NAME

       umad_recv - receive umad

SYNOPSIS

       #include <infiniband/umad.h>

       int umad_recv(int portid, void *umad, int *length, int timeout_ms);

DESCRIPTION

       umad_recv()  waits up to timeout_ms milliseconds for a packet to be received from the port
       specified by portid.  The packet is copied to the umad buffer if there is sufficient  room
       and  the received length is indicated.  If the buffer is not large enough, the size of the
       umad buffer needed is returned in length.  A negative timeout_ms makes the function  block
       until a packet is received. A timeout_ms parameter of zero indicates a non blocking read.

       Note length is a pointer to the length of the data portion of the umad buffer.  This means
       that umad must point to a buffer at least umad_size() + *length bytes long.

       Note also that *length must be >= 256 bytes.

RETURN VALUE

       umad_recv() returns non negative receiving agentid on success, and  a  negative  value  on
       error as follows:
        -EINVAL      invalid port handle or agentid or *length is less than the minimum supported
        -EIO         receive operation failed
        -EWOULDBLOCK non blocking read can't be fulfilled

SEE ALSO

       umad_poll(3)

AUTHOR

       Hal Rosenstock <halr@voltaire.com>