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"
41 #define STREAMS_MAX 256
42 #define SERVER_FD_MAX 16
43 #define TIMEOUT ((int) (10*MSEC_PER_SEC))
45 typedef struct Stream Stream
;
47 typedef struct Server
{
54 bool syslog_is_stream
;
56 LIST_HEAD(Stream
, streams
);
60 typedef enum StreamTarget
{
65 typedef enum StreamState
{
89 char buffer
[LINE_MAX
];
92 LIST_FIELDS(Stream
, stream
);
95 static int stream_log(Stream
*s
, char *p
, usec_t ts
) {
97 char header_priority
[16], header_time
[64], header_pid
[16];
98 struct iovec iovec
[5];
104 priority
= s
->priority
;
108 p
[1] >= '0' && p
[1] <= '7' &&
111 /* Detected priority prefix */
112 priority
= LOG_MAKEPRI(LOG_FAC(priority
), (p
[1] - '0'));
121 * The format glibc uses to talk to the syslog daemon is:
123 * <priority>time process[pid]: msg
125 * The format the kernel uses is:
129 * We extend the latter to include the process name and pid.
132 snprintf(header_priority
, sizeof(header_priority
), "<%i>",
133 s
->target
== STREAM_SYSLOG
? priority
: LOG_PRI(priority
));
134 char_array_0(header_priority
);
136 if (s
->target
== STREAM_SYSLOG
) {
140 t
= (time_t) (ts
/ USEC_PER_SEC
);
141 if (!(tm
= localtime(&t
)))
144 if (strftime(header_time
, sizeof(header_time
), "%h %e %T ", tm
) <= 0)
148 snprintf(header_pid
, sizeof(header_pid
), "[%lu]: ", (unsigned long) s
->pid
);
149 char_array_0(header_pid
);
152 IOVEC_SET_STRING(iovec
[0], header_priority
);
154 if (s
->target
== STREAM_SYSLOG
) {
155 struct msghdr msghdr
;
157 struct cmsghdr cmsghdr
;
158 uint8_t buf
[CMSG_SPACE(sizeof(struct ucred
))];
163 control
.cmsghdr
.cmsg_level
= SOL_SOCKET
;
164 control
.cmsghdr
.cmsg_type
= SCM_CREDENTIALS
;
165 control
.cmsghdr
.cmsg_len
= CMSG_LEN(sizeof(struct ucred
));
167 ucred
= (struct ucred
*) CMSG_DATA(&control
.cmsghdr
);
172 IOVEC_SET_STRING(iovec
[1], header_time
);
173 IOVEC_SET_STRING(iovec
[2], s
->process
);
174 IOVEC_SET_STRING(iovec
[3], header_pid
);
175 IOVEC_SET_STRING(iovec
[4], p
);
177 /* When using syslog via SOCK_STREAM seperate the messages by NUL chars */
178 if (s
->server
->syslog_is_stream
)
182 msghdr
.msg_iov
= iovec
;
183 msghdr
.msg_iovlen
= ELEMENTSOF(iovec
);
184 msghdr
.msg_control
= &control
;
185 msghdr
.msg_controllen
= control
.cmsghdr
.cmsg_len
;
190 if ((n
= sendmsg(s
->server
->syslog_fd
, &msghdr
, MSG_NOSIGNAL
)) < 0)
193 if (!s
->server
->syslog_is_stream
||
194 (size_t) n
>= IOVEC_TOTAL_SIZE(iovec
, ELEMENTSOF(iovec
)))
197 IOVEC_INCREMENT(iovec
, ELEMENTSOF(iovec
), n
);
200 } else if (s
->target
== STREAM_KMSG
) {
201 IOVEC_SET_STRING(iovec
[1], s
->process
);
202 IOVEC_SET_STRING(iovec
[2], header_pid
);
203 IOVEC_SET_STRING(iovec
[3], p
);
204 IOVEC_SET_STRING(iovec
[4], (char*) "\n");
206 if (writev(s
->server
->kmsg_fd
, iovec
, ELEMENTSOF(iovec
)) < 0)
209 assert_not_reached("Unknown log target");
214 static int stream_line(Stream
*s
, char *p
, usec_t ts
) {
225 if (streq(p
, "syslog"))
226 s
->target
= STREAM_SYSLOG
;
227 else if (streq(p
, "kmsg")) {
229 if (s
->server
->kmsg_fd
>= 0 && s
->uid
== 0)
230 s
->target
= STREAM_KMSG
;
232 log_warning("/dev/kmsg logging not available.");
236 log_warning("Failed to parse log target line.");
239 s
->state
= STREAM_PRIORITY
;
242 case STREAM_PRIORITY
:
243 if ((r
= safe_atoi(p
, &s
->priority
)) < 0) {
244 log_warning("Failed to parse log priority line: %m");
248 if (s
->priority
< 0) {
249 log_warning("Log priority negative: %m");
253 s
->state
= STREAM_PROCESS
;
257 if (!(s
->process
= strdup(p
)))
260 s
->state
= STREAM_PREFIX
;
265 if ((r
= parse_boolean(p
)) < 0)
269 s
->state
= STREAM_RUNNING
;
273 return stream_log(s
, p
, ts
);
276 assert_not_reached("Unknown stream state");
279 static int stream_scan(Stream
*s
, usec_t ts
) {
287 remaining
= s
->length
;
291 if (!(newline
= memchr(p
, '\n', remaining
)))
296 if ((r
= stream_line(s
, p
, ts
)) >= 0) {
297 remaining
-= newline
-p
+1;
303 memmove(s
->buffer
, p
, remaining
);
304 s
->length
= remaining
;
310 static int stream_process(Stream
*s
, usec_t ts
) {
315 if ((l
= read(s
->fd
, s
->buffer
+s
->length
, LINE_MAX
-s
->length
)) < 0) {
320 log_warning("Failed to read from stream: %m");
329 r
= stream_scan(s
, ts
);
337 static void stream_free(Stream
*s
) {
341 assert(s
->server
->n_streams
> 0);
342 s
->server
->n_streams
--;
343 LIST_REMOVE(Stream
, stream
, s
->server
->streams
, s
);
349 epoll_ctl(s
->server
->epoll_fd
, EPOLL_CTL_DEL
, s
->fd
, NULL
);
351 close_nointr_nofail(s
->fd
);
358 static int stream_new(Server
*s
, int server_fd
) {
362 socklen_t len
= sizeof(ucred
);
363 struct epoll_event ev
;
368 if ((fd
= accept4(server_fd
, NULL
, NULL
, SOCK_NONBLOCK
|SOCK_CLOEXEC
)) < 0)
371 if (s
->n_streams
>= STREAMS_MAX
) {
372 log_warning("Too many connections, refusing connection.");
373 close_nointr_nofail(fd
);
377 if (!socket_tcpwrap(fd
, "systemd-logger")) {
378 close_nointr_nofail(fd
);
382 if (!(stream
= new0(Stream
, 1))) {
383 close_nointr_nofail(fd
);
389 if (getsockopt(stream
->fd
, SOL_SOCKET
, SO_PEERCRED
, &ucred
, &len
) < 0) {
394 if (shutdown(fd
, SHUT_WR
) < 0) {
400 ev
.data
.ptr
= stream
;
402 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, fd
, &ev
) < 0) {
407 stream
->pid
= ucred
.pid
;
408 stream
->uid
= ucred
.uid
;
409 stream
->gid
= ucred
.gid
;
412 LIST_PREPEND(Stream
, stream
, s
->streams
, stream
);
422 static void server_done(Server
*s
) {
427 stream_free(s
->streams
);
429 for (i
= 0; i
< s
->n_server_fd
; i
++)
430 close_nointr_nofail(SD_LISTEN_FDS_START
+i
);
432 if (s
->syslog_fd
>= 0)
433 close_nointr_nofail(s
->syslog_fd
);
435 if (s
->epoll_fd
>= 0)
436 close_nointr_nofail(s
->epoll_fd
);
439 close_nointr_nofail(s
->kmsg_fd
);
442 static int server_init(Server
*s
, unsigned n_sockets
) {
447 struct sockaddr_un un
;
451 assert(n_sockets
> 0);
455 s
->n_server_fd
= n_sockets
;
459 if ((s
->epoll_fd
= epoll_create1(EPOLL_CLOEXEC
)) < 0) {
461 log_error("Failed to create epoll object: %m");
465 for (i
= 0; i
< n_sockets
; i
++) {
466 struct epoll_event ev
;
469 fd
= SD_LISTEN_FDS_START
+i
;
471 if ((r
= sd_is_socket(fd
, AF_UNSPEC
, SOCK_STREAM
, 1)) < 0) {
472 log_error("Failed to determine file descriptor type: %s", strerror(-r
));
477 log_error("Wrong file descriptor type.");
482 /* We use ev.data.ptr instead of ev.data.fd here,
483 * since on 64bit archs fd is 32bit while a pointer is
484 * 64bit. To make sure we can easily distuingish fd
485 * values and pointer values we want to make sure to
486 * write the full field unconditionally. */
490 ev
.data
.ptr
= INT_TO_PTR(fd
);
491 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, fd
, &ev
) < 0) {
493 log_error("Failed to add server fd to epoll object: %m");
499 sa
.un
.sun_family
= AF_UNIX
;
500 strncpy(sa
.un
.sun_path
, "/dev/log", sizeof(sa
.un
.sun_path
));
502 if ((s
->syslog_fd
= socket(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0)) < 0) {
504 log_error("Failed to create log fd: %m");
508 if (connect(s
->syslog_fd
, &sa
.sa
, sizeof(sa
)) < 0) {
509 close_nointr_nofail(s
->syslog_fd
);
511 if ((s
->syslog_fd
= socket(AF_UNIX
, SOCK_STREAM
|SOCK_CLOEXEC
, 0)) < 0) {
513 log_error("Failed to create log fd: %m");
517 if (connect(s
->syslog_fd
, &sa
.sa
, sizeof(sa
)) < 0) {
519 log_error("Failed to connect log socket to /dev/log: %m");
523 s
->syslog_is_stream
= true;
525 s
->syslog_is_stream
= false;
527 /* /dev/kmsg logging is strictly optional */
528 if ((s
->kmsg_fd
= open("/dev/kmsg", O_WRONLY
|O_NOCTTY
|O_CLOEXEC
)) < 0)
529 log_warning("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %m");
538 static int process_event(Server
*s
, struct epoll_event
*ev
) {
543 /* Yes, this is a bit ugly, we assume that that valid pointers
544 * are > SD_LISTEN_FDS_START+SERVER_FD_MAX. Which is certainly
545 * true on Linux (and probably most other OSes, too, since the
546 * first 4k usually are part of a separate null pointer
547 * dereference page. */
549 if (PTR_TO_INT(ev
->data
.ptr
) >= SD_LISTEN_FDS_START
&&
550 PTR_TO_INT(ev
->data
.ptr
) < SD_LISTEN_FDS_START
+(int)s
->n_server_fd
) {
552 if (ev
->events
!= EPOLLIN
) {
553 log_info("Got invalid event from epoll. (1)");
557 if ((r
= stream_new(s
, PTR_TO_INT(ev
->data
.ptr
))) < 0) {
558 log_info("Failed to accept new connection: %s", strerror(-r
));
564 Stream
*stream
= ev
->data
.ptr
;
566 ts
= now(CLOCK_REALTIME
);
568 if (!(ev
->events
& EPOLLIN
)) {
569 log_info("Got invalid event from epoll. (2)");
574 if ((r
= stream_process(stream
, ts
)) <= 0) {
577 log_info("Got error on stream: %s", strerror(-r
));
587 int main(int argc
, char *argv
[]) {
589 int r
= EXIT_FAILURE
, n
;
591 if (getppid() != 1) {
592 log_error("This program should be invoked by init only.");
597 log_error("This program does not take arguments.");
601 log_set_target(LOG_TARGET_SYSLOG_OR_KMSG
);
602 log_parse_environment();
605 if ((n
= sd_listen_fds(true)) < 0) {
606 log_error("Failed to read listening file descriptors from environment: %s", strerror(-r
));
610 if (n
<= 0 || n
> SERVER_FD_MAX
) {
611 log_error("No or too many file descriptors passed.");
615 if (server_init(&server
, (unsigned) n
) < 0)
618 log_debug("systemd-logger running as pid %lu", (unsigned long) getpid());
622 "STATUS=Processing requests...");
625 struct epoll_event event
;
628 if ((k
= epoll_wait(server
.epoll_fd
,
630 server
.n_streams
<= 0 ? TIMEOUT
: -1)) < 0) {
635 log_error("epoll_wait() failed: %m");
642 if (process_event(&server
, &event
) < 0)
648 log_debug("systemd-logger stopped as pid %lu", (unsigned long) getpid());
652 "STATUS=Shutting down...");
654 server_done(&server
);