Added ext2 subdirectory support (#6)

* updated ext2-test rule

* added strtok

* added ext2 subdirectory support

* reverted partition numbers

* simplified parsing

* reworked parsing logic

* reverted qloader2.cfg

src/fs/ext2fs.c

@@ -200,32 +200,61 @@ static int ext2fs_get_inode(struct ext2fs_inode *ret, uint64_t drive, struct par
     return 0;
 }
 
-static int ext2fs_parse_dirent(struct ext2fs_dir_entry *dir, struct ext2fs_file_handle *fd, const char *filename) {
-    uint64_t offset = fd->root_inode.i_blocks[0] * fd->block_size;
+static int ext2fs_parse_dirent(struct ext2fs_dir_entry *dir, struct ext2fs_file_handle *fd, struct ext2fs_superblock *sb, const char *path) {
+    int path_len = strlen(path);
 
-    while (offset < fd->root_inode.i_size + offset) {
-        // preliminary read
-        read_partition(fd->drive, &fd->part, dir, offset, sizeof(struct ext2fs_dir_entry));
+    char *cpy = path;
 
-        // name read
-        char* name = balloc(dir->name_len);
-        read_partition(fd->drive, &fd->part, name, offset + sizeof(struct ext2fs_dir_entry), dir->name_len);
+    if (*cpy = '/')
+        cpy++;
 
-        int r = strncmp(filename, name, dir->name_len);
+    int token_count;
+    for (int i = 0; i < path_len; i++) {
+        if (cpy[i] == '/')
+            token_count++;
+    }
 
-        brewind(dir->name_len);
+    const char *delimiter = "/";
+    char *token;
+    struct ext2fs_inode *current = &fd->root_inode;
 
-        if (!r) {
-            return 0;
+    for (int i = 0; i < (token_count + 1); i++) {
+        token = strtok(cpy, delimiter);
+
+        uint64_t offset = current->i_blocks[0] * fd->block_size;
+
+        while (offset < current->i_size + offset) {
+            // preliminary read
+            read_partition(fd->drive, &fd->part, dir, offset, sizeof(struct ext2fs_dir_entry));
+
+            // name read
+            char* name = balloc(dir->name_len);
+            read_partition(fd->drive, &fd->part, name, offset + sizeof(struct ext2fs_dir_entry), dir->name_len);
+
+            int r = strncmp(token, name, dir->name_len);
+
+            brewind(dir->name_len);
+
+            if (!r) {
+                if (i == token_count)
+                    return 0;
+                else
+                    break;
+            }
+
+            offset += dir->rec_len;
         }
 
-        offset += dir->rec_len;
+        cpy = NULL;
+
+        // update the current inode
+        ext2fs_get_inode(current, fd->drive, &fd->part, dir->inode, sb);
     }
 
     return 1;
 }
 
-int ext2fs_open(struct ext2fs_file_handle *ret, int drive, int partition, const char* filename) {
+int ext2fs_open(struct ext2fs_file_handle *ret, int drive, int partition, const char *path) {
     get_part(&ret->part, drive, partition);
 
     ret->drive = drive;
@@ -238,14 +267,14 @@ int ext2fs_open(struct ext2fs_file_handle *ret, int drive, int partition, const
     ext2fs_get_inode(&ret->root_inode, drive, &ret->part, 2, &sb);
 
     struct ext2fs_dir_entry entry;
-    ext2fs_parse_dirent(&entry, ret, filename);
+    ext2fs_parse_dirent(&entry, ret, &sb, path);
     ext2fs_get_inode(&ret->inode, drive, &ret->part, entry.inode, &sb);
     ret->size = ret->inode.i_size;
 
     return 0;
 }
 
-int ext2fs_read(struct ext2fs_file_handle *file, void* buf, uint64_t loc, uint64_t count) {
+int ext2fs_read(struct ext2fs_file_handle *file, void *buf, uint64_t loc, uint64_t count) {
     // TODO: add support for the indirect block pointers
 
     for (uint64_t progress = 0; progress < count;) {

src/fs/ext2fs.h

@@ -3,6 +3,7 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include <stdbool.h>
 #include <drivers/disk.h>
 #include <lib/libc.h>
 #include <lib/blib.h>
@@ -61,7 +62,7 @@ struct ext2fs_file_handle {
 
 int ext2fs_check_signature(int drive, int partition);
 
-int ext2fs_open(struct ext2fs_file_handle *ret, int drive, int partition, const char* filename);
-int ext2fs_read(struct ext2fs_file_handle *file, void* buf, uint64_t loc, uint64_t count);
+int ext2fs_open(struct ext2fs_file_handle *ret, int drive, int partition, const char *path);
+int ext2fs_read(struct ext2fs_file_handle *file, void *buf, uint64_t loc, uint64_t count);
 
 #endif

src/lib/libc.c

@@ -111,3 +111,36 @@ size_t strlen(const char *str) {
 
     return len;
 }
+
+char *strtok(char *str, const char *delimiter) {
+    static char* buffer;
+
+    if (str != NULL) {
+        buffer = str;
+    }
+
+    if (buffer[0] == '\0') {
+        return NULL;
+    }
+
+    char* ret = buffer;
+
+    for (char* b = buffer; *b != '\0'; b++) {
+        for (const char* d = delimiter; *d != '\0'; d++) {
+            if(*b == *d) {
+                *b     = '\0';
+                buffer = b + 1;
+
+                // Skip the beginning delimiters
+                if (b == ret) {
+                    ret++;
+                    continue;
+                }
+
+                return ret;
+            }
+        }
+    }
+
+    return ret;
+}

src/lib/libc.h

@@ -13,5 +13,6 @@ char *strncpy(char *, const char *, size_t);
 size_t strlen(const char *);
 int strcmp(const char *, const char *);
 int strncmp(const char *, const char *, size_t);
+char *strtok(char *str, const char *delimiter);
 
 #endif