src/udev/udev-event.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2
   3 #include <ctype.h>
   4 #include <errno.h>
   5 #include <fcntl.h>
   6 #include <net/if.h>
   7 #include <stddef.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/wait.h>
  11 #include <unistd.h>
  12
  13 #include "sd-event.h"
  14
  15 #include "alloc-util.h"
  16 #include "device-private.h"
  17 #include "device-util.h"
  18 #include "fd-util.h"
  19 #include "fs-util.h"
  20 #include "format-util.h"
  21 #include "libudev-util.h"
  22 #include "netlink-util.h"
  23 #include "parse-util.h"
  24 #include "path-util.h"
  25 #include "process-util.h"
  26 #include "rlimit-util.h"
  27 #include "signal-util.h"
  28 #include "stdio-util.h"
  29 #include "string-util.h"
  30 #include "strv.h"
  31 #include "strxcpyx.h"
  32 #include "udev-builtin.h"
  33 #include "udev-event.h"
  34 #include "udev-node.h"
  35 #include "udev-util.h"
  36 #include "udev-watch.h"
  37 #include "user-util.h"
  38
  39 typedef struct Spawn {
  40         const char *cmd;
  41         pid_t pid;
  42         usec_t timeout_warn_usec;
  43         usec_t timeout_usec;
  44         usec_t event_birth_usec;
  45         bool accept_failure;
  46         int fd_stdout;
  47         int fd_stderr;
  48         char *result;
  49         size_t result_size;
  50         size_t result_len;
  51 } Spawn;
  52
  53 UdevEvent *udev_event_new(sd_device *dev, usec_t exec_delay_usec, sd_netlink *rtnl) {
  54         UdevEvent *event;
  55
  56         assert(dev);
  57
  58         event = new(UdevEvent, 1);
  59         if (!event)
  60                 return NULL;
  61
  62         *event = (UdevEvent) {
  63                 .dev = sd_device_ref(dev),
  64                 .birth_usec = now(CLOCK_MONOTONIC),
  65                 .exec_delay_usec = exec_delay_usec,
  66                 .rtnl = sd_netlink_ref(rtnl),
  67                 .uid = UID_INVALID,
  68                 .gid = GID_INVALID,
  69                 .mode = MODE_INVALID,
  70         };
  71
  72         return event;
  73 }
  74
  75 UdevEvent *udev_event_free(UdevEvent *event) {
  76         if (!event)
  77                 return NULL;
  78
  79         sd_device_unref(event->dev);
  80         sd_device_unref(event->dev_db_clone);
  81         sd_netlink_unref(event->rtnl);
  82         ordered_hashmap_free_free_key(event->run_list);
  83         ordered_hashmap_free_free_free(event->seclabel_list);
  84         free(event->program_result);
  85         free(event->name);
  86
  87         return mfree(event);
  88 }
  89
  90 typedef enum {
  91         FORMAT_SUBST_DEVNODE,
  92         FORMAT_SUBST_ATTR,
  93         FORMAT_SUBST_ENV,
  94         FORMAT_SUBST_KERNEL,
  95         FORMAT_SUBST_KERNEL_NUMBER,
  96         FORMAT_SUBST_DRIVER,
  97         FORMAT_SUBST_DEVPATH,
  98         FORMAT_SUBST_ID,
  99         FORMAT_SUBST_MAJOR,
 100         FORMAT_SUBST_MINOR,
 101         FORMAT_SUBST_RESULT,
 102         FORMAT_SUBST_PARENT,
 103         FORMAT_SUBST_NAME,
 104         FORMAT_SUBST_LINKS,
 105         FORMAT_SUBST_ROOT,
 106         FORMAT_SUBST_SYS,
 107         _FORMAT_SUBST_TYPE_MAX,
 108         _FORMAT_SUBST_TYPE_INVALID = -1
 109 } FormatSubstitutionType;
 110
 111 struct subst_map_entry {
 112         const char *name;
 113         const char fmt;
 114         FormatSubstitutionType type;
 115 };
 116
 117 static const struct subst_map_entry map[] = {
 118            { .name = "devnode",  .fmt = 'N', .type = FORMAT_SUBST_DEVNODE },
 119            { .name = "tempnode", .fmt = 'N', .type = FORMAT_SUBST_DEVNODE }, /* deprecated */
 120            { .name = "attr",     .fmt = 's', .type = FORMAT_SUBST_ATTR },
 121            { .name = "sysfs",    .fmt = 's', .type = FORMAT_SUBST_ATTR }, /* deprecated */
 122            { .name = "env",      .fmt = 'E', .type = FORMAT_SUBST_ENV },
 123            { .name = "kernel",   .fmt = 'k', .type = FORMAT_SUBST_KERNEL },
 124            { .name = "number",   .fmt = 'n', .type = FORMAT_SUBST_KERNEL_NUMBER },
 125            { .name = "driver",   .fmt = 'd', .type = FORMAT_SUBST_DRIVER },
 126            { .name = "devpath",  .fmt = 'p', .type = FORMAT_SUBST_DEVPATH },
 127            { .name = "id",       .fmt = 'b', .type = FORMAT_SUBST_ID },
 128            { .name = "major",    .fmt = 'M', .type = FORMAT_SUBST_MAJOR },
 129            { .name = "minor",    .fmt = 'm', .type = FORMAT_SUBST_MINOR },
 130            { .name = "result",   .fmt = 'c', .type = FORMAT_SUBST_RESULT },
 131            { .name = "parent",   .fmt = 'P', .type = FORMAT_SUBST_PARENT },
 132            { .name = "name",     .fmt = 'D', .type = FORMAT_SUBST_NAME },
 133            { .name = "links",    .fmt = 'L', .type = FORMAT_SUBST_LINKS },
 134            { .name = "root",     .fmt = 'r', .type = FORMAT_SUBST_ROOT },
 135            { .name = "sys",      .fmt = 'S', .type = FORMAT_SUBST_SYS },
 136 };
 137
 138 static const char *format_type_to_string(FormatSubstitutionType t) {
 139         for (size_t i = 0; i < ELEMENTSOF(map); i++)
 140                 if (map[i].type == t)
 141                         return map[i].name;
 142         return NULL;
 143 }
 144
 145 static char format_type_to_char(FormatSubstitutionType t) {
 146         for (size_t i = 0; i < ELEMENTSOF(map); i++)
 147                 if (map[i].type == t)
 148                         return map[i].fmt;
 149         return '\0';
 150 }
 151
 152 static int get_subst_type(const char **str, bool strict, FormatSubstitutionType *ret_type, char ret_attr[static UTIL_PATH_SIZE]) {
 153         const char *p = *str, *q = NULL;
 154         size_t i;
 155
 156         assert(str);
 157         assert(*str);
 158         assert(ret_type);
 159         assert(ret_attr);
 160
 161         if (*p == '$') {
 162                 p++;
 163                 if (*p == '$') {
 164                         *str = p;
 165                         return 0;
 166                 }
 167                 for (i = 0; i < ELEMENTSOF(map); i++)
 168                         if ((q = startswith(p, map[i].name)))
 169                                 break;
 170         } else if (*p == '%') {
 171                 p++;
 172                 if (*p == '%') {
 173                         *str = p;
 174                         return 0;
 175                 }
 176
 177                 for (i = 0; i < ELEMENTSOF(map); i++)
 178                         if (*p == map[i].fmt) {
 179                                 q = p + 1;
 180                                 break;
 181                         }
 182         } else
 183                 return 0;
 184         if (!q)
 185                 /* When 'strict' flag is set, then '$' and '%' must be escaped. */
 186                 return strict ? -EINVAL : 0;
 187
 188         if (*q == '{') {
 189                 const char *start, *end;
 190                 size_t len;
 191
 192                 start = q + 1;
 193                 end = strchr(start, '}');
 194                 if (!end)
 195                         return -EINVAL;
 196
 197                 len = end - start;
 198                 if (len == 0 || len >= UTIL_PATH_SIZE)
 199                         return -EINVAL;
 200
 201                 strnscpy(ret_attr, UTIL_PATH_SIZE, start, len);
 202                 q = end + 1;
 203         } else
 204                 *ret_attr = '\0';
 205
 206         *str = q;
 207         *ret_type = map[i].type;
 208         return 1;
 209 }
 210
 211 static int safe_atou_optional_plus(const char *s, unsigned *ret) {
 212         const char *p;
 213         int r;
 214
 215         assert(s);
 216         assert(ret);
 217
 218         /* Returns 1 if plus, 0 if no plus, negative on error */
 219
 220         p = endswith(s, "+");
 221         if (p)
 222                 s = strndupa(s, p - s);
 223
 224         r = safe_atou(s, ret);
 225         if (r < 0)
 226                 return r;
 227
 228         return !!p;
 229 }
 230
 231 static ssize_t udev_event_subst_format(
 232                 UdevEvent *event,
 233                 FormatSubstitutionType type,
 234                 const char *attr,
 235                 char *dest,
 236                 size_t l) {
 237         sd_device *parent, *dev = event->dev;
 238         const char *val = NULL;
 239         char *s = dest;
 240         int r;
 241
 242         switch (type) {
 243         case FORMAT_SUBST_DEVPATH:
 244                 r = sd_device_get_devpath(dev, &val);
 245                 if (r < 0)
 246                         return r;
 247                 l = strpcpy(&s, l, val);
 248                 break;
 249         case FORMAT_SUBST_KERNEL:
 250                 r = sd_device_get_sysname(dev, &val);
 251                 if (r < 0)
 252                         return r;
 253                 l = strpcpy(&s, l, val);
 254                 break;
 255         case FORMAT_SUBST_KERNEL_NUMBER:
 256                 r = sd_device_get_sysnum(dev, &val);
 257                 if (r == -ENOENT)
 258                         goto null_terminate;
 259                 if (r < 0)
 260                         return r;
 261                 l = strpcpy(&s, l, val);
 262                 break;
 263         case FORMAT_SUBST_ID:
 264                 if (!event->dev_parent)
 265                         goto null_terminate;
 266                 r = sd_device_get_sysname(event->dev_parent, &val);
 267                 if (r < 0)
 268                         return r;
 269                 l = strpcpy(&s, l, val);
 270                 break;
 271         case FORMAT_SUBST_DRIVER:
 272                 if (!event->dev_parent)
 273                         goto null_terminate;
 274                 r = sd_device_get_driver(event->dev_parent, &val);
 275                 if (r == -ENOENT)
 276                         goto null_terminate;
 277                 if (r < 0)
 278                         return r;
 279                 l = strpcpy(&s, l, val);
 280                 break;
 281         case FORMAT_SUBST_MAJOR:
 282         case FORMAT_SUBST_MINOR: {
 283                 dev_t devnum;
 284
 285                 r = sd_device_get_devnum(dev, &devnum);
 286                 if (r < 0 && r != -ENOENT)
 287                         return r;
 288                 l = strpcpyf(&s, l, "%u", r < 0 ? 0 : type == FORMAT_SUBST_MAJOR ? major(devnum) : minor(devnum));
 289                 break;
 290         }
 291         case FORMAT_SUBST_RESULT: {
 292                 unsigned index = 0; /* 0 means whole string */
 293                 bool has_plus;
 294
 295                 if (!event->program_result)
 296                         goto null_terminate;
 297
 298                 if (!isempty(attr)) {
 299                         r = safe_atou_optional_plus(attr, &index);
 300                         if (r < 0)
 301                                 return r;
 302
 303                         has_plus = r;
 304                 }
 305
 306                 if (index == 0)
 307                         l = strpcpy(&s, l, event->program_result);
 308                 else {
 309                         const char *start, *p;
 310                         unsigned i;
 311
 312                         p = skip_leading_chars(event->program_result, NULL);
 313
 314                         for (i = 1; i < index; i++) {
 315                                 while (*p && !strchr(WHITESPACE, *p))
 316                                         p++;
 317                                 p = skip_leading_chars(p, NULL);
 318                                 if (*p == '\0')
 319                                         break;
 320                         }
 321                         if (i != index) {
 322                                 log_device_debug(dev, "requested part of result string not found");
 323                                 goto null_terminate;
 324                         }
 325
 326                         start = p;
 327                         /* %c{2+} copies the whole string from the second part on */
 328                         if (has_plus)
 329                                 l = strpcpy(&s, l, start);
 330                         else {
 331                                 while (*p && !strchr(WHITESPACE, *p))
 332                                         p++;
 333                                 l = strnpcpy(&s, l, start, p - start);
 334                         }
 335                 }
 336                 break;
 337         }
 338         case FORMAT_SUBST_ATTR: {
 339                 char vbuf[UTIL_NAME_SIZE];
 340                 int count;
 341
 342                 if (isempty(attr))
 343                         return -EINVAL;
 344
 345                 /* try to read the value specified by "[dmi/id]product_name" */
 346                 if (util_resolve_subsys_kernel(attr, vbuf, sizeof(vbuf), true) == 0)
 347                         val = vbuf;
 348
 349                 /* try to read the attribute the device */
 350                 if (!val)
 351                         (void) sd_device_get_sysattr_value(dev, attr, &val);
 352
 353                 /* try to read the attribute of the parent device, other matches have selected */
 354                 if (!val && event->dev_parent && event->dev_parent != dev)
 355                         (void) sd_device_get_sysattr_value(event->dev_parent, attr, &val);
 356
 357                 if (!val)
 358                         goto null_terminate;
 359
 360                 /* strip trailing whitespace, and replace unwanted characters */
 361                 if (val != vbuf)
 362                         strscpy(vbuf, sizeof(vbuf), val);
 363                 delete_trailing_chars(vbuf, NULL);
 364                 count = util_replace_chars(vbuf, UDEV_ALLOWED_CHARS_INPUT);
 365                 if (count > 0)
 366                         log_device_debug(dev, "%i character(s) replaced", count);
 367                 l = strpcpy(&s, l, vbuf);
 368                 break;
 369         }
 370         case FORMAT_SUBST_PARENT:
 371                 r = sd_device_get_parent(dev, &parent);
 372                 if (r == -ENODEV)
 373                         goto null_terminate;
 374                 if (r < 0)
 375                         return r;
 376                 r = sd_device_get_devname(parent, &val);
 377                 if (r == -ENOENT)
 378                         goto null_terminate;
 379                 if (r < 0)
 380                         return r;
 381                 l = strpcpy(&s, l, val + STRLEN("/dev/"));
 382                 break;
 383         case FORMAT_SUBST_DEVNODE:
 384                 r = sd_device_get_devname(dev, &val);
 385                 if (r == -ENOENT)
 386                         goto null_terminate;
 387                 if (r < 0)
 388                         return r;
 389                 l = strpcpy(&s, l, val);
 390                 break;
 391         case FORMAT_SUBST_NAME:
 392                 if (event->name)
 393                         l = strpcpy(&s, l, event->name);
 394                 else if (sd_device_get_devname(dev, &val) >= 0)
 395                         l = strpcpy(&s, l, val + STRLEN("/dev/"));
 396                 else {
 397                         r = sd_device_get_sysname(dev, &val);
 398                         if (r < 0)
 399                                 return r;
 400                         l = strpcpy(&s, l, val);
 401                 }
 402                 break;
 403         case FORMAT_SUBST_LINKS:
 404                 FOREACH_DEVICE_DEVLINK(dev, val)
 405                         if (s == dest)
 406                                 l = strpcpy(&s, l, val + STRLEN("/dev/"));
 407                         else
 408                                 l = strpcpyl(&s, l, " ", val + STRLEN("/dev/"), NULL);
 409                 if (s == dest)
 410                         goto null_terminate;
 411                 break;
 412         case FORMAT_SUBST_ROOT:
 413                 l = strpcpy(&s, l, "/dev");
 414                 break;
 415         case FORMAT_SUBST_SYS:
 416                 l = strpcpy(&s, l, "/sys");
 417                 break;
 418         case FORMAT_SUBST_ENV:
 419                 if (isempty(attr))
 420                         return -EINVAL;
 421                 r = sd_device_get_property_value(dev, attr, &val);
 422                 if (r == -ENOENT)
 423                         goto null_terminate;
 424                 if (r < 0)
 425                         return r;
 426                 l = strpcpy(&s, l, val);
 427                 break;
 428         default:
 429                 assert_not_reached("Unknown format substitution type");
 430         }
 431
 432         return s - dest;
 433
 434 null_terminate:
 435         *s = '\0';
 436         return 0;
 437 }
 438
 439 ssize_t udev_event_apply_format(UdevEvent *event,
 440                                 const char *src, char *dest, size_t size,
 441                                 bool replace_whitespace) {
 442         const char *s = src;
 443         int r;
 444
 445         assert(event);
 446         assert(event->dev);
 447         assert(src);
 448         assert(dest);
 449         assert(size > 0);
 450
 451         while (*s) {
 452                 FormatSubstitutionType type;
 453                 char attr[UTIL_PATH_SIZE];
 454                 ssize_t subst_len;
 455
 456                 r = get_subst_type(&s, false, &type, attr);
 457                 if (r < 0)
 458                         return log_device_warning_errno(event->dev, r, "Invalid format string, ignoring: %s", src);
 459                 if (r == 0) {
 460                         if (size < 2) /* need space for this char and the terminating NUL */
 461                                 break;
 462                         *dest++ = *s++;
 463                         size--;
 464                         continue;
 465                 }
 466
 467                 subst_len = udev_event_subst_format(event, type, attr, dest, size);
 468                 if (subst_len < 0)
 469                         return log_device_warning_errno(event->dev, subst_len,
 470                                                         "Failed to substitute variable '$%s' or apply format '%%%c', ignoring: %m",
 471                                                         format_type_to_string(type), format_type_to_char(type));
 472
 473                 /* FORMAT_SUBST_RESULT handles spaces itself */
 474                 if (replace_whitespace && type != FORMAT_SUBST_RESULT)
 475                         /* util_replace_whitespace can replace in-place,
 476                          * and does nothing if subst_len == 0 */
 477                         subst_len = util_replace_whitespace(dest, dest, subst_len);
 478
 479                 dest += subst_len;
 480                 size -= subst_len;
 481         }
 482
 483         assert(size >= 1);
 484         *dest = '\0';
 485         return size;
 486 }
 487
 488 int udev_check_format(const char *value, size_t *offset, const char **hint) {
 489         FormatSubstitutionType type;
 490         const char *s = value;
 491         char attr[UTIL_PATH_SIZE];
 492         int r;
 493
 494         while (*s) {
 495                 r = get_subst_type(&s, true, &type, attr);
 496                 if (r < 0) {
 497                         if (offset)
 498                                 *offset = s - value;
 499                         if (hint)
 500                                 *hint = "invalid substitution type";
 501                         return r;
 502                 } else if (r == 0) {
 503                         s++;
 504                         continue;
 505                 }
 506
 507                 if (IN_SET(type, FORMAT_SUBST_ATTR, FORMAT_SUBST_ENV) && isempty(attr)) {
 508                         if (offset)
 509                                 *offset = s - value;
 510                         if (hint)
 511                                 *hint = "attribute value missing";
 512                         return -EINVAL;
 513                 }
 514
 515                 if (type == FORMAT_SUBST_RESULT && !isempty(attr)) {
 516                         unsigned i;
 517
 518                         r = safe_atou_optional_plus(attr, &i);
 519                         if (r < 0) {
 520                                 if (offset)
 521                                         *offset = s - value;
 522                                 if (hint)
 523                                         *hint = "attribute value not a valid number";
 524                                 return r;
 525                         }
 526                 }
 527         }
 528
 529         return 0;
 530 }
 531
 532 static int on_spawn_io(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
 533         Spawn *spawn = userdata;
 534         char buf[4096], *p;
 535         size_t size;
 536         ssize_t l;
 537
 538         assert(spawn);
 539         assert(fd == spawn->fd_stdout || fd == spawn->fd_stderr);
 540         assert(!spawn->result || spawn->result_len < spawn->result_size);
 541
 542         if (fd == spawn->fd_stdout && spawn->result) {
 543                 p = spawn->result + spawn->result_len;
 544                 size = spawn->result_size - spawn->result_len;
 545         } else {
 546                 p = buf;
 547                 size = sizeof(buf);
 548         }
 549
 550         l = read(fd, p, size - 1);
 551         if (l < 0) {
 552                 if (errno != EAGAIN)
 553                         log_error_errno(errno, "Failed to read stdout of '%s': %m", spawn->cmd);
 554
 555                 return 0;
 556         }
 557
 558         p[l] = '\0';
 559         if (fd == spawn->fd_stdout && spawn->result)
 560                 spawn->result_len += l;
 561
 562         /* Log output only if we watch stderr. */
 563         if (l > 0 && spawn->fd_stderr >= 0) {
 564                 _cleanup_strv_free_ char **v = NULL;
 565                 char **q;
 566
 567                 v = strv_split_newlines(p);
 568                 if (!v)
 569                         return 0;
 570
 571                 STRV_FOREACH(q, v)
 572                         log_debug("'%s'(%s) '%s'", spawn->cmd,
 573                                   fd == spawn->fd_stdout ? "out" : "err", *q);
 574         }
 575
 576         return 0;
 577 }
 578
 579 static int on_spawn_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
 580         Spawn *spawn = userdata;
 581         char timeout[FORMAT_TIMESPAN_MAX];
 582
 583         assert(spawn);
 584
 585         kill_and_sigcont(spawn->pid, SIGKILL);
 586
 587         log_error("Spawned process '%s' ["PID_FMT"] timed out after %s, killing", spawn->cmd, spawn->pid,
 588                   format_timespan(timeout, sizeof(timeout), spawn->timeout_usec, USEC_PER_SEC));
 589
 590         return 1;
 591 }
 592
 593 static int on_spawn_timeout_warning(sd_event_source *s, uint64_t usec, void *userdata) {
 594         Spawn *spawn = userdata;
 595         char timeout[FORMAT_TIMESPAN_MAX];
 596
 597         assert(spawn);
 598
 599         log_warning("Spawned process '%s' ["PID_FMT"] is taking longer than %s to complete", spawn->cmd, spawn->pid,
 600                     format_timespan(timeout, sizeof(timeout), spawn->timeout_warn_usec, USEC_PER_SEC));
 601
 602         return 1;
 603 }
 604
 605 static int on_spawn_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata) {
 606         Spawn *spawn = userdata;
 607         int ret = -EIO;
 608
 609         assert(spawn);
 610
 611         switch (si->si_code) {
 612         case CLD_EXITED:
 613                 if (si->si_status == 0)
 614                         log_debug("Process '%s' succeeded.", spawn->cmd);
 615                 else
 616                         log_full(spawn->accept_failure ? LOG_DEBUG : LOG_WARNING,
 617                                  "Process '%s' failed with exit code %i.", spawn->cmd, si->si_status);
 618                 ret = si->si_status;
 619                 break;
 620         case CLD_KILLED:
 621         case CLD_DUMPED:
 622                 log_error("Process '%s' terminated by signal %s.", spawn->cmd, signal_to_string(si->si_status));
 623                 break;
 624         default:
 625                 log_error("Process '%s' failed due to unknown reason.", spawn->cmd);
 626         }
 627
 628         sd_event_exit(sd_event_source_get_event(s), ret);
 629         return 1;
 630 }
 631
 632 static int spawn_wait(Spawn *spawn) {
 633         _cleanup_(sd_event_unrefp) sd_event *e = NULL;
 634         int r;
 635
 636         assert(spawn);
 637
 638         r = sd_event_new(&e);
 639         if (r < 0)
 640                 return r;
 641
 642         if (spawn->timeout_usec > 0) {
 643                 usec_t usec, age_usec;
 644
 645                 usec = now(CLOCK_MONOTONIC);
 646                 age_usec = usec - spawn->event_birth_usec;
 647                 if (age_usec < spawn->timeout_usec) {
 648                         if (spawn->timeout_warn_usec > 0 &&
 649                             spawn->timeout_warn_usec < spawn->timeout_usec &&
 650                             spawn->timeout_warn_usec > age_usec) {
 651                                 spawn->timeout_warn_usec -= age_usec;
 652
 653                                 r = sd_event_add_time(e, NULL, CLOCK_MONOTONIC,
 654                                                       usec + spawn->timeout_warn_usec, USEC_PER_SEC,
 655                                                       on_spawn_timeout_warning, spawn);
 656                                 if (r < 0)
 657                                         return r;
 658                         }
 659
 660                         spawn->timeout_usec -= age_usec;
 661
 662                         r = sd_event_add_time(e, NULL, CLOCK_MONOTONIC,
 663                                               usec + spawn->timeout_usec, USEC_PER_SEC, on_spawn_timeout, spawn);
 664                         if (r < 0)
 665                                 return r;
 666                 }
 667         }
 668
 669         if (spawn->fd_stdout >= 0) {
 670                 r = sd_event_add_io(e, NULL, spawn->fd_stdout, EPOLLIN, on_spawn_io, spawn);
 671                 if (r < 0)
 672                         return r;
 673         }
 674
 675         if (spawn->fd_stderr >= 0) {
 676                 r = sd_event_add_io(e, NULL, spawn->fd_stderr, EPOLLIN, on_spawn_io, spawn);
 677                 if (r < 0)
 678                         return r;
 679         }
 680
 681         r = sd_event_add_child(e, NULL, spawn->pid, WEXITED, on_spawn_sigchld, spawn);
 682         if (r < 0)
 683                 return r;
 684
 685         return sd_event_loop(e);
 686 }
 687
 688 int udev_event_spawn(UdevEvent *event,
 689                      usec_t timeout_usec,
 690                      bool accept_failure,
 691                      const char *cmd,
 692                      char *result, size_t ressize) {
 693         _cleanup_close_pair_ int outpipe[2] = {-1, -1}, errpipe[2] = {-1, -1};
 694         _cleanup_strv_free_ char **argv = NULL;
 695         char **envp = NULL;
 696         Spawn spawn;
 697         pid_t pid;
 698         int r;
 699
 700         assert(event);
 701         assert(event->dev);
 702         assert(result || ressize == 0);
 703
 704         /* pipes from child to parent */
 705         if (result || log_get_max_level() >= LOG_INFO)
 706                 if (pipe2(outpipe, O_NONBLOCK|O_CLOEXEC) != 0)
 707                         return log_error_errno(errno, "Failed to create pipe for command '%s': %m", cmd);
 708
 709         if (log_get_max_level() >= LOG_INFO)
 710                 if (pipe2(errpipe, O_NONBLOCK|O_CLOEXEC) != 0)
 711                         return log_error_errno(errno, "Failed to create pipe for command '%s': %m", cmd);
 712
 713         argv = strv_split_full(cmd, NULL, SPLIT_QUOTES|SPLIT_RELAX);
 714         if (!argv)
 715                 return log_oom();
 716
 717         if (isempty(argv[0]))
 718                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 719                                        "Invalid command '%s'", cmd);
 720
 721         /* allow programs in /usr/lib/udev/ to be called without the path */
 722         if (!path_is_absolute(argv[0])) {
 723                 char *program;
 724
 725                 program = path_join(UDEVLIBEXECDIR, argv[0]);
 726                 if (!program)
 727                         return log_oom();
 728
 729                 free_and_replace(argv[0], program);
 730         }
 731
 732         r = device_get_properties_strv(event->dev, &envp);
 733         if (r < 0)
 734                 return log_device_error_errno(event->dev, r, "Failed to get device properties");
 735
 736         log_debug("Starting '%s'", cmd);
 737
 738         r = safe_fork("(spawn)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
 739         if (r < 0)
 740                 return log_error_errno(r, "Failed to fork() to execute command '%s': %m", cmd);
 741         if (r == 0) {
 742                 if (rearrange_stdio(-1, outpipe[WRITE_END], errpipe[WRITE_END]) < 0)
 743                         _exit(EXIT_FAILURE);
 744
 745                 (void) close_all_fds(NULL, 0);
 746                 (void) rlimit_nofile_safe();
 747
 748                 execve(argv[0], argv, envp);
 749                 _exit(EXIT_FAILURE);
 750         }
 751
 752         /* parent closed child's ends of pipes */
 753         outpipe[WRITE_END] = safe_close(outpipe[WRITE_END]);
 754         errpipe[WRITE_END] = safe_close(errpipe[WRITE_END]);
 755
 756         spawn = (Spawn) {
 757                 .cmd = cmd,
 758                 .pid = pid,
 759                 .accept_failure = accept_failure,
 760                 .timeout_warn_usec = udev_warn_timeout(timeout_usec),
 761                 .timeout_usec = timeout_usec,
 762                 .event_birth_usec = event->birth_usec,
 763                 .fd_stdout = outpipe[READ_END],
 764                 .fd_stderr = errpipe[READ_END],
 765                 .result = result,
 766                 .result_size = ressize,
 767         };
 768         r = spawn_wait(&spawn);
 769         if (r < 0)
 770                 return log_error_errno(r, "Failed to wait for spawned command '%s': %m", cmd);
 771
 772         if (result)
 773                 result[spawn.result_len] = '\0';
 774
 775         return r; /* 0 for success, and positive if the program failed */
 776 }
 777
 778 static int rename_netif(UdevEvent *event) {
 779         sd_device *dev = event->dev;
 780         const char *oldname;
 781         int ifindex, r;
 782
 783         if (!event->name)
 784                 return 0; /* No new name is requested. */
 785
 786         r = sd_device_get_sysname(dev, &oldname);
 787         if (r < 0)
 788                 return log_device_error_errno(dev, r, "Failed to get sysname: %m");
 789
 790         if (streq(event->name, oldname))
 791                 return 0; /* The interface name is already requested name. */
 792
 793         if (!device_for_action(dev, DEVICE_ACTION_ADD))
 794                 return 0; /* Rename the interface only when it is added. */
 795
 796         r = sd_device_get_ifindex(dev, &ifindex);
 797         if (r == -ENOENT)
 798                 return 0; /* Device is not a network interface. */
 799         if (r < 0)
 800                 return log_device_error_errno(dev, r, "Failed to get ifindex: %m");
 801
 802         r = rtnl_set_link_name(&event->rtnl, ifindex, event->name);
 803         if (r < 0)
 804                 return log_device_error_errno(dev, r, "Failed to rename network interface %i from '%s' to '%s': %m",
 805                                               ifindex, oldname, event->name);
 806
 807         /* Set ID_RENAMING boolean property here, and drop it in the corresponding move uevent later. */
 808         r = device_add_property(dev, "ID_RENAMING", "1");
 809         if (r < 0)
 810                 return log_device_warning_errno(dev, r, "Failed to add 'ID_RENAMING' property: %m");
 811
 812         r = device_rename(dev, event->name);
 813         if (r < 0)
 814                 return log_device_warning_errno(dev, r, "Failed to update properties with new name '%s': %m", event->name);
 815
 816         log_device_debug(dev, "Network interface %i is renamed from '%s' to '%s'", ifindex, oldname, event->name);
 817
 818         return 1;
 819 }
 820
 821 static int update_devnode(UdevEvent *event) {
 822         sd_device *dev = event->dev;
 823         int r;
 824
 825         r = sd_device_get_devnum(dev, NULL);
 826         if (r == -ENOENT)
 827                 return 0;
 828         if (r < 0)
 829                 return log_device_error_errno(dev, r, "Failed to get devnum: %m");
 830
 831         /* remove/update possible left-over symlinks from old database entry */
 832         if (event->dev_db_clone)
 833                 (void) udev_node_update_old_links(dev, event->dev_db_clone);
 834
 835         if (!uid_is_valid(event->uid)) {
 836                 r = device_get_devnode_uid(dev, &event->uid);
 837                 if (r < 0 && r != -ENOENT)
 838                         return log_device_error_errno(dev, r, "Failed to get devnode UID: %m");
 839         }
 840
 841         if (!gid_is_valid(event->gid)) {
 842                 r = device_get_devnode_gid(dev, &event->gid);
 843                 if (r < 0 && r != -ENOENT)
 844                         return log_device_error_errno(dev, r, "Failed to get devnode GID: %m");
 845         }
 846
 847         if (event->mode == MODE_INVALID) {
 848                 r = device_get_devnode_mode(dev, &event->mode);
 849                 if (r < 0 && r != -ENOENT)
 850                         return log_device_error_errno(dev, r, "Failed to get devnode mode: %m");
 851         }
 852         if (event->mode == MODE_INVALID && gid_is_valid(event->gid) && event->gid > 0)
 853                 /* If group is set, but mode is not set, "upgrade" mode for the group. */
 854                 event->mode = 0660;
 855
 856         bool apply_mac = device_for_action(dev, DEVICE_ACTION_ADD);
 857
 858         return udev_node_add(dev, apply_mac, event->mode, event->uid, event->gid, event->seclabel_list);
 859 }
 860
 861 static void event_execute_rules_on_remove(
 862                 UdevEvent *event,
 863                 usec_t timeout_usec,
 864                 Hashmap *properties_list,
 865                 UdevRules *rules) {
 866
 867         sd_device *dev = event->dev;
 868         int r;
 869
 870         r = device_read_db_internal(dev, true);
 871         if (r < 0)
 872                 log_device_debug_errno(dev, r, "Failed to read database under /run/udev/data/: %m");
 873
 874         r = device_tag_index(dev, NULL, false);
 875         if (r < 0)
 876                 log_device_debug_errno(dev, r, "Failed to remove corresponding tag files under /run/udev/tag/, ignoring: %m");
 877
 878         r = device_delete_db(dev);
 879         if (r < 0)
 880                 log_device_debug_errno(dev, r, "Failed to delete database under /run/udev/data/, ignoring: %m");
 881
 882         if (sd_device_get_devnum(dev, NULL) >= 0)
 883                 (void) udev_watch_end(dev);
 884
 885         (void) udev_rules_apply_to_event(rules, event, timeout_usec, properties_list);
 886
 887         if (sd_device_get_devnum(dev, NULL) >= 0)
 888                 (void) udev_node_remove(dev);
 889 }
 890
 891 static int udev_event_on_move(UdevEvent *event) {
 892         sd_device *dev = event->dev;
 893         int r;
 894
 895         if (event->dev_db_clone &&
 896             sd_device_get_devnum(dev, NULL) < 0) {
 897                 r = device_copy_properties(dev, event->dev_db_clone);
 898                 if (r < 0)
 899                         log_device_debug_errno(dev, r, "Failed to copy properties from cloned sd_device object, ignoring: %m");
 900         }
 901
 902         /* Drop previously added property */
 903         r = device_add_property(dev, "ID_RENAMING", NULL);
 904         if (r < 0)
 905                 return log_device_debug_errno(dev, r, "Failed to remove 'ID_RENAMING' property: %m");
 906
 907         return 0;
 908 }
 909
 910 int udev_event_execute_rules(UdevEvent *event,
 911                              usec_t timeout_usec,
 912                              Hashmap *properties_list,
 913                              UdevRules *rules) {
 914         const char *subsystem;
 915         DeviceAction action;
 916         sd_device *dev;
 917         int r;
 918
 919         assert(event);
 920         assert(rules);
 921
 922         dev = event->dev;
 923
 924         r = sd_device_get_subsystem(dev, &subsystem);
 925         if (r < 0)
 926                 return log_device_error_errno(dev, r, "Failed to get subsystem: %m");
 927
 928         r = device_get_action(dev, &action);
 929         if (r < 0)
 930                 return log_device_error_errno(dev, r, "Failed to get ACTION: %m");
 931
 932         if (action == DEVICE_ACTION_REMOVE) {
 933                 event_execute_rules_on_remove(event, timeout_usec, properties_list, rules);
 934                 return 0;
 935         }
 936
 937         r = device_clone_with_db(dev, &event->dev_db_clone);
 938         if (r < 0)
 939                 return log_device_debug_errno(dev, r, "Failed to clone sd_device object: %m");
 940
 941         if (event->dev_db_clone && sd_device_get_devnum(dev, NULL) >= 0)
 942                 /* Disable watch during event processing. */
 943                 (void) udev_watch_end(event->dev_db_clone);
 944
 945         if (action == DEVICE_ACTION_MOVE) {
 946                 r = udev_event_on_move(event);
 947                 if (r < 0)
 948                         return r;
 949         }
 950
 951         r = udev_rules_apply_to_event(rules, event, timeout_usec, properties_list);
 952         if (r < 0)
 953                 return log_device_debug_errno(dev, r, "Failed to apply udev rules: %m");
 954
 955         r = rename_netif(event);
 956         if (r < 0)
 957                 return r;
 958
 959         r = update_devnode(event);
 960         if (r < 0)
 961                 return r;
 962
 963         /* preserve old, or get new initialization timestamp */
 964         r = device_ensure_usec_initialized(dev, event->dev_db_clone);
 965         if (r < 0)
 966                 return log_device_debug_errno(dev, r, "Failed to set initialization timestamp: %m");
 967
 968         /* (re)write database file */
 969         r = device_tag_index(dev, event->dev_db_clone, true);
 970         if (r < 0)
 971                 return log_device_debug_errno(dev, r, "Failed to update tags under /run/udev/tag/: %m");
 972
 973         r = device_update_db(dev);
 974         if (r < 0)
 975                 return log_device_debug_errno(dev, r, "Failed to update database under /run/udev/data/: %m");
 976
 977         device_set_is_initialized(dev);
 978
 979         event->dev_db_clone = sd_device_unref(event->dev_db_clone);
 980
 981         return 0;
 982 }
 983
 984 void udev_event_execute_run(UdevEvent *event, usec_t timeout_usec) {
 985         const char *command;
 986         void *val;
 987         Iterator i;
 988         int r;
 989
 990         ORDERED_HASHMAP_FOREACH_KEY(val, command, event->run_list, i) {
 991                 UdevBuiltinCommand builtin_cmd = PTR_TO_UDEV_BUILTIN_CMD(val);
 992
 993                 if (builtin_cmd != _UDEV_BUILTIN_INVALID) {
 994                         log_device_debug(event->dev, "Running built-in command \"%s\"", command);
 995                         r = udev_builtin_run(event->dev, builtin_cmd, command, false);
 996                         if (r < 0)
 997                                 log_device_debug_errno(event->dev, r, "Failed to run built-in command \"%s\", ignoring: %m", command);
 998                 } else {
 999                         if (event->exec_delay_usec > 0) {
1000                                 char buf[FORMAT_TIMESPAN_MAX];
1001
1002                                 log_device_debug(event->dev, "Delaying execution of \"%s\" for %s.",
1003                                                  command, format_timespan(buf, sizeof(buf), event->exec_delay_usec, USEC_PER_SEC));
1004                                 (void) usleep(event->exec_delay_usec);
1005                         }
1006
1007                         log_device_debug(event->dev, "Running command \"%s\"", command);
1008                         r = udev_event_spawn(event, timeout_usec, false, command, NULL, 0);
1009                         if (r > 0) /* returned value is positive when program fails */
1010                                 log_device_debug(event->dev, "Command \"%s\" returned %d (error), ignoring.", command, r);
1011                 }
1012         }
1013 }