/*
 * osd_initiator - Main body of the osd initiator library.
 *
 * Note: The file does not contain the advanced security functionality which
 * is only needed by the security_manager's initiators.
 *
 * Copyright (C) 2008 Panasas Inc.  All rights reserved.
 *
 * Authors:
 *   Boaz Harrosh <bharrosh@panasas.com>
 *   Benny Halevy <bhalevy@panasas.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
 *
 * 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 Panasas company 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 ``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 REGENTS OR CONTRIBUTORS 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 <scsi/osd_initiator.h>
#include <scsi/osd_sec.h>
#include <scsi/scsi_device.h>

#include "osd_debug.h"

enum { OSD_REQ_RETRIES = 1 };

MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
MODULE_DESCRIPTION("open-osd initiator library libosd.ko");
MODULE_LICENSE("GPL");

static inline void build_test(void)
{
	/* structures were not packed */
	BUILD_BUG_ON(sizeof(struct osd_capability) != OSD_CAP_LEN);
	BUILD_BUG_ON(sizeof(struct osdv1_cdb) != OSDv1_TOTAL_CDB_LEN);
}

static unsigned _osd_req_cdb_len(struct osd_request *or)
{
	return OSDv1_TOTAL_CDB_LEN;
}

void osd_dev_init(struct osd_dev *osdd, struct scsi_device *scsi_device)
{
	memset(osdd, 0, sizeof(*osdd));
	osdd->scsi_device = scsi_device;
	osdd->def_timeout = BLK_DEFAULT_SG_TIMEOUT;
	/* TODO: Allocate pools for osd_request attributes ... */
}
EXPORT_SYMBOL(osd_dev_init);

void osd_dev_fini(struct osd_dev *osdd)
{
	/* TODO: De-allocate pools */

	osdd->scsi_device = NULL;
}
EXPORT_SYMBOL(osd_dev_fini);

static struct osd_request *_osd_request_alloc(gfp_t gfp)
{
	struct osd_request *or;

	/* TODO: Use mempool with one saved request */
	or = kzalloc(sizeof(*or), gfp);
	return or;
}

static void _osd_request_free(struct osd_request *or)
{
	kfree(or);
}

struct osd_request *osd_start_request(struct osd_dev *dev, gfp_t gfp)
{
	struct osd_request *or;

	or = _osd_request_alloc(gfp);
	if (!or)
		return NULL;

	or->osd_dev = dev;
	or->alloc_flags = gfp;
	or->timeout = dev->def_timeout;
	or->retries = OSD_REQ_RETRIES;

	return or;
}
EXPORT_SYMBOL(osd_start_request);

/*
 * If osd_finalize_request() was called but the request was not executed through
 * the block layer, then we must release BIOs.
 */
static void _abort_unexecuted_bios(struct request *rq)
{
	struct bio *bio;

	while ((bio = rq->bio) != NULL) {
		rq->bio = bio->bi_next;
		bio_endio(bio, 0);
	}
}

void osd_end_request(struct osd_request *or)
{
	struct request *rq = or->request;

	if (rq) {
		if (rq->next_rq) {
			_abort_unexecuted_bios(rq->next_rq);
			blk_put_request(rq->next_rq);
		}

		_abort_unexecuted_bios(rq);
		blk_put_request(rq);
	}
	_osd_request_free(or);
}
EXPORT_SYMBOL(osd_end_request);

int osd_execute_request(struct osd_request *or)
{
	return blk_execute_rq(or->request->q, NULL, or->request, 0);
}
EXPORT_SYMBOL(osd_execute_request);

static void osd_request_async_done(struct request *req, int error)
{
	struct osd_request *or = req->end_io_data;

	or->async_error = error;

	if (error)
		OSD_DEBUG("osd_request_async_done error recieved %d\n", error);

	if (or->async_done)
		or->async_done(or, or->async_private);
	else
		osd_end_request(or);
}

int osd_execute_request_async(struct osd_request *or,
	osd_req_done_fn *done, void *private)
{
	or->request->end_io_data = or;
	or->async_private = private;
	or->async_done = done;

	blk_execute_rq_nowait(or->request->q, NULL, or->request, 0,
			      osd_request_async_done);
	return 0;
}
EXPORT_SYMBOL(osd_execute_request_async);

/*
 * Common to all OSD commands
 */

static void _osdv1_req_encode_common(struct osd_request *or,
	__be16 act, const struct osd_obj_id *obj, u64 offset, u64 len)
{
	struct osdv1_cdb *ocdb = &or->cdb.v1;

	/*
	 * For speed, the commands
	 *	OSD_ACT_PERFORM_SCSI_COMMAND	, V1 0x8F7E, V2 0x8F7C
	 *	OSD_ACT_SCSI_TASK_MANAGEMENT	, V1 0x8F7F, V2 0x8F7D
	 * are not supported here. Should pass zero and set after the call
	 */
	act &= cpu_to_be16(~0x0080); /* V1 action code */

	OSD_DEBUG("OSDv1 execute opcode 0x%x\n", be16_to_cpu(act));

	ocdb->h.varlen_cdb.opcode = VARIABLE_LENGTH_CMD;
	ocdb->h.varlen_cdb.additional_cdb_length = OSD_ADDITIONAL_CDB_LENGTH;
	ocdb->h.varlen_cdb.service_action = act;

	ocdb->h.partition = cpu_to_be64(obj->partition);
	ocdb->h.object = cpu_to_be64(obj->id);
	ocdb->h.v1.length = cpu_to_be64(len);
	ocdb->h.v1.start_address = cpu_to_be64(offset);
}

static void _osd_req_encode_common(struct osd_request *or,
	__be16 act, const struct osd_obj_id *obj, u64 offset, u64 len)
{
	_osdv1_req_encode_common(or, act, obj, offset, len);
}

/*
 * Device commands
 */
void osd_req_format(struct osd_request *or, u64 tot_capacity)
{
	_osd_req_encode_common(or, OSD_ACT_FORMAT_OSD, &osd_root_object, 0,
				tot_capacity);
}
EXPORT_SYMBOL(osd_req_format);

/*
 * Partition commands
 */
static void _osd_req_encode_partition(struct osd_request *or,
	__be16 act, osd_id partition)
{
	struct osd_obj_id par = {
		.partition = partition,
		.id = 0,
	};

	_osd_req_encode_common(or, act, &par, 0, 0);
}

void osd_req_create_partition(struct osd_request *or, osd_id partition)
{
	_osd_req_encode_partition(or, OSD_ACT_CREATE_PARTITION, partition);
}
EXPORT_SYMBOL(osd_req_create_partition);

void osd_req_remove_partition(struct osd_request *or, osd_id partition)
{
	_osd_req_encode_partition(or, OSD_ACT_REMOVE_PARTITION, partition);
}
EXPORT_SYMBOL(osd_req_remove_partition);

/*
 * Object commands
 */
void osd_req_create_object(struct osd_request *or, struct osd_obj_id *obj)
{
	_osd_req_encode_common(or, OSD_ACT_CREATE, obj, 0, 0);
}
EXPORT_SYMBOL(osd_req_create_object);

void osd_req_remove_object(struct osd_request *or, struct osd_obj_id *obj)
{
	_osd_req_encode_common(or, OSD_ACT_REMOVE, obj, 0, 0);
}
EXPORT_SYMBOL(osd_req_remove_object);

void osd_req_write(struct osd_request *or,
	const struct osd_obj_id *obj, struct bio *bio, u64 offset)
{
	_osd_req_encode_common(or, OSD_ACT_WRITE, obj, offset, bio->bi_size);
	WARN_ON(or->out.bio || or->out.total_bytes);
	bio->bi_rw |= (1 << BIO_RW);
	or->out.bio = bio;
	or->out.total_bytes = bio->bi_size;
}
EXPORT_SYMBOL(osd_req_write);

void osd_req_read(struct osd_request *or,
	const struct osd_obj_id *obj, struct bio *bio, u64 offset)
{
	_osd_req_encode_common(or, OSD_ACT_READ, obj, offset, bio->bi_size);
	WARN_ON(or->in.bio || or->in.total_bytes);
	bio->bi_rw &= ~(1 << BIO_RW);
	or->in.bio = bio;
	or->in.total_bytes = bio->bi_size;
}
EXPORT_SYMBOL(osd_req_read);

/*
 * osd_finalize_request and helpers
 */

static int _init_blk_request(struct osd_request *or,
	bool has_in, bool has_out)
{
	gfp_t flags = or->alloc_flags;
	struct scsi_device *scsi_device = or->osd_dev->scsi_device;
	struct request_queue *q = scsi_device->request_queue;
	struct request *req;
	int ret = -ENOMEM;

	req = blk_get_request(q, has_out, flags);
	if (!req)
		goto out;

	or->request = req;
	req->cmd_type = REQ_TYPE_BLOCK_PC;
	req->timeout = or->timeout;
	req->retries = or->retries;
	req->sense = or->sense;
	req->sense_len = 0;

	if (has_out) {
		or->out.req = req;
		if (has_in) {
			/* allocate bidi request */
			req = blk_get_request(q, READ, flags);
			if (!req) {
				OSD_DEBUG("blk_get_request for bidi failed\n");
				goto out;
			}
			req->cmd_type = REQ_TYPE_BLOCK_PC;
			or->in.req = or->request->next_rq = req;
		}
	} else if (has_in)
		or->in.req = req;

	ret = 0;
out:
	OSD_DEBUG("or=%p has_in=%d has_out=%d => %d, %p\n",
			or, has_in, has_out, ret, or->request);
	return ret;
}

int osd_finalize_request(struct osd_request *or,
	u8 options, const void *cap, const u8 *cap_key)
{
	struct osd_cdb_head *cdbh = osd_cdb_head(&or->cdb);
	bool has_in, has_out;
	int ret;

	if (options & OSD_REQ_FUA)
		cdbh->options |= OSD_CDB_FUA;

	if (options & OSD_REQ_DPO)
		cdbh->options |= OSD_CDB_DPO;

	if (options & OSD_REQ_BYPASS_TIMESTAMPS)
		cdbh->timestamp_control = OSD_CDB_BYPASS_TIMESTAMPS;

	osd_set_caps(&or->cdb, cap);

	has_in = or->in.bio || or->get_attr.total_bytes;
	has_out = or->out.bio || or->set_attr.total_bytes ||
		or->enc_get_attr.total_bytes;

	ret = _init_blk_request(or, has_in, has_out);
	if (ret) {
		OSD_DEBUG("_init_blk_request failed\n");
		return ret;
	}

	if (or->out.bio) {
		ret = blk_rq_append_bio(or->request->q, or->out.req,
					or->out.bio);
		if (ret) {
			OSD_DEBUG("blk_rq_append_bio out failed\n");
			return ret;
		}
		OSD_DEBUG("out bytes=%llu (bytes_req=%u)\n",
			_LLU(or->out.total_bytes), or->out.req->data_len);
	}
	if (or->in.bio) {
		ret = blk_rq_append_bio(or->request->q, or->in.req, or->in.bio);
		if (ret) {
			OSD_DEBUG("blk_rq_append_bio in failed\n");
			return ret;
		}
		OSD_DEBUG("in bytes=%llu (bytes_req=%u)\n",
			_LLU(or->in.total_bytes), or->in.req->data_len);
	}

	if (!or->attributes_mode)
		or->attributes_mode = OSD_CDB_GET_SET_ATTR_LISTS;
	cdbh->command_specific_options |= or->attributes_mode;

	or->request->cmd = or->cdb.buff;
	or->request->cmd_len = _osd_req_cdb_len(or);

	return 0;
}
EXPORT_SYMBOL(osd_finalize_request);

/*
 * Implementation of osd_sec.h API
 * TODO: Move to a separate osd_sec.c file at a later stage.
 */

enum { OSD_SEC_CAP_V1_ALL_CAPS =
	OSD_SEC_CAP_APPEND | OSD_SEC_CAP_OBJ_MGMT | OSD_SEC_CAP_REMOVE   |
	OSD_SEC_CAP_CREATE | OSD_SEC_CAP_SET_ATTR | OSD_SEC_CAP_GET_ATTR |
	OSD_SEC_CAP_WRITE  | OSD_SEC_CAP_READ     | OSD_SEC_CAP_POL_SEC  |
	OSD_SEC_CAP_GLOBAL | OSD_SEC_CAP_DEV_MGMT
};

void osd_sec_init_nosec_doall_caps(void *caps,
	const struct osd_obj_id *obj, bool is_collection, const bool is_v1)
{
	struct osd_capability *cap = caps;
	u8 type;
	u8 descriptor_type;

	if (likely(obj->id)) {
		if (unlikely(is_collection)) {
			type = OSD_SEC_OBJ_COLLECTION;
			descriptor_type = is_v1 ? OSD_SEC_OBJ_DESC_OBJ :
						  OSD_SEC_OBJ_DESC_COL;
		} else {
			type = OSD_SEC_OBJ_USER;
			descriptor_type = OSD_SEC_OBJ_DESC_OBJ;
		}
		WARN_ON(!obj->partition);
	} else {
		type = obj->partition ? OSD_SEC_OBJ_PARTITION :
					OSD_SEC_OBJ_ROOT;
		descriptor_type = OSD_SEC_OBJ_DESC_PAR;
	}

	memset(cap, 0, sizeof(*cap));

	cap->h.format = OSD_SEC_CAP_FORMAT_VER1;
	cap->h.integrity_algorithm__key_version = 0; /* MAKE_BYTE(0, 0); */
	cap->h.security_method = OSD_SEC_NOSEC;
/*	cap->expiration_time;
	cap->AUDIT[30-10];
	cap->discriminator[42-30];
	cap->object_created_time; */
	cap->h.object_type = type;
	osd_sec_set_caps(&cap->h, OSD_SEC_CAP_V1_ALL_CAPS);
	cap->h.object_descriptor_type = descriptor_type;
	cap->od.obj_desc.policy_access_tag = 0;
	cap->od.obj_desc.allowed_partition_id = cpu_to_be64(obj->partition);
	cap->od.obj_desc.allowed_object_id = cpu_to_be64(obj->id);
}
EXPORT_SYMBOL(osd_sec_init_nosec_doall_caps);

void osd_set_caps(struct osd_cdb *cdb, const void *caps)
{
	memcpy(&cdb->v1.caps, caps, OSDv1_CAP_LEN);
}