target_core_fabric_lib.c

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/*******************************************************************************
 * Filename:  target_core_fabric_lib.c
 *
 * This file contains generic high level protocol identifier and PR
 * handlers for TCM fabric modules
 *
 * Copyright (c) 2010 Rising Tide Systems, Inc.
 * Copyright (c) 2010 Linux-iSCSI.org
 *
 * Nicholas A. Bellinger <[email protected]>
 *
 * 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 <linux/kernel.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>

#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include <target/target_core_configfs.h>

#include "target_core_internal.h"
#include "target_core_pr.h"

/*
 * Handlers for Serial Attached SCSI (SAS)
 */
u8 sas_get_fabric_proto_ident(struct se_portal_group *se_tpg)
{
    /*
     * Return a SAS Serial SCSI Protocol identifier for loopback operations
     * This is defined in  section 7.5.1 Table 362 in spc4r17
     */
    return 0x6;
}
EXPORT_SYMBOL(sas_get_fabric_proto_ident);

u32 sas_get_pr_transport_id(
    struct se_portal_group *se_tpg,
    struct se_node_acl *se_nacl,
    struct t10_pr_registration *pr_reg,
    int *format_code,
    unsigned char *buf)
{
    unsigned char *ptr;
    int ret;

    /*
     * Set PROTOCOL IDENTIFIER to 6h for SAS
     */
    buf[0] = 0x06;
    /*
     * From spc4r17, 7.5.4.7 TransportID for initiator ports using SCSI
     * over SAS Serial SCSI Protocol
     */
    ptr = &se_nacl->initiatorname[4]; /* Skip over 'naa. prefix */

    ret = hex2bin(&buf[4], ptr, 8);
    if (ret < 0)
        pr_debug("sas transport_id: invalid hex string\n");

    /*
     * The SAS Transport ID is a hardcoded 24-byte length
     */
    return 24;
}
EXPORT_SYMBOL(sas_get_pr_transport_id);

u32 sas_get_pr_transport_id_len(
    struct se_portal_group *se_tpg,
    struct se_node_acl *se_nacl,
    struct t10_pr_registration *pr_reg,
    int *format_code)
{
    *format_code = 0;
    /*
     * From spc4r17, 7.5.4.7 TransportID for initiator ports using SCSI
     * over SAS Serial SCSI Protocol
     *
     * The SAS Transport ID is a hardcoded 24-byte length
     */
    return 24;
}
EXPORT_SYMBOL(sas_get_pr_transport_id_len);

/*
 * Used for handling SCSI fabric dependent TransportIDs in SPC-3 and above
 * Persistent Reservation SPEC_I_PT=1 and PROUT REGISTER_AND_MOVE operations.
 */
char *sas_parse_pr_out_transport_id(
    struct se_portal_group *se_tpg,
    const char *buf,
    u32 *out_tid_len,
    char **port_nexus_ptr)
{
    /*
     * Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
     * for initiator ports using SCSI over SAS Serial SCSI Protocol
     *
     * The TransportID for a SAS Initiator Port is of fixed size of
     * 24 bytes, and SAS does not contain a I_T nexus identifier,
     * so we return the **port_nexus_ptr set to NULL.
     */
    *port_nexus_ptr = NULL;
    *out_tid_len = 24;

    return (char *)&buf[4];
}
EXPORT_SYMBOL(sas_parse_pr_out_transport_id);

/*
 * Handlers for Fibre Channel Protocol (FCP)
 */
u8 fc_get_fabric_proto_ident(struct se_portal_group *se_tpg)
{
    return 0x0; /* 0 = fcp-2 per SPC4 section 7.5.1 */
}
EXPORT_SYMBOL(fc_get_fabric_proto_ident);

u32 fc_get_pr_transport_id_len(
    struct se_portal_group *se_tpg,
    struct se_node_acl *se_nacl,
    struct t10_pr_registration *pr_reg,
    int *format_code)
{
    *format_code = 0;
    /*
     * The FC Transport ID is a hardcoded 24-byte length
     */
    return 24;
}
EXPORT_SYMBOL(fc_get_pr_transport_id_len);

u32 fc_get_pr_transport_id(
    struct se_portal_group *se_tpg,
    struct se_node_acl *se_nacl,
    struct t10_pr_registration *pr_reg,
    int *format_code,
    unsigned char *buf)
{
    unsigned char *ptr;
    int i, ret;
    u32 off = 8;

    /*
     * PROTOCOL IDENTIFIER is 0h for FCP-2
     *
     * From spc4r17, 7.5.4.2 TransportID for initiator ports using
     * SCSI over Fibre Channel
     *
     * We convert the ASCII formatted N Port name into a binary
     * encoded TransportID.
     */
    ptr = &se_nacl->initiatorname[0];

    for (i = 0; i < 24; ) {
        if (!strncmp(&ptr[i], ":", 1)) {
            i++;
            continue;
        }
        ret = hex2bin(&buf[off++], &ptr[i], 1);
        if (ret < 0)
            pr_debug("fc transport_id: invalid hex string\n");
        i += 2;
    }
    /*
     * The FC Transport ID is a hardcoded 24-byte length
     */
    return 24;
}
EXPORT_SYMBOL(fc_get_pr_transport_id);

char *fc_parse_pr_out_transport_id(
    struct se_portal_group *se_tpg,
    const char *buf,
    u32 *out_tid_len,
    char **port_nexus_ptr)
{
    /*
     * The TransportID for a FC N Port is of fixed size of
     * 24 bytes, and FC does not contain a I_T nexus identifier,
     * so we return the **port_nexus_ptr set to NULL.
     */
    *port_nexus_ptr = NULL;
    *out_tid_len = 24;

     return (char *)&buf[8];
}
EXPORT_SYMBOL(fc_parse_pr_out_transport_id);

/*
 * Handlers for Internet Small Computer Systems Interface (iSCSI)
 */

u8 iscsi_get_fabric_proto_ident(struct se_portal_group *se_tpg)
{
    /*
     * This value is defined for "Internet SCSI (iSCSI)"
     * in spc4r17 section 7.5.1 Table 362
     */
    return 0x5;
}
EXPORT_SYMBOL(iscsi_get_fabric_proto_ident);

u32 iscsi_get_pr_transport_id(
    struct se_portal_group *se_tpg,
    struct se_node_acl *se_nacl,
    struct t10_pr_registration *pr_reg,
    int *format_code,
    unsigned char *buf)
{
    u32 off = 4, padding = 0;
    u16 len = 0;

    spin_lock_irq(&se_nacl->nacl_sess_lock);
    /*
     * Set PROTOCOL IDENTIFIER to 5h for iSCSI
    */
    buf[0] = 0x05;
    /*
     * From spc4r17 Section 7.5.4.6: TransportID for initiator
     * ports using SCSI over iSCSI.
     *
     * The null-terminated, null-padded (see 4.4.2) ISCSI NAME field
     * shall contain the iSCSI name of an iSCSI initiator node (see
     * RFC 3720). The first ISCSI NAME field byte containing an ASCII
     * null character terminates the ISCSI NAME field without regard for
     * the specified length of the iSCSI TransportID or the contents of
     * the ADDITIONAL LENGTH field.
     */
    len = sprintf(&buf[off], "%s", se_nacl->initiatorname);
    /*
     * Add Extra byte for NULL terminator
     */
    len++;
    /*
     * If there is ISID present with the registration and *format code == 1
     * 1, use iSCSI Initiator port TransportID format.
     *
     * Otherwise use iSCSI Initiator device TransportID format that
     * does not contain the ASCII encoded iSCSI Initiator iSID value
     * provied by the iSCSi Initiator during the iSCSI login process.
     */
    if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
        /*
         * Set FORMAT CODE 01b for iSCSI Initiator port TransportID
         * format.
         */
        buf[0] |= 0x40;
        /*
         * From spc4r17 Section 7.5.4.6: TransportID for initiator
         * ports using SCSI over iSCSI.  Table 390
         *
         * The SEPARATOR field shall contain the five ASCII
         * characters ",i,0x".
         *
         * The null-terminated, null-padded ISCSI INITIATOR SESSION ID
         * field shall contain the iSCSI initiator session identifier
         * (see RFC 3720) in the form of ASCII characters that are the
         * hexadecimal digits converted from the binary iSCSI initiator
         * session identifier value. The first ISCSI INITIATOR SESSION
         * ID field byte containing an ASCII null character
         */
        buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
        buf[off+len] = 0x69; off++; /* ASCII Character: "i" */
        buf[off+len] = 0x2c; off++; /* ASCII Character: "," */
        buf[off+len] = 0x30; off++; /* ASCII Character: "0" */
        buf[off+len] = 0x78; off++; /* ASCII Character: "x" */
        len += 5;
        buf[off+len] = pr_reg->pr_reg_isid[0]; off++;
        buf[off+len] = pr_reg->pr_reg_isid[1]; off++;
        buf[off+len] = pr_reg->pr_reg_isid[2]; off++;
        buf[off+len] = pr_reg->pr_reg_isid[3]; off++;
        buf[off+len] = pr_reg->pr_reg_isid[4]; off++;
        buf[off+len] = pr_reg->pr_reg_isid[5]; off++;
        buf[off+len] = '\0'; off++;
        len += 7;
    }
    spin_unlock_irq(&se_nacl->nacl_sess_lock);
    /*
     * The ADDITIONAL LENGTH field specifies the number of bytes that follow
     * in the TransportID. The additional length shall be at least 20 and
     * shall be a multiple of four.
    */
    padding = ((-len) & 3);
    if (padding != 0)
        len += padding;

    buf[2] = ((len >> 8) & 0xff);
    buf[3] = (len & 0xff);
    /*
     * Increment value for total payload + header length for
     * full status descriptor
     */
    len += 4;

    return len;
}
EXPORT_SYMBOL(iscsi_get_pr_transport_id);

u32 iscsi_get_pr_transport_id_len(
    struct se_portal_group *se_tpg,
    struct se_node_acl *se_nacl,
    struct t10_pr_registration *pr_reg,
    int *format_code)
{
    u32 len = 0, padding = 0;

    spin_lock_irq(&se_nacl->nacl_sess_lock);
    len = strlen(se_nacl->initiatorname);
    /*
     * Add extra byte for NULL terminator
     */
    len++;
    /*
     * If there is ISID present with the registration, use format code:
     * 01b: iSCSI Initiator port TransportID format
     *
     * If there is not an active iSCSI session, use format code:
     * 00b: iSCSI Initiator device TransportID format
     */
    if (pr_reg->isid_present_at_reg) {
        len += 5; /* For ",i,0x" ASCII separator */
        len += 7; /* For iSCSI Initiator Session ID + Null terminator */
        *format_code = 1;
    } else
        *format_code = 0;
    spin_unlock_irq(&se_nacl->nacl_sess_lock);
    /*
     * The ADDITIONAL LENGTH field specifies the number of bytes that follow
     * in the TransportID. The additional length shall be at least 20 and
     * shall be a multiple of four.
     */
    padding = ((-len) & 3);
    if (padding != 0)
        len += padding;
    /*
     * Increment value for total payload + header length for
     * full status descriptor
     */
    len += 4;

    return len;
}
EXPORT_SYMBOL(iscsi_get_pr_transport_id_len);

char *iscsi_parse_pr_out_transport_id(
    struct se_portal_group *se_tpg,
    const char *buf,
    u32 *out_tid_len,
    char **port_nexus_ptr)
{
    char *p;
    u32 tid_len, padding;
    int i;
    u16 add_len;
    u8 format_code = (buf[0] & 0xc0);
    /*
     * Check for FORMAT CODE 00b or 01b from spc4r17, section 7.5.4.6:
     *
     *       TransportID for initiator ports using SCSI over iSCSI,
     *       from Table 388 -- iSCSI TransportID formats.
     *
     *    00b     Initiator port is identified using the world wide unique
     *            SCSI device name of the iSCSI initiator
     *            device containing the initiator port (see table 389).
     *    01b     Initiator port is identified using the world wide unique
     *            initiator port identifier (see table 390).10b to 11b
     *            Reserved
     */
    if ((format_code != 0x00) && (format_code != 0x40)) {
        pr_err("Illegal format code: 0x%02x for iSCSI"
            " Initiator Transport ID\n", format_code);
        return NULL;
    }
    /*
     * If the caller wants the TransportID Length, we set that value for the
     * entire iSCSI Tarnsport ID now.
     */
     if (out_tid_len != NULL) {
        add_len = ((buf[2] >> 8) & 0xff);
        add_len |= (buf[3] & 0xff);

        tid_len = strlen(&buf[4]);
        tid_len += 4; /* Add four bytes for iSCSI Transport ID header */
        tid_len += 1; /* Add one byte for NULL terminator */
        padding = ((-tid_len) & 3);
        if (padding != 0)
            tid_len += padding;

        if ((add_len + 4) != tid_len) {
            pr_debug("LIO-Target Extracted add_len: %hu "
                "does not match calculated tid_len: %u,"
                " using tid_len instead\n", add_len+4, tid_len);
            *out_tid_len = tid_len;
        } else
            *out_tid_len = (add_len + 4);
    }
    /*
     * Check for ',i,0x' separator between iSCSI Name and iSCSI Initiator
     * Session ID as defined in Table 390 - iSCSI initiator port TransportID
     * format.
     */
    if (format_code == 0x40) {
        p = strstr(&buf[4], ",i,0x");
        if (!p) {
            pr_err("Unable to locate \",i,0x\" separator"
                " for Initiator port identifier: %s\n",
                &buf[4]);
            return NULL;
        }
        *p = '\0'; /* Terminate iSCSI Name */
        p += 5; /* Skip over ",i,0x" separator */

        *port_nexus_ptr = p;
        /*
         * Go ahead and do the lower case conversion of the received
         * 12 ASCII characters representing the ISID in the TransportID
         * for comparison against the running iSCSI session's ISID from
         * iscsi_target.c:lio_sess_get_initiator_sid()
         */
        for (i = 0; i < 12; i++) {
            if (isdigit(*p)) {
                p++;
                continue;
            }
            *p = tolower(*p);
            p++;
        }
    }

    return (char *)&buf[4];
}
EXPORT_SYMBOL(iscsi_parse_pr_out_transport_id);