1 files changed, 387 insertions, 0 deletions
diff --git a/internal/admin/domainperms.go b/internal/admin/domainperms.go
new file mode 100644
index 000000000..fa686df43
--- /dev/null
+++ b/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
+}