1 /*
2  * volume_id - reads filesystem label and uuid
3  *
4  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
5  *
6  *	This library is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU Lesser General Public
8  *	License as published by the Free Software Foundation; either
9  *	version 2.1 of the License, or (at your option) any later version.
10  *
11  *	This library is distributed in the hope that it will be useful,
12  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  *	Lesser General Public License for more details.
15  *
16  *	You should have received a copy of the GNU Lesser General Public
17  *	License along with this library; if not, write to the Free Software
18  *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19  */
20 
21 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_LINUXSWAP) += linux_swap.o
22 
23 //config:
24 //config:config FEATURE_VOLUMEID_LINUXSWAP
25 //config:	bool "linux swap filesystem"
26 //config:	default y
27 //config:	depends on VOLUMEID
28 //config:	help
29 //config:	  TODO
30 //config:
31 
32 #include "volume_id_internal.h"
33 
34 struct swap_header_v1_2 {
35 	uint8_t		bootbits[1024];
36 	uint32_t	version;
37 	uint32_t	last_page;
38 	uint32_t	nr_badpages;
39 	uint8_t		uuid[16];
40 	uint8_t		volume_name[16];
41 } PACKED;
42 
43 #define LARGEST_PAGESIZE			0x4000
44 
volume_id_probe_linux_swap(struct volume_id * id)45 int FAST_FUNC volume_id_probe_linux_swap(struct volume_id *id /*,uint64_t off*/)
46 {
47 #define off ((uint64_t)0)
48 	struct swap_header_v1_2 *sw;
49 	const uint8_t *buf;
50 	unsigned page;
51 
52 	dbg("probing at offset 0x%llx", (unsigned long long) off);
53 
54 	/* the swap signature is at the end of the PAGE_SIZE */
55 	for (page = 0x1000; page <= LARGEST_PAGESIZE; page <<= 1) {
56 			buf = volume_id_get_buffer(id, off + page-10, 10);
57 			if (buf == NULL)
58 				return -1;
59 
60 			if (memcmp(buf, "SWAP-SPACE", 10) == 0) {
61 //				id->type_version[0] = '1';
62 //				id->type_version[1] = '\0';
63 				goto found;
64 			}
65 
66 			if (memcmp(buf, "SWAPSPACE2", 10) == 0
67 			 || memcmp(buf, "S1SUSPEND", 9) == 0
68 			 || memcmp(buf, "S2SUSPEND", 9) == 0
69 			 || memcmp(buf, "ULSUSPEND", 9) == 0
70 			) {
71 				sw = volume_id_get_buffer(id, off, sizeof(struct swap_header_v1_2));
72 				if (sw == NULL)
73 					return -1;
74 //				id->type_version[0] = '2';
75 //				id->type_version[1] = '\0';
76 //				volume_id_set_label_raw(id, sw->volume_name, 16);
77 				volume_id_set_label_string(id, sw->volume_name, 16);
78 				volume_id_set_uuid(id, sw->uuid, UUID_DCE);
79 				goto found;
80 			}
81 	}
82 	return -1;
83 
84 found:
85 //	volume_id_set_usage(id, VOLUME_ID_OTHER);
86 	IF_FEATURE_BLKID_TYPE(id->type = "swap";)
87 
88 	return 0;
89 }
90