RFC7143 states that Initiator decides what type of authentication to
use:

The initiator MUST continue with:
    CHAP_N=<N> CHAP_R=<R>
or, if it requires target authentication, with:
    CHAP_N=<N> CHAP_R=<R> CHAP_I=<I> CHAP_C=<C>

Allow one way authentication if mutual authentication is configured.  That
passes some tests from Windows HLK for Mutual CHAP with iSNS.

Link: https://lore.kernel.org/r/20220718152555.17084-5-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Allow negotiating AuthMethod=None at CSG=0 (Security Negotiation) when
authentication is not required. That is required by the CHAP test in
Windows HLK.

Link: https://lore.kernel.org/r/20220718152555.17084-4-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

RFC7143 allows both Base64 and Hex encoding for CHAP binary entities like
Challenge and Response. Currently the Linux iSCSI target supports only Hex
encoding.

Add support for Base64 encoded CHAP Challenge and CHAP Response required
for CHAP tests in Windows HLK.

Link: https://lore.kernel.org/r/20220718152555.17084-3-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Variable length SCSI commands are transferred over iSCSI via two CDB
buffers - in Basic Header Segment and in Additional Header Segment (AHS).
Since AHS is not supported yet, a target reads just BHS (48 byte) from TCP
and treats the remaining octets as a next new iSCSI PDU that causes
protocol errors.

Add support for the Extended CDB AHS type.

Link: https://lore.kernel.org/r/20220718152555.17084-2-d.bogdanov@yadro.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

When building with Clang we encounter these warnings:
| drivers/target/iscsi/iscsi_target_login.c:719:24: error: format
| specifies type 'unsigned short' but the argument has type 'int'
| [-Werror,-Wformat] " from node: %s\n", atomic_read(&sess->nconn),
-
| drivers/target/iscsi/iscsi_target_login.c:767:12: error: format
| specifies type 'unsigned short' but the argument has type 'int'
| [-Werror,-Wformat] " %s\n", atomic_read(&sess->nconn),
-
| drivers/target/iscsi/iscsi_target.c:4365:12: error: format specifies
| type 'unsigned short' but the argument has type 'int' [-Werror,-Wformat]
| " %s\n", atomic_read(&sess->nconn)

For all warnings, the format specifier is '%hu' which describes an unsigned
short. The resulting type of atomic_read is an int. The proposed fix is to
listen to Clang and swap the format specifier.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Link: https://lore.kernel.org/r/20220718180421.49697-1-justinstitt@google.com
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Fix following coccicheck error:

./drivers/target/iscsi/iscsi_target_nego.c:831:13-26: ERROR: se_nacl is NULL but dereferenced.

Link: https://lore.kernel.org/r/20220613014321.107045-1-yang.lee@linux.alibaba.com
Fixes: a75fcb0912a5 ("scsi: target: iscsi: Extract auth functions")
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Add acls/{ACL}/attrib/authentication attribute that controls authentication
for particular ACL. By default, this attribute inherits a value of the
authentication attribute of the target port group to keep backward
compatibility.

Authentication attribute has 3 states:

 "0" - authentication is turned off for this ACL

 "1" - authentication is required for this ACL

 "-1" - authentication is inherited from TPG

Link: https://lore.kernel.org/r/20220523095905.26070-4-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Create functions that answers simple questions: Whether authentication is
required, what credentials, whether connection is autenticated.

Link: https://lore.kernel.org/r/20220523095905.26070-3-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

iSCSI target is cluttered with open-coded container_of() conversions from
se_nacl to iscsi_node_acl. The code could be cleaned by introducing a
helper - to_iscsi_nacl() (similar to other helpers in target core).

While at it, make another iSCSI conversion helper consistent and rename
iscsi_tpg() helper to to_iscsi_tpg().

Link: https://lore.kernel.org/r/20220523095905.26070-2-d.bogdanov@yadro.com
Reviewed-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin@yadro.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Pull SCSI updates from James Bottomley:
 "This consists of a small set of driver updates (lpfc, ufs, mpt3sas
  mpi3mr, iscsi target). Apart from that this is mostly small fixes with
  very few core changes (the biggest one being VPD caching)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (177 commits)
  scsi: target: tcmu: Avoid holding XArray lock when calling lock_page
  scsi: elx: efct: Remove NULL check after calling container_of()
  scsi: dpt_i2o: Drop redundant spinlock initialization
  scsi: qedf: Remove redundant variable op
  scsi: hisi_sas: Fix memory ordering in hisi_sas_task_deliver()
  scsi: fnic: Replace DMA mask of 64 bits with 47 bits
  scsi: mpi3mr: Add target device related sysfs attributes
  scsi: mpi3mr: Add shost related sysfs attributes
  scsi: elx: efct: Remove redundant memset() statement
  scsi: megaraid_sas: Remove redundant memset() statement
  scsi: mpi3mr: Return error if dma_alloc_coherent() fails
  scsi: hisi_sas: Fix rescan after deleting a disk
  scsi: hisi_sas: Use sas_ata_wait_after_reset() in IT nexus reset
  scsi: libsas: Refactor sas_ata_hard_reset()
  scsi: mpt3sas: Update driver version to 42.100.00.00
  scsi: mpt3sas: Fix junk chars displayed while printing ChipName
  scsi: ipr: Use kobj_to_dev()
  scsi: mpi3mr: Fix a NULL vs IS_ERR() bug in mpi3mr_bsg_init()
  scsi: bnx2fc: Avoid using get_cpu() in bnx2fc_cmd_alloc()
  scsi: libfc: Remove get_cpu() semantics in fc_exch_em_alloc()
  ...