udev_db.c revision 95776dc6ec174f47fa4dd4d8abf5d457223e5dd4
/*
* udev_db.c
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004-2005 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 version 2 of the License.
*
* 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, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include "udev.h"
static int devpath_to_db_path(const char *devpath, char *filename, size_t len)
{
size_t start, end, i;
/* add location of db files */
strlcpy(filename, udev_root, len);
start = strlcat(filename, "/"DB_DIR, len);
end = strlcat(filename, devpath, len);
if (end > len)
end = len;
/* replace '/' to transform path into a filename */
for (i = start+1; i < end; i++)
if (filename[i] == '/')
filename[i] = PATH_TO_NAME_CHAR;
return 0;
}
static int db_file_to_devpath(const char *filename, char *devpath, size_t len)
{
size_t end, i;
strlcpy(devpath, "/", len);
end = strlcat(devpath, filename, len);
/* replace PATH_TO_NAME_CHAR to transform name into devpath */
for (i = 1; i < end; i++)
if (devpath[i] == PATH_TO_NAME_CHAR)
devpath[i] = '/';
return 0;
}
int udev_db_add_device(struct udevice *udev)
{
char filename[PATH_SIZE];
if (udev->test_run)
return 0;
devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
create_path(filename);
/*
* create only a symlink with the name as the target
* if we don't have any interesting data to remember
*/
if (strcmp(udev->name, udev->dev->kernel) == 0 &&
list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
!udev->partitions && !udev->ignore_remove) {
dbg("nothing interesting to store, create symlink");
unlink(filename);
if (symlink(udev->name, filename) != 0) {
err("unable to create db link '%s': %s", filename, strerror(errno));
return -1;
}
} else {
struct name_entry *name_loop;
FILE *f;
f = fopen(filename, "w");
if (f == NULL) {
err("unable to create db file '%s': %s", filename, strerror(errno));
return -1;
}
dbg("storing data for device '%s' in '%s'", udev->dev->devpath, filename);
fprintf(f, "N:%s\n", udev->name);
list_for_each_entry(name_loop, &udev->symlink_list, node)
fprintf(f, "S:%s\n", name_loop->name);
fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
if (udev->partitions)
fprintf(f, "A:%u\n", udev->partitions);
if (udev->ignore_remove)
fprintf(f, "R:%u\n", udev->ignore_remove);
list_for_each_entry(name_loop, &udev->env_list, node)
fprintf(f, "E:%s\n", name_loop->name);
fclose(f);
}
return 0;
}
int udev_db_get_device(struct udevice *udev, const char *devpath)
{
struct stat stats;
char filename[PATH_SIZE];
char line[PATH_SIZE];
unsigned int major, minor;
char *bufline;
char *buf;
size_t bufsize;
size_t cur;
size_t count;
strlcpy(udev->dev->devpath, devpath, sizeof(udev->dev->devpath));
devpath_to_db_path(devpath, filename, sizeof(filename));
if (lstat(filename, &stats) != 0) {
info("no db file to read %s: %s", filename, strerror(errno));
return -1;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[NAME_SIZE];
int target_len;
info("found a symlink as db file");
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
info("error reading db link %s: %s", filename, strerror(errno));
return -1;
}
dbg("db link points to '%s'", target);
strlcpy(udev->name, target, sizeof(udev->name));
return 0;
}
if (file_map(filename, &buf, &bufsize) != 0) {
info("error reading db file %s: %s", filename, strerror(errno));
return -1;
}
cur = 0;
while (cur < bufsize) {
count = buf_get_line(buf, bufsize, cur);
bufline = &buf[cur];
cur += count+1;
switch(bufline[0]) {
case 'N':
if (count > sizeof(udev->name))
count = sizeof(udev->name);
memcpy(udev->name, &bufline[2], count-2);
udev->name[count-2] = '\0';
break;
case 'M':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
sscanf(line, "%u:%u", &major, &minor);
udev->devt = makedev(major, minor);
break;
case 'S':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
name_list_add(&udev->symlink_list, line, 0);
break;
case 'A':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
udev->partitions = atoi(line);
break;
case 'R':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
udev->ignore_remove = atoi(line);
break;
case 'E':
if (count > sizeof(line))
count = sizeof(line);
memcpy(line, &bufline[2], count-2);
line[count-2] = '\0';
name_list_add(&udev->env_list, line, 0);
break;
}
}
file_unmap(buf, bufsize);
if (udev->name[0] == '\0')
return -1;
return 0;
}
int udev_db_delete_device(struct udevice *udev)
{
char filename[PATH_SIZE];
devpath_to_db_path(udev->dev->devpath, filename, sizeof(filename));
unlink(filename);
return 0;
}
int udev_db_lookup_name(const char *name, char *devpath, size_t len)
{
char dbpath[PATH_MAX];
DIR *dir;
int found = 0;
strlcpy(dbpath, udev_root, sizeof(dbpath));
strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
dir = opendir(dbpath);
if (dir == NULL) {
info("no udev_db available '%s': %s", dbpath, strerror(errno));
return -1;
}
while (!found) {
struct dirent *ent;
char filename[PATH_SIZE];
char nodename[PATH_SIZE];
struct stat stats;
char *bufline;
char *buf;
size_t bufsize;
size_t cur;
size_t count;
ent = readdir(dir);
if (ent == NULL || ent->d_name[0] == '\0')
break;
if (ent->d_name[0] == '.')
continue;
snprintf(filename, sizeof(filename), "%s/%s", dbpath, ent->d_name);
filename[sizeof(filename)-1] = '\0';
dbg("looking at '%s'", filename);
if (lstat(filename, &stats) != 0) {
info("unable to read %s: %s", filename, strerror(errno));
continue;
}
if ((stats.st_mode & S_IFMT) == S_IFLNK) {
char target[NAME_SIZE];
int target_len;
info("found a symlink as db file");
target_len = readlink(filename, target, sizeof(target));
if (target_len > 0)
target[target_len] = '\0';
else {
info("error reading db link %s: %s", filename, strerror(errno));
return -1;
}
dbg("db link points to '%s'", target);
if (strcmp(name, target) == 0) {
db_file_to_devpath(ent->d_name, devpath, len);
found =1;
}
continue;
}
if (file_map(filename, &buf, &bufsize) != 0) {
info("unable to read db file '%s': %s", filename, strerror(errno));
continue;
}
cur = 0;
while (cur < bufsize && !found) {
count = buf_get_line(buf, bufsize, cur);
bufline = &buf[cur];
cur += count+1;
switch(bufline[0]) {
case 'N':
case 'S':
if (count > sizeof(nodename))
count = sizeof(nodename);
memcpy(nodename, &bufline[2], count-2);
nodename[count-2] = '\0';
dbg("compare '%s' '%s'", nodename, name);
if (strcmp(nodename, name) == 0) {
db_file_to_devpath(ent->d_name, devpath, len);
found = 1;
}
break;
default:
continue;
}
}
file_unmap(buf, bufsize);
}
closedir(dir);
if (found)
return 0;
else
return -1;
}
int udev_db_get_all_entries(struct list_head *name_list)
{
char dbpath[PATH_MAX];
DIR *dir;
strlcpy(dbpath, udev_root, sizeof(dbpath));
strlcat(dbpath, "/"DB_DIR, sizeof(dbpath));
dir = opendir(dbpath);
if (dir == NULL) {
info("no udev_db available '%s': %s", dbpath, strerror(errno));
return -1;
}
while (1) {
struct dirent *ent;
char filename[PATH_SIZE] = "/";
size_t end, i;
ent = readdir(dir);
if (ent == NULL || ent->d_name[0] == '\0')
break;
if (ent->d_name[0] == '.')
continue;
end = strlcat(filename, ent->d_name, sizeof(filename));
for (i = 1; i < end; i++)
if (filename[i] == PATH_TO_NAME_CHAR)
filename[i] = '/';
name_list_add(name_list, filename, 1);
dbg("added '%s'", filename);
}
closedir(dir);
return 0;
}