Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

transport: use uint32 to track chuck length #91

Merged
merged 1 commit into from
Jan 2, 2025
Merged

transport: use uint32 to track chuck length #91

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 17 additions & 10 deletions transport/frame.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ import (
"errors"
"fmt"
"io"
"math"
"os"
"path/filepath"
"time"
Expand Down Expand Up @@ -149,9 +150,12 @@ func (t *Framer) MsgWriter() (io.WriteCloser, error) {

var endOfChunks = []byte("\n##\n")

// Defined in https://www.rfc-editor.org/rfc/rfc6242#section-4.2
const maxChunk = math.MaxUint32

type chunkReader struct {
r *bufio.Reader
chunkLeft int
chunkLeft uint32
}

func (r *chunkReader) readHeader() error {
Expand Down Expand Up @@ -180,13 +184,13 @@ func (r *chunkReader) readHeader() error {
if _, err := r.r.Discard(2); err != nil {
return err
}
// not stricly needed but it is the responsibility of this function to
// not strictly needed but it is the responsibility of this function to
// update chunkLeft.
r.chunkLeft = 0
return io.EOF
}

var n int
var n uint32
for {
c, err := r.r.ReadByte()
if err != nil {
Expand All @@ -199,10 +203,9 @@ func (r *chunkReader) readHeader() error {
if c < '0' || c > '9' {
return ErrMalformedChunk
}
n = n*10 + int(c) - '0'
n = n*10 + uint32(c) - '0'
}

const maxChunk = 4294967295
if n < 1 || n > maxChunk {
return ErrMalformedChunk
}
Expand All @@ -215,20 +218,24 @@ func (r *chunkReader) Read(p []byte) (int, error) {
if r.r == nil {
return 0, ErrInvalidIO
}
// make sure we can't try to read more than the max chunk
p = p[:maxChunk]

// done with existing chunck so grab the next one
// done with existing chunk so grab the next one
if r.chunkLeft <= 0 {
if err := r.readHeader(); err != nil {
return 0, err
}
}

if len(p) > r.chunkLeft {
// XXX: This potential down conversion should be safe cause we resize p
// above. Hopefully no one is trying to read 4GB in one call.
if uint32(len(p)) > r.chunkLeft {
p = p[:r.chunkLeft]
}

n, err := r.r.Read(p)
r.chunkLeft -= n
r.chunkLeft -= uint32(n)
return n, err
}

Expand Down Expand Up @@ -274,11 +281,11 @@ func (r *chunkReader) Close() error {
}
}

n, err := r.r.Discard(r.chunkLeft)
n, err := r.r.Discard(int(r.chunkLeft))
if err != nil {
return err
}
r.chunkLeft -= n
r.chunkLeft -= uint32(n)
}
}

Expand Down
Loading