/
msgpipeline.go
646 lines (562 loc) · 18.4 KB
/
msgpipeline.go
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/*
Maddy Mail Server - Composable all-in-one email server.
Copyright © 2019-2020 Max Mazurov <fox.cpp@disroot.org>, Maddy Mail Server contributors
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package msgpipeline
import (
"context"
"github.com/emersion/go-message/textproto"
"github.com/emersion/go-smtp"
"github.com/foxcpp/maddy/framework/address"
"github.com/foxcpp/maddy/framework/buffer"
"github.com/foxcpp/maddy/framework/config"
"github.com/foxcpp/maddy/framework/dns"
"github.com/foxcpp/maddy/framework/exterrors"
"github.com/foxcpp/maddy/framework/log"
"github.com/foxcpp/maddy/framework/module"
"github.com/foxcpp/maddy/internal/modify"
"github.com/foxcpp/maddy/internal/target"
"golang.org/x/sync/errgroup"
)
// MsgPipeline is a object that is responsible for selecting delivery targets
// for the message and running necessary checks and modifiers.
//
// It implements module.DeliveryTarget.
//
// It is not a "module object" and is intended to be used as part of message
// source (Submission, SMTP, JMAP modules) implementation.
type MsgPipeline struct {
msgpipelineCfg
Hostname string
Resolver dns.Resolver
// Used to indicate the pipeline is handling messages received from the
// external source and not from any other module. That is, this MsgPipeline
// is an instance embedded in endpoint/smtp implementation, for example.
//
// This is a hack since only MsgPipeline can execute some operations at the
// right time but it is not a good idea to execute them multiple multiple
// times for a single message that might be actually handled my multiple
// pipelines via 'msgpipeline' module or 'reroute' directive.
//
// At the moment, the only such operation is the addition of the Received
// header field. See where it happens for explanation on why it is done
// exactly in this place.
FirstPipeline bool
Log log.Logger
}
type rcptIn struct {
t module.Table
block *rcptBlock
}
type sourceBlock struct {
checks []module.Check
modifiers modify.Group
rejectErr error
rcptIn []rcptIn
perRcpt map[string]*rcptBlock
defaultRcpt *rcptBlock
}
type rcptBlock struct {
checks []module.Check
modifiers modify.Group
rejectErr error
targets []module.DeliveryTarget
}
func New(globals map[string]interface{}, cfg []config.Node) (*MsgPipeline, error) {
parsedCfg, err := parseMsgPipelineRootCfg(globals, cfg)
return &MsgPipeline{
msgpipelineCfg: parsedCfg,
Resolver: dns.DefaultResolver(),
}, err
}
func (d *MsgPipeline) RunEarlyChecks(ctx context.Context, state *smtp.ConnectionState) error {
eg, checkCtx := errgroup.WithContext(ctx)
// TODO: See if there is some point in parallelization of this
// function.
for _, check := range d.globalChecks {
earlyCheck, ok := check.(module.EarlyCheck)
if !ok {
continue
}
eg.Go(func() error {
return earlyCheck.CheckConnection(checkCtx, state)
})
}
return eg.Wait()
}
// Start starts new message delivery, runs connection and sender checks, sender modifiers
// and selects source block from config to use for handling.
//
// Returned module.Delivery implements PartialDelivery. If underlying target doesn't
// support it, msgpipeline will copy the returned error for all recipients handled
// by target.
func (d *MsgPipeline) Start(ctx context.Context, msgMeta *module.MsgMetadata, mailFrom string) (module.Delivery, error) {
dd := msgpipelineDelivery{
d: d,
rcptModifiersState: make(map[*rcptBlock]module.ModifierState),
deliveries: make(map[module.DeliveryTarget]*delivery),
msgMeta: msgMeta,
log: target.DeliveryLogger(d.Log, msgMeta),
}
dd.checkRunner = newCheckRunner(msgMeta, dd.log, d.Resolver)
dd.checkRunner.doDMARC = d.doDMARC
if msgMeta.OriginalRcpts == nil {
msgMeta.OriginalRcpts = map[string]string{}
}
if err := dd.start(ctx, msgMeta, mailFrom); err != nil {
dd.close()
return nil, err
}
return &dd, nil
}
func (dd *msgpipelineDelivery) start(ctx context.Context, msgMeta *module.MsgMetadata, mailFrom string) error {
var err error
if err := dd.checkRunner.checkConnSender(ctx, dd.d.globalChecks, mailFrom); err != nil {
return err
}
if mailFrom, err = dd.initRunGlobalModifiers(ctx, msgMeta, mailFrom); err != nil {
return err
}
sourceBlock, err := dd.srcBlockForAddr(mailFrom)
if err != nil {
return err
}
if sourceBlock.rejectErr != nil {
dd.log.Debugf("sender %s rejected with error: %v", mailFrom, sourceBlock.rejectErr)
return sourceBlock.rejectErr
}
dd.sourceBlock = sourceBlock
if err := dd.checkRunner.checkConnSender(ctx, sourceBlock.checks, mailFrom); err != nil {
return err
}
sourceModifiersState, err := sourceBlock.modifiers.ModStateForMsg(ctx, msgMeta)
if err != nil {
return err
}
mailFrom, err = sourceModifiersState.RewriteSender(ctx, mailFrom)
if err != nil {
return err
}
dd.sourceModifiersState = sourceModifiersState
dd.sourceAddr = mailFrom
return nil
}
func (dd *msgpipelineDelivery) initRunGlobalModifiers(ctx context.Context, msgMeta *module.MsgMetadata, mailFrom string) (string, error) {
globalModifiersState, err := dd.d.globalModifiers.ModStateForMsg(ctx, msgMeta)
if err != nil {
return "", err
}
mailFrom, err = globalModifiersState.RewriteSender(ctx, mailFrom)
if err != nil {
globalModifiersState.Close()
return "", err
}
dd.globalModifiersState = globalModifiersState
return mailFrom, nil
}
func (dd *msgpipelineDelivery) srcBlockForAddr(mailFrom string) (sourceBlock, error) {
var cleanFrom = mailFrom
if mailFrom != "" {
var err error
cleanFrom, err = address.ForLookup(mailFrom)
if err != nil {
return sourceBlock{}, &exterrors.SMTPError{
Code: 501,
EnhancedCode: exterrors.EnhancedCode{5, 1, 7},
Message: "Unable to normalize the sender address",
Err: err,
}
}
}
for _, srcIn := range dd.d.sourceIn {
_, ok, err := srcIn.t.Lookup(cleanFrom)
if err != nil {
dd.log.Error("source_in lookup failed", err, "key", cleanFrom)
continue
}
if !ok {
continue
}
return srcIn.block, nil
}
// First try to match against complete address.
srcBlock, ok := dd.d.perSource[cleanFrom]
if !ok {
// Then try domain-only.
_, domain, err := address.Split(cleanFrom)
// mailFrom != "" is added as a special condition
// instead of extending address.Split because ""
// is not a valid RFC 282 address and only a special
// value for SMTP.
if err != nil && cleanFrom != "" {
return sourceBlock{}, &exterrors.SMTPError{
Code: 501,
EnhancedCode: exterrors.EnhancedCode{5, 1, 3},
Message: "Invalid sender address",
Err: err,
Reason: "Can't extract local-part and host-part",
}
}
// domain is already case-folded and normalized by the message source.
srcBlock, ok = dd.d.perSource[domain]
if !ok {
// Fallback to the default source block.
srcBlock = dd.d.defaultSource
dd.log.Debugf("sender %s matched by default rule", mailFrom)
} else {
dd.log.Debugf("sender %s matched by domain rule '%s'", mailFrom, domain)
}
} else {
dd.log.Debugf("sender %s matched by address rule '%s'", mailFrom, cleanFrom)
}
return srcBlock, nil
}
type delivery struct {
module.Delivery
// Recipient addresses this delivery object is used for, original values (not modified by RewriteRcpt).
recipients []string
}
type msgpipelineDelivery struct {
d *MsgPipeline
globalModifiersState module.ModifierState
sourceModifiersState module.ModifierState
rcptModifiersState map[*rcptBlock]module.ModifierState
log log.Logger
sourceAddr string
sourceBlock sourceBlock
deliveries map[module.DeliveryTarget]*delivery
msgMeta *module.MsgMetadata
checkRunner *checkRunner
}
func (dd *msgpipelineDelivery) AddRcpt(ctx context.Context, to string) error {
if err := dd.checkRunner.checkRcpt(ctx, dd.d.globalChecks, to); err != nil {
return err
}
if err := dd.checkRunner.checkRcpt(ctx, dd.sourceBlock.checks, to); err != nil {
return err
}
originalTo := to
newTo, err := dd.globalModifiersState.RewriteRcpt(ctx, to)
if err != nil {
return err
}
dd.log.Debugln("global rcpt modifiers:", to, "=>", newTo)
to = newTo
newTo, err = dd.sourceModifiersState.RewriteRcpt(ctx, to)
if err != nil {
return err
}
dd.log.Debugln("per-source rcpt modifiers:", to, "=>", newTo)
to = newTo
wrapErr := func(err error) error {
return exterrors.WithFields(err, map[string]interface{}{
"effective_rcpt": to,
})
}
rcptBlock, err := dd.rcptBlockForAddr(to)
if err != nil {
return wrapErr(err)
}
if rcptBlock.rejectErr != nil {
return wrapErr(rcptBlock.rejectErr)
}
if err := dd.checkRunner.checkRcpt(ctx, rcptBlock.checks, to); err != nil {
return wrapErr(err)
}
rcptModifiersState, err := dd.getRcptModifiers(ctx, rcptBlock, to)
if err != nil {
return wrapErr(err)
}
newTo, err = rcptModifiersState.RewriteRcpt(ctx, to)
if err != nil {
rcptModifiersState.Close()
return wrapErr(err)
}
dd.log.Debugln("per-rcpt modifiers:", to, "=>", newTo)
to = newTo
wrapErr = func(err error) error {
return exterrors.WithFields(err, map[string]interface{}{
"effective_rcpt": to,
})
}
if originalTo != to {
dd.msgMeta.OriginalRcpts[to] = originalTo
}
for _, tgt := range rcptBlock.targets {
// Do not wrap errors coming from nested pipeline target delivery since
// that pipeline itself will insert effective_rcpt field and could do
// its own rewriting - we do not want to hide it from the admin in
// error messages.
wrapErr := wrapErr
if _, ok := tgt.(*MsgPipeline); ok {
wrapErr = func(err error) error { return err }
}
delivery, err := dd.getDelivery(ctx, tgt)
if err != nil {
return wrapErr(err)
}
if err := delivery.AddRcpt(ctx, to); err != nil {
return wrapErr(err)
}
delivery.recipients = append(delivery.recipients, originalTo)
}
return nil
}
func (dd *msgpipelineDelivery) Body(ctx context.Context, header textproto.Header, body buffer.Buffer) error {
if err := dd.checkRunner.checkBody(ctx, dd.d.globalChecks, header, body); err != nil {
return err
}
if err := dd.checkRunner.checkBody(ctx, dd.sourceBlock.checks, header, body); err != nil {
return err
}
for blk := range dd.rcptModifiersState {
if err := dd.checkRunner.checkBody(ctx, blk.checks, header, body); err != nil {
return err
}
}
if dd.d.FirstPipeline {
// Add Received *after* checks to make sure they see the message literally
// how we received it BUT place it below any other field that might be
// added by applyResults (including Authentication-Results)
// per recommendation in RFC 7001, Section 4 (see GH issue #135).
received, err := target.GenerateReceived(ctx, dd.msgMeta, dd.d.Hostname, dd.msgMeta.OriginalFrom)
if err != nil {
return err
}
header.Add("Received", received)
}
if err := dd.checkRunner.applyResults(dd.d.Hostname, &header); err != nil {
return err
}
// Run modifiers after Authentication-Results addition to make
// sure signatures, etc will cover it.
if err := dd.globalModifiersState.RewriteBody(ctx, &header, body); err != nil {
return err
}
if err := dd.sourceModifiersState.RewriteBody(ctx, &header, body); err != nil {
return err
}
for _, modifiers := range dd.rcptModifiersState {
if err := modifiers.RewriteBody(ctx, &header, body); err != nil {
return err
}
}
for _, delivery := range dd.deliveries {
if err := delivery.Body(ctx, header, body); err != nil {
return err
}
dd.log.Debugf("delivery.Body ok, Delivery object = %T", delivery)
}
return nil
}
// statusCollector wraps StatusCollector and adds reverse translation
// of recipients for all statuses.]
//
// We can't let delivery targets set statuses directly because they see
// modified addresses (RewriteRcpt) and we are supposed to report
// statuses using original values. Additionally, we should still avoid
// collect-and-them-report approach since statuses should be reported
// as soon as possible (that is required by LMTP).
type statusCollector struct {
originalRcpts map[string]string
wrapped module.StatusCollector
}
func (sc statusCollector) SetStatus(rcptTo string, err error) {
original, ok := sc.originalRcpts[rcptTo]
if ok {
rcptTo = original
}
sc.wrapped.SetStatus(rcptTo, err)
}
func (dd *msgpipelineDelivery) BodyNonAtomic(ctx context.Context, c module.StatusCollector, header textproto.Header, body buffer.Buffer) {
setStatusAll := func(err error) {
for _, delivery := range dd.deliveries {
for _, rcpt := range delivery.recipients {
c.SetStatus(rcpt, err)
}
}
}
if err := dd.checkRunner.checkBody(ctx, dd.d.globalChecks, header, body); err != nil {
setStatusAll(err)
return
}
if err := dd.checkRunner.checkBody(ctx, dd.sourceBlock.checks, header, body); err != nil {
setStatusAll(err)
return
}
// Run modifiers after Authentication-Results addition to make
// sure signatures, etc will cover it.
if err := dd.globalModifiersState.RewriteBody(ctx, &header, body); err != nil {
setStatusAll(err)
return
}
if err := dd.sourceModifiersState.RewriteBody(ctx, &header, body); err != nil {
setStatusAll(err)
return
}
for _, modifiers := range dd.rcptModifiersState {
if err := modifiers.RewriteBody(ctx, &header, body); err != nil {
setStatusAll(err)
return
}
}
for _, delivery := range dd.deliveries {
partDelivery, ok := delivery.Delivery.(module.PartialDelivery)
if ok {
partDelivery.BodyNonAtomic(ctx, statusCollector{
originalRcpts: dd.msgMeta.OriginalRcpts,
wrapped: c,
}, header, body)
continue
}
if err := delivery.Body(ctx, header, body); err != nil {
for _, rcpt := range delivery.recipients {
c.SetStatus(rcpt, err)
}
}
}
}
func (dd msgpipelineDelivery) Commit(ctx context.Context) error {
dd.close()
for _, delivery := range dd.deliveries {
if err := delivery.Commit(ctx); err != nil {
// No point in Committing remaining deliveries, everything is broken already.
return err
}
}
return nil
}
func (dd *msgpipelineDelivery) close() {
dd.checkRunner.close()
if dd.globalModifiersState != nil {
dd.globalModifiersState.Close()
}
if dd.sourceModifiersState != nil {
dd.sourceModifiersState.Close()
}
for _, modifiers := range dd.rcptModifiersState {
modifiers.Close()
}
}
func (dd msgpipelineDelivery) Abort(ctx context.Context) error {
dd.close()
var lastErr error
for _, delivery := range dd.deliveries {
if err := delivery.Abort(ctx); err != nil {
dd.log.Debugf("delivery.Abort failure, Delivery object = %T: %v", delivery, err)
lastErr = err
// Continue anyway and try to Abort all remaining delivery objects.
}
}
return lastErr
}
func (dd *msgpipelineDelivery) rcptBlockForAddr(rcptTo string) (*rcptBlock, error) {
cleanRcpt, err := address.ForLookup(rcptTo)
if err != nil {
return nil, &exterrors.SMTPError{
Code: 553,
EnhancedCode: exterrors.EnhancedCode{5, 1, 2},
Message: "Unable to normalize the recipient address",
Err: err,
}
}
for _, rcptIn := range dd.sourceBlock.rcptIn {
_, ok, err := rcptIn.t.Lookup(cleanRcpt)
if err != nil {
dd.log.Error("destination_in lookup failed", err, "key", cleanRcpt)
continue
}
if !ok {
continue
}
return rcptIn.block, nil
}
// First try to match against complete address.
rcptBlock, ok := dd.sourceBlock.perRcpt[cleanRcpt]
if !ok {
// Then try domain-only.
_, domain, err := address.Split(cleanRcpt)
if err != nil {
return nil, &exterrors.SMTPError{
Code: 501,
EnhancedCode: exterrors.EnhancedCode{5, 1, 3},
Message: "Invalid recipient address",
Err: err,
Reason: "Can't extract local-part and host-part",
}
}
// domain is already case-folded and normalized because it is a part of
// cleanRcpt.
rcptBlock, ok = dd.sourceBlock.perRcpt[domain]
if !ok {
// Fallback to the default source block.
rcptBlock = dd.sourceBlock.defaultRcpt
dd.log.Debugf("recipient %s matched by default rule (clean = %s)", rcptTo, cleanRcpt)
} else {
dd.log.Debugf("recipient %s matched by domain rule '%s'", rcptTo, domain)
}
} else {
dd.log.Debugf("recipient %s matched by address rule '%s'", rcptTo, cleanRcpt)
}
return rcptBlock, nil
}
func (dd *msgpipelineDelivery) getRcptModifiers(ctx context.Context, rcptBlock *rcptBlock, rcptTo string) (module.ModifierState, error) {
rcptModifiersState, ok := dd.rcptModifiersState[rcptBlock]
if ok {
return rcptModifiersState, nil
}
rcptModifiersState, err := rcptBlock.modifiers.ModStateForMsg(ctx, dd.msgMeta)
if err != nil {
return nil, err
}
newSender, err := rcptModifiersState.RewriteSender(ctx, dd.sourceAddr)
if err == nil && newSender != dd.sourceAddr {
dd.log.Msg("Per-recipient modifier changed sender address. This is not supported and will "+
"be ignored.", "rcpt", rcptTo, "originalFrom", dd.sourceAddr, "modifiedFrom", newSender)
}
dd.rcptModifiersState[rcptBlock] = rcptModifiersState
return rcptModifiersState, nil
}
func (dd *msgpipelineDelivery) getDelivery(ctx context.Context, tgt module.DeliveryTarget) (*delivery, error) {
delivery_, ok := dd.deliveries[tgt]
if ok {
return delivery_, nil
}
deliveryObj, err := tgt.Start(ctx, dd.msgMeta, dd.sourceAddr)
if err != nil {
dd.log.Debugf("tgt.Start(%s) failure, target = %s: %v", dd.sourceAddr, objectName(tgt), err)
return nil, err
}
delivery_ = &delivery{Delivery: deliveryObj}
dd.log.Debugf("tgt.Start(%s) ok, target = %s", dd.sourceAddr, objectName(tgt))
dd.deliveries[tgt] = delivery_
return delivery_, nil
}
// Mock returns a MsgPipeline that merely delivers messages to a specified target
// and runs a set of checks.
//
// It is meant for use in tests for modules that embed a pipeline object.
func Mock(tgt module.DeliveryTarget, globalChecks []module.Check) *MsgPipeline {
return &MsgPipeline{
msgpipelineCfg: msgpipelineCfg{
globalChecks: globalChecks,
perSource: map[string]sourceBlock{},
defaultSource: sourceBlock{
perRcpt: map[string]*rcptBlock{},
defaultRcpt: &rcptBlock{
targets: []module.DeliveryTarget{tgt},
},
},
},
}
}