lib: add pttype.c for PT types detection

This is a small fragment from libdisk (from xfsprogs). The final
solution will be to move the library to util-linux-ng.

Signed-off-by: Karel Zak <kzak@redhat.com>

5 files changed, 276 insertions, 3 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index b9314a972..24acb9f6b 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -16,4 +16,5 @@ dist_noinst_HEADERS = \
 	setproctitle.h \
 	swapheader.h \
 	widechar.h \
-	xstrncpy.h
+	xstrncpy.h \
+	pttype.h
diff --git a/include/pttype.h b/include/pttype.h
new file mode 100644
index 000000000..d6fe8128c
--- /dev/null
+++ b/include/pttype.h
@@ -0,0 +1,10 @@
+#ifndef PTTYPE_H
+#define PTTYPE_H
+
+/*
+ * Note that this is a temporary solution. The final solution will be to move
+ * libdisk from xfsprogs to util-linux-ng.
+ */
+extern const char *get_pt_type(const char *device);
+
+#endif
diff --git a/lib/.gitignore b/lib/.gitignore
index 025150b97..0be0fd86c 100644
--- a/lib/.gitignore
+++ b/lib/.gitignore
@@ -1,2 +1,3 @@
 test_blkdev
 test_ismounted
+test_pttype
diff --git a/lib/Makefile.am b/lib/Makefile.am
index cd4871aa3..f813f6855 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,9 +1,10 @@
 include $(top_srcdir)/config/include-Makefile.am
 
-noinst_PROGRAMS = test_blkdev test_ismounted
+noinst_PROGRAMS = test_blkdev test_ismounted test_pttype
 
 test_blkdev_SOURCES = blkdev.c
 test_ismounted_SOURCES = ismounted.c
+test_pttype_SOURCES = pttype.c
 
 if LINUX
 test_blkdev_SOURCES += linux_version.c
@@ -11,5 +12,5 @@ endif
 
 test_blkdev_CFLAGS = -DTEST_PROGRAM
 test_ismounted_CFLAGS = -DTEST_PROGRAM
-
+test_pttype_CFLAGS = -DTEST_PROGRAM
 
diff --git a/lib/pttype.c b/lib/pttype.c
new file mode 100644
index 000000000..429b47551
--- /dev/null
+++ b/lib/pttype.c
@@ -0,0 +1,260 @@
+/*
+ * Based on libdisk from xfsprogs and Linux fdisk.
+ *
+ * Copyright (c) 2000-2001 Silicon Graphics, Inc.
+ * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
+ */
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <stdlib.h>
+
+#include "blkdev.h"
+
+/*
+ * SGI
+ */
+struct sgi_device_parameter { /* 48 bytes */
+	unsigned char  skew;
+	unsigned char  gap1;
+	unsigned char  gap2;
+	unsigned char  sparecyl;
+	unsigned short pcylcount;
+	unsigned short head_vol0;
+	unsigned short ntrks;	/* tracks in cyl 0 or vol 0 */
+	unsigned char  cmd_tag_queue_depth;
+	unsigned char  unused0;
+	unsigned short unused1;
+	unsigned short nsect;	/* sectors/tracks in cyl 0 or vol 0 */
+	unsigned short bytes;
+	unsigned short ilfact;
+	unsigned int   flags;		/* controller flags */
+	unsigned int   datarate;
+	unsigned int   retries_on_error;
+	unsigned int   ms_per_word;
+	unsigned short xylogics_gap1;
+	unsigned short xylogics_syncdelay;
+	unsigned short xylogics_readdelay;
+	unsigned short xylogics_gap2;
+	unsigned short xylogics_readgate;
+	unsigned short xylogics_writecont;
+};
+
+#define	SGI_VOLHDR	0x00
+/* 1 and 2 were used for drive types no longer supported by SGI */
+#define	SGI_SWAP	0x03
+/* 4 and 5 were for filesystem types SGI haven't ever supported on MIPS CPUs */
+#define	SGI_VOLUME	0x06
+#define	SGI_EFS		0x07
+#define	SGI_LVOL	0x08
+#define	SGI_RLVOL	0x09
+#define	SGI_XFS		0x0a
+#define	SGI_XFSLOG	0x0b
+#define	SGI_XLV		0x0c
+#define	SGI_XVM		0x0d
+#define	ENTIRE_DISK	SGI_VOLUME
+/*
+ * controller flags
+ */
+#define	SECTOR_SLIP	0x01
+#define	SECTOR_FWD	0x02
+#define	TRACK_FWD	0x04
+#define	TRACK_MULTIVOL	0x08
+#define	IGNORE_ERRORS	0x10
+#define	RESEEK		0x20
+#define	CMDTAGQ_ENABLE	0x40
+
+struct sgi_volume_header {
+	unsigned int   magic;		 /* expect SGI_LABEL_MAGIC */
+	unsigned short boot_part;        /* active boot partition */
+	unsigned short swap_part;        /* active swap partition */
+	unsigned char  boot_file[16];    /* name of the bootfile */
+	struct sgi_device_parameter devparam;	/*  1 * 48 bytes */
+	struct volume_directory {		/* 15 * 16 bytes */
+		unsigned char vol_file_name[8];	/* a character array */
+		unsigned int  vol_file_start;	/* number of logical block */
+		unsigned int  vol_file_size;	/* number of bytes */
+	} directory[15];
+	struct sgi_partition {			/* 16 * 12 bytes */
+		unsigned int num_sectors;	/* number of blocks */
+		unsigned int start_sector;	/* must be cylinder aligned */
+		unsigned int id;
+	} partitions[16];
+	unsigned int   csum;
+	unsigned int   fillbytes;
+};
+
+#define	SGI_LABEL_MAGIC		0x0be5a941
+
+static uint32_t
+twos_complement_32bit_sum(u_int32_t *base, int size)
+{
+	int i;
+	u_int32_t sum = 0;
+
+	size = size / sizeof(u_int32_t);
+	for (i = 0; i < size; i++)
+		sum = sum - ntohl(base[i]);
+	return sum;
+}
+
+static int
+sgi_parttable(char *base)
+{
+	u_int32_t csum;
+	struct sgi_volume_header *vh = (struct sgi_volume_header *) base;
+
+	if (ntohl(vh->magic) != SGI_LABEL_MAGIC)
+		return 0;
+	csum = twos_complement_32bit_sum((uint32_t *)vh,
+				sizeof(struct sgi_volume_header));
+	return !csum;
+}
+
+/*
+ * DOS
+ */
+static int
+dos_parttable(char *base)
+{
+	return (base[510] == 0x55 && base[511] == 0xaa);
+}
+
+/*
+ * AIX
+ */
+typedef struct {
+	unsigned int   magic;        /* expect AIX_LABEL_MAGIC */
+	/* ... */
+} aix_partition;
+
+#define	AIX_LABEL_MAGIC		0xc9c2d4c1
+#define	AIX_LABEL_MAGIC_SWAPPED	0xc1d4c2c9
+#define aixlabel(x) ((aix_partition *)x)
+
+static int
+aix_parttable(char *base)
+{
+	return (aixlabel(base)->magic == AIX_LABEL_MAGIC ||
+		aixlabel(base)->magic == AIX_LABEL_MAGIC_SWAPPED);
+}
+
+/*
+ * SUN
+ */
+typedef struct {
+	unsigned char info[128];   /* Informative text string */
+	unsigned char spare0[14];
+	struct sun_info {
+		unsigned char spare1;
+		unsigned char id;
+		unsigned char spare2;
+		unsigned char flags;
+	} infos[8];
+	unsigned char spare1[246]; /* Boot information etc. */
+	unsigned short rspeed;     /* Disk rotational speed */
+	unsigned short pcylcount;  /* Physical cylinder count */
+	unsigned short sparecyl;   /* extra sects per cylinder */
+	unsigned char spare2[4];   /* More magic... */
+	unsigned short ilfact;     /* Interleave factor */
+	unsigned short ncyl;       /* Data cylinder count */
+	unsigned short nacyl;      /* Alt. cylinder count */
+	unsigned short ntrks;      /* Tracks per cylinder */
+	unsigned short nsect;      /* Sectors per track */
+	unsigned char spare3[4];   /* Even more magic... */
+	struct sun_partition {
+		u_int32_t start_cylinder;
+		u_int32_t num_sectors;
+	} partitions[8];
+	unsigned short magic;      /* Magic number */
+	unsigned short csum;       /* Label xor'd checksum */
+} sun_partition;
+
+#define SUN_LABEL_MAGIC          0xDABE
+#define SUN_LABEL_MAGIC_SWAPPED  0xBEDA
+#define sunlabel(x) ((sun_partition *)x)
+
+static int
+sun_parttable(char *base)
+{
+	unsigned short *ush;
+	int csum = 0;
+
+	if (sunlabel(base)->magic != SUN_LABEL_MAGIC &&
+	    sunlabel(base)->magic != SUN_LABEL_MAGIC_SWAPPED)
+		return csum;
+	ush = ((unsigned short *) (sunlabel(base) + 1)) - 1;
+	while (ush >= (unsigned short *)sunlabel(base))
+		csum ^= *ush--;
+	return !csum;
+}
+
+/*
+ * MAC
+ */
+typedef struct {
+	unsigned short magic;
+	/* ... */
+} mac_partition;
+
+#define MAC_LABEL_MAGIC		0x4552
+#define MAC_PARTITION_MAGIC	0x504d
+#define MAC_OLD_PARTITION_MAGIC	0x5453
+#define maclabel(x) ((mac_partition *)x)
+
+static int
+mac_parttable(char *base)
+{
+	return (ntohs(maclabel(base)->magic) == MAC_LABEL_MAGIC ||
+		ntohs(maclabel(base)->magic) == MAC_PARTITION_MAGIC ||
+		ntohs(maclabel(base)->magic) == MAC_OLD_PARTITION_MAGIC);
+}
+
+const char *
+get_pt_type(const char *device)
+{
+	int	fd;
+	char	*type = NULL;
+	char	buf[DEFAULT_SECTOR_SIZE];
+
+	if ((fd = open(device, O_RDONLY)) < 0)
+		;
+	else if (read(fd, buf, DEFAULT_SECTOR_SIZE) != DEFAULT_SECTOR_SIZE)
+		;
+	else {
+		if (sgi_parttable(buf))
+			type = "SGI";
+		else if (sun_parttable(buf))
+			type = "Sun";
+		else if (aix_parttable(buf))
+			type = "AIX";
+		else if (dos_parttable(buf))
+			type = "DOS";
+		else if (mac_parttable(buf))
+			type = "Mac";
+	}
+
+	if (fd >= 0)
+		close(fd);
+	return type;
+}
+
+#ifdef TEST_PROGRAM
+int
+main(int argc, char **argv)
+{
+	const char *type;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <device>\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	type = get_pt_type(argv[1]);
+	if (type)
+		printf("Partition type: %s\n", type);
+	exit(EXIT_SUCCESS);
+}
+#endif