[Iscsitarget-devel] [PATCH] Bugfix: avoid digest calculation for skipped data

[Arne R. <arn...@xi...>]

Hi,

the following patch will avoid data digest calculation for PDUs whose
data has been skipped already for various reasons, because

a) IET will crash under certain circumstances, e.g. a Data Out for an
inexistent SCSI command arrives and is consequently skipped - this will
hit the assert() in digest_data().

b) we're not interested in the digest, anyway ;-)

Arne

diff -ruN r1267.local/kernel/digest.c r1267.ddfix/kernel/digest.c
--- r1267.local/kernel/digest.c	2005-11-22 00:41:34.000000000 +0100
+++ r1267.ddfix/kernel/digest.c	2005-11-28 17:03:59.000000000 +0100
@@ -233,15 +233,22 @@
 int digest_rx_data(struct iscsi_cmnd *cmnd)
 {
 	struct tio *tio;
+	struct iscsi_cmnd *scsi_cmnd;
+	struct iscsi_data_out_hdr *req;
 	u32 offset, crc;
 
-	if (cmnd_opcode(cmnd) == ISCSI_OP_SCSI_DATA_OUT) {
-		struct iscsi_cmnd *scsi_cmnd = cmnd->req;
-		struct iscsi_data_out_hdr *req = (struct iscsi_data_out_hdr *)&cmnd->pdu.bhs;
-
+	switch (cmnd_opcode(cmnd)) {
+	case ISCSI_OP_SCSI_REJECT:
+	case ISCSI_OP_PDU_REJECT:
+	case ISCSI_OP_DATA_REJECT:
+		return 0;
+	case ISCSI_OP_SCSI_DATA_OUT:
+		scsi_cmnd = cmnd->req;
+		req = (struct iscsi_data_out_hdr *)&cmnd->pdu.bhs;
 		tio = scsi_cmnd->tio;
 		offset = be32_to_cpu(req->buffer_offset);
-	} else {
+		break;
+	default:
 		tio = cmnd->tio;
 		offset = 0;
 	}