iscsi-scst: Add internal_portal parameter

Add an internal_portal parameter to allow specified portals to
bypass CHAP controls for both discovery and target login.  If not
populated, then the current behavior will be preserved.

iscsi-scst/README

@@ -200,6 +200,13 @@ is /sys/kernel/scst_tgt/targets/iscsi. It has the following entries:
    iSCSI-SCST attributes before it starts accepting new connections. 0
    by default.
 
+ - internal_portal - May designate one or more existing portals as being
+   internal.  This will eliminate the need to supply a CHAP user/secret
+   during discovery or target login to any targets configured on those
+   portals.  This is particularly useful for internal targets used as
+   part of ALUA configuration.  Multiple addresses may be supplied,
+   separated by space characters.  Empty by default.
+
  - link_local - if set, makes the response to an IPv6 SendTargets include
    any link local addresses. Default is set.
 
@@ -552,6 +559,7 @@ both iSCSI-SCST targets will look like:
 |       |-- IncomingUser
 |       |-- OutgoingUser
 |       |-- enabled
+|       |-- internal_portal
 |       |-- iSNSServer
 |       |-- iqn.2006-10.net.vlnb:tgt
 |       |   |-- DataDigest

iscsi-scst/usr/event.c

@@ -654,6 +654,18 @@ static int handle_e_get_attr_value(int fd, const struct iscsi_kern_event *event)
 		snprintf(res_str, sizeof(res_str), "%d\n", send_targets_link_local);
 		if (send_targets_link_local != DEFAULT_SEND_TARGETS_LINK_LOCAL)
 			add_key_mark(res_str, sizeof(res_str), 0);
+	} else if (strcasecmp(ISCSI_INTERNAL_PORTAL_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;
+		}
+		if (internal_portal) {
+			snprintf(res_str, sizeof(res_str), "%s\n", internal_portal);
+			add_key_mark(res_str, sizeof(res_str), 0);
+		} else
+			snprintf(res_str, sizeof(res_str), "\n");
 	} else	{
 		log_error("Unknown attribute %s", pp);
 		res = -EINVAL;
@@ -669,6 +681,14 @@ static int handle_e_get_attr_value(int fd, const struct iscsi_kern_event *event)
 	return res;
 }
 
+static bool is_addr(char *addr)
+{
+	struct in_addr ia;
+	struct in6_addr ia6;
+
+	return (inet_pton(AF_INET, addr, &ia) == 1) || inet_pton(AF_INET6, addr, &ia6);
+}
+
 static int handle_target_redirect(struct target *target, char *p)
 {
 	int res = 0;
@@ -1094,6 +1114,51 @@ static int handle_e_set_attr_value(int fd, const struct iscsi_kern_event *event)
 			res = -EINVAL;
 			goto out_free;
 		}
+	} else if (strcasecmp(ISCSI_INTERNAL_PORTAL_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;
+		}
+		p = config_strip_string(p);
+		if (!p || *p == '\0') {
+			free(internal_portal);
+			internal_portal = NULL;
+		} else {
+			/* We have been provided with a string, check the contents. */
+			if (strchr(p, ' ')) {
+				char *portals = strdup(p);
+				char *portal;
+
+				if (!portals) {
+					log_error("Memory error (internal_portal)");
+					res = -ENOMEM;
+					goto out_free;
+				}
+
+				portal = strtok(portals, " ");
+				while (portal != NULL) {
+					if (!is_addr(portal)) {
+						free(portals);
+						log_error("Invalid address supplied %s", portal);
+						res = -EINVAL;
+						goto out_free;
+					}
+					portal = strtok(NULL, " ");
+				}
+				free(portals);
+			} else {
+				/* No spaces */
+				if (!is_addr(p)) {
+					log_error("Invalid address supplied %s", p);
+					res = -EINVAL;
+					goto out_free;
+				}
+			}
+			free(internal_portal);
+			internal_portal = strdup(p);
+		}
 	} else	{
 		log_error("Unknown attribute %s", pp);
 		res = -EINVAL;

iscsi-scst/usr/iscsi_scstd.c

@@ -962,6 +962,9 @@ int main(int argc, char **argv)
 	if (err != 0)
 		exit(err);
 	err = kernel_attr_add(NULL, ISCSI_LINK_LOCAL_ATTR_NAME, 0644, 0);
+	if (err != 0)
+		exit(err);
+	err = kernel_attr_add(NULL, ISCSI_INTERNAL_PORTAL_ATTR_NAME, 0644, 0);
 	if (err != 0)
 		exit(err);
 

iscsi-scst/usr/iscsid.c

@@ -27,6 +27,7 @@
 #include "iscsid.h"
 
 int iscsi_enabled;
+char *internal_portal;
 
 static u32 ttt;
 
@@ -1011,6 +1012,32 @@ static int cmnd_exec_auth(struct connection *conn)
 	return res;
 }
 
+static bool on_internal_portal(struct connection *conn)
+{
+	if (!internal_portal)
+		return false;
+
+	if (strchr(internal_portal, ' ')) {
+		char *portals = strdup(internal_portal);
+
+		if (portals) {
+			char *portal = strtok(portals, " ");
+
+			while (portal != NULL) {
+				if (!strcmp(portal, conn->target_portal)) {
+					free(portals);
+					return true;
+				}
+				portal = strtok(NULL, " ");
+			}
+			free(portals);
+		}
+		return false;
+	} else {
+		return !strcmp(internal_portal, conn->target_portal);
+	}
+}
+
 static void cmnd_exec_login(struct connection *conn)
 {
 	struct iscsi_login_req_hdr *req = (struct iscsi_login_req_hdr *)&conn->req.bhs;
@@ -1083,7 +1110,8 @@ static void cmnd_exec_login(struct connection *conn)
 			login_start(conn);
 			if (rsp->status_class)
 				return;
-			if (!accounts_empty(conn->tid, ISCSI_USER_DIR_INCOMING))
+			if (!accounts_empty(conn->tid, ISCSI_USER_DIR_INCOMING) &&
+				!on_internal_portal(conn))
 				goto auth_err;
 			if (rsp->status_class)
 				return;

iscsi-scst/usr/iscsid.h

@@ -265,6 +265,7 @@ extern const char *get_error_str(int error);
 
 /* iscsid.c */
 extern int iscsi_enabled;
+extern char *internal_portal;
 
 extern int cmnd_execute(struct connection *conn);
 extern void cmnd_finish(struct connection *conn);

iscsi-scst/usr/param.h

@@ -21,6 +21,7 @@
 #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_INTERNAL_PORTAL_ATTR_NAME		"internal_portal"
 #define ISCSI_PER_PORTAL_ACL_ATTR_NAME		"per_portal_acl"
 #define ISCSI_TARGET_REDIRECTION_ATTR_NAME	"redirect"
 #define ISCSI_TARGET_REDIRECTION_VALUE_TEMP	"temp"