[feature] Fetch + create domain permissions from subscriptions nightly (#3635)

* peepeepoopoo

* test domain perm subs

* swagger

* envparsing

* dries your wets

* start on docs

* finish up docs

* copy paste errors

* rename actions package

* rename force -> skipCache

* move obfuscate parse nearer to where err is checked

* make higherPrios a simple slice

* don't use receiver for permsFrom funcs

* add more context to error logs

* defer finished log

* use switch for permType instead of if/else

* thanks linter, love you <3

* validate csv headers before full read

* use bufio scanner

internal/admin/actions.go

@@ -0,0 +1,190 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"context"
+	"slices"
+	"sync"
+	"time"
+
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtscontext"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/workers"
+)
+
+func errActionConflict(action *gtsmodel.AdminAction) gtserror.WithCode {
+	err := gtserror.NewfAt(
+		4, // Include caller's function name.
+		"an action (%s) is currently running (duration %s) which conflicts with the attempted action",
+		action.Key(), time.Since(action.CreatedAt),
+	)
+
+	const help = "wait until this action is complete and try again"
+	return gtserror.NewErrorConflict(err, err.Error(), help)
+}
+
+type Actions struct {
+	// Map of running actions.
+	running map[string]*gtsmodel.AdminAction
+
+	// Lock for running admin actions.
+	//
+	// Not embedded struct, to shield
+	// from access by outside packages.
+	m sync.Mutex
+
+	// DB for storing, updating,
+	// deleting admin actions etc.
+	db db.DB
+
+	// Workers for queuing
+	// admin action side effects.
+	workers *workers.Workers
+}
+
+func New(db db.DB, workers *workers.Workers) *Actions {
+	return &Actions{
+		running: make(map[string]*gtsmodel.AdminAction),
+		db:      db,
+		workers: workers,
+	}
+}
+
+type ActionF func(context.Context) gtserror.MultiError
+
+// Run runs the given admin action by executing the supplied function.
+//
+// Run handles locking, action insertion and updating, so you don't have to!
+//
+// If an action is already running which overlaps/conflicts with the
+// given action, an ErrorWithCode 409 will be returned.
+//
+// If execution of the provided function returns errors, the errors
+// will be updated on the provided admin action in the database.
+func (a *Actions) Run(
+	ctx context.Context,
+	adminAction *gtsmodel.AdminAction,
+	f ActionF,
+) gtserror.WithCode {
+	actionKey := adminAction.Key()
+
+	// LOCK THE MAP HERE, since we're
+	// going to do some operations on it.
+	a.m.Lock()
+
+	// Bail if an action with
+	// this key is already running.
+	running, ok := a.running[actionKey]
+	if ok {
+		a.m.Unlock()
+		return errActionConflict(running)
+	}
+
+	// Action with this key not
+	// yet running, create it.
+	if err := a.db.PutAdminAction(ctx, adminAction); err != nil {
+		err = gtserror.Newf("db error putting admin action %s: %w", actionKey, err)
+
+		// Don't store in map
+		// if there's an error.
+		a.m.Unlock()
+		return gtserror.NewErrorInternalError(err)
+	}
+
+	// Action was inserted,
+	// store in map.
+	a.running[actionKey] = adminAction
+
+	// UNLOCK THE MAP HERE, since
+	// we're done modifying it for now.
+	a.m.Unlock()
+
+	go func() {
+		// Use a background context with existing values.
+		ctx = gtscontext.WithValues(context.Background(), ctx)
+
+		// Run the thing and collect errors.
+		if errs := f(ctx); errs != nil {
+			adminAction.Errors = make([]string, 0, len(errs))
+			for _, err := range errs {
+				adminAction.Errors = append(adminAction.Errors, err.Error())
+			}
+		}
+
+		// Action is no longer running:
+		// remove from running map.
+		a.m.Lock()
+		delete(a.running, actionKey)
+		a.m.Unlock()
+
+		// Mark as completed in the db,
+		// storing errors for later review.
+		adminAction.CompletedAt = time.Now()
+		if err := a.db.UpdateAdminAction(ctx, adminAction, "completed_at", "errors"); err != nil {
+			log.Errorf(ctx, "db error marking action %s as completed: %q", actionKey, err)
+		}
+	}()
+
+	return nil
+}
+
+// GetRunning sounds like a threat, but it actually just
+// returns all of the currently running actions held by
+// the Actions struct, ordered by ID descending.
+func (a *Actions) GetRunning() []*gtsmodel.AdminAction {
+	a.m.Lock()
+	defer a.m.Unlock()
+
+	// Assemble all currently running actions.
+	running := make([]*gtsmodel.AdminAction, 0, len(a.running))
+	for _, action := range a.running {
+		running = append(running, action)
+	}
+
+	// Order by ID descending (creation date).
+	slices.SortFunc(
+		running,
+		func(a *gtsmodel.AdminAction, b *gtsmodel.AdminAction) int {
+			const k = -1
+			switch {
+			case a.ID > b.ID:
+				return +k
+			case a.ID < b.ID:
+				return -k
+			default:
+				return 0
+			}
+		},
+	)
+
+	return running
+}
+
+// TotalRunning is a sequel to the classic
+// 1972 environmental-themed science fiction
+// film Silent Running, starring Bruce Dern.
+func (a *Actions) TotalRunning() int {
+	a.m.Lock()
+	defer a.m.Unlock()
+
+	return len(a.running)
+}

internal/admin/actions_test.go

@@ -0,0 +1,180 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package admin_test
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/id"
+	"github.com/superseriousbusiness/gotosocial/testrig"
+)
+
+const (
+	rMediaPath    = "../../testrig/media"
+	rTemplatePath = "../../web/template"
+)
+
+type ActionsTestSuite struct {
+	suite.Suite
+}
+
+func (suite *ActionsTestSuite) SetupSuite() {
+	testrig.InitTestConfig()
+	testrig.InitTestLog()
+}
+
+func (suite *ActionsTestSuite) TestActionOverlap() {
+	var (
+		testStructs = testrig.SetupTestStructs(rMediaPath, rTemplatePath)
+		ctx         = context.Background()
+	)
+	defer testrig.TearDownTestStructs(testStructs)
+
+	// Suspend account.
+	action1 := &gtsmodel.AdminAction{
+		ID:             id.NewULID(),
+		TargetCategory: gtsmodel.AdminActionCategoryAccount,
+		TargetID:       "01H90S1CXQ97J9625C5YBXZWGT",
+		Type:           gtsmodel.AdminActionSuspend,
+		AccountID:      "01H90S1ZZXP4N74H4A9RVW1MRP",
+	}
+	key1 := action1.Key()
+	suite.Equal("account/01H90S1CXQ97J9625C5YBXZWGT", key1)
+
+	// Unsuspend account.
+	action2 := &gtsmodel.AdminAction{
+		ID:             id.NewULID(),
+		TargetCategory: gtsmodel.AdminActionCategoryAccount,
+		TargetID:       "01H90S1CXQ97J9625C5YBXZWGT",
+		Type:           gtsmodel.AdminActionUnsuspend,
+		AccountID:      "01H90S1ZZXP4N74H4A9RVW1MRP",
+	}
+	key2 := action2.Key()
+	suite.Equal("account/01H90S1CXQ97J9625C5YBXZWGT", key2)
+
+	errWithCode := testStructs.State.AdminActions.Run(
+		ctx,
+		action1,
+		func(ctx context.Context) gtserror.MultiError {
+			// Noop, just sleep (mood).
+			time.Sleep(3 * time.Second)
+			return nil
+		},
+	)
+	suite.NoError(errWithCode)
+
+	// While first action is sleeping, try to
+	// process another with the same key.
+	errWithCode = testStructs.State.AdminActions.Run(
+		ctx,
+		action2,
+		func(ctx context.Context) gtserror.MultiError {
+			return nil
+		},
+	)
+	if errWithCode == nil {
+		suite.FailNow("expected error with code, but error was nil")
+	}
+
+	// Code should be 409.
+	suite.Equal(http.StatusConflict, errWithCode.Code())
+
+	// Wait for action to finish.
+	if !testrig.WaitFor(func() bool {
+		return testStructs.State.AdminActions.TotalRunning() == 0
+	}) {
+		suite.FailNow("timed out waiting for admin action(s) to finish")
+	}
+
+	// Try again.
+	errWithCode = testStructs.State.AdminActions.Run(
+		ctx,
+		action2,
+		func(ctx context.Context) gtserror.MultiError {
+			return nil
+		},
+	)
+	suite.NoError(errWithCode)
+
+	// Wait for action to finish.
+	if !testrig.WaitFor(func() bool {
+		return testStructs.State.AdminActions.TotalRunning() == 0
+	}) {
+		suite.FailNow("timed out waiting for admin action(s) to finish")
+	}
+}
+
+func (suite *ActionsTestSuite) TestActionWithErrors() {
+	var (
+		testStructs = testrig.SetupTestStructs(rMediaPath, rTemplatePath)
+		ctx         = context.Background()
+	)
+	defer testrig.TearDownTestStructs(testStructs)
+
+	// Suspend a domain.
+	action := &gtsmodel.AdminAction{
+		ID:             id.NewULID(),
+		TargetCategory: gtsmodel.AdminActionCategoryDomain,
+		TargetID:       "example.org",
+		Type:           gtsmodel.AdminActionSuspend,
+		AccountID:      "01H90S1ZZXP4N74H4A9RVW1MRP",
+	}
+
+	errWithCode := testStructs.State.AdminActions.Run(
+		ctx,
+		action,
+		func(ctx context.Context) gtserror.MultiError {
+			// Noop, just return some errs.
+			return gtserror.MultiError{
+				db.ErrNoEntries,
+				errors.New("fucky wucky"),
+			}
+		},
+	)
+	suite.NoError(errWithCode)
+
+	// Wait for action to finish.
+	if !testrig.WaitFor(func() bool {
+		return testStructs.State.AdminActions.TotalRunning() == 0
+	}) {
+		suite.FailNow("timed out waiting for admin action(s) to finish")
+	}
+
+	// Get action from the db.
+	dbAction, err := testStructs.State.DB.GetAdminAction(ctx, action.ID)
+	if err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	suite.EqualValues([]string{
+		"sql: no rows in result set",
+		"fucky wucky",
+	}, dbAction.Errors)
+}
+
+func TestActionsTestSuite(t *testing.T) {
+	suite.Run(t, new(ActionsTestSuite))
+}

internal/admin/domainkeys.go

@@ -0,0 +1,51 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"context"
+	"time"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+func (a *Actions) DomainKeysExpireF(domain string) ActionF {
+	return func(ctx context.Context) gtserror.MultiError {
+		var (
+			expiresAt = time.Now()
+			errs      gtserror.MultiError
+		)
+
+		// For each account on this domain, expire
+		// the public key and update the account.
+		if err := a.rangeDomainAccounts(ctx, domain, func(account *gtsmodel.Account) {
+			account.PublicKeyExpiresAt = expiresAt
+			if err := a.db.UpdateAccount(ctx,
+				account,
+				"public_key_expires_at",
+			); err != nil {
+				errs.Appendf("db error updating account: %w", err)
+			}
+		}); err != nil {
+			errs.Appendf("db error ranging through accounts: %w", err)
+		}
+
+		return errs
+	}
+}

internal/admin/domainperms.go

@@ -0,0 +1,387 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"codeberg.org/gruf/go-kv"
+
+	"github.com/superseriousbusiness/gotosocial/internal/ap"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/messages"
+)
+
+// Returns an AdminActionF for
+// domain allow side effects.
+func (a *Actions) DomainAllowF(
+	actionID string,
+	domainAllow *gtsmodel.DomainAllow,
+) ActionF {
+	return func(ctx context.Context) gtserror.MultiError {
+		l := log.
+			WithContext(ctx).
+			WithFields(kv.Fields{
+				{"action", "allow"},
+				{"actionID", actionID},
+				{"domain", domainAllow.Domain},
+			}...)
+
+		// Log start + finish.
+		l.Info("processing side effects")
+		errs := a.domainAllowSideEffects(ctx, domainAllow)
+		l.Info("finished processing side effects")
+
+		return errs
+	}
+}
+
+func (a *Actions) domainAllowSideEffects(
+	ctx context.Context,
+	allow *gtsmodel.DomainAllow,
+) gtserror.MultiError {
+	if config.GetInstanceFederationMode() == config.InstanceFederationModeAllowlist {
+		// We're running in allowlist mode,
+		// so there are no side effects to
+		// process here.
+		return nil
+	}
+
+	// We're running in blocklist mode or
+	// some similar mode which necessitates
+	// domain allow side effects if a block
+	// was in place when the allow was created.
+	//
+	// So, check if there's a block.
+	block, err := a.db.GetDomainBlock(ctx, allow.Domain)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		errs := gtserror.NewMultiError(1)
+		errs.Appendf("db error getting domain block %s: %w", allow.Domain, err)
+		return errs
+	}
+
+	if block == nil {
+		// No block?
+		// No problem!
+		return nil
+	}
+
+	// There was a block, over which the new
+	// allow ought to take precedence. To account
+	// for this, just run side effects as though
+	// the domain was being unblocked, while
+	// leaving the existing block in place.
+	//
+	// Any accounts that were suspended by
+	// the block will be unsuspended and be
+	// able to interact with the instance again.
+	return a.domainUnblockSideEffects(ctx, block)
+}
+
+// Returns an AdminActionF for
+// domain unallow side effects.
+func (a *Actions) DomainUnallowF(
+	actionID string,
+	domainAllow *gtsmodel.DomainAllow,
+) ActionF {
+	return func(ctx context.Context) gtserror.MultiError {
+		l := log.
+			WithContext(ctx).
+			WithFields(kv.Fields{
+				{"action", "unallow"},
+				{"actionID", actionID},
+				{"domain", domainAllow.Domain},
+			}...)
+
+		// Log start + finish.
+		l.Info("processing side effects")
+		errs := a.domainUnallowSideEffects(ctx, domainAllow)
+		l.Info("finished processing side effects")
+
+		return errs
+	}
+}
+
+func (a *Actions) domainUnallowSideEffects(
+	ctx context.Context,
+	allow *gtsmodel.DomainAllow,
+) gtserror.MultiError {
+	if config.GetInstanceFederationMode() == config.InstanceFederationModeAllowlist {
+		// We're running in allowlist mode,
+		// so there are no side effects to
+		// process here.
+		return nil
+	}
+
+	// We're running in blocklist mode or
+	// some similar mode which necessitates
+	// domain allow side effects if a block
+	// was in place when the allow was removed.
+	//
+	// So, check if there's a block.
+	block, err := a.db.GetDomainBlock(ctx, allow.Domain)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		errs := gtserror.NewMultiError(1)
+		errs.Appendf("db error getting domain block %s: %w", allow.Domain, err)
+		return errs
+	}
+
+	if block == nil {
+		// No block?
+		// No problem!
+		return nil
+	}
+
+	// There was a block, over which the previous
+	// allow was taking precedence. Now that the
+	// allow has been removed, we should put the
+	// side effects of the block back in place.
+	//
+	// To do this, process the block side effects
+	// again as though the block were freshly
+	// created. This will mark all accounts from
+	// the blocked domain as suspended, and clean
+	// up their follows/following, media, etc.
+	return a.domainBlockSideEffects(ctx, block)
+}
+
+func (a *Actions) DomainBlockF(
+	actionID string,
+	domainBlock *gtsmodel.DomainBlock,
+) ActionF {
+	return func(ctx context.Context) gtserror.MultiError {
+		l := log.
+			WithContext(ctx).
+			WithFields(kv.Fields{
+				{"action", "block"},
+				{"actionID", actionID},
+				{"domain", domainBlock.Domain},
+			}...)
+
+		skip, err := a.skipBlockSideEffects(ctx, domainBlock.Domain)
+		if err != nil {
+			return err
+		}
+
+		if skip != "" {
+			l.Infof("skipping side effects: %s", skip)
+			return nil
+		}
+
+		l.Info("processing side effects")
+		errs := a.domainBlockSideEffects(ctx, domainBlock)
+		l.Info("finished processing side effects")
+
+		return errs
+	}
+}
+
+// domainBlockSideEffects processes the side effects of a domain block:
+//
+//  1. Strip most info away from the instance entry for the domain.
+//  2. Pass each account from the domain to the processor for deletion.
+//
+// It should be called asynchronously, since it can take a while when
+// there are many accounts present on the given domain.
+func (a *Actions) domainBlockSideEffects(
+	ctx context.Context,
+	block *gtsmodel.DomainBlock,
+) gtserror.MultiError {
+	var errs gtserror.MultiError
+
+	// If we have an instance entry for this domain,
+	// update it with the new block ID and clear all fields
+	instance, err := a.db.GetInstance(ctx, block.Domain)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		errs.Appendf("db error getting instance %s: %w", block.Domain, err)
+		return errs
+	}
+
+	if instance != nil {
+		// We had an entry for this domain.
+		columns := stubbifyInstance(instance, block.ID)
+		if err := a.db.UpdateInstance(ctx, instance, columns...); err != nil {
+			errs.Appendf("db error updating instance: %w", err)
+			return errs
+		}
+	}
+
+	// For each account that belongs to this domain,
+	// process an account delete message to remove
+	// that account's posts, media, etc.
+	if err := a.rangeDomainAccounts(ctx, block.Domain, func(account *gtsmodel.Account) {
+		if err := a.workers.Client.Process(ctx, &messages.FromClientAPI{
+			APObjectType:   ap.ActorPerson,
+			APActivityType: ap.ActivityDelete,
+			GTSModel:       block,
+			Origin:         account,
+			Target:         account,
+		}); err != nil {
+			errs.Append(err)
+		}
+	}); err != nil {
+		errs.Appendf("db error ranging through accounts: %w", err)
+	}
+
+	return errs
+}
+
+func (a *Actions) DomainUnblockF(
+	actionID string,
+	domainBlock *gtsmodel.DomainBlock,
+) ActionF {
+	return func(ctx context.Context) gtserror.MultiError {
+		l := log.
+			WithContext(ctx).
+			WithFields(kv.Fields{
+				{"action", "unblock"},
+				{"actionID", actionID},
+				{"domain", domainBlock.Domain},
+			}...)
+
+		l.Info("processing side effects")
+		errs := a.domainUnblockSideEffects(ctx, domainBlock)
+		l.Info("finished processing side effects")
+
+		return errs
+	}
+}
+
+// domainUnblockSideEffects processes the side effects of undoing a
+// domain block:
+//
+//  1. Mark instance entry as no longer suspended.
+//  2. Mark each account from the domain as no longer suspended, if the
+//     suspension origin corresponds to the ID of the provided domain block.
+//
+// It should be called asynchronously, since it can take a while when
+// there are many accounts present on the given domain.
+func (a *Actions) domainUnblockSideEffects(
+	ctx context.Context,
+	block *gtsmodel.DomainBlock,
+) gtserror.MultiError {
+	var errs gtserror.MultiError
+
+	// Update instance entry for this domain, if we have it.
+	instance, err := a.db.GetInstance(ctx, block.Domain)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		errs.Appendf("db error getting instance %s: %w", block.Domain, err)
+	}
+
+	if instance != nil {
+		// We had an entry, update it to signal
+		// that it's no longer suspended.
+		instance.SuspendedAt = time.Time{}
+		instance.DomainBlockID = ""
+		if err := a.db.UpdateInstance(
+			ctx,
+			instance,
+			"suspended_at",
+			"domain_block_id",
+		); err != nil {
+			errs.Appendf("db error updating instance: %w", err)
+			return errs
+		}
+	}
+
+	// Unsuspend all accounts whose suspension origin was this domain block.
+	if err := a.rangeDomainAccounts(ctx, block.Domain, func(account *gtsmodel.Account) {
+		if account.SuspensionOrigin == "" || account.SuspendedAt.IsZero() {
+			// Account wasn't suspended, nothing to do.
+			return
+		}
+
+		if account.SuspensionOrigin != block.ID {
+			// Account was suspended, but not by
+			// this domain block, leave it alone.
+			return
+		}
+
+		// Account was suspended by this domain
+		// block, mark it as unsuspended.
+		account.SuspendedAt = time.Time{}
+		account.SuspensionOrigin = ""
+
+		if err := a.db.UpdateAccount(
+			ctx,
+			account,
+			"suspended_at",
+			"suspension_origin",
+		); err != nil {
+			errs.Appendf("db error updating account %s: %w", account.Username, err)
+		}
+	}); err != nil {
+		errs.Appendf("db error ranging through accounts: %w", err)
+	}
+
+	return errs
+}
+
+// skipBlockSideEffects checks if side effects of block creation
+// should be skipped for the given domain, taking account of
+// instance federation mode, and existence of any allows
+// which ought to "shield" this domain from being blocked.
+//
+// If the caller should skip, the returned string will be non-zero
+// and will be set to a reason why side effects should be skipped.
+//
+//   - blocklist mode + allow exists: "..." (skip)
+//   - blocklist mode + no allow:     ""    (don't skip)
+//   - allowlist mode + allow exists: ""    (don't skip)
+//   - allowlist mode + no allow:     ""    (don't skip)
+func (a *Actions) skipBlockSideEffects(
+	ctx context.Context,
+	domain string,
+) (string, gtserror.MultiError) {
+	var (
+		skip string // Assume "" (don't skip).
+		errs gtserror.MultiError
+	)
+
+	// Never skip block side effects in allowlist mode.
+	fediMode := config.GetInstanceFederationMode()
+	if fediMode == config.InstanceFederationModeAllowlist {
+		return skip, errs
+	}
+
+	// We know we're in blocklist mode.
+	//
+	// We want to skip domain block side
+	// effects if an allow is already
+	// in place which overrides the block.
+
+	// Check if an explicit allow exists for this domain.
+	domainAllow, err := a.db.GetDomainAllow(ctx, domain)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		errs.Appendf("error getting domain allow: %w", err)
+		return skip, errs
+	}
+
+	if domainAllow != nil {
+		skip = "running in blocklist mode, and an explicit allow exists for this domain"
+		return skip, errs
+	}
+
+	return skip, errs
+}

internal/admin/util.go

@@ -0,0 +1,99 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package admin
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+// stubbifyInstance renders the given instance as a stub,
+// removing most information from it and marking it as
+// suspended.
+//
+// For caller's convenience, this function returns the db
+// names of all columns that are updated by it.
+func stubbifyInstance(instance *gtsmodel.Instance, domainBlockID string) []string {
+	instance.Title = ""
+	instance.SuspendedAt = time.Now()
+	instance.DomainBlockID = domainBlockID
+	instance.ShortDescription = ""
+	instance.Description = ""
+	instance.Terms = ""
+	instance.ContactEmail = ""
+	instance.ContactAccountUsername = ""
+	instance.ContactAccountID = ""
+	instance.Version = ""
+
+	return []string{
+		"title",
+		"suspended_at",
+		"domain_block_id",
+		"short_description",
+		"description",
+		"terms",
+		"contact_email",
+		"contact_account_username",
+		"contact_account_id",
+		"version",
+	}
+}
+
+// rangeDomainAccounts iterates through all accounts
+// originating from the given domain, and calls the
+// provided range function on each account.
+//
+// If an error is returned while selecting accounts,
+// the loop will stop and return the error.
+func (a *Actions) rangeDomainAccounts(
+	ctx context.Context,
+	domain string,
+	rangeF func(*gtsmodel.Account),
+) error {
+	var (
+		limit = 50   // Limit selection to avoid spiking mem/cpu.
+		maxID string // Start with empty string to select from top.
+	)
+
+	for {
+		// Get (next) page of accounts.
+		accounts, err := a.db.GetInstanceAccounts(ctx, domain, maxID, limit)
+		if err != nil && !errors.Is(err, db.ErrNoEntries) {
+			// Real db error.
+			return gtserror.Newf("db error getting instance accounts: %w", err)
+		}
+
+		if len(accounts) == 0 {
+			// No accounts left, we're done.
+			return nil
+		}
+
+		// Set next max ID for paging down.
+		maxID = accounts[len(accounts)-1].ID
+
+		// Call provided range function.
+		for _, account := range accounts {
+			rangeF(account)
+		}
+	}
+}