usr/src/cmd/hotplugd/hotplugd_rcm.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <errno.h>
  31 #include <string.h>
  32 #include <librcm.h>
  33 #include <libhotplug.h>
  34 #include <libhotplug_impl.h>
  35 #include <sys/sunddi.h>
  36 #include <sys/ddi_hp.h>
  37 #include "hotplugd_impl.h"
  38
  39 /*
  40  * Define structures for a path-to-usage lookup table.
  41  */
  42 typedef struct info_entry {
  43         char                    *rsrc;
  44         char                    *usage;
  45         struct info_entry       *next;
  46 } info_entry_t;
  47
  48 typedef struct {
  49         char            *path;
  50         info_entry_t    *entries;
  51 } info_table_t;
  52
  53 /*
  54  * Define callback argument used when getting resources.
  55  */
  56 typedef struct {
  57         int     error;
  58         int     n_rsrcs;
  59         char    **rsrcs;
  60         char    path[MAXPATHLEN];
  61         char    connection[MAXPATHLEN];
  62         char    dev_path[MAXPATHLEN];
  63 } resource_cb_arg_t;
  64
  65 /*
  66  * Define callback argument used when merging info.
  67  */
  68 typedef struct {
  69         int             error;
  70         info_table_t    *table;
  71         size_t          table_len;
  72         char            path[MAXPATHLEN];
  73         char            connection[MAXPATHLEN];
  74 } merge_cb_arg_t;
  75
  76 /*
  77  * Local functions.
  78  */
  79 static int      merge_rcm_info(hp_node_t root, rcm_info_t *info);
  80 static int      get_rcm_usage(char **rsrcs, rcm_info_t **info_p);
  81 static int      build_table(rcm_info_t *info, info_table_t **tablep,
  82                     size_t *table_lenp);
  83 static void     free_table(info_table_t *table, size_t table_len);
  84 static int      resource_callback(hp_node_t node, void *argp);
  85 static int      merge_callback(hp_node_t node, void *argp);
  86 static int      rsrc2path(const char *rsrc, char *path);
  87 static int      compare_info(const void *a, const void *b);
  88
  89 /*
  90  * copy_usage()
  91  *
  92  *      Given an information snapshot, get the corresponding
  93  *      RCM usage information and merge it into the snapshot.
  94  */
  95 int
  96 copy_usage(hp_node_t root)
  97 {
  98         rcm_info_t      *info = NULL;
  99         char            **rsrcs = NULL;
 100         int             rv;
 101
 102         /* Get resource names */
 103         if ((rv = rcm_resources(root, &rsrcs)) != 0) {
 104                 log_err("Cannot get RCM resources (%s)\n", strerror(rv));
 105                 return (rv);
 106         }
 107
 108         /* Do nothing if no resources */
 109         if (rsrcs == NULL)
 110                 return (0);
 111
 112         /* Get RCM usage information */
 113         if ((rv = get_rcm_usage(rsrcs, &info)) != 0) {
 114                 log_err("Cannot get RCM information (%s)\n", strerror(rv));
 115                 free_rcm_resources(rsrcs);
 116                 return (rv);
 117         }
 118
 119         /* Done with resource names */
 120         free_rcm_resources(rsrcs);
 121
 122         /* If there is RCM usage information, merge it in */
 123         if (info != NULL) {
 124                 rv = merge_rcm_info(root, info);
 125                 rcm_free_info(info);
 126                 return (rv);
 127         }
 128
 129         return (0);
 130 }
 131
 132 /*
 133  * rcm_resources()
 134  *
 135  *      Given the root of a hotplug information snapshot,
 136  *      construct a list of RCM compatible resource names.
 137  */
 138 int
 139 rcm_resources(hp_node_t root, char ***rsrcsp)
 140 {
 141         resource_cb_arg_t       arg;
 142
 143         /* Initialize results */
 144         *rsrcsp = NULL;
 145
 146         /* Traverse snapshot to get resources */
 147         (void) memset(&arg, 0, sizeof (resource_cb_arg_t));
 148         (void) hp_traverse(root, &arg, resource_callback);
 149
 150         /* Check for errors */
 151         if (arg.error != 0) {
 152                 free_rcm_resources(arg.rsrcs);
 153                 return (arg.error);
 154         }
 155
 156         /* Success */
 157         *rsrcsp = arg.rsrcs;
 158         return (0);
 159 }
 160
 161 /*
 162  * free_rcm_resources()
 163  *
 164  *      Free a table of RCM resource names.
 165  */
 166 void
 167 free_rcm_resources(char **rsrcs)
 168 {
 169         int     i;
 170
 171         if (rsrcs != NULL) {
 172                 for (i = 0; rsrcs[i] != NULL; i++)
 173                         free(rsrcs[i]);
 174                 free(rsrcs);
 175         }
 176 }
 177
 178 /*
 179  * rcm_offline()
 180  *
 181  *      Implement an RCM offline request.
 182  *
 183  *      NOTE: errors from RCM will be merged into the snapshot.
 184  */
 185 int
 186 rcm_offline(char **rsrcs, uint_t flags, hp_node_t root)
 187 {
 188         rcm_handle_t    *handle;
 189         rcm_info_t      *info = NULL;
 190         uint_t          rcm_flags = 0;
 191         int             rv = 0;
 192
 193         dprintf("rcm_offline()\n");
 194
 195         /* Set flags */
 196         if (flags & HPFORCE)
 197                 rcm_flags |= RCM_FORCE;
 198         if (flags & HPQUERY)
 199                 rcm_flags |= RCM_QUERY;
 200
 201         /* Allocate RCM handle */
 202         if (rcm_alloc_handle(NULL, 0, NULL, &handle) != RCM_SUCCESS) {
 203                 log_err("Cannot allocate RCM handle (%s)\n", strerror(errno));
 204                 return (EFAULT);
 205         }
 206
 207         /* Request RCM offline */
 208         if (rcm_request_offline_list(handle, rsrcs, rcm_flags,
 209             &info) != RCM_SUCCESS)
 210                 rv = EBUSY;
 211
 212         /* RCM handle is no longer needed */
 213         (void) rcm_free_handle(handle);
 214
 215         /*
 216          * Check if RCM returned any information tuples.  If so,
 217          * then also check if the RCM operation failed, and possibly
 218          * merge the RCM info into the caller's hotplug snapshot.
 219          */
 220         if (info != NULL) {
 221                 if (rv != 0)
 222                         (void) merge_rcm_info(root, info);
 223                 rcm_free_info(info);
 224         }
 225
 226         return (rv);
 227 }
 228
 229 /*
 230  * rcm_online()
 231  *
 232  *      Implement an RCM online notification.
 233  */
 234 void
 235 rcm_online(char **rsrcs)
 236 {
 237         rcm_handle_t    *handle;
 238         rcm_info_t      *info = NULL;
 239
 240         dprintf("rcm_online()\n");
 241
 242         if (rcm_alloc_handle(NULL, 0, NULL, &handle) != RCM_SUCCESS) {
 243                 log_err("Cannot allocate RCM handle (%s)\n", strerror(errno));
 244                 return;
 245         }
 246
 247         (void) rcm_notify_online_list(handle, rsrcs, 0, &info);
 248
 249         (void) rcm_free_handle(handle);
 250
 251         if (info != NULL)
 252                 rcm_free_info(info);
 253 }
 254
 255 /*
 256  * rcm_remove()
 257  *
 258  *      Implement an RCM remove notification.
 259  */
 260 void
 261 rcm_remove(char **rsrcs)
 262 {
 263         rcm_handle_t    *handle;
 264         rcm_info_t      *info = NULL;
 265
 266         dprintf("rcm_remove()\n");
 267
 268         if (rcm_alloc_handle(NULL, 0, NULL, &handle) != RCM_SUCCESS) {
 269                 log_err("Cannot allocate RCM handle (%s)\n", strerror(errno));
 270                 return;
 271         }
 272
 273         (void) rcm_notify_remove_list(handle, rsrcs, 0, &info);
 274
 275         (void) rcm_free_handle(handle);
 276
 277         if (info != NULL)
 278                 rcm_free_info(info);
 279 }
 280
 281 /*
 282  * get_rcm_usage()
 283  *
 284  *      Lookup usage information for a set of resources from RCM.
 285  */
 286 static int
 287 get_rcm_usage(char **rsrcs, rcm_info_t **info_p)
 288 {
 289         rcm_handle_t    *handle;
 290         rcm_info_t      *info = NULL;
 291         int             rv = 0;
 292
 293         /* No-op if no RCM resources */
 294         if (rsrcs == NULL)
 295                 return (0);
 296
 297         /* Allocate RCM handle */
 298         if (rcm_alloc_handle(NULL, RCM_NOPID, NULL, &handle) != RCM_SUCCESS) {
 299                 log_err("Cannot allocate RCM handle (%s)\n", strerror(errno));
 300                 return (EFAULT);
 301         }
 302
 303         /* Get usage information from RCM */
 304         if (rcm_get_info_list(handle, rsrcs,
 305             RCM_INCLUDE_DEPENDENT | RCM_INCLUDE_SUBTREE,
 306             &info) != RCM_SUCCESS) {
 307                 log_err("Failed to get RCM information (%s)\n",
 308                     strerror(errno));
 309                 rv = EFAULT;
 310         }
 311
 312         /* RCM handle is no longer needed */
 313         (void) rcm_free_handle(handle);
 314
 315         *info_p = info;
 316         return (rv);
 317 }
 318
 319 /*
 320  * merge_rcm_info()
 321  *
 322  *      Merge RCM information into a hotplug information snapshot.
 323  *      First a lookup table is built to map lists of RCM usage to
 324  *      pathnames.  Then during a full traversal of the snapshot,
 325  *      the lookup table is used for each node to find matching
 326  *      RCM info tuples for each path in the snapshot.
 327  */
 328 static int
 329 merge_rcm_info(hp_node_t root, rcm_info_t *info)
 330 {
 331         merge_cb_arg_t          arg;
 332         info_table_t            *table;
 333         size_t                  table_len;
 334         int                     rv;
 335
 336         /* Build a lookup table, mapping paths to usage information */
 337         if ((rv = build_table(info, &table, &table_len)) != 0) {
 338                 log_err("Cannot build RCM lookup table (%s)\n", strerror(rv));
 339                 return (rv);
 340         }
 341
 342         /* Stop if no valid entries were inserted in table */
 343         if ((table == NULL) || (table_len == 0)) {
 344                 log_err("Unable to gather RCM usage.\n");
 345                 return (0);
 346         }
 347
 348         /* Initialize callback argument */
 349         (void) memset(&arg, 0, sizeof (merge_cb_arg_t));
 350         arg.table = table;
 351         arg.table_len = table_len;
 352
 353         /* Perform a merge traversal */
 354         (void) hp_traverse(root, (void *)&arg, merge_callback);
 355
 356         /* Done with the table */
 357         free_table(table, table_len);
 358
 359         /* Check for errors */
 360         if (arg.error != 0) {
 361                 log_err("Cannot merge RCM information (%s)\n", strerror(rv));
 362                 return (rv);
 363         }
 364
 365         return (0);
 366 }
 367
 368 /*
 369  * resource_callback()
 370  *
 371  *      A callback function for hp_traverse() that builds an RCM
 372  *      compatible list of resource path names.  The array has
 373  *      been pre-allocated based on results from the related
 374  *      callback resource_count_callback().
 375  */
 376 static int
 377 resource_callback(hp_node_t node, void *argp)
 378 {
 379         resource_cb_arg_t       *arg = (resource_cb_arg_t *)argp;
 380         char                    **new_rsrcs;
 381         size_t                  new_size;
 382         int                     type;
 383
 384         /* Get node type */
 385         type = hp_type(node);
 386
 387         /* Prune OFFLINE ports */
 388         if ((type == HP_NODE_PORT) && HP_IS_OFFLINE(hp_state(node)))
 389                 return (HP_WALK_PRUNECHILD);
 390
 391         /* Skip past non-devices */
 392         if (type != HP_NODE_DEVICE)
 393                 return (HP_WALK_CONTINUE);
 394
 395         /* Lookup resource path */
 396         if (hp_path(node, arg->path, arg->connection) != 0) {
 397                 log_err("Cannot get RCM resource path.\n");
 398                 arg->error = EFAULT;
 399                 return (HP_WALK_TERMINATE);
 400         }
 401
 402         /* Insert "/devices" to path name */
 403         (void) snprintf(arg->dev_path, MAXPATHLEN, "/devices%s", arg->path);
 404
 405         /*
 406          * Grow resource array to accomodate new /devices path.
 407          * NOTE: include an extra NULL pointer at end of array.
 408          */
 409         new_size = (arg->n_rsrcs + 2) * sizeof (char *);
 410         if (arg->rsrcs == NULL)
 411                 new_rsrcs = (char **)malloc(new_size);
 412         else
 413                 new_rsrcs = (char **)realloc(arg->rsrcs, new_size);
 414         if (new_rsrcs != NULL) {
 415                 arg->rsrcs = new_rsrcs;
 416         } else {
 417                 log_err("Cannot allocate RCM resource array.\n");
 418                 arg->error = ENOMEM;
 419                 return (HP_WALK_TERMINATE);
 420         }
 421
 422         /* Initialize new entries */
 423         arg->rsrcs[arg->n_rsrcs] = strdup(arg->dev_path);
 424         arg->rsrcs[arg->n_rsrcs + 1] = NULL;
 425
 426         /* Check for errors */
 427         if (arg->rsrcs[arg->n_rsrcs] == NULL) {
 428                 log_err("Cannot allocate RCM resource path.\n");
 429                 arg->error = ENOMEM;
 430                 return (HP_WALK_TERMINATE);
 431         }
 432
 433         /* Increment resource count */
 434         arg->n_rsrcs += 1;
 435
 436         /* Do not visit children */
 437         return (HP_WALK_PRUNECHILD);
 438 }
 439
 440 /*
 441  * merge_callback()
 442  *
 443  *      A callback function for hp_traverse() that merges RCM information
 444  *      tuples into an existing hotplug information snapshot.  The RCM
 445  *      information will be turned into HP_NODE_USAGE nodes.
 446  */
 447 static int
 448 merge_callback(hp_node_t node, void *argp)
 449 {
 450         merge_cb_arg_t  *arg = (merge_cb_arg_t *)argp;
 451         hp_node_t       usage;
 452         info_table_t    lookup;
 453         info_table_t    *slot;
 454         info_entry_t    *entry;
 455         int             rv;
 456
 457         /* Only process device nodes (other nodes cannot have usage) */
 458         if (hp_type(node) != HP_NODE_DEVICE)
 459                 return (HP_WALK_CONTINUE);
 460
 461         /* Get path of current node, using buffer provided in 'arg' */
 462         if ((rv = hp_path(node, arg->path, arg->connection)) != 0) {
 463                 log_err("Cannot lookup hotplug path (%s)\n", strerror(rv));
 464                 arg->error = rv;
 465                 return (HP_WALK_TERMINATE);
 466         }
 467
 468         /* Check the lookup table for associated usage */
 469         lookup.path = arg->path;
 470         if ((slot = bsearch(&lookup, arg->table, arg->table_len,
 471             sizeof (info_table_t), compare_info)) == NULL)
 472                 return (HP_WALK_CONTINUE);
 473
 474         /* Usage information was found.  Append HP_NODE_USAGE nodes. */
 475         for (entry = slot->entries; entry != NULL; entry = entry->next) {
 476
 477                 /* Allocate a new usage node */
 478                 usage = (hp_node_t)calloc(1, sizeof (struct hp_node));
 479                 if (usage == NULL) {
 480                         log_err("Cannot allocate hotplug usage node.\n");
 481                         arg->error = ENOMEM;
 482                         return (HP_WALK_TERMINATE);
 483                 }
 484
 485                 /* Initialize the usage node's contents */
 486                 usage->hp_type = HP_NODE_USAGE;
 487                 if ((usage->hp_name = strdup(entry->rsrc)) == NULL) {
 488                         log_err("Cannot allocate hotplug usage node name.\n");
 489                         free(usage);
 490                         arg->error = ENOMEM;
 491                         return (HP_WALK_TERMINATE);
 492                 }
 493                 if ((usage->hp_usage = strdup(entry->usage)) == NULL) {
 494                         log_err("Cannot allocate hotplug usage node info.\n");
 495                         free(usage->hp_name);
 496                         free(usage);
 497                         arg->error = ENOMEM;
 498                         return (HP_WALK_TERMINATE);
 499                 }
 500
 501                 /* Link the usage node as a child of the device node */
 502                 usage->hp_parent = node;
 503                 usage->hp_sibling = node->hp_child;
 504                 node->hp_child = usage;
 505         }
 506
 507         return (HP_WALK_CONTINUE);
 508 }
 509
 510 /*
 511  * build_table()
 512  *
 513  *      Build a lookup table that will be used to map paths to their
 514  *      corresponding RCM information tuples.
 515  */
 516 static int
 517 build_table(rcm_info_t *info, info_table_t **tablep, size_t *table_lenp)
 518 {
 519         rcm_info_tuple_t        *tuple;
 520         info_entry_t            *entry;
 521         info_table_t            *slot;
 522         info_table_t            *table;
 523         size_t                  table_len;
 524         const char              *rsrc;
 525         const char              *usage;
 526         char                    path[MAXPATHLEN];
 527
 528         /* Initialize results */
 529         *tablep = NULL;
 530         *table_lenp = 0;
 531
 532         /* Count the RCM info tuples to determine the table's size */
 533         table_len = 0;
 534         for (tuple = NULL; (tuple = rcm_info_next(info, tuple)) != NULL; )
 535                 table_len++;
 536
 537         /* If the table would be empty, then do nothing */
 538         if (table_len == 0)
 539                 return (ENOENT);
 540
 541         /* Allocate the lookup table */
 542         table = (info_table_t *)calloc(table_len, sizeof (info_table_t));
 543         if (table == NULL)
 544                 return (ENOMEM);
 545
 546         /*
 547          * Fill in the lookup table.  Fill one slot in the table
 548          * for each device path that has a set of associated RCM
 549          * information tuples.  In some cases multiple tuples will
 550          * be joined together within the same slot.
 551          */
 552         slot = NULL;
 553         table_len = 0;
 554         for (tuple = NULL; (tuple = rcm_info_next(info, tuple)) != NULL; ) {
 555
 556                 /*
 557                  * Extract RCM resource name and usage description.
 558                  *
 559                  * NOTE: skip invalid tuples to return as much as possible.
 560                  */
 561                 if (((rsrc = rcm_info_rsrc(tuple)) == NULL) ||
 562                     ((usage = rcm_info_info(tuple)) == NULL)) {
 563                         log_err("RCM returned invalid resource or usage.\n");
 564                         continue;
 565                 }
 566
 567                 /*
 568                  * Try to convert the RCM resource name to a hotplug path.
 569                  * If conversion succeeds and this path differs from the
 570                  * current slot in the table, then initialize the next
 571                  * slot in the table.
 572                  */
 573                 if ((rsrc2path(rsrc, path) == 0) &&
 574                     ((slot == NULL) || (strcmp(slot->path, path) != 0))) {
 575                         slot = &table[table_len];
 576                         if ((slot->path = strdup(path)) == NULL) {
 577                                 log_err("Cannot build info table slot.\n");
 578                                 free_table(table, table_len);
 579                                 return (ENOMEM);
 580                         }
 581                         table_len++;
 582                 }
 583
 584                 /* Append current usage to entry list in the current slot */
 585                 if (slot != NULL) {
 586
 587                         /* Allocate new entry */
 588                         entry = (info_entry_t *)malloc(sizeof (info_entry_t));
 589                         if (entry == NULL) {
 590                                 log_err("Cannot allocate info table entry.\n");
 591                                 free_table(table, table_len);
 592                                 return (ENOMEM);
 593                         }
 594
 595                         /* Link entry into current slot list */
 596                         entry->next = slot->entries;
 597                         slot->entries = entry;
 598
 599                         /* Initialize entry values */
 600                         if (((entry->rsrc = strdup(rsrc)) == NULL) ||
 601                             ((entry->usage = strdup(usage)) == NULL)) {
 602                                 log_err("Cannot build info table entry.\n");
 603                                 free_table(table, table_len);
 604                                 return (ENOMEM);
 605                         }
 606                 }
 607         }
 608
 609         /* Check if valid entries were inserted in table */
 610         if (table_len == 0) {
 611                 free(table);
 612                 return (0);
 613         }
 614
 615         /* Sort the lookup table by hotplug path */
 616         qsort(table, table_len, sizeof (info_table_t), compare_info);
 617
 618         /* Done */
 619         *tablep = table;
 620         *table_lenp = table_len;
 621         return (0);
 622 }
 623
 624 /*
 625  * free_table()
 626  *
 627  *      Destroy a lookup table.
 628  */
 629 static void
 630 free_table(info_table_t *table, size_t table_len)
 631 {
 632         info_entry_t    *entry;
 633         int             index;
 634
 635         if (table != NULL) {
 636                 for (index = 0; index < table_len; index++) {
 637                         free(table[index].path);
 638                         while (table[index].entries != NULL) {
 639                                 entry = table[index].entries;
 640                                 table[index].entries = entry->next;
 641                                 free(entry->rsrc);
 642                                 free(entry->usage);
 643                                 free(entry);
 644                         }
 645                 }
 646                 free(table);
 647         }
 648 }
 649
 650 /*
 651  * rsrc2path()
 652  *
 653  *      Convert from an RCM resource name to a hotplug device path.
 654  */
 655 static int
 656 rsrc2path(const char *rsrc, char *path)
 657 {
 658         char    *s;
 659         char    tmp[MAXPATHLEN];
 660
 661         /* Only convert /dev and /devices paths */
 662         if (strncmp(rsrc, "/dev", 4) == 0) {
 663
 664                 /* Follow symbolic links for /dev paths */
 665                 if (realpath(rsrc, tmp) == NULL) {
 666                         log_err("Cannot resolve RCM resource (%s)\n",
 667                             strerror(errno));
 668                         return (-1);
 669                 }
 670
 671                 /* Remove the leading "/devices" part */
 672                 (void) strlcpy(path, &tmp[strlen(S_DEVICES)], MAXPATHLEN);
 673
 674                 /* Remove any trailing minor node part */
 675                 if ((s = strrchr(path, ':')) != NULL)
 676                         *s = '\0';
 677
 678                 /* Successfully converted */
 679                 return (0);
 680         }
 681
 682         /* Not converted */
 683         return (-1);
 684 }
 685
 686 /*
 687  * compare_info()
 688  *
 689  *      Compare two slots in the lookup table that maps paths to usage.
 690  *
 691  *      NOTE: for use with qsort() and bsearch().
 692  */
 693 static int
 694 compare_info(const void *a, const void *b)
 695 {
 696         info_table_t    *slot_a = (info_table_t *)a;
 697         info_table_t    *slot_b = (info_table_t *)b;
 698
 699         return (strcmp(slot_a->path, slot_b->path));
 700 }