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-rw-r--r--src/journal/journald-console.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/src/journal/journald-console.c b/src/journal/journald-console.c
new file mode 100644
index 0000000..2035e2d
--- /dev/null
+++ b/src/journal/journald-console.c
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <time.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "io-util.h"
+#include "journald-console.h"
+#include "journald-server.h"
+#include "parse-util.h"
+#include "process-util.h"
+#include "stdio-util.h"
+#include "terminal-util.h"
+
+static bool prefix_timestamp(void) {
+
+ static int cached_printk_time = -1;
+
+ if (_unlikely_(cached_printk_time < 0)) {
+ _cleanup_free_ char *p = NULL;
+
+ cached_printk_time =
+ read_one_line_file("/sys/module/printk/parameters/time", &p) >= 0
+ && parse_boolean(p) > 0;
+ }
+
+ return cached_printk_time;
+}
+
+void server_forward_console(
+ Server *s,
+ int priority,
+ const char *identifier,
+ const char *message,
+ const struct ucred *ucred) {
+
+ struct iovec iovec[5];
+ struct timespec ts;
+ char tbuf[STRLEN("[] ") + DECIMAL_STR_MAX(ts.tv_sec) + DECIMAL_STR_MAX(ts.tv_nsec)-3 + 1];
+ char header_pid[STRLEN("[]: ") + DECIMAL_STR_MAX(pid_t)];
+ _cleanup_free_ char *ident_buf = NULL;
+ _cleanup_close_ int fd = -1;
+ const char *tty;
+ int n = 0;
+
+ assert(s);
+ assert(message);
+
+ if (LOG_PRI(priority) > s->max_level_console)
+ return;
+
+ /* First: timestamp */
+ if (prefix_timestamp()) {
+ assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
+ xsprintf(tbuf, "[%5"PRI_TIME".%06"PRI_NSEC"] ",
+ ts.tv_sec,
+ (nsec_t)ts.tv_nsec / 1000);
+
+ iovec[n++] = IOVEC_MAKE_STRING(tbuf);
+ }
+
+ /* Second: identifier and PID */
+ if (ucred) {
+ if (!identifier) {
+ (void) get_process_comm(ucred->pid, &ident_buf);
+ identifier = ident_buf;
+ }
+
+ xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid);
+
+ if (identifier)
+ iovec[n++] = IOVEC_MAKE_STRING(identifier);
+
+ iovec[n++] = IOVEC_MAKE_STRING(header_pid);
+ } else if (identifier) {
+ iovec[n++] = IOVEC_MAKE_STRING(identifier);
+ iovec[n++] = IOVEC_MAKE_STRING(": ");
+ }
+
+ /* Fourth: message */
+ iovec[n++] = IOVEC_MAKE_STRING(message);
+ iovec[n++] = IOVEC_MAKE_STRING("\n");
+
+ tty = s->tty_path ?: "/dev/console";
+
+ /* Before you ask: yes, on purpose we open/close the console for each log line we write individually. This is a
+ * good strategy to avoid journald getting killed by the kernel's SAK concept (it doesn't fix this entirely,
+ * but minimizes the time window the kernel might end up killing journald due to SAK). It also makes things
+ * easier for us so that we don't have to recover from hangups and suchlike triggered on the console. */
+
+ fd = open_terminal(tty, O_WRONLY|O_NOCTTY|O_CLOEXEC);
+ if (fd < 0) {
+ log_debug_errno(fd, "Failed to open %s for logging: %m", tty);
+ return;
+ }
+
+ if (writev(fd, iovec, n) < 0)
+ log_debug_errno(errno, "Failed to write to %s for logging: %m", tty);
+}