tor-android/external/badvpn_dns/udevmonitor/NCDUdevCache.c

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2015-01-25 11:08:34 +00:00
/**
* @file NCDUdevCache.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <stdlib.h>
#include <string.h>
#include <misc/offset.h>
#include <misc/string_begins_with.h>
#include <misc/concat_strings.h>
#include <misc/compare.h>
#include <base/BLog.h>
#include <udevmonitor/NCDUdevCache.h>
#include <generated/blog_channel_NCDUdevCache.h>
static int string_comparator (void *unused, const char **str1, const char **str2)
{
int c = strcmp(*str1, *str2);
return B_COMPARE(c, 0);
}
static void free_device (NCDUdevCache *o, struct NCDUdevCache_device *device)
{
if (device->is_cleaned) {
// remove from cleaned devices list
LinkedList1_Remove(&o->cleaned_devices_list, &device->cleaned_devices_list_node);
} else {
// remove from devices tree
BAVL_Remove(&o->devices_tree, &device->devices_tree_node);
}
// free map
BStringMap_Free(&device->map);
// free structure
free(device);
}
static struct NCDUdevCache_device * lookup_device (NCDUdevCache *o, const char *devpath)
{
BAVLNode *tree_node = BAVL_LookupExact(&o->devices_tree, &devpath);
if (!tree_node) {
return NULL;
}
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
return device;
}
static void rename_devices (NCDUdevCache *o, const char *prefix, const char *new_prefix)
{
ASSERT(strlen(prefix) > 0)
size_t prefix_len = strlen(prefix);
// lookup prefix
BAVLNode *tree_node = BAVL_Lookup(&o->devices_tree, &prefix);
if (!tree_node) {
return;
}
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
// if the result does not begin with prefix, we might gave gotten the device before all
// devices beginning with prefix, so skip it
if (!string_begins_with(device->devpath, prefix)) {
tree_node = BAVL_GetNext(&o->devices_tree, tree_node);
}
while (tree_node) {
// get next node (must be here because we rename this device)
BAVLNode *next_tree_node = BAVL_GetNext(&o->devices_tree, tree_node);
// get device
device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
// if it doesn't begin with prefix, we're done
if (!string_begins_with(device->devpath, prefix)) {
break;
}
// build new devpath
char *new_devpath = concat_strings(2, new_prefix, device->devpath + prefix_len);
if (!new_devpath) {
BLog(BLOG_ERROR, "concat_strings failed");
goto fail_loop0;
}
// make sure the new name does not exist
if (BAVL_LookupExact(&o->devices_tree, &new_devpath)) {
BLog(BLOG_ERROR, "rename destination already exists");
goto fail_loop1;
}
BLog(BLOG_DEBUG, "rename %s -> %s", device->devpath, new_devpath);
// remove from tree
BAVL_Remove(&o->devices_tree, &device->devices_tree_node);
// update devpath in map
if (!BStringMap_Set(&device->map, "DEVPATH", new_devpath)) {
BLog(BLOG_ERROR, "BStringMap_Set failed");
ASSERT_EXECUTE(BAVL_Insert(&o->devices_tree, &device->devices_tree_node, NULL))
goto fail_loop1;
}
// update devpath pointer
device->devpath = BStringMap_Get(&device->map, "DEVPATH");
ASSERT(device->devpath)
// insert to tree
ASSERT_EXECUTE(BAVL_Insert(&o->devices_tree, &device->devices_tree_node, NULL))
fail_loop1:
free(new_devpath);
fail_loop0:
tree_node = next_tree_node;
}
}
static int add_device (NCDUdevCache *o, BStringMap map)
{
ASSERT(BStringMap_Get(&map, "DEVPATH"))
// alloc structure
struct NCDUdevCache_device *device = malloc(sizeof(*device));
if (!device) {
BLog(BLOG_ERROR, "malloc failed");
goto fail0;
}
// init map
device->map = map;
// set device path
device->devpath = BStringMap_Get(&device->map, "DEVPATH");
// insert to devices tree
BAVLNode *ex_node;
if (!BAVL_Insert(&o->devices_tree, &device->devices_tree_node, &ex_node)) {
BLog(BLOG_DEBUG, "update %s", device->devpath);
// get existing device
struct NCDUdevCache_device *ex_device = UPPER_OBJECT(ex_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!ex_device->is_cleaned)
// remove exiting device
free_device(o, ex_device);
// insert
ASSERT_EXECUTE(BAVL_Insert(&o->devices_tree, &device->devices_tree_node, NULL))
} else {
BLog(BLOG_DEBUG, "add %s", device->devpath);
}
// set not cleaned
device->is_cleaned = 0;
// set refreshed
device->is_refreshed = 1;
return 1;
fail0:
return 0;
}
void NCDUdevCache_Init (NCDUdevCache *o)
{
// init devices tree
BAVL_Init(&o->devices_tree, OFFSET_DIFF(struct NCDUdevCache_device, devpath, devices_tree_node), (BAVL_comparator)string_comparator, NULL);
// init cleaned devices list
LinkedList1_Init(&o->cleaned_devices_list);
DebugObject_Init(&o->d_obj);
}
void NCDUdevCache_Free (NCDUdevCache *o)
{
DebugObject_Free(&o->d_obj);
// free cleaned devices
LinkedList1Node *list_node;
while (list_node = LinkedList1_GetFirst(&o->cleaned_devices_list)) {
struct NCDUdevCache_device *device = UPPER_OBJECT(list_node, struct NCDUdevCache_device, cleaned_devices_list_node);
ASSERT(device->is_cleaned)
free_device(o, device);
}
// free devices
BAVLNode *tree_node;
while (tree_node = BAVL_GetFirst(&o->devices_tree)) {
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
free_device(o, device);
}
}
const BStringMap * NCDUdevCache_Query (NCDUdevCache *o, const char *devpath)
{
DebugObject_Access(&o->d_obj);
// lookup device
struct NCDUdevCache_device *device = lookup_device(o, devpath);
if (!device) {
return NULL;
}
// return map
return &device->map;
}
int NCDUdevCache_Event (NCDUdevCache *o, BStringMap map)
{
DebugObject_Access(&o->d_obj);
// get device path
const char *devpath = BStringMap_Get(&map, "DEVPATH");
if (!devpath) {
BLog(BLOG_ERROR, "missing DEVPATH");
goto fail;
}
// get action
const char *action = BStringMap_Get(&map, "ACTION");
// if this is a remove event, remove device if we have it
if (action && !strcmp(action, "remove")) {
// remove existing device
struct NCDUdevCache_device *device = lookup_device(o, devpath);
if (device) {
BLog(BLOG_DEBUG, "remove %s", devpath);
free_device(o, device);
} else {
BLog(BLOG_DEBUG, "remove unknown %s", devpath);
}
// eat map
BStringMap_Free(&map);
return 1;
}
// if this is a move event, remove old device and contaned devices
if (action && !strcmp(action, "move")) {
const char *devpath_old = BStringMap_Get(&map, "DEVPATH_OLD");
if (!devpath_old) {
goto fail_rename0;
}
// remove old device
struct NCDUdevCache_device *old_device = lookup_device(o, devpath_old);
if (old_device) {
BLog(BLOG_DEBUG, "remove moved %s", old_device->devpath);
free_device(o, old_device);
}
// construct prefix "<devpath_old>/" and new prefix "<devpath>/"
char *prefix = concat_strings(2, devpath_old, "/");
if (!prefix) {
BLog(BLOG_ERROR, "concat_strings failed");
goto fail_rename0;;
}
char *new_prefix = concat_strings(2, devpath, "/");
if (!new_prefix) {
BLog(BLOG_ERROR, "concat_strings failed");
goto fail_rename1;
}
// rename devices with paths starting with prefix
rename_devices(o, prefix, new_prefix);
free(new_prefix);
fail_rename1:
free(prefix);
fail_rename0:;
}
// add device
if (!add_device(o, map)) {
BLog(BLOG_DEBUG, "failed to add device %s", devpath);
goto fail;
}
return 1;
fail:
return 0;
}
void NCDUdevCache_StartClean (NCDUdevCache *o)
{
DebugObject_Access(&o->d_obj);
// mark all devices not refreshed
BAVLNode *tree_node = BAVL_GetFirst(&o->devices_tree);
while (tree_node) {
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
// set device not refreshed
device->is_refreshed = 0;
tree_node = BAVL_GetNext(&o->devices_tree, tree_node);
}
}
void NCDUdevCache_FinishClean (NCDUdevCache *o)
{
DebugObject_Access(&o->d_obj);
// move all devices not marked refreshed to the cleaned devices list
BAVLNode *tree_node = BAVL_GetFirst(&o->devices_tree);
while (tree_node) {
BAVLNode *next_tree_node = BAVL_GetNext(&o->devices_tree, tree_node);
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
if (!device->is_refreshed) {
BLog(BLOG_DEBUG, "clean %s", device->devpath);
// remove from devices tree
BAVL_Remove(&o->devices_tree, &device->devices_tree_node);
// insert to cleaned devices list
LinkedList1_Append(&o->cleaned_devices_list, &device->cleaned_devices_list_node);
// set device cleaned
device->is_cleaned = 1;
}
tree_node = next_tree_node;
}
}
int NCDUdevCache_GetCleanedDevice (NCDUdevCache *o, BStringMap *out_map)
{
DebugObject_Access(&o->d_obj);
// get cleaned device
LinkedList1Node *list_node = LinkedList1_GetFirst(&o->cleaned_devices_list);
if (!list_node) {
return 0;
}
struct NCDUdevCache_device *device = UPPER_OBJECT(list_node, struct NCDUdevCache_device, cleaned_devices_list_node);
ASSERT(device->is_cleaned)
// remove from cleaned devices list
LinkedList1_Remove(&o->cleaned_devices_list, &device->cleaned_devices_list_node);
// give away map
*out_map = device->map;
// free structure
free(device);
return 1;
}
const char * NCDUdevCache_First (NCDUdevCache *o)
{
DebugObject_Access(&o->d_obj);
BAVLNode *tree_node = BAVL_GetFirst(&o->devices_tree);
if (!tree_node) {
return NULL;
}
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
return device->devpath;
}
const char * NCDUdevCache_Next (NCDUdevCache *o, const char *key)
{
ASSERT(BAVL_LookupExact(&o->devices_tree, &key))
BAVLNode *tree_node = BAVL_GetNext(&o->devices_tree, BAVL_LookupExact(&o->devices_tree, &key));
if (!tree_node) {
return NULL;
}
struct NCDUdevCache_device *device = UPPER_OBJECT(tree_node, struct NCDUdevCache_device, devices_tree_node);
ASSERT(!device->is_cleaned)
return device->devpath;
}