/* SPDX-License-Identifier: MIT */
/* Copyright (C) 2014 by John Cronin
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "crc32.h"
#include "guid.h"
#include "part_ids.h"
#include "unaligned.h"
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct partition {
GUID type;
GUID uuid;
uint64_t attrs;
long src_length;
FILE *src;
struct partition *next; /* TODO why build a list? */
int id;
int sect_start;
int sect_length;
char name[52];
};
#define MAX_PART_NAME (36U)
#define MIN_SECTOR_SIZE (512U)
#define MAX_SECTOR_SIZE (4096U)
/*
* UEFI says 128 is the "minimum size" but since we're generating the image we
* get to pick; and we're fine with 128 for now; anything else would probably
* also mess with other GPT tools?
*/
#define PART_ENTRY_SIZE (128U)
/*
* TODO Everything else says 92 instead, and that's also what gdisk does when
* it creates a GPT. It's a mystery why the code here uses 96 instead.
*/
#define GPT_HEADER_SIZE (96U)
static void
dump_help(char *fname);
static int
check_parts();
static int
parse_opts(int argc, char **argv);
static void
write_output();
static inline int
min(const int a, const int b)
{
return a < b ? a : b;
}
static size_t sect_size = MIN_SECTOR_SIZE;
static long image_sects = 0;
static long min_image_sects = 2048;
static struct partition *first_part = NULL;
static struct partition *last_part = NULL;
static FILE *output = NULL;
static GUID disk_guid;
static int part_count;
static int header_sectors;
static int first_usable_sector;
static int secondary_headers_sect;
static int secondary_gpt_sect;
int
main(int argc, char *argv[])
{
random_guid(&disk_guid);
if (parse_opts(argc, argv) != 0) {
exit(EXIT_FAILURE);
}
if (output == NULL) {
fprintf(stderr, "no output file specified\n");
dump_help(argv[0]);
exit(EXIT_FAILURE);
}
if (first_part == NULL) {
fprintf(stderr, "no partitions specified\n");
dump_help(argv[0]);
exit(EXIT_FAILURE);
}
if (check_parts() != 0) {
exit(EXIT_FAILURE);
}
write_output();
fclose(output);
exit(EXIT_SUCCESS);
}
static int
parse_opts(int argc, char *argv[])
{
int i = 1;
int cur_part_id = 0;
struct partition *cur_part = NULL;
/* First, parse global options */
while (i < argc) {
if (!strcmp(argv[i], "--output") || !strcmp(argv[i], "-o")) {
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr, "no output file specified\n");
return -1;
}
output = fopen(argv[i], "w+");
if (output == NULL) {
fprintf(stderr,
"unable to open %s for writing (%s)\n",
argv[i], strerror(errno));
return -1;
}
i++;
} else if (!strcmp(argv[i], "--disk-guid")) {
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr,
"no disk guid file specified\n");
return -1;
}
if (parse_guid(argv[i], &disk_guid) != 0) {
fprintf(stderr, "invalid disk uuid (%s)\n",
argv[i]);
return -1;
}
i++;
} else if (!strcmp(argv[i], "--help") ||
!strcmp(argv[i], "-h")) {
dump_help(argv[0]);
return -1;
} else if (!strcmp(argv[i], "--sector-size")) {
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr, "sector size not specified\n");
return -1;
}
sect_size = atoi(argv[i]);
if (sect_size < MIN_SECTOR_SIZE ||
sect_size > MAX_SECTOR_SIZE ||
sect_size % MIN_SECTOR_SIZE) {
fprintf(stderr,
"invalid sector size (%zu) - must be "
">= %u and <= %u and "
"a multiple of %u",
sect_size, MIN_SECTOR_SIZE,
MAX_SECTOR_SIZE, MIN_SECTOR_SIZE);
return -1;
}
i++;
} else if (!strcmp(argv[i], "--minimum-image-size") ||
!strcmp(argv[i], "-s")) {
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr,
"minimum image size not specified\n");
return -1;
}
min_image_sects = atoi(argv[i]);
if (min_image_sects < 2048) {
fprintf(stderr, "minimum image size must be at "
"least 2048 sectors\n");
return -1;
}
i++;
} else if (!strcmp(argv[i], "--image-size")) {
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr, "image size not specified\n");
return -1;
}
image_sects = atoi(argv[i]);
i++;
} else if (!strcmp(argv[i], "--part") || !strcmp(argv[i], "-p"))
break;
else {
fprintf(stderr, "unknown argument - %s\n", argv[i]);
dump_help(argv[0]);
return i;
}
}
/* Now parse partitions */
while (i < argc) {
if (!strcmp(argv[i], "--part") || !strcmp(argv[i], "-p")) {
/* Store the current partition data if there is one */
if (cur_part != NULL) {
if (last_part == NULL) {
first_part = last_part = cur_part;
cur_part->next = NULL;
} else {
last_part->next = cur_part;
last_part = cur_part;
cur_part->next = NULL;
}
}
/* Allocate a new partition structure */
cur_part = calloc(1, sizeof(*cur_part));
if (cur_part == NULL) {
fprintf(stderr, "out of memory allocating "
"partition structure\n");
return -1;
}
cur_part_id++;
cur_part->id = cur_part_id;
snprintf(cur_part->name, sizeof(cur_part->name),
"part%i", cur_part_id);
/* Get the filename of the partition image */
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr,
"no partition image specified for "
"partition %i\n",
cur_part_id);
return -1;
}
cur_part->src = fopen(argv[i], "r");
if (cur_part->src == NULL) {
fprintf(stderr,
"unable to open partition image (%s) "
"for partition (%i) - %s\n",
argv[i], cur_part_id, strerror(errno));
return -1;
}
i++;
} else if (!strcmp(argv[i], "--name") ||
!strcmp(argv[i], "-n")) {
if (cur_part == NULL) {
fprintf(stderr, "--part must be specified "
"before --name argument\n");
return -1;
}
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr,
"partition name not specified %i\n",
cur_part_id);
return -1;
}
/*
* TODO we would really need to check the number of
* UTF-8 characters and not the number of bytes here...
*/
if (strlen(argv[i]) > MAX_PART_NAME) {
fprintf(stderr,
"partition name too long (max %u)\n",
MAX_PART_NAME);
return -1;
}
static_assert(sizeof(cur_part->name) >= MAX_PART_NAME,
"more space for name in struct partition");
strcpy(cur_part->name, argv[i]);
i++;
} else if (!strcmp(argv[i], "--type") ||
(!strcmp(argv[i], "-t"))) {
if (cur_part == NULL) {
fprintf(stderr, "--part must be specifed "
"before --type argument\n");
return -1;
}
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr,
"partition type not specified %i\n",
cur_part_id);
return -1;
}
if (parse_guid(argv[i], &cur_part->type) != 0) {
fprintf(stderr,
"invalid partition type (%s) for "
"partition %i\n",
argv[i], cur_part_id);
return -1;
}
i++;
} else if (!strcmp(argv[i], "--uuid") ||
(!strcmp(argv[i], "-u"))) {
if (cur_part == NULL) {
fprintf(stderr, "--part must be specifed "
"before --uuid argument\n");
return -1;
}
i++;
if (i == argc || argv[i][0] == '-') {
fprintf(stderr,
"partition uuid not specified %i\n",
cur_part_id);
return -1;
}
if (parse_guid(argv[i], &cur_part->uuid) != 0) {
fprintf(stderr,
"invalid partition uuid (%s) for "
"partition %i\n",
argv[i], cur_part_id);
return -1;
}
i++;
} else {
fprintf(stderr, "unknown argument - %s\n", argv[i]);
dump_help(argv[0]);
return i;
}
}
if (cur_part != NULL) {
if (last_part == NULL) {
first_part = last_part = cur_part;
cur_part->next = NULL;
} else {
last_part->next = cur_part;
last_part = cur_part;
cur_part->next = NULL;
}
}
return 0;
}
static void
dump_help(char *fname)
{
printf("Usage: %s -o <output_file> [-h] [--disk-guid GUID] "
"[--sector-size sect_size] [-s min_image_size] "
"[partition def 0] [part def 1] ... [part def n]\n"
" Partition definition: --part <image_file> --type <type> "
"[--uuid uuid] [--name name]\n"
" Please see the README file for further information\n",
fname);
}
static int
check_parts()
{
/* Iterate through the partitions, checking validity */
int cur_part_id = 0;
int cur_sect;
struct partition *cur_part;
int header_length;
int needed_file_length;
/* Count partitions */
cur_part = first_part;
part_count = 0;
while (cur_part) {
part_count++;
cur_part = cur_part->next;
}
/* Determine the sectors needed for MBR, GPT header and partition
* entries */
cur_sect = 2; /* MBR + GPT header */
header_length = part_count * PART_ENTRY_SIZE;
header_sectors = header_length / sect_size;
if (header_length % sect_size) {
header_sectors++;
}
/* The GPT entry array must be a minimum of 16,384 bytes (reports
* wikipedia and testdisk, but not the UEFI spec)
*/
if (header_sectors < (int)(16384 / sect_size)) {
header_sectors = (int)(16384 / sect_size);
}
cur_sect += header_sectors;
first_usable_sector = cur_sect;
cur_part = first_part;
while (cur_part) {
long cur_part_file_len;
cur_part_id++;
if (guid_is_zero(&cur_part->type)) {
fprintf(stderr,
"partition type not specified for partition "
"%i\n",
cur_part_id);
return -1;
}
/* TODO is this appropriate? check the spec! */
if (guid_is_zero(&cur_part->uuid)) {
random_guid(&cur_part->uuid);
}
if (cur_part->sect_start == 0) {
cur_part->sect_start = cur_sect;
} else if (cur_part->sect_start < cur_sect) {
fprintf(stderr,
"unable to start partition %i at sector %i "
"(would conflict with other data)\n",
cur_part_id, cur_part->sect_start);
return -1;
}
fseek(cur_part->src, 0, SEEK_END);
cur_part_file_len = ftell(cur_part->src);
fseek(cur_part->src, 0, SEEK_SET);
if (cur_part->sect_length == 0) {
cur_part->sect_length = cur_part_file_len / sect_size;
if (cur_part_file_len % sect_size) {
cur_part->sect_length++;
}
}
cur_sect = cur_part->sect_start + cur_part->sect_length;
cur_part = cur_part->next;
}
/* Add space for the secondary GPT */
needed_file_length = cur_sect + 1 + header_sectors;
if (image_sects == 0) {
if (needed_file_length > min_image_sects) {
image_sects = needed_file_length;
} else {
image_sects = min_image_sects;
}
} else if (image_sects < needed_file_length) {
fprintf(stderr,
"requested image size (%zu) is too small to hold the "
"partitions\n",
image_sects * sect_size);
return -1;
}
secondary_headers_sect = image_sects - 1 - header_sectors;
secondary_gpt_sect = image_sects - 1;
return 0;
}
static void
panic(const char *msg)
{
fprintf(stderr, "panic: %s", msg);
exit(EXIT_FAILURE);
}
/*
* Write the "protective MBR" to FILE *output.
*/
static void
write_mbr(void)
{
uint8_t mbr[MAX_SECTOR_SIZE] = {0};
assert(sect_size <= sizeof(mbr));
/* entry for "Partition 1" starts here */
uint8_t *p1 = mbr + 446;
/* boot indicator = 0, start CHS = 0x000200 */
set_u32(p1 + 0, 0x00020000);
/* OSType 0xee = GPT Protective, EndingCHS = 0xffffff */
set_u32(p1 + 4, 0xffffffee);
/* StartingLBA = 1 */
set_u32(p1 + 8, 0x00000001);
/* number of sectors in partition */
if (image_sects > 0xffffffff) {
set_u32(p1 + 12, 0xffffffff);
} else {
assert(image_sects > 1); /* 0 sectors is not allowed */
set_u32(p1 + 12, image_sects - 1);
}
/* Signature */
set_u16(mbr + 510, 0xaa55);
if (fwrite(mbr, 1, sect_size, output) != sect_size) {
panic("fwrite failed");
}
}
static void
write_output(void)
{
uint8_t *parts;
struct partition *cur_part;
write_mbr();
/* Define GPT headers */
uint8_t gpt[MAX_SECTOR_SIZE] = {0};
assert(sect_size <= sizeof(gpt));
uint8_t gpt2[MAX_SECTOR_SIZE] = {0};
assert(sect_size <= sizeof(gpt2));
set_u64(gpt + 0, 0x5452415020494645ULL); /* Signature */
set_u32(gpt + 8, 0x00010000UL); /* Revision */
set_u32(gpt + 12, GPT_HEADER_SIZE); /* HeaderSize */
set_u32(gpt + 16, 0); /* HeaderCRC32 */
set_u32(gpt + 20, 0); /* Reserved */
set_u64(gpt + 24, 0x1); /* MyLBA */
set_u64(gpt + 32, secondary_gpt_sect); /* AlternateLBA */
set_u64(gpt + 40, first_usable_sector); /* FirstUsableLBA */
set_u64(gpt + 48, secondary_headers_sect - 1); /* LastUsableLBA */
guid_to_bytestring(gpt + 56, &disk_guid); /* DiskGUID */
set_u64(gpt + 72, 0x2); /* PartitionEntryLBA */
set_u32(gpt + 80, part_count); /* NumberOfPartitionEntries */
set_u32(gpt + 84, PART_ENTRY_SIZE); /* SizeOfPartitionEntry */
set_u32(gpt + 88, 0); /* PartitionEntryArrayCRC32 */
/* Define GPT partition entries */
parts = calloc(header_sectors, sect_size);
if (parts == NULL) {
panic("calloc failed");
}
cur_part = first_part;
int i = 0;
while (cur_part) {
int char_id;
guid_to_bytestring(parts + i * PART_ENTRY_SIZE + 0,
&cur_part->type); /* PartitionTypeGUID */
guid_to_bytestring(parts + i * PART_ENTRY_SIZE + 16,
&cur_part->uuid); /* UniquePartitionGUID */
set_u64(parts + i * PART_ENTRY_SIZE + 32,
cur_part->sect_start); /* StartingLBA */
set_u64(parts + i * PART_ENTRY_SIZE + 40,
cur_part->sect_start + cur_part->sect_length -
1); /* EndingLBA */
set_u64(parts + i * PART_ENTRY_SIZE + 48,
cur_part->attrs); /* Attributes */
/*
* TODO settle missing UTF-16LE conversion issue somehow,
* possibly by simply limiting the tool to ASCII here?
* TODO used to be "&& char_id < 35" but MAX_PART_NAME is 36
* now so which is correct? do we need a "double zero" at the
* end or not? what does the spec say? sfdisk works with 36
* chars and if we try 37 it just ignores the extra one, so
* there's some indication that no "double zero" is needed and
* that 36 is indeed the correct limit
*/
int len = min(strlen(cur_part->name), MAX_PART_NAME);
for (char_id = 0; char_id < len; char_id++) {
set_u16(parts + i * PART_ENTRY_SIZE + 56 + char_id * 2,
cur_part->name[char_id]);
}
i++;
cur_part = cur_part->next;
}
/* Do CRC calculations on the partition table entries and GPT headers */
uint32_t parts_crc;
CalculateCrc32(parts, part_count * PART_ENTRY_SIZE, &parts_crc);
set_u32(gpt + 88, parts_crc);
uint32_t gpt_crc;
CalculateCrc32(gpt, GPT_HEADER_SIZE, &gpt_crc);
set_u32(gpt + 16, gpt_crc);
memcpy(gpt2, gpt, GPT_HEADER_SIZE);
set_u32(gpt2 + 16, 0); /* HeaderCRC32 */
set_u64(gpt2 + 24, secondary_gpt_sect); /* MyLBA */
set_u64(gpt2 + 32, 0x1); /* AlternateLBA */
set_u64(gpt2 + 72, secondary_headers_sect); /* PartitionEntryLBA */
uint32_t gpt2_crc;
CalculateCrc32(gpt2, GPT_HEADER_SIZE, &gpt2_crc);
set_u32(gpt2 + 16, gpt2_crc);
/* Write primary GPT and headers */
if (fwrite(gpt, 1, sect_size, output) != sect_size) {
panic("fwrite failed");
}
if (fwrite(parts, 1, header_sectors * sect_size, output) !=
header_sectors * sect_size) {
panic("fwrite failed");
}
/* Write partitions */
cur_part = first_part;
uint8_t image_buf[MAX_SECTOR_SIZE] = {0};
assert(sect_size <= sizeof(image_buf));
while (cur_part) {
size_t bytes_read;
size_t bytes_written = 0;
fseek(output, cur_part->sect_start * sect_size, SEEK_SET);
while ((bytes_read = fread(
image_buf, 1, sect_size, cur_part->src)) > 0) {
size_t bytes_to_write = bytes_read;
/* Determine how much to write */
if ((bytes_written + bytes_to_write) >
(size_t)(cur_part->sect_length * sect_size))
bytes_to_write =
cur_part->sect_length * sect_size -
bytes_written;
if (fwrite(image_buf, 1, bytes_to_write, output) !=
bytes_to_write) {
panic("fwrite failed");
}
bytes_written += bytes_to_write;
}
cur_part = cur_part->next;
}
/* Write secondary GPT partition headers and header */
fseek(output, secondary_headers_sect * sect_size, SEEK_SET);
if (fwrite(parts, 1, header_sectors * sect_size, output) !=
header_sectors * sect_size) {
panic("fwrite failed");
}
fseek(output, secondary_gpt_sect * sect_size, SEEK_SET);
if (fwrite(gpt2, 1, sect_size, output) != sect_size) {
panic("fwrite failed");
}
free(parts);
}