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
  49 /* Command line argument handling */
  50 typedef enum PStoreStorage {
  51         PSTORE_STORAGE_NONE,
  52         PSTORE_STORAGE_EXTERNAL,
  53         PSTORE_STORAGE_JOURNAL,
  54         _PSTORE_STORAGE_MAX,
  55         _PSTORE_STORAGE_INVALID = -EINVAL,
  56 } PStoreStorage;
  57
  58 static const char* const pstore_storage_table[_PSTORE_STORAGE_MAX] = {
  59         [PSTORE_STORAGE_NONE] = "none",
  60         [PSTORE_STORAGE_EXTERNAL] = "external",
  61         [PSTORE_STORAGE_JOURNAL] = "journal",
  62 };
  63
  64 DEFINE_PRIVATE_STRING_TABLE_LOOKUP(pstore_storage, PStoreStorage);
  65 static DEFINE_CONFIG_PARSE_ENUM(config_parse_pstore_storage, pstore_storage, PStoreStorage, "Failed to parse storage setting");
  66
  67 static PStoreStorage arg_storage = PSTORE_STORAGE_EXTERNAL;
  68
  69 static bool arg_unlink = true;
  70 static const char *arg_sourcedir = "/sys/fs/pstore";
  71 static const char *arg_archivedir = "/var/lib/systemd/pstore";
  72
  73 static int parse_config(void) {
  74         static const ConfigTableItem items[] = {
  75                 { "PStore", "Unlink",  config_parse_bool,           0, &arg_unlink },
  76                 { "PStore", "Storage", config_parse_pstore_storage, 0, &arg_storage },
  77                 {}
  78         };
  79
  80         return config_parse_many_nulstr(
  81                         PKGSYSCONFDIR "/pstore.conf",
  82                         CONF_PATHS_NULSTR("systemd/pstore.conf.d"),
  83                         "PStore\0",
  84                         config_item_table_lookup, items,
  85                         CONFIG_PARSE_WARN,
  86                         NULL,
  87                         NULL);
  88 }
  89
  90 /* File list handling - PStoreEntry is the struct and
  91  * and PStoreEntry is the type that contains all info
  92  * about a pstore entry.  */
  93 typedef struct PStoreEntry {
  94         struct dirent dirent;
  95         bool is_binary;
  96         bool handled;
  97         char *content;
  98         size_t content_size;
  99 } PStoreEntry;
 100
 101 typedef struct PStoreList {
 102         PStoreEntry *entries;
 103         size_t n_entries;
 104 } PStoreList;
 105
 106 static void pstore_entries_reset(PStoreList *list) {
 107         for (size_t i = 0; i < list->n_entries; i++)
 108                 free(list->entries[i].content);
 109         free(list->entries);
 110         list->n_entries = 0;
 111 }
 112
 113 static int compare_pstore_entries(const PStoreEntry *a, const PStoreEntry *b) {
 114         return strcmp(a->dirent.d_name, b->dirent.d_name);
 115 }
 116
 117 static int move_file(PStoreEntry *pe, const char *subdir1, const char *subdir2) {
 118         _cleanup_free_ char *ifd_path = NULL, *ofd_path = NULL;
 119         _cleanup_free_ void *field = NULL;
 120         const char *suffix, *message;
 121         struct iovec iovec[2];
 122         int n_iovec = 0, r;
 123
 124         if (pe->handled)
 125                 return 0;
 126
 127         ifd_path = path_join(arg_sourcedir, pe->dirent.d_name);
 128         if (!ifd_path)
 129                 return log_oom();
 130
 131         ofd_path = path_join(arg_archivedir, subdir1, subdir2, pe->dirent.d_name);
 132         if (!ofd_path)
 133                 return log_oom();
 134
 135         /* Always log to the journal */
 136         suffix = arg_storage == PSTORE_STORAGE_EXTERNAL ? strjoina(" moved to ", ofd_path) : (char *)".";
 137         message = strjoina("MESSAGE=PStore ", pe->dirent.d_name, suffix);
 138         iovec[n_iovec++] = IOVEC_MAKE_STRING(message);
 139
 140         if (pe->content_size > 0) {
 141                 size_t field_size;
 142
 143                 field_size = strlen("FILE=") + pe->content_size;
 144                 field = malloc(field_size);
 145                 if (!field)
 146                         return log_oom();
 147                 memcpy(stpcpy(field, "FILE="), pe->content, pe->content_size);
 148                 iovec[n_iovec++] = IOVEC_MAKE(field, field_size);
 149         }
 150
 151         r = sd_journal_sendv(iovec, n_iovec);
 152         if (r < 0)
 153                 return log_error_errno(r, "Failed to log pstore entry: %m");
 154
 155         if (arg_storage == PSTORE_STORAGE_EXTERNAL) {
 156                 /* Move file from pstore to external storage */
 157                 r = mkdir_parents(ofd_path, 0755);
 158                 if (r < 0)
 159                         return log_error_errno(r, "Failed to create directory %s: %m", ofd_path);
 160                 r = copy_file_atomic(ifd_path, ofd_path, 0600, 0, 0, COPY_REPLACE);
 161                 if (r < 0)
 162                         return log_error_errno(r, "Failed to copy_file_atomic: %s to %s", ifd_path, ofd_path);
 163         }
 164
 165         /* If file copied properly, remove it from pstore */
 166         if (arg_unlink)
 167                 (void) unlink(ifd_path);
 168
 169         pe->handled = true;
 170
 171         return 0;
 172 }
 173
 174 static int append_dmesg(PStoreEntry *pe, const char *subdir1, const char *subdir2) {
 175         /* Append dmesg chunk to end, create if needed */
 176         _cleanup_free_ char *ofd_path = NULL;
 177         _cleanup_close_ int ofd = -1;
 178         ssize_t wr;
 179
 180         assert(pe);
 181
 182         if (pe->content_size == 0)
 183                 return 0;
 184
 185         ofd_path = path_join(arg_archivedir, subdir1, subdir2, "dmesg.txt");
 186         if (!ofd_path)
 187                 return log_oom();
 188
 189         ofd = open(ofd_path, O_CREAT|O_NOFOLLOW|O_NOCTTY|O_CLOEXEC|O_APPEND|O_WRONLY, 0640);
 190         if (ofd < 0)
 191                 return log_error_errno(ofd, "Failed to open file %s: %m", ofd_path);
 192         wr = write(ofd, pe->content, pe->content_size);
 193         if (wr < 0)
 194                 return log_error_errno(errno, "Failed to store dmesg to %s: %m", ofd_path);
 195         if ((size_t)wr != pe->content_size)
 196                 return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to store dmesg to %s. %zu bytes are lost.", ofd_path, pe->content_size - wr);
 197
 198         return 0;
 199 }
 200
 201 static int process_dmesg_files(PStoreList *list) {
 202         /* Move files, reconstruct dmesg.txt */
 203         _cleanup_free_ char *erst_subdir = NULL;
 204         uint64_t last_record_id = 0;
 205
 206         /* When dmesg is written into pstore, it is done so in small chunks, whatever the exchange buffer
 207          * size is with the underlying pstore backend (ie. EFI may be ~2KiB), which means an example
 208          * pstore with approximately 64KB of storage may have up to roughly 32 dmesg files, some likely
 209          * related.
 210          *
 211          * Here we look at the dmesg filename and try to discern if files are part of a related group,
 212          * meaning the same original dmesg.
 213          *
 214          * The dmesg- filename contains the backend-type and the Common Platform Error Record, CPER,
 215          * record id, a 64-bit number.
 216          *
 217          * Files are processed in reverse lexigraphical order so as to properly reconstruct original dmesg.*/
 218
 219         for (size_t n = list->n_entries; n > 0; n--) {
 220                 PStoreEntry *pe;
 221                 char *p;
 222
 223                 pe = &list->entries[n-1];
 224
 225                 if (pe->handled)
 226                         continue;
 227                 if (endswith(pe->dirent.d_name, ".enc.z")) /* indicates a problem */
 228                         continue;
 229                 if (!startswith(pe->dirent.d_name, "dmesg-"))
 230                         continue;
 231
 232                 if ((p = startswith(pe->dirent.d_name, "dmesg-efi-"))) {
 233                         /* For the EFI backend, the 3 least significant digits of record id encodes a
 234                          * "count" number, the next 2 least significant digits for the dmesg part
 235                          * (chunk) number, and the remaining digits as the timestamp.  See
 236                          * linux/drivers/firmware/efi/efi-pstore.c in efi_pstore_write(). */
 237                         _cleanup_free_ char *subdir1 = NULL, *subdir2 = NULL;
 238                         size_t plen = strlen(p);
 239
 240                         if (plen < 6)
 241                                 continue;
 242
 243                         /* Extract base record id */
 244                         subdir1 = strndup(p, plen - 5);
 245                         if (!subdir1)
 246                                 return log_oom();
 247                         /* Extract "count" field */
 248                         subdir2 = strndup(p + plen - 3, 3);
 249                         if (!subdir2)
 250                                 return log_oom();
 251
 252                         /* Now move file from pstore to archive storage */
 253                         (void) move_file(pe, subdir1, subdir2);
 254
 255                         /* Append to the dmesg */
 256                         (void) append_dmesg(pe, subdir1, subdir2);
 257                 } else if ((p = startswith(pe->dirent.d_name, "dmesg-erst-"))) {
 258                         /* For the ERST backend, the record is a monotonically increasing number, seeded as
 259                          * a timestamp. See linux/drivers/acpi/apei/erst.c in erst_writer(). */
 260                         uint64_t record_id;
 261
 262                         if (safe_atou64(p, &record_id) < 0)
 263                                 continue;
 264                         if (last_record_id - 1 != record_id)
 265                                 /* A discontinuity in the number has been detected, this current record id
 266                                  * will become the directory name for all pieces of the dmesg in this
 267                                  * series. */
 268                                 if (free_and_strdup(&erst_subdir, p) < 0)
 269                                         return log_oom();
 270
 271                         /* Now move file from pstore to archive storage */
 272                         (void) move_file(pe, erst_subdir, NULL);
 273
 274                         /* Append to the dmesg */
 275                         (void) append_dmesg(pe, erst_subdir, NULL);
 276
 277                         /* Update, but keep erst_subdir for next file */
 278                         last_record_id = record_id;
 279                 } else
 280                         log_debug("Unknown backend, ignoring \"%s\".", pe->dirent.d_name);
 281         }
 282         return 0;
 283 }
 284
 285 static int list_files(PStoreList *list, const char *sourcepath) {
 286         _cleanup_(closedirp) DIR *dirp = NULL;
 287         int r;
 288
 289         dirp = opendir(sourcepath);
 290         if (!dirp)
 291                 return log_error_errno(errno, "Failed to opendir %s: %m", sourcepath);
 292
 293         FOREACH_DIRENT(de, dirp, return log_error_errno(errno, "Failed to iterate through %s: %m", sourcepath)) {
 294                 _cleanup_free_ char *ifd_path = NULL;
 295
 296                 ifd_path = path_join(sourcepath, de->d_name);
 297                 if (!ifd_path)
 298                         return log_oom();
 299
 300                 _cleanup_free_ char *buf = NULL;
 301                 size_t buf_size;
 302
 303                 /* Now read contents of pstore file */
 304                 r = read_full_virtual_file(ifd_path, &buf, &buf_size);
 305                 if (r < 0) {
 306                         log_warning_errno(r, "Failed to read file %s, skipping: %m", ifd_path);
 307                         continue;
 308                 }
 309
 310                 if (!GREEDY_REALLOC(list->entries, list->n_entries + 1))
 311                         return log_oom();
 312
 313                 list->entries[list->n_entries++] = (PStoreEntry) {
 314                         .dirent = *de,
 315                         .content = TAKE_PTR(buf),
 316                         .content_size = buf_size,
 317                         .is_binary = true,
 318                         .handled = false,
 319                 };
 320         }
 321
 322         return 0;
 323 }
 324
 325 static int run(int argc, char *argv[]) {
 326         _cleanup_(pstore_entries_reset) PStoreList list = {};
 327         int r;
 328
 329         log_setup();
 330
 331         if (argc == 3) {
 332                 arg_sourcedir = argv[1];
 333                 arg_archivedir = argv[2];
 334         } else if (argc > 1)
 335                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 336                                        "This program takes zero or two arguments.");
 337
 338         /* Ignore all parse errors */
 339         (void) parse_config();
 340
 341         log_debug("Selected storage: %s.", pstore_storage_to_string(arg_storage));
 342         log_debug("Selected unlink: %s.", yes_no(arg_unlink));
 343
 344         if (arg_storage == PSTORE_STORAGE_NONE)
 345                 /* Do nothing, intentionally, leaving pstore untouched */
 346                 return 0;
 347
 348         /* Obtain list of files in pstore */
 349         r = list_files(&list, arg_sourcedir);
 350         if (r < 0)
 351                 return r;
 352
 353         /* Handle each pstore file */
 354         /* Sort files lexigraphically ascending, generally needed by all */
 355         typesafe_qsort(list.entries, list.n_entries, compare_pstore_entries);
 356
 357         /* Process known file types */
 358         (void) process_dmesg_files(&list);
 359
 360         /* Move left over files out of pstore */
 361         for (size_t n = 0; n < list.n_entries; n++)
 362                 (void) move_file(&list.entries[n], NULL, NULL);
 363
 364         return 0;
 365 }
 366
 367 DEFINE_MAIN_FUNCTION(run);