diff options
Diffstat (limited to 'pkg/sentry/usermem/bytes_io.go')
-rw-r--r-- | pkg/sentry/usermem/bytes_io.go | 141 |
1 files changed, 0 insertions, 141 deletions
diff --git a/pkg/sentry/usermem/bytes_io.go b/pkg/sentry/usermem/bytes_io.go deleted file mode 100644 index 7898851b3..000000000 --- a/pkg/sentry/usermem/bytes_io.go +++ /dev/null @@ -1,141 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package usermem - -import ( - "gvisor.dev/gvisor/pkg/sentry/context" - "gvisor.dev/gvisor/pkg/sentry/safemem" - "gvisor.dev/gvisor/pkg/syserror" -) - -const maxInt = int(^uint(0) >> 1) - -// BytesIO implements IO using a byte slice. Addresses are interpreted as -// offsets into the slice. Reads and writes beyond the end of the slice return -// EFAULT. -type BytesIO struct { - Bytes []byte -} - -// CopyOut implements IO.CopyOut. -func (b *BytesIO) CopyOut(ctx context.Context, addr Addr, src []byte, opts IOOpts) (int, error) { - rngN, rngErr := b.rangeCheck(addr, len(src)) - if rngN == 0 { - return 0, rngErr - } - return copy(b.Bytes[int(addr):], src[:rngN]), rngErr -} - -// CopyIn implements IO.CopyIn. -func (b *BytesIO) CopyIn(ctx context.Context, addr Addr, dst []byte, opts IOOpts) (int, error) { - rngN, rngErr := b.rangeCheck(addr, len(dst)) - if rngN == 0 { - return 0, rngErr - } - return copy(dst[:rngN], b.Bytes[int(addr):]), rngErr -} - -// ZeroOut implements IO.ZeroOut. -func (b *BytesIO) ZeroOut(ctx context.Context, addr Addr, toZero int64, opts IOOpts) (int64, error) { - if toZero > int64(maxInt) { - return 0, syserror.EINVAL - } - rngN, rngErr := b.rangeCheck(addr, int(toZero)) - if rngN == 0 { - return 0, rngErr - } - zeroSlice := b.Bytes[int(addr) : int(addr)+rngN] - for i := range zeroSlice { - zeroSlice[i] = 0 - } - return int64(rngN), rngErr -} - -// CopyOutFrom implements IO.CopyOutFrom. -func (b *BytesIO) CopyOutFrom(ctx context.Context, ars AddrRangeSeq, src safemem.Reader, opts IOOpts) (int64, error) { - dsts, rngErr := b.blocksFromAddrRanges(ars) - n, err := src.ReadToBlocks(dsts) - if err != nil { - return int64(n), err - } - return int64(n), rngErr -} - -// CopyInTo implements IO.CopyInTo. -func (b *BytesIO) CopyInTo(ctx context.Context, ars AddrRangeSeq, dst safemem.Writer, opts IOOpts) (int64, error) { - srcs, rngErr := b.blocksFromAddrRanges(ars) - n, err := dst.WriteFromBlocks(srcs) - if err != nil { - return int64(n), err - } - return int64(n), rngErr -} - -func (b *BytesIO) rangeCheck(addr Addr, length int) (int, error) { - if length == 0 { - return 0, nil - } - if length < 0 { - return 0, syserror.EINVAL - } - max := Addr(len(b.Bytes)) - if addr >= max { - return 0, syserror.EFAULT - } - end, ok := addr.AddLength(uint64(length)) - if !ok || end > max { - return int(max - addr), syserror.EFAULT - } - return length, nil -} - -func (b *BytesIO) blocksFromAddrRanges(ars AddrRangeSeq) (safemem.BlockSeq, error) { - switch ars.NumRanges() { - case 0: - return safemem.BlockSeq{}, nil - case 1: - block, err := b.blockFromAddrRange(ars.Head()) - return safemem.BlockSeqOf(block), err - default: - blocks := make([]safemem.Block, 0, ars.NumRanges()) - for !ars.IsEmpty() { - block, err := b.blockFromAddrRange(ars.Head()) - if block.Len() != 0 { - blocks = append(blocks, block) - } - if err != nil { - return safemem.BlockSeqFromSlice(blocks), err - } - ars = ars.Tail() - } - return safemem.BlockSeqFromSlice(blocks), nil - } -} - -func (b *BytesIO) blockFromAddrRange(ar AddrRange) (safemem.Block, error) { - n, err := b.rangeCheck(ar.Start, int(ar.Length())) - if n == 0 { - return safemem.Block{}, err - } - return safemem.BlockFromSafeSlice(b.Bytes[int(ar.Start) : int(ar.Start)+n]), err -} - -// BytesIOSequence returns an IOSequence representing the given byte slice. -func BytesIOSequence(buf []byte) IOSequence { - return IOSequence{ - IO: &BytesIO{buf}, - Addrs: AddrRangeSeqOf(AddrRange{0, Addr(len(buf))}), - } -} |