Connectionless-mode Service Primitives

DL_UNITDATA_REQ

Conveys one DLSDU from the DLS user to the DLS provider for transmission to a peer DLS user. DLPI requires applications using this primitive to run as root.

Because connectionless data transfer is an unacknowledged service, the DLS provider makes no guarantees of delivery of connectionless DLSDUs. It is the responsibility of the DLS user to do any necessary sequencing or retransmission of DLSDUs in the event of a presumed loss.

Format

The message consists of one M_PROTO message block containing the structure shown below, followed by one or more M_DATA blocks containing at least one byte of data. The amount of user data that may be transferred in a single DLSDU is limited. This limit is conveyed by the parameter dl_max_sdu in the DL_INFO_ACK primitive.

typedef struct {
ulong dl_primitive;
ulong dl_dest_addr_length;
ulong dl_dest_addr_offset;
dl_priority_t  dl_priority;
} dl_unitdata_req_t;

Parameters

dl_primitive

dl_dest_addr_length

dl_dest_addr_offset

dl_priority

State

The message is valid in state DL_IDLE.

New State

The resulting state is unchanged.

Response

If the DLS provider accepts the data for transmission, there is no response. This does not, however, guarantee that the data will be delivered to the destination DLS user, since the connectionless data transfer is not a confirmed service.

If the request is erroneous, DL_UDERROR_IND is returned, and the resulting state is unchanged.

If for some reason the request cannot be processed, the DLS provider may generate a DL_UDERROR_IND to report the problem. There is, however, no guarantee that such an error report will be generated for all undeliverable data units, since connectionless data transfer is not a confirmed service.

Reasons for Failure

DL_BADADDR

DL_BADDATA

DL_OUTSTATE

DL_UNSUPPORTED

Security Containment

With the Security Containment product version B.11.23.01 or later, HP DLPI will allow transmision of IP/ARP frame only for users with PRIV_NETADMIN privilege.

See “Fine-grained Privileges with Security Containment Release” for more details.

DL_UNITDATA_IND

Conveys one DLSDU from the DLS provider to the DLS user.

Format

The message consists of one M_PROTO message block containing the structure shown below, followed by one or more M_DATA blocks containing at least one byte of data. The amount of user data that may be transferred in a single DLSDU is limited. This limit is conveyed by the parameter dl_max_sdu in the DL_INFO_ACK primitive.

typedef struct {
ulong dl_primitive;
ulong dl_dest_addr_length;
ulong dl_dest_addr_offset;
ulong dl_src_addr_length;
ulong dl_src_addr_offset;
ulong dl_group_address;
} dl_unitdata_ind_t;

Parameters

dl_primitive

dl_dest_addr_length

dl_dest_addr_offset

dl_src_addr_length

dl_src_addr_offset

dl_group_address

State

The message is valid in any attached state.

New State

The resulting state is unchanged.

DL_UDERROR_IND

Informs the DLS user that a previously sent DL_UNITDATA_REQ produced an error or could not be delivered. The primitive indicates the destination DLSAP address associated with the failed request, and conveys an error value that specifies the reason for failure.

Format

The message consists of either one M_PROTO message block or one M_PCPROTO message block containing the structure shown below.

typedef struct {
ulong dl_primitive;
ulong dl_dest_addr_length;
ulong dl_dest_addr_offset;
ulong dl_unix_errno;
ulong dl_errno;
} dl_uderror_ind_t;

Parameters

dl_primitive

dl_dest_addr_length

dl_dest_addr_offset

dl_unix_errno

dl_errno

State

The message is valid in state DL_IDLE.

New State

The resulting state is unchanged.