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

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <mqueue.h>
   4 #include <netinet/in.h>
   5 #include <poll.h>
   6 #include <stdio.h>
   7 #include <sys/stat.h>
   8 #include <sys/un.h>
   9 #include <unistd.h>
  10
  11 #include "sd-daemon.h"
  12
  13 #include "alloc-util.h"
  14 #include "errno-util.h"
  15 #include "extract-word.h"
  16 #include "fd-util.h"
  17 #include "fs-util.h"
  18 #include "io-util.h"
  19 #include "iovec-util.h"
  20 #include "log.h"
  21 #include "missing_magic.h"
  22 #include "parse-util.h"
  23 #include "path-util.h"
  24 #include "pidfd-util.h"
  25 #include "process-util.h"
  26 #include "socket-util.h"
  27 #include "stat-util.h"
  28 #include "strv.h"
  29 #include "time-util.h"
  30
  31 #define SNDBUF_SIZE (8*1024*1024)
  32
  33 static void unsetenv_listen(bool unset_environment) {
  34         if (!unset_environment)
  35                 return;
  36
  37         assert_se(unsetenv("LISTEN_PID") == 0);
  38         assert_se(unsetenv("LISTEN_FDS") == 0);
  39         assert_se(unsetenv("LISTEN_FDNAMES") == 0);
  40 }
  41
  42 _public_ int sd_listen_fds(int unset_environment) {
  43         const char *e;
  44         int n, r;
  45         pid_t pid;
  46
  47         e = getenv("LISTEN_PID");
  48         if (!e) {
  49                 r = 0;
  50                 goto finish;
  51         }
  52
  53         r = parse_pid(e, &pid);
  54         if (r < 0)
  55                 goto finish;
  56
  57         /* Is this for us? */
  58         if (getpid_cached() != pid) {
  59                 r = 0;
  60                 goto finish;
  61         }
  62
  63         e = getenv("LISTEN_FDS");
  64         if (!e) {
  65                 r = 0;
  66                 goto finish;
  67         }
  68
  69         r = safe_atoi(e, &n);
  70         if (r < 0)
  71                 goto finish;
  72
  73         assert_cc(SD_LISTEN_FDS_START < INT_MAX);
  74         if (n <= 0 || n > INT_MAX - SD_LISTEN_FDS_START) {
  75                 r = -EINVAL;
  76                 goto finish;
  77         }
  78
  79         for (int fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd++) {
  80                 r = fd_cloexec(fd, true);
  81                 if (r < 0)
  82                         goto finish;
  83         }
  84
  85         r = n;
  86
  87 finish:
  88         unsetenv_listen(unset_environment);
  89         return r;
  90 }
  91
  92 _public_ int sd_listen_fds_with_names(int unset_environment, char ***ret_names) {
  93         _cleanup_strv_free_ char **l = NULL;
  94         bool have_names;
  95         int n_names = 0, n_fds;
  96         const char *e;
  97         int r;
  98
  99         if (!ret_names)
 100                 return sd_listen_fds(unset_environment);
 101
 102         e = getenv("LISTEN_FDNAMES");
 103         if (e) {
 104                 n_names = strv_split_full(&l, e, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
 105                 if (n_names < 0) {
 106                         unsetenv_listen(unset_environment);
 107                         return n_names;
 108                 }
 109
 110                 have_names = true;
 111         } else
 112                 have_names = false;
 113
 114         n_fds = sd_listen_fds(unset_environment);
 115         if (n_fds <= 0)
 116                 return n_fds;
 117
 118         if (have_names) {
 119                 if (n_names != n_fds)
 120                         return -EINVAL;
 121         } else {
 122                 r = strv_extend_n(&l, "unknown", n_fds);
 123                 if (r < 0)
 124                         return r;
 125         }
 126
 127         *ret_names = TAKE_PTR(l);
 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                 if (S_ISCHR(st_fd.st_mode) && S_ISCHR(st_path.st_mode))
 184                         return st_path.st_rdev == st_fd.st_rdev;
 185
 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         int r;
 403
 404         /* Check that the fd is valid */
 405         r = fd_validate(fd);
 406         if (r < 0)
 407                 return r;
 408
 409         if (mq_getattr(fd, &attr) < 0) {
 410                 if (errno == EBADF)
 411                         /* A non-mq fd (or an invalid one, but we ruled that out above) */
 412                         return 0;
 413                 return -errno;
 414         }
 415
 416         if (path) {
 417                 _cleanup_free_ char *fpath = NULL;
 418                 struct stat a, b;
 419
 420                 assert_return(path_is_absolute(path), -EINVAL);
 421
 422                 if (fstat(fd, &a) < 0)
 423                         return -errno;
 424
 425                 fpath = path_join("/dev/mqueue", path);
 426                 if (!fpath)
 427                         return -ENOMEM;
 428
 429                 if (stat(fpath, &b) < 0)
 430                         return -errno;
 431
 432                 if (!stat_inode_same(&a, &b))
 433                         return 0;
 434         }
 435
 436         return 1;
 437 }
 438
 439 static int vsock_bind_privileged_port(int fd) {
 440         union sockaddr_union sa = {
 441                 .vm.svm_family = AF_VSOCK,
 442                 .vm.svm_cid = VMADDR_CID_ANY,
 443                 .vm.svm_port = 1023,
 444         };
 445         int r;
 446
 447         assert(fd >= 0);
 448
 449         do
 450                 r = RET_NERRNO(bind(fd, &sa.sa, sizeof(sa.vm)));
 451         while (r == -EADDRINUSE && --sa.vm.svm_port > 0);
 452
 453         return r;
 454 }
 455
 456 static int pid_notify_with_fds_internal(
 457                 pid_t pid,
 458                 const char *state,
 459                 const int *fds,
 460                 size_t n_fds) {
 461
 462         SocketAddress address;
 463         struct iovec iovec;
 464         struct msghdr msghdr = {
 465                 .msg_iov = &iovec,
 466                 .msg_iovlen = 1,
 467                 .msg_name = &address.sockaddr,
 468         };
 469         _cleanup_close_ int fd = -EBADF;
 470         int type, r;
 471
 472         assert_return(state, -EINVAL);
 473         assert_return(fds || n_fds == 0, -EINVAL);
 474
 475         /* Let's make sure the multiplications below don't overflow, and also return a recognizable error in
 476          * case the caller tries to send more fds than the kernel limit. The kernel would return EINVAL which
 477          * is not too useful I'd say. */
 478         if (n_fds > SCM_MAX_FD)
 479                 return -E2BIG;
 480
 481         const char *e = getenv("NOTIFY_SOCKET");
 482         if (!e)
 483                 return 0;
 484
 485         /* Allow AF_UNIX and AF_VSOCK, reject the rest. */
 486         r = socket_address_parse_unix(&address, e);
 487         if (r == -EPROTO)
 488                 r = socket_address_parse_vsock(&address, e);
 489         if (r < 0)
 490                 return r;
 491         msghdr.msg_namelen = address.size;
 492
 493         /* If we didn't get an address (which is a normal pattern when specifying VSOCK tuples) error out,
 494          * we always require a specific CID. */
 495         if (address.sockaddr.vm.svm_family == AF_VSOCK && address.sockaddr.vm.svm_cid == VMADDR_CID_ANY)
 496                 return -EINVAL;
 497
 498         type = address.type == 0 ? SOCK_DGRAM : address.type;
 499
 500         /* At the time of writing QEMU does not yet support AF_VSOCK + SOCK_DGRAM and returns
 501          * ENODEV. Fallback to SOCK_SEQPACKET in that case. */
 502         fd = socket(address.sockaddr.sa.sa_family, type|SOCK_CLOEXEC, 0);
 503         if (fd < 0) {
 504                 if (!(ERRNO_IS_NOT_SUPPORTED(errno) || errno == ENODEV) || address.sockaddr.sa.sa_family != AF_VSOCK || address.type > 0)
 505                         return log_debug_errno(errno, "Failed to open %s notify socket to '%s': %m", socket_address_type_to_string(type), e);
 506
 507                 type = SOCK_SEQPACKET;
 508                 fd = socket(address.sockaddr.sa.sa_family, type|SOCK_CLOEXEC, 0);
 509                 if (fd < 0 && ERRNO_IS_NOT_SUPPORTED(errno)) {
 510                         type = SOCK_STREAM;
 511                         fd = socket(address.sockaddr.sa.sa_family, type|SOCK_CLOEXEC, 0);
 512                 }
 513                 if (fd < 0)
 514                         return log_debug_errno(errno, "Failed to open %s socket to '%s': %m", socket_address_type_to_string(type), e);
 515         }
 516
 517         if (address.sockaddr.sa.sa_family == AF_VSOCK) {
 518                 r = vsock_bind_privileged_port(fd);
 519                 if (r < 0 && !ERRNO_IS_PRIVILEGE(r))
 520                         return log_debug_errno(r, "Failed to bind socket to privileged port: %m");
 521         }
 522
 523         if (IN_SET(type, SOCK_STREAM, SOCK_SEQPACKET)) {
 524                 if (connect(fd, &address.sockaddr.sa, address.size) < 0)
 525                         return log_debug_errno(errno, "Failed to connect socket to '%s': %m", e);
 526
 527                 msghdr.msg_name = NULL;
 528                 msghdr.msg_namelen = 0;
 529         }
 530
 531         (void) fd_inc_sndbuf(fd, SNDBUF_SIZE);
 532
 533         iovec = IOVEC_MAKE_STRING(state);
 534
 535         bool send_ucred =
 536                 (pid != 0 && pid != getpid_cached()) ||
 537                 getuid() != geteuid() ||
 538                 getgid() != getegid();
 539
 540         if (n_fds > 0 || send_ucred) {
 541                 struct cmsghdr *cmsg;
 542
 543                 /* CMSG_SPACE(0) may return value different than zero, which results in miscalculated controllen. */
 544                 msghdr.msg_controllen =
 545                         (n_fds > 0 ? CMSG_SPACE(sizeof(int) * n_fds) : 0) +
 546                         (send_ucred ? CMSG_SPACE(sizeof(struct ucred)) : 0);
 547
 548                 msghdr.msg_control = alloca0(msghdr.msg_controllen);
 549
 550                 cmsg = CMSG_FIRSTHDR(&msghdr);
 551                 if (n_fds > 0) {
 552                         cmsg->cmsg_level = SOL_SOCKET;
 553                         cmsg->cmsg_type = SCM_RIGHTS;
 554                         cmsg->cmsg_len = CMSG_LEN(sizeof(int) * n_fds);
 555
 556                         memcpy(CMSG_DATA(cmsg), fds, sizeof(int) * n_fds);
 557
 558                         if (send_ucred)
 559                                 assert_se(cmsg = CMSG_NXTHDR(&msghdr, cmsg));
 560                 }
 561
 562                 if (send_ucred) {
 563                         struct ucred *ucred;
 564
 565                         cmsg->cmsg_level = SOL_SOCKET;
 566                         cmsg->cmsg_type = SCM_CREDENTIALS;
 567                         cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
 568
 569                         ucred = CMSG_TYPED_DATA(cmsg, struct ucred);
 570                         ucred->pid = pid != 0 ? pid : getpid_cached();
 571                         ucred->uid = getuid();
 572                         ucred->gid = getgid();
 573                 }
 574         }
 575
 576         ssize_t n;
 577
 578         do {
 579                 /* First try with fake ucred data, as requested */
 580                 n = sendmsg(fd, &msghdr, MSG_NOSIGNAL);
 581                 if (n < 0) {
 582                         if (!send_ucred)
 583                                 return log_debug_errno(errno, "Failed to send notify message to '%s': %m", e);
 584
 585                         /* If that failed, try with our own ucred instead */
 586                         msghdr.msg_controllen -= CMSG_SPACE(sizeof(struct ucred));
 587                         if (msghdr.msg_controllen == 0)
 588                                 msghdr.msg_control = NULL;
 589
 590                         n = 0;
 591                         send_ucred = false;
 592                 } else {
 593                         /* Unless we're using SOCK_STREAM, we expect to write all the contents immediately. */
 594                         if (type != SOCK_STREAM && (size_t) n < iovec_total_size(msghdr.msg_iov, msghdr.msg_iovlen))
 595                                 return -EIO;
 596
 597                         /* Make sure we only send fds and ucred once, even if we're using SOCK_STREAM. */
 598                         msghdr.msg_control = NULL;
 599                         msghdr.msg_controllen = 0;
 600                 }
 601         } while (!iovec_increment(msghdr.msg_iov, msghdr.msg_iovlen, n));
 602
 603         if (address.sockaddr.sa.sa_family == AF_VSOCK && IN_SET(type, SOCK_STREAM, SOCK_SEQPACKET)) {
 604                 /* For AF_VSOCK, we need to close the socket to signal the end of the message. */
 605                 if (shutdown(fd, SHUT_WR) < 0)
 606                         return log_debug_errno(errno, "Failed to shutdown notify socket: %m");
 607
 608                 char c;
 609                 n = recv(fd, &c, sizeof(c), MSG_NOSIGNAL);
 610                 if (n < 0)
 611                         return log_debug_errno(errno, "Failed to wait for EOF on notify socket: %m");
 612                 if (n > 0)
 613                         return log_debug_errno(SYNTHETIC_ERRNO(EPROTO), "Unexpectedly received data on notify socket.");
 614         }
 615
 616         return 1;
 617 }
 618
 619 static void unsetenv_notify(bool unset_environment) {
 620         if (!unset_environment)
 621                 return;
 622
 623         assert_se(unsetenv("NOTIFY_SOCKET") == 0);
 624 }
 625
 626 _public_ int sd_pid_notify_with_fds(
 627                 pid_t pid,
 628                 int unset_environment,
 629                 const char *state,
 630                 const int *fds,
 631                 unsigned n_fds) {
 632
 633         int r;
 634
 635         r = pid_notify_with_fds_internal(pid, state, fds, n_fds);
 636         unsetenv_notify(unset_environment);
 637         return r;
 638 }
 639
 640 _public_ int sd_pid_notify_barrier(pid_t pid, int unset_environment, uint64_t timeout) {
 641         _cleanup_close_pair_ int pipe_fd[2] = EBADF_PAIR;
 642         int r;
 643
 644         r = RET_NERRNO(pipe2(pipe_fd, O_CLOEXEC));
 645         if (r < 0)
 646                 goto finish;
 647
 648         r = pid_notify_with_fds_internal(pid, "BARRIER=1", &pipe_fd[1], 1);
 649         if (r <= 0)
 650                 goto finish;
 651
 652         pipe_fd[1] = safe_close(pipe_fd[1]);
 653
 654         r = fd_wait_for_event(pipe_fd[0], 0 /* POLLHUP is implicit */, timeout);
 655         if (r < 0)
 656                 goto finish;
 657         if (r == 0) {
 658                 r = -ETIMEDOUT;
 659                 goto finish;
 660         }
 661
 662         r = 1;
 663 finish:
 664         unsetenv_notify(unset_environment);
 665         return r;
 666 }
 667
 668 _public_ int sd_notify_barrier(int unset_environment, uint64_t timeout) {
 669         return sd_pid_notify_barrier(0, unset_environment, timeout);
 670 }
 671
 672 _public_ int sd_pid_notify(pid_t pid, int unset_environment, const char *state) {
 673         return sd_pid_notify_with_fds(pid, unset_environment, state, NULL, 0);
 674 }
 675
 676 _public_ int sd_notify(int unset_environment, const char *state) {
 677         return sd_pid_notify_with_fds(0, unset_environment, state, NULL, 0);
 678 }
 679
 680 _public_ int sd_pid_notifyf(pid_t pid, int unset_environment, const char *format, ...) {
 681         _cleanup_free_ char *p = NULL;
 682         int r;
 683
 684         if (format) {
 685                 va_list ap;
 686
 687                 va_start(ap, format);
 688                 r = vasprintf(&p, format, ap);
 689                 va_end(ap);
 690
 691                 if (r < 0) {
 692                         r = -ENOMEM;
 693                         goto finish;
 694                 }
 695         }
 696
 697         r = pid_notify_with_fds_internal(pid, p, /* fds= */ NULL, /* n_fds= */ 0);
 698
 699 finish:
 700         unsetenv_notify(unset_environment);
 701         return r;
 702 }
 703
 704 _public_ int sd_notifyf(int unset_environment, const char *format, ...) {
 705         _cleanup_free_ char *p = NULL;
 706         int r;
 707
 708         if (format) {
 709                 va_list ap;
 710
 711                 va_start(ap, format);
 712                 r = vasprintf(&p, format, ap);
 713                 va_end(ap);
 714
 715                 if (r < 0) {
 716                         r = -ENOMEM;
 717                         goto finish;
 718                 }
 719         }
 720
 721         r = pid_notify_with_fds_internal(/* pid= */ 0, p, /* fds= */ NULL, /* n_fds= */ 0);
 722
 723 finish:
 724         unsetenv_notify(unset_environment);
 725         return r;
 726 }
 727
 728 _public_ int sd_pid_notifyf_with_fds(
 729                 pid_t pid,
 730                 int unset_environment,
 731                 const int *fds, size_t n_fds,
 732                 const char *format, ...) {
 733
 734         _cleanup_free_ char *p = NULL;
 735         int r;
 736
 737         if (format) {
 738                 va_list ap;
 739
 740                 va_start(ap, format);
 741                 r = vasprintf(&p, format, ap);
 742                 va_end(ap);
 743
 744                 if (r < 0) {
 745                         r = -ENOMEM;
 746                         goto finish;
 747                 }
 748         }
 749
 750         r = pid_notify_with_fds_internal(pid, p, fds, n_fds);
 751
 752 finish:
 753         unsetenv_notify(unset_environment);
 754         return r;
 755 }
 756
 757 _public_ int sd_pidfd_get_inode_id(int pidfd, uint64_t *ret) {
 758         int r;
 759
 760         assert_return(pidfd >= 0, -EBADF);
 761
 762         /* Are pidfds backed by pidfs where the unique inode id is relevant? Note that the pidfd
 763          * passed to us is extrinsic and hence cannot be trusted to initialize our "have_pidfs" cache,
 764          * instead pidfd_check_pidfs() will allocate one internally. */
 765         r = pidfd_check_pidfs(/* pid_fd = */ -EBADF);
 766         if (r <= 0)
 767                 return -EOPNOTSUPP;
 768
 769         r = fd_is_fs_type(pidfd, PID_FS_MAGIC);
 770         if (r < 0)
 771                 return r;
 772         if (r == 0)
 773                 return -EBADF; /* pidfs is definitely around, so it's the fd that's of invalid type */
 774
 775         return pidfd_get_inode_id_impl(pidfd, ret);
 776 }
 777
 778 _public_ int sd_booted(void) {
 779         int r;
 780
 781         /* We test whether the runtime unit file directory has been created. This takes place in mount-setup.c,
 782          * so is guaranteed to happen very early during boot. */
 783
 784         r = access_nofollow("/run/systemd/system/", F_OK);
 785         if (r >= 0)
 786                 return true;
 787         if (r == -ENOENT)
 788                 return false;
 789
 790         return r;
 791 }
 792
 793 static void unsetenv_watchdog(bool unset_environment) {
 794         if (!unset_environment)
 795                 return;
 796
 797         assert_se(unsetenv("WATCHDOG_USEC") == 0);
 798         assert_se(unsetenv("WATCHDOG_PID") == 0);
 799 }
 800
 801 _public_ int sd_watchdog_enabled(int unset_environment, uint64_t *usec) {
 802         const char *s, *p = ""; /* p is set to dummy value to do unsetting */
 803         uint64_t u;
 804         int r;
 805
 806         s = getenv("WATCHDOG_USEC");
 807         if (!s) {
 808                 r = 0;
 809                 goto finish;
 810         }
 811
 812         r = safe_atou64(s, &u);
 813         if (r < 0)
 814                 goto finish;
 815         if (!timestamp_is_set(u)) {
 816                 r = -EINVAL;
 817                 goto finish;
 818         }
 819
 820         p = getenv("WATCHDOG_PID");
 821         if (p) {
 822                 pid_t pid;
 823
 824                 r = parse_pid(p, &pid);
 825                 if (r < 0)
 826                         goto finish;
 827
 828                 /* Is this for us? */
 829                 if (getpid_cached() != pid) {
 830                         r = 0;
 831                         goto finish;
 832                 }
 833         }
 834
 835         if (usec)
 836                 *usec = u;
 837
 838         r = 1;
 839
 840 finish:
 841         unsetenv_watchdog(unset_environment);
 842         return r;
 843 }