[thirdparty/systemd.git] / src / udev / libudev-queue.c

/*
 * libudev - interface to udev device information
 *
 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
 * Copyright (C) 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <dirent.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/stat.h>

#include "libudev.h"
#include "libudev-private.h"

/**
 * SECTION:libudev-queue
 * @short_description: access to currently active events
 *
 * The udev daemon processes events asynchronously. All events which do not have
 * interdependencies run in parallel. This exports the current state of the
 * event processing queue, and the current event sequence numbers from the kernel
 * and the udev daemon.
 */

/**
 * udev_queue:
 *
 * Opaque object representing the current event queue in the udev daemon.
 */
struct udev_queue {
        struct udev *udev;
        int refcount;
        struct udev_list queue_list;
};

/**
 * udev_queue_new:
 * @udev: udev library context
 *
 * The initial refcount is 1, and needs to be decremented to
 * release the resources of the udev queue context.
 *
 * Returns: the udev queue context, or #NULL on error.
 **/
UDEV_EXPORT struct udev_queue *udev_queue_new(struct udev *udev)
{
        struct udev_queue *udev_queue;

        if (udev == NULL)
                return NULL;

        udev_queue = calloc(1, sizeof(struct udev_queue));
        if (udev_queue == NULL)
                return NULL;
        udev_queue->refcount = 1;
        udev_queue->udev = udev;
        udev_list_init(udev, &udev_queue->queue_list, false);
        return udev_queue;
}

/**
 * udev_queue_ref:
 * @udev_queue: udev queue context
 *
 * Take a reference of a udev queue context.
 *
 * Returns: the same udev queue context.
 **/
UDEV_EXPORT struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue)
{
        if (udev_queue == NULL)
                return NULL;
        udev_queue->refcount++;
        return udev_queue;
}

/**
 * udev_queue_unref:
 * @udev_queue: udev queue context
 *
 * Drop a reference of a udev queue context. If the refcount reaches zero,
 * the resources of the queue context will be released.
 **/
UDEV_EXPORT void udev_queue_unref(struct udev_queue *udev_queue)
{
        if (udev_queue == NULL)
                return;
        udev_queue->refcount--;
        if (udev_queue->refcount > 0)
                return;
        udev_list_cleanup(&udev_queue->queue_list);
        free(udev_queue);
}

/**
 * udev_queue_get_udev:
 * @udev_queue: udev queue context
 *
 * Retrieve the udev library context the queue context was created with.
 *
 * Returns: the udev library context.
 **/
UDEV_EXPORT struct udev *udev_queue_get_udev(struct udev_queue *udev_queue)
{
        if (udev_queue == NULL)
                return NULL;
        return udev_queue->udev;
}

unsigned long long int udev_get_kernel_seqnum(struct udev *udev)
{
        char filename[UTIL_PATH_SIZE];
        unsigned long long int seqnum;
        int fd;
        char buf[32];
        ssize_t len;

        util_strscpyl(filename, sizeof(filename), udev_get_sys_path(udev), "/kernel/uevent_seqnum", NULL);
        fd = open(filename, O_RDONLY|O_CLOEXEC);
        if (fd < 0)
                return 0;
        len = read(fd, buf, sizeof(buf));
        close(fd);
        if (len <= 2)
                return 0;
        buf[len-1] = '\0';
        seqnum = strtoull(buf, NULL, 10);
        return seqnum;
}

/**
 * udev_queue_get_kernel_seqnum:
 * @udev_queue: udev queue context
 *
 * Returns: the current kernel event sequence number.
 **/
UDEV_EXPORT unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
{
        unsigned long long int seqnum;

        if (udev_queue == NULL)
                return -EINVAL;

        seqnum = udev_get_kernel_seqnum(udev_queue->udev);
        dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
        return seqnum;
}

int udev_queue_read_seqnum(FILE *queue_file, unsigned long long int *seqnum)
{
        if (fread(seqnum, sizeof(unsigned long long int), 1, queue_file) != 1)
                return -1;

        return 0;
}

ssize_t udev_queue_skip_devpath(FILE *queue_file)
{
        unsigned short int len;

        if (fread(&len, sizeof(unsigned short int), 1, queue_file) == 1) {
                char *devpath = alloca(len);

                /* use fread to skip, fseek might drop buffered data */
                if (fread(devpath, 1, len, queue_file) == len)
                        return len;
        }

        return -1;
}

ssize_t udev_queue_read_devpath(FILE *queue_file, char *devpath, size_t size)
{
        unsigned short int read_bytes = 0;
        unsigned short int len;

        if (fread(&len, sizeof(unsigned short int), 1, queue_file) != 1)
                return -1;

        read_bytes = (len < size - 1) ? len : size - 1;
        if (fread(devpath, 1, read_bytes, queue_file) != read_bytes)
                return -1;
        devpath[read_bytes] = '\0';

        /* if devpath was too long, skip unread characters */
        if (read_bytes != len) {
                unsigned short int skip_bytes = len - read_bytes;
                char *buf = alloca(skip_bytes);

                if (fread(buf, 1, skip_bytes, queue_file) != skip_bytes)
                        return -1;
        }

        return read_bytes;
}

static FILE *open_queue_file(struct udev_queue *udev_queue, unsigned long long int *seqnum_start)
{
        char filename[UTIL_PATH_SIZE];
        FILE *queue_file;

        util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev_queue->udev), "/queue.bin", NULL);
        queue_file = fopen(filename, "re");
        if (queue_file == NULL)
                return NULL;

        if (udev_queue_read_seqnum(queue_file, seqnum_start) < 0) {
                err(udev_queue->udev, "corrupt queue file\n");
                fclose(queue_file);
                return NULL;
        }

        return queue_file;
}

/**
 * udev_queue_get_udev_seqnum:
 * @udev_queue: udev queue context
 *
 * Returns: the last known udev event sequence number.
 **/
UDEV_EXPORT unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
{
        unsigned long long int seqnum_udev;
        FILE *queue_file;

        queue_file = open_queue_file(udev_queue, &seqnum_udev);
        if (queue_file == NULL)
                return 0;

        for (;;) {
                unsigned long long int seqnum;
                ssize_t devpath_len;

                if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
                        break;
                devpath_len = udev_queue_skip_devpath(queue_file);
                if (devpath_len < 0)
                        break;
                if (devpath_len > 0)
                        seqnum_udev = seqnum;
        }

        fclose(queue_file);
        return seqnum_udev;
}

/**
 * udev_queue_get_udev_is_active:
 * @udev_queue: udev queue context
 *
 * Returns: a flag indicating if udev is active.
 **/
UDEV_EXPORT int udev_queue_get_udev_is_active(struct udev_queue *udev_queue)
{
        unsigned long long int seqnum_start;
        FILE *queue_file;

        queue_file = open_queue_file(udev_queue, &seqnum_start);
        if (queue_file == NULL)
                return 0;

        fclose(queue_file);
        return 1;
}

/**
 * udev_queue_get_queue_is_empty:
 * @udev_queue: udev queue context
 *
 * Returns: a flag indicating if udev is currently handling events.
 **/
UDEV_EXPORT int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
{
        unsigned long long int seqnum_kernel;
        unsigned long long int seqnum_udev = 0;
        int queued = 0;
        int is_empty = 0;
        FILE *queue_file;

        if (udev_queue == NULL)
                return -EINVAL;
        queue_file = open_queue_file(udev_queue, &seqnum_udev);
        if (queue_file == NULL)
                return 1;

        for (;;) {
                unsigned long long int seqnum;
                ssize_t devpath_len;

                if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
                        break;
                devpath_len = udev_queue_skip_devpath(queue_file);
                if (devpath_len < 0)
                        break;

                if (devpath_len > 0) {
                        queued++;
                        seqnum_udev = seqnum;
                } else {
                        queued--;
                }
        }

        if (queued > 0) {
                dbg(udev_queue->udev, "queue is not empty\n");
                goto out;
        }

        seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
        if (seqnum_udev < seqnum_kernel) {
                dbg(udev_queue->udev, "queue is empty but kernel events still pending [%llu]<->[%llu]\n",
                                      seqnum_kernel, seqnum_udev);
                goto out;
        }

        dbg(udev_queue->udev, "queue is empty\n");
        is_empty = 1;

out:
        fclose(queue_file);
        return is_empty;
}

/**
 * udev_queue_get_seqnum_sequence_is_finished:
 * @udev_queue: udev queue context
 * @start: first event sequence number
 * @end: last event sequence number
 *
 * Returns: a flag indicating if any of the sequence numbers in the given range is currently active.
 **/
UDEV_EXPORT int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue,
                                               unsigned long long int start, unsigned long long int end)
{
        unsigned long long int seqnum;
        ssize_t devpath_len;
        int unfinished;
        FILE *queue_file;

        if (udev_queue == NULL)
                return -EINVAL;
        queue_file = open_queue_file(udev_queue, &seqnum);
        if (queue_file == NULL)
                return 1;
        if (start < seqnum)
                start = seqnum;
        if (start > end) {
                fclose(queue_file);
                return 1;
        }
        if (end - start > INT_MAX - 1) {
                fclose(queue_file);
                return -EOVERFLOW;
        }

        /*
         * we might start with 0, and handle the initial seqnum
         * only when we find an entry in the queue file
         **/
        unfinished = end - start;

        do {
                if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
                        break;
                devpath_len = udev_queue_skip_devpath(queue_file);
                if (devpath_len < 0)
                        break;

                /*
                 * we might start with an empty or re-build queue file, where
                 * the initial seqnum is not recorded as finished
                 */
                if (start == seqnum && devpath_len > 0)
                        unfinished++;

                if (devpath_len == 0) {
                        if (seqnum >= start && seqnum <= end)
                                unfinished--;
                }
        } while (unfinished > 0);

        fclose(queue_file);

        return (unfinished == 0);
}

/**
 * udev_queue_get_seqnum_is_finished:
 * @udev_queue: udev queue context
 * @seqnum: sequence number
 *
 * Returns: a flag indicating if the given sequence number is currently active.
 **/
UDEV_EXPORT int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
{
        if (!udev_queue_get_seqnum_sequence_is_finished(udev_queue, seqnum, seqnum))
                return 0;

        dbg(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
        return 1;
}

/**
 * udev_queue_get_queued_list_entry:
 * @udev_queue: udev queue context
 *
 * Returns: the first entry of the list of queued events.
 **/
UDEV_EXPORT struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue)
{
        unsigned long long int seqnum;
        FILE *queue_file;

        if (udev_queue == NULL)
                return NULL;
        udev_list_cleanup(&udev_queue->queue_list);

        queue_file = open_queue_file(udev_queue, &seqnum);
        if (queue_file == NULL)
                return NULL;

        for (;;) {
                char syspath[UTIL_PATH_SIZE];
                char *s;
                size_t l;
                ssize_t len;
                char seqnum_str[32];
                struct udev_list_entry *list_entry;

                if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
                        break;
                snprintf(seqnum_str, sizeof(seqnum_str), "%llu", seqnum);

                s = syspath;
                l = util_strpcpyl(&s, sizeof(syspath), udev_get_sys_path(udev_queue->udev), NULL);
                len = udev_queue_read_devpath(queue_file, s, l);
                if (len < 0)
                        break;

                if (len > 0) {
                        udev_list_entry_add(&udev_queue->queue_list, syspath, seqnum_str);
                } else {
                        udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_queue->queue_list)) {
                                if (strcmp(seqnum_str, udev_list_entry_get_value(list_entry)) == 0) {
                                        udev_list_entry_delete(list_entry);
                                        break;
                                }
                        }
                }
        }
        fclose(queue_file);

        return udev_list_get_entry(&udev_queue->queue_list);
}

struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue);
UDEV_EXPORT struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue)
{
        errno = ENOSYS;
        return NULL;
}
Commit	Line	Data
64ccdf82 KS	1	/*
	2	* libudev - interface to udev device information
	3	*
	4	* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
f503f6b2	5	* Copyright (C) 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
64ccdf82	6	*
4061ab9f KS	7	* This library is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU Lesser General Public
	9	* License as published by the Free Software Foundation; either
	10	* version 2.1 of the License, or (at your option) any later version.
64ccdf82 KS	11	*/
	12
	13	#include <stdio.h>
	14	#include <stdlib.h>
	15	#include <stddef.h>
	16	#include <unistd.h>
	17	#include <errno.h>
	18	#include <string.h>
	19	#include <dirent.h>
	20	#include <fcntl.h>
f503f6b2	21	#include <limits.h>
64ccdf82 KS	22	#include <sys/stat.h>
	23
	24	#include "libudev.h"
	25	#include "libudev-private.h"
	26
ce1d6d7f KS	27	/**
	28	* SECTION:libudev-queue
	29	* @short_description: access to currently active events
	30	*
a7d29d15 KS	31	* The udev daemon processes events asynchronously. All events which do not have
	32	* interdependencies run in parallel. This exports the current state of the
	33	* event processing queue, and the current event sequence numbers from the kernel
ce1d6d7f KS	34	* and the udev daemon.
	35	*/
	36
	37	/**
	38	* udev_queue:
	39	*
	40	* Opaque object representing the current event queue in the udev daemon.
	41	*/
64ccdf82	42	struct udev_queue {
912541b0 KS	43	struct udev *udev;
	44	int refcount;
	45	struct udev_list queue_list;
64ccdf82 KS	46	};
64ccdf82 KS	47
8d6bc73a KS	48	/**
	49	* udev_queue_new:
	50	* @udev: udev library context
	51	*
	52	* The initial refcount is 1, and needs to be decremented to
	53	* release the resources of the udev queue context.
	54	*
	55	* Returns: the udev queue context, or #NULL on error.
	56	**/
666fcf03	57	UDEV_EXPORT struct udev_queue udev_queue_new(struct udev udev)
64ccdf82	58	{
912541b0 KS	59	struct udev_queue *udev_queue;
	60
	61	if (udev == NULL)
	62	return NULL;
	63
	64	udev_queue = calloc(1, sizeof(struct udev_queue));
	65	if (udev_queue == NULL)
	66	return NULL;
	67	udev_queue->refcount = 1;
	68	udev_queue->udev = udev;
	69	udev_list_init(udev, &udev_queue->queue_list, false);
	70	return udev_queue;
64ccdf82 KS	71	}
64ccdf82 KS	72
8d6bc73a KS	73	/**
	74	* udev_queue_ref:
	75	* @udev_queue: udev queue context
	76	*
	77	* Take a reference of a udev queue context.
	78	*
	79	* Returns: the same udev queue context.
	80	**/
666fcf03	81	UDEV_EXPORT struct udev_queue udev_queue_ref(struct udev_queue udev_queue)
64ccdf82	82	{
912541b0 KS	83	if (udev_queue == NULL)
	84	return NULL;
	85	udev_queue->refcount++;
	86	return udev_queue;
64ccdf82 KS	87	}
64ccdf82 KS	88
8d6bc73a KS	89	/**
	90	* udev_queue_unref:
	91	* @udev_queue: udev queue context
	92	*
	93	* Drop a reference of a udev queue context. If the refcount reaches zero,
	94	* the resources of the queue context will be released.
	95	**/
666fcf03	96	UDEV_EXPORT void udev_queue_unref(struct udev_queue *udev_queue)
64ccdf82	97	{
912541b0 KS	98	if (udev_queue == NULL)
	99	return;
	100	udev_queue->refcount--;
	101	if (udev_queue->refcount > 0)
	102	return;
	103	udev_list_cleanup(&udev_queue->queue_list);
	104	free(udev_queue);
64ccdf82 KS	105	}
64ccdf82 KS	106
8d6bc73a KS	107	/**
	108	* udev_queue_get_udev:
	109	* @udev_queue: udev queue context
	110	*
	111	* Retrieve the udev library context the queue context was created with.
	112	*
	113	* Returns: the udev library context.
	114	**/
666fcf03	115	UDEV_EXPORT struct udev udev_queue_get_udev(struct udev_queue udev_queue)
64ccdf82	116	{
912541b0 KS	117	if (udev_queue == NULL)
	118	return NULL;
	119	return udev_queue->udev;
64ccdf82 KS	120	}
64ccdf82 KS	121
f503f6b2	122	unsigned long long int udev_get_kernel_seqnum(struct udev *udev)
64ccdf82	123	{
912541b0 KS	124	char filename[UTIL_PATH_SIZE];
	125	unsigned long long int seqnum;
	126	int fd;
	127	char buf[32];
	128	ssize_t len;
	129
	130	util_strscpyl(filename, sizeof(filename), udev_get_sys_path(udev), "/kernel/uevent_seqnum", NULL);
	131	fd = open(filename, O_RDONLY\|O_CLOEXEC);
	132	if (fd < 0)
	133	return 0;
	134	len = read(fd, buf, sizeof(buf));
	135	close(fd);
	136	if (len <= 2)
	137	return 0;
	138	buf[len-1] = '\0';
	139	seqnum = strtoull(buf, NULL, 10);
	140	return seqnum;
64ccdf82 KS	141	}
64ccdf82 KS	142
8d6bc73a KS	143	/**
	144	* udev_queue_get_kernel_seqnum:
	145	* @udev_queue: udev queue context
	146	*
	147	* Returns: the current kernel event sequence number.
	148	**/
666fcf03	149	UDEV_EXPORT unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
64ccdf82	150	{
912541b0	151	unsigned long long int seqnum;
64ccdf82	152
912541b0 KS	153	if (udev_queue == NULL)
912541b0 KS	154	return -EINVAL;
f503f6b2	155
912541b0 KS	156	seqnum = udev_get_kernel_seqnum(udev_queue->udev);
	157	dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
	158	return seqnum;
64ccdf82 KS	159	}
64ccdf82 KS	160
f503f6b2 AJ	161	int udev_queue_read_seqnum(FILE queue_file, unsigned long long int seqnum)
f503f6b2 AJ	162	{
912541b0 KS	163	if (fread(seqnum, sizeof(unsigned long long int), 1, queue_file) != 1)
912541b0 KS	164	return -1;
f503f6b2	165
912541b0	166	return 0;
f503f6b2 AJ	167	}
	168
	169	ssize_t udev_queue_skip_devpath(FILE *queue_file)
	170	{
912541b0	171	unsigned short int len;
f503f6b2	172
912541b0	173	if (fread(&len, sizeof(unsigned short int), 1, queue_file) == 1) {
fc863dea	174	char *devpath = alloca(len);
f503f6b2	175
912541b0 KS	176	/* use fread to skip, fseek might drop buffered data */
	177	if (fread(devpath, 1, len, queue_file) == len)
	178	return len;
	179	}
f503f6b2	180
912541b0	181	return -1;
f503f6b2 AJ	182	}
	183
	184	ssize_t udev_queue_read_devpath(FILE queue_file, char devpath, size_t size)
	185	{
912541b0 KS	186	unsigned short int read_bytes = 0;
912541b0 KS	187	unsigned short int len;
f503f6b2	188
912541b0 KS	189	if (fread(&len, sizeof(unsigned short int), 1, queue_file) != 1)
912541b0 KS	190	return -1;
f503f6b2	191
912541b0 KS	192	read_bytes = (len < size - 1) ? len : size - 1;
	193	if (fread(devpath, 1, read_bytes, queue_file) != read_bytes)
	194	return -1;
	195	devpath[read_bytes] = '\0';
f503f6b2	196
912541b0 KS	197	/* if devpath was too long, skip unread characters */
	198	if (read_bytes != len) {
	199	unsigned short int skip_bytes = len - read_bytes;
fc863dea	200	char *buf = alloca(skip_bytes);
f503f6b2	201
912541b0 KS	202	if (fread(buf, 1, skip_bytes, queue_file) != skip_bytes)
	203	return -1;
	204	}
f503f6b2	205
912541b0	206	return read_bytes;
f503f6b2 AJ	207	}
	208
	209	static FILE open_queue_file(struct udev_queue udev_queue, unsigned long long int *seqnum_start)
11d5eec2	210	{
912541b0 KS	211	char filename[UTIL_PATH_SIZE];
912541b0 KS	212	FILE *queue_file;
11d5eec2	213
912541b0 KS	214	util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev_queue->udev), "/queue.bin", NULL);
	215	queue_file = fopen(filename, "re");
	216	if (queue_file == NULL)
	217	return NULL;
f503f6b2	218
912541b0 KS	219	if (udev_queue_read_seqnum(queue_file, seqnum_start) < 0) {
	220	err(udev_queue->udev, "corrupt queue file\n");
	221	fclose(queue_file);
	222	return NULL;
	223	}
f503f6b2	224
912541b0	225	return queue_file;
f503f6b2 AJ	226	}
f503f6b2 AJ	227
8d6bc73a KS	228	/**
	229	* udev_queue_get_udev_seqnum:
	230	* @udev_queue: udev queue context
	231	*
	232	* Returns: the last known udev event sequence number.
	233	**/
666fcf03	234	UDEV_EXPORT unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
f503f6b2	235	{
912541b0 KS	236	unsigned long long int seqnum_udev;
	237	FILE *queue_file;
	238
	239	queue_file = open_queue_file(udev_queue, &seqnum_udev);
	240	if (queue_file == NULL)
	241	return 0;
	242
	243	for (;;) {
	244	unsigned long long int seqnum;
	245	ssize_t devpath_len;
	246
	247	if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
	248	break;
	249	devpath_len = udev_queue_skip_devpath(queue_file);
	250	if (devpath_len < 0)
	251	break;
	252	if (devpath_len > 0)
	253	seqnum_udev = seqnum;
	254	}
	255
	256	fclose(queue_file);
	257	return seqnum_udev;
f503f6b2 AJ	258	}
f503f6b2 AJ	259
8d6bc73a KS	260	/**
	261	* udev_queue_get_udev_is_active:
	262	* @udev_queue: udev queue context
	263	*
	264	* Returns: a flag indicating if udev is active.
	265	**/
666fcf03	266	UDEV_EXPORT int udev_queue_get_udev_is_active(struct udev_queue *udev_queue)
f503f6b2	267	{
912541b0 KS	268	unsigned long long int seqnum_start;
912541b0 KS	269	FILE *queue_file;
f503f6b2	270
912541b0 KS	271	queue_file = open_queue_file(udev_queue, &seqnum_start);
	272	if (queue_file == NULL)
	273	return 0;
f503f6b2	274
912541b0 KS	275	fclose(queue_file);
912541b0 KS	276	return 1;
11d5eec2 KS	277	}
11d5eec2 KS	278
8d6bc73a KS	279	/**
	280	* udev_queue_get_queue_is_empty:
	281	* @udev_queue: udev queue context
	282	*
	283	* Returns: a flag indicating if udev is currently handling events.
	284	**/
666fcf03	285	UDEV_EXPORT int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
64ccdf82	286	{
912541b0 KS	287	unsigned long long int seqnum_kernel;
	288	unsigned long long int seqnum_udev = 0;
	289	int queued = 0;
	290	int is_empty = 0;
	291	FILE *queue_file;
	292
	293	if (udev_queue == NULL)
	294	return -EINVAL;
	295	queue_file = open_queue_file(udev_queue, &seqnum_udev);
	296	if (queue_file == NULL)
	297	return 1;
	298
	299	for (;;) {
	300	unsigned long long int seqnum;
	301	ssize_t devpath_len;
	302
	303	if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
	304	break;
	305	devpath_len = udev_queue_skip_devpath(queue_file);
	306	if (devpath_len < 0)
	307	break;
	308
	309	if (devpath_len > 0) {
	310	queued++;
	311	seqnum_udev = seqnum;
	312	} else {
	313	queued--;
	314	}
	315	}
	316
	317	if (queued > 0) {
	318	dbg(udev_queue->udev, "queue is not empty\n");
	319	goto out;
	320	}
	321
	322	seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
	323	if (seqnum_udev < seqnum_kernel) {
	324	dbg(udev_queue->udev, "queue is empty but kernel events still pending [%llu]<->[%llu]\n",
6997e3b2	325	seqnum_kernel, seqnum_udev);
912541b0 KS	326	goto out;
	327	}
	328
	329	dbg(udev_queue->udev, "queue is empty\n");
	330	is_empty = 1;
f503f6b2 AJ	331
f503f6b2 AJ	332	out:
912541b0 KS	333	fclose(queue_file);
912541b0 KS	334	return is_empty;
64ccdf82 KS	335	}
64ccdf82 KS	336
8d6bc73a KS	337	/**
	338	* udev_queue_get_seqnum_sequence_is_finished:
	339	* @udev_queue: udev queue context
	340	* @start: first event sequence number
	341	* @end: last event sequence number
	342	*
2906cbba	343	* Returns: a flag indicating if any of the sequence numbers in the given range is currently active.
8d6bc73a	344	**/
666fcf03	345	UDEV_EXPORT int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue,
912541b0	346	unsigned long long int start, unsigned long long int end)
64ccdf82	347	{
912541b0 KS	348	unsigned long long int seqnum;
	349	ssize_t devpath_len;
	350	int unfinished;
	351	FILE *queue_file;
	352
	353	if (udev_queue == NULL)
	354	return -EINVAL;
	355	queue_file = open_queue_file(udev_queue, &seqnum);
	356	if (queue_file == NULL)
	357	return 1;
	358	if (start < seqnum)
	359	start = seqnum;
	360	if (start > end) {
	361	fclose(queue_file);
	362	return 1;
	363	}
	364	if (end - start > INT_MAX - 1) {
	365	fclose(queue_file);
	366	return -EOVERFLOW;
	367	}
	368
	369	/*
	370	* we might start with 0, and handle the initial seqnum
	371	* only when we find an entry in the queue file
	372	**/
	373	unfinished = end - start;
	374
	375	do {
	376	if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
	377	break;
	378	devpath_len = udev_queue_skip_devpath(queue_file);
	379	if (devpath_len < 0)
	380	break;
	381
	382	/*
	383	* we might start with an empty or re-build queue file, where
	384	* the initial seqnum is not recorded as finished
	385	*/
	386	if (start == seqnum && devpath_len > 0)
	387	unfinished++;
	388
	389	if (devpath_len == 0) {
	390	if (seqnum >= start && seqnum <= end)
	391	unfinished--;
	392	}
	393	} while (unfinished > 0);
	394
	395	fclose(queue_file);
	396
	397	return (unfinished == 0);
f503f6b2 AJ	398	}
f503f6b2 AJ	399
8d6bc73a KS	400	/**
	401	* udev_queue_get_seqnum_is_finished:
	402	* @udev_queue: udev queue context
	403	* @seqnum: sequence number
	404	*
2906cbba	405	* Returns: a flag indicating if the given sequence number is currently active.
8d6bc73a	406	**/
666fcf03	407	UDEV_EXPORT int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
f503f6b2	408	{
912541b0 KS	409	if (!udev_queue_get_seqnum_sequence_is_finished(udev_queue, seqnum, seqnum))
912541b0 KS	410	return 0;
f503f6b2	411
912541b0 KS	412	dbg(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
912541b0 KS	413	return 1;
64ccdf82 KS	414	}
64ccdf82 KS	415
8d6bc73a KS	416	/**
	417	* udev_queue_get_queued_list_entry:
	418	* @udev_queue: udev queue context
	419	*
	420	* Returns: the first entry of the list of queued events.
	421	**/
666fcf03	422	UDEV_EXPORT struct udev_list_entry udev_queue_get_queued_list_entry(struct udev_queue udev_queue)
64ccdf82	423	{
912541b0 KS	424	unsigned long long int seqnum;
	425	FILE *queue_file;
	426
	427	if (udev_queue == NULL)
	428	return NULL;
	429	udev_list_cleanup(&udev_queue->queue_list);
	430
	431	queue_file = open_queue_file(udev_queue, &seqnum);
	432	if (queue_file == NULL)
	433	return NULL;
	434
	435	for (;;) {
	436	char syspath[UTIL_PATH_SIZE];
	437	char *s;
	438	size_t l;
	439	ssize_t len;
	440	char seqnum_str[32];
	441	struct udev_list_entry *list_entry;
	442
	443	if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
	444	break;
	445	snprintf(seqnum_str, sizeof(seqnum_str), "%llu", seqnum);
	446
	447	s = syspath;
	448	l = util_strpcpyl(&s, sizeof(syspath), udev_get_sys_path(udev_queue->udev), NULL);
	449	len = udev_queue_read_devpath(queue_file, s, l);
	450	if (len < 0)
	451	break;
	452
	453	if (len > 0) {
	454	udev_list_entry_add(&udev_queue->queue_list, syspath, seqnum_str);
	455	} else {
	456	udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_queue->queue_list)) {
	457	if (strcmp(seqnum_str, udev_list_entry_get_value(list_entry)) == 0) {
	458	udev_list_entry_delete(list_entry);
	459	break;
	460	}
	461	}
	462	}
	463	}
	464	fclose(queue_file);
	465
	466	return udev_list_get_entry(&udev_queue->queue_list);
64ccdf82 KS	467	}
64ccdf82 KS	468
289a1821	469	struct udev_list_entry udev_queue_get_failed_list_entry(struct udev_queue udev_queue);
666fcf03	470	UDEV_EXPORT struct udev_list_entry udev_queue_get_failed_list_entry(struct udev_queue udev_queue)
64ccdf82	471	{
912541b0 KS	472	errno = ENOSYS;
912541b0 KS	473	return NULL;
64ccdf82	474	}