[PATCH 3.16 105/192] iscsi-target: Add login_keys_workaround attribute for non RFC initiators

Ben Hutchings
2017-10-09T12:46:37Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

commit 138d351eefb727ab9e41a3dc5f112ceb4f6e59f2 upstream.

This patch re-introduces part of a long standing login workaround that
was recently dropped by:

commit 1c99de981f30b3e7868b8d20ce5479fa1c0fea46
Author: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Sun Apr 2 13:36:44 2017 -0700

iscsi-target: Drop work-around for legacy GlobalSAN initiator

Namely, the workaround for FirstBurstLength ended up being required by
Mellanox Flexboot PXE boot ROMs as reported by Robert.

So this patch re-adds the work-around for FirstBurstLength within
iscsi_check_proposer_for_optional_reply(), and makes the key optional
to respond when the initiator does not propose, nor respond to it.

Also as requested by Arun, this patch introduces a new TPG attribute
named 'login_keys_workaround' that controls the use of both the
FirstBurstLength workaround, as well as the two other existing
workarounds for gPXE iSCSI boot client.

By default, the workaround is enabled with login_keys_workaround=1,
since Mellanox FlexBoot requires it, and Arun has verified the Qlogic
MSFT initiator already proposes FirstBurstLength, so it's uneffected
by this re-adding this part of the original work-around.

Reported-by: Robert LeBlanc <robert@leblancnet.us>
Cc: Robert LeBlanc <robert@leblancnet.us>
Reviewed-by: Arun Easi <arun.easi@cavium.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[bwh: Backported to 3.16:
- Use DEF_TPG_ATTRIB() + TPG_ATTR() to define the attribute
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1057,6 +1057,8 @@ TPG_ATTR(default_erl, S_IRUGO | S_IWUSR)
*/
DEF_TPG_ATTRIB(t10_pi);
TPG_ATTR(t10_pi, S_IRUGO | S_IWUSR);
+DEF_TPG_ATTRIB(login_keys_workaround);
+TPG_ATTR(login_keys_workaround, S_IRUGO | S_IWUSR);

static struct configfs_attribute *lio_target_tpg_attrib_attrs[] = {
&iscsi_tpg_attrib_authentication.attr,
@@ -1070,6 +1072,7 @@ static struct configfs_attribute *lio_ta
&iscsi_tpg_attrib_demo_mode_discovery.attr,
&iscsi_tpg_attrib_default_erl.attr,
&iscsi_tpg_attrib_t10_pi.attr,
+ &iscsi_tpg_attrib_login_keys_workaround.attr,
NULL,
};

--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -887,7 +887,8 @@ static int iscsi_target_handle_csg_zero(
SENDER_TARGET,
login->rsp_buf,
&login->rsp_length,
- conn->param_list);
+ conn->param_list,
+ conn->tpg->tpg_attrib.login_keys_workaround);
if (ret < 0)
return -1;

@@ -957,7 +958,8 @@ static int iscsi_target_handle_csg_one(s
SENDER_TARGET,
login->rsp_buf,
&login->rsp_length,
- conn->param_list);
+ conn->param_list,
+ conn->tpg->tpg_attrib.login_keys_workaround);
if (ret < 0) {
iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
ISCSI_LOGIN_STATUS_INIT_ERR);
--- a/drivers/target/iscsi/iscsi_target_parameters.c
+++ b/drivers/target/iscsi/iscsi_target_parameters.c
@@ -787,7 +787,8 @@ static int iscsi_check_for_auth_key(char
return 0;
}

-static void iscsi_check_proposer_for_optional_reply(struct iscsi_param *param)
+static void iscsi_check_proposer_for_optional_reply(struct iscsi_param *param,
+ bool keys_workaround)
{
if (IS_TYPE_BOOL_AND(param)) {
if (!strcmp(param->value, NO))
@@ -795,19 +796,31 @@ static void iscsi_check_proposer_for_opt
} else if (IS_TYPE_BOOL_OR(param)) {
if (!strcmp(param->value, YES))
SET_PSTATE_REPLY_OPTIONAL(param);
- /*
- * Required for gPXE iSCSI boot client
- */
- if (!strcmp(param->name, IMMEDIATEDATA))
- SET_PSTATE_REPLY_OPTIONAL(param);
+
+ if (keys_workaround) {
+ /*
+ * Required for gPXE iSCSI boot client
+ */
+ if (!strcmp(param->name, IMMEDIATEDATA))
+ SET_PSTATE_REPLY_OPTIONAL(param);
+ }
} else if (IS_TYPE_NUMBER(param)) {
if (!strcmp(param->name, MAXRECVDATASEGMENTLENGTH))
SET_PSTATE_REPLY_OPTIONAL(param);
- /*
- * Required for gPXE iSCSI boot client
- */
- if (!strcmp(param->name, MAXCONNECTIONS))
- SET_PSTATE_REPLY_OPTIONAL(param);
+
+ if (keys_workaround) {
+ /*
+ * Required for Mellanox Flexboot PXE boot ROM
+ */
+ if (!strcmp(param->name, FIRSTBURSTLENGTH))
+ SET_PSTATE_REPLY_OPTIONAL(param);
+
+ /*
+ * Required for gPXE iSCSI boot client
+ */
+ if (!strcmp(param->name, MAXCONNECTIONS))
+ SET_PSTATE_REPLY_OPTIONAL(param);
+ }
} else if (IS_PHASE_DECLARATIVE(param))
SET_PSTATE_REPLY_OPTIONAL(param);
}
@@ -1657,7 +1670,8 @@ int iscsi_encode_text_output(
u8 sender,
char *textbuf,
u32 *length,
- struct iscsi_param_list *param_list)
+ struct iscsi_param_list *param_list,
+ bool keys_workaround)
{
char *output_buf = NULL;
struct iscsi_extra_response *er;
@@ -1693,7 +1707,8 @@ int iscsi_encode_text_output(
*length += 1;
output_buf = textbuf + *length;
SET_PSTATE_PROPOSER(param);
- iscsi_check_proposer_for_optional_reply(param);
+ iscsi_check_proposer_for_optional_reply(param,
+ keys_workaround);
pr_debug("Sending key: %s=%s\n",
param->name, param->value);
}
--- a/drivers/target/iscsi/iscsi_target_parameters.h
+++ b/drivers/target/iscsi/iscsi_target_parameters.h
@@ -40,7 +40,7 @@ extern int iscsi_extract_key_value(char
extern int iscsi_update_param_value(struct iscsi_param *, char *);
extern int iscsi_decode_text_input(u8, u8, char *, u32, struct iscsi_conn *);
extern int iscsi_encode_text_output(u8, u8, char *, u32 *,
- struct iscsi_param_list *);
+ struct iscsi_param_list *, bool);
extern int iscsi_check_negotiated_keys(struct iscsi_param_list *);
extern void iscsi_set_connection_parameters(struct iscsi_conn_ops *,
struct iscsi_param_list *);
--- a/drivers/target/iscsi/iscsi_target_tpg.c
+++ b/drivers/target/iscsi/iscsi_target_tpg.c
@@ -228,6 +228,7 @@ static void iscsit_set_default_tpg_attri
a->demo_mode_discovery = TA_DEMO_MODE_DISCOVERY;
a->default_erl = TA_DEFAULT_ERL;
a->t10_pi = TA_DEFAULT_T10_PI;
+ a->login_keys_workaround = TA_DEFAULT_LOGIN_KEYS_WORKAROUND;
}

int iscsit_tpg_add_portal_group(struct iscsi_tiqn *tiqn, struct iscsi_portal_group *tpg)
@@ -878,3 +879,21 @@ int iscsit_ta_t10_pi(

return 0;
}
+
+int iscsit_ta_login_keys_workaround(
+ struct iscsi_portal_group *tpg,
+ u32 flag)
+{
+ struct iscsi_tpg_attrib *a = &tpg->tpg_attrib;
+
+ if ((flag != 0) && (flag != 1)) {
+ pr_err("Illegal value %d\n", flag);
+ return -EINVAL;
+ }
+
+ a->login_keys_workaround = flag;
+ pr_debug("iSCSI_TPG[%hu] - TPG enabled bit for login keys workaround: %s ",
+ tpg->tpgt, (a->login_keys_workaround) ? "ON" : "OFF");
+
+ return 0;
+}
--- a/drivers/target/iscsi/iscsi_target_tpg.h
+++ b/drivers/target/iscsi/iscsi_target_tpg.h
@@ -39,5 +39,6 @@ extern int iscsit_ta_prod_mode_write_pro
extern int iscsit_ta_demo_mode_discovery(struct iscsi_portal_group *, u32);
extern int iscsit_ta_default_erl(struct iscsi_portal_group *, u32);
extern int iscsit_ta_t10_pi(struct iscsi_portal_group *, u32);
+extern int iscsit_ta_login_keys_workaround(struct iscsi_portal_group *, u32);

#endif /* ISCSI_TARGET_TPG_H */
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -60,6 +60,14 @@
#define TA_CACHE_CORE_NPS 0
/* T10 protection information disabled by default */
#define TA_DEFAULT_T10_PI 0
+/*
+ * Used to control the sending of keys with optional to respond state bit,
+ * as a workaround for non RFC compliant initiators,that do not propose,
+ * nor respond to specific keys required for login to complete.
+ *
+ * See iscsi_check_proposer_for_optional_reply() for more details.
+ */
+#define TA_DEFAULT_LOGIN_KEYS_WORKAROUND 1

#define ISCSI_IOV_DATA_BUFFER 5

@@ -774,6 +782,7 @@ struct iscsi_tpg_attrib {
u32 demo_mode_discovery;
u32 default_erl;
u8 t10_pi;
+ u32 login_keys_workaround;
struct iscsi_portal_group *tpg;
};