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gerrit.openbmc.org / openbmc / bmcweb / 8e73b9064fdd414b9a71806a44f0e0f176b5a88d
commit8e73b9064fdd414b9a71806a44f0e0f176b5a88d[log] [tgz]
authorXinnan Xie <xiexinnan@bytedance.com>Wed Aug 23 11:14:48 2023 +0800
committerEd Tanous <ed@tanous.net>Thu Aug 24 16:21:32 2023 +0000
treea85f7d8f7eaf21dd8b7db99ebd18e57466e5735a
parente7c2991e044d2e31f911a237b7ee41197b7d018c [diff]
kvm_websocket: Fix crash on dangling reference

Kvm_websocket captures the this pointer in the handler lambda of the
socket. When the callback is called, if the object has been destructed,
there will be a crash problem. This is fixed by using weak_from_this in
the callback, if the object was destructed, the callback just returns
without doing anything.

Tested:
1. Open two kvm sessions in WebUI, and keep refreshing in one of the
pages, there is a small chance of coredump happening.
Debug infomation shows:
```
bmcweb[5331]: DEBUG: doRead. conn:0x28d19a0. this: 0x284d470
bmcweb[5331]: DEBUG: doRead. conn:0x28d19a0. this: 0x284d470
bmcweb[5331]: DEBUG: doRead. conn:0x28d19a0. this: 0x284d470
bmcweb[5331]: DEBUG: doRead. conn:0x28d19a0. this: 0x284d470
bmcweb[5331]: DEBUG: doRead. conn:0x28d19a0. this: 0x284d470
bmcweb[5331]: DEBUG: onclose. conn:0x28d19a0
bmcweb[5331]: DEBUG: doRead. conn:0x2876648. this: 0x284d470
systemd[1]: bmeweb.service: Main process exited, code=dumped, status=11/SEGV
systemd[1]: bmcweb.service: Failed with result 'core-dump
systemd[1]: Started Start bmweb server.
```
2. After this fix no coredump occurred.

Change-Id: I7bba9b67c470def90ddb1e471a0ac95edd6165e5
Signed-off-by: Xinnan Xie <xiexinnan@bytedance.com>
1 file changed
tree: a85f7d8f7eaf21dd8b7db99ebd18e57466e5735a
  1. .github/
  2. config/
  3. http/
  4. include/
  5. redfish-core/
  6. scripts/
  7. src/
  8. static/
  9. subprojects/
  10. test/
  11. .clang-format
  12. .clang-tidy
  13. .dockerignore
  14. .gitignore
  15. .markdownlint.yaml
  16. .openbmc-enforce-gitlint
  17. .prettierignore
  18. .shellcheck
  19. AGGREGATION.md
  20. CLIENTS.md
  21. COMMON_ERRORS.md
  22. DBUS_USAGE.md
  23. DEVELOPING.md
  24. HEADERS.md
  25. LICENSE
  26. meson.build
  27. meson_options.txt
  28. OEM_SCHEMAS.md
  29. OWNERS
  30. README.md
  31. Redfish.md
  32. run-ci
  33. setup.cfg
  34. TESTING.md
README.md

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, 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 setup 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.

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.

Redfish Aggregation

bmcweb is capable of aggregating resources from satellite BMCs. Refer to AGGREGATION.md for more information on how to enable and use this feature.