[iscsi] Include credentials in iBFT only if used during iSCSI login

Avoid passing credentials in the iBFT that were available but not
required for login.  This works around a problem in the Microsoft
iSCSI initiator, which will refuse to initiate sessions if the CHAP
password is fewer than 12 characters, even if the target ends up not
asking for CHAP authentication.

src/arch/i386/interface/pcbios/ibft.c

 	ibft_set_ipaddr ( ipaddr, in );
 }
 
+/**
+ * Read IP address from iBFT (for debugging)
+ *
+ * @v strings		iBFT string block descriptor
+ * @v string		String field
+ * @ret ipaddr		IP address string
+ */
+static const char * ibft_ipaddr ( struct ibft_ipaddr *ipaddr ) {
+	return inet_ntoa ( ipaddr->in );
+}
+
 /**
  * Allocate a string within iBFT
  *
 	return 0;
 }
 
+/**
+ * Read string from iBFT (for debugging)
+ *
+ * @v strings		iBFT string block descriptor
+ * @v string		String field
+ * @ret data		String content (or "<empty>")
+ */
+static const char * ibft_string ( struct ibft_string_block *strings,
+				  struct ibft_string *string ) {
+	return ( ( ( char * ) strings->table ) + string->offset );
+}
+
 /**
  * Fill in NIC portion of iBFT
  *
 
 	/* Extract values from DHCP configuration */
 	ibft_set_ipaddr_option ( &nic->ip_address, &ip_setting );
+	DBG ( "iBFT NIC IP = %s\n", ibft_ipaddr ( &nic->ip_address ) );
 	ibft_set_ipaddr_option ( &nic->gateway, &gateway_setting );
+	DBG ( "iBFT NIC gateway = %s\n", ibft_ipaddr ( &nic->gateway ) );
 	ibft_set_ipaddr_option ( &nic->dns[0], &dns_setting );
+	DBG ( "iBFT NIC DNS = %s\n", ibft_ipaddr ( &nic->dns[0] ) );
 	if ( ( rc = ibft_set_string_option ( strings, &nic->hostname,
 					     &hostname_setting ) ) != 0 )
 		return rc;
+	DBG ( "iBFT NIC hostname = %s\n",
+	      ibft_string ( strings, &nic->hostname ) );
 
 	/* Derive subnet mask prefix from subnet mask */
 	fetch_ipv4_setting ( NULL, &netmask_setting, &netmask_addr );
 		netmask_addr.s_addr >>= 1;
 	}
 	nic->subnet_mask_prefix = netmask_count;
+	DBG ( "iBFT NIC subnet = /%d\n", nic->subnet_mask_prefix );
 
 	/* Extract values from net-device configuration */
 	memcpy ( nic->mac_address, netdev->ll_addr,
 		 sizeof ( nic->mac_address ) );
+	DBG ( "iBFT NIC MAC = %s\n",
+	      netdev->ll_protocol->ntoa ( nic->mac_address ) );
 	nic->pci_bus_dev_func = netdev->dev->desc.location;
+	DBG ( "iBFT NIC PCI = %04x\n", nic->pci_bus_dev_func );
 
 	return 0;
 }
 	if ( ( rc = ibft_set_string ( strings, &initiator->initiator_name,
 				      initiator_iqn ) ) != 0 )
 		return rc;
+	DBG ( "iBFT initiator hostname = %s\n",
+	      ibft_string ( strings, &initiator->initiator_name ) );
 
 	return 0;
 }
 				   struct iscsi_session *iscsi ) {
 	int rc;
 
-	if ( ! iscsi->initiator_username )
+	if ( ! ( iscsi->status & ISCSI_STATUS_AUTH_FORWARD_REQUIRED ) )
 		return 0;
+
+	assert ( iscsi->initiator_username );
 	assert ( iscsi->initiator_password );
 
 	target->chap_type = IBFT_CHAP_ONE_WAY;
 	if ( ( rc = ibft_set_string ( strings, &target->chap_name,
 				      iscsi->initiator_username ) ) != 0 )
 		return rc;
+	DBG ( "iBFT target username = %s\n",
+	      ibft_string ( strings, &target->chap_name ) );
 	if ( ( rc = ibft_set_string ( strings, &target->chap_secret,
 				      iscsi->initiator_password ) ) != 0 )
 		return rc;
+	DBG ( "iBFT target password = <redacted>\n" );
+
 	return 0;
 }
 
 					   struct iscsi_session *iscsi ) {
 	int rc;
 
-	if ( ! iscsi->target_username )
+	if ( ! ( iscsi->status & ISCSI_STATUS_AUTH_REVERSE_REQUIRED ) )
 		return 0;
-	assert ( iscsi->target_password );
+
 	assert ( iscsi->initiator_username );
 	assert ( iscsi->initiator_password );
+	assert ( iscsi->target_username );
+	assert ( iscsi->target_password );
 
 	target->chap_type = IBFT_CHAP_MUTUAL;
 	if ( ( rc = ibft_set_string ( strings, &target->reverse_chap_name,
 				      iscsi->target_username ) ) != 0 )
 		return rc;
+	DBG ( "iBFT target reverse username = %s\n",
+	      ibft_string ( strings, &target->chap_name ) );
 	if ( ( rc = ibft_set_string ( strings, &target->reverse_chap_secret,
 				      iscsi->target_password ) ) != 0 )
 		return rc;
+	DBG ( "iBFT target reverse password = <redacted>\n" );
+
 	return 0;
 }
 
 
 	/* Fill in Target values */
 	ibft_set_ipaddr ( &target->ip_address, sin_target->sin_addr );
+	DBG ( "iBFT target IP = %s\n", ibft_ipaddr ( &target->ip_address ) );
 	target->socket = ntohs ( sin_target->sin_port );
+	DBG ( "iBFT target port = %d\n", target->socket );
 	if ( ( rc = ibft_set_string ( strings, &target->target_name,
 				      iscsi->target_iqn ) ) != 0 )
 		return rc;
+	DBG ( "iBFT target name = %s\n",
+	      ibft_string ( strings, &target->target_name ) );
 	if ( ( rc = ibft_fill_target_chap ( target, strings, iscsi ) ) != 0 )
 		return rc;
 	if ( ( rc = ibft_fill_target_reverse_chap ( target, strings,

src/include/gpxe/iscsi.h

 	char *target_username;
 	/** Target password (if any) */
 	char *target_password;
-	/** Target has authenticated acceptably */
-	int target_auth_ok;
 	/** CHAP challenge (for target auth only)
 	 *
 	 * This is a block of random data; the first byte is used as
 /** Mask for all iSCSI "needs to send" flags */
 #define ISCSI_STATUS_STRINGS_MASK 0xff00
 
+/** Target has requested forward (initiator) authentication */
+#define ISCSI_STATUS_AUTH_FORWARD_REQUIRED 0x00010000
+
+/** Initiator requires target (reverse) authentication */
+#define ISCSI_STATUS_AUTH_REVERSE_REQUIRED 0x00020000
+
+/** Target authenticated itself correctly */
+#define ISCSI_STATUS_AUTH_REVERSE_OK 0x00040000
+
 /** Maximum number of retries at connecting */
 #define ISCSI_MAX_RETRIES 2
 

src/net/tcp/iscsi.c

 	/* Enter security negotiation phase */
 	iscsi->status = ( ISCSI_STATUS_SECURITY_NEGOTIATION_PHASE |
 			  ISCSI_STATUS_STRINGS_SECURITY );
+	if ( iscsi->target_username )
+		iscsi->status |= ISCSI_STATUS_AUTH_REVERSE_REQUIRED;
 
 	/* Assign fresh initiator task tag */
 	iscsi->itt++;
 	/* Clear connection status */
 	iscsi->status = 0;
 
-	/* Deauthenticate target */
-	iscsi->target_auth_ok = 0;
-
 	/* Reset TX and RX state machines */
 	iscsi->tx_state = ISCSI_TX_IDLE;
 	iscsi->rx_state = ISCSI_RX_BHS;
 static int iscsi_handle_authmethod_value ( struct iscsi_session *iscsi,
 					   const char *value ) {
 
-	/* Mark target as authenticated if no authentication required */
-	if ( ! iscsi->target_username )
-		iscsi->target_auth_ok = 1;
-
 	/* If server requests CHAP, send the CHAP_A string */
 	if ( strcmp ( value, "CHAP" ) == 0 ) {
 		DBGC ( iscsi, "iSCSI %p initiating CHAP authentication\n",
 		       iscsi );
-		iscsi->status |= ISCSI_STATUS_STRINGS_CHAP_ALGORITHM;
+		iscsi->status |= ( ISCSI_STATUS_STRINGS_CHAP_ALGORITHM |
+				   ISCSI_STATUS_AUTH_FORWARD_REQUIRED );
 	}
 
 	return 0;
 	assert ( i == iscsi->chap.response_len );
 
 	/* Mark session as authenticated */
-	iscsi->target_auth_ok = 1;
+	iscsi->status |= ISCSI_STATUS_AUTH_REVERSE_OK;
 
 	return 0;
 }
 
 	/* Handle login transitions */
 	if ( response->flags & ISCSI_LOGIN_FLAG_TRANSITION ) {
+		iscsi->status &= ~( ISCSI_STATUS_PHASE_MASK |
+				    ISCSI_STATUS_STRINGS_MASK );
 		switch ( response->flags & ISCSI_LOGIN_NSG_MASK ) {
 		case ISCSI_LOGIN_NSG_OPERATIONAL_NEGOTIATION:
-			iscsi->status =
+			iscsi->status |=
 				( ISCSI_STATUS_OPERATIONAL_NEGOTIATION_PHASE |
 				  ISCSI_STATUS_STRINGS_OPERATIONAL );
 			break;
 		case ISCSI_LOGIN_NSG_FULL_FEATURE_PHASE:
-			iscsi->status = ISCSI_STATUS_FULL_FEATURE_PHASE;
+			iscsi->status |= ISCSI_STATUS_FULL_FEATURE_PHASE;
 			break;
 		default:
 			DBGC ( iscsi, "iSCSI %p got invalid response flags "
 	}
 
 	/* Check that target authentication was successful (if required) */
-	if ( ! iscsi->target_auth_ok ) {
+	if ( ( iscsi->status & ISCSI_STATUS_AUTH_REVERSE_REQUIRED ) &&
+	     ! ( iscsi->status & ISCSI_STATUS_AUTH_REVERSE_OK ) ) {
 		DBGC ( iscsi, "iSCSI %p nefarious target tried to bypass "
 		       "authentication\n", iscsi );
 		return -EPROTO;