feat: moved file system code around

kernel/vfs/lfs/ustar.c

@@ -0,0 +1,97 @@
+//
+// Created by rick on 11-03-21.
+//
+#include <attributes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include <myke/vfs/blockdev.h>
+
+typedef struct {
+    char filename[100];
+    uint64_t mode;
+    uint64_t uid;
+    uint64_t gid;
+    char filesize[12];
+    char lastmod[12];
+    uint64_t checksum;
+    char type;
+    char linked[100];
+    char magic[6];
+    char version[2];
+    char username[32];
+    char groupname[32];
+    uint64_t device_major;
+    uint64_t device_minor;
+    char prefix[155];
+} att_packed ustar_sector;
+
+typedef struct {
+    ustar_sector sector;
+    uint32_t lba;
+} ustar_inode;
+
+typedef struct {
+    ustar_inode *first_inode;
+    const block_device_t *device;
+} ustar_fs;
+
+const char *ustar_magic = "ustar";
+const char *ustar_version = "00";
+
+#define USTAR_TYPE_FILE '0'
+#define USTAR_TYPE_LINK '1'
+#define USTAR_TYPE_SYMBOL '2'
+#define USTAR_TYPE_CHAR '3'
+#define USTAR_TYPE_BLOCK '4'
+#define USTAR_TYPE_DIR '5'
+#define USTAR_TYPE_FIFO '6'
+
+#define SECTOR_SIZE 512
+
+long ustar_oct_to_long(char *oct, uint32_t size) {
+    char value[size + 1];
+    memcpy(value, oct, size);
+    value[size] = 0;
+    return strtol(value, NULL, 8);
+}
+
+bool ustar_sector_valid(ustar_sector *sector) {
+    return strncmp(ustar_magic, sector->magic, 6) == 0;
+}
+
+ustar_sector *ustar_next(ustar_sector *current) {
+    if (ustar_sector_valid(current)) {
+        return NULL;
+    }
+
+    long filesize = ustar_oct_to_long(current->filesize, 12);
+
+    long offset = (((filesize + SECTOR_SIZE - 1) / SECTOR_SIZE) + 1) * SECTOR_SIZE;
+
+    ustar_sector *next = ((void *) current) + offset;
+    return ustar_sector_valid(next) ? next : NULL;
+}
+
+uint8_t ustar_check_device(const block_device_t *device, uint8_t *first_sector) {
+    ustar_sector *sector = (ustar_sector *) first_sector;
+    if (!ustar_sector_valid(sector)) {
+        return BLOCK_DEV_DRIVER_CHECK_NO_MATCH;
+    }
+
+    ustar_fs *fs = malloc(sizeof(ustar_fs));
+    fs->first_inode = malloc(sizeof(ustar_inode));
+    memcpy(&fs->first_inode->sector, first_sector, sizeof(ustar_sector));
+    fs->first_inode->lba = 0;
+    fs->device = device;
+
+    return BLOCK_DEV_DRIVER_CHECK_OK;
+}
+
+BLOCK_DEV_DRIVER(300) = {
+        .name = "ustar",
+        .check_device = ustar_check_device,
+        .free_device = NULL,
+};