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/* SPDX-License-Identifier: LGPL-2.1+ */
/* Copyright © 2019 Oracle and/or its affiliates. */
/* Generally speaking, the pstore contains a small number of files
* that in turn contain a small amount of data. */
#include <errno.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <sys/prctl.h>
#include <sys/xattr.h>
#include <unistd.h>
#include "sd-daemon.h"
#include "sd-journal.h"
#include "sd-login.h"
#include "sd-messages.h"
#include "acl-util.h"
#include "alloc-util.h"
#include "capability-util.h"
#include "cgroup-util.h"
#include "compress.h"
#include "conf-parser.h"
#include "copy.h"
#include "dirent-util.h"
#include "escape.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "io-util.h"
#include "journal-importer.h"
#include "log.h"
#include "macro.h"
#include "main-func.h"
#include "missing.h"
#include "mkdir.h"
#include "parse-util.h"
#include "process-util.h"
#include "signal-util.h"
#include "socket-util.h"
#include "special.h"
#include "sort-util.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "tmpfile-util.h"
#include "user-util.h"
#include "util.h"
/* Command line argument handling */
typedef enum PStoreStorage {
PSTORE_STORAGE_NONE,
PSTORE_STORAGE_EXTERNAL,
PSTORE_STORAGE_JOURNAL,
_PSTORE_STORAGE_MAX,
_PSTORE_STORAGE_INVALID = -1
} PStoreStorage;
static const char* const pstore_storage_table[_PSTORE_STORAGE_MAX] = {
[PSTORE_STORAGE_NONE] = "none",
[PSTORE_STORAGE_EXTERNAL] = "external",
[PSTORE_STORAGE_JOURNAL] = "journal",
};
DEFINE_PRIVATE_STRING_TABLE_LOOKUP(pstore_storage, PStoreStorage);
static DEFINE_CONFIG_PARSE_ENUM(config_parse_pstore_storage, pstore_storage, PStoreStorage, "Failed to parse storage setting");
static PStoreStorage arg_storage = PSTORE_STORAGE_EXTERNAL;
static bool arg_unlink = true;
static const char *arg_sourcedir = "/sys/fs/pstore";
static const char *arg_archivedir = "/var/lib/systemd/pstore";
static int parse_config(void) {
static const ConfigTableItem items[] = {
{ "PStore", "Unlink", config_parse_bool, 0, &arg_unlink },
{ "PStore", "Storage", config_parse_pstore_storage, 0, &arg_storage },
{}
};
return config_parse_many_nulstr(PKGSYSCONFDIR "/pstore.conf",
CONF_PATHS_NULSTR("systemd/pstore.conf.d"),
"PStore\0",
config_item_table_lookup, items,
CONFIG_PARSE_WARN, NULL);
}
/* File list handling - PStoreEntry is the struct and
* and PStoreEntry is the type that contains all info
* about a pstore entry. */
typedef struct PStoreEntry {
struct dirent dirent;
bool is_binary;
bool handled;
char *content;
size_t content_size;
} PStoreEntry;
typedef struct PStoreList {
PStoreEntry *entries;
size_t n_entries;
size_t n_entries_allocated;
} PStoreList;
static void pstore_entries_reset(PStoreList *list) {
for (size_t i = 0; i < list->n_entries; i++)
free(list->entries[i].content);
free(list->entries);
list->n_entries = 0;
}
static int compare_pstore_entries(const void *_a, const void *_b) {
PStoreEntry *a = (PStoreEntry *)_a, *b = (PStoreEntry *)_b;
return strcmp(a->dirent.d_name, b->dirent.d_name);
}
static int move_file(PStoreEntry *pe, const char *subdir) {
_cleanup_free_ char *ifd_path = NULL, *ofd_path = NULL;
_cleanup_free_ void *field = NULL;
const char *suffix, *message;
struct iovec iovec[2];
int n_iovec = 0, r;
if (pe->handled)
return 0;
ifd_path = path_join(arg_sourcedir, pe->dirent.d_name);
if (!ifd_path)
return log_oom();
ofd_path = path_join(arg_archivedir, subdir, pe->dirent.d_name);
if (!ofd_path)
return log_oom();
/* Always log to the journal */
suffix = arg_storage == PSTORE_STORAGE_EXTERNAL ? strjoina(" moved to ", ofd_path) : (char *)".";
message = strjoina("MESSAGE=PStore ", pe->dirent.d_name, suffix);
iovec[n_iovec++] = IOVEC_MAKE_STRING(message);
if (pe->content_size > 0) {
size_t field_size;
field_size = strlen("FILE=") + pe->content_size;
field = malloc(field_size);
if (!field)
return log_oom();
memcpy(stpcpy(field, "FILE="), pe->content, pe->content_size);
iovec[n_iovec++] = IOVEC_MAKE(field, field_size);
}
r = sd_journal_sendv(iovec, n_iovec);
if (r < 0)
return log_error_errno(r, "Failed to log pstore entry: %m");
if (arg_storage == PSTORE_STORAGE_EXTERNAL) {
/* Move file from pstore to external storage */
r = mkdir_parents(ofd_path, 0755);
if (r < 0)
return log_error_errno(r, "Failed to create directory %s: %m", ofd_path);
r = copy_file_atomic(ifd_path, ofd_path, 0600, 0, 0, COPY_REPLACE);
if (r < 0)
return log_error_errno(r, "Failed to copy_file_atomic: %s to %s", ifd_path, ofd_path);
}
/* If file copied properly, remove it from pstore */
if (arg_unlink)
(void) unlink(ifd_path);
pe->handled = true;
return 0;
}
static int write_dmesg(const char *dmesg, size_t size, const char *id) {
_cleanup_(unlink_and_freep) char *tmp_path = NULL;
_cleanup_free_ char *ofd_path = NULL;
_cleanup_close_ int ofd = -1;
ssize_t wr;
int r;
if (isempty(dmesg) || size == 0)
return 0;
ofd_path = path_join(arg_archivedir, id, "dmesg.txt");
if (!ofd_path)
return log_oom();
ofd = open_tmpfile_linkable(ofd_path, O_CLOEXEC|O_CREAT|O_TRUNC|O_WRONLY, &tmp_path);
if (ofd < 0)
return log_error_errno(ofd, "Failed to open temporary file %s: %m", ofd_path);
wr = write(ofd, dmesg, size);
if (wr < 0)
return log_error_errno(errno, "Failed to store dmesg to %s: %m", ofd_path);
if (wr != (ssize_t)size)
return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to store dmesg to %s. %zu bytes are lost.", ofd_path, size - wr);
r = link_tmpfile(ofd, tmp_path, ofd_path);
if (r < 0)
return log_error_errno(r, "Failed to write temporary file %s: %m", ofd_path);
tmp_path = mfree(tmp_path);
return 0;
}
static void process_dmesg_files(PStoreList *list) {
/* Move files, reconstruct dmesg.txt */
_cleanup_free_ char *dmesg = NULL, *dmesg_id = NULL;
size_t dmesg_size = 0;
PStoreEntry *pe;
/* Handle each dmesg file: files processed in reverse
* order so as to properly reconstruct original dmesg */
for (size_t n = list->n_entries; n > 0; n--) {
bool move_file_and_continue = false;
_cleanup_free_ char *pe_id = NULL;
char *p;
size_t plen;
pe = &list->entries[n-1];
if (pe->handled)
continue;
if (!startswith(pe->dirent.d_name, "dmesg-"))
continue;
if (endswith(pe->dirent.d_name, ".enc.z")) /* indicates a problem */
move_file_and_continue = true;
p = strrchr(pe->dirent.d_name, '-');
if (!p)
move_file_and_continue = true;
if (move_file_and_continue) {
/* A dmesg file on which we do NO additional processing */
(void) move_file(pe, NULL);
continue;
}
/* See if this file is one of a related group of files
* in order to reconstruct dmesg */
/* When dmesg is written into pstore, it is done so in
* small chunks, whatever the exchange buffer size is
* with the underlying pstore backend (ie. EFI may be
* ~2KiB), which means an example pstore with approximately
* 64KB of storage may have up to roughly 32 dmesg files
* that could be related, depending upon the size of the
* original dmesg.
*
* Here we look at the dmesg filename and try to discern
* if files are part of a related group, meaning the same
* original dmesg.
*
* The two known pstore backends are EFI and ERST. These
* backends store data in the Common Platform Error
* Record, CPER, format. The dmesg- filename contains the
* CPER record id, a 64bit number (in decimal notation).
* In Linux, the record id is encoded with two digits for
* the dmesg part (chunk) number and 3 digits for the
* count number. So allowing an additional digit to
* compensate for advancing time, this code ignores the
* last six digits of the filename in determining the
* record id.
*
* For the EFI backend, the record id encodes an id in the
* upper 32 bits, and a timestamp in the lower 32-bits.
* So ignoring the least significant 6 digits has proven
* to generally identify related dmesg entries. */
#define PSTORE_FILENAME_IGNORE 6
/* determine common portion of record id */
++p; /* move beyond dmesg- */
plen = strlen(p);
if (plen > PSTORE_FILENAME_IGNORE) {
pe_id = memdup_suffix0(p, plen - PSTORE_FILENAME_IGNORE);
if (!pe_id) {
log_oom();
return;
}
} else
pe_id = mfree(pe_id);
/* Now move file from pstore to archive storage */
move_file(pe, pe_id);
/* If the current record id is NOT the same as the
* previous record id, then start a new dmesg.txt file */
if (!pe_id || !dmesg_id || !streq(pe_id, dmesg_id)) {
/* Encountered a new dmesg group, close out old one, open new one */
if (dmesg) {
(void) write_dmesg(dmesg, dmesg_size, dmesg_id);
dmesg = mfree(dmesg);
dmesg_size = 0;
}
/* now point dmesg_id to storage of pe_id */
free_and_replace(dmesg_id, pe_id);
}
/* Reconstruction of dmesg is done as a useful courtesy, do not log errors */
dmesg = realloc(dmesg, dmesg_size + strlen(pe->dirent.d_name) + strlen(":\n") + pe->content_size + 1);
if (dmesg) {
dmesg_size += sprintf(&dmesg[dmesg_size], "%s:\n", pe->dirent.d_name);
if (pe->content) {
memcpy(&dmesg[dmesg_size], pe->content, pe->content_size);
dmesg_size += pe->content_size;
}
}
pe_id = mfree(pe_id);
}
if (dmesg)
(void) write_dmesg(dmesg, dmesg_size, dmesg_id);
}
static int list_files(PStoreList *list, const char *sourcepath) {
_cleanup_(closedirp) DIR *dirp = NULL;
struct dirent *de;
int r;
dirp = opendir(sourcepath);
if (!dirp)
return log_error_errno(errno, "Failed to opendir %s: %m", sourcepath);
FOREACH_DIRENT(de, dirp, return log_error_errno(errno, "Failed to iterate through %s: %m", sourcepath)) {
_cleanup_free_ char *ifd_path = NULL;
ifd_path = path_join(sourcepath, de->d_name);
if (!ifd_path)
return log_oom();
_cleanup_free_ char *buf = NULL;
size_t buf_size;
/* Now read contents of pstore file */
r = read_full_file(ifd_path, &buf, &buf_size);
if (r < 0) {
log_warning_errno(r, "Failed to read file %s, skipping: %m", ifd_path);
continue;
}
if (!GREEDY_REALLOC(list->entries, list->n_entries_allocated, list->n_entries + 1))
return log_oom();
list->entries[list->n_entries++] = (PStoreEntry) {
.dirent = *de,
.content = TAKE_PTR(buf),
.content_size = buf_size,
.is_binary = true,
.handled = false,
};
}
return 0;
}
static int run(int argc, char *argv[]) {
_cleanup_(pstore_entries_reset) PStoreList list = {};
int r;
log_setup_service();
if (argc > 1)
return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
"This program takes no arguments.");
/* Ignore all parse errors */
(void) parse_config();
log_debug("Selected storage '%s'.", pstore_storage_to_string(arg_storage));
log_debug("Selected Unlink '%d'.", arg_unlink);
if (arg_storage == PSTORE_STORAGE_NONE)
/* Do nothing, intentionally, leaving pstore untouched */
return 0;
/* Obtain list of files in pstore */
r = list_files(&list, arg_sourcedir);
if (r < 0)
return r;
/* Handle each pstore file */
/* Sort files lexigraphically ascending, generally needed by all */
qsort_safe(list.entries, list.n_entries, sizeof(PStoreEntry), compare_pstore_entries);
/* Process known file types */
process_dmesg_files(&list);
/* Move left over files out of pstore */
for (size_t n = 0; n < list.n_entries; n++)
move_file(&list.entries[n], NULL);
return 0;
}
DEFINE_MAIN_FUNCTION(run);