1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/lspart.c	Fri Oct 14 07:45:44 2011 +0300
     1.3 @@ -0,0 +1,228 @@
     1.4 +#include <stdio.h>
     1.5 +#include <stdlib.h>
     1.6 +#include <string.h>
     1.7 +#include <inttypes.h>
     1.8 +#include <errno.h>
     1.9 +#include <unistd.h>
    1.10 +#include <fcntl.h>
    1.11 +#include "ptype.h"
    1.12 +
    1.13 +#define PATTR_ACT_BIT	(1 << 9)
    1.14 +#define PATTR_PRIM_BIT	(1 << 10)
    1.15 +
    1.16 +#define PTYPE(attr)		((attr) & 0xff)
    1.17 +#define IS_ACT(attr)	((attr) & PATTR_ACT_BIT)
    1.18 +#define IS_PRIM(attr)	((attr) & PATTR_PRIM_BIT)
    1.19 +
    1.20 +struct partition {
    1.21 +	uint32_t start_sect;
    1.22 +	size_t size_sect;
    1.23 +
    1.24 +	unsigned int attr;
    1.25 +
    1.26 +	struct partition *next;
    1.27 +};
    1.28 +
    1.29 +struct part_record {
    1.30 +	uint8_t stat;
    1.31 +	uint8_t first_head, first_cyl, first_sect;
    1.32 +	uint8_t type;
    1.33 +	uint8_t last_head, last_cyl, last_sect;
    1.34 +	uint32_t first_lba;
    1.35 +	uint32_t nsect_lba;
    1.36 +} __attribute__((packed));
    1.37 +
    1.38 +static void print_parlist(struct partition *plist);
    1.39 +
    1.40 +static struct partition *load_parlist(void);
    1.41 +static uint16_t bootsig(const char *sect);
    1.42 +static int read_sector(void *buf, uint32_t sector);
    1.43 +static const char *printsz(unsigned int sz);
    1.44 +static const char *ptype_name(int type);
    1.45 +
    1.46 +int bdev;
    1.47 +
    1.48 +int main(int argc, char **argv)
    1.49 +{
    1.50 +	struct partition *plist;
    1.51 +
    1.52 +	if(argc != 2) {
    1.53 +		fprintf(stderr, "usage: %s <block device>\n", argv[0]);
    1.54 +		return 1;
    1.55 +	}
    1.56 +
    1.57 +	if((bdev = open(argv[1], O_RDONLY)) == -1) {
    1.58 +		fprintf(stderr, "failed to open %s: %s\n", argv[1], strerror(errno));
    1.59 +		return 1;
    1.60 +	}
    1.61 +
    1.62 +	if((plist = load_parlist())) {
    1.63 +		printf("partitions:\n");
    1.64 +		print_parlist(plist);
    1.65 +	}
    1.66 +
    1.67 +	return 0;
    1.68 +}
    1.69 +
    1.70 +static void print_parlist(struct partition *plist)
    1.71 +{
    1.72 +	int idx = 0;
    1.73 +
    1.74 +	while(plist) {
    1.75 +		printf("%d%c ", idx++, IS_ACT(plist->attr) ? '*' : ' ');
    1.76 +		printf("(%s) %-20s ", IS_PRIM(plist->attr) ? "pri" : "log", ptype_name(PTYPE(plist->attr)));
    1.77 +		printf("start: %-10lu ", (unsigned long)plist->start_sect);
    1.78 +		printf("size: %-10lu [%s]\n", (unsigned long)plist->size_sect, printsz(plist->size_sect));
    1.79 +		plist = plist->next;
    1.80 +	}
    1.81 +}
    1.82 +
    1.83 +
    1.84 +#define BOOTSIG_OFFS	510
    1.85 +#define PTABLE_OFFS		0x1be
    1.86 +
    1.87 +#define BOOTSIG			0xaa55
    1.88 +
    1.89 +#define IS_MBR			(sidx == 0)
    1.90 +#define IS_FIRST_EBR	(!IS_MBR && (first_ebr_offs == 0))
    1.91 +static struct partition *load_parlist(void)
    1.92 +{
    1.93 +	char *sect;
    1.94 +	struct partition *phead = 0, *ptail = 0;
    1.95 +	uint32_t sidx = 0;
    1.96 +	uint32_t first_ebr_offs = 0;
    1.97 +	int i, num_bootrec = 0;
    1.98 +
    1.99 +	if(!(sect = malloc(512))) {
   1.100 +		perror("failed to allocate sector buffer");
   1.101 +		return 0;
   1.102 +	}
   1.103 +
   1.104 +
   1.105 +	do {
   1.106 +		int num_rec;
   1.107 +		struct part_record *prec;
   1.108 +
   1.109 +		if(IS_FIRST_EBR) {
   1.110 +			first_ebr_offs = sidx;
   1.111 +		}
   1.112 +
   1.113 +		if(read_sector(sect, sidx) == -1) {
   1.114 +			goto err;
   1.115 +		}
   1.116 +		if(bootsig(sect) != BOOTSIG) {
   1.117 +			fprintf(stderr, "invalid/corrupted partition table, sector %lu has no magic\n", (unsigned long)sidx);
   1.118 +			goto err;
   1.119 +		}
   1.120 +		prec = (struct part_record*)(sect + PTABLE_OFFS);
   1.121 +
   1.122 +		/* MBR has 4 records, EBRs have 2 */
   1.123 +		num_rec = IS_MBR ? 4 : 2;
   1.124 +
   1.125 +		for(i=0; i<num_rec; i++) {
   1.126 +			struct partition *pnode;
   1.127 +
   1.128 +			/* ignore empty partitions in the MBR, stop if encountered in an EBR */
   1.129 +			if(prec[i].type == 0) {
   1.130 +				if(num_bootrec > 0) {
   1.131 +					sidx = 0;
   1.132 +					break;
   1.133 +				}
   1.134 +				continue;
   1.135 +			}
   1.136 +
   1.137 +			/* ignore extended partitions and setup sector index to read
   1.138 +			 * the next logical partition afterwards.
   1.139 +			 */
   1.140 +			if(prec[i].type == PTYPE_EXT || prec[i].type == PTYPE_EXT_LBA) {
   1.141 +				/* all EBR start fields are relative to the first EBR offset */
   1.142 +				sidx = first_ebr_offs + prec[i].first_lba;
   1.143 +				continue;
   1.144 +			}
   1.145 +
   1.146 +			if(!(pnode = malloc(sizeof *pnode))) {
   1.147 +				perror("failed to allocate partition list node");
   1.148 +				goto err;
   1.149 +			}
   1.150 +
   1.151 +			pnode->attr = prec[i].type;
   1.152 +
   1.153 +			if(prec[i].stat & 0x80) {
   1.154 +				pnode->attr |= PATTR_ACT_BIT;
   1.155 +			}
   1.156 +			if(IS_MBR) {
   1.157 +				pnode->attr |= PATTR_PRIM_BIT;
   1.158 +			}
   1.159 +			pnode->start_sect = prec[i].first_lba + first_ebr_offs;
   1.160 +			pnode->size_sect = prec[i].nsect_lba;
   1.161 +			pnode->next = 0;
   1.162 +
   1.163 +			/* append to the list */
   1.164 +			if(!phead) {
   1.165 +				phead = ptail = pnode;
   1.166 +			} else {
   1.167 +				ptail->next = pnode;
   1.168 +				ptail = pnode;
   1.169 +			}
   1.170 +		}
   1.171 +
   1.172 +		num_bootrec++;
   1.173 +	} while(sidx > 0);
   1.174 +
   1.175 +	free(sect);
   1.176 +	return phead;
   1.177 +
   1.178 +err:
   1.179 +	free(sect);
   1.180 +	while(phead) {
   1.181 +		void *tmp = phead;
   1.182 +		phead = phead->next;
   1.183 +		free(tmp);
   1.184 +	}
   1.185 +	return 0;
   1.186 +}
   1.187 +
   1.188 +static uint16_t bootsig(const char *sect)
   1.189 +{
   1.190 +	return *(uint16_t*)(sect + BOOTSIG_OFFS);
   1.191 +}
   1.192 +
   1.193 +static int read_sector(void *buf, uint32_t sector)
   1.194 +{
   1.195 +	if(lseek(bdev, (off_t)sector * 512, SEEK_SET) == -1) {
   1.196 +		fprintf(stderr, "read_sector: failed to seek: %s\n", strerror(errno));
   1.197 +		return -1;
   1.198 +	}
   1.199 +	if(read(bdev, buf, 512) != 512) {
   1.200 +		fprintf(stderr, "failed to read sector %lu: %s\n", (unsigned long)sector, strerror(errno));
   1.201 +		return -1;
   1.202 +	}
   1.203 +	return 0;
   1.204 +}
   1.205 +
   1.206 +const char *printsz(unsigned int sz)
   1.207 +{
   1.208 +	int i = 0;
   1.209 +	const char *suffix[] = { "kb", "mb", "gb", "tb", "pb", 0 };
   1.210 +	static char buf[512];
   1.211 +
   1.212 +	while(sz > 1024 && suffix[i + 1]) {
   1.213 +		sz /= 1024;
   1.214 +		i++;
   1.215 +	}
   1.216 +
   1.217 +	sprintf(buf, "%u %s", sz, suffix[i]);
   1.218 +	return buf;
   1.219 +}
   1.220 +
   1.221 +static const char *ptype_name(int type)
   1.222 +{
   1.223 +	int i;
   1.224 +
   1.225 +	for(i=0; i<PTYPES_SIZE; i++) {
   1.226 +		if(partypes[i].type == type) {
   1.227 +			return partypes[i].name;
   1.228 +		}
   1.229 +	}
   1.230 +	return "unknown";
   1.231 +}