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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* fstree.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include "fstree.h"
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <stdio.h>
#include <errno.h>
static void free_recursive(tree_node_t *n)
{
tree_node_t *it;
if (S_ISDIR(n->mode)) {
while (n->data.children != NULL) {
it = n->data.children;
n->data.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.children;
while (n != NULL) {
if (strncmp(n->name, name, len) == 0 && n->name[len] == '\0')
break;
n = n->next;
}
return n;
}
static void insert_sorted(tree_node_t *root, tree_node_t *n)
{
tree_node_t *it = root->data.children, *prev = NULL;
while (it != NULL && strcmp(it->name, n->name) < 0) {
prev = it;
it = it->next;
}
n->parent = root;
n->next = it;
if (prev == NULL) {
root->data.children = n;
} else {
prev->next = n;
}
}
static tree_node_t *mknode(tree_node_t *parent, const char *name,
size_t name_len, const char *extra,
const struct stat *sb)
{
tree_node_t *n;
size_t size;
char *ptr;
size = sizeof(tree_node_t) + name_len + 1;
if (extra != NULL)
size += strlen(extra) + 1;
n = calloc(1, size);
if (n == NULL)
return NULL;
n->xattr_idx = 0xFFFFFFFF;
n->uid = sb->st_uid;
n->gid = sb->st_gid;
n->mode = sb->st_mode;
n->mod_time = sb->st_mtime;
n->link_count = 1;
n->name = (char *)n->payload;
memcpy(n->name, name, name_len);
if (extra != NULL) {
ptr = n->name + name_len + 1;
strcpy(ptr, extra);
} else {
ptr = NULL;
}
switch (sb->st_mode & S_IFMT) {
case S_IFREG:
n->data.file.input_file = ptr;
break;
case S_IFLNK:
n->mode = S_IFLNK | 0777;
n->data.target = ptr;
break;
case S_IFBLK:
case S_IFCHR:
n->data.devno = sb->st_rdev;
break;
case S_IFDIR:
n->link_count = 2;
break;
default:
break;
}
if (parent->link_count == 0xFFFFFFFF) {
free(n);
errno = EMLINK;
return NULL;
}
insert_sorted(parent, n);
parent->link_count++;
return n;
}
int fstree_init(fstree_t *fs, const fstree_defaults_t *defaults)
{
memset(fs, 0, sizeof(*fs));
fs->defaults = *defaults;
fs->root = calloc(1, sizeof(tree_node_t) + 1);
if (fs->root == NULL) {
perror("initializing file system tree");
return -1;
}
fs->root->xattr_idx = 0xFFFFFFFF;
fs->root->uid = defaults->uid;
fs->root->gid = defaults->gid;
fs->root->mode = S_IFDIR | (defaults->mode & 07777);
fs->root->mod_time = defaults->mtime;
fs->root->link_count = 2;
fs->root->name = (char *)fs->root->payload;
fs->root->flags |= FLAG_DIR_CREATED_IMPLICITLY;
return 0;
}
void fstree_cleanup(fstree_t *fs)
{
free_recursive(fs->root);
free(fs->inodes);
memset(fs, 0, sizeof(*fs));
}
tree_node_t *fstree_get_node_by_path(fstree_t *fs, tree_node_t *root,
const char *path, bool create_implicitly,
bool stop_at_parent)
{
const char *end;
tree_node_t *n;
size_t len;
while (*path != '\0') {
while (*path == '/')
++path;
if (!S_ISDIR(root->mode)) {
errno = ENOTDIR;
return NULL;
}
end = strchr(path, '/');
if (end == NULL) {
if (stop_at_parent)
break;
len = strlen(path);
} else {
len = end - path;
}
n = child_by_name(root, path, len);
if (n == NULL) {
struct stat sb;
if (!create_implicitly) {
errno = ENOENT;
return NULL;
}
memset(&sb, 0, sizeof(sb));
sb.st_mode = S_IFDIR | (fs->defaults.mode & 07777);
sb.st_uid = fs->defaults.uid;
sb.st_gid = fs->defaults.gid;
sb.st_mtime = fs->defaults.mtime;
n = mknode(root, path, len, NULL, &sb);
if (n == NULL)
return NULL;
n->flags |= FLAG_DIR_CREATED_IMPLICITLY;
}
root = n;
path = path + len;
}
return root;
}
tree_node_t *fstree_add_generic(fstree_t *fs, const char *path,
const struct stat *sb, const char *extra)
{
tree_node_t *child, *parent;
const char *name;
if (S_ISLNK(sb->st_mode) && extra == NULL) {
errno = EINVAL;
return NULL;
}
if (*path == '\0') {
child = fs->root;
assert(child != NULL);
goto out;
}
parent = fstree_get_node_by_path(fs, fs->root, path, true, true);
if (parent == NULL)
return NULL;
name = strrchr(path, '/');
name = (name == NULL ? path : (name + 1));
child = child_by_name(parent, name, strlen(name));
out:
if (child != NULL) {
if (!S_ISDIR(child->mode) || !S_ISDIR(sb->st_mode) ||
!(child->flags & FLAG_DIR_CREATED_IMPLICITLY)) {
errno = EEXIST;
return NULL;
}
child->uid = sb->st_uid;
child->gid = sb->st_gid;
child->mode = sb->st_mode;
child->mod_time = sb->st_mtime;
child->flags &= ~FLAG_DIR_CREATED_IMPLICITLY;
return child;
}
return mknode(parent, name, strlen(name), extra, sb);
}
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