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allow distro search to be entirely data driven (#2265)
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Signed-off-by: Alex Goodman <[email protected]>
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@wagoodman
wagoodman authored Nov 21, 2024
1 parent 2dd1024 commit df54421
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Showing 4 changed files with 633 additions and 26 deletions.
252 changes: 231 additions & 21 deletions grype/db/v6/affected_package_store.go
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,9 @@ package v6

import (
"encoding/json"
"errors"
"fmt"
"regexp"

"gorm.io/gorm"

Expand All @@ -11,6 +13,9 @@ import (

var NoDistroSpecified = &DistroSpecifier{}
var AnyDistroSpecified *DistroSpecifier
var ErrMissingDistroIdentification = errors.New("missing distro name or codename")
var ErrDistroNotPresent = errors.New("distro not present")
var ErrMultipleOSMatches = errors.New("multiple OS matches found but not allowed")

type GetAffectedPackageOptions struct {
PreloadOS bool
Expand All @@ -20,11 +25,64 @@ type GetAffectedPackageOptions struct {
Distro *DistroSpecifier
}

// DistroSpecifier is a struct that represents a distro in a way that can be used to query the affected package store.
type DistroSpecifier struct {
Name string
// Name of the distro as identified by the ID field in /etc/os-release
Name string

// MajorVersion is the first field in the VERSION_ID field in /etc/os-release (e.g. 7 in "7.0.1406")
MajorVersion string

// MinorVersion is the second field in the VERSION_ID field in /etc/os-release (e.g. 0 in "7.0.1406")
MinorVersion string
Codename string

// LabelVersion is mutually exclusive to MajorVersion and MinorVersion and tends to represent the
// VERSION_ID when it is not a version number (e.g. "edge" or "unstable")
LabelVersion string

// Codename is the CODENAME field in /etc/os-release (e.g. "wheezy" for debian 7)
Codename string

// AllowMultiple specifies whether we intend to allow for multiple distro identities to be matched.
AllowMultiple bool
}

func (d DistroSpecifier) version() string {
if d.MajorVersion != "" && d.MinorVersion != "" {
return d.MajorVersion + "." + d.MinorVersion
}

if d.MajorVersion != "" {
return d.MajorVersion
}

if d.LabelVersion != "" {
return d.LabelVersion
}

if d.Codename != "" {
return d.Codename
}

return ""
}

func (d DistroSpecifier) matchesVersionPattern(pattern string) bool {
// check if version or version label matches the given regex
r, err := regexp.Compile(pattern)
if err != nil {
log.Tracef("failed to compile distro specifier regex pattern %q: %v", pattern, err)
return false
}

if r.MatchString(d.version()) {
return true
}

if d.LabelVersion != "" {
return r.MatchString(d.LabelVersion)
}
return false
}

type AffectedPackageStoreWriter interface {
Expand Down Expand Up @@ -90,7 +148,7 @@ func (s *affectedPackageStore) getNonDistroPackageByName(packageName string, con
query = query.Where("operating_system_id IS NULL")
}

query = s.handlePacakge(query, packageName, config)
query = s.handlePackage(query, packageName, config)
query = s.handlePreload(query, config)

err := query.Find(&pkgs).Error
Expand All @@ -112,15 +170,31 @@ func (s *affectedPackageStore) getNonDistroPackageByName(packageName string, con
}

func (s *affectedPackageStore) getPackageByNameAndDistro(packageName string, config GetAffectedPackageOptions) ([]AffectedPackageHandle, error) {
var resolvedDistros []OperatingSystem
var err error
if config.Distro != NoDistroSpecified || config.Distro != AnyDistroSpecified {
resolvedDistros, err = s.resolveDistro(*config.Distro)
if err != nil {
return nil, fmt.Errorf("unable to resolve distro: %w", err)
}

switch {
case len(resolvedDistros) == 0:
return nil, ErrDistroNotPresent
case len(resolvedDistros) > 1 && !config.Distro.AllowMultiple:
return nil, ErrMultipleOSMatches
}
}

var pkgs []AffectedPackageHandle
query := s.db.Joins("JOIN packages ON affected_package_handles.package_id = packages.id").
Joins("JOIN operating_systems ON affected_package_handles.operating_system_id = operating_systems.id")

query = s.handlePacakge(query, packageName, config)
query = s.handleDistro(query, config.Distro)
query = s.handlePackage(query, packageName, config)
query = s.handleDistros(query, resolvedDistros)
query = s.handlePreload(query, config)

err := query.Find(&pkgs).Error
err = query.Find(&pkgs).Error
if err != nil {
return nil, fmt.Errorf("unable to fetch affected package record: %w", err)
}
Expand All @@ -137,34 +211,170 @@ func (s *affectedPackageStore) getPackageByNameAndDistro(packageName string, con
return pkgs, nil
}

func (s *affectedPackageStore) handlePacakge(query *gorm.DB, packageName string, config GetAffectedPackageOptions) *gorm.DB {
query = query.Where("packages.name = ?", packageName)

if config.PackageType != "" {
query = query.Where("packages.type = ?", config.PackageType)
func (s *affectedPackageStore) resolveDistro(d DistroSpecifier) ([]OperatingSystem, error) {
if d.Name == "" && d.Codename == "" {
return nil, ErrMissingDistroIdentification
}
return query
}

func (s *affectedPackageStore) handleDistro(query *gorm.DB, d *DistroSpecifier) *gorm.DB {
if d == AnyDistroSpecified {
return query
// search for aliases for the given distro; we intentionally map some OSs to other OSs in terms of
// vulnerability (e.g. `centos` is an alias for `rhel`). If an alias is found always use that alias in
// searches (there will never be anything in the DB for aliased distros).
if err := s.applyAlias(&d); err != nil {
return nil, err
}

query := s.db.Model(&OperatingSystem{})

if d.Name != "" {
query = query.Where("operating_systems.name = ?", d.Name)
query = query.Where("name = ?", d.Name)
}

if d.Codename != "" {
query = query.Where("operating_systems.codename = ?", d.Codename)
query = query.Where("codename = ?", d.Codename)
}

if d.LabelVersion != "" {
query = query.Where("label_version = ?", d.LabelVersion)
}

return s.searchForDistroVersionVariants(query, d)
}

func (s *affectedPackageStore) searchForDistroVersionVariants(query *gorm.DB, d DistroSpecifier) ([]OperatingSystem, error) {
var allOs []OperatingSystem

handleQuery := func(q *gorm.DB, desc string) ([]OperatingSystem, error) {
err := q.Find(&allOs).Error
if err == nil {
return allOs, nil
}
if !errors.Is(err, gorm.ErrRecordNotFound) {
return nil, fmt.Errorf("failed to query distro by %s: %w", desc, err)
}
return nil, nil
}

if d.MajorVersion == "" && d.MinorVersion == "" {
return handleQuery(query, "name and codename only")
}

// search by the most specific criteria first, then fallback

var result []OperatingSystem
var err error
if d.MajorVersion != "" {
query = query.Where("operating_systems.major_version = ?", d.MajorVersion)
if d.MinorVersion != "" {
// non-empty major and minor versions
specificQuery := query.Session(&gorm.Session{}).Where("major_version = ? AND minor_version = ?", d.MajorVersion, d.MinorVersion)
result, err = handleQuery(specificQuery, "major and minor versions")
if err != nil || len(result) > 0 {
return result, err
}
}

// fallback to major version only, requiring the minor version to be blank. Note: it is important that we don't
// match on any record with the given major version, we must only match on records that are intentionally empty
// minor version. For instance, the DB may have rhel 8.1, 8.2, 8.3, 8.4, etc. We don't want to arbitrarily match
// on one of these or match even the latest version, as even that may yield incorrect vulnerability matching
// results. We are only intending to allow matches for when the vulnerability data is only specified at the major version level.
majorExclusiveQuery := query.Session(&gorm.Session{}).Where("major_version = ? AND minor_version = ?", d.MajorVersion, "")
result, err = handleQuery(majorExclusiveQuery, "exclusively major version")
if err != nil || len(result) > 0 {
return result, err
}

// fallback to major version for any minor version
majorQuery := query.Session(&gorm.Session{}).Where("major_version = ?", d.MajorVersion)
result, err = handleQuery(majorQuery, "major version with any minor version")
if err != nil || len(result) > 0 {
return result, err
}
}

return allOs, nil
}

func (s *affectedPackageStore) applyAlias(d *DistroSpecifier) error {
if d.Name == "" {
return nil
}

var aliases []OperatingSystemAlias
err := s.db.Where("name = ?", d.Name).Find(&aliases).Error
if err != nil {
if !errors.Is(err, gorm.ErrRecordNotFound) {
return fmt.Errorf("failed to resolve alias for distro %q: %w", d.Name, err)
}
return nil
}

var alias *OperatingSystemAlias

for _, a := range aliases {
if a.Codename != "" && a.Codename != d.Codename {
continue
}

if a.Version != "" && a.Version != d.version() {
continue
}

if a.VersionPattern != "" && !d.matchesVersionPattern(a.VersionPattern) {
continue
}

alias = &a
break
}

if d.MinorVersion != "" {
query = query.Where("operating_systems.minor_version = ?", d.MinorVersion)
if alias == nil {
return nil
}

if alias.ReplacementName != nil {
d.Name = *alias.ReplacementName
}

if alias.Rolling {
d.MajorVersion = ""
d.MinorVersion = ""
}

if alias.ReplacementMajorVersion != nil {
d.MajorVersion = *alias.ReplacementMajorVersion
}

if alias.ReplacementMinorVersion != nil {
d.MinorVersion = *alias.ReplacementMinorVersion
}

if alias.ReplacementLabelVersion != nil {
d.LabelVersion = *alias.ReplacementLabelVersion
}

return nil
}

func (s *affectedPackageStore) handlePackage(query *gorm.DB, packageName string, config GetAffectedPackageOptions) *gorm.DB {
query = query.Where("packages.name = ?", packageName)

if config.PackageType != "" {
query = query.Where("packages.type = ?", config.PackageType)
}
return query
}

func (s *affectedPackageStore) handleDistros(query *gorm.DB, resolvedDistros []OperatingSystem) *gorm.DB {
var count int
for _, o := range resolvedDistros {
if o.ID != 0 {
if count == 0 {
query = query.Where("operating_systems.id = ?", o.ID)
} else {
query = query.Or("operating_systems.id = ?", o.ID)
}
count++
}
}
return query
}
Expand Down
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