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-rw-r--r--lib/sqfs/dir_writer.c287
1 files changed, 287 insertions, 0 deletions
diff --git a/lib/sqfs/dir_writer.c b/lib/sqfs/dir_writer.c
new file mode 100644
index 0000000..3ef3bc7
--- /dev/null
+++ b/lib/sqfs/dir_writer.c
@@ -0,0 +1,287 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * dir_writer.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "sqfs/inode.h"
+#include "sqfs/dir.h"
+#include "util.h"
+
+#include <sys/stat.h>
+#include <endian.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+typedef struct dir_entry_t {
+ struct dir_entry_t *next;
+ uint64_t inode_ref;
+ uint32_t inode_num;
+ uint16_t type;
+ size_t name_len;
+ char name[];
+} dir_entry_t;
+
+typedef struct index_ent_t {
+ struct index_ent_t *next;
+ dir_entry_t *ent;
+ uint64_t block;
+ uint32_t index;
+} index_ent_t;
+
+struct sqfs_dir_writer_t {
+ dir_entry_t *list;
+ dir_entry_t *list_end;
+
+ index_ent_t *idx;
+ index_ent_t *idx_end;
+
+ uint64_t dir_ref;
+ size_t dir_size;
+ size_t idx_size;
+ meta_writer_t *dm;
+};
+
+static int get_type(mode_t mode)
+{
+ switch (mode & S_IFMT) {
+ case S_IFSOCK: return SQFS_INODE_SOCKET;
+ case S_IFIFO: return SQFS_INODE_FIFO;
+ case S_IFLNK: return SQFS_INODE_SLINK;
+ case S_IFBLK: return SQFS_INODE_BDEV;
+ case S_IFCHR: return SQFS_INODE_CDEV;
+ case S_IFDIR: return SQFS_INODE_DIR;
+ case S_IFREG: return SQFS_INODE_FILE;
+ default:
+ assert(0);
+ }
+}
+
+static void writer_reset(sqfs_dir_writer_t *writer)
+{
+ dir_entry_t *ent;
+ index_ent_t *idx;
+
+ while (writer->idx != NULL) {
+ idx = writer->idx;
+ writer->idx = idx->next;
+ free(idx);
+ }
+
+ while (writer->list != NULL) {
+ ent = writer->list;
+ writer->list = ent->next;
+ free(ent);
+ }
+
+ writer->list_end = NULL;
+ writer->idx_end = NULL;
+ writer->dir_ref = 0;
+ writer->dir_size = 0;
+ writer->idx_size = 0;
+}
+
+sqfs_dir_writer_t *sqfs_dir_writer_create(meta_writer_t *dm)
+{
+ sqfs_dir_writer_t *writer = calloc(1, sizeof(*writer));
+
+ if (writer == NULL) {
+ perror("creating directory writer");
+ return NULL;
+ }
+
+ writer->dm = dm;
+ return writer;
+}
+
+void sqfs_dir_writer_destroy(sqfs_dir_writer_t *writer)
+{
+ writer_reset(writer);
+ free(writer);
+}
+
+int sqfs_dir_writer_begin(sqfs_dir_writer_t *writer)
+{
+ uint32_t offset;
+ uint64_t block;
+
+ writer_reset(writer);
+
+ meta_writer_get_position(writer->dm, &block, &offset);
+ writer->dir_ref = (block << 16) | offset;
+ return 0;
+}
+
+int sqfs_dir_writer_add_entry(sqfs_dir_writer_t *writer, const char *name,
+ uint32_t inode_num, uint64_t inode_ref,
+ mode_t mode)
+{
+ dir_entry_t *ent = alloc_flex(sizeof(*ent), 1, strlen(name));
+
+ if (ent == NULL) {
+ perror("creating directory entry");
+ return -1;
+ }
+
+ ent->inode_ref = inode_ref;
+ ent->inode_num = inode_num;
+ ent->type = get_type(mode);
+ ent->name_len = strlen(name);
+ memcpy(ent->name, name, ent->name_len);
+
+ if (writer->list_end == NULL) {
+ writer->list = writer->list_end = ent;
+ } else {
+ writer->list_end->next = ent;
+ writer->list_end = ent;
+ }
+
+ writer->dir_size += sizeof(ent) + ent->name_len;
+ return 0;
+}
+
+static size_t get_conseq_entry_count(uint32_t offset, dir_entry_t *head)
+{
+ size_t size, count = 0;
+ dir_entry_t *it;
+ int32_t diff;
+
+ size = (offset + sizeof(sqfs_dir_header_t)) % SQFS_META_BLOCK_SIZE;
+
+ for (it = head; it != NULL; it = it->next) {
+ if ((it->inode_ref >> 16) != (head->inode_ref >> 16))
+ break;
+
+ diff = it->inode_num - head->inode_num;
+
+ if (diff > 32767 || diff < -32767)
+ break;
+
+ size += sizeof(sqfs_dir_entry_t) + it->name_len;
+
+ if (count > 0 && size > SQFS_META_BLOCK_SIZE)
+ break;
+
+ count += 1;
+
+ if (count == SQFS_MAX_DIR_ENT)
+ break;
+ }
+
+ return count;
+}
+
+static int add_header(sqfs_dir_writer_t *writer, size_t count,
+ dir_entry_t *ref, uint64_t block)
+{
+ sqfs_dir_header_t hdr;
+ index_ent_t *idx;
+
+ hdr.count = htole32(count - 1);
+ hdr.start_block = htole32(ref->inode_ref >> 16);
+ hdr.inode_number = htole32(ref->inode_num);
+
+ if (meta_writer_append(writer->dm, &hdr, sizeof(hdr)))
+ return -1;
+
+ idx = calloc(1, sizeof(*idx));
+ if (idx == NULL) {
+ perror("creating directory index entry");
+ return -1;
+ }
+
+ idx->ent = ref;
+ idx->block = block;
+ idx->index = writer->dir_size;
+
+ if (writer->idx_end == NULL) {
+ writer->idx = writer->idx_end = idx;
+ } else {
+ writer->idx_end->next = idx;
+ writer->idx_end = idx;
+ }
+
+ writer->dir_size += sizeof(hdr);
+ writer->idx_size += 1;
+ return 0;
+}
+
+int sqfs_dir_writer_end(sqfs_dir_writer_t *writer)
+{
+ dir_entry_t *it, *first;
+ sqfs_dir_entry_t ent;
+ uint16_t *diff_u16;
+ size_t i, count;
+ uint32_t offset;
+ uint64_t block;
+
+ for (it = writer->list; it != NULL; ) {
+ meta_writer_get_position(writer->dm, &block, &offset);
+ count = get_conseq_entry_count(offset, it);
+
+ if (add_header(writer, count, it, block))
+ return -1;
+
+ first = it;
+
+ for (i = 0; i < count; ++i) {
+ ent.offset = htole16(it->inode_ref & 0x0000FFFF);
+ ent.inode_diff = it->inode_num - first->inode_num;
+ ent.type = htole16(it->type);
+ ent.size = htole16(it->name_len - 1);
+
+ diff_u16 = (uint16_t *)&ent.inode_diff;
+ *diff_u16 = htole16(*diff_u16);
+
+ if (meta_writer_append(writer->dm, &ent, sizeof(ent)))
+ return -1;
+
+ if (meta_writer_append(writer->dm, it->name, it->name_len))
+ return -1;
+
+ it = it->next;
+ }
+ }
+
+ return 0;
+}
+
+size_t sqfs_dir_writer_get_size(sqfs_dir_writer_t *writer)
+{
+ return writer->dir_size;
+}
+
+uint64_t sqfs_dir_writer_get_dir_reference(sqfs_dir_writer_t *writer)
+{
+ return writer->dir_ref;
+}
+
+size_t sqfs_dir_writer_get_index_size(sqfs_dir_writer_t *writer)
+{
+ return writer->idx_size;
+}
+
+int sqfs_dir_writer_write_index(sqfs_dir_writer_t *writer,
+ meta_writer_t *im)
+{
+ sqfs_dir_index_t ent;
+ index_ent_t *idx;
+
+ for (idx = writer->idx; idx != NULL; idx = idx->next) {
+ ent.start_block = htole32(idx->block);
+ ent.index = htole32(idx->index);
+ ent.size = htole32(idx->ent->name_len - 1);
+
+ if (meta_writer_append(im, &ent, sizeof(ent)))
+ return -1;
+
+ if (meta_writer_append(im, idx->ent->name, idx->ent->name_len))
+ return -1;
+ }
+
+ return 0;
+}
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