xenial (7) irda.7.gz

NAME

       irda - The Linux-IrDA protocol stack

SYNOPSIS

       #include <linux/irda.h>

       stream_s = socket(PF_INET, SOCK_STREAM, 0);
       seqpkt_s = socket(PF_INET, SOCK_SEQPACKET, 0);
       dgram_s = socket(PF_INET, SOCK_DGRAM, IRDAPROTO_UNITDATA);
       ultra_s = socket(PF_INET, SOCK_DGRAM, IRDAPROTO_ULTRA);

DESCRIPTION

       Linux-IrDA is a complete implementation of the various IrDA protocols and IrDA drivers for Linux.

       The  configuration  of  the  low  level  of  the IrDA stack (IrDA ports) and the various IrDA drivers are
       described in irattach(8).

       The usage of the higher layers of the IrDA stack (IrCOMM, IrLPT, IrNET, IrLAN, OBEX...) are described  in
       their respective man pages.

       The  core of the Linux-IrDA protocol stack is composed of the IrLAP, IrLMP, IrTTP and IrIAS protocols and
       is implemented as a kernel module. The programmer's interface for the IrDA stack  is  socket  based.  For
       more information on sockets, see socket(7).

       Note  that  higher  level IrDA protocols may offer a different programmer's interface. For example IrCOMM
       offers a TTY based interface and OBEX is available through a user space library.

SOCKETS TYPE

       The Linux-IrDA socket interface offers 4 types of sockets:

       Stream socket - SOCK_STREAM, 0
              Stream sockets provides a reliable, stream oriented, full duplex connection between two sockets on
              top  of IrTTP, similar to TCP sockets. IrTTP guarantees that the data arrives in order and manages
              flow contol, IrLAP retransmits lost packets.
              Stream sockets does not preserve record boundaries.

       SeqPacket socket - SOCK_SEQPACKET, 0
              SeqPacket sockets provides a reliable, datagram  oriented,  full  duplex  connection  between  two
              sockets on top of IrTTP.  IrTTP guarantees that the data arrives in order and manages flow contol,
              IrLAP retransmits lost packets.
              SeqPacket sockets preserve record boundaries. Large datagrams will be fragmented as needed.

       Datagram socket - SOCK_DGRAM, IRDAPROTO_UNITDATA
              SeqPacket sockets provides a reliable, datagram  oriented,  full  duplex  connection  between  two
              sockets  on  top  of IrLMP.  There is no guarantees that the data arrives in order and there is no
              flow contol, however IrLAP retransmits lost packets.
              Datagram sockets preserve record boundaries. No fragmentation is provided, datagrams  larger  than
              the IrDA link MTU are truncated or discarded.

       Ultra socket - SOCK_DGRAM, IRDAPROTO_ULTRA
              Ultra sockets provides a connectionless, unreliable datagram packet service on top of IrLAP-Ultra.
              Ultra datagrams are sent and receive only when no IrLAP connection is  established  and  otherwise
              discarded.  They are always transmitted at 9600 bauds. Datagrams may be lost, reordered, and there
              is no flow control.
              Ultra sockets preserve record boundaries. No fragmentation is provided, datagrams larger than  the
              Ultra MTU (382 bytes) are truncated or discarded.

ADDRESS FORMAT

       An  IrDA  socket  address  is  defined  as a combination of an IrDA interface address and a service name.
       Service names are automatically resolved to lsap through the IrIAP protocol.

           struct sockaddr_irda {
               sa_family_t sir_family;   /* AF_IRDA */
               __u8        sir_lsap_sel; /* LSAP selector */
               __u32       sir_addr;     /* Device address */
               char        sir_name[25]; /* Usually <service>:IrDA:TinyTP */
           };

       sin_family is always set to AF_IRDA.  sir_lsap_sel is usually not used.  sir_addr is the address  of  the
       peer and optional (and that case the first peer discoverd will be used).  sir_name is the service name of
       the socket.

SOCKET OPTIONS

       IrDA sockets supports some protocol specific socket options that can be set with setsockopt(2)  and  read
       with getsockopt(2).  The socket option level for IrDA is SOL_IRLMP.

       Options that can be set:

       IRLMP_IAS_SET
              Set an entry in the local IAS database.

       IRLMP_IAS_DEL
              Delete an entry from the local IAS database.

       IRLMP_MAX_SDU_SIZE
              Set maximum receive MTU for SeqPacket sockets.

       IRLMP_HINTS_SET
              Set IrDA hint bits to be advertised to peers.

       IRLMP_HINT_MASK_SET
              Set IrDA hint bits filter to be used when performing discovery.

       Options that can be get:

       IRLMP_ENUMDEVICES
              Perform link level discovery and return the content of the discovery log.

       IRLMP_MAX_SDU_SIZE
              Get maximum receive MTU.

       IRLMP_IAS_GET
              Get an entry from the local IAS database.

       IRLMP_IAS_QUERY
              Query an entry in IAS database of a peer using IrIAP.

       IRLMP_WAITDEVICE
              Block until a new device is discovered. Experimental feature, use with caution.

AUTHOR

       Jean Tourrilhes - jt@hpl.hp.com

SEE ALSO

       irattach(8), irdadump(8), irnet(4), irnetd(8).