str_to_gensio(3) Library Functions Manual str_to_gensio(3)

str_to_gensio, str_to_gensio_child, gensio_acc_str_to_gensio - Create a gensio from a string

#include <gensio/gensio.h>


struct gensio_os_funcs *o,
gensio_event cb, void *user_data,
struct gensio **io);

struct gensio_os_funcs *o,
gensio_event cb, void *user_data,
struct gensio **io);

const char *str, struct gensio_os_funcs *o,
gensio_event cb, void *user_data,
struct gensio **io);

const void *gdata,
const char * const args[],
struct gensio_os_funcs *o,
gensio_event cb, void *user_data,
struct gensio **new_gensio);

struct gensio *child,
const char * const args[],
struct gensio_os_funcs *o,
gensio_event cb, void *user_data,
struct gensio **new_gensio);

str_to_gensio allocates a new gensio stack based upon the given string str.

str_to_gensio_child allocates a partial gensio stack and stacks it on top of the given child. Note that if the child is already open, you should use gesnio_open_nochild() to open just this gensio. This can only be used to allocate filter gensios.

gensio_acc_str_to_gensio allocates a gensio based upon the given accepter. The availability and use of this varies from gensio to gensio, but it can be used on UDP to create a gensio that uses the UDP ports that the accepter owns. This will come from the first address/port that the accepter is on for TCP and UDP. It will bind to all the address/ports for SCTP. To use this, you must specify a string that exactly matches the layers of the accepter. So, for instance, if the accepter is "telnet,ssl(CA=x1,key=x2,cert=x3),sctp,3095", then the string must be in the form "telnet,ssl(CA=x2),sctp,otherserver,3820" The layers are exactly the same, but you can vary the options to the layers.

To directly allocation gensios, you can use gensio_terminal_alloc and gensio_filter_alloc. A terminal gensio is one at the bottom of the stack. The gdata parameter depends on the particular gensio. For instance, for serialdev it is a string specifying the device and serial parameters. For stdio it is an argv array. See gensio.5 under "Direct Allocation" for the particular gensio for what gdata is.

A filter gensio is one that has a child. You can use these two functions to allocate a gensio stack directly, not using a string format.

The cb and user_data parameters set a function that will be called when events come in on the gensio. user_data is unused by the gensio stack itself, it is there for the user and may be anything the user wishes. cb may be NULL before the gensio is opened, but must be set before it is opened. In particular, the cb does not need to be set if other gensios will be stacked on top of it in the future, as the gensios stacked on top will set the cb and user_data values.

The new gensio is returned in io. It will be in the closed state.

Zero is returned on success, or a gensio error on failure.

gensio_set_callback(3), gensio_err(3), gensio(5)

22 Feb 2019