From d5ecebc4900df7f6e8dff0717574668885110553 Mon Sep 17 00:00:00 2001 From: Steve French Date: Fri, 28 Jun 2019 02:04:18 -0500 Subject: 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 Reviewed-by: Ronnie Sahlberg --- fs/cifs/smb2ops.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 54 insertions(+), 6 deletions(-) (limited to 'fs/cifs') diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 75f3348a471e..c4047ad7b43f 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -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; -- cgit v1.2.3-58-ga151