diff --git a/library/std/src/sys/windows/fs.rs b/library/std/src/sys/windows/fs.rs index 373157bd9e836..956db577d5371 100644 --- a/library/std/src/sys/windows/fs.rs +++ b/library/std/src/sys/windows/fs.rs @@ -1403,24 +1403,40 @@ fn symlink_junction_inner(original: &Path, junction: &Path) -> io::Result<()> { opts.custom_flags(c::FILE_FLAG_OPEN_REPARSE_POINT | c::FILE_FLAG_BACKUP_SEMANTICS); let f = File::open(junction, &opts)?; let h = f.as_inner().as_raw_handle(); - unsafe { let mut data = Align8([MaybeUninit::::uninit(); c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE]); let data_ptr = data.0.as_mut_ptr(); + let data_end = data_ptr.add(c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE); let db = data_ptr.cast::(); // Zero the header to ensure it's fully initialized, including reserved parameters. *db = mem::zeroed(); - let buf = ptr::addr_of_mut!((*db).ReparseTarget).cast::(); - let mut i = 0; + let reparse_target_slice = { + let buf_start = ptr::addr_of_mut!((*db).ReparseTarget).cast::(); + // Compute offset in bytes and then divide so that we round down + // rather than hit any UB (admittedly this arithmetic should work + // out so that this isn't necessary) + let buf_len_bytes = usize::try_from(data_end.byte_offset_from(buf_start)).unwrap(); + let buf_len_wchars = buf_len_bytes / core::mem::size_of::(); + core::slice::from_raw_parts_mut(buf_start, buf_len_wchars) + }; + // FIXME: this conversion is very hacky - let v = br"\??\"; - let v = v.iter().map(|x| *x as u16); - for c in v.chain(original.as_os_str().encode_wide()) { - *buf.add(i) = c; + let iter = br"\??\" + .iter() + .map(|x| *x as u16) + .chain(original.as_os_str().encode_wide()) + .chain(core::iter::once(0)); + let mut i = 0; + for c in iter { + if i >= reparse_target_slice.len() { + return Err(crate::io::const_io_error!( + crate::io::ErrorKind::InvalidFilename, + "Input filename is too long" + )); + } + reparse_target_slice[i] = c; i += 1; } - *buf.add(i) = 0; - i += 1; (*db).ReparseTag = c::IO_REPARSE_TAG_MOUNT_POINT; (*db).ReparseTargetMaximumLength = (i * 2) as c::WORD; (*db).ReparseTargetLength = ((i - 1) * 2) as c::WORD; diff --git a/src/bootstrap/Cargo.lock b/src/bootstrap/Cargo.lock index 965dfa5f39867..a158d1f718e2c 100644 --- a/src/bootstrap/Cargo.lock +++ b/src/bootstrap/Cargo.lock @@ -45,6 +45,7 @@ dependencies = [ "hex", "ignore", "is-terminal", + "junction", "libc", "object", "once_cell", @@ -349,6 +350,16 @@ version = "1.0.2" source = "registry+https://github.com/rust-lang/crates.io-index" checksum = "112c678d4050afce233f4f2852bb2eb519230b3cf12f33585275537d7e41578d" +[[package]] +name = "junction" +version = "1.0.0" +source = "registry+https://github.com/rust-lang/crates.io-index" +checksum = "ca39ef0d69b18e6a2fd14c2f0a1d593200f4a4ed949b240b5917ab51fac754cb" +dependencies = [ + "scopeguard", + "winapi", +] + [[package]] name = "lazy_static" version = "1.4.0" diff --git a/src/bootstrap/Cargo.toml b/src/bootstrap/Cargo.toml index 2fbe7aa57aa52..eeda6d7c121f7 100644 --- a/src/bootstrap/Cargo.toml +++ b/src/bootstrap/Cargo.toml @@ -61,6 +61,9 @@ sysinfo = { version = "0.26.0", optional = true } [target.'cfg(not(target_os = "solaris"))'.dependencies] fd-lock = "3.0.8" +[target.'cfg(windows)'.dependencies.junction] +version = "1.0.0" + [target.'cfg(windows)'.dependencies.windows] version = "0.46.0" features = [ diff --git a/src/bootstrap/util.rs b/src/bootstrap/util.rs index 9a6aaffe22b24..2e1adbf63bb10 100644 --- a/src/bootstrap/util.rs +++ b/src/bootstrap/util.rs @@ -146,106 +146,9 @@ pub fn symlink_dir(config: &Config, src: &Path, dest: &Path) -> io::Result<()> { fs::symlink(src, dest) } - // Creating a directory junction on windows involves dealing with reparse - // points and the DeviceIoControl function, and this code is a skeleton of - // what can be found here: - // - // http://www.flexhex.com/docs/articles/hard-links.phtml #[cfg(windows)] fn symlink_dir_inner(target: &Path, junction: &Path) -> io::Result<()> { - use std::ffi::OsStr; - use std::os::windows::ffi::OsStrExt; - - use windows::{ - core::PCWSTR, - Win32::Foundation::{CloseHandle, HANDLE}, - Win32::Storage::FileSystem::{ - CreateFileW, FILE_ACCESS_FLAGS, FILE_FLAG_BACKUP_SEMANTICS, - FILE_FLAG_OPEN_REPARSE_POINT, FILE_SHARE_DELETE, FILE_SHARE_READ, FILE_SHARE_WRITE, - MAXIMUM_REPARSE_DATA_BUFFER_SIZE, OPEN_EXISTING, - }, - Win32::System::Ioctl::FSCTL_SET_REPARSE_POINT, - Win32::System::SystemServices::{GENERIC_WRITE, IO_REPARSE_TAG_MOUNT_POINT}, - Win32::System::IO::DeviceIoControl, - }; - - #[allow(non_snake_case)] - #[repr(C)] - struct REPARSE_MOUNTPOINT_DATA_BUFFER { - ReparseTag: u32, - ReparseDataLength: u32, - Reserved: u16, - ReparseTargetLength: u16, - ReparseTargetMaximumLength: u16, - Reserved1: u16, - ReparseTarget: u16, - } - - fn to_u16s>(s: S) -> io::Result> { - Ok(s.as_ref().encode_wide().chain(Some(0)).collect()) - } - - // We're using low-level APIs to create the junction, and these are more - // picky about paths. For example, forward slashes cannot be used as a - // path separator, so we should try to canonicalize the path first. - let target = fs::canonicalize(target)?; - - fs::create_dir(junction)?; - - let path = to_u16s(junction)?; - - let h = unsafe { - CreateFileW( - PCWSTR(path.as_ptr()), - FILE_ACCESS_FLAGS(GENERIC_WRITE), - FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, - None, - OPEN_EXISTING, - FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, - HANDLE::default(), - ) - } - .map_err(|_| io::Error::last_os_error())?; - - unsafe { - #[repr(C, align(8))] - struct Align8(T); - let mut data = Align8([0u8; MAXIMUM_REPARSE_DATA_BUFFER_SIZE as usize]); - let db = data.0.as_mut_ptr() as *mut REPARSE_MOUNTPOINT_DATA_BUFFER; - let buf = core::ptr::addr_of_mut!((*db).ReparseTarget) as *mut u16; - let mut i = 0; - // FIXME: this conversion is very hacky - let v = br"\??\"; - let v = v.iter().map(|x| *x as u16); - for c in v.chain(target.as_os_str().encode_wide().skip(4)) { - *buf.offset(i) = c; - i += 1; - } - *buf.offset(i) = 0; - i += 1; - - (*db).ReparseTag = IO_REPARSE_TAG_MOUNT_POINT; - (*db).ReparseTargetMaximumLength = (i * 2) as u16; - (*db).ReparseTargetLength = ((i - 1) * 2) as u16; - (*db).ReparseDataLength = ((*db).ReparseTargetLength + 12) as u32; - - let mut ret = 0u32; - DeviceIoControl( - h, - FSCTL_SET_REPARSE_POINT, - Some(db.cast()), - (*db).ReparseDataLength + 8, - None, - 0, - Some(&mut ret), - None, - ) - .ok() - .map_err(|_| io::Error::last_os_error())?; - } - - unsafe { CloseHandle(h) }; - Ok(()) + junction::create(&target, &junction) } }