[thirdparty/systemd.git] / src / kmsg-syslogd.c

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <sys/socket.h>
#include <sys/types.h>
#include <assert.h>
#include <time.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <sys/poll.h>
#include <sys/epoll.h>
#include <sys/un.h>
#include <fcntl.h>
#include <sys/signalfd.h>

#include "util.h"
#include "log.h"
#include "sd-daemon.h"
#include "fdset.h"

#define SERVER_FD_MAX 16
#define TIMEOUT ((int) (10*MSEC_PER_SEC))

typedef struct Stream Stream;

typedef struct Server {
        FDSet *syslog_fds;
        int kmsg_fd;
        int epoll_fd;
        int signal_fd;
} Server;

static void server_done(Server *s) {
        assert(s);

        if (s->epoll_fd >= 0)
                close_nointr_nofail(s->epoll_fd);

        if (s->kmsg_fd >= 0)
                close_nointr_nofail(s->kmsg_fd);

        if (s->signal_fd >= 0)
                close_nointr_nofail(s->signal_fd);

        if (s->syslog_fds)
                fdset_free(s->syslog_fds);
}

static int server_init(Server *s, unsigned n_sockets) {
        int r;
        unsigned i;
        struct epoll_event ev;
        sigset_t mask;

        assert(s);
        assert(n_sockets > 0);

        zero(*s);

        s->kmsg_fd = s->signal_fd = -1;

        if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
                r = -errno;
                log_error("Failed to create epoll object: %s", strerror(errno));
                goto fail;
        }

        if (!(s->syslog_fds = fdset_new())) {
                r = -ENOMEM;
                log_error("Failed to allocate file descriptor set: %s", strerror(errno));
                goto fail;
        }

        for (i = 0; i < n_sockets; i++) {
                int fd, one = 1;

                fd = SD_LISTEN_FDS_START+i;

                if ((r = sd_is_socket(fd, AF_UNSPEC, SOCK_DGRAM, -1)) < 0) {
                        log_error("Failed to determine file descriptor type: %s", strerror(-r));
                        goto fail;
                }

                if (!r) {
                        log_error("Wrong file descriptor type.");
                        r = -EINVAL;
                        goto fail;
                }

                if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
                        log_error("SO_PASSCRED failed: %m");

                zero(ev);
                ev.events = EPOLLIN;
                ev.data.fd = fd;
                if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
                        r = -errno;
                        log_error("Failed to add server fd to epoll object: %s", strerror(errno));
                        goto fail;
                }

                if ((r = fdset_put(s->syslog_fds, fd)) < 0) {
                        log_error("Failed to store file descriptor in set: %s", strerror(-r));
                        goto fail;
                }
        }

        if ((s->kmsg_fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC)) < 0) {
                log_error("Failed to open /dev/kmsg for logging: %m");
                return -errno;
        }

        assert_se(sigemptyset(&mask) == 0);
        sigset_add_many(&mask, SIGINT, SIGTERM, -1);
        assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);

        if ((s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0) {
                log_error("signalfd(): %m");
                return -errno;
        }

        zero(ev);
        ev.events = EPOLLIN;
        ev.data.fd = s->signal_fd;

        if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
                log_error("epoll_ctl(): %m");
                return -errno;
        }

        return 0;

fail:
        server_done(s);
        return r;
}

static int read_priority(const char **buf) {
        int priority;
        size_t n;
        const char *p;
        int a, b, c;

        assert(buf);
        assert(*buf);

        p = *buf;
        n = strlen(p);

        if (n < 3 || p[0] != '<')
                goto fail;

        if (p[2] == '>') {
                a = b = 0;
                c = undecchar(p[1]);
                p += 3;
        } else if (n >= 4 && p[3] == '>') {
                a = 0;
                b = undecchar(p[1]);
                c = undecchar(p[2]);
                p += 4;
        } else if (n >= 5 && p[4] == '>') {
                a = undecchar(p[1]);
                b = undecchar(p[2]);
                c = undecchar(p[3]);
                p += 5;
        } else
                goto fail;

        if (a < 0 || b < 0 || c < 0)
                goto fail;

        *buf = p;

        priority = 100*a + 10*b + c;
        return LOG_PRI(priority);

fail:
        return LOG_INFO;
}

static void skip_date(const char **buf) {
        enum {
                LETTER,
                SPACE,
                NUMBER,
                SPACE_OR_NUMBER,
                COLON
        } sequence[] = {
                LETTER, LETTER, LETTER,
                SPACE,
                SPACE_OR_NUMBER, NUMBER,
                SPACE,
                SPACE_OR_NUMBER, NUMBER,
                COLON,
                SPACE_OR_NUMBER, NUMBER,
                COLON,
                SPACE_OR_NUMBER, NUMBER,
                SPACE
        };

        const char *p;
        unsigned i;

        assert(buf);
        assert(*buf);

        p = *buf;

        for (i = 0; i < ELEMENTSOF(sequence); i++, p++) {

                if (!*p)
                        return;

                switch (sequence[i]) {

                case SPACE:
                        if (*p != ' ')
                                return;
                        break;

                case SPACE_OR_NUMBER:
                        if (*p == ' ')
                                break;

                        /* fall through */

                case NUMBER:
                        if (*p < '0' || *p > '9')
                                return;

                        break;

                case LETTER:
                        if (!(*p >= 'A' && *p <= 'Z') &&
                            !(*p >= 'a' && *p <= 'z'))
                                return;

                        break;

                case COLON:
                        if (*p != ':')
                                return;
                        break;

                }
        }

        *buf = p;
}

static int read_process(const char **buf, struct iovec *iovec) {
        const char *p;
        size_t l;

        assert(buf);
        assert(*buf);
        assert(iovec);

        p = *buf;

        p += strspn(p, WHITESPACE);
        l = strcspn(p, WHITESPACE);

        if (l <= 0 ||
            p[l-1] != ':')
                return 0;

        l--;

        if (p[l-1] == ']') {
                size_t k = l-1;

                for (;;) {

                        if (p[k] == '[') {
                                l = k;
                                break;
                        }

                        if (k == 0)
                                break;

                        k--;
                }
        }

        iovec->iov_base = (char*) p;
        iovec->iov_len = l;
        *buf = p + l;
        return 1;
}

static void skip_pid(const char **buf) {
        const char *p;

        assert(buf);
        assert(*buf);

        p = *buf;

        if (*p != '[')
                return;

        p++;
        p += strspn(p, "0123456789");

        if (*p != ']')
                return;

        p++;

        *buf = p;
}

static int write_message(Server *s, const char *buf, struct ucred *ucred) {
        ssize_t k;
        char priority[4], pid[16];
        struct iovec iovec[5];
        unsigned i = 0;
        char *process = NULL;
        int r = 0;

        assert(s);
        assert(buf);

        /* First, set priority field */
        snprintf(priority, sizeof(priority), "<%i>", read_priority(&buf));
        char_array_0(priority);
        IOVEC_SET_STRING(iovec[i++], priority);

        /* Second, skip date */
        skip_date(&buf);

        /* Then, add process if set */
        if (read_process(&buf, &iovec[i]) > 0)
                i++;
        else if (ucred && get_process_name(ucred->pid, &process) >= 0)
                IOVEC_SET_STRING(iovec[i++], process);

        /* Skip the stored PID if we have a better one */
        if (ucred) {
                snprintf(pid, sizeof(pid), "[%lu]: ", (unsigned long) ucred->pid);
                char_array_0(pid);
                IOVEC_SET_STRING(iovec[i++], pid);

                skip_pid(&buf);

                if (*buf == ':')
                        buf++;

                buf += strspn(buf, WHITESPACE);
        }

        /* Is the remaining message empty? */
        if (*buf) {

                /* And the rest is the message */
                IOVEC_SET_STRING(iovec[i++], buf);
                IOVEC_SET_STRING(iovec[i++], "\n");

                if ((k = writev(s->kmsg_fd, iovec, i)) <= 0) {
                        log_error("Failed to write log message to kmsg: %s", k < 0 ? strerror(errno) : "short write");
                        r = k < 0 ? -errno : -EIO;
                }
        }

        free(process);

        return r;
}

static int process_event(Server *s, struct epoll_event *ev) {
        assert(s);

        if (ev->events != EPOLLIN) {
                log_info("Got invalid event from epoll.");
                return -EIO;
        }

        if (ev->data.fd == s->signal_fd) {
                struct signalfd_siginfo sfsi;
                ssize_t n;

                if ((n = read(s->signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {

                        if (n >= 0)
                                return -EIO;

                        if (errno == EINTR || errno == EAGAIN)
                                return 0;

                        return -errno;
                }

                log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
                return 0;

        } else {
                for (;;) {
                        char buf[LINE_MAX+1];
                        struct msghdr msghdr;
                        struct iovec iovec;
                        struct ucred *ucred;
                        union {
                                struct cmsghdr cmsghdr;
                                uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
                        } control;
                        ssize_t n;
                        int k;
                        char *e;

                        zero(iovec);
                        iovec.iov_base = buf;
                        iovec.iov_len = sizeof(buf)-1;

                        zero(control);
                        zero(msghdr);
                        msghdr.msg_iov = &iovec;
                        msghdr.msg_iovlen = 1;
                        msghdr.msg_control = &control;
                        msghdr.msg_controllen = sizeof(control);

                        if ((n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT)) < 0) {

                                if (errno == EINTR || errno == EAGAIN)
                                        return 1;

                                log_error("recvmsg() failed: %m");
                                return -errno;
                        }

                        if (msghdr.msg_controllen >= CMSG_LEN(sizeof(struct ucred)) &&
                            control.cmsghdr.cmsg_level == SOL_SOCKET &&
                            control.cmsghdr.cmsg_type == SCM_CREDENTIALS &&
                            control.cmsghdr.cmsg_len == CMSG_LEN(sizeof(struct ucred)))
                                ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
                        else
                                ucred = NULL;

                        if ((e = memchr(buf, '\n', n)))
                                *e = 0;
                        else
                                buf[n] = 0;

                        if ((k = write_message(s, strstrip(buf), ucred)) < 0)
                                return k;
                }
        }

        return 1;
}

int main(int argc, char *argv[]) {
        Server server;
        int r = EXIT_FAILURE, n;

        if (getppid() != 1) {
                log_error("This program should be invoked by init only.");
                return EXIT_FAILURE;
        }

        if (argc > 1) {
                log_error("This program does not take arguments.");
                return EXIT_FAILURE;
        }

        log_set_target(LOG_TARGET_KMSG);
        log_parse_environment();
        log_open();

        if ((n = sd_listen_fds(true)) < 0) {
                log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
                return EXIT_FAILURE;
        }

        if (n <= 0 || n > SERVER_FD_MAX) {
                log_error("No or too many file descriptors passed.");
                return EXIT_FAILURE;
        }

        if (server_init(&server, (unsigned) n) < 0)
                return EXIT_FAILURE;

        log_debug("systemd-kmsg-syslogd running as pid %lu", (unsigned long) getpid());

        sd_notify(false,
                  "READY=1\n"
                  "STATUS=Processing messages...");

        for (;;) {
                struct epoll_event event;
                int k;

                if ((k = epoll_wait(server.epoll_fd, &event, 1, TIMEOUT)) < 0) {

                        if (errno == EINTR)
                                continue;

                        log_error("epoll_wait() failed: %m");
                        goto fail;
                }

                if (k <= 0)
                        break;

                if ((k = process_event(&server, &event)) < 0)
                        goto fail;

                if (k == 0)
                        break;
        }

        r = EXIT_SUCCESS;

        log_debug("systemd-kmsg-syslogd stopped as pid %lu", (unsigned long) getpid());

fail:
        sd_notify(false,
                  "STATUS=Shutting down...");

        server_done(&server);

        return r;
}
Commit	Line	Data
addab137 LP	1	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/
	2
	3	/***
	4	This file is part of systemd.
	5
	6	Copyright 2010 Lennart Poettering
	7
	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.
	12
	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.
	17
	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/>.
	20	***/
	21
	22	#include <sys/socket.h>
	23	#include <sys/types.h>
	24	#include <assert.h>
	25	#include <time.h>
	26	#include <string.h>
	27	#include <stdio.h>
	28	#include <errno.h>
	29	#include <unistd.h>
	30	#include <sys/poll.h>
	31	#include <sys/epoll.h>
	32	#include <sys/un.h>
	33	#include <fcntl.h>
	34	#include <sys/signalfd.h>
	35
	36	#include "util.h"
	37	#include "log.h"
	38	#include "sd-daemon.h"
	39	#include "fdset.h"
	40
	41	#define SERVER_FD_MAX 16
	42	#define TIMEOUT ((int) (10*MSEC_PER_SEC))
	43
	44	typedef struct Stream Stream;
	45
	46	typedef struct Server {
	47	FDSet *syslog_fds;
	48	int kmsg_fd;
	49	int epoll_fd;
	50	int signal_fd;
	51	} Server;
	52
	53	static void server_done(Server *s) {
	54	assert(s);
	55
	56	if (s->epoll_fd >= 0)
	57	close_nointr_nofail(s->epoll_fd);
	58
	59	if (s->kmsg_fd >= 0)
	60	close_nointr_nofail(s->kmsg_fd);
	61
	62	if (s->signal_fd >= 0)
	63	close_nointr_nofail(s->signal_fd);
	64
65	if (s->syslog_fds)
66	fdset_free(s->syslog_fds);
67	}
68
69	static int server_init(Server *s, unsigned n_sockets) {
70	int r;
71	unsigned i;
72	struct epoll_event ev;
73	sigset_t mask;
74
75	assert(s);
76	assert(n_sockets > 0);
77
78	zero(*s);
79
80	s->kmsg_fd = s->signal_fd = -1;
81
82	if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
83	r = -errno;
84	log_error("Failed to create epoll object: %s", strerror(errno));
85	goto fail;
86	}
87
88	if (!(s->syslog_fds = fdset_new())) {
89	r = -ENOMEM;
90	log_error("Failed to allocate file descriptor set: %s", strerror(errno));
91	goto fail;
92	}
93
94	for (i = 0; i < n_sockets; i++) {
95	int fd, one = 1;
96
97	fd = SD_LISTEN_FDS_START+i;
98
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));
101	goto fail;
102	}
103
104	if (!r) {
105	log_error("Wrong file descriptor type.");
106	r = -EINVAL;
107	goto fail;
108	}
109
110	if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
111	log_error("SO_PASSCRED failed: %m");
112
113	zero(ev);
114	ev.events = EPOLLIN;
115	ev.data.fd = fd;
116	if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
117	r = -errno;
118	log_error("Failed to add server fd to epoll object: %s", strerror(errno));
119	goto fail;
120	}
121
122	if ((r = fdset_put(s->syslog_fds, fd)) < 0) {
123	log_error("Failed to store file descriptor in set: %s", strerror(-r));
124	goto fail;
125	}
126	}
127
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");
130	return -errno;
131	}
132
133	assert_se(sigemptyset(&mask) == 0);
134	sigset_add_many(&mask, SIGINT, SIGTERM, -1);
135	assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
136
137	if ((s->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK\|SFD_CLOEXEC)) < 0) {
138	log_error("signalfd(): %m");
139	return -errno;
140	}
141
142	zero(ev);
143	ev.events = EPOLLIN;
144	ev.data.fd = s->signal_fd;
145
146	if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, s->signal_fd, &ev) < 0) {
147	log_error("epoll_ctl(): %m");
148	return -errno;
149	}
150
151	return 0;
152
153	fail:
154	server_done(s);
155	return r;
156	}
157
158	static int read_priority(const char **buf) {
159	int priority;
160	size_t n;
161	const char *p;
162	int a, b, c;
163
164	assert(buf);
165	assert(*buf);
166
167	p = *buf;
168	n = strlen(p);
169
170	if (n < 3 \|\| p[0] != '<')
171	goto fail;
172
173	if (p[2] == '>') {
174	a = b = 0;
175	c = undecchar(p[1]);
176	p += 3;
177	} else if (n >= 4 && p[3] == '>') {
178	a = 0;
179	b = undecchar(p[1]);
180	c = undecchar(p[2]);
181	p += 4;
182	} else if (n >= 5 && p[4] == '>') {
183	a = undecchar(p[1]);
184	b = undecchar(p[2]);
185	c = undecchar(p[3]);
186	p += 5;
187	} else
188	goto fail;
189
190	if (a < 0 \|\| b < 0 \|\| c < 0)
191	goto fail;
192
193	*buf = p;
194
195	priority = 100a + 10b + c;
196	return LOG_PRI(priority);
197
198	fail:
199	return LOG_INFO;
200	}
201
202	static void skip_date(const char **buf) {
203	enum {
204	LETTER,
205	SPACE,
206	NUMBER,
207	SPACE_OR_NUMBER,
208	COLON
209	} sequence[] = {
210	LETTER, LETTER, LETTER,
211	SPACE,
212	SPACE_OR_NUMBER, NUMBER,
213	SPACE,
214	SPACE_OR_NUMBER, NUMBER,
215	COLON,
216	SPACE_OR_NUMBER, NUMBER,
217	COLON,
218	SPACE_OR_NUMBER, NUMBER,
219	SPACE
220	};
221
222	const char *p;
223	unsigned i;
224
225	assert(buf);
226	assert(*buf);
227
228	p = *buf;
229
230	for (i = 0; i < ELEMENTSOF(sequence); i++, p++) {
231
232	if (!*p)
233	return;
234
235	switch (sequence[i]) {
236
237	case SPACE:
238	if (*p != ' ')
239	return;
240	break;
241
242	case SPACE_OR_NUMBER:
243	if (*p == ' ')
244	break;
245
246	/* fall through */
247
248	case NUMBER:
249	if (p < '0' \|\| p > '9')
250	return;
251
252	break;
253
254	case LETTER:
255	if (!(p >= 'A' && p <= 'Z') &&
256	!(p >= 'a' && p <= 'z'))
257	return;
258
259	break;
260
261	case COLON:
262	if (*p != ':')
263	return;
264	break;
265
266	}
267	}
268
269	*buf = p;
270	}
271
272	static int read_process(const char *buf, struct iovec iovec) {
273	const char *p;
274	size_t l;
275
276	assert(buf);
277	assert(*buf);
278	assert(iovec);
279
280	p = *buf;
281
282	p += strspn(p, WHITESPACE);
283	l = strcspn(p, WHITESPACE);
284
285	if (l <= 0 \|\|
286	p[l-1] != ':')
287	return 0;
288
289	l--;
290
291	if (p[l-1] == ']') {
292	size_t k = l-1;
293
294	for (;;) {
295
296	if (p[k] == '[') {
297	l = k;
298	break;
299	}
300
301	if (k == 0)
302	break;
303
304	k--;
305	}
306	}
307
308	iovec->iov_base = (char*) p;
309	iovec->iov_len = l;
310	*buf = p + l;
311	return 1;
312	}
313
314	static void skip_pid(const char **buf) {
315	const char *p;
316
317	assert(buf);
318	assert(*buf);
319
320	p = *buf;
321
322	if (*p != '[')
323	return;
324
325	p++;
326	p += strspn(p, "0123456789");
327
328	if (*p != ']')
329	return;
330
331	p++;
332
333	*buf = p;
334	}
335
336	static int write_message(Server s, const char buf, struct ucred *ucred) {
337	ssize_t k;
338	char priority[4], pid[16];
339	struct iovec iovec[5];
340	unsigned i = 0;
341	char *process = NULL;
342	int r = 0;
343
344	assert(s);
345	assert(buf);
346
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);
351
352	/* Second, skip date */
353	skip_date(&buf);
354
355	/* Then, add process if set */
356	if (read_process(&buf, &iovec[i]) > 0)
357	i++;
358	else if (ucred && get_process_name(ucred->pid, &process) >= 0)
359	IOVEC_SET_STRING(iovec[i++], process);
360
361	/* Skip the stored PID if we have a better one */
362	if (ucred) {
363	snprintf(pid, sizeof(pid), "[%lu]: ", (unsigned long) ucred->pid);
364	char_array_0(pid);
365	IOVEC_SET_STRING(iovec[i++], pid);
366
367	skip_pid(&buf);
368
369	if (*buf == ':')
370	buf++;
371
372	buf += strspn(buf, WHITESPACE);
373	}
374
375	/* Is the remaining message empty? */
376	if (*buf) {
377
378	/* And the rest is the message */
379	IOVEC_SET_STRING(iovec[i++], buf);
380	IOVEC_SET_STRING(iovec[i++], "\n");
381
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;
385	}
386	}
387
388	free(process);
389
390	return r;
391	}
392
393	static int process_event(Server s, struct epoll_event ev) {
394	assert(s);
395
396	if (ev->events != EPOLLIN) {
397	log_info("Got invalid event from epoll.");
398	return -EIO;
399	}
400
401	if (ev->data.fd == s->signal_fd) {
402	struct signalfd_siginfo sfsi;
403	ssize_t n;
404
405	if ((n = read(s->signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
406
407	if (n >= 0)
408	return -EIO;
409
410	if (errno == EINTR \|\| errno == EAGAIN)
411	return 0;
412
413	return -errno;
414	}
415
416	log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
417	return 0;
418
419	} else {
420	for (;;) {
421	char buf[LINE_MAX+1];
422	struct msghdr msghdr;
423	struct iovec iovec;
424	struct ucred *ucred;
425	union {
426	struct cmsghdr cmsghdr;
427	uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
428	} control;
429	ssize_t n;
430	int k;
431	char *e;
432
433	zero(iovec);
434	iovec.iov_base = buf;
435	iovec.iov_len = sizeof(buf)-1;
436
437	zero(control);
438	zero(msghdr);
439	msghdr.msg_iov = &iovec;
440	msghdr.msg_iovlen = 1;
441	msghdr.msg_control = &control;
442	msghdr.msg_controllen = sizeof(control);
443
444	if ((n = recvmsg(ev->data.fd, &msghdr, MSG_DONTWAIT)) < 0) {
445
446	if (errno == EINTR \|\| errno == EAGAIN)
447	return 1;
448
449	log_error("recvmsg() failed: %m");
450	return -errno;
451	}
452
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);
458	else
459	ucred = NULL;
460
461	if ((e = memchr(buf, '\n', n)))
462	*e = 0;
463	else
464	buf[n] = 0;
465
466	if ((k = write_message(s, strstrip(buf), ucred)) < 0)
467	return k;
468	}
469	}
470
471	return 1;
472	}
473
474	int main(int argc, char *argv[]) {
475	Server server;
22f4096c	476	int r = EXIT_FAILURE, n;
addab137 LP	477
	478	if (getppid() != 1) {
	479	log_error("This program should be invoked by init only.");
22f4096c	480	return EXIT_FAILURE;
addab137 LP	481	}
	482
	483	if (argc > 1) {
	484	log_error("This program does not take arguments.");
22f4096c	485	return EXIT_FAILURE;
addab137 LP	486	}
	487
	488	log_set_target(LOG_TARGET_KMSG);
	489	log_parse_environment();
	490	log_open();
	491
	492	if ((n = sd_listen_fds(true)) < 0) {
	493	log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
22f4096c	494	return EXIT_FAILURE;
addab137 LP	495	}
	496
	497	if (n <= 0 \|\| n > SERVER_FD_MAX) {
	498	log_error("No or too many file descriptors passed.");
22f4096c	499	return EXIT_FAILURE;
addab137 LP	500	}
	501
	502	if (server_init(&server, (unsigned) n) < 0)
22f4096c	503	return EXIT_FAILURE;
addab137 LP	504
	505	log_debug("systemd-kmsg-syslogd running as pid %lu", (unsigned long) getpid());
	506
	507	sd_notify(false,
	508	"READY=1\n"
	509	"STATUS=Processing messages...");
	510
	511	for (;;) {
	512	struct epoll_event event;
	513	int k;
	514
	515	if ((k = epoll_wait(server.epoll_fd, &event, 1, TIMEOUT)) < 0) {
	516
	517	if (errno == EINTR)
	518	continue;
	519
	520	log_error("epoll_wait() failed: %m");
	521	goto fail;
	522	}
	523
	524	if (k <= 0)
	525	break;
	526
	527	if ((k = process_event(&server, &event)) < 0)
	528	goto fail;
	529
	530	if (k == 0)
	531	break;
	532	}
	533
22f4096c	534	r = EXIT_SUCCESS;
addab137 LP	535
	536	log_debug("systemd-kmsg-syslogd stopped as pid %lu", (unsigned long) getpid());
	537
	538	fail:
	539	sd_notify(false,
	540	"STATUS=Shutting down...");
	541
	542	server_done(&server);
	543
	544	return r;
	545	}