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-rw-r--r--fs/ntfs3/attrlist.c473
1 files changed, 473 insertions, 0 deletions
diff --git a/fs/ntfs3/attrlist.c b/fs/ntfs3/attrlist.c
new file mode 100644
index 000000000..0c6a68e71
--- /dev/null
+++ b/fs/ntfs3/attrlist.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *
+ * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
+ *
+ */
+
+#include <linux/fs.h>
+
+#include "debug.h"
+#include "ntfs.h"
+#include "ntfs_fs.h"
+
+/*
+ * al_is_valid_le
+ *
+ * Return: True if @le is valid.
+ */
+static inline bool al_is_valid_le(const struct ntfs_inode *ni,
+ struct ATTR_LIST_ENTRY *le)
+{
+ if (!le || !ni->attr_list.le || !ni->attr_list.size)
+ return false;
+
+ return PtrOffset(ni->attr_list.le, le) + le16_to_cpu(le->size) <=
+ ni->attr_list.size;
+}
+
+void al_destroy(struct ntfs_inode *ni)
+{
+ run_close(&ni->attr_list.run);
+ kfree(ni->attr_list.le);
+ ni->attr_list.le = NULL;
+ ni->attr_list.size = 0;
+ ni->attr_list.dirty = false;
+}
+
+/*
+ * ntfs_load_attr_list
+ *
+ * This method makes sure that the ATTRIB list, if present,
+ * has been properly set up.
+ */
+int ntfs_load_attr_list(struct ntfs_inode *ni, struct ATTRIB *attr)
+{
+ int err;
+ size_t lsize;
+ void *le = NULL;
+
+ if (ni->attr_list.size)
+ return 0;
+
+ if (!attr->non_res) {
+ lsize = le32_to_cpu(attr->res.data_size);
+ /* attr is resident: lsize < record_size (1K or 4K) */
+ le = kvmalloc(al_aligned(lsize), GFP_KERNEL);
+ if (!le) {
+ err = -ENOMEM;
+ goto out;
+ }
+ memcpy(le, resident_data(attr), lsize);
+ } else if (attr->nres.svcn) {
+ err = -EINVAL;
+ goto out;
+ } else {
+ u16 run_off = le16_to_cpu(attr->nres.run_off);
+
+ lsize = le64_to_cpu(attr->nres.data_size);
+
+ run_init(&ni->attr_list.run);
+
+ if (run_off > le32_to_cpu(attr->size)) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = run_unpack_ex(&ni->attr_list.run, ni->mi.sbi, ni->mi.rno,
+ 0, le64_to_cpu(attr->nres.evcn), 0,
+ Add2Ptr(attr, run_off),
+ le32_to_cpu(attr->size) - run_off);
+ if (err < 0)
+ goto out;
+
+ /* attr is nonresident.
+ * The worst case:
+ * 1T (2^40) extremely fragmented file.
+ * cluster = 4K (2^12) => 2^28 fragments
+ * 2^9 fragments per one record => 2^19 records
+ * 2^5 bytes of ATTR_LIST_ENTRY per one record => 2^24 bytes.
+ *
+ * the result is 16M bytes per attribute list.
+ * Use kvmalloc to allocate in range [several Kbytes - dozen Mbytes]
+ */
+ le = kvmalloc(al_aligned(lsize), GFP_KERNEL);
+ if (!le) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = ntfs_read_run_nb(ni->mi.sbi, &ni->attr_list.run, 0, le,
+ lsize, NULL);
+ if (err)
+ goto out;
+ }
+
+ ni->attr_list.size = lsize;
+ ni->attr_list.le = le;
+
+ return 0;
+
+out:
+ ni->attr_list.le = le;
+ al_destroy(ni);
+
+ return err;
+}
+
+/*
+ * al_enumerate
+ *
+ * Return:
+ * * The next list le.
+ * * If @le is NULL then return the first le.
+ */
+struct ATTR_LIST_ENTRY *al_enumerate(struct ntfs_inode *ni,
+ struct ATTR_LIST_ENTRY *le)
+{
+ size_t off;
+ u16 sz;
+
+ if (!le) {
+ le = ni->attr_list.le;
+ } else {
+ sz = le16_to_cpu(le->size);
+ if (sz < sizeof(struct ATTR_LIST_ENTRY)) {
+ /* Impossible 'cause we should not return such le. */
+ return NULL;
+ }
+ le = Add2Ptr(le, sz);
+ }
+
+ /* Check boundary. */
+ off = PtrOffset(ni->attr_list.le, le);
+ if (off + sizeof(struct ATTR_LIST_ENTRY) > ni->attr_list.size) {
+ /* The regular end of list. */
+ return NULL;
+ }
+
+ sz = le16_to_cpu(le->size);
+
+ /* Check le for errors. */
+ if (sz < sizeof(struct ATTR_LIST_ENTRY) ||
+ off + sz > ni->attr_list.size ||
+ sz < le->name_off + le->name_len * sizeof(short)) {
+ return NULL;
+ }
+
+ return le;
+}
+
+/*
+ * al_find_le
+ *
+ * Find the first le in the list which matches type, name and VCN.
+ *
+ * Return: NULL if not found.
+ */
+struct ATTR_LIST_ENTRY *al_find_le(struct ntfs_inode *ni,
+ struct ATTR_LIST_ENTRY *le,
+ const struct ATTRIB *attr)
+{
+ CLST svcn = attr_svcn(attr);
+
+ return al_find_ex(ni, le, attr->type, attr_name(attr), attr->name_len,
+ &svcn);
+}
+
+/*
+ * al_find_ex
+ *
+ * Find the first le in the list which matches type, name and VCN.
+ *
+ * Return: NULL if not found.
+ */
+struct ATTR_LIST_ENTRY *al_find_ex(struct ntfs_inode *ni,
+ struct ATTR_LIST_ENTRY *le,
+ enum ATTR_TYPE type, const __le16 *name,
+ u8 name_len, const CLST *vcn)
+{
+ struct ATTR_LIST_ENTRY *ret = NULL;
+ u32 type_in = le32_to_cpu(type);
+
+ while ((le = al_enumerate(ni, le))) {
+ u64 le_vcn;
+ int diff = le32_to_cpu(le->type) - type_in;
+
+ /* List entries are sorted by type, name and VCN. */
+ if (diff < 0)
+ continue;
+
+ if (diff > 0)
+ return ret;
+
+ if (le->name_len != name_len)
+ continue;
+
+ le_vcn = le64_to_cpu(le->vcn);
+ if (!le_vcn) {
+ /*
+ * Compare entry names only for entry with vcn == 0.
+ */
+ diff = ntfs_cmp_names(le_name(le), name_len, name,
+ name_len, ni->mi.sbi->upcase,
+ true);
+ if (diff < 0)
+ continue;
+
+ if (diff > 0)
+ return ret;
+ }
+
+ if (!vcn)
+ return le;
+
+ if (*vcn == le_vcn)
+ return le;
+
+ if (*vcn < le_vcn)
+ return ret;
+
+ ret = le;
+ }
+
+ return ret;
+}
+
+/*
+ * al_find_le_to_insert
+ *
+ * Find the first list entry which matches type, name and VCN.
+ */
+static struct ATTR_LIST_ENTRY *al_find_le_to_insert(struct ntfs_inode *ni,
+ enum ATTR_TYPE type,
+ const __le16 *name,
+ u8 name_len, CLST vcn)
+{
+ struct ATTR_LIST_ENTRY *le = NULL, *prev;
+ u32 type_in = le32_to_cpu(type);
+
+ /* List entries are sorted by type, name and VCN. */
+ while ((le = al_enumerate(ni, prev = le))) {
+ int diff = le32_to_cpu(le->type) - type_in;
+
+ if (diff < 0)
+ continue;
+
+ if (diff > 0)
+ return le;
+
+ if (!le->vcn) {
+ /*
+ * Compare entry names only for entry with vcn == 0.
+ */
+ diff = ntfs_cmp_names(le_name(le), le->name_len, name,
+ name_len, ni->mi.sbi->upcase,
+ true);
+ if (diff < 0)
+ continue;
+
+ if (diff > 0)
+ return le;
+ }
+
+ if (le64_to_cpu(le->vcn) >= vcn)
+ return le;
+ }
+
+ return prev ? Add2Ptr(prev, le16_to_cpu(prev->size)) : ni->attr_list.le;
+}
+
+/*
+ * al_add_le
+ *
+ * Add an "attribute list entry" to the list.
+ */
+int al_add_le(struct ntfs_inode *ni, enum ATTR_TYPE type, const __le16 *name,
+ u8 name_len, CLST svcn, __le16 id, const struct MFT_REF *ref,
+ struct ATTR_LIST_ENTRY **new_le)
+{
+ int err;
+ struct ATTRIB *attr;
+ struct ATTR_LIST_ENTRY *le;
+ size_t off;
+ u16 sz;
+ size_t asize, new_asize, old_size;
+ u64 new_size;
+ typeof(ni->attr_list) *al = &ni->attr_list;
+
+ /*
+ * Compute the size of the new 'le'
+ */
+ sz = le_size(name_len);
+ old_size = al->size;
+ new_size = old_size + sz;
+ asize = al_aligned(old_size);
+ new_asize = al_aligned(new_size);
+
+ /* Scan forward to the point at which the new 'le' should be inserted. */
+ le = al_find_le_to_insert(ni, type, name, name_len, svcn);
+ off = PtrOffset(al->le, le);
+
+ if (new_size > asize) {
+ void *ptr = kmalloc(new_asize, GFP_NOFS);
+
+ if (!ptr)
+ return -ENOMEM;
+
+ memcpy(ptr, al->le, off);
+ memcpy(Add2Ptr(ptr, off + sz), le, old_size - off);
+ le = Add2Ptr(ptr, off);
+ kfree(al->le);
+ al->le = ptr;
+ } else {
+ memmove(Add2Ptr(le, sz), le, old_size - off);
+ }
+ *new_le = le;
+
+ al->size = new_size;
+
+ le->type = type;
+ le->size = cpu_to_le16(sz);
+ le->name_len = name_len;
+ le->name_off = offsetof(struct ATTR_LIST_ENTRY, name);
+ le->vcn = cpu_to_le64(svcn);
+ le->ref = *ref;
+ le->id = id;
+ memcpy(le->name, name, sizeof(short) * name_len);
+
+ err = attr_set_size(ni, ATTR_LIST, NULL, 0, &al->run, new_size,
+ &new_size, true, &attr);
+ if (err) {
+ /* Undo memmove above. */
+ memmove(le, Add2Ptr(le, sz), old_size - off);
+ al->size = old_size;
+ return err;
+ }
+
+ al->dirty = true;
+
+ if (attr && attr->non_res) {
+ err = ntfs_sb_write_run(ni->mi.sbi, &al->run, 0, al->le,
+ al->size, 0);
+ if (err)
+ return err;
+ al->dirty = false;
+ }
+
+ return 0;
+}
+
+/*
+ * al_remove_le - Remove @le from attribute list.
+ */
+bool al_remove_le(struct ntfs_inode *ni, struct ATTR_LIST_ENTRY *le)
+{
+ u16 size;
+ size_t off;
+ typeof(ni->attr_list) *al = &ni->attr_list;
+
+ if (!al_is_valid_le(ni, le))
+ return false;
+
+ /* Save on stack the size of 'le' */
+ size = le16_to_cpu(le->size);
+ off = PtrOffset(al->le, le);
+
+ memmove(le, Add2Ptr(le, size), al->size - (off + size));
+
+ al->size -= size;
+ al->dirty = true;
+
+ return true;
+}
+
+/*
+ * al_delete_le - Delete first le from the list which matches its parameters.
+ */
+bool al_delete_le(struct ntfs_inode *ni, enum ATTR_TYPE type, CLST vcn,
+ const __le16 *name, size_t name_len,
+ const struct MFT_REF *ref)
+{
+ u16 size;
+ struct ATTR_LIST_ENTRY *le;
+ size_t off;
+ typeof(ni->attr_list) *al = &ni->attr_list;
+
+ /* Scan forward to the first le that matches the input. */
+ le = al_find_ex(ni, NULL, type, name, name_len, &vcn);
+ if (!le)
+ return false;
+
+ off = PtrOffset(al->le, le);
+
+next:
+ if (off >= al->size)
+ return false;
+ if (le->type != type)
+ return false;
+ if (le->name_len != name_len)
+ return false;
+ if (name_len && ntfs_cmp_names(le_name(le), name_len, name, name_len,
+ ni->mi.sbi->upcase, true))
+ return false;
+ if (le64_to_cpu(le->vcn) != vcn)
+ return false;
+
+ /*
+ * The caller specified a segment reference, so we have to
+ * scan through the matching entries until we find that segment
+ * reference or we run of matching entries.
+ */
+ if (ref && memcmp(ref, &le->ref, sizeof(*ref))) {
+ off += le16_to_cpu(le->size);
+ le = Add2Ptr(al->le, off);
+ goto next;
+ }
+
+ /* Save on stack the size of 'le'. */
+ size = le16_to_cpu(le->size);
+ /* Delete the le. */
+ memmove(le, Add2Ptr(le, size), al->size - (off + size));
+
+ al->size -= size;
+ al->dirty = true;
+
+ return true;
+}
+
+int al_update(struct ntfs_inode *ni, int sync)
+{
+ int err;
+ struct ATTRIB *attr;
+ typeof(ni->attr_list) *al = &ni->attr_list;
+
+ if (!al->dirty || !al->size)
+ return 0;
+
+ /*
+ * Attribute list increased on demand in al_add_le.
+ * Attribute list decreased here.
+ */
+ err = attr_set_size(ni, ATTR_LIST, NULL, 0, &al->run, al->size, NULL,
+ false, &attr);
+ if (err)
+ goto out;
+
+ if (!attr->non_res) {
+ memcpy(resident_data(attr), al->le, al->size);
+ } else {
+ err = ntfs_sb_write_run(ni->mi.sbi, &al->run, 0, al->le,
+ al->size, sync);
+ if (err)
+ goto out;
+
+ attr->nres.valid_size = attr->nres.data_size;
+ }
+
+ ni->mi.dirty = true;
+ al->dirty = false;
+
+out:
+ return err;
+}