Implemented iSCSI discovery and related portal group and portals handling. Also fixed some bugs and iSCSI emulation layer now handles any block size. Finally, more multipath related stuff.

5 files changed, 1182 insertions, 467 deletions

diff --git a/README.md b/README.md
index 15b0d78..f4e8efc 100644
--- a/README.md
+++ b/README.md
@@ -490,11 +490,29 @@ The _iscsi.conf_ file is the main configuration file for the iSCSI implementatio
 ; scsi-device- sections will be processed in order, always inherit from the [iscsi] and [scsi]
 ; sections and are matched case sensitive
 
+[iscsi-portal-group-1]
+; Portal group access level (warning) specifying invalid access levels will default to private
+; access!). Default is Private
+; Private   All target nodes in this portal group will not be sent in discovery requests
+; Public    All target nodes in this portal group are visible in discovery requests
+Access=Private
+
+[iscsi-portal-group-2]
+; Portal group access level (warning) specifying invalid access levels will default to private
+; access!). Default is Private
+; Private   All target nodes in this portal group will not be sent in discovery requests
+; Public    All target nodes in this portal group are visible in discovery requests
+Access=Public
+
 [iscsi]
-; Target name check level (warning) specifying invalid check levels will default to full
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=1
+
+; Target name check level (warning) specifying invalid check levels will default to relaxed
 ; validation!). Default is Relaxed
 ; Full      Target name is checked for full standaard compliance (recommended)
-; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI.
+; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI
 ; None      No checking at all (be careful)
 TargetNameCheck=Relaxed
 
@@ -525,14 +543,14 @@ MaxRecvDataSegmentLength=65536
 ; MediaChanger     Media changer device
 DeviceType=Direct
 
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=512
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=512
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
@@ -545,14 +563,18 @@ Removable=true
 ; end with .iso extension. Block sizes are set to 2 KiB for CD-ROM, DVD and BluRay type devices
 ; and the physical read only emulation flag is enabled
 [scsi-device-*.iso]
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=2
+
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=2048
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=2048
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
@@ -567,14 +589,18 @@ PhysicalReadOnly=true
 ; end with .ISO extension. Block sizes are set to 2 KiB for CD-ROM, DVD and BluRay type devices
 ; and the physical read only emulation flag is enabled
 [scsi-device-*.ISO]
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=2
+
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=2048
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=2048
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
diff --git a/pkg/config/iscsi.conf b/pkg/config/iscsi.conf
index 0e1ca49..85c31a1 100644
--- a/pkg/config/iscsi.conf
+++ b/pkg/config/iscsi.conf
@@ -8,11 +8,29 @@
 ; scsi-device- sections will be processed in order, always inherit from the [iscsi] and [scsi]
 ; sections and are matched case sensitive
 
+[iscsi-portal-group-1]
+; Portal group access level (warning) specifying invalid access levels will default to private
+; access!). Default is Private
+; Private   All target nodes in this portal group will not be sent in discovery requests
+; Public    All target nodes in this portal group are visible in discovery requests
+Access=Private
+
+[iscsi-portal-group-2]
+; Portal group access level (warning) specifying invalid access levels will default to private
+; access!). Default is Private
+; Private   All target nodes in this portal group will not be sent in discovery requests
+; Public    All target nodes in this portal group are visible in discovery requests
+Access=Public
+
 [iscsi]
-; Target name check level (warning) specifying invalid check levels will default to full
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=1
+
+; Target name check level (warning) specifying invalid check levels will default to relaxed
 ; validation!). Default is Relaxed
 ; Full      Target name is checked for full standaard compliance (recommended)
-; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI.
+; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI
 ; None      No checking at all (be careful)
 TargetNameCheck=Relaxed
 
@@ -170,14 +188,14 @@ ErrorRecoveryLevel=0
 ; MediaChanger     Media changer device
 DeviceType=Direct
 
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=512
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=512
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
@@ -208,14 +226,18 @@ WriteCache=false
 ; end with .iso extension. Block sizes are set to 2 KiB for CD-ROM, DVD and BluRay type devices
 ; and the physical read only emulation flag is enabled
 [scsi-device-*.iso]
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=2
+
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=2048
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=2048
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
@@ -230,14 +252,18 @@ PhysicalReadOnly=true
 ; end with .ISO extension. Block sizes are set to 2 KiB for CD-ROM, DVD and BluRay type devices
 ; and the physical read only emulation flag is enabled
 [scsi-device-*.ISO]
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=2
+
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=2048
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=2048
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
diff --git a/pkg/config/server.conf b/pkg/config/server.conf
index 3a7cd04..443a76e 100644
--- a/pkg/config/server.conf
+++ b/pkg/config/server.conf
@@ -93,11 +93,29 @@ consoleMask=ERROR WARNING MINOR INFO
 ; Whether timestamps should be output to console too (or just to file if false)
 consoleTimestamps=false
 
+[iscsi-portal-group-1]
+; Portal group access level (warning) specifying invalid access levels will default to private
+; access!). Default is Private
+; Private   All target nodes in this portal group will not be sent in discovery requests
+; Public    All target nodes in this portal group are visible in discovery requests
+Access=Private
+
+[iscsi-portal-group-2]
+; Portal group access level (warning) specifying invalid access levels will default to private
+; access!). Default is Private
+; Private   All target nodes in this portal group will not be sent in discovery requests
+; Public    All target nodes in this portal group are visible in discovery requests
+Access=Public
+
 [iscsi]
-; Target name check level (warning) specifying invalid check levels will default to full
+; Default portal group tag (warning) specifying invalid portal group tags will default to first
+; portal group!). Default is 1
+PortalGroupTag=1
+
+; Target name check level (warning) specifying invalid check levels will default to relaxed
 ; validation!). Default is Relaxed
 ; Full      Target name is checked for full standaard compliance (recommended)
-; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI.
+; Relaxed   All invalid characters according to standard will be allowed if not an IQN, NAA or EUI
 ; None      No checking at all (be careful)
 TargetNameCheck=Relaxed
 
@@ -255,14 +273,14 @@ ErrorRecoveryLevel=0
 ; MediaChanger     Media changer device
 DeviceType=Direct
 
-; Physical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; physical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Physical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed physical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 PhysicalBlockSize=512
 
-; Logical block size of emulated device, rounded up to nearest power of two). Default is 512 for
-; supporting ancient systems. Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed
-; logical block sizes range from 256 to 32768 bytes (32 KiB). Default is 512 bytes
+; Logical block size of emulated device). Default is 512 for supporting ancient systems.
+; Should be set to 2048 for CD-ROM, DVD and BluRay devices. Allowed logical block sizes range
+; from 1 to 2147483647 bytes (2 GiB). Default is 512 bytes
 LogicalBlockSize=512
 
 ; Device is emulated as removable. Should be enabled for CD-ROM, DVD and BluRay and disabled for
diff --git a/src/server/iscsi.c b/src/server/iscsi.c
index c4a124c..b56df20 100644
--- a/src/server/iscsi.c
+++ b/src/server/iscsi.c
@@ -30,9 +30,13 @@
 #include <string.h>
 #include <inttypes.h>
 #include <strings.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
 #include <sys/socket.h>
 #include <sys/types.h>
+#include <sys/un.h>
 #include <dnbd3/config.h>
+#include <dnbd3/config/server.h>
 #include <dnbd3/shared/log.h>
 #include <dnbd3/shared/sockhelper.h>
 #include <dnbd3/types.h>
@@ -40,6 +44,7 @@
 #include <time.h>
 #include <unistd.h>
 
+#include "altservers.h"
 #include "fileutil.h"
 #include "globals.h"
 #include "helper.h"
@@ -1075,7 +1080,7 @@ int iscsi_create()
 			return -1;
 		}
 
-		globvec->devices = iscsi_hashmap_create( _maxImages );
+		globvec->devices = iscsi_hashmap_create( 0U );
 
 		if ( globvec->devices == NULL ) {
 			logadd( LOG_ERROR, "iscsi_create: Out of memory while allocating iSCSI global vector devices hash map" );
@@ -1096,7 +1101,7 @@ int iscsi_create()
 			return -1;
 		}
 
-		globvec->portal_groups = iscsi_hashmap_create( 1U );
+		globvec->portal_groups = iscsi_hashmap_create( 0U );
 
 		if ( globvec->portal_groups == NULL ) {
 			logadd( LOG_ERROR, "iscsi_create: Out of memory while allocating iSCSI global vector portal groups hash map" );
@@ -1121,7 +1126,7 @@ int iscsi_create()
 			return -1;
 		}
 
-		globvec->target_nodes = iscsi_hashmap_create( _maxImages );
+		globvec->target_nodes = iscsi_hashmap_create( 0U );
 
 		if ( globvec->target_nodes == NULL ) {
 			logadd( LOG_ERROR, "iscsi_create: Out of memory while allocating iSCSI global vector target nodes hash map" );
@@ -1150,7 +1155,7 @@ int iscsi_create()
 			return -1;
 		}
 
-		globvec->sessions = iscsi_hashmap_create( _maxClients );
+		globvec->sessions = iscsi_hashmap_create( 0U );
 
 		if ( globvec->sessions == NULL ) {
 			logadd( LOG_ERROR, "iscsi_create: Out of memory while allocating iSCSI global vector sessions hash map" );
@@ -1312,25 +1317,25 @@ int iscsi_create()
 			return -1;
 		}
 
-		globvec->flags                          = (ISCSI_GLOBALS_FLAGS_CHAP_DISABLE | ISCSI_GLOBALS_FLAGS_INIT_R2T | ISCSI_GLOBALS_FLAGS_IMMEDIATE_DATA | ISCSI_GLOBALS_FLAGS_DATA_PDU_IN_ORDER | ISCSI_GLOBALS_FLAGS_DATA_SEQ_IN_ORDER | ISCSI_GLOBALS_FLAGS_SCSI_IO_REMOVABLE | ISCSI_GLOBALS_FLAGS_SCSI_IO_WRITE_PROTECT);
-		globvec->target_name_check              = ISCSI_GLOBALS_TARGET_NAME_CHECK_RELAXED;
-		globvec->max_sessions                   = 0U;
-		globvec->header_digest                  = 0;
-		globvec->data_digest                    = 0;
-		globvec->scsi_device_type               = ISCSI_SCSI_BASIC_INQUIRY_DATA_PERIPHERAL_TYPE_DIRECT;
-		globvec->max_recv_ds_len                = ISCSI_DEFAULT_MAX_RECV_DS_LEN;
-		globvec->max_session_conns              = ISCSI_GLOBALS_DEFAULT_MAX_CONNECTIONS;
-		globvec->max_outstanding_r2t            = ISCSI_GLOBALS_DEFAULT_MAX_OUTSTANDING_R2T;
-		globvec->default_time_to_wait           = ISCSI_GLOBALS_DEFAULT_TIME_TO_WAIT;
-		globvec->default_time_to_retain         = ISCSI_GLOBALS_DEFAULT_TIME_TO_RETAIN;
-		globvec->first_burst_len                = ISCSI_GLOBALS_DEFAULT_FIRST_BURST_LEN;
-		globvec->max_burst_len                  = ISCSI_GLOBALS_DEFAULT_MAX_BURST_LEN;
-		globvec->err_recovery_level             = ISCSI_GLOBALS_DEFAULT_ERR_RECOVERY_LEVEL;
-		globvec->chap_group                     = 0L;
-		globvec->scsi_physical_block_size       = ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE;
-		globvec->scsi_physical_block_size_shift = iscsi_get_log2_of_pow2( globvec->scsi_physical_block_size );
-		globvec->scsi_logical_block_size        = ISCSI_SCSI_EMU_BLOCK_SIZE;
-		globvec->scsi_logical_block_size_shift  = iscsi_get_log2_of_pow2( globvec->scsi_logical_block_size );
+		globvec->flags                    = (ISCSI_GLOBALS_FLAGS_CHAP_DISABLE | ISCSI_GLOBALS_FLAGS_INIT_R2T | ISCSI_GLOBALS_FLAGS_IMMEDIATE_DATA | ISCSI_GLOBALS_FLAGS_DATA_PDU_IN_ORDER | ISCSI_GLOBALS_FLAGS_DATA_SEQ_IN_ORDER | ISCSI_GLOBALS_FLAGS_SCSI_IO_REMOVABLE | ISCSI_GLOBALS_FLAGS_SCSI_IO_WRITE_PROTECT);
+		globvec->target_name_check        = ISCSI_GLOBALS_TARGET_NAME_CHECK_RELAXED;
+		globvec->max_sessions             = 0U;
+		globvec->header_digest            = 0;
+		globvec->data_digest              = 0;
+		globvec->scsi_device_type         = ISCSI_SCSI_BASIC_INQUIRY_DATA_PERIPHERAL_TYPE_DIRECT;
+		atomic_init( &globvec->connections, 0 );
+		globvec->pg_tag                   = 1UL;
+		globvec->max_recv_ds_len          = ISCSI_DEFAULT_MAX_RECV_DS_LEN;
+		globvec->max_session_conns        = ISCSI_GLOBALS_DEFAULT_MAX_CONNECTIONS;
+		globvec->max_outstanding_r2t      = ISCSI_GLOBALS_DEFAULT_MAX_OUTSTANDING_R2T;
+		globvec->default_time_to_wait     = ISCSI_GLOBALS_DEFAULT_TIME_TO_WAIT;
+		globvec->default_time_to_retain   = ISCSI_GLOBALS_DEFAULT_TIME_TO_RETAIN;
+		globvec->first_burst_len          = ISCSI_GLOBALS_DEFAULT_FIRST_BURST_LEN;
+		globvec->max_burst_len            = ISCSI_GLOBALS_DEFAULT_MAX_BURST_LEN;
+		globvec->err_recovery_level       = ISCSI_GLOBALS_DEFAULT_ERR_RECOVERY_LEVEL;
+		globvec->chap_group               = 0L;
+		globvec->scsi_physical_block_size = ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE;
+		globvec->scsi_logical_block_size  = ISCSI_SCSI_EMU_BLOCK_SIZE;
 
 		iscsi_config_load( globvec );
 
@@ -1553,7 +1558,56 @@ static int iscsi_config_load_from_ini(void *user_data, const char *section, cons
 {
 	iscsi_globals *globvec = (iscsi_globals *) user_data;
 
-	if ( strcasecmp( section, ISCSI_GLOBALS_SECTION_ISCSI ) == 0 ) {
+	if ( (strncasecmp( section, ISCSI_GLOBALS_SECTION_ISCSI_PORTAL_GROUP_PREFIX, ISCSI_STRLEN(ISCSI_GLOBALS_SECTION_ISCSI_PORTAL_GROUP_PREFIX) ) == 0) ) {
+		int32_t num_value = iscsi_config_parse_int( (((uint8_t *) section) + ISCSI_STRLEN(ISCSI_GLOBALS_SECTION_ISCSI_PORTAL_GROUP_PREFIX)) );
+
+		if ( num_value <= 0L )
+			num_value = 1L;
+
+		uint64_t pg_tag = (uint64_t) num_value;
+		int flags       = ISCSI_PORTAL_GROUP_FLAGS_PRIVATE;
+
+		pthread_rwlock_rdlock( &globvec->portal_groups_rwlock );
+
+		iscsi_portal_group *portal_group = NULL;
+		int rc                           = iscsi_hashmap_get( globvec->portal_groups, (uint8_t *) &pg_tag, sizeof(pg_tag), (uint8_t **) &portal_group );
+
+		if ( portal_group == NULL ) {
+			pthread_rwlock_unlock( &globvec->portal_groups_rwlock );
+			pthread_rwlock_wrlock( &globvec->portal_groups_rwlock );
+			rc = iscsi_hashmap_get( globvec->portal_groups, (uint8_t *) &pg_tag, sizeof(pg_tag), (uint8_t **) &portal_group );
+
+			if ( portal_group == NULL ) {
+				portal_group = iscsi_portal_group_create( pg_tag, flags );
+
+				if ( portal_group == NULL ) {
+					pthread_rwlock_unlock( &globvec->portal_groups_rwlock );
+
+					return 0;
+				}
+
+				rc = iscsi_hashmap_put( globvec->portal_groups, (uint8_t *) &portal_group->tag, sizeof(portal_group->tag), (uint8_t *) portal_group );
+
+				if ( rc < 0 ) {
+					iscsi_portal_group_destroy( portal_group );
+					pthread_rwlock_unlock( &globvec->portal_groups_rwlock );
+
+					return 0;
+				}
+			}
+		} else {
+			portal_group->tag = pg_tag;
+		}
+
+		if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_ISCSI_PORTAL_GROUP_KEY_ACCESS ) == 0 ) {
+			if ( strcasecmp( value, "Public" ) == 0 )
+				flags &= ~ISCSI_PORTAL_GROUP_FLAGS_PRIVATE;
+
+			portal_group->flags = flags;
+		}
+
+		pthread_rwlock_unlock( &globvec->portal_groups_rwlock );
+	} else if ( strcasecmp( section, ISCSI_GLOBALS_SECTION_ISCSI ) == 0 ) {
 		const int32_t num_value = iscsi_config_parse_int( (uint8_t *) value );
 
 		if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_ISCSI_KEY_TARGET_NAME_CHECK ) == 0 ) {
@@ -1569,6 +1623,9 @@ static int iscsi_config_load_from_ini(void *user_data, const char *section, cons
 			globvec->header_digest = ((strcasecmp( value, "CRC32C" ) == 0) ? ISCSI_DIGEST_SIZE : 0);
 		} else if ( strcasecmp( key, ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_DATA_DIGEST ) == 0 ) {
 			globvec->data_digest = ((strcasecmp( value, "CRC32C" ) == 0) ? ISCSI_DIGEST_SIZE : 0);
+		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_ISCSI_KEY_PORTAL_GROUP_TAG ) == 0 ) {
+			if ( num_value > 0L )
+				globvec->pg_tag = num_value;
 		} else if ( strcasecmp( key, ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_MAX_RECV_DS_LEN ) == 0 ) {
 			if ( (num_value >= 512L) && (num_value <= (int32_t) ISCSI_MAX_DS_SIZE) )
 				globvec->max_recv_ds_len = num_value;
@@ -1639,19 +1696,11 @@ static int iscsi_config_load_from_ini(void *user_data, const char *section, cons
 			else
 				globvec->scsi_device_type = ISCSI_SCSI_BASIC_INQUIRY_DATA_PERIPHERAL_TYPE_DIRECT;
 		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_SCSI_KEY_PHYSICAL_BLOCK_SIZE ) == 0 ) {
-			num_value = iscsi_align_pow2_ceil( num_value );
-
-			if ( (num_value >= 256L) && (num_value <= 32768L) ) {
-				globvec->scsi_physical_block_size       = num_value;
-				globvec->scsi_physical_block_size_shift = iscsi_get_log2_of_pow2( num_value );
-			}
+			if ( num_value > 0L )
+				globvec->scsi_physical_block_size = num_value;
 		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_SCSI_KEY_LOGICAL_BLOCK_SIZE ) == 0 ) {
-			num_value = iscsi_align_pow2_ceil( num_value );
-
-			if ( (num_value >= 256L) && (num_value <= 32768L) ) {
-				globvec->scsi_logical_block_size       = num_value;
-				globvec->scsi_logical_block_size_shift = iscsi_get_log2_of_pow2( num_value );
-			}
+			if ( num_value > 0L )
+				globvec->scsi_logical_block_size = num_value;
 		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_SCSI_KEY_REMOVABLE ) == 0 ) {
 			if ( num_value != ISCSI_GLOBALS_CONFIG_TYPE_VALUE_ERROR ) {
 				if ( num_value != 0L )
@@ -1756,21 +1805,20 @@ static int iscsi_config_load_from_ini(void *user_data, const char *section, cons
 			if ( (globvec->flags & ISCSI_GLOBALS_FLAGS_SCSI_IO_WRITE_CACHE) != 0 )
 				scsi_device_config->flags |= ISCSI_GLOBALS_SCSI_DEVICE_CONFIG_FLAGS_SCSI_IO_WRITE_CACHE;
 
-			scsi_device_config->header_digest                  = globvec->header_digest;
-			scsi_device_config->data_digest                    = globvec->data_digest;
-			scsi_device_config->scsi_device_type               = globvec->scsi_device_type;
-			scsi_device_config->max_recv_ds_len                = globvec->max_recv_ds_len;
-			scsi_device_config->max_session_conns              = globvec->max_session_conns;
-			scsi_device_config->max_outstanding_r2t            = globvec->max_outstanding_r2t;
-			scsi_device_config->default_time_to_wait           = globvec->default_time_to_wait;
-			scsi_device_config->default_time_to_retain         = globvec->default_time_to_retain;
-			scsi_device_config->first_burst_len                = globvec->first_burst_len;
-			scsi_device_config->max_burst_len                  = globvec->max_burst_len;
-			scsi_device_config->err_recovery_level             = globvec->err_recovery_level;
-			scsi_device_config->scsi_physical_block_size       = globvec->scsi_physical_block_size;
-			scsi_device_config->scsi_physical_block_size_shift = globvec->scsi_physical_block_size_shift;
-			scsi_device_config->scsi_logical_block_size        = globvec->scsi_logical_block_size;
-			scsi_device_config->scsi_logical_block_size_shift  = globvec->scsi_logical_block_size_shift;
+			scsi_device_config->header_digest            = globvec->header_digest;
+			scsi_device_config->data_digest              = globvec->data_digest;
+			scsi_device_config->scsi_device_type         = globvec->scsi_device_type;
+			scsi_device_config->pg_tag                   = globvec->pg_tag;
+			scsi_device_config->max_recv_ds_len          = globvec->max_recv_ds_len;
+			scsi_device_config->max_session_conns        = globvec->max_session_conns;
+			scsi_device_config->max_outstanding_r2t      = globvec->max_outstanding_r2t;
+			scsi_device_config->default_time_to_wait     = globvec->default_time_to_wait;
+			scsi_device_config->default_time_to_retain   = globvec->default_time_to_retain;
+			scsi_device_config->first_burst_len          = globvec->first_burst_len;
+			scsi_device_config->max_burst_len            = globvec->max_burst_len;
+			scsi_device_config->err_recovery_level       = globvec->err_recovery_level;
+			scsi_device_config->scsi_physical_block_size = globvec->scsi_physical_block_size;
+			scsi_device_config->scsi_logical_block_size  = globvec->scsi_logical_block_size;
 
 			rc = iscsi_hashmap_put( globvec->scsi_device_config, hash_key, key_len, (uint8_t *) scsi_device_config );
 
@@ -1790,6 +1838,9 @@ static int iscsi_config_load_from_ini(void *user_data, const char *section, cons
 			scsi_device_config->header_digest = ((strcasecmp( value, "CRC32C" ) == 0) ? ISCSI_DIGEST_SIZE : 0);
 		} else if ( strcasecmp( key, ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_DATA_DIGEST ) == 0 ) {
 			scsi_device_config->data_digest = ((strcasecmp( value, "CRC32C" ) == 0) ? ISCSI_DIGEST_SIZE : 0);
+		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_ISCSI_KEY_PORTAL_GROUP_TAG ) == 0 ) {
+			if ( num_value > 0L )
+				scsi_device_config->pg_tag = num_value;
 		} else if ( strcasecmp( key, ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_MAX_RECV_DS_LEN ) == 0 ) {
 			if ( (num_value >= 512L) && (num_value <= (int32_t) ISCSI_MAX_DS_SIZE) )
 				scsi_device_config->max_recv_ds_len = num_value;
@@ -1856,19 +1907,11 @@ static int iscsi_config_load_from_ini(void *user_data, const char *section, cons
 			else
 				scsi_device_config->scsi_device_type = ISCSI_SCSI_BASIC_INQUIRY_DATA_PERIPHERAL_TYPE_DIRECT;
 		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_SCSI_KEY_PHYSICAL_BLOCK_SIZE ) == 0 ) {
-			num_value = iscsi_align_pow2_ceil( num_value );
-
-			if ( (num_value >= 256L) && (num_value <= 32768L) ) {
-				scsi_device_config->scsi_physical_block_size       = num_value;
-				scsi_device_config->scsi_physical_block_size_shift = iscsi_get_log2_of_pow2( num_value );
-			}
+			if ( num_value > 0L )
+				scsi_device_config->scsi_physical_block_size = num_value;
 		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_SCSI_KEY_LOGICAL_BLOCK_SIZE ) == 0 ) {
-			num_value = iscsi_align_pow2_ceil( num_value );
-
-			if ( (num_value >= 256L) && (num_value <= 32768L) ) {
-				scsi_device_config->scsi_logical_block_size       = num_value;
-				scsi_device_config->scsi_logical_block_size_shift = iscsi_get_log2_of_pow2( num_value );
-			}
+			if ( num_value > 0L )
+				scsi_device_config->scsi_logical_block_size = num_value;
 		} else if ( strcasecmp( key, ISCSI_GLOBALS_SECTION_SCSI_KEY_REMOVABLE ) == 0 ) {
 			if ( num_value != ISCSI_GLOBALS_CONFIG_TYPE_VALUE_ERROR ) {
 				if ( num_value != 0L )
@@ -2091,6 +2134,11 @@ int32_t iscsi_config_get(uint8_t *name, const int type)
 
 					break;
 				}
+				case ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG : {
+					return scsi_device_config->pg_tag;
+
+					break;
+				}
 				case ISCSI_GLOBALS_CONFIG_TYPE_MAX_RECV_DS_LEN : {
 					return scsi_device_config->max_recv_ds_len;
 
@@ -2131,18 +2179,13 @@ int32_t iscsi_config_get(uint8_t *name, const int type)
 
 					break;
 				}
-				case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE : {
-					return scsi_device_config->scsi_physical_block_size;
-
-					break;
-				}
 				case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_DEVICE_TYPE : {
 					return scsi_device_config->scsi_device_type;
 
 					break;
 				}
-				case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT : {
-					return scsi_device_config->scsi_physical_block_size_shift;
+				case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE : {
+					return scsi_device_config->scsi_physical_block_size;
 
 					break;
 				}
@@ -2151,11 +2194,6 @@ int32_t iscsi_config_get(uint8_t *name, const int type)
 
 					break;
 				}
-				case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT : {
-					return scsi_device_config->scsi_logical_block_size_shift;
-
-					break;
-				}
 				case ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_INIT_R2T : {
 					return (((scsi_device_config->flags & ISCSI_GLOBALS_SCSI_DEVICE_CONFIG_FLAGS_INIT_R2T) != 0) ? 1L : 0L);
 
@@ -2224,6 +2262,11 @@ int32_t iscsi_config_get(uint8_t *name, const int type)
 
 			break;
 		}
+		case ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG : {
+			return iscsi_globvec->pg_tag;
+
+			break;
+		}
 		case ISCSI_GLOBALS_CONFIG_TYPE_MAX_RECV_DS_LEN : {
 			return iscsi_globvec->max_recv_ds_len;
 
@@ -2279,21 +2322,11 @@ int32_t iscsi_config_get(uint8_t *name, const int type)
 
 			break;
 		}
-		case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT : {
-			return iscsi_globvec->scsi_physical_block_size_shift;
-
-			break;
-		}
 		case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE : {
 			return iscsi_globvec->scsi_logical_block_size;
 
 			break;
 		}
-		case ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT : {
-			return iscsi_globvec->scsi_logical_block_size_shift;
-
-			break;
-		}
 		case ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_DISABLE : {
 			return (((iscsi_globvec->flags & ISCSI_GLOBALS_FLAGS_CHAP_DISABLE) != 0) ? 1L : 0L);
 
@@ -2699,7 +2732,7 @@ static int iscsi_get_int_key_value_pair(iscsi_hashmap *key_value_pairs, const ui
  */
 static int iscsi_add_int_key_value_pair(iscsi_hashmap *key_value_pairs, const uint8_t *key, const int32_t value)
 {
-	const uint8_t *hash_val = iscsi_sprintf_alloc( "%" PRId32, value );
+	uint8_t *hash_val = iscsi_sprintf_alloc( "%" PRId32, value );
 
 	if ( hash_val == NULL ) {
 		logadd( LOG_ERROR, "iscsi_add_int_key_value_pair: Out of memory allocating integer value." );
@@ -2707,7 +2740,11 @@ static int iscsi_add_int_key_value_pair(iscsi_hashmap *key_value_pairs, const ui
 		return -1;
 	}
 
-	return iscsi_add_key_value_pair( key_value_pairs, key, hash_val );
+	const int rc = iscsi_add_key_value_pair( key_value_pairs, key, hash_val );
+
+	free( hash_val );
+
+	return rc;
 }
 
 /**
@@ -3755,10 +3792,11 @@ void iscsi_portal_group_del_portal(iscsi_portal_group *portal_group, iscsi_porta
  *
  * @param[in] host Host / IP address of the portal.
  * @param[in] port Port of the portal.
+ * @param[in] type Type of socket.
  * @return Pointer to iSCSI portal structure or NULL
  * in case of an error (memory exhausted).
  */
-iscsi_portal *iscsi_portal_create(const uint8_t *host, const uint8_t *port)
+iscsi_portal *iscsi_portal_create(const uint8_t *host, const uint8_t *port, const uint type)
 {
 	iscsi_portal *portal = (iscsi_portal *) malloc( sizeof(struct iscsi_portal) );
 
@@ -3794,6 +3832,7 @@ iscsi_portal *iscsi_portal_create(const uint8_t *host, const uint8_t *port)
 
 	memcpy( portal->port, port, port_len );
 
+	portal->type = type;
 	portal->sock = -1;
 
 	return portal;
@@ -3907,6 +3946,12 @@ void iscsi_scsi_task_create(iscsi_scsi_task *scsi_task, iscsi_scsi_task_xfer_com
 void iscsi_scsi_task_destroy(iscsi_scsi_task *scsi_task)
 {
 	if ( (scsi_task != NULL) && (--scsi_task->ref == 0UL) ) {
+		if ( scsi_task->sense_data != NULL ) {
+			free( scsi_task->sense_data );
+
+			scsi_task->sense_data = NULL;
+		}
+
 		if ( scsi_task->buf != NULL ) {
 			if ( (scsi_task->flags & ISCSI_SCSI_TASK_FLAGS_XFER_WRITE) == 0 )
 				free( scsi_task->buf );
@@ -5056,34 +5101,14 @@ static inline bool iscsi_scsi_emu_io_type_is_supported(const dnbd3_image_t *imag
  */
 static inline uint64_t iscsi_scsi_emu_physical_block_get_count(const dnbd3_image_t *image)
 {
-	int32_t block_size_shift = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT );
-
-	if ( block_size_shift <= 0L )
-		block_size_shift = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT );
-
-	return (((image->realFilesize + ((1ULL << (uint64_t) block_size_shift) - 1ULL)) ) >> (uint32_t) block_size_shift);
-}
+	int32_t block_size = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE );
 
-/**
- * @brief Retrieves the bit shift of a physical block in bytes for a DNBD3 image.
- *
- * This function depends on DNBD3 image
- * properties.
- *
- * @param[in] image Pointer to DNBD3 image to retrieve
- * the physical bit shift size. May NOT
- * be NULL, so be careful.
- * @return The physical block size in bytes as a
- * bit shift count.
- */
-static inline uint32_t iscsi_scsi_emu_physical_block_get_size_shift(const dnbd3_image_t *image)
-{
-	int32_t block_size_shift = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT );
+	if ( block_size <= 0L )
+		block_size = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE );
 
-	if ( block_size_shift <= 0L )
-		block_size_shift = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT );
+	const uint64_t block_end = (image->realFilesize + ((uint64_t) block_size - 1ULL));
 
-	return block_size_shift;
+	return (iscsi_is_pow2( block_size ) ? (block_end >> (uint64_t) iscsi_get_log2_of_pow2( block_size )) : (block_end / (uint64_t) block_size));
 }
 
 /**
@@ -5104,7 +5129,7 @@ static inline uint32_t iscsi_scsi_emu_physical_block_get_size(const dnbd3_image_
 	if ( block_size <= 0L )
 		block_size = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE );
 
-	return block_size;
+	return (uint32_t) block_size;
 }
 
 /**
@@ -5120,34 +5145,14 @@ static inline uint32_t iscsi_scsi_emu_physical_block_get_size(const dnbd3_image_
  */
 static inline uint64_t iscsi_scsi_emu_block_get_count(const dnbd3_image_t *image)
 {
-	int32_t block_size_shift = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT );
-
-	if ( block_size_shift <= 0L )
-		block_size_shift = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT );
-
-	return (((image->realFilesize + ((1ULL << (uint64_t) block_size_shift) - 1ULL)) ) >> (uint32_t) block_size_shift);
-}
+	int32_t block_size = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE );
 
-/**
- * @brief Retrieves the bit shift of a logical block in bytes for a DNBD3 image.
- *
- * This function depends on DNBD3 image
- * properties.
- *
- * @param[in] image Pointer to DNBD3 image to retrieve
- * the logical block bit shift size.
- * May NOT be NULL, so be careful.
- * @return The logical block size in bytes as a
- * bit shift count.
- */
-static inline uint32_t iscsi_scsi_emu_block_get_size_shift(const dnbd3_image_t *image)
-{
-	int32_t block_size_shift = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT );
+	if ( block_size <= 0L )
+		block_size = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE );
 
-	if ( block_size_shift <= 0L )
-		block_size_shift = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT );
+	const uint64_t block_end = (image->realFilesize + ((uint64_t) block_size - 1ULL));
 
-	return block_size_shift;
+	return (iscsi_is_pow2( block_size ) ? (block_end >> (uint64_t) iscsi_get_log2_of_pow2( block_size )) : (block_end / (uint64_t) block_size));
 }
 
 /**
@@ -5168,26 +5173,7 @@ static inline uint32_t iscsi_scsi_emu_block_get_size(const dnbd3_image_t *image)
 	if ( block_size <= 0L )
 		block_size = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE );
 
-	return block_size;
-}
-
-/**
- * @brief Retrieves the bit shift ratio between logical and physical block size for a DNBD3 image.
- *
- * This function depends on DNBD3 image
- * properties.
- *
- * @param[in] image Pointer to DNBD3 image to retrieve
- * the ratio between the logical and
- * physical block size. May NOT be
- * NULL, so be careful.
- * @return The ratio between logical and physical
- * block size as a logical bit shift
- * count.
- */
-static inline uint32_t iscsi_scsi_emu_block_get_ratio_shift(const dnbd3_image_t *image)
-{
-	return (iscsi_scsi_emu_physical_block_get_size_shift( image ) - iscsi_scsi_emu_block_get_size_shift( image ));
+	return (uint32_t) block_size;
 }
 
 /**
@@ -5205,7 +5191,26 @@ static inline uint32_t iscsi_scsi_emu_block_get_ratio_shift(const dnbd3_image_t
  */
 static inline uint32_t iscsi_scsi_emu_block_get_ratio(const dnbd3_image_t *image)
 {
-	return (1UL << iscsi_scsi_emu_block_get_ratio_shift( image ));
+	int32_t physical_block_size = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE );
+
+	if ( physical_block_size <= 0L )
+		physical_block_size = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE );
+
+	int32_t logical_block_size = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE );
+
+	if ( logical_block_size <= 0L )
+		logical_block_size = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE );
+
+	if ( physical_block_size < logical_block_size )
+		return 0UL;
+
+	const bool logical_block_size_pow2 = iscsi_is_pow2( logical_block_size );
+	uint32_t logical_block_size_shift;
+
+	if ( logical_block_size_pow2 )
+		logical_block_size_shift = iscsi_get_log2_of_pow2( logical_block_size );
+
+	return ((logical_block_size_pow2 ? ((uint32_t) physical_block_size >> logical_block_size_shift) : ((uint32_t) physical_block_size / (uint32_t) logical_block_size)));
 }
 
 /**
@@ -5656,7 +5661,7 @@ static int iscsi_scsi_emu_block_read_write(dnbd3_image_t *image, iscsi_scsi_task
 	uint32_t block_size_shift;
 
 	if ( block_size_pow2 )
-		block_size_shift = iscsi_scsi_emu_block_get_size_shift( image );
+		block_size_shift = iscsi_get_log2_of_pow2( block_size );
 
 	const uint32_t max_xfer_len = (block_size_pow2 ? (ISCSI_SCSI_EMU_MAX_XFER_LEN >> block_size_shift) : (ISCSI_SCSI_EMU_MAX_XFER_LEN / block_size));
 
@@ -6084,7 +6089,8 @@ static int iscsi_scsi_emu_block_process(iscsi_scsi_task *scsi_task)
 
 					buf->flags = 0;
 
-					const uint8_t exponent = (uint8_t) iscsi_scsi_emu_block_get_ratio_shift( lun->image );
+					const uint32_t ratio   = iscsi_scsi_emu_block_get_ratio( lun->image );
+					const uint8_t exponent = (uint8_t) ((ratio != 0UL) ? iscsi_get_log2_of_pow2( ratio ) : 0UL);
 
 					buf->exponents = ISCSI_SCSI_SERVICE_ACTION_IN_16_PARAM_DATA_PUT_LBPPB_EXPONENT((exponent <= ISCSI_SCSI_SERVICE_ACTION_IN_16_PARAM_DATA_LBPPB_EXPONENT_MASK) ? exponent : 0U);
 
@@ -6635,22 +6641,28 @@ static int iscsi_scsi_emu_primary_inquiry(dnbd3_image_t *image, iscsi_scsi_task
 
 				vpd_page_block_limits_inquiry_data_pkt->flags = 0;
 
-				const uint32_t block_size_shift = iscsi_scsi_emu_block_get_size_shift( image );
-				uint32_t blocks                 = (ISCSI_SCSI_EMU_MAX_XFER_LEN >> block_size_shift);
+				const uint32_t block_size  = iscsi_scsi_emu_block_get_size( image );
+				const bool block_size_pow2 = iscsi_is_pow2( block_size );
+				uint32_t block_size_shift;
+
+				if ( block_size_pow2 )
+					block_size_shift = iscsi_get_log2_of_pow2( block_size );
+
+				uint32_t blocks = (block_size_pow2 ? (ISCSI_SCSI_EMU_MAX_XFER_LEN >> block_size_shift) : (ISCSI_SCSI_EMU_MAX_XFER_LEN / block_size));
 
 				if ( blocks > 255UL )
 					blocks = 255UL;
 
 				vpd_page_block_limits_inquiry_data_pkt->max_cmp_write_len = (uint8_t) blocks;
 
-				uint32_t optimal_blocks = (ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE >> block_size_shift);
+				uint32_t optimal_blocks = (block_size_pow2 ? (ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE >> block_size_shift) : (ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE / block_size));
 
 				if ( optimal_blocks == 0UL )
 					optimal_blocks = 1UL;
 
 				iscsi_put_be16( (uint8_t *) &vpd_page_block_limits_inquiry_data_pkt->optimal_granularity_xfer_len, (uint16_t) optimal_blocks );
 
-				blocks = (ISCSI_SCSI_EMU_MAX_UNMAP_LBA_COUNT >> block_size_shift);
+				blocks = (block_size_pow2 ? (ISCSI_SCSI_EMU_MAX_UNMAP_LBA_COUNT >> block_size_shift) : (ISCSI_SCSI_EMU_MAX_UNMAP_LBA_COUNT / block_size));
 
 				iscsi_put_be32( (uint8_t *) &vpd_page_block_limits_inquiry_data_pkt->max_xfer_len, blocks );
 				iscsi_put_be32( (uint8_t *) &vpd_page_block_limits_inquiry_data_pkt->optimal_xfer_len, blocks );
@@ -8489,7 +8501,7 @@ static iscsi_scsi_lun *iscsi_target_node_device_lun_find(iscsi_device *device, c
  * @param[in] name Pointer to IQN name of target node,
  * may NOT be NULL, so be careful.
  * @param[in] alias Pointer to alias of IQN name.
- * @param[in] index Target node index number.
+ * @param[in] pg_tag Portal group tag associated with this target node.
  * @param[in] lun_id LUN identifier to associate with underlying SCSI device.
  * @param[in] queue_depth Maximum queue depth.
  * @param[in] flags Flags for this target node.
@@ -8499,7 +8511,7 @@ static iscsi_scsi_lun *iscsi_target_node_device_lun_find(iscsi_device *device, c
  * @return Pointer to iSCSI target node on successful
  * operation or NULL in case of an error.
  */
-iscsi_target_node *iscsi_target_node_create(uint8_t *name, const uint8_t *alias, const int index, const int lun_id, const uint queue_depth, const int flags, const int32_t chap_group, const int header_digest, const int data_digest)
+iscsi_target_node *iscsi_target_node_create(uint8_t *name, const uint8_t *alias, const uint64_t pg_tag, const int lun_id, const uint queue_depth, const int flags, const int32_t chap_group, const int header_digest, const int data_digest)
 {
 	if ( (name == NULL) || (iscsi_target_node_check_name( name ) < 0) || (iscsi_target_node_check_flags( flags, chap_group ) < 0) )
 		return NULL;
@@ -8667,7 +8679,7 @@ iscsi_target_node *iscsi_target_node_create(uint8_t *name, const uint8_t *alias,
 		return NULL;
 	}
 
-	target->num           = index;
+	target->pg_tag        = pg_tag;
 	target->queue_depth   = queue_depth;
 	target->flags         = flags;
 	target->header_digest = header_digest;
@@ -8732,7 +8744,38 @@ void iscsi_target_node_destroy(iscsi_target_node *target)
 }
 
 /**
- * @brief Sends a buffer from a source iSCSI IQN to target iSCSI IQNs.
+ * @brief Checks if an initiator iSCSI IQN name is allowed to access a specified target node be shown in discovery.
+ *
+ * This function currently checks whether the
+ * portal group is private and if the IQN name
+ * itself for correctness since there is no
+ * access control support.
+ *
+ * @param[in] target Pointer to iSCSI target node which
+ * should be checked. May NOT be NULL, so be
+ * careful.
+ * @param[in] iqn Pointer to string containing the IQN
+ * name to be allowed. NULL is an prohibited
+ * value here, so take caution.
+ * @retval true The iSCSI IQN name is allowed for discovery.
+ * @retval false The iSCSI IQN name is ignored in discovery.
+ */
+static bool iscsi_target_node_iscsi_name_allowed(iscsi_target_node *target, const uint8_t *iqn)
+{
+	if ( (target == NULL) || (iqn == NULL) )
+		return false;
+
+	iscsi_portal_group *portal_group = NULL;
+	const int rc = iscsi_hashmap_get( iscsi_globvec->portal_groups, (uint8_t *) &target->pg_tag, sizeof(target->pg_tag), (uint8_t **) &portal_group );
+
+	if ( (portal_group == NULL) || (portal_group->flags & ISCSI_PORTAL_GROUP_FLAGS_PRIVATE) != 0 )
+		return false;
+
+	return (iscsi_target_node_check_name( iqn ) >= 0);
+}
+
+/**
+ * @brief Sends a target node discovery source iSCSI IQN to a buffer for target IQNs.
  *
  * This function sends a buffer starting from a
  * specified position to one, multiple or all
@@ -8740,22 +8783,277 @@ void iscsi_target_node_destroy(iscsi_target_node *target)
  * This function also checks the input and output
  * IQN for conforming to iSCSI specifications.
  *
- * @param[in] conn Pointer to iSCSI connection to write the buffer.
+ * @param[in] target_send Pointer to iSCSI target discovery send
+ * structure and may NOT be NULL, so be careful.
+ * @param[in] src Pointer to string containing the source IQN.
+ * NULL is not allowed here, take caution.
+ * @param[in] src_len Length of source buffer in bytes.
+ * @return The new position of the written data or a
+ * negative error code otherwise.
+ */
+static bool iscsi_target_node_send_copy(iscsi_target_node_send_name *target_send, const uint8_t *src, const uint32_t src_len)
+{
+	const uint32_t pos = target_send->pos;
+	const uint32_t len = target_send->len;
+
+	if ( pos >= len )
+		return true;
+
+	const uint32_t prev_target_send_total_size = target_send->prev_target_send_total_size;
+
+	if ( prev_target_send_total_size < src_len ) {
+		const uint32_t exp_len = (src_len - prev_target_send_total_size);
+		uint32_t buf_len       = (len - pos);
+
+		if ( buf_len > exp_len )
+			buf_len = exp_len;
+
+		memcpy( (target_send->buf + pos), (src + prev_target_send_total_size), buf_len );
+
+		target_send->pos                        += buf_len;
+		target_send->prev_target_send_total_size = 0UL;
+	} else {
+		target_send->prev_target_send_total_size -= src_len;
+	}
+
+	return false;
+}
+
+/**
+ * @brief Sends an iSCSI portal for iSCSI discovery to a buffer.
+ *
+ * Callback function for each element while iterating
+ * through the iSCSI portals to send for discovery.
+ *
+ * @param[in] key Pointer to zero padded key. NULL is
+ * an invalid pointer here, so be careful.
+ * @param[in] key_size Number of bytes for the key.
+ * @param[in] value Value of the key, NULL creates an
+ * empty key assignment.
+ * @param[in,out] user_data Pointer to a data structure
+ * containing the iSCSI connection, the destination
+ * target node IQN to be searched for, the source
+ * target node IQN, the pointer to output buffer, the
+ * position in bytes to put the next target address, the
+ * buffer length in bytes and the pointer to a
+ * boolean value indicating if the buffer is full
+ * and may NOT be NULL, so be careful.
+ * @retval -2 Memory exhausted during execution. Therefore,
+ * no further searching is needed.
+ * @retval -1 The portal has been sent. Therefore,
+ * no further searching is needed.
+ * @retval 0 The portal to be sent has not been found
+ * yet.
+ */
+int iscsi_target_node_portals_send_callback(uint8_t *key UNUSED, const size_t key_size UNUSED, uint8_t *value, uint8_t *user_data)
+{
+	iscsi_target_node_send_name *target_send = (iscsi_target_node_send_name *) user_data;
+	iscsi_portal *portal                     = (iscsi_portal *) value;
+	uint8_t *server_host                     = portal->host;
+
+	if ( (strcmp( (char *) server_host, "[::]" ) == 0) || (strcmp( (char *) server_host, "0.0.0.0" ) == 0) ) {
+		switch ( portal->type ) {
+			case ISCSI_PORTAL_TYPE_IPV4 :
+			case ISCSI_PORTAL_TYPE_IPV6 : {
+				server_host = target_send->conn->target_host;
+
+				break;
+			}
+			default : {
+				return 0;
+
+				break;
+			}
+		}
+	}
+
+	const uint32_t len = snprintf( NULL, 0, "%s=%s:%s,%" PRIu64, ISCSI_LOGIN_AUTH_SECURITY_TEXT_KEY_TARGET_ADDRESS, server_host, portal->port, portal->group->tag );
+	uint8_t *tmp_buf;
+
+	if ( len > target_send->tmp_len ) {
+		target_send->tmp_len = iscsi_align_pow2_ceil((len + len));
+
+		tmp_buf = realloc( target_send->tmp_buf, target_send->tmp_len );
+
+		if ( tmp_buf == NULL ) {
+			logadd( LOG_ERROR, "iscsi_target_node_portals_send_callback: Out of memory while allocating temporary buffer for iSCSI target node discovery" );
+
+			target_send->pos = -1L;
+
+			return -2;
+		}
+
+		target_send->tmp_buf = tmp_buf;
+	} else {
+		tmp_buf = target_send->tmp_buf;
+	}
+
+	memset( tmp_buf, 0, (len + 1UL) );
+
+	if ( target_send->prev_target_send_total_size < len )
+		snprintf( (char *) tmp_buf, (len + 1UL), "%s=%s:%s,%" PRIu64, ISCSI_LOGIN_AUTH_SECURITY_TEXT_KEY_TARGET_ADDRESS, server_host, portal->port, portal->group->tag );
+
+	target_send->buf_full = iscsi_target_node_send_copy( target_send, tmp_buf, (len + 1UL) );
+
+	if ( target_send->buf_full )
+		return -1;
+
+	return 0;
+}
+
+/**
+ * @brief Sends all iSCSI portals for iSCSI discovery to a buffer.
+ *
+ * This function retrieves the relevant portal group
+ * in order to iterate its portals.
+ *
+ * @param[in] target Pointer to iSCSI target node and may
+ * NOT be NULL, so be careful.
+ * @param[in] target_send Pointer to iSCSI target discovery send
+ * structure. NULL is NOT allowed here, so
+ * take caution.
+ * @return Current buffer position in bytes or a negative
+ * error code otherwise.
+ */
+static uint32_t iscsi_target_node_portals_send(iscsi_target_node *target, iscsi_target_node_send_name *target_send)
+{
+	iscsi_portal_group *portal_group = NULL;
+	const int rc = iscsi_hashmap_get( iscsi_globvec->portal_groups, (uint8_t *) &target->pg_tag, sizeof(target->pg_tag), (uint8_t **) &portal_group );
+
+	if ( (portal_group == NULL) || (portal_group->flags & ISCSI_PORTAL_GROUP_FLAGS_PRIVATE) != 0 )
+		return target_send->pos;
+
+	iscsi_hashmap_iterate( portal_group->portals, iscsi_target_node_portals_send_callback, (uint8_t *) target_send );
+
+	return target_send->pos;
+}
+
+/**
+ * @brief Sends an iSCSI discovery source target node IQN for a specific target IQN to a buffer.
+ *
+ * Callback function for each element while iterating
+ * through the iSCSI target nodes to send for
+ * discovery.
+ *
+ * @param[in] key Pointer to zero padded key. NULL is
+ * an invalid pointer here, so be careful.
+ * @param[in] key_size Number of bytes for the key.
+ * @param[in] value Value of the key, NULL creates an
+ * empty key assignment.
+ * @param[in,out] user_data Pointer to a data structure
+ * containing the iSCSI connection, the destination
+ * target node IQN to be searched for, the source
+ * target node IQN, the pointer to output buffer, the
+ * position in bytes to put the next target address, the
+ * buffer length in bytes and the pointer to a
+ * boolean value indicating if the buffer is full
+ * and may NOT be NULL, so be careful.
+ * @retval -2 Memory exhausted during execution. Therefore,
+ * no further searching is needed.
+ * @retval -1 The target node has been sent. Therefore,
+ * no further searching is needed.
+ * @retval 0 The target node to be sent has not been found
+ * yet.
+ */
+int iscsi_target_node_send_callback(uint8_t *key UNUSED, const size_t key_size UNUSED, uint8_t *value, uint8_t *user_data)
+{
+	iscsi_target_node_send_name *target_send = (iscsi_target_node_send_name *) user_data;
+	iscsi_target_node *target                = (iscsi_target_node *) value;
+
+	if ( (target_send->dst_iqn != NULL) && (strcasecmp( (char *) target_send->dst_iqn, (char *) target->name ) != 0) )
+		return 0;
+
+	const bool rc = iscsi_target_node_iscsi_name_allowed( target, target_send->src_iqn );
+
+	if ( !rc )
+		return 0;
+
+	const uint32_t len = snprintf( NULL, 0, "%s=%s", ISCSI_LOGIN_AUTH_SECURITY_TEXT_KEY_TARGET_NAME, target->name );
+	uint8_t *tmp_buf;
+
+	if ( len > target_send->tmp_len ) {
+		target_send->tmp_len = iscsi_align_pow2_ceil((len + len));
+
+		tmp_buf = realloc( target_send->tmp_buf, target_send->tmp_len );
+
+		if ( tmp_buf == NULL ) {
+			logadd( LOG_ERROR, "iscsi_target_node_send_callback: Out of memory while allocating temporary buffer for iSCSI target node discovery" );
+
+			target_send->pos = -1L;
+
+			return -2;
+		}
+
+		target_send->tmp_buf = tmp_buf;
+	} else {
+		tmp_buf = target_send->tmp_buf;
+	}
+
+	memset( tmp_buf, 0, (len + 1UL) );
+
+	if ( target_send->prev_target_send_total_size < len )
+		snprintf( (char *) tmp_buf, (len + 1UL), "%s=%s", ISCSI_LOGIN_AUTH_SECURITY_TEXT_KEY_TARGET_NAME, target->name );
+
+	target_send->buf_full = iscsi_target_node_send_copy( target_send, tmp_buf, (len + 1UL) );
+
+	if ( target_send->buf_full )
+		return -1;
+
+	target_send->pos = iscsi_target_node_portals_send( target, target_send );
+
+	if ( target_send->buf_full )
+		return -1;
+
+	return 0;
+}
+
+/**
+ * @brief Sends a target node discovery source iSCSI IQN to a buffer for target IQNs.
+ *
+ * This function sends a buffer starting from a
+ * specified position to one, multiple or all
+ * target IQNs.\n
+ * This function also checks the input and output
+ * IQN for conforming to iSCSI specifications.
+ *
+ * @param[in] conn Pointer to iSCSI connection to write the buffer,
+ * may NOT be NULL, so be careful.
  * @param[in] dst_iqn Pointer to string containing the target IQNs,
  * NULL is not allowed here, take caution.
  * @param[in] src_iqn Pointer to string containing the source IQN.
  * May NOT be NULL, so be careful.
- * @param[in] buf Pointer to output buffer.
+ * @param[out] buf Pointer to output buffer. NULL is forbidden
+ * here, so take caution.
  * @param[in] pos Position in buffer in bytes to start sending.
  * @param[in] len Length of buffer in bytes.
  * @return The new position of the written data or a
  * negative error code otherwise.
  */
-int32_t iscsi_target_node_send(iscsi_connection *conn, const uint8_t *dst_iqn, const uint8_t *src_iqn, uint8_t *buf, const uint32_t pos, const uint32_t len)
+int32_t iscsi_target_node_send(iscsi_connection *conn, uint8_t *dst_iqn, uint8_t *src_iqn, uint8_t *buf, const uint32_t pos, const uint32_t len)
 {
-	// TODO: Implement function.
+	if ( pos >= len ) {
+		buf[len - 1] = '\0';
 
-	return -1;
+		return (int32_t) len;
+	}
+
+	iscsi_target_node_send_name target_send = {conn, ((strcasecmp( (char *) dst_iqn, "ALL" ) != 0) ? dst_iqn : NULL), src_iqn, NULL, buf, pos, len, 0UL, conn->target_send_total_size, false};
+
+	pthread_rwlock_rdlock( &iscsi_globvec->target_nodes_rwlock );
+	pthread_rwlock_rdlock( &iscsi_globvec->portal_groups_rwlock );
+	iscsi_hashmap_iterate( iscsi_globvec->target_nodes, iscsi_target_node_send_callback, (uint8_t *) &target_send );
+	pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
+	pthread_rwlock_unlock( &iscsi_globvec->target_nodes_rwlock );
+
+	if ( target_send.tmp_buf != NULL )
+		free( target_send.tmp_buf );
+
+	if ( target_send.buf_full )
+		conn->target_send_total_size += target_send.pos;
+	else
+		conn->target_send_total_size = 0UL;
+
+	return (int32_t) target_send.pos;
 }
 
 /**
@@ -9050,7 +9348,12 @@ iscsi_target_node *iscsi_target_node_find(uint8_t *target_name)
 			if ( data_digest < 0L )
 				data_digest = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_DATA_DIGEST );
 
-			target = iscsi_target_node_create( target_name, NULL, 0, image->rid, 16U, 0, 0L, (int) header_digest, (int) data_digest );
+			int32_t pg_tag = iscsi_config_get( (uint8_t *) image->name, ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG );
+
+			if ( pg_tag <= 0L )
+				pg_tag = iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG );
+
+			target = iscsi_target_node_create( target_name, NULL, pg_tag, image->rid, 16U, 0, 0L, (int) header_digest, (int) data_digest );
 
 			if ( target == NULL ) {
 				logadd( LOG_ERROR, "iscsi_target_node_find: iSCSI target node not found" );
@@ -9072,11 +9375,11 @@ iscsi_target_node *iscsi_target_node_find(uint8_t *target_name)
 				return NULL;
 			}
 
-			int rc = iscsi_hashmap_put( iscsi_globvec->target_nodes, (uint8_t *) hash_key, key_len, (uint8_t *) target );
+			int rc = iscsi_hashmap_put( iscsi_globvec->target_nodes, hash_key, key_len, (uint8_t *) target );
 
 			if ( rc < 0 ) {
 				pthread_rwlock_unlock( &iscsi_globvec->target_nodes_rwlock );
-				iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
+				iscsi_hashmap_key_destroy( hash_key );
 				iscsi_target_node_destroy( target );
 
 				return NULL;
@@ -9492,29 +9795,19 @@ iscsi_connection *iscsi_connection_create(iscsi_portal *portal, const int sock)
 	}
 
 	conn->partial_pairs        = NULL;
-	conn->text_key_value_pairs = iscsi_hashmap_create( ((sizeof(iscsi_connection_key_value_pair_lut) / sizeof(struct iscsi_key_value_pair_lut_entry)) - 1) );
-
-	if ( conn->text_key_value_pairs == NULL ) {
-		logadd( LOG_ERROR, "iscsi_create_connection: Out of memory while allocating iSCSI text key / value pair hash map" );
-
-		iscsi_hashmap_iterate( conn->key_value_pairs, iscsi_hashmap_key_destroy_value_callback, NULL );
-		iscsi_hashmap_destroy( conn->key_value_pairs );
-		free( conn );
-
-		return NULL;
-	}
-
-	conn->text_partial_pairs = NULL;
-	conn->device             = NULL;
-	conn->init_port          = NULL;
-	conn->init_name          = NULL;
-	conn->init_adr           = NULL;
-	conn->target             = NULL;
-	conn->target_port        = NULL;
-	conn->target_name_short  = NULL;
-	conn->portal_host        = NULL;
-	conn->portal_port        = NULL;
-	conn->pdu_processing     = NULL;
+	conn->text_key_value_pairs = NULL;
+	conn->text_partial_pairs   = NULL;
+	conn->device               = NULL;
+	conn->init_port            = NULL;
+	conn->init_name            = NULL;
+	conn->init_adr             = NULL;
+	conn->target               = NULL;
+	conn->target_port          = NULL;
+	conn->target_name_short    = NULL;
+	conn->target_host          = NULL;
+	conn->portal_host          = NULL;
+	conn->portal_port          = NULL;
+	conn->pdu_processing       = NULL;
 
 	iscsi_list_create( &conn->scsi_data_in_queued_tasks );
 
@@ -9525,7 +9818,6 @@ iscsi_connection *iscsi_connection_create(iscsi_portal *portal, const int sock)
 	iscsi_list_create( &conn->r2t_tasks_active );
 	iscsi_list_create( &conn->r2t_tasks_queue );
 
-	conn->target_send_total_size   = 0U;
 	conn->scsi_data_in_cnt         = 0U;
 	conn->scsi_data_out_cnt        = 0U;
 	conn->task_cnt                 = 0U;
@@ -9538,6 +9830,7 @@ iscsi_connection *iscsi_connection_create(iscsi_portal *portal, const int sock)
 	conn->flags                    = 0;
 	conn->state                    = ISCSI_CONNECT_STATE_INVALID;
 	conn->login_phase              = ISCSI_LOGIN_RESPONSE_FLAGS_NEXT_STAGE_SECURITY_NEGOTIATION;
+	conn->target_send_total_size   = 0UL;
 	conn->max_recv_ds_len          = ISCSI_DEFAULT_RECV_DS_LEN;
 	conn->pg_tag                   = portal->group->tag;
 	conn->isid.a                   = 0;
@@ -9557,7 +9850,7 @@ iscsi_connection *iscsi_connection_create(iscsi_portal *portal, const int sock)
 
 	iscsi_list_create( &conn->exec_queue );
 
-	conn->stat_iscsi_opcodes = iscsi_hashmap_create( 256U );
+	conn->stat_iscsi_opcodes = iscsi_hashmap_create( 0U );
 
 	if ( conn->stat_iscsi_opcodes == NULL ) {
 		logadd( LOG_ERROR, "iscsi_create: Out of memory while initializing iSCSI global vector iSCSI opcode statistics" );
@@ -9570,7 +9863,7 @@ iscsi_connection *iscsi_connection_create(iscsi_portal *portal, const int sock)
 		return NULL;
 	}
 
-	conn->stat_scsi_opcodes = iscsi_hashmap_create( 256U );
+	conn->stat_scsi_opcodes = iscsi_hashmap_create( 0U );
 
 	if ( conn->stat_scsi_opcodes == NULL ) {
 		logadd( LOG_ERROR, "iscsi_create: Out of memory while initializing iSCSI global vector iSCSI SCSI opcode statistics" );
@@ -9723,6 +10016,12 @@ void iscsi_connection_destroy(iscsi_connection *conn)
 			conn->portal_host = NULL;
 		}
 
+		if ( conn->target_host != NULL ) {
+			free( conn->target_host );
+
+			conn->target_host = NULL;
+		}
+
 		if ( conn->target_name_short != NULL ) {
 			free( conn->target_name_short );
 
@@ -10246,7 +10545,7 @@ static uint8_t *iscsi_negotiate_key_value_pair_all(const iscsi_key_value_pair *k
 		}
 	}
 
-	return key_value_pair->value;
+	return old_value;
 }
 
 /**
@@ -10407,7 +10706,7 @@ int iscsi_negotiate_key_value_pair_callback(uint8_t *key, const size_t key_size,
  */
 int32_t iscsi_negotiate_key_value_pairs(iscsi_connection *conn, iscsi_hashmap *key_value_pairs, uint8_t *buf, const uint32_t pos, const uint32_t len)
 {
-	if ( pos > len ) {
+	if ( pos >= len ) {
 		buf[len - 1UL] = '\0';
 
 		return len;
@@ -11094,13 +11393,9 @@ static iscsi_session *iscsi_session_get_by_tsih(const uint16_t tsih)
 	const uint64_t hash_key = tsih;
 	iscsi_session *session;
 
-	pthread_rwlock_rdlock( &iscsi_globvec->sessions_rwlock );
-
-	int rc = iscsi_hashmap_get( iscsi_globvec->sessions, (uint8_t *) &hash_key, sizeof(hash_key), (uint8_t **) &session );
+	const int rc = iscsi_hashmap_get( iscsi_globvec->sessions, (uint8_t *) &hash_key, sizeof(hash_key), (uint8_t **) &session );
 
-	pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
-
-	return ((rc == 0) ? session : NULL);
+	return ((rc >= 0) ? session : NULL);
 }
 
 /**
@@ -11120,20 +11415,46 @@ static iscsi_session *iscsi_session_get_by_tsih(const uint16_t tsih)
  */
 static uint16_t iscsi_session_append(iscsi_connection *conn, const uint8_t *init_port_name, const uint16_t tsih)
 {
+	pthread_rwlock_rdlock( &iscsi_globvec->sessions_rwlock );
 	iscsi_session *session = iscsi_session_get_by_tsih( tsih );
 
-	if ( (session == NULL) || (conn->pg_tag != session->tag) || (strcasecmp( (char *) init_port_name, (char *) iscsi_port_get_name( session->init_port ) ) != 0) || (conn->target != session->target) )
+	if ( (session == NULL) || (conn->pg_tag != session->tag) || (strcasecmp( (char *) init_port_name, (char *) iscsi_port_get_name( session->init_port ) ) != 0) || (conn->target != session->target) ) {
+		pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
+
 		return (ISCSI_LOGIN_RESPONSE_STATUS_CLASS_CLIENT_ERR << 8U) | ISCSI_LOGIN_RESPONSE_STATUS_DETAILS_CLIENT_ERR_NO_SESSION_SPANNING;
+	}
+
+	if ( atomic_load_explicit( &session->conns, memory_order_acquire ) >= session->max_conns ) {
+		pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
 
-	if ( atomic_load_explicit( &session->conns, memory_order_acquire ) >= session->max_conns )
 		return (ISCSI_LOGIN_RESPONSE_STATUS_CLASS_CLIENT_ERR << 8U) | ISCSI_LOGIN_RESPONSE_STATUS_DETAILS_CLIENT_ERR_TOO_MANY_CONNECTIONS;
+	}
 
-	conn->session = session;
+	pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
+	pthread_rwlock_wrlock( &iscsi_globvec->sessions_rwlock );
+
+	session = iscsi_session_get_by_tsih( tsih );
+
+	if ( (session == NULL) || (conn->pg_tag != session->tag) || (strcasecmp( (char *) init_port_name, (char *) iscsi_port_get_name( session->init_port ) ) != 0) || (conn->target != session->target) ) {
+		pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
+
+		return (ISCSI_LOGIN_RESPONSE_STATUS_CLASS_CLIENT_ERR << 8U) | ISCSI_LOGIN_RESPONSE_STATUS_DETAILS_CLIENT_ERR_NO_SESSION_SPANNING;
+	}
+
+	if ( atomic_load_explicit( &session->conns, memory_order_acquire ) >= session->max_conns ) {
+		pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
+
+		return (ISCSI_LOGIN_RESPONSE_STATUS_CLASS_CLIENT_ERR << 8U) | ISCSI_LOGIN_RESPONSE_STATUS_DETAILS_CLIENT_ERR_TOO_MANY_CONNECTIONS;
+	}
 
 	iscsi_list_enqueue( &session->conn_list, &conn->node );
 
 	atomic_fetch_add_explicit( &session->conns, 1UL, memory_order_release );
 
+	pthread_rwlock_unlock( &iscsi_globvec->sessions_rwlock );
+
+	conn->session = session;
+
 	return (ISCSI_LOGIN_RESPONSE_STATUS_CLASS_SUCCESS << 8U) | ISCSI_LOGIN_RESPONSE_STATUS_DETAILS_SUCCESS;
 }
 
@@ -12226,7 +12547,7 @@ static int iscsi_connection_pdu_header_handle_text_req(iscsi_connection *conn, i
 
 	if ( conn->session->current_text_init_task_tag == 0xFFFFFFFFUL )
 		conn->session->current_text_init_task_tag = init_task_tag;
-	else
+	else if ( conn->session->current_text_init_task_tag != init_task_tag )
 		return iscsi_connection_handle_reject( conn, pdu, ISCSI_REJECT_REASON_PROTOCOL_ERR );
 
 	return ISCSI_CONNECT_PDU_READ_OK;
@@ -12317,7 +12638,6 @@ int iscsi_r2t_send(iscsi_connection *conn, iscsi_task *task, uint32_t *r2t_sn, c
 	iscsi_put_be32( (uint8_t *) &r2t_pkt->stat_sn, conn->stat_sn );
 	iscsi_put_be32( (uint8_t *) &r2t_pkt->exp_cmd_sn, atomic_load_explicit( &conn->session->exp_cmd_sn, memory_order_acquire ) );
 	iscsi_put_be32( (uint8_t *) &r2t_pkt->max_cmd_sn, atomic_load_explicit( &conn->session->max_cmd_sn, memory_order_acquire ) );
-	r2t_pkt->data_sn = 0UL;
 	iscsi_put_be32( (uint8_t *) &r2t_pkt->r2t_sn, (*r2t_sn)++ );
 
 	task->r2t_data_sn = 0UL;
@@ -13181,10 +13501,19 @@ static int iscsi_connection_login_session_normal(iscsi_connection *conn, iscsi_p
 		return rc;
 
 	iscsi_device *device = target->device;
+	uint64_t pg_tag      = (uint64_t) iscsi_config_get( device->name, ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG );
+
+	if ((int64_t) pg_tag <= 0L )
+		pg_tag = (uint64_t) iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG );
+
+	if ( conn->pg_tag != pg_tag ) {
+		conn->pg_tag   = pg_tag;
+		target->pg_tag = pg_tag;
+	}
 
 	conn->device      = device;
 	conn->target      = target;
-	conn->target_port = iscsi_device_find_port_by_portal_group_tag( device, conn->pg_tag );
+	conn->target_port = iscsi_device_find_port_by_portal_group_tag( device, pg_tag );
 
 	rc = iscsi_connection_login_check_session( conn, login_response_pdu, init_port_name, cid );
 
@@ -13452,7 +13781,7 @@ static int iscsi_connection_handle_login_phase_none(iscsi_connection *conn, iscs
 	if ( type == ISCSI_SESSION_TYPE_DISCOVERY ) {
 		conn->session->max_conns = 1UL;
 
-		rc = iscsi_add_int_key_value_pair( conn->session->key_value_pairs, (uint8_t *) ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_MAX_CONNECTIONS, conn->session->max_conns );
+		rc = iscsi_update_int_key_value_pair( conn->session->key_value_pairs, (uint8_t *) ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_MAX_CONNECTIONS, conn->session->max_conns );
 
 		if ( rc < 0 )
 			return ISCSI_CONNECT_PDU_READ_ERR_LOGIN_PARAMETER;
@@ -13790,10 +14119,13 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 		return ISCSI_CONNECT_PDU_READ_ERR_FATAL;
 	}
 
-	if ( (pdu->ds_len == 0UL) && (iscsi_hashmap_size( key_value_pairs ) == 0U) ) {
-		iscsi_hashmap *tmp_hashmap = key_value_pairs;
+	const bool text_ack = ((pdu->ds_len == 0UL) && (iscsi_hashmap_size( key_value_pairs ) == 0U) && (conn->text_key_value_pairs != NULL));
+
+	if ( text_ack ) {
+		iscsi_hashmap_destroy( key_value_pairs );
+
 		key_value_pairs            = conn->text_key_value_pairs;
-		conn->text_key_value_pairs = tmp_hashmap;
+		conn->text_key_value_pairs = NULL;
 	}
 
 	iscsi_pdu *response_pdu = iscsi_connection_pdu_create( conn, 0U, conn->header_digest, conn->max_recv_ds_len, conn->data_digest );
@@ -13830,7 +14162,7 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 	if ( (text_req_pkt->flags & ISCSI_TEXT_REQ_FLAGS_FINAL) != 0 )
 		text_response_pkt->flags |= (int8_t) ISCSI_TEXT_RESPONSE_FLAGS_FINAL;
 
-	text_req_pkt->reserved = 0U;
+	text_response_pkt->reserved = 0U;
 
 	uint8_t *send_targets_val;
 	rc = iscsi_get_key_value_pair( key_value_pairs, (uint8_t *) ISCSI_LOGIN_AUTH_SESSION_TEXT_KEY_SEND_TARGETS, &send_targets_val );
@@ -13857,7 +14189,7 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 			ds_len = iscsi_target_node_send( conn, send_targets_val, conn->init_name, (uint8_t *) response_pdu->ds_cmd_data, ds_len, response_pdu->len );
 		} else {
 			if ( send_targets_val[0] == '\0' )
-				send_targets_val = conn->target_port->name;
+				send_targets_val = conn->target->name;
 
 			if ( strcasecmp( (char *) send_targets_val, "ALL" ) == 0 ) {
 				iscsi_key_value_pair *key_value_pair;
@@ -13877,7 +14209,7 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 			}
 		}
 
-		if ( conn->target_send_total_size == 0U ) {
+		if ( conn->target_send_total_size != 0UL ) {
 			text_response_pkt->flags |= (int8_t) ISCSI_TEXT_RESPONSE_FLAGS_CONTINUE;
 			text_response_pkt->flags &= (int8_t) ~ISCSI_TEXT_RESPONSE_FLAGS_FINAL;
 		}
@@ -13891,7 +14223,10 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 		return ISCSI_CONNECT_PDU_READ_ERR_FATAL;
 	}
 
-	if ( conn->target_send_total_size == 0U ) {
+	if ( conn->target_send_total_size == 0UL ) {
+		if ( text_ack )
+			conn->text_key_value_pairs = NULL;
+
 		iscsi_hashmap_iterate( key_value_pairs, iscsi_hashmap_key_destroy_value_callback, NULL );
 		iscsi_hashmap_destroy( key_value_pairs );
 	} else {
@@ -13904,7 +14239,7 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 	text_response_pkt->lun           = text_req_pkt->lun; // Copying over doesn't change endianess.
 	text_response_pkt->init_task_tag = text_req_pkt->init_task_tag; // Copying over doesn't change endianess.
 
-	if ( (text_req_pkt->flags & ISCSI_TEXT_REQ_FLAGS_FINAL) != 0 ) {
+	if ( (text_response_pkt->flags & ISCSI_TEXT_RESPONSE_FLAGS_FINAL) != 0 ) {
 		text_response_pkt->target_xfer_tag = 0xFFFFFFFFUL; // Minus one does not require endianess conversion
 
 		conn->session->current_text_init_task_tag = 0xFFFFFFFFUL;
@@ -13914,13 +14249,13 @@ static int iscsi_connection_pdu_data_handle_text_req(iscsi_connection *conn, isc
 
 	iscsi_put_be32( (uint8_t *) &text_response_pkt->stat_sn, conn->stat_sn++ );
 
-	if ( (text_response_pkt->opcode & ISCSI_OPCODE_FLAGS_IMMEDIATE) == 0 )
+	if ( (text_req_pkt->opcode & ISCSI_OPCODE_FLAGS_IMMEDIATE) == 0 )
 		atomic_fetch_add_explicit( &conn->session->max_cmd_sn, 1UL, memory_order_release );
 
 	iscsi_put_be32( (uint8_t *) &text_response_pkt->exp_cmd_sn, atomic_load_explicit( &conn->session->exp_cmd_sn, memory_order_acquire ) );
 	iscsi_put_be32( (uint8_t *) &text_response_pkt->max_cmd_sn, atomic_load_explicit( &conn->session->max_cmd_sn, memory_order_acquire ) );
-	text_response_pkt->reserved2[0] = 0ULL;
-	text_response_pkt->reserved2[1] = 0ULL;
+	text_response_pkt->reserved2 = 0ULL;
+	text_response_pkt->reserved3 = 0UL;
 
 	iscsi_connection_pdu_write( conn, response_pdu, iscsi_connection_pdu_text_complete, (uint8_t *) conn );
 
@@ -14314,6 +14649,310 @@ int iscsi_connection_pdu_handle(iscsi_connection *conn)
 }
 
 /**
+ * @brief Adds iSCSI portals to a specified iSCSI portal group.
+ *
+ * Callback function for each element while iterating
+ * through the iSCSI portal groups.
+ *
+ * @param[in] key Pointer to zero padded key. NULL is
+ * an invalid pointer here, so be careful.
+ * @param[in] key_size Number of bytes for the key.
+ * @param[in] value Value of the key, NULL creates an
+ * empty key assignment.
+ * @param[in,out] user_data Pointer to a data structure
+ * containing the client socket, the iSCSI portal of
+ * this running instance, the host name, the port and
+ * a write locked flag which indicates changes to either
+ * the portal group or portals have been added and may
+ * NOT be NULL, so be careful.
+ * @retval -1 One of the iSCSI portals could NOT be
+ * added and therefore, an error occured and no further
+ * processing is needed.
+ * @retval 0 The iSCSI portal has been created and added
+ * successfully.
+ */
+int iscsi_connection_handle_add_portals_callback(uint8_t *key UNUSED, const size_t key_size UNUSED, uint8_t *value, uint8_t *user_data)
+{
+	struct sockaddr_storage server_addr;
+	char server_hostname[sizeof(struct sockaddr_un)];
+	iscsi_connection_handle_add_portals *add_portals = (iscsi_connection_handle_add_portals *) user_data;
+	iscsi_portal_group *portal_group                 = (iscsi_target_node *) value;
+	socklen_t server_addr_len                        = sizeof(server_addr);
+	const int sock                                   = add_portals->sock;
+
+	if ( getpeername( sock, (struct sockaddr *) &server_addr, &server_addr_len ) != 0 )
+		return -1;
+
+	void *server_host;
+	int server_port;
+	uint server_type;
+
+	switch ( server_addr.ss_family ) {
+		case AF_UNIX : {
+			server_host = &((struct sockaddr_un *) &server_addr)->sun_path;
+
+			break;
+		}
+		case AF_INET : {
+			server_host = &((struct sockaddr_in *) &server_addr)->sin_addr;
+
+			break;
+		}
+		case AF_INET6 : {
+			server_host = &((struct sockaddr_in6 *) &server_addr)->sin6_addr;
+
+			break;
+		}
+		default : {
+			return -1;
+
+			break;
+		}
+	}
+
+	inet_ntop( server_addr.ss_family, server_host, server_hostname, sizeof(server_hostname) );
+
+	if ( getsockname( sock, (struct sockaddr *) &server_addr, &server_addr_len ) != 0 )
+		return -1;
+
+	switch ( server_addr.ss_family ) {
+		case AF_UNIX : {
+			server_port = ntohs( ((struct sockaddr_un *) &server_addr)->sun_family );
+			server_type = ISCSI_PORTAL_TYPE_SOCK;
+
+			break;
+		}
+		case AF_INET : {
+			server_port = ntohs( ((struct sockaddr_in *) &server_addr)->sin_port );
+			server_type = ISCSI_PORTAL_TYPE_IPV4;
+
+			break;
+		}
+		case AF_INET6 : {
+			server_port = ntohs( ((struct sockaddr_in6 *) &server_addr)->sin6_port );
+			server_type = ISCSI_PORTAL_TYPE_IPV6;
+
+			break;
+		}
+		default : {
+			return -1;
+
+			break;
+		}
+	}
+
+	uint8_t *port = iscsi_sprintf_alloc( "%" PRIu16, server_port );
+
+	if ( port == NULL ) {
+		logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating iSCSI portal port number" );
+
+		return -1;
+	}
+
+	uint host_len = (uint) strlen( server_hostname );
+	uint8_t *host = malloc( (host_len + 1U) );
+
+	if ( host == NULL ) {
+		logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating iSCSI portal host name" );
+
+		free( port );
+
+		return -1;
+	}
+
+	memcpy( host, server_hostname, host_len );
+	host[host_len] = '\0';
+
+	uint8_t *tmp_buf = iscsi_sprintf_alloc( "%s:%s", host, port );
+
+	if ( tmp_buf == NULL ) {
+		logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating temporarily iSCSI portal name" );
+
+		free( host );
+		free( port );
+
+		return -1;
+	}
+
+	uint key_len      = (uint) (strlen( (char *) tmp_buf ) + 1U);
+	uint8_t *hash_key = iscsi_hashmap_key_create( tmp_buf, key_len );
+
+	free( tmp_buf );
+
+	if ( hash_key == NULL ) {
+		logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating temporarily iSCSI portal name hash key" );
+
+		free( host );
+		free( port );
+
+		return -1;
+	}
+
+	iscsi_portal *portal = NULL;
+	int rc               = iscsi_hashmap_get( portal_group->portals, hash_key, key_len, (uint8_t **) &portal );
+
+	if ( portal == NULL ) {
+		if ( !add_portals->write_locked ) {
+			add_portals->write_locked = true;
+
+			pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
+			pthread_rwlock_wrlock( &iscsi_globvec->portal_groups_rwlock );
+		}
+
+		rc = iscsi_hashmap_get( portal_group->portals, hash_key, key_len, (uint8_t **) &portal );
+
+		if ( portal == NULL ) {
+			portal = iscsi_portal_create( host, port, server_type );
+
+			if ( portal == NULL ) {
+				logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating iSCSI portal" );
+
+				iscsi_hashmap_key_destroy( hash_key );
+				free( host );
+				free( port );
+
+				return -1;
+			}
+
+			rc = iscsi_portal_group_add_portal( portal_group, portal );
+
+			if ( rc < 0 ) {
+				iscsi_portal_destroy( portal );
+				iscsi_hashmap_key_destroy( hash_key );
+				free( host );
+				free( port );
+
+				return -1;
+			}
+		}
+	}
+
+	iscsi_hashmap_key_destroy( hash_key );
+
+	if ( add_portals->portal == NULL )
+		add_portals->portal = portal;
+
+	if ( add_portals->host == NULL )
+		add_portals->host = host;
+
+	if ( add_portals->port == NULL )
+		add_portals->port = port;
+
+	for ( int i = 0; i < SERVER_MAX_ALTS; i++ ) {
+		altservers_toString( i, server_hostname, sizeof(server_hostname) );
+
+		if ( (server_hostname[0] == '\0') || (server_hostname[0] == '<') )
+			continue;
+
+		uint8_t *alt_server_port       = memchr( server_hostname, ':', sizeof(server_hostname) );
+		const uint alt_server_host_len = ((alt_server_port != NULL) ? (uint) (alt_server_port++ - (uint8_t *) server_hostname) : (uint) strlen( server_hostname ));
+		uint8_t *alt_server_host       = malloc( (alt_server_host_len + 1U) );
+		const uint alt_server_type     = ((server_hostname[0] == '[') ? ISCSI_PORTAL_TYPE_IPV6 : ISCSI_PORTAL_TYPE_IPV4);
+
+		if ( alt_server_host == NULL ) {
+			logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating iSCSI alternative portal host name" );
+
+			free( host );
+			free( port );
+
+			return -1;
+		}
+
+		memcpy( alt_server_host, server_hostname, alt_server_host_len );
+		alt_server_host[alt_server_host_len] = '\0';
+
+		uint8_t *tmp_buf;
+
+		if ( alt_server_port != NULL )
+			tmp_buf = iscsi_sprintf_alloc( "%s:%s", alt_server_host, alt_server_port );
+		else
+			tmp_buf = iscsi_sprintf_alloc( "%s:%u", alt_server_host, PORT );
+
+		if ( tmp_buf == NULL ) {
+			logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating temporarily iSCSI alternative portal name" );
+
+			free( alt_server_host );
+			free( host );
+			free( port );
+
+			return -1;
+		}
+
+		key_len  = (uint) (strlen( (char *) tmp_buf ) + 1U);
+		hash_key = iscsi_hashmap_key_create( tmp_buf, key_len );
+
+		free( tmp_buf );
+
+		if ( hash_key == NULL ) {
+			logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating temporarily iSCSI alternative portal name hash key" );
+
+			free( alt_server_host );
+			free( host );
+			free( port );
+
+			return -1;
+		}
+
+		if ( alt_server_port == NULL ) {
+			alt_server_port = (uint8_t *) strchr( (char *) hash_key, ':' );
+			alt_server_port++;
+		}
+
+		iscsi_portal *portal = NULL;
+		rc = iscsi_hashmap_get( portal_group->portals, hash_key, key_len, (uint8_t **) &portal );
+
+		if ( portal == NULL ) {
+			if ( !add_portals->write_locked ) {
+				add_portals->write_locked = true;
+
+				pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
+				pthread_rwlock_wrlock( &iscsi_globvec->portal_groups_rwlock );
+			}
+
+			rc = iscsi_hashmap_get( portal_group->portals, hash_key, key_len, (uint8_t **) &portal );
+
+			if ( portal == NULL ) {
+				portal = iscsi_portal_create( alt_server_host, alt_server_port, alt_server_type );
+
+				if ( portal == NULL ) {
+					logadd( LOG_ERROR, "iscsi_connection_handle_add_portals_callback: Out of memory while allocating iSCSI alternative portal" );
+
+					iscsi_hashmap_key_destroy( hash_key );
+					free( alt_server_host );
+					free( host );
+					free( port );
+
+					return -1;
+				}
+
+				rc = iscsi_portal_group_add_portal( portal_group, portal );
+
+				if ( rc < 0 ) {
+					iscsi_portal_destroy( portal );
+					iscsi_hashmap_key_destroy( hash_key );
+					free( alt_server_host );
+					free( host );
+					free( port );
+
+					return -1;
+				}
+			}
+		}
+
+		iscsi_hashmap_key_destroy( hash_key );
+		free( alt_server_host );
+	}
+
+	if ( add_portals->host != host )
+		free( host );
+
+	if ( add_portals->port != port )
+		free( port );
+
+	return 0;
+}
+
+/**
  * @brief Handles an iSCSI connection until connection is closed.
  *
  * This function creates an iSCSI portal group
@@ -14339,8 +14978,7 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ
 		return;
 	}
 
-	// sock_setTimeout( client->sock, 1000L * 3600L ); // TODO: Remove after finishing iSCSI implementation
-
+	const int sock    = client->sock;
 	uint recv_buf_len = (uint) iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_FIRST_BURST_LEN );
 
 	if ( recv_buf_len < 4096U )
@@ -14354,53 +14992,38 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ
 	uint send_buf_len = recv_buf_len;
 
 	recv_buf_len  = (uint) ISCSI_ALIGN(recv_buf_len, ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE);
-	setsockopt( client->sock, SOL_SOCKET, SO_RCVBUF, &recv_buf_len, sizeof(recv_buf_len)); // Not being able to set the buffer is NOT fatal, so ignore error.
+	setsockopt( sock, SOL_SOCKET, SO_RCVBUF, &recv_buf_len, sizeof(recv_buf_len)); // Not being able to set the buffer is NOT fatal, so ignore error.
 
 	send_buf_len += (uint) (ISCSI_DEFAULT_RECV_DS_LEN << 2UL);
 	send_buf_len  = (uint) ISCSI_ALIGN(send_buf_len, ISCSI_SCSI_EMU_PHYSICAL_BLOCK_SIZE);
-	setsockopt( client->sock, SOL_SOCKET, SO_SNDBUF, &send_buf_len, sizeof(send_buf_len)); // Not being able to set the buffer is NOT fatal, so ignore error.
+	setsockopt( sock, SOL_SOCKET, SO_SNDBUF, &send_buf_len, sizeof(send_buf_len)); // Not being able to set the buffer is NOT fatal, so ignore error.
+
+	// sock_setTimeout( sock, 1000L * 3600L ); // TODO: Remove after finishing iSCSI implementation
 
 	pthread_rwlock_rdlock( &iscsi_globvec->portal_groups_rwlock );
 
-	uint64_t *hash_key;
 	iscsi_portal_group *portal_group = NULL;
-	const uint64_t pg_tag            = 1ULL;
+	const uint64_t pg_tag            = (uint64_t) iscsi_config_get( NULL, ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG );
 	int rc                           = iscsi_hashmap_get( iscsi_globvec->portal_groups, (uint8_t *) &pg_tag, sizeof(pg_tag), (uint8_t **) &portal_group );
+	bool write_locked                = false;
 
 	if ( portal_group == NULL ) {
+		write_locked = true;
+
 		pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
 		pthread_rwlock_wrlock( &iscsi_globvec->portal_groups_rwlock );
 		rc = iscsi_hashmap_get( iscsi_globvec->portal_groups, (uint8_t *) &pg_tag, sizeof(pg_tag), (uint8_t **) &portal_group );
 
 		if ( portal_group == NULL ) {
-			hash_key = (uint64_t *) malloc( sizeof(uint64_t) );
-
-			if ( hash_key == NULL ) {
-				logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI portal group" );
-
-				pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-				pthread_rwlock_unlock( &iscsi_globvec_rwlock );
-
-				return;
-			}
-
-			iscsi_hashmap_key_create_id( iscsi_globvec->portal_groups, hash_key );
-			portal_group = iscsi_portal_group_create( *hash_key, 0 );
+			portal_group = iscsi_portal_group_create( pg_tag, ISCSI_PORTAL_GROUP_FLAGS_PRIVATE );
 
 			if ( portal_group == NULL ) {
-				logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI portal group" );
-
-				iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
 				pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
 				pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 
 				return;
 			}
 
-			portal_group->tag = *hash_key;
-
-			iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
-
 			rc = iscsi_hashmap_put( iscsi_globvec->portal_groups, (uint8_t *) &portal_group->tag, sizeof(portal_group->tag), (uint8_t *) portal_group );
 
 			if ( rc < 0 ) {
@@ -14413,141 +15036,78 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ
 		}
 	}
 
+	iscsi_connection_handle_add_portals add_portals = {sock, NULL, NULL, NULL, write_locked};
+	rc = iscsi_hashmap_iterate( iscsi_globvec->portal_groups, iscsi_connection_handle_add_portals_callback, (uint8_t *) &add_portals );
 	pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-	host_to_string( &client->host, client->hostName, HOSTNAMELEN );
-
-	const uint8_t *port = memchr( client->hostName, ':', HOSTNAMELEN );
-	const uint host_len = ((port != NULL) ? (uint) (port++ - (uint8_t *) client->hostName) : (uint) strlen( client->hostName ));
-	uint8_t *host       = malloc( (host_len + 1U) );
-
-	if ( host == NULL ) {
-		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI portal host name" );
-
-		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 
-		return;
-	}
-
-	memcpy( host, client->hostName, host_len );
-	host[host_len] = '\0';
-
-	uint8_t *tmp_buf;
-
-	if ( port != NULL )
-		tmp_buf = iscsi_sprintf_alloc( "%s:%s", host, port );
-	else
-		tmp_buf = iscsi_sprintf_alloc( "%s:%u", host, PORT );
-
-	if ( tmp_buf == NULL ) {
-		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating temporarily iSCSI portal name" );
-
-		free( host );
-		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
-
-		return;
-	}
-
-	const uint key_len = (uint) (strlen( (char *) tmp_buf ) + 1U);
-
-	hash_key = (uint64_t *) iscsi_hashmap_key_create( tmp_buf, key_len );
-
-	free( tmp_buf );
-
-	if ( hash_key == NULL ) {
-		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating temporarily iSCSI portal name hash key" );
-
-		free( host );
-		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
-
-		return;
-	}
-
-	if ( port == NULL ) {
-		port = (uint8_t *) strchr( (char *) hash_key, ':' );
-		port++;
-	}
-
-	iscsi_portal *portal = iscsi_portal_create( host, port );
-
-	if ( portal == NULL ) {
-		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI portal" );
-
-		iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
-		free( host );
+	if ( rc < 0 ) {
 		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 
 		return;
 	}
 
-	pthread_rwlock_wrlock( &iscsi_globvec->portal_groups_rwlock );
+	iscsi_connection *conn = iscsi_connection_create( add_portals.portal, sock );
 
-	rc = iscsi_portal_group_add_portal( portal_group, portal );
+	if ( conn == NULL ) {
+		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI connection" );
 
-	if ( rc < 0 ) {
-		pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-		iscsi_portal_destroy( portal );
-		iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
-		free( host );
+		free( add_portals.host );
+		free( add_portals.port );
 		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 
 		return;
 	}
 
-	iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
-	free( host );
+	conn->target_host = (uint8_t *) strdup( (char *) add_portals.host );
 
-	iscsi_connection *conn = iscsi_connection_create( portal, client->sock );
+	if ( conn->target_host == NULL ) {
+		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI connection target host name" );
 
-	if ( conn == NULL ) {
-		logadd( LOG_ERROR, "iscsi_connection_handle: Out of memory while allocating iSCSI connection" );
-
-		iscsi_portal_group_del_portal( portal_group, portal );
-		pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-		iscsi_portal_destroy( portal );
+		iscsi_connection_destroy( conn );
+		free( add_portals.host );
+		free( add_portals.port );
 		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 
 		return;
 	}
 
+	conn->portal_host    = add_portals.host;
+	conn->portal_port    = add_portals.port;
 	conn->pdu_processing = iscsi_connection_pdu_create( conn, 0U, 0, 0UL, 0 );
 
 	if ( conn->pdu_processing == NULL ) {
 		iscsi_connection_destroy( conn );
-		iscsi_portal_group_del_portal( portal_group, portal );
-		pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-		iscsi_portal_destroy( portal );
 		pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 
 		return;
 	}
 
-	pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-
 	memcpy( conn->pdu_processing->bhs_pkt, request, len );
 
 	conn->pdu_processing->bhs_pos = len;
+	conn->id                      = atomic_fetch_add_explicit( &iscsi_globvec->connections, 1, memory_order_acq_rel );
 	conn->pdu_recv_state          = ISCSI_CONNECT_PDU_RECV_STATE_WAIT_PDU_HDR;
 
 	logadd( LOG_INFO, "" );
-	logadd( LOG_INFO, "iSCSI connection opened for device %s from initiator %s using port %s and portal %s:%s", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) portal->host, (char *) portal->port );
+	logadd( LOG_INFO, "iSCSI connection opened for device %s from initiator %s using port %s and portal %s:%s", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) add_portals.portal->host, (char *) add_portals.portal->port );
 
 	while ( iscsi_connection_pdu_handle( conn ) >= ISCSI_CONNECT_PDU_READ_OK ) {
 	}
 
 	iscsi_hashmap_bucket *stat_bucket;
 
-	logadd( LOG_INFO, "iSCSI connection closed for device %s from initiator %s using port %s and portal %s:%s", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) portal->host, (char *) portal->port );
+	logadd( LOG_INFO, "iSCSI connection closed for device %s from initiator %s using port %s and portal %s:%s", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) add_portals.portal->host, (char *) add_portals.portal->port );
 
 	iscsi_list_foreach_node ( &conn->stat_iscsi_opcodes->list, stat_bucket ) {
 		uint64_t *stat_opcode = (uint64_t *) stat_bucket->value;
 
-		logadd( LOG_INFO, "iSCSI opcode usage statistics for device %s from initiator %s using port %s and portal %s:%s: Opcode 0x%02" PRIX64 " has been received %" PRIu64 " times until connection drop.", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) portal->host, (char *) portal->port, *(uint64_t *) stat_bucket->key, *stat_opcode );
+		logadd( LOG_INFO, "iSCSI opcode usage statistics for device %s from initiator %s using port %s and portal %s:%s: Opcode 0x%02" PRIX64 " has been received %" PRIu64 " times until connection drop.", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) add_portals.portal->host, (char *) add_portals.portal->port, *(uint64_t *) stat_bucket->key, *stat_opcode );
 	}
 
 	iscsi_list_foreach_node ( &conn->stat_scsi_opcodes->list, stat_bucket ) {
 		uint64_t *stat_opcode = (uint64_t *) stat_bucket->value;
 
-		logadd( LOG_INFO, "iSCSI SCSI CDB opcode usage statistics for device %s from initiator %s using port %s and portal %s:%s: SCSI CDB opcode 0x%02" PRIX64 " has been received %" PRIu64 " times until connection drop.", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) portal->host, (char *) portal->port, *(uint64_t *) stat_bucket->key, *stat_opcode );
+		logadd( LOG_INFO, "iSCSI SCSI CDB opcode usage statistics for device %s from initiator %s using port %s and portal %s:%s: SCSI CDB opcode 0x%02" PRIX64 " has been received %" PRIu64 " times until connection drop.", (conn->device != NULL ? (char *) conn->device->name : "(null)"), (char *) conn->init_name, ((conn->init_port != NULL) ? (char *) conn->init_port->name : "(null)"), (char *) add_portals.portal->host, (char *) add_portals.portal->port, *(uint64_t *) stat_bucket->key, *stat_opcode );
 	}
 
 	iscsi_session *session = conn->session;
@@ -14579,13 +15139,13 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ
 				conn->device = NULL;
 
 				const uint key_len = (uint) (strlen( (char *) device->name ) + 1U);
-				hash_key           = (uint64_t *) iscsi_hashmap_key_create( device->name, key_len );
+				uint8_t *hash_key  = iscsi_hashmap_key_create( device->name, key_len );
 
 				if ( hash_key != NULL ) {
 					target->device = NULL;
 
-					iscsi_hashmap_remove_free( iscsi_globvec->devices, (uint8_t *) hash_key, key_len, iscsi_device_destroy_callback, NULL );
-					iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
+					iscsi_hashmap_remove_free( iscsi_globvec->devices, hash_key, key_len, iscsi_device_destroy_callback, NULL );
+					iscsi_hashmap_key_destroy( hash_key );
 				}
 			}
 
@@ -14601,11 +15161,11 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ
 				conn->target = NULL;
 
 				const uint key_len = (uint) (strlen( (char *) target->name ) + 1U);
-				hash_key           = (uint64_t *) iscsi_hashmap_key_create( target->name, key_len );
+				uint8_t *hash_key  = iscsi_hashmap_key_create( target->name, key_len );
 
 				if ( hash_key != NULL ) {
-					iscsi_hashmap_remove_free( iscsi_globvec->target_nodes, (uint8_t *) hash_key, key_len, iscsi_target_node_destroy_callback, NULL );
-					iscsi_hashmap_key_destroy( (uint8_t *) hash_key );
+					iscsi_hashmap_remove_free( iscsi_globvec->target_nodes, hash_key, key_len, iscsi_target_node_destroy_callback, NULL );
+					iscsi_hashmap_key_destroy( hash_key );
 				}
 			}
 
@@ -14615,10 +15175,5 @@ void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *requ
 
 	iscsi_connection_destroy( conn );
 
-	pthread_rwlock_wrlock( &iscsi_globvec->portal_groups_rwlock );
-	iscsi_portal_group_del_portal( portal_group, portal );
-	iscsi_portal_destroy( portal );
-	pthread_rwlock_unlock( &iscsi_globvec->portal_groups_rwlock );
-
 	pthread_rwlock_unlock( &iscsi_globvec_rwlock );
 }
diff --git a/src/server/iscsi.h b/src/server/iscsi.h
index 29121c6..4d825f4 100644
--- a/src/server/iscsi.h
+++ b/src/server/iscsi.h
@@ -776,7 +776,6 @@ void iscsi_hashmap_destroy(iscsi_hashmap *map); // Deallocates the hash map obje
                                                 // Use iscsi_hashmap_iterate to deallocate the elements themselves
 
 uint8_t *iscsi_hashmap_key_create(const uint8_t *data, const size_t len); // Creates a key suitable for hashmap usage (ensures 8-byte boundary and zero padding)
-void iscsi_hashmap_key_create_id(iscsi_hashmap *map, uint64_t *key); // Creates an unique key identifier suitable for hashmap usage (ensures 8-byte boundary and zero padding)
 void iscsi_hashmap_key_destroy(uint8_t *key); // Deallocates all resources acquired by iscsi_hashmap_create_key
 int iscsi_hashmap_key_destroy_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // Deallocates a key in a hash map
 int iscsi_hashmap_destroy_value_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // Deallocates a value in a hash map
@@ -6026,9 +6025,6 @@ typedef struct __attribute__((packed)) iscsi_r2t_packet {
     /// MaxCmdSN.
     uint32_t max_cmd_sn;
 
-    /// DataSN.
-    uint32_t data_sn;
-
     /// Ready To Transfer Sequence Number (R2TSN) is the R2T PDU input PDU number within the command identified by the Initiator Task Tag. For bidirectional commands, R2T and Data-In PDUs share the input PDU numbering sequence.
     uint32_t r2t_sn;
 
@@ -6488,7 +6484,10 @@ typedef struct __attribute__((packed)) iscsi_text_response_packet {
     uint32_t max_cmd_sn;
 
     /// Reserved for future usage, always MUST be 0.
-    uint64_t reserved2[2];
+    uint64_t reserved2;
+
+    /// Reserved for future usage, always MUST be 0.
+    uint32_t reserved3;
 
     /// Optional header digest.
     iscsi_header_digest hdr_digest;
@@ -9340,7 +9339,7 @@ typedef struct __attribute__((packed)) iscsi_snack_req_packet {
     uint32_t exp_stat_sn;
 
     /// Reserved for future usage, always MUST be 0.
-    uint32_t reserved3;
+    uint64_t reserved3;
 
     /**
      * @brief BegRun.
@@ -9938,6 +9937,9 @@ int iscsi_parse_key_value_pairs(iscsi_hashmap *key_value_pairs, const uint8_t *p
 #define ISCSI_GLOBALS_SECTION_SCSI               "scsi"
 
 
+/// iSCSI main global data: iSCSI INI configuration iSCSI section portal group tag key identifier string.
+#define ISCSI_GLOBALS_SECTION_ISCSI_KEY_PORTAL_GROUP_TAG         "PortalGroupTag"
+
 /// iSCSI main global data: iSCSI INI configuration iSCSI section target name check key identifier string.
 #define ISCSI_GLOBALS_SECTION_ISCSI_KEY_TARGET_NAME_CHECK        "TargetNameCheck"
 
@@ -9976,96 +9978,101 @@ int iscsi_parse_key_value_pairs(iscsi_hashmap *key_value_pairs, const uint8_t *p
 #define ISCSI_GLOBALS_SECTION_SCSI_KEY_WRITE_CACHE         "WriteCache"
 
 
+/// iSCSI main global data: iSCSI portal group specific INI configuration section prefix identifier string.
+#define ISCSI_GLOBALS_SECTION_ISCSI_PORTAL_GROUP_PREFIX "iscsi-portal-group-"
+
+
+/// iSCSI main global data: iSCSI INI configuration iSCSI section portal group tag key identifier string.
+#define ISCSI_GLOBALS_SECTION_ISCSI_PORTAL_GROUP_KEY_ACCESS "Access"
+
+
 /// iSCSI main global data: iSCSI SCSI device specific INI configuration section prefix identifier string.
 #define ISCSI_GLOBALS_SECTION_SCSI_DEVICE_PREFIX "scsi-device-"
 
 
+/// iSCSI main global data config type: Portal group tag.
+#define ISCSI_GLOBALS_CONFIG_TYPE_PORTAL_GROUP_TAG                  0
+
 /// iSCSI main global data config type: Header digest (CRC32), always MUST be 0 or 4 for now.
-#define ISCSI_GLOBALS_CONFIG_TYPE_HEADER_DIGEST                     0
+#define ISCSI_GLOBALS_CONFIG_TYPE_HEADER_DIGEST                     1
 
 /// iSCSI main global data config type: Data digest (CRC32), always MUST be 0 or 4 for now.
-#define ISCSI_GLOBALS_CONFIG_TYPE_DATA_DIGEST                       1
+#define ISCSI_GLOBALS_CONFIG_TYPE_DATA_DIGEST                       2
 
 /// iSCSI main global data config type: Maximum receive DataSegment length in bytes.
-#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_RECV_DS_LEN                   2
+#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_RECV_DS_LEN                   3
 
 /// iSCSI main global data config type: Maximum number of connections per session.
-#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_SESSION_CONNS                 3
+#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_SESSION_CONNS                 4
 
 /// iSCSI main global data config type: Ready to transfer maximum outstanding value.
-#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_OUTSTANDING_R2T               4
+#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_OUTSTANDING_R2T               5
 
 /// iSCSI main global data config type: Default time to wait.
-#define ISCSI_GLOBALS_CONFIG_TYPE_DEFAULT_TIME_TO_WAIT              5
+#define ISCSI_GLOBALS_CONFIG_TYPE_DEFAULT_TIME_TO_WAIT              6
 
 /// iSCSI main global data config type: Default time to retain.
-#define ISCSI_GLOBALS_CONFIG_TYPE_DEFAULT_TIME_TO_RETAIN            6
+#define ISCSI_GLOBALS_CONFIG_TYPE_DEFAULT_TIME_TO_RETAIN            7
 
 /// iSCSI main global data config type: First burst length.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FIRST_BURST_LEN                   7
+#define ISCSI_GLOBALS_CONFIG_TYPE_FIRST_BURST_LEN                   8
 
 /// iSCSI main global data config type: Maximum burst length.
-#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_BURST_LEN                     8
+#define ISCSI_GLOBALS_CONFIG_TYPE_MAX_BURST_LEN                     9
 
 /// iSCSI main global data config type: Error recovery level.
-#define ISCSI_GLOBALS_CONFIG_TYPE_ERR_RECOVERY_LEVEL                9
+#define ISCSI_GLOBALS_CONFIG_TYPE_ERR_RECOVERY_LEVEL               10
 
 /// iSCSI main global data config type: CHAP authentication group.
-#define ISCSI_GLOBALS_CONFIG_TYPE_CHAP_GROUP                       10
+#define ISCSI_GLOBALS_CONFIG_TYPE_CHAP_GROUP                       11
 
 /// iSCSI main global data config type: SCSI emulation for device type.
-#define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_DEVICE_TYPE                 11
+#define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_DEVICE_TYPE                 12
 
 /// iSCSI main global data config type: SCSI emulation for physical block size.
-#define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE         12
-
-/// iSCSI main global data config type: SCSI emulation for physical block size shift count.
-#define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE_SHIFT   13
+#define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_PHYSICAL_BLOCK_SIZE         13
 
 /// iSCSI main global data config type: SCSI emulation for logical block size.
 #define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE          14
 
-/// iSCSI main global data config type: SCSI emulation for logical block size shift count.
-#define ISCSI_GLOBALS_CONFIG_TYPE_SCSI_LOGICAL_BLOCK_SIZE_SHIFT    15
-
 /// iSCSI main global data config type: CHAP authentication is disabled.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_DISABLE               16
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_DISABLE               15
 
 /// iSCSI main global data config type: CHAP authentication is required.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_REQUIRE               17
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_REQUIRE               16
 
 /// iSCSI main global data config type: CHAP authentication is mutual.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_MUTUAL                18
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_CHAP_MUTUAL                17
 
 /// iSCSI main global data config type: Initial ready to transfer.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_INIT_R2T                   19
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_INIT_R2T                   18
 
 /// iSCSI main global data config type: Immediate data.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_IMMEDIATE_DATA             20
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_IMMEDIATE_DATA             19
 
 /// iSCSI main global data config type: Data PDU in order.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_DATA_PDU_IN_ORDER          21
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_DATA_PDU_IN_ORDER          20
 
 /// iSCSI main global data config type: Data sequence in order.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_DATA_SEQ_IN_ORDER          22
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_DATA_SEQ_IN_ORDER          21
 
 /// iSCSI main global data config type: SCSI emulation for I/O removable device.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_REMOVABLE          23
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_REMOVABLE          22
 
 /// iSCSI main global data config type: SCSI emulation for I/O UNMAP supporting device.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_UNMAP              24
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_UNMAP              23
 
 /// iSCSI main global data config type: SCSI emulation for I/O non-rotating device.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_NO_ROTATION        25
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_NO_ROTATION        24
 
 /// iSCSI main global data config type: SCSI emulation for I/O physical read only device.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_PHYSICAL_READ_ONLY 26
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_PHYSICAL_READ_ONLY 25
 
 /// iSCSI main global data config type: SCSI emulation for I/O write protected device.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_WRITE_PROTECT      27
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_WRITE_PROTECT      26
 
 /// iSCSI main global data config type: SCSI emulation for I/O write cache device.
-#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_WRITE_CACHE        28
+#define ISCSI_GLOBALS_CONFIG_TYPE_FLAGS_SCSI_IO_WRITE_CACHE        27
 
 
 /// iSCSI main global data config type: Value error result.
@@ -10123,6 +10130,9 @@ typedef struct iscsi_scsi_device_config {
     /// SCSI emulation: Device type.
     uint scsi_device_type;
 
+    /// Default portal group tag;
+    uint32_t pg_tag;
+
     /// Maximum receive DataSegment length in bytes.
     uint32_t max_recv_ds_len;
 
@@ -10150,14 +10160,8 @@ typedef struct iscsi_scsi_device_config {
     /// SCSI emulation: Physical block size.
     uint32_t scsi_physical_block_size;
 
-    /// SCSI emulation: Physical block size shift count.
-    uint32_t scsi_physical_block_size_shift;
-
     /// SCSI emulation: Logical block size.
     uint32_t scsi_logical_block_size;
-
-    /// SCSI emulation: Logical block size shift count.
-    uint32_t scsi_logical_block_size_shift;
 } iscsi_scsi_device_config;
 
 
@@ -10315,6 +10319,12 @@ typedef struct iscsi_globals {
     /// SCSI emulation: Device type.
     uint scsi_device_type;
 
+    /// Total number of connections so far.
+    _Atomic int connections;
+
+    /// Default portal group tag;
+    uint32_t pg_tag;
+
     /// Maximum receive DataSegment length in bytes.
     uint32_t max_recv_ds_len;
 
@@ -10345,14 +10355,8 @@ typedef struct iscsi_globals {
     /// SCSI emulation: Physical block size.
     uint32_t scsi_physical_block_size;
 
-    /// SCSI emulation: Physical block size shift count.
-    uint32_t scsi_physical_block_size_shift;
-
     /// SCSI emulation: Logical block size.
     uint32_t scsi_logical_block_size;
-
-    /// SCSI emulation: Logical block size shift count.
-    uint32_t scsi_logical_block_size_shift;
 } iscsi_globals;
 
 
@@ -10372,7 +10376,7 @@ int32_t iscsi_config_get(uint8_t *name, const int type); // Retrieves a configur
 
 
 /**
- * @brief iSCSI portal group: Private portal group if set, public otherwise.
+ * @brief iSCSI portal group flags: Private portal group if set, public otherwise.
  *
  * When redirecting logins, there are two portal group types: public and
  * private.\n
@@ -10382,16 +10386,16 @@ int32_t iscsi_config_get(uint8_t *name, const int type); // Retrieves a configur
  * Private portal groups instead do not return their portals during
  * the discovery session.
  */
-#define ISCSI_PORTAL_GROUP_PRIVATE      (1 << 0)
+#define ISCSI_PORTAL_GROUP_FLAGS_PRIVATE      (1 << 0)
 
-/// iSCSI portal group: CHAP authentication is disabled.
-#define ISCSI_PORTAL_GROUP_CHAP_DISABLE (1 << 1)
+/// iSCSI portal group flags: CHAP authentication is disabled.
+#define ISCSI_PORTAL_GROUP_FLAGS_CHAP_DISABLE (1 << 1)
 
-/// iSCSI portal group: CHAP authentication is required.
-#define ISCSI_PORTAL_GROUP_CHAP_REQUIRE (1 << 2)
+/// iSCSI portal group flags: CHAP authentication is required.
+#define ISCSI_PORTAL_GROUP_FLAGS_CHAP_REQUIRE (1 << 2)
 
-/// iSCSI portal group: CHAP authentication is mutual.
-#define ISCSI_PORTAL_GROUP_CHAP_MUTUAL  (1 << 3)
+/// iSCSI portal group flags: CHAP authentication is mutual.
+#define ISCSI_PORTAL_GROUP_FLAGS_CHAP_MUTUAL  (1 << 3)
 
 
 /**
@@ -10418,6 +10422,19 @@ typedef struct iscsi_portal_group {
 } iscsi_portal_group;
 
 
+/// iSCSI portal type: None.
+#define ISCSI_PORTAL_TYPE_NONE 0U
+
+/// iSCSI portal type: Local (unix) socket.
+#define ISCSI_PORTAL_TYPE_SOCK 1U
+
+/// iSCSI portal type: IPv4 socket.
+#define ISCSI_PORTAL_TYPE_IPV4 2U
+
+/// iSCSI portal type: IPv6 socket.
+#define ISCSI_PORTAL_TYPE_IPV6 3U
+
+
 /**
  * @brief iSCSI portal.
  *
@@ -10434,7 +10451,10 @@ typedef struct iscsi_portal {
     /// Port of the portal.
     uint8_t *port;
 
-    /// TCP/IP socket for the portal.
+    /// Socket type.
+    uint type;
+
+    /// Socket file descriptor for the portal.
     int sock;
 } iscsi_portal;
 
@@ -10445,7 +10465,7 @@ void iscsi_portal_group_destroy(iscsi_portal_group *portal_group); // Deallocate
 int iscsi_portal_group_add_portal(iscsi_portal_group *portal_group, iscsi_portal *portal); // Adds an iSCSI portal to the iSCSI portal group hash map
 void iscsi_portal_group_del_portal(iscsi_portal_group *portal_group, iscsi_portal *portal); // Removes an iSCSI portal from the iSCSI portal group hash map
 
-iscsi_portal *iscsi_portal_create(const uint8_t *host, const uint8_t *port); // Allocates and initializes an iSCSI portal structure
+iscsi_portal *iscsi_portal_create(const uint8_t *host, const uint8_t *port, const uint type); // Allocates and initializes an iSCSI portal structure
 int iscsi_portal_destroy_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // iSCSI portal destructor callback for hash map
 void iscsi_portal_destroy(iscsi_portal *portal);
 
@@ -11171,8 +11191,8 @@ typedef struct iscsi_target_node {
     /// Associated iSCSI device.
     iscsi_device *device;
 
-    /// Target node number.
-    uint num;
+    /// Portal group tag associated with this target node.
+    uint64_t pg_tag;
 
     /// Queue depth.
     uint queue_depth;
@@ -11195,6 +11215,45 @@ typedef struct iscsi_target_node {
 
 
 /**
+ * @brief iSCSI target node send by name.
+ *
+ * This structure is used by iterating through
+ * all iSCSI target nodes sending by name.
+ */
+typedef struct iscsi_target_node_send_name {
+    /// iSCSI connection sending the target nodes.
+    iscsi_connection *conn;
+
+    /// The IQN of the target node to send. NULL matches all target nodes.
+    uint8_t *dst_iqn;
+
+    /// The initiator IQN to send.
+    uint8_t *src_iqn;
+
+    /// Copy buffer for key and value pairs.
+    uint8_t *tmp_buf;
+
+    /// Buffer where to store the key and value pairs of target nodes to send.
+    uint8_t *buf;
+
+    /// Position of buffer in bytes where to start filling key and value pairs of target nodes to send.
+    uint32_t pos;
+
+    /// Length of buffer in bytes where to start filling key and value pairs of target nodes to send.
+    uint32_t len;
+
+    /// Length of copy buffer in bytes for key and value pairs.
+    uint32_t tmp_len;
+
+    /// Previous iSCSI SendTargets total number of bytes completed.
+    uint32_t prev_target_send_total_size;
+
+    /// True if the submitted buffer would overflow.
+    bool buf_full;
+} iscsi_target_node_send_name;
+
+
+/**
  * @brief iSCSI target node search by name.
  *
  * This structure is used by iterating through
@@ -11458,6 +11517,9 @@ typedef struct iscsi_connection {
     /// iSCSI target short name.
     uint8_t *target_name_short;
 
+    /// iSCSI target host name.
+    uint8_t *target_host;
+
     /// iSCSI portal host name.
     uint8_t *portal_host;
 
@@ -11485,9 +11547,6 @@ typedef struct iscsi_connection {
     /// Doubly linked list containing queued Ready To Transfer (R2T) tasks.
     iscsi_list r2t_tasks_queue;
 
-    /// iSCSI SendTargets total number of bytes completed.
-    uint target_send_total_size;
-
     /// iSCSI SCSI Data In count.
     uint scsi_data_in_cnt;
 
@@ -11506,7 +11565,7 @@ typedef struct iscsi_connection {
     /// iSCSI connection contains a data digest (CRC32), always MUST be 0 or 4 for now.
     int data_digest;
 
-    /// Internal connection identifier (key of iSCSI global vector hash map).
+    /// Internal unique connection identifier.
     int id;
 
     /// Connected TCP/IP socket.
@@ -11524,6 +11583,9 @@ typedef struct iscsi_connection {
     /// iSCSI connection login phase.
     int login_phase;
 
+    /// iSCSI SendTargets total number of bytes completed.
+    uint32_t target_send_total_size;
+
     /// Maximum receive DataSegment length in bytes.
     uint32_t max_recv_ds_len;
 
@@ -11845,6 +11907,31 @@ typedef struct iscsi_task {
 } iscsi_task;
 
 
+/**
+ * @brief iSCSI portal group iterator for adding portals.
+ *
+ * This structure is used by iterating through
+ * all iSCSI portal groups and adding all
+ * portals to each portal group.
+ */
+typedef struct iscsi_connection_handle_add_portals {
+    /// DNBD3 client socket to be used for a specified iSCSI connection.
+    int sock;
+
+    /// iSCSI portal which contains the portal to be used for a specified iSCSI connection.
+    iscsi_portal *portal;
+
+    /// Host IP address string to be used for a specified iSCSI connection.
+    uint8_t *host;
+
+    /// Port string to be used for a specified iSCSI connection.
+    uint8_t *port;
+
+    /// iSCSI portal group or portals have been added and write lock is necessary.
+    bool write_locked;
+} iscsi_connection_handle_add_portals;
+
+
 iscsi_task *iscsi_task_create(iscsi_connection *conn, iscsi_task *parent, iscsi_scsi_task_xfer_complete_callback callback); // Allocates and initializes an iSCSI task structure
 void iscsi_task_destroy_callback(iscsi_scsi_task *scsi_task); // Deallocates all resources of the iSCSI task of an iSCSI SCSI task
 void iscsi_task_destroy(iscsi_task *task); // Deallocates resources acquired by iscsi_task_create
@@ -11869,11 +11956,13 @@ int iscsi_device_port_add(iscsi_device *device, const uint8_t *name, const uint6
 void iscsi_device_scsi_task_queue(iscsi_device *device, iscsi_scsi_task *scsi_task); // Enqueues an iSCSI SCSI task to the first LUN of an iSCSI device
 
 int iscsi_target_node_create_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // Creates, initializes and adds a portal group to an iSCSI target node
-iscsi_target_node *iscsi_target_node_create(uint8_t *name, const uint8_t *alias, const int index, const int lun_id, const uint queue_depth, const int flags, const int32_t chap_group, const int header_digest, const int data_digest); // Creates and initializes an iSCSI target node
+iscsi_target_node *iscsi_target_node_create(uint8_t *name, const uint8_t *alias, const uint64_t pg_tag, const int lun_id, const uint queue_depth, const int flags, const int32_t chap_group, const int header_digest, const int data_digest); // Creates and initializes an iSCSI target node
 int iscsi_target_node_destroy_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // iSCSI target node destructor callback for hash map
 void iscsi_target_node_destroy(iscsi_target_node *target); // Deallocates all resources acquired by iscsi_target_node_create
 
-int32_t iscsi_target_node_send(iscsi_connection *conn, const uint8_t *dst_iqn, const uint8_t *src_iqn, uint8_t *buf, const uint32_t pos, const uint32_t len); // Sends a buffer from a source iSCSI IQN to target iSCSI IQNs
+int iscsi_target_node_portals_send_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // Sends an iSCSI portal for iSCSI discovery to a buffer
+int iscsi_target_node_send_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // Sends an iSCSI discovery source target node IQN for a specific target IQN to a buffer
+int32_t iscsi_target_node_send(iscsi_connection *conn, uint8_t *dst_iqn, uint8_t *src_iqn, uint8_t *buf, const uint32_t pos, const uint32_t len); // Sends a target node discovery source iSCSI IQN to a buffer for target IQNs
 uint64_t iscsi_target_node_wwn_get(const uint8_t *name); // Calculates the WWN using 64-bit IEEE Extended NAA for a name
 dnbd3_image_t *iscsi_target_node_image_get(uint8_t *iqn); // Extracts the DNBD3 image out of an iSCSI IQN string and opens the DNBD3 image
 iscsi_device *iscsi_target_node_device_attach(iscsi_target_node *target, uint8_t *target_name); // Creates a new iSCSI device and attaches it to a specified iSCSI target node if no device was connected yet
@@ -11928,6 +12017,7 @@ int iscsi_connection_read_iov_data(iscsi_connection *conn, struct iovec *iov, in
 void iscsi_connection_pdu_write(iscsi_connection *conn, iscsi_pdu *pdu, iscsi_connection_xfer_complete_callback callback, uint8_t *user_data);
 
 int iscsi_connection_pdu_handle(iscsi_connection *conn); // Handles incoming PDU data, read up to 16 fragments at once
+int iscsi_connection_handle_add_portals_callback(uint8_t *key, const size_t key_size, uint8_t *value, uint8_t *user_data); // Adds iSCSI portals to a specified iSCSI portal group
 void iscsi_connection_handle(dnbd3_client_t *client, const dnbd3_request_t *request, const int len); // Handles an iSCSI connection until connection is closed
 
 #ifdef __cplusplus