bsd/kern/process_policy.c

   1 /*
   2  * Copyright (c) 2005-2016 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*
  30  * process policy syscall implementation
  31  */
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.h>
  36 #include <sys/malloc.h>
  37 #include <sys/proc_internal.h>
  38 #include <sys/proc.h>
  39 #include <sys/kauth.h>
  40 #include <sys/unistd.h>
  41 #include <sys/buf.h>
  42 #include <sys/ioctl.h>
  43 #include <sys/vm.h>
  44 #include <sys/user.h>
  45
  46 #include <security/audit/audit.h>
  47
  48 #include <mach/machine.h>
  49 #include <mach/mach_types.h>
  50 #include <mach/vm_param.h>
  51 #include <kern/task.h>
  52 #include <kern/kalloc.h>
  53 #include <kern/assert.h>
  54 #include <kern/policy_internal.h>
  55
  56 #include <vm/vm_kern.h>
  57 #include <vm/vm_map.h>
  58 #include <mach/host_info.h>
  59 #include <mach/task_info.h>
  60 #include <mach/thread_info.h>
  61 #include <mach/vm_region.h>
  62
  63 #include <sys/process_policy.h>
  64 #include <sys/proc_info.h>
  65 #include <sys/bsdtask_info.h>
  66 #include <sys/kdebug.h>
  67 #include <sys/sysproto.h>
  68 #include <sys/msgbuf.h>
  69
  70 #include <machine/machine_routines.h>
  71
  72 #include <kern/ipc_misc.h>
  73 #include <vm/vm_protos.h>
  74
  75 static int handle_lowresource(int scope, int action, int policy, int policy_subtype, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  76 static int handle_cpuuse(int action, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  77 static int handle_apptype(int scope, int action, int policy, int policy_subtype, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  78 static int handle_boost(int scope, int action, int policy, int policy_subtype, user_addr_t attrp, proc_t proc, uint64_t target_threadid);
  79
  80 extern kern_return_t task_suspend(task_t);
  81 extern kern_return_t task_resume(task_t);
  82
  83
  84 /***************************** process_policy ********************/
  85
  86 /*
  87  *int process_policy(int scope, int action, int policy, int policy_subtype,
  88  *                   proc_policy_attribute_t * attrp, pid_t target_pid,
  89  *                   uint64_t target_threadid)
  90  *{ int process_policy(int scope, int action, int policy, int policy_subtype,
  91  * user_addr_t attrp, pid_t target_pid, uint64_t target_threadid); }
  92  */
  93
  94 /* system call implementation */
  95 int
  96 process_policy(__unused struct proc *p, struct process_policy_args * uap, __unused int32_t *retval)
  97 {
  98         int error = 0;
  99         int scope = uap->scope;
 100         int policy = uap->policy;
 101         int action = uap->action;
 102         int policy_subtype = uap->policy_subtype;
 103         user_addr_t attrp = uap->attrp;
 104         pid_t target_pid = uap->target_pid;
 105         uint64_t target_threadid = uap->target_threadid;
 106         proc_t target_proc = PROC_NULL;
 107         proc_t curp = current_proc();
 108         kauth_cred_t my_cred;
 109
 110         if ((scope != PROC_POLICY_SCOPE_PROCESS) && (scope != PROC_POLICY_SCOPE_THREAD)) {
 111                 return(EINVAL);
 112         }
 113
 114         if (target_pid == 0 || target_pid == proc_selfpid())
 115                 target_proc = proc_self();
 116         else
 117                 target_proc = proc_find(target_pid);
 118
 119         if (target_proc == PROC_NULL)
 120                 return(ESRCH);
 121
 122         my_cred = kauth_cred_get();
 123
 124         /*
 125          * Resoure starvation control can be used by unpriv resource owner but priv at the time of ownership claim. This is
 126          * checked in low resource handle routine. So bypass the checks here.
 127          */
 128         if ((policy != PROC_POLICY_RESOURCE_STARVATION) &&
 129                 (policy != PROC_POLICY_APPTYPE) &&
 130                 (!kauth_cred_issuser(my_cred) && curp != p))
 131         {
 132                 error = EPERM;
 133                 goto out;
 134         }
 135
 136 #if CONFIG_MACF
 137         switch (policy) {
 138                 case PROC_POLICY_BOOST:
 139                 case PROC_POLICY_RESOURCE_USAGE:
 140                         /* These policies do their own appropriate mac checks */
 141                         break;
 142                 default:
 143                         error = mac_proc_check_sched(curp, target_proc);
 144                         if (error) goto out;
 145                         break;
 146         }
 147 #endif /* CONFIG_MACF */
 148
 149         switch(policy) {
 150                 case PROC_POLICY_BACKGROUND:
 151                         error = ENOTSUP;
 152                         break;
 153                 case PROC_POLICY_HARDWARE_ACCESS:
 154                         error = ENOTSUP;
 155                         break;
 156                 case PROC_POLICY_RESOURCE_STARVATION:
 157                         error = handle_lowresource(scope, action, policy, policy_subtype, attrp, target_proc, target_threadid);
 158                         break;
 159                 case PROC_POLICY_RESOURCE_USAGE:
 160                         switch(policy_subtype) {
 161                                 case PROC_POLICY_RUSAGE_NONE:
 162                                 case PROC_POLICY_RUSAGE_WIREDMEM:
 163                                 case PROC_POLICY_RUSAGE_VIRTMEM:
 164                                 case PROC_POLICY_RUSAGE_DISK:
 165                                 case PROC_POLICY_RUSAGE_NETWORK:
 166                                 case PROC_POLICY_RUSAGE_POWER:
 167                                         return(ENOTSUP);
 168                                 default:
 169                                         return(EINVAL);
 170                                 case PROC_POLICY_RUSAGE_CPU:
 171                                         break;
 172                         }
 173
 174                         error = handle_cpuuse(action, attrp, target_proc, target_threadid);
 175                         break;
 176                 case PROC_POLICY_APPTYPE:
 177                         error = handle_apptype(scope, action, policy, policy_subtype, attrp, target_proc, target_threadid);
 178                         break;
 179                 case PROC_POLICY_BOOST:
 180                         error = handle_boost(scope, action, policy, policy_subtype, attrp, target_proc, target_threadid);
 181                         break;
 182                 default:
 183                         error = EINVAL;
 184                         break;
 185         }
 186
 187 out:
 188         proc_rele(target_proc);
 189         return(error);
 190 }
 191
 192 static int
 193 handle_lowresource(__unused int scope, int action, __unused int policy, int policy_subtype, __unused user_addr_t attrp, proc_t proc, __unused uint64_t target_threadid)
 194 {
 195         int error = 0;
 196
 197         switch(policy_subtype) {
 198                 case PROC_POLICY_RS_NONE:
 199                 case PROC_POLICY_RS_VIRTUALMEM:
 200                         break;
 201                 default:
 202                         return(EINVAL);
 203         }
 204
 205         if (action == PROC_POLICY_ACTION_RESTORE)
 206                 error = proc_resetpcontrol(proc_pid(proc));
 207         else
 208                 error = EINVAL;
 209
 210         return(error);
 211 }
 212
 213
 214 static int
 215 handle_cpuuse(int action, user_addr_t attrp, proc_t proc, __unused uint64_t target_threadid)
 216 {
 217         proc_policy_cpuusage_attr_t     cpuattr;
 218 #if CONFIG_MACF
 219         proc_t                          curp = current_proc();
 220 #endif
 221         int                             entitled = FALSE;
 222         Boolean                         canEnable = FALSE;
 223         uint64_t                        interval = -1ULL;
 224         int                             error = 0;
 225         uint8_t                         percentage;
 226
 227 #if CONFIG_MACF
 228         /*
 229          * iOS only allows processes to override their own CPU usage monitor
 230          * parameters if they have com.apple.private.kernel.override-cpumon.
 231          *
 232          * Until rdar://24799462 improves our scheme, we are also using the
 233          * same entitlement to indicate which processes can resume monitoring
 234          * when they otherwise wouldn't be able to.
 235          */
 236         entitled = (mac_proc_check_cpumon(curp) == 0) ? TRUE : FALSE;
 237         canEnable = (entitled && action == PROC_POLICY_ACTION_ENABLE);
 238
 239         if (!canEnable && curp != proc) {
 240                 /* can the current process change scheduling parameters? */
 241                 error = mac_proc_check_sched(curp, proc);
 242                 if (error)      return error;
 243         }
 244 #endif
 245
 246         switch (action) {
 247                 case PROC_POLICY_ACTION_GET:
 248                         error = proc_get_task_ruse_cpu(proc->task, &cpuattr.ppattr_cpu_attr,
 249                                         &percentage,
 250                                         &cpuattr.ppattr_cpu_attr_interval,
 251                                         &cpuattr.ppattr_cpu_attr_deadline);
 252                         if (error == 0) {
 253                                 cpuattr.ppattr_cpu_percentage = percentage;
 254                                 cpuattr.ppattr_cpu_attr_interval /= NSEC_PER_SEC;
 255                                 error = copyout((proc_policy_cpuusage_attr_t *)&cpuattr, (user_addr_t)attrp, sizeof(proc_policy_cpuusage_attr_t));
 256                         }
 257                         break;
 258
 259                 case PROC_POLICY_ACTION_APPLY:
 260                 case PROC_POLICY_ACTION_SET:
 261                         error = copyin((user_addr_t)attrp, (proc_policy_cpuusage_attr_t *)&cpuattr, sizeof(proc_policy_cpuusage_attr_t));
 262                         if (error != 0) {
 263                                 return (error);
 264                         }
 265
 266                         /*
 267                          * The process_policy API uses seconds as the units for the interval,
 268                          * but the mach task policy SPI uses nanoseconds. Do the conversion,
 269                          * but preserve -1 as it has special meaning.
 270                          */
 271                         if (cpuattr.ppattr_cpu_attr_interval != -1ULL) {
 272                                 interval = cpuattr.ppattr_cpu_attr_interval * NSEC_PER_SEC;
 273                         } else {
 274                                 interval = -1ULL;
 275                         }
 276
 277                         error = proc_set_task_ruse_cpu(proc->task, cpuattr.ppattr_cpu_attr,
 278                                         cpuattr.ppattr_cpu_percentage,
 279                                         interval,
 280                                         cpuattr.ppattr_cpu_attr_deadline,
 281                                         entitled);
 282                         break;
 283
 284                 /* restore process to prior state */
 285                 case PROC_POLICY_ACTION_RESTORE:
 286                         error = proc_clear_task_ruse_cpu(proc->task, entitled);
 287                         break;
 288
 289                 /* re-enable suspended monitor */
 290                 case PROC_POLICY_ACTION_ENABLE:
 291                         error = task_resume_cpumon(proc->task);
 292                         break;
 293
 294                 case PROC_POLICY_ACTION_REMOVE:
 295
 296                 default:
 297                         error = EINVAL;
 298                         break;
 299
 300         }
 301
 302         return(error);
 303 }
 304
 305
 306 static int
 307 handle_apptype(         int scope,
 308                         int action,
 309                __unused int policy,
 310                         int policy_subtype,
 311                __unused user_addr_t attrp,
 312                         proc_t target_proc,
 313                __unused uint64_t target_threadid)
 314 {
 315         int error = 0;
 316
 317         if (scope != PROC_POLICY_SCOPE_PROCESS)
 318                 return (EINVAL);
 319
 320         /* Temporary compatibility with old importance donation interface until libproc is moved to new boost calls */
 321         switch (policy_subtype) {
 322                 case PROC_POLICY_IOS_DONATEIMP:
 323                         if (action != PROC_POLICY_ACTION_ENABLE)
 324                                 return (EINVAL);
 325                         if (target_proc != current_proc())
 326                                 return (EINVAL);
 327
 328                         /* PROCESS ENABLE APPTYPE DONATEIMP */
 329                         task_importance_mark_donor(target_proc->task, TRUE);
 330
 331                         return(0);
 332
 333                 case PROC_POLICY_IOS_HOLDIMP:
 334                         if (action != PROC_POLICY_ACTION_ENABLE)
 335                                 return (EINVAL);
 336                         if (target_proc != current_proc())
 337                                 return (EINVAL);
 338
 339                         /* PROCESS ENABLE APPTYPE HOLDIMP */
 340                         error = task_importance_hold_legacy_external_assertion(current_task(), 1);
 341
 342                         return(error);
 343
 344                 case PROC_POLICY_IOS_DROPIMP:
 345                         if (action != PROC_POLICY_ACTION_ENABLE)
 346                                 return (EINVAL);
 347                         if (target_proc != current_proc())
 348                                 return (EINVAL);
 349
 350                         /* PROCESS ENABLE APPTYPE DROPIMP */
 351                         error = task_importance_drop_legacy_external_assertion(current_task(), 1);
 352
 353                         return(error);
 354
 355                 default:
 356                         /* continue to TAL handling */
 357                         break;
 358         }
 359
 360         if (policy_subtype != PROC_POLICY_OSX_APPTYPE_TAL)
 361                 return (EINVAL);
 362
 363         /* need to be super user to do this */
 364         if (kauth_cred_issuser(kauth_cred_get()) == 0)
 365                 return (EPERM);
 366
 367         if (proc_task_is_tal(target_proc->task) == FALSE)
 368                 return (EINVAL);
 369
 370         switch (action) {
 371                 case PROC_POLICY_ACTION_ENABLE:
 372                         /* PROCESS ENABLE APPTYPE TAL */
 373                         proc_set_task_policy(target_proc->task,
 374                                              TASK_POLICY_ATTRIBUTE, TASK_POLICY_TAL,
 375                                              TASK_POLICY_ENABLE);
 376                         break;
 377                 case PROC_POLICY_ACTION_DISABLE:
 378                         /* PROCESS DISABLE APPTYPE TAL */
 379                         proc_set_task_policy(target_proc->task,
 380                                              TASK_POLICY_ATTRIBUTE, TASK_POLICY_TAL,
 381                                              TASK_POLICY_DISABLE);
 382                         break;
 383                 default:
 384                         return (EINVAL);
 385         }
 386
 387         return(0);
 388 }
 389
 390 static int
 391 handle_boost(int scope,
 392              int action,
 393     __unused int policy,
 394              int policy_subtype,
 395     __unused user_addr_t attrp,
 396              proc_t target_proc,
 397     __unused uint64_t target_threadid)
 398 {
 399         int error = 0;
 400
 401         assert(policy == PROC_POLICY_BOOST);
 402
 403         if (scope != PROC_POLICY_SCOPE_PROCESS)
 404                 return (EINVAL);
 405
 406         if (target_proc != current_proc())
 407                 return (EINVAL);
 408
 409         switch(policy_subtype) {
 410                 case PROC_POLICY_IMP_IMPORTANT:
 411                         if (task_is_importance_receiver_type(target_proc->task) == FALSE)
 412                                 return (EINVAL);
 413
 414                         switch (action) {
 415                                 case PROC_POLICY_ACTION_HOLD:
 416                                         /* PROCESS HOLD BOOST IMPORTANT */
 417                                         error = task_importance_hold_legacy_external_assertion(current_task(), 1);
 418                                         break;
 419                                 case PROC_POLICY_ACTION_DROP:
 420                                         /* PROCESS DROP BOOST IMPORTANT */
 421                                         error = task_importance_drop_legacy_external_assertion(current_task(), 1);
 422                                         break;
 423                                 default:
 424                                         error = (EINVAL);
 425                                         break;
 426                         }
 427                         break;
 428
 429                 case PROC_POLICY_IMP_DONATION:
 430 #if CONFIG_MACF
 431                         error = mac_proc_check_sched(current_proc(), target_proc);
 432                         if (error) return error;
 433 #endif
 434                         switch (action) {
 435                                 case PROC_POLICY_ACTION_SET:
 436                                         /* PROCESS SET BOOST DONATION */
 437                                         task_importance_mark_donor(target_proc->task, TRUE);
 438                                         break;
 439                                 default:
 440                                         error = (EINVAL);
 441                                         break;
 442                         }
 443                         break;
 444
 445                 default:
 446                         error = (EINVAL);
 447                         break;
 448         }
 449
 450         return(error);
 451 }
 452
 453
 454 /*
 455  * KPI to determine if a pid is currently backgrounded.
 456  * Returns ESRCH if pid cannot be found or has started exiting.
 457  * Returns EINVAL if state is NULL.
 458  * Sets *state to 1 if pid is backgrounded, and 0 otherwise.
 459  */
 460 int
 461 proc_pidbackgrounded(pid_t pid, uint32_t* state)
 462 {
 463         proc_t target_proc = PROC_NULL;
 464
 465         if (state == NULL)
 466                 return(EINVAL);
 467
 468         target_proc = proc_find(pid);
 469
 470         if (target_proc == PROC_NULL)
 471                 return(ESRCH);
 472
 473         if ( proc_get_effective_task_policy(target_proc->task, TASK_POLICY_DARWIN_BG) ) {
 474                 *state = 1;
 475         } else {
 476                 *state = 0;
 477         }
 478
 479         proc_rele(target_proc);
 480         return (0);
 481 }
 482
 483 /*
 484  * Get the darwin background state of the originator. If the current
 485  * process app type is App, then it is the originator, else if it is
 486  * a Daemon, then creator of the Resource Accounting attribute of
 487  * the current thread voucher is the originator of the work.
 488  */
 489 int
 490 proc_get_originatorbgstate(uint32_t *is_backgrounded)
 491 {
 492         uint32_t bgstate;
 493         proc_t p = current_proc();
 494         uint32_t flagsp;
 495         kern_return_t kr;
 496         pid_t pid;
 497         int ret;
 498         thread_t thread = current_thread();
 499
 500         bgstate = proc_get_effective_thread_policy(thread, TASK_POLICY_DARWIN_BG);
 501
 502         /* If current thread or task backgrounded, return background */
 503         if (bgstate) {
 504                 *is_backgrounded = 1;
 505                 return 0;
 506         }
 507
 508         /* Check if current process app type is App, then return foreground */
 509         proc_get_darwinbgstate(p->task, &flagsp);
 510         if ((flagsp & PROC_FLAG_APPLICATION) == PROC_FLAG_APPLICATION) {
 511                 *is_backgrounded = 0;
 512                 return 0;
 513         }
 514
 515         /*
 516          * Get the current voucher origin pid and it's bgstate.The pid
 517          * returned here might not be valid or may have been recycled.
 518          */
 519         kr = thread_get_current_voucher_origin_pid(&pid);
 520         if (kr != KERN_SUCCESS) {
 521                 if (kr == KERN_INVALID_TASK)
 522                         return ESRCH;
 523                 else if (kr == KERN_INVALID_VALUE)
 524                         return ENOATTR;
 525                 else
 526                         return EINVAL;
 527         }
 528
 529         ret = proc_pidbackgrounded(pid, is_backgrounded);
 530         return ret;
 531 }
 532
 533 int
 534 proc_apply_resource_actions(void * bsdinfo, __unused int type, int action)
 535 {
 536         proc_t p = (proc_t)bsdinfo;
 537
 538         switch(action) {
 539                 case PROC_POLICY_RSRCACT_THROTTLE:
 540                         /* no need to do anything */
 541                         break;
 542
 543                 case PROC_POLICY_RSRCACT_SUSPEND:
 544                         task_suspend(p->task);
 545                         break;
 546
 547                 case PROC_POLICY_RSRCACT_TERMINATE:
 548                         psignal(p, SIGKILL);
 549                         break;
 550
 551                 case PROC_POLICY_RSRCACT_NOTIFY_KQ:
 552                         /* not implemented */
 553                         break;
 554
 555                 case PROC_POLICY_RSRCACT_NOTIFY_EXC:
 556                         panic("shouldn't be applying exception notification to process!");
 557                         break;
 558         }
 559
 560         return(0);
 561 }
 562
 563 int
 564 proc_restore_resource_actions(void * bsdinfo, __unused int type, int action)
 565 {
 566         proc_t p = (proc_t)bsdinfo;
 567
 568         switch(action) {
 569                 case PROC_POLICY_RSRCACT_THROTTLE:
 570                 case PROC_POLICY_RSRCACT_TERMINATE:
 571                 case PROC_POLICY_RSRCACT_NOTIFY_KQ:
 572                 case PROC_POLICY_RSRCACT_NOTIFY_EXC:
 573                         /* no need to do anything */
 574                         break;
 575
 576                 case PROC_POLICY_RSRCACT_SUSPEND:
 577                         task_resume(p->task);
 578                         break;
 579
 580         }
 581
 582         return(0);
 583 }
 584