src/pstore/pstore.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 /* Copyright © 2019 Oracle and/or its affiliates. */
   4
   5 /* Generally speaking, the pstore contains a small number of files
   6  * that in turn contain a small amount of data.  */
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <stdio_ext.h>
  10 #include <sys/prctl.h>
  11 #include <sys/xattr.h>
  12 #include <unistd.h>
  13
  14 #include "sd-daemon.h"
  15 #include "sd-journal.h"
  16 #include "sd-login.h"
  17 #include "sd-messages.h"
  18
  19 #include "acl-util.h"
  20 #include "alloc-util.h"
  21 #include "capability-util.h"
  22 #include "cgroup-util.h"
  23 #include "compress.h"
  24 #include "conf-parser.h"
  25 #include "copy.h"
  26 #include "dirent-util.h"
  27 #include "escape.h"
  28 #include "fd-util.h"
  29 #include "fileio.h"
  30 #include "fs-util.h"
  31 #include "io-util.h"
  32 #include "journal-importer.h"
  33 #include "log.h"
  34 #include "macro.h"
  35 #include "main-func.h"
  36 #include "mkdir.h"
  37 #include "parse-util.h"
  38 #include "process-util.h"
  39 #include "signal-util.h"
  40 #include "socket-util.h"
  41 #include "special.h"
  42 #include "sort-util.h"
  43 #include "string-table.h"
  44 #include "string-util.h"
  45 #include "strv.h"
  46 #include "tmpfile-util.h"
  47 #include "user-util.h"
  48 #include "util.h"
  49
  50 /* Command line argument handling */
  51 typedef enum PStoreStorage {
  52         PSTORE_STORAGE_NONE,
  53         PSTORE_STORAGE_EXTERNAL,
  54         PSTORE_STORAGE_JOURNAL,
  55         _PSTORE_STORAGE_MAX,
  56         _PSTORE_STORAGE_INVALID = -EINVAL,
  57 } PStoreStorage;
  58
  59 static const char* const pstore_storage_table[_PSTORE_STORAGE_MAX] = {
  60         [PSTORE_STORAGE_NONE] = "none",
  61         [PSTORE_STORAGE_EXTERNAL] = "external",
  62         [PSTORE_STORAGE_JOURNAL] = "journal",
  63 };
  64
  65 DEFINE_PRIVATE_STRING_TABLE_LOOKUP(pstore_storage, PStoreStorage);
  66 static DEFINE_CONFIG_PARSE_ENUM(config_parse_pstore_storage, pstore_storage, PStoreStorage, "Failed to parse storage setting");
  67
  68 static PStoreStorage arg_storage = PSTORE_STORAGE_EXTERNAL;
  69
  70 static bool arg_unlink = true;
  71 static const char *arg_sourcedir = "/sys/fs/pstore";
  72 static const char *arg_archivedir = "/var/lib/systemd/pstore";
  73
  74 static int parse_config(void) {
  75         static const ConfigTableItem items[] = {
  76                 { "PStore", "Unlink",  config_parse_bool,           0, &arg_unlink },
  77                 { "PStore", "Storage", config_parse_pstore_storage, 0, &arg_storage },
  78                 {}
  79         };
  80
  81         return config_parse_many_nulstr(
  82                         PKGSYSCONFDIR "/pstore.conf",
  83                         CONF_PATHS_NULSTR("systemd/pstore.conf.d"),
  84                         "PStore\0",
  85                         config_item_table_lookup, items,
  86                         CONFIG_PARSE_WARN,
  87                         NULL,
  88                         NULL);
  89 }
  90
  91 /* File list handling - PStoreEntry is the struct and
  92  * and PStoreEntry is the type that contains all info
  93  * about a pstore entry.  */
  94 typedef struct PStoreEntry {
  95         struct dirent dirent;
  96         bool is_binary;
  97         bool handled;
  98         char *content;
  99         size_t content_size;
 100 } PStoreEntry;
 101
 102 typedef struct PStoreList {
 103         PStoreEntry *entries;
 104         size_t n_allocated;
 105         size_t n_entries;
 106 } PStoreList;
 107
 108 static void pstore_entries_reset(PStoreList *list) {
 109         for (size_t i = 0; i < list->n_entries; i++)
 110                 free(list->entries[i].content);
 111         free(list->entries);
 112         list->n_entries = 0;
 113 }
 114
 115 static int compare_pstore_entries(const PStoreEntry *a, const PStoreEntry *b) {
 116         return strcmp(a->dirent.d_name, b->dirent.d_name);
 117 }
 118
 119 static int move_file(PStoreEntry *pe, const char *subdir) {
 120         _cleanup_free_ char *ifd_path = NULL, *ofd_path = NULL;
 121         _cleanup_free_ void *field = NULL;
 122         const char *suffix, *message;
 123         struct iovec iovec[2];
 124         int n_iovec = 0, r;
 125
 126         if (pe->handled)
 127                 return 0;
 128
 129         ifd_path = path_join(arg_sourcedir, pe->dirent.d_name);
 130         if (!ifd_path)
 131                 return log_oom();
 132
 133         ofd_path = path_join(arg_archivedir, subdir, pe->dirent.d_name);
 134         if (!ofd_path)
 135                 return log_oom();
 136
 137         /* Always log to the journal */
 138         suffix = arg_storage == PSTORE_STORAGE_EXTERNAL ? strjoina(" moved to ", ofd_path) : (char *)".";
 139         message = strjoina("MESSAGE=PStore ", pe->dirent.d_name, suffix);
 140         iovec[n_iovec++] = IOVEC_MAKE_STRING(message);
 141
 142         if (pe->content_size > 0) {
 143                 size_t field_size;
 144
 145                 field_size = strlen("FILE=") + pe->content_size;
 146                 field = malloc(field_size);
 147                 if (!field)
 148                         return log_oom();
 149                 memcpy(stpcpy(field, "FILE="), pe->content, pe->content_size);
 150                 iovec[n_iovec++] = IOVEC_MAKE(field, field_size);
 151         }
 152
 153         r = sd_journal_sendv(iovec, n_iovec);
 154         if (r < 0)
 155                 return log_error_errno(r, "Failed to log pstore entry: %m");
 156
 157         if (arg_storage == PSTORE_STORAGE_EXTERNAL) {
 158                 /* Move file from pstore to external storage */
 159                 r = mkdir_parents(ofd_path, 0755);
 160                 if (r < 0)
 161                         return log_error_errno(r, "Failed to create directory %s: %m", ofd_path);
 162                 r = copy_file_atomic(ifd_path, ofd_path, 0600, 0, 0, COPY_REPLACE);
 163                 if (r < 0)
 164                         return log_error_errno(r, "Failed to copy_file_atomic: %s to %s", ifd_path, ofd_path);
 165         }
 166
 167         /* If file copied properly, remove it from pstore */
 168         if (arg_unlink)
 169                 (void) unlink(ifd_path);
 170
 171         pe->handled = true;
 172
 173         return 0;
 174 }
 175
 176 static int write_dmesg(const char *dmesg, size_t size, const char *id) {
 177         _cleanup_(unlink_and_freep) char *tmp_path = NULL;
 178         _cleanup_free_ char *ofd_path = NULL;
 179         _cleanup_close_ int ofd = -1;
 180         ssize_t wr;
 181         int r;
 182
 183         if (size == 0)
 184                 return 0;
 185
 186         assert(dmesg);
 187
 188         ofd_path = path_join(arg_archivedir, id, "dmesg.txt");
 189         if (!ofd_path)
 190                 return log_oom();
 191
 192         ofd = open_tmpfile_linkable(ofd_path, O_CLOEXEC|O_CREAT|O_TRUNC|O_WRONLY, &tmp_path);
 193         if (ofd < 0)
 194                 return log_error_errno(ofd, "Failed to open temporary file %s: %m", ofd_path);
 195         wr = write(ofd, dmesg, size);
 196         if (wr < 0)
 197                 return log_error_errno(errno, "Failed to store dmesg to %s: %m", ofd_path);
 198         if (wr != (ssize_t)size)
 199                 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to store dmesg to %s. %zu bytes are lost.", ofd_path, size - wr);
 200         r = link_tmpfile(ofd, tmp_path, ofd_path);
 201         if (r < 0)
 202                 return log_error_errno(r, "Failed to write temporary file %s: %m", ofd_path);
 203         tmp_path = mfree(tmp_path);
 204
 205         return 0;
 206 }
 207
 208 static void process_dmesg_files(PStoreList *list) {
 209         /* Move files, reconstruct dmesg.txt */
 210         _cleanup_free_ char *dmesg = NULL, *dmesg_id = NULL;
 211         size_t dmesg_size = 0, dmesg_allocated = 0;
 212         bool dmesg_bad = false;
 213         PStoreEntry *pe;
 214
 215         /* Handle each dmesg file: files processed in reverse
 216          * order so as to properly reconstruct original dmesg */
 217         for (size_t n = list->n_entries; n > 0; n--) {
 218                 bool move_file_and_continue = false;
 219                 _cleanup_free_ char *pe_id = NULL;
 220                 char *p;
 221                 size_t plen;
 222
 223                 pe = &list->entries[n-1];
 224
 225                 if (pe->handled)
 226                         continue;
 227                 if (!startswith(pe->dirent.d_name, "dmesg-"))
 228                         continue;
 229
 230                 if (endswith(pe->dirent.d_name, ".enc.z")) /* indicates a problem */
 231                         move_file_and_continue = true;
 232                 p = strrchr(pe->dirent.d_name, '-');
 233                 if (!p)
 234                         move_file_and_continue = true;
 235
 236                 if (move_file_and_continue) {
 237                         /* A dmesg file on which we do NO additional processing */
 238                         (void) move_file(pe, NULL);
 239                         continue;
 240                 }
 241
 242                 /* See if this file is one of a related group of files
 243                  * in order to reconstruct dmesg */
 244
 245                 /* When dmesg is written into pstore, it is done so in
 246                  * small chunks, whatever the exchange buffer size is
 247                  * with the underlying pstore backend (ie. EFI may be
 248                  * ~2KiB), which means an example pstore with approximately
 249                  * 64KB of storage may have up to roughly 32 dmesg files
 250                  * that could be related, depending upon the size of the
 251                  * original dmesg.
 252                  *
 253                  * Here we look at the dmesg filename and try to discern
 254                  * if files are part of a related group, meaning the same
 255                  * original dmesg.
 256                  *
 257                  * The two known pstore backends are EFI and ERST. These
 258                  * backends store data in the Common Platform Error
 259                  * Record, CPER, format. The dmesg- filename contains the
 260                  * CPER record id, a 64bit number (in decimal notation).
 261                  * In Linux, the record id is encoded with two digits for
 262                  * the dmesg part (chunk) number and 3 digits for the
 263                  * count number. So allowing an additional digit to
 264                  * compensate for advancing time, this code ignores the
 265                  * last six digits of the filename in determining the
 266                  * record id.
 267                  *
 268                  * For the EFI backend, the record id encodes an id in the
 269                  * upper 32 bits, and a timestamp in the lower 32-bits.
 270                  * So ignoring the least significant 6 digits has proven
 271                  * to generally identify related dmesg entries.  */
 272 #define PSTORE_FILENAME_IGNORE 6
 273
 274                 /* determine common portion of record id */
 275                 ++p; /* move beyond dmesg- */
 276                 plen = strlen(p);
 277                 if (plen > PSTORE_FILENAME_IGNORE) {
 278                         pe_id = memdup_suffix0(p, plen - PSTORE_FILENAME_IGNORE);
 279                         if (!pe_id) {
 280                                 log_oom();
 281                                 return;
 282                         }
 283                 } else
 284                         pe_id = mfree(pe_id);
 285
 286                 /* Now move file from pstore to archive storage */
 287                 move_file(pe, pe_id);
 288
 289                 if (dmesg_bad)
 290                         continue;
 291
 292                 /* If the current record id is NOT the same as the
 293                  * previous record id, then start a new dmesg.txt file */
 294                 if (!streq_ptr(pe_id, dmesg_id)) {
 295                         /* Encountered a new dmesg group, close out old one, open new one */
 296                         (void) write_dmesg(dmesg, dmesg_size, dmesg_id);
 297                         dmesg_size = 0;
 298
 299                         /* now point dmesg_id to storage of pe_id */
 300                         free_and_replace(dmesg_id, pe_id);
 301                 }
 302
 303                 /* Reconstruction of dmesg is done as a useful courtesy: do not fail, but don't write garbled
 304                  * output either. */
 305                 size_t needed = strlen(pe->dirent.d_name) + strlen(":\n") + pe->content_size + 1;
 306                 if (!GREEDY_REALLOC(dmesg, dmesg_allocated, dmesg_size + needed)) {
 307                         log_oom();
 308                         dmesg_bad = true;
 309                         continue;
 310                 }
 311
 312                 dmesg_size += sprintf(dmesg + dmesg_size, "%s:\n", pe->dirent.d_name);
 313                 if (pe->content) {
 314                         memcpy(dmesg + dmesg_size, pe->content, pe->content_size);
 315                         dmesg_size += pe->content_size;
 316                 }
 317
 318                 pe_id = mfree(pe_id);
 319         }
 320
 321         if (!dmesg_bad)
 322                 (void) write_dmesg(dmesg, dmesg_size, dmesg_id);
 323 }
 324
 325 static int list_files(PStoreList *list, const char *sourcepath) {
 326         _cleanup_(closedirp) DIR *dirp = NULL;
 327         struct dirent *de;
 328         int r;
 329
 330         dirp = opendir(sourcepath);
 331         if (!dirp)
 332                 return log_error_errno(errno, "Failed to opendir %s: %m", sourcepath);
 333
 334         FOREACH_DIRENT(de, dirp, return log_error_errno(errno, "Failed to iterate through %s: %m", sourcepath)) {
 335                 _cleanup_free_ char *ifd_path = NULL;
 336
 337                 ifd_path = path_join(sourcepath, de->d_name);
 338                 if (!ifd_path)
 339                         return log_oom();
 340
 341                 _cleanup_free_ char *buf = NULL;
 342                 size_t buf_size;
 343
 344                 /* Now read contents of pstore file */
 345                 r = read_full_virtual_file(ifd_path, &buf, &buf_size);
 346                 if (r < 0) {
 347                         log_warning_errno(r, "Failed to read file %s, skipping: %m", ifd_path);
 348                         continue;
 349                 }
 350
 351                 if (!GREEDY_REALLOC(list->entries, list->n_allocated, list->n_entries + 1))
 352                         return log_oom();
 353
 354                 list->entries[list->n_entries++] = (PStoreEntry) {
 355                         .dirent = *de,
 356                         .content = TAKE_PTR(buf),
 357                         .content_size = buf_size,
 358                         .is_binary = true,
 359                         .handled = false,
 360                 };
 361         }
 362
 363         return 0;
 364 }
 365
 366 static int run(int argc, char *argv[]) {
 367         _cleanup_(pstore_entries_reset) PStoreList list = {};
 368         int r;
 369
 370         log_setup();
 371
 372         if (argc == 3) {
 373                 arg_sourcedir = argv[1];
 374                 arg_archivedir = argv[2];
 375         } else if (argc > 1)
 376                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 377                                        "This program takes zero or two arguments.");
 378
 379         /* Ignore all parse errors */
 380         (void) parse_config();
 381
 382         log_debug("Selected storage: %s.", pstore_storage_to_string(arg_storage));
 383         log_debug("Selected unlink: %s.", yes_no(arg_unlink));
 384
 385         if (arg_storage == PSTORE_STORAGE_NONE)
 386                 /* Do nothing, intentionally, leaving pstore untouched */
 387                 return 0;
 388
 389         /* Obtain list of files in pstore */
 390         r = list_files(&list, arg_sourcedir);
 391         if (r < 0)
 392                 return r;
 393
 394         /* Handle each pstore file */
 395         /* Sort files lexigraphically ascending, generally needed by all */
 396         typesafe_qsort(list.entries, list.n_entries, compare_pstore_entries);
 397
 398         /* Process known file types */
 399         process_dmesg_files(&list);
 400
 401         /* Move left over files out of pstore */
 402         for (size_t n = 0; n < list.n_entries; n++)
 403                 move_file(&list.entries[n], NULL);
 404
 405         return 0;
 406 }
 407
 408 DEFINE_MAIN_FUNCTION(run);