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smb3: Allow query of symlinks stored as reparse points 

The 'NFS' style symlinks (see MS-FSCC 2.1.2.4) were not
being queried properly in query_symlink. Fix this.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
alistair/sunxi64-5.4-dsi
Steve French 2019-06-28 02:04:18 -05:00
parent f2caf901c1
commit d5ecebc490
1 changed files with 54 additions and 6 deletions
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60
fs/cifs/smb2ops.c
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@ -2373,6 +2373,39 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
return rc;
}
static int
parse_reparse_posix(struct reparse_posix_data *symlink_buf,
u32 plen, char **target_path,
struct cifs_sb_info *cifs_sb)
{
unsigned int len;
/* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
len = le16_to_cpu(symlink_buf->ReparseDataLength);
if (len + sizeof(struct reparse_data_buffer) > plen) {
cifs_dbg(VFS, "srv returned malformed symlink buffer\n");
return -EINVAL;
}
if (le64_to_cpu(symlink_buf->InodeType) != NFS_SPECFILE_LNK) {
cifs_dbg(VFS, "%lld not a supported symlink type\n",
le64_to_cpu(symlink_buf->InodeType));
return -EOPNOTSUPP;
}
*target_path = cifs_strndup_from_utf16(
symlink_buf->PathBuffer,
len, true, cifs_sb->local_nls);
if (!(*target_path))
return -ENOMEM;
convert_delimiter(*target_path, '/');
cifs_dbg(FYI, "%s: target path: %s\n", __func__, *target_path);
return 0;
}
static int
parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
u32 plen, char **target_path,
@ -2381,11 +2414,7 @@ parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
unsigned int sub_len;
unsigned int sub_offset;
/* We only handle Symbolic Link : MS-FSCC 2.1.2.4 */
if (le32_to_cpu(symlink_buf->ReparseTag) != IO_REPARSE_TAG_SYMLINK) {
cifs_dbg(VFS, "srv returned invalid symlink buffer\n");
return -EIO;
}
/* We handle Symbolic Link reparse tag here. See: MS-FSCC 2.1.2.4 */
sub_offset = le16_to_cpu(symlink_buf->SubstituteNameOffset);
sub_len = le16_to_cpu(symlink_buf->SubstituteNameLength);
@ -2407,6 +2436,25 @@ parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
return 0;
}
static int
parse_reparse_point(struct reparse_symlink_data_buffer *buf,
u32 plen, char **target_path,
struct cifs_sb_info *cifs_sb)
{
/* See MS-FSCC 2.1.2 */
if (le32_to_cpu(buf->ReparseTag) == IO_REPARSE_TAG_NFS)
return parse_reparse_posix((struct reparse_posix_data *)buf,
plen, target_path, cifs_sb);
else if (le32_to_cpu(buf->ReparseTag) == IO_REPARSE_TAG_SYMLINK)
return parse_reparse_symlink(buf, plen, target_path,
cifs_sb);
cifs_dbg(VFS, "srv returned invalid symlink buffer tag:%d\n",
le32_to_cpu(buf->ReparseTag));
return -EIO;
}
#define SMB2_SYMLINK_STRUCT_SIZE \
(sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp))
@ -2547,7 +2595,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
goto querty_exit;
}
rc = parse_reparse_symlink(
rc = parse_reparse_point(
(struct reparse_symlink_data_buffer *)reparse_buf,
plen, target_path, cifs_sb);
goto querty_exit;