1 files changed, 829 insertions, 0 deletions

diff --git a/src/lib-storage/index/imapc/imapc-save.c b/src/lib-storage/index/imapc/imapc-save.c
new file mode 100644
index 0000000..c50f46b
--- /dev/null
+++ b/src/lib-storage/index/imapc/imapc-save.c
@@ -0,0 +1,829 @@
+/* Copyright (c) 2011-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "str.h"
+#include "istream.h"
+#include "istream-crlf.h"
+#include "ostream.h"
+#include "imap-date.h"
+#include "imap-util.h"
+#include "imap-seqset.h"
+#include "imap-quote.h"
+#include "index-mail.h"
+#include "mail-copy.h"
+#include "mailbox-list-private.h"
+#include "imapc-msgmap.h"
+#include "imapc-storage.h"
+#include "imapc-sync.h"
+#include "imapc-mail.h"
+#include "seq-set-builder.h"
+
+struct imapc_save_context {
+	struct mail_save_context ctx;
+
+	struct imapc_mailbox *mbox;
+	struct imapc_mailbox *src_mbox;
+	struct mail_index_transaction *trans;
+
+	int fd;
+	char *temp_path;
+	struct istream *input;
+
+	uint32_t dest_uid_validity;
+	ARRAY_TYPE(seq_range) dest_saved_uids;
+	unsigned int save_count;
+
+	bool failed:1;
+	bool finished:1;
+};
+
+struct imapc_save_cmd_context {
+	struct imapc_save_context *ctx;
+	int ret;
+};
+
+#define IMAPC_SAVECTX(s)	container_of(s, struct imapc_save_context, ctx)
+#define IMAPC_SERVER_CMDLINE_MAX_LEN 	8000
+
+void imapc_transaction_save_rollback(struct mail_save_context *_ctx);
+static void imapc_mail_copy_bulk_flush(struct imapc_mailbox *mbox);
+
+struct mail_save_context *
+imapc_save_alloc(struct mailbox_transaction_context *t)
+{
+	struct imapc_mailbox *mbox = IMAPC_MAILBOX(t->box);
+	struct imapc_save_context *ctx;
+
+	i_assert((t->flags & MAILBOX_TRANSACTION_FLAG_EXTERNAL) != 0);
+
+	if (t->save_ctx == NULL) {
+		ctx = i_new(struct imapc_save_context, 1);
+		ctx->ctx.transaction = t;
+		ctx->mbox = mbox;
+		ctx->src_mbox = NULL;
+		ctx->trans = t->itrans;
+		ctx->fd = -1;
+		t->save_ctx = &ctx->ctx;
+	}
+	return t->save_ctx;
+}
+
+int imapc_save_begin(struct mail_save_context *_ctx, struct istream *input)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+	const char *path;
+
+	i_assert(ctx->fd == -1);
+
+	if (imapc_storage_client_handle_auth_failure(ctx->mbox->storage->client))
+		return -1;
+
+	ctx->fd = imapc_client_create_temp_fd(ctx->mbox->storage->client->client,
+					      &path);
+	if (ctx->fd == -1) {
+		mail_set_critical(_ctx->dest_mail,
+				  "Couldn't create temp file %s", path);
+		ctx->failed = TRUE;
+		return -1;
+	}
+	/* we may not know the size of the input, or be sure that it contains
+	   only CRLFs. so we'll always first write the mail to a temp file and
+	   upload it from there to remote server. */
+	ctx->finished = FALSE;
+	ctx->temp_path = i_strdup(path);
+	ctx->input = i_stream_create_crlf(input);
+	_ctx->data.output = o_stream_create_fd_file(ctx->fd, 0, FALSE);
+	o_stream_cork(_ctx->data.output);
+	return 0;
+}
+
+int imapc_save_continue(struct mail_save_context *_ctx)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+
+	if (ctx->failed)
+		return -1;
+
+	if (index_storage_save_continue(_ctx, ctx->input, NULL) < 0) {
+		ctx->failed = TRUE;
+		return -1;
+	}
+	return 0;
+}
+
+static void imapc_save_appenduid(struct imapc_save_context *ctx,
+				 const struct imapc_command_reply *reply,
+				 uint32_t *uid_r)
+{
+	const char *const *args;
+	uint32_t uid_validity, dest_uid;
+
+	*uid_r = 0;
+
+	/* <uidvalidity> <dest uid-set> */
+	args = t_strsplit(reply->resp_text_value, " ");
+	if (str_array_length(args) != 2)
+		return;
+
+	if (str_to_uint32(args[0], &uid_validity) < 0)
+		return;
+	if (ctx->dest_uid_validity == 0)
+		ctx->dest_uid_validity = uid_validity;
+	else if (ctx->dest_uid_validity != uid_validity)
+		return;
+
+	if (str_to_uint32(args[1], &dest_uid) == 0) {
+		seq_range_array_add_with_init(&ctx->dest_saved_uids,
+					      32, dest_uid);
+		*uid_r = dest_uid;
+	}
+}
+
+static void
+imapc_save_add_to_index(struct imapc_save_context *ctx, uint32_t uid)
+{
+	struct mail *_mail = ctx->ctx.dest_mail;
+	struct index_mail *imail = INDEX_MAIL(_mail);
+	uint32_t seq;
+
+	/* we'll temporarily append messages and at commit time expunge
+	   them all, since we can't guarantee that no one else has saved
+	   messages to remote server during our transaction */
+	mail_index_append(ctx->trans, uid, &seq);
+	mail_set_seq_saving(_mail, seq);
+	imail->data.no_caching = TRUE;
+	imail->data.forced_no_caching = TRUE;
+
+	if (ctx->fd != -1) {
+		struct imapc_mail *imapc_mail = IMAPC_MAIL(_mail);
+		imail->data.stream = i_stream_create_fd_autoclose(&ctx->fd, 0);
+		imapc_mail->header_fetched = TRUE;
+		imapc_mail->body_fetched = TRUE;
+		/* The saved stream wasn't actually read, but it needs to be
+		   set accessed to avoid assert-crash. */
+		_mail->mail_stream_accessed = TRUE;
+		imapc_mail_init_stream(imapc_mail);
+	}
+
+	ctx->save_count++;
+}
+
+static void imapc_save_callback(const struct imapc_command_reply *reply,
+				void *context)
+{
+	struct imapc_save_cmd_context *ctx = context;
+	uint32_t uid = 0;
+
+	if (reply->state == IMAPC_COMMAND_STATE_OK) {
+		if (reply->resp_text_key != NULL &&
+		    strcasecmp(reply->resp_text_key, "APPENDUID") == 0)
+			imapc_save_appenduid(ctx->ctx, reply, &uid);
+		imapc_save_add_to_index(ctx->ctx, uid);
+		ctx->ret = 0;
+	} else if (imapc_storage_client_handle_auth_failure(ctx->ctx->mbox->storage->client)) {
+		ctx->ret = -1;
+	} else if (reply->state == IMAPC_COMMAND_STATE_NO) {
+		imapc_copy_error_from_reply(ctx->ctx->mbox->storage,
+					    MAIL_ERROR_PARAMS, reply);
+		ctx->ret = -1;
+	} else {
+		mailbox_set_critical(&ctx->ctx->mbox->box,
+			"imapc: APPEND failed: %s", reply->text_full);
+		ctx->ret = -1;
+	}
+	imapc_client_stop(ctx->ctx->mbox->storage->client->client);
+}
+
+static void
+imapc_save_noop_callback(const struct imapc_command_reply *reply ATTR_UNUSED,
+			 void *context)
+{
+	struct imapc_save_cmd_context *ctx = context;
+
+	/* we don't really care about the reply */
+	ctx->ret = 0;
+	imapc_client_stop(ctx->ctx->mbox->storage->client->client);
+}
+
+static void
+imapc_copy_rollback_store_callback(const struct imapc_command_reply *reply ATTR_UNUSED,
+				   void *context)
+{
+	struct imapc_save_context *ctx = context;
+	/* Can't do much about a non successful STORE here */
+	if (reply->state != IMAPC_COMMAND_STATE_OK) {
+		e_error(ctx->src_mbox->box.event,
+			"imapc: Failed to set \\Deleted flag for rolling back "
+			"failed copy: %s", reply->text_full);
+		ctx->src_mbox->rollback_pending = FALSE;
+		ctx->finished = TRUE;
+		ctx->failed = TRUE;
+	} else {
+		i_assert(ctx->src_mbox->rollback_pending);
+	}
+	/* No need stop the imapc client here there is always an additional
+	   expunge callback after this. */
+}
+
+static void
+imapc_copy_rollback_expunge_callback(const struct imapc_command_reply *reply ATTR_UNUSED,
+				     void *context)
+{
+	struct imapc_save_context *ctx = context;
+
+	/* Can't do much about a non successful EXPUNGE here */
+	if (reply->state != IMAPC_COMMAND_STATE_OK) {
+		e_error(ctx->src_mbox->box.event,
+			"imapc: Failed to expunge messages for rolling back "
+			"failed copy: %s", reply->text_full);
+		ctx->src_mbox->rollback_pending = FALSE;
+		ctx->finished = TRUE;
+		ctx->failed = TRUE;
+	} else {
+		ctx->finished = TRUE;
+		ctx->src_mbox->rollback_pending = FALSE;
+	}
+	imapc_client_stop(ctx->src_mbox->storage->client->client);
+}
+
+static void
+imapc_append_keywords(string_t *str, struct mail_keywords *kw)
+{
+	const ARRAY_TYPE(keywords) *kw_arr;
+	const char *kw_str;
+	unsigned int i;
+
+	kw_arr = mail_index_get_keywords(kw->index);
+	for (i = 0; i < kw->count; i++) {
+		kw_str = array_idx_elem(kw_arr, kw->idx[i]);
+		if (str_len(str) > 1)
+			str_append_c(str, ' ');
+		str_append(str, kw_str);
+	}
+}
+
+static int imapc_save_append(struct imapc_save_context *ctx)
+{
+	struct mail_save_context *_ctx = &ctx->ctx;
+	struct mail_save_data *mdata = &_ctx->data;
+	struct imapc_command *cmd;
+	struct imapc_save_cmd_context sctx;
+	struct istream *input;
+	const char *flags = "", *internaldate = "";
+
+	if (mdata->flags != 0 || mdata->keywords != NULL) {
+		string_t *str = t_str_new(64);
+
+		str_append(str, " (");
+		imap_write_flags(str, mdata->flags & ENUM_NEGATE(MAIL_RECENT),
+				 NULL);
+		if (mdata->keywords != NULL)
+			imapc_append_keywords(str, mdata->keywords);
+		str_append_c(str, ')');
+		flags = str_c(str);
+	}
+	if (mdata->received_date != (time_t)-1) {
+		internaldate = t_strdup_printf(" \"%s\"",
+			imap_to_datetime(mdata->received_date));
+	}
+
+	ctx->mbox->exists_received = FALSE;
+
+	input = i_stream_create_fd(ctx->fd, IO_BLOCK_SIZE);
+	sctx.ctx = ctx;
+	sctx.ret = -2;
+	cmd = imapc_client_cmd(ctx->mbox->storage->client->client,
+			       imapc_save_callback, &sctx);
+	imapc_command_sendf(cmd, "APPEND %s%1s%1s %p",
+		imapc_mailbox_get_remote_name(ctx->mbox),
+		flags, internaldate, input);
+	i_stream_unref(&input);
+	while (sctx.ret == -2)
+		imapc_mailbox_run(ctx->mbox);
+
+	if (sctx.ret == 0 && ctx->mbox->selected &&
+	    !ctx->mbox->exists_received) {
+		/* e.g. Courier doesn't send EXISTS reply before the tagged
+		   APPEND reply. That isn't exactly required by the IMAP RFC,
+		   but it makes the behavior better. See if NOOP finds
+		   the mail. */
+		sctx.ret = -2;
+		cmd = imapc_client_cmd(ctx->mbox->storage->client->client,
+				       imapc_save_noop_callback, &sctx);
+		imapc_command_set_flags(cmd, IMAPC_COMMAND_FLAG_RETRIABLE);
+		imapc_command_send(cmd, "NOOP");
+		while (sctx.ret == -2)
+			imapc_mailbox_run(ctx->mbox);
+	}
+	return sctx.ret;
+}
+
+int imapc_save_finish(struct mail_save_context *_ctx)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+	struct mail_storage *storage = _ctx->transaction->box->storage;
+
+	ctx->finished = TRUE;
+
+	if (!ctx->failed) {
+		if (o_stream_finish(_ctx->data.output) < 0) {
+			if (!mail_storage_set_error_from_errno(storage)) {
+				mail_set_critical(_ctx->dest_mail,
+					"write(%s) failed: %s", ctx->temp_path,
+					o_stream_get_error(_ctx->data.output));
+			}
+			ctx->failed = TRUE;
+		}
+	}
+
+	if (!ctx->failed) {
+		if (imapc_save_append(ctx) < 0)
+			ctx->failed = TRUE;
+	}
+
+	o_stream_unref(&_ctx->data.output);
+	i_stream_unref(&ctx->input);
+	i_close_fd_path(&ctx->fd, ctx->temp_path);
+	i_free(ctx->temp_path);
+	index_save_context_free(_ctx);
+	return ctx->failed ? -1 : 0;
+}
+
+void imapc_save_cancel(struct mail_save_context *_ctx)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+
+	ctx->failed = TRUE;
+	(void)imapc_transaction_save_commit_pre(_ctx);
+	(void)imapc_save_finish(_ctx);
+}
+
+static void imapc_copy_bulk_finish(struct imapc_save_context *ctx)
+{
+	while (ctx->src_mbox != NULL && ctx->src_mbox->pending_copy_request != NULL)
+		imapc_mailbox_run_nofetch(ctx->src_mbox);
+}
+
+int imapc_transaction_save_commit_pre(struct mail_save_context *_ctx)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+	struct mail_transaction_commit_changes *changes =
+		_ctx->transaction->changes;
+	uint32_t i, last_seq;
+
+	i_assert(ctx->finished || ctx->failed);
+
+	/* expunge all added messages from index before commit */
+	last_seq = mail_index_view_get_messages_count(_ctx->transaction->view);
+	if (last_seq == 0)
+		return -1;
+	for (i = 0; i < ctx->save_count; i++)
+		mail_index_expunge(ctx->trans, last_seq - i);
+
+	if (!ctx->failed && array_is_created(&ctx->dest_saved_uids)) {
+		changes->uid_validity = ctx->dest_uid_validity;
+		array_append_array(&changes->saved_uids, &ctx->dest_saved_uids);
+	}
+	return 0;
+}
+
+int imapc_transaction_save_commit(struct mailbox_transaction_context *t)
+{
+       struct imapc_save_context *ctx = NULL;
+       struct imapc_mailbox *src_mbox = NULL;
+
+       if (t->save_ctx != NULL) {
+               ctx = IMAPC_SAVECTX(t->save_ctx);
+               src_mbox = ctx->src_mbox;
+       }
+
+       if (src_mbox != NULL && src_mbox->pending_copy_request != NULL) {
+	       /* If there is still a copy command to send flush it now */
+	       imapc_mail_copy_bulk_flush(src_mbox);
+	       imapc_copy_bulk_finish(ctx);
+       }
+
+       if (ctx != NULL)
+	       return ctx->failed ? -1 : 0;
+       return 0;
+}
+
+void imapc_transaction_save_commit_post(struct mail_save_context *_ctx,
+					struct mail_index_transaction_commit_result *result ATTR_UNUSED)
+{
+	imapc_transaction_save_rollback(_ctx);
+}
+
+static void
+imapc_expunge_construct_cmd_str(string_t *store_cmd,
+				string_t *expunge_cmd,
+				string_t *uids)
+{
+	str_append(store_cmd, "UID STORE ");
+	str_append_str(store_cmd, uids);
+	str_append(store_cmd, " +FLAGS (\\Deleted)");
+	str_append(expunge_cmd, "UID EXPUNGE ");
+	str_append_str(expunge_cmd, uids);
+	/* Clear already appened uids */
+	str_truncate(uids, 0);
+}
+
+static void
+imapc_expunge_send_cmd_str(struct imapc_save_context *ctx,
+			   string_t *uids)
+{
+	struct imapc_command *store_cmd, *expunge_cmd;
+
+	string_t *store_cmd_str, *expunge_cmd_str;
+	store_cmd_str = t_str_new(128);
+	expunge_cmd_str = t_str_new(128);
+
+	imapc_expunge_construct_cmd_str(store_cmd_str, expunge_cmd_str, uids);
+	/* Make sure line length is less than 8k */
+	i_assert(str_len(store_cmd_str) < IMAPC_SERVER_CMDLINE_MAX_LEN);
+	i_assert(str_len(expunge_cmd_str) < IMAPC_SERVER_CMDLINE_MAX_LEN);
+
+	store_cmd = imapc_client_mailbox_cmd(ctx->src_mbox->client_box,
+					     imapc_copy_rollback_store_callback,
+					     ctx);
+	expunge_cmd = imapc_client_mailbox_cmd(ctx->src_mbox->client_box,
+					       imapc_copy_rollback_expunge_callback,
+					       ctx);
+	ctx->src_mbox->rollback_pending = TRUE;
+	imapc_command_send(store_cmd, str_c(store_cmd_str));
+	imapc_command_send(expunge_cmd, str_c(expunge_cmd_str));
+}
+
+static void
+imapc_rollback_send_expunge(struct imapc_save_context *ctx)
+{
+	string_t *uids_str;
+	struct seqset_builder *seqset_builder;
+	struct seq_range_iter iter;
+	unsigned int i = 0;
+	uint32_t uid;
+
+	if (!array_not_empty(&ctx->src_mbox->copy_rollback_expunge_uids))
+		return;
+
+	uids_str = t_str_new(128);
+	seqset_builder = seqset_builder_init(uids_str);
+	seq_range_array_iter_init(&iter, &ctx->src_mbox->copy_rollback_expunge_uids);
+
+	/* Iterate over all uids that must be rolled back */
+	while (seq_range_array_iter_nth(&iter, i++, &uid)) {
+		/* Try to add the to the seqset builder while respecting
+		   the maximum length of IMAPC_SERVER_CMDLINE_MAX_LEN. */
+		if (!seqset_builder_try_add(seqset_builder,
+					    IMAPC_SERVER_CMDLINE_MAX_LEN -
+					    strlen("UID STORE  +FLAGS (\\Deleted)"),
+					    uid)) {
+			/* Maximum length is reached send the rollback
+			   and wait for it to be finished. */
+			imapc_expunge_send_cmd_str(ctx, uids_str);
+			while (ctx->src_mbox->rollback_pending)
+				imapc_mailbox_run_nofetch(ctx->src_mbox);
+
+			/* Truncate the uids_str and create a new
+			   seqset_builder for the next command */
+			seqset_builder_deinit(&seqset_builder);
+			str_truncate(uids_str, 0);
+			seqset_builder = seqset_builder_init(uids_str);
+			/* Make sure the current uid which is part of
+			   the next uid_str */
+			seqset_builder_add(seqset_builder, uid);
+		}
+	}
+	if (str_len(uids_str) > 0)
+		imapc_expunge_send_cmd_str(ctx, uids_str);
+	while (ctx->src_mbox->rollback_pending)
+		imapc_mailbox_run_nofetch(ctx->src_mbox);
+}
+
+static void imapc_copy_bulk_ctx_deinit(struct imapc_save_context *ctx)
+{
+	/* Clean up the pending copy and the context attached to it */
+	str_truncate(ctx->src_mbox->pending_copy_cmd, 0);
+	i_free(ctx->src_mbox->copy_dest_box);
+}
+
+void imapc_transaction_save_rollback(struct mail_save_context *_ctx)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+
+       if ((ctx->src_mbox != NULL && ctx->src_mbox->pending_copy_request != NULL) ||
+	   !ctx->finished) {
+	       /* There is still a pending copy which should not be send
+		  as rollback() is called or the transaction has not yet
+		  finished and rollback is called */
+	       ctx->failed = TRUE;
+	       (void)imapc_transaction_save_commit_pre(_ctx);
+
+	       i_assert(ctx->finished || ctx->src_mbox != NULL);
+	       /* Clean up the pending copy and the context attached to it */
+	       if (ctx->src_mbox != NULL) {
+		       if (ctx->src_mbox->pending_copy_request != NULL) {
+			       seqset_builder_deinit(&ctx->src_mbox->pending_copy_request->uidset_builder);
+			       i_free(ctx->src_mbox->pending_copy_request);
+		       }
+		       imapc_copy_bulk_ctx_deinit(ctx);
+		       imapc_client_stop(ctx->src_mbox->storage->client->client);
+	       }
+       }
+
+	/* Expunge all added messages from index */
+	if (ctx->failed && array_is_created(&ctx->dest_saved_uids)) {
+		i_assert(ctx->src_mbox != NULL);
+		seq_range_array_merge(&ctx->src_mbox->copy_rollback_expunge_uids, &ctx->dest_saved_uids);
+		/* Make sure context is not finished already */
+		ctx->finished = FALSE;
+		imapc_rollback_send_expunge(ctx);
+		array_free(&ctx->dest_saved_uids);
+	}
+
+	if (ctx->finished || ctx->failed) {
+		array_free(&ctx->dest_saved_uids);
+		i_free(ctx);
+	}
+}
+
+static bool imapc_save_copyuid(struct imapc_save_context *ctx,
+			       const struct imapc_command_reply *reply,
+			       uint32_t *uid_r)
+{
+	ARRAY_TYPE(seq_range) dest_uidset, source_uidset;
+	struct seq_range_iter iter;
+	const char *const *args;
+	uint32_t uid_validity;
+
+	*uid_r = 0;
+
+	/* <uidvalidity> <source uid-set> <dest uid-set> */
+	args = t_strsplit(reply->resp_text_value, " ");
+	if (str_array_length(args) != 3)
+		return FALSE;
+
+	if (str_to_uint32(args[0], &uid_validity) < 0)
+		return FALSE;
+	if (ctx->dest_uid_validity == 0)
+		ctx->dest_uid_validity = uid_validity;
+	else if (ctx->dest_uid_validity != uid_validity)
+		return FALSE;
+
+	t_array_init(&source_uidset, 8);
+	t_array_init(&dest_uidset, 8);
+
+	if (imap_seq_set_nostar_parse(args[1], &source_uidset) < 0)
+		return FALSE;
+	if (imap_seq_set_nostar_parse(args[2], &dest_uidset) < 0)
+		return FALSE;
+
+	if (!array_is_created(&ctx->dest_saved_uids))
+		i_array_init(&ctx->dest_saved_uids, 8);
+
+	seq_range_array_merge(&ctx->dest_saved_uids, &dest_uidset);
+
+	seq_range_array_iter_init(&iter, &dest_uidset);
+	(void)seq_range_array_iter_nth(&iter, 0, uid_r);
+	return TRUE;
+}
+
+static void imapc_copy_set_error(struct imapc_save_context *sctx,
+				 const struct imapc_command_reply *reply)
+{
+	sctx->failed = TRUE;
+
+	if (reply->state != IMAPC_COMMAND_STATE_BAD)
+		imapc_copy_error_from_reply(sctx->mbox->storage,
+					    MAIL_ERROR_PARAMS, reply);
+	else
+		mailbox_set_critical(&sctx->mbox->box,
+				     "imapc: COPY failed: %s",
+				     reply->text_full);
+}
+
+static void
+imapc_copy_simple_callback(const struct imapc_command_reply *reply,
+			   void *context)
+{
+	struct imapc_save_cmd_context *ctx = context;
+	uint32_t uid = 0;
+
+	if (reply->state == IMAPC_COMMAND_STATE_OK) {
+		if (reply->resp_text_key != NULL &&
+		    strcasecmp(reply->resp_text_key, "COPYUID") == 0)
+			imapc_save_copyuid(ctx->ctx, reply, &uid);
+		imapc_save_add_to_index(ctx->ctx, uid);
+		ctx->ret = 0;
+	} else if (reply->state == IMAPC_COMMAND_STATE_NO) {
+		imapc_copy_error_from_reply(ctx->ctx->mbox->storage,
+					    MAIL_ERROR_PARAMS, reply);
+		ctx->ret = -1;
+	} else {
+		mailbox_set_critical(&ctx->ctx->mbox->box,
+			"imapc: COPY failed: %s", reply->text_full);
+		ctx->ret = -1;
+	}
+	imapc_client_stop(ctx->ctx->mbox->storage->client->client);
+}
+
+static int
+imapc_copy_simple(struct mail_save_context *_ctx, struct mail *mail)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+	struct mailbox_transaction_context *_t = _ctx->transaction;
+	struct imapc_save_cmd_context sctx;
+	struct imapc_command *cmd;
+
+	sctx.ret = -2;
+	sctx.ctx = ctx;
+	cmd = imapc_client_mailbox_cmd(ctx->src_mbox->client_box,
+				       imapc_copy_simple_callback,
+				       &sctx);
+	imapc_command_sendf(cmd, "UID COPY %u %s", mail->uid, _t->box->name);
+	while (sctx.ret == -2)
+		imapc_mailbox_run(ctx->src_mbox);
+	ctx->finished = TRUE;
+	return sctx.ret;
+}
+
+static void imapc_copy_bulk_callback(const struct imapc_command_reply *reply,
+				     void *context)
+{
+	struct imapc_copy_request *request = context;
+	struct imapc_save_context *ctx = request->sctx;
+	struct imapc_mailbox *mbox = ctx->src_mbox;
+	unsigned int uid;
+
+	i_assert(mbox != NULL);
+	i_assert(request == mbox->pending_copy_request);
+
+	/* Check the reply state and add uid's to index and
+	   dest_saved_uids. */
+	if (ctx->failed) {
+		/* If the saving already failed try to find UIDs already
+		   copied from the reply so that rollback can expunge
+		   them */
+		if (null_strcasecmp(reply->resp_text_key, "COPYUID") == 0) {
+			(void)imapc_save_copyuid(ctx, reply, &uid);
+			imapc_transaction_save_rollback(&ctx->ctx);
+		}
+	} else if (reply->state == IMAPC_COMMAND_STATE_OK) {
+		if (reply->resp_text_key != NULL &&
+		   strcasecmp(reply->resp_text_key, "COPYUID") == 0 &&
+		   imapc_save_copyuid(ctx, reply, &uid)) {
+			ctx->finished = TRUE;
+		}
+	} else {
+		imapc_copy_set_error(ctx, reply);
+	}
+
+	ctx->src_mbox->pending_copy_request = NULL;
+	i_free(request);
+	imapc_client_stop(mbox->storage->client->client);
+}
+
+static void imapc_mail_copy_bulk_flush(struct imapc_mailbox *mbox)
+{
+	struct imapc_command *cmd;
+
+	i_assert(mbox != NULL);
+	i_assert(mbox->pending_copy_request != NULL);
+	i_assert(mbox->client_box != NULL);
+
+	cmd = imapc_client_mailbox_cmd(mbox->client_box,
+				       imapc_copy_bulk_callback,
+				       mbox->pending_copy_request);
+
+	seqset_builder_deinit(&mbox->pending_copy_request->uidset_builder);
+
+	str_append(mbox->pending_copy_cmd, " ");
+	imap_append_astring(mbox->pending_copy_cmd, mbox->copy_dest_box);
+
+	imapc_command_send(cmd, str_c(mbox->pending_copy_cmd));
+
+	imapc_copy_bulk_ctx_deinit(mbox->pending_copy_request->sctx);
+}
+
+static bool
+imapc_mail_copy_bulk_try_merge(struct imapc_mailbox *mbox, uint32_t uid,
+			       const char *box)
+{
+	i_assert(str_begins(str_c(mbox->pending_copy_cmd), "UID COPY "));
+
+	if (strcmp(box, mbox->copy_dest_box) != 0) {
+		/* Not the same mailbox merging not possible */
+		return FALSE;
+	}
+	return seqset_builder_try_add(mbox->pending_copy_request->uidset_builder,
+				      IMAPC_SERVER_CMDLINE_MAX_LEN, uid);
+}
+
+static void
+imapc_mail_copy_bulk_delayed_send_or_merge(struct imapc_save_context *ctx,
+					   uint32_t uid,
+					   const char *box)
+{
+	struct imapc_mailbox *mbox = ctx->src_mbox;
+
+	if (mbox->pending_copy_request != NULL &&
+	    !imapc_mail_copy_bulk_try_merge(mbox, uid, box)) {
+		/* send the previous COPY and create new one after
+		   waiting for this one to be finished. */
+		imapc_mail_copy_bulk_flush(mbox);
+		imapc_copy_bulk_finish(mbox->pending_copy_request->sctx);
+	}
+	if (mbox->pending_copy_request == NULL) {
+		mbox->pending_copy_request =
+			i_new(struct imapc_copy_request, 1);
+		str_printfa(mbox->pending_copy_cmd, "UID COPY ");
+		mbox->pending_copy_request->uidset_builder =
+			seqset_builder_init(mbox->pending_copy_cmd);
+		seqset_builder_add(mbox->pending_copy_request->uidset_builder,
+				   uid);
+		mbox->copy_dest_box = i_strdup(box);
+	} else {
+		i_assert(mbox->pending_copy_request->sctx == ctx);
+	}
+	mbox->pending_copy_request->sctx = ctx;
+}
+
+static int
+imapc_copy_bulk(struct imapc_save_context *ctx, struct mail *mail)
+{
+	struct imapc_mailbox *mbox = IMAPC_MAILBOX(ctx->ctx.transaction->box);
+
+	imapc_mail_copy_bulk_delayed_send_or_merge(ctx, mail->uid,
+						   imapc_mailbox_get_remote_name(mbox));
+	imapc_save_add_to_index(ctx, 0);
+
+	return ctx->failed ? -1 : 0;
+}
+
+static bool imapc_is_mail_expunged(struct imapc_mailbox *mbox, uint32_t uid)
+{
+	if (array_is_created(&mbox->delayed_expunged_uids) &&
+	    seq_range_exists(&mbox->delayed_expunged_uids, uid))
+		return TRUE;
+	if (mbox->delayed_sync_trans == NULL)
+		return FALSE;
+
+	struct mail_index_view *view =
+		mail_index_transaction_get_view(mbox->delayed_sync_trans);
+	uint32_t seq;
+	return mail_index_lookup_seq(view, uid, &seq) &&
+		mail_index_transaction_is_expunged(mbox->delayed_sync_trans, seq);
+}
+
+int imapc_copy(struct mail_save_context *_ctx, struct mail *mail)
+{
+	struct imapc_save_context *ctx = IMAPC_SAVECTX(_ctx);
+	struct mailbox_transaction_context *_t = _ctx->transaction;
+	struct imapc_msgmap *src_msgmap;
+	uint32_t rseq;
+	int ret;
+
+	i_assert((_t->flags & MAILBOX_TRANSACTION_FLAG_EXTERNAL) != 0);
+
+	if (_t->box->storage == mail->box->storage) {
+		/* Currently we don't support copying mails from multiple
+		   different source mailboxes within the same transaction. */
+		i_assert(ctx->src_mbox == NULL || &ctx->src_mbox->box == mail->box);
+		ctx->src_mbox = IMAPC_MAILBOX(mail->box);
+		if (!mail->expunged && imapc_is_mail_expunged(ctx->mbox, mail->uid))
+			mail_set_expunged(mail);
+		/* same server, we can use COPY for the mail */
+		src_msgmap =
+			imapc_client_mailbox_get_msgmap(ctx->src_mbox->client_box);
+		if (mail->expunged ||
+		    !imapc_msgmap_uid_to_rseq(src_msgmap, mail->uid, &rseq)) {
+			mail_storage_set_error(mail->box->storage,
+					       MAIL_ERROR_EXPUNGED,
+					       "Some of the requested messages no longer exist.");
+			ctx->finished = TRUE;
+			index_save_context_free(_ctx);
+			return -1;
+		}
+		/* Mail has not been expunged and can be copied. */
+		if (ctx->mbox->capabilities == 0) {
+			/* The destination mailbox has not yet been selected
+			   so the capabilities are unknown */
+			if (imapc_client_get_capabilities(ctx->mbox->storage->client->client,
+						      &ctx->mbox->capabilities) < 0) {
+				mail_storage_set_error(mail->box->storage,
+						       MAIL_ERROR_UNAVAILABLE,
+						       "Failed to determine capabilities for mailbox.");
+				ctx->finished = TRUE;
+				index_save_context_free(_ctx);
+				return -1;
+			}
+		}
+		if ((ctx->mbox->capabilities & IMAPC_CAPABILITY_UIDPLUS) != 0)
+			ret = imapc_copy_bulk(ctx, mail);
+		else
+			ret = imapc_copy_simple(_ctx, mail);
+		index_save_context_free(_ctx);
+		return ret;
+	}
+	return mail_storage_copy(_ctx, mail);
+}