src/import/pull-job.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <sys/stat.h>
   5 #include <sys/xattr.h>
   6
   7 #include "alloc-util.h"
   8 #include "fd-util.h"
   9 #include "format-util.h"
  10 #include "gcrypt-util.h"
  11 #include "hexdecoct.h"
  12 #include "import-util.h"
  13 #include "io-util.h"
  14 #include "machine-pool.h"
  15 #include "parse-util.h"
  16 #include "pull-common.h"
  17 #include "pull-job.h"
  18 #include "string-util.h"
  19 #include "strv.h"
  20 #include "sync-util.h"
  21 #include "xattr-util.h"
  22
  23 void pull_job_close_disk_fd(PullJob *j) {
  24         if (!j)
  25                 return;
  26
  27         if (j->close_disk_fd)
  28                 safe_close(j->disk_fd);
  29
  30         j->disk_fd = -1;
  31 }
  32
  33 PullJob* pull_job_unref(PullJob *j) {
  34         if (!j)
  35                 return NULL;
  36
  37         pull_job_close_disk_fd(j);
  38
  39         curl_glue_remove_and_free(j->glue, j->curl);
  40         curl_slist_free_all(j->request_header);
  41
  42         import_compress_free(&j->compress);
  43
  44         if (j->checksum_ctx)
  45 #if PREFER_OPENSSL
  46                 EVP_MD_CTX_free(j->checksum_ctx);
  47 #else
  48                 gcry_md_close(j->checksum_ctx);
  49 #endif
  50
  51         free(j->url);
  52         free(j->etag);
  53         strv_free(j->old_etags);
  54         free(j->payload);
  55         free(j->checksum);
  56
  57         return mfree(j);
  58 }
  59
  60 static void pull_job_finish(PullJob *j, int ret) {
  61         assert(j);
  62
  63         if (IN_SET(j->state, PULL_JOB_DONE, PULL_JOB_FAILED))
  64                 return;
  65
  66         if (ret == 0) {
  67                 j->state = PULL_JOB_DONE;
  68                 j->progress_percent = 100;
  69                 log_info("Download of %s complete.", j->url);
  70         } else {
  71                 j->state = PULL_JOB_FAILED;
  72                 j->error = ret;
  73         }
  74
  75         if (j->on_finished)
  76                 j->on_finished(j);
  77 }
  78
  79 static int pull_job_restart(PullJob *j, const char *new_url) {
  80         int r;
  81
  82         assert(j);
  83         assert(new_url);
  84
  85         r = free_and_strdup(&j->url, new_url);
  86         if (r < 0)
  87                 return r;
  88
  89         j->state = PULL_JOB_INIT;
  90         j->error = 0;
  91         j->payload = mfree(j->payload);
  92         j->payload_size = 0;
  93         j->written_compressed = 0;
  94         j->written_uncompressed = 0;
  95         j->content_length = UINT64_MAX;
  96         j->etag = mfree(j->etag);
  97         j->etag_exists = false;
  98         j->mtime = 0;
  99         j->checksum = mfree(j->checksum);
 100
 101         curl_glue_remove_and_free(j->glue, j->curl);
 102         j->curl = NULL;
 103
 104         curl_slist_free_all(j->request_header);
 105         j->request_header = NULL;
 106
 107         import_compress_free(&j->compress);
 108
 109         if (j->checksum_ctx) {
 110 #if PREFER_OPENSSL
 111                 EVP_MD_CTX_free(j->checksum_ctx);
 112 #else
 113                 gcry_md_close(j->checksum_ctx);
 114 #endif
 115                 j->checksum_ctx = NULL;
 116         }
 117
 118         r = pull_job_begin(j);
 119         if (r < 0)
 120                 return r;
 121
 122         return 0;
 123 }
 124
 125 void pull_job_curl_on_finished(CurlGlue *g, CURL *curl, CURLcode result) {
 126         PullJob *j = NULL;
 127         CURLcode code;
 128         long protocol;
 129         int r;
 130
 131         if (curl_easy_getinfo(curl, CURLINFO_PRIVATE, (char **)&j) != CURLE_OK)
 132                 return;
 133
 134         if (!j || IN_SET(j->state, PULL_JOB_DONE, PULL_JOB_FAILED))
 135                 return;
 136
 137         if (result != CURLE_OK) {
 138                 r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Transfer failed: %s", curl_easy_strerror(result));
 139                 goto finish;
 140         }
 141
 142         code = curl_easy_getinfo(curl, CURLINFO_PROTOCOL, &protocol);
 143         if (code != CURLE_OK) {
 144                 r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve response code: %s", curl_easy_strerror(code));
 145                 goto finish;
 146         }
 147
 148         if (IN_SET(protocol, CURLPROTO_HTTP, CURLPROTO_HTTPS)) {
 149                 long status;
 150
 151                 code = curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &status);
 152                 if (code != CURLE_OK) {
 153                         r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve response code: %s", curl_easy_strerror(code));
 154                         goto finish;
 155                 }
 156
 157                 if (status == 304) {
 158                         log_info("Image already downloaded. Skipping download.");
 159                         j->etag_exists = true;
 160                         r = 0;
 161                         goto finish;
 162                 } else if (status >= 300) {
 163
 164                         if (status == 404 && j->on_not_found) {
 165                                 _cleanup_free_ char *new_url = NULL;
 166
 167                                 /* This resource wasn't found, but the implementor wants to maybe let us know a new URL, query for it. */
 168                                 r = j->on_not_found(j, &new_url);
 169                                 if (r < 0)
 170                                         goto finish;
 171
 172                                 if (r > 0) { /* A new url to use */
 173                                         assert(new_url);
 174
 175                                         r = pull_job_restart(j, new_url);
 176                                         if (r < 0)
 177                                                 goto finish;
 178
 179                                         code = curl_easy_getinfo(j->curl, CURLINFO_RESPONSE_CODE, &status);
 180                                         if (code != CURLE_OK) {
 181                                                 r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve response code: %s", curl_easy_strerror(code));
 182                                                 goto finish;
 183                                         }
 184
 185                                         if (status == 0)
 186                                                 return;
 187                                 }
 188                         }
 189
 190                         r = log_error_errno(
 191                                         status == 404 ? SYNTHETIC_ERRNO(ENOMEDIUM) : SYNTHETIC_ERRNO(EIO), /* Make the most common error recognizable */
 192                                         "HTTP request to %s failed with code %li.", j->url, status);
 193                         goto finish;
 194                 } else if (status < 200) {
 195                         r = log_error_errno(SYNTHETIC_ERRNO(EIO), "HTTP request to %s finished with unexpected code %li.", j->url, status);
 196                         goto finish;
 197                 }
 198         }
 199
 200         if (j->state != PULL_JOB_RUNNING) {
 201                 r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Premature connection termination.");
 202                 goto finish;
 203         }
 204
 205         if (j->content_length != UINT64_MAX &&
 206             j->content_length != j->written_compressed) {
 207                 r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Download truncated.");
 208                 goto finish;
 209         }
 210
 211         if (j->checksum_ctx) {
 212                 unsigned checksum_len;
 213 #if PREFER_OPENSSL
 214                 uint8_t k[EVP_MAX_MD_SIZE];
 215
 216                 r = EVP_DigestFinal_ex(j->checksum_ctx, k, &checksum_len);
 217                 if (r == 0) {
 218                         r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to get checksum.");
 219                         goto finish;
 220                 }
 221                 assert(checksum_len <= sizeof k);
 222 #else
 223                 const uint8_t *k;
 224
 225                 k = gcry_md_read(j->checksum_ctx, GCRY_MD_SHA256);
 226                 if (!k) {
 227                         r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to get checksum.");
 228                         goto finish;
 229                 }
 230
 231                 checksum_len = gcry_md_get_algo_dlen(GCRY_MD_SHA256);
 232 #endif
 233
 234                 j->checksum = hexmem(k, checksum_len);
 235                 if (!j->checksum) {
 236                         r = log_oom();
 237                         goto finish;
 238                 }
 239
 240                 log_debug("SHA256 of %s is %s.", j->url, j->checksum);
 241         }
 242
 243         /* Do a couple of finishing disk operations, but only if we are the sole owner of the file (i.e. no
 244          * offset is specified, which indicates we only own the file partially) */
 245
 246         if (j->disk_fd >= 0) {
 247
 248                 if (S_ISREG(j->disk_stat.st_mode)) {
 249
 250                         if (j->offset == UINT64_MAX) {
 251
 252                                 if (j->written_compressed > 0) {
 253                                         /* Make sure the file size is right, in case the file was sparse and we just seeked
 254                                          * for the last part */
 255                                         if (ftruncate(j->disk_fd, j->written_uncompressed) < 0) {
 256                                                 r = log_error_errno(errno, "Failed to truncate file: %m");
 257                                                 goto finish;
 258                                         }
 259                                 }
 260
 261                                 if (j->etag)
 262                                         (void) fsetxattr(j->disk_fd, "user.source_etag", j->etag, strlen(j->etag), 0);
 263                                 if (j->url)
 264                                         (void) fsetxattr(j->disk_fd, "user.source_url", j->url, strlen(j->url), 0);
 265
 266                                 if (j->mtime != 0) {
 267                                         struct timespec ut;
 268
 269                                         timespec_store(&ut, j->mtime);
 270
 271                                         if (futimens(j->disk_fd, (struct timespec[]) { ut, ut }) < 0)
 272                                                 log_debug_errno(errno, "Failed to adjust atime/mtime of created image, ignoring: %m");
 273
 274                                         r = fd_setcrtime(j->disk_fd, j->mtime);
 275                                         if (r < 0)
 276                                                 log_debug_errno(r, "Failed to adjust crtime of created image, ignoring: %m");
 277                                 }
 278                         }
 279
 280                         if (j->sync) {
 281                                 r = fsync_full(j->disk_fd);
 282                                 if (r < 0) {
 283                                         log_error_errno(r, "Failed to synchronize file to disk: %m");
 284                                         goto finish;
 285                                 }
 286                         }
 287
 288                 } else if (S_ISBLK(j->disk_stat.st_mode) && j->sync) {
 289
 290                         if (fsync(j->disk_fd) < 0) {
 291                                 r = log_error_errno(errno, "Failed to synchronize block device: %m");
 292                                 goto finish;
 293                         }
 294                 }
 295         }
 296
 297         log_info("Acquired %s.", FORMAT_BYTES(j->written_uncompressed));
 298
 299         r = 0;
 300
 301 finish:
 302         pull_job_finish(j, r);
 303 }
 304
 305 static int pull_job_write_uncompressed(const void *p, size_t sz, void *userdata) {
 306         PullJob *j = userdata;
 307         bool too_much = false;
 308         int r;
 309
 310         assert(j);
 311         assert(p);
 312         assert(sz > 0);
 313
 314         if (j->written_uncompressed > UINT64_MAX - sz)
 315                 return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "File too large, overflow");
 316
 317         if (j->written_uncompressed >= j->uncompressed_max) {
 318                 too_much = true;
 319                 goto finish;
 320         }
 321
 322         if (j->written_uncompressed + sz > j->uncompressed_max) {
 323                 too_much = true;
 324                 sz = j->uncompressed_max - j->written_uncompressed; /* since we have the data in memory
 325                                                                      * already, we might as well write it to
 326                                                                      * disk to the max */
 327         }
 328
 329         if (j->disk_fd >= 0) {
 330
 331                 if (S_ISREG(j->disk_stat.st_mode) && j->offset == UINT64_MAX) {
 332                         ssize_t n;
 333
 334                         n = sparse_write(j->disk_fd, p, sz, 64);
 335                         if (n < 0)
 336                                 return log_error_errno((int) n, "Failed to write file: %m");
 337                         if ((size_t) n < sz)
 338                                 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Short write");
 339                 } else {
 340                         r = loop_write(j->disk_fd, p, sz, false);
 341                         if (r < 0)
 342                                 return log_error_errno(r, "Failed to write file: %m");
 343                 }
 344         }
 345
 346         if (j->disk_fd < 0 || j->force_memory) {
 347                 if (!GREEDY_REALLOC(j->payload, j->payload_size + sz))
 348                         return log_oom();
 349
 350                 memcpy(j->payload + j->payload_size, p, sz);
 351                 j->payload_size += sz;
 352         }
 353
 354         j->written_uncompressed += sz;
 355
 356 finish:
 357         if (too_much)
 358                 return log_error_errno(SYNTHETIC_ERRNO(EFBIG), "File overly large, refusing.");
 359
 360         return 0;
 361 }
 362
 363 static int pull_job_write_compressed(PullJob *j, void *p, size_t sz) {
 364         int r;
 365
 366         assert(j);
 367         assert(p);
 368
 369         if (sz <= 0)
 370                 return 0;
 371
 372         if (j->written_compressed + sz < j->written_compressed)
 373                 return log_error_errno(SYNTHETIC_ERRNO(EOVERFLOW), "File too large, overflow");
 374
 375         if (j->written_compressed + sz > j->compressed_max)
 376                 return log_error_errno(SYNTHETIC_ERRNO(EFBIG), "File overly large, refusing.");
 377
 378         if (j->content_length != UINT64_MAX &&
 379             j->written_compressed + sz > j->content_length)
 380                 return log_error_errno(SYNTHETIC_ERRNO(EFBIG),
 381                                        "Content length incorrect.");
 382
 383         if (j->checksum_ctx) {
 384 #if PREFER_OPENSSL
 385                 r = EVP_DigestUpdate(j->checksum_ctx, p, sz);
 386                 if (r == 0)
 387                         return log_error_errno(SYNTHETIC_ERRNO(EIO),
 388                                                "Could not hash chunk.");
 389 #else
 390                 gcry_md_write(j->checksum_ctx, p, sz);
 391 #endif
 392         }
 393
 394         r = import_uncompress(&j->compress, p, sz, pull_job_write_uncompressed, j);
 395         if (r < 0)
 396                 return r;
 397
 398         j->written_compressed += sz;
 399
 400         return 0;
 401 }
 402
 403 static int pull_job_open_disk(PullJob *j) {
 404         int r;
 405
 406         assert(j);
 407
 408         if (j->on_open_disk) {
 409                 r = j->on_open_disk(j);
 410                 if (r < 0)
 411                         return r;
 412         }
 413
 414         if (j->disk_fd >= 0) {
 415                 if (fstat(j->disk_fd, &j->disk_stat) < 0)
 416                         return log_error_errno(errno, "Failed to stat disk file: %m");
 417
 418                 if (j->offset != UINT64_MAX) {
 419                         if (lseek(j->disk_fd, j->offset, SEEK_SET) == (off_t) -1)
 420                                 return log_error_errno(errno, "Failed to seek on file descriptor: %m");
 421                 }
 422         }
 423
 424         if (j->calc_checksum) {
 425 #if PREFER_OPENSSL
 426                 j->checksum_ctx = EVP_MD_CTX_new();
 427                 if (!j->checksum_ctx)
 428                         return log_oom();
 429
 430                 r = EVP_DigestInit_ex(j->checksum_ctx, EVP_sha256(), NULL);
 431                 if (r == 0)
 432                         return log_error_errno(SYNTHETIC_ERRNO(EIO),
 433                                                "Failed to initialize hash context.");
 434 #else
 435                 initialize_libgcrypt(false);
 436
 437                 if (gcry_md_open(&j->checksum_ctx, GCRY_MD_SHA256, 0) != 0)
 438                         return log_error_errno(SYNTHETIC_ERRNO(EIO),
 439                                                "Failed to initialize hash context.");
 440 #endif
 441         }
 442
 443         return 0;
 444 }
 445
 446 static int pull_job_detect_compression(PullJob *j) {
 447         _cleanup_free_ uint8_t *stub = NULL;
 448         size_t stub_size;
 449
 450         int r;
 451
 452         assert(j);
 453
 454         r = import_uncompress_detect(&j->compress, j->payload, j->payload_size);
 455         if (r < 0)
 456                 return log_error_errno(r, "Failed to initialize compressor: %m");
 457         if (r == 0)
 458                 return 0;
 459
 460         log_debug("Stream is compressed: %s", import_compress_type_to_string(j->compress.type));
 461
 462         r = pull_job_open_disk(j);
 463         if (r < 0)
 464                 return r;
 465
 466         /* Now, take the payload we read so far, and decompress it */
 467         stub = j->payload;
 468         stub_size = j->payload_size;
 469
 470         j->payload = NULL;
 471         j->payload_size = 0;
 472
 473         j->state = PULL_JOB_RUNNING;
 474
 475         r = pull_job_write_compressed(j, stub, stub_size);
 476         if (r < 0)
 477                 return r;
 478
 479         return 0;
 480 }
 481
 482 static size_t pull_job_write_callback(void *contents, size_t size, size_t nmemb, void *userdata) {
 483         PullJob *j = userdata;
 484         size_t sz = size * nmemb;
 485         int r;
 486
 487         assert(contents);
 488         assert(j);
 489
 490         switch (j->state) {
 491
 492         case PULL_JOB_ANALYZING:
 493                 /* Let's first check what it actually is */
 494
 495                 if (!GREEDY_REALLOC(j->payload, j->payload_size + sz)) {
 496                         r = log_oom();
 497                         goto fail;
 498                 }
 499
 500                 memcpy(j->payload + j->payload_size, contents, sz);
 501                 j->payload_size += sz;
 502
 503                 r = pull_job_detect_compression(j);
 504                 if (r < 0)
 505                         goto fail;
 506
 507                 break;
 508
 509         case PULL_JOB_RUNNING:
 510
 511                 r = pull_job_write_compressed(j, contents, sz);
 512                 if (r < 0)
 513                         goto fail;
 514
 515                 break;
 516
 517         case PULL_JOB_DONE:
 518         case PULL_JOB_FAILED:
 519                 r = -ESTALE;
 520                 goto fail;
 521
 522         default:
 523                 assert_not_reached();
 524         }
 525
 526         return sz;
 527
 528 fail:
 529         pull_job_finish(j, r);
 530         return 0;
 531 }
 532
 533 static int http_status_ok(CURLcode status) {
 534         /* Consider all HTTP status code in the 2xx range as OK */
 535         return status >= 200 && status <= 299;
 536 }
 537
 538 static int http_status_etag_exists(CURLcode status) {
 539         /* This one is special, it's triggered by our etag mgmt logic */
 540         return status == 304;
 541 }
 542
 543 static size_t pull_job_header_callback(void *contents, size_t size, size_t nmemb, void *userdata) {
 544         _cleanup_free_ char *length = NULL, *last_modified = NULL, *etag = NULL;
 545         size_t sz = size * nmemb;
 546         PullJob *j = userdata;
 547         CURLcode code;
 548         long status;
 549         int r;
 550
 551         assert(contents);
 552         assert(j);
 553
 554         if (IN_SET(j->state, PULL_JOB_DONE, PULL_JOB_FAILED)) {
 555                 r = -ESTALE;
 556                 goto fail;
 557         }
 558
 559         assert(j->state == PULL_JOB_ANALYZING);
 560
 561         code = curl_easy_getinfo(j->curl, CURLINFO_RESPONSE_CODE, &status);
 562         if (code != CURLE_OK) {
 563                 r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve response code: %s", curl_easy_strerror(code));
 564                 goto fail;
 565         }
 566
 567         if (http_status_ok(status) || http_status_etag_exists(status)) {
 568                 /* Check Etag on OK and etag exists responses. */
 569
 570                 r = curl_header_strdup(contents, sz, "ETag:", &etag);
 571                 if (r < 0) {
 572                         log_oom();
 573                         goto fail;
 574                 }
 575                 if (r > 0) {
 576                         free_and_replace(j->etag, etag);
 577
 578                         if (strv_contains(j->old_etags, j->etag)) {
 579                                 log_info("Image already downloaded. Skipping download. (%s)", j->etag);
 580                                 j->etag_exists = true;
 581                                 pull_job_finish(j, 0);
 582                                 return sz;
 583                         }
 584
 585                         return sz;
 586                 }
 587         }
 588
 589         if (!http_status_ok(status)) /* Let's ignore the rest here, these requests are probably redirects and
 590                                       * stuff where the headers aren't interesting to us */
 591                 return sz;
 592
 593         r = curl_header_strdup(contents, sz, "Content-Length:", &length);
 594         if (r < 0) {
 595                 log_oom();
 596                 goto fail;
 597         }
 598         if (r > 0) {
 599                 (void) safe_atou64(length, &j->content_length);
 600
 601                 if (j->content_length != UINT64_MAX) {
 602                         if (j->content_length > j->compressed_max) {
 603                                 r = log_error_errno(SYNTHETIC_ERRNO(EFBIG), "Content too large.");
 604                                 goto fail;
 605                         }
 606
 607                         log_info("Downloading %s for %s.", FORMAT_BYTES(j->content_length), j->url);
 608                 }
 609
 610                 return sz;
 611         }
 612
 613         r = curl_header_strdup(contents, sz, "Last-Modified:", &last_modified);
 614         if (r < 0) {
 615                 log_oom();
 616                 goto fail;
 617         }
 618         if (r > 0) {
 619                 (void) curl_parse_http_time(last_modified, &j->mtime);
 620                 return sz;
 621         }
 622
 623         if (j->on_header) {
 624                 r = j->on_header(j, contents, sz);
 625                 if (r < 0)
 626                         goto fail;
 627         }
 628
 629         return sz;
 630
 631 fail:
 632         pull_job_finish(j, r);
 633         return 0;
 634 }
 635
 636 static int pull_job_progress_callback(void *userdata, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow) {
 637         PullJob *j = userdata;
 638         unsigned percent;
 639         usec_t n;
 640
 641         assert(j);
 642
 643         if (dltotal <= 0)
 644                 return 0;
 645
 646         percent = ((100 * dlnow) / dltotal);
 647         n = now(CLOCK_MONOTONIC);
 648
 649         if (n > j->last_status_usec + USEC_PER_SEC &&
 650             percent != j->progress_percent &&
 651             dlnow < dltotal) {
 652
 653                 if (n - j->start_usec > USEC_PER_SEC && dlnow > 0) {
 654                         usec_t left, done;
 655
 656                         done = n - j->start_usec;
 657                         left = (usec_t) (((double) done * (double) dltotal) / dlnow) - done;
 658
 659                         log_info("Got %u%% of %s. %s left at %s/s.",
 660                                  percent,
 661                                  j->url,
 662                                  FORMAT_TIMESPAN(left, USEC_PER_SEC),
 663                                  FORMAT_BYTES((uint64_t) ((double) dlnow / ((double) done / (double) USEC_PER_SEC))));
 664                 } else
 665                         log_info("Got %u%% of %s.", percent, j->url);
 666
 667                 j->progress_percent = percent;
 668                 j->last_status_usec = n;
 669
 670                 if (j->on_progress)
 671                         j->on_progress(j);
 672         }
 673
 674         return 0;
 675 }
 676
 677 int pull_job_new(
 678                 PullJob **ret,
 679                 const char *url,
 680                 CurlGlue *glue,
 681                 void *userdata) {
 682
 683         _cleanup_(pull_job_unrefp) PullJob *j = NULL;
 684         _cleanup_free_ char *u = NULL;
 685
 686         assert(url);
 687         assert(glue);
 688         assert(ret);
 689
 690         u = strdup(url);
 691         if (!u)
 692                 return -ENOMEM;
 693
 694         j = new(PullJob, 1);
 695         if (!j)
 696                 return -ENOMEM;
 697
 698         *j = (PullJob) {
 699                 .state = PULL_JOB_INIT,
 700                 .disk_fd = -1,
 701                 .close_disk_fd = true,
 702                 .userdata = userdata,
 703                 .glue = glue,
 704                 .content_length = UINT64_MAX,
 705                 .start_usec = now(CLOCK_MONOTONIC),
 706                 .compressed_max = 64LLU * 1024LLU * 1024LLU * 1024LLU, /* 64GB safety limit */
 707                 .uncompressed_max = 64LLU * 1024LLU * 1024LLU * 1024LLU, /* 64GB safety limit */
 708                 .url = TAKE_PTR(u),
 709                 .offset = UINT64_MAX,
 710                 .sync = true,
 711         };
 712
 713         *ret = TAKE_PTR(j);
 714
 715         return 0;
 716 }
 717
 718 int pull_job_begin(PullJob *j) {
 719         int r;
 720
 721         assert(j);
 722
 723         if (j->state != PULL_JOB_INIT)
 724                 return -EBUSY;
 725
 726         r = curl_glue_make(&j->curl, j->url, j);
 727         if (r < 0)
 728                 return r;
 729
 730         if (!strv_isempty(j->old_etags)) {
 731                 _cleanup_free_ char *cc = NULL, *hdr = NULL;
 732
 733                 cc = strv_join(j->old_etags, ", ");
 734                 if (!cc)
 735                         return -ENOMEM;
 736
 737                 hdr = strjoin("If-None-Match: ", cc);
 738                 if (!hdr)
 739                         return -ENOMEM;
 740
 741                 if (!j->request_header) {
 742                         j->request_header = curl_slist_new(hdr, NULL);
 743                         if (!j->request_header)
 744                                 return -ENOMEM;
 745                 } else {
 746                         struct curl_slist *l;
 747
 748                         l = curl_slist_append(j->request_header, hdr);
 749                         if (!l)
 750                                 return -ENOMEM;
 751
 752                         j->request_header = l;
 753                 }
 754         }
 755
 756         if (j->request_header) {
 757                 if (curl_easy_setopt(j->curl, CURLOPT_HTTPHEADER, j->request_header) != CURLE_OK)
 758                         return -EIO;
 759         }
 760
 761         if (curl_easy_setopt(j->curl, CURLOPT_WRITEFUNCTION, pull_job_write_callback) != CURLE_OK)
 762                 return -EIO;
 763
 764         if (curl_easy_setopt(j->curl, CURLOPT_WRITEDATA, j) != CURLE_OK)
 765                 return -EIO;
 766
 767         if (curl_easy_setopt(j->curl, CURLOPT_HEADERFUNCTION, pull_job_header_callback) != CURLE_OK)
 768                 return -EIO;
 769
 770         if (curl_easy_setopt(j->curl, CURLOPT_HEADERDATA, j) != CURLE_OK)
 771                 return -EIO;
 772
 773         if (curl_easy_setopt(j->curl, CURLOPT_XFERINFOFUNCTION, pull_job_progress_callback) != CURLE_OK)
 774                 return -EIO;
 775
 776         if (curl_easy_setopt(j->curl, CURLOPT_XFERINFODATA, j) != CURLE_OK)
 777                 return -EIO;
 778
 779         if (curl_easy_setopt(j->curl, CURLOPT_NOPROGRESS, 0) != CURLE_OK)
 780                 return -EIO;
 781
 782         r = curl_glue_add(j->glue, j->curl);
 783         if (r < 0)
 784                 return r;
 785
 786         j->state = PULL_JOB_ANALYZING;
 787
 788         return 0;
 789 }