diff options
Diffstat (limited to 'src/journal/bsod.c')
| -rw-r--r-- | src/journal/bsod.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/src/journal/bsod.c b/src/journal/bsod.c new file mode 100644 index 0000000..a88cb66 --- /dev/null +++ b/src/journal/bsod.c @@ -0,0 +1,311 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <getopt.h> +#include <linux/vt.h> +#include <stdio.h> +#include <sys/ioctl.h> + +#include "sd-id128.h" +#include "sd-journal.h" + +#include "alloc-util.h" +#include "build.h" +#include "fd-util.h" +#include "fileio.h" +#include "io-util.h" +#include "log.h" +#include "logs-show.h" +#include "main-func.h" +#include "pretty-print.h" +#include "qrcode-util.h" +#include "sigbus.h" +#include "signal-util.h" +#include "sysctl-util.h" +#include "terminal-util.h" + +static bool arg_continuous = false; + +static int help(void) { + _cleanup_free_ char *link = NULL; + int r; + + r = terminal_urlify_man("systemd-bsod", "8", &link); + if (r < 0) + return log_oom(); + + printf("%s\n\n" + "%sFilter the journal to fetch the first message from the\n" + "current boot with an emergency log level and displays it\n" + "as a string and a QR code.\n\n%s" + " -h --help Show this help\n" + " --version Show package version\n" + " -c --continuous Make systemd-bsod wait continuously\n" + " for changes in the journal\n" + "\nSee the %s for details.\n", + program_invocation_short_name, + ansi_highlight(), + ansi_normal(), + link); + + return 0; +} + +static int acquire_first_emergency_log_message(char **ret) { + _cleanup_(sd_journal_closep) sd_journal *j = NULL; + _cleanup_free_ char *message = NULL; + const void *d; + size_t l; + int r; + + assert(ret); + + r = sd_journal_open(&j, SD_JOURNAL_LOCAL_ONLY); + if (r < 0) + return log_error_errno(r, "Failed to open journal: %m"); + + r = add_match_this_boot(j, NULL); + if (r < 0) + return log_warning_errno(r, "Failed to add boot ID filter: %m"); + + r = sd_journal_add_match(j, "_UID=0", 0); + if (r < 0) + return log_warning_errno(r, "Failed to add User ID filter: %m"); + + assert_cc(0 == LOG_EMERG); + r = sd_journal_add_match(j, "PRIORITY=0", 0); + if (r < 0) + return log_warning_errno(r, "Failed to add Emergency filter: %m"); + + r = sd_journal_seek_head(j); + if (r < 0) + return log_error_errno(r, "Failed to seek to start of journal: %m"); + + for (;;) { + r = sd_journal_next(j); + if (r < 0) + return log_error_errno(r, "Failed to read next journal entry: %m"); + if (r > 0) + break; + + if (!arg_continuous) { + log_debug("No emergency level entries in the journal"); + *ret = NULL; + return 0; + } + + r = sd_journal_wait(j, UINT64_MAX); + if (r < 0) + return log_error_errno(r, "Failed to wait for changes: %m"); + } + + r = sd_journal_get_data(j, "MESSAGE", &d, &l); + if (r < 0) + return log_error_errno(r, "Failed to read journal message: %m"); + + message = memdup_suffix0((const char*)d + STRLEN("MESSAGE="), l - STRLEN("MESSAGE=")); + if (!message) + return log_oom(); + + *ret = TAKE_PTR(message); + + return 0; +} + +static int find_next_free_vt(int fd, int *ret_free_vt, int *ret_original_vt) { + struct vt_stat terminal_status; + + assert(fd >= 0); + assert(ret_free_vt); + assert(ret_original_vt); + + if (ioctl(fd, VT_GETSTATE, &terminal_status) < 0) + return -errno; + + for (size_t i = 0; i < sizeof(terminal_status.v_state) * 8; i++) + if ((terminal_status.v_state & (1 << i)) == 0) { + *ret_free_vt = i; + *ret_original_vt = terminal_status.v_active; + return 0; + } + + return log_error_errno(SYNTHETIC_ERRNO(ENOTTY), "No free VT found: %m"); +} + +static int display_emergency_message_fullscreen(const char *message) { + int r, ret = 0, free_vt = 0, original_vt = 0; + unsigned qr_code_start_row = 1, qr_code_start_column = 1; + char tty[STRLEN("/dev/tty") + DECIMAL_STR_MAX(int) + 1]; + _cleanup_close_ int fd = -EBADF; + _cleanup_fclose_ FILE *stream = NULL; + char read_character_buffer = '\0'; + struct winsize w = { + .ws_col = 80, + .ws_row = 25, + }; + + assert(message); + + fd = open_terminal("/dev/tty1", O_RDWR|O_NOCTTY|O_CLOEXEC); + if (fd < 0) + return log_error_errno(fd, "Failed to open tty1: %m"); + + r = find_next_free_vt(fd, &free_vt, &original_vt); + if (r < 0) + return log_error_errno(r, "Failed to find a free VT: %m"); + + xsprintf(tty, "/dev/tty%d", free_vt + 1); + + r = open_terminal(tty, O_RDWR|O_NOCTTY|O_CLOEXEC); + if (r < 0) + return log_error_errno(fd, "Failed to open tty: %m"); + + close_and_replace(fd, r); + + if (ioctl(fd, TIOCGWINSZ, &w) < 0) + log_warning_errno(errno, "Failed to fetch tty size, ignoring: %m"); + + if (ioctl(fd, VT_ACTIVATE, free_vt + 1) < 0) + return log_error_errno(errno, "Failed to activate tty: %m"); + + r = loop_write(fd, ANSI_BACKGROUND_BLUE ANSI_HOME_CLEAR, SIZE_MAX); + if (r < 0) + log_warning_errno(r, "Failed to clear terminal, ignoring: %m"); + + r = set_terminal_cursor_position(fd, 2, 4); + if (r < 0) + log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m"); + + r = loop_write(fd, "The current boot has failed!", SIZE_MAX); + if (r < 0) { + ret = log_warning_errno(r, "Failed to write to terminal: %m"); + goto cleanup; + } + + qr_code_start_row = w.ws_row * 3U / 5U; + qr_code_start_column = w.ws_col * 3U / 4U; + r = set_terminal_cursor_position(fd, 4, 4); + if (r < 0) + log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m"); + + r = loop_write(fd, message, SIZE_MAX); + if (r < 0) { + ret = log_warning_errno(r, "Failed to write emergency message to terminal: %m"); + goto cleanup; + } + + r = fdopen_independent(fd, "r+", &stream); + if (r < 0) { + ret = log_error_errno(errno, "Failed to open output file: %m"); + goto cleanup; + } + + r = print_qrcode_full(stream, "Scan the QR code", message, qr_code_start_row, qr_code_start_column, w.ws_col, w.ws_row); + if (r < 0) + log_warning_errno(r, "QR code could not be printed, ignoring: %m"); + + r = set_terminal_cursor_position(fd, w.ws_row - 1, w.ws_col * 2U / 5U); + if (r < 0) + log_warning_errno(r, "Failed to move terminal cursor position, ignoring: %m"); + + r = loop_write(fd, "Press any key to exit...", SIZE_MAX); + if (r < 0) { + ret = log_warning_errno(r, "Failed to write to terminal: %m"); + goto cleanup; + } + + r = read_one_char(stream, &read_character_buffer, USEC_INFINITY, NULL); + if (r < 0 && r != -EINTR) + ret = log_error_errno(r, "Failed to read character: %m"); + +cleanup: + if (ioctl(fd, VT_ACTIVATE, original_vt) < 0) + return log_error_errno(errno, "Failed to switch back to original VT: %m"); + + return ret; +} + +static int parse_argv(int argc, char * argv[]) { + + enum { + ARG_VERSION = 0x100, + }; + + static const struct option options[] = { + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, ARG_VERSION }, + { "continuous", no_argument, NULL, 'c' }, + {} + }; + + int c; + + assert(argc >= 0); + assert(argv); + + while ((c = getopt_long(argc, argv, "hc", options, NULL)) >= 0) + + switch (c) { + + case 'h': + return help(); + + case ARG_VERSION: + return version(); + + case 'c': + arg_continuous = true; + break; + + case '?': + return -EINVAL; + + default: + assert_not_reached(); + } + + if (optind < argc) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "%s takes no argument.", + program_invocation_short_name); + return 1; +} + +static int run(int argc, char *argv[]) { + /* Don't use SA_RESTART here, as we don't want to restart syscalls on signal + * to get out of read_one_char() when needed */ + static const struct sigaction nop_sigaction = { + .sa_handler = nop_signal_handler, + .sa_flags = 0, + }; + _cleanup_free_ char *message = NULL; + int r; + + log_open(); + log_parse_environment(); + + sigbus_install(); + + r = parse_argv(argc, argv); + if (r <= 0) + return r; + + r = acquire_first_emergency_log_message(&message); + if (r < 0) + return log_error_errno(r, "Failed to acquire first emergency log message: %m"); + + if (!message) { + log_debug("No emergency-level entries"); + return 0; + } + + assert_se(sigaction_many(&nop_sigaction, SIGTERM, SIGINT) >= 0); + + r = display_emergency_message_fullscreen((const char*) message); + if (r < 0) + return log_error_errno(r, "Failed to display emergency message on terminal: %m"); + + return 0; +} + +DEFINE_MAIN_FUNCTION(run); |