linux/drivers/target/target_core_fabric_lib.c
Mike Christie 639341bf88 scsi: target: Handle short iSIDs
SPC4 has:

The first ISCSI INITIATOR SESSION ID field byte containing an ASCII null
character terminates the ISCSI INITIATOR SESSION ID field without regard
for the specified length of the iSCSI TransportID or the contents of the
ADDITIONAL LENGTH field.
----------------------------------------

which sounds like we can get an iSID shorter than 12 chars. SPC and the
iSCSI RFC do not say how to handle that case other than just cutting off
the iSID. This patch just makes sure that if we get an iSID like that, we
only copy/send that string.

There is no OS that does this right now, so there was no test case.  I did
test with sg utils to check it works as expected and nothing breaks.

Link: https://lore.kernel.org/r/1593654203-12442-8-git-send-email-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2020-07-08 00:14:34 -04:00

420 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*******************************************************************************
* Filename: target_core_fabric_lib.c
*
* This file contains generic high level protocol identifier and PR
* handlers for TCM fabric modules
*
* (c) Copyright 2010-2013 Datera, Inc.
*
* Nicholas A. Bellinger <nab@linux-iscsi.org>
*
******************************************************************************/
/*
* See SPC4, section 7.5 "Protocol specific parameters" for details
* on the formats implemented in this file.
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <asm/unaligned.h>
#include <scsi/scsi_proto.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>
#include "target_core_internal.h"
#include "target_core_pr.h"
static int sas_get_pr_transport_id(
struct se_node_acl *nacl,
int *format_code,
unsigned char *buf)
{
int ret;
/* Skip over 'naa. prefix */
ret = hex2bin(&buf[4], &nacl->initiatorname[4], 8);
if (ret) {
pr_debug("%s: invalid hex string\n", __func__);
return ret;
}
return 24;
}
static int fc_get_pr_transport_id(
struct se_node_acl *se_nacl,
int *format_code,
unsigned char *buf)
{
unsigned char *ptr;
int i, ret;
u32 off = 8;
/*
* We convert the ASCII formatted N Port name into a binary
* encoded TransportID.
*/
ptr = &se_nacl->initiatorname[0];
for (i = 0; i < 23; ) {
if (!strncmp(&ptr[i], ":", 1)) {
i++;
continue;
}
ret = hex2bin(&buf[off++], &ptr[i], 1);
if (ret < 0) {
pr_debug("%s: invalid hex string\n", __func__);
return ret;
}
i += 2;
}
/*
* The FC Transport ID is a hardcoded 24-byte length
*/
return 24;
}
static int sbp_get_pr_transport_id(
struct se_node_acl *nacl,
int *format_code,
unsigned char *buf)
{
int ret;
ret = hex2bin(&buf[8], nacl->initiatorname, 8);
if (ret) {
pr_debug("%s: invalid hex string\n", __func__);
return ret;
}
return 24;
}
static int srp_get_pr_transport_id(
struct se_node_acl *nacl,
int *format_code,
unsigned char *buf)
{
const char *p;
unsigned len, count, leading_zero_bytes;
int rc;
p = nacl->initiatorname;
if (strncasecmp(p, "0x", 2) == 0)
p += 2;
len = strlen(p);
if (len % 2)
return -EINVAL;
count = min(len / 2, 16U);
leading_zero_bytes = 16 - count;
memset(buf + 8, 0, leading_zero_bytes);
rc = hex2bin(buf + 8 + leading_zero_bytes, p, count);
if (rc < 0) {
pr_debug("hex2bin failed for %s: %d\n", p, rc);
return rc;
}
return 24;
}
static int iscsi_get_pr_transport_id(
struct se_node_acl *se_nacl,
struct t10_pr_registration *pr_reg,
int *format_code,
unsigned char *buf)
{
u32 off = 4, padding = 0;
int isid_len;
u16 len = 0;
spin_lock_irq(&se_nacl->nacl_sess_lock);
/*
* Only null terminate the last field.
*
* From spc4r37 section 7.6.4.6: TransportID for initiator ports using
* SCSI over iSCSI.
*
* Table 507 TPID=0 Initiator device TransportID
*
* The null-terminated, null-padded (see 4.3.2) ISCSI NAME field shall
* contain the iSCSI name of an iSCSI initiator node (see RFC 7143).
* 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);
off += len;
if ((*format_code == 1) && (pr_reg->isid_present_at_reg)) {
/*
* Set FORMAT CODE 01b for iSCSI Initiator port TransportID
* format.
*/
buf[0] |= 0x40;
/*
* From spc4r37 Section 7.6.4.6
*
* Table 508 TPID=1 Initiator port TransportID.
*
* The ISCSI NAME field shall not be null-terminated
* (see 4.3.2) and shall not be padded.
*
* 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 terminates
* the ISCSI INITIATOR SESSION ID field without regard for the
* specified length of the iSCSI TransportID or the contents
* of the ADDITIONAL LENGTH field.
*/
buf[off++] = 0x2c; /* ASCII Character: "," */
buf[off++] = 0x69; /* ASCII Character: "i" */
buf[off++] = 0x2c; /* ASCII Character: "," */
buf[off++] = 0x30; /* ASCII Character: "0" */
buf[off++] = 0x78; /* ASCII Character: "x" */
len += 5;
isid_len = sprintf(buf + off, "%s", pr_reg->pr_reg_isid);
off += isid_len;
len += isid_len;
}
buf[off] = '\0';
len += 1;
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;
put_unaligned_be16(len, &buf[2]);
/*
* Increment value for total payload + header length for
* full status descriptor
*/
len += 4;
return len;
}
static int iscsi_get_pr_transport_id_len(
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 += strlen(pr_reg->pr_reg_isid);
*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;
}
static char *iscsi_parse_pr_out_transport_id(
struct se_portal_group *se_tpg,
char *buf,
u32 *out_tid_len,
char **port_nexus_ptr)
{
char *p;
int i;
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) {
/* The shift works thanks to integer promotion rules */
*out_tid_len = get_unaligned_be16(&buf[2]);
/* Add four bytes for iSCSI Transport ID header */
*out_tid_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++) {
/*
* The first ISCSI INITIATOR SESSION ID field byte
* containing an ASCII null character terminates the
* ISCSI INITIATOR SESSION ID field without regard for
* the specified length of the iSCSI TransportID or the
* contents of the ADDITIONAL LENGTH field.
*/
if (*p == '\0')
break;
if (isdigit(*p)) {
p++;
continue;
}
*p = tolower(*p);
p++;
}
} else
*port_nexus_ptr = NULL;
return &buf[4];
}
int target_get_pr_transport_id_len(struct se_node_acl *nacl,
struct t10_pr_registration *pr_reg, int *format_code)
{
switch (nacl->se_tpg->proto_id) {
case SCSI_PROTOCOL_FCP:
case SCSI_PROTOCOL_SBP:
case SCSI_PROTOCOL_SRP:
case SCSI_PROTOCOL_SAS:
break;
case SCSI_PROTOCOL_ISCSI:
return iscsi_get_pr_transport_id_len(nacl, pr_reg, format_code);
default:
pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
return -EINVAL;
}
/*
* Most transports use a fixed length 24 byte identifier.
*/
*format_code = 0;
return 24;
}
int target_get_pr_transport_id(struct se_node_acl *nacl,
struct t10_pr_registration *pr_reg, int *format_code,
unsigned char *buf)
{
switch (nacl->se_tpg->proto_id) {
case SCSI_PROTOCOL_SAS:
return sas_get_pr_transport_id(nacl, format_code, buf);
case SCSI_PROTOCOL_SBP:
return sbp_get_pr_transport_id(nacl, format_code, buf);
case SCSI_PROTOCOL_SRP:
return srp_get_pr_transport_id(nacl, format_code, buf);
case SCSI_PROTOCOL_FCP:
return fc_get_pr_transport_id(nacl, format_code, buf);
case SCSI_PROTOCOL_ISCSI:
return iscsi_get_pr_transport_id(nacl, pr_reg, format_code,
buf);
default:
pr_err("Unknown proto_id: 0x%02x\n", nacl->se_tpg->proto_id);
return -EINVAL;
}
}
const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg,
char *buf, u32 *out_tid_len, char **port_nexus_ptr)
{
u32 offset;
switch (tpg->proto_id) {
case SCSI_PROTOCOL_SAS:
/*
* Assume the FORMAT CODE 00b from spc4r17, 7.5.4.7 TransportID
* for initiator ports using SCSI over SAS Serial SCSI Protocol.
*/
offset = 4;
break;
case SCSI_PROTOCOL_SBP:
case SCSI_PROTOCOL_SRP:
case SCSI_PROTOCOL_FCP:
offset = 8;
break;
case SCSI_PROTOCOL_ISCSI:
return iscsi_parse_pr_out_transport_id(tpg, buf, out_tid_len,
port_nexus_ptr);
default:
pr_err("Unknown proto_id: 0x%02x\n", tpg->proto_id);
return NULL;
}
*port_nexus_ptr = NULL;
*out_tid_len = 24;
return buf + offset;
}