Writing an io-sock Module

In addition to developing an io-sock driver, you can use the API function calls and structures described in Writing Network Drivers for io-sock to write an io-sock module.

When you are developing an io-sock module, you must include io-sock header files (found in usr/include/devs), which include the required QNX header files. Don't include the QNX header files directly—it can result in compilation or runtime errors.

You can add the io-sock version of the header files by including mods.mk, which specifies the proper search paths, in your common.mk.

For the best guide to the use of the FreeBSD driver APIs, go to the FreeBSD 13.5 manual pages at https://www.freebsd.org/cgi/man.cgi and search in the section 9 - Kernel Interface.

The following sample module and makefile illustrate the minimum requirements. They don't include any useful functionality.

/*
 * io-sock simple sample module
 */
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <qnx/qnx_modload.h>

int mod_ver = IOSOCK_VERSION_CUR;

SYSCTL_INT(_qnx_module, OID_AUTO, sample, CTLFLAG_RD, &mod_ver, 0,
            "Version");

static void
run_module(void)
{
        printf("sample module ran\n");
}

static int
module_event_handler(module_t mod, int what, void *arg __unused)
{

        switch (what) {
        case MOD_LOAD:
                run_module();
                break;
        default:
                printf("Unsupported module event:%d\n", what);
                return (EOPNOTSUPP);
        }

        return (0);
}

static moduledata_t modsam_moduledata = {
        "module_sample",
        module_event_handler,
        NULL
};

MODULE_VERSION(modsam, 1);
DECLARE_MODULE(modsam, modsam_moduledata, SI_SUB_PSEUDO, SI_ORDER_ANY);

struct _iosock_module_version iosock_module_version =
    IOSOCK_MODULE_VER_SYM_INIT;

static void
modsam_uninit(void *arg)
{
}
/*
 * If code is added to sam_uninit, then SI_SUB_DUMMY needs to be
 * changed to SI_SUB_DRIVERS.  With SI_SUB_DUMMY, sam_uninit does
 * not get called.
 */
SYSUNINIT(modsam_uninit, SI_SUB_DUMMY, SI_ORDER_ANY, modsam_uninit, NULL);

ifndef QCONFIG
QCONFIG=qconfig.mk
endif

include $(QCONFIG)

INSTALLDIR=    /lib/dll

define PINFO
PINFO DESCRIPTION=Sample io-sock module
endef

EXTRA_CLEAN+= $(PROJECT_ROOT)/mods-sample.use

define MODULE_SPECIFIC_OPTIONS

This can specify any module information

endef

include devs/mods.mk