Patch from Abhilash Sankar <Abhilash.S@hcl.com> with some fixes

Issue:
------------
The DevRegAttribute is sending a different Source Attribute (ISCSI name) which
represents the Storage Node for each target. So Microsoft isns server considers
the last request as the storage node and doesn't discover the previous targets.

Root Cause
----------------
Function ISNS_FUNC_DEV_ATTR_REG

Target A
Source attribute
            ISCSI-Name = <IQN A Name>
Operating Attribute
            ISCSI-Name  = <IQN A Name>
Flags
Replace Access = 1

Target B
Source attribute
               ISCSI-Name = <IQN B Name>
Operating Attribute
               ISCSI-Name  = <IQN B Name>
Replace Access = 1

So as per the request format Microsoft isns Server always takes the last target
as the source node. and register the same. Hence it doesn't discover the
targets other than last one. The Source Attribute has to be fixed for all targets. It
would be better if we use the first target iscsi name (rather than the last target
iscsi name) as source attribute iscsi name to represent the storage node.



git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@3863 d57e44dd-8a1f-0410-8b47-8ef2f437770f

iscsi-scst/usr/event.c

@@ -616,7 +616,15 @@ static int handle_e_get_attr_value(int fd, const struct iscsi_kern_event *event)
 			add_key_mark(res_str, sizeof(res_str), 0);
 		} else
 			snprintf(res_str, sizeof(res_str), "%s\n", "");
-	} else {
+	} else if (strcasecmp(ISCSI_ISNS_ENTITY_ATTR_NAME, pp) == 0)	{
+		if (target != NULL) {
+			log_error("Not NULL target %s for global attribute %s",
+				target->name, pp);
+			res = -EINVAL;
+			goto out_free;
+		}
+		snprintf(res_str, sizeof(res_str), "%s", isns_entity_target_name);
+	} else	{
 		log_error("Unknown attribute %s", pp);
 		res = -EINVAL;
 		goto out_free;
@@ -992,7 +1000,10 @@ static int handle_e_set_attr_value(int fd, const struct iscsi_kern_event *event)
 			}
 		} else
 			goto out_free_server;
-	} else {
+	} else if (strcasecmp(ISCSI_ISNS_ENTITY_ATTR_NAME, pp) == 0) {
+		pp = config_sep_string(&p);
+		strlcpy(isns_entity_target_name, pp, sizeof(isns_entity_target_name));
+	} else	{
 		log_error("Unknown attribute %s", pp);
 		res = -EINVAL;
 		goto out_free;

iscsi-scst/usr/iscsi_scstd.c

@@ -721,6 +721,10 @@ int main(int argc, char **argv)
 			S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR, 0);
 	if (err != 0)
 		exit(err);
+	err = kernel_attr_add(NULL, ISCSI_ISNS_ENTITY_ATTR_NAME,
+			S_IRUSR|S_IRGRP|S_IROTH|S_IWUSR, 0);
+	if (err != 0)
+		exit(err);
 #endif
 
 	if ((ipc_fd = iscsi_adm_request_listen()) < 0) {

iscsi-scst/usr/iscsid.h

@@ -375,6 +375,7 @@ extern int iscsi_attr_replace(struct __qelem *attrs_list, const char *sysfs_name
 /* isns.c */
 extern char *isns_server;
 extern int isns_access_control;
+extern char isns_entity_target_name[ISCSI_NAME_LEN];
 extern int isns_timeout;
 extern int isns_init(void);
 extern int isns_handle(int is_timeout);

iscsi-scst/usr/isns.c

@@ -58,6 +58,7 @@ struct isns_initiator {
 
 char *isns_server;
 int isns_access_control;
+char isns_entity_target_name[ISCSI_NAME_LEN];
 int isns_timeout = -1;
 
 static LIST_HEAD(qry_list);
@@ -299,16 +300,15 @@ static int isns_scn_register(void)
 	tlv = (struct isns_tlv *)hdr->pdu;
 	max_buf = sizeof(buf) - offsetof(struct isns_hdr, pdu);
 
-	target = list_entry(targets_list.q_forw, struct target, tlist);
-
-	err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
+	if (strlen(isns_entity_target_name) < 1) {
+		target = list_entry(targets_list.q_forw, struct target, tlist);
+		err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
 			strlen(target->name) + 1, target->name);
-	if (err < 0)
-		goto out;
-	length += err;
+	} else {
+		err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
+		strlen(isns_entity_target_name) + 1, isns_entity_target_name);
+	}
 
-	err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
-			 strlen(target->name) + 1, target->name);
 	if (err < 0)
 		goto out;
 	length += err;
@@ -502,11 +502,15 @@ int isns_target_register(char *name)
 	tlv = (struct isns_tlv *)hdr->pdu;
 	max_buf = sizeof(buf) - offsetof(struct isns_hdr, pdu);
 
-        target = list_entry(targets_list.q_back, struct target, tlist);
-
-	err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
+	if (strlen(isns_entity_target_name) < 1) {
+		target = list_entry(targets_list.q_forw, struct target, tlist);
+		err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
 				strlen(target->name) + 1, target->name);
-	if (err < 0)
+	} else {
+		err = isns_tlv_set(&tlv, max_buf - length, ISNS_ATTR_ISCSI_NAME,
+				strlen(isns_entity_target_name) + 1, isns_entity_target_name);
+	}
+if (err < 0)
 		goto out;
         length += err;
 

iscsi-scst/usr/param.h

@@ -20,6 +20,7 @@
 #define ISCSI_ISNS_SERVER_ATTR_NAME		"iSNSServer"
 #define ISCSI_ISNS_ACCESS_CONTROL_ATTR_NAME	"iSNSAccessControl"
 #define ISCSI_ENABLED_ATTR_NAME			"enabled"
+#define ISCSI_ISNS_ENTITY_ATTR_NAME			"isns_entity_name"
 #define ISCSI_ALLOWED_PORTAL_ATTR_NAME		"allowed_portal"
 #define ISCSI_PER_PORTAL_ACL_ATTR_NAME		"per_portal_acl"
 #define ISCSI_TARGET_REDIRECTION_ATTR_NAME	"redirect"