1/*-
2 * Copyright (c) 2002 Marcel Moolenaar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#if HAVE_NBTOOL_CONFIG_H
28#include "nbtool_config.h"
29#endif
30
31#include <sys/cdefs.h>
32#ifdef __FBSDID
33__FBSDID("$FreeBSD: src/sbin/gpt/recover.c,v 1.8 2005/08/31 01:47:19 marcel Exp $");
34#endif
35#ifdef __RCSID
36__RCSID("$NetBSD: recover.c,v 1.19 2020/12/13 21:55:25 jnemeth Exp $");
37#endif
38
39#include <sys/types.h>
40
41#include <err.h>
42#include <stddef.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46#include <unistd.h>
47
48#include "map.h"
49#include "gpt.h"
50#include "gpt_private.h"
51
52static int cmd_recover(gpt_t, int, char *[]);
53
54static const char *recoverhelp[] = {
55	"",
56};
57
58struct gpt_cmd c_recover = {
59	"recover",
60	cmd_recover,
61	recoverhelp, __arraycount(recoverhelp),
62	GPT_SYNC,
63};
64
65#define usage() gpt_usage(NULL, &c_recover)
66
67static int
68recover_gpt_hdr(gpt_t gpt, int type, off_t last)
69{
70	const char *name, *origname;
71	map_t *dgpt, dtbl, sgpt, stbl __unused;
72	struct gpt_hdr *hdr;
73
74	if (gpt_add_hdr(gpt, type, last) == -1)
75		return -1;
76
77	switch (type) {
78	case MAP_TYPE_PRI_GPT_HDR:
79		dgpt = &gpt->gpt;
80		dtbl = gpt->tbl;
81		sgpt = gpt->tpg;
82		stbl = gpt->lbt;
83		origname = "secondary";
84		name = "primary";
85		break;
86	case MAP_TYPE_SEC_GPT_HDR:
87		dgpt = &gpt->tpg;
88		dtbl = gpt->lbt;
89		sgpt = gpt->gpt;
90		stbl = gpt->tbl;
91		origname = "primary";
92		name = "secondary";
93		break;
94	default:
95		gpt_warn(gpt, "Bad table type %d", type);
96		return -1;
97	}
98
99	memcpy((*dgpt)->map_data, sgpt->map_data, gpt->secsz);
100	hdr = (*dgpt)->map_data;
101	hdr->hdr_lba_self = htole64((uint64_t)(*dgpt)->map_start);
102	hdr->hdr_lba_alt = htole64((uint64_t)sgpt->map_start);
103	hdr->hdr_lba_table = htole64((uint64_t)dtbl->map_start);
104	hdr->hdr_crc_self = 0;
105	hdr->hdr_crc_self = htole32(crc32(hdr, le32toh(hdr->hdr_size)));
106	if (gpt_write(gpt, *dgpt) == -1) {
107		gpt_warnx(gpt, "Writing %s GPT header failed", name);
108		return -1;
109	}
110	gpt_msg(gpt, "Recovered %s GPT header from %s", name, origname);
111	return 0;
112}
113
114static int
115recover_gpt_tbl(gpt_t gpt, int type, off_t start)
116{
117	const char *name, *origname;
118	map_t *dtbl, stbl;
119
120	switch (type) {
121	case MAP_TYPE_PRI_GPT_TBL:
122		dtbl = &gpt->tbl;
123		stbl = gpt->lbt;
124		origname = "secondary";
125		name = "primary";
126		break;
127	case MAP_TYPE_SEC_GPT_TBL:
128		dtbl = &gpt->lbt;
129		stbl = gpt->tbl;
130		origname = "primary";
131		name = "secondary";
132		break;
133	default:
134		gpt_warn(gpt, "Bad table type %d", type);
135		return -1;
136	}
137
138	*dtbl = map_add(gpt, start, stbl->map_size, type, stbl->map_data, 0);
139	if (*dtbl == NULL) {
140		gpt_warnx(gpt, "Adding %s GPT table failed", name);
141		return -1;
142	}
143	if (gpt_write(gpt, *dtbl) == -1) {
144		gpt_warnx(gpt, "Writing %s GPT table failed", name);
145		return -1;
146	}
147	gpt_msg(gpt, "Recovered %s GPT table from %s", name, origname);
148	return 0;
149}
150
151static int
152recover(gpt_t gpt)
153{
154	off_t last = gpt_last(gpt);
155	map_t map;
156	struct mbr *mbr;
157
158	if (map_find(gpt, MAP_TYPE_MBR) != NULL) {
159		gpt_warnx(gpt, "Device contains an MBR");
160		return -1;
161	}
162
163	gpt->gpt = map_find(gpt, MAP_TYPE_PRI_GPT_HDR);
164	gpt->tpg = map_find(gpt, MAP_TYPE_SEC_GPT_HDR);
165	gpt->tbl = map_find(gpt, MAP_TYPE_PRI_GPT_TBL);
166	gpt->lbt = map_find(gpt, MAP_TYPE_SEC_GPT_TBL);
167
168	if (gpt->gpt == NULL && gpt->tpg == NULL) {
169		gpt_warnx(gpt, "No primary or secondary GPT headers, "
170		    "can't recover");
171		return -1;
172	}
173	if (gpt->tbl == NULL && gpt->lbt == NULL) {
174		gpt_warnx(gpt, "No primary or secondary GPT tables, "
175		    "can't recover");
176		return -1;
177	}
178
179	if (gpt->gpt != NULL &&
180	    le64toh(((struct gpt_hdr *)(gpt->gpt->map_data))->hdr_lba_alt) !=
181	    (uint64_t)last) {
182		gpt_warnx(gpt, "Media size has changed, please use "
183		   "'%s resizedisk'", getprogname());
184		return -1;
185	}
186
187	if (gpt->tbl != NULL && gpt->lbt == NULL) {
188		if (recover_gpt_tbl(gpt, MAP_TYPE_SEC_GPT_TBL,
189		    last - gpt->tbl->map_size) == -1)
190			return -1;
191	} else if (gpt->tbl == NULL && gpt->lbt != NULL) {
192		if (recover_gpt_tbl(gpt, MAP_TYPE_PRI_GPT_TBL, 2LL) == -1)
193			return -1;
194	}
195
196	if (gpt->gpt != NULL && gpt->tpg == NULL) {
197		if (recover_gpt_hdr(gpt, MAP_TYPE_SEC_GPT_HDR, last) == -1)
198			return -1;
199	} else if (gpt->gpt == NULL && gpt->tpg != NULL) {
200		if (recover_gpt_hdr(gpt, MAP_TYPE_PRI_GPT_HDR, 1LL) == -1)
201			return -1;
202	}
203
204	/*
205	 * Create PMBR if it doesn't already exist.
206	 */
207	if (map_find(gpt, MAP_TYPE_PMBR) == NULL) {
208		if (map_free(gpt, 0LL, 1LL) == 0) {
209			gpt_warnx(gpt, "No room for the PMBR");
210			return -1;
211		}
212		mbr = gpt_read(gpt, 0LL, 1);
213		if (mbr == NULL) {
214			gpt_warnx(gpt, "Error reading MBR");
215			return -1;
216		}
217		memset(mbr, 0, sizeof(*mbr));
218		mbr->mbr_sig = htole16(MBR_SIG);
219		gpt_create_pmbr_part(mbr->mbr_part, last, 0);
220
221		map = map_add(gpt, 0LL, 1LL, MAP_TYPE_PMBR, mbr, 1);
222		if (gpt_write(gpt, map) == -1) {
223			gpt_warn(gpt, "Can't write PMBR");
224			return -1;
225		}
226		gpt_msg(gpt,
227		    "Recreated PMBR (you may need to rerun 'gpt biosboot'");
228	}
229	return 0;
230}
231
232static int
233cmd_recover(gpt_t gpt, int argc, char *argv[])
234{
235	int ch;
236
237	while ((ch = getopt(argc, argv, "r")) != -1) {
238		switch(ch) {
239		default:
240			return usage();
241		}
242	}
243
244	if (argc != optind)
245		return usage();
246
247	return recover(gpt);
248}
249