Merging upstream version 256.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 477 insertions, 0 deletions

diff --git a/src/journal/journalctl-show.c b/src/journal/journalctl-show.c
new file mode 100644
index 0000000..e8ffc72
--- /dev/null
+++ b/src/journal/journalctl-show.c
@@ -0,0 +1,477 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <unistd.h>
+
+#include "sd-event.h"
+
+#include "fileio.h"
+#include "journalctl.h"
+#include "journalctl-filter.h"
+#include "journalctl-show.h"
+#include "journalctl-util.h"
+#include "logs-show.h"
+#include "terminal-util.h"
+
+#define PROCESS_INOTIFY_INTERVAL 1024   /* Every 1024 messages processed */
+
+typedef struct Context {
+        sd_journal *journal;
+        bool has_cursor;
+        bool need_seek;
+        bool since_seeked;
+        bool ellipsized;
+        bool previous_boot_id_valid;
+        sd_id128_t previous_boot_id;
+        sd_id128_t previous_boot_id_output;
+        dual_timestamp previous_ts_output;
+} Context;
+
+static void context_done(Context *c) {
+        assert(c);
+
+        sd_journal_close(c->journal);
+}
+
+static int seek_journal(Context *c) {
+        sd_journal *j = ASSERT_PTR(ASSERT_PTR(c)->journal);
+        _cleanup_free_ char *cursor_from_file = NULL;
+        const char *cursor = NULL;
+        bool after_cursor = false;
+        int r;
+
+        if (arg_cursor || arg_after_cursor) {
+                assert(!!arg_cursor != !!arg_after_cursor);
+
+                cursor = arg_cursor ?: arg_after_cursor;
+                after_cursor = arg_after_cursor;
+
+        } else if (arg_cursor_file) {
+                r = read_one_line_file(arg_cursor_file, &cursor_from_file);
+                if (r < 0 && r != -ENOENT)
+                        return log_error_errno(r, "Failed to read cursor file %s: %m", arg_cursor_file);
+                if (r > 0) {
+                        cursor = cursor_from_file;
+                        after_cursor = true;
+                }
+        }
+
+        if (cursor) {
+                c->has_cursor = true;
+
+                r = sd_journal_seek_cursor(j, cursor);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to seek to cursor: %m");
+
+                r = sd_journal_step_one(j, !arg_reverse);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to iterate through journal: %m");
+
+                if (after_cursor && r > 0) {
+                        /* With --after-cursor=/--cursor-file= we want to skip the first entry only if it's
+                         * the entry the cursor is pointing at, otherwise, if some journal filters are used,
+                         * we might skip the first entry of the filter match, which leads to unexpectedly
+                         * missing journal entries. */
+                        int k;
+
+                        k = sd_journal_test_cursor(j, cursor);
+                        if (k < 0)
+                                return log_error_errno(k, "Failed to test cursor against current entry: %m");
+                        if (k > 0)
+                                /* Current entry matches the one our cursor is pointing at, so let's try
+                                 * to advance the next entry. */
+                                r = sd_journal_step_one(j, !arg_reverse);
+                }
+
+                if (r == 0 && !arg_follow)
+                        /* We couldn't find the next entry after the cursor. */
+                        arg_lines = 0;
+
+        } else if (arg_reverse || arg_lines_needs_seek_end()) {
+                /* If --reverse and/or --lines=N are specified, things get a little tricky. First we seek to
+                 * the place of --until if specified, otherwise seek to tail. Then, if --reverse is
+                 * specified, we search backwards and let the output counter in show() handle --lines for us.
+                 * If --reverse is unspecified, we just jump backwards arg_lines and search afterwards from
+                 * there. */
+
+                if (arg_until_set) {
+                        r = sd_journal_seek_realtime_usec(j, arg_until);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to seek to date: %m");
+                } else {
+                        r = sd_journal_seek_tail(j);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to seek to tail: %m");
+                }
+
+                if (arg_reverse)
+                        r = sd_journal_previous(j);
+                else /* arg_lines_needs_seek_end */
+                        r = sd_journal_previous_skip(j, arg_lines);
+
+        } else if (arg_since_set) {
+                /* This is placed after arg_reverse and arg_lines. If --since is used without
+                 * both, we seek to the place of --since and search afterwards from there.
+                 * If used with --reverse or --lines, we seek to the tail first and check if
+                 * the entry is within the range of --since later. */
+
+                r = sd_journal_seek_realtime_usec(j, arg_since);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to seek to date: %m");
+                c->since_seeked = true;
+
+                r = sd_journal_next(j);
+
+        } else {
+                r = sd_journal_seek_head(j);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to seek to head: %m");
+
+                r = sd_journal_next(j);
+        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to iterate through journal: %m");
+        if (r == 0)
+                c->need_seek = true;
+
+        return 0;
+}
+
+static int show(Context *c) {
+        sd_journal *j = ASSERT_PTR(ASSERT_PTR(c)->journal);
+        int r, n_shown = 0;
+
+        OutputFlags flags =
+                arg_all * OUTPUT_SHOW_ALL |
+                arg_full * OUTPUT_FULL_WIDTH |
+                colors_enabled() * OUTPUT_COLOR |
+                arg_catalog * OUTPUT_CATALOG |
+                arg_utc * OUTPUT_UTC |
+                arg_truncate_newline * OUTPUT_TRUNCATE_NEWLINE |
+                arg_no_hostname * OUTPUT_NO_HOSTNAME;
+
+        while (arg_lines < 0 || n_shown < arg_lines || arg_follow) {
+                size_t highlight[2] = {};
+
+                if (c->need_seek) {
+                        r = sd_journal_step_one(j, !arg_reverse);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to iterate through journal: %m");
+                        if (r == 0)
+                                break;
+                }
+
+                if (arg_until_set && !arg_reverse && (arg_lines < 0 || arg_since_set || c->has_cursor)) {
+                        /* If --lines= is set, we usually rely on the n_shown to tell us when to stop.
+                         * However, if --since= or one of the cursor argument is set too, we may end up
+                         * having less than --lines= to output. In this case let's also check if the entry
+                         * is in range. */
+
+                        usec_t usec;
+
+                        r = sd_journal_get_realtime_usec(j, &usec);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to determine timestamp: %m");
+                        if (usec > arg_until)
+                                break;
+                }
+
+                if (arg_since_set && (arg_reverse || !c->since_seeked)) {
+                        usec_t usec;
+
+                        r = sd_journal_get_realtime_usec(j, &usec);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to determine timestamp: %m");
+
+                        if (usec < arg_since) {
+                                if (arg_reverse)
+                                        break; /* Reached the earliest entry */
+
+                                /* arg_lines >= 0 (!since_seeked):
+                                 * We jumped arg_lines back and it seems to be too much */
+                                r = sd_journal_seek_realtime_usec(j, arg_since);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to seek to date: %m");
+                                c->since_seeked = true;
+
+                                c->need_seek = true;
+                                continue;
+                        }
+                        c->since_seeked = true; /* We're surely within the range of --since now */
+                }
+
+                if (!arg_merge && !arg_quiet) {
+                        sd_id128_t boot_id;
+
+                        r = sd_journal_get_monotonic_usec(j, NULL, &boot_id);
+                        if (r >= 0) {
+                                if (c->previous_boot_id_valid &&
+                                    !sd_id128_equal(boot_id, c->previous_boot_id))
+                                        printf("%s-- Boot "SD_ID128_FORMAT_STR" --%s\n",
+                                               ansi_highlight(), SD_ID128_FORMAT_VAL(boot_id), ansi_normal());
+
+                                c->previous_boot_id = boot_id;
+                                c->previous_boot_id_valid = true;
+                        }
+                }
+
+                if (arg_compiled_pattern) {
+                        const void *message;
+                        size_t len;
+
+                        r = sd_journal_get_data(j, "MESSAGE", &message, &len);
+                        if (r < 0) {
+                                if (r == -ENOENT) {
+                                        c->need_seek = true;
+                                        continue;
+                                }
+
+                                return log_error_errno(r, "Failed to get MESSAGE field: %m");
+                        }
+
+                        assert_se(message = startswith(message, "MESSAGE="));
+
+                        r = pattern_matches_and_log(arg_compiled_pattern, message,
+                                                    len - strlen("MESSAGE="), highlight);
+                        if (r < 0)
+                                return r;
+                        if (r == 0) {
+                                c->need_seek = true;
+                                continue;
+                        }
+                }
+
+                r = show_journal_entry(stdout, j, arg_output, 0, flags,
+                                       arg_output_fields, highlight, &c->ellipsized,
+                                       &c->previous_ts_output, &c->previous_boot_id_output);
+                c->need_seek = true;
+                if (r == -EADDRNOTAVAIL)
+                        break;
+                if (r < 0)
+                        return r;
+
+                n_shown++;
+
+                /* If journalctl take a long time to process messages, and during that time journal file
+                 * rotation occurs, a journalctl client will keep those rotated files open until it calls
+                 * sd_journal_process(), which typically happens as a result of calling sd_journal_wait() below
+                 * in the "following" case.  By periodically calling sd_journal_process() during the processing
+                 * loop we shrink the window of time a client instance has open file descriptors for rotated
+                 * (deleted) journal files. */
+                if ((n_shown % PROCESS_INOTIFY_INTERVAL) == 0) {
+                        r = sd_journal_process(j);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to process inotify events: %m");
+                }
+        }
+
+        return n_shown;
+}
+
+static int show_and_fflush(Context *c, sd_event_source *s) {
+        int r;
+
+        assert(c);
+        assert(s);
+
+        r = show(c);
+        if (r < 0)
+                return sd_event_exit(sd_event_source_get_event(s), r);
+
+        fflush(stdout);
+        return 0;
+}
+
+static int on_journal_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Context *c = ASSERT_PTR(userdata);
+        int r;
+
+        assert(s);
+
+        r = sd_journal_process(c->journal);
+        if (r < 0) {
+                log_error_errno(r, "Failed to process journal events: %m");
+                return sd_event_exit(sd_event_source_get_event(s), r);
+        }
+
+        return show_and_fflush(c, s);
+}
+
+static int on_first_event(sd_event_source *s, void *userdata) {
+        return show_and_fflush(userdata, s);
+}
+
+static int on_signal(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        assert(s);
+        assert(si);
+        assert(IN_SET(si->ssi_signo, SIGTERM, SIGINT));
+
+        return sd_event_exit(sd_event_source_get_event(s), si->ssi_signo);
+}
+
+static int setup_event(Context *c, int fd, sd_event **ret) {
+        _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+        int r;
+
+        assert(arg_follow);
+        assert(c);
+        assert(fd >= 0);
+        assert(ret);
+
+        r = sd_event_default(&e);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate sd_event object: %m");
+
+        (void) sd_event_add_signal(e, NULL, SIGTERM | SD_EVENT_SIGNAL_PROCMASK, on_signal, NULL);
+        (void) sd_event_add_signal(e, NULL, SIGINT | SD_EVENT_SIGNAL_PROCMASK, on_signal, NULL);
+
+        r = sd_event_add_io(e, NULL, fd, EPOLLIN, &on_journal_event, c);
+        if (r < 0)
+                return log_error_errno(r, "Failed to add io event source for journal: %m");
+
+        /* Also keeps an eye on STDOUT, and exits as soon as we see a POLLHUP on that, i.e. when it is closed. */
+        r = sd_event_add_io(e, NULL, STDOUT_FILENO, EPOLLHUP|EPOLLERR, NULL, INT_TO_PTR(-ECANCELED));
+        if (r == -EPERM)
+                /* Installing an epoll watch on a regular file doesn't work and fails with EPERM. Which is
+                 * totally OK, handle it gracefully. epoll_ctl() documents EPERM as the error returned when
+                 * the specified fd doesn't support epoll, hence it's safe to check for that. */
+                log_debug_errno(r, "Unable to install EPOLLHUP watch on stderr, not watching for hangups.");
+        else if (r < 0)
+                return log_error_errno(r, "Failed to add io event source for stdout: %m");
+
+        if (arg_lines != 0 || arg_since_set) {
+                r = sd_event_add_defer(e, NULL, on_first_event, c);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add defer event source: %m");
+        }
+
+        *ret = TAKE_PTR(e);
+        return 0;
+}
+
+static int update_cursor(sd_journal *j) {
+        _cleanup_free_ char *cursor = NULL;
+        int r;
+
+        assert(j);
+
+        if (!arg_show_cursor && !arg_cursor_file)
+                return 0;
+
+        r = sd_journal_get_cursor(j, &cursor);
+        if (r == -EADDRNOTAVAIL)
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to get cursor: %m");
+
+        if (arg_show_cursor)
+                printf("-- cursor: %s\n", cursor);
+
+        if (arg_cursor_file) {
+                r = write_string_file(arg_cursor_file, cursor, WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_ATOMIC);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to write new cursor to %s: %m", arg_cursor_file);
+        }
+
+        return 0;
+}
+
+int action_show(char **matches) {
+        _cleanup_(context_done) Context c = {};
+        int n_shown, r, poll_fd = -EBADF;
+
+        assert(arg_action == ACTION_SHOW);
+
+        (void) signal(SIGWINCH, columns_lines_cache_reset);
+
+        r = acquire_journal(&c.journal);
+        if (r < 0)
+                return r;
+
+        if (!journal_boot_has_effect(c.journal))
+                return arg_compiled_pattern ? -ENOENT : 0;
+
+        r = add_filters(c.journal, matches);
+        if (r < 0)
+                return r;
+
+        r = seek_journal(&c);
+        if (r < 0)
+                return r;
+
+        /* Opening the fd now means the first sd_journal_wait() will actually wait */
+        if (arg_follow) {
+                poll_fd = sd_journal_get_fd(c.journal);
+                if (poll_fd == -EMFILE) {
+                        log_warning_errno(poll_fd, "Insufficient watch descriptors available. Reverting to -n.");
+                        arg_follow = false;
+                } else if (poll_fd == -EMEDIUMTYPE)
+                        return log_error_errno(poll_fd, "The --follow switch is not supported in conjunction with reading from STDIN.");
+                else if (poll_fd < 0)
+                        return log_error_errno(poll_fd, "Failed to get journal fd: %m");
+        }
+
+        if (!arg_follow)
+                pager_open(arg_pager_flags);
+
+        if (!arg_quiet && (arg_lines != 0 || arg_follow) && DEBUG_LOGGING) {
+                usec_t start, end;
+                char start_buf[FORMAT_TIMESTAMP_MAX], end_buf[FORMAT_TIMESTAMP_MAX];
+
+                r = sd_journal_get_cutoff_realtime_usec(c.journal, &start, &end);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to get cutoff: %m");
+                if (r > 0) {
+                        if (arg_follow)
+                                printf("-- Journal begins at %s. --\n",
+                                       format_timestamp_maybe_utc(start_buf, sizeof(start_buf), start));
+                        else
+                                printf("-- Journal begins at %s, ends at %s. --\n",
+                                       format_timestamp_maybe_utc(start_buf, sizeof(start_buf), start),
+                                       format_timestamp_maybe_utc(end_buf, sizeof(end_buf), end));
+                }
+        }
+
+        if (arg_follow) {
+                _cleanup_(sd_event_unrefp) sd_event *e = NULL;
+                int sig;
+
+                assert(poll_fd >= 0);
+
+                r = setup_event(&c, poll_fd, &e);
+                if (r < 0)
+                        return r;
+
+                r = sd_event_loop(e);
+                if (r < 0)
+                        return r;
+                sig = r;
+
+                r = update_cursor(c.journal);
+                if (r < 0)
+                        return r;
+
+                /* re-send the original signal. */
+                return sig;
+        }
+
+        r = show(&c);
+        if (r < 0)
+                return r;
+        n_shown = r;
+
+        if (n_shown == 0 && !arg_quiet)
+                printf("-- No entries --\n");
+
+        r = update_cursor(c.journal);
+        if (r < 0)
+                return r;
+
+        if (arg_compiled_pattern && n_shown == 0)
+                /* --grep was used, no error was thrown, but the pattern didn't
+                 * match anything. Let's mimic grep's behavior here and return
+                 * a non-zero exit code, so journalctl --grep can be used
+                 * in scripts and such */
+                return -ENOENT;
+
+        return 0;
+}