From ea7e32bec1b9d9e5b159d80ceb563c702e28b02a Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Mon, 18 Nov 2013 10:55:10 -0800
Subject: [PATCH] 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>
---
drivers/target/iscsi/iscsi_target_core.h | 1 +
drivers/target/iscsi/iscsi_target_util.c | 18 ++++++++++--------
2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index f2094d2f8eef..8dcb3c1aa801 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -193,6 +193,7 @@ enum recover_cmdsn_ret_table {
CMDSN_NORMAL_OPERATION = 0,
CMDSN_LOWER_THAN_EXP = 1,
CMDSN_HIGHER_THAN_EXP = 2,
+ CMDSN_MAXCMDSN_OVERRUN = 3,
};
/* Used for iscsi_handle_immediate_data() return values */
diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 45b8fd13fa72..9064926a0370 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -242,9 +242,9 @@ static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cm
*/
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 @@ int iscsit_sequence_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
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);
--
GitLab