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/*
* (C) Copyright 2010 Intel Corporation
*
* Author: Auke Kok <auke-jan.h.kok@intel.com>
*
* 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; version 2
* of the License.
*/
#define _GNU_SOURCE
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
/*
* dev_info - filter table
*
* devices found in sysfs often require different base permissions or
* group/owner ids. To set things up as correctly as possible, we
* traverse a table with overrides. The table is parsed in order and
* multiple fields can hit (e.g. one with the ALL wildcard, and one
* specific for the minor node number). The last field to hit will
* effectively be used.
*
* ALL in the minor node field marks all minor nodes to use that field.
* ALL in the major node field marks the end of the table.
*
* a non-NULL string in the 'dir' field allows you to prepend a
* path between the device node and the /dev/ folder name. This is
* mostly used for alsa and v4l device nodes.
*/
#define DEV "/dev"
#define ALL 256
struct dev_info {
unsigned int major;
unsigned int minor; /* 256 = all */
const char *dir;
const char *owner;
const char *group;
unsigned int perms;
int uid; /* -1 in these fields cause owner/group to be */
int gid; /* looked up in /etc/group and /etc/passwd */
};
static struct dev_info di_chr[] = {
{ 1, 1, NULL, "root", "kmem", 0640, 0, -1 }, /* mem */
{ 1, 2, NULL, "root", "kmem", 0640, 0, -1 }, /* kmem */
{ 1, 3, NULL, "root", "root", 0666, 0, 0 }, /* null */
{ 1, 4, NULL, "root", "kmem", 0640, 0, -1 }, /* port */
{ 1, 5, NULL, "root", "root", 0666, 0, 0 }, /* zero */
{ 1, 7, NULL, "root", "root", 0666, 0, 0 }, /* full */
{ 1, 8, NULL, "root", "root", 0666, 0, 0 }, /* random */
{ 1, 9, NULL, "root", "root", 0666, 0, 0 }, /* urandom */
{ 2, ALL, NULL, "root", "tty", 0660, 0, -1 }, /* pty */
{ 3, ALL, NULL, "root", "tty", 0660, 0, -1 }, /* tty* */
{ 4, ALL, NULL, "root", "tty", 0660, 0, -1 }, /* ttyS* */
{ 5, 0, NULL, "root", "tty", 0666, 0, -1 }, /* tty */
{ 5, 1, NULL, "root", "tty", 0600, 0, -1 }, /* console */
{ 5, 2, NULL, "root", "tty", 0666, 0, -1 }, /* ptmx */
{ 7, ALL, NULL, "root", "tty", 0660, 0, -1 }, /* vcs* */
{ 13, ALL, "input", "root", "video", 0660, 0, -1 }, /* input */
{ 10, 232, NULL, "root", "kvm", 0660, 0, -1 }, /* kvm */
{ 14, ALL, NULL, "root", "audio", 0660, 0, -1 }, /* oss */
{ 21, ALL, NULL, "root", "disk", 0640, 0, -1 }, /* sg* */
{ 29, ALL, NULL, "root", "video", 0600, 0, -1 }, /* fb* */
{ 81, ALL, "v4l", "root", "video", 0660, 0, -1 }, /* v4l */
{ 116, ALL, "snd", "root", "audio", 0660, 0, -1 }, /* alsa */
{ 189, ALL, "usb", "root", "root", 0600, 0, 0 }, /* usb */
{ 226, ALL, "dri", "root", "video", 0660, 0, 0 }, /* dri */
/* terminate */
{ ALL, 0, NULL, NULL, NULL, 0, 0, 0 },
};
static struct dev_info di_blk[] = {
{ 1, ALL, NULL, "root", "disk", 0640, 0, -1 }, /* ram* */
{ 8, ALL, NULL, "root", "disk", 0640, 0, -1 }, /* sd* */
{ 11, ALL, NULL, "root", "cdrom", 0640, 0, -1 }, /* sr* */
/* terminate */
{ ALL, 0, NULL, NULL, NULL, 0, 0, 0 },
};
static void node_add(int type, unsigned int maj, unsigned int min,
char* name, struct dev_info *di)
{
struct passwd *p;
struct group *g;
unsigned int perms = 0660;
int owner = 0;
int group = 0;
char path[PATH_MAX];
int n = 0;
/* defaults */
snprintf(path, PATH_MAX, "%s/%s", DEV, name);
while (di[n].major != ALL) {
if (maj != di[n].major)
goto out;
if ((min != di[n].minor) && (di[n].minor != ALL))
goto out;
if (di[n].dir != NULL) {
snprintf(path, PATH_MAX, "%s/%s", DEV, di[n].dir);
mkdir(path, 0755);
snprintf(path, PATH_MAX, "%s/%s/%s", DEV, di[n].dir, name);
}
perms = di[n].perms;
if (di[n].uid == -1) {
p = getpwnam(di[n].owner);
if (p) {
owner = p->pw_uid;
di[n].uid = owner;
}
} else {
owner = di[n].uid;
}
if (di[n].gid == -1) {
g = getgrnam(di[n].group);
if (g) {
group = g->gr_gid;
di[n].gid = group;
}
} else {
group = di[n].gid;
}
/* don't break, allow more filters to hit */
out:
n++;
}
if ((owner == 0) && (group == 0)) {
mknod(path, type | perms, makedev(maj, min));
} else {
if (mknod(path, type, makedev(maj, min)))
return;
if (chown(path, owner, group))
return;
chmod(path, perms);
}
}
static void walk(const char *dir, int type, struct dev_info *di)
{
DIR *d;
struct dirent *entry;
char path[PATH_MAX];
ssize_t len;
unsigned int maj;
unsigned int min;
d = opendir(dir);
if (!d)
return;
while ((entry = readdir(d))) {
char p[PATH_MAX];
if ((strcmp(".", entry->d_name) == 0) ||
(strcmp("..", entry->d_name) == 0))
continue;
sscanf(entry->d_name, "%d:%d", &maj, &min);
snprintf(p, PATH_MAX, "%s/%s", dir, entry->d_name);
len = readlink(p, path, PATH_MAX - 1);
if (len != -1)
path[len] = '\0';
node_add(type, maj, min, basename(path), di);
}
closedir(d);
}
void populate_dev_blk(void)
{
int u = umask(0000);
walk("/sys/dev/block", S_IFBLK, di_blk);
umask(u);
}
void populate_dev_chr(void)
{
int u = umask(0000);
walk("/sys/dev/char", S_IFCHR, di_chr);
umask(u);
}
static struct option opts[] = {
{ "block", 0, NULL, 'b' },
{ "char", 0, NULL, 'c' },
{ "help", 0, NULL, 'h' },
{ 0, 0, NULL, 0 }
};
void usage(const char *name)
{
printf("Usage: %s [OPTION...]\n", name);
printf(" -b, --block Only create block device nodes\n");
printf(" -c, --char Only create char device nodes \n");
printf(" -h, --help Show this help message\n");
}
int main(int argc, char **argv)
{
int c;
int i;
int blk = 1;
int chr = 1;
while (1) {
c = getopt_long(argc, argv, "bch", opts, &i);
if (c == -1)
break;
switch (c) {
case 'b':
chr = 0;
break;
case 'c':
blk = 0;
break;
case 'h':
usage(argv[0]);
exit (EXIT_SUCCESS);
break;
default:
break;
}
}
if (blk)
populate_dev_blk();
if (chr)
populate_dev_chr();
exit (EXIT_SUCCESS);
}
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