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allow to include/exclude decisions per web ACL based on origin/scenario #94

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161 changes: 114 additions & 47 deletions cmd/root.go
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Original file line number Diff line number Diff line change
Expand Up @@ -61,41 +61,16 @@
return nil
}

func processDecisions(decisions *models.DecisionsStreamResponse, supportedActions []string) waf.Decisions {
d := waf.Decisions{
V4Add: make(map[string][]*string),
V6Add: make(map[string][]*string),
V4Del: make(map[string][]*string),
V6Del: make(map[string][]*string),
CountriesAdd: make(map[string][]wafv2types.CountryCode),
CountriesDel: make(map[string][]wafv2types.CountryCode),
}
func processDecisions(decisions *models.DecisionsStreamResponse, supportedActions []string) []cfg.ProcessedDecision {
processed := make([]cfg.ProcessedDecision, 0)

for _, decision := range decisions.New {
decisionType := strings.ToLower(*decision.Type)
if !slices.Contains(supportedActions, decisionType) {
decisionType = "fallback"
}

if strings.ToLower(*decision.Scope) == "ip" || strings.ToLower(*decision.Scope) == "range" {
if strings.Contains(*decision.Value, ":") {
if !strings.Contains(*decision.Value, "/") {
d.V6Add[decisionType] = append(d.V6Add[decisionType], aws.String(fmt.Sprintf("%s/128", *decision.Value)))
} else {
d.V6Add[decisionType] = append(d.V6Add[decisionType], decision.Value)
}
} else {
if !strings.Contains(*decision.Value, "/") {
d.V4Add[decisionType] = append(d.V4Add[decisionType], aws.String(fmt.Sprintf("%s/32", *decision.Value)))
} else {
d.V4Add[decisionType] = append(d.V4Add[decisionType], decision.Value)
}
}
} else if strings.ToLower(*decision.Scope) == "country" {
d.CountriesAdd[decisionType] = append(d.CountriesAdd[decisionType], wafv2types.CountryCode(*decision.Value))
} else {
log.Errorf("unsupported scope: %s", *decision.Scope)
}
processed = append(processed, buildProcessedDecision(decision, decisionType, "add")...)
}

for _, decision := range decisions.Deleted {
Expand All @@ -104,31 +79,117 @@
decisionType = "fallback"
}

if strings.ToLower(*decision.Scope) == "ip" || strings.ToLower(*decision.Scope) == "range" {
if strings.Contains(*decision.Value, ":") {
if !strings.Contains(*decision.Value, "/") {
d.V6Del[decisionType] = append(d.V6Del[decisionType], aws.String(fmt.Sprintf("%s/128", *decision.Value)))
} else {
d.V6Del[decisionType] = append(d.V6Del[decisionType], decision.Value)
}
} else {
if !strings.Contains(*decision.Value, "/") {
d.V4Del[decisionType] = append(d.V4Del[decisionType], aws.String(fmt.Sprintf("%s/32", *decision.Value)))
} else {
d.V4Del[decisionType] = append(d.V4Del[decisionType], decision.Value)
}
processed = append(processed, buildProcessedDecision(decision, decisionType, "del")...)
}

return processed
}

func buildProcessedDecision(decision *models.Decision, decisionType string, op string) []cfg.ProcessedDecision {
if decision == nil || decision.Scope == nil || decision.Value == nil {
return nil
}

scope := strings.ToLower(*decision.Scope)
value := *decision.Value
origin := ""
scenario := ""

if decision.Origin != nil {
origin = *decision.Origin
}

if decision.Scenario != nil {
scenario = *decision.Scenario
}

switch scope {
case "ip", "range":
if strings.Contains(value, ":") {
if !strings.Contains(value, "/") {
value = fmt.Sprintf("%s/128", value)
}
} else if strings.ToLower(*decision.Scope) == "country" {
d.CountriesDel[decisionType] = append(d.CountriesDel[decisionType], wafv2types.CountryCode(*decision.Value))
} else {
log.Errorf("unsupported scope: %s", *decision.Scope)

return []cfg.ProcessedDecision{{
Action: decisionType,
Target: "v6",
Value: value,
Op: op,
Origin: origin,
Scenario: scenario,
}}
}

if !strings.Contains(value, "/") {
value = fmt.Sprintf("%s/32", value)
}

return []cfg.ProcessedDecision{{
Action: decisionType,
Target: "v4",
Value: value,
Op: op,
Origin: origin,
Scenario: scenario,
}}
case "country":
return []cfg.ProcessedDecision{{
Action: decisionType,
Target: "country",
Value: value,
Op: op,
Origin: origin,
Scenario: scenario,
}}
default:
log.Errorf("unsupported scope: %s", scope)
}

return nil
}

func aggregateDecisions(processed []cfg.ProcessedDecision) waf.Decisions {
d := waf.Decisions{
V4Add: make(map[string][]*string),
V6Add: make(map[string][]*string),
V4Del: make(map[string][]*string),
V6Del: make(map[string][]*string),
CountriesAdd: make(map[string][]wafv2types.CountryCode),
CountriesDel: make(map[string][]wafv2types.CountryCode),
}

for _, p := range processed {
switch p.Target {
case "v4":
switch p.Op {
case "add":
d.V4Add[p.Action] = append(d.V4Add[p.Action], aws.String(p.Value))
case "del":
d.V4Del[p.Action] = append(d.V4Del[p.Action], aws.String(p.Value))
}
case "v6":
switch p.Op {
case "add":
d.V6Add[p.Action] = append(d.V6Add[p.Action], aws.String(p.Value))
case "del":
d.V6Del[p.Action] = append(d.V6Del[p.Action], aws.String(p.Value))
}
case "country":
switch p.Op {
case "add":
d.CountriesAdd[p.Action] = append(d.CountriesAdd[p.Action], wafv2types.CountryCode(p.Value))
case "del":
d.CountriesDel[p.Action] = append(d.CountriesDel[p.Action], wafv2types.CountryCode(p.Value))
}
default:
log.Errorf("unsupported target: %s", p.Target)
}
}

return d
}

func Execute() error {

Check failure on line 192 in cmd/root.go

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GitHub Actions / golangci-lint + codeql 

function-length: maximum number of lines per function exceeded; max 153 but got 159 (revive)
configPath := flag.String("c", "", "path to crowdsec-aws-waf-bouncer.yaml")
bouncerVersion := flag.Bool("version", false, "display version and exit")
traceMode := flag.Bool("trace", false, "set trace mode")
Expand Down Expand Up @@ -265,9 +326,15 @@
continue
}

d := processDecisions(decisions, config.SupportedActions)
processed := processDecisions(decisions, config.SupportedActions)

for _, w := range wafInstances {
w.DecisionsChan <- d
filteredDecisions := w.GetDecisionsFilter().Apply(processed)
if len(filteredDecisions) == 0 {
continue
}

w.DecisionsChan <- aggregateDecisions(filteredDecisions)
}
}
}
Expand Down
114 changes: 101 additions & 13 deletions pkg/cfg/config.go
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Original file line number Diff line number Diff line change
Expand Up @@ -30,27 +30,107 @@
SupportedActions []string `yaml:"supported_actions"`
}

type DecisionsFilter struct {
IncludeOrigins []string `yaml:"include_origins"`
ExcludeOrigins []string `yaml:"exclude_origins"`
IncludeScenarios []string `yaml:"include_scenarios"`
ExcludeScenarios []string `yaml:"exclude_scenarios"`
}

type ProcessedDecision struct {
Action string
Target string // v4, v6, country
Value string
Op string // add or del
Origin string
Scenario string
}

func (d DecisionsFilter) isEmpty() bool {
return len(d.IncludeOrigins) == 0 &&
len(d.ExcludeOrigins) == 0 &&
len(d.IncludeScenarios) == 0 &&
len(d.ExcludeScenarios) == 0
}

func matchValue(value *string, include []string, exclude []string) bool {
if value == nil {
return false
}

for _, excluded := range exclude {
if strings.EqualFold(excluded, *value) {
return false
}
}

if len(include) == 0 {
return true
}

for _, allowed := range include {
if strings.EqualFold(allowed, *value) {
return true
}
}

return false
}

func (d DecisionsFilter) allow(decision ProcessedDecision) bool {
if d.isEmpty() {
return true
}

if !matchValue(&decision.Origin, d.IncludeOrigins, d.ExcludeOrigins) {
return false
}

if !matchValue(&decision.Scenario, d.IncludeScenarios, d.ExcludeScenarios) {
return false
}

return true
}

func (d DecisionsFilter) Apply(decisions []ProcessedDecision) []ProcessedDecision {
if d.isEmpty() {
return decisions
}

filtered := make([]ProcessedDecision, 0, len(decisions))

for _, decision := range decisions {
if d.allow(decision) {
filtered = append(filtered, decision)
}
}

return filtered
}

type AclConfig struct {
WebACLName string `yaml:"web_acl_name"`
RuleGroupName string `yaml:"rule_group_name"`
Region string `yaml:"region"`
Scope string `yaml:"scope"`
IpsetPrefix string `yaml:"ipset_prefix"`
FallbackAction string `yaml:"fallback_action"`
AWSProfile string `yaml:"aws_profile"`
IPHeader string `yaml:"ip_header"`
IPHeaderPosition string `yaml:"ip_header_position"`
Capacity int `yaml:"capacity"`
CloudWatchEnabled bool `yaml:"cloudwatch_enabled"`
CloudWatchMetricName string `yaml:"cloudwatch_metric_name"`
SampleRequests bool `yaml:"sample_requests"`
WebACLName string `yaml:"web_acl_name"`
RuleGroupName string `yaml:"rule_group_name"`
Region string `yaml:"region"`
Scope string `yaml:"scope"`
IpsetPrefix string `yaml:"ipset_prefix"`
FallbackAction string `yaml:"fallback_action"`
AWSProfile string `yaml:"aws_profile"`
IPHeader string `yaml:"ip_header"`
IPHeaderPosition string `yaml:"ip_header_position"`
Capacity int `yaml:"capacity"`
CloudWatchEnabled bool `yaml:"cloudwatch_enabled"`
CloudWatchMetricName string `yaml:"cloudwatch_metric_name"`
SampleRequests bool `yaml:"sample_requests"`
DecisionsFilter DecisionsFilter `yaml:"decisions_filter"`
}

var ValidActions = []string{"ban", "captcha", "count"}
var validScopes = []string{"REGIONAL", "CLOUDFRONT"}
var validIpHeaderPosition = []string{"FIRST", "LAST", "ANY"}

func getConfigFromEnv(config *bouncerConfig) {

Check failure on line 133 in pkg/cfg/config.go

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cyclomatic: function getConfigFromEnv has cyclomatic complexity 50 (> max enabled 46) (revive)
var (
key string
value string
Expand Down Expand Up @@ -124,6 +204,14 @@
log.Warnf("Invalid value for %s: %s, defaulting to false", key, value)
acl.SampleRequests = false
}
case "DECISIONS_FILTER_INCLUDE_ORIGINS":
acl.DecisionsFilter.IncludeOrigins = strings.Split(value, ",")
case "DECISIONS_FILTER_EXCLUDE_ORIGINS":
acl.DecisionsFilter.ExcludeOrigins = strings.Split(value, ",")
case "DECISIONS_FILTER_INCLUDE_SCENARIOS":
acl.DecisionsFilter.IncludeScenarios = strings.Split(value, ",")
case "DECISIONS_FILTER_EXCLUDE_SCENARIOS":
acl.DecisionsFilter.ExcludeScenarios = strings.Split(value, ",")
}
} else {
switch key {
Expand Down
8 changes: 8 additions & 0 deletions pkg/waf/waf.go
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Original file line number Diff line number Diff line change
Expand Up @@ -701,6 +701,14 @@ func (w *WAF) UpdateGeoSet(ctx context.Context, d Decisions) error {
return nil
}

func (w *WAF) GetDecisionsFilter() cfg.DecisionsFilter {
if w.config == nil {
return cfg.DecisionsFilter{}
}

return w.config.DecisionsFilter
}

func (w *WAF) Process(ctx context.Context) error {
for {
select {
Expand Down
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