Target/sbc: Set protection operation and relevant checks

SBC-3 mandates the protection checks that must be
performed in the rdprotect/wrprotect field. Use them.
According to backstore device pi_attributes and
cdb rdprotect/wrprotect field.

(Fix incorrect se_cmd->prot_type -> TARGET_PROT_NORMAL
 comparision in transport_generic_new_cmd - nab)
(Fix missing break in sbc_set_prot_op_checks - DanC + Sagi)

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 74 insertions, 15 deletions

diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 77e6531fb0a1..a1e75dd636ac 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -569,30 +569,85 @@ sbc_compare_and_write(struct se_cmd *cmd)
         return TCM_NO_SENSE;
 }
 
+static int
+sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
+                       bool is_write, struct se_cmd *cmd)
+{
+        if (is_write) {
+                cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
+                                         TARGET_PROT_DOUT_INSERT;
+                switch (protect) {
+                case 0x0:
+                case 0x3:
+                        cmd->prot_checks = 0;
+                        break;
+                case 0x1:
+                case 0x5:
+                        cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
+                        if (prot_type == TARGET_DIF_TYPE1_PROT)
+                                cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
+                        break;
+                case 0x2:
+                        if (prot_type == TARGET_DIF_TYPE1_PROT)
+                                cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
+                        break;
+                case 0x4:
+                        cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
+                        break;
+                default:
+                        pr_err("Unsupported protect field %d\n", protect);
+                        return -EINVAL;
+                }
+        } else {
+                cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
+                                         TARGET_PROT_DIN_STRIP;
+                switch (protect) {
+                case 0x0:
+                case 0x1:
+                case 0x5:
+                        cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
+                        if (prot_type == TARGET_DIF_TYPE1_PROT)
+                                cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
+                        break;
+                case 0x2:
+                        if (prot_type == TARGET_DIF_TYPE1_PROT)
+                                cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
+                        break;
+                case 0x3:
+                        cmd->prot_checks = 0;
+                        break;
+                case 0x4:
+                        cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
+                        break;
+                default:
+                        pr_err("Unsupported protect field %d\n", protect);
+                        return -EINVAL;
+                }
+        }
+
+        return 0;
+}
+
 static bool
 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
-               u32 sectors)
+               u32 sectors, bool is_write)
 {
+        u8 protect = cdb[1] >> 5;
+
         if (!cmd->t_prot_sg || !cmd->t_prot_nents)
                 return true;
 
         switch (dev->dev_attrib.pi_prot_type) {
         case TARGET_DIF_TYPE3_PROT:
-                if (!(cdb[1] & 0xe0))
-                        return true;
-
                 cmd->reftag_seed = 0xffffffff;
                 break;
         case TARGET_DIF_TYPE2_PROT:
-                if (cdb[1] & 0xe0)
+                if (protect)
                         return false;
 
                 cmd->reftag_seed = cmd->t_task_lba;
                 break;
         case TARGET_DIF_TYPE1_PROT:
-                if (!(cdb[1] & 0xe0))
-                        return true;
-
                 cmd->reftag_seed = cmd->t_task_lba;
                 break;
         case TARGET_DIF_TYPE0_PROT:
@@ -600,6 +655,10 @@ sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
                 return true;
         }
 
+        if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
+                                   is_write, cmd))
+                return false;
+
         cmd->prot_type = dev->dev_attrib.pi_prot_type;
         cmd->prot_length = dev->prot_length * sectors;
         cmd->prot_handover = PROT_SEPERATED;
@@ -628,7 +687,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_10(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors))
+                if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
@@ -639,7 +698,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_12(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors))
+                if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
@@ -650,7 +709,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_16(cdb);
                 cmd->t_task_lba = transport_lba_64(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors))
+                if (!sbc_check_prot(dev, cmd, cdb, sectors, false))
                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 
                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
@@ -669,7 +728,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_10(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors))
+                if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 
                 if (cdb[1] & 0x8)
@@ -682,7 +741,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_12(cdb);
                 cmd->t_task_lba = transport_lba_32(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors))
+                if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 
                 if (cdb[1] & 0x8)
@@ -695,7 +754,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
                 sectors = transport_get_sectors_16(cdb);
                 cmd->t_task_lba = transport_lba_64(cdb);
 
-                if (!sbc_check_prot(dev, cmd, cdb, sectors))
+                if (!sbc_check_prot(dev, cmd, cdb, sectors, true))
                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 
                 if (cdb[1] & 0x8)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 6ddd4cfc53ba..4653d826e595 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2206,7 +2206,7 @@ transport_generic_new_cmd(struct se_cmd *cmd)
                                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
                 }
 
-                if (cmd->prot_type != TARGET_PROT_NORMAL) {
+                if (cmd->prot_op != TARGET_PROT_NORMAL) {
                         ret = target_alloc_sgl(&cmd->t_prot_sg,
                                                &cmd->t_prot_nents,
                                                cmd->prot_length, true);