[iscsi] Change default initiator IQN

The default initiator IQN is "iqn.2000-09.org.etherboot:UNKNOWN".
This is problematic for two reasons:

  a) the etherboot.org domain (and hence the associated IQN namespace)
     is not under the control of the iPXE project, and

  b) some targets (correctly) refuse to allow concurrent connections
     from different initiators using the same initiator IQN.

Solve both problems by changing the default initiator IQN to be

  iqn.2010-04.org.ipxe:<hostname> if a hostname is set, or

  iqn.2010-04.org.ipxe:<uuid> if no hostname is set.

Explicit initiator IQNs set via DHCP option 203 are not affected by
this change.

Unfortunately, this change is likely to break some existing
configurations, where ACL rules have been put in place referring to
the old default initiator IQN.  Users may need to update ACLs, or
force the use of the old IQN using an iPXE script line such as

  set initiator-iqn iqn.2000-09.org.etherboot:UNKNOWN

or a dhcpd.conf option such as

   option iscsi-initiator-iqn "iqn.2000-09.org.etherboot:UNKNOWN"

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/block/ibft.c

  *
  * @v initiator		Initiator portion of iBFT
  * @v strings		iBFT string block descriptor
+ * @v iscsi		iSCSI session
  * @ret rc		Return status code
  */
 static int ibft_fill_initiator ( struct ibft_initiator *initiator,
-				 struct ibft_strings *strings ) {
-	const char *initiator_iqn = iscsi_initiator_iqn();
+				 struct ibft_strings *strings,
+				 struct iscsi_session *iscsi ) {
 	int rc;
 
 	/* Fill in common header */
 
 	/* Fill in hostname */
 	if ( ( rc = ibft_set_string ( strings, &initiator->initiator_name,
-				      initiator_iqn ) ) != 0 )
+				      iscsi->initiator_iqn ) ) != 0 )
 		return rc;
 	DBG ( "iBFT initiator hostname = %s\n",
 	      ibft_string ( strings, &initiator->initiator_name ) );
 	/* Fill in NIC, Initiator and Target blocks */
 	if ( ( rc = ibft_fill_nic ( &ibft->nic, &strings, netdev ) ) != 0 )
 		return rc;
-	if ( ( rc = ibft_fill_initiator ( &ibft->initiator,
-					  &strings ) ) != 0 )
+	if ( ( rc = ibft_fill_initiator ( &ibft->initiator, &strings,
+					  iscsi ) ) != 0 )
 		return rc;
 	if ( ( rc = ibft_fill_target ( &ibft->target, &strings,
 				       iscsi ) ) != 0 )

src/include/ipxe/iscsi.h

 	/** Transport-layer socket */
 	struct interface socket;
 
+	/** Initiator IQN */
+	char *initiator_iqn;
 	/** Target address */
 	char *target_address;
 	/** Target port */
 /** Target authenticated itself correctly */
 #define ISCSI_STATUS_AUTH_REVERSE_OK 0x00040000
 
-extern const char * iscsi_initiator_iqn ( void );
+/** Default initiator IQN prefix */
+#define ISCSI_DEFAULT_IQN_PREFIX "iqn.2010-04.org.ipxe"
 
 #endif /* _IPXE_ISCSI_H */

src/net/tcp/iscsi.c

 	__einfo_error ( EINFO_EINVAL_NO_TARGET_IQN )
 #define EINFO_EINVAL_NO_TARGET_IQN \
 	__einfo_uniqify ( EINFO_EINVAL, 0x04, "No target IQN" )
+#define EINVAL_NO_INITIATOR_IQN \
+	__einfo_error ( EINFO_EINVAL_NO_INITIATOR_IQN )
+#define EINFO_EINVAL_NO_INITIATOR_IQN \
+	__einfo_uniqify ( EINFO_EINVAL, 0x05, "No initiator IQN" )
 #define EIO_TARGET_UNAVAILABLE \
 	__einfo_error ( EINFO_EIO_TARGET_UNAVAILABLE )
 #define EINFO_EIO_TARGET_UNAVAILABLE \
 #define EINFO_EPROTO_INVALID_CHAP_RESPONSE \
 	__einfo_uniqify ( EINFO_EPROTO, 0x04, "Invalid CHAP response" )
 
-/** iSCSI initiator name (explicitly specified) */
-static char *iscsi_explicit_initiator_iqn;
-
-/** Default iSCSI initiator name (constructed from hostname) */
-static char *iscsi_default_initiator_iqn;
-
-/** iSCSI initiator username */
-static char *iscsi_initiator_username;
-
-/** iSCSI initiator password */
-static char *iscsi_initiator_password;
-
-/** iSCSI target username */
-static char *iscsi_target_username;
-
-/** iSCSI target password */
-static char *iscsi_target_password;
-
 static void iscsi_start_tx ( struct iscsi_session *iscsi );
 static void iscsi_start_login ( struct iscsi_session *iscsi );
 static void iscsi_start_data_out ( struct iscsi_session *iscsi,
 	struct iscsi_session *iscsi =
 		container_of ( refcnt, struct iscsi_session, refcnt );
 
+	free ( iscsi->initiator_iqn );
 	free ( iscsi->target_address );
 	free ( iscsi->target_iqn );
 	free ( iscsi->initiator_username );
 				    "TargetName=%s%c"
 				    "SessionType=Normal%c"
 				    "AuthMethod=%s%c",
-				    iscsi_initiator_iqn(), 0,
+				    iscsi->initiator_iqn, 0,
 				    iscsi->target_iqn, 0, 0,
 				    auth_method, 0 );
 	}
 	NUM_RP_COMPONENTS
 };
 
+/** iSCSI initiator IQN setting */
+struct setting initiator_iqn_setting __setting = {
+	.name = "initiator-iqn",
+	.description = "iSCSI initiator name",
+	.tag = DHCP_ISCSI_INITIATOR_IQN,
+	.type = &setting_type_string,
+};
+
+/** iSCSI reverse username setting */
+struct setting reverse_username_setting __setting = {
+	.name = "reverse-username",
+	.description = "Reverse user name",
+	.tag = DHCP_EB_REVERSE_USERNAME,
+	.type = &setting_type_string,
+};
+
+/** iSCSI reverse password setting */
+struct setting reverse_password_setting __setting = {
+	.name = "reverse-password",
+	.description = "Reverse password",
+	.tag = DHCP_EB_REVERSE_PASSWORD,
+	.type = &setting_type_string,
+};
+
 /**
  * Parse iSCSI root path
  *
 }
 
 /**
- * Set iSCSI authentication details
+ * Fetch iSCSI settings
  *
  * @v iscsi		iSCSI session
- * @v initiator_username Initiator username, if any
- * @v initiator_password Initiator password, if any
- * @v target_username	Target username, if any
- * @v target_password	Target password, if any
  * @ret rc		Return status code
  */
-static int iscsi_set_auth ( struct iscsi_session *iscsi,
-			    const char *initiator_username,
-			    const char *initiator_password,
-			    const char *target_username,
-			    const char *target_password ) {
-
-	/* Check for initiator or target credentials */
-	if ( initiator_username || initiator_password ||
-	     target_username || target_password ) {
-
-		/* We must have at least an initiator username+password */
-		if ( ! ( initiator_username && initiator_password ) )
-			goto invalid_auth;
-
-		/* Store initiator credentials */
-		iscsi->initiator_username = strdup ( initiator_username );
-		if ( ! iscsi->initiator_username )
-			return -ENOMEM;
-		iscsi->initiator_password = strdup ( initiator_password );
-		if ( ! iscsi->initiator_password )
-			return -ENOMEM;
-
-		/* Check for target credentials */
-		if ( target_username || target_password ) {
+static int iscsi_fetch_settings ( struct iscsi_session *iscsi ) {
+	char *hostname;
+	union uuid uuid;
+	int len;
 
-			/* We must have target username+password */
-			if ( ! ( target_username && target_password ) )
-				goto invalid_auth;
+	/* Fetch relevant settings.  Don't worry about freeing on
+	 * error, since iscsi_free() will take care of that anyway.
+	 */
+	if ( ( len = fetch_string_setting_copy ( NULL, &username_setting,
+					  &iscsi->initiator_username ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not fetch username: %s\n",
+		       iscsi, strerror ( len ) );
+		return len;
+	}
+	if ( ( len = fetch_string_setting_copy ( NULL, &password_setting,
+					  &iscsi->initiator_password ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not fetch password: %s\n",
+		       iscsi, strerror ( len ) );
+		return len;
+	}
+	if ( ( len = fetch_string_setting_copy( NULL, &reverse_username_setting,
+					     &iscsi->target_username ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not fetch reverse username: %s\n",
+		       iscsi, strerror ( len ) );
+		return len;
+	}
+	if ( ( len = fetch_string_setting_copy( NULL, &reverse_password_setting,
+					     &iscsi->target_password ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not fetch reverse password: %s\n",
+		       iscsi, strerror ( len ) );
+		return len;
+	}
 
-			/* Store target credentials */
-			iscsi->target_username = strdup ( target_username );
-			if ( ! iscsi->target_username )
-				return -ENOMEM;
-			iscsi->target_password = strdup ( target_password );
-			if ( ! iscsi->target_password )
-				return -ENOMEM;
+	/* Find a suitable initiator name */
+	if ( ( len = fetch_string_setting_copy ( NULL, &initiator_iqn_setting,
+					       &iscsi->initiator_iqn ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not fetch initiator IQN: %s\n",
+		       iscsi, strerror ( len ) );
+		return len;
+	}
+	if ( iscsi->initiator_iqn )
+		return 0;
+	if ( ( len = fetch_string_setting_copy ( NULL, &hostname_setting,
+						&hostname ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not fetch hostname: %s\n",
+		       iscsi, strerror ( len ) );
+		return len;
+	}
+	if ( hostname ) {
+		len = asprintf ( &iscsi->initiator_iqn,
+				 ISCSI_DEFAULT_IQN_PREFIX ":%s", hostname );
+		free ( hostname );
+		if ( len < 0 ) {
+			DBGC ( iscsi, "iSCSI %p could not allocate initiator "
+			       "IQN\n", iscsi );
+			return -ENOMEM;
 		}
+		assert ( iscsi->initiator_iqn );
+		return 0;
+	}
+	if ( ( len = fetch_uuid_setting ( NULL, &uuid_setting, &uuid ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p has no suitable initiator IQN\n",
+		       iscsi );
+		return -EINVAL_NO_INITIATOR_IQN;
+	}
+	if ( ( len = asprintf ( &iscsi->initiator_iqn,
+				ISCSI_DEFAULT_IQN_PREFIX ":%s",
+				uuid_ntoa ( &uuid ) ) ) < 0 ) {
+		DBGC ( iscsi, "iSCSI %p could not allocate initiator IQN\n",
+		       iscsi );
+		return -ENOMEM;
 	}
+	assert ( iscsi->initiator_iqn );
 
 	return 0;
+}
+
 
- invalid_auth:
-	DBGC ( iscsi, "iSCSI %p invalid credentials: initiator "
-	       "%sname,%spw, target %sname,%spw\n", iscsi,
-	       ( initiator_username ? "" : "no " ),
-	       ( initiator_password ? "" : "no " ),
-	       ( target_username ? "" : "no " ),
-	       ( target_password ? "" : "no " ) );
-	return -EINVAL_BAD_CREDENTIAL_MIX;
+/**
+ * Check iSCSI authentication details
+ *
+ * @v iscsi		iSCSI session
+ * @ret rc		Return status code
+ */
+static int iscsi_check_auth ( struct iscsi_session *iscsi ) {
+
+	/* Check for invalid authentication combinations */
+	if ( ( /* Initiator username without password (or vice-versa) */
+		( !! iscsi->initiator_username ) ^
+		( !! iscsi->initiator_password ) ) ||
+	     ( /* Target username without password (or vice-versa) */
+		( !! iscsi->target_username ) ^
+		( !! iscsi->target_password ) ) ||
+	     ( /* Target (reverse) without initiator (forward) */
+		( iscsi->target_username &&
+		  ( ! iscsi->initiator_username ) ) ) ) {
+		DBGC ( iscsi, "iSCSI %p invalid credentials: initiator "
+		       "%sname,%spw, target %sname,%spw\n", iscsi,
+		       ( iscsi->initiator_username ? "" : "no " ),
+		       ( iscsi->initiator_password ? "" : "no " ),
+		       ( iscsi->target_username ? "" : "no " ),
+		       ( iscsi->target_password ? "" : "no " ) );
+		return -EINVAL_BAD_CREDENTIAL_MIX;
+	}
+
+	return 0;
 }
 
 /**
 	if ( ( rc = iscsi_parse_root_path ( iscsi, uri->opaque ) ) != 0 )
 		goto err_parse_root_path;
 	/* Set fields not specified by root path */
-	if ( ( rc = iscsi_set_auth ( iscsi,
-				     iscsi_initiator_username,
-				     iscsi_initiator_password,
-				     iscsi_target_username,
-				     iscsi_target_password ) ) != 0 )
-		goto err_set_auth;
+	if ( ( rc = iscsi_fetch_settings ( iscsi ) ) != 0 )
+		goto err_fetch_settings;
+	/* Validate authentication */
+	if ( ( rc = iscsi_check_auth ( iscsi ) ) != 0 )
+		goto err_check_auth;
 
 	/* Sanity checks */
 	if ( ! iscsi->target_address ) {
 		rc = -EINVAL_NO_TARGET_IQN;
 		goto err_sanity_iqn;
 	}
+	DBGC ( iscsi, "iSCSI %p initiator %s\n",iscsi, iscsi->initiator_iqn );
+	DBGC ( iscsi, "iSCSI %p target %s %s\n",
+	       iscsi, iscsi->target_address, iscsi->target_iqn );
 
 	/* Open socket */
 	if ( ( rc = iscsi_open_connection ( iscsi ) ) != 0 )
  err_open_connection:
  err_sanity_iqn:
  err_sanity_address:
- err_set_auth:
+ err_check_auth:
+ err_fetch_settings:
  err_parse_root_path:
 	iscsi_close ( iscsi, rc );
 	ref_put ( &iscsi->refcnt );
 	.scheme = "iscsi",
 	.open = iscsi_open,
 };
-
-/****************************************************************************
- *
- * Settings
- *
- */
-
-/** iSCSI initiator IQN setting */
-struct setting initiator_iqn_setting __setting = {
-	.name = "initiator-iqn",
-	.description = "iSCSI initiator name",
-	.tag = DHCP_ISCSI_INITIATOR_IQN,
-	.type = &setting_type_string,
-};
-
-/** iSCSI reverse username setting */
-struct setting reverse_username_setting __setting = {
-	.name = "reverse-username",
-	.description = "Reverse user name",
-	.tag = DHCP_EB_REVERSE_USERNAME,
-	.type = &setting_type_string,
-};
-
-/** iSCSI reverse password setting */
-struct setting reverse_password_setting __setting = {
-	.name = "reverse-password",
-	.description = "Reverse password",
-	.tag = DHCP_EB_REVERSE_PASSWORD,
-	.type = &setting_type_string,
-};
-
-/** An iSCSI string setting */
-struct iscsi_string_setting {
-	/** Setting */
-	struct setting *setting;
-	/** String to update */
-	char **string;
-	/** String prefix */
-	const char *prefix;
-};
-
-/** iSCSI string settings */
-static struct iscsi_string_setting iscsi_string_settings[] = {
-	{
-		.setting = &initiator_iqn_setting,
-		.string = &iscsi_explicit_initiator_iqn,
-		.prefix = "",
-	},
-	{
-		.setting = &username_setting,
-		.string = &iscsi_initiator_username,
-		.prefix = "",
-	},
-	{
-		.setting = &password_setting,
-		.string = &iscsi_initiator_password,
-		.prefix = "",
-	},
-	{
-		.setting = &reverse_username_setting,
-		.string = &iscsi_target_username,
-		.prefix = "",
-	},
-	{
-		.setting = &reverse_password_setting,
-		.string = &iscsi_target_password,
-		.prefix = "",
-	},
-	{
-		.setting = &hostname_setting,
-		.string = &iscsi_default_initiator_iqn,
-		.prefix = "iqn.2000-01.org.etherboot:",
-	},
-};
-
-/**
- * Apply iSCSI setting
- *
- * @v setting		iSCSI string setting
- * @ret rc		Return status code
- */
-static int apply_iscsi_string_setting ( struct iscsi_string_setting *setting ){
-	size_t prefix_len;
-	int setting_len;
-	size_t len;
-	int check_len;
-	char *p;
-
-	/* Free old string */
-	free ( *setting->string );
-	*setting->string = NULL;
-
-	/* Allocate new string */
-	prefix_len = strlen ( setting->prefix );
-	setting_len = fetch_setting_len ( NULL, setting->setting );
-	if ( setting_len < 0 ) {
-		/* Missing settings are not errors; leave strings as NULL */
-		return 0;
-	}
-	len = ( prefix_len + setting_len + 1 );
-	p = *setting->string = malloc ( len );
-	if ( ! p )
-		return -ENOMEM;
-
-	/* Fill new string */
-	strcpy ( p, setting->prefix );
-	check_len = fetch_string_setting ( NULL, setting->setting,
-					   ( p + prefix_len ),
-					   ( len - prefix_len ) );
-	assert ( check_len == setting_len );
-
-	return 0;
-}
-
-/**
- * Apply iSCSI settings
- *
- * @ret rc		Return status code
- */
-static int apply_iscsi_settings ( void ) {
-	struct iscsi_string_setting *setting;
-	unsigned int i;
-	int rc;
-
-	for ( i = 0 ; i < ( sizeof ( iscsi_string_settings ) /
-			    sizeof ( iscsi_string_settings[0] ) ) ; i++ ) {
-		setting = &iscsi_string_settings[i];
-		if ( ( rc = apply_iscsi_string_setting ( setting ) ) != 0 ) {
-			DBG ( "iSCSI could not apply setting %s\n",
-			      setting->setting->name );
-			return rc;
-		}
-	}
-
-	return 0;
-}
-
-/** iSCSI settings applicator */
-struct settings_applicator iscsi_settings_applicator __settings_applicator = {
-	.apply = apply_iscsi_settings,
-};
-
-/****************************************************************************
- *
- * Initiator name
- *
- */
-
-/**
- * Get iSCSI initiator IQN
- *
- * @v iscsi		iSCSI session
- * @ret rc		Return status code
- */
-const char * iscsi_initiator_iqn ( void ) {
-
-	if ( iscsi_explicit_initiator_iqn )
-		return iscsi_explicit_initiator_iqn;
-	if ( iscsi_default_initiator_iqn )
-		return iscsi_default_initiator_iqn;
-	return "iqn.2000-09.org.etherboot:UNKNOWN";
-}