1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2011 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
23 #include <sys/epoll.h>
26 #include <sys/socket.h>
28 #include <systemd/sd-messages.h>
31 #include "journald-server.h"
32 #include "journald-kmsg.h"
33 #include "journald-syslog.h"
35 void server_forward_kmsg(
38 const char *identifier,
40 struct ucred *ucred) {
42 struct iovec iovec[5];
43 char header_priority[6], header_pid[16];
45 char *ident_buf = NULL;
48 assert(priority >= 0);
49 assert(priority <= 999);
52 if (_unlikely_(LOG_PRI(priority) > s->max_level_kmsg))
55 if (_unlikely_(s->dev_kmsg_fd < 0))
58 /* Never allow messages with kernel facility to be written to
59 * kmsg, regardless where the data comes from. */
60 priority = syslog_fixup_facility(priority);
62 /* First: priority field */
63 snprintf(header_priority, sizeof(header_priority), "<%i>", priority);
64 char_array_0(header_priority);
65 IOVEC_SET_STRING(iovec[n++], header_priority);
67 /* Second: identifier and PID */
70 get_process_comm(ucred->pid, &ident_buf);
71 identifier = ident_buf;
74 snprintf(header_pid, sizeof(header_pid), "[%lu]: ", (unsigned long) ucred->pid);
75 char_array_0(header_pid);
78 IOVEC_SET_STRING(iovec[n++], identifier);
80 IOVEC_SET_STRING(iovec[n++], header_pid);
81 } else if (identifier) {
82 IOVEC_SET_STRING(iovec[n++], identifier);
83 IOVEC_SET_STRING(iovec[n++], ": ");
87 IOVEC_SET_STRING(iovec[n++], message);
88 IOVEC_SET_STRING(iovec[n++], "\n");
90 if (writev(s->dev_kmsg_fd, iovec, n) < 0)
91 log_debug("Failed to write to /dev/kmsg for logging: %s", strerror(errno));
96 static bool is_us(const char *pid) {
101 if (parse_pid(pid, &t) < 0)
104 return t == getpid();
107 static void dev_kmsg_record(Server *s, char *p, size_t l) {
108 struct iovec iovec[N_IOVEC_META_FIELDS + 7 + N_IOVEC_KERNEL_FIELDS + 2 + N_IOVEC_UDEV_FIELDS];
109 char *message = NULL, *syslog_priority = NULL, *syslog_pid = NULL, *syslog_facility = NULL, *syslog_identifier = NULL, *source_time = NULL;
111 unsigned n = 0, z = 0, j;
112 unsigned long long usec;
113 char *identifier = NULL, *pid = NULL, *e, *f, *k;
116 char *kernel_device = NULL;
124 e = memchr(p, ',', l);
129 r = safe_atoi(p, &priority);
130 if (r < 0 || priority < 0 || priority > 999)
133 if (s->forward_to_kmsg && (priority & LOG_FACMASK) != LOG_KERN)
138 e = memchr(p, ',', l);
143 r = safe_atou64(p, &serial);
147 if (s->kernel_seqnum) {
148 /* We already read this one? */
149 if (serial < *s->kernel_seqnum)
152 /* Did we lose any? */
153 if (serial > *s->kernel_seqnum)
154 server_driver_message(s, SD_MESSAGE_JOURNAL_MISSED, "Missed %llu kernel messages", (unsigned long long) serial - *s->kernel_seqnum - 1);
156 /* Make sure we never read this one again. Note that
157 * we always store the next message serial we expect
158 * here, simply because this makes handling the first
159 * message with serial 0 easy. */
160 *s->kernel_seqnum = serial + 1;
165 f = memchr(p, ';', l);
168 /* Kernel 3.6 has the flags field, kernel 3.5 lacks that */
169 e = memchr(p, ',', l);
174 r = safe_atollu(p, &usec);
180 e = memchr(p, '\n', l);
189 for (j = 0; l > 0 && j < N_IOVEC_KERNEL_FIELDS; j++) {
191 /* Meta data fields attached */
198 e = memchr(k, '\n', l);
204 m = cunescape_length_with_prefix(k, e - k, "_KERNEL_");
208 if (startswith(m, "_KERNEL_DEVICE="))
209 kernel_device = m + 15;
211 IOVEC_SET_STRING(iovec[n++], m);
219 struct udev_device *ud;
221 ud = udev_device_new_from_device_id(s->udev, kernel_device);
224 struct udev_list_entry *ll;
227 g = udev_device_get_devnode(ud);
229 b = strappend("_UDEV_DEVNODE=", g);
231 IOVEC_SET_STRING(iovec[n++], b);
236 g = udev_device_get_sysname(ud);
238 b = strappend("_UDEV_SYSNAME=", g);
240 IOVEC_SET_STRING(iovec[n++], b);
246 ll = udev_device_get_devlinks_list_entry(ud);
247 udev_list_entry_foreach(ll, ll) {
249 if (j > N_IOVEC_UDEV_FIELDS)
252 g = udev_list_entry_get_name(ll);
254 b = strappend("_UDEV_DEVLINK=", g);
256 IOVEC_SET_STRING(iovec[n++], b);
264 udev_device_unref(ud);
268 if (asprintf(&source_time, "_SOURCE_MONOTONIC_TIMESTAMP=%llu", usec) >= 0)
269 IOVEC_SET_STRING(iovec[n++], source_time);
271 IOVEC_SET_STRING(iovec[n++], "_TRANSPORT=kernel");
273 if (asprintf(&syslog_priority, "PRIORITY=%i", priority & LOG_PRIMASK) >= 0)
274 IOVEC_SET_STRING(iovec[n++], syslog_priority);
276 if ((priority & LOG_FACMASK) == LOG_KERN)
277 IOVEC_SET_STRING(iovec[n++], "SYSLOG_IDENTIFIER=kernel");
279 pl -= syslog_parse_identifier((const char**) &p, &identifier, &pid);
281 /* Avoid any messages we generated ourselves via
282 * log_info() and friends. */
283 if (pid && is_us(pid))
287 syslog_identifier = strappend("SYSLOG_IDENTIFIER=", identifier);
288 if (syslog_identifier)
289 IOVEC_SET_STRING(iovec[n++], syslog_identifier);
293 syslog_pid = strappend("SYSLOG_PID=", pid);
295 IOVEC_SET_STRING(iovec[n++], syslog_pid);
298 if (asprintf(&syslog_facility, "SYSLOG_FACILITY=%i", LOG_FAC(priority)) >= 0)
299 IOVEC_SET_STRING(iovec[n++], syslog_facility);
302 message = cunescape_length_with_prefix(p, pl, "MESSAGE=");
304 IOVEC_SET_STRING(iovec[n++], message);
306 server_dispatch_message(s, iovec, n, ELEMENTSOF(iovec), NULL, NULL, NULL, 0, NULL, priority);
309 for (j = 0; j < z; j++)
310 free(iovec[j].iov_base);
313 free(syslog_priority);
314 free(syslog_identifier);
316 free(syslog_facility);
322 int server_read_dev_kmsg(Server *s) {
323 char buffer[8192+1]; /* the kernel-side limit per record is 8K currently */
327 assert(s->dev_kmsg_fd >= 0);
329 l = read(s->dev_kmsg_fd, buffer, sizeof(buffer) - 1);
333 /* Old kernels who don't allow reading from /dev/kmsg
334 * return EINVAL when we try. So handle this cleanly,
335 * but don' try to ever read from it again. */
336 if (errno == EINVAL) {
337 epoll_ctl(s->epoll_fd, EPOLL_CTL_DEL, s->dev_kmsg_fd, NULL);
341 if (errno == EAGAIN || errno == EINTR || errno == EPIPE)
344 log_error("Failed to read from kernel: %m");
348 dev_kmsg_record(s, buffer, l);
352 int server_flush_dev_kmsg(Server *s) {
357 if (s->dev_kmsg_fd < 0)
360 if (!s->dev_kmsg_readable)
363 log_debug("Flushing /dev/kmsg...");
366 r = server_read_dev_kmsg(s);
377 int server_open_dev_kmsg(Server *s) {
378 struct epoll_event ev;
382 s->dev_kmsg_fd = open("/dev/kmsg", O_RDWR|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
383 if (s->dev_kmsg_fd < 0) {
384 log_warning("Failed to open /dev/kmsg, ignoring: %m");
390 ev.data.fd = s->dev_kmsg_fd;
391 if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->dev_kmsg_fd, &ev) < 0) {
393 /* This will fail with EPERM on older kernels where
394 * /dev/kmsg is not readable. */
398 log_error("Failed to add /dev/kmsg fd to epoll object: %m");
402 s->dev_kmsg_readable = true;
407 int server_open_kernel_seqnum(Server *s) {
413 /* We store the seqnum we last read in an mmaped file. That
414 * way we can just use it like a variable, but it is
415 * persistent and automatically flushed at reboot. */
417 fd = open("/run/systemd/journal/kernel-seqnum", O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0644);
419 log_error("Failed to open /run/systemd/journal/kernel-seqnum, ignoring: %m");
423 if (posix_fallocate(fd, 0, sizeof(uint64_t)) < 0) {
424 log_error("Failed to allocate sequential number file, ignoring: %m");
425 close_nointr_nofail(fd);
429 p = mmap(NULL, sizeof(uint64_t), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
430 if (p == MAP_FAILED) {
431 log_error("Failed to map sequential number file, ignoring: %m");
432 close_nointr_nofail(fd);
436 close_nointr_nofail(fd);
437 s->kernel_seqnum = p;