*** empty log message ***

1 files changed, 138 insertions, 0 deletions

diff --git a/balkan/dos.c b/balkan/dos.c
new file mode 100644
index 000000000..e37a53f69
--- /dev/null
+++ b/balkan/dos.c
@@ -0,0 +1,138 @@
+/* DOS style partitioning */
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "balkan.h"
+
+struct singlePartition {
+    unsigned char active;
+    unsigned char startHead;
+    unsigned char startSector;
+    unsigned char startCyl;
+    unsigned char type;
+    unsigned char endHead;
+    unsigned char endSector;
+    unsigned char endCyl;
+    unsigned int  start;		/* in sectors */
+    unsigned int  size;			/* in sectors */
+};
+
+struct singlePartitionTable {
+    struct singlePartition parts[4];
+};
+
+/* Location of partition table in MBR */
+#define TABLE_OFFSET		446
+#define MBR_MAGIC       	0x55aa
+#define MBR_MAGIC_OFFSET	510
+#define SECTOR_SIZE		512
+
+#define DOSP_TYPE_EXTENDED	5
+
+long long llseek(int fd, long long offset, int whence);
+
+static int readSingleTable(int fd, struct singlePartitionTable * table,
+			long long partSector) {
+    unsigned char sector[SECTOR_SIZE];
+    unsigned short magic;
+
+    if (llseek(fd, ((long long) SECTOR_SIZE * (long long) partSector),
+	       SEEK_SET) < 0)
+	return BALKAN_ERROR_ERRNO;
+
+    if (read(fd, sector, sizeof(sector)) != sizeof(sector))
+	return BALKAN_ERROR_ERRNO;
+
+    magic = (sector[MBR_MAGIC_OFFSET] << 8) + sector[MBR_MAGIC_OFFSET + 1];
+    if (magic != MBR_MAGIC)
+	return BALKAN_ERROR_BADMAGIC;
+
+    memcpy(table, sector + TABLE_OFFSET, sizeof(struct singlePartitionTable));
+
+    return 0;
+}
+
+static int readNextTable(int fd, struct partitionTable * table, int nextNum, 
+		  long long partSector, long long sectorOffset) {
+    struct singlePartitionTable singleTable;
+    int rc;
+    int i;
+    int gotExtended = 0;
+
+    if ((rc = readSingleTable(fd, &singleTable, partSector + sectorOffset)))
+	return rc;
+
+    if (nextNum > 4) {
+	/* This is an extended table */
+	if (singleTable.parts[2].size || singleTable.parts[3].size)
+	    return BALKAN_ERROR_BADTABLE;
+    }
+
+    for (i = 0; i < 4; i++) {
+	if (!singleTable.parts[i].size) continue;
+	if (singleTable.parts[i].type == DOSP_TYPE_EXTENDED &&
+	    nextNum >= 5) continue;
+
+	table->parts[nextNum].startSector = singleTable.parts[i].start + 
+					    sectorOffset;
+	table->parts[nextNum].size = singleTable.parts[i].size;
+	table->parts[nextNum].type = singleTable.parts[i].type;
+
+	nextNum++;
+    }
+
+    /* look for extended partitions */
+    for (i = 0; i < 4; i++) {
+	if (!singleTable.parts[i].size) continue;
+
+	if (singleTable.parts[i].type == DOSP_TYPE_EXTENDED) {
+	    if (gotExtended) return BALKAN_ERROR_BADTABLE;
+	    gotExtended = 1;
+
+	    if (sectorOffset)
+		rc = readNextTable(fd, table, nextNum > 5 ? nextNum : 5, 
+				   singleTable.parts[i].start, sectorOffset);
+	    else
+		rc = readNextTable(fd, table, nextNum > 5 ? nextNum : 5, 
+				   0, singleTable.parts[i].start);
+
+	    if (rc) return rc;
+	}
+    }
+
+    return 0;
+}
+
+int dospReadTable(int fd, struct partitionTable * table) {
+    int i;
+
+    table->maxNumPartitions = 16;
+
+    for (i = 0; i < table->maxNumPartitions; i++)
+	table->parts[i].type = -1;
+
+    table->sectorSize = SECTOR_SIZE;
+
+    return readNextTable(fd, table, 0, 0, 0);
+}
+
+#ifdef STANDALONE_TEST
+
+void main() {
+    int fd;
+    int i;
+    struct partitionTable table;
+
+    fd = open("/dev/hda", O_RDONLY);
+
+    printf("rc= %d\n", dospReadTable(fd, &table));
+
+    for (i = 0; i < table.maxNumPartitions; i++) {
+	if (table.parts[i].type == -1) continue;
+
+	printf("%d: %x %d\n", i, table.parts[i].type, table.parts[i].size);
+    }
+}
+
+#endif