[[vty]] == The Osmocom VTY Interface All human interaction with Osmocom software is typically performed via an interactive command-line interface called the _VTY_. NOTE: Integration of your programs and scripts should *not* be done via the telnet VTY interface, which is intended for human interaction only: the VTY responses may arbitrarily change in ways obvious to humans, while your scripts' parsing will likely break often. For external software to interact with Osmocom programs (besides using the dedicated protocols), it is strongly recommended to use the Control interface instead of the VTY, and to actively request / implement the Control interface commands as required for your use case. The interactive telnet VTY is used to * explore the current status of the system, including its configuration parameters, but also to view run-time state and statistics, * review the currently active (running) configuration, * perform interactive changes to the configuration (for those items that do not require a program restart), * store the current running configuration to the config file, * enable or disable logging; to the VTY itself or to other targets. The Virtual Tele Type (VTY) has the concept of __nodes__ and __commands__. Each command has a name and arguments. The name may contain a space to group several similar commands into a specific group. The arguments can be a single word, a string, numbers, ranges or a list of options. The available commands depend on the current node. there are various keyboard shortcuts to ease finding commands and the possible argument values. Configuration file parsing during program start is actually performed the VTY's CONFIG node, which is also available in the telnet VTY. Apart from that, the telnet VTY features various interactive commands to query and instruct a running Osmocom program. A main difference is that during config file parsing, consistent indenting of parent vs. child nodes is required, while the interactive VTY ignores indenting and relies on the 'exit' command to return to a parent node. NOTE: In the 'CONFIG' node, it is not well documented which commands take immediate effect without requiring a program restart. To save your current config with changes you may have made, you may use the `write file` command to *overwrite* your config file with the current configuration, after which you should be able to restart the program with all changes taking effect. This chapter explains most of the common nodes and commands. A more detailed list is available in various programs' VTY reference manuals, e.g. see <>. There are common patterns for the parameters, these include IPv4 addresses, number ranges, a word, a line of text and choice. The following will explain the commonly used syntactical patterns: .VTY Parameter Patterns [options="header",cols="35%,25%,40%"] |=============== |Pattern|Example|Explanation |`A.B.C.D`|`127.0.0.1`|An IPv4 address |`A.B.C.D/M`|`192.168.1.0/24`|An IPv4 address and mask |`X:X::X:X`|`::1`|An IPv6 address |`X:X::X:X/M`|`::1/128`|An IPv6 address and mask |`TEXT`|`example01`|A single string without any spaces, tabs |`.TEXT`|`Some information`|A line of text |`(OptionA\|OptionB\|OptionC)`|`OptionA`|A choice between a list of available options |`<0-10>`|`5`|A number from a range |=============== === Accessing the telnet VTY The VTY of a given Osmocom program is implemented as a telnet server, listening to a specific TCP port. Please see <> to check for the default TCP port number of the VTY interface of the specific Osmocom software you would like to connect to. As telnet is insecure and offers neither strong authentication nor encryption, the VTY by default only binds to localhost (127.0.0.1) and will thus not be reachable by other hosts on the network. WARNING: By default, any user with access to the machine running the Osmocom software will be able to connect to the VTY. We assume that such systems are single-user systems, and anyone with local access to the system also is authorized to access the VTY. If you require stronger security, you may consider using the packet filter of your operating system to restrict access to the Osmocom VTY ports further. === VTY Nodes The VTY by default has the following minimal nodes: VIEW:: When connecting to a telnet VTY, you will be on the 'VIEW' node. As its name implies, it can only be used to view the system status, but it does not provide commands to alter the system state or configuration. As long as you are in the non-privileged 'VIEW' node, your prompt will end in a `>` character. ENABLE:: The 'ENABLE' node is entered by the `enable` command, from the 'VIEW' node. Changing into the 'ENABLE' node will unlock all kinds of commands that allow you to alter the system state or perform any other change to it. The 'ENABLE' node and its children are signified by a '#' character at the end of your prompt. + You can change back from the 'ENABLE' node to the 'VIEW' node by using the `disable` command. CONFIG:: The 'CONFIG' node is entered by the `configure terminal` command from the 'ENABLE' node. The config node is used to change the run-time configuration parameters of the system. The prompt will indicate that you are in the config node by a `(config)#` prompt suffix. + You can always leave the 'CONFIG' node or any of its children by using the `end` command. + This node is also automatically entered at the time the configuration file is read. All configuration file lines are processed as if they were entered from the VTY 'CONFIG' node at start-up. Other:: Depending on the specific Osmocom program you are running, there will be few or more other nodes, typically below the 'CONFIG' node. For example, the OsmoBSC has nodes for each BTS, and within the BTS node one for each TRX, and within the TRX node one for each Timeslot. === Interactive help The VTY features an interactive help system, designed to help you to efficiently navigate is commands. NOTE: The VTY is present on most Osmocom GSM/UMTS/GPRS software, thus this chapter is present in all the relevant manuals. The detailed examples below assume you are executing them on the OsmoMSC VTY. They will work in similar fashion on the other VTY interfaces, while the node structure will differ in each program. ==== The question-mark (`?`) command If you type a single `?` at the prompt, the VTY will display possible completions at the exact location of your currently entered command. If you type `?` at an otherwise empty command (without having entered even only a partial command), you will get a list of the first word of all possible commands available at this node: .Example: Typing `?` at start of OsmoMSC prompt ---- OsmoMSC> <1> show Show running system information list Print command list exit Exit current mode and down to previous mode help Description of the interactive help system enable Turn on privileged mode command terminal Set terminal line parameters who Display who is on vty logging Configure logging no Negate a command or set its defaults sms SMS related commands subscriber Operations on a Subscriber ---- <1> Type `?` here at the prompt, the `?` itself will not be printed. If you have already entered a partial command, `?` will help you to review possible options of how to continue the command. Let's say you remember that `show` is used to investigate the system status, but you don't remember the exact name of the object. Hitting `?` after typing `show` will help out: .Example: Typing `?` after a partial command ---- OsmoMSC> show <1> version Displays program version online-help Online help history Display the session command history cs7 ITU-T Signaling System 7 logging Show current logging configuration alarms Show current logging configuration talloc-context Show talloc memory hierarchy stats Show statistical values asciidoc Asciidoc generation rate-counters Show all rate counters fsm Show information about finite state machines fsm-instances Show information about finite state machine instances sgs-connections Show SGs interface connections / MMEs subscriber Operations on a Subscriber bsc BSC connection Subscriber Connections transaction Transactions statistics Display network statistics sms-queue Display SMSqueue statistics smpp SMPP Interface ---- <1> Type `?` after the `show` command, the `?` itself will not be printed. You may pick the `bsc` object and type `?` again: .Example: Typing `?` after `show bsc` ---- OsmoMSC> show bsc ---- By presenting `` as the only option, the VTY tells you that your command is complete without any remaining arguments being available, and that you should hit enter, a.k.a. "carriage return". ==== TAB completion The VTY supports tab (tabulator) completion. Simply type any partial command and press ``, and it will either show you a list of possible expansions, or completes the command if there's only one choice. .Example: Use of `` pressed after typing only `s` as command ---- OsmoMSC> s<1> show sms subscriber ---- <1> Type `` here. At this point, you may choose `show`, and then press `` again: .Example: Use of `` pressed after typing `show` command ---- OsmoMSC> show <1> version online-help history cs7 logging alarms talloc-context stats asciidoc rate-counters fsm fsm-instances sgs-connections subscriber bsc connection transaction statistics sms-queue smpp ---- <1> Type `` here. ==== The `list` command The `list` command will give you a full list of all commands and their arguments available at the current node: .Example: Typing `list` at start of OsmoMSC 'VIEW' node prompt ---- OsmoMSC> list show version show online-help list exit help enable terminal length <0-512> terminal no length who show history show cs7 instance <0-15> users show cs7 (sua|m3ua|ipa) [<0-65534>] show cs7 instance <0-15> asp show cs7 instance <0-15> as (active|all|m3ua|sua) show cs7 instance <0-15> sccp addressbook show cs7 instance <0-15> sccp users show cs7 instance <0-15> sccp ssn <0-65535> show cs7 instance <0-15> sccp connections show cs7 instance <0-15> sccp timers logging enable logging disable logging filter all (0|1) logging color (0|1) logging timestamp (0|1) logging print extended-timestamp (0|1) logging print category (0|1) logging print category-hex (0|1) logging print level (0|1) logging print file (0|1|basename) [last] logging set-log-mask MASK logging level (rll|cc|mm|rr|mncc|pag|msc|mgcp|ho|db|ref|ctrl|smpp|ranap|vlr|iucs|bssap|sgs|lglobal|llapd|linp|lmux|lmi|lmib|lsms|lctrl|lgtp|lstats|lgsup|loap|lss7|lsccp|lsua|lm3ua|lmgcp|ljibuf|lrspro) (debug|info|notice|error|fatal) logging level set-all (debug|info|notice|error|fatal) logging level force-all (debug|info|notice|error|fatal) no logging level force-all show logging vty show alarms show talloc-context (application|all) (full|brief|DEPTH) show talloc-context (application|all) (full|brief|DEPTH) tree ADDRESS show talloc-context (application|all) (full|brief|DEPTH) filter REGEXP show stats show stats level (global|peer|subscriber) show asciidoc counters show rate-counters show fsm NAME show fsm all show fsm-instances NAME show fsm-instances all show sgs-connections show subscriber (msisdn|extension|imsi|tmsi|id) ID show subscriber cache show bsc show connection show transaction sms send pending sms delete expired subscriber create imsi ID subscriber (msisdn|extension|imsi|tmsi|id) ID sms sender (msisdn|extension|imsi|tmsi|id) SENDER_ID send .LINE subscriber (msisdn|extension|imsi|tmsi|id) ID silent-sms sender (msisdn|extension|imsi|tmsi|id) SENDER_ID send .LINE subscriber (msisdn|extension|imsi|tmsi|id) ID silent-call start (any|tch/f|tch/any|sdcch) subscriber (msisdn|extension|imsi|tmsi|id) ID silent-call stop subscriber (msisdn|extension|imsi|tmsi|id) ID ussd-notify (0|1|2) .TEXT subscriber (msisdn|extension|imsi|tmsi|id) ID ms-test close-loop (a|b|c|d|e|f|i) subscriber (msisdn|extension|imsi|tmsi|id) ID ms-test open-loop subscriber (msisdn|extension|imsi|tmsi|id) ID paging show statistics show sms-queue logging filter imsi IMSI show smpp esme ---- TIP: Remember, the list of available commands will change significantly depending on the Osmocom program you are accessing, its software version and the current node you're at. Compare the above example of the OsmoMSC 'VIEW' node with the list of the OsmoMSC 'NETWORK' config node: .Example: Typing `list` at start of OsmoMSC 'NETWORK' config node prompt ---- OsmoMSC(config-net)# list help list write terminal write file write memory write show running-config exit end network country code <1-999> mobile network code <0-999> short name NAME long name NAME encryption a5 <0-3> [<0-3>] [<0-3>] [<0-3>] authentication (optional|required) rrlp mode (none|ms-based|ms-preferred|ass-preferred) mm info (0|1) timezone <-19-19> (0|15|30|45) timezone <-19-19> (0|15|30|45) <0-2> no timezone periodic location update <6-1530> no periodic location update ---- ==== The attribute system The VTY allows to edit the configuration at runtime. For many VTY commands the configuration change is immediately valid but for some commands a change becomes valid on a certain event only. In some cases it is even necessary to restart the whole process. To give the user an overview, which configuration change applies when, the VTY implemets a system of attribute flags, which can be displayed using the `show` command with the parameter `vty-attributes` .Example: Typing `show vty-attributes` at the VTY prompt ---- OsmoBSC> show vty-attributes Global attributes: ^ This command is hidden (check expert mode) ! This command applies immediately @ This command applies on VTY node exit Library specific attributes: A This command applies on ASP restart I This command applies on IPA link establishment L This command applies on E1 line update Application specific attributes: o This command applies on A-bis OML link (re)establishment r This command applies on A-bis RSL link (re)establishment l This command applies for newly created lchans ---- The attributes are symbolized through a single ASCII letter (flag) and do exist in three levels. This is more or less due to the technical aspects of the VTY implementation. For the user, the level of an attribute has only informative purpose. The global attributes, which can be found under the same attribute letter in every osmocom application, exist on the top level. The Library specific attributes below are used in various osmocom libraries. Like with the global attributes the attribute flag letter stays the same throughout every osmocom application here as well. On the third level one can find the application specific attributes. Those are unique to each osmocom application and the attribute letters may have different meanings in different osmocom applications. To make the user more aware of this, lowercase letters were used as attribute flags. The `list` command with the parameter `with-flags` displays a list of available commands on the current VTY node, along with attribute columns on the left side. Those columns contain the attribute flag letters to indicate to the user how the command behaves in terms of how and when the configuration change takes effect. .Example: Typing `list with-flags` at the VTY prompt ---- OsmoBSC(config-net-bts)# list with-flags . ... help . ... list [with-flags] . ... show vty-attributes . ... show vty-attributes (application|library|global) . ... write terminal . ... write file [PATH] . ... write memory . ... write . ... show running-config <1> . ... exit . ... end . o.. type (unknown|bs11|nanobts|rbs2000|nokia_site|sysmobts) <2> . ... description .TEXT . ... no description . o.. band BAND . .r. cell_identity <0-65535> <3> . .r. dtx uplink [force] . .r. dtx downlink . .r. no dtx uplink . .r. no dtx downlink . .r. location_area_code <0-65535> . o.. base_station_id_code <0-63> . o.. ipa unit-id <0-65534> <0-255> . o.. ipa rsl-ip A.B.C.D . o.. nokia_site skip-reset (0|1) ! ... nokia_site no-local-rel-conf (0|1) <4> ! ... nokia_site bts-reset-timer <15-100> <4> ---- <1> This command has no attributes assigned. <2> This command applies on A-bis OML link (re)establishment. <3> This command applies on A-bis RSL link (re)establishment. <4> This command applies immediately. There are multiple columns because a single command may be associated with multiple attributes at the same time. To improve readability each flag letter gets a dedicated column. Empty spaces in the column are marked with a dot (".") In some cases the listing will contain commands that are associated with no flags at all. Those commands either play an exceptional role (interactive commands outside "configure terminal", vty node navigation commands, commands to show / write the config file) or will require a full restart of the overall process to take effect. ==== The expert mode Some VTY commands are considered relatively dangerous if used in production operation, so the general approach is to hide them. This means that they don't show up anywhere but the source code, but can still be executed. On the one hand, this approach reduces the risk of an accidental invocation and potential service degradation; on the other, it complicates intentional use of the hidden commands. The VTY features so-called __expert__ mode, that makes the hidden commands appear in the interactive help, as well as in the XML VTY reference, just like normal ones. This mode can be activated from the 'VIEW' node by invoking the `enable` command with the parameter `expert-mode`. It remains active for the individual VTY session, and gets disabled automatically when the user switches back to the 'VIEW' node or terminates the session. A special attribute in the output of the `list with-flags` command indicates whether a given command is hidden in normal mode, or is a regular command: .Example: Hidden commands in the output of the `list with-flags` command ---- OsmoBSC> enable expert-mode <1> OsmoBSC# list with-flags ... ^ bts <0-255> (activate-all-lchan|deactivate-all-lchan) <2> ^ bts <0-255> trx <0-255> (activate-all-lchan|deactivate-all-lchan) <2> . bts <0-255> trx <0-255> timeslot <0-7> sub-slot <0-7> mdcx A.B.C.D <0-65535> <3> ^ bts <0-255> trx <0-255> timeslot <0-7> sub-slot <0-7> (borken|unused) <2> . bts <0-255> trx <0-255> timeslot <0-7> sub-slot <0-7> handover <0-255> <3> . bts <0-255> trx <0-255> timeslot <0-7> sub-slot <0-7> assignment <3> . bts <0-255> smscb-command (normal|schedule|default) <1-4> HEXSTRING <3> ... ---- <1> This command enables the __expert__ mode. <2> This is a hidden command (only shown in the __expert__ mode). <3> This is a regular command that is always shown regardless of the mode.