libudev: add queue interface

1 files changed, 286 insertions, 0 deletions

diff --git a/udev/lib/libudev-queue.c b/udev/lib/libudev-queue.c
new file mode 100644
index 0000000000..3ca533b1e0
--- /dev/null
+++ b/udev/lib/libudev-queue.c
@@ -0,0 +1,286 @@
+/*
+ * libudev - interface to udev device information
+ *
+ * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * This program 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.
+ *
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#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 <sys/stat.h>
+
+#include "libudev.h"
+#include "libudev-private.h"
+
+struct udev_queue {
+	struct udev *udev;
+	int refcount;
+	unsigned long long int last_seen_udev_seqnum;
+	struct list_node queue_list;
+	struct list_node failed_list;
+};
+
+struct udev_queue *udev_queue_new(struct udev *udev)
+{
+	struct udev_queue *udev_queue;
+
+	if (udev == NULL)
+		return NULL;
+
+	udev_queue = malloc(sizeof(struct udev_queue));
+	if (udev_queue == NULL)
+		return NULL;
+	memset(udev_queue, 0x00, sizeof(struct udev_queue));
+	udev_queue->refcount = 1;
+	udev_queue->udev = udev;
+	list_init(&udev_queue->queue_list);
+	list_init(&udev_queue->failed_list);
+	return udev_queue;
+}
+
+struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue)
+{
+	if (udev_queue == NULL)
+		return NULL;
+	udev_queue->refcount++;
+	return udev_queue;
+}
+
+void udev_queue_unref(struct udev_queue *udev_queue)
+{
+	if (udev_queue == NULL)
+		return;
+	udev_queue->refcount--;
+	if (udev_queue->refcount > 0)
+		return;
+	list_cleanup(udev_queue->udev, &udev_queue->queue_list);
+	list_cleanup(udev_queue->udev, &udev_queue->failed_list);
+	free(udev_queue);
+}
+
+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_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
+{
+	char filename[UTIL_PATH_SIZE];
+	unsigned long long int seqnum;
+	int fd;
+	char buf[32];
+	ssize_t len;
+
+	if (udev_queue == NULL)
+		return -EINVAL;
+	util_strlcpy(filename, udev_get_sys_path(udev_queue->udev), sizeof(filename));
+	util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
+	fd = open(filename, O_RDONLY);
+	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);
+	info(udev_queue->udev, "seqnum=%llu\n", seqnum);
+	return seqnum;
+}
+
+unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
+{
+	char filename[UTIL_PATH_SIZE];
+	unsigned long long int seqnum;
+	int fd;
+	char buf[32];
+	ssize_t len;
+
+	if (udev_queue == NULL)
+		return -EINVAL;
+	util_strlcpy(filename, udev_get_dev_path(udev_queue->udev), sizeof(filename));
+	util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
+	fd = open(filename, O_RDONLY);
+	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);
+	info(udev_queue->udev, "seqnum=%llu\n", seqnum);
+	udev_queue->last_seen_udev_seqnum = seqnum;
+	return seqnum;
+}
+
+int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
+{
+	char queuename[UTIL_PATH_SIZE];
+	struct stat statbuf;
+	unsigned long long int seqnum_kernel;
+
+	if (udev_queue == NULL)
+		return -EINVAL;
+	util_strlcpy(queuename, udev_get_dev_path(udev_queue->udev), sizeof(queuename));
+	util_strlcat(queuename, "/.udev/queue", sizeof(queuename));
+	if (stat(queuename, &statbuf) == 0) {
+		info(udev_queue->udev, "queue is not empty\n");
+		return 0;
+	}
+	seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
+	if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
+		info(udev_queue->udev, "queue is empty\n");
+		return 1;
+	}
+	udev_queue_get_udev_seqnum(udev_queue);
+	if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
+		info(udev_queue->udev, "queue is empty\n");
+		return 1;
+	}
+	info(udev_queue->udev, "queue is empty, but kernel events still pending [%llu]<->[%llu]\n",
+	     seqnum_kernel, udev_queue->last_seen_udev_seqnum);
+	return 0;
+}
+
+int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
+{
+	char filename[UTIL_PATH_SIZE];
+	struct stat statbuf;
+
+	if (udev_queue == NULL)
+		return -EINVAL;
+	/* if we have not seen this seqnum, check if it is/was already queued */
+	if (seqnum < udev_queue->last_seen_udev_seqnum) {
+		udev_queue_get_udev_seqnum(udev_queue);
+		if (seqnum < udev_queue->last_seen_udev_seqnum)
+			return 0;
+	}
+	snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
+		 udev_get_dev_path(udev_queue->udev), seqnum);
+	if (stat(filename, &statbuf) == 0)
+		return 0;
+	info(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
+	return 1;
+}
+
+struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue)
+{
+	char path[UTIL_PATH_SIZE];
+	DIR *dir;
+	struct dirent *dent;
+
+	if (udev_queue == NULL)
+		return NULL;
+	list_cleanup(udev_queue->udev, &udev_queue->queue_list);
+	util_strlcpy(path, udev_get_dev_path(udev_queue->udev), sizeof(path));
+	util_strlcat(path, "/.udev/queue", sizeof(path));
+	dir = opendir(path);
+	if (dir == NULL)
+		return NULL;
+	for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+		char filename[UTIL_PATH_SIZE];
+		char syspath[UTIL_PATH_SIZE];
+		size_t syslen;
+		ssize_t len;
+
+		if (dent->d_name[0] == '.')
+			continue;
+		util_strlcpy(filename, path, sizeof(filename));
+		util_strlcat(filename, "/", sizeof(filename));
+		util_strlcat(filename, dent->d_name, sizeof(filename));
+
+		syslen = util_strlcpy(syspath, udev_get_sys_path(udev_queue->udev), sizeof(syspath));
+		len = readlink(filename, &syspath[syslen], sizeof(syspath)-syslen);
+		if (len < 0 || len >= (ssize_t)(sizeof(syspath)-syslen))
+			continue;
+		syspath[syslen + len] = '\0';
+		info(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
+		list_entry_add(udev_queue->udev, &udev_queue->queue_list, syspath, dent->d_name, 0, 0);
+	}
+	closedir(dir);
+	return list_get_entry(&udev_queue->queue_list);
+}
+
+struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue)
+{
+	char path[UTIL_PATH_SIZE];
+	DIR *dir;
+	struct dirent *dent;
+
+	if (udev_queue == NULL)
+		return NULL;
+	list_cleanup(udev_queue->udev, &udev_queue->failed_list);
+	util_strlcpy(path, udev_get_dev_path(udev_queue->udev), sizeof(path));
+	util_strlcat(path, "/.udev/failed", sizeof(path));
+	dir = opendir(path);
+	if (dir == NULL)
+		return NULL;
+	for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
+		char filename[UTIL_PATH_SIZE];
+		char syspath[UTIL_PATH_SIZE];
+		struct stat statbuf;
+		size_t syslen;
+		ssize_t len;
+
+		if (dent->d_name[0] == '.')
+			continue;
+		util_strlcpy(filename, path, sizeof(filename));
+		util_strlcat(filename, "/", sizeof(filename));
+		util_strlcat(filename, dent->d_name, sizeof(filename));
+
+		syslen = util_strlcpy(syspath, udev_get_sys_path(udev_queue->udev), sizeof(syspath));
+		len = readlink(filename, &syspath[syslen], sizeof(syspath)-syslen);
+		if (len < 0 || len >= (ssize_t)(sizeof(syspath)-syslen))
+			continue;
+		syspath[syslen + len] = '\0';
+		info(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
+		util_strlcpy(filename, syspath, sizeof(filename));
+		util_strlcat(filename, "/uevent", sizeof(filename));
+		if (stat(filename, &statbuf) != 0)
+			continue;
+		list_entry_add(udev_queue->udev, &udev_queue->failed_list, syspath, NULL, 0, 0);
+	}
+	closedir(dir);
+	return list_get_entry(&udev_queue->failed_list);
+}
+
+int queue_export_udev_seqnum(struct udev_queue *udev_queue, unsigned long long int seqnum)
+{
+	return 0;
+}
+
+extern int queue_export_device_queued(struct udev_queue *udev_queue, struct udev_device *udev_device)
+{
+	return 0;
+}
+
+extern int queue_export_device_finished(struct udev_queue *udev_queue, struct udev_device *udev_device)
+{
+	return 0;
+}
+
+extern int queue_export_device_failed(struct udev_queue *udev_queue, struct udev_device *udev_device)
+{
+	return 0;
+}