github.com/leonlxy/hyperledger@v1.0.0-alpha.0.20170427033203-34922035d248/core/chaincode/platforms/golang/platform.go

/*
Copyright IBM Corp. 2016 All Rights Reserved.

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 golang

import (
	"archive/tar"
	"bytes"
	"compress/gzip"
	"errors"
	"fmt"
	"net/url"
	"os"
	"path/filepath"
	"strings"

	"regexp"

	"github.com/hyperledger/fabric/core/chaincode/platforms/util"
	cutil "github.com/hyperledger/fabric/core/container/util"
	pb "github.com/hyperledger/fabric/protos/peer"
)

// Platform for chaincodes written in Go
type Platform struct {
}

// Returns whether the given file or directory exists or not
func pathExists(path string) (bool, error) {
	_, err := os.Stat(path)
	if err == nil {
		return true, nil
	}
	if os.IsNotExist(err) {
		return false, nil
	}
	return true, err
}

func decodeUrl(spec *pb.ChaincodeSpec) (string, error) {
	var urlLocation string
	if strings.HasPrefix(spec.ChaincodeId.Path, "http://") {
		urlLocation = spec.ChaincodeId.Path[7:]
	} else if strings.HasPrefix(spec.ChaincodeId.Path, "https://") {
		urlLocation = spec.ChaincodeId.Path[8:]
	} else {
		urlLocation = spec.ChaincodeId.Path
	}

	if len(urlLocation) < 2 {
		return "", errors.New("ChaincodeSpec's path/URL invalid")
	}

	if strings.LastIndex(urlLocation, "/") == len(urlLocation)-1 {
		urlLocation = urlLocation[:len(urlLocation)-1]
	}

	return urlLocation, nil
}

// ValidateSpec validates Go chaincodes
func (goPlatform *Platform) ValidateSpec(spec *pb.ChaincodeSpec) error {
	path, err := url.Parse(spec.ChaincodeId.Path)
	if err != nil || path == nil {
		return fmt.Errorf("invalid path: %s", err)
	}

	//we have no real good way of checking existence of remote urls except by downloading and testin
	//which we do later anyway. But we *can* - and *should* - test for existence of local paths.
	//Treat empty scheme as a local filesystem path
	if path.Scheme == "" {
		gopath := os.Getenv("GOPATH")
		// Only take the first element of GOPATH
		gopath = filepath.SplitList(gopath)[0]
		pathToCheck := filepath.Join(gopath, "src", spec.ChaincodeId.Path)
		exists, err := pathExists(pathToCheck)
		if err != nil {
			return fmt.Errorf("Error validating chaincode path: %s", err)
		}
		if !exists {
			return fmt.Errorf("Path to chaincode does not exist: %s", spec.ChaincodeId.Path)
		}
	}
	return nil
}

func (goPlatform *Platform) ValidateDeploymentSpec(cds *pb.ChaincodeDeploymentSpec) error {

	if cds.CodePackage == nil || len(cds.CodePackage) == 0 {
		// Nothing to validate if no CodePackage was included
		return nil
	}

	// FAB-2122: Scan the provided tarball to ensure it only contains source-code under
	// /src/$packagename.  We do not want to allow something like ./pkg/shady.a to be installed under
	// $GOPATH within the container.  Note, we do not look deeper than the path at this time
	// with the knowledge that only the go/cgo compiler will execute for now.  We will remove the source
	// from the system after the compilation as an extra layer of protection.
	//
	// It should be noted that we cannot catch every threat with these techniques.  Therefore,
	// the container itself needs to be the last line of defense and be configured to be
	// resilient in enforcing constraints. However, we should still do our best to keep as much
	// garbage out of the system as possible.
	re := regexp.MustCompile(`(/)?src/.*`)
	is := bytes.NewReader(cds.CodePackage)
	gr, err := gzip.NewReader(is)
	if err != nil {
		return fmt.Errorf("failure opening codepackage gzip stream: %s", err)
	}
	tr := tar.NewReader(gr)

	for {
		header, err := tr.Next()
		if err != nil {
			// We only get here if there are no more entries to scan
			break
		}

		// --------------------------------------------------------------------------------------
		// Check name for conforming path
		// --------------------------------------------------------------------------------------
		if !re.MatchString(header.Name) {
			return fmt.Errorf("Illegal file detected in payload: \"%s\"", header.Name)
		}

		// --------------------------------------------------------------------------------------
		// Check that file mode makes sense
		// --------------------------------------------------------------------------------------
		// Acceptable flags:
		//      ISREG      == 0100000
		//      -rw-rw-rw- == 0666
		//
		// Anything else is suspect in this context and will be rejected
		// --------------------------------------------------------------------------------------
		if header.Mode&^0100666 != 0 {
			return fmt.Errorf("Illegal file mode detected for file %s: %o", header.Name, header.Mode)
		}
	}

	return nil
}

// WritePackage writes the Go chaincode package
func (goPlatform *Platform) GetDeploymentPayload(spec *pb.ChaincodeSpec) ([]byte, error) {

	var err error

	inputbuf := bytes.NewBuffer(nil)
	gw := gzip.NewWriter(inputbuf)
	tw := tar.NewWriter(gw)

	//ignore the generated hash. Just use the tw
	//The hash could be used in a future enhancement
	//to check, warn of duplicate installs etc.
	_, err = collectChaincodeFiles(spec, tw)
	if err != nil {
		return nil, err
	}

	err = writeChaincodePackage(spec, tw)

	tw.Close()
	gw.Close()

	if err != nil {
		return nil, err
	}

	payload := inputbuf.Bytes()

	return payload, nil
}

func (goPlatform *Platform) GenerateDockerfile(cds *pb.ChaincodeDeploymentSpec) (string, error) {

	var buf []string

	buf = append(buf, "FROM "+cutil.GetDockerfileFromConfig("chaincode.golang.runtime"))
	buf = append(buf, "ADD binpackage.tar /usr/local/bin")

	dockerFileContents := strings.Join(buf, "\n")

	return dockerFileContents, nil
}

func (goPlatform *Platform) GenerateDockerBuild(cds *pb.ChaincodeDeploymentSpec, tw *tar.Writer) error {
	spec := cds.ChaincodeSpec

	pkgname, err := decodeUrl(spec)
	if err != nil {
		return fmt.Errorf("could not decode url: %s", err)
	}

	const ldflags = "-linkmode external -extldflags '-static'"

	codepackage := bytes.NewReader(cds.CodePackage)
	binpackage := bytes.NewBuffer(nil)
	err = util.DockerBuild(util.DockerBuildOptions{
		Cmd:          fmt.Sprintf("GOPATH=/chaincode/input:$GOPATH go build -ldflags \"%s\" -o /chaincode/output/chaincode %s", ldflags, pkgname),
		InputStream:  codepackage,
		OutputStream: binpackage,
	})
	if err != nil {
		return err
	}

	return cutil.WriteBytesToPackage("binpackage.tar", binpackage.Bytes(), tw)
}