diff options
Diffstat (limited to 'udev_remove.c')
| -rw-r--r-- | udev_remove.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/udev_remove.c b/udev_remove.c new file mode 100644 index 0000000000..7ad7c2402a --- /dev/null +++ b/udev_remove.c @@ -0,0 +1,190 @@ +/* + * udev-remove.c + * + * Userspace devfs + * + * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> + * + * + * 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 <string.h> +#include <stdio.h> +#include <fcntl.h> +#include <unistd.h> +#include <errno.h> + +#include "udev.h" +#include "udev_lib.h" +#include "udev_version.h" +#include "logging.h" +#include "namedev.h" +#include "udevdb.h" + +static int delete_path(char *path) +{ + char *pos; + int retval; + + pos = strrchr(path, '/'); + while (1) { + *pos = '\0'; + pos = strrchr(path, '/'); + + /* don't remove the last one */ + if ((pos == path) || (pos == NULL)) + break; + + /* remove if empty */ + retval = rmdir(path); + if (errno == ENOENT) + retval = 0; + if (retval) { + if (errno == ENOTEMPTY) + return 0; + dbg("rmdir(%s) failed with error '%s'", + path, strerror(errno)); + break; + } + dbg("removed '%s'", path); + } + return 0; +} + +/** Remove all permissions on the device node, before + * unlinking it. This fixes a security issue. + * If the user created a hard-link to the device node, + * he can't use it any longer, because he lost permission + * to do so. + */ +static int secure_unlink(const char *filename) +{ + int retval; + + retval = chown(filename, 0, 0); + if (retval) { + dbg("chown(%s, 0, 0) failed with error '%s'", + filename, strerror(errno)); + /* We continue nevertheless. + * I think it's very unlikely for chown + * to fail here, if the file exists. + */ + } + retval = chmod(filename, 0000); + if (retval) { + dbg("chmod(%s, 0000) failed with error '%s'", + filename, strerror(errno)); + /* We continue nevertheless. */ + } + retval = unlink(filename); + if (errno == ENOENT) + retval = 0; + if (retval) { + dbg("unlink(%s) failed with error '%s'", + filename, strerror(errno)); + } + return retval; +} + +static int delete_node(struct udevice *dev) +{ + char filename[NAME_SIZE]; + char linkname[NAME_SIZE]; + char partitionname[NAME_SIZE]; + int retval; + int i; + char *pos; + int len; + + strfieldcpy(filename, udev_root); + strfieldcat(filename, dev->name); + + info("removing device node '%s'", filename); + retval = secure_unlink(filename); + if (retval) + return retval; + + /* remove partition nodes */ + if (dev->partitions > 0) { + info("removing partitions '%s[1-%i]'", filename, dev->partitions); + for (i = 1; i <= dev->partitions; i++) { + strfieldcpy(partitionname, filename); + strintcat(partitionname, i); + secure_unlink(partitionname); + } + } + + /* remove subdirectories */ + if (strchr(dev->name, '/')) + delete_path(filename); + + foreach_strpart(dev->symlink, " ", pos, len) { + strfieldcpymax(linkname, pos, len+1); + strfieldcpy(filename, udev_root); + strfieldcat(filename, linkname); + + dbg("unlinking symlink '%s'", filename); + retval = unlink(filename); + if (errno == ENOENT) + retval = 0; + if (retval) { + dbg("unlink(%s) failed with error '%s'", + filename, strerror(errno)); + return retval; + } + if (strchr(dev->symlink, '/')) { + delete_path(filename); + } + } + + return retval; +} + +/* + * Look up the sysfs path in the database to see if we have named this device + * something different from the kernel name. If we have, us it. If not, use + * the default kernel name for lack of anything else to know to do. + */ +int udev_remove_device(const char *path, const char *subsystem) +{ + struct udevice dev; + char *temp; + int retval; + + memset(&dev, 0x00, sizeof(dev)); + + retval = udevdb_get_dev(path, &dev); + if (retval != 0) { + dbg("'%s' not found in database, falling back on default name", path); + temp = strrchr(path, '/'); + if (temp == NULL) + return -ENODEV; + strfieldcpy(dev.name, &temp[1]); + } + dbg("name='%s'", dev.name); + + dev.type = get_device_type(path, subsystem); + dev_d_send(&dev, subsystem, path); + udevdb_delete_dev(path); + + if (dev.type == 'b' || dev.type == 'c') + retval = delete_node(&dev); + else if (dev.type == 'n') + retval = 0; + + return retval; +} |