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git.ipfire.org Git - thirdparty/systemd.git/blob - src/kmsg-syslogd.c
1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 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 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/socket.h>
23 #include <sys/types.h>
31 #include <sys/epoll.h>
34 #include <sys/signalfd.h>
38 #include "sd-daemon.h"
41 #define SERVER_FD_MAX 16
42 #define TIMEOUT ((int) (10*MSEC_PER_SEC))
44 typedef struct Stream Stream
;
46 typedef struct Server
{
53 static void server_done(Server
*s
) {
57 close_nointr_nofail(s
->epoll_fd
);
60 close_nointr_nofail(s
->kmsg_fd
);
62 if (s
->signal_fd
>= 0)
63 close_nointr_nofail(s
->signal_fd
);
66 fdset_free(s
->syslog_fds
);
69 static int server_init(Server
*s
, unsigned n_sockets
) {
72 struct epoll_event ev
;
76 assert(n_sockets
> 0);
80 s
->kmsg_fd
= s
->signal_fd
= -1;
82 if ((s
->epoll_fd
= epoll_create1(EPOLL_CLOEXEC
)) < 0) {
84 log_error("Failed to create epoll object: %s", strerror(errno
));
88 if (!(s
->syslog_fds
= fdset_new())) {
90 log_error("Failed to allocate file descriptor set: %s", strerror(errno
));
94 for (i
= 0; i
< n_sockets
; i
++) {
97 fd
= SD_LISTEN_FDS_START
+i
;
99 if ((r
= sd_is_socket(fd
, AF_UNSPEC
, SOCK_DGRAM
, -1)) < 0) {
100 log_error("Failed to determine file descriptor type: %s", strerror(-r
));
105 log_error("Wrong file descriptor type.");
110 if (setsockopt(fd
, SOL_SOCKET
, SO_PASSCRED
, &one
, sizeof(one
)) < 0)
111 log_error("SO_PASSCRED failed: %m");
116 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, fd
, &ev
) < 0) {
118 log_error("Failed to add server fd to epoll object: %s", strerror(errno
));
122 if ((r
= fdset_put(s
->syslog_fds
, fd
)) < 0) {
123 log_error("Failed to store file descriptor in set: %s", strerror(-r
));
128 if ((s
->kmsg_fd
= open("/dev/kmsg", O_WRONLY
|O_NOCTTY
|O_CLOEXEC
)) < 0) {
129 log_error("Failed to open /dev/kmsg for logging: %m");
133 assert_se(sigemptyset(&mask
) == 0);
134 sigset_add_many(&mask
, SIGINT
, SIGTERM
, -1);
135 assert_se(sigprocmask(SIG_SETMASK
, &mask
, NULL
) == 0);
137 if ((s
->signal_fd
= signalfd(-1, &mask
, SFD_NONBLOCK
|SFD_CLOEXEC
)) < 0) {
138 log_error("signalfd(): %m");
144 ev
.data
.fd
= s
->signal_fd
;
146 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, s
->signal_fd
, &ev
) < 0) {
147 log_error("epoll_ctl(): %m");
158 static int read_priority(const char **buf
) {
170 if (n
< 3 || p
[0] != '<')
177 } else if (n
>= 4 && p
[3] == '>') {
182 } else if (n
>= 5 && p
[4] == '>') {
190 if (a
< 0 || b
< 0 || c
< 0)
195 priority
= 100*a
+ 10*b
+ c
;
196 return LOG_PRI(priority
);
202 static void skip_date(const char **buf
) {
210 LETTER
, LETTER
, LETTER
,
212 SPACE_OR_NUMBER
, NUMBER
,
214 SPACE_OR_NUMBER
, NUMBER
,
216 SPACE_OR_NUMBER
, NUMBER
,
218 SPACE_OR_NUMBER
, NUMBER
,
230 for (i
= 0; i
< ELEMENTSOF(sequence
); i
++, p
++) {
235 switch (sequence
[i
]) {
242 case SPACE_OR_NUMBER
:
249 if (*p
< '0' || *p
> '9')
255 if (!(*p
>= 'A' && *p
<= 'Z') &&
256 !(*p
>= 'a' && *p
<= 'z'))
272 static int read_process(const char **buf
, struct iovec
*iovec
) {
282 p
+= strspn(p
, WHITESPACE
);
283 l
= strcspn(p
, WHITESPACE
);
308 iovec
->iov_base
= (char*) p
;
314 static void skip_pid(const char **buf
) {
326 p
+= strspn(p
, "0123456789");
336 static int write_message(Server
*s
, const char *buf
, struct ucred
*ucred
) {
338 char priority
[4], pid
[16];
339 struct iovec iovec
[5];
341 char *process
= NULL
;
347 /* First, set priority field */
348 snprintf(priority
, sizeof(priority
), "<%i>", read_priority(&buf
));
349 char_array_0(priority
);
350 IOVEC_SET_STRING(iovec
[i
++], priority
);
352 /* Second, skip date */
355 /* Then, add process if set */
356 if (read_process(&buf
, &iovec
[i
]) > 0)
358 else if (ucred
&& get_process_name(ucred
->pid
, &process
) >= 0)
359 IOVEC_SET_STRING(iovec
[i
++], process
);
361 /* Skip the stored PID if we have a better one */
363 snprintf(pid
, sizeof(pid
), "[%lu]: ", (unsigned long) ucred
->pid
);
365 IOVEC_SET_STRING(iovec
[i
++], pid
);
372 buf
+= strspn(buf
, WHITESPACE
);
375 /* Is the remaining message empty? */
378 /* And the rest is the message */
379 IOVEC_SET_STRING(iovec
[i
++], buf
);
380 IOVEC_SET_STRING(iovec
[i
++], "\n");
382 if ((k
= writev(s
->kmsg_fd
, iovec
, i
)) <= 0) {
383 log_error("Failed to write log message to kmsg: %s", k
< 0 ? strerror(errno
) : "short write");
384 r
= k
< 0 ? -errno
: -EIO
;
393 static int process_event(Server
*s
, struct epoll_event
*ev
) {
396 if (ev
->events
!= EPOLLIN
) {
397 log_info("Got invalid event from epoll.");
401 if (ev
->data
.fd
== s
->signal_fd
) {
402 struct signalfd_siginfo sfsi
;
405 if ((n
= read(s
->signal_fd
, &sfsi
, sizeof(sfsi
))) != sizeof(sfsi
)) {
410 if (errno
== EINTR
|| errno
== EAGAIN
)
416 log_debug("Received SIG%s", strna(signal_to_string(sfsi
.ssi_signo
)));
421 char buf
[LINE_MAX
+1];
422 struct msghdr msghdr
;
426 struct cmsghdr cmsghdr
;
427 uint8_t buf
[CMSG_SPACE(sizeof(struct ucred
))];
434 iovec
.iov_base
= buf
;
435 iovec
.iov_len
= sizeof(buf
)-1;
439 msghdr
.msg_iov
= &iovec
;
440 msghdr
.msg_iovlen
= 1;
441 msghdr
.msg_control
= &control
;
442 msghdr
.msg_controllen
= sizeof(control
);
444 if ((n
= recvmsg(ev
->data
.fd
, &msghdr
, MSG_DONTWAIT
)) < 0) {
446 if (errno
== EINTR
|| errno
== EAGAIN
)
449 log_error("recvmsg() failed: %m");
453 if (msghdr
.msg_controllen
>= CMSG_LEN(sizeof(struct ucred
)) &&
454 control
.cmsghdr
.cmsg_level
== SOL_SOCKET
&&
455 control
.cmsghdr
.cmsg_type
== SCM_CREDENTIALS
&&
456 control
.cmsghdr
.cmsg_len
== CMSG_LEN(sizeof(struct ucred
)))
457 ucred
= (struct ucred
*) CMSG_DATA(&control
.cmsghdr
);
461 if ((e
= memchr(buf
, '\n', n
)))
466 if ((k
= write_message(s
, strstrip(buf
), ucred
)) < 0)
474 int main(int argc
, char *argv
[]) {
476 int r
= EXIT_FAILURE
, n
;
478 if (getppid() != 1) {
479 log_error("This program should be invoked by init only.");
484 log_error("This program does not take arguments.");
488 log_set_target(LOG_TARGET_KMSG
);
489 log_parse_environment();
492 if ((n
= sd_listen_fds(true)) < 0) {
493 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r
));
497 if (n
<= 0 || n
> SERVER_FD_MAX
) {
498 log_error("No or too many file descriptors passed.");
502 if (server_init(&server
, (unsigned) n
) < 0)
505 log_debug("systemd-kmsg-syslogd running as pid %lu", (unsigned long) getpid());
509 "STATUS=Processing messages...");
512 struct epoll_event event
;
515 if ((k
= epoll_wait(server
.epoll_fd
, &event
, 1, TIMEOUT
)) < 0) {
520 log_error("epoll_wait() failed: %m");
527 if ((k
= process_event(&server
, &event
)) < 0)
536 log_debug("systemd-kmsg-syslogd stopped as pid %lu", (unsigned long) getpid());
540 "STATUS=Shutting down...");
542 server_done(&server
);