merge main into forkmanforkman

3 files changed, 491 insertions, 7 deletions

diff --git a/kernel/fs/fs.c b/kernel/fs/fs.c
index a887ca4..ef031f2 100644
--- a/kernel/fs/fs.c
+++ b/kernel/fs/fs.c
@@ -1,5 +1,6 @@
 #include <lib.h>
 #include <comus/fs.h>
+#include <comus/fs/tar.h>
 #include <comus/mboot.h>
 #include <comus/error.h>
 
@@ -50,9 +51,9 @@ static void load_fs(struct disk *disk)
 	fs->fs_id = disk->d_id;
 	fs->fs_present = 1;
 
-	// // try examplefs
-	// if (example_mount(fs) == SUCCESS)
-	// 	return;
+	// try tarfs
+	if (tar_mount(fs) == SUCCESS)
+		return;
 
 	fs->fs_present = 0;
 	WARN("failed to load fs on disk %u", disk->d_id);
@@ -122,13 +123,16 @@ int fs_find_file_rel(struct file *rel, char *rel_path, struct file *res)
 static int disk_read_rd(struct disk *disk, size_t offset, size_t len,
 						uint8_t *buffer)
 {
-	if (offset + len >= disk->rd.len) {
+	if (offset >= disk->rd.len) {
 		WARN("attempted to read past length of ramdisk");
 		return -E_BAD_PARAM;
 	}
 
+	if (disk->rd.len - offset < len)
+		len = disk->rd.len - offset;
+
 	memcpy(buffer, disk->rd.start + offset, len);
-	return 0;
+	return len;
 }
 
 static int disk_read_ata(struct disk *disk, size_t offset, size_t len,
@@ -181,13 +185,16 @@ int disk_read(struct disk *disk, size_t offset, size_t len, void *buffer)
 static int disk_write_rd(struct disk *disk, size_t offset, size_t len,
 						 uint8_t *buffer)
 {
-	if (offset + len >= disk->rd.len) {
+	if (offset >= disk->rd.len) {
 		WARN("attempted to write past length of ramdisk");
 		return -E_BAD_PARAM;
 	}
 
+	if (disk->rd.len - offset < len)
+		len = disk->rd.len - offset;
+
 	memcpy(disk->rd.start + offset, buffer, len);
-	return 0;
+	return len;
 }
 
 static int disk_write_ata(struct disk *disk, size_t offset, size_t len,
diff --git a/kernel/fs/ramfs.c b/kernel/fs/ramfs.c
new file mode 100644
index 0000000..0c92c96
--- /dev/null
+++ b/kernel/fs/ramfs.c
@@ -0,0 +1,171 @@
+#include <comus/fs.h>
+/*#include <lib.h>
+//#include <comus/tar.h>
+//#include <string.h>
+#include <comus/ramfs.h>
+
+#define NOERROR 0
+#define ERROR 1
+
+int ramfs_check_exists(const char *name) {
+    for(int i = 0; i < numberOfFiles; i++) {
+        if(memcmp(allTheFiles[i].name, name, strlen(allTheFiles[i].name)) == 0) {
+            // found it
+            return i;
+        }
+    }
+    // doesn't exist
+    return -1;
+}
+int ramfs_create(const char *name) {
+    if(ramfs_check_exists(name) != -1) {
+        // already exists
+        return ERROR;
+    }
+    struct file *newFile;
+    *newFile->name = name;
+    newFile->size = 0;
+    newFile->data = kalloc(MAX_FILE_SIZE);
+    newFile = &allTheFiles[numberOfFiles];
+
+}
+
+int ramfs_delete(const char *name) {
+    int i = ramfs_check_exists(name);
+    if(i >= 0) {
+        kfree(allTheFiles[i].data);
+        for(int j = i; j < numberOfFiles; j++) {
+            allTheFiles[j] = allTheFiles[j+1];
+            numberOfFiles -= 1;
+        }
+        return NOERROR;
+
+    }
+    return ERROR;
+}
+
+int ramfs_read(const char *name, char *buffer, size_t len) {
+    int i = ramfs_check_exists(name);
+    if(i >= 0) {
+        memcpy(buffer, allTheFiles[i].data, len);
+        return NOERROR;
+    }
+    return ERROR;
+}
+
+
+int ramfs_write(const char *name, char *buffer) {
+    int i = ramfs_check_exists(name);
+    if(i >= 0) {
+        memcpy(buffer)
+    }
+}
+
+// here we return the index of the file as well.
+*int ramfs_find_file(root *r, const char *fullpath, const char *name, file *out, directory *outDirectory) {
+    directory *location = r->root;
+    if(ramfs_find_directory(r, fullpath, name, location) == NOERROR) {
+        for(int i = 0; i < location->file_count; i++) {
+            if(strcmp(location->files[i]->name, name) == 0) {
+                outDirectory = location;
+                out = location->files[i];
+                return i;
+            }
+        }
+
+    }
+    return -1;
+}
+int ramfs_find_directory(root *r, const char *fullpath, const char *name, directory *out) {
+    directory *location = r->root;
+    char *path = fullpath;
+    char *tempPath = strtok(tempPath, "/");
+    while(tempPath != NULL) {
+        bool wasItFound = false;
+
+        for(int i = 0; i < location->directory_count; i++) {
+            if(strcmp(location->directories[i]->name, tempPath) == 0) {
+                // yay we found it;
+                location = location->directories[i];
+                wasItFound = true;
+                break;
+
+            }
+        }
+        if(!wasItFound) {
+            return ERROR;
+        }
+        tempPath = strtok(NULL, "/");
+
+    }
+    out = location;
+    return NOERROR;
+
+}
+
+int ramfs_create_file(root *r, const char *fullpath, const char *name) {
+    // trace through the path
+    // struct ramfs_directory *location = r->root;
+    directory *location = r->root;
+
+    if(ramfs_find_directory(r, fullpath, name, location) == NOERROR) {
+        if(location->file_count >= MAX_FILES) {
+            return ERROR;
+        }
+        file *newFile = malloc(sizeof(file));
+        strcpy(newFile->name, name);
+        newFile->size = 0;
+        newFile->data = malloc(MAX_FILE_SIZE);
+        location->files[location->file_count] = newFile;
+        location->file_count += 1;
+
+        return NOERROR;
+
+    }
+    return ERROR;
+}
+
+int ramfs_delete_file(root *r, const char *fullpath, const char *name) {
+    directory *location;
+    if(ramfs_find_directory(r, fullpath, name, location) == NOERROR) {
+        file *find_file;
+        int file_index = ramfs_find_file(r, fullpath, name, find_file, location) >= 0;
+        if(file_index >= 0) {
+            free(location->files[file_index]->data);
+            free(location->files[file_index]);
+            for(int i = file_index + 1; i < location->file_count; i++) {
+                location->files[i-1] = location->files[i];
+                //memcpy(location->files[i-1], location->files[i], location->files[i]->size);
+                //free(location->files[i]);
+            }
+            location->file_count -= 1;
+            return NOERROR;
+        }
+        return ERROR;
+
+    }
+    return ERROR;
+}
+
+int ramfs_create_directory() {
+
+}
+
+int ramfs_delete_directory() {
+}
+
+int ramfs_write() {
+
+}
+
+
+root *ramfs_init() {
+    root *r = malloc(sizeof(root));
+    r->root = malloc(sizeof(directory));
+    strcpy(r->root->name, "/");
+    r->root->file_count = 0;
+    r->root->directory_count = 0;
+    return r;
+}
+
+*/
diff --git a/kernel/fs/tar.c b/kernel/fs/tar.c
new file mode 100644
index 0000000..5f02c34
--- /dev/null
+++ b/kernel/fs/tar.c
@@ -0,0 +1,306 @@
+#include <comus/fs.h>
+#include <lib.h>
+#include <comus/tar.h>
+
+// the placements of these values mimics their placement in standard UStar
+struct tar_header {
+	char name[100]; // 0-99
+	char mode[8]; // 100-107
+	char ownerUID[8]; // 108-115
+	char groupUID[8]; // 116-123
+	char fileSize[12]; // 124-135
+	char lastMod[12]; // 136-147
+	char checksum[8]; // 148-155
+	char type_flag; // 156
+	char linked_name[100]; // 157-256
+	char magic[6]; // 257-262
+	char version[2]; // 263-264
+	char username[32]; // 265-296
+	char groupname[32]; // 297-328
+	char majorNum[8]; // 329-336
+	char minorNum[8]; // 337-344
+	char prefix[155]; // 345-499
+	char notUsed[12]; // 500-511
+};
+#define TAR_SIZE 512
+#define TMAGIC "ustar" /* ustar and a null */
+#define TMAGLEN 6
+#define TVERSION "00" /* 00 and no null */
+#define TVERSLEN 2
+#define ERROR_TAR 1
+#define NOERROR_TAR 0
+
+#define REGTYPE '0' /* regular file */
+#define DIRTYPE '5' /* directory */
+
+struct tar_file {
+	struct file file;
+	struct file_system *fs;
+	size_t len;
+	size_t offset;
+	size_t sect;
+};
+// read_tar_header reads what is in tar
+int read_tar_header(struct disk *disk, uint32_t sect, struct tar_header *hdr)
+{
+	if (disk_read(disk, sect * TAR_SIZE, TAR_SIZE, hdr) < TAR_SIZE) {
+		return ERROR_TAR;
+	}
+	if (memcmp(hdr->magic, TMAGIC, TMAGLEN) != 0 ||
+		memcmp(hdr->version, TVERSION, TVERSLEN) != 0) {
+		return ERROR_TAR;
+	}
+	return NOERROR_TAR;
+}
+
+/// @brief
+/// @param f the file to be read
+/// @param buffer the buffer that the content of the file is read into
+/// @param len
+/// @return
+int tar_read(struct file *f, void *buffer, size_t len)
+{
+	struct tar_file *tf = (struct tar_file *)f;
+	long size = MIN((tf->len - tf->offset), len);
+	if (tf->file.f_type != F_REG || size < 1) {
+		return ERROR_TAR;
+	}
+	size = disk_read(tf->fs->fs_disk, (tf->sect + 1) * TAR_SIZE + tf->offset,
+					 size, buffer);
+	tf->offset += size;
+	return size;
+}
+//static int read_tar()
+// we are assuming that things are formatted correctly.
+int find_file(struct file_system *fs, const char *filepath, size_t *sect,
+			  size_t *sect_return, struct tar_header *outHeader)
+{
+	//char *tempFilePath = filepath;
+	struct tar_header hdr;
+	size_t curr_sect;
+	if (sect == NULL) {
+		curr_sect = 0;
+	} else {
+		curr_sect = *sect;
+	}
+	while (1 == 1) {
+		if (read_tar_header(fs->fs_disk, curr_sect, &hdr) != 0) {
+			return ERROR_TAR;
+		}
+		if (memcmp(hdr.name, filepath, strlen(filepath) + 1) != 0) {
+			// didn't find it.
+
+			curr_sect +=
+				((strtoull(hdr.fileSize, NULL, 8) + TAR_SIZE - 1) / TAR_SIZE) +
+				1;
+			continue;
+		} else {
+			*outHeader = hdr;
+			*sect_return = curr_sect;
+			if (sect != NULL) {
+				sect += curr_sect;
+			}
+			return NOERROR_TAR;
+		}
+	}
+	return ERROR_TAR;
+}
+int find_file_redux(struct file_system *fs, const char *filepath, size_t *sect,
+					size_t *sect_return, struct tar_header *outHeader)
+{
+	struct tar_header hdr;
+	size_t curr_sect;
+	if (sect == NULL) {
+		curr_sect = 0;
+	} else {
+		curr_sect = *sect;
+	}
+	while (1 == 1) {
+		if (read_tar_header(fs->fs_disk, curr_sect, &hdr) != 0) {
+			return ERROR_TAR;
+		}
+		if (memcmp(hdr.name, filepath,
+				   MIN(strlen(filepath), strlen(hdr.name))) != 0) {
+			// didn't find it.
+
+			curr_sect +=
+				((strtoull(hdr.fileSize, NULL, 8) + TAR_SIZE - 1) / TAR_SIZE) +
+				1;
+			continue;
+		} else {
+			*outHeader = hdr;
+			*sect_return = curr_sect;
+			if (sect != NULL) {
+				sect += curr_sect +
+						((strtoull(hdr.fileSize, NULL, 8) + TAR_SIZE - 1) /
+						 TAR_SIZE) +
+						1;
+			}
+			return NOERROR_TAR;
+		}
+	}
+	return ERROR_TAR; // it should never actually reach here.
+}
+
+void tar_close(struct file *f)
+{
+	kfree(f);
+}
+
+int tar_seek(struct file *f, long int offsetAdd, int theSeek)
+{
+	struct tar_file *tf = (struct tar_file *)f;
+	if (theSeek == SEEK_SET) {
+		tf->offset = offsetAdd;
+		return tf->offset;
+	} else if (theSeek == SEEK_CUR) {
+		tf->offset = tf->offset + offsetAdd;
+		return tf->offset;
+	} else if (theSeek == SEEK_END) {
+		tf->offset = tf->len + offsetAdd;
+		return tf->offset;
+	} else {
+		return -1;
+	}
+}
+
+int tar_write(struct file *f, const void *buffer, size_t len)
+{
+	// tar doesn't do write lol. This is just here so there is something to send to write
+	(void)f;
+	(void)buffer;
+	(void)len;
+	return ERROR_TAR;
+}
+
+/*int tar_ents(struct file *f, struct dirent *d, size_t dIndex) {
+    struct tar_header hdr;
+    struct tar_header dir;
+    struct tar_file *tf = (struct tar_file*) f;
+    size_t sect = 0;
+    size_t sect_off = 0;
+    size_t curr_index = 0;
+    if(read_tar_header(tf->fs->fs_disk, sect, &hdr) != 0) {
+        return ERROR_TAR;
+    }
+    while(1 == 1) {
+        if(find_file_redux(tf->fs, dir.name, &sect_off, &sect, &dir) != 0) {
+            return ERROR_TAR;
+        }
+        if(curr_index < dIndex) {
+            curr_index += 1;
+        } else if(curr_index > dIndex) {
+            // something went seriously wrong
+            return ERROR_TAR;
+        } else {
+            d->d_namelen = strlen(hdr.name);
+            dir.type_flag = DIRTYPE;
+            d->d_offset = dIndex;
+            memcpy(d->d_name, hdr.name, d->d_namelen + 1);
+            return NOERROR_TAR;
+        }
+
+
+    }
+
+
+}*/
+
+int tar_ents(struct file *f, struct dirent *ent, size_t entry)
+{
+	struct tar_file *tf;
+	struct tar_header dir, hdr;
+	size_t sect;
+	size_t sect_off = 0;
+	size_t idx = 0;
+
+	tf = (struct tar_file *)f;
+	sect = 0;
+
+	if (tf->file.f_type != F_DIR)
+		return -1;
+
+	if (read_tar_header(tf->fs->fs_disk, sect, &dir)) {
+		return ERROR_TAR;
+	}
+
+	while (1) {
+		if (find_file_redux(tf->fs, dir.name, &sect_off, &sect, &hdr))
+			return ERROR_TAR;
+
+		if (idx != entry) {
+			idx++;
+			continue;
+		}
+
+		ent->d_offset = entry;
+		ent->d_namelen = strlen(hdr.name);
+		memcpy(ent->d_name, hdr.name, ent->d_namelen + 1);
+		return NOERROR_TAR;
+	}
+
+	return ERROR_TAR;
+}
+
+// opens up the tar file at fullpath, and puts it in out.
+int tar_open(struct file_system *fs, const char *fullpath, int flags,
+			 struct file **out)
+{
+	struct tar_header hdr;
+	struct tar_file *newFile;
+	size_t sect_result;
+	find_file(fs, fullpath, NULL, &sect_result, &hdr);
+	if (flags != O_RDONLY) {
+		return ERROR_TAR;
+	}
+	newFile = kalloc(sizeof(struct tar_file));
+
+	newFile->file.f_type = F_REG;
+	newFile->fs = fs;
+	newFile->file.read = tar_read;
+	newFile->file.close = tar_close;
+	newFile->file.write = tar_write; // doesn't actually work;
+	newFile->file.ents = tar_ents;
+	newFile->file.seek = tar_seek;
+	newFile->offset = 0;
+	newFile->len = strtoull(hdr.fileSize, NULL, 8);
+	newFile->sect = sect_result;
+
+	*out = (struct file *)newFile;
+	return NOERROR_TAR;
+}
+
+// gets stats at the file at fullpath, putting them in out.
+int tar_stat(struct file_system *fs, const char *fullpath, struct stat *out)
+{
+	struct tar_header hdr;
+	size_t sect_result;
+	find_file(fs, fullpath, NULL, &sect_result, &hdr);
+	out->s_length = strtoull(hdr.fileSize, NULL, 8);
+	if (hdr.type_flag == REGTYPE) {
+		out->s_type = F_REG;
+	} else if (hdr.type_flag == DIRTYPE) {
+		out->s_type = F_DIR;
+	} else {
+		// wth
+		return ERROR_TAR;
+	}
+	return NOERROR_TAR;
+}
+
+// use tar for the filesystem.
+int tar_mount(struct file_system *fs)
+{
+	struct tar_header hdr;
+	// reads into hdr
+	if (read_tar_header(fs->fs_disk, 0, &hdr) == 0) {
+		fs->fs_name = "tar";
+		fs->open = tar_open;
+		fs->stat = tar_stat;
+		fs->fs_present = true;
+		return NOERROR_TAR;
+	}
+	return ERROR_TAR;
+}
+
+// no need to unmount, since mount just overrides whatever it was using previously.
\ No newline at end of file