release/picobsd/doc/src/UCI.html

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   2 <! $FreeBSD: src/release/picobsd/doc/src/UCI.html,v 1.4 1999/08/28 01:33:24 peter Exp $ >
   3 <body>
   4 <h1><center>            Unified Configuration Interface Project
   5 </center></h1>
   6
   7 <p>The idea behind this project is to completely replace currently
   8 used configuration approach, which is based on several shell scripts, and to
   9 provide ability to change system behaviour basing on set of well-defined
  10 parameters' hierarchy. One of the goals is also to provide an object
  11 oriented model of the OS management and structure, instead of currently
  12 used (inconsistent) procedural model of system/service startup/shutdown.</p>
  13
  14 <p>This project involves such issues as:
  15 <ul>
  16 <li>
  17 providing consistent view of the system and its functional subsystems as
  18 a set of interrelated objects equipped with certain properties.
  19 </li>
  20 <li>
  21 providing global approach to user interface, either command-line or with GUI
  22 front-ends.
  23 </li>
  24 <li>
  25 managing system resources and subsystems. This includes managing
  26 static and dynamic interdependencies between subsystems, ability to
  27 upgrade/downgrade specific subsystems on-the-fly.
  28 </li>
  29 </ul>
  30 </p>
  31
  32 <p><i><b>This is work in progress</b> - I'm aware that many pieces
  33 are either completely missing or misplaced. Please send any comments and
  34 changes you seem appropriate either directly to me, or better to
  35 freebsd-small@freebsd.org. I'll gladly welcome anyone who can help with
  36 design and/or implementation.</i></p>
  37
  38
  39 <hr>
  40
  41 <h1><center>            Unified Configuration Interface
  42 </center></h1>
  43
  44 <ul>
  45 <li>
  46 <p>Let's first introduce the following terms:
  47 <ul>
  48 <li>
  49 <b>management base</b> - the actual structure holding configuration and
  50 information data according to defined structure. This structure will most
  51 probably have a form of tree (possibly with cross-branch links or some other
  52 mechanism representing mutual dependencies) - the way it's stored is
  53 something which needs to be discussed.
  54 </li>
  55 <li>
  56 <b>user interface</b> - a method (and agent) for presenting data stored in
  57 management base in such a way that it can be viewed and modified by
  58 legitimate users.
  59 </li>
  60 <li>
  61 <b>system monitor</b> - an entity performing actual configuration and monitoring
  62 tasks, from one side dealing with management base, and from the other
  63 dealing with the system resources and subsystems, and from yet another dealing
  64 either directly with the user (thus acting as a user interface),
  65 or passing requests to other entity which acts as user interface.
  66 </li>
  67 <li>
  68 <b>subsystem</b> - a package containing programs, configuration data, as well
  69 as installing/deinstalling/start/stop stubs, which form together one logical
  70 entity performing specific services on behalf of the system. Each subsystem
  71 is viewed as an object with specific properties, dependencies, which is able
  72 to generate events, service general requests common to all such subsystems,
  73 and provide specific services to other subsystems.
  74 </li>
  75 </ul>
  76 </li>
  77 <li>
  78 <p>One possible approach to storing the management data is to use already
  79 existing framework known as MIB, as defined in applicable RFCs.</p>
  80
  81 <p>This approach has several advantages: it represents well thought-out work
  82 of many experienced individuals and teams, it has already proven to be
  83 useful, it's widely used and accepted, it's easily extensible, it's able to
  84 represent quite complicated objects, etc.</p>
  85
  86 <p>It has some drawbacks, as well: e.g. there is no standard mechanism for
  87 representing events and indirectly related objects, it tends to create
  88 deep and narrow trees which require to descent several levels to change some
  89 commonly used parameters, it doesn't say anything about the mutual
  90 dependencies between objects and parameters (except parent-child-sibling),
  91 and about required sequence to properly set their parameters, etc.</p>
  92
  93 <p>These issues are not directly addressed in standards, and real
  94 implementations (known to me) have to implement these additional mechanisms
  95 "behind the scenes", so that their workings are not obvious nor easily
  96 accessible (let alone changeable).</p>
  97
  98 <p>So, if we decide to use it, we need to address these issues somehow.
  99 The next point presents one possible approach to this dilemma.</p>
 100 </li>
 101 <li>
 102 <p>The term "object" used in the following discussion represents a functional
 103 subsystem, such as system service, usually performed by some specific
 104 process (or, a set of global system parameters, in which case the system
 105 monitor agent is the service itself). </p>
 106
 107 <p>Each object represented in management base can be characterized by
 108 following properties:
 109 <ul>
 110 <li>
 111 its internal state, possibly consisting of several parameters and currently
 112 performed functions, but represented to the rest of the system as a symbolic
 113 state, one of set of states common to all objects.
 114 </li>
 115 <li>
 116 a temporary space for new sets of parameters, which are being supplied by
 117 other subsystems, prior to their actual application,
 118 </li>
 119 <li>
 120 FSM definition, describing state transitions in reaction to received events,
 121 </li>
 122 <li>
 123 list of events it can generate and accept,
 124 </li>
 125 <li>
 126 list of dependencies on other objects' states and services,
 127 </li>
 128 <li>
 129 list of requests it can handle,
 130 </li>
 131 <li>
 132 list of parameters it can accept and/or provide, with their valid ranges.
 133 </li>
 134 </ul>
 135 </p>
 136
 137 <p>A few words on system startup: the system startup routines should ensure
 138 that dependencies can be unwound into linear, ordered list. If it's not
 139 possible, they should detect possible deadlocks at runtime, and act as an
 140 arbiter between conflicting parties (or signal an error). In case of
 141 unsatisfied dependency on some missing subsystem, the system monitor will
 142 act appropriately as described below (in paragraph on request handling).</p>
 143
 144 <p>The <b>set of symbolic states</b> may consist of the following states,
 145 depicting object's current internal state (as described by its FSM):
 146
 147 <center><table border>
 148 <tr><th>Name</th><th>Meaning</th></tr>
 149 <tr>
 150 <td>INIT</td><td>the subsystem is initializing itself, possibly loading
 151 necessary data and binaries from permanent storage.</td>
 152 </tr>
 153 <tr>
 154 <td>CHECK</td><td>performing consistency check on newly supplied parameter values</td>
 155 </tr>
 156 <tr>
 157 <td>READY</td><td>ready to start performing its primary function, but not started</td>
 158 </tr>
 159 <tr>
 160 <td>START</td><td>start-up tasks (related to its primary function, as opposed
 161 to INIT which is related to its own initialization)</td>
 162 </tr>
 163 <tr>
 164 <td>STOP</td><td>stop (shutdown) tasks (when the object intends to stop
 165 performing its function). This can involve unloading data and binaries from
 166 main memory.</td>
 167 </tr>
 168 <tr>
 169 <td>RUN</td><td>primary (work) phase</td>
 170 </tr>
 171 <tr>
 172 <td>IDLE</td><td>waiting for some external event to happen</td>
 173 </tr>
 174 <tr>
 175 <td>BUSY</td><td>the subsystem is busy (either with performing some
 176 high-priority task, or just simply hung), and cannot be interrupted without
 177 complete restart,</td>
 178 </tr>
 179 <tr>
 180 <td>ERROR</td><td>this object is either improperly configured, or
 181 malfunctioning</td>
 182 </tr>
 183 <tr>
 184 <td>(other...)</td><td>(other...)</td>
 185 </tr>
 186 </table></center>
 187 </p>
 188
 189 <p>The <b>set of possible actions</b> may include the following actions:</p>
 190
 191 <center><table border>
 192 <tr><th>Name</th><th>Meaning</th></tr>
 193 <tr>
 194 <td>LIST_EV_REQ</td><td>get list of events the subsystem can generate</td>
 195 </tr>
 196 <tr>
 197 <td>LIST_ACT_REQ</td><td>get list of actions the subsystem can respond to</td>
 198 </tr>
 199 <tr>
 200 <td>GET_DEF_REQ</td><td>get definition of given parameter (the arguments, and
 201 valid ranges)</td>
 202 </tr>
 203 <tr>
 204 <td>SET_REQ</td><td>set given parameter to given value (this value will
 205 be used only after COMMIT_REQ)</td>
 206 </tr>
 207 <tr>
 208 <td>GET_REQ</td><td>get currently used value of given parameter</td>
 209 </tr>
 210 <tr>
 211 <td>COMMIT_REQ</td><td>commit changes supplied in last transaction to currently
 212 used set of parameters</td>
 213 </tr>
 214 <tr>
 215 <td>ROLLBACK_REQ</td><td>revert last commit</td>
 216 </tr>
 217 <tr>
 218 <td>INIT_REQ</td><td>perform initialization tasks</td>
 219 </tr>
 220 <tr>
 221 <td>START_REQ</td><td>start performing primary function</td>
 222 </tr>
 223 <tr>
 224 <td>STOP_REQ</td><td>stop performing primary function</td>
 225 </tr>
 226 <tr>
 227 <td>RESTART_REQ</td><td>restart operation, possibly forcefully</td>
 228 </tr>
 229 <tr>
 230 <td>NOTIFY_REQ</td><td>notify me of any changes in your state</td>
 231 </tr>
 232 <tr>
 233 <td>CHECK_REQ</td><td>perform self-consistency check</td>
 234 </tr>
 235 <tr>
 236 <td>UPGRADE_REQ</td><td>upgrade the subsystem - this possibly involves
 237 downloading necessary pieces via network to permanent storage area. The
 238 upgrade process should be transactional, and should save the older version
 239 of the subsystem in case the DOWNGRADE_REQ should be issued.</td>
 240 </tr>
 241 <tr>
 242 <td>DOWNGRADE_REQ</td><td>downgrade the subsystem - restore the previous
 243 version of the subsystem from the copy on permanent storage.</td>
 244 </tr>
 245 <tr>
 246 <td>UNINSTALL_REQ</td><td>uninstall the subsystem completely - possibly
 247 freeing the space on permanent storage.</td>
 248 </tr>
 249 <tr>
 250 <td>(other...)</td><td>(other...)</td>
 251 </tr>
 252 </table></center>
 253 <p><i>(Each request includes source service identifier and credentials of
 254 the sender)</i></p>
 255
 256 <p>The <b>set of events</b> which can be generated by subsystems may include
 257 the following:</p>
 258
 259 <center><table border>
 260 <tr><th>Name</th><th>Meaning</th></tr>
 261 <tr>
 262 <td>EV_ACK</td><td>positive acknowledge of the last operation</td>
 263 </tr>
 264 <tr>
 265 <td>EV_NACK</td><td>negative acknowledge of the last operation</td>
 266 </tr>
 267 <tr>
 268 <td>EV_CHANGE</td><td>change notification (includes the name of changed
 269 parameter, and/or FSM state change)</td>
 270 </tr>
 271 <tr>
 272 <td>EV_DEP</td><td>signal the dependency on another subsystem - ask for
 273 existence of the service. Probably there should be two types of the dependency:
 274 a soft one (where the subsystem can still function even if the dependency is
 275 unresolved) and a hard one (when the existence and proper functioning of the
 276 other subsystem is mandatory for its function).</td>
 277 </tr>
 278 <tr>
 279 <td>(other...)</td><td>(other...)</td>
 280 </tr>
 281 </table></center>
 282
 283 <p>One of event attributes can be a flag which says that this particular event
 284 is a directed, or broadcast message. In case of directed message, it should
 285 be forwarded only to interested parties. Broadcast message is sent to all
 286 subsystems.</p>
 287
 288 <p>System monitor agent will process these events and route them to
 289 appropriate subsystems which are registered with it. Generally, if some
 290 subsystem is dependent on some other, it will want to also receive all events
 291 generated by the other subsystem.</p>
 292
 293 <p>In case the subsystem
 294 is missing, and the system monitor received events signalling that some other
 295 subsystem is depending on it, the system monitor should arrange either for
 296 installing necessary pieces from some media (be it permanent storage, or the
 297 network), or to send an EV_NACK to the requesting subsystem. It's the
 298 responsibility of the requesting subsystem to deal with such case
 299 appropriately to the type of dependency (i.e. either "hard" or "soft").
 300
 301 <p>Ideally, the system monitor agent will be equipped with routines to
 302 serialize the management data into human-readable form, so that it's easily
 303 stored, backed up, and repaired in case of inconsistencies.</p>
 304 </li>
 305 <li>
 306 <p>Actual user interface is still quite another story: I've seen UIs which
 307 merely followed the standard MIBs, and menus were composed of actual OID
 308 numbers plus DESCRIPTION field. In my experience, they are (barely)
 309 acceptable, though due to the usual width and depth of MIB trees you had to
 310 traverse several levels down and up in order to change some (protocol-wise)
 311 related parameters.</p>
 312
 313 <p>More acceptable UI would collect interrelated items under common menu
 314 entries, irrespectibly of their actual position in the MIB tree.</p>
 315
 316 <p>A worthwhile goal to pursue is to create such an UI which could guide
 317 you through the most common configuration tasks, while at the same time
 318 allowing for unrestricted and quick use by power users. This can be done
 319 either as a set of configuration "wizards" or extensive hinting, command
 320 completion, etc.</p>
 321 </li>
 322 <li>
 323 <p>The management database should be easily exportable via standard
 324 protocols, such as SNMP or LDAP.</p>
 325
 326 <p>Most known to me (if not all) implementations of agents for these
 327 protocols are (contrary to their name) quite heavy-weight - so their use
 328 should be either optional, or replaced with some other light-weight
 329 protocol and a proxy agent running on other machine. One example of
 330 such proxy agent is existing UCD-SNMP implementation which in
 331 significant part follows the sysctl(3) tree, merely exporting it as
 332 a part of the MIB trees.</p>
 333
 334 <p>It's worthwhile to consider also use of other protocols such as
 335 DHCP (and BOOTP), Service Location Protocol (SLP - RFC2165) for easy
 336 integration with LAN resources, easy initial configuration, and peer
 337 discovery.</p>
 338 </li>
 339 <li>
 340 <p>All operations performed by system monitor agent should be transactional,
 341 i.e. it should be possible to commit a set of changes as one logical entity,
 342 and be sure that either it's applied in whole, or not at all. This includes
 343 also ability to abort processing in the middle.</p>
 344
 345 <p>This probably means that each object (subsystem) should be able to store
 346 not only its current configuration data, but also the newly supplied config
 347 data that are to be applied after the transaction ends successfuly.</p>
 348
 349 <p>Operations should be verified against allowed values, as well as against
 350 allowed credentials, and basing on this either committed or aborted.</p>
 351 </li>
 352 <li>
 353 <p>A few notes on possible implementation of system monitor:</p>
 354 <ul>
 355 <li>
 356 let's assume that all configuration information is read on startup
 357 by some specialized daemon (this can be part of init(8) as well),
 358 which then performs role of communication agent through which passes
 359 all configuration information, be it request for change, request
 360 for info, request for start / shutdown, or notification about the change.
 361 </li>
 362 <li>
 363 configuration information itself is stored either in binary database, or as
 364 a filesystem hierachy mimicking configuration items hierarchy.
 365 </li>
 366 <li>
 367 each user-level program performing some task (such as routing daemon, inetd
 368 etc) is either equipped with the ability to communicate with config agent, or
 369 is relinked with special stub which fakes to the program necessary config
 370 files and events (such as signals to reread configuration).
 371 <p>This probably means also that some libc routines would have to be replaced,
 372 because they assume reading configuration from certain disk files.</p>
 373
 374 <p>Since each such subsystem needs to implement some common actions such as
 375 installing, deinstalling, start/stop etc, we could use already present
 376 system of packages (with some minor modifications) to easily achieve
 377 part of the goals (i.e. install/deinstall/upgrade/downgrade/stop/start).</p>
 378 </li>
 379 <li>
 380 each subsystem performing some task requests its initial config data
 381 from system monitor, at the same time registering with it to receive
 382 configuration events, such as request to re-read data, to provide currently
 383 used config data, return status, react for signals, restarts, etc...
 384 </li>
 385 <li>
 386 system monitor acts as a meeting point for all producers and consumers
 387 of events and config data. It needs to maintain a table of registered
 388 subsystems, set of events they provide, set of events they want to receive,
 389 etc.. Basing on this table, it  routes appropriate information to
 390 appropriate parties.
 391 </li>
 392 <li>
 393 user interface is then just one of clients of system monitor, albeit possessing
 394 special privileges.
 395 </li>
 396 <li>
 397 one of important tasks of system monitor, in case given
 398 object (subsystem) registers with it to be notified about certain events, is
 399 to ensure that such type of event can be possibly generated. This is to
 400 prevent subsystems from waiting for events coming from other non-existent
 401 subsystems. See the discussion above on satisfying dependencies.
 402 </li>
 403 </ul>
 404 <i><p>NOTE: this is one possible approach - a centralized one. It's worth to
 405 consider other approach, distributed, in which case each object (subsystem)
 406 sends and listens to the data at a meeting point specific to each other
 407 object. This eliminates (or drastically minimizes) the role of system
 408 monitor which is a single point of failure in centralized case.</p></i>
 409 </li>
 410 </ul>
 411
 412 <hr>
 413
 414 <p>Here is my initial proposal for the User Interface hierarchy:</p>
 415
 416 <ul>
 417 <li>
 418 System configuration.
 419         <ol>
 420         <li>
 421         Boot device and file <br>
 422         <small>Name of the boot device (possibly networked) and boot
 423         image.</small>
 424                 <ol>
 425                 <li>
 426                 (Enumeration of available devices)
 427                         <ol>
 428                         <li>
 429                         (Enumeration of available files)
 430                         </li>
 431                         </ol>
 432                 </li>
 433                 </ol>
 434         </li>
 435         <li>
 436         Config file <br>
 437         <small>Configuration file management - loading and saving, either
 438         local or remote (if applicable). </small>
 439                 <ol>
 440                 <li>
 441                 Load / Save
 442                         <ol>
 443                         <li>
 444                         Source / Destination <br>
 445                         (Enumeration of available storage places, possibly
 446                         networked)
 447                         </li>
 448                         </ol>
 449                 </li>
 450                 <li>
 451                 Edit directly (geek mode)
 452                 </li>
 453                 </ol>
 454         </li>
 455         <li>
 456         Subsystems <br>
 457                 <ol>
 458                 <li>
 459                 Module management <br>
 460                 <small>Optional hardware drivers and protocol modules
 461                 management.</small>
 462                         <ol>
 463                         <li>
 464                         (Enumeration of available loadable modules)
 465                                 <ol>
 466                                 <li>
 467                                 Load / unload / status
 468                                 </li>
 469                                 </ol>
 470                         </li>
 471                         </ol>
 472                 </li>
 473                 <li>
 474                 Package management<br>
 475                 <small>Management of basic and optional system services.</small>
 476                         <ol>
 477                         <li>
 478                         (Enumeration of locally available packages)
 479                                 <ol>
 480                                 <li>
 481                                 Start / Stop / Status / Configure
 482                                 </li>
 483                                 </ol>
 484                         </li>
 485                         </ol>
 486                 </li>
 487                 <li>
 488                 Default source of service packages<br>
 489                 <small>Where to automatically get the missing packages from.
 490                 </small>
 491                         <ol>
 492                         <li>
 493                         (Enumeration of available media) <br>
 494                         (local and remote disks, ftp, http)
 495                         </li>
 496                         </ol>
 497                 </li>
 498                 </ol>
 499         </li>
 500         <li>
 501         Resource management
 502                 <ol>
 503                 <li>
 504                 Memory consumption <br>
 505                 <small>This is entry point to a subtree, which allows to set
 506                 up various resource limits for subsystems, services and
 507                 processes.</small>
 508                 </li>
 509                 <li>
 510                 Space consumption<br>
 511                 <small>(Things like minimal free space on permanent storage..)
 512                 </small>
 513                 </li>
 514                 <li>
 515                 Task priorities
 516                 <small>This includes not only currently running tasks, but all
 517                 which can possibly be started.</small>
 518                         <ol>
 519                         <li>
 520                         List / Modify
 521                         </li>
 522                         </ol>
 523                 </li>
 524                 </ol>
 525         </li>
 526         <li>
 527         System console
 528         </li>
 529         <li>
 530         Virtual consoles (if applicable)
 531         </li>
 532         <li>
 533         System Date / Time Zone
 534         </li>
 535         <li>
 536         Banner
 537         </li>
 538         <li>
 539         Logging
 540                 <ol>
 541                 <li>
 542                 Local logging
 543                 </li>
 544                 <li>
 545                 Remote logging
 546                 </li>
 547                 </ol>
 548         </li>
 549         </ol>
 550 </li>
 551 <li>
 552 Network configuration.
 553         <ol>
 554         <li>
 555         Hostname and Domain
 556         </li>
 557         <li>
 558         Interfaces
 559                 <ol>
 560                 <li>
 561                 (Enumeration of physical interfaces) <br>
 562                 (Enumeration of virtual interfaces, if applicable) <br>
 563                 (Options for creating virtual interfaces, if applicable)
 564                         <ol>
 565                         <li>
 566                         Interface options (speed, media, encapsulation,
 567                         description, etc.)
 568                         </li>
 569                         <li>
 570                         ARP
 571                         </li>
 572                         <li>
 573                         Bridging
 574                         </li>
 575                         <li>
 576                         IP
 577                                 <ol>
 578                                 <li>
 579                                 Adress / netmask / alias
 580                                 </li>
 581                                 </ol>
 582                         </li>
 583                         <li>
 584                         IPX
 585                         </li>
 586                         <li>
 587                         AppleTalk
 588                         </li>
 589                         </ol>
 590                 </li>
 591                 </ol>
 592         </li>
 593         <li>
 594         Protocol Options
 595                 <ol>
 596                 <li>
 597                 IP, UDP, TCP, ARP, IPX, ATM ... <br>
 598                 (Enumeration of available protocols)
 599                         <ol>
 600                         <li>
 601                         (Enumeration of protocol specific options, such as
 602                         buffer sizes, algorithms, ARP tables etc)
 603                                 <ol>
 604                                 <li>
 605                                 List / Add / Delete / Modify / Set (where
 606                                 applicable)
 607                                 </li>
 608                                 </ol>
 609                         </li>
 610                         </ol>
 611                 </li>
 612                 </ol>
 613         </li>
 614         <li>
 615         Routes
 616                 <ol>
 617                 <li>
 618                 List
 619                 </li>
 620                 <li>
 621                 Static
 622                         <ol>
 623                         <li>
 624                         Add / Delete / List
 625                                 <ol>
 626                                 <li>
 627                                 (route expression)
 628                                 </li>
 629                                 </ol>
 630                         </li>
 631                         </ol>
 632                 </li>
 633                 <li>
 634                 Dynamic
 635                         <ol>
 636                         <li>
 637                         (Enumeration of available routing protocols)
 638                                 <ol>
 639                                 <li>
 640                                 Add / Delete / List
 641                                         <ol>
 642                                         <li>
 643                                         (route expression)
 644                                         </li>
 645                                         </ol>
 646                                 </li>
 647                                 </ol>
 648                         </li>
 649                         </ol>
 650                 </li>
 651                 </ol>
 652         </li>
 653         <li>
 654         Network services
 655                 <ol>
 656                 <li>
 657                 DNS
 658                         <ol>
 659                         <li>
 660                         Hosts
 661                                 <ol>
 662                                 <li>
 663                                 Add / Delete / List
 664                                         <ol>
 665                                         <li>
 666                                         (hosts definitions)
 667                                         </li>
 668                                         </ol>
 669                                 </li>
 670                                 </ol>
 671                         </li>
 672                         <li>
 673                         Resolvers
 674                                 <ol>
 675                                 <li>
 676                                 Add / Delete / List
 677                                         <ol>
 678                                         <li>
 679                                         (hosts addresses)
 680                                         </li>
 681                                         </ol>
 682                                 </li>
 683                                 </ol>
 684                         </li>
 685                         <li>
 686                         Local DNS server config
 687                         </li>
 688                         </ol>
 689                 </li>
 690                 <li>
 691                 PPP
 692                         <ol>
 693                         <li>
 694                         Server
 695                         </li>
 696                         <li>
 697                         Client
 698                         </li>
 699                         </ol>
 700                 </li>
 701                 <li>
 702                 NFS
 703                         <ol>
 704                         <li>
 705                         Server
 706                         </li>
 707                         <li>
 708                         Client
 709                         </li>
 710                         </ol>
 711                 </li>
 712                 <li>
 713                 NIS
 714                 </li>
 715                 <li>
 716                 DHCP
 717                         <ol>
 718                         <li>
 719                         Add / Delete / Reserve / List
 720                                 <ol>
 721                                 <li>
 722                                 (IP address expressions)
 723                                 </li>
 724                                 </ol>
 725                         </li>
 726                         </ol>
 727                 </li>
 728                 <li>
 729                 SNMP
 730                         <ol>
 731                         <li>
 732                         Protocol version
 733                         </li>
 734                         <li>
 735                         Send traps to...
 736                         </li>
 737                         <li>
 738                         Access Control Lists <br>
 739                         <small>(This is either full-blown ACL system in case
 740                         of SNMPv2, or a community string for SNMPv1.)</small>
 741                         </li>
 742                         </ol>
 743                 </li>
 744                 <li>
 745                 Printing
 746                         <ol>
 747                         <li>
 748                         Local / Remote
 749                                 <ol>
 750                                 <li>
 751                                 Printers
 752                                         <ol>
 753                                         <li>
 754                                         Add / Modify / Delete / List
 755                                         </li>
 756                                         </ol>
 757                                 </li>
 758                                 <li>
 759                                 Queues
 760                                         <ol>
 761                                         <li>
 762                                         Priority / Delete / List
 763                                         </li>
 764                                         </ol>
 765                                 </li>
 766                                 </ol>
 767                         </li>
 768                         </ol>
 769                 </li>
 770                 <li>
 771                 SMB services
 772                 </li>
 773                 <li>
 774                 Network Address Translation
 775                 </li>
 776                 <li>
 777                 Packet filters
 778                 </li>
 779                 <li>
 780                 Bandwidth Manager
 781                 </li>
 782                 <li>
 783                 NTP
 784                 </li>
 785                 <li>
 786                 Remote Access
 787                 </li>
 788                 </ol>
 789         </li>
 790         </ol>
 791 <li>
 792 User management.
 793         <ol>
 794         <li>
 795         User accounts
 796                 <ol>
 797                 <li>
 798                 Add / Delete / Modify / List
 799                         <ol>
 800                         <li>
 801                         Name / Password / ACL
 802                         </li>
 803                         </ol>
 804                 </li>
 805                 </ol>
 806         </li>
 807         <li>
 808         User profiles
 809                 <ol>
 810                 <li>
 811                 Access Control Lists.
 812                         <ol>
 813                         <li>
 814                         Add / Delete / Modify / List
 815                                 <ol>
 816                                 <li>
 817                                 Name / Template / Definition
 818                                 </li>
 819                                 </ol>
 820                         </li>
 821                         </ol>
 822                 </li>
 823                 <li>
 824                 ACL Templates
 825                         <ol>
 826                         <li>
 827                         Add / Delete / Modify / List
 828                                 <ol>
 829                                 <li>
 830                                 Name
 831                                         <ol>
 832                                         <li>
 833                                         Command restrictions list
 834                                         </li>
 835                                         <li>
 836                                         Location restrictions list
 837                                         </li>
 838                                         <li>
 839                                         Resources restrictions list
 840                                         </li>
 841                                         <li>
 842                                         Time restrictions list
 843                                         </li>
 844                                         <li>
 845                                         Authentication methods
 846                                                 <ol>
 847                                                 <li>
 848                                                 Unix passwd
 849                                                 </li>
 850                                                 <li>
 851                                                 S/Key
 852                                                 </li>
 853                                                 <li>
 854                                                 Kerberos
 855                                                 </li>
 856                                                 <li>
 857                                                 Radius
 858                                                 </li>
 859                                                 <li>
 860                                                 TACACS
 861                                                 </li>
 862                                                 </ol>
 863                                         </li>
 864                                         </ol>
 865                                 </li>
 866                                 </ol>
 867                         </li>
 868                         </ol>
 869                 </li>
 870                 </ol>
 871         </li>
 872         </ol>
 873 </li>
 874 <li>
 875 Other services
 876         <ol>
 877         <li>
 878         Cron tasks
 879         </li>
 880         </ol>
 881 </li>
 882 <li>
 883 Filesystems.
 884         <ol>
 885         <li>
 886         Local / Remote
 887                 <ol>
 888                 <li>
 889                 (Enumeration of available FS-s)
 890                         <ol>
 891                         <li>
 892                         FS / Mounting point / Options
 893                         </li>
 894                         </ol>
 895                 </li>
 896                 <li>
 897                 Swap Partition / Swap File
 898                         <ol>
 899                         <li>
 900                         Create / Turn on
 901                         </li>
 902                         </ol>
 903                 </ol>
 904         </li>
 905         </ol>
 906 </li>
 907 <li>
 908 Environment
 909         <ol>
 910         <li>
 911         Set / Unset / List
 912         </li>
 913         </ol>
 914 </li>
 915 <li>
 916 System status
 917         <ol>
 918         <li>
 919         (Enumeration of available status items)
 920         </li>
 921         </ol>
 922 </li>
 923 <li>
 924 Diagnostics
 925         <ol>
 926         <li>
 927         Debug
 928                 <ol>
 929                 <li>
 930                 (Enumeration of subsystems hierarchy, those of which can
 931                 provide debugging data)
 932                         <ol>
 933                         <li>
 934                         Set / Clear / Level
 935                         </li>
 936                         </ol>
 937                 </li>
 938                 </ol>
 939         </li>
 940         <li>
 941         System messages
 942         </li>
 943         <li>
 944         Ping / traceroute / rtquery
 945         </li>
 946         </ol>
 947 </li>
 948 </ul>
 949
 950 <hr>
 951 <i>
 952 <p>Please send your comments to <A HREF="mailto:abial@freebsd.org">
 953 Andrzej Bialecki</a></p>
 954 <p>Last modified:
 955 @DATE@
 956 </p>
 957 </i>
 958
 959 </body>
 960 </html>