iscsi-target: Fix discovery with INADDR_ANY and IN6ADDR_ANY_INIT

This patch addresses a bug with sendtargets discovery where INADDR_ANY (0.0.0.0)
+ IN6ADDR_ANY_INIT ([0:0:0:0:0:0:0:0]) network portals where incorrectly being
reported back to initiators instead of the address of the connecting interface.
To address this, save local socket ->getname() output during iscsi login setup,
and makes iscsit_build_sendtargets_response() return these TargetAddress keys
when INADDR_ANY or IN6ADDR_ANY_INIT portals are in use.

Reported-by: Dax Kelson <dkelson@gurulabs.com>
Reported-by: Andy Grover <agrover@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target.c

@@ -3164,6 +3164,30 @@ static int iscsit_send_task_mgt_rsp(
 	return 0;
 }
 
+static bool iscsit_check_inaddr_any(struct iscsi_np *np)
+{
+	bool ret = false;
+
+	if (np->np_sockaddr.ss_family == AF_INET6) {
+		const struct sockaddr_in6 sin6 = {
+			.sin6_addr = IN6ADDR_ANY_INIT };
+		struct sockaddr_in6 *sock_in6 =
+			 (struct sockaddr_in6 *)&np->np_sockaddr;
+
+		if (!memcmp(sock_in6->sin6_addr.s6_addr,
+				sin6.sin6_addr.s6_addr, 16))
+			ret = true;
+	} else {
+		struct sockaddr_in * sock_in =
+			(struct sockaddr_in *)&np->np_sockaddr;
+
+		if (sock_in->sin_addr.s_addr == INADDR_ANY)
+			ret = true;
+	}
+
+	return ret;
+}
+
 static int iscsit_build_sendtargets_response(struct iscsi_cmd *cmd)
 {
 	char *payload = NULL;
@@ -3213,12 +3237,17 @@ static int iscsit_build_sendtargets_response(struct iscsi_cmd *cmd)
 			spin_lock(&tpg->tpg_np_lock);
 			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
 						tpg_np_list) {
+				struct iscsi_np *np = tpg_np->tpg_np;
+				bool inaddr_any = iscsit_check_inaddr_any(np);
+
 				len = sprintf(buf, "TargetAddress="
 					"%s%s%s:%hu,%hu",
-					(tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) ?
-					"[" : "", tpg_np->tpg_np->np_ip,
-					(tpg_np->tpg_np->np_sockaddr.ss_family == AF_INET6) ?
-					"]" : "", tpg_np->tpg_np->np_port,
+					(np->np_sockaddr.ss_family == AF_INET6) ?
+					"[" : "", (inaddr_any == false) ?
+						np->np_ip : conn->local_ip,
+					(np->np_sockaddr.ss_family == AF_INET6) ?
+					"]" : "", (inaddr_any == false) ?
+						np->np_port : conn->local_port,
 					tpg->tpgt);
 				len += 1;
 

drivers/target/iscsi/iscsi_target_core.h

@@ -508,6 +508,7 @@ struct iscsi_conn {
 	u16			cid;
 	/* Remote TCP Port */
 	u16			login_port;
+	u16			local_port;
 	int			net_size;
 	u32			auth_id;
 #define CONNFLAG_SCTP_STRUCT_FILE			0x01
@@ -527,6 +528,7 @@ struct iscsi_conn {
 	unsigned char		bad_hdr[ISCSI_HDR_LEN];
 #define IPV6_ADDRESS_SPACE				48
 	unsigned char		login_ip[IPV6_ADDRESS_SPACE];
+	unsigned char		local_ip[IPV6_ADDRESS_SPACE];
 	int			conn_usage_count;
 	int			conn_waiting_on_uc;
 	atomic_t		check_immediate_queue;

drivers/target/iscsi/iscsi_target_login.c

@@ -615,8 +615,8 @@ static int iscsi_post_login_handler(
 		}
 
 		pr_debug("iSCSI Login successful on CID: %hu from %s to"
-			" %s:%hu,%hu\n", conn->cid, conn->login_ip, np->np_ip,
-				np->np_port, tpg->tpgt);
+			" %s:%hu,%hu\n", conn->cid, conn->login_ip,
+			conn->local_ip, conn->local_port, tpg->tpgt);
 
 		list_add_tail(&conn->conn_list, &sess->sess_conn_list);
 		atomic_inc(&sess->nconn);
@@ -658,7 +658,8 @@ static int iscsi_post_login_handler(
 	sess->session_state = TARG_SESS_STATE_LOGGED_IN;
 
 	pr_debug("iSCSI Login successful on CID: %hu from %s to %s:%hu,%hu\n",
-		conn->cid, conn->login_ip, np->np_ip, np->np_port, tpg->tpgt);
+		conn->cid, conn->login_ip, conn->local_ip, conn->local_port,
+		tpg->tpgt);
 
 	spin_lock_bh(&sess->conn_lock);
 	list_add_tail(&conn->conn_list, &sess->sess_conn_list);
@@ -1020,6 +1021,18 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 		snprintf(conn->login_ip, sizeof(conn->login_ip), "%pI6c",
 				&sock_in6.sin6_addr.in6_u);
 		conn->login_port = ntohs(sock_in6.sin6_port);
+
+		if (conn->sock->ops->getname(conn->sock,
+				(struct sockaddr *)&sock_in6, &err, 0) < 0) {
+			pr_err("sock_ops->getname() failed.\n");
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+					ISCSI_LOGIN_STATUS_TARGET_ERROR);
+			goto new_sess_out;
+		}
+		snprintf(conn->local_ip, sizeof(conn->local_ip), "%pI6c",
+				&sock_in6.sin6_addr.in6_u);
+		conn->local_port = ntohs(sock_in6.sin6_port);
+
 	} else {
 		memset(&sock_in, 0, sizeof(struct sockaddr_in));
 
@@ -1032,14 +1045,24 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 		}
 		sprintf(conn->login_ip, "%pI4", &sock_in.sin_addr.s_addr);
 		conn->login_port = ntohs(sock_in.sin_port);
+
+		if (conn->sock->ops->getname(conn->sock,
+				(struct sockaddr *)&sock_in, &err, 0) < 0) {
+			pr_err("sock_ops->getname() failed.\n");
+			iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+					ISCSI_LOGIN_STATUS_TARGET_ERROR);
+			goto new_sess_out;
+		}
+		sprintf(conn->local_ip, "%pI4", &sock_in.sin_addr.s_addr);
+		conn->local_port = ntohs(sock_in.sin_port);
 	}
 
 	conn->network_transport = np->np_network_transport;
 
 	pr_debug("Received iSCSI login request from %s on %s Network"
 			" Portal %s:%hu\n", conn->login_ip,
 		(conn->network_transport == ISCSI_TCP) ? "TCP" : "SCTP",
-			np->np_ip, np->np_port);
+			conn->local_ip, conn->local_port);
 
 	pr_debug("Moving to TARG_CONN_STATE_IN_LOGIN.\n");
 	conn->conn_state	= TARG_CONN_STATE_IN_LOGIN;