add ability to load rulesets from directory

This commit is contained in:
Kevin Pham
2023-11-14 15:42:26 -06:00
parent 6bff28e18d
commit e87d19d7f5
5 changed files with 474 additions and 75 deletions

274
pkg/ruleset/ruleset.go Normal file
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package ruleset
import (
"errors"
"fmt"
"io"
"log"
"net/http"
"os"
"path/filepath"
"regexp"
"strings"
"compress/gzip"
"gopkg.in/yaml.v3"
)
type Regex struct {
Match string `yaml:"match"`
Replace string `yaml:"replace"`
}
type RuleSet []Rule
type Rule struct {
Domain string `yaml:"domain,omitempty"`
Domains []string `yaml:"domains,omitempty"`
Paths []string `yaml:"paths,omitempty"`
Headers struct {
UserAgent string `yaml:"user-agent,omitempty"`
XForwardedFor string `yaml:"x-forwarded-for,omitempty"`
Referer string `yaml:"referer,omitempty"`
Cookie string `yaml:"cookie,omitempty"`
CSP string `yaml:"content-security-policy,omitempty"`
} `yaml:"headers,omitempty"`
GoogleCache bool `yaml:"googleCache,omitempty"`
RegexRules []Regex `yaml:"regexRules"`
Injections []struct {
Position string `yaml:"position"`
Append string `yaml:"append"`
Prepend string `yaml:"prepend"`
Replace string `yaml:"replace"`
} `yaml:"injections"`
}
// NewRulesetFromEnv creates a new RuleSet based on the RULESET environment variable.
// It logs a warning and returns an empty RuleSet if the RULESET environment variable is not set.
// If the RULESET is set but the rules cannot be loaded, it panics.
func NewRulesetFromEnv() RuleSet {
rulesPath, ok := os.LookupEnv("RULESET")
if !ok {
log.Printf("WARN: No ruleset specified. Set the `RULESET` environment variable to load one for a better success rate.")
return RuleSet{}
}
ruleSet, err := NewRuleset(rulesPath)
if err != nil {
log.Panicln(ruleSet)
}
return ruleSet
}
// NewRuleset loads a RuleSet from a given string of rule paths, separated by semicolons.
// It supports loading rules from both local file paths and remote URLs.
// Returns a RuleSet and an error if any issues occur during loading.
func NewRuleset(rulePaths string) (RuleSet, error) {
ruleSet := RuleSet{}
errs := []error{}
rp := strings.Split(rulePaths, ";")
for _, rule := range rp {
rulePath := strings.Trim(rule, " ")
var err error
isRemote, _ := regexp.MatchString(`^https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()!@:%_\+.~#?&\/\/=]*)`, rulePath)
if isRemote {
err = ruleSet.loadRulesFromRemoteFile(rulePath)
} else {
err = ruleSet.loadRulesFromLocalDir(rulePath)
}
if err != nil {
e := errors.New(fmt.Sprintf("WARN: failed to load ruleset from ''%s", rulePath))
errs = append(errs, errors.Join(e, err))
continue
}
}
if len(errs) != 0 {
e := errors.New(fmt.Sprintf("WARN: failed to load %d rulesets", len(rp)))
errs = append(errs, e)
// panic if the user specified a local ruleset, but it wasn't found on disk
// don't fail silently
for _, err := range errs {
if errors.Is(os.ErrNotExist, err) {
e := fmt.Errorf("PANIC: ruleset '%s' not found", err)
panic(errors.Join(e, err))
}
}
// else, bubble up any errors, such as syntax or remote host issues
return ruleSet, errors.Join(errs...)
}
ruleSet.PrintStats()
return ruleSet, nil
}
// ================== RULESET loading logic ===================================
// loadRulesFromLocalDir loads rules from a local directory specified by the path.
// It walks through the directory, loading rules from YAML files.
// Returns an error if the directory cannot be accessed
// If there is an issue loading any file, it will be skipped
func (rs *RuleSet) loadRulesFromLocalDir(path string) error {
_, err := os.Stat(path)
if err != nil {
return err
}
yamlRegex := regexp.MustCompile(`.*\.ya?ml`)
err = filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if info.IsDir() {
return nil
}
if isYaml := yamlRegex.MatchString(path); !isYaml {
return nil
}
err = rs.loadRulesFromLocalFile(path)
if err != nil {
log.Printf("WARN: failed to load directory ruleset '%s': %s, skipping", path, err)
return nil
}
log.Printf("INFO: loaded ruleset %s\n", path)
return nil
})
if err != nil {
return err
}
return nil
}
// loadRulesFromLocalFile loads rules from a local YAML file specified by the path.
// Returns an error if the file cannot be read or if there's a syntax error in the YAML.
func (rs *RuleSet) loadRulesFromLocalFile(path string) error {
yamlFile, err := os.ReadFile(path)
if err != nil {
e := errors.New(fmt.Sprintf("failed to read rules from local file: '%s'", path))
return errors.Join(e, err)
}
var r RuleSet
err = yaml.Unmarshal(yamlFile, &r)
if err != nil {
e := errors.New(fmt.Sprintf("failed to load rules from local file, possible syntax error in '%s'", path))
ee := errors.Join(e, err)
if _, ok := os.LookupEnv("DEBUG"); ok {
debugPrintRule(string(yamlFile), ee)
}
return ee
}
*rs = append(*rs, r...)
return nil
}
// loadRulesFromRemoteFile loads rules from a remote URL.
// It supports plain and gzip compressed content.
// Returns an error if there's an issue accessing the URL or if there's a syntax error in the YAML.
func (rs *RuleSet) loadRulesFromRemoteFile(rulesUrl string) error {
var r RuleSet
resp, err := http.Get(rulesUrl)
if err != nil {
e := errors.New(fmt.Sprintf("failed to load rules from remote url '%s'", rulesUrl))
return errors.Join(e, err)
}
defer resp.Body.Close()
if resp.StatusCode >= 400 {
e := errors.New(fmt.Sprintf("failed to load rules from remote url (%s) on '%s'", resp.Status, rulesUrl))
return errors.Join(e, err)
}
var reader io.Reader
isGzip := strings.HasSuffix(rulesUrl, ".gz") || strings.HasSuffix(rulesUrl, ".gzip") || resp.Header.Get("content-encoding") == "gzip"
if isGzip {
reader, err = gzip.NewReader(resp.Body)
if err != nil {
return fmt.Errorf("failed to create gzip reader for URL '%s' with status code '%s': %w", rulesUrl, resp.Status, err)
}
} else {
reader = resp.Body
}
err = yaml.NewDecoder(reader).Decode(&r)
if err != nil {
e := errors.New(fmt.Sprintf("failed to load rules from remote url '%s' with status code '%s' and possible syntax error", rulesUrl, resp.Status))
ee := errors.Join(e, err)
return ee
}
*rs = append(*rs, r...)
return nil
}
// ================= utility methods ==========================
// Yaml returns the ruleset as a Yaml string
func (rs *RuleSet) Yaml() (string, error) {
y, err := yaml.Marshal(rs)
if err != nil {
return "", err
}
return string(y), nil
}
// GzipYaml returns an io.Reader that streams the Gzip-compressed YAML representation of the RuleSet.
func (rs *RuleSet) GzipYaml() (io.Reader, error) {
pr, pw := io.Pipe()
go func() {
defer pw.Close()
gw := gzip.NewWriter(pw)
defer gw.Close()
if err := yaml.NewEncoder(gw).Encode(rs); err != nil {
gw.Close() // Ensure to close the gzip writer
pw.CloseWithError(err)
return
}
}()
return pr, nil
}
// Domains extracts and returns a slice of all domains present in the RuleSet.
func (rs *RuleSet) Domains() []string {
var domains []string
for _, rule := range *rs {
domains = append(domains, rule.Domain)
domains = append(domains, rule.Domains...)
}
return domains
}
// DomainCount returns the count of unique domains present in the RuleSet.
func (rs *RuleSet) DomainCount() int {
return len(rs.Domains())
}
// Count returns the total number of rules in the RuleSet.
func (rs *RuleSet) Count() int {
return len(*rs)
}
// PrintStats logs the number of rules and domains loaded in the RuleSet.
func (rs *RuleSet) PrintStats() {
log.Printf("INFO: Loaded %d rules for %d domains\n", rs.Count(), rs.DomainCount())
}
// debugPrintRule is a utility function for printing a rule and associated error for debugging purposes.
func debugPrintRule(rule string, err error) {
fmt.Println("------------------------------ BEGIN DEBUG RULESET -----------------------------")
fmt.Printf("%s\n", err.Error())
fmt.Println("--------------------------------------------------------------------------------")
fmt.Println(rule)
fmt.Println("------------------------------ END DEBUG RULESET -------------------------------")
}

153
pkg/ruleset/ruleset_test.go Normal file
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package ruleset
import (
"os"
"path/filepath"
"testing"
"time"
"github.com/gofiber/fiber/v2"
"github.com/stretchr/testify/assert"
)
var (
validYAML = `
- domain: example.com
regexRules:
- match: "^http:"
replace: "https:"`
invalidYAML = `
- domain: [thisIsATestYamlThatIsMeantToFail.example]
regexRules:
- match: "^http:"
replace: "https:"
- match: "[incomplete"`
)
func TestLoadRulesFromRemoteFile(t *testing.T) {
app := fiber.New()
defer app.Shutdown()
app.Get("/valid-config.yml", func(c *fiber.Ctx) error {
c.SendString(validYAML)
return nil
})
app.Get("/invalid-config.yml", func(c *fiber.Ctx) error {
c.SendString(invalidYAML)
return nil
})
app.Get("/valid-config.gz", func(c *fiber.Ctx) error {
c.Set("Content-Type", "application/octet-stream")
rs, err := loadRuleFromString(validYAML)
if err != nil {
t.Errorf("failed to load valid yaml from string: %s", err.Error())
}
s, err := rs.GzipYaml()
if err != nil {
t.Errorf("failed to load gzip serialize yaml: %s", err.Error())
}
err = c.SendStream(s)
if err != nil {
t.Errorf("failed to stream gzip serialized yaml: %s", err.Error())
}
return nil
})
// Start the server in a goroutine
go func() {
if err := app.Listen("127.0.0.1:9999"); err != nil {
t.Errorf("Server failed to start: %s", err.Error())
}
}()
// Wait for the server to start
time.Sleep(time.Second * 1)
rs, err := NewRuleset("http://127.0.0.1:9999/valid-config.yml")
if err != nil {
t.Errorf("failed to load plaintext ruleset from http server: %s", err.Error())
}
assert.Equal(t, rs[0].Domain, "example.com")
rs, err = NewRuleset("http://127.0.0.1:9999/valid-config.gz")
if err != nil {
t.Errorf("failed to load gzipped ruleset from http server: %s", err.Error())
}
assert.Equal(t, rs[0].Domain, "example.com")
os.Setenv("RULESET", "http://127.0.0.1:9999/valid-config.gz")
rs = NewRulesetFromEnv()
if !assert.Equal(t, rs[0].Domain, "example.com") {
t.Error("expected no errors loading ruleset from gzip url using environment variable, but got one")
}
}
func loadRuleFromString(yaml string) (RuleSet, error) {
// Create a temporary file and load it
tmpFile, _ := os.CreateTemp("", "ruleset*.yaml")
defer os.Remove(tmpFile.Name())
tmpFile.WriteString(yaml)
rs := RuleSet{}
err := rs.loadRulesFromLocalFile(tmpFile.Name())
return rs, err
}
// TestLoadRulesFromLocalFile tests the loading of rules from a local YAML file.
func TestLoadRulesFromLocalFile(t *testing.T) {
rs, err := loadRuleFromString(validYAML)
if err != nil {
t.Errorf("Failed to load rules from valid YAML: %s", err)
}
assert.Equal(t, rs[0].Domain, "example.com")
assert.Equal(t, rs[0].RegexRules[0].Match, "^http:")
assert.Equal(t, rs[0].RegexRules[0].Replace, "https:")
_, err = loadRuleFromString(invalidYAML)
if err == nil {
t.Errorf("Expected an error when loading invalid YAML, but got none")
}
}
// TestLoadRulesFromLocalDir tests the loading of rules from a local nested directory full of yaml rulesets
func TestLoadRulesFromLocalDir(t *testing.T) {
// Create a temporary directory
baseDir, err := os.MkdirTemp("", "ruleset_test")
if err != nil {
t.Fatalf("Failed to create temporary directory: %s", err)
}
defer os.RemoveAll(baseDir)
// Create a nested subdirectory
nestedDir := filepath.Join(baseDir, "nested")
err = os.Mkdir(nestedDir, 0755)
if err != nil {
t.Fatalf("Failed to create nested directory: %s", err)
}
// Create a nested subdirectory
nestedTwiceDir := filepath.Join(nestedDir, "nestedTwice")
err = os.Mkdir(nestedTwiceDir, 0755)
testCases := []string{"test.yaml", "test2.yaml", "test-3.yaml", "test 4.yaml", "1987.test.yaml.yml", "foobar.example.com.yaml", "foobar.com.yml"}
for _, fileName := range testCases {
filePath := filepath.Join(nestedDir, "2x-"+fileName)
os.WriteFile(filePath, []byte(validYAML), 0644)
filePath = filepath.Join(nestedDir, fileName)
os.WriteFile(filePath, []byte(validYAML), 0644)
filePath = filepath.Join(baseDir, "base-"+fileName)
os.WriteFile(filePath, []byte(validYAML), 0644)
}
rs := RuleSet{}
err = rs.loadRulesFromLocalDir(baseDir)
assert.NoError(t, err)
assert.Equal(t, rs.Count(), len(testCases)*3)
for _, rule := range rs {
assert.Equal(t, rule.Domain, "example.com")
assert.Equal(t, rule.RegexRules[0].Match, "^http:")
assert.Equal(t, rule.RegexRules[0].Replace, "https:")
}
}