iscsi-target: Reject unsupported multi PDU text command sequence

This patch adds a check to reject text commands with F_BIT=0 ||
C_BIT=1, as multi PDU text command sequences are currently
unsupported.

This avoids the case where a text command received with F_BIT=0,
was generating a text response with F_BIT=1 which is a protocol
error according to RFC-3720 Section 10.11.1.

Reported-by: Arshad Hussain <arshad.hussain@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index ab64cbbb4976..ba9787d24c12 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1948,6 +1948,13 @@ iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
                                          (unsigned char *)hdr);
         }
 
+        if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
+             (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
+                pr_err("Multi sequence text commands currently not supported\n");
+                return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
+                                        (unsigned char *)hdr);
+        }
+
         pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
                 " ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
                 hdr->exp_statsn, payload_length);