From 3f9e1172b736400f343c4521ebeac1923a7f541b Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Fri, 19 Dec 2014 01:12:22 +0000
Subject: [PATCH] Slightly polish iSCSI parameters negotiation.

MFC after:	1 week
---
 sys/dev/iscsi/iscsi.c   | 4 ++++
 usr.sbin/ctld/login.c   | 2 +-
 usr.sbin/iscsid/login.c | 9 +++++++--
 3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/sys/dev/iscsi/iscsi.c b/sys/dev/iscsi/iscsi.c
index f9edc8246c31..0d762aadb837 100644
--- a/sys/dev/iscsi/iscsi.c
+++ b/sys/dev/iscsi/iscsi.c
@@ -2157,6 +2157,10 @@ iscsi_action_scsiio(struct iscsi_session *is, union ccb *ccb)
 			ISCSI_SESSION_DEBUG(is, "len %zd -> %zd", len, is->is_first_burst_length);
 			len = is->is_first_burst_length;
 		}
+		if (len > is->is_max_data_segment_length) {
+			ISCSI_SESSION_DEBUG(is, "len %zd -> %zd", len, is->is_max_data_segment_length);
+			len = is->is_max_data_segment_length;
+		}
 
 		error = icl_pdu_append_data(request, csio->data_ptr, len, M_NOWAIT);
 		if (error != 0) {
diff --git a/usr.sbin/ctld/login.c b/usr.sbin/ctld/login.c
index 7add09b5d9bc..5358e4b979a1 100644
--- a/usr.sbin/ctld/login.c
+++ b/usr.sbin/ctld/login.c
@@ -558,7 +558,7 @@ login_negotiate_key(struct pdu *request, const char *name,
 			tmp = MAX_DATA_SEGMENT_LENGTH;
 		}
 		conn->conn_max_data_segment_length = tmp;
-		keys_add_int(response_keys, name, tmp);
+		keys_add_int(response_keys, name, MAX_DATA_SEGMENT_LENGTH);
 	} else if (strcmp(name, "MaxBurstLength") == 0) {
 		tmp = strtoul(value, NULL, 10);
 		if (tmp <= 0) {
diff --git a/usr.sbin/iscsid/login.c b/usr.sbin/iscsid/login.c
index 360b0ef186ab..1338970a036a 100644
--- a/usr.sbin/iscsid/login.c
+++ b/usr.sbin/iscsid/login.c
@@ -388,6 +388,11 @@ login_negotiate_key(struct connection *conn, const char *name,
 		if (tmp <= 0)
 			log_errx(1, "received invalid "
 			    "MaxRecvDataSegmentLength");
+		if (tmp > ISCSI_MAX_DATA_SEGMENT_LENGTH) {
+			log_debugx("capping MaxRecvDataSegmentLength "
+			    "from %d to %d", tmp, ISCSI_MAX_DATA_SEGMENT_LENGTH);
+			tmp = ISCSI_MAX_DATA_SEGMENT_LENGTH;
+		}
 		conn->conn_max_data_segment_length = tmp;
 	} else if (strcmp(name, "MaxBurstLength") == 0) {
 		if (conn->conn_immediate_data) {
@@ -451,10 +456,11 @@ login_negotiate(struct connection *conn)
 
 		keys_add(request_keys, "ImmediateData", "Yes");
 		keys_add_int(request_keys, "MaxBurstLength",
-		    ISCSI_MAX_DATA_SEGMENT_LENGTH);
+		    2 * ISCSI_MAX_DATA_SEGMENT_LENGTH);
 		keys_add_int(request_keys, "FirstBurstLength",
 		    ISCSI_MAX_DATA_SEGMENT_LENGTH);
 		keys_add(request_keys, "InitialR2T", "Yes");
+		keys_add(request_keys, "MaxOutstandingR2T", "1");
 	} else {
 		keys_add(request_keys, "HeaderDigest", "None");
 		keys_add(request_keys, "DataDigest", "None");
@@ -465,7 +471,6 @@ login_negotiate(struct connection *conn)
 	keys_add(request_keys, "DefaultTime2Wait", "0");
 	keys_add(request_keys, "DefaultTime2Retain", "0");
 	keys_add(request_keys, "ErrorRecoveryLevel", "0");
-	keys_add(request_keys, "MaxOutstandingR2T", "1");
 	keys_save(request_keys, request);
 	keys_delete(request_keys);
 	request_keys = NULL;