fiasco: Add support for unpacking multiple parts of one image

Fiasco mmc image contains layout and two parts in one data section. First
part is FAT32 partition (MyDocs) and second part is tar archive for second
ext3 partition (/home). This change extends fiasco parser to load all parts
from one data section and correctly unpack all parts.

1 files changed, 103 insertions, 49 deletions

diff --git a/src/fiasco.c b/src/fiasco.c
index 890e1c0..a0caf1a 100644
--- a/src/fiasco.c
+++ b/src/fiasco.c
@@ -74,6 +74,8 @@ struct fiasco * fiasco_alloc_from_file(const char * file) {
 	uint16_t hash;
 	off_t offset;
 	struct image * image;
+	struct image_part * image_part;
+	struct image_part * image_parts;
 
 	char hwrev[9];
 	unsigned char buf[512];
@@ -188,6 +190,8 @@ struct fiasco * fiasco_alloc_from_file(const char * file) {
 		memset(hwrevs, 0, sizeof(hwrevs));
 		memset(version, 0, sizeof(version));
 		memset(layout, 0, sizeof(layout));
+		image_part = NULL;
+		image_parts = NULL;
 
 		while ( count8 > 0 ) {
 
@@ -237,6 +241,36 @@ struct fiasco * fiasco_alloc_from_file(const char * file) {
 				memset(layout, 0, sizeof(layout));
 				strncpy(layout, (char *)buf, length8);
 				VERBOSE("layout\n");
+			} else if ( byte == '4' ) {
+				VERBOSE("data part\n");
+				if ( length8 < 16 ) {
+					VERBOSE("       (damaged)\n");
+				} else {
+					if ( image_parts ) {
+						image_part->next = calloc(1, sizeof(struct image_part));
+						if ( ! image_part->next )
+							FIASCO_READ_ERROR(fiasco, "Cannot allocate image");
+						image_part = image_part->next;
+					} else {
+						image_parts = calloc(1, sizeof(struct image_part));
+						if ( ! image_parts )
+							FIASCO_READ_ERROR(fiasco, "Cannot allocate image");
+						image_part = image_parts;
+					}
+					image_part->offset = ntohl(*(uint32_t *)&buf[4]);
+					image_part->size = ntohl(*(uint32_t *)&buf[12]);
+					if ( length8 > 16 ) {
+						image_part->name = calloc(1, length8-16+1);
+						if ( image_part->name )
+							memcpy(image_part->name, &buf[16], length8-16);
+					}
+					VERBOSE("       unknown: 0x%02x 0x%02x 0x%02x 0x%02x\n", buf[0], buf[1], buf[2], buf[3]);
+					VERBOSE("       offset: %u bytes\n", image_part->offset);
+					VERBOSE("       unknown: 0x%02x 0x%02x 0x%02x 0x%02x\n", buf[8], buf[9], buf[10], buf[11]);
+					VERBOSE("       size: %u bytes\n", image_part->size);
+					if ( image_part->name )
+						VERBOSE("       partition name: %s\n", image_part->name);
+				}
 			} else {
 				VERBOSE("unknown ('%c':%#x)\n", byte, byte);
 			}
@@ -262,7 +296,7 @@ struct fiasco * fiasco_alloc_from_file(const char * file) {
 		VERBOSE("   hwrevs: %s\n", hwrevs);
 		VERBOSE("   data at: %#08x\n", (unsigned int)offset);
 
-		image = image_alloc_from_shared_fd(fiasco->fd, length, offset, hash, type, device, hwrevs, version, layout);
+		image = image_alloc_from_shared_fd(fiasco->fd, length, offset, hash, type, device, hwrevs, version, layout, image_parts);
 
 		if ( ! image )
 			FIASCO_READ_ERROR(fiasco, "Cannot allocate image");
@@ -516,8 +550,10 @@ int fiasco_unpack(struct fiasco * fiasco, const char * dir) {
 	char * name;
 	char * layout_name;
 	struct image * image;
+	struct image_part * image_part;
 	struct image_list * image_list;
-	uint32_t size;
+	uint32_t offset, size, need, total_size, written;
+	int part_num;
 	char cwd[256];
 	unsigned char buf[4096];
 
@@ -543,69 +579,29 @@ int fiasco_unpack(struct fiasco * fiasco, const char * dir) {
 
 	while ( image_list ) {
 
-		fd = -1;
-		name = NULL;
-		layout_name = NULL;
-
 		image = image_list->image;
 
-		name = image_name_alloc_from_values(image);
-		if ( ! name )
-			return -1;
-
 		printf("\n");
 		printf("Unpacking image...\n");
 		image_print_info(image);
 
 		if ( image->layout ) {
 
-			layout_name = calloc(1, strlen(name) + sizeof(".layout")-1 + 1);
+			name = image_name_alloc_from_values(image, -1);
+			if ( ! name )
+				ALLOC_ERROR_RETURN(-1);
+
+			layout_name = calloc(1, strlen(name) + sizeof("_layout")-1 + 1);
 			if ( ! layout_name ) {
 				free(name);
 				ALLOC_ERROR_RETURN(-1);
 			}
 
-			sprintf(layout_name, "%s.layout", name);
+			sprintf(layout_name, "%s_layout", name);
+			free(name);
 
 			printf("    Layout file: %s\n", layout_name);
 
-		}
-
-		printf("    Output file: %s\n", name);
-
-		if ( ! simulate ) {
-			fd = open(name, O_RDWR|O_CREAT|O_TRUNC, 0644);
-			if ( fd < 0 ) {
-				ERROR_INFO("Cannot create output file %s", name);
-				free(name);
-				free(layout_name);
-				return -1;
-			}
-		}
-
-		image_seek(image, 0);
-		while ( 1 ) {
-			size = image_read(image, buf, sizeof(buf));
-			if ( size == 0 )
-				break;
-			if ( ! simulate ) {
-				if ( write(fd, buf, size) != (ssize_t)size ) {
-					ERROR_INFO_STR(name, "Cannot write %d bytes", size);
-					close(fd);
-					free(name);
-					free(layout_name);
-					return -1;
-				}
-			}
-		}
-
-		free(name);
-
-		if ( ! simulate )
-			close(fd);
-
-		if ( image->layout ) {
-
 			if ( ! simulate ) {
 				fd = open(layout_name, O_RDWR|O_CREAT|O_TRUNC, 0644);
 				if ( fd < 0 ) {
@@ -631,6 +627,64 @@ int fiasco_unpack(struct fiasco * fiasco, const char * dir) {
 
 		}
 
+		part_num = 0;
+		image_part = image->parts;
+
+		do {
+
+			offset = image_part ? image_part->offset : 0;
+			total_size = image_part ? image_part->size : image->size;
+
+			name = image_name_alloc_from_values(image, image_part ? part_num : -1);
+			if ( ! name )
+				ALLOC_ERROR_RETURN(-1);
+
+			if ( image_part && ( part_num > 0 || image_part->next ) )
+				printf("    Output file part %d: %s\n", part_num+1, name);
+			else
+				printf("    Output file: %s\n", name);
+
+			if ( ! simulate ) {
+				fd = open(name, O_RDWR|O_CREAT|O_TRUNC, 0644);
+				if ( fd < 0 ) {
+					ERROR_INFO("Cannot create output file %s", name);
+					free(name);
+					return -1;
+				}
+			}
+
+			written = 0;
+			image_seek(image, offset);
+			while ( written < total_size ) {
+				need = total_size - written;
+				if ( need > sizeof(buf) )
+					need = sizeof(buf);
+				size = image_read(image, buf, need);
+				if ( size == 0 )
+					break;
+				if ( ! simulate ) {
+					if ( write(fd, buf, size) != (ssize_t)size ) {
+						ERROR_INFO_STR(name, "Cannot write %d bytes", size);
+						close(fd);
+						free(name);
+						return -1;
+					}
+				}
+				written += size;
+			}
+
+			free(name);
+
+			if ( ! simulate )
+				close(fd);
+
+			if ( image_part ) {
+				image_part = image_part->next;
+				part_num++;
+			}
+
+		} while ( image_part );
+
 		image_list = image_list->next;
 
 	}