edd_id.c revision 1aa1e24848903d11780db1ade355be73ad61a937
/*
* edd_id - naming of BIOS disk devices via EDD
*
* Copyright (C) 2005 John Hull <John_Hull@Dell.com>
* Copyright (C) 2005 Kay Sievers <kay.sievers@vrfy.org>
*
* 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.
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>
#include <dirent.h>
#include <stdint.h>
#include "../../udev.h"
#ifdef USE_LOG
void log_message(int priority, const char *format, ...)
{
va_list args;
static int udev_log = -1;
if (udev_log == -1) {
const char *value;
value = getenv("UDEV_LOG");
if (value)
udev_log = log_priority(value);
else
udev_log = LOG_ERR;
}
if (priority > udev_log)
return;
va_start(args, format);
vsyslog(priority, format, args);
va_end(args);
}
#endif
int main(int argc, char *argv[])
{
const char *node = NULL;
int i;
int export = 0;
uint32_t disk_id;
uint16_t mbr_valid;
struct dirent *dent;
int disk_fd;
int sysfs_fd;
DIR *dir = NULL;
int rc = 1;
char *match = NULL;
logging_init("edd_id");
for (i = 1 ; i < argc; i++) {
char *arg = argv[i];
if (strcmp(arg, "--export") == 0) {
export = 1;
} else
node = arg;
}
if (!node) {
err("no node specified");
fprintf(stderr, "no node specified\n");
goto exit;
}
/* check for kernel support */
dir = opendir("/sys/firmware/edd");
if (!dir) {
info("no kernel EDD support");
fprintf(stderr, "no kernel EDD support\n");
rc = 2;
goto exit;
}
disk_fd = open(node, O_RDONLY);
if (disk_fd < 0) {
info("unable to open '%s'", node);
fprintf(stderr, "unable to open '%s'\n", node);
rc = 3;
goto closedir;
}
/* check for valid MBR signature */
if (lseek(disk_fd, 510, SEEK_SET) < 0) {
info("seek to MBR validity failed '%s'", node);
rc = 4;
goto close;
}
if (read(disk_fd, &mbr_valid, sizeof(mbr_valid)) != sizeof(mbr_valid)) {
info("read MBR validity failed '%s'", node);
rc = 5;
goto close;
}
if (mbr_valid != 0xAA55) {
fprintf(stderr, "no valid MBR signature '%s'\n", node);
info("no valid MBR signature '%s'", node);
rc=6;
goto close;
}
/* read EDD signature */
if (lseek(disk_fd, 440, SEEK_SET) < 0) {
info("seek to signature failed '%s'", node);
rc = 7;
goto close;
}
if (read(disk_fd, &disk_id, sizeof(disk_id)) != sizeof(disk_id)) {
info("read signature failed '%s'", node);
rc = 8;
goto close;
}
/* all zero is invalid */
info("read id 0x%08x from '%s'", disk_id, node);
if (disk_id == 0) {
fprintf(stderr, "no EDD signature '%s'\n", node);
info("'%s' signature is zero", node);
rc = 9;
goto close;
}
/* lookup signature in sysfs to determine the name */
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
char file[PATH_SIZE];
char sysfs_id_buf[256];
uint32_t sysfs_id;
ssize_t size;
if (dent->d_name[0] == '.')
continue;
snprintf(file, sizeof(file), "/sys/firmware/edd/%s/mbr_signature", dent->d_name);
file[sizeof(file)-1] = '\0';
sysfs_fd = open(file, O_RDONLY);
if (sysfs_fd < 0) {
info("unable to open sysfs '%s'", file);
continue;
}
size = read(sysfs_fd, sysfs_id_buf, sizeof(sysfs_id_buf)-1);
close(sysfs_fd);
if (size < 0) {
info("read sysfs '%s' failed", file);
continue;
}
sysfs_id_buf[size] = '\0';
info("read '%s' from '%s'", sysfs_id_buf, file);
sysfs_id = strtoul(sysfs_id_buf, NULL, 16);
if (disk_id == sysfs_id) {
if (!match) {
match = dent->d_name;
} else {
info("'%s' does not have a unique signature", node);
fprintf(stderr, "'%s' does not have a unique signature\n", node);
rc=10;
goto exit;
}
}
}
if (export)
printf("ID_EDD=%s\n", match);
else
printf("%s\n", match);
rc = 0;
close:
close(disk_fd);
closedir:
closedir(dir);
exit:
logging_close();
return rc;
}