iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel.  More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

   * RFC-3720 defined request / response state machines and support for
     all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
     include/scsi/iscsi_proto.h PDU definitions
   * Target v4.1 compatible control plane using the generic layout in
     target_core_fabric_configfs.c and fabric dependent attributes
     within /sys/kernel/config/target/iscsi/ subdirectories.
   * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
   * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
   * iSCSI Error Recovery Hierarchy support
   * Per iSCSI connection RX/TX thread pair scheduling affinity
   * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
   * CHAP Authentication support using libcrypto
   * Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
     transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
      iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_auth.h b/drivers/target/iscsi/iscsi_target_auth.h
new file mode 100644
index 000000000000..2f463c09626d
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_auth.h
@@ -0,0 +1,31 @@
+#ifndef _ISCSI_CHAP_H_
+#define _ISCSI_CHAP_H_
+
+#define CHAP_DIGEST_MD5         5
+#define CHAP_DIGEST_SHA         6
+
+#define CHAP_CHALLENGE_LENGTH   16
+#define CHAP_CHALLENGE_STR_LEN  4096
+#define MAX_RESPONSE_LENGTH     64      /* sufficient for MD5 */
+#define MAX_CHAP_N_SIZE         512
+
+#define MD5_SIGNATURE_SIZE      16      /* 16 bytes in a MD5 message digest */
+
+#define CHAP_STAGE_CLIENT_A     1
+#define CHAP_STAGE_SERVER_AIC   2
+#define CHAP_STAGE_CLIENT_NR    3
+#define CHAP_STAGE_CLIENT_NRIC  4
+#define CHAP_STAGE_SERVER_NR    5
+
+extern u32 chap_main_loop(struct iscsi_conn *, struct iscsi_node_auth *, char *, char *,
+                                int *, int *);
+
+struct iscsi_chap {
+        unsigned char   digest_type;
+        unsigned char   id;
+        unsigned char   challenge[CHAP_CHALLENGE_LENGTH];
+        unsigned int    authenticate_target;
+        unsigned int    chap_state;
+} ____cacheline_aligned;
+
+#endif   /*** _ISCSI_CHAP_H_ ***/