clair/ext/featurefmt/dpkg/dpkg.go
2017-01-22 23:02:51 -05:00

122 lines
3.7 KiB
Go

// Copyright 2017 clair 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 dpkg implements a featurefmt.Lister for dpkg packages.
package dpkg
import (
"bufio"
"regexp"
"strings"
"github.com/coreos/pkg/capnslog"
"github.com/coreos/clair/database"
"github.com/coreos/clair/ext/featurefmt"
"github.com/coreos/clair/ext/versionfmt"
"github.com/coreos/clair/ext/versionfmt/dpkg"
"github.com/coreos/clair/pkg/tarutil"
)
var (
log = capnslog.NewPackageLogger("github.com/coreos/clair", "ext/featurefmt/dpkg")
dpkgSrcCaptureRegexp = regexp.MustCompile(`Source: (?P<name>[^\s]*)( \((?P<version>.*)\))?`)
dpkgSrcCaptureRegexpNames = dpkgSrcCaptureRegexp.SubexpNames()
)
type lister struct{}
func init() {
featurefmt.RegisterLister("dpkg", &lister{})
}
func (l lister) ListFeatures(files tarutil.FilesMap) ([]database.FeatureVersion, error) {
f, hasFile := files["var/lib/dpkg/status"]
if !hasFile {
return []database.FeatureVersion{}, nil
}
// Create a map to store packages and ensure their uniqueness
packagesMap := make(map[string]database.FeatureVersion)
var pkg database.FeatureVersion
var err error
scanner := bufio.NewScanner(strings.NewReader(string(f)))
for scanner.Scan() {
line := scanner.Text()
if strings.HasPrefix(line, "Package: ") {
// Package line
// Defines the name of the package
pkg.Feature.Name = strings.TrimSpace(strings.TrimPrefix(line, "Package: "))
pkg.Version = ""
} else if strings.HasPrefix(line, "Source: ") {
// Source line (Optionnal)
// Gives the name of the source package
// May also specifies a version
srcCapture := dpkgSrcCaptureRegexp.FindAllStringSubmatch(line, -1)[0]
md := map[string]string{}
for i, n := range srcCapture {
md[dpkgSrcCaptureRegexpNames[i]] = strings.TrimSpace(n)
}
pkg.Feature.Name = md["name"]
if md["version"] != "" {
version := md["version"]
err = versionfmt.Valid(dpkg.ParserName, version)
if err != nil {
log.Warningf("could not parse package version '%s': %s. skipping", string(line[1]), err.Error())
} else {
pkg.Version = version
}
}
} else if strings.HasPrefix(line, "Version: ") && pkg.Version == "" {
// Version line
// Defines the version of the package
// This version is less important than a version retrieved from a Source line
// because the Debian vulnerabilities often skips the epoch from the Version field
// which is not present in the Source version, and because +bX revisions don't matter
version := strings.TrimPrefix(line, "Version: ")
err = versionfmt.Valid(dpkg.ParserName, version)
if err != nil {
log.Warningf("could not parse package version '%s': %s. skipping", string(line[1]), err.Error())
} else {
pkg.Version = version
}
}
// Add the package to the result array if we have all the informations
if pkg.Feature.Name != "" && pkg.Version != "" {
packagesMap[pkg.Feature.Name+"#"+pkg.Version] = pkg
pkg.Feature.Name = ""
pkg.Version = ""
}
}
// Convert the map to a slice
packages := make([]database.FeatureVersion, 0, len(packagesMap))
for _, pkg := range packagesMap {
packages = append(packages, pkg)
}
return packages, nil
}
func (l lister) RequiredFilenames() []string {
return []string{"var/lib/dpkg/status"}
}