[klibc] include insmod in klibc?

Daniel Thaler daniel at dthaler.de
Tue Oct 19 11:44:22 PDT 2004


Hello,

I feel that the klibc package should include an insmod that can be used 
on an initramfs. While it is possible to use an insmod built statically 
against glibc, such a binary is (comparatively) huge at 565K.

The attached insmod.c is essentially the insmod.c from module-init-tools 
minus a couple of lines related to calling the old (2.4) version of 
insmod for backward compat.

BTW: Insmod compiled with klibc is 1.4K small.

Daniel Thaler
-------------- next part --------------
/* insmod.c: insert a module into the kernel.
    Copyright (C) 2001  Rusty Russell.
    Copyright (C) 2002  Rusty Russell, IBM Corporation.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <asm/unistd.h>


#define streq(a,b) (strcmp((a),(b)) == 0)

extern long init_module(void *, unsigned long, const char *);

static void print_usage(const char *progname)
{
	fprintf(stderr, "Usage: %s filename [args]\n", progname);
	exit(1);
}

/* We use error numbers in a loose translation... */
static const char *moderror(int err)
{
	switch (err) {
	case ENOEXEC:
		return "Invalid module format";
	case ENOENT:
		return "Unknown symbol in module";
	case ESRCH:
		return "Module has wrong symbol version";
	case EINVAL:
		return "Invalid parameters";
	default:
		return strerror(err);
	}
}

static void *grab_file(const char *filename, unsigned long *size)
{
	unsigned int max = 16384;
	int ret, fd;
	void *buffer = malloc(max);

	if (streq(filename, "-"))
		fd = dup(STDIN_FILENO);
	else
		fd = open(filename, O_RDONLY, 0);

	if (fd < 0)
		return NULL;

	*size = 0;
	while ((ret = read(fd, buffer + *size, max - *size)) > 0) {
		*size += ret;
		if (*size == max)
			buffer = realloc(buffer, max *= 2);
	}
	if (ret < 0) {
		free(buffer);
		buffer = NULL;
	}
	close(fd);
	return buffer;
}

int main(int argc, char *argv[])
{
	unsigned int i;
	long int ret;
	unsigned long len;
	void *file;
	char *filename, *options = strdup("");
	char *progname = argv[0];

	if (argv[1] && (streq(argv[1], "--version") || streq(argv[1], "-V"))) {
		puts("klibc insmod");
		exit(0);
	}

	/* Ignore old options, for backwards compat. */
	while (argv[1] && (streq(argv[1], "-p")
			   || streq(argv[1], "-s")
			   || streq(argv[1], "-f"))) {
		argv++;
		argc--;
	}

	filename = argv[1];
	if (!filename)
		print_usage(progname);

	/* Rest is options */
	for (i = 2; i < argc; i++) {
		options = realloc(options,
				  strlen(options) + 2 + strlen(argv[i]) + 2);
		/* Spaces handled by "" pairs, but no way of escaping
                   quotes */
		if (strchr(argv[i], ' '))
			strcat(options, "\"");
		strcat(options, argv[i]);
		if (strchr(argv[i], ' '))
			strcat(options, "\"");
		strcat(options, " ");
	}

	file = grab_file(filename, &len);
	if (!file) {
		fprintf(stderr, "insmod: can't read '%s': %s\n",
			filename, strerror(errno));
		exit(1);
	}

	ret = init_module(file, len, options);
	if (ret != 0) {
		fprintf(stderr, "insmod: error inserting '%s': %li %s\n",
			filename, ret, moderror(errno));
		exit(1);
	}
	exit(0);
}


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