githubmirror/efivar

src/linux-scsi.c
307 строк10 KB
Peter Jones
SPDX-ify all the license text in source files.
03 фев 2020, 21:37
03 фев 2020, 21:37ce42f1d
// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * libefiboot - library for the manipulation of EFI boot variables
 * Copyright 2012-2019 Red Hat, Inc.
 */

#include "fix_coverity.h"

#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdint.h>
#include <sys/param.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 *path, 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)
{
	const char *current = path;
	int rc;
	int pos0 = -1, pos1 = -1, pos2 = -1;

	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, "%nhost%d/%n", scsi_host, &pos0, &pos1);
	debug("current:'%s' rc:%d pos0:%d pos1:%d\n", current, rc, pos0, pos1);
	dbgmk("         ", pos0, pos1);
	if (rc != 1)
	        return -1;
	current += pos1;
	pos0 = pos1 = -1;

	/*
	 * 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, "%nport-%d:%d%n:%d%n",
		    &pos0, &tosser0, &tosser1, &pos1, &tosser2, &pos2);
	debug("current:'%s' rc:%d pos0:%d pos1:%d pos2:%d\n", current, rc, pos0, pos1, pos2);
	dbgmk("         ", pos0, MAX(pos1, pos2));
	if (rc == 3) {
		if (remote_port_id)
			*remote_port_id = tosser2;
		pos1 = pos2;
	} else if (rc == 2) {
		if (local_port_id)
			*local_port_id = tosser1;
	} else if (rc != 0) {
		return -1;
	} else {
		pos1 = 0;
	}
	current += pos1;

	if (current[0] == '/')
		current += 1;
	pos0 = pos1 = pos2 = -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, "%nexpander-%d:%d/%n", &pos0, &tosser0, &tosser1, &pos1);
        debug("current:'%s' rc:%d pos0:%d pos1:%d\n", current, rc, pos0, pos1);
	dbgmk("         ", pos0, pos1);
        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;
		current += pos1;
		pos0 = pos1 = -1;

                /*
                 * if we have that, we should have a 3-part port next
                 */
                debug("searching for port-2:0:2/");
                rc = sscanf(current, "%nport-%d:%d:%d/%n", &pos0, &tosser0, &tosser1, &tosser2, &pos1);
                debug("current:'%s' rc:%d pos0:%d pos1:%d\n", current, rc, pos0, pos1);
		dbgmk("         ", pos0, pos1);
                if (rc != 3) {
                        efi_error("Couldn't parse port expander port string");
                        return -1;
                }
		current += pos1;
        }
	pos0 = pos1 = -1;

        /* 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, "%nend_device-%d:%d%n:%d%n",
		    &pos0, &tosser0, &tosser1, &pos1, &tosser2, &pos2);
        debug("current:'%s' rc:%d pos0:%d\n", current, rc, pos0);
	dbgmk("         ", pos0, MAX(pos1, pos2));
	if (rc == 3) {
		if (remote_port_id)
			*remote_port_id = tosser2;
		pos1 = pos2;
	} else if (rc == 2) {
		if (local_port_id)
			*local_port_id = tosser1;
	} else {
		pos1 = 0;
	}
	current += pos1;
	pos0 = pos1 = pos2 = -1;

        if (current[0] == '/')
		current += 1;

	/* now:
	 * /target4:0:0/
	 */
	uint64_t tosser3;
	debug("searching for target4:0:0/");
	rc = sscanf(current, "%ntarget%d:%d:%"PRIu64"/%n",
		    &pos0, &tosser0, &tosser1, &tosser3, &pos1);
	debug("current:'%s' rc:%d pos0:%d pos1:%d\n", current, rc, pos0, pos1);
	dbgmk("         ", pos0, pos1);
	if (rc != 3)
	        return -1;
	current += pos1;
	pos0 = pos1 = -1;

	/* now:
	 * %d:%d:%d:%llu/
	 */
	debug("searching for 4:0:0:0/");
	rc = sscanf(current, "%n%d:%d:%d:%"PRIu64"/%n",
	            &pos0, scsi_bus, scsi_device, scsi_target, scsi_lun, &pos1);
	debug("current:'%s' rc:%d pos0:%d pos1:%d\n", current, rc, pos0, pos1);
	dbgmk("         ", pos0, pos1);
	if (rc != 4)
	        return -1;
	current += pos1;

	debug("current:'%s' sz:%zd", current, current - path);
	return current - path;
}

static ssize_t
parse_scsi(struct device *dev, const char *path, const char *root UNUSED)
{
	const char *current = path;
	uint32_t scsi_host, scsi_bus, scsi_device, scsi_target;
	uint64_t scsi_lun;
	int pos0, pos1;
	int rc;

	debug("entry");

	debug("searching device for ../../../0:0:0:0");
	pos0 = pos1 = -1;
	rc = sscanf(dev->device, "../../../%n%d:%d:%d:%"PRIu64"%n",
		    &pos0,
	            &dev->scsi_info.scsi_bus,
	            &dev->scsi_info.scsi_device,
	            &dev->scsi_info.scsi_target,
	            &dev->scsi_info.scsi_lun,
	            &pos1);
	debug("device:'%s' rc:%d pos0:%d pos1:%d\n", dev->device, rc, pos0, pos1);
	dbgmk("        ", pos0, pos1);
	if (rc != 4)
	        return 0;

	pos0 = parse_scsi_link(current, &scsi_host, &scsi_bus, &scsi_device,
			       &scsi_target, &scsi_lun, NULL, NULL, NULL);
	if (pos0 < 0)
	        return 0;
	current += pos0;

	/*
	 * 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;
	}

	debug("current:'%s' sz:%zd\n", current, current - path);
	return current - path;
}

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