diff options
-rw-r--r-- | pkg/sentry/fs/file.go | 23 | ||||
-rw-r--r-- | pkg/sentry/fs/file_operations.go | 9 | ||||
-rw-r--r-- | pkg/sentry/fs/file_overlay.go | 9 | ||||
-rw-r--r-- | pkg/sentry/fs/fsutil/file.go | 6 | ||||
-rw-r--r-- | pkg/sentry/fs/inotify.go | 5 | ||||
-rw-r--r-- | pkg/sentry/fs/splice.go | 162 | ||||
-rw-r--r-- | pkg/sentry/kernel/pipe/buffer.go | 25 | ||||
-rw-r--r-- | pkg/sentry/kernel/pipe/pipe.go | 82 | ||||
-rw-r--r-- | pkg/sentry/kernel/pipe/reader_writer.go | 76 | ||||
-rw-r--r-- | pkg/sentry/socket/epsocket/epsocket.go | 134 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/linux64.go | 4 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/sys_splice.go | 86 | ||||
-rw-r--r-- | pkg/tcpip/header/udp.go | 5 | ||||
-rw-r--r-- | pkg/tcpip/stack/transport_test.go | 4 | ||||
-rw-r--r-- | pkg/tcpip/tcpip.go | 48 | ||||
-rw-r--r-- | pkg/tcpip/transport/icmp/endpoint.go | 4 | ||||
-rw-r--r-- | pkg/tcpip/transport/raw/endpoint.go | 7 | ||||
-rw-r--r-- | pkg/tcpip/transport/tcp/endpoint.go | 68 | ||||
-rw-r--r-- | pkg/tcpip/transport/udp/endpoint.go | 14 | ||||
-rw-r--r-- | test/syscalls/linux/BUILD | 3 | ||||
-rw-r--r-- | test/syscalls/linux/pipe.cc | 14 | ||||
-rw-r--r-- | test/syscalls/linux/sendfile.cc | 69 | ||||
-rw-r--r-- | test/syscalls/linux/splice.cc | 194 |
23 files changed, 770 insertions, 281 deletions
diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go index bb8117f89..c0a6e884b 100644 --- a/pkg/sentry/fs/file.go +++ b/pkg/sentry/fs/file.go @@ -515,6 +515,11 @@ type lockedReader struct { // File is the file to read from. File *File + + // Offset is the offset to start at. + // + // This applies only to Read, not ReadAt. + Offset int64 } // Read implements io.Reader.Read. @@ -522,7 +527,8 @@ func (r *lockedReader) Read(buf []byte) (int, error) { if r.Ctx.Interrupted() { return 0, syserror.ErrInterrupted } - n, err := r.File.FileOperations.Read(r.Ctx, r.File, usermem.BytesIOSequence(buf), r.File.offset) + n, err := r.File.FileOperations.Read(r.Ctx, r.File, usermem.BytesIOSequence(buf), r.Offset) + r.Offset += n return int(n), err } @@ -544,11 +550,21 @@ type lockedWriter struct { // File is the file to write to. File *File + + // Offset is the offset to start at. + // + // This applies only to Write, not WriteAt. + Offset int64 } // Write implements io.Writer.Write. func (w *lockedWriter) Write(buf []byte) (int, error) { - return w.WriteAt(buf, w.File.offset) + if w.Ctx.Interrupted() { + return 0, syserror.ErrInterrupted + } + n, err := w.WriteAt(buf, w.Offset) + w.Offset += int64(n) + return int(n), err } // WriteAt implements io.Writer.WriteAt. @@ -562,6 +578,9 @@ func (w *lockedWriter) WriteAt(buf []byte, offset int64) (int, error) { // io.Copy, since our own Write interface does not have this same // contract. Enforce that here. for written < len(buf) { + if w.Ctx.Interrupted() { + return written, syserror.ErrInterrupted + } var n int64 n, err = w.File.FileOperations.Write(w.Ctx, w.File, usermem.BytesIOSequence(buf[written:]), offset+int64(written)) if n > 0 { diff --git a/pkg/sentry/fs/file_operations.go b/pkg/sentry/fs/file_operations.go index d86f5bf45..b88303f17 100644 --- a/pkg/sentry/fs/file_operations.go +++ b/pkg/sentry/fs/file_operations.go @@ -15,6 +15,8 @@ package fs import ( + "io" + "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/memmap" @@ -105,8 +107,11 @@ type FileOperations interface { // on the destination, following by a buffered copy with standard Read // and Write operations. // + // If dup is set, the data should be duplicated into the destination + // and retained. + // // The same preconditions as Read apply. - WriteTo(ctx context.Context, file *File, dst *File, opts SpliceOpts) (int64, error) + WriteTo(ctx context.Context, file *File, dst io.Writer, count int64, dup bool) (int64, error) // Write writes src to file at offset and returns the number of bytes // written which must be greater than or equal to 0. Like Read, file @@ -126,7 +131,7 @@ type FileOperations interface { // source. See WriteTo for details regarding how this is called. // // The same preconditions as Write apply; FileFlags.Write must be set. - ReadFrom(ctx context.Context, file *File, src *File, opts SpliceOpts) (int64, error) + ReadFrom(ctx context.Context, file *File, src io.Reader, count int64) (int64, error) // Fsync writes buffered modifications of file and/or flushes in-flight // operations to backing storage based on syncType. The range to sync is diff --git a/pkg/sentry/fs/file_overlay.go b/pkg/sentry/fs/file_overlay.go index 9820f0b13..225e40186 100644 --- a/pkg/sentry/fs/file_overlay.go +++ b/pkg/sentry/fs/file_overlay.go @@ -15,6 +15,7 @@ package fs import ( + "io" "sync" "gvisor.dev/gvisor/pkg/refs" @@ -268,9 +269,9 @@ func (f *overlayFileOperations) Read(ctx context.Context, file *File, dst userme } // WriteTo implements FileOperations.WriteTo. -func (f *overlayFileOperations) WriteTo(ctx context.Context, file *File, dst *File, opts SpliceOpts) (n int64, err error) { +func (f *overlayFileOperations) WriteTo(ctx context.Context, file *File, dst io.Writer, count int64, dup bool) (n int64, err error) { err = f.onTop(ctx, file, func(file *File, ops FileOperations) error { - n, err = ops.WriteTo(ctx, file, dst, opts) + n, err = ops.WriteTo(ctx, file, dst, count, dup) return err // Will overwrite itself. }) return @@ -285,9 +286,9 @@ func (f *overlayFileOperations) Write(ctx context.Context, file *File, src userm } // ReadFrom implements FileOperations.ReadFrom. -func (f *overlayFileOperations) ReadFrom(ctx context.Context, file *File, src *File, opts SpliceOpts) (n int64, err error) { +func (f *overlayFileOperations) ReadFrom(ctx context.Context, file *File, src io.Reader, count int64) (n int64, err error) { // See above; f.upper must be non-nil. - return f.upper.FileOperations.ReadFrom(ctx, f.upper, src, opts) + return f.upper.FileOperations.ReadFrom(ctx, f.upper, src, count) } // Fsync implements FileOperations.Fsync. diff --git a/pkg/sentry/fs/fsutil/file.go b/pkg/sentry/fs/fsutil/file.go index 626b9126a..fc5b3b1a1 100644 --- a/pkg/sentry/fs/fsutil/file.go +++ b/pkg/sentry/fs/fsutil/file.go @@ -15,6 +15,8 @@ package fsutil import ( + "io" + "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/fs" @@ -228,12 +230,12 @@ func (FileNoIoctl) Ioctl(context.Context, *fs.File, usermem.IO, arch.SyscallArgu type FileNoSplice struct{} // WriteTo implements fs.FileOperations.WriteTo. -func (FileNoSplice) WriteTo(context.Context, *fs.File, *fs.File, fs.SpliceOpts) (int64, error) { +func (FileNoSplice) WriteTo(context.Context, *fs.File, io.Writer, int64, bool) (int64, error) { return 0, syserror.ENOSYS } // ReadFrom implements fs.FileOperations.ReadFrom. -func (FileNoSplice) ReadFrom(context.Context, *fs.File, *fs.File, fs.SpliceOpts) (int64, error) { +func (FileNoSplice) ReadFrom(context.Context, *fs.File, io.Reader, int64) (int64, error) { return 0, syserror.ENOSYS } diff --git a/pkg/sentry/fs/inotify.go b/pkg/sentry/fs/inotify.go index c7f4e2d13..ba3e0233d 100644 --- a/pkg/sentry/fs/inotify.go +++ b/pkg/sentry/fs/inotify.go @@ -15,6 +15,7 @@ package fs import ( + "io" "sync" "sync/atomic" @@ -172,7 +173,7 @@ func (i *Inotify) Read(ctx context.Context, _ *File, dst usermem.IOSequence, _ i } // WriteTo implements FileOperations.WriteTo. -func (*Inotify) WriteTo(context.Context, *File, *File, SpliceOpts) (int64, error) { +func (*Inotify) WriteTo(context.Context, *File, io.Writer, int64, bool) (int64, error) { return 0, syserror.ENOSYS } @@ -182,7 +183,7 @@ func (*Inotify) Fsync(context.Context, *File, int64, int64, SyncType) error { } // ReadFrom implements FileOperations.ReadFrom. -func (*Inotify) ReadFrom(context.Context, *File, *File, SpliceOpts) (int64, error) { +func (*Inotify) ReadFrom(context.Context, *File, io.Reader, int64) (int64, error) { return 0, syserror.ENOSYS } diff --git a/pkg/sentry/fs/splice.go b/pkg/sentry/fs/splice.go index eed1c2854..b03b7f836 100644 --- a/pkg/sentry/fs/splice.go +++ b/pkg/sentry/fs/splice.go @@ -18,7 +18,6 @@ import ( "io" "sync/atomic" - "gvisor.dev/gvisor/pkg/secio" "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/syserror" ) @@ -33,146 +32,131 @@ func Splice(ctx context.Context, dst *File, src *File, opts SpliceOpts) (int64, } // Check whether or not the objects being sliced are stream-oriented - // (i.e. pipes or sockets). If yes, we elide checks and offset locks. - srcPipe := IsPipe(src.Dirent.Inode.StableAttr) || IsSocket(src.Dirent.Inode.StableAttr) - dstPipe := IsPipe(dst.Dirent.Inode.StableAttr) || IsSocket(dst.Dirent.Inode.StableAttr) + // (i.e. pipes or sockets). For all stream-oriented files and files + // where a specific offiset is not request, we acquire the file mutex. + // This has two important side effects. First, it provides the standard + // protection against concurrent writes that would mutate the offset. + // Second, it prevents Splice deadlocks. Only internal anonymous files + // implement the ReadFrom and WriteTo methods directly, and since such + // anonymous files are referred to by a unique fs.File object, we know + // that the file mutex takes strict precedence over internal locks. + // Since we enforce lock ordering here, we can't deadlock by using + // using a file in two different splice operations simultaneously. + srcPipe := !IsRegular(src.Dirent.Inode.StableAttr) + dstPipe := !IsRegular(dst.Dirent.Inode.StableAttr) + dstAppend := !dstPipe && dst.Flags().Append + srcLock := srcPipe || !opts.SrcOffset + dstLock := dstPipe || !opts.DstOffset || dstAppend - if !dstPipe && !opts.DstOffset && !srcPipe && !opts.SrcOffset { + switch { + case srcLock && dstLock: switch { case dst.UniqueID < src.UniqueID: // Acquire dst first. if !dst.mu.Lock(ctx) { return 0, syserror.ErrInterrupted } - defer dst.mu.Unlock() if !src.mu.Lock(ctx) { + dst.mu.Unlock() return 0, syserror.ErrInterrupted } - defer src.mu.Unlock() case dst.UniqueID > src.UniqueID: // Acquire src first. if !src.mu.Lock(ctx) { return 0, syserror.ErrInterrupted } - defer src.mu.Unlock() if !dst.mu.Lock(ctx) { + src.mu.Unlock() return 0, syserror.ErrInterrupted } - defer dst.mu.Unlock() case dst.UniqueID == src.UniqueID: // Acquire only one lock; it's the same file. This is a // bit of a edge case, but presumably it's possible. if !dst.mu.Lock(ctx) { return 0, syserror.ErrInterrupted } - defer dst.mu.Unlock() + srcLock = false // Only need one unlock. } // Use both offsets (locked). opts.DstStart = dst.offset opts.SrcStart = src.offset - } else if !dstPipe && !opts.DstOffset { + case dstLock: // Acquire only dst. if !dst.mu.Lock(ctx) { return 0, syserror.ErrInterrupted } - defer dst.mu.Unlock() opts.DstStart = dst.offset // Safe: locked. - } else if !srcPipe && !opts.SrcOffset { + case srcLock: // Acquire only src. if !src.mu.Lock(ctx) { return 0, syserror.ErrInterrupted } - defer src.mu.Unlock() opts.SrcStart = src.offset // Safe: locked. } - // Check append-only mode and the limit. - if !dstPipe { + var err error + if dstAppend { unlock := dst.Dirent.Inode.lockAppendMu(dst.Flags().Append) defer unlock() - if dst.Flags().Append { - if opts.DstOffset { - // We need to acquire the lock. - if !dst.mu.Lock(ctx) { - return 0, syserror.ErrInterrupted - } - defer dst.mu.Unlock() - } - // Figure out the appropriate offset to use. - if err := dst.offsetForAppend(ctx, &opts.DstStart); err != nil { - return 0, err - } - } + // Figure out the appropriate offset to use. + err = dst.offsetForAppend(ctx, &opts.DstStart) + } + if err == nil && !dstPipe { // Enforce file limits. limit, ok := dst.checkLimit(ctx, opts.DstStart) switch { case ok && limit == 0: - return 0, syserror.ErrExceedsFileSizeLimit + err = syserror.ErrExceedsFileSizeLimit case ok && limit < opts.Length: opts.Length = limit // Cap the write. } } + if err != nil { + if dstLock { + dst.mu.Unlock() + } + if srcLock { + src.mu.Unlock() + } + return 0, err + } - // Attempt to do a WriteTo; this is likely the most efficient. - // - // The underlying implementation may be able to donate buffers. - newOpts := SpliceOpts{ - Length: opts.Length, - SrcStart: opts.SrcStart, - SrcOffset: !srcPipe, - Dup: opts.Dup, - DstStart: opts.DstStart, - DstOffset: !dstPipe, + // Construct readers and writers for the splice. This is used to + // provide a safer locking path for the WriteTo/ReadFrom operations + // (since they will otherwise go through public interface methods which + // conflict with locking done above), and simplifies the fallback path. + w := &lockedWriter{ + Ctx: ctx, + File: dst, + Offset: opts.DstStart, } - n, err := src.FileOperations.WriteTo(ctx, src, dst, newOpts) - if n == 0 && err != nil { - // Attempt as a ReadFrom. If a WriteTo, a ReadFrom may also - // be more efficient than a copy if buffers are cached or readily - // available. (It's unlikely that they can actually be donate - n, err = dst.FileOperations.ReadFrom(ctx, dst, src, newOpts) + r := &lockedReader{ + Ctx: ctx, + File: src, + Offset: opts.SrcStart, } - if n == 0 && err != nil { - // If we've failed up to here, and at least one of the sources - // is a pipe or socket, then we can't properly support dup. - // Return an error indicating that this operation is not - // supported. - if (srcPipe || dstPipe) && newOpts.Dup { - return 0, syserror.EINVAL - } - // We failed to splice the files. But that's fine; we just fall - // back to a slow path in this case. This copies without doing - // any mode changes, so should still be more efficient. - var ( - r io.Reader - w io.Writer - ) - fw := &lockedWriter{ - Ctx: ctx, - File: dst, - } - if newOpts.DstOffset { - // Use the provided offset. - w = secio.NewOffsetWriter(fw, newOpts.DstStart) - } else { - // Writes will proceed with no offset. - w = fw - } - fr := &lockedReader{ - Ctx: ctx, - File: src, - } - if newOpts.SrcOffset { - // Limit to the given offset and length. - r = io.NewSectionReader(fr, opts.SrcStart, opts.Length) - } else { - // Limit just to the given length. - r = &io.LimitedReader{fr, opts.Length} - } + // Attempt to do a WriteTo; this is likely the most efficient. + n, err := src.FileOperations.WriteTo(ctx, src, w, opts.Length, opts.Dup) + if n == 0 && err != nil && err != syserror.ErrWouldBlock && !opts.Dup { + // Attempt as a ReadFrom. If a WriteTo, a ReadFrom may also be + // more efficient than a copy if buffers are cached or readily + // available. (It's unlikely that they can actually be donated). + n, err = dst.FileOperations.ReadFrom(ctx, dst, r, opts.Length) + } - // Copy between the two. - n, err = io.Copy(w, r) + // Support one last fallback option, but only if at least one of + // the source and destination are regular files. This is because + // if we block at some point, we could lose data. If the source is + // not a pipe then reading is not destructive; if the destination + // is a regular file, then it is guaranteed not to block writing. + if n == 0 && err != nil && err != syserror.ErrWouldBlock && !opts.Dup && (!dstPipe || !srcPipe) { + // Fallback to an in-kernel copy. + n, err = io.Copy(w, &io.LimitedReader{ + R: r, + N: opts.Length, + }) } // Update offsets, if required. @@ -185,5 +169,13 @@ func Splice(ctx context.Context, dst *File, src *File, opts SpliceOpts) (int64, } } + // Drop locks. + if dstLock { + dst.mu.Unlock() + } + if srcLock { + src.mu.Unlock() + } + return n, err } diff --git a/pkg/sentry/kernel/pipe/buffer.go b/pkg/sentry/kernel/pipe/buffer.go index 69ef2a720..95bee2d37 100644 --- a/pkg/sentry/kernel/pipe/buffer.go +++ b/pkg/sentry/kernel/pipe/buffer.go @@ -15,6 +15,7 @@ package pipe import ( + "io" "sync" "gvisor.dev/gvisor/pkg/sentry/safemem" @@ -67,6 +68,17 @@ func (b *buffer) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, error) { return n, err } +// WriteFromReader writes to the buffer from an io.Reader. +func (b *buffer) WriteFromReader(r io.Reader, count int64) (int64, error) { + dst := b.data[b.write:] + if count < int64(len(dst)) { + dst = b.data[b.write:][:count] + } + n, err := r.Read(dst) + b.write += n + return int64(n), err +} + // ReadToBlocks implements safemem.Reader.ReadToBlocks. func (b *buffer) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { src := safemem.BlockSeqOf(safemem.BlockFromSafeSlice(b.data[b.read:b.write])) @@ -75,6 +87,19 @@ func (b *buffer) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error) { return n, err } +// ReadToWriter reads from the buffer into an io.Writer. +func (b *buffer) ReadToWriter(w io.Writer, count int64, dup bool) (int64, error) { + src := b.data[b.read:b.write] + if count < int64(len(src)) { + src = b.data[b.read:][:count] + } + n, err := w.Write(src) + if !dup { + b.read += n + } + return int64(n), err +} + // bufferPool is a pool for buffers. var bufferPool = sync.Pool{ New: func() interface{} { diff --git a/pkg/sentry/kernel/pipe/pipe.go b/pkg/sentry/kernel/pipe/pipe.go index 247e2928e..93b50669f 100644 --- a/pkg/sentry/kernel/pipe/pipe.go +++ b/pkg/sentry/kernel/pipe/pipe.go @@ -23,7 +23,6 @@ import ( "gvisor.dev/gvisor/pkg/sentry/context" "gvisor.dev/gvisor/pkg/sentry/fs" - "gvisor.dev/gvisor/pkg/sentry/usermem" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/waiter" ) @@ -173,13 +172,24 @@ func (p *Pipe) Open(ctx context.Context, d *fs.Dirent, flags fs.FileFlags) *fs.F } } +type readOps struct { + // left returns the bytes remaining. + left func() int64 + + // limit limits subsequence reads. + limit func(int64) + + // read performs the actual read operation. + read func(*buffer) (int64, error) +} + // read reads data from the pipe into dst and returns the number of bytes // read, or returns ErrWouldBlock if the pipe is empty. // // Precondition: this pipe must have readers. -func (p *Pipe) read(ctx context.Context, dst usermem.IOSequence) (int64, error) { +func (p *Pipe) read(ctx context.Context, ops readOps) (int64, error) { // Don't block for a zero-length read even if the pipe is empty. - if dst.NumBytes() == 0 { + if ops.left() == 0 { return 0, nil } @@ -196,12 +206,12 @@ func (p *Pipe) read(ctx context.Context, dst usermem.IOSequence) (int64, error) } // Limit how much we consume. - if dst.NumBytes() > p.size { - dst = dst.TakeFirst64(p.size) + if ops.left() > p.size { + ops.limit(p.size) } done := int64(0) - for dst.NumBytes() > 0 { + for ops.left() > 0 { // Pop the first buffer. first := p.data.Front() if first == nil { @@ -209,10 +219,9 @@ func (p *Pipe) read(ctx context.Context, dst usermem.IOSequence) (int64, error) } // Copy user data. - n, err := dst.CopyOutFrom(ctx, first) + n, err := ops.read(first) done += int64(n) p.size -= n - dst = dst.DropFirst64(n) // Empty buffer? if first.Empty() { @@ -230,12 +239,57 @@ func (p *Pipe) read(ctx context.Context, dst usermem.IOSequence) (int64, error) return done, nil } +// dup duplicates all data from this pipe into the given writer. +// +// There is no blocking behavior implemented here. The writer may propagate +// some blocking error. All the writes must be complete writes. +func (p *Pipe) dup(ctx context.Context, ops readOps) (int64, error) { + p.mu.Lock() + defer p.mu.Unlock() + + // Is the pipe empty? + if p.size == 0 { + if !p.HasWriters() { + // See above. + return 0, nil + } + return 0, syserror.ErrWouldBlock + } + + // Limit how much we consume. + if ops.left() > p.size { + ops.limit(p.size) + } + + done := int64(0) + for buf := p.data.Front(); buf != nil; buf = buf.Next() { + n, err := ops.read(buf) + done += n + if err != nil { + return done, err + } + } + + return done, nil +} + +type writeOps struct { + // left returns the bytes remaining. + left func() int64 + + // limit should limit subsequent writes. + limit func(int64) + + // write should write to the provided buffer. + write func(*buffer) (int64, error) +} + // write writes data from sv into the pipe and returns the number of bytes // written. If no bytes are written because the pipe is full (or has less than // atomicIOBytes free capacity), write returns ErrWouldBlock. // // Precondition: this pipe must have writers. -func (p *Pipe) write(ctx context.Context, src usermem.IOSequence) (int64, error) { +func (p *Pipe) write(ctx context.Context, ops writeOps) (int64, error) { p.mu.Lock() defer p.mu.Unlock() @@ -246,17 +300,16 @@ func (p *Pipe) write(ctx context.Context, src usermem.IOSequence) (int64, error) // POSIX requires that a write smaller than atomicIOBytes (PIPE_BUF) be // atomic, but requires no atomicity for writes larger than this. - wanted := src.NumBytes() + wanted := ops.left() if avail := p.max - p.size; wanted > avail { if wanted <= p.atomicIOBytes { return 0, syserror.ErrWouldBlock } - // Limit to the available capacity. - src = src.TakeFirst64(avail) + ops.limit(avail) } done := int64(0) - for src.NumBytes() > 0 { + for ops.left() > 0 { // Need a new buffer? last := p.data.Back() if last == nil || last.Full() { @@ -266,10 +319,9 @@ func (p *Pipe) write(ctx context.Context, src usermem.IOSequence) (int64, error) } // Copy user data. - n, err := src.CopyInTo(ctx, last) + n, err := ops.write(last) done += int64(n) p.size += n - src = src.DropFirst64(n) // Handle errors. if err != nil { diff --git a/pkg/sentry/kernel/pipe/reader_writer.go b/pkg/sentry/kernel/pipe/reader_writer.go index f69dbf27b..7c307f013 100644 --- a/pkg/sentry/kernel/pipe/reader_writer.go +++ b/pkg/sentry/kernel/pipe/reader_writer.go @@ -15,6 +15,7 @@ package pipe import ( + "io" "math" "syscall" @@ -55,7 +56,45 @@ func (rw *ReaderWriter) Release() { // Read implements fs.FileOperations.Read. func (rw *ReaderWriter) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) { - n, err := rw.Pipe.read(ctx, dst) + n, err := rw.Pipe.read(ctx, readOps{ + left: func() int64 { + return dst.NumBytes() + }, + limit: func(l int64) { + dst = dst.TakeFirst64(l) + }, + read: func(buf *buffer) (int64, error) { + n, err := dst.CopyOutFrom(ctx, buf) + dst = dst.DropFirst64(n) + return n, err + }, + }) + if n > 0 { + rw.Pipe.Notify(waiter.EventOut) + } + return n, err +} + +// WriteTo implements fs.FileOperations.WriteTo. +func (rw *ReaderWriter) WriteTo(ctx context.Context, _ *fs.File, w io.Writer, count int64, dup bool) (int64, error) { + ops := readOps{ + left: func() int64 { + return count + }, + limit: func(l int64) { + count = l + }, + read: func(buf *buffer) (int64, error) { + n, err := buf.ReadToWriter(w, count, dup) + count -= n + return n, err + }, + } + if dup { + // There is no notification for dup operations. + return rw.Pipe.dup(ctx, ops) + } + n, err := rw.Pipe.read(ctx, ops) if n > 0 { rw.Pipe.Notify(waiter.EventOut) } @@ -64,7 +103,40 @@ func (rw *ReaderWriter) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequ // Write implements fs.FileOperations.Write. func (rw *ReaderWriter) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error) { - n, err := rw.Pipe.write(ctx, src) + n, err := rw.Pipe.write(ctx, writeOps{ + left: func() int64 { + return src.NumBytes() + }, + limit: func(l int64) { + src = src.TakeFirst64(l) + }, + write: func(buf *buffer) (int64, error) { + n, err := src.CopyInTo(ctx, buf) + src = src.DropFirst64(n) + return n, err + }, + }) + if n > 0 { + rw.Pipe.Notify(waiter.EventIn) + } + return n, err +} + +// ReadFrom implements fs.FileOperations.WriteTo. +func (rw *ReaderWriter) ReadFrom(ctx context.Context, _ *fs.File, r io.Reader, count int64) (int64, error) { + n, err := rw.Pipe.write(ctx, writeOps{ + left: func() int64 { + return count + }, + limit: func(l int64) { + count = l + }, + write: func(buf *buffer) (int64, error) { + n, err := buf.WriteFromReader(r, count) + count -= n + return n, err + }, + }) if n > 0 { rw.Pipe.Notify(waiter.EventIn) } diff --git a/pkg/sentry/socket/epsocket/epsocket.go b/pkg/sentry/socket/epsocket/epsocket.go index 0e37ce61b..3e05e40fe 100644 --- a/pkg/sentry/socket/epsocket/epsocket.go +++ b/pkg/sentry/socket/epsocket/epsocket.go @@ -26,6 +26,7 @@ package epsocket import ( "bytes" + "io" "math" "reflect" "sync" @@ -227,7 +228,6 @@ type SocketOperations struct { fsutil.FileNoopFlush `state:"nosave"` fsutil.FileNoFsync `state:"nosave"` fsutil.FileNoMMap `state:"nosave"` - fsutil.FileNoSplice `state:"nosave"` fsutil.FileUseInodeUnstableAttr `state:"nosave"` socket.SendReceiveTimeout *waiter.Queue @@ -412,17 +412,58 @@ func (s *SocketOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOS return int64(n), nil } -// ioSequencePayload implements tcpip.Payload. It copies user memory bytes on demand -// based on the requested size. +// WriteTo implements fs.FileOperations.WriteTo. +func (s *SocketOperations) WriteTo(ctx context.Context, _ *fs.File, dst io.Writer, count int64, dup bool) (int64, error) { + s.readMu.Lock() + defer s.readMu.Unlock() + + // Copy as much data as possible. + done := int64(0) + for count > 0 { + // This may return a blocking error. + if err := s.fetchReadView(); err != nil { + return done, err.ToError() + } + + // Write to the underlying file. + n, err := dst.Write(s.readView) + done += int64(n) + count -= int64(n) + if dup { + // That's all we support for dup. This is generally + // supported by any Linux system calls, but the + // expectation is that now a caller will call read to + // actually remove these bytes from the socket. + return done, nil + } + + // Drop that part of the view. + s.readView.TrimFront(n) + if err != nil { + return done, err + } + } + + return done, nil +} + +// ioSequencePayload implements tcpip.Payload. +// +// t copies user memory bytes on demand based on the requested size. type ioSequencePayload struct { ctx context.Context src usermem.IOSequence } -// Get implements tcpip.Payload. -func (i *ioSequencePayload) Get(size int) ([]byte, *tcpip.Error) { - if size > i.Size() { - size = i.Size() +// FullPayload implements tcpip.Payloader.FullPayload +func (i *ioSequencePayload) FullPayload() ([]byte, *tcpip.Error) { + return i.Payload(int(i.src.NumBytes())) +} + +// Payload implements tcpip.Payloader.Payload. +func (i *ioSequencePayload) Payload(size int) ([]byte, *tcpip.Error) { + if max := int(i.src.NumBytes()); size > max { + size = max } v := buffer.NewView(size) if _, err := i.src.CopyIn(i.ctx, v); err != nil { @@ -431,11 +472,6 @@ func (i *ioSequencePayload) Get(size int) ([]byte, *tcpip.Error) { return v, nil } -// Size implements tcpip.Payload. -func (i *ioSequencePayload) Size() int { - return int(i.src.NumBytes()) -} - // DropFirst drops the first n bytes from underlying src. func (i *ioSequencePayload) DropFirst(n int) { i.src = i.src.DropFirst(int(n)) @@ -469,6 +505,76 @@ func (s *SocketOperations) Write(ctx context.Context, _ *fs.File, src usermem.IO return int64(n), nil } +// readerPayload implements tcpip.Payloader. +// +// It allocates a view and reads from a reader on-demand, based on available +// capacity in the endpoint. +type readerPayload struct { + ctx context.Context + r io.Reader + count int64 + err error +} + +// FullPayload implements tcpip.Payloader.FullPayload. +func (r *readerPayload) FullPayload() ([]byte, *tcpip.Error) { + return r.Payload(int(r.count)) +} + +// Payload implements tcpip.Payloader.Payload. +func (r *readerPayload) Payload(size int) ([]byte, *tcpip.Error) { + if size > int(r.count) { + size = int(r.count) + } + v := buffer.NewView(size) + n, err := r.r.Read(v) + if n > 0 { + // We ignore the error here. It may re-occur on subsequent + // reads, but for now we can enqueue some amount of data. + r.count -= int64(n) + return v[:n], nil + } + if err == syserror.ErrWouldBlock { + return nil, tcpip.ErrWouldBlock + } else if err != nil { + r.err = err // Save for propation. + return nil, tcpip.ErrBadAddress + } + + // There is no data and no error. Return an error, which will propagate + // r.err, which will be nil. This is the desired result: (0, nil). + return nil, tcpip.ErrBadAddress +} + +// ReadFrom implements fs.FileOperations.ReadFrom. +func (s *SocketOperations) ReadFrom(ctx context.Context, _ *fs.File, r io.Reader, count int64) (int64, error) { + f := &readerPayload{ctx: ctx, r: r, count: count} + n, resCh, err := s.Endpoint.Write(f, tcpip.WriteOptions{}) + if err == tcpip.ErrWouldBlock { + return 0, syserror.ErrWouldBlock + } + + if resCh != nil { + t := ctx.(*kernel.Task) + if err := t.Block(resCh); err != nil { + return 0, syserr.FromError(err).ToError() + } + + n, _, err = s.Endpoint.Write(f, tcpip.WriteOptions{ + // Reads may be destructive but should be very fast, + // so we can't release the lock while copying data. + Atomic: true, + }) + } + if err == tcpip.ErrWouldBlock { + return n, syserror.ErrWouldBlock + } else if err != nil { + return int64(n), f.err // Propagate error. + } + + return int64(n), nil +} + // Readiness returns a mask of ready events for socket s. func (s *SocketOperations) Readiness(mask waiter.EventMask) waiter.EventMask { r := s.Endpoint.Readiness(mask) @@ -2060,7 +2166,7 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to [] n, _, err = s.Endpoint.Write(v, opts) } dontWait := flags&linux.MSG_DONTWAIT != 0 - if err == nil && (n >= int64(v.Size()) || dontWait) { + if err == nil && (n >= v.src.NumBytes() || dontWait) { // Complete write. return int(n), nil } @@ -2085,7 +2191,7 @@ func (s *SocketOperations) SendMsg(t *kernel.Task, src usermem.IOSequence, to [] return 0, syserr.TranslateNetstackError(err) } - if err == nil && v.Size() == 0 || err != nil && err != tcpip.ErrWouldBlock { + if err == nil && v.src.NumBytes() == 0 || err != nil && err != tcpip.ErrWouldBlock { return int(total), nil } diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go index ed996ba51..150999fb8 100644 --- a/pkg/sentry/syscalls/linux/linux64.go +++ b/pkg/sentry/syscalls/linux/linux64.go @@ -320,8 +320,8 @@ var AMD64 = &kernel.SyscallTable{ 272: syscalls.PartiallySupported("unshare", Unshare, "Mount, cgroup namespaces not supported. Network namespaces supported but must be empty.", nil), 273: syscalls.Error("set_robust_list", syserror.ENOSYS, "Obsolete.", nil), 274: syscalls.Error("get_robust_list", syserror.ENOSYS, "Obsolete.", nil), - 275: syscalls.PartiallySupported("splice", Splice, "Stub implementation.", []string{"gvisor.dev/issue/138"}), // TODO(b/29354098) - 276: syscalls.ErrorWithEvent("tee", syserror.ENOSYS, "", []string{"gvisor.dev/issue/138"}), // TODO(b/29354098) + 275: syscalls.Supported("splice", Splice), + 276: syscalls.Supported("tee", Tee), 277: syscalls.PartiallySupported("sync_file_range", SyncFileRange, "Full data flush is not guaranteed at this time.", nil), 278: syscalls.ErrorWithEvent("vmsplice", syserror.ENOSYS, "", []string{"gvisor.dev/issue/138"}), // TODO(b/29354098) 279: syscalls.CapError("move_pages", linux.CAP_SYS_NICE, "", nil), // requires cap_sys_nice (mostly) diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go index 8a98fedcb..f0a292f2f 100644 --- a/pkg/sentry/syscalls/linux/sys_splice.go +++ b/pkg/sentry/syscalls/linux/sys_splice.go @@ -29,9 +29,8 @@ func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonB total int64 n int64 err error - ch chan struct{} - inW bool - outW bool + inCh chan struct{} + outCh chan struct{} ) for opts.Length > 0 { n, err = fs.Splice(t, outFile, inFile, opts) @@ -43,35 +42,33 @@ func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonB break } - // Are we a registered waiter? - if ch == nil { - ch = make(chan struct{}, 1) - } - if !inW && !inFile.Flags().NonBlocking { - w, _ := waiter.NewChannelEntry(ch) - inFile.EventRegister(&w, EventMaskRead) - defer inFile.EventUnregister(&w) - inW = true // Registered. - } else if !outW && !outFile.Flags().NonBlocking { - w, _ := waiter.NewChannelEntry(ch) - outFile.EventRegister(&w, EventMaskWrite) - defer outFile.EventUnregister(&w) - outW = true // Registered. - } - - // Was anything registered? If no, everything is non-blocking. - if !inW && !outW { - break - } - - if (!inW || inFile.Readiness(EventMaskRead) != 0) && (!outW || outFile.Readiness(EventMaskWrite) != 0) { - // Something became ready, try again without blocking. - continue + // Note that the blocking behavior here is a bit different than the + // normal pattern. Because we need to have both data to read and data + // to write simultaneously, we actually explicitly block on both of + // these cases in turn before returning to the splice operation. + if inFile.Readiness(EventMaskRead) == 0 { + if inCh == nil { + inCh = make(chan struct{}, 1) + inW, _ := waiter.NewChannelEntry(inCh) + inFile.EventRegister(&inW, EventMaskRead) + defer inFile.EventUnregister(&inW) + continue // Need to refresh readiness. + } + if err = t.Block(inCh); err != nil { + break + } } - - // Block until there's data. - if err = t.Block(ch); err != nil { - break + if outFile.Readiness(EventMaskWrite) == 0 { + if outCh == nil { + outCh = make(chan struct{}, 1) + outW, _ := waiter.NewChannelEntry(outCh) + outFile.EventRegister(&outW, EventMaskWrite) + defer outFile.EventUnregister(&outW) + continue // Need to refresh readiness. + } + if err = t.Block(outCh); err != nil { + break + } } } @@ -149,7 +146,7 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc Length: count, SrcOffset: true, SrcStart: offset, - }, false) + }, outFile.Flags().NonBlocking) // Copy out the new offset. if _, err := t.CopyOut(offsetAddr, n+offset); err != nil { @@ -159,7 +156,7 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc // Send data using splice. n, err = doSplice(t, outFile, inFile, fs.SpliceOpts{ Length: count, - }, false) + }, outFile.Flags().NonBlocking) } // We can only pass a single file to handleIOError, so pick inFile @@ -181,12 +178,6 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal return 0, nil, syserror.EINVAL } - // Only non-blocking is meaningful. Note that unlike in Linux, this - // flag is applied consistently. We will have either fully blocking or - // non-blocking behavior below, regardless of the underlying files - // being spliced to. It's unclear if this is a bug or not yet. - nonBlocking := (flags & linux.SPLICE_F_NONBLOCK) != 0 - // Get files. outFile := t.GetFile(outFD) if outFile == nil { @@ -200,6 +191,13 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } defer inFile.DecRef() + // The operation is non-blocking if anything is non-blocking. + // + // N.B. This is a rather simplistic heuristic that avoids some + // poor edge case behavior since the exact semantics here are + // underspecified and vary between versions of Linux itself. + nonBlock := inFile.Flags().NonBlocking || outFile.Flags().NonBlocking || (flags&linux.SPLICE_F_NONBLOCK != 0) + // Construct our options. // // Note that exactly one of the underlying buffers must be a pipe. We @@ -257,7 +255,7 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } // Splice data. - n, err := doSplice(t, outFile, inFile, opts, nonBlocking) + n, err := doSplice(t, outFile, inFile, opts, nonBlock) // See above; inFile is chosen arbitrarily here. return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "splice", inFile) @@ -275,9 +273,6 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo return 0, nil, syserror.EINVAL } - // Only non-blocking is meaningful. - nonBlocking := (flags & linux.SPLICE_F_NONBLOCK) != 0 - // Get files. outFile := t.GetFile(outFD) if outFile == nil { @@ -301,11 +296,14 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo return 0, nil, syserror.EINVAL } + // The operation is non-blocking if anything is non-blocking. + nonBlock := inFile.Flags().NonBlocking || outFile.Flags().NonBlocking || (flags&linux.SPLICE_F_NONBLOCK != 0) + // Splice data. n, err := doSplice(t, outFile, inFile, fs.SpliceOpts{ Length: count, Dup: true, - }, nonBlocking) + }, nonBlock) // See above; inFile is chosen arbitrarily here. return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "tee", inFile) diff --git a/pkg/tcpip/header/udp.go b/pkg/tcpip/header/udp.go index c1f454805..74412c894 100644 --- a/pkg/tcpip/header/udp.go +++ b/pkg/tcpip/header/udp.go @@ -27,6 +27,11 @@ const ( udpChecksum = 6 ) +const ( + // UDPMaximumPacketSize is the largest possible UDP packet. + UDPMaximumPacketSize = 0xffff +) + // UDPFields contains the fields of a UDP packet. It is used to describe the // fields of a packet that needs to be encoded. type UDPFields struct { diff --git a/pkg/tcpip/stack/transport_test.go b/pkg/tcpip/stack/transport_test.go index 87d1e0d0d..847d02982 100644 --- a/pkg/tcpip/stack/transport_test.go +++ b/pkg/tcpip/stack/transport_test.go @@ -65,13 +65,13 @@ func (*fakeTransportEndpoint) Read(*tcpip.FullAddress) (buffer.View, tcpip.Contr return buffer.View{}, tcpip.ControlMessages{}, nil } -func (f *fakeTransportEndpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (f *fakeTransportEndpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { if len(f.route.RemoteAddress) == 0 { return 0, nil, tcpip.ErrNoRoute } hdr := buffer.NewPrependable(int(f.route.MaxHeaderLength())) - v, err := p.Get(p.Size()) + v, err := p.FullPayload() if err != nil { return 0, nil, err } diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index ebf8a2d04..2534069ab 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -261,31 +261,34 @@ type FullAddress struct { Port uint16 } -// Payload provides an interface around data that is being sent to an endpoint. -// This allows the endpoint to request the amount of data it needs based on -// internal buffers without exposing them. 'p.Get(p.Size())' reads all the data. -type Payload interface { - // Get returns a slice containing exactly 'min(size, p.Size())' bytes. - Get(size int) ([]byte, *Error) - - // Size returns the payload size. - Size() int +// Payloader is an interface that provides data. +// +// This interface allows the endpoint to request the amount of data it needs +// based on internal buffers without exposing them. +type Payloader interface { + // FullPayload returns all available bytes. + FullPayload() ([]byte, *Error) + + // Payload returns a slice containing at most size bytes. + Payload(size int) ([]byte, *Error) } -// SlicePayload implements Payload on top of slices for convenience. +// SlicePayload implements Payloader for slices. +// +// This is typically used for tests. type SlicePayload []byte -// Get implements Payload. -func (s SlicePayload) Get(size int) ([]byte, *Error) { - if size > s.Size() { - size = s.Size() - } - return s[:size], nil +// FullPayload implements Payloader.FullPayload. +func (s SlicePayload) FullPayload() ([]byte, *Error) { + return s, nil } -// Size implements Payload. -func (s SlicePayload) Size() int { - return len(s) +// Payload implements Payloader.Payload. +func (s SlicePayload) Payload(size int) ([]byte, *Error) { + if size > len(s) { + size = len(s) + } + return s[:size], nil } // A ControlMessages contains socket control messages for IP sockets. @@ -338,7 +341,7 @@ type Endpoint interface { // ErrNoLinkAddress and a notification channel is returned for the caller to // block. Channel is closed once address resolution is complete (success or // not). The channel is only non-nil in this case. - Write(Payload, WriteOptions) (int64, <-chan struct{}, *Error) + Write(Payloader, WriteOptions) (int64, <-chan struct{}, *Error) // Peek reads data without consuming it from the endpoint. // @@ -432,6 +435,11 @@ type WriteOptions struct { // EndOfRecord has the same semantics as Linux's MSG_EOR. EndOfRecord bool + + // Atomic means that all data fetched from Payloader must be written to the + // endpoint. If Atomic is false, then data fetched from the Payloader may be + // discarded if available endpoint buffer space is unsufficient. + Atomic bool } // SockOpt represents socket options which values have the int type. diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go index e1f622af6..3db060384 100644 --- a/pkg/tcpip/transport/icmp/endpoint.go +++ b/pkg/tcpip/transport/icmp/endpoint.go @@ -204,7 +204,7 @@ func (e *endpoint) prepareForWrite(to *tcpip.FullAddress) (retry bool, err *tcpi // Write writes data to the endpoint's peer. This method does not block // if the data cannot be written. -func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.) if opts.More { return 0, nil, tcpip.ErrInvalidOptionValue @@ -289,7 +289,7 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha } } - v, err := p.Get(p.Size()) + v, err := p.FullPayload() if err != nil { return 0, nil, err } diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go index 13e17e2a6..cf1c5c433 100644 --- a/pkg/tcpip/transport/raw/endpoint.go +++ b/pkg/tcpip/transport/raw/endpoint.go @@ -207,7 +207,7 @@ func (ep *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMes } // Write implements tcpip.Endpoint.Write. -func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (ep *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // MSG_MORE is unimplemented. This also means that MSG_EOR is a no-op. if opts.More { return 0, nil, tcpip.ErrInvalidOptionValue @@ -220,9 +220,8 @@ func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64 return 0, nil, tcpip.ErrInvalidEndpointState } - payloadBytes, err := payload.Get(payload.Size()) + payloadBytes, err := p.FullPayload() if err != nil { - ep.mu.RUnlock() return 0, nil, err } @@ -230,7 +229,7 @@ func (ep *endpoint) Write(payload tcpip.Payload, opts tcpip.WriteOptions) (int64 // destination address, route using that address. if !ep.associated { ip := header.IPv4(payloadBytes) - if !ip.IsValid(payload.Size()) { + if !ip.IsValid(len(payloadBytes)) { ep.mu.RUnlock() return 0, nil, tcpip.ErrInvalidOptionValue } diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index ac927569a..dd931f88c 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -806,7 +806,7 @@ func (e *endpoint) isEndpointWritableLocked() (int, *tcpip.Error) { } // Write writes data to the endpoint's peer. -func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // Linux completely ignores any address passed to sendto(2) for TCP sockets // (without the MSG_FASTOPEN flag). Corking is unimplemented, so opts.More // and opts.EndOfRecord are also ignored. @@ -821,47 +821,52 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha return 0, nil, err } - e.sndBufMu.Unlock() - e.mu.RUnlock() - - // Nothing to do if the buffer is empty. - if p.Size() == 0 { - return 0, nil, nil + // We can release locks while copying data. + // + // This is not possible if atomic is set, because we can't allow the + // available buffer space to be consumed by some other caller while we + // are copying data in. + if !opts.Atomic { + e.sndBufMu.Unlock() + e.mu.RUnlock() } - // Copy in memory without holding sndBufMu so that worker goroutine can - // make progress independent of this operation. - v, perr := p.Get(avail) - if perr != nil { + // Fetch data. + v, perr := p.Payload(avail) + if perr != nil || len(v) == 0 { + if opts.Atomic { // See above. + e.sndBufMu.Unlock() + e.mu.RUnlock() + } + // Note that perr may be nil if len(v) == 0. return 0, nil, perr } - e.mu.RLock() - e.sndBufMu.Lock() + if !opts.Atomic { // See above. + e.mu.RLock() + e.sndBufMu.Lock() - // Because we released the lock before copying, check state again - // to make sure the endpoint is still in a valid state for a - // write. - avail, err = e.isEndpointWritableLocked() - if err != nil { - e.sndBufMu.Unlock() - e.mu.RUnlock() - return 0, nil, err - } + // Because we released the lock before copying, check state again + // to make sure the endpoint is still in a valid state for a write. + avail, err = e.isEndpointWritableLocked() + if err != nil { + e.sndBufMu.Unlock() + e.mu.RUnlock() + return 0, nil, err + } - // Discard any excess data copied in due to avail being reduced due to a - // simultaneous write call to the socket. - if avail < len(v) { - v = v[:avail] + // Discard any excess data copied in due to avail being reduced due + // to a simultaneous write call to the socket. + if avail < len(v) { + v = v[:avail] + } } // Add data to the send queue. - l := len(v) s := newSegmentFromView(&e.route, e.id, v) - e.sndBufUsed += l - e.sndBufInQueue += seqnum.Size(l) + e.sndBufUsed += len(v) + e.sndBufInQueue += seqnum.Size(len(v)) e.sndQueue.PushBack(s) - e.sndBufMu.Unlock() // Release the endpoint lock to prevent deadlocks due to lock // order inversion when acquiring workMu. @@ -875,7 +880,8 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha // Let the protocol goroutine do the work. e.sndWaker.Assert() } - return int64(l), nil, nil + + return int64(len(v)), nil, nil } // Peek reads data without consuming it from the endpoint. diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index dccb9a7eb..6ac7c067a 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -15,7 +15,6 @@ package udp import ( - "math" "sync" "gvisor.dev/gvisor/pkg/tcpip" @@ -277,17 +276,12 @@ func (e *endpoint) connectRoute(nicid tcpip.NICID, addr tcpip.FullAddress, netPr // Write writes data to the endpoint's peer. This method does not block // if the data cannot be written. -func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { +func (e *endpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) { // MSG_MORE is unimplemented. (This also means that MSG_EOR is a no-op.) if opts.More { return 0, nil, tcpip.ErrInvalidOptionValue } - if p.Size() > math.MaxUint16 { - // Payload can't possibly fit in a packet. - return 0, nil, tcpip.ErrMessageTooLong - } - to := opts.To e.mu.RLock() @@ -370,10 +364,14 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (int64, <-cha } } - v, err := p.Get(p.Size()) + v, err := p.FullPayload() if err != nil { return 0, nil, err } + if len(v) > header.UDPMaximumPacketSize { + // Payload can't possibly fit in a packet. + return 0, nil, tcpip.ErrMessageTooLong + } ttl := route.DefaultTTL() if header.IsV4MulticastAddress(route.RemoteAddress) || header.IsV6MulticastAddress(route.RemoteAddress) { diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 34057e3d0..df00d2c14 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1867,7 +1867,9 @@ cc_binary( "//test/util:temp_path", "//test/util:test_main", "//test/util:test_util", + "//test/util:thread_util", "@com_google_absl//absl/strings", + "@com_google_absl//absl/time", "@com_google_googletest//:gtest", ], ) @@ -1901,6 +1903,7 @@ cc_binary( "//test/util:test_util", "//test/util:thread_util", "@com_google_absl//absl/strings", + "@com_google_absl//absl/time", "@com_google_googletest//:gtest", ], ) diff --git a/test/syscalls/linux/pipe.cc b/test/syscalls/linux/pipe.cc index 65afb90f3..10e2a6dfc 100644 --- a/test/syscalls/linux/pipe.cc +++ b/test/syscalls/linux/pipe.cc @@ -168,6 +168,20 @@ TEST_P(PipeTest, Write) { EXPECT_EQ(wbuf, rbuf); } +TEST_P(PipeTest, WritePage) { + SKIP_IF(!CreateBlocking()); + + std::vector<char> wbuf(kPageSize); + RandomizeBuffer(wbuf.data(), wbuf.size()); + std::vector<char> rbuf(wbuf.size()); + + ASSERT_THAT(write(wfd_.get(), wbuf.data(), wbuf.size()), + SyscallSucceedsWithValue(wbuf.size())); + ASSERT_THAT(read(rfd_.get(), rbuf.data(), rbuf.size()), + SyscallSucceedsWithValue(rbuf.size())); + EXPECT_EQ(memcmp(rbuf.data(), wbuf.data(), wbuf.size()), 0); +} + TEST_P(PipeTest, NonBlocking) { SKIP_IF(!CreateNonBlocking()); diff --git a/test/syscalls/linux/sendfile.cc b/test/syscalls/linux/sendfile.cc index 9167ab066..4502e7fb4 100644 --- a/test/syscalls/linux/sendfile.cc +++ b/test/syscalls/linux/sendfile.cc @@ -19,9 +19,12 @@ #include "gmock/gmock.h" #include "gtest/gtest.h" #include "absl/strings/string_view.h" +#include "absl/time/clock.h" +#include "absl/time/time.h" #include "test/util/file_descriptor.h" #include "test/util/temp_path.h" #include "test/util/test_util.h" +#include "test/util/thread_util.h" namespace gvisor { namespace testing { @@ -442,6 +445,72 @@ TEST(SendFileTest, SendToNotARegularFile) { EXPECT_THAT(sendfile(outf.get(), inf.get(), nullptr, 0), SyscallFailsWithErrno(EINVAL)); } + +TEST(SendFileTest, SendPipeWouldBlock) { + // Create temp file. + constexpr char kData[] = + "The fool doth think he is wise, but the wise man knows himself to be a " + "fool."; + constexpr int kDataSize = sizeof(kData) - 1; + const TempPath in_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( + GetAbsoluteTestTmpdir(), kData, TempPath::kDefaultFileMode)); + + // Open the input file as read only. + const FileDescriptor inf = + ASSERT_NO_ERRNO_AND_VALUE(Open(in_file.path(), O_RDONLY)); + + // Setup the output named pipe. + int fds[2]; + ASSERT_THAT(pipe2(fds, O_NONBLOCK), SyscallSucceeds()); + const FileDescriptor rfd(fds[0]); + const FileDescriptor wfd(fds[1]); + + // Fill up the pipe's buffer. + int pipe_size = -1; + ASSERT_THAT(pipe_size = fcntl(wfd.get(), F_GETPIPE_SZ), SyscallSucceeds()); + std::vector<char> buf(2 * pipe_size); + ASSERT_THAT(write(wfd.get(), buf.data(), buf.size()), + SyscallSucceedsWithValue(pipe_size)); + + EXPECT_THAT(sendfile(wfd.get(), inf.get(), nullptr, kDataSize), + SyscallFailsWithErrno(EWOULDBLOCK)); +} + +TEST(SendFileTest, SendPipeBlocks) { + // Create temp file. + constexpr char kData[] = + "The fault, dear Brutus, is not in our stars, but in ourselves."; + constexpr int kDataSize = sizeof(kData) - 1; + const TempPath in_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( + GetAbsoluteTestTmpdir(), kData, TempPath::kDefaultFileMode)); + + // Open the input file as read only. + const FileDescriptor inf = + ASSERT_NO_ERRNO_AND_VALUE(Open(in_file.path(), O_RDONLY)); + + // Setup the output named pipe. + int fds[2]; + ASSERT_THAT(pipe(fds), SyscallSucceeds()); + const FileDescriptor rfd(fds[0]); + const FileDescriptor wfd(fds[1]); + + // Fill up the pipe's buffer. + int pipe_size = -1; + ASSERT_THAT(pipe_size = fcntl(wfd.get(), F_GETPIPE_SZ), SyscallSucceeds()); + std::vector<char> buf(pipe_size); + ASSERT_THAT(write(wfd.get(), buf.data(), buf.size()), + SyscallSucceedsWithValue(pipe_size)); + + ScopedThread t([&]() { + absl::SleepFor(absl::Milliseconds(100)); + ASSERT_THAT(read(rfd.get(), buf.data(), buf.size()), + SyscallSucceedsWithValue(pipe_size)); + }); + + EXPECT_THAT(sendfile(wfd.get(), inf.get(), nullptr, kDataSize), + SyscallSucceedsWithValue(kDataSize)); +} + } // namespace } // namespace testing diff --git a/test/syscalls/linux/splice.cc b/test/syscalls/linux/splice.cc index e25f264f6..85232cb1f 100644 --- a/test/syscalls/linux/splice.cc +++ b/test/syscalls/linux/splice.cc @@ -14,12 +14,16 @@ #include <fcntl.h> #include <sys/eventfd.h> +#include <sys/resource.h> #include <sys/sendfile.h> +#include <sys/time.h> #include <unistd.h> #include "gmock/gmock.h" #include "gtest/gtest.h" #include "absl/strings/string_view.h" +#include "absl/time/clock.h" +#include "absl/time/time.h" #include "test/util/file_descriptor.h" #include "test/util/temp_path.h" #include "test/util/test_util.h" @@ -36,23 +40,23 @@ TEST(SpliceTest, TwoRegularFiles) { const TempPath out_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); // Open the input file as read only. - const FileDescriptor inf = + const FileDescriptor in_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(in_file.path(), O_RDONLY)); // Open the output file as write only. - const FileDescriptor outf = + const FileDescriptor out_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(out_file.path(), O_WRONLY)); // Verify that it is rejected as expected; regardless of offsets. loff_t in_offset = 0; loff_t out_offset = 0; - EXPECT_THAT(splice(inf.get(), &in_offset, outf.get(), &out_offset, 1, 0), + EXPECT_THAT(splice(in_fd.get(), &in_offset, out_fd.get(), &out_offset, 1, 0), SyscallFailsWithErrno(EINVAL)); - EXPECT_THAT(splice(inf.get(), nullptr, outf.get(), &out_offset, 1, 0), + EXPECT_THAT(splice(in_fd.get(), nullptr, out_fd.get(), &out_offset, 1, 0), SyscallFailsWithErrno(EINVAL)); - EXPECT_THAT(splice(inf.get(), &in_offset, outf.get(), nullptr, 1, 0), + EXPECT_THAT(splice(in_fd.get(), &in_offset, out_fd.get(), nullptr, 1, 0), SyscallFailsWithErrno(EINVAL)); - EXPECT_THAT(splice(inf.get(), nullptr, outf.get(), nullptr, 1, 0), + EXPECT_THAT(splice(in_fd.get(), nullptr, out_fd.get(), nullptr, 1, 0), SyscallFailsWithErrno(EINVAL)); } @@ -75,8 +79,6 @@ TEST(SpliceTest, SamePipe) { } TEST(TeeTest, SamePipe) { - SKIP_IF(IsRunningOnGvisor()); - // Create a new pipe. int fds[2]; ASSERT_THAT(pipe(fds), SyscallSucceeds()); @@ -95,11 +97,9 @@ TEST(TeeTest, SamePipe) { } TEST(TeeTest, RegularFile) { - SKIP_IF(IsRunningOnGvisor()); - // Open some file. const TempPath in_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor inf = + const FileDescriptor in_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(in_file.path(), O_RDWR)); // Create a new pipe. @@ -109,9 +109,9 @@ TEST(TeeTest, RegularFile) { const FileDescriptor wfd(fds[1]); // Attempt to tee from the file. - EXPECT_THAT(tee(inf.get(), wfd.get(), kPageSize, 0), + EXPECT_THAT(tee(in_fd.get(), wfd.get(), kPageSize, 0), SyscallFailsWithErrno(EINVAL)); - EXPECT_THAT(tee(rfd.get(), inf.get(), kPageSize, 0), + EXPECT_THAT(tee(rfd.get(), in_fd.get(), kPageSize, 0), SyscallFailsWithErrno(EINVAL)); } @@ -142,7 +142,7 @@ TEST(SpliceTest, FromEventFD) { constexpr uint64_t kEventFDValue = 1; int efd; ASSERT_THAT(efd = eventfd(kEventFDValue, 0), SyscallSucceeds()); - const FileDescriptor inf(efd); + const FileDescriptor in_fd(efd); // Create a new pipe. int fds[2]; @@ -152,7 +152,7 @@ TEST(SpliceTest, FromEventFD) { // Splice 8-byte eventfd value to pipe. constexpr int kEventFDSize = 8; - EXPECT_THAT(splice(inf.get(), nullptr, wfd.get(), nullptr, kEventFDSize, 0), + EXPECT_THAT(splice(in_fd.get(), nullptr, wfd.get(), nullptr, kEventFDSize, 0), SyscallSucceedsWithValue(kEventFDSize)); // Contents should be equal. @@ -166,7 +166,7 @@ TEST(SpliceTest, FromEventFD) { TEST(SpliceTest, FromEventFDOffset) { int efd; ASSERT_THAT(efd = eventfd(0, 0), SyscallSucceeds()); - const FileDescriptor inf(efd); + const FileDescriptor in_fd(efd); // Create a new pipe. int fds[2]; @@ -179,7 +179,7 @@ TEST(SpliceTest, FromEventFDOffset) { // This is not allowed because eventfd doesn't support pread. constexpr int kEventFDSize = 8; loff_t in_off = 0; - EXPECT_THAT(splice(inf.get(), &in_off, wfd.get(), nullptr, kEventFDSize, 0), + EXPECT_THAT(splice(in_fd.get(), &in_off, wfd.get(), nullptr, kEventFDSize, 0), SyscallFailsWithErrno(EINVAL)); } @@ -200,28 +200,29 @@ TEST(SpliceTest, ToEventFDOffset) { int efd; ASSERT_THAT(efd = eventfd(0, 0), SyscallSucceeds()); - const FileDescriptor outf(efd); + const FileDescriptor out_fd(efd); // Attempt to splice 8-byte eventfd value to pipe with offset. // // This is not allowed because eventfd doesn't support pwrite. loff_t out_off = 0; - EXPECT_THAT(splice(rfd.get(), nullptr, outf.get(), &out_off, kEventFDSize, 0), - SyscallFailsWithErrno(EINVAL)); + EXPECT_THAT( + splice(rfd.get(), nullptr, out_fd.get(), &out_off, kEventFDSize, 0), + SyscallFailsWithErrno(EINVAL)); } TEST(SpliceTest, ToPipe) { // Open the input file. const TempPath in_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor inf = + const FileDescriptor in_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(in_file.path(), O_RDWR)); // Fill with some random data. std::vector<char> buf(kPageSize); RandomizeBuffer(buf.data(), buf.size()); - ASSERT_THAT(write(inf.get(), buf.data(), buf.size()), + ASSERT_THAT(write(in_fd.get(), buf.data(), buf.size()), SyscallSucceedsWithValue(kPageSize)); - ASSERT_THAT(lseek(inf.get(), 0, SEEK_SET), SyscallSucceedsWithValue(0)); + ASSERT_THAT(lseek(in_fd.get(), 0, SEEK_SET), SyscallSucceedsWithValue(0)); // Create a new pipe. int fds[2]; @@ -230,7 +231,7 @@ TEST(SpliceTest, ToPipe) { const FileDescriptor wfd(fds[1]); // Splice to the pipe. - EXPECT_THAT(splice(inf.get(), nullptr, wfd.get(), nullptr, kPageSize, 0), + EXPECT_THAT(splice(in_fd.get(), nullptr, wfd.get(), nullptr, kPageSize, 0), SyscallSucceedsWithValue(kPageSize)); // Contents should be equal. @@ -243,13 +244,13 @@ TEST(SpliceTest, ToPipe) { TEST(SpliceTest, ToPipeOffset) { // Open the input file. const TempPath in_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor inf = + const FileDescriptor in_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(in_file.path(), O_RDWR)); // Fill with some random data. std::vector<char> buf(kPageSize); RandomizeBuffer(buf.data(), buf.size()); - ASSERT_THAT(write(inf.get(), buf.data(), buf.size()), + ASSERT_THAT(write(in_fd.get(), buf.data(), buf.size()), SyscallSucceedsWithValue(kPageSize)); // Create a new pipe. @@ -261,7 +262,7 @@ TEST(SpliceTest, ToPipeOffset) { // Splice to the pipe. loff_t in_offset = kPageSize / 2; EXPECT_THAT( - splice(inf.get(), &in_offset, wfd.get(), nullptr, kPageSize / 2, 0), + splice(in_fd.get(), &in_offset, wfd.get(), nullptr, kPageSize / 2, 0), SyscallSucceedsWithValue(kPageSize / 2)); // Contents should be equal to only the second part. @@ -286,22 +287,22 @@ TEST(SpliceTest, FromPipe) { // Open the input file. const TempPath out_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor outf = + const FileDescriptor out_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(out_file.path(), O_RDWR)); // Splice to the output file. - EXPECT_THAT(splice(rfd.get(), nullptr, outf.get(), nullptr, kPageSize, 0), + EXPECT_THAT(splice(rfd.get(), nullptr, out_fd.get(), nullptr, kPageSize, 0), SyscallSucceedsWithValue(kPageSize)); // The offset of the output should be equal to kPageSize. We assert that and // reset to zero so that we can read the contents and ensure they match. - EXPECT_THAT(lseek(outf.get(), 0, SEEK_CUR), + EXPECT_THAT(lseek(out_fd.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(kPageSize)); - ASSERT_THAT(lseek(outf.get(), 0, SEEK_SET), SyscallSucceedsWithValue(0)); + ASSERT_THAT(lseek(out_fd.get(), 0, SEEK_SET), SyscallSucceedsWithValue(0)); // Contents should be equal. std::vector<char> rbuf(kPageSize); - ASSERT_THAT(read(outf.get(), rbuf.data(), rbuf.size()), + ASSERT_THAT(read(out_fd.get(), rbuf.data(), rbuf.size()), SyscallSucceedsWithValue(kPageSize)); EXPECT_EQ(memcmp(rbuf.data(), buf.data(), buf.size()), 0); } @@ -321,18 +322,19 @@ TEST(SpliceTest, FromPipeOffset) { // Open the input file. const TempPath out_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - const FileDescriptor outf = + const FileDescriptor out_fd = ASSERT_NO_ERRNO_AND_VALUE(Open(out_file.path(), O_RDWR)); // Splice to the output file. loff_t out_offset = kPageSize / 2; - EXPECT_THAT(splice(rfd.get(), nullptr, outf.get(), &out_offset, kPageSize, 0), - SyscallSucceedsWithValue(kPageSize)); + EXPECT_THAT( + splice(rfd.get(), nullptr, out_fd.get(), &out_offset, kPageSize, 0), + SyscallSucceedsWithValue(kPageSize)); // Content should reflect the splice. We write to a specific offset in the // file, so the internals should now be allocated sparsely. std::vector<char> rbuf(kPageSize); - ASSERT_THAT(read(outf.get(), rbuf.data(), rbuf.size()), + ASSERT_THAT(read(out_fd.get(), rbuf.data(), rbuf.size()), SyscallSucceedsWithValue(kPageSize)); std::vector<char> zbuf(kPageSize / 2); memset(zbuf.data(), 0, zbuf.size()); @@ -404,8 +406,6 @@ TEST(SpliceTest, Blocking) { } TEST(TeeTest, Blocking) { - SKIP_IF(IsRunningOnGvisor()); - // Create two new pipes. int first[2], second[2]; ASSERT_THAT(pipe(first), SyscallSucceeds()); @@ -440,6 +440,49 @@ TEST(TeeTest, Blocking) { EXPECT_EQ(memcmp(rbuf.data(), buf.data(), kPageSize), 0); } +TEST(TeeTest, BlockingWrite) { + // Create two new pipes. + int first[2], second[2]; + ASSERT_THAT(pipe(first), SyscallSucceeds()); + const FileDescriptor rfd1(first[0]); + const FileDescriptor wfd1(first[1]); + ASSERT_THAT(pipe(second), SyscallSucceeds()); + const FileDescriptor rfd2(second[0]); + const FileDescriptor wfd2(second[1]); + + // Make some data available to be read. + std::vector<char> buf1(kPageSize); + RandomizeBuffer(buf1.data(), buf1.size()); + ASSERT_THAT(write(wfd1.get(), buf1.data(), buf1.size()), + SyscallSucceedsWithValue(kPageSize)); + + // Fill up the write pipe's buffer. + int pipe_size = -1; + ASSERT_THAT(pipe_size = fcntl(wfd2.get(), F_GETPIPE_SZ), SyscallSucceeds()); + std::vector<char> buf2(pipe_size); + ASSERT_THAT(write(wfd2.get(), buf2.data(), buf2.size()), + SyscallSucceedsWithValue(pipe_size)); + + ScopedThread t([&]() { + absl::SleepFor(absl::Milliseconds(100)); + ASSERT_THAT(read(rfd2.get(), buf2.data(), buf2.size()), + SyscallSucceedsWithValue(pipe_size)); + }); + + // Attempt a tee immediately; it should block. + EXPECT_THAT(tee(rfd1.get(), wfd2.get(), kPageSize, 0), + SyscallSucceedsWithValue(kPageSize)); + + // Thread should be joinable. + t.Join(); + + // Content should reflect the tee. + std::vector<char> rbuf(kPageSize); + ASSERT_THAT(read(rfd2.get(), rbuf.data(), rbuf.size()), + SyscallSucceedsWithValue(kPageSize)); + EXPECT_EQ(memcmp(rbuf.data(), buf1.data(), kPageSize), 0); +} + TEST(SpliceTest, NonBlocking) { // Create two new pipes. int first[2], second[2]; @@ -457,8 +500,6 @@ TEST(SpliceTest, NonBlocking) { } TEST(TeeTest, NonBlocking) { - SKIP_IF(IsRunningOnGvisor()); - // Create two new pipes. int first[2], second[2]; ASSERT_THAT(pipe(first), SyscallSucceeds()); @@ -473,6 +514,79 @@ TEST(TeeTest, NonBlocking) { SyscallFailsWithErrno(EAGAIN)); } +TEST(TeeTest, MultiPage) { + // Create two new pipes. + int first[2], second[2]; + ASSERT_THAT(pipe(first), SyscallSucceeds()); + const FileDescriptor rfd1(first[0]); + const FileDescriptor wfd1(first[1]); + ASSERT_THAT(pipe(second), SyscallSucceeds()); + const FileDescriptor rfd2(second[0]); + const FileDescriptor wfd2(second[1]); + + // Make some data available to be read. + std::vector<char> wbuf(8 * kPageSize); + RandomizeBuffer(wbuf.data(), wbuf.size()); + ASSERT_THAT(write(wfd1.get(), wbuf.data(), wbuf.size()), + SyscallSucceedsWithValue(wbuf.size())); + + // Attempt a tee immediately; it should complete. + EXPECT_THAT(tee(rfd1.get(), wfd2.get(), wbuf.size(), 0), + SyscallSucceedsWithValue(wbuf.size())); + + // Content should reflect the tee. + std::vector<char> rbuf(wbuf.size()); + ASSERT_THAT(read(rfd2.get(), rbuf.data(), rbuf.size()), + SyscallSucceedsWithValue(rbuf.size())); + EXPECT_EQ(memcmp(rbuf.data(), wbuf.data(), rbuf.size()), 0); + ASSERT_THAT(read(rfd1.get(), rbuf.data(), rbuf.size()), + SyscallSucceedsWithValue(rbuf.size())); + EXPECT_EQ(memcmp(rbuf.data(), wbuf.data(), rbuf.size()), 0); +} + +TEST(SpliceTest, FromPipeMaxFileSize) { + // Create a new pipe. + int fds[2]; + ASSERT_THAT(pipe(fds), SyscallSucceeds()); + const FileDescriptor rfd(fds[0]); + const FileDescriptor wfd(fds[1]); + + // Fill with some random data. + std::vector<char> buf(kPageSize); + RandomizeBuffer(buf.data(), buf.size()); + ASSERT_THAT(write(wfd.get(), buf.data(), buf.size()), + SyscallSucceedsWithValue(kPageSize)); + + // Open the input file. + const TempPath out_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + const FileDescriptor out_fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(out_file.path(), O_RDWR)); + + EXPECT_THAT(ftruncate(out_fd.get(), 13 << 20), SyscallSucceeds()); + EXPECT_THAT(lseek(out_fd.get(), 0, SEEK_END), + SyscallSucceedsWithValue(13 << 20)); + + // Set our file size limit. + sigset_t set; + sigemptyset(&set); + sigaddset(&set, SIGXFSZ); + TEST_PCHECK(sigprocmask(SIG_BLOCK, &set, nullptr) == 0); + rlimit rlim = {}; + rlim.rlim_cur = rlim.rlim_max = (13 << 20); + EXPECT_THAT(setrlimit(RLIMIT_FSIZE, &rlim), SyscallSucceeds()); + + // Splice to the output file. + EXPECT_THAT( + splice(rfd.get(), nullptr, out_fd.get(), nullptr, 3 * kPageSize, 0), + SyscallFailsWithErrno(EFBIG)); + + // Contents should be equal. + std::vector<char> rbuf(kPageSize); + ASSERT_THAT(read(rfd.get(), rbuf.data(), rbuf.size()), + SyscallSucceedsWithValue(kPageSize)); + EXPECT_EQ(memcmp(rbuf.data(), buf.data(), buf.size()), 0); +} + } // namespace } // namespace testing |