diff options
Diffstat (limited to 'lib/fstree/fstree.c')
| -rw-r--r-- | lib/fstree/fstree.c | 200 |
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)); +} |