src/pstore/pstore.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   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 = -1
  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_entries;
 105         size_t n_entries_allocated;
 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 void *_a, const void *_b) {
 116         PStoreEntry *a = (PStoreEntry *)_a, *b = (PStoreEntry *)_b;
 117         return strcmp(a->dirent.d_name, b->dirent.d_name);
 118 }
 119
 120 static int move_file(PStoreEntry *pe, const char *subdir) {
 121         _cleanup_free_ char *ifd_path = NULL, *ofd_path = NULL;
 122         _cleanup_free_ void *field = NULL;
 123         const char *suffix, *message;
 124         struct iovec iovec[2];
 125         int n_iovec = 0, r;
 126
 127         if (pe->handled)
 128                 return 0;
 129
 130         ifd_path = path_join(arg_sourcedir, pe->dirent.d_name);
 131         if (!ifd_path)
 132                 return log_oom();
 133
 134         ofd_path = path_join(arg_archivedir, subdir, pe->dirent.d_name);
 135         if (!ofd_path)
 136                 return log_oom();
 137
 138         /* Always log to the journal */
 139         suffix = arg_storage == PSTORE_STORAGE_EXTERNAL ? strjoina(" moved to ", ofd_path) : (char *)".";
 140         message = strjoina("MESSAGE=PStore ", pe->dirent.d_name, suffix);
 141         iovec[n_iovec++] = IOVEC_MAKE_STRING(message);
 142
 143         if (pe->content_size > 0) {
 144                 size_t field_size;
 145
 146                 field_size = strlen("FILE=") + pe->content_size;
 147                 field = malloc(field_size);
 148                 if (!field)
 149                         return log_oom();
 150                 memcpy(stpcpy(field, "FILE="), pe->content, pe->content_size);
 151                 iovec[n_iovec++] = IOVEC_MAKE(field, field_size);
 152         }
 153
 154         r = sd_journal_sendv(iovec, n_iovec);
 155         if (r < 0)
 156                 return log_error_errno(r, "Failed to log pstore entry: %m");
 157
 158         if (arg_storage == PSTORE_STORAGE_EXTERNAL) {
 159                 /* Move file from pstore to external storage */
 160                 r = mkdir_parents(ofd_path, 0755);
 161                 if (r < 0)
 162                         return log_error_errno(r, "Failed to create directory %s: %m", ofd_path);
 163                 r = copy_file_atomic(ifd_path, ofd_path, 0600, 0, 0, COPY_REPLACE);
 164                 if (r < 0)
 165                         return log_error_errno(r, "Failed to copy_file_atomic: %s to %s", ifd_path, ofd_path);
 166         }
 167
 168         /* If file copied properly, remove it from pstore */
 169         if (arg_unlink)
 170                 (void) unlink(ifd_path);
 171
 172         pe->handled = true;
 173
 174         return 0;
 175 }
 176
 177 static int write_dmesg(const char *dmesg, size_t size, const char *id) {
 178         _cleanup_(unlink_and_freep) char *tmp_path = NULL;
 179         _cleanup_free_ char *ofd_path = NULL;
 180         _cleanup_close_ int ofd = -1;
 181         ssize_t wr;
 182         int r;
 183
 184         if (size == 0)
 185                 return 0;
 186
 187         assert(dmesg);
 188
 189         ofd_path = path_join(arg_archivedir, id, "dmesg.txt");
 190         if (!ofd_path)
 191                 return log_oom();
 192
 193         ofd = open_tmpfile_linkable(ofd_path, O_CLOEXEC|O_CREAT|O_TRUNC|O_WRONLY, &tmp_path);
 194         if (ofd < 0)
 195                 return log_error_errno(ofd, "Failed to open temporary file %s: %m", ofd_path);
 196         wr = write(ofd, dmesg, size);
 197         if (wr < 0)
 198                 return log_error_errno(errno, "Failed to store dmesg to %s: %m", ofd_path);
 199         if (wr != (ssize_t)size)
 200                 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to store dmesg to %s. %zu bytes are lost.", ofd_path, size - wr);
 201         r = link_tmpfile(ofd, tmp_path, ofd_path);
 202         if (r < 0)
 203                 return log_error_errno(r, "Failed to write temporary file %s: %m", ofd_path);
 204         tmp_path = mfree(tmp_path);
 205
 206         return 0;
 207 }
 208
 209 static void process_dmesg_files(PStoreList *list) {
 210         /* Move files, reconstruct dmesg.txt */
 211         _cleanup_free_ char *dmesg = NULL, *dmesg_id = NULL;
 212         size_t dmesg_size = 0, dmesg_allocated = 0;
 213         bool dmesg_bad = false;
 214         PStoreEntry *pe;
 215
 216         /* Handle each dmesg file: files processed in reverse
 217          * order so as to properly reconstruct original dmesg */
 218         for (size_t n = list->n_entries; n > 0; n--) {
 219                 bool move_file_and_continue = false;
 220                 _cleanup_free_ char *pe_id = NULL;
 221                 char *p;
 222                 size_t plen;
 223
 224                 pe = &list->entries[n-1];
 225
 226                 if (pe->handled)
 227                         continue;
 228                 if (!startswith(pe->dirent.d_name, "dmesg-"))
 229                         continue;
 230
 231                 if (endswith(pe->dirent.d_name, ".enc.z")) /* indicates a problem */
 232                         move_file_and_continue = true;
 233                 p = strrchr(pe->dirent.d_name, '-');
 234                 if (!p)
 235                         move_file_and_continue = true;
 236
 237                 if (move_file_and_continue) {
 238                         /* A dmesg file on which we do NO additional processing */
 239                         (void) move_file(pe, NULL);
 240                         continue;
 241                 }
 242
 243                 /* See if this file is one of a related group of files
 244                  * in order to reconstruct dmesg */
 245
 246                 /* When dmesg is written into pstore, it is done so in
 247                  * small chunks, whatever the exchange buffer size is
 248                  * with the underlying pstore backend (ie. EFI may be
 249                  * ~2KiB), which means an example pstore with approximately
 250                  * 64KB of storage may have up to roughly 32 dmesg files
 251                  * that could be related, depending upon the size of the
 252                  * original dmesg.
 253                  *
 254                  * Here we look at the dmesg filename and try to discern
 255                  * if files are part of a related group, meaning the same
 256                  * original dmesg.
 257                  *
 258                  * The two known pstore backends are EFI and ERST. These
 259                  * backends store data in the Common Platform Error
 260                  * Record, CPER, format. The dmesg- filename contains the
 261                  * CPER record id, a 64bit number (in decimal notation).
 262                  * In Linux, the record id is encoded with two digits for
 263                  * the dmesg part (chunk) number and 3 digits for the
 264                  * count number. So allowing an additional digit to
 265                  * compensate for advancing time, this code ignores the
 266                  * last six digits of the filename in determining the
 267                  * record id.
 268                  *
 269                  * For the EFI backend, the record id encodes an id in the
 270                  * upper 32 bits, and a timestamp in the lower 32-bits.
 271                  * So ignoring the least significant 6 digits has proven
 272                  * to generally identify related dmesg entries.  */
 273 #define PSTORE_FILENAME_IGNORE 6
 274
 275                 /* determine common portion of record id */
 276                 ++p; /* move beyond dmesg- */
 277                 plen = strlen(p);
 278                 if (plen > PSTORE_FILENAME_IGNORE) {
 279                         pe_id = memdup_suffix0(p, plen - PSTORE_FILENAME_IGNORE);
 280                         if (!pe_id) {
 281                                 log_oom();
 282                                 return;
 283                         }
 284                 } else
 285                         pe_id = mfree(pe_id);
 286
 287                 /* Now move file from pstore to archive storage */
 288                 move_file(pe, pe_id);
 289
 290                 if (dmesg_bad)
 291                         continue;
 292
 293                 /* If the current record id is NOT the same as the
 294                  * previous record id, then start a new dmesg.txt file */
 295                 if (!streq_ptr(pe_id, dmesg_id)) {
 296                         /* Encountered a new dmesg group, close out old one, open new one */
 297                         (void) write_dmesg(dmesg, dmesg_size, dmesg_id);
 298                         dmesg_size = 0;
 299
 300                         /* now point dmesg_id to storage of pe_id */
 301                         free_and_replace(dmesg_id, pe_id);
 302                 }
 303
 304                 /* Reconstruction of dmesg is done as a useful courtesy: do not fail, but don't write garbled
 305                  * output either. */
 306                 size_t needed = strlen(pe->dirent.d_name) + strlen(":\n") + pe->content_size + 1;
 307                 if (!GREEDY_REALLOC(dmesg, dmesg_allocated, dmesg_size + needed)) {
 308                         log_warning_errno(ENOMEM, "Failed to write dmesg file: %m");
 309                         dmesg_bad = true;
 310                         continue;
 311                 }
 312
 313                 dmesg_size += sprintf(dmesg + dmesg_size, "%s:\n", pe->dirent.d_name);
 314                 if (pe->content) {
 315                         memcpy(dmesg + dmesg_size, pe->content, pe->content_size);
 316                         dmesg_size += pe->content_size;
 317                 }
 318
 319                 pe_id = mfree(pe_id);
 320         }
 321
 322         if (!dmesg_bad)
 323                 (void) write_dmesg(dmesg, dmesg_size, dmesg_id);
 324 }
 325
 326 static int list_files(PStoreList *list, const char *sourcepath) {
 327         _cleanup_(closedirp) DIR *dirp = NULL;
 328         struct dirent *de;
 329         int r;
 330
 331         dirp = opendir(sourcepath);
 332         if (!dirp)
 333                 return log_error_errno(errno, "Failed to opendir %s: %m", sourcepath);
 334
 335         FOREACH_DIRENT(de, dirp, return log_error_errno(errno, "Failed to iterate through %s: %m", sourcepath)) {
 336                 _cleanup_free_ char *ifd_path = NULL;
 337
 338                 ifd_path = path_join(sourcepath, de->d_name);
 339                 if (!ifd_path)
 340                         return log_oom();
 341
 342                 _cleanup_free_ char *buf = NULL;
 343                 size_t buf_size;
 344
 345                 /* Now read contents of pstore file */
 346                 r = read_full_file(ifd_path, &buf, &buf_size);
 347                 if (r < 0) {
 348                         log_warning_errno(r, "Failed to read file %s, skipping: %m", ifd_path);
 349                         continue;
 350                 }
 351
 352                 if (!GREEDY_REALLOC(list->entries, list->n_entries_allocated, list->n_entries + 1))
 353                         return log_oom();
 354
 355                 list->entries[list->n_entries++] = (PStoreEntry) {
 356                         .dirent = *de,
 357                         .content = TAKE_PTR(buf),
 358                         .content_size = buf_size,
 359                         .is_binary = true,
 360                         .handled = false,
 361                 };
 362         }
 363
 364         return 0;
 365 }
 366
 367 static int run(int argc, char *argv[]) {
 368         _cleanup_(pstore_entries_reset) PStoreList list = {};
 369         int r;
 370
 371         log_setup_service();
 372
 373         if (argc == 3) {
 374                 arg_sourcedir = argv[1];
 375                 arg_archivedir = argv[2];
 376         } else if (argc > 1)
 377                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 378                                        "This program takes zero or two arguments.");
 379
 380         /* Ignore all parse errors */
 381         (void) parse_config();
 382
 383         log_debug("Selected storage: %s.", pstore_storage_to_string(arg_storage));
 384         log_debug("Selected unlink: %s.", yes_no(arg_unlink));
 385
 386         if (arg_storage == PSTORE_STORAGE_NONE)
 387                 /* Do nothing, intentionally, leaving pstore untouched */
 388                 return 0;
 389
 390         /* Obtain list of files in pstore */
 391         r = list_files(&list, arg_sourcedir);
 392         if (r < 0)
 393                 return r;
 394
 395         /* Handle each pstore file */
 396         /* Sort files lexigraphically ascending, generally needed by all */
 397         qsort_safe(list.entries, list.n_entries, sizeof(PStoreEntry), compare_pstore_entries);
 398
 399         /* Process known file types */
 400         process_dmesg_files(&list);
 401
 402         /* Move left over files out of pstore */
 403         for (size_t n = 0; n < list.n_entries; n++)
 404                 move_file(&list.entries[n], NULL);
 405
 406         return 0;
 407 }
 408
 409 DEFINE_MAIN_FUNCTION(run);