diff options
Diffstat (limited to 'block/cmd-filter.c')
| -rw-r--r-- | block/cmd-filter.c | 334 |
1 files changed, 334 insertions, 0 deletions
diff --git a/block/cmd-filter.c b/block/cmd-filter.c new file mode 100644 index 000000000000..eec4404fd357 --- /dev/null +++ b/block/cmd-filter.c @@ -0,0 +1,334 @@ +/* + * Copyright 2004 Peter M. Jones <pjones@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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 Licens + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- + * + */ + +#include <linux/list.h> +#include <linux/genhd.h> +#include <linux/spinlock.h> +#include <linux/parser.h> +#include <linux/capability.h> +#include <linux/bitops.h> + +#include <scsi/scsi.h> +#include <linux/cdrom.h> + +int blk_cmd_filter_verify_command(struct blk_scsi_cmd_filter *filter, + unsigned char *cmd, mode_t *f_mode) +{ + /* root can do any command. */ + if (capable(CAP_SYS_RAWIO)) + return 0; + + /* if there's no filter set, assume we're filtering everything out */ + if (!filter) + return -EPERM; + + /* Anybody who can open the device can do a read-safe command */ + if (test_bit(cmd[0], filter->read_ok)) + return 0; + + /* Write-safe commands require a writable open */ + if (test_bit(cmd[0], filter->write_ok) && (*f_mode & FMODE_WRITE)) + return 0; + + return -EPERM; +} +EXPORT_SYMBOL(blk_cmd_filter_verify_command); + +int blk_verify_command(struct file *file, unsigned char *cmd) +{ + struct gendisk *disk; + struct inode *inode; + + if (!file) + return -EINVAL; + + inode = file->f_dentry->d_inode; + if (!inode) + return -EINVAL; + + disk = inode->i_bdev->bd_disk; + + return blk_cmd_filter_verify_command(&disk->cmd_filter, + cmd, &file->f_mode); +} +EXPORT_SYMBOL(blk_verify_command); + +/* and now, the sysfs stuff */ +static ssize_t rcf_cmds_show(struct blk_scsi_cmd_filter *filter, char *page, + int rw) +{ + char *npage = page; + unsigned long *okbits; + int i; + + if (rw == READ) + okbits = filter->read_ok; + else + okbits = filter->write_ok; + + for (i = 0; i < BLK_SCSI_MAX_CMDS; i++) { + if (test_bit(i, okbits)) { + sprintf(npage, "%02x", i); + npage += 2; + if (i < BLK_SCSI_MAX_CMDS - 1) + sprintf(npage++, " "); + } + } + + if (npage != page) + npage += sprintf(npage, "\n"); + + return npage - page; +} + +static ssize_t rcf_readcmds_show(struct blk_scsi_cmd_filter *filter, char *page) +{ + return rcf_cmds_show(filter, page, READ); +} + +static ssize_t rcf_writecmds_show(struct blk_scsi_cmd_filter *filter, + char *page) +{ + return rcf_cmds_show(filter, page, WRITE); +} + +static ssize_t rcf_cmds_store(struct blk_scsi_cmd_filter *filter, + const char *page, size_t count, int rw) +{ + ssize_t ret = 0; + unsigned long okbits[BLK_SCSI_CMD_PER_LONG], *target_okbits; + int cmd, status, len; + substring_t ss; + + memset(&okbits, 0, sizeof(okbits)); + + for (len = strlen(page); len > 0; len -= 3) { + if (len < 2) + break; + ss.from = (char *) page + ret; + ss.to = (char *) page + ret + 2; + ret += 3; + status = match_hex(&ss, &cmd); + /* either of these cases means invalid input, so do nothing. */ + if (status || cmd >= BLK_SCSI_MAX_CMDS) + return -EINVAL; + + __set_bit(cmd, okbits); + } + + if (rw == READ) + target_okbits = filter->read_ok; + else + target_okbits = filter->write_ok; + + memmove(target_okbits, okbits, sizeof(okbits)); + return count; +} + +static ssize_t rcf_readcmds_store(struct blk_scsi_cmd_filter *filter, + const char *page, size_t count) +{ + return rcf_cmds_store(filter, page, count, READ); +} + +static ssize_t rcf_writecmds_store(struct blk_scsi_cmd_filter *filter, + const char *page, size_t count) +{ + return rcf_cmds_store(filter, page, count, WRITE); +} + +struct rcf_sysfs_entry { + struct attribute attr; + ssize_t (*show)(struct blk_scsi_cmd_filter *, char *); + ssize_t (*store)(struct blk_scsi_cmd_filter *, const char *, size_t); +}; + +static struct rcf_sysfs_entry rcf_readcmds_entry = { + .attr = { .name = "read_table", .mode = S_IRUGO | S_IWUSR }, + .show = rcf_readcmds_show, + .store = rcf_readcmds_store, +}; + +static struct rcf_sysfs_entry rcf_writecmds_entry = { + .attr = {.name = "write_table", .mode = S_IRUGO | S_IWUSR }, + .show = rcf_writecmds_show, + .store = rcf_writecmds_store, +}; + +static struct attribute *default_attrs[] = { + &rcf_readcmds_entry.attr, + &rcf_writecmds_entry.attr, + NULL, +}; + +#define to_rcf(atr) container_of((atr), struct rcf_sysfs_entry, attr) + +static ssize_t +rcf_attr_show(struct kobject *kobj, struct attribute *attr, char *page) +{ + struct rcf_sysfs_entry *entry = to_rcf(attr); + struct blk_scsi_cmd_filter *filter; + + filter = container_of(kobj, struct blk_scsi_cmd_filter, kobj); + if (entry->show) + return entry->show(filter, page); + + return 0; +} + +static ssize_t +rcf_attr_store(struct kobject *kobj, struct attribute *attr, + const char *page, size_t length) +{ + struct rcf_sysfs_entry *entry = to_rcf(attr); + struct blk_scsi_cmd_filter *filter; + + if (!capable(CAP_SYS_RAWIO)) + return -EPERM; + + if (!entry->store) + return -EINVAL; + + filter = container_of(kobj, struct blk_scsi_cmd_filter, kobj); + return entry->store(filter, page, length); +} + +static struct sysfs_ops rcf_sysfs_ops = { + .show = rcf_attr_show, + .store = rcf_attr_store, +}; + +static struct kobj_type rcf_ktype = { + .sysfs_ops = &rcf_sysfs_ops, + .default_attrs = default_attrs, +}; + +#ifndef MAINTENANCE_IN_CMD +#define MAINTENANCE_IN_CMD 0xa3 +#endif + +static void rcf_set_defaults(struct blk_scsi_cmd_filter *filter) +{ + /* Basic read-only commands */ + __set_bit(TEST_UNIT_READY, filter->read_ok); + __set_bit(REQUEST_SENSE, filter->read_ok); + __set_bit(READ_6, filter->read_ok); + __set_bit(READ_10, filter->read_ok); + __set_bit(READ_12, filter->read_ok); + __set_bit(READ_16, filter->read_ok); + __set_bit(READ_BUFFER, filter->read_ok); + __set_bit(READ_DEFECT_DATA, filter->read_ok); + __set_bit(READ_CAPACITY, filter->read_ok); + __set_bit(READ_LONG, filter->read_ok); + __set_bit(INQUIRY, filter->read_ok); + __set_bit(MODE_SENSE, filter->read_ok); + __set_bit(MODE_SENSE_10, filter->read_ok); + __set_bit(LOG_SENSE, filter->read_ok); + __set_bit(START_STOP, filter->read_ok); + __set_bit(GPCMD_VERIFY_10, filter->read_ok); + __set_bit(VERIFY_16, filter->read_ok); + __set_bit(REPORT_LUNS, filter->read_ok); + __set_bit(SERVICE_ACTION_IN, filter->read_ok); + __set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok); + __set_bit(MAINTENANCE_IN_CMD, filter->read_ok); + __set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok); + + /* Audio CD commands */ + __set_bit(GPCMD_PLAY_CD, filter->read_ok); + __set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok); + __set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok); + __set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok); + __set_bit(GPCMD_PAUSE_RESUME, filter->read_ok); + + /* CD/DVD data reading */ + __set_bit(GPCMD_READ_CD, filter->read_ok); + __set_bit(GPCMD_READ_CD_MSF, filter->read_ok); + __set_bit(GPCMD_READ_DISC_INFO, filter->read_ok); + __set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok); + __set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok); + __set_bit(GPCMD_READ_HEADER, filter->read_ok); + __set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok); + __set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok); + __set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok); + __set_bit(GPCMD_REPORT_KEY, filter->read_ok); + __set_bit(GPCMD_SCAN, filter->read_ok); + __set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok); + __set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok); + __set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok); + __set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok); + __set_bit(GPCMD_SEEK, filter->read_ok); + __set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok); + + /* Basic writing commands */ + __set_bit(WRITE_6, filter->write_ok); + __set_bit(WRITE_10, filter->write_ok); + __set_bit(WRITE_VERIFY, filter->write_ok); + __set_bit(WRITE_12, filter->write_ok); + __set_bit(WRITE_VERIFY_12, filter->write_ok); + __set_bit(WRITE_16, filter->write_ok); + __set_bit(WRITE_LONG, filter->write_ok); + __set_bit(WRITE_LONG_2, filter->write_ok); + __set_bit(ERASE, filter->write_ok); + __set_bit(GPCMD_MODE_SELECT_10, filter->write_ok); + __set_bit(MODE_SELECT, filter->write_ok); + __set_bit(LOG_SELECT, filter->write_ok); + __set_bit(GPCMD_BLANK, filter->write_ok); + __set_bit(GPCMD_CLOSE_TRACK, filter->write_ok); + __set_bit(GPCMD_FLUSH_CACHE, filter->write_ok); + __set_bit(GPCMD_FORMAT_UNIT, filter->write_ok); + __set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok); + __set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok); + __set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok); + __set_bit(GPCMD_SEND_EVENT, filter->write_ok); + __set_bit(GPCMD_SEND_KEY, filter->write_ok); + __set_bit(GPCMD_SEND_OPC, filter->write_ok); + __set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok); + __set_bit(GPCMD_SET_SPEED, filter->write_ok); + __set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok); + __set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok); + __set_bit(GPCMD_SET_STREAMING, filter->write_ok); +} + +int blk_register_filter(struct gendisk *disk) +{ + int ret; + struct blk_scsi_cmd_filter *filter = &disk->cmd_filter; + struct kobject *parent = kobject_get(disk->holder_dir->parent); + + if (!parent) + return -ENODEV; + + ret = kobject_init_and_add(&filter->kobj, &rcf_ktype, parent, + "%s", "cmd_filter"); + + if (ret < 0) + return ret; + + rcf_set_defaults(filter); + return 0; +} + +void blk_unregister_filter(struct gendisk *disk) +{ + struct blk_scsi_cmd_filter *filter = &disk->cmd_filter; + + kobject_put(&filter->kobj); + kobject_put(disk->holder_dir->parent); +} + |