2 files changed, 40 insertions, 3 deletions

diff --git a/include/scsi/iscsi_proto.h b/include/scsi/iscsi_proto.h
index 751c81eaa7f3..6947082eee6d 100644
--- a/include/scsi/iscsi_proto.h
+++ b/include/scsi/iscsi_proto.h
@@ -27,7 +27,7 @@
 #define ISCSI_LISTEN_PORT       3260
 
 /* Padding word length */
-#define PAD_WORD_LEN            4
+#define ISCSI_PAD_LEN           4
 
 /*
  * useful common(control and data pathes) macro
@@ -147,6 +147,14 @@ struct iscsi_rlength_ahdr {
         __be32 read_length;
 };
 
+/* Extended CDB AHS */
+struct iscsi_ecdb_ahdr {
+        __be16 ahslength;       /* CDB length - 15, including reserved byte */
+        uint8_t ahstype;
+        uint8_t reserved;
+        uint8_t ecdb[260 - 16]; /* 4-byte aligned extended CDB spillover */
+};
+
 /* SCSI Response Header */
 struct iscsi_cmd_rsp {
         uint8_t opcode;
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index e1fb3d0927b0..a9a9e869188d 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -78,6 +78,9 @@ enum {
 #define ISCSI_ADDRESS_BUF_LEN           64
 
 enum {
+        /* this is the maximum possible storage for AHSs */
+        ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
+                                sizeof(struct iscsi_rlength_ahdr),
         ISCSI_DIGEST_SIZE = sizeof(__u32),
 };
 
@@ -102,10 +105,13 @@ enum {
 
 struct iscsi_cmd_task {
         /*
-         * Becuae LLDs allocate their hdr differently, this is a pointer to
-         * that storage. It must be setup at session creation time.
+         * Because LLDs allocate their hdr differently, this is a pointer
+         * and length to that storage. It must be setup at session
+         * creation time.
          */
         struct iscsi_cmd        *hdr;
+        unsigned short          hdr_max;
+        unsigned short          hdr_len;        /* accumulated size of hdr used */
         int                     itt;            /* this ITT */
 
         uint32_t                unsol_datasn;
@@ -124,6 +130,11 @@ struct iscsi_cmd_task {
         void                    *dd_data;       /* driver/transport data */
 };
 
+static inline void* iscsi_next_hdr(struct iscsi_cmd_task *ctask)
+{
+        return (void*)ctask->hdr + ctask->hdr_len;
+}
+
 struct iscsi_conn {
         struct iscsi_cls_conn   *cls_conn;      /* ptr to class connection */
         void                    *dd_data;       /* iscsi_transport data */
@@ -342,4 +353,22 @@ extern void iscsi_requeue_ctask(struct iscsi_cmd_task *ctask);
 extern void iscsi_pool_free(struct iscsi_queue *, void **);
 extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int);
 
+/*
+ * inline functions to deal with padding.
+ */
+static inline unsigned int
+iscsi_padded(unsigned int len)
+{
+        return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
+}
+
+static inline unsigned int
+iscsi_padding(unsigned int len)
+{
+        len &= (ISCSI_PAD_LEN - 1);
+        if (len)
+                len = ISCSI_PAD_LEN - len;
+        return len;
+}
+
 #endif