src/libsystemd/sd-daemon/sd-daemon.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <limits.h>
   5 #include <mqueue.h>
   6 #include <netinet/in.h>
   7 #include <poll.h>
   8 #include <stdarg.h>
   9 #include <stddef.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <sys/stat.h>
  13 #include <sys/un.h>
  14 #include <unistd.h>
  15
  16 #include "sd-daemon.h"
  17
  18 #include "alloc-util.h"
  19 #include "fd-util.h"
  20 #include "fs-util.h"
  21 #include "io-util.h"
  22 #include "parse-util.h"
  23 #include "path-util.h"
  24 #include "process-util.h"
  25 #include "socket-util.h"
  26 #include "stat-util.h"
  27 #include "strv.h"
  28 #include "time-util.h"
  29
  30 #define SNDBUF_SIZE (8*1024*1024)
  31
  32 static void unsetenv_all(bool unset_environment) {
  33         if (!unset_environment)
  34                 return;
  35
  36         assert_se(unsetenv("LISTEN_PID") == 0);
  37         assert_se(unsetenv("LISTEN_FDS") == 0);
  38         assert_se(unsetenv("LISTEN_FDNAMES") == 0);
  39 }
  40
  41 _public_ int sd_listen_fds(int unset_environment) {
  42         const char *e;
  43         int n, r;
  44         pid_t pid;
  45
  46         e = getenv("LISTEN_PID");
  47         if (!e) {
  48                 r = 0;
  49                 goto finish;
  50         }
  51
  52         r = parse_pid(e, &pid);
  53         if (r < 0)
  54                 goto finish;
  55
  56         /* Is this for us? */
  57         if (getpid_cached() != pid) {
  58                 r = 0;
  59                 goto finish;
  60         }
  61
  62         e = getenv("LISTEN_FDS");
  63         if (!e) {
  64                 r = 0;
  65                 goto finish;
  66         }
  67
  68         r = safe_atoi(e, &n);
  69         if (r < 0)
  70                 goto finish;
  71
  72         assert_cc(SD_LISTEN_FDS_START < INT_MAX);
  73         if (n <= 0 || n > INT_MAX - SD_LISTEN_FDS_START) {
  74                 r = -EINVAL;
  75                 goto finish;
  76         }
  77
  78         for (int fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++) {
  79                 r = fd_cloexec(fd, true);
  80                 if (r < 0)
  81                         goto finish;
  82         }
  83
  84         r = n;
  85
  86 finish:
  87         unsetenv_all(unset_environment);
  88         return r;
  89 }
  90
  91 _public_ int sd_listen_fds_with_names(int unset_environment, char ***names) {
  92         _cleanup_strv_free_ char **l = NULL;
  93         bool have_names;
  94         int n_names = 0, n_fds;
  95         const char *e;
  96         int r;
  97
  98         if (!names)
  99                 return sd_listen_fds(unset_environment);
 100
 101         e = getenv("LISTEN_FDNAMES");
 102         if (e) {
 103                 n_names = strv_split_full(&l, e, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
 104                 if (n_names < 0) {
 105                         unsetenv_all(unset_environment);
 106                         return n_names;
 107                 }
 108
 109                 have_names = true;
 110         } else
 111                 have_names = false;
 112
 113         n_fds = sd_listen_fds(unset_environment);
 114         if (n_fds <= 0)
 115                 return n_fds;
 116
 117         if (have_names) {
 118                 if (n_names != n_fds)
 119                         return -EINVAL;
 120         } else {
 121                 r = strv_extend_n(&l, "unknown", n_fds);
 122                 if (r < 0)
 123                         return r;
 124         }
 125
 126         *names = TAKE_PTR(l);
 127
 128         return n_fds;
 129 }
 130
 131 _public_ int sd_is_fifo(int fd, const char *path) {
 132         struct stat st_fd;
 133
 134         assert_return(fd >= 0, -EBADF);
 135
 136         if (fstat(fd, &st_fd) < 0)
 137                 return -errno;
 138
 139         if (!S_ISFIFO(st_fd.st_mode))
 140                 return 0;
 141
 142         if (path) {
 143                 struct stat st_path;
 144
 145                 if (stat(path, &st_path) < 0) {
 146
 147                         if (IN_SET(errno, ENOENT, ENOTDIR))
 148                                 return 0;
 149
 150                         return -errno;
 151                 }
 152
 153                 return stat_inode_same(&st_path, &st_fd);
 154         }
 155
 156         return 1;
 157 }
 158
 159 _public_ int sd_is_special(int fd, const char *path) {
 160         struct stat st_fd;
 161
 162         assert_return(fd >= 0, -EBADF);
 163
 164         if (fstat(fd, &st_fd) < 0)
 165                 return -errno;
 166
 167         if (!S_ISREG(st_fd.st_mode) && !S_ISCHR(st_fd.st_mode))
 168                 return 0;
 169
 170         if (path) {
 171                 struct stat st_path;
 172
 173                 if (stat(path, &st_path) < 0) {
 174
 175                         if (IN_SET(errno, ENOENT, ENOTDIR))
 176                                 return 0;
 177
 178                         return -errno;
 179                 }
 180
 181                 if (S_ISREG(st_fd.st_mode) && S_ISREG(st_path.st_mode))
 182                         return stat_inode_same(&st_path, &st_fd);
 183                 else if (S_ISCHR(st_fd.st_mode) && S_ISCHR(st_path.st_mode))
 184                         return st_path.st_rdev == st_fd.st_rdev;
 185                 else
 186                         return 0;
 187         }
 188
 189         return 1;
 190 }
 191
 192 static int is_socket_internal(int fd, int type, int listening) {
 193         struct stat st_fd;
 194
 195         assert_return(fd >= 0, -EBADF);
 196         assert_return(type >= 0, -EINVAL);
 197
 198         if (fstat(fd, &st_fd) < 0)
 199                 return -errno;
 200
 201         if (!S_ISSOCK(st_fd.st_mode))
 202                 return 0;
 203
 204         if (type != 0) {
 205                 int other_type = 0;
 206                 socklen_t l = sizeof(other_type);
 207
 208                 if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &other_type, &l) < 0)
 209                         return -errno;
 210
 211                 if (l != sizeof(other_type))
 212                         return -EINVAL;
 213
 214                 if (other_type != type)
 215                         return 0;
 216         }
 217
 218         if (listening >= 0) {
 219                 int accepting = 0;
 220                 socklen_t l = sizeof(accepting);
 221
 222                 if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &accepting, &l) < 0)
 223                         return -errno;
 224
 225                 if (l != sizeof(accepting))
 226                         return -EINVAL;
 227
 228                 if (!accepting != !listening)
 229                         return 0;
 230         }
 231
 232         return 1;
 233 }
 234
 235 _public_ int sd_is_socket(int fd, int family, int type, int listening) {
 236         int r;
 237
 238         assert_return(fd >= 0, -EBADF);
 239         assert_return(family >= 0, -EINVAL);
 240
 241         r = is_socket_internal(fd, type, listening);
 242         if (r <= 0)
 243                 return r;
 244
 245         if (family > 0) {
 246                 union sockaddr_union sockaddr = {};
 247                 socklen_t l = sizeof(sockaddr);
 248
 249                 if (getsockname(fd, &sockaddr.sa, &l) < 0)
 250                         return -errno;
 251
 252                 if (l < sizeof(sa_family_t))
 253                         return -EINVAL;
 254
 255                 return sockaddr.sa.sa_family == family;
 256         }
 257
 258         return 1;
 259 }
 260
 261 _public_ int sd_is_socket_inet(int fd, int family, int type, int listening, uint16_t port) {
 262         union sockaddr_union sockaddr = {};
 263         socklen_t l = sizeof(sockaddr);
 264         int r;
 265
 266         assert_return(fd >= 0, -EBADF);
 267         assert_return(IN_SET(family, 0, AF_INET, AF_INET6), -EINVAL);
 268
 269         r = is_socket_internal(fd, type, listening);
 270         if (r <= 0)
 271                 return r;
 272
 273         if (getsockname(fd, &sockaddr.sa, &l) < 0)
 274                 return -errno;
 275
 276         if (l < sizeof(sa_family_t))
 277                 return -EINVAL;
 278
 279         if (!IN_SET(sockaddr.sa.sa_family, AF_INET, AF_INET6))
 280                 return 0;
 281
 282         if (family != 0)
 283                 if (sockaddr.sa.sa_family != family)
 284                         return 0;
 285
 286         if (port > 0) {
 287                 unsigned sa_port;
 288
 289                 r = sockaddr_port(&sockaddr.sa, &sa_port);
 290                 if (r < 0)
 291                         return r;
 292
 293                 return port == sa_port;
 294         }
 295
 296         return 1;
 297 }
 298
 299 _public_ int sd_is_socket_sockaddr(int fd, int type, const struct sockaddr* addr, unsigned addr_len, int listening) {
 300         union sockaddr_union sockaddr = {};
 301         socklen_t l = sizeof(sockaddr);
 302         int r;
 303
 304         assert_return(fd >= 0, -EBADF);
 305         assert_return(addr, -EINVAL);
 306         assert_return(addr_len >= sizeof(sa_family_t), -ENOBUFS);
 307         assert_return(IN_SET(addr->sa_family, AF_INET, AF_INET6), -EPFNOSUPPORT);
 308
 309         r = is_socket_internal(fd, type, listening);
 310         if (r <= 0)
 311                 return r;
 312
 313         if (getsockname(fd, &sockaddr.sa, &l) < 0)
 314                 return -errno;
 315
 316         if (l < sizeof(sa_family_t))
 317                 return -EINVAL;
 318
 319         if (sockaddr.sa.sa_family != addr->sa_family)
 320                 return 0;
 321
 322         if (sockaddr.sa.sa_family == AF_INET) {
 323                 const struct sockaddr_in *in = (const struct sockaddr_in *) addr;
 324
 325                 if (l < sizeof(struct sockaddr_in) || addr_len < sizeof(struct sockaddr_in))
 326                         return -EINVAL;
 327
 328                 if (in->sin_port != 0 &&
 329                     sockaddr.in.sin_port != in->sin_port)
 330                         return false;
 331
 332                 return sockaddr.in.sin_addr.s_addr == in->sin_addr.s_addr;
 333
 334         } else {
 335                 const struct sockaddr_in6 *in = (const struct sockaddr_in6 *) addr;
 336
 337                 if (l < sizeof(struct sockaddr_in6) || addr_len < sizeof(struct sockaddr_in6))
 338                         return -EINVAL;
 339
 340                 if (in->sin6_port != 0 &&
 341                     sockaddr.in6.sin6_port != in->sin6_port)
 342                         return false;
 343
 344                 if (in->sin6_flowinfo != 0 &&
 345                     sockaddr.in6.sin6_flowinfo != in->sin6_flowinfo)
 346                         return false;
 347
 348                 if (in->sin6_scope_id != 0 &&
 349                     sockaddr.in6.sin6_scope_id != in->sin6_scope_id)
 350                         return false;
 351
 352                 return memcmp(sockaddr.in6.sin6_addr.s6_addr, in->sin6_addr.s6_addr,
 353                               sizeof(in->sin6_addr.s6_addr)) == 0;
 354         }
 355 }
 356
 357 _public_ int sd_is_socket_unix(int fd, int type, int listening, const char *path, size_t length) {
 358         union sockaddr_union sockaddr = {};
 359         socklen_t l = sizeof(sockaddr);
 360         int r;
 361
 362         assert_return(fd >= 0, -EBADF);
 363
 364         r = is_socket_internal(fd, type, listening);
 365         if (r <= 0)
 366                 return r;
 367
 368         if (getsockname(fd, &sockaddr.sa, &l) < 0)
 369                 return -errno;
 370
 371         if (l < sizeof(sa_family_t))
 372                 return -EINVAL;
 373
 374         if (sockaddr.sa.sa_family != AF_UNIX)
 375                 return 0;
 376
 377         if (path) {
 378                 if (length == 0)
 379                         length = strlen(path);
 380
 381                 if (length == 0)
 382                         /* Unnamed socket */
 383                         return l == offsetof(struct sockaddr_un, sun_path);
 384
 385                 if (path[0])
 386                         /* Normal path socket */
 387                         return
 388                                 (l >= offsetof(struct sockaddr_un, sun_path) + length + 1) &&
 389                                 memcmp(path, sockaddr.un.sun_path, length+1) == 0;
 390                 else
 391                         /* Abstract namespace socket */
 392                         return
 393                                 (l == offsetof(struct sockaddr_un, sun_path) + length) &&
 394                                 memcmp(path, sockaddr.un.sun_path, length) == 0;
 395         }
 396
 397         return 1;
 398 }
 399
 400 _public_ int sd_is_mq(int fd, const char *path) {
 401         struct mq_attr attr;
 402
 403         /* Check that the fd is valid */
 404         assert_return(fcntl(fd, F_GETFD) >= 0, -errno);
 405
 406         if (mq_getattr(fd, &attr) < 0) {
 407                 if (errno == EBADF)
 408                         /* A non-mq fd (or an invalid one, but we ruled that out above) */
 409                         return 0;
 410                 return -errno;
 411         }
 412
 413         if (path) {
 414                 _cleanup_free_ char *fpath = NULL;
 415                 struct stat a, b;
 416
 417                 assert_return(path_is_absolute(path), -EINVAL);
 418
 419                 if (fstat(fd, &a) < 0)
 420                         return -errno;
 421
 422                 fpath = path_join("/dev/mqueue", path);
 423                 if (!fpath)
 424                         return -ENOMEM;
 425
 426                 if (stat(fpath, &b) < 0)
 427                         return -errno;
 428
 429                 if (!stat_inode_same(&a, &b))
 430                         return 0;
 431         }
 432
 433         return 1;
 434 }
 435
 436 static int vsock_bind_privileged_port(int fd) {
 437         union sockaddr_union sa = {
 438                 .vm.svm_family = AF_VSOCK,
 439                 .vm.svm_cid = VMADDR_CID_ANY,
 440                 .vm.svm_port = 1023,
 441         };
 442         int r;
 443
 444         assert(fd >= 0);
 445
 446         do
 447                 r = RET_NERRNO(bind(fd, &sa.sa, sizeof(sa.vm)));
 448         while (r == -EADDRINUSE && --sa.vm.svm_port > 0);
 449
 450         return r;
 451 }
 452
 453 static int pid_notify_with_fds_internal(
 454                 pid_t pid,
 455                 const char *state,
 456                 const int *fds,
 457                 unsigned n_fds) {
 458         SocketAddress address;
 459         struct iovec iovec;
 460         struct msghdr msghdr = {
 461                 .msg_iov = &iovec,
 462                 .msg_iovlen = 1,
 463                 .msg_name = &address.sockaddr,
 464         };
 465         _cleanup_close_ int fd = -EBADF;
 466         struct cmsghdr *cmsg = NULL;
 467         const char *e;
 468         bool send_ucred;
 469         ssize_t n;
 470         int type, r;
 471
 472         if (!state)
 473                 return -EINVAL;
 474
 475         if (n_fds > 0 && !fds)
 476                 return -EINVAL;
 477
 478         e = getenv("NOTIFY_SOCKET");
 479         if (!e)
 480                 return 0;
 481
 482         /* Allow AF_UNIX and AF_VSOCK, reject the rest. */
 483         r = socket_address_parse_unix(&address, e);
 484         if (r == -EPROTO)
 485                 r = socket_address_parse_vsock(&address, e);
 486         if (r < 0)
 487                 return r;
 488         msghdr.msg_namelen = address.size;
 489
 490         /* If we didn't get an address (which is a normal pattern when specifying VSOCK tuples) error out,
 491          * we always require a specific CID. */
 492         if (address.sockaddr.vm.svm_family == AF_VSOCK && address.sockaddr.vm.svm_cid == VMADDR_CID_ANY)
 493                 return -EINVAL;
 494
 495         type = address.type == 0 ? SOCK_DGRAM : address.type;
 496
 497         /* At the time of writing QEMU does not yet support AF_VSOCK + SOCK_DGRAM and returns
 498          * ENODEV. Fallback to SOCK_SEQPACKET in that case. */
 499         fd = socket(address.sockaddr.sa.sa_family, type|SOCK_CLOEXEC, 0);
 500         if (fd < 0) {
 501                 if (!(ERRNO_IS_NOT_SUPPORTED(errno) || errno == ENODEV) || address.sockaddr.sa.sa_family != AF_VSOCK || address.type > 0)
 502                         return log_debug_errno(errno, "Failed to open %s notify socket to '%s': %m", socket_address_type_to_string(type), e);
 503
 504                 type = SOCK_SEQPACKET;
 505                 fd = socket(address.sockaddr.sa.sa_family, type|SOCK_CLOEXEC, 0);
 506                 if (fd < 0 && ERRNO_IS_NOT_SUPPORTED(errno)) {
 507                         type = SOCK_STREAM;
 508                         fd = socket(address.sockaddr.sa.sa_family, type|SOCK_CLOEXEC, 0);
 509                 }
 510                 if (fd < 0)
 511                         return log_debug_errno(errno, "Failed to open %s socket to '%s': %m", socket_address_type_to_string(type), e);
 512         }
 513
 514         if (address.sockaddr.sa.sa_family == AF_VSOCK) {
 515                 r = vsock_bind_privileged_port(fd);
 516                 if (r < 0 && !ERRNO_IS_PRIVILEGE(r))
 517                         return log_debug_errno(r, "Failed to bind socket to privileged port: %m");
 518         }
 519
 520         if (IN_SET(type, SOCK_STREAM, SOCK_SEQPACKET)) {
 521                 if (connect(fd, &address.sockaddr.sa, address.size) < 0)
 522                         return log_debug_errno(errno, "Failed to connect socket to '%s': %m", e);
 523
 524                 msghdr.msg_name = NULL;
 525                 msghdr.msg_namelen = 0;
 526         }
 527
 528         (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
 529
 530         iovec = IOVEC_MAKE_STRING(state);
 531
 532         send_ucred =
 533                 (pid != 0 && pid != getpid_cached()) ||
 534                 getuid() != geteuid() ||
 535                 getgid() != getegid();
 536
 537         if (n_fds > 0 || send_ucred) {
 538                 /* CMSG_SPACE(0) may return value different than zero, which results in miscalculated controllen. */
 539                 msghdr.msg_controllen =
 540                         (n_fds > 0 ? CMSG_SPACE(sizeof(int) * n_fds) : 0) +
 541                         (send_ucred ? CMSG_SPACE(sizeof(struct ucred)) : 0);
 542
 543                 msghdr.msg_control = alloca0(msghdr.msg_controllen);
 544
 545                 cmsg = CMSG_FIRSTHDR(&msghdr);
 546                 if (n_fds > 0) {
 547                         cmsg->cmsg_level = SOL_SOCKET;
 548                         cmsg->cmsg_type = SCM_RIGHTS;
 549                         cmsg->cmsg_len = CMSG_LEN(sizeof(int) * n_fds);
 550
 551                         memcpy(CMSG_DATA(cmsg), fds, sizeof(int) * n_fds);
 552
 553                         if (send_ucred)
 554                                 assert_se(cmsg = CMSG_NXTHDR(&msghdr, cmsg));
 555                 }
 556
 557                 if (send_ucred) {
 558                         struct ucred *ucred;
 559
 560                         cmsg->cmsg_level = SOL_SOCKET;
 561                         cmsg->cmsg_type = SCM_CREDENTIALS;
 562                         cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
 563
 564                         ucred = CMSG_TYPED_DATA(cmsg, struct ucred);
 565                         ucred->pid = pid != 0 ? pid : getpid_cached();
 566                         ucred->uid = getuid();
 567                         ucred->gid = getgid();
 568                 }
 569         }
 570
 571         do {
 572                 /* First try with fake ucred data, as requested */
 573                 n = sendmsg(fd, &msghdr, MSG_NOSIGNAL);
 574                 if (n < 0) {
 575                         if (!send_ucred)
 576                                 return log_debug_errno(errno, "Failed to send notify message to '%s': %m", e);
 577
 578                         /* If that failed, try with our own ucred instead */
 579                         msghdr.msg_controllen -= CMSG_SPACE(sizeof(struct ucred));
 580                         if (msghdr.msg_controllen == 0)
 581                                 msghdr.msg_control = NULL;
 582
 583                         n = 0;
 584                         send_ucred = false;
 585                 } else {
 586                         /* Unless we're using SOCK_STREAM, we expect to write all the contents immediately. */
 587                         if (type != SOCK_STREAM && (size_t) n < IOVEC_TOTAL_SIZE(msghdr.msg_iov, msghdr.msg_iovlen))
 588                                 return -EIO;
 589
 590                         /* Make sure we only send fds and ucred once, even if we're using SOCK_STREAM. */
 591                         msghdr.msg_control = NULL;
 592                         msghdr.msg_controllen = 0;
 593                 }
 594         } while (!IOVEC_INCREMENT(msghdr.msg_iov, msghdr.msg_iovlen, n));
 595
 596         return 1;
 597 }
 598
 599 _public_ int sd_pid_notify_with_fds(
 600                 pid_t pid,
 601                 int unset_environment,
 602                 const char *state,
 603                 const int *fds,
 604                 unsigned n_fds) {
 605
 606         int r;
 607
 608         r = pid_notify_with_fds_internal(pid, state, fds, n_fds);
 609
 610         if (unset_environment)
 611                 assert_se(unsetenv("NOTIFY_SOCKET") == 0);
 612
 613         return r;
 614 }
 615
 616 _public_ int sd_pid_notify_barrier(pid_t pid, int unset_environment, uint64_t timeout) {
 617         _cleanup_close_pair_ int pipe_fd[2] = PIPE_EBADF;
 618         int r;
 619
 620         if (pipe2(pipe_fd, O_CLOEXEC) < 0)
 621                 return -errno;
 622
 623         r = sd_pid_notify_with_fds(pid, unset_environment, "BARRIER=1", &pipe_fd[1], 1);
 624         if (r <= 0)
 625                 return r;
 626
 627         pipe_fd[1] = safe_close(pipe_fd[1]);
 628
 629         r = fd_wait_for_event(pipe_fd[0], 0 /* POLLHUP is implicit */, timeout);
 630         if (r < 0)
 631                 return r;
 632         if (r == 0)
 633                 return -ETIMEDOUT;
 634
 635         return 1;
 636 }
 637
 638 _public_ int sd_notify_barrier(int unset_environment, uint64_t timeout) {
 639         return sd_pid_notify_barrier(0, unset_environment, timeout);
 640 }
 641
 642 _public_ int sd_pid_notify(pid_t pid, int unset_environment, const char *state) {
 643         return sd_pid_notify_with_fds(pid, unset_environment, state, NULL, 0);
 644 }
 645
 646 _public_ int sd_notify(int unset_environment, const char *state) {
 647         return sd_pid_notify_with_fds(0, unset_environment, state, NULL, 0);
 648 }
 649
 650 _public_ int sd_pid_notifyf(pid_t pid, int unset_environment, const char *format, ...) {
 651         _cleanup_free_ char *p = NULL;
 652         int r;
 653
 654         if (format) {
 655                 va_list ap;
 656
 657                 va_start(ap, format);
 658                 r = vasprintf(&p, format, ap);
 659                 va_end(ap);
 660
 661                 if (r < 0 || !p)
 662                         return -ENOMEM;
 663         }
 664
 665         return sd_pid_notify(pid, unset_environment, p);
 666 }
 667
 668 _public_ int sd_notifyf(int unset_environment, const char *format, ...) {
 669         _cleanup_free_ char *p = NULL;
 670         int r;
 671
 672         if (format) {
 673                 va_list ap;
 674
 675                 va_start(ap, format);
 676                 r = vasprintf(&p, format, ap);
 677                 va_end(ap);
 678
 679                 if (r < 0 || !p)
 680                         return -ENOMEM;
 681         }
 682
 683         return sd_pid_notify(0, unset_environment, p);
 684 }
 685
 686 _public_ int sd_pid_notifyf_with_fds(
 687                 pid_t pid,
 688                 int unset_environment,
 689                 const int *fds, size_t n_fds,
 690                 const char *format, ...) {
 691
 692         _cleanup_free_ char *p = NULL;
 693         int r;
 694
 695         /* Paranoia check: we traditionally used 'unsigned' as array size, but we nowadays more correctly use
 696          * 'size_t'. sd_pid_notifyf_with_fds() and sd_pid_notify_with_fds() are from different eras, hence
 697          * differ in this. Let's catch resulting incompatibilites early, even though they are pretty much
 698          * theoretic only */
 699         if (n_fds > UINT_MAX)
 700                 return -E2BIG;
 701
 702         if (format) {
 703                 va_list ap;
 704
 705                 va_start(ap, format);
 706                 r = vasprintf(&p, format, ap);
 707                 va_end(ap);
 708
 709                 if (r < 0 || !p)
 710                         return -ENOMEM;
 711         }
 712
 713         return sd_pid_notify_with_fds(pid, unset_environment, p, fds, n_fds);
 714 }
 715
 716 _public_ int sd_booted(void) {
 717         /* We test whether the runtime unit file directory has been
 718          * created. This takes place in mount-setup.c, so is
 719          * guaranteed to happen very early during boot. */
 720
 721         if (laccess("/run/systemd/system/", F_OK) >= 0)
 722                 return true;
 723
 724         if (errno == ENOENT)
 725                 return false;
 726
 727         return -errno;
 728 }
 729
 730 _public_ int sd_watchdog_enabled(int unset_environment, uint64_t *usec) {
 731         const char *s, *p = ""; /* p is set to dummy value to do unsetting */
 732         uint64_t u;
 733         int r = 0;
 734
 735         s = getenv("WATCHDOG_USEC");
 736         if (!s)
 737                 goto finish;
 738
 739         r = safe_atou64(s, &u);
 740         if (r < 0)
 741                 goto finish;
 742         if (!timestamp_is_set(u)) {
 743                 r = -EINVAL;
 744                 goto finish;
 745         }
 746
 747         p = getenv("WATCHDOG_PID");
 748         if (p) {
 749                 pid_t pid;
 750
 751                 r = parse_pid(p, &pid);
 752                 if (r < 0)
 753                         goto finish;
 754
 755                 /* Is this for us? */
 756                 if (getpid_cached() != pid) {
 757                         r = 0;
 758                         goto finish;
 759                 }
 760         }
 761
 762         if (usec)
 763                 *usec = u;
 764
 765         r = 1;
 766
 767 finish:
 768         if (unset_environment && s)
 769                 assert_se(unsetenv("WATCHDOG_USEC") == 0);
 770         if (unset_environment && p)
 771                 assert_se(unsetenv("WATCHDOG_PID") == 0);
 772
 773         return r;
 774 }