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   6 .TH SMF_METHOD 5 "June 6, 2016"
   7 .SH NAME
   8 smf_method \- service management framework conventions for methods
   9 .SH DESCRIPTION
  10 .LP
  11 The class of services managed by \fBsvc.startd\fR(1M) in the service management
  12 framework, \fBsmf\fR(5), consists of applications that fit a simple
  13 \fBfork\fR(2)-\fBexec\fR(2) model. The \fBsvc.startd\fR(1M) master daemon and
  14 other restarters support the \fBfork\fR(2)-\fBexec\fR(2) model, potentially
  15 with additional capabilities. The \fBsvc.startd\fR(1M) daemon and other
  16 restarters require that the methods which activate, manipulate, or examine a
  17 service instance follow the conventions described in this manual page.
  18 .SS "Invocation form"
  19 .LP
  20 The form of a method invocation is not dictated by convention. In some cases, a
  21 method invocation might consist of the direct invocation of the daemon or other
  22 binary executable that provides the service. For cases in which an executable
  23 script or other mediating executable is used, the convention recommends the
  24 form:
  25 .sp
  26 .in +2
  27 .nf
  28 /path/to/method_executable abbr_method_name
  29 .fi
  30 .in -2
  31 
  32 .sp
  33 .LP
  34 The \fIabbr_method_name\fR used for the recommended form is a supported method
  35 such as \fBstart\fR or \fBstop\fR. The set of methods supported by a restarter
  36 is given on the related restarter page. The \fBsvc.startd\fR(1M) daemon
  37 supports \fBstart\fR, \fBstop\fR, and \fBrefresh\fR methods.
  38 .sp
  39 .LP
  40 A restarter might define other kinds of methods beyond those referenced in this
  41 page. The conventions surrounding such extensions are defined by the restarter
  42 and might not be identical to those given here.
  43 .SS "Environment Variables"
  44 .LP
  45 The restarter provides four environment variables to the method that determine
  46 the context in which the method is invoked.
  47 .sp
  48 .ne 2
  49 .na
  50 \fB\fBSMF_FMRI\fR\fR
  51 .ad
  52 .sp .6
  53 .RS 4n
  54 The service fault management resource identifier (FMRI) of the instance for
  55 which the method is invoked.
  56 .RE
  57 
  58 .sp
  59 .ne 2
  60 .na
  61 \fB\fBSMF_METHOD\fR\fR
  62 .ad
  63 .sp .6
  64 .RS 4n
  65 The full name of the method being invoked, such as \fBstart\fR or \fBstop\fR.
  66 .RE
  67 
  68 .sp
  69 .ne 2
  70 .na
  71 \fB\fBSMF_RESTARTER\fR\fR
  72 .ad
  73 .sp .6
  74 .RS 4n
  75 The service FMRI of the restarter that invokes the method
  76 .RE
  77 
  78 .sp
  79 .ne 2
  80 .na
  81 \fB\fBSMF_ZONENAME\fR\fR
  82 .ad
  83 .sp .6
  84 .RS 4n
  85 The name of the zone in which the method is running. This can also be obtained
  86 by using the \fBzonename\fR(1) command.
  87 .RE
  88 
  89 .sp
  90 .LP
  91 These variables should be removed from the environment prior to the invocation
  92 of any persistent process by the method. A convenience shell function,
  93 \fBsmf_clear_env\fR, is given for service authors who use Bourne-compatible
  94 shell scripting to compose service methods in the include file described below.
  95 .sp
  96 .LP
  97 The method context can cause other environment variables to be set as described
  98 below.
  99 .SS "Method Definition"
 100 .LP
 101 A method is defined minimally by three properties in a propertygroup of type
 102 \fBmethod\fR.
 103 .sp
 104 .LP
 105 These properties are:
 106 .sp
 107 .ne 2
 108 .na
 109 \fBexec (\fIastring\fR)\fR
 110 .ad
 111 .RS 27n
 112 Method executable string.
 113 .RE
 114 
 115 .sp
 116 .ne 2
 117 .na
 118 \fBtimeout_seconds (\fIcount\fR)\fR
 119 .ad
 120 .RS 27n
 121 Number of seconds before method times out. See the \fBTimeouts\fR section for
 122 more detail.
 123 .RE
 124 
 125 .sp
 126 .ne 2
 127 .na
 128 \fBtype (\fIastring\fR)\fR
 129 .ad
 130 .RS 27n
 131 Method type. Currently always set to \fBmethod\fR.
 132 .RE
 133 
 134 .sp
 135 .LP
 136 A Method Context can be defined to further refine the execution environment of
 137 the method. See the \fBMethod Context\fR section for more information.
 138 .SS "Method Tokens"
 139 .LP
 140 When defined in the \fBexec\fR string of the method by the restarter
 141 \fBsvc.startd\fR, a set of tokens are parsed and expanded with appropriate
 142 value. Other restarters might not support method tokens. The delegated
 143 restarter for inet services, \fBinetd\fR(1M), does not support the following
 144 method expansions.
 145 .sp
 146 .ne 2
 147 .na
 148 \fB\fB%%\fR\fR
 149 .ad
 150 .sp .6
 151 .RS 4n
 152 %
 153 .RE
 154 
 155 .sp
 156 .ne 2
 157 .na
 158 \fB\fB%r\fR\fR
 159 .ad
 160 .sp .6
 161 .RS 4n
 162 Name of the restarter, such as \fBsvc.startd\fR
 163 .RE
 164 
 165 .sp
 166 .ne 2
 167 .na
 168 \fB\fB%m\fR\fR
 169 .ad
 170 .sp .6
 171 .RS 4n
 172 The full name of the method being invoked, such as \fBstart\fR or \fBstop\fR.
 173 .RE
 174 
 175 .sp
 176 .ne 2
 177 .na
 178 \fB\fB%s\fR\fR
 179 .ad
 180 .sp .6
 181 .RS 4n
 182 Name of the service
 183 .RE
 184 
 185 .sp
 186 .ne 2
 187 .na
 188 \fB\fB%i\fR\fR
 189 .ad
 190 .sp .6
 191 .RS 4n
 192 Name of the instance
 193 .RE
 194 
 195 .sp
 196 .ne 2
 197 .na
 198 \fB\fB\fR\fB%f\fR\fR
 199 .ad
 200 .sp .6
 201 .RS 4n
 202 FMRI of the instance
 203 .RE
 204 
 205 .sp
 206 .ne 2
 207 .na
 208 \fB\fB%{prop[:,]}\fR\fR
 209 .ad
 210 .sp .6
 211 .RS 4n
 212 Value(s) of a property. The \fBprop\fR might be a property FMRI, a property
 213 group name and a property name separated by a \fB/\fR, or a property name in
 214 the \fBapplication\fR property group. These values can be followed by a \fB,\fR
 215 (comma) or \fB:\fR (colon). If present, the separators are used to separate
 216 multiple values. If absent, a space is used. The following shell metacharacters
 217 encountered in string values are quoted with a \ (backslash):
 218 .sp
 219 .in +2
 220 .nf
 221 ; & ( ) | ^ < > newline space tab  \  " '
 222 .fi
 223 .in -2
 224 
 225 An invalid expansion constitutes method failure.
 226 .RE
 227 
 228 .sp
 229 .LP
 230 Two explicit tokens can be used in the place of method commands.
 231 .sp
 232 .ne 2
 233 .na
 234 \fB\fB:kill [-signal]\fR\fR
 235 .ad
 236 .sp .6
 237 .RS 4n
 238 Sends the specified signal, which is \fBSIGTERM\fR by default, to all processes
 239 in the primary instance contract. Always returns \fBSMF_EXIT_OK\fR. This token
 240 should be used to replace common \fBpkill\fR invocations.
 241 .RE
 242 
 243 .sp
 244 .ne 2
 245 .na
 246 \fB\fB:true\fR\fR
 247 .ad
 248 .sp .6
 249 .RS 4n
 250 Always returns \fBSMF_EXIT_OK\fR. This token should be used for methods that
 251 are required by the restarter but which are unnecessary for the particular
 252 service implementation.
 253 .RE
 254 
 255 .SS "Exiting and Exit Status"
 256 .LP
 257 The required behavior of a start method is to delay exiting until the service
 258 instance is ready to answer requests or is otherwise functional.
 259 .sp
 260 .LP
 261 The following exit status codes are defined in \fB<libscf.h>\fR and in the
 262 shell support file.
 263 .sp
 264 
 265 .sp
 266 .TS
 267 l l l
 268 l l l .
 269 \fBSMF_EXIT_OK\fR       \fB0\fR T{
 270 Method exited, performing its operation successfully.
 271 T}
 272 \fBSMF_EXIT_ERR_FATAL\fR        \fB95\fR        T{
 273 Method failed fatally and is unrecoverable without administrative intervention.
 274 T}
 275 \fBSMF_EXIT_ERR_CONFIG\fR       \fB96\fR        T{
 276 Unrecoverable configuration error. A common condition that returns this exit status is the absence of required configuration files for an enabled service instance.
 277 T}
 278 \fBSMF_EXIT_ERR_NOSMF\fR        \fB99\fR        T{
 279 Method has been mistakenly invoked outside the \fBsmf\fR(5) facility. Services that depend on \fBsmf\fR(5) capabilities should exit with this status value.
 280 T}
 281 \fBSMF_EXIT_ERR_PERM\fR \fB100\fR       T{
 282 Method requires a form of permission such as file access, privilege, authorization, or other credential that is not available when invoked.
 283 T}
 284 \fBSMF_EXIT_ERR_OTHER\fR        \fBnon-zero\fR  T{
 285 Any non-zero exit status from a method is treated as an unknown error. A series of unknown errors can be diagnosed as a fault by the restarter or on behalf of the restarter.
 286 T}
 287 .TE
 288 
 289 .sp
 290 .LP
 291 Use of a precise exit code allows the responsible restarter to categorize an
 292 error response as likely to be intermittent and worth pursuing restart or
 293 permanent and request administrative intervention.
 294 .SS "Timeouts"
 295 .LP
 296 Each method can have an independent timeout, given in seconds. The choice of a
 297 particular timeout should be based on site expectations for detecting a method
 298 failure due to non-responsiveness. Sites with replicated filesystems or other
 299 failover resources can elect to lengthen method timeouts from the default.
 300 Sites with no remote resources can elect to shorten the timeouts. Method
 301 timeout is specified by the \fBtimeout_seconds\fR property.
 302 .sp
 303 .LP
 304 If you specify \fB0 timeout_seconds\fR for a method, it declares to the
 305 restarter that there is no timeout for the service. This setting is not
 306 preferred, but is available for services that absolutely require it.
 307 .sp
 308 .LP
 309 \fB-1 timeout_seconds\fR is also accepted, but is a deprecated specification.
 310 .SS "Shell Programming Support"
 311 .LP
 312 A set of environment variables that define the above exit status values is
 313 provided with convenience shell functions in the file
 314 \fB/lib/svc/share/smf_include.sh\fR. This file is a Bourne shell script
 315 suitable for inclusion via the source operator in any Bourne-compatible shell.
 316 .sp
 317 .LP
 318 To assist in the composition of scripts that can serve as SMF methods as well
 319 as \fB/etc/init.d\fR scripts, the \fBsmf_present()\fR shell function is
 320 provided. If the \fBsmf\fR(5) facility is not available, \fBsmf_present()\fR
 321 returns a non-zero exit status.
 322 .sp
 323 .LP
 324 One possible structure for such a script follows:
 325 .sp
 326 .in +2
 327 .nf
 328 if smf_present; then
 329       # Shell code to run application as managed service
 330       ....
 331 
 332       smf_clear_env
 333 else
 334       # Shell code to run application as /etc/init.d script
 335       ....
 336 fi
 337 .fi
 338 .in -2
 339 
 340 .sp
 341 .LP
 342 This example shows the use of both convenience functions that are provided.
 343 .SS "Method Context"
 344 .LP
 345 The service management facility offers a common mechanism set the context in
 346 which the \fBfork\fR(2)-\fBexec\fR(2) model services execute.
 347 .sp
 348 .LP
 349 The desired method context should be provided by the service developer. All
 350 service instances should run with the lowest level of privileges possible to
 351 limit potential security compromises.
 352 .sp
 353 .LP
 354 A method context can contain the following properties:
 355 .sp
 356 .ne 2
 357 .na
 358 \fB\fBuse_profile\fR\fR
 359 .ad
 360 .sp .6
 361 .RS 4n
 362 A boolean that specifies whether the profile should be used instead of the
 363 \fBuser\fR, \fBgroup\fR, \fBprivileges\fR, and \fBlimit_privileges\fR
 364 properties.
 365 .RE
 366 
 367 .sp
 368 .ne 2
 369 .na
 370 \fBenvironment\fR
 371 .ad
 372 .sp .6
 373 .RS 4n
 374 Environment variables to insert into the environment of the method, in the form
 375 of a number of \fBNAME=value\fR strings.
 376 .RE
 377 
 378 .sp
 379 .ne 2
 380 .na
 381 \fB\fBprofile\fR\fR
 382 .ad
 383 .sp .6
 384 .RS 4n
 385 The name of an RBAC (role-based access control) profile which, along with the
 386 method executable, identifies an entry in \fBexec_attr\fR(4).
 387 .RE
 388 
 389 .sp
 390 .ne 2
 391 .na
 392 \fB\fBuser\fR\fR
 393 .ad
 394 .sp .6
 395 .RS 4n
 396 The user ID in numeric or text form.
 397 .RE
 398 
 399 .sp
 400 .ne 2
 401 .na
 402 \fB\fBgroup\fR\fR
 403 .ad
 404 .sp .6
 405 .RS 4n
 406 The group ID in numeric or text form.
 407 .RE
 408 
 409 .sp
 410 .ne 2
 411 .na
 412 \fB\fBsupp_groups\fR\fR
 413 .ad
 414 .sp .6
 415 .RS 4n
 416 An optional string that specifies the supplemental group memberships by ID, in
 417 numeric or text form.
 418 .RE
 419 
 420 .sp
 421 .ne 2
 422 .na
 423 \fB\fBprivileges\fR\fR
 424 .ad
 425 .sp .6
 426 .RS 4n
 427 An optional string specifying the privilege set as defined in
 428 \fBprivileges\fR(5).
 429 .RE
 430 
 431 .sp
 432 .ne 2
 433 .na
 434 \fB\fBlimit_privileges\fR\fR
 435 .ad
 436 .sp .6
 437 .RS 4n
 438 An optional string specifying the limit privilege set as defined in
 439 \fBprivileges\fR(5).
 440 .RE
 441 
 442 .sp
 443 .ne 2
 444 .na
 445 \fB\fBworking_directory\fR\fR
 446 .ad
 447 .sp .6
 448 .RS 4n
 449 The home directory from which to launch the method. \fB:home\fR can be used as
 450 a token to indicate the home directory of the user whose \fBuid\fR is used to
 451 launch the method. If the property is unset, \fB:home\fR is used.
 452 .RE
 453 
 454 .sp
 455 .ne 2
 456 .na
 457 \fB\fBsecurity_flags\fR\fR
 458 .ad
 459 .sp .6
 460 .RS 4n
 461 The security flags to apply when launching the method.  See \fBsecurity-flags\fR(5).
 462 .sp
 463 .LP
 464 The "default" keyword specifies those flags specified in
 465 \fBsvc:/system/process-security\fR.  The "all" keyword enables all flags, the
 466 "none" keyword enables no flags.  The "current" keyword specifies the current
 467 flags.  Flags may be added by specifying their name (optionally preceded
 468 by '+'), and removed by preceding their name with '-').
 469 .sp
 470 .LP
 471 Use of "all" has associated risks, as future versions of the system may
 472 include further flags which may harm poorly implemented software.
 473 .RE
 474 
 475 .sp
 476 .ne 2
 477 .na
 478 \fB\fBcorefile_pattern\fR\fR
 479 .ad
 480 .sp .6
 481 .RS 4n
 482 An optional string that specifies the corefile pattern to use for the service,
 483 as per \fBcoreadm\fR(1M). Most restarters supply a default. Setting this
 484 property overrides local customizations to the global core pattern.
 485 .RE
 486 
 487 .sp
 488 .ne 2
 489 .na
 490 \fB\fBproject\fR\fR
 491 .ad
 492 .sp .6
 493 .RS 4n
 494 The project ID in numeric or text form. \fB:default\fR can be used as a token
 495 to indicate a project identified by \fBgetdefaultproj\fR(3PROJECT) for the user
 496 whose \fBuid\fR is used to launch the method.
 497 .RE
 498 
 499 .sp
 500 .ne 2
 501 .na
 502 \fB\fBresource_pool\fR\fR
 503 .ad
 504 .sp .6
 505 .RS 4n
 506 The resource pool name on which to launch the method. \fB:default\fR can be
 507 used as a token to indicate the pool specified in the \fBproject\fR(4) entry
 508 given in the \fBproject\fR attribute above.
 509 .RE
 510 
 511 .sp
 512 .LP
 513 The method context can be set for the entire service instance by specifying a
 514 \fBmethod_context\fR property group for the service or instance. A method might
 515 override the instance method context by providing the method context properties
 516 on the method property group.
 517 .sp
 518 .LP
 519 Invalid method context settings always lead to failure of the method, with the
 520 exception of invalid environment variables that issue warnings.
 521 .sp
 522 .LP
 523 In addition to the context defined above, many \fBfork\fR(2)-\fBexec\fR(2)
 524 model restarters also use the following conventions when invoking executables
 525 as methods:
 526 .sp
 527 .ne 2
 528 .na
 529 \fBArgument array\fR
 530 .ad
 531 .sp .6
 532 .RS 4n
 533 The arguments in \fBargv[]\fR are set consistently with the result \fB/bin/sh
 534 -c\fR of the \fBexec\fR string.
 535 .RE
 536 
 537 .sp
 538 .ne 2
 539 .na
 540 \fBFile descriptors\fR
 541 .ad
 542 .sp .6
 543 .RS 4n
 544 File descriptor \fB0\fR is \fB/dev/null\fR. File descriptors \fB1\fR and
 545 \fB2\fR are recommended to be a per-service log file.
 546 .RE
 547 
 548 .SH FILES
 549 .ne 2
 550 .na
 551 \fB\fB/lib/svc/share/smf_include.sh\fR\fR
 552 .ad
 553 .sp .6
 554 .RS 4n
 555 Definitions of exit status values.
 556 .RE
 557 
 558 .sp
 559 .ne 2
 560 .na
 561 \fB\fB/usr/include/libscf.h\fR\fR
 562 .ad
 563 .sp .6
 564 .RS 4n
 565 Definitions of exit status codes.
 566 .RE
 567 
 568 .SH SEE ALSO
 569 .LP
 570 \fBzonename\fR(1), \fBcoreadm\fR(1M), \fBinetd\fR(1M), \fBsvccfg\fR(1M),
 571 \fBsvc.startd\fR(1M), \fBexec\fR(2), \fBfork\fR(2),
 572 \fBgetdefaultproj\fR(3PROJECT), \fBexec_attr\fR(4), \fBproject\fR(4),
 573 \fBservice_bundle\fR(4), \fBattributes\fR(5), \fBprivileges\fR(5),
 574 \fBrbac\fR(5), \fBsmf\fR(5), \fBsmf_bootstrap\fR(5), \fBzones\fR(5),
 575 \fBsecurity-flags\fR(5)
 576 .SH NOTES
 577 .LP
 578 The present version of \fBsmf\fR(5) does not support multiple repositories.
 579 .sp
 580 .LP
 581 When a service is configured to be started as root but with privileges
 582 different from \fBlimit_privileges\fR, the resulting process is privilege
 583 aware.  This can be surprising to developers who expect \fBseteuid(<non-zero
 584 UID>)\fR to reduce privileges to basic or less.