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git.ipfire.org Git - people/ms/systemd.git/blob - logger.c
1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
3 #include <sys/socket.h>
12 #include <sys/epoll.h>
20 #define STREAM_BUFFER 2048
21 #define STREAMS_MAX 256
22 #define SERVER_FD_START 3
23 #define SERVER_FD_MAX 16
24 #define TIMEOUT ((int) (10*MSEC_PER_SEC))
26 typedef struct Stream Stream
;
28 typedef struct Server
{
35 LIST_HEAD(Stream
, streams
);
39 typedef enum StreamState
{
46 typedef enum LogTarget
{
64 char buffer
[STREAM_BUFFER
];
67 LIST_FIELDS(Stream
, stream
);
70 #define IOVEC_SET_STRING(iovec, s) \
72 (iovec).iov_base = s; \
73 (iovec).iov_len = strlen(s); \
76 static int stream_log(Stream
*s
, char *p
, usec_t timestamp
) {
78 char header_priority
[16], header_time
[64], header_pid
[16];
80 struct iovec iovec
[5];
89 * The format glibc uses to talk to the syslog daemon is:
91 * <priority>time process[pid]: msg
93 * The format the kernel uses is:
97 * We extend the latter to include the process name and pid.
100 snprintf(header_priority
, sizeof(header_priority
), "<%i>",
101 s
->target
== LOG_TARGET_SYSLOG
? s
->priority
: LOG_PRI(s
->priority
));
102 char_array_0(header_priority
);
104 if (s
->target
== LOG_TARGET_SYSLOG
) {
108 t
= (time_t) (timestamp
/ USEC_PER_SEC
);
109 if (!(tm
= localtime(&t
)))
112 if (strftime(header_time
, sizeof(header_time
), "%h %e %T ", tm
) <= 0)
116 snprintf(header_pid
, sizeof(header_pid
), "[%llu]: ", (unsigned long long) s
->pid
);
117 char_array_0(header_pid
);
120 IOVEC_SET_STRING(iovec
[0], header_priority
);
122 if (s
->target
== LOG_TARGET_SYSLOG
) {
123 IOVEC_SET_STRING(iovec
[1], header_time
);
124 IOVEC_SET_STRING(iovec
[2], s
->process
);
125 IOVEC_SET_STRING(iovec
[3], header_pid
);
126 IOVEC_SET_STRING(iovec
[4], p
);
129 msghdr
.msg_iov
= iovec
;
130 msghdr
.msg_iovlen
= ELEMENTSOF(iovec
);
132 if (sendmsg(s
->server
->syslog_fd
, &msghdr
, MSG_NOSIGNAL
) < 0)
135 } else if (s
->target
== LOG_TARGET_KMSG
) {
136 IOVEC_SET_STRING(iovec
[1], s
->process
);
137 IOVEC_SET_STRING(iovec
[2], header_pid
);
138 IOVEC_SET_STRING(iovec
[3], p
);
139 IOVEC_SET_STRING(iovec
[4], "\n");
141 if (writev(s
->server
->kmsg_fd
, iovec
, ELEMENTSOF(iovec
)) < 0)
144 assert_not_reached("Unknown log target");
149 static int stream_line(Stream
*s
, char *p
, usec_t timestamp
) {
159 case STREAM_LOG_TARGET
:
160 if (streq(p
, "syslog"))
161 s
->target
= LOG_TARGET_SYSLOG
;
162 else if (streq(p
, "kmsg")) {
164 if (s
->server
->kmsg_fd
>= 0 && s
->uid
== 0)
165 s
->target
= LOG_TARGET_KMSG
;
167 log_warning("/dev/kmsg logging not available.");
171 log_warning("Failed to parse log target line.");
174 s
->state
= STREAM_PRIORITY
;
177 case STREAM_PRIORITY
:
178 if ((r
= safe_atoi(p
, &s
->priority
)) < 0) {
179 log_warning("Failed to parse log priority line: %s", strerror(errno
));
183 if (s
->priority
< 0) {
184 log_warning("Log priority negative: %s", strerror(errno
));
188 s
->state
= STREAM_PROCESS
;
192 if (!(s
->process
= strdup(p
)))
195 s
->state
= STREAM_RUNNING
;
199 return stream_log(s
, p
, timestamp
);
202 assert_not_reached("Unknown stream state");
205 static int stream_scan(Stream
*s
, usec_t timestamp
) {
213 remaining
= s
->length
;
217 if (!(newline
= memchr(p
, '\n', remaining
)))
222 if ((r
= stream_line(s
, p
, timestamp
)) >= 0) {
223 remaining
-= newline
-p
+1;
229 memmove(s
->buffer
, p
, remaining
);
230 s
->length
= remaining
;
236 static int stream_process(Stream
*s
, usec_t timestamp
) {
241 if ((l
= read(s
->fd
, s
->buffer
+s
->length
, STREAM_BUFFER
-s
->length
)) < 0) {
246 log_warning("Failed to read from stream: %s", strerror(errno
));
255 r
= stream_scan(s
, timestamp
);
263 static void stream_free(Stream
*s
) {
267 assert(s
->server
->n_streams
> 0);
268 s
->server
->n_streams
--;
269 LIST_REMOVE(Stream
, stream
, s
->server
->streams
, s
);
275 epoll_ctl(s
->server
->epoll_fd
, EPOLL_CTL_DEL
, s
->fd
, NULL
);
277 assert_se(close_nointr(s
->fd
) == 0);
284 static int stream_new(Server
*s
, int server_fd
) {
288 socklen_t len
= sizeof(ucred
);
289 struct epoll_event ev
;
294 if ((fd
= accept4(server_fd
, NULL
, NULL
, SOCK_NONBLOCK
|SOCK_CLOEXEC
)) < 0)
297 if (s
->n_streams
>= STREAMS_MAX
) {
298 log_warning("Too many connections, refusing connection.");
299 assert_se(close_nointr(fd
) == 0);
303 if (!(stream
= new0(Stream
, 1))) {
304 assert_se(close_nointr(fd
) == 0);
310 if (getsockopt(stream
->fd
, SOL_SOCKET
, SO_PEERCRED
, &ucred
, &len
) < 0) {
315 if (shutdown(fd
, SHUT_WR
) < 0) {
321 ev
.data
.ptr
= stream
;
323 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, fd
, &ev
) < 0) {
328 stream
->pid
= ucred
.pid
;
329 stream
->uid
= ucred
.uid
;
332 LIST_PREPEND(Stream
, stream
, s
->streams
, stream
);
342 static int verify_environment(unsigned *n_sockets
) {
343 unsigned long long pid
;
348 assert_se(n_sockets
);
350 if (!(e
= getenv("LISTEN_PID"))) {
351 log_error("Missing $LISTEN_PID environment variable.");
355 if ((r
= safe_atollu(e
, &pid
)) < 0) {
356 log_error("Failed to parse $LISTEN_PID: %s", strerror(-r
));
360 if (pid
!= (unsigned long long) getpid()) {
361 log_error("Socket nor for me.");
365 if (!(e
= getenv("LISTEN_FDS"))) {
366 log_error("Missing $LISTEN_FDS environment variable.");
370 if ((r
= safe_atou(e
, &ns
)) < 0) {
371 log_error("Failed to parse $LISTEN_FDS: %s", strerror(-r
));
375 if (ns
<= 0 || ns
> SERVER_FD_MAX
) {
376 log_error("Wrong number of file descriptors passed: %s", e
);
385 static void server_done(Server
*s
) {
390 stream_free(s
->streams
);
392 for (i
= 0; i
< s
->n_server_fd
; i
++)
393 assert_se(close_nointr(SERVER_FD_START
+i
) == 0);
395 if (s
->syslog_fd
>= 0)
396 assert_se(close_nointr(s
->syslog_fd
) == 0);
398 if (s
->epoll_fd
>= 0)
399 assert_se(close_nointr(s
->epoll_fd
) == 0);
402 assert_se(close_nointr(s
->kmsg_fd
) == 0);
405 static int server_init(Server
*s
, unsigned n_sockets
) {
410 struct sockaddr_un un
;
414 assert(n_sockets
> 0);
418 s
->n_server_fd
= n_sockets
;
422 if ((s
->epoll_fd
= epoll_create1(EPOLL_CLOEXEC
)) < 0) {
424 log_error("Failed to create epoll object: %s", strerror(errno
));
428 for (i
= 0; i
< n_sockets
; i
++) {
429 struct epoll_event ev
;
433 ev
.data
.ptr
= UINT_TO_PTR(SERVER_FD_START
+i
);
434 if (epoll_ctl(s
->epoll_fd
, EPOLL_CTL_ADD
, SERVER_FD_START
+i
, &ev
) < 0) {
436 log_error("Failed to add server fd to epoll object: %s", strerror(errno
));
441 if ((s
->syslog_fd
= socket(AF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0)) < 0) {
443 log_error("Failed to create log fd: %s", strerror(errno
));
448 sa
.un
.sun_family
= AF_UNIX
;
449 strncpy(sa
.un
.sun_path
, "/dev/log", sizeof(sa
.un
.sun_path
));
451 if (connect(s
->syslog_fd
, &sa
.sa
, sizeof(sa
)) < 0) {
453 log_error("Failed to connect log socket to /dev/log: %s", strerror(errno
));
457 /* /dev/kmsg logging is strictly optional */
458 if ((s
->kmsg_fd
= open("/dev/kmsg", O_WRONLY
|O_NOCTTY
|O_CLOEXEC
)) < 0)
459 log_debug("Failed to open /dev/kmsg for logging, disabling kernel log buffer support: %s", strerror(errno
));
468 static int process_event(Server
*s
, struct epoll_event
*ev
) {
473 /* Yes, this is a bit ugly, we assume that that valid pointers
474 * are > SERVER_FD_START+SERVER_FD_MAX. Which is certainly
475 * true on Linux (and probably most other OSes, too, since the
476 * first 4k usually are part of a seperate null pointer
477 * dereference page. */
479 if (PTR_TO_UINT(ev
->data
.ptr
) >= SERVER_FD_START
&&
480 PTR_TO_UINT(ev
->data
.ptr
) < SERVER_FD_START
+s
->n_server_fd
) {
482 if (ev
->events
!= POLLIN
) {
483 log_info("Got invalid event from epoll. (1)");
487 if ((r
= stream_new(s
, PTR_TO_UINT(ev
->data
.ptr
))) < 0) {
488 log_info("Failed to accept new connection: %s", strerror(-r
));
494 Stream
*stream
= ev
->data
.ptr
;
496 timestamp
= now(CLOCK_REALTIME
);
498 if (!(ev
->events
& POLLIN
)) {
499 log_info("Got invalid event from epoll. (3)");
504 if ((r
= stream_process(stream
, timestamp
)) <= 0) {
507 log_info("Got error on stream: %s", strerror(-r
));
517 int main(int argc
, char *argv
[]) {
522 log_info("systemd-logger running as pid %llu", (unsigned long long) getpid());
524 if (verify_environment(&n
) < 0)
527 if (server_init(&server
, n
) < 0)
531 struct epoll_event event
;
534 if ((n
= epoll_wait(server
.epoll_fd
,
536 server
.n_streams
<= 0 ? TIMEOUT
: -1)) < 0) {
541 log_error("epoll_wait() failed: %s", strerror(errno
));
548 if ((r
= process_event(&server
, &event
)) < 0)
554 server_done(&server
);
556 log_info("systemd-logger stopped as pid %llu", (unsigned long long) getpid());