/* https://github.com/cirosantilli/linux-kernel-module-cheat#myinsmod */

#define _GNU_SOURCE
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>

#define init_module(module_image, len, param_values) syscall(__NR_init_module, module_image, len, param_values)
#define finit_module(fd, param_values, flags) syscall(__NR_finit_module, fd, param_values, flags)

int main(int argc, char **argv) {
	const char *params;
	int fd, use_finit;
	size_t image_size;
	struct stat st;
	void *image;

	/* CLI handling. */
	if (argc < 2) {
		puts("Usage ./prog mymodule.ko [args="" [use_finit=0]");
		return EXIT_FAILURE;
	}
	if (argc < 3) {
		params = "";
	} else {
		params = argv[2];
	}
	if (argc < 4) {
		use_finit = 0;
	} else {
		use_finit = (argv[3][0] != '0');
	}

	/* Action. */
	fd = open(argv[1], O_RDONLY);
	if (use_finit) {
		puts("finit");
		if (finit_module(fd, params, 0) != 0) {
			perror("finit_module");
			return EXIT_FAILURE;
		}
		close(fd);
	} else {
		puts("init");
		fstat(fd, &st);
		image_size = st.st_size;
		image = malloc(image_size);
		read(fd, image, image_size);
		close(fd);
		if (init_module(image, image_size, params) != 0) {
			perror("init_module");
			return EXIT_FAILURE;
		}
		free(image);
	}
	return EXIT_SUCCESS;
}