Merge pull request #936 from aymanbagabas/more-packpv5.10.1

Respect pktline error-line errors

1 files changed, 120 insertions, 0 deletions

diff --git a/plumbing/protocol/packp/gitproto.go b/plumbing/protocol/packp/gitproto.go
new file mode 100644
index 0000000..0b7ff8f
--- /dev/null
+++ b/plumbing/protocol/packp/gitproto.go
@@ -0,0 +1,120 @@
+package packp
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/go-git/go-git/v5/plumbing/format/pktline"
+)
+
+var (
+	// ErrInvalidGitProtoRequest is returned by Decode if the input is not a
+	// valid git protocol request.
+	ErrInvalidGitProtoRequest = fmt.Errorf("invalid git protocol request")
+)
+
+// GitProtoRequest is a command request for the git protocol.
+// It is used to send the command, endpoint, and extra parameters to the
+// remote.
+// See https://git-scm.com/docs/pack-protocol#_git_transport
+type GitProtoRequest struct {
+	RequestCommand string
+	Pathname       string
+
+	// Optional
+	Host string
+
+	// Optional
+	ExtraParams []string
+}
+
+// validate validates the request.
+func (g *GitProtoRequest) validate() error {
+	if g.RequestCommand == "" {
+		return fmt.Errorf("%w: empty request command", ErrInvalidGitProtoRequest)
+	}
+
+	if g.Pathname == "" {
+		return fmt.Errorf("%w: empty pathname", ErrInvalidGitProtoRequest)
+	}
+
+	return nil
+}
+
+// Encode encodes the request into the writer.
+func (g *GitProtoRequest) Encode(w io.Writer) error {
+	if w == nil {
+		return ErrNilWriter
+	}
+
+	if err := g.validate(); err != nil {
+		return err
+	}
+
+	p := pktline.NewEncoder(w)
+	req := fmt.Sprintf("%s %s\x00", g.RequestCommand, g.Pathname)
+	if host := g.Host; host != "" {
+		req += fmt.Sprintf("host=%s\x00", host)
+	}
+
+	if len(g.ExtraParams) > 0 {
+		req += "\x00"
+		for _, param := range g.ExtraParams {
+			req += param + "\x00"
+		}
+	}
+
+	if err := p.Encode([]byte(req)); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// Decode decodes the request from the reader.
+func (g *GitProtoRequest) Decode(r io.Reader) error {
+	s := pktline.NewScanner(r)
+	if !s.Scan() {
+		err := s.Err()
+		if err == nil {
+			return ErrInvalidGitProtoRequest
+		}
+		return err
+	}
+
+	line := string(s.Bytes())
+	if len(line) == 0 {
+		return io.EOF
+	}
+
+	if line[len(line)-1] != 0 {
+		return fmt.Errorf("%w: missing null terminator", ErrInvalidGitProtoRequest)
+	}
+
+	parts := strings.SplitN(line, " ", 2)
+	if len(parts) != 2 {
+		return fmt.Errorf("%w: short request", ErrInvalidGitProtoRequest)
+	}
+
+	g.RequestCommand = parts[0]
+	params := strings.Split(parts[1], string(null))
+	if len(params) < 1 {
+		return fmt.Errorf("%w: missing pathname", ErrInvalidGitProtoRequest)
+	}
+
+	g.Pathname = params[0]
+	if len(params) > 1 {
+		g.Host = strings.TrimPrefix(params[1], "host=")
+	}
+
+	if len(params) > 2 {
+		for _, param := range params[2:] {
+			if param != "" {
+				g.ExtraParams = append(g.ExtraParams, param)
+			}
+		}
+	}
+
+	return nil
+}