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FIDO_DEV_SET_IO_FUNCTIONS(3)                          Library Functions Manual

NAME
     fido_dev_set_io_functions, fido_dev_set_sigmask - FIDO 2 device I/O
     interface

SYNOPSIS
     #include <fido.h>

     typedef void *fido_dev_io_open_t(const char *);
     typedef void  fido_dev_io_close_t(void *);
     typedef int   fido_dev_io_read_t(void *, unsigned char *, size_t, int);
     typedef int   fido_dev_io_write_t(void *, const unsigned char *, size_t);

     typedef struct fido_dev_io {
             fido_dev_io_open_t  *open;
             fido_dev_io_close_t *close;
             fido_dev_io_read_t  *read;
             fido_dev_io_write_t *write;
     } fido_dev_io_t;

     #ifdef _WIN32
     typedef int fido_sigset_t;
     #else
     typedef sigset_t fido_sigset_t;
     #endif
     int
     fido_dev_set_io_functions(fido_dev_t *dev, const fido_dev_io_t *io);

     int
     fido_dev_set_sigmask(fido_dev_t *dev, const fido_sigset_t *sigmask);

DESCRIPTION
     The fido_dev_set_io_functions() function sets the I/O handlers used by
     libfido2 to talk to dev.  By default, these handlers are set to the
     operating system's native HID or NFC interfaces.  They are defined as
     follows:

     fido_dev_open_t
             Receives a const char * holding a path and opens the
             corresponding device, returning a non-NULL opaque pointer on
             success and NULL on error.

     fido_dev_close_t
             Receives the opaque pointer returned by fido_dev_open_t and
             closes the device.

     fido_dev_read_t
             Reads a single transmission unit (HID report, APDU) from a
             device.  The first parameter is the opaque pointer returned by
             fido_dev_open_t.  The second parameter is the read buffer, and
             the third parameter is the read buffer size.  The fourth
             parameter is the number of milliseconds the caller is willing to
             sleep, should the call need to block.  If this value holds -1,
             fido_dev_read_t may block indefinitely.  On success, the number
             of bytes read is returned.  On error, -1 is returned.

     fido_dev_write_t
             Writes a single transmission unit (HID report, APDU) to dev.  The
             first parameter is the opaque pointer returned by
             fido_dev_open_t.  The second parameter is the write buffer, and
             the third parameter is the number of bytes to be written.  A
             fido_dev_write_t may block.  On success, the number of bytes
             written is returned.  On error, -1 is returned.

     When calling fido_dev_set_io_functions(), the open, close, read, and
     write fields of io may not be NULL.

     No references to io are held by fido_dev_set_io_functions().

     The fido_dev_set_sigmask() function may be used to specify a non-NULL
     signal mask sigmask to be used while libfido2's default I/O handlers wait
     on dev.  On UNIX-like operating systems, fido_sigset_t is defined as
     sigset_t.  On Windows, fido_sigset_t is defined as int and
     fido_dev_set_sigmask() is a no-op.

     No references to sigmask are held by fido_dev_set_sigmask().

RETURN VALUES
     On success, fido_dev_set_io_functions() and fido_dev_set_sigmask() return
     FIDO_OK.  On error, a different error code defined in <fido/err.h> is
     returned.

NetBSD 9.99                $Mdocdate: May 25 2018 $                NetBSD 9.99