Snap for 8570526 from 67803003190004a55215c16fe9905dbaac1cfe74 to mainline-mediaprovider-releaseaml_mpr_331918000aml_mpr_331812020aml_mpr_331711020aml_mpr_331613010aml_mpr_331512020aml_mpr_331412040aml_mpr_331311080aml_mpr_331112050aml_mpr_331112030aml_mpr_331011070aml_mpr_330911040aml_mpr_330811020android13-mainline-mediaprovider-release

Change-Id: I94ec7f2f2aaace6ee4e95215f319d67a5571cdbf

1 files changed, 281 insertions, 0 deletions

diff --git a/partition.c b/partition.c
new file mode 100644
index 0000000..240f0f5
--- /dev/null
+++ b/partition.c
@@ -0,0 +1,281 @@
+/*  Copyright 2021 Alain Knaff.
+ *  This file is part of mtools.
+ *
+ *  Mtools is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Mtools is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Mtools.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Buffer read/write module
+ */
+
+#include "sysincludes.h"
+#include "msdos.h"
+#include "mtools.h"
+#include "partition.h"
+
+typedef struct Partition_t {
+	struct Stream_t head;
+
+	mt_off_t offset; /* Offset, in bytes */
+	mt_off_t size; /* size, in bytes */
+	uint32_t nbSect; /* size, in sectors */
+	
+	uint8_t pos;
+
+	uint8_t sectors;
+	uint8_t heads;
+	uint16_t cyclinders;
+} Partition_t;
+
+static __inline__ void print_hsc(hsc *h)
+{
+	printf(" h=%d s=%d c=%d\n",
+	       head(*h), sector(*h), cyl(*h));
+}
+
+/*
+ * Make sure range [ start, end ] does not overlap with partition i
+ */
+static int overlapCheck(struct partition *partTable, unsigned int i,
+			uint32_t start, uint32_t end) {
+	struct partition *partition = &partTable[i];
+	if(!partition->sys_ind)
+		return 0; /* Partition not allocated => ok */
+	if(end > BEGIN(partition) &&
+	   (start < END(partition) || END(partition) < BEGIN(partition)))
+		/* overlap */
+		return -1;
+	return 0;
+}
+
+unsigned int findOverlap(struct partition *partTable, unsigned int until,
+			 uint32_t start, uint32_t end)
+{
+	unsigned int i;
+	for(i=1; i <= until; i++)
+		if(overlapCheck(partTable, i, start, end))
+			return i;
+	return 0;
+}
+
+
+int consistencyCheck(struct partition *partTable, int doprint,
+		     int verbose,
+		     int *has_activated, uint32_t tot_sectors,
+		     struct device *used_dev UNUSEDP,
+		     unsigned int target_partition)
+{
+	unsigned int i;
+	bool inconsistency;
+
+	/* quick consistency check */
+	inconsistency = 0;
+	*has_activated = 0;
+	for(i=1; i<=4; i++){
+		unsigned int j;
+		struct partition *partition = &partTable[i];
+		if(!partition->sys_ind)
+			continue;
+		if(partition->boot_ind)
+			(*has_activated)++;
+
+		if(END(partition) < BEGIN(partition)) {
+			fprintf(stderr,
+				"End of partition %d before its begin\n",
+				i);
+		}
+
+		if((j = findOverlap(partTable, i-1,
+				    BEGIN(partition), END(partition)))) {
+			fprintf(stderr,
+				"Partitions %d and %d overlap\n",
+				j, i);
+			inconsistency=1;
+		}
+
+		if(tot_sectors && END(partition) >tot_sectors) {
+			fprintf(stderr,
+				"Partition %d extends beyond end of disk\n", i);
+		}
+
+		if(doprint && verbose) {
+			if(i==target_partition)
+				putchar('*');
+			else
+				putchar(' ');
+			printf("Partition %d\n",i);
+
+			printf("  active=%x\n", partition->boot_ind);
+			printf("  start:");
+			print_hsc(&partition->start);
+			printf("  type=0x%x\n", partition->sys_ind);
+			printf("  end:");
+			print_hsc(&partition->end);
+			printf("  start=%d\n", BEGIN(partition));
+			printf("  nr=%d\n", _DWORD(partition->nr_sects));
+			printf("\n");
+		}
+	}
+	return inconsistency;
+}
+
+
+static int limit_size(Partition_t *This, mt_off_t start, size_t *len)
+{
+	if(start > This->size)
+		return -1;
+	limitSizeToOffT(len, This->size - start);
+	return 0;
+}
+
+static ssize_t partition_pread(Stream_t *Stream, char *buf,
+			       mt_off_t start, size_t len)
+{
+	DeclareThis(Partition_t);
+	if(limit_size(This, start, &len) < 0)
+		return -1;
+	return PREADS(This->head.Next, buf, start+This->offset, len);
+}
+
+static ssize_t partition_pwrite(Stream_t *Stream, char *buf,
+				mt_off_t start, size_t len)
+{
+	DeclareThis(Partition_t);
+	if(limit_size(This, start, &len) < 0)
+		return -1;
+	return PWRITES(This->head.Next, buf, start+This->offset, len);
+}
+
+static int partition_data(Stream_t *Stream, time_t *date, mt_off_t *size,
+			  int *type, uint32_t *address)
+{
+	DeclareThis(Partition_t);
+
+	if(date || type || address) {
+		int ret = GET_DATA(This->head.Next, date, NULL, type, address);
+		if(ret < 0)
+			return ret;
+	}
+	if(size)
+		*size = This->size * 512;
+	return 0;
+}
+
+
+static int partition_geom(Stream_t *Stream, struct device *dev,
+			  UNUSEDP struct device *orig_dev)
+{
+	DeclareThis(Partition_t);
+
+	if(!dev->tot_sectors)
+		dev->tot_sectors = This->nbSect;
+
+	return 0;
+}
+
+static Class_t PartitionClass = {
+	0,
+	0,
+	partition_pread,
+	partition_pwrite,
+	0, /* flush */
+	0, /* free */
+	partition_geom, /* set_geom */
+	partition_data, /* get_data */
+	0, /* pre-allocate */
+	get_dosConvert_pass_through, /* dos convert */
+	0, /* discard */
+};
+
+Stream_t *OpenPartition(Stream_t *Next, struct device *dev,
+			char *errmsg, mt_off_t *maxSize) {
+	Partition_t *This;
+	int has_activated;
+	unsigned char buf[2048];
+	struct partition *partTable=(struct partition *)(buf+ 0x1ae);
+	uint32_t partOff;
+	struct partition *partition;
+
+	if(!dev || (dev->partition > 4) || (dev->partition <= 0)) {
+	    fprintf(stderr,
+		    "Invalid partition %d (must be between 1 and 4), ignoring it\n",
+		    dev->partition);
+	    return NULL;
+	}
+
+	This = New(Partition_t);
+	if (!This){
+		printOom();
+		return 0;
+	}
+	memset((void*)This, 0, sizeof(Partition_t));
+	init_head(&This->head, &PartitionClass, Next);
+
+
+	/* read the first sector, or part of it */
+	if (force_pread(This->head.Next, (char*) buf, 0, 512) != 512)
+		goto exit_0;
+	if( _WORD(buf+510) != 0xaa55) {
+		/* Not a partition table */
+		if(errmsg)
+			sprintf(errmsg,
+				"Device does not have a BIOS partition table\n");
+		goto exit_0;
+	}
+	partition = &partTable[dev->partition];
+	if(!partition->sys_ind) {
+		if(errmsg)
+			sprintf(errmsg,
+				"Partition %d does not exist\n",
+				dev->partition);
+		goto exit_0;
+	}
+
+	partOff = BEGIN(partition);
+	if (maxSize) {
+		if (partOff > (smt_off_t)(*maxSize >> 9)) {
+			if(errmsg)
+				sprintf(errmsg,"init: Big disks not supported");
+			goto exit_0;
+		}
+		*maxSize -= partOff << 9;
+		maximize(*maxSize, ((mt_off_t)PART_SIZE(partition)) << 9);
+	}
+
+	This->offset = (mt_off_t) partOff << 9;
+
+	if(!mtools_skip_check &&
+	   consistencyCheck((struct partition *)(buf+0x1ae), 0, 0,
+			    &has_activated, dev->tot_sectors, dev, 0)) {
+		fprintf(stderr,
+			"Warning: inconsistent partition table\n");
+		fprintf(stderr,
+			"Possibly unpartitioned device\n");
+		fprintf(stderr,
+			"\n*** Maybe try without partition=%d in "
+			"device definition ***\n\n",
+			dev->partition);
+		fprintf(stderr,
+			"If this is a PCMCIA card, or a disk "
+			"partitioned on another computer, this "
+			"message may be in error: add "
+			"mtools_skip_check=1 to your .mtoolsrc "
+			"file to suppress this warning\n");
+	}
+	dev->tot_sectors = This->nbSect = PART_SIZE(partition);
+	This->size = (mt_off_t) This->nbSect << 9;
+	return &This->head;
+ exit_0:
+	Free(This);
+	return NULL;
+}
+