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>
38 #include "sd-daemon.h"
42 #define STREAMS_MAX 4096
43 #define SERVER_FD_MAX 16
44 #define TIMEOUT_MSEC ((int) (DEFAULT_EXIT_USEC/USEC_PER_MSEC))
46 typedef struct Stream Stream
;
48 typedef struct Server
{
55 bool syslog_is_stream
;
57 LIST_HEAD(Stream
, streams
);
61 typedef enum StreamTarget
{
66 typedef enum StreamState
{
91 char buffer
[LINE_MAX
];
94 LIST_FIELDS(Stream
, stream
);
97 static int stream_log(Stream
*s
, char *p
, usec_t ts
) {
99 char header_priority
[16], header_time
[64], header_pid
[16];
100 struct iovec iovec
[5];
106 priority
= s
->priority
;
109 parse_syslog_priority(&p
, &priority
);
114 /* Patch in LOG_USER facility if necessary */
115 if ((priority
& LOG_FACMASK
) == 0)
116 priority
= LOG_USER
| LOG_PRI(priority
);
119 * The format glibc uses to talk to the syslog daemon is:
121 * <priority>time process[pid]: msg
123 * The format the kernel uses is:
127 * We extend the latter to include the process name and pid.
130 snprintf(header_priority
, sizeof(header_priority
), "<%i>", priority
);
131 char_array_0(header_priority
);
133 if (s
->target
== STREAM_SYSLOG
) {
137 t
= (time_t) (ts
/ USEC_PER_SEC
);
138 if (!(tm
= localtime(&t
)))
141 if (strftime(header_time
, sizeof(header_time
), "%h %e %T ", tm
) <= 0)
145 snprintf(header_pid
, sizeof(header_pid
), "[%lu]: ", (unsigned long) s
->pid
);
146 char_array_0(header_pid
);
149 IOVEC_SET_STRING(iovec
[0], header_priority
);
151 if (s
->target
== STREAM_SYSLOG
) {
152 struct msghdr msghdr
;
154 struct cmsghdr cmsghdr
;
155 uint8_t buf
[CMSG_SPACE(sizeof(struct ucred
))];
160 control
.cmsghdr
.cmsg_level
= SOL_SOCKET
;
161 control
.cmsghdr
.cmsg_type
= SCM_CREDENTIALS
;
162 control
.cmsghdr
.cmsg_len
= CMSG_LEN(sizeof(struct ucred
));
164 ucred
= (struct ucred
*) CMSG_DATA(&control
.cmsghdr
);
169 IOVEC_SET_STRING(iovec
[1], header_time
);
170 IOVEC_SET_STRING(iovec
[2], s
->process
);
171 IOVEC_SET_STRING(iovec
[3], header_pid
);
172 IOVEC_SET_STRING(iovec
[4], p
);
174 /* When using syslog via SOCK_STREAM separate the messages by NUL chars */
175 if (s
->server
->syslog_is_stream
)
179 msghdr
.msg_iov
= iovec
;
180 msghdr
.msg_iovlen
= ELEMENTSOF(iovec
);
181 msghdr
.msg_control
= &control
;
182 msghdr
.msg_controllen
= control
.cmsghdr
.cmsg_len
;
187 if ((n
= sendmsg(s
->server
->syslog_fd
, &msghdr
, MSG_NOSIGNAL
)) < 0) {
189 if (errno
== ESRCH
) {
192 /* Hmm, maybe the process this
193 * line originates from is
194 * dead? Then let's patch in
195 * our own pid and retry,
196 * since we have nothing
201 if (ucred
->pid
!= our_pid
) {
202 ucred
->pid
= our_pid
;
210 if (!s
->server
->syslog_is_stream
||
211 (size_t) n
>= IOVEC_TOTAL_SIZE(iovec
, ELEMENTSOF(iovec
)))
214 IOVEC_INCREMENT(iovec
, ELEMENTSOF(iovec
), n
);
217 } else if (s
->target
== STREAM_KMSG
) {
218 IOVEC_SET_STRING(iovec
[1], s
->process
);
219 IOVEC_SET_STRING(iovec
[2], header_pid
);
220 IOVEC_SET_STRING(iovec
[3], p
);
221 IOVEC_SET_STRING(iovec
[4], (char*) "\n");
223 if (writev(s
->server
->kmsg_fd
, iovec
, ELEMENTSOF(iovec
)) < 0)
226 assert_not_reached("Unknown log target");
228 if (s
->tee_console
) {
231 if ((console
= open_terminal("/dev/console", O_WRONLY
|O_NOCTTY
|O_CLOEXEC
)) >= 0) {
232 IOVEC_SET_STRING(iovec
[0], s
->process
);
233 IOVEC_SET_STRING(iovec
[1], header_pid
);
234 IOVEC_SET_STRING(iovec
[2], p
);
235 IOVEC_SET_STRING(iovec
[3], (char*) "\n");
237 writev(console
, iovec
, 4);
245 static int stream_line(Stream
*s
, char *p
, usec_t ts
) {
256 if (streq(p
, "syslog") || streq(p
, "syslog+console"))
257 s
->target
= STREAM_SYSLOG
;
258 else if (streq(p
, "kmsg") || streq(p
, "kmsg+console")) {
260 if (s
->server
->kmsg_fd
>= 0 && s
->uid
== 0)
261 s
->target
= STREAM_KMSG
;
263 log_warning("/dev/kmsg logging not available.");
267 log_warning("Failed to parse log target line.");
271 if (endswith(p
, "+console"))
272 s
->tee_console
= true;
274 s
->state
= STREAM_PRIORITY
;
277 case STREAM_PRIORITY
:
278 if ((r
= safe_atoi(p
, &s
->priority
)) < 0) {
279 log_warning("Failed to parse log priority line: %m");
283 if (s
->priority
< 0) {
284 log_warning("Log priority negative: %m");
288 s
->state
= STREAM_PROCESS
;
292 if (!(s
->process
= strdup(p
)))
295 s
->state
= STREAM_PREFIX
;
300 if ((r
= parse_boolean(p
)) < 0)
304 s
->state
= STREAM_RUNNING
;
308 return stream_log(s
, p
, ts
);
311 assert_not_reached("Unknown stream state");
314 static int stream_scan(Stream
*s
, usec_t ts
) {
322 remaining
= s
->length
;
326 if (!(newline
= memchr(p
, '\n', remaining
)))
331 if ((r
= stream_line(s
, p
, ts
)) >= 0) {
332 remaining
-= newline
-p
+1;
338 memmove(s
->buffer
, p
, remaining
);
339 s
->length
= remaining
;
345 static int stream_process(Stream
*s
, usec_t ts
) {
350 if ((l
= read(s
->fd
, s
->buffer
+s
->length
, LINE_MAX
-s
->length
)) < 0) {
355 log_warning("Failed to read from stream: %m");
364 r
= stream_scan(s
, ts
);
372 static void stream_free(Stream
*s
) {
376 assert(s
->server
->n_streams
> 0);
377 s
->server
->n_streams
--;
378 LIST_REMOVE(Stream
, stream
, s
->server
->streams
, s
);
384 epoll_ctl(s
->server
->epoll_fd
, EPOLL_CTL_DEL
, s
->fd
, NULL
);
386 close_nointr_nofail(s
->fd
);
393 static int stream_new(Server
*s
, int server_fd
) {
397 socklen_t len
= sizeof(ucred
);
398 struct epoll_event ev
;
403 if ((fd
= accept4(server_fd
, NULL
, NULL
, SOCK_NONBLOCK
|SOCK_CLOEXEC
)) < 0)
406 if (s
->n_streams
>= STREAMS_MAX
) {
407 log_warning("Too many connections, refusing connection.");
408 close_nointr_nofail(fd
);
412 if (!socket_tcpwrap(fd
, "systemd-logger")) {
413 close_nointr_nofail(fd
);
417 if (!(stream
= new0(Stream
, 1))) {
418 close_nointr_nofail(fd
);
424 if (getsockopt(stream
->fd
, SOL_SOCKET
, SO_PEERCRED
, &ucred
, &len
) < 0) {
429 if (shutdown(fd
, SHUT_WR
) < 0) {
435 ev
.data
.ptr
= stream
;
437 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, fd
, &ev
) < 0) {
442 stream
->pid
= ucred
.pid
;
443 stream
->uid
= ucred
.uid
;
444 stream
->gid
= ucred
.gid
;
447 LIST_PREPEND(Stream
, stream
, s
->streams
, stream
);
457 static void server_done(Server
*s
) {
462 stream_free(s
->streams
);
464 for (i
= 0; i
< s
->n_server_fd
; i
++)
465 close_nointr_nofail(SD_LISTEN_FDS_START
+i
);
467 if (s
->syslog_fd
>= 0)
468 close_nointr_nofail(s
->syslog_fd
);
470 if (s
->epoll_fd
>= 0)
471 close_nointr_nofail(s
->epoll_fd
);
474 close_nointr_nofail(s
->kmsg_fd
);
477 static int server_init(Server
*s
, unsigned n_sockets
) {
482 struct sockaddr_un un
;
486 assert(n_sockets
> 0);
490 s
->n_server_fd
= n_sockets
;
494 if ((s
->epoll_fd
= epoll_create1(EPOLL_CLOEXEC
)) < 0) {
496 log_error("Failed to create epoll object: %m");
500 for (i
= 0; i
< n_sockets
; i
++) {
501 struct epoll_event ev
;
504 fd
= SD_LISTEN_FDS_START
+i
;
506 if ((r
= sd_is_socket(fd
, AF_UNSPEC
, SOCK_STREAM
, 1)) < 0) {
507 log_error("Failed to determine file descriptor type: %s", strerror(-r
));
512 log_error("Wrong file descriptor type.");
517 /* We use ev.data.ptr instead of ev.data.fd here,
518 * since on 64bit archs fd is 32bit while a pointer is
519 * 64bit. To make sure we can easily distinguish fd
520 * values and pointer values we want to make sure to
521 * write the full field unconditionally. */
525 ev
.data
.ptr
= INT_TO_PTR(fd
);
526 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, fd
, &ev
) < 0) {
528 log_error("Failed to add server fd to epoll object: %m");
534 sa
.un
.sun_family
= AF_UNIX
;
535 strncpy(sa
.un
.sun_path
, "/dev/log", sizeof(sa
.un
.sun_path
));
537 if ((s
->syslog_fd
= socket(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0)) < 0) {
539 log_error("Failed to create log fd: %m");
543 if (connect(s
->syslog_fd
, &sa
.sa
, sizeof(sa
)) < 0) {
544 close_nointr_nofail(s
->syslog_fd
);
546 if ((s
->syslog_fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
, 0)) < 0) {
548 log_error("Failed to create log fd: %m");
552 if (connect(s
->syslog_fd
, &sa
.sa
, sizeof(sa
)) < 0) {
554 log_error("Failed to connect log socket to /dev/log: %m");
558 s
->syslog_is_stream
= true;
560 s
->syslog_is_stream
= false;
562 /* /dev/kmsg logging is strictly optional */
563 if ((s
->kmsg_fd
= open("/dev/kmsg", O_WRONLY
|O_NOCTTY
|O_CLOEXEC
)) < 0)
564 log_warning("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %m");
573 static int process_event(Server
*s
, struct epoll_event
*ev
) {
578 /* Yes, this is a bit ugly, we assume that that valid pointers
579 * are > SD_LISTEN_FDS_START+SERVER_FD_MAX. Which is certainly
580 * true on Linux (and probably most other OSes, too, since the
581 * first 4k usually are part of a separate null pointer
582 * dereference page. */
584 if (PTR_TO_INT(ev
->data
.ptr
) >= SD_LISTEN_FDS_START
&&
585 PTR_TO_INT(ev
->data
.ptr
) < SD_LISTEN_FDS_START
+(int)s
->n_server_fd
) {
587 if (ev
->events
!= EPOLLIN
) {
588 log_info("Got invalid event from epoll. (1)");
592 if ((r
= stream_new(s
, PTR_TO_INT(ev
->data
.ptr
))) < 0) {
593 log_info("Failed to accept new connection: %s", strerror(-r
));
599 Stream
*stream
= ev
->data
.ptr
;
601 ts
= now(CLOCK_REALTIME
);
603 if (!(ev
->events
& EPOLLIN
)) {
604 log_info("Got invalid event from epoll. (2)");
609 if ((r
= stream_process(stream
, ts
)) <= 0) {
612 log_info("Got error on stream: %s", strerror(-r
));
622 int main(int argc
, char *argv
[]) {
624 int r
= EXIT_FAILURE
, n
;
626 if (getppid() != 1) {
627 log_error("This program should be invoked by init only.");
632 log_error("This program does not take arguments.");
636 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG
);
637 log_parse_environment();
642 if ((n
= sd_listen_fds(true)) < 0) {
643 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r
));
647 if (n
<= 0 || n
> SERVER_FD_MAX
) {
648 log_error("No or too many file descriptors passed.");
652 if (server_init(&server
, (unsigned) n
) < 0)
655 log_debug("systemd-logger running as pid %lu", (unsigned long) getpid());
659 "STATUS=Processing requests...");
662 struct epoll_event event
;
665 if ((k
= epoll_wait(server
.epoll_fd
,
667 server
.n_streams
<= 0 ? TIMEOUT_MSEC
: -1)) < 0) {
672 log_error("epoll_wait() failed: %m");
679 if (process_event(&server
, &event
) < 0)
685 log_debug("systemd-logger stopped as pid %lu", (unsigned long) getpid());
689 "STATUS=Shutting down...");
691 server_done(&server
);