97 lines
2.7 KiB
Go
97 lines
2.7 KiB
Go
package ipallowlist
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import (
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"context"
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"errors"
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"fmt"
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"net/http"
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"github.com/rs/zerolog/log"
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"github.com/traefik/traefik/v3/pkg/config/dynamic"
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"github.com/traefik/traefik/v3/pkg/ip"
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"github.com/traefik/traefik/v3/pkg/middlewares"
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"github.com/traefik/traefik/v3/pkg/middlewares/observability"
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"go.opentelemetry.io/otel/trace"
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)
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const (
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typeName = "IPAllowLister"
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)
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// ipAllowLister is a middleware that provides Checks of the Requesting IP against a set of Allowlists.
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type ipAllowLister struct {
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next http.Handler
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allowLister *ip.Checker
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strategy ip.Strategy
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name string
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rejectStatusCode int
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}
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// New builds a new IPAllowLister given a list of CIDR-Strings to allow.
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func New(ctx context.Context, next http.Handler, config dynamic.IPAllowList, name string) (http.Handler, error) {
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logger := middlewares.GetLogger(ctx, name, typeName)
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logger.Debug().Msg("Creating middleware")
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if len(config.SourceRange) == 0 {
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return nil, errors.New("sourceRange is empty, IPAllowLister not created")
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}
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rejectStatusCode := config.RejectStatusCode
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// If RejectStatusCode is not given, default to Forbidden (403).
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if rejectStatusCode == 0 {
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rejectStatusCode = http.StatusForbidden
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} else if http.StatusText(rejectStatusCode) == "" {
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return nil, fmt.Errorf("invalid HTTP status code %d", rejectStatusCode)
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}
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checker, err := ip.NewChecker(config.SourceRange)
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if err != nil {
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return nil, fmt.Errorf("cannot parse CIDRs %s: %w", config.SourceRange, err)
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}
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strategy, err := config.IPStrategy.Get()
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if err != nil {
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return nil, err
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}
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logger.Debug().Msgf("Setting up IPAllowLister with sourceRange: %s", config.SourceRange)
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return &ipAllowLister{
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strategy: strategy,
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allowLister: checker,
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next: next,
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name: name,
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rejectStatusCode: rejectStatusCode,
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}, nil
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}
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func (al *ipAllowLister) GetTracingInformation() (string, string, trace.SpanKind) {
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return al.name, typeName, trace.SpanKindInternal
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}
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func (al *ipAllowLister) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
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logger := middlewares.GetLogger(req.Context(), al.name, typeName)
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ctx := logger.WithContext(req.Context())
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clientIP := al.strategy.GetIP(req)
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err := al.allowLister.IsAuthorized(clientIP)
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if err != nil {
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msg := fmt.Sprintf("Rejecting IP %s: %v", clientIP, err)
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logger.Debug().Msg(msg)
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observability.SetStatusErrorf(req.Context(), msg)
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reject(ctx, al.rejectStatusCode, rw)
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return
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}
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logger.Debug().Msgf("Accepting IP %s", clientIP)
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al.next.ServeHTTP(rw, req)
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}
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func reject(ctx context.Context, statusCode int, rw http.ResponseWriter) {
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rw.WriteHeader(statusCode)
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_, err := rw.Write([]byte(http.StatusText(statusCode)))
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if err != nil {
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log.Ctx(ctx).Error().Err(err).Send()
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}
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}
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