crowdsec/pkg/cwhub/loader.go
2022-04-11 16:13:20 +02:00

424 lines
12 KiB
Go

package cwhub
import (
"encoding/json"
//"errors"
"fmt"
"io/ioutil"
"sort"
"github.com/pkg/errors"
"golang.org/x/mod/semver"
//"log"
"os"
"path/filepath"
"strings"
"github.com/crowdsecurity/crowdsec/pkg/csconfig"
log "github.com/sirupsen/logrus"
)
/*the walk/parser_visit function can't receive extra args*/
var hubdir, installdir string
func parser_visit(path string, f os.FileInfo, err error) error {
var target Item
var local bool
var hubpath string
var inhub bool
var fname string
var ftype string
var fauthor string
var stage string
path, err = filepath.Abs(path)
if err != nil {
return err
}
//we only care about files
if f == nil || f.IsDir() {
return nil
}
//we only care about yaml files
if !strings.HasSuffix(f.Name(), ".yaml") && !strings.HasSuffix(f.Name(), ".yml") {
return nil
}
subs := strings.Split(path, "/")
log.Tracef("path:%s, hubdir:%s, installdir:%s", path, hubdir, installdir)
/*we're in hub (~/.hub/hub/)*/
if strings.HasPrefix(path, hubdir) {
log.Tracef("in hub dir")
inhub = true
//.../hub/parsers/s00-raw/crowdsec/skip-pretag.yaml
//.../hub/scenarios/crowdsec/ssh_bf.yaml
//.../hub/profiles/crowdsec/linux.yaml
if len(subs) < 4 {
log.Fatalf("path is too short : %s (%d)", path, len(subs))
}
fname = subs[len(subs)-1]
fauthor = subs[len(subs)-2]
stage = subs[len(subs)-3]
ftype = subs[len(subs)-4]
} else if strings.HasPrefix(path, installdir) { /*we're in install /etc/crowdsec/<type>/... */
log.Tracef("in install dir")
if len(subs) < 3 {
log.Fatalf("path is too short : %s (%d)", path, len(subs))
}
///.../config/parser/stage/file.yaml
///.../config/postoverflow/stage/file.yaml
///.../config/scenarios/scenar.yaml
///.../config/collections/linux.yaml //file is empty
fname = subs[len(subs)-1]
stage = subs[len(subs)-2]
ftype = subs[len(subs)-3]
fauthor = ""
} else {
return fmt.Errorf("File '%s' is not from hub '%s' nor from the configuration directory '%s'", path, hubdir, installdir)
}
log.Tracef("stage:%s ftype:%s", stage, ftype)
//log.Printf("%s -> name:%s stage:%s", path, fname, stage)
if stage == SCENARIOS {
ftype = SCENARIOS
stage = ""
} else if stage == COLLECTIONS {
ftype = COLLECTIONS
stage = ""
} else if ftype != PARSERS && ftype != PARSERS_OVFLW /*its a PARSER / PARSER_OVFLW with a stage */ {
return fmt.Errorf("unknown configuration type for file '%s'", path)
}
log.Tracef("CORRECTED [%s] by [%s] in stage [%s] of type [%s]", fname, fauthor, stage, ftype)
/*
we can encounter 'collections' in the form of a symlink :
/etc/crowdsec/.../collections/linux.yaml -> ~/.hub/hub/collections/.../linux.yaml
when the collection is installed, both files are created
*/
//non symlinks are local user files or hub files
if f.Mode()&os.ModeSymlink == 0 {
local = true
log.Tracef("%s isn't a symlink", path)
} else {
hubpath, err = os.Readlink(path)
if err != nil {
return fmt.Errorf("unable to read symlink of %s", path)
}
//the symlink target doesn't exist, user might have removed ~/.hub/hub/...yaml without deleting /etc/crowdsec/....yaml
_, err := os.Lstat(hubpath)
if os.IsNotExist(err) {
log.Infof("%s is a symlink to %s that doesn't exist, deleting symlink", path, hubpath)
//remove the symlink
if err = os.Remove(path); err != nil {
return fmt.Errorf("failed to unlink %s: %+v", path, err)
}
return nil
}
log.Tracef("%s points to %s", path, hubpath)
}
//if it's not a symlink and not in hub, it's a local file, don't bother
if local && !inhub {
log.Tracef("%s is a local file, skip", path)
skippedLocal++
// log.Printf("local scenario, skip.")
target.Name = fname
target.Stage = stage
target.Installed = true
target.Type = ftype
target.Local = true
target.LocalPath = path
target.UpToDate = true
x := strings.Split(path, "/")
target.FileName = x[len(x)-1]
hubIdx[ftype][fname] = target
return nil
}
//try to find which configuration item it is
log.Tracef("check [%s] of %s", fname, ftype)
match := false
for k, v := range hubIdx[ftype] {
log.Tracef("check [%s] vs [%s] : %s", fname, v.RemotePath, ftype+"/"+stage+"/"+fname+".yaml")
if fname != v.FileName {
log.Tracef("%s != %s (filename)", fname, v.FileName)
continue
}
//wrong stage
if v.Stage != stage {
continue
}
/*if we are walking hub dir, just mark present files as downloaded*/
if inhub {
//wrong author
if fauthor != v.Author {
continue
}
//wrong file
if v.Name+".yaml" != fauthor+"/"+fname && v.Name+".yml" != fauthor+"/"+fname {
continue
}
if path == hubdir+"/"+v.RemotePath {
log.Tracef("marking %s as downloaded", v.Name)
v.Downloaded = true
}
} else {
//wrong file
//<type>/<stage>/<author>/<name>.yaml
if !strings.HasSuffix(hubpath, v.RemotePath) {
//log.Printf("wrong file %s %s", hubpath, spew.Sdump(v))
continue
}
}
sha, err := getSHA256(path)
if err != nil {
log.Fatalf("Failed to get sha of %s : %v", path, err)
}
//let's reverse sort the versions to deal with hash collisions (#154)
versions := make([]string, 0, len(v.Versions))
for k := range v.Versions {
versions = append(versions, k)
}
sort.Sort(sort.Reverse(sort.StringSlice(versions)))
for _, version := range versions {
val := v.Versions[version]
if sha != val.Digest {
//log.Printf("matching filenames, wrong hash %s != %s -- %s", sha, val.Digest, spew.Sdump(v))
continue
}
/*we got an exact match, update struct*/
if !inhub {
log.Tracef("found exact match for %s, version is %s, latest is %s", v.Name, version, v.Version)
v.LocalPath = path
v.LocalVersion = version
v.Tainted = false
v.Downloaded = true
/*if we're walking the hub, present file doesn't means installed file*/
v.Installed = true
v.LocalHash = sha
x := strings.Split(path, "/")
target.FileName = x[len(x)-1]
}
if version == v.Version {
log.Tracef("%s is up-to-date", v.Name)
v.UpToDate = true
}
match = true
break
}
if !match {
log.Tracef("got tainted match for %s : %s", v.Name, path)
skippedTainted += 1
//the file and the stage is right, but the hash is wrong, it has been tainted by user
if !inhub {
v.LocalPath = path
v.Installed = true
}
v.UpToDate = false
v.LocalVersion = "?"
v.Tainted = true
v.LocalHash = sha
x := strings.Split(path, "/")
target.FileName = x[len(x)-1]
}
//update the entry if appropriate
if _, ok := hubIdx[ftype][k]; !ok {
hubIdx[ftype][k] = v
} else if !inhub {
hubIdx[ftype][k] = v
}
return nil
}
log.Infof("Ignoring file %s of type %s", path, ftype)
return nil
}
func CollecDepsCheck(v *Item) error {
if GetVersionStatus(v) != 0 { //not up-to-date
log.Debugf("%s dependencies not checked : not up-to-date", v.Name)
return nil
}
/*if it's a collection, ensure all the items are installed, or tag it as tainted*/
if v.Type == COLLECTIONS {
log.Tracef("checking submembers of %s installed:%t", v.Name, v.Installed)
var tmp = [][]string{v.Parsers, v.PostOverflows, v.Scenarios, v.Collections}
for idx, ptr := range tmp {
ptrtype := ItemTypes[idx]
for _, p := range ptr {
val, ok := hubIdx[ptrtype][p]
if !ok {
log.Fatalf("Referred %s %s in collection %s doesn't exist.", ptrtype, p, v.Name)
}
log.Tracef("check %s installed:%t", val.Name, val.Installed)
if !v.Installed {
continue
}
if val.Type == COLLECTIONS {
log.Tracef("collec, recurse.")
if err := CollecDepsCheck(&val); err != nil {
return fmt.Errorf("sub collection %s is broken : %s", val.Name, err)
}
hubIdx[ptrtype][p] = val
}
//propagate the state of sub-items to set
if val.Tainted {
v.Tainted = true
return fmt.Errorf("tainted %s %s, tainted.", ptrtype, p)
}
if !val.Installed && v.Installed {
v.Tainted = true
return fmt.Errorf("missing %s %s, tainted.", ptrtype, p)
}
if !val.UpToDate {
v.UpToDate = false
return fmt.Errorf("outdated %s %s", ptrtype, p)
}
skip := false
for idx := range val.BelongsToCollections {
if val.BelongsToCollections[idx] == v.Name {
skip = true
}
}
if !skip {
val.BelongsToCollections = append(val.BelongsToCollections, v.Name)
}
hubIdx[ptrtype][p] = val
log.Tracef("checking for %s - tainted:%t uptodate:%t", p, v.Tainted, v.UpToDate)
}
}
}
return nil
}
func SyncDir(hub *csconfig.Hub, dir string) (error, []string) {
hubdir = hub.HubDir
installdir = hub.ConfigDir
warnings := []string{}
/*For each, scan PARSERS, PARSERS_OVFLW, SCENARIOS and COLLECTIONS last*/
for _, scan := range ItemTypes {
cpath, err := filepath.Abs(fmt.Sprintf("%s/%s", dir, scan))
if err != nil {
log.Errorf("failed %s : %s", cpath, err)
}
err = filepath.Walk(cpath, parser_visit)
if err != nil {
return err, warnings
}
}
for k, v := range hubIdx[COLLECTIONS] {
if v.Installed {
versStat := GetVersionStatus(&v)
if versStat == 0 { //latest
if err := CollecDepsCheck(&v); err != nil {
warnings = append(warnings, fmt.Sprintf("dependency of %s : %s", v.Name, err))
hubIdx[COLLECTIONS][k] = v
}
} else if versStat == 1 { //not up-to-date
warnings = append(warnings, fmt.Sprintf("update for collection %s available (currently:%s, latest:%s)", v.Name, v.LocalVersion, v.Version))
} else { //version is higher than the highest available from hub?
warnings = append(warnings, fmt.Sprintf("collection %s is in the future (currently:%s, latest:%s)", v.Name, v.LocalVersion, v.Version))
}
log.Debugf("installed (%s) - status:%d | installed:%s | latest : %s | full : %+v", v.Name, semver.Compare("v"+v.Version, "v"+v.LocalVersion), v.LocalVersion, v.Version, v.Versions)
}
}
return nil, warnings
}
/* Updates the infos from HubInit() with the local state */
func LocalSync(hub *csconfig.Hub) (error, []string) {
skippedLocal = 0
skippedTainted = 0
err, warnings := SyncDir(hub, hub.ConfigDir)
if err != nil {
return fmt.Errorf("failed to scan %s : %s", hub.ConfigDir, err), warnings
}
err, _ = SyncDir(hub, hub.HubDir)
if err != nil {
return fmt.Errorf("failed to scan %s : %s", hub.HubDir, err), warnings
}
return nil, warnings
}
func GetHubIdx(hub *csconfig.Hub) error {
if hub == nil {
return fmt.Errorf("no configuration found for hub")
}
log.Debugf("loading hub idx %s", hub.HubIndexFile)
bidx, err := ioutil.ReadFile(hub.HubIndexFile)
if err != nil {
return errors.Wrap(err, "unable to read index file")
}
ret, err := LoadPkgIndex(bidx)
if err != nil {
if !errors.Is(err, ReferenceMissingError) {
log.Fatalf("Unable to load existing index : %v.", err)
}
return err
}
hubIdx = ret
err, _ = LocalSync(hub)
if err != nil {
log.Fatalf("Failed to sync Hub index with local deployment : %v", err)
}
return nil
}
/*LoadPkgIndex loads a local .index.json file and returns the map of parsers/scenarios/collections associated*/
func LoadPkgIndex(buff []byte) (map[string]map[string]Item, error) {
var err error
var RawIndex map[string]map[string]Item
var missingItems []string
if err = json.Unmarshal(buff, &RawIndex); err != nil {
return nil, fmt.Errorf("failed to unmarshal index : %v", err)
}
log.Debugf("%d item types in hub index", len(ItemTypes))
/*Iterate over the different types to complete struct */
for _, itemType := range ItemTypes {
/*complete struct*/
log.Tracef("%d item", len(RawIndex[itemType]))
for idx, item := range RawIndex[itemType] {
item.Name = idx
item.Type = itemType
x := strings.Split(item.RemotePath, "/")
item.FileName = x[len(x)-1]
RawIndex[itemType][idx] = item
/*if it's a collection, check its sub-items are present*/
//XX should be done later
if itemType == COLLECTIONS {
var tmp = [][]string{item.Parsers, item.PostOverflows, item.Scenarios, item.Collections}
for idx, ptr := range tmp {
ptrtype := ItemTypes[idx]
for _, p := range ptr {
if _, ok := RawIndex[ptrtype][p]; !ok {
log.Errorf("Referred %s %s in collection %s doesn't exist.", ptrtype, p, item.Name)
missingItems = append(missingItems, p)
}
}
}
}
}
}
if len(missingItems) > 0 {
return RawIndex, fmt.Errorf("%q : %w", missingItems, ReferenceMissingError)
}
return RawIndex, nil
}