/* * SCSI Block Commands (SBC) parsing and emulation. * * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc. * Copyright (c) 2005, 2006, 2007 SBE, Inc. * Copyright (c) 2007-2010 Rising Tide Systems * Copyright (c) 2008-2010 Linux-iSCSI.org * * Nicholas A. Bellinger * * 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, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include #include #include #include #include "target_core_internal.h" #include "target_core_ua.h" static sense_reason_t sbc_emulate_readcapacity(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; unsigned long long blocks_long = dev->transport->get_blocks(dev); unsigned char *rbuf; unsigned char buf[8]; u32 blocks; if (blocks_long >= 0x00000000ffffffff) blocks = 0xffffffff; else blocks = (u32)blocks_long; buf[0] = (blocks >> 24) & 0xff; buf[1] = (blocks >> 16) & 0xff; buf[2] = (blocks >> 8) & 0xff; buf[3] = blocks & 0xff; buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff; buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff; buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff; buf[7] = dev->dev_attrib.block_size & 0xff; rbuf = transport_kmap_data_sg(cmd); if (!rbuf) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); transport_kunmap_data_sg(cmd); target_complete_cmd(cmd, GOOD); return 0; } static sense_reason_t sbc_emulate_readcapacity_16(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; unsigned char *rbuf; unsigned char buf[32]; unsigned long long blocks = dev->transport->get_blocks(dev); memset(buf, 0, sizeof(buf)); buf[0] = (blocks >> 56) & 0xff; buf[1] = (blocks >> 48) & 0xff; buf[2] = (blocks >> 40) & 0xff; buf[3] = (blocks >> 32) & 0xff; buf[4] = (blocks >> 24) & 0xff; buf[5] = (blocks >> 16) & 0xff; buf[6] = (blocks >> 8) & 0xff; buf[7] = blocks & 0xff; buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff; buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff; buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff; buf[11] = dev->dev_attrib.block_size & 0xff; /* * Set Thin Provisioning Enable bit following sbc3r22 in section * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled. */ if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) buf[14] = 0x80; rbuf = transport_kmap_data_sg(cmd); if (!rbuf) return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length)); transport_kunmap_data_sg(cmd); target_complete_cmd(cmd, GOOD); return 0; } int spc_get_write_same_sectors(struct se_cmd *cmd) { u32 num_blocks; if (cmd->t_task_cdb[0] == WRITE_SAME) num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]); else if (cmd->t_task_cdb[0] == WRITE_SAME_16) num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]); else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */ num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]); /* * Use the explicit range when non zero is supplied, otherwise calculate * the remaining range based on ->get_blocks() - starting LBA. */ if (num_blocks) return num_blocks; return cmd->se_dev->transport->get_blocks(cmd->se_dev) - cmd->t_task_lba + 1; } EXPORT_SYMBOL(spc_get_write_same_sectors); static sense_reason_t sbc_emulate_noop(struct se_cmd *cmd) { target_complete_cmd(cmd, GOOD); return 0; } static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors) { return cmd->se_dev->dev_attrib.block_size * sectors; } static int sbc_check_valid_sectors(struct se_cmd *cmd) { struct se_device *dev = cmd->se_dev; unsigned long long end_lba; u32 sectors; sectors = cmd->data_length / dev->dev_attrib.block_size; end_lba = dev->transport->get_blocks(dev) + 1; if (cmd->t_task_lba + sectors > end_lba) { pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n", cmd->t_task_lba, sectors, end_lba); return -EINVAL; } return 0; } static inline u32 transport_get_sectors_6(unsigned char *cdb) { /* * Use 8-bit sector value. SBC-3 says: * * A TRANSFER LENGTH field set to zero specifies that 256 * logical blocks shall be written. Any other value * specifies the number of logical blocks that shall be * written. */ return cdb[4] ? : 256; } static inline u32 transport_get_sectors_10(unsigned char *cdb) { return (u32)(cdb[7] << 8) + cdb[8]; } static inline u32 transport_get_sectors_12(unsigned char *cdb) { return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9]; } static inline u32 transport_get_sectors_16(unsigned char *cdb) { return (u32)(cdb[10] << 24) + (cdb[11] << 16) + (cdb[12] << 8) + cdb[13]; } /* * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants */ static inline u32 transport_get_sectors_32(unsigned char *cdb) { return (u32)(cdb[28] << 24) + (cdb[29] << 16) + (cdb[30] << 8) + cdb[31]; } static inline u32 transport_lba_21(unsigned char *cdb) { return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3]; } static inline u32 transport_lba_32(unsigned char *cdb) { return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5]; } static inline unsigned long long transport_lba_64(unsigned char *cdb) { unsigned int __v1, __v2; __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5]; __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9]; return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32; } /* * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs */ static inline unsigned long long transport_lba_64_ext(unsigned char *cdb) { unsigned int __v1, __v2; __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15]; __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19]; return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32; } static int sbc_write_same_supported(struct se_device *dev, unsigned char *flags) { if ((flags[0] & 0x04) || (flags[0] & 0x02)) { pr_err("WRITE_SAME PBDATA and LBDATA" " bits not supported for Block Discard" " Emulation\n"); return -ENOSYS; } /* * Currently for the emulated case we only accept * tpws with the UNMAP=1 bit set. */ if (!(flags[0] & 0x08)) { pr_err("WRITE_SAME w/o UNMAP bit not" " supported for Block Discard Emulation\n"); return -ENOSYS; } return 0; } static void xdreadwrite_callback(struct se_cmd *cmd) { unsigned char *buf, *addr; struct scatterlist *sg; unsigned int offset; int i; int count; /* * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command * * 1) read the specified logical block(s); * 2) transfer logical blocks from the data-out buffer; * 3) XOR the logical blocks transferred from the data-out buffer with * the logical blocks read, storing the resulting XOR data in a buffer; * 4) if the DISABLE WRITE bit is set to zero, then write the logical * blocks transferred from the data-out buffer; and * 5) transfer the resulting XOR data to the data-in buffer. */ buf = kmalloc(cmd->data_length, GFP_KERNEL); if (!buf) { pr_err("Unable to allocate xor_callback buf\n"); return; } /* * Copy the scatterlist WRITE buffer located at cmd->t_data_sg * into the locally allocated *buf */ sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf, cmd->data_length); /* * Now perform the XOR against the BIDI read memory located at * cmd->t_mem_bidi_list */ offset = 0; for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) { addr = kmap_atomic(sg_page(sg)); if (!addr) goto out; for (i = 0; i < sg->length; i++) *(addr + sg->offset + i) ^= *(buf + offset + i); offset += sg->length; kunmap_atomic(addr); } out: kfree(buf); } sense_reason_t sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) { struct se_device *dev = cmd->se_dev; unsigned char *cdb = cmd->t_task_cdb; unsigned int size; u32 sectors = 0; sense_reason_t ret; switch (cdb[0]) { case READ_6: sectors = transport_get_sectors_6(cdb); cmd->t_task_lba = transport_lba_21(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case READ_10: sectors = transport_get_sectors_10(cdb); cmd->t_task_lba = transport_lba_32(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case READ_12: sectors = transport_get_sectors_12(cdb); cmd->t_task_lba = transport_lba_32(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case READ_16: sectors = transport_get_sectors_16(cdb); cmd->t_task_lba = transport_lba_64(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case WRITE_6: sectors = transport_get_sectors_6(cdb); cmd->t_task_lba = transport_lba_21(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case WRITE_10: case WRITE_VERIFY: sectors = transport_get_sectors_10(cdb); cmd->t_task_lba = transport_lba_32(cdb); if (cdb[1] & 0x8) cmd->se_cmd_flags |= SCF_FUA; cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case WRITE_12: sectors = transport_get_sectors_12(cdb); cmd->t_task_lba = transport_lba_32(cdb); if (cdb[1] & 0x8) cmd->se_cmd_flags |= SCF_FUA; cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case WRITE_16: sectors = transport_get_sectors_16(cdb); cmd->t_task_lba = transport_lba_64(cdb); if (cdb[1] & 0x8) cmd->se_cmd_flags |= SCF_FUA; cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; cmd->execute_cmd = ops->execute_rw; break; case XDWRITEREAD_10: if (cmd->data_direction != DMA_TO_DEVICE || !(cmd->se_cmd_flags & SCF_BIDI)) return TCM_INVALID_CDB_FIELD; sectors = transport_get_sectors_10(cdb); cmd->t_task_lba = transport_lba_32(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; /* * Setup BIDI XOR callback to be run after I/O completion. */ cmd->execute_cmd = ops->execute_rw; cmd->transport_complete_callback = &xdreadwrite_callback; if (cdb[1] & 0x8) cmd->se_cmd_flags |= SCF_FUA; break; case VARIABLE_LENGTH_CMD: { u16 service_action = get_unaligned_be16(&cdb[8]); switch (service_action) { case XDWRITEREAD_32: sectors = transport_get_sectors_32(cdb); /* * Use WRITE_32 and READ_32 opcodes for the emulated * XDWRITE_READ_32 logic. */ cmd->t_task_lba = transport_lba_64_ext(cdb); cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB; /* * Setup BIDI XOR callback to be run during after I/O * completion. */ cmd->execute_cmd = ops->execute_rw; cmd->transport_complete_callback = &xdreadwrite_callback; if (cdb[1] & 0x8) cmd->se_cmd_flags |= SCF_FUA; break; case WRITE_SAME_32: if (!ops->execute_write_same) return TCM_UNSUPPORTED_SCSI_OPCODE; sectors = transport_get_sectors_32(cdb); if (!sectors) { pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not" " supported\n"); return TCM_INVALID_CDB_FIELD; } size = sbc_get_size(cmd, 1); cmd->t_task_lba = get_unaligned_be64(&cdb[12]); if (sbc_write_same_supported(dev, &cdb[10]) < 0) return TCM_UNSUPPORTED_SCSI_OPCODE; cmd->execute_cmd = ops->execute_write_same; break; default: pr_err("VARIABLE_LENGTH_CMD service action" " 0x%04x not supported\n", service_action); return TCM_UNSUPPORTED_SCSI_OPCODE; } break; } case READ_CAPACITY: size = READ_CAP_LEN; cmd->execute_cmd = sbc_emulate_readcapacity; break; case SERVICE_ACTION_IN: switch (cmd->t_task_cdb[1] & 0x1f) { case SAI_READ_CAPACITY_16: cmd->execute_cmd = sbc_emulate_readcapacity_16; break; default: pr_err("Unsupported SA: 0x%02x\n", cmd->t_task_cdb[1] & 0x1f); return TCM_INVALID_CDB_FIELD; } size = (cdb[10] << 24) | (cdb[11] << 16) | (cdb[12] << 8) | cdb[13]; break; case SYNCHRONIZE_CACHE: case SYNCHRONIZE_CACHE_16: if (!ops->execute_sync_cache) return TCM_UNSUPPORTED_SCSI_OPCODE; /* * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE */ if (cdb[0] == SYNCHRONIZE_CACHE) { sectors = transport_get_sectors_10(cdb); cmd->t_task_lba = transport_lba_32(cdb); } else { sectors = transport_get_sectors_16(cdb); cmd->t_task_lba = transport_lba_64(cdb); } size = sbc_get_size(cmd, sectors); /* * Check to ensure that LBA + Range does not exceed past end of * device for IBLOCK and FILEIO ->do_sync_cache() backend calls */ if (cmd->t_task_lba || sectors) { if (sbc_check_valid_sectors(cmd) < 0) return TCM_INVALID_CDB_FIELD; } cmd->execute_cmd = ops->execute_sync_cache; break; case UNMAP: if (!ops->execute_unmap) return TCM_UNSUPPORTED_SCSI_OPCODE; size = get_unaligned_be16(&cdb[7]); cmd->execute_cmd = ops->execute_unmap; break; case WRITE_SAME_16: if (!ops->execute_write_same) return TCM_UNSUPPORTED_SCSI_OPCODE; sectors = transport_get_sectors_16(cdb); if (!sectors) { pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n"); return TCM_INVALID_CDB_FIELD; } size = sbc_get_size(cmd, 1); cmd->t_task_lba = get_unaligned_be64(&cdb[2]); if (sbc_write_same_supported(dev, &cdb[1]) < 0) return TCM_UNSUPPORTED_SCSI_OPCODE; cmd->execute_cmd = ops->execute_write_same; break; case WRITE_SAME: if (!ops->execute_write_same) return TCM_UNSUPPORTED_SCSI_OPCODE; sectors = transport_get_sectors_10(cdb); if (!sectors) { pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n"); return TCM_INVALID_CDB_FIELD; } size = sbc_get_size(cmd, 1); cmd->t_task_lba = get_unaligned_be32(&cdb[2]); /* * Follow sbcr26 with WRITE_SAME (10) and check for the existence * of byte 1 bit 3 UNMAP instead of original reserved field */ if (sbc_write_same_supported(dev, &cdb[1]) < 0) return TCM_UNSUPPORTED_SCSI_OPCODE; cmd->execute_cmd = ops->execute_write_same; break; case VERIFY: size = 0; cmd->execute_cmd = sbc_emulate_noop; break; case REZERO_UNIT: case SEEK_6: case SEEK_10: /* * There are still clients out there which use these old SCSI-2 * commands. This mainly happens when running VMs with legacy * guest systems, connected via SCSI command pass-through to * iSCSI targets. Make them happy and return status GOOD. */ size = 0; cmd->execute_cmd = sbc_emulate_noop; break; default: ret = spc_parse_cdb(cmd, &size); if (ret) return ret; } /* reject any command that we don't have a handler for */ if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd) return TCM_UNSUPPORTED_SCSI_OPCODE; if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) { unsigned long long end_lba; if (sectors > dev->dev_attrib.fabric_max_sectors) { printk_ratelimited(KERN_ERR "SCSI OP %02xh with too" " big sectors %u exceeds fabric_max_sectors:" " %u\n", cdb[0], sectors, dev->dev_attrib.fabric_max_sectors); return TCM_INVALID_CDB_FIELD; } if (sectors > dev->dev_attrib.hw_max_sectors) { printk_ratelimited(KERN_ERR "SCSI OP %02xh with too" " big sectors %u exceeds backend hw_max_sectors:" " %u\n", cdb[0], sectors, dev->dev_attrib.hw_max_sectors); return TCM_INVALID_CDB_FIELD; } end_lba = dev->transport->get_blocks(dev) + 1; if (cmd->t_task_lba + sectors > end_lba) { pr_err("cmd exceeds last lba %llu " "(lba %llu, sectors %u)\n", end_lba, cmd->t_task_lba, sectors); return TCM_INVALID_CDB_FIELD; } size = sbc_get_size(cmd, sectors); } return target_cmd_size_check(cmd, size); } EXPORT_SYMBOL(sbc_parse_cdb); u32 sbc_get_device_type(struct se_device *dev) { return TYPE_DISK; } EXPORT_SYMBOL(sbc_get_device_type);