pef-config (8) - Linux Man Pages
pef-config: configure PEF values
NAMEipmi-pef-config - configure PEF values
DESCRIPTIONIpmi-pef-config is a Platform Event Filtering (PEF) configuration utility. This configuration tool is for advanced IPMI users and generally not-required for IPMI to function. Most IPMI users will not need to use this tool. For configuration of general BMC parameters, sensors, or chassis, please see the bmc-config(8), ipmi-sensors-config(8), and ipmi-chassis-config(8) tools respectively. For some OEM specific configurations, please see ipmi-oem(8).
Listed below are general IPMI options, tool specific options, trouble shooting information, workaround information, examples, and known issues. For a general introduction to FreeIPMI please see freeipmi(7). See GENERAL USE below for a description on how most will want to use Ipmi-pef-config.
GENERAL OPTIONSThe following options are general options for configuring IPMI communication and executing general tool commands.
- -D IPMIDRIVER, --driver-type=IPMIDRIVER
- Specify the driver type to use instead of doing an auto selection. The currently available outofband drivers are LAN and LAN_2_0, which perform IPMI 1.5 and IPMI 2.0 respectively. The currently available inband drivers are KCS, SSIF, OPENIPMI, and SUNBMC.
- Do not probe in-band IPMI devices for default settings.
- Specify the in-band driver address to be used instead of the probed value. DRIVER-ADDRESS should be prefixed with "0x" for a hex value and '0' for an octal value.
- Specify the in-band driver device path to be used instead of the probed path.
- Specify the in-band driver register spacing instead of the probed value. Argument is in bytes (i.e. 32bit register spacing = 4)
- Specify the in-band driver target channel number to send IPMI requests to.--target-slave-address=SLAVE-ADDRESSFR
- Specify the in-band driver target slave number to send IPMI requests to.-h IPMIHOST1,IPMIHOST2,..., --hostname=IPMIHOST1[:PORT],IPMIHOST2[:PORT],...
- Specify the remote host(s) to communicate with. Multiple hostnames may be separated by comma or may be specified in a range format; see HOSTRANGED SUPPORT below. An optional port can be specified with each host, which may be useful in port forwarding or similar situations.
- -u USERNAME, --username=USERNAME
- Specify the username to use when authenticating with the remote host. If not specified, a null (i.e. anonymous) username is assumed. The user must have atleast ADMIN privileges in order for this tool to operate fully.
- -p PASSWORD, --password=PASSWORD
- Specify the password to use when authenticationg with the remote host. If not specified, a null password is assumed. Maximum password length is 16 for IPMI 1.5 and 20 for IPMI 2.0.
- -P, --password-prompt
- Prompt for password to avoid possibility of listing it in process lists.
- -k K_G, --k-g=K_G
- Specify the K_g BMC key to use when authenticating with the remote host for IPMI 2.0. If not specified, a null key is assumed. To input the key in hexadecimal form, prefix the string with '0x'. E.g., the key 'abc' can be entered with the either the string 'abc' or the string '0x616263'
- -K, --k-g-prompt
- Prompt for k-g to avoid possibility of listing it in process lists.
- Specify the session timeout in milliseconds. Defaults to 20000 milliseconds (20 seconds) if not specified.
- Specify the packet retransmission timeout in milliseconds. Defaults to 1000 milliseconds (1 second) if not specified. The retransmission timeout cannot be larger than the session timeout.
- -a AUTHENTICATION-TYPE, --authentication-type=AUTHENTICATION-TYPE
- Specify the IPMI 1.5 authentication type to use. The currently available authentication types are NONE, STRAIGHT_PASSWORD_KEY, MD2, and MD5. Defaults to MD5 if not specified.
- -I CIPHER-SUITE-ID, --cipher-suite-id=CIPHER-SUITE-ID
Specify the IPMI 2.0 cipher suite ID to use. The Cipher Suite ID
identifies a set of authentication, integrity, and confidentiality
algorithms to use for IPMI 2.0 communication. The authentication
algorithm identifies the algorithm to use for session setup, the
integrity algorithm identifies the algorithm to use for session packet
signatures, and the confidentiality algorithm identifies the algorithm
to use for payload encryption. Defaults to cipher suite ID 3 if not
specified. The following cipher suite ids are currently supported:
0 - Authentication Algorithm = None; Integrity Algorithm = None; Confidentiality Algorithm = None
1 - Authentication Algorithm = HMAC-SHA1; Integrity Algorithm = None; Confidentiality Algorithm = None
2 - Authentication Algorithm = HMAC-SHA1; Integrity Algorithm = HMAC-SHA1-96; Confidentiality Algorithm = None
3 - Authentication Algorithm = HMAC-SHA1; Integrity Algorithm = HMAC-SHA1-96; Confidentiality Algorithm = AES-CBC-128
6 - Authentication Algorithm = HMAC-MD5; Integrity Algorithm = None; Confidentiality Algorithm = None
7 - Authentication Algorithm = HMAC-MD5; Integrity Algorithm = HMAC-MD5-128; Confidentiality Algorithm = None
8 - Authentication Algorithm = HMAC-MD5; Integrity Algorithm = HMAC-MD5-128; Confidentiality Algorithm = AES-CBC-128
11 - Authentication Algorithm = HMAC-MD5; Integrity Algorithm = MD5-128; Confidentiality Algorithm = None
12 - Authentication Algorithm = HMAC-MD5; Integrity Algorithm = MD5-128; Confidentiality Algorithm = AES-CBC-128
15 - Authentication Algorithm = HMAC-SHA256; Integrity Algorithm = None; Confidentiality Algorithm = None
16 - Authentication Algorithm = HMAC-SHA256; Integrity Algorithm = HMAC_SHA256_128; Confidentiality Algorithm = None
17 - Authentication Algorithm = HMAC-SHA256; Integrity Algorithm = HMAC_SHA256_128; Confidentiality Algorithm = AES-CBC-128
- -l PRIVILEGE-LEVEL, --privilege-level=PRIVILEGE-LEVEL
- Specify the privilege level to be used. The currently available privilege levels are USER, OPERATOR, and ADMIN. Defaults to ADMIN if not specified.
- Specify an alternate configuration file.
- -W WORKAROUNDS, --workaround-flags=WORKAROUNDS
- Specify workarounds to vendor compliance issues. Multiple workarounds can be specified separated by commas. A special command line flag of "none", will indicate no workarounds (may be useful for overriding configured defaults). See WORKAROUNDS below for a list of available workarounds.
- Turn on debugging.
- -?, --help
- Output a help list and exit.
- Output a usage message and exit.
- -V, --version
- Output the program version and exit.
IPMI-PEF-CONFIG OPTIONSThe following options are specific to Ipmi-pef-config.
- -i, --info
- Show general information about PEF configuration.
CONFIG OPTIONSThe following options are used to read, write, and find differences in configuration values.
- -o, --checkout
- Fetch configuration information.
- -c, --commit
- Update configuration information from a config file or key pairs.
- -d, --diff
- Show differences between stored information and a config file or key pairs.
- -n FILENAME, --filename=FILENAME
- Specify a config file for checkout/commit/diff. If specified with checkout, cannot use with multiple hosts or with --always-prefix.
- -e "KEY=VALUE", --key-pair="KEY=VALUE"
- Specify KEY=VALUE pairs for checkout/commit/diff. Specify KEY by SectionName:FieldName. This option can be used multiple times. On commit, any KEY=VALUE pairs will overwrite any pairs specified in a file with --filename.
- -S SECTION, --section=SECTION
- Specify a SECTION for checkout. This option can be used multiple times.
- -L, --listsections
- List available sections for checkout. Some sections in the list may not be checked out by default and may require verbosity to be increased.
- -v, --verbose
- Output verbose information. When used with --checkout, additional uncommon sections and/or fields will be shown. In ipmi-pef-config, this includes checking out sections for each channel on a system, if multiple channels exist.
- Output very verbose information. Output additional detailed information about what fields can and cannot be checked out, and sometimes the reason why. Sometimes output fields that are identified as unsupported on the motherboard.
- Use an specific channel number for LAN configuration. Particularly useful if motherboard contains multiple LAN channels and a user wishes to use a specific one.
HOSTRANGED OPTIONSThe following options manipulate hostranged output. See HOSTRANGED SUPPORT below for additional information on hostranges.
- -B, --buffer-output
- Buffer hostranged output. For each node, buffer standard output until the node has completed its IPMI operation. When specifying this option, data may appear to output slower to the user since the the entire IPMI operation must complete before any data can be output. See HOSTRANGED SUPPORT below for additional information.
- -C, --consolidate-output
- Consolidate hostranged output. The complete standard output from every node specified will be consolidated so that nodes with identical output are not output twice. A header will list those nodes with the consolidated output. When this option is specified, no output can be seen until the IPMI operations to all nodes has completed. If the user breaks out of the program early, all currently consolidated output will be dumped. See HOSTRANGED SUPPORT below for additional information.
- -F NUM, --fanout=NUM
- Specify multiple host fanout. A "sliding window" (or fanout) algorithm is used for parallel IPMI communication so that slower nodes or timed out nodes will not impede parallel communication. The maximum number of threads available at the same time is limited by the fanout. The default is 64.
- -E, --eliminate
- Eliminate hosts determined as undetected by ipmidetect. This attempts to remove the common issue of hostranged execution timing out due to several nodes being removed from service in a large cluster. The ipmidetectd daemon must be running on the node executing the command.
- Always prefix output, even if only one host is specified or communicating in-band. This option is primarily useful for scripting purposes. Option will be ignored if specified with the -C option.
GENERAL USEMost users of will want to:
A) Run with --checkout to get a copy of the current configuration and store it in a file. The standard output can be redirected to a file or a file can be specified with the --filename option.
B) Edit the configuration file with an editor.
C) Commit the configuration back using the --commit option and specifying the configuration file with the --filename option. The configuration can be committed to multiple hosts in parallel via the hostrange support.
Although not typically necessarily, some motherboards do not store configuration values in non-volatile memory. Therefore, after system reboots, some configuration values may have changed. The user may wish to run configuration tools on each boot to ensure configuration values remain.
EDITING THE CHECKOUT FILEOptions for editing fields in the checkout file are usually listed in a comment above the field. When there are to many options to make it practical, they are listed here in the MAN page.
- Sensor_Type Options
- Reserved, Temperature, Voltage, Current, Fan, Physical_Security, Platform_Security_Violation_Attempt, Processor, Power_Supply, Power_Unit, Cooling_Device, Other_Units_Based_Sensor, Memory, Drive_Slot, Post_Memory_Resize, System_Firmware_Progress, Event_Logging_Disabled, Watchdog1, System_Event, Critical_Interrupt, Button_Switch, Module_Board, Microcontroller_Coprocessor, Add_In_Card, Chassis, Chip_Set, Other_FRU, Cable_Interconnect, Terminator, System_Boot_Initiated, Boot_Error, OS_Boot, OS_Critical_Stop, Slot_Connector, System_ACPI_Power_State, Watchdog2, Platform_Alert, Entity_Presence, Monitor_Asic_IC, Lan, Management_Subsystem_Health, Battery, Session_Audit, Version_Change, FRU_State, and Any
IPMI-PEF-CONFIG SPECIAL CASE CONFIGURATION INFORMATIONOn some motherboards, multiple channels may exist for LAN IPMI communication. If multiple channels exist, configuration of both channels can be viewed and ultimately configured by running --checkout under verbose mode. Each section name will be suffixed appropriately with the word Channel and the channel number. For example, you might see a Community_String_Channel_1 and Community_String_Channel_3, where you can configure the Community String on Channels 1 and 3 respectively.
HOSTRANGED SUPPORTMultiple hosts can be input either as an explicit comma separated lists of hosts or a range of hostnames in the general form: prefix[n-m,l-k,...], where n < m and l < k, etc. The later form should not be confused with regular expression character classes (also denoted by ). For example, foo does not represent foo1 or foo9, but rather represents a degenerate range: foo19.
This range syntax is meant only as a convenience on clusters with a prefixNN naming convention and specification of ranges should not be considered necessary -- the list foo1,foo9 could be specified as such, or by the range foo[1,9].
Some examples of range usage follow:
foo[01-05] instead of foo01,foo02,foo03,foo04,foo05 foo[7,9-10] instead of foo7,foo9,foo10 foo[0-3] instead of foo0,foo1,foo2,foo3
As a reminder to the reader, some shells will interpret brackets ([ and ]) for pattern matching. Depending on your shell, it may be necessary to enclose ranged lists within quotes.
When multiple hosts are specified by the user, a thread will be executed for each host in parallel up to the configured fanout (which can be adjusted via the -F option). This will allow communication to large numbers of nodes far more quickly than if done in serial.
By default, standard output from each node specified will be output with the hostname prepended to each line. Although this output is readable in many situations, it may be difficult to read in other situations. For example, output from multiple nodes may be mixed together. The -B and -C options can be used to change this default.
GENERAL TROUBLESHOOTINGMost often, IPMI problems are due to configuration problems.
IPMI over LAN problems involve a misconfiguration of the remote machine's BMC. Double check to make sure the following are configured properly in the remote machine's BMC: IP address, MAC address, subnet mask, username, user enablement, user privilege, password, LAN privilege, LAN enablement, and allowed authentication type(s). For IPMI 2.0 connections, double check to make sure the cipher suite privilege(s) and K_g key are configured properly. The bmc-config(8) tool can be used to check and/or change these configuration settings.
Inband IPMI problems are typically caused by improperly configured drivers or non-standard BMCs.
In addition to the troubleshooting tips below, please see WORKAROUNDS below to also if there are any vendor specific bugs that have been discovered and worked around.
Listed below are many of the common issues for error messages. For additional support, please e-mail the <freeipmi-users [at] gnu.org> mailing list.
"username invalid" - The username entered (or a NULL username if none was entered) is not available on the remote machine. It may also be possible the remote BMC's username configuration is incorrect.
"password invalid" - The password entered (or a NULL password if none was entered) is not correct. It may also be possible the password for the user is not correctly configured on the remote BMC.
"password verification timeout" - Password verification has timed out. A "password invalid" error (described above) or a generic "session timeout" (described below) occurred. During this point in the protocol it cannot be differentiated which occurred.
"k_g invalid" - The K_g key entered (or a NULL K_g key if none was entered) is not correct. It may also be possible the K_g key is not correctly configured on the remote BMC.
"privilege level insufficient" - An IPMI command requires a higher user privilege than the one authenticated with. Please try to authenticate with a higher privilege. This may require authenticating to a different user which has a higher maximum privilege.
"privilege level cannot be obtained for this user" - The privilege level you are attempting to authenticate with is higher than the maximum allowed for this user. Please try again with a lower privilege. It may also be possible the maximum privilege level allowed for a user is not configured properly on the remote BMC.
"authentication type unavailable for attempted privilege level" - The authentication type you wish to authenticate with is not available for this privilege level. Please try again with an alternate authentication type or alternate privilege level. It may also be possible the available authentication types you can authenticate with are not correctly configured on the remote BMC.
"cipher suite id unavailable" - The cipher suite id you wish to authenticate with is not available on the remote BMC. Please try again with an alternate cipher suite id. It may also be possible the available cipher suite ids are not correctly configured on the remote BMC.
"ipmi 2.0 unavailable" - IPMI 2.0 was not discovered on the remote machine. Please try to use IPMI 1.5 instead.
"connection timeout" - Initial IPMI communication failed. A number of potential errors are possible, including an invalid hostname specified, an IPMI IP address cannot be resolved, IPMI is not enabled on the remote server, the network connection is bad, etc. Please verify configuration and connectivity.
"session timeout" - The IPMI session has timed out. Please reconnect. If this error occurs often, you may wish to increase the retransmission timeout. Some remote BMCs are considerably slower than others.
"device not found" - The specified device could not be found. Please check configuration or inputs and try again.
"driver timeout" - Communication with the driver or device has timed out. Please try again.
"message timeout" - Communication with the driver or device has timed out. Please try again.
"BMC busy" - The BMC is currently busy. It may be processing information or have too many simultaneous sessions to manage. Please wait and try again.
"could not find inband device" - An inband device could not be found. Please check configuration or specify specific device or driver on the command line.
"driver timeout" - The inband driver has timed out communicating to the local BMC or service processor. The BMC or service processor may be busy or (worst case) possibly non-functioning.
WORKAROUNDSWith so many different vendors implementing their own IPMI solutions, different vendors may implement their IPMI protocols incorrectly. The following describes a number of workarounds currently available to handle discovered compliance issues. When possible, workarounds have been implemented so they will be transparent to the user. However, some will require the user to specify a workaround be used via the -W option.
The hardware listed below may only indicate the hardware that a problem was discovered on. Newer versions of hardware may fix the problems indicated below. Similar machines from vendors may or may not exhibit the same problems. Different vendors may license their firmware from the same IPMI firmware developer, so it may be worthwhile to try workarounds listed below even if your motherboard is not listed.
If you believe your hardware has an additional compliance issue that needs a workaround to be implemented, please contact the FreeIPMI maintainers on <freeipmi-users [at] gnu.org> or <freeipmi-devel [at] gnu.org>.
assumeio - This workaround flag will assume inband interfaces communicate with system I/O rather than being memory-mapped. This will work around systems that report invalid base addresses. Those hitting this issue may see "device not supported" or "could not find inband device" errors. Issue observed on HP ProLiant DL145 G1.
spinpoll - This workaround flag will inform some inband drivers (most notably the KCS driver) to spin while polling rather than putting the process to sleep. This may significantly improve the wall clock running time of tools because an operating system scheduler's granularity may be much larger than the time it takes to perform a single IPMI message transaction. However, by spinning, your system may be performing less useful work by not contexting out the tool for a more useful task.
authcap - This workaround flag will skip early checks for username capabilities, authentication capabilities, and K_g support and allow IPMI authentication to succeed. It works around multiple issues in which the remote system does not properly report username capabilities, authentication capabilities, or K_g status. Those hitting this issue may see "username invalid", "authentication type unavailable for attempted privilege level", or "k_g invalid" errors. Issue observed on Asus P5M2/P5MT-R/RS162-E4/RX4, Intel SR1520ML/X38ML, and Sun Fire 2200/4150/4450 with ELOM.
nochecksumcheck - This workaround flag will tell FreeIPMI to not check the checksums returned from IPMI command responses. It works around systems that return invalid checksums due to implementation errors, but the packet is otherwise valid. Users are cautioned on the use of this option, as it removes validation of packet integrity in a number of circumstances. However, it is unlikely to be an issue in most situations. Those hitting this issue may see "connection timeout", "session timeout", or "password verification timeout" errors. On IPMI 1.5 connections, the "noauthcodecheck" workaround may also needed too. Issue observed on Supermicro X9SCM-iiF, Supermicro X9DRi-F, and Supermicro X9DRFR.
idzero - This workaround flag will allow empty session IDs to be accepted by the client. It works around IPMI sessions that report empty session IDs to the client. Those hitting this issue may see "session timeout" errors. Issue observed on Tyan S2882 with M3289 BMC.
unexpectedauth - This workaround flag will allow unexpected non-null authcodes to be checked as though they were expected. It works around an issue when packets contain non-null authentication data when they should be null due to disabled per-message authentication. Those hitting this issue may see "session timeout" errors. Issue observed on Dell PowerEdge 2850,SC1425. Confirmed fixed on newer firmware.
forcepermsg - This workaround flag will force per-message authentication to be used no matter what is advertised by the remote system. It works around an issue when per-message authentication is advertised as disabled on the remote system, but it is actually required for the protocol. Those hitting this issue may see "session timeout" errors. Issue observed on IBM eServer 325.
endianseq - This workaround flag will flip the endian of the session sequence numbers to allow the session to continue properly. It works around IPMI 1.5 session sequence numbers that are the wrong endian. Those hitting this issue may see "session timeout" errors. Issue observed on some Sun ILOM 1.0/2.0 (depends on service processor endian).
noauthcodecheck - This workaround flag will tell FreeIPMI to not check the authentication codes returned from IPMI 1.5 command responses. It works around systems that return invalid authentication codes due to hashing or implementation errors. Users are cautioned on the use of this option, as it removes an authentication check verifying the validity of a packet. However, in most organizations, this is unlikely to be a security issue. Those hitting this issue may see "connection timeout", "session timeout", or "password verification timeout" errors. Issue observed on Xyratex FB-H8-SRAY.
intel20 - This workaround flag will work around several Intel IPMI 2.0 authentication issues. The issues covered include padding of usernames, and password truncation if the authentication algorithm is HMAC-MD5-128. Those hitting this issue may see "username invalid", "password invalid", or "k_g invalid" errors. Issue observed on Intel SE7520AF2 with Intel Server Management Module (Professional Edition).
supermicro20 - This workaround flag will work around several Supermicro IPMI 2.0 authentication issues on motherboards w/ Peppercon IPMI firmware. The issues covered include handling invalid length authentication codes. Those hitting this issue may see "password invalid" errors. Issue observed on Supermicro H8QME with SIMSO daughter card. Confirmed fixed on newerver firmware.
sun20 - This workaround flag will work work around several Sun IPMI 2.0 authentication issues. The issues covered include invalid lengthed hash keys, improperly hashed keys, and invalid cipher suite records. Those hitting this issue may see "password invalid" or "bmc error" errors. Issue observed on Sun Fire 4100/4200/4500 with ILOM. This workaround automatically includes the "opensesspriv" workaround.
opensesspriv - This workaround flag will slightly alter FreeIPMI's IPMI 2.0 connection protocol to workaround an invalid hashing algorithm used by the remote system. The privilege level sent during the Open Session stage of an IPMI 2.0 connection is used for hashing keys instead of the privilege level sent during the RAKP1 connection stage. Those hitting this issue may see "password invalid", "k_g invalid", or "bad rmcpplus status code" errors. Issue observed on Sun Fire 4100/4200/4500 with ILOM, Inventec 5441/Dell Xanadu II, Supermicro X8DTH, Supermicro X8DTG, Intel S5500WBV/Penguin Relion 700, Intel S2600JF/Appro 512X, and Quanta QSSC-S4R/Appro GB812X-CN. This workaround is automatically triggered with the "sun20" workaround.
integritycheckvalue - This workaround flag will work around an invalid integrity check value during an IPMI 2.0 session establishment when using Cipher Suite ID 0. The integrity check value should be 0 length, however the remote motherboard responds with a non-empty field. Those hitting this issue may see "k_g invalid" errors. Issue observed on Supermicro X8DTG, Supermicro X8DTU, and Intel S5500WBV/Penguin Relion 700, and Intel S2600JF/Appro 512X.
No IPMI 1.5 Support - Some motherboards that support IPMI 2.0 have been found to not support IPMI 1.5. Those hitting this issue may see "ipmi 2.0 unavailable" or "connection timeout" errors. This issue can be worked around by using IPMI 2.0 instead of IPMI 1.5 by specifying --driver-type=LAN_2_0. Issue observed on HP Proliant DL 145.
slowcommit - This workaround will slow down commits to the BMC by sleeping one second between the commit of sections. It works around motherboards that have BMCs that can be overwhelmed by commits. Those hitting this issue may see commit errors or commits not being written to the BMC. Issue observed on Supermicro H8QME.
veryslowcommit - This workaround will slow down commits to the BMC by sleeping one second between the commit of every key. It works around motherboards that have BMCs that can be overwhelmed by commits. Those hitting this issue may see commit errors or commits not being written to the BMC. Issue observed on Quanta S99Q/Dell FS12-TY.
EXAMPLES# ipmi-pef-config --checkout
Output all configuration information to the console.
# ipmi-pef-config --checkout --filename=pef-data1.conf
Store all configuration information in pef-data1.conf.
# ipmi-pef-config --diff --filename=pef-data2.conf
Show all difference between the current configuration and the pef-data2.conf file.
# ipmi-pef-config --commit --filename=pef-data1.conf
Commit all configuration values from the pef-data1.conf file.
DIAGNOSTICSUpon successful execution, exit status is 0. On non-fatal error, exit status is 1. On fatal error, exit status is 2.
If multiple hosts are specified for communication, the exit status is 0 if and only if all targets successfully execute. If any non-fatal error occurs, exit status is 1. If any fatal error occurs, exit status is 2.
KNOWN ISSUESOn older operating systems, if you input your username, password, and other potentially security relevant information on the command line, this information may be discovered by other users when using tools like the ps(1) command or looking in the /proc file system. It is generally more secure to input password information with options like the -P or -K options. Configuring security relevant information in the FreeIPMI configuration file would also be an appropriate way to hide this information.
In order to prevent brute force attacks, some BMCs will temporarily "lock up" after a number of remote authentication errors. You may need to wait awhile in order to this temporary "lock up" to pass before you may authenticate again.
REPORTING BUGSReport bugs to <freeipmi-users [at] gnu.org> or <freeipmi-devel [at] gnu.org>.
COPYRIGHTCopyright © 2007-2012 FreeIPMI Core Team.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.