+/*
+ * symlink.c
+ *
+ * Code to read and set symbolic links in WIM files.
+ */
+
+/*
+ * Copyright (C) 2012, 2013 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 "buffer_io.h"
#include "lookup_table.h"
#include "sha1.h"
#include <errno.h>
+/* None of this file is ever needed in Win32 builds because the reparse point
+ * buffers are not parsed. */
+#if !defined(__WIN32__)
+
/*
* Find the symlink target of a symbolic link or junction point in the WIM.
*
- * See http://msdn.microsoft.com/en-us/library/cc232006(v=prot.10).aspx
- * Except the first 8 bytes aren't included in the resource (presumably because
- * we already know the reparse tag from the dentry, and we already know the
- * reparse tag len from the lookup table entry resource length).
+ * See http://msdn.microsoft.com/en-us/library/cc232006(v=prot.10).aspx for a
+ * description of the format of the so-called "reparse point data buffers".
+ *
+ * But, in the WIM format, the first 8 bytes of the reparse point data buffer
+ * are omitted, presumably because we already know the reparse tag from the
+ * dentry, and we already know the reparse tag length from the lookup table
+ * entry resource length.
*/
-static ssize_t get_symlink_name(const u8 *resource, size_t resource_len,
- char *buf, size_t buf_len,
- u32 reparse_tag)
+static ssize_t
+get_symlink_name(const void *resource, size_t resource_len, char *buf,
+ size_t buf_len, u32 reparse_tag)
{
- const u8 *p = resource;
+ const void *p = resource;
u16 substitute_name_offset;
u16 substitute_name_len;
u16 print_name_offset;
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 {
}
if (header_size + substitute_name_offset + substitute_name_len > resource_len)
return -EIO;
- link_target = utf16_to_utf8(p + substitute_name_offset,
- substitute_name_len,
- &link_target_len);
- if (!link_target)
- return -EIO;
+ ret = utf16le_to_tstr((const utf16lechar*)(p + substitute_name_offset),
+ substitute_name_len,
+ &link_target, &link_target_len);
+ if (ret)
+ return -errno;
if (link_target_len + 1 > buf_len) {
ret = -ENAMETOOLONG;
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... */
+ * 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] == '\\')
return ret;
}
-void *make_symlink_reparse_data_buf(const char *symlink_target, size_t *len_ret)
+static int
+make_symlink_reparse_data_buf(const char *symlink_target,
+ size_t *len_ret, void **buf_ret)
{
- size_t utf8_len = strlen(symlink_target);
- size_t utf16_len;
- char *name_utf16 = utf8_to_utf16(symlink_target, utf8_len, &utf16_len);
- if (!name_utf16)
- 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;
- 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); /* Substitute name length */
- p = put_u16(p, utf16_len); /* Print name offset */
- p = put_u16(p, utf16_len); /* Print name length */
- p = put_u32(p, 1);
- p = put_bytes(p, utf16_len, name_utf16);
- p = put_bytes(p, utf16_len, name_utf16);
- /*DEBUG("utf16_len = %zu, len = %zu", utf16_len, len);*/
- *len_ret = len;
-out:
- FREE(name_utf16);
- return buf;
-}
+ utf16lechar *name_utf16le;
+ size_t name_utf16le_nbytes;
+ int ret;
-/* 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)
-{
- struct resource_entry *res_entry;
- struct lookup_table_entry *lte;
- u16 i = 0;
- const u8 *hash = dentry->hash;
-
- wimlib_assert(dentry_is_symlink(dentry));
-
- while (1) {
- if ((lte = __lookup_resource(w->lookup_table, hash)))
- break;
- if (i == dentry->num_ads)
- return -EIO;
- hash = dentry->ads_entries[i].hash;
- i++;
- }
- res_entry = <e->resource_entry;
- if (res_entry->original_size > 10000)
- return -EIO;
+ ret = tstr_to_utf16le(symlink_target, strlen(symlink_target),
+ &name_utf16le, &name_utf16le_nbytes);
+ if (ret != 0)
+ return ret;
+
+ for (size_t i = 0; i < name_utf16le_nbytes / 2; i++)
+ if (name_utf16le[i] == cpu_to_le16('/'))
+ name_utf16le[i] = cpu_to_le16('\\');
- char __res_buf[res_entry->original_size];
- const char *res_buf;
- if (lte->is_symlink && lte->symlink_buf) {
- res_buf = lte->symlink_buf;
+ size_t len = 12 + name_utf16le_nbytes * 2;
+ void *buf = MALLOC(len);
+ if (buf) {
+ void *p = buf;
+ p = put_u16(p, name_utf16le_nbytes); /* Substitute name offset */
+ p = put_u16(p, name_utf16le_nbytes); /* Substitute name length */
+ p = put_u16(p, 0); /* Print name offset */
+ p = put_u16(p, name_utf16le_nbytes); /* Print name length */
+ p = put_u32(p, 1); /* flags: 0 iff *full* target, including drive letter??? */
+ p = put_bytes(p, name_utf16le_nbytes, name_utf16le);
+ p = put_bytes(p, name_utf16le_nbytes, name_utf16le);
+ *len_ret = len;
+ *buf_ret = buf;
+ ret = 0;
} else {
- res_buf = __res_buf;
- 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)
- return -EIO;
- res_buf = __res_buf;
+ ret = WIMLIB_ERR_NOMEM;
}
- return get_symlink_name(res_buf, res_entry->original_size, buf,
- buf_len, dentry->reparse_tag);
+ FREE(name_utf16le);
+ return ret;
}
-static int dentry_set_symlink_buf(struct dentry *dentry,
- const u8 symlink_buf_hash[])
+/* Get the symlink target from a WIM inode.
+ *
+ * The inode may be either a "real" symlink (reparse tag
+ * WIM_IO_REPARSE_TAG_SYMLINK), or it may be a junction point (reparse tag
+ * WIM_IO_REPARSE_TAG_MOUNT_POINT).
+ */
+ssize_t
+inode_readlink(const struct wim_inode *inode, char *buf, size_t buf_len,
+ const WIMStruct *w, bool threadsafe)
{
- struct ads_entry *ads_entries;
-
- ads_entries = CALLOC(2, sizeof(struct ads_entry));
- if (!ads_entries)
- return WIMLIB_ERR_NOMEM;
- memcpy(ads_entries[1].hash, symlink_buf_hash, WIM_HASH_SIZE);
- dentry_free_ads_entries(dentry);
- dentry->num_ads = 2;
- dentry->ads_entries = ads_entries;
- return 0;
+ const struct wim_lookup_table_entry *lte;
+ int ret;
+
+ wimlib_assert(inode_is_symlink(inode));
+
+ lte = inode_unnamed_lte(inode, w->lookup_table);
+ if (!lte)
+ return -EIO;
+
+ if (wim_resource_size(lte) > 10000)
+ return -EIO;
+
+ u8 res_buf[wim_resource_size(lte)];
+ ret = read_full_resource_into_buf(lte, res_buf, threadsafe);
+ if (ret != 0)
+ return -EIO;
+ return get_symlink_name(res_buf, wim_resource_size(lte), buf,
+ buf_len, inode->i_reparse_tag);
}
-int dentry_set_symlink(struct dentry *dentry, const char *target,
- struct lookup_table *lookup_table,
- struct lookup_table_entry **lte_ret)
+/*
+ * 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 wim_inode *inode,
+ const char *target,
+ struct wim_lookup_table *lookup_table,
+ struct wim_lookup_table_entry **lte_ret)
{
int ret;
size_t symlink_buf_len;
- struct lookup_table_entry *lte = NULL, *existing_lte;
- u8 symlink_buf_hash[WIM_HASH_SIZE];
+ struct wim_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;
+
+ ret = make_symlink_reparse_data_buf(target, &symlink_buf_len,
+ &symlink_buf);
+ if (ret)
+ return ret;
DEBUG("Made symlink reparse data buf (len = %zu, name len = %zu)",
- symlink_buf_len, ret);
-
+ 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) {
- existing_lte->refcnt++;
+ lte = existing_lte;
+ FREE(symlink_buf);
+ symlink_buf = NULL;
} else {
DEBUG("Creating new lookup table entry for symlink buf");
lte = new_lookup_table_entry();
ret = WIMLIB_ERR_NOMEM;
goto out_free_symlink_buf;
}
- lte->is_symlink = true;
- lte->symlink_buf = 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;
- memcpy(lte->hash, symlink_buf_hash, WIM_HASH_SIZE);
+ copy_hash(lte->hash, symlink_buf_hash);
}
- ret = dentry_set_symlink_buf(dentry, symlink_buf_hash);
-
- if (ret != 0)
- goto out_free_lte;
+ inode->i_lte = lte;
+ inode->i_resolved = 1;
DEBUG("Loaded symlink buf");
- if (!existing_lte)
+ if (existing_lte)
+ lte->refcnt++;
+ else
lookup_table_insert(lookup_table, lte);
if (lte_ret)
*lte_ret = lte;
return 0;
-out_free_lte:
- FREE(lte);
out_free_symlink_buf:
FREE(symlink_buf);
return ret;
}
+
+#endif /* !defined(__WIN32__) */
git://wimlib.net / wimlib / blobdiff