iscsi-target: Do not reject non-immediate CmdSNs exceeding MaxCmdSN
This patch changes iscsit_sequence_cmd() logic to no longer reject
non-immediate CmdSNs that exceed MaxCmdSN with a protocol error,
but instead silently ignore them.
This is done to correctly follow RFC-3720 Section 3.2.2.1:
For non-immediate commands, the CmdSN field can take any
value from ExpCmdSN to MaxCmdSN inclusive. The target MUST silently
ignore any non-immediate command outside of this range or non-
immediate duplicates within the range.
Reported-by: Santosh Kulkarni <santosh.kulkarni@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 45b8fd1..9064926 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -242,9 +242,9 @@
*/
if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
pr_err("Received CmdSN: 0x%08x is greater than"
- " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
+ " MaxCmdSN: 0x%08x, ignoring.\n", cmdsn,
sess->max_cmd_sn);
- ret = CMDSN_ERROR_CANNOT_RECOVER;
+ ret = CMDSN_MAXCMDSN_OVERRUN;
} else if (cmdsn == sess->exp_cmd_sn) {
sess->exp_cmd_sn++;
@@ -303,14 +303,16 @@
ret = CMDSN_HIGHER_THAN_EXP;
break;
case CMDSN_LOWER_THAN_EXP:
+ case CMDSN_MAXCMDSN_OVERRUN:
+ default:
cmd->i_state = ISTATE_REMOVE;
iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
- ret = cmdsn_ret;
- break;
- default:
- reason = ISCSI_REASON_PROTOCOL_ERROR;
- reject = true;
- ret = cmdsn_ret;
+ /*
+ * Existing callers for iscsit_sequence_cmd() will silently
+ * ignore commands with CMDSN_LOWER_THAN_EXP, so force this
+ * return for CMDSN_MAXCMDSN_OVERRUN as well..
+ */
+ ret = CMDSN_LOWER_THAN_EXP;
break;
}
mutex_unlock(&conn->sess->cmdsn_mutex);