Initial commit

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 200 insertions, 0 deletions

diff --git a/lib/fstree/fstree.c b/lib/fstree/fstree.c
new file mode 100644
index 0000000..2722b4a
--- /dev/null
+++ b/lib/fstree/fstree.c
@@ -0,0 +1,200 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "fstree.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+static tree_node_t *mknode(tree_node_t *parent, const char *name,
+			   size_t name_len, size_t extra_len,
+			   uint16_t mode, uint32_t uid, uint32_t gid)
+{
+	size_t size = sizeof(tree_node_t) + extra_len;
+	tree_node_t *n;
+
+	switch (mode & S_IFMT) {
+	case S_IFDIR:
+		size += sizeof(*n->data.dir);
+		break;
+	case S_IFREG:
+		size += sizeof(*n->data.file);
+		break;
+	}
+
+	n = calloc(1, size + name_len + 1);
+	if (n == NULL)
+		return NULL;
+
+	if (parent != NULL) {
+		n->next = parent->data.dir->children;
+		parent->data.dir->children = n;
+	}
+
+	n->uid = uid;
+	n->gid = gid;
+	n->mode = mode;
+
+	switch (mode & S_IFMT) {
+	case S_IFDIR:
+		n->data.dir = (dir_info_t *)n->payload;
+		break;
+	case S_IFREG:
+		n->data.file = (file_info_t *)n->payload;
+		break;
+	case S_IFLNK:
+		n->data.slink_target = (char *)n->payload;
+		break;
+	}
+
+	n->name = (char *)n + size;
+	memcpy(n->name, name, name_len);
+	return n;
+}
+
+static void free_recursive(tree_node_t *n)
+{
+	tree_node_t *it;
+
+	if (S_ISDIR(n->mode)) {
+		while (n->data.dir->children != NULL) {
+			it = n->data.dir->children;
+			n->data.dir->children = it->next;
+
+			free_recursive(it);
+		}
+	}
+
+	free(n);
+}
+
+static tree_node_t *child_by_name(tree_node_t *root, const char *name,
+				  size_t len)
+{
+	tree_node_t *n = root->data.dir->children;
+
+	while (n != NULL) {
+		if (strncmp(n->name, name, len) == 0 && n->name[len] == '\0')
+			break;
+
+		n = n->next;
+	}
+
+	return n;
+}
+
+static tree_node_t *get_parent_node(fstree_t *fs, tree_node_t *root,
+				    const char *path)
+{
+	const char *end;
+	tree_node_t *n;
+
+	for (;;) {
+		if (!S_ISDIR(root->mode)) {
+			errno = ENOTDIR;
+			return NULL;
+		}
+
+		end = strchr(path, '/');
+		if (end == NULL)
+			break;
+
+		n = child_by_name(root, path, end - path);
+
+		if (n == NULL) {
+			n = mknode(root, path, end - path, 0,
+				   S_IFDIR | fs->default_mode,
+				   fs->default_uid, fs->default_gid);
+			if (n == NULL)
+				return NULL;
+
+			n->data.dir->created_implicitly = true;
+		}
+
+		root = n;
+		path = end + 1;
+	}
+
+	return root;
+}
+
+tree_node_t *fstree_add(fstree_t *fs, const char *path, uint16_t mode,
+			uint32_t uid, uint32_t gid, size_t extra_len)
+{
+	tree_node_t *child, *parent;
+	const char *name;
+
+	name = strrchr(path, '/');
+	name = (name == NULL ? path : (name + 1));
+
+	parent = get_parent_node(fs, fs->root, path);
+	if (parent == NULL)
+		return NULL;
+
+	child = child_by_name(parent, name, strlen(name));
+	if (child != NULL) {
+		if (S_ISDIR(child->mode) && S_ISDIR(mode) &&
+		    child->data.dir->created_implicitly) {
+			child->data.dir->created_implicitly = false;
+			return child;
+		}
+
+		errno = EEXIST;
+		return NULL;
+	}
+
+	return mknode(parent, name, strlen(name), extra_len, mode, uid, gid);
+}
+
+tree_node_t *fstree_add_file(fstree_t *fs, const char *path, uint16_t mode,
+			     uint32_t uid, uint32_t gid, uint64_t filesz,
+			     const char *input)
+{
+	tree_node_t *node;
+	size_t count, extra;
+	char *ptr;
+
+	count = filesz / fs->block_size;
+	extra = sizeof(uint32_t) * count + strlen(input) + 1;
+
+	mode &= 07777;
+	node = fstree_add(fs, path, S_IFREG | mode, uid, gid, extra);
+
+	if (node != NULL) {
+		ptr = (char *)(node->data.file->blocksizes + count);
+		strcpy(ptr, input);
+
+		node->data.file->input_file = ptr;
+		node->data.file->size = filesz;
+	}
+	return node;
+}
+
+int fstree_init(fstree_t *fs, size_t block_size, uint32_t mtime,
+		uint16_t default_mode, uint32_t default_uid,
+		uint32_t default_gid)
+{
+	memset(fs, 0, sizeof(*fs));
+
+	fs->default_uid = default_uid;
+	fs->default_gid = default_gid;
+	fs->default_mode = default_mode & 07777;
+	fs->default_mtime = mtime;
+	fs->block_size = block_size;
+
+	fs->root = mknode(NULL, "", 0, 0, S_IFDIR | fs->default_mode,
+			  default_uid, default_gid);
+
+	if (fs->root == NULL) {
+		perror("initializing file system tree");
+		return -1;
+	}
+
+	return 0;
+}
+
+void fstree_cleanup(fstree_t *fs)
+{
+	free_recursive(fs->root);
+	memset(fs, 0, sizeof(*fs));
+}