+/*
+ * symlink.c
+ *
+ * Code to read and set symbolic links in WIM files.
+ */
+
+/*
+ * Copyright (C) 2012 Eric Biggers
+ *
+ * This file is part of wimlib, a library for working with WIM files.
+ *
+ * wimlib is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+ * A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with wimlib; if not, see http://www.gnu.org/licenses/.
+ */
+
#include "dentry.h"
#include "io.h"
#include "lookup_table.h"
+#include "sha1.h"
+#include <errno.h>
/*
* Find the symlink target of a symbolic link or junction point in the WIM.
*/
static ssize_t get_symlink_name(const u8 *resource, size_t resource_len,
char *buf, size_t buf_len,
- bool is_junction_point)
+ u32 reparse_tag)
{
const u8 *p = resource;
u16 substitute_name_offset;
unsigned header_size;
char *translated_target;
bool is_absolute;
+ u32 flags;
if (resource_len < 12)
return -EIO;
p = get_u16(p, &substitute_name_len);
p = get_u16(p, &print_name_offset);
p = get_u16(p, &print_name_len);
- if (is_junction_point) {
+ get_u32(p, &flags);
+
+ wimlib_assert(reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK ||
+ reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT);
+
+ /* I think that some junction points incorrectly get marked as symbolic
+ * links. So, parse the link buffer as a symlink if the flags seem
+ * plausible. */
+ if (flags <= 1)
+ reparse_tag = WIM_IO_REPARSE_TAG_SYMLINK;
+
+ if (reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT) {
header_size = 8;
} else {
- u32 flags;
- p = get_u32(p, &flags);
is_absolute = (flags & 1) ? false : true;
header_size = 12;
+ p += 4;
}
if (header_size + substitute_name_offset + substitute_name_len > resource_len)
return -EIO;
- link_target = utf16_to_utf8(p + substitute_name_offset,
+ link_target = utf16_to_utf8((const char *)p + substitute_name_offset,
substitute_name_len,
&link_target_len);
}
translated_target = link_target;
- if (is_junction_point || is_absolute) {
+ if (reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT || is_absolute) {
if (link_target_len < 7
|| memcmp(translated_target, "\\??\\", 4) != 0
|| translated_target[4] == '\0'
}
translated_target += 4;
link_target_len -= 4;
+ /* There's a drive letter, so just leave the backslashes since
+ * it won't go anyhwere on UNIX anyway...
+ *
+ * XXX
+ * NTFS-3g tries to re-map these links to actually point to
+ * something, so maybe we could do something like that here
+ * XXX*/
+ } else {
+ for (size_t i = 0; i < link_target_len; i++)
+ if (translated_target[i] == '\\')
+ translated_target[i] = '/';
}
- for (size_t i = 0; i < link_target_len; i++)
- if (translated_target[i] == '\\')
- translated_target[i] = '/';
memcpy(buf, translated_target, link_target_len + 1);
ret = link_target_len;
return NULL;
/*DEBUG("utf16_len = %zu", utf16_len);*/
for (size_t i = 0; i < utf16_len / 2; i++)
- if (((u16*)name_utf16)[i] == to_le16('/'))
- ((u16*)name_utf16)[i] = to_le16('\\');
- size_t len = 12 + utf16_len * 2;
+ if (((u16*)name_utf16)[i] == cpu_to_le16('/'))
+ ((u16*)name_utf16)[i] = cpu_to_le16('\\');
+ size_t len = 12 + utf16_len * 2 + 4;
void *buf = MALLOC(len);
if (!buf)
goto out;
+ /* XXX Fix absolute paths */
u8 *p = buf;
- p = put_u16(p, 0); /* Substitute name offset */
+ p = put_u16(p, utf16_len + 2); /* Substitute name offset */
p = put_u16(p, utf16_len); /* Substitute name length */
- p = put_u16(p, utf16_len); /* Print name offset */
+ p = put_u16(p, 0); /* Print name offset */
p = put_u16(p, utf16_len); /* Print name length */
- p = put_u32(p, (symlink_target[0] == '/') ? 0 : 1);
- p = put_bytes(p, utf16_len, name_utf16);
- p = put_bytes(p, utf16_len, name_utf16);
+ p = put_u32(p, 1);
+ p = put_bytes(p, utf16_len, (const u8*)name_utf16);
+ p = put_u16(p, 0);
+ p = put_bytes(p, utf16_len, (const u8*)name_utf16);
+ p = put_u16(p, 0);
/*DEBUG("utf16_len = %zu, len = %zu", utf16_len, len);*/
*len_ret = len;
out:
return buf;
}
-/* Get the symlink target from a dentry that's already checked to be either a
- * "real" symlink or a junction point. */
-ssize_t dentry_readlink(const struct dentry *dentry, char *buf, size_t buf_len,
- const WIMStruct *w)
+/* Get the symlink target from a dentry.
+ *
+ * The dentry may be either "real" symlink or a junction point.
+ */
+ssize_t inode_readlink(const struct inode *inode, char *buf, size_t buf_len,
+ const WIMStruct *w)
{
- struct ads_entry *ads;
- struct lookup_table_entry *entry;
- struct resource_entry *res_entry;
- bool is_junction_point;
-
- wimlib_assert(dentry_is_symlink(dentry));
-
- if (dentry->reparse_tag == WIM_IO_REPARSE_TAG_SYMLINK) {
- is_junction_point = false;
- /*
- * This is of course not actually documented, but what I think is going
- * on here is that the symlink dentries have 2 alternate data streams;
- * one is the default data stream, which is not used and is empty, and
- * one is the symlink buffer data stream, which is confusingly also
- * unnamed, but isn't empty as it contains the symlink target within the
- * resource.
- */
- if (dentry->num_ads != 2)
- return -EIO;
- if ((entry = __lookup_resource(w->lookup_table, dentry->ads_entries[0].hash)))
- goto do_readlink;
- if ((entry = __lookup_resource(w->lookup_table, dentry->ads_entries[1].hash)))
- goto do_readlink;
- } else {
- wimlib_assert(dentry->reparse_tag == WIM_IO_REPARSE_TAG_MOUNT_POINT);
+ const struct lookup_table_entry *lte;
+ int ret;
- is_junction_point = true;
+ wimlib_assert(inode_is_symlink(inode));
- if ((entry = __lookup_resource(w->lookup_table, dentry->hash)))
- goto do_readlink;
- }
- return -EIO;
-do_readlink:
- res_entry = &entry->resource_entry;
- if (res_entry->original_size > 10000)
+ lte = inode_unnamed_lte(inode, w->lookup_table);
+ if (!lte)
return -EIO;
- char res_buf[res_entry->original_size];
- if (read_full_resource(w->fp, res_entry->size,
- res_entry->original_size,
- res_entry->offset,
- wim_resource_compression_type(w, res_entry),
- res_buf) != 0)
+
+ if (wim_resource_size(lte) > 10000)
+ return -EIO;
+
+ u8 res_buf[wim_resource_size(lte)];
+ ret = read_full_wim_resource(lte, res_buf);
+ if (ret != 0)
return -EIO;
- return get_symlink_name(res_buf, res_entry->original_size, buf,
- buf_len, is_junction_point);
+ return get_symlink_name(res_buf, wim_resource_size(lte), buf,
+ buf_len, inode->reparse_tag);
+}
+
+/*
+ * Sets @inode to be a symbolic link pointing to @target.
+ *
+ * A lookup table entry for the symbolic link data buffer is created and
+ * inserted into @lookup_table, unless there is an existing lookup table entry
+ * for the exact same data, in which its reference count is incremented.
+ *
+ * The lookup table entry is returned in @lte_ret.
+ *
+ * On failure @dentry and @lookup_table are not modified.
+ */
+int inode_set_symlink(struct inode *inode, const char *target,
+ struct lookup_table *lookup_table,
+ struct lookup_table_entry **lte_ret)
+
+{
+ int ret;
+ size_t symlink_buf_len;
+ struct lookup_table_entry *lte = NULL, *existing_lte;
+ u8 symlink_buf_hash[SHA1_HASH_SIZE];
+ void *symlink_buf;
+
+ symlink_buf = make_symlink_reparse_data_buf(target, &symlink_buf_len);
+ if (!symlink_buf)
+ return WIMLIB_ERR_NOMEM;
+
+ DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
+ symlink_buf_len, symlink_buf_len);
+
+ sha1_buffer(symlink_buf, symlink_buf_len, symlink_buf_hash);
+
+ existing_lte = __lookup_resource(lookup_table, symlink_buf_hash);
+
+ if (existing_lte) {
+ lte = existing_lte;
+ FREE(symlink_buf);
+ symlink_buf = NULL;
+ } else {
+ DEBUG("Creating new lookup table entry for symlink buf");
+ lte = new_lookup_table_entry();
+ if (!lte) {
+ ret = WIMLIB_ERR_NOMEM;
+ goto out_free_symlink_buf;
+ }
+ lte->resource_location = RESOURCE_IN_ATTACHED_BUFFER;
+ lte->attached_buffer = symlink_buf;
+ lte->resource_entry.original_size = symlink_buf_len;
+ lte->resource_entry.size = symlink_buf_len;
+ copy_hash(lte->hash, symlink_buf_hash);
+ }
+
+ inode->lte = lte;
+ inode->resolved = true;
+
+ DEBUG("Loaded symlink buf");
+
+ if (existing_lte)
+ lte->refcnt++;
+ else
+ lookup_table_insert(lookup_table, lte);
+ if (lte_ret)
+ *lte_ret = lte;
+ return 0;
+out_free_lte:
+ if (lte != existing_lte)
+ FREE(lte);
+out_free_symlink_buf:
+ FREE(symlink_buf);
+ return ret;
}
git://wimlib.net / wimlib / blobdiff