7.4 Asynchronous Messages
7.4.4 Error Message
There are times when the switch needs to notify the controller of a problem. This is done with the OFPT_ERROR_MSG message:
/* OFPT_ERROR: Error message (datapath -> controller). */ struct ofp_error_msg {
struct ofp_header header;
uint16_t type; uint16_t code;
uint8_t data[0]; /* Variable-length data. Interpreted based on the type and code. No padding. */ };
OFP_ASSERT(sizeof(struct ofp_error_msg) == 12);
The type value indicates the high-level type of error. The code value is interpreted based on the type. The data is variable in length and interpreted based on the type and code. Unless specified otherwise, the data field contains at least 64 bytes of the failed request that caused the error message to be generated, if the failed request is shorter than 64 bytes it should be the full request without any padding.
If the error message is in response to a specific message from the controller, e.g., OFPET_BAD_REQUEST, OFPET_BAD_ACTION, OFPET_BAD_INSTRUCTION, OFPET_BAD_MATCH, or OFPET_FLOW_MOD_FAILED, then the xid field of the header must match that of the offending message.
Error codes ending in _EPERM correspond to a permissions error generated by, for example, an OpenFlow hypervisor interposing between a controller and switch.
Currently defined error types are:
/* Values for ’type’ in ofp_error_message. These values are immutable: they * will not change in future versions of the protocol (although new values may * be added). */
enum ofp_error_type {
OFPET_HELLO_FAILED = 0, /* Hello protocol failed. */ OFPET_BAD_REQUEST = 1, /* Request was not understood. */ OFPET_BAD_ACTION = 2, /* Error in action description. */ OFPET_BAD_INSTRUCTION = 3, /* Error in instruction list. */ OFPET_BAD_MATCH = 4, /* Error in match. */
OFPET_FLOW_MOD_FAILED = 5, /* Problem modifying flow entry. */ OFPET_GROUP_MOD_FAILED = 6, /* Problem modifying group entry. */ OFPET_PORT_MOD_FAILED = 7, /* Port mod request failed. */ OFPET_TABLE_MOD_FAILED = 8, /* Table mod request failed. */ OFPET_QUEUE_OP_FAILED = 9, /* Queue operation failed. */ OFPET_SWITCH_CONFIG_FAILED = 10, /* Switch config request failed. */ OFPET_ROLE_REQUEST_FAILED = 11, /* Controller Role request failed. */ OFPET_METER_MOD_FAILED = 12, /* Error in meter. */
OFPET_TABLE_FEATURES_FAILED = 13, /* Setting table features failed. */ OFPET_EXPERIMENTER = 0xffff /* Experimenter error messages. */ };
For the OFPET_HELLO_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_HELLO_FAILED. ’data’ contains an
* ASCII text string that may give failure details. */ enum ofp_hello_failed_code {
OFPHFC_INCOMPATIBLE = 0, /* No compatible version. */ OFPHFC_EPERM = 1, /* Permissions error. */ };
The data field contains an ASCII text string that adds detail on why the error occurred. For the OFPET_BAD_REQUEST error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_BAD_REQUEST. ’data’ contains at least
* the first 64 bytes of the failed request. */ enum ofp_bad_request_code {
OFPBRC_BAD_VERSION = 0, /* ofp_header.version not supported. */ OFPBRC_BAD_TYPE = 1, /* ofp_header.type not supported. */
OFPBRC_BAD_MULTIPART = 2, /* ofp_multipart_request.type not supported. */ OFPBRC_BAD_EXPERIMENTER = 3, /* Experimenter id not supported
* (in ofp_experimenter_header or * ofp_multipart_request or * ofp_multipart_reply). */
OFPBRC_EPERM = 5, /* Permissions error. */
OFPBRC_BAD_LEN = 6, /* Wrong request length for type. */
OFPBRC_BUFFER_EMPTY = 7, /* Specified buffer has already been used. */ OFPBRC_BUFFER_UNKNOWN = 8, /* Specified buffer does not exist. */ OFPBRC_BAD_TABLE_ID = 9, /* Specified table-id invalid or does not
* exist. */
OFPBRC_IS_SLAVE = 10, /* Denied because controller is slave. */ OFPBRC_BAD_PORT = 11, /* Invalid port. */
OFPBRC_BAD_PACKET = 12, /* Invalid packet in packet-out. */ OFPBRC_MULTIPART_BUFFER_OVERFLOW = 13, /* ofp_multipart_request
overflowed the assigned buffer. */ };
For the OFPET_BAD_ACTION error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_BAD_ACTION. ’data’ contains at least
* the first 64 bytes of the failed request. */ enum ofp_bad_action_code {
OFPBAC_BAD_TYPE = 0, /* Unknown or unsupported action type. */ OFPBAC_BAD_LEN = 1, /* Length problem in actions. */
OFPBAC_BAD_EXPERIMENTER = 2, /* Unknown experimenter id specified. */ OFPBAC_BAD_EXP_TYPE = 3, /* Unknown action for experimenter id. */ OFPBAC_BAD_OUT_PORT = 4, /* Problem validating output port. */ OFPBAC_BAD_ARGUMENT = 5, /* Bad action argument. */
OFPBAC_EPERM = 6, /* Permissions error. */
OFPBAC_TOO_MANY = 7, /* Can’t handle this many actions. */ OFPBAC_BAD_QUEUE = 8, /* Problem validating output queue. */ OFPBAC_BAD_OUT_GROUP = 9, /* Invalid group id in forward action. */ OFPBAC_MATCH_INCONSISTENT = 10, /* Action can’t apply for this match,
or Set-Field missing prerequisite. */ OFPBAC_UNSUPPORTED_ORDER = 11, /* Action order is unsupported for the
action list in an Apply-Actions instruction */ OFPBAC_BAD_TAG = 12, /* Actions uses an unsupported
tag/encap. */
OFPBAC_BAD_SET_TYPE = 13, /* Unsupported type in SET_FIELD action. */ OFPBAC_BAD_SET_LEN = 14, /* Length problem in SET_FIELD action. */ OFPBAC_BAD_SET_ARGUMENT = 15, /* Bad argument in SET_FIELD action. */ };
For the OFPET_BAD_INSTRUCTION error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_BAD_INSTRUCTION. ’data’ contains at least
* the first 64 bytes of the failed request. */ enum ofp_bad_instruction_code {
OFPBIC_UNKNOWN_INST = 0, /* Unknown instruction. */
OFPBIC_UNSUP_INST = 1, /* Switch or table does not support the instruction. */
OFPBIC_BAD_TABLE_ID = 2, /* Invalid Table-ID specified. */
OFPBIC_UNSUP_METADATA = 3, /* Metadata value unsupported by datapath. */ OFPBIC_UNSUP_METADATA_MASK = 4, /* Metadata mask value unsupported by
datapath. */
OFPBIC_BAD_EXPERIMENTER = 5, /* Unknown experimenter id specified. */ OFPBIC_BAD_EXP_TYPE = 6, /* Unknown instruction for experimenter id. */ OFPBIC_BAD_LEN = 7, /* Length problem in instructions. */
OFPBIC_EPERM = 8, /* Permissions error. */ };
For the OFPET_BAD_MATCH error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_BAD_MATCH. ’data’ contains at least
* the first 64 bytes of the failed request. */ enum ofp_bad_match_code {
OFPBMC_BAD_TYPE = 0, /* Unsupported match type specified by the match */
OFPBMC_BAD_LEN = 1, /* Length problem in match. */
OFPBMC_BAD_TAG = 2, /* Match uses an unsupported tag/encap. */ OFPBMC_BAD_DL_ADDR_MASK = 3, /* Unsupported datalink addr mask - switch
does not support arbitrary datalink address mask. */
OFPBMC_BAD_NW_ADDR_MASK = 4, /* Unsupported network addr mask - switch does not support arbitrary network address mask. */
OFPBMC_BAD_WILDCARDS = 5, /* Unsupported combination of fields masked or omitted in the match. */
OFPBMC_BAD_FIELD = 6, /* Unsupported field type in the match. */ OFPBMC_BAD_VALUE = 7, /* Unsupported value in a match field. */ OFPBMC_BAD_MASK = 8, /* Unsupported mask specified in the match,
field is not dl-address or nw-address. */ OFPBMC_BAD_PREREQ = 9, /* A prerequisite was not met. */
OFPBMC_DUP_FIELD = 10, /* A field type was duplicated. */ OFPBMC_EPERM = 11, /* Permissions error. */
};
For the OFPET_FLOW_MOD_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_FLOW_MOD_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_flow_mod_failed_code {
OFPFMFC_UNKNOWN = 0, /* Unspecified error. */
OFPFMFC_TABLE_FULL = 1, /* Flow not added because table was full. */ OFPFMFC_BAD_TABLE_ID = 2, /* Table does not exist */
OFPFMFC_OVERLAP = 3, /* Attempted to add overlapping flow with CHECK_OVERLAP flag set. */
OFPFMFC_EPERM = 4, /* Permissions error. */
OFPFMFC_BAD_TIMEOUT = 5, /* Flow not added because of unsupported idle/hard timeout. */
OFPFMFC_BAD_COMMAND = 6, /* Unsupported or unknown command. */ OFPFMFC_BAD_FLAGS = 7, /* Unsupported or unknown flags. */ };
For the OFPET_GROUP_MOD_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_GROUP_MOD_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_group_mod_failed_code {
OFPGMFC_GROUP_EXISTS = 0, /* Group not added because a group ADD attempted to replace an
already-present group. */ OFPGMFC_INVALID_GROUP = 1, /* Group not added because Group
specified is invalid. */
sharing with select groups. */ OFPGMFC_OUT_OF_GROUPS = 3, /* The group table is full. */
OFPGMFC_OUT_OF_BUCKETS = 4, /* The maximum number of action buckets for a group has been exceeded. */ OFPGMFC_CHAINING_UNSUPPORTED = 5, /* Switch does not support groups that
forward to groups. */
OFPGMFC_WATCH_UNSUPPORTED = 6, /* This group cannot watch the watch_port or watch_group specified. */
OFPGMFC_LOOP = 7, /* Group entry would cause a loop. */ OFPGMFC_UNKNOWN_GROUP = 8, /* Group not modified because a group
MODIFY attempted to modify a non-existent group. */
OFPGMFC_CHAINED_GROUP = 9, /* Group not deleted because another group is forwarding to it. */
OFPGMFC_BAD_TYPE = 10, /* Unsupported or unknown group type. */ OFPGMFC_BAD_COMMAND = 11, /* Unsupported or unknown command. */ OFPGMFC_BAD_BUCKET = 12, /* Error in bucket. */
OFPGMFC_BAD_WATCH = 13, /* Error in watch port/group. */ OFPGMFC_EPERM = 14, /* Permissions error. */
};
For the OFPET_PORT_MOD_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_PORT_MOD_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_port_mod_failed_code {
OFPPMFC_BAD_PORT = 0, /* Specified port number does not exist. */ OFPPMFC_BAD_HW_ADDR = 1, /* Specified hardware address does not
* match the port number. */ OFPPMFC_BAD_CONFIG = 2, /* Specified config is invalid. */ OFPPMFC_BAD_ADVERTISE = 3, /* Specified advertise is invalid. */ OFPPMFC_EPERM = 4, /* Permissions error. */
};
For the OFPET_TABLE_MOD_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_TABLE_MOD_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_table_mod_failed_code {
OFPTMFC_BAD_TABLE = 0, /* Specified table does not exist. */ OFPTMFC_BAD_CONFIG = 1, /* Specified config is invalid. */ OFPTMFC_EPERM = 2, /* Permissions error. */
};
For the OFPET_QUEUE_OP_FAILED error type, the following codes are currently defined: /* ofp_error msg ’code’ values for OFPET_QUEUE_OP_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request */ enum ofp_queue_op_failed_code {
OFPQOFC_BAD_PORT = 0, /* Invalid port (or port does not exist). */ OFPQOFC_BAD_QUEUE = 1, /* Queue does not exist. */
OFPQOFC_EPERM = 2, /* Permissions error. */ };
For the OFPET_SWITCH_CONFIG_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_SWITCH_CONFIG_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_switch_config_failed_code {
OFPSCFC_BAD_FLAGS = 0, /* Specified flags is invalid. */ OFPSCFC_BAD_LEN = 1, /* Specified len is invalid. */ OFPSCFC_EPERM = 2, /* Permissions error. */ };
For the OFPET_ROLE_REQUEST_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_ROLE_REQUEST_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_role_request_failed_code {
OFPRRFC_STALE = 0, /* Stale Message: old generation_id. */ OFPRRFC_UNSUP = 1, /* Controller role change unsupported. */ OFPRRFC_BAD_ROLE = 2, /* Invalid role. */
};
For the OFPET_METER_MOD_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_METER_MOD_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_meter_mod_failed_code {
OFPMMFC_UNKNOWN = 0, /* Unspecified error. */
OFPMMFC_METER_EXISTS = 1, /* Meter not added because a Meter ADD * attempted to replace an existing Meter. */ OFPMMFC_INVALID_METER = 2, /* Meter not added because Meter specified
* is invalid,
* or invalid meter in meter action. */ OFPMMFC_UNKNOWN_METER = 3, /* Meter not modified because a Meter MODIFY
* attempted to modify a non-existent Meter, * or bad meter in meter action. */
OFPMMFC_BAD_COMMAND = 4, /* Unsupported or unknown command. */ OFPMMFC_BAD_FLAGS = 5, /* Flag configuration unsupported. */ OFPMMFC_BAD_RATE = 6, /* Rate unsupported. */
OFPMMFC_BAD_BURST = 7, /* Burst size unsupported. */ OFPMMFC_BAD_BAND = 8, /* Band unsupported. */ OFPMMFC_BAD_BAND_VALUE = 9, /* Band value unsupported. */ OFPMMFC_OUT_OF_METERS = 10, /* No more meters available. */ OFPMMFC_OUT_OF_BANDS = 11, /* The maximum number of properties
* for a meter has been exceeded. */ };
For the OFPET_TABLE_FEATURES_FAILED error type, the following codes are currently defined: /* ofp_error_msg ’code’ values for OFPET_TABLE_FEATURES_FAILED. ’data’ contains
* at least the first 64 bytes of the failed request. */ enum ofp_table_features_failed_code {
OFPTFFC_BAD_TABLE = 0, /* Specified table does not exist. */ OFPTFFC_BAD_METADATA = 1, /* Invalid metadata mask. */
OFPTFFC_BAD_TYPE = 2, /* Unknown property type. */ OFPTFFC_BAD_LEN = 3, /* Length problem in properties. */ OFPTFFC_BAD_ARGUMENT = 4, /* Unsupported property value. */ OFPTFFC_EPERM = 5, /* Permissions error. */
};
For the OFPET_EXPERIMENTER error type, the error message is defined by the following structure and fields, followed by experimenter defined data:
/* OFPET_EXPERIMENTER: Error message (datapath -> controller). */ struct ofp_error_experimenter_msg {
struct ofp_header header;
uint16_t type; /* OFPET_EXPERIMENTER. */ uint16_t exp_type; /* Experimenter defined. */
uint32_t experimenter; /* Experimenter ID which takes the same form as in struct ofp_experimenter_header. */ uint8_t data[0]; /* Variable-length data. Interpreted based
on the type and code. No padding. */ };
OFP_ASSERT(sizeof(struct ofp_error_experimenter_msg) == 16);
The experimenter field is the Experimenter ID, which takes the same form as in struct ofp_experimenter (see 7.5.4).