add edd_id tool to match BIOS EDD disk information

Thanks to:
    John Hull <John_Hull@Dell.com>
    Matt Domsch <Matt_Domsch@Dell.com>

Signed-off-by: Kay Sievers <kay.sievers@suse.de>

1 files changed, 184 insertions, 0 deletions

diff --git a/extras/edd_id/edd_id.c b/extras/edd_id/edd_id.c
new file mode 100644
index 0000000000..504aac36e6
--- /dev/null
+++ b/extras/edd_id/edd_id.c
@@ -0,0 +1,184 @@
+/*
+ * 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 <errno.h>
+#include <dirent.h>
+#include <stdint.h>
+
+#include "../../logging.h"
+#include "../../udev_utils.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;
+
+	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 (export)
+				printf("ID_EDD=%s\n", dent->d_name);
+			else
+				printf("%s\n", dent->d_name);
+			rc = 0;
+			break;
+		}
+	}
+
+close:
+	close(disk_fd);
+closedir:
+	closedir(dir);
+exit:
+	logging_close();
+	return rc;
+}