--- /dev/null
+From: Maxim Suhanov <dfirblog@gmail.com>
+Date: Mon, 28 Aug 2023 16:40:07 +0300
+Subject: fs/ntfs: Make code more readable
+
+Move some calls used to access NTFS attribute header fields into
+functions with human-readable names.
+
+Suggested-by: Daniel Kiper <daniel.kiper@oracle.com>
+Signed-off-by: Maxim Suhanov <dfirblog@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/fs/ntfs.c | 48 +++++++++++++++++++++++++++++++++---------------
+ 1 file changed, 33 insertions(+), 15 deletions(-)
+
+diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c
+index ff5e374..de435aa 100644
+--- a/grub-core/fs/ntfs.c
++++ b/grub-core/fs/ntfs.c
+@@ -52,6 +52,24 @@ u64at (void *ptr, grub_size_t ofs)
+ return grub_le_to_cpu64 (grub_get_unaligned64 ((char *) ptr + ofs));
+ }
+
++static grub_uint16_t
++first_attr_off (void *mft_buf_ptr)
++{
++ return u16at (mft_buf_ptr, 0x14);
++}
++
++static grub_uint16_t
++res_attr_data_off (void *res_attr_ptr)
++{
++ return u16at (res_attr_ptr, 0x14);
++}
++
++static grub_uint32_t
++res_attr_data_len (void *res_attr_ptr)
++{
++ return u32at (res_attr_ptr, 0x10);
++}
++
+ grub_ntfscomp_func_t grub_ntfscomp_func;
+
+ static grub_err_t
+@@ -106,7 +124,7 @@ init_attr (struct grub_ntfs_attr *at, struct grub_ntfs_file *mft)
+ {
+ at->mft = mft;
+ at->flags = (mft == &mft->data->mmft) ? GRUB_NTFS_AF_MMFT : 0;
+- at->attr_nxt = mft->buf + u16at (mft->buf, 0x14);
++ at->attr_nxt = mft->buf + first_attr_off (mft->buf);
+ at->attr_end = at->emft_buf = at->edat_buf = at->sbuf = NULL;
+ }
+
+@@ -154,7 +172,7 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr)
+ return NULL;
+ }
+
+- new_pos = &at->emft_buf[u16at (at->emft_buf, 0x14)];
++ new_pos = &at->emft_buf[first_attr_off (at->emft_buf)];
+ while (*new_pos != 0xFF)
+ {
+ if ((*new_pos == *at->attr_cur)
+@@ -213,7 +231,7 @@ find_attr (struct grub_ntfs_attr *at, grub_uint8_t attr)
+ }
+ else
+ {
+- at->attr_nxt = at->attr_end + u16at (pa, 0x14);
++ at->attr_nxt = at->attr_end + res_attr_data_off (pa);
+ at->attr_end = at->attr_end + u32at (pa, 4);
+ pa_end = at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR);
+ }
+@@ -399,20 +417,20 @@ read_data (struct grub_ntfs_attr *at, grub_uint8_t *pa, grub_uint8_t *dest,
+
+ if (pa[8] == 0)
+ {
+- if (ofs + len > u32at (pa, 0x10))
++ if (ofs + len > res_attr_data_len (pa))
+ return grub_error (GRUB_ERR_BAD_FS, "read out of range");
+
+- if (u32at (pa, 0x10) > (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
++ if (res_attr_data_len (pa) > (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
+ return grub_error (GRUB_ERR_BAD_FS, "resident attribute too large");
+
+ if (pa >= at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR))
+ return grub_error (GRUB_ERR_BAD_FS, "resident attribute out of range");
+
+- if (u16at (pa, 0x14) + u32at (pa, 0x10) >
++ if (res_attr_data_off (pa) + res_attr_data_len (pa) >
+ (grub_addr_t) at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR) - (grub_addr_t) pa)
+ return grub_error (GRUB_ERR_BAD_FS, "resident attribute out of range");
+
+- grub_memcpy (dest, pa + u16at (pa, 0x14) + ofs, len);
++ grub_memcpy (dest, pa + res_attr_data_off (pa) + ofs, len);
+ return 0;
+ }
+
+@@ -556,7 +574,7 @@ init_file (struct grub_ntfs_file *mft, grub_uint64_t mftno)
+ (unsigned long long) mftno);
+
+ if (!pa[8])
+- mft->size = u32at (pa, 0x10);
++ mft->size = res_attr_data_len (pa);
+ else
+ mft->size = u64at (pa, 0x30);
+
+@@ -805,7 +823,7 @@ grub_ntfs_iterate_dir (grub_fshelp_node_t dir,
+ (u32at (cur_pos, 0x18) != 0x490024) ||
+ (u32at (cur_pos, 0x1C) != 0x300033))
+ continue;
+- cur_pos += u16at (cur_pos, 0x14);
++ cur_pos += res_attr_data_off (cur_pos);
+ if (*cur_pos != 0x30) /* Not filename index */
+ continue;
+ break;
+@@ -834,7 +852,7 @@ grub_ntfs_iterate_dir (grub_fshelp_node_t dir,
+ {
+ int is_resident = (cur_pos[8] == 0);
+
+- bitmap_len = ((is_resident) ? u32at (cur_pos, 0x10) :
++ bitmap_len = ((is_resident) ? res_attr_data_len (cur_pos) :
+ u32at (cur_pos, 0x28));
+
+ bmp = grub_malloc (bitmap_len);
+@@ -855,14 +873,14 @@ grub_ntfs_iterate_dir (grub_fshelp_node_t dir,
+ goto done;
+ }
+
+- if (u16at (cur_pos, 0x14) + u32at (cur_pos, 0x10) >
++ if (res_attr_data_off (cur_pos) + res_attr_data_len (cur_pos) >
+ (grub_addr_t) at->mft->buf + (at->mft->data->mft_size << GRUB_NTFS_BLK_SHR) - (grub_addr_t) cur_pos)
+ {
+ grub_error (GRUB_ERR_BAD_FS, "resident bitmap out of range");
+ goto done;
+ }
+
+- grub_memcpy (bmp, cur_pos + u16at (cur_pos, 0x14),
++ grub_memcpy (bmp, cur_pos + res_attr_data_off (cur_pos),
+ bitmap_len);
+ }
+ else
+@@ -1226,12 +1244,12 @@ grub_ntfs_label (grub_device_t device, char **label)
+ goto fail;
+ }
+
+- if ((pa) && (pa[8] == 0) && (u32at (pa, 0x10)))
++ if ((pa) && (pa[8] == 0) && (res_attr_data_len (pa)))
+ {
+ int len;
+
+- len = u32at (pa, 0x10) / 2;
+- pa += u16at (pa, 0x14);
++ len = res_attr_data_len (pa) / 2;
++ pa += res_attr_data_off (pa);
+ if (mft->buf + (mft->data->mft_size << GRUB_NTFS_BLK_SHR) - pa >= 2 * len)
+ *label = get_utf8 (pa, len);
+ else
projects / grub2.git / blobdiff