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-rw-r--r--util-linux/fdisk_gpt.c203
1 files changed, 203 insertions, 0 deletions
diff --git a/util-linux/fdisk_gpt.c b/util-linux/fdisk_gpt.c
new file mode 100644
index 000000000..98803ec88
--- /dev/null
+++ b/util-linux/fdisk_gpt.c
@@ -0,0 +1,203 @@
1#if ENABLE_FEATURE_GPT_LABEL
2/*
3 * Copyright (C) 2010 Kevin Cernekee <cernekee@gmail.com>
4 *
5 * Licensed under GPLv2, see file LICENSE in this source tree.
6 */
7
8#define GPT_MAGIC 0x5452415020494645ULL
9enum {
10 LEGACY_GPT_TYPE = 0xee,
11 GPT_MAX_PARTS = 256,
12 GPT_MAX_PART_ENTRY_LEN = 4096,
13 GUID_LEN = 16,
14};
15
16typedef struct {
17 uint64_t magic;
18 uint32_t revision;
19 uint32_t hdr_size;
20 uint32_t hdr_crc32;
21 uint32_t reserved;
22 uint64_t current_lba;
23 uint64_t backup_lba;
24 uint64_t first_usable_lba;
25 uint64_t last_usable_lba;
26 uint8_t disk_guid[GUID_LEN];
27 uint64_t first_part_lba;
28 uint32_t n_parts;
29 uint32_t part_entry_len;
30 uint32_t part_array_crc32;
31} gpt_header;
32
33typedef struct {
34 uint8_t type_guid[GUID_LEN];
35 uint8_t part_guid[GUID_LEN];
36 uint64_t lba_start;
37 uint64_t lba_end;
38 uint64_t flags;
39 uint16_t name[36];
40} gpt_partition;
41
42static gpt_header *gpt_hdr;
43
44static char *part_array;
45static unsigned int n_parts;
46static unsigned int part_array_len;
47static unsigned int part_entry_len;
48
49static uint32_t *crc32_table;
50
51static inline gpt_partition *
52gpt_part(int i)
53{
54 if (i >= n_parts) {
55 return NULL;
56 }
57 return (gpt_partition *)&part_array[i * part_entry_len];
58}
59
60/* TODO: move to libbb */
61static uint32_t
62gpt_crc32(void *buf, int len)
63{
64 uint32_t crc = 0xffffffff;
65
66 for (; len > 0; len--, buf++) {
67 crc = crc32_table[(crc ^ *((char *)buf)) & 0xff] ^ (crc >> 8);
68 }
69 return crc ^ 0xffffffff;
70}
71
72static void
73gpt_print_guid(uint8_t *buf)
74{
75 printf(
76 "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
77 buf[3], buf[2], buf[1], buf[0],
78 buf[5], buf[4],
79 buf[7], buf[6],
80 buf[8], buf[9],
81 buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]);
82}
83
84/* TODO: real unicode support */
85static void
86gpt_print_wide(uint16_t *s, int max_len)
87{
88 int i = 0;
89
90 while (i < max_len) {
91 if (*s == 0)
92 return;
93 fputc(*s, stdout);
94 s++;
95 }
96}
97
98static void
99gpt_list_table(int xtra UNUSED_PARAM)
100{
101 int i;
102 char numstr6[6];
103
104 numstr6[5] = '\0';
105
106 smart_ulltoa5(total_number_of_sectors, numstr6, " KMGTPEZY");
107 printf("Disk %s: %llu sectors, %s\n", disk_device,
108 (unsigned long long)total_number_of_sectors,
109 numstr6);
110 printf("Logical sector size: %u\n", sector_size);
111 printf("Disk identifier (GUID): ");
112 gpt_print_guid(gpt_hdr->disk_guid);
113 printf("\nPartition table holds up to %u entries\n",
114 (int)SWAP_LE32(gpt_hdr->n_parts));
115 printf("First usable sector is %llu, last usable sector is %llu\n\n",
116 (unsigned long long)SWAP_LE64(gpt_hdr->first_usable_lba),
117 (unsigned long long)SWAP_LE64(gpt_hdr->last_usable_lba));
118
119 printf("Number Start (sector) End (sector) Size Code Name\n");
120 for (i = 0; i < n_parts; i++) {
121 gpt_partition *p = gpt_part(i);
122 if (p->lba_start) {
123 smart_ulltoa5(1 + SWAP_LE64(p->lba_end) - SWAP_LE64(p->lba_start),
124 numstr6, " KMGTPEZY");
125 printf("%4u %15llu %15llu %11s %04x ",
126 i + 1,
127 (unsigned long long)SWAP_LE64(p->lba_start),
128 (unsigned long long)SWAP_LE64(p->lba_end),
129 numstr6,
130 0x0700 /* FIXME */);
131 gpt_print_wide(p->name, 18);
132 printf("\n");
133 }
134 }
135}
136
137static int
138check_gpt_label(void)
139{
140 struct partition *first = pt_offset(MBRbuffer, 0);
141 struct pte pe;
142 uint32_t crc;
143
144 /* LBA 0 contains the legacy MBR */
145
146 if (!valid_part_table_flag(MBRbuffer)
147 || first->sys_ind != LEGACY_GPT_TYPE
148 ) {
149 current_label_type = 0;
150 return 0;
151 }
152
153 /* LBA 1 contains the GPT header */
154
155 read_pte(&pe, 1);
156 gpt_hdr = (void *)pe.sectorbuffer;
157
158 if (gpt_hdr->magic != SWAP_LE64(GPT_MAGIC)) {
159 current_label_type = 0;
160 return 0;
161 }
162
163 if (!crc32_table) {
164 crc32_table = crc32_filltable(NULL, 0);
165 }
166
167 crc = SWAP_LE32(gpt_hdr->hdr_crc32);
168 gpt_hdr->hdr_crc32 = 0;
169 if (gpt_crc32(gpt_hdr, SWAP_LE32(gpt_hdr->hdr_size)) != crc) {
170 /* FIXME: read the backup table */
171 puts("\nwarning: GPT header CRC is invalid\n");
172 }
173
174 n_parts = SWAP_LE32(gpt_hdr->n_parts);
175 part_entry_len = SWAP_LE32(gpt_hdr->part_entry_len);
176 if (n_parts > GPT_MAX_PARTS
177 || part_entry_len > GPT_MAX_PART_ENTRY_LEN
178 || SWAP_LE32(gpt_hdr->hdr_size) > sector_size
179 ) {
180 puts("\nwarning: unable to parse GPT disklabel\n");
181 current_label_type = 0;
182 return 0;
183 }
184
185 part_array_len = n_parts * part_entry_len;
186 part_array = xmalloc(part_array_len);
187 seek_sector(SWAP_LE64(gpt_hdr->first_part_lba));
188 if (full_read(dev_fd, part_array, part_array_len) != part_array_len) {
189 fdisk_fatal(unable_to_read);
190 }
191
192 if (gpt_crc32(part_array, part_array_len) != gpt_hdr->part_array_crc32) {
193 /* FIXME: read the backup table */
194 puts("\nwarning: GPT array CRC is invalid\n");
195 }
196
197 puts("Found valid GPT with protective MBR; using GPT\n");
198
199 current_label_type = LABEL_GPT;
200 return 1;
201}
202
203#endif /* GPT_LABEL */
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