to the closest equivalent Redfish privilege level.

Configuration

bmcweb is configured per the meson build files. Available options are documented in meson_options.txt

Compile bmcweb with default options:

meson builddir
ninja -C builddir

If any of the dependencies are not found on the host system during configuration, meson will automatically download them via its wrap dependencies mentioned in bmcweb/subprojects.

Debug logging

bmcweb by default is compiled with runtime logging disabled, as a performance consideration. To enable it in a standalone build, add the

-Dlogging='enabled'

option to your configure flags. If building within Yocto, add the following to your local.conf.

EXTRA_OEMESON:pn-bmcweb:append = "-Dbmcweb-logging='enabled'"

Use of persistent data

bmcweb relies on some on-system data for storage of persistent data that is internal to the process. Details on the exact data stored and when it is read/written can seen from the persistent_data namespace.

TLS certificate generation

When SSL support is enabled and a usable certificate is not found, bmcweb will generate a self-signed a certificate before launching the server. Please see the bmcweb source code for details on the parameters this certificate is built with.