/*
 * libefiboot - library for the manipulation of EFI boot variables
 * Copyright 2012-2018 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the
 * License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see
 * <http://www.gnu.org/licenses/>.
 *
 */

#include "fix_coverity.h"

#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdint.h>
#include <unistd.h>

#include "efiboot.h"

/*
 * support for Old-school SCSI devices
 */

/*
 * helper for scsi formats...
 */
ssize_t HIDDEN
parse_scsi_link(const char *current, uint32_t *scsi_host,
	        uint32_t *scsi_bus, uint32_t *scsi_device,
	        uint32_t *scsi_target, uint64_t *scsi_lun,
	        uint32_t *local_port_id, uint32_t *remote_port_id,
	        uint32_t *remote_target_id)
{
	int rc;
	int sz = 0;
	int pos0 = 0, pos1 = 0;

	debug("entry");
	/*
	 * This structure is completely ridiculous.
	 *
	 * /dev/sdc as SAS looks like:
	 * /sys/dev/block/8:32 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc
	 * /dev/sdc1 looks like:
	 * /sys/dev/block/8:33 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc/sdc1
	 *
	 * OR
	 *
	 * /dev/sdc as SAS looks like:
	 * /sys/dev/block/8:32 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:2:0/end_device-4:2:0/target4:2:0/4:2:0:0/block/sdc
	 * /dev/sdc1 looks like:
	 * /sys/dev/block/8:33 -> ../../devices/pci0000:00/0000:00:01.0/0000:01:00.0/host4/port-4:2:0/end_device-4:2:0/target4:2:0/4:2:0:0/block/sdc/sdc1
	 *
	 * /sys/block/sdc/device looks like:
	 * device-> ../../../4:2:0:0
	 *
	 * OR
	 *
	 * 8:0 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda
	 * 8:1 -> ../../devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
	 *
	 * /sys/block/sda/device looks like:
	 * device -> ../../../2:0:0:0 *
	 *
	 * sas_address exists, but it's hard to find:
	 * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address
	 * but sas_host_address is nowhere to be found, and sas_address
	 * doesn't directly exist under /sys/class/ anywhere.  So you actually
	 * have to go to
	 * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/sas_device/expander-2:0/sas_address
	 * and chop that off to
	 * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/
	 * and then add a bunch of port and end device crap to it to get:
	 * /sys/devices/pci0000:74/0000:74:02.0/host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/sas_device/end_device-2:0:2/sas_address

	 */

	/*
	 * So we start when current is:
	 * host4/port-4:0/end_device-4:0/target4:0:0/4:0:0:0/block/sdc/sdc1
	 * or
	 * host2/port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
	 */
	uint32_t tosser0, tosser1, tosser2;

	/* ignore a bunch of stuff
	 *    host4/port-4:0
	 * or host4/port-4:0:0
	 */
	debug("searching for host4/");
	rc = sscanf(current, "host%d/%n", scsi_host, &pos0);
	debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
	if (rc != 1)
	        return -1;
	sz += pos0;
	pos0 = 0;

	/*
	 * We might have this next:
	 * port-2:0/expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
	 * or:
	 * port-2:0/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
	 * or maybe (not sure):
	 * port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
	 */
	debug("searching for port-4:0 or port-4:0:0");
	rc = sscanf(current+sz, "port-%d:%d%n:%d%n", &tosser0,
	            &tosser1, &pos0, &tosser2, &pos1);
	debug("current:\"%s\" rc:%d pos0:%d pos1:%d\n", current+sz, rc, pos0, pos1);
	if (rc == 2 || rc == 3) {
	        sz += pos0;
	        pos0 = 0;
	        if (local_port_id && rc == 2)
	                *local_port_id = tosser1;
	        if (remote_port_id && rc == 3)
	                *remote_port_id = tosser2;

	        if (current[sz] == '/')
	                sz += 1;

	        /*
	         * We might have this next:
	         * expander-2:0/port-2:0:2/end_device-2:0:2/target2:0:0/2:0:0:0/block/sda/sda1
	         *                       ^ port id
	         *                     ^ scsi target id
	         *                   ^ host number
	         *          ^ host number
	         * We don't actually care about either number in expander-.../,
	         * because they're replicated in all the other places.  We just need
	         * to get past it.
	         */
	        debug("searching for expander-4:0/");
	        rc = sscanf(current+sz, "expander-%d:%d/%n", &tosser0, &tosser1, &pos0);
	        debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
	        if (rc == 2) {
	                if (!remote_target_id) {
	                        efi_error("Device is PHY is a remote target, but remote_target_id is NULL");
	                        return -1;
	                }
	                *remote_target_id = tosser1;
	                sz += pos0;
	                pos0 = 0;

	                /*
	                 * if we have that, we should have a 3-part port next
	                 */
	                debug("searching for port-2:0:2/");
	                rc = sscanf(current+sz, "port-%d:%d:%d/%n", &tosser0, &tosser1, &tosser2, &pos0);
	                debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
	                if (rc != 3) {
	                        efi_error("Couldn't parse port expander port string");
	                        return -1;
	                }
	                sz += pos0;
	        }
	        pos0 = 0;

	        /* next:
	         *    /end_device-4:0
	         * or /end_device-4:0:0
	         * awesomely these are the exact same fields that go into port-blah,
	         * but we don't care for now about any of them anyway.
	         */
	        debug("searching for end_device-4:0/ or end_device-4:0:0/");
	        rc = sscanf(current + sz, "end_device-%d:%d%n", &tosser0, &tosser1, &pos0);
	        debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
	        if (rc != 2)
	                return -1;

	        pos1 = 0;
	        rc = sscanf(current + sz + pos0, ":%d%n", &tosser2, &pos1);
	        if (rc != 0 && rc != 1)
	                return -1;
	        if (remote_port_id && rc == 1)
	                *remote_port_id = tosser2;
	        if (local_port_id && rc == 0)
	                *local_port_id = tosser1;
	        sz += pos0 + pos1;
	        pos0 = pos1 = 0;

	        if (current[sz] == '/')
	                sz += 1;
	} else if (rc != 0) {
	        return -1;
	}

	/* now:
	 * /target4:0:0/
	 */
	uint64_t tosser3;
	debug("searching for target4:0:0/");
	rc = sscanf(current + sz, "target%d:%d:%"PRIu64"/%n", &tosser0, &tosser1,
	            &tosser3, &pos0);
	debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
	if (rc != 3)
	        return -1;
	sz += pos0;
	pos0 = 0;

	/* now:
	 * %d:%d:%d:%llu/
	 */
	debug("searching for 4:0:0:0/");
	rc = sscanf(current + sz, "%d:%d:%d:%"PRIu64"/%n",
	            scsi_bus, scsi_device, scsi_target, scsi_lun, &pos0);
	debug("current:\"%s\" rc:%d pos0:%d\n", current+sz, rc, pos0);
	if (rc != 4)
	        return -1;
	sz += pos0;

	debug("returning %d", sz);
	return sz;
}

static ssize_t
parse_scsi(struct device *dev, const char *current, const char *root UNUSED)
{
	uint32_t scsi_host, scsi_bus, scsi_device, scsi_target;
	uint64_t scsi_lun;
	ssize_t sz;
	int pos;
	int rc;

	debug("entry");

	debug("searching for ../../../0:0:0:0");
	rc = sscanf(dev->device, "../../../%d:%d:%d:%"PRIu64"%n",
	            &dev->scsi_info.scsi_bus,
	            &dev->scsi_info.scsi_device,
	            &dev->scsi_info.scsi_target,
	            &dev->scsi_info.scsi_lun,
	            &pos);
	debug("current:\"%s\" rc:%d pos:%d\n", dev->device, rc, pos);
	if (rc != 4)
	        return 0;

	sz = parse_scsi_link(current, &scsi_host,
	                      &scsi_bus, &scsi_device,
	                      &scsi_target, &scsi_lun,
	                      NULL, NULL, NULL);
	if (sz < 0)
	        return 0;

	/*
	 * SCSI disks can have up to 16 partitions, or 4 bits worth
	 * and have one bit for the disk number.
	 */
	if (dev->major == 8) {
	        dev->interface_type = scsi;
	        dev->disknum = (dev->minor >> 4);
	        set_part(dev, dev->minor & 0xF);
	} else if (dev->major >= 65 && dev->major <= 71) {
	        dev->interface_type = scsi;
	        dev->disknum = 16*(dev->major-64) + (dev->minor >> 4);
	        set_part(dev, dev->minor & 0xF);
	} else if (dev->major >= 128 && dev->major <= 135) {
	        dev->interface_type = scsi;
	        dev->disknum = 16*(dev->major-128) + (dev->minor >> 4);
	        set_part(dev, dev->minor & 0xF);
	} else {
	        efi_error("couldn't parse scsi major/minor");
	        return -1;
	}

	return sz;
}

static ssize_t
dp_create_scsi(struct device *dev,
	       uint8_t *buf,  ssize_t size, ssize_t off)
{
	ssize_t sz = 0;

	debug("entry");

	sz = efidp_make_scsi(buf + off, size ? size - off : 0,
	                     dev->scsi_info.scsi_target,
	                     dev->scsi_info.scsi_lun);
	if (sz < 0)
	        efi_error("efidp_make_scsi() failed");

	return sz;
}

enum interface_type scsi_iftypes[] = { scsi, unknown };

struct dev_probe HIDDEN scsi_parser = {
	.name = "scsi",
	.iftypes = scsi_iftypes,
	.flags = DEV_PROVIDES_HD,
	.parse = parse_scsi,
	.create = dp_create_scsi,
};

// vim:fenc=utf-8:tw=75:noet
