EIPMI

EIPMI is a native Erlang/OTP application for RMCP/IPMI. It implements the remote console part of the IPMI LAN interface, as specified here. To provide a low threshold for learning and using EIPMI it is designed close to the well known inet API (think of gen_udp). It supports IPMI v1.5 as well as v2.0 (RMCP+).

Contributing

If you whish to contribute fixes or enhancements, use rebar3 fmt -w to format your code before committing. Also, you should always write proper edoc module documentation. When writing documentation, please try to keep the tone simple and on a higher abstraction level, so that users may understand the concepts without having to know too much of the standard.

The modules eipmi_request and eipmi_response are a starting point for developers that want add support for not yet implemented request/response pairs. To add support for a new request the encoding of the corresponding IPMI data part needs to be added to the eipmi_request module. To add support for a new response the decoding of the corresponding IPMI data part needs to be added to the eipmi_response module. As soon as encoding and decoding is implemented the command is ready to be issued using eipmi:raw/4. For features that need to combine multiple requests (e.g. reading the FRU) it would be even more nice to add a corresponding frontend API function to the eipmi module.

Documentation

The following sections will give a brief description of the EIPMI features as well as some usage examples for developers integrating the application into their project. Additional information can be found in the projects EDoc/source documentation. The EIPMI API functions are exported by the eipmi module.

Sessions & Authentication

EIPMI does all the necessary session handling for the user as soon as a session is requested using eipmi:open/1 or eipmi:open/2. However, according to the capabilities of the target BMC the user eventually has to pass in user and password credentials using the Options argument of eipmi:open/2. A user process can immediatelly start using a session. All requests received before the session is established will be queued and issued after the session is established.

All authentication mechanisms mentioned in the specification are supported, including anonymous, null user and non-null user. Additionally, all digester algorithms proposed by the specification are supported.

In case the target BMC only supports non-null users the options user and password need to be passed in a call to eipmi:open/2. In case null users are configured on the BMC only the password option will be required. If the BMC supports anonymous logins no options need to be set.

A session may be shared between mutliple processes. While the requests of one process will be synchronous and thus ordered, requests from different processes will not block each other. However, flow control is not performed by the session and a user has to ensure that only a limited number of processes issue concurrent requests over the same session.

The API of EIPMI has been designed to be as similar as possible to existing erlang protocol implementations (e.g. gen_udp). Therefore, the session owner (the process calling open/1,2) will get asynchronous messages for its sessions. The messages are sent using ordinary Erlang messaging and should be handled accordingly. Be prepared to receive messages of the following form:

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address() | inet:hostname(),
 established}

The session was successfully established and activated.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {closed, Reason :: term()}}

The session was closed with the provided reason.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {decode_error, Reason :: term()}}

A received packet could not be decoded.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {timeout, {eipmi:request(), RqSeqNr :: 0..63}}}

The corresponding request timed out.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {unhandled, {call, Request :: term()}}}

The session received an invalid gen_server call.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {unhandled, {cast, Request :: term()}}}

The session received an invalid gen_server cast.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {unhandled, {info, Info :: term()}}}

The session received an invalid message.

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 SELEntry :: eipmi:sel_entry()}

A forwarded entry from the System Event Log (only when automatic SEL polling is enabled).

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 {sel_read_error, Reason :: term()}}

An error occured when polling the System Event Log (only when automatic SEL polling is enabled).

{ipmi,
 Session :: eipmi:session(),
 Address :: inet:ip4_address(),
 Trap :: eipmi:trap()}

An IPMI platform event trap forwarded by the trap handling mechanism (only if enabled).

An established session will be kept alive by the session state machine until either eipmi:close/1 gets called or the owner process exits.

Platform Event Traps

EIPMI is capable of receiving and forwarding platform event traps. In order to receive trap events you will need to have trap handling enabled and have at least one IPMI session open to the respective target device. The events will then be delivered to all owners of currently open sessions to this device.

Traps will automatically be acknowledged using the PET Acknowledge command if their sequence number (cookie) is set/specified. To enable trap handling you will need to set at least one port number for the trap_ports property in the EIPMI application environment, e.g. in your sys.config add the following

...
{eipmi, [{trap_ports, [162]}]},
...

Please be aware that depending on the chosen port (to be standard compliant you will need to use port 162) your VM will need the permission to open internet privileged ports.

Usage

The eipmi module contains the whole functionality this project currently has to offer. It defines functions to manage sessions as well as functions to issue implemented requests. Additionally it contains functions that abstract functionality that usually need in-detail knowledge of the IPMI standard, e.g. reading SDR or SEL entries.

The general process of session establishment is briefly outlined in the next paragraphs. IPMI device discovery usually starts with a PING message to the target host:

case eipmi:ping("10.1.31.11") of
     pong ->
          ipmi_supported;
     pang ->
          ipmi_not_supported
end,

After successful device discovery an actual session can be opened. This example will open a session, read the FRU with id 253 and close the session again.

{ok, Session} = eipmi:open("10.1.31.11"),
{ok, {fru_data, FruInfo}} = eipmi:read_fru(Session, 253),
BoardArea = proplists:get_value(board_area, FruInfo),
Name = proplists:get_value(name, BoardArea),
Serial = proplists:get_value(serial_number, BoardArea),
error_logger:info_msg("Board ~s has serial number ~s.~n", [Name, Serial]),
eipmi:close(Session),

The following snippet first reads the BMC's Sensor Data Record Repository and then returns the complete FRU inventory based on the found FRU Device Locator Records.

{ok, Session} = eipmi:open("10.1.31.11"),
{ok, SDRRepository} = eipmi:get_sdr_repository(Session),
{ok, FruInventory} = eipmi:read_fru_inventory(Session, SDRRepository),
error_logger:info_msg("FRU inventory:~n~p~n", [FruInventory]),
eipmi:close(Session),

EIPMI also allows to send raw requests over a session. However, raw does not mean that binary data can be sent directly. The corresponding request/response encode/decode functionality must be present. The following snippet will issue the Set Session Privilege Level command, trying to set the current session privilege to administrator.

{ok, Response} = eipmi:raw(Session, 16#06, 16#3b, [{privilege, administrator}]),
NewPrivilege = proplists:get_value(privilege, Response),
error_logger:info_msg("New privilege level is ~p.~n", [NewPrivilege]),

History

Master (4.1.1)

Currently no difference to latest tag.

Version 4.1.0

• Enhance performance of session lookups (thanks to @IslandUsurper)
• Drop (official) support for OTP releases older than 24.3 (currently it should still work with older versions)

Version 4.0.0

• Add support for the Get/Set System Boot Options command (thanks to @IslandUsurper)
• Add support for RMCP+ (IPMI v2.0, big thanks to @IslandUsurper)
• Add support for the Get/Set Chassis Capabilities command (thanks to @IslandUsurper)
• Add support for the Get Chassis Status command (thanks to @IslandUsurper)
• Add support for the Chassis Control command (thanks to @IslandUsurper)
• Add support for the Chassis Reset command (thanks to @IslandUsurper)
• Add support for the Chassis Identify command (thanks to @IslandUsurper)
• Add support for the Set Power Restore Policy command (thanks to @IslandUsurper)
• Add support for the Get System Restart Cause command (thanks to @IslandUsurper)
• Add support for the Set Front Panel Enables command (thanks to @IslandUsurper)
• Add support for the Set Power Cycle Interval command (thanks to @IslandUsurper)
• Add support for the Get POH Counter command (thanks to @IslandUsurper)
• Drop support for OTP releases older than 22.2

Version 3.0.0

• Drop support for OTP releases older than 18.3
• Add support for receiving/decoding/dispatching IPMI Platform Event and SNMP (RFC 1157) Trap messages
• Support for the Get LAN Configuration Parameters command
• Support for the Set LAN Configuration Parameters command
• Add eipmi:sessions/0 and remove return value from eipmi:info/0

Version 2.0.1

• Fix SDR timestamp handling
• Enhance/harden response dispatching
• Enhance robustness of SEL polling
• Minor bug fixes

Version 2.0.0

• eipmi is now available on hex.pm
• Make project compatible to rebar3/hex
• Rename eipmi:stats/0 to eipmi:info/0
• Switch asynchronous notifications from gen_event to Erlang messages
• Introduce the concept of session owners
• Extended support for reading sensors

Version 1.2.7

• Fix SDR timestamp handling

Version 1.2.6

• Enhance/harden response dispatching
• Enhance robustness of SEL polling

Version 1.2.5

• Allow FRU fields with broken type/length field

Version 1.2.4

• Allow periodic SEL polling to fail for 30 seconds

Version 1.2.3

• Unify error returns of eipmi:read_fru/2 and eipmi:read_frus/2

Version 1.2.2

• Fix decoding of AMC P2P Connectivity Records
• Make session more robust against decode errors

Version 1.2.1

• Allow non-standard sensor ids (plain string without type)
• Fix calls to deprecated crypto API

Version 1.2.0

• Improved session startup (now synchronous)
• Improved connection loss detection

Version 1.1.0

• Support the Send Message command (needed for OEM requests) as well as double bridged requests
• New to_list functions for FRU and SDR entries
• Fix sensor readings for threshold and generic sensors

Version 1.0.0

• Compliant to IPMI v1.5 (LAN interface only)
• Presence Ping
• Session management including session keep alive
• Support for lots of requests/responses/sensors from the IPMI v1.5 standard
• Support for lots of requests/responses/sensors defined by the PICMG (ATCA/µTCA)
• Automatic polling of the System Event Log (SEL)