Line data    Source code

       1             : /* SPDX-License-Identifier: LGPL-2.1+ */
       2             : 
       3             : #include <fcntl.h>
       4             : #include <sys/socket.h>
       5             : #include <time.h>
       6             : 
       7             : #include "alloc-util.h"
       8             : #include "fd-util.h"
       9             : #include "fileio.h"
      10             : #include "format-util.h"
      11             : #include "io-util.h"
      12             : #include "journald-console.h"
      13             : #include "journald-server.h"
      14             : #include "parse-util.h"
      15             : #include "process-util.h"
      16             : #include "stdio-util.h"
      17             : #include "terminal-util.h"
      18             : 
      19           0 : static bool prefix_timestamp(void) {
      20             : 
      21             :         static int cached_printk_time = -1;
      22             : 
      23           0 :         if (_unlikely_(cached_printk_time < 0)) {
      24           0 :                 _cleanup_free_ char *p = NULL;
      25             : 
      26           0 :                 cached_printk_time =
      27           0 :                         read_one_line_file("/sys/module/printk/parameters/time", &p) >= 0
      28           0 :                         && parse_boolean(p) > 0;
      29             :         }
      30             : 
      31           0 :         return cached_printk_time;
      32             : }
      33             : 
      34           0 : void server_forward_console(
      35             :                 Server *s,
      36             :                 int priority,
      37             :                 const char *identifier,
      38             :                 const char *message,
      39             :                 const struct ucred *ucred) {
      40             : 
      41             :         struct iovec iovec[5];
      42             :         struct timespec ts;
      43             :         char tbuf[STRLEN("[] ") + DECIMAL_STR_MAX(ts.tv_sec) + DECIMAL_STR_MAX(ts.tv_nsec)-3 + 1];
      44             :         char header_pid[STRLEN("[]: ") + DECIMAL_STR_MAX(pid_t)];
      45           0 :         _cleanup_free_ char *ident_buf = NULL;
      46           0 :         _cleanup_close_ int fd = -1;
      47             :         const char *tty;
      48           0 :         int n = 0;
      49             : 
      50           0 :         assert(s);
      51           0 :         assert(message);
      52             : 
      53           0 :         if (LOG_PRI(priority) > s->max_level_console)
      54           0 :                 return;
      55             : 
      56             :         /* First: timestamp */
      57           0 :         if (prefix_timestamp()) {
      58           0 :                 assert_se(clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
      59           0 :                 xsprintf(tbuf, "[%5"PRI_TIME".%06"PRI_NSEC"] ",
      60             :                          ts.tv_sec,
      61             :                          (nsec_t)ts.tv_nsec / 1000);
      62             : 
      63           0 :                 iovec[n++] = IOVEC_MAKE_STRING(tbuf);
      64             :         }
      65             : 
      66             :         /* Second: identifier and PID */
      67           0 :         if (ucred) {
      68           0 :                 if (!identifier) {
      69           0 :                         get_process_comm(ucred->pid, &ident_buf);
      70           0 :                         identifier = ident_buf;
      71             :                 }
      72             : 
      73           0 :                 xsprintf(header_pid, "["PID_FMT"]: ", ucred->pid);
      74             : 
      75           0 :                 if (identifier)
      76           0 :                         iovec[n++] = IOVEC_MAKE_STRING(identifier);
      77             : 
      78           0 :                 iovec[n++] = IOVEC_MAKE_STRING(header_pid);
      79           0 :         } else if (identifier) {
      80           0 :                 iovec[n++] = IOVEC_MAKE_STRING(identifier);
      81           0 :                 iovec[n++] = IOVEC_MAKE_STRING(": ");
      82             :         }
      83             : 
      84             :         /* Fourth: message */
      85           0 :         iovec[n++] = IOVEC_MAKE_STRING(message);
      86           0 :         iovec[n++] = IOVEC_MAKE_STRING("\n");
      87             : 
      88           0 :         tty = s->tty_path ?: "/dev/console";
      89             : 
      90             :         /* Before you ask: yes, on purpose we open/close the console for each log line we write individually. This is a
      91             :          * good strategy to avoid journald getting killed by the kernel's SAK concept (it doesn't fix this entirely,
      92             :          * but minimizes the time window the kernel might end up killing journald due to SAK). It also makes things
      93             :          * easier for us so that we don't have to recover from hangups and suchlike triggered on the console. */
      94             : 
      95           0 :         fd = open_terminal(tty, O_WRONLY|O_NOCTTY|O_CLOEXEC);
      96           0 :         if (fd < 0) {
      97           0 :                 log_debug_errno(fd, "Failed to open %s for logging: %m", tty);
      98           0 :                 return;
      99             :         }
     100             : 
     101           0 :         if (writev(fd, iovec, n) < 0)
     102           0 :                 log_debug_errno(errno, "Failed to write to %s for logging: %m", tty);
     103             : }