[deb_xorg-server.git] / hw / xquartz / console_redirect.c

/*
 * Copyright (c) 2011-2012 Apple Inc. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT.  IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
 * HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Except as contained in this notice, the name(s) of the above
 * copyright holders shall not be used in advertising or otherwise to
 * promote the sale, use or other dealings in this Software without
 * prior written authorization.
 */

#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#else
#define DEBUG_CONSOLE_REDIRECT 1
#define HAVE_LIBDISPATCH       1
#endif

#include <assert.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/event.h>
#include <asl.h>
#include <errno.h>
#include <fcntl.h>

#include "console_redirect.h"

#define BUF_SIZE 512

#ifdef HAVE_LIBDISPATCH
#include <dispatch/dispatch.h>

static dispatch_queue_t redirect_serial_q;
static dispatch_group_t read_source_group;
#else
#include <pthread.h>

static pthread_t redirect_pthread;
static pthread_mutex_t redirect_fds_lock = PTHREAD_MUTEX_INITIALIZER;

static int kq;

/* Notifications to our reader thread */
#define ASL_REDIRECT_TERMINATE ((void *)(uintptr_t)1)
#endif

typedef struct {
    int level;
    aslclient asl;
    aslmsg msg;

    /* Buffered reading */
    char *buf;
    char *w;

#ifdef HAVE_LIBDISPATCH
    dispatch_source_t read_source;
#endif
} asl_redirect;

static asl_redirect *redirect_fds = NULL;
static int n_redirect_fds = 0;

/* Read from the FD until there is no more to read and redirect to ASL.
 * Preconditions:
 *      1: pthread_mutex_lock lock is held (pthreads) or called
 *         from the appropriate serial queue for operating on
 *         redirect_fds
 *      2: fd corresponds to a valid entry in redirect_fds
 *
 * Return values:
 *      If the pipe is closed, EOF is returned regardless of how many bytes
 *      were processed.  If the pipe is still open, the number of read bytes
 *      is returned.
 */
static inline int
_read_redirect(int fd, int flush)
{
    int total_read = 0;
    int nbytes;
    asl_redirect *aslr = &redirect_fds[fd];

    while ((nbytes =
                read(fd, aslr->w,
                     BUF_SIZE - (aslr->w - aslr->buf) - 1)) > 0) {
        char *s, *p;

        /* Increment our returned number read */
        total_read += nbytes;

        /* Increment our write location */
        aslr->w += nbytes;
        aslr->w[0] = '\0';

        /* One line at a time */
        for (p = aslr->buf; p < aslr->w; p = s + 1) {
            // Find null or \n
            for (s = p; *s && *s != '\n'; s++) ;
            if (*s == '\n') {
                *s = '\0';
            }

            if (s < aslr->w || aslr->buf == p) {
                /* Either the first of multiple messages or one message which is larger than our buffer */
                asl_log(aslr->asl, aslr->msg, aslr->level, "%s", p);
            }
            else {
                /* We reached the end of the buffer, move this chunk to the start. */
                memmove(aslr->buf, p, BUF_SIZE - (p - aslr->buf));
                aslr->w = aslr->buf + (s - p);
                break;
            }
        }

        if (p == aslr->w) {
            /* Start writing at the beginning in the case where we flushed */
            aslr->w = aslr->buf;
        }
    }

    /* Flush if requested or we're at EOF */
    if (flush || nbytes == 0) {
        if (aslr->w > aslr->buf) {
            *aslr->w = '\0';
            asl_log(aslr->asl, aslr->msg, aslr->level, "%s", aslr->buf);
        }
    }

    if (nbytes == 0)
        return EOF;
    return total_read;
}

#ifdef HAVE_LIBDISPATCH
static void
read_from_source(void *_source)
{
    dispatch_source_t source = (dispatch_source_t)_source;
    int fd = dispatch_source_get_handle(source);
    if (_read_redirect(fd, 0) == EOF) {
        dispatch_source_cancel(source);
    }
}

static void
cancel_source(void *_source)
{
    dispatch_source_t source = (dispatch_source_t)_source;
    int fd = dispatch_source_get_handle(source);
    asl_redirect *aslr = &redirect_fds[fd];

    /* Flush the buffer */
    _read_redirect(fd, 1);

    close(fd);
    free(aslr->buf);
    memset(aslr, 0, sizeof(*aslr));
    dispatch_release(source);
    dispatch_group_leave(read_source_group);
}

#else /* !HAVE_LIBDISPATCH */
static void *
redirect_thread(void *ctx __unused)
{
    struct kevent ev;
    int n;

    while (1) {
        n = kevent(kq, NULL, 0, &ev, 1, NULL);

        /* Bail on errors */
        if (n < 0) {
            asl_log(NULL, NULL, ASL_LEVEL_ERR, "kevent failure: %s",
                    strerror(errno));
            break;
        }

        /* This should not happen */
        if (n == 0)
            continue;

        switch (ev.filter) {
        case EVFILT_READ:
            pthread_mutex_lock(&redirect_fds_lock);
            {
                int fd = ev.ident;
                int close_fd = 0;
                asl_redirect *aslr = &redirect_fds[fd];

                if (fd < 0 || fd >= n_redirect_fds || aslr->buf == NULL) {
                    asl_log(NULL, NULL, ASL_LEVEL_ERR,
                            "Unexpected file descriptor: %d",
                            fd);
                    goto next;
                }

                if (ev.flags & EV_EOF) {
                    close_fd = 1;
                    if (EOF != _read_redirect(fd, 1)) {
                        asl_log(
                            NULL, NULL, ASL_LEVEL_ERR,
                            "kevent reported EOF on %d, but read doesn't concur.",
                            fd);
                    }
                }
                else {
                    close_fd = (EOF == _read_redirect(fd, 0));
                }

                if (close_fd) {
                    EV_SET(&ev, fd, EVFILT_READ, EV_DELETE, 0, 0, 0);
                    kevent(kq, &ev, 1, NULL, 0, NULL);
                    close(fd);
                    free(aslr->buf);
                    memset(aslr, 0, sizeof(*aslr));
                }
            }
next:
            pthread_mutex_unlock(&redirect_fds_lock);

        case EVFILT_TIMER:
            if (ev.udata == ASL_REDIRECT_TERMINATE)
                return NULL;

        default:
            ;
            ;
        }
    }

    return NULL;
}
#endif

static void
redirect_atexit(void)
{
    /* stdout is linebuffered, so flush the buffer */
    if (redirect_fds[STDOUT_FILENO].buf)
        fflush(stdout);

#ifdef HAVE_LIBDISPATCH
    {
        int i;

        /* Cancel all of our dispatch sources, so they flush to ASL */
        for (i = 0; i < n_redirect_fds; i++)
            if (redirect_fds[i].read_source)
                dispatch_source_cancel(redirect_fds[i].read_source);

        /* Wait at least three seconds for our sources to flush to ASL */
        dispatch_group_wait(read_source_group,
                            dispatch_time(DISPATCH_TIME_NOW, 3LL *
                                          NSEC_PER_SEC));
    }
#else
    {
        struct kevent ev;

        /* Tell our reader thread it is time to pack up and go home */
        EV_SET(&ev, 0, EVFILT_TIMER, EV_ADD | EV_ONESHOT, 0, 0,
               ASL_REDIRECT_TERMINATE);
        kevent(kq, &ev, 1, NULL, 0, NULL);

        pthread_join(redirect_pthread, NULL);
    }
#endif
}

#ifdef HAVE_LIBDISPATCH
static void
xq_asl_init(void *ctx __unused)
#else
static void
xq_asl_init(void)
#endif
{
    assert((redirect_fds = calloc(16, sizeof(*redirect_fds))) != NULL);
    n_redirect_fds = 16;

#ifdef HAVE_LIBDISPATCH
    redirect_serial_q = dispatch_queue_create("com.apple.asl-redirect", NULL);
    assert(redirect_serial_q != NULL);

    read_source_group = dispatch_group_create();
    assert(read_source_group != NULL);
#else
    assert((kq = kqueue()) != -1);
    assert(pthread_create(&redirect_pthread, NULL, redirect_thread,
                          NULL) == 0);
#endif

    atexit(redirect_atexit);
}

#if MAC_OS_X_VERSION_MIN_REQUIRED < 1050
#define fls(v) xq_fls(v)

static inline int fls(int value) {
    unsigned int b, v;

    v = *((unsigned int *)&value);

    for(b=0 ; v ; v >>= 1 , b++);

    return b;
}
#endif

int
xq_asl_log_fd(aslclient asl, aslmsg msg, int level, int fd)
{
#ifdef HAVE_LIBDISPATCH
    int err __block = 0;
    static dispatch_once_t once_control;
    dispatch_once_f(&once_control, NULL, xq_asl_init);
#else
    int err = 0;
    static pthread_once_t once_control = PTHREAD_ONCE_INIT;
    assert(pthread_once(&once_control, xq_asl_init) == 0);
#endif

    if (fd < 0)
        return EBADF;

#ifdef HAVE_LIBDISPATCH
#define BLOCK_DONE return
    dispatch_sync(redirect_serial_q, ^
#else
#define BLOCK_DONE goto done
    assert(pthread_mutex_lock(&redirect_fds_lock) == 0);
#endif
                  {
                      /* Reallocate if we need more space */
                      if (fd >= n_redirect_fds) {
                          size_t new_n = 1 << (fls(fd) + 1);
                          asl_redirect *new_array =
                              realloc(redirect_fds, new_n *
                                      sizeof(*redirect_fds));
                          if (!new_array) {
                              err = errno;
                              BLOCK_DONE;
                          }
                          redirect_fds = new_array;
                          memset(redirect_fds + n_redirect_fds, 0, (new_n -
                                 n_redirect_fds) * sizeof(*redirect_fds));
                          n_redirect_fds = new_n;
                      }

                      /* If we're already listening on it, return error. */
                      if (redirect_fds[fd].buf != NULL) {
                          err = EBADF;
                          BLOCK_DONE;
                      }

                      /* Initialize our buffer */
                      redirect_fds[fd].buf = (char *)malloc(BUF_SIZE);
                      if (redirect_fds[fd].buf == NULL) {
                          err = errno;
                          BLOCK_DONE;
                      }
                      redirect_fds[fd].w = redirect_fds[fd].buf;

                      /* Store our ASL settings */
                      redirect_fds[fd].level = level;
                      redirect_fds[fd].asl = asl;
                      redirect_fds[fd].msg = msg;

                      /* Don't block on reads from this fd */
                      fcntl(fd, F_SETFL,
                            O_NONBLOCK);

                      /* Start listening */
#ifdef HAVE_LIBDISPATCH
                      {
                          dispatch_source_t read_source =
                              dispatch_source_create(
                                  DISPATCH_SOURCE_TYPE_READ, fd, 0,
                                  redirect_serial_q);
                          redirect_fds[fd].read_source = read_source;
                          dispatch_set_context(read_source, read_source);
                          dispatch_source_set_event_handler_f(read_source,
                                                              read_from_source);
                          dispatch_source_set_cancel_handler_f(read_source,
                                                               cancel_source);
                          dispatch_group_enter(read_source_group);
                          dispatch_resume(read_source);
                      }
#else
                      {
                          struct kevent ev;
                          EV_SET(&ev, fd, EVFILT_READ, EV_ADD, 0, 0, 0);
                          kevent(kq, &ev, 1, NULL, 0, NULL);
                      }
#endif
                  }
#ifdef HAVE_LIBDISPATCH
                  );
#else
done:
                  assert(pthread_mutex_unlock(&redirect_fds_lock) == 0);
#endif
#undef BLOCK_DONE

    return err;
}

int
xq_asl_capture_fd(aslclient asl, aslmsg msg, int level, int fd)
{
    int pipepair[2];

    /* Create pipe */
    if (pipe(pipepair) == -1)
        return errno;

    /* Close the read fd but not the write fd on exec */
    if (fcntl(pipepair[0], F_SETFD, FD_CLOEXEC) == -1)
        return errno;

    /* Replace the existing fd */
    if (dup2(pipepair[1], fd) == -1) {
        close(pipepair[0]);
        close(pipepair[1]);
        return errno;
    }

    /* If we capture STDOUT_FILENO, make sure we linebuffer stdout */
    if (fd == STDOUT_FILENO)
        setlinebuf(stdout);

    /* Close the duplicate fds since they've been reassigned */
    close(pipepair[1]);

    /* Hand off the read end of our pipe to xq_asl_log_fd */
    return xq_asl_log_fd(asl, msg, level, pipepair[0]);
}

#ifdef DEBUG_CONSOLE_REDIRECT
int
main(int argc __unused, char * *argv __unused)
{
    xq_asl_capture_fd(NULL, NULL, ASL_LEVEL_NOTICE, STDOUT_FILENO);
    xq_asl_capture_fd(NULL, NULL, ASL_LEVEL_ERR, STDERR_FILENO);

    fprintf(stderr, "TEST ERR1\n");
    fprintf(stdout, "TEST OUT1\n");
    fprintf(stderr, "TEST ERR2\n");
    fprintf(stdout, "TEST OUT2\n");
    system("/bin/echo SYST OUT");
    system("/bin/echo SYST ERR >&2");
    fprintf(stdout, "TEST OUT3\n");
    fprintf(stdout, "TEST OUT4\n");
    fprintf(stderr, "TEST ERR3\n");
    fprintf(stderr, "TEST ERR4\n");

    exit(0);
}
#endif
Commit	Line	Data
a09e091a JB	1	/*
	2	* Copyright (c) 2011-2012 Apple Inc. All rights reserved.
	3	*
	4	* Permission is hereby granted, free of charge, to any person
	5	* obtaining a copy of this software and associated documentation files
	6	* (the "Software"), to deal in the Software without restriction,
	7	* including without limitation the rights to use, copy, modify, merge,
	8	* publish, distribute, sublicense, and/or sell copies of the Software,
	9	* and to permit persons to whom the Software is furnished to do so,
	10	* subject to the following conditions:
	11	*
	12	* The above copyright notice and this permission notice shall be
	13	* included in all copies or substantial portions of the Software.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	16	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	17	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	18	* NONINFRINGEMENT. IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
	19	* HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
	20	* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
	22	* DEALINGS IN THE SOFTWARE.
	23	*
	24	* Except as contained in this notice, the name(s) of the above
	25	* copyright holders shall not be used in advertising or otherwise to
	26	* promote the sale, use or other dealings in this Software without
	27	* prior written authorization.
	28	*/
	29
	30	#ifdef HAVE_DIX_CONFIG_H
	31	#include <dix-config.h>
	32	#else
	33	#define DEBUG_CONSOLE_REDIRECT 1
	34	#define HAVE_LIBDISPATCH 1
	35	#endif
	36
	37	#include <assert.h>
	38	#include <unistd.h>
	39	#include <stdio.h>
	40	#include <string.h>
	41	#include <stdlib.h>
	42	#include <sys/types.h>
	43	#include <sys/event.h>
	44	#include <asl.h>
	45	#include <errno.h>
	46	#include <fcntl.h>
	47
	48	#include "console_redirect.h"
	49
	50	#define BUF_SIZE 512
	51
	52	#ifdef HAVE_LIBDISPATCH
	53	#include <dispatch/dispatch.h>
	54
	55	static dispatch_queue_t redirect_serial_q;
	56	static dispatch_group_t read_source_group;
	57	#else
	58	#include <pthread.h>
	59
	60	static pthread_t redirect_pthread;
	61	static pthread_mutex_t redirect_fds_lock = PTHREAD_MUTEX_INITIALIZER;
	62
	63	static int kq;
	64
65	/* Notifications to our reader thread */
66	#define ASL_REDIRECT_TERMINATE ((void *)(uintptr_t)1)
67	#endif
68
69	typedef struct {
70	int level;
71	aslclient asl;
72	aslmsg msg;
73
74	/* Buffered reading */
75	char *buf;
76	char *w;
77
78	#ifdef HAVE_LIBDISPATCH
79	dispatch_source_t read_source;
80	#endif
81	} asl_redirect;
82
83	static asl_redirect *redirect_fds = NULL;
84	static int n_redirect_fds = 0;
85
86	/* Read from the FD until there is no more to read and redirect to ASL.
87	* Preconditions:
88	* 1: pthread_mutex_lock lock is held (pthreads) or called
89	* from the appropriate serial queue for operating on
90	* redirect_fds
91	* 2: fd corresponds to a valid entry in redirect_fds
92	*
93	* Return values:
94	* If the pipe is closed, EOF is returned regardless of how many bytes
95	* were processed. If the pipe is still open, the number of read bytes
96	* is returned.
97	*/
98	static inline int
99	_read_redirect(int fd, int flush)
100	{
101	int total_read = 0;
102	int nbytes;
103	asl_redirect *aslr = &redirect_fds[fd];
104
105	while ((nbytes =
106	read(fd, aslr->w,
107	BUF_SIZE - (aslr->w - aslr->buf) - 1)) > 0) {
108	char s, p;
109
110	/* Increment our returned number read */
111	total_read += nbytes;
112
113	/* Increment our write location */
114	aslr->w += nbytes;
115	aslr->w[0] = '\0';
116
117	/* One line at a time */
118	for (p = aslr->buf; p < aslr->w; p = s + 1) {
119	// Find null or \n
120	for (s = p; s && s != '\n'; s++) ;
121	if (*s == '\n') {
122	*s = '\0';
123	}
124
125	if (s < aslr->w \|\| aslr->buf == p) {
126	/* Either the first of multiple messages or one message which is larger than our buffer */
127	asl_log(aslr->asl, aslr->msg, aslr->level, "%s", p);
128	}
129	else {
130	/* We reached the end of the buffer, move this chunk to the start. */
131	memmove(aslr->buf, p, BUF_SIZE - (p - aslr->buf));
132	aslr->w = aslr->buf + (s - p);
133	break;
134	}
135	}
136
137	if (p == aslr->w) {
138	/* Start writing at the beginning in the case where we flushed */
139	aslr->w = aslr->buf;
140	}
141	}
142
143	/* Flush if requested or we're at EOF */
144	if (flush \|\| nbytes == 0) {
145	if (aslr->w > aslr->buf) {
146	*aslr->w = '\0';
147	asl_log(aslr->asl, aslr->msg, aslr->level, "%s", aslr->buf);
148	}
149	}
150
151	if (nbytes == 0)
152	return EOF;
153	return total_read;
154	}
155
156	#ifdef HAVE_LIBDISPATCH
157	static void
158	read_from_source(void *_source)
159	{
160	dispatch_source_t source = (dispatch_source_t)_source;
161	int fd = dispatch_source_get_handle(source);
162	if (_read_redirect(fd, 0) == EOF) {
163	dispatch_source_cancel(source);
164	}
165	}
166
167	static void
168	cancel_source(void *_source)
169	{
170	dispatch_source_t source = (dispatch_source_t)_source;
171	int fd = dispatch_source_get_handle(source);
172	asl_redirect *aslr = &redirect_fds[fd];
173
174	/* Flush the buffer */
175	_read_redirect(fd, 1);
176
177	close(fd);
178	free(aslr->buf);
179	memset(aslr, 0, sizeof(*aslr));
180	dispatch_release(source);
181	dispatch_group_leave(read_source_group);
182	}
183
184	#else /* !HAVE_LIBDISPATCH */
185	static void *
186	redirect_thread(void *ctx __unused)
187	{
188	struct kevent ev;
189	int n;
190
191	while (1) {
192	n = kevent(kq, NULL, 0, &ev, 1, NULL);
193
194	/* Bail on errors */
195	if (n < 0) {
196	asl_log(NULL, NULL, ASL_LEVEL_ERR, "kevent failure: %s",
197	strerror(errno));
198	break;
199	}
200
201	/* This should not happen */
202	if (n == 0)
203	continue;
204
205	switch (ev.filter) {
206	case EVFILT_READ:
207	pthread_mutex_lock(&redirect_fds_lock);
208	{
209	int fd = ev.ident;
210	int close_fd = 0;
211	asl_redirect *aslr = &redirect_fds[fd];
212
213	if (fd < 0 \|\| fd >= n_redirect_fds \|\| aslr->buf == NULL) {
214	asl_log(NULL, NULL, ASL_LEVEL_ERR,
215	"Unexpected file descriptor: %d",
216	fd);
217	goto next;
218	}
219
220	if (ev.flags & EV_EOF) {
221	close_fd = 1;
222	if (EOF != _read_redirect(fd, 1)) {
223	asl_log(
224	NULL, NULL, ASL_LEVEL_ERR,
225	"kevent reported EOF on %d, but read doesn't concur.",
226	fd);
227	}
228	}
229	else {
230	close_fd = (EOF == _read_redirect(fd, 0));
231	}
232
233	if (close_fd) {
234	EV_SET(&ev, fd, EVFILT_READ, EV_DELETE, 0, 0, 0);
235	kevent(kq, &ev, 1, NULL, 0, NULL);
236	close(fd);
237	free(aslr->buf);
238	memset(aslr, 0, sizeof(*aslr));
239	}
240	}
241	next:
242	pthread_mutex_unlock(&redirect_fds_lock);
243
244	case EVFILT_TIMER:
245	if (ev.udata == ASL_REDIRECT_TERMINATE)
246	return NULL;
247
248	default:
249	;
250	;
251	}
252	}
253
254	return NULL;
255	}
256	#endif
257
258	static void
259	redirect_atexit(void)
260	{
261	/* stdout is linebuffered, so flush the buffer */
262	if (redirect_fds[STDOUT_FILENO].buf)
263	fflush(stdout);
264
265	#ifdef HAVE_LIBDISPATCH
266	{
267	int i;
268
269	/* Cancel all of our dispatch sources, so they flush to ASL */
270	for (i = 0; i < n_redirect_fds; i++)
271	if (redirect_fds[i].read_source)
272	dispatch_source_cancel(redirect_fds[i].read_source);
273
274	/* Wait at least three seconds for our sources to flush to ASL */
275	dispatch_group_wait(read_source_group,
276	dispatch_time(DISPATCH_TIME_NOW, 3LL *
277	NSEC_PER_SEC));
278	}
279	#else
280	{
281	struct kevent ev;
282
283	/* Tell our reader thread it is time to pack up and go home */
284	EV_SET(&ev, 0, EVFILT_TIMER, EV_ADD \| EV_ONESHOT, 0, 0,
285	ASL_REDIRECT_TERMINATE);
286	kevent(kq, &ev, 1, NULL, 0, NULL);
287
288	pthread_join(redirect_pthread, NULL);
289	}
290	#endif
291	}
292
293	#ifdef HAVE_LIBDISPATCH
294	static void
295	xq_asl_init(void *ctx __unused)
296	#else
297	static void
298	xq_asl_init(void)
299	#endif
300	{
301	assert((redirect_fds = calloc(16, sizeof(*redirect_fds))) != NULL);
302	n_redirect_fds = 16;
303
304	#ifdef HAVE_LIBDISPATCH
305	redirect_serial_q = dispatch_queue_create("com.apple.asl-redirect", NULL);
306	assert(redirect_serial_q != NULL);
307
308	read_source_group = dispatch_group_create();
309	assert(read_source_group != NULL);
310	#else
311	assert((kq = kqueue()) != -1);
312	assert(pthread_create(&redirect_pthread, NULL, redirect_thread,
313	NULL) == 0);
314	#endif
315
316	atexit(redirect_atexit);
317	}
318
319	#if MAC_OS_X_VERSION_MIN_REQUIRED < 1050
320	#define fls(v) xq_fls(v)
321
322	static inline int fls(int value) {
323	unsigned int b, v;
324
325	v = ((unsigned int )&value);
326
327	for(b=0 ; v ; v >>= 1 , b++);
328
329	return b;
330	}
331	#endif
332
333	int
334	xq_asl_log_fd(aslclient asl, aslmsg msg, int level, int fd)
335	{
336	#ifdef HAVE_LIBDISPATCH
337	int err __block = 0;
338	static dispatch_once_t once_control;
339	dispatch_once_f(&once_control, NULL, xq_asl_init);
340	#else
341	int err = 0;
342	static pthread_once_t once_control = PTHREAD_ONCE_INIT;
343	assert(pthread_once(&once_control, xq_asl_init) == 0);
344	#endif
345
346	if (fd < 0)
347	return EBADF;
348
349	#ifdef HAVE_LIBDISPATCH
350	#define BLOCK_DONE return
351	dispatch_sync(redirect_serial_q, ^
352	#else
353	#define BLOCK_DONE goto done
354	assert(pthread_mutex_lock(&redirect_fds_lock) == 0);
355	#endif
356	{
357	/* Reallocate if we need more space */
358	if (fd >= n_redirect_fds) {
359	size_t new_n = 1 << (fls(fd) + 1);
360	asl_redirect *new_array =
361	realloc(redirect_fds, new_n *
362	sizeof(*redirect_fds));
363	if (!new_array) {
364	err = errno;
365	BLOCK_DONE;
366	}
367	redirect_fds = new_array;
368	memset(redirect_fds + n_redirect_fds, 0, (new_n -
369	n_redirect_fds) * sizeof(*redirect_fds));
370	n_redirect_fds = new_n;
371	}
372
373	/* If we're already listening on it, return error. */
374	if (redirect_fds[fd].buf != NULL) {
375	err = EBADF;
376	BLOCK_DONE;
377	}
378
379	/* Initialize our buffer */
380	redirect_fds[fd].buf = (char *)malloc(BUF_SIZE);
381	if (redirect_fds[fd].buf == NULL) {
382	err = errno;
383	BLOCK_DONE;
384	}
385	redirect_fds[fd].w = redirect_fds[fd].buf;
386
387	/* Store our ASL settings */
388	redirect_fds[fd].level = level;
389	redirect_fds[fd].asl = asl;
390	redirect_fds[fd].msg = msg;
391
392	/* Don't block on reads from this fd */
393	fcntl(fd, F_SETFL,
394	O_NONBLOCK);
395
396	/* Start listening */
397	#ifdef HAVE_LIBDISPATCH
398	{
399	dispatch_source_t read_source =
400	dispatch_source_create(
401	DISPATCH_SOURCE_TYPE_READ, fd, 0,
402	redirect_serial_q);
403	redirect_fds[fd].read_source = read_source;
404	dispatch_set_context(read_source, read_source);
405	dispatch_source_set_event_handler_f(read_source,
406	read_from_source);
407	dispatch_source_set_cancel_handler_f(read_source,
408	cancel_source);
409	dispatch_group_enter(read_source_group);
410	dispatch_resume(read_source);
411	}
412	#else
413	{
414	struct kevent ev;
415	EV_SET(&ev, fd, EVFILT_READ, EV_ADD, 0, 0, 0);
416	kevent(kq, &ev, 1, NULL, 0, NULL);
417	}
418	#endif
419	}
420	#ifdef HAVE_LIBDISPATCH
421	);
422	#else
423	done:
424	assert(pthread_mutex_unlock(&redirect_fds_lock) == 0);
425	#endif
426	#undef BLOCK_DONE
427
428	return err;
429	}
430
431	int
432	xq_asl_capture_fd(aslclient asl, aslmsg msg, int level, int fd)
433	{
434	int pipepair[2];
435
436	/* Create pipe */
437	if (pipe(pipepair) == -1)
438	return errno;
439
440	/* Close the read fd but not the write fd on exec */
441	if (fcntl(pipepair[0], F_SETFD, FD_CLOEXEC) == -1)
442	return errno;
443
444	/* Replace the existing fd */
445	if (dup2(pipepair[1], fd) == -1) {
446	close(pipepair[0]);
447	close(pipepair[1]);
448	return errno;
449	}
450
451	/* If we capture STDOUT_FILENO, make sure we linebuffer stdout */
452	if (fd == STDOUT_FILENO)
453	setlinebuf(stdout);
454
455	/* Close the duplicate fds since they've been reassigned */
456	close(pipepair[1]);
457
458	/* Hand off the read end of our pipe to xq_asl_log_fd */
459	return xq_asl_log_fd(asl, msg, level, pipepair[0]);
460	}
461
462	#ifdef DEBUG_CONSOLE_REDIRECT
463	int
464	main(int argc __unused, char * *argv __unused)
465	{
466	xq_asl_capture_fd(NULL, NULL, ASL_LEVEL_NOTICE, STDOUT_FILENO);
467	xq_asl_capture_fd(NULL, NULL, ASL_LEVEL_ERR, STDERR_FILENO);
468
469	fprintf(stderr, "TEST ERR1\n");
470	fprintf(stdout, "TEST OUT1\n");
471	fprintf(stderr, "TEST ERR2\n");
472	fprintf(stdout, "TEST OUT2\n");
473	system("/bin/echo SYST OUT");
474	system("/bin/echo SYST ERR >&2");
475	fprintf(stdout, "TEST OUT3\n");
476	fprintf(stdout, "TEST OUT4\n");
477	fprintf(stderr, "TEST ERR3\n");
478	fprintf(stderr, "TEST ERR4\n");
479
480	exit(0);
481	}
482	#endif