1 files changed, 833 insertions, 0 deletions

diff --git a/src/lib-storage/index/mbox/mbox-save.c b/src/lib-storage/index/mbox/mbox-save.c
new file mode 100644
index 0000000..2fb3e19
--- /dev/null
+++ b/src/lib-storage/index/mbox/mbox-save.c
@@ -0,0 +1,833 @@
+/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "ioloop.h"
+#include "array.h"
+#include "base64.h"
+#include "hostpid.h"
+#include "randgen.h"
+#include "istream.h"
+#include "ostream.h"
+#include "str.h"
+#include "write-full.h"
+#include "istream-header-filter.h"
+#include "istream-crlf.h"
+#include "istream-concat.h"
+#include "message-parser.h"
+#include "mail-user.h"
+#include "index-mail.h"
+#include "mbox-storage.h"
+#include "mbox-file.h"
+#include "mbox-from.h"
+#include "mbox-lock.h"
+#include "mbox-md5.h"
+#include "mbox-sync-private.h"
+
+#include <stddef.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <utime.h>
+
+#define MBOX_DELIVERY_ID_RAND_BYTES (64/8)
+
+struct mbox_save_context {
+	struct mail_save_context ctx;
+
+	struct mbox_mailbox *mbox;
+	struct mail_index_transaction *trans;
+	uoff_t append_offset, mail_offset;
+	time_t orig_atime;
+
+	string_t *headers;
+	size_t space_end_idx;
+	uint32_t seq, next_uid, uid_validity;
+
+	struct istream *input;
+	struct ostream *output;
+	uoff_t extra_hdr_offset, eoh_offset;
+	char last_char;
+
+	struct mbox_md5_context *mbox_md5_ctx;
+	char *x_delivery_id_header;
+
+	bool synced:1;
+	bool failed:1;
+	bool finished:1;
+};
+
+#define MBOX_SAVECTX(s)		container_of(s, struct mbox_save_context, ctx)
+
+static void ostream_error(struct mbox_save_context *ctx, const char *func)
+{
+	mbox_ostream_set_syscall_error(ctx->mbox, ctx->output, func);
+	ctx->failed = TRUE;
+}
+
+static void write_stream_error(struct mbox_save_context *ctx)
+{
+	ostream_error(ctx, "write()");
+}
+
+static void lseek_stream_error(struct mbox_save_context *ctx)
+{
+	ostream_error(ctx, "o_stream_seek()");
+}
+
+static int mbox_seek_to_end(struct mbox_save_context *ctx, uoff_t *offset)
+{
+	struct stat st;
+	char ch;
+	int fd;
+
+	if (ctx->mbox->mbox_writeonly) {
+		*offset = 0;
+		return 0;
+	}
+
+	fd = ctx->mbox->mbox_fd;
+	if (fstat(fd, &st) < 0) {
+		mbox_set_syscall_error(ctx->mbox, "fstat()");
+		return -1;
+	}
+
+	ctx->orig_atime = st.st_atime;
+
+	*offset = (uoff_t)st.st_size;
+	if (st.st_size == 0)
+		return 0;
+
+	if (lseek(fd, st.st_size-1, SEEK_SET) < 0) {
+                mbox_set_syscall_error(ctx->mbox, "lseek()");
+		return -1;
+	}
+
+	if (read(fd, &ch, 1) != 1) {
+		mbox_set_syscall_error(ctx->mbox, "read()");
+		return -1;
+	}
+
+	if (ch != '\n') {
+		if (write_full(fd, "\n", 1) < 0) {
+			mbox_set_syscall_error(ctx->mbox, "write()");
+			return -1;
+		}
+		*offset += 1;
+	}
+
+	return 0;
+}
+
+static int mbox_append_lf(struct mbox_save_context *ctx)
+{
+	if (o_stream_send(ctx->output, "\n", 1) < 0) {
+		write_stream_error(ctx);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int write_from_line(struct mbox_save_context *ctx, time_t received_date,
+			   const char *from_envelope)
+{
+	int ret;
+
+	T_BEGIN {
+		const char *line;
+
+		if (from_envelope == NULL) {
+			struct mail_storage *storage =
+				&ctx->mbox->storage->storage;
+
+			from_envelope =
+				strchr(storage->user->username, '@') != NULL ?
+				storage->user->username :
+				t_strconcat(storage->user->username,
+					    "@", my_hostdomain(), NULL);
+		} else if (*from_envelope == '\0') {
+			/* can't write empty envelope */
+			from_envelope = "MAILER-DAEMON";
+		}
+
+		/* save in local timezone, no matter what it was given with */
+		line = mbox_from_create(from_envelope, received_date);
+
+		if ((ret = o_stream_send_str(ctx->output, line)) < 0)
+			write_stream_error(ctx);
+	} T_END;
+	return ret;
+}
+
+static int mbox_write_content_length(struct mbox_save_context *ctx)
+{
+	uoff_t end_offset;
+	const char *str;
+	size_t len;
+
+	i_assert(ctx->eoh_offset != UOFF_T_MAX);
+
+	if (ctx->mbox->mbox_writeonly) {
+		/* we can't seek, don't set Content-Length */
+		return 0;
+	}
+
+	end_offset = ctx->output->offset;
+
+	/* write Content-Length headers */
+	str = t_strdup_printf("\nContent-Length: %s",
+			      dec2str(end_offset - ctx->eoh_offset));
+	len = strlen(str);
+
+	/* flush manually here so that we don't confuse seek() errors with
+	   buffer flushing errors */
+	if (o_stream_flush(ctx->output) < 0) {
+		write_stream_error(ctx);
+		return -1;
+	}
+	if (o_stream_seek(ctx->output, ctx->extra_hdr_offset +
+			  ctx->space_end_idx - len) < 0) {
+		lseek_stream_error(ctx);
+		return -1;
+	}
+
+	if (o_stream_send(ctx->output, str, len) < 0 ||
+	    o_stream_flush(ctx->output) < 0) {
+		write_stream_error(ctx);
+		return -1;
+	}
+
+	if (o_stream_seek(ctx->output, end_offset) < 0) {
+		lseek_stream_error(ctx);
+		return -1;
+	}
+	return 0;
+}
+
+static void mbox_save_init_sync(struct mailbox_transaction_context *t)
+{
+	struct mbox_mailbox *mbox = MBOX_MAILBOX(t->box);
+	struct mbox_save_context *ctx = MBOX_SAVECTX(t->save_ctx);
+	const struct mail_index_header *hdr;
+	struct mail_index_view *view;
+
+	/* open a new view to get the header. this is required if we just
+	   synced the mailbox so we can get updated next_uid. */
+	mail_index_refresh(mbox->box.index);
+	view = mail_index_view_open(mbox->box.index);
+	hdr = mail_index_get_header(view);
+
+	ctx->next_uid = hdr->next_uid;
+	ctx->uid_validity = hdr->uid_validity;
+	ctx->synced = TRUE;
+
+	mail_index_view_close(&view);
+}
+
+static void status_flags_append(string_t *str, enum mail_flags flags,
+				const struct mbox_flag_type *flags_list)
+{
+	int i;
+
+	flags ^= MBOX_NONRECENT_KLUDGE;
+	for (i = 0; flags_list[i].chr != 0; i++) {
+		if ((flags & flags_list[i].flag) != 0)
+			str_append_c(str, flags_list[i].chr);
+	}
+}
+
+static void mbox_save_append_flag_headers(string_t *str, enum mail_flags flags)
+{
+	/* write the Status: header always. It always gets added soon anyway. */
+	str_append(str, "Status: ");
+	status_flags_append(str, flags, mbox_status_flags);
+	str_append_c(str, '\n');
+
+	if ((flags & XSTATUS_FLAGS_MASK) != 0) {
+		str_append(str, "X-Status: ");
+		status_flags_append(str, flags, mbox_xstatus_flags);
+		str_append_c(str, '\n');
+	}
+}
+
+static void
+mbox_save_append_keyword_headers(struct mbox_save_context *ctx,
+				 struct mail_keywords *keywords)
+{
+	unsigned char space[MBOX_HEADER_PADDING+1 +
+			    sizeof("Content-Length: \n")-1 + MAX_INT_STRLEN];
+	const ARRAY_TYPE(keywords) *keyword_names_list;
+	const char *const *keyword_names;
+	unsigned int i, count, keyword_names_count;
+
+	keyword_names_list = mail_index_get_keywords(ctx->mbox->box.index);
+	keyword_names = array_get(keyword_names_list, &keyword_names_count);
+
+	str_append(ctx->headers, "X-Keywords:");
+	count = keywords == NULL ? 0 : keywords->count;
+	for (i = 0; i < count; i++) {
+		i_assert(keywords->idx[i] < keyword_names_count);
+
+		str_append_c(ctx->headers, ' ');
+		str_append(ctx->headers, keyword_names[keywords->idx[i]]);
+	}
+
+	memset(space, ' ', sizeof(space));
+	str_append_data(ctx->headers, space, sizeof(space));
+	ctx->space_end_idx = str_len(ctx->headers);
+	str_append_c(ctx->headers, '\n');
+}
+
+static int
+mbox_save_init_file(struct mbox_save_context *ctx,
+		    struct mbox_transaction_context *t)
+{
+	struct mailbox_transaction_context *_t = &t->t;
+	struct mbox_mailbox *mbox = ctx->mbox;
+	struct mail_storage *storage = &mbox->storage->storage;
+	int ret;
+
+	if (mbox_is_backend_readonly(ctx->mbox)) {
+		mail_storage_set_error(storage, MAIL_ERROR_PERM,
+				       "Read-only mbox");
+		return -1;
+	}
+
+	if (ctx->append_offset == UOFF_T_MAX) {
+		/* first appended mail in this transaction */
+		if (t->write_lock_id == 0) {
+			if (mbox_lock(mbox, F_WRLCK, &t->write_lock_id) <= 0)
+				return -1;
+		}
+
+		if (mbox->mbox_fd == -1) {
+			if (mbox_file_open(mbox) < 0)
+				return -1;
+		}
+
+		/* update mbox_sync_dirty state */
+		ret = mbox_sync_has_changed(mbox, TRUE);
+		if (ret < 0)
+			return -1;
+	}
+
+	if (!ctx->synced) {
+		/* we'll need to assign UID for the mail immediately. */
+		if (mbox_sync(mbox, 0) < 0)
+			return -1;
+		mbox_save_init_sync(_t);
+	}
+
+	/* the syncing above could have changed the append offset */
+	if (ctx->append_offset == UOFF_T_MAX) {
+		if (mbox_seek_to_end(ctx, &ctx->append_offset) < 0)
+			return -1;
+
+		i_assert(mbox->mbox_fd != -1);
+		ctx->output = o_stream_create_fd_file(mbox->mbox_fd,
+						      ctx->append_offset,
+						      FALSE);
+		o_stream_cork(ctx->output);
+	}
+	return 0;
+}
+
+static void
+save_header_callback(struct header_filter_istream *input ATTR_UNUSED,
+		     struct message_header_line *hdr,
+		     bool *matched, struct mbox_save_context *ctx)
+{
+	if (hdr != NULL) {
+		if (str_begins(hdr->name, "From ")) {
+			/* we can't allow From_-lines in headers. there's no
+			   legitimate reason for allowing them in any case,
+			   so just drop them. */
+			*matched = TRUE;
+			return;
+		}
+
+		if (!*matched && ctx->mbox_md5_ctx != NULL)
+			ctx->mbox->md5_v.more(ctx->mbox_md5_ctx, hdr);
+	}
+}
+
+static void mbox_save_x_delivery_id(struct mbox_save_context *ctx)
+{
+	unsigned char md5_result[MD5_RESULTLEN];
+	buffer_t *buf;
+	string_t *str;
+	void *randbuf;
+
+	buf = t_buffer_create(256);
+	buffer_append(buf, &ioloop_time, sizeof(ioloop_time));
+	buffer_append(buf, &ioloop_timeval.tv_usec,
+		      sizeof(ioloop_timeval.tv_usec));
+
+	randbuf = buffer_append_space_unsafe(buf, MBOX_DELIVERY_ID_RAND_BYTES);
+	random_fill(randbuf, MBOX_DELIVERY_ID_RAND_BYTES);
+
+	md5_get_digest(buf->data, buf->used, md5_result);
+
+	str = t_str_new(128);
+	str_append(str, "X-Delivery-ID: ");
+	base64_encode(md5_result, sizeof(md5_result), str);
+	str_append_c(str, '\n');
+
+	ctx->x_delivery_id_header = i_strdup(str_c(str));
+}
+
+static struct istream *
+mbox_save_get_input_stream(struct mbox_save_context *ctx, struct istream *input)
+{
+	struct istream *filter, *ret, *cache_input, *streams[3];
+
+	/* filter out unwanted headers and keep track of headers' MD5 sum */
+	filter = i_stream_create_header_filter(input, HEADER_FILTER_EXCLUDE |
+					       HEADER_FILTER_NO_CR |
+					       HEADER_FILTER_ADD_MISSING_EOH |
+					       HEADER_FILTER_END_BODY_WITH_LF,
+					       mbox_save_drop_headers,
+					       mbox_save_drop_headers_count,
+					       save_header_callback, ctx);
+
+	if ((ctx->mbox->storage->storage.flags &
+	     MAIL_STORAGE_FLAG_KEEP_HEADER_MD5) != 0) {
+		/* we're using MD5 sums to generate POP3 UIDLs.
+		   clients don't like it much if there are duplicates,
+		   so make sure that there can't be any by appending
+		   our own X-Delivery-ID header. */
+		const char *hdr;
+
+		T_BEGIN {
+			mbox_save_x_delivery_id(ctx);
+		} T_END;
+		hdr = ctx->x_delivery_id_header;
+
+		streams[0] = i_stream_create_from_data(hdr, strlen(hdr));
+		streams[1] = filter;
+		streams[2] = NULL;
+		ret = i_stream_create_concat(streams);
+		i_stream_unref(&filter);
+		filter = ret;
+	}
+
+	/* convert linefeeds to wanted format */
+	ret = ctx->mbox->storage->storage.set->mail_save_crlf ?
+		i_stream_create_crlf(filter) : i_stream_create_lf(filter);
+	i_stream_unref(&filter);
+
+	/* caching creates a tee stream */
+	cache_input = index_mail_cache_parse_init(ctx->ctx.dest_mail, ret);
+	i_stream_unref(&ret);
+	ret = cache_input;
+	return ret;
+}
+
+struct mail_save_context *
+mbox_save_alloc(struct mailbox_transaction_context *t)
+{
+	struct mbox_mailbox *mbox = MBOX_MAILBOX(t->box);
+	struct mbox_save_context *ctx;
+
+	i_assert((t->flags & MAILBOX_TRANSACTION_FLAG_EXTERNAL) != 0);
+
+	if (t->save_ctx == NULL) {
+		ctx = i_new(struct mbox_save_context, 1);
+		ctx->ctx.transaction = t;
+		ctx->mbox = mbox;
+		ctx->trans = t->itrans;
+		ctx->append_offset = UOFF_T_MAX;
+		ctx->headers = str_new(default_pool, 512);
+		ctx->mail_offset = UOFF_T_MAX;
+		t->save_ctx = &ctx->ctx;
+	}
+	return t->save_ctx;
+}
+
+int mbox_save_begin(struct mail_save_context *_ctx, struct istream *input)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+	struct mail_save_data *mdata = &_ctx->data;
+	struct mbox_transaction_context *t = MBOX_TRANSCTX(_ctx->transaction);
+	enum mail_flags save_flags;
+	uint64_t offset;
+
+	/* FIXME: we could write timezone_offset to From-line.. */
+	if (mdata->received_date == (time_t)-1)
+		mdata->received_date = ioloop_time;
+
+	ctx->failed = FALSE;
+	ctx->seq = 0;
+
+	if (mbox_save_init_file(ctx, t) < 0) {
+		ctx->failed = TRUE;
+		return -1;
+	}
+
+	save_flags = mdata->flags;
+	if (mdata->uid == 0)
+		save_flags |= MAIL_RECENT;
+	str_truncate(ctx->headers, 0);
+	if (ctx->synced) {
+		if (ctx->mbox->mbox_save_md5)
+			ctx->mbox_md5_ctx = ctx->mbox->md5_v.init();
+		if (ctx->next_uid < mdata->uid) {
+			/* we can use the wanted UID */
+			ctx->next_uid = mdata->uid;
+		}
+		if (ctx->output->offset == 0) {
+			/* writing the first mail. Insert X-IMAPbase as well. */
+			str_printfa(ctx->headers, "X-IMAPbase: %u %010u\n",
+				    ctx->uid_validity, ctx->next_uid);
+		}
+		str_printfa(ctx->headers, "X-UID: %u\n", ctx->next_uid);
+
+		mail_index_append(ctx->trans, ctx->next_uid, &ctx->seq);
+		mail_index_update_flags(ctx->trans, ctx->seq, MODIFY_REPLACE,
+					save_flags & ENUM_NEGATE(MAIL_RECENT));
+		if (mdata->keywords != NULL) {
+			mail_index_update_keywords(ctx->trans, ctx->seq,
+						   MODIFY_REPLACE,
+						   mdata->keywords);
+		}
+		if (mdata->min_modseq != 0) {
+			mail_index_update_modseq(ctx->trans, ctx->seq,
+						 mdata->min_modseq);
+		}
+
+		offset = ctx->output->offset == 0 ? 0 :
+			ctx->output->offset - 1;
+		mail_index_update_ext(ctx->trans, ctx->seq,
+				      ctx->mbox->mbox_ext_idx, &offset, NULL);
+		ctx->next_uid++;
+
+		/* parse and cache the mail headers as we read it */
+		mail_set_seq_saving(_ctx->dest_mail, ctx->seq);
+	}
+	mbox_save_append_flag_headers(ctx->headers, save_flags);
+	mbox_save_append_keyword_headers(ctx, mdata->keywords);
+	str_append_c(ctx->headers, '\n');
+
+	i_assert(ctx->mbox->mbox_lock_type == F_WRLCK);
+
+	ctx->mail_offset = ctx->output->offset;
+	ctx->eoh_offset = UOFF_T_MAX;
+	ctx->last_char = '\n';
+
+	if (write_from_line(ctx, mdata->received_date, mdata->from_envelope) < 0)
+		ctx->failed = TRUE;
+	else
+		ctx->input = mbox_save_get_input_stream(ctx, input);
+	return ctx->failed ? -1 : 0;
+}
+
+static int mbox_save_body_input(struct mbox_save_context *ctx)
+{
+	const unsigned char *data;
+	size_t size;
+
+	data = i_stream_get_data(ctx->input, &size);
+	if (size > 0) {
+		if (o_stream_send(ctx->output, data, size) < 0) {
+			write_stream_error(ctx);
+			return -1;
+		}
+		ctx->last_char = data[size-1];
+		i_stream_skip(ctx->input, size);
+	}
+	return 0;
+}
+
+static int mbox_save_body(struct mbox_save_context *ctx)
+{
+	ssize_t ret;
+
+	while ((ret = i_stream_read(ctx->input)) != -1) {
+		if (mbox_save_body_input(ctx) < 0)
+			return -1;
+		/* i_stream_read() may have returned 0 at EOF
+		   because of this parser */
+		index_mail_cache_parse_continue(ctx->ctx.dest_mail);
+		if (ret == 0)
+			return 0;
+	}
+
+	i_assert(ctx->last_char == '\n');
+	return 0;
+}
+
+static int mbox_save_finish_headers(struct mbox_save_context *ctx)
+{
+	i_assert(ctx->eoh_offset == UOFF_T_MAX);
+
+	/* append our own headers and ending empty line */
+	ctx->extra_hdr_offset = ctx->output->offset;
+	if (o_stream_send(ctx->output, str_data(ctx->headers),
+			  str_len(ctx->headers)) < 0) {
+		write_stream_error(ctx);
+		return -1;
+	}
+	ctx->eoh_offset = ctx->output->offset;
+	return 0;
+}
+
+int mbox_save_continue(struct mail_save_context *_ctx)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+	const unsigned char *data;
+	size_t i, size;
+	ssize_t ret;
+
+	if (ctx->failed)
+		return -1;
+
+	if (ctx->eoh_offset != UOFF_T_MAX) {
+		/* writing body */
+		return mbox_save_body(ctx);
+	}
+
+	while ((ret = i_stream_read_more(ctx->input, &data, &size)) > 0) {
+		for (i = 0; i < size; i++) {
+			if (data[i] == '\n' &&
+			    ((i == 0 && ctx->last_char == '\n') ||
+			     (i > 0 && data[i-1] == '\n'))) {
+				/* end of headers. we don't need to worry about
+				   CRs because they're dropped */
+				break;
+			}
+		}
+		if (i != size) {
+			/* found end of headers. write the rest of them
+			   (not including the finishing empty line) */
+			if (o_stream_send(ctx->output, data, i) < 0) {
+				write_stream_error(ctx);
+				return -1;
+			}
+			ctx->last_char = '\n';
+			i_stream_skip(ctx->input, i + 1);
+			break;
+		}
+
+		if (o_stream_send(ctx->output, data, size) < 0) {
+			write_stream_error(ctx);
+			return -1;
+		}
+		i_assert(size > 0);
+		ctx->last_char = data[size-1];
+		i_stream_skip(ctx->input, size);
+		index_mail_cache_parse_continue(ctx->ctx.dest_mail);
+	}
+	if (ret == 0)
+		return 0;
+	if (ctx->input->stream_errno != 0) {
+		i_error("read(%s) failed: %s", i_stream_get_name(ctx->input),
+			i_stream_get_error(ctx->input));
+		ctx->failed = TRUE;
+		return -1;
+	}
+
+	i_assert(ctx->last_char == '\n');
+
+	if (ctx->mbox_md5_ctx != NULL) {
+		unsigned char hdr_md5_sum[16];
+
+		if (ctx->x_delivery_id_header != NULL) {
+			struct message_header_line hdr;
+
+			i_zero(&hdr);
+			hdr.name = ctx->x_delivery_id_header;
+			hdr.name_len = sizeof("X-Delivery-ID")-1;
+			hdr.middle = (const unsigned char *)hdr.name +
+				hdr.name_len;
+			hdr.middle_len = 2;
+			hdr.value = hdr.full_value =
+				hdr.middle + hdr.middle_len;
+			hdr.value_len = strlen((const char *)hdr.value);
+			ctx->mbox->md5_v.more(ctx->mbox_md5_ctx, &hdr);
+		}
+		ctx->mbox->md5_v.finish(ctx->mbox_md5_ctx, hdr_md5_sum);
+		mail_index_update_ext(ctx->trans, ctx->seq,
+				      ctx->mbox->md5hdr_ext_idx,
+				      hdr_md5_sum, NULL);
+	}
+
+	if (mbox_save_finish_headers(ctx) < 0)
+		return -1;
+
+	/* write body */
+	if (mbox_save_body_input(ctx) < 0)
+		return -1;
+	return ctx->input->eof ? 0 : mbox_save_body(ctx);
+}
+
+int mbox_save_finish(struct mail_save_context *_ctx)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+
+	if (!ctx->failed && ctx->eoh_offset == UOFF_T_MAX)
+		(void)mbox_save_finish_headers(ctx);
+
+	if (ctx->output != NULL) {
+		/* make sure everything is written */
+		if (o_stream_flush(ctx->output) < 0)
+			write_stream_error(ctx);
+	}
+
+	ctx->finished = TRUE;
+	if (!ctx->failed) {
+		i_assert(ctx->output != NULL);
+		T_BEGIN {
+			if (mbox_write_content_length(ctx) < 0 ||
+			    mbox_append_lf(ctx) < 0)
+				ctx->failed = TRUE;
+		} T_END;
+	}
+
+	index_mail_cache_parse_deinit(ctx->ctx.dest_mail,
+				      ctx->ctx.data.received_date,
+				      !ctx->failed);
+	if (ctx->input != NULL)
+		i_stream_destroy(&ctx->input);
+
+	if (ctx->failed && ctx->mail_offset != UOFF_T_MAX) {
+		/* saving this mail failed - truncate back to beginning of it */
+		i_assert(ctx->output != NULL);
+		(void)o_stream_flush(ctx->output);
+		if (ftruncate(ctx->mbox->mbox_fd, (off_t)ctx->mail_offset) < 0)
+			mbox_set_syscall_error(ctx->mbox, "ftruncate()");
+		(void)o_stream_seek(ctx->output, ctx->mail_offset);
+		ctx->mail_offset = UOFF_T_MAX;
+	}
+
+	if (ctx->seq != 0 && ctx->failed) {
+		index_storage_save_abort_last(&ctx->ctx, ctx->seq);
+	}
+	index_save_context_free(_ctx);
+	return ctx->failed ? -1 : 0;
+}
+
+void mbox_save_cancel(struct mail_save_context *_ctx)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+
+	ctx->failed = TRUE;
+	(void)mbox_save_finish(_ctx);
+}
+
+static void mbox_transaction_save_deinit(struct mbox_save_context *ctx)
+{
+	o_stream_destroy(&ctx->output);
+	str_free(&ctx->headers);
+}
+
+static void mbox_save_truncate(struct mbox_save_context *ctx)
+{
+	if (ctx->append_offset == UOFF_T_MAX || ctx->mbox->mbox_fd == -1)
+		return;
+
+	i_assert(ctx->mbox->mbox_lock_type == F_WRLCK);
+
+	/* failed, truncate file back to original size. output stream needs to
+	   be flushed before truncating so unref() won't write anything. */
+	if (ctx->output != NULL)
+		(void)o_stream_flush(ctx->output);
+
+	if (ftruncate(ctx->mbox->mbox_fd, (off_t)ctx->append_offset) < 0)
+		mbox_set_syscall_error(ctx->mbox, "ftruncate()");
+}
+
+int mbox_transaction_save_commit_pre(struct mail_save_context *_ctx)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+	struct mailbox_transaction_context *_t = _ctx->transaction;
+	struct mbox_mailbox *mbox = ctx->mbox;
+	struct stat st;
+	int ret = 0;
+
+	i_assert(ctx->finished);
+	i_assert(mbox->mbox_fd != -1);
+
+	if (fstat(mbox->mbox_fd, &st) < 0) {
+		mbox_set_syscall_error(mbox, "fstat()");
+		ret = -1;
+	}
+
+	if (ctx->synced) {
+		_t->changes->uid_validity = ctx->uid_validity;
+		mail_index_append_finish_uids(ctx->trans, 0,
+					      &_t->changes->saved_uids);
+
+		mail_index_update_header(ctx->trans,
+			offsetof(struct mail_index_header, next_uid),
+			&ctx->next_uid, sizeof(ctx->next_uid), FALSE);
+
+		if (ret == 0) {
+			mbox->mbox_hdr.sync_mtime = st.st_mtime;
+			mbox->mbox_hdr.sync_size = st.st_size;
+			mail_index_update_header_ext(ctx->trans,
+						     mbox->mbox_ext_idx,
+						     0, &mbox->mbox_hdr,
+						     sizeof(mbox->mbox_hdr));
+		}
+	}
+
+	if (ret == 0 && ctx->orig_atime != st.st_atime) {
+		/* try to set atime back to its original value.
+		   (it'll fail with EPERM for shared mailboxes where we aren't
+		   the file's owner) */
+		struct utimbuf buf;
+
+		buf.modtime = st.st_mtime;
+		buf.actime = ctx->orig_atime;
+		if (utime(mailbox_get_path(&mbox->box), &buf) < 0 &&
+		    errno != EPERM)
+			mbox_set_syscall_error(mbox, "utime()");
+	}
+
+	if (ctx->output != NULL) {
+		/* flush the final LF */
+		if (o_stream_flush(ctx->output) < 0)
+			write_stream_error(ctx);
+	}
+	if (mbox->mbox_fd != -1 && !mbox->mbox_writeonly &&
+	    mbox->storage->storage.set->parsed_fsync_mode != FSYNC_MODE_NEVER) {
+		if (fdatasync(mbox->mbox_fd) < 0) {
+			mbox_set_syscall_error(mbox, "fdatasync()");
+			mbox_save_truncate(ctx);
+			ret = -1;
+		}
+	}
+
+	mbox_transaction_save_deinit(ctx);
+	if (ret < 0)
+		i_free(ctx);
+	return ret;
+}
+
+void mbox_transaction_save_commit_post(struct mail_save_context *_ctx,
+				       struct mail_index_transaction_commit_result *result ATTR_UNUSED)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+
+	i_assert(ctx->mbox->mbox_lock_type == F_WRLCK);
+
+	if (ctx->synced) {
+		/* after saving mails with UIDs we need to update
+		   the last-uid */
+		(void)mbox_sync(ctx->mbox, MBOX_SYNC_HEADER |
+				MBOX_SYNC_REWRITE);
+	}
+	i_free(ctx);
+}
+
+void mbox_transaction_save_rollback(struct mail_save_context *_ctx)
+{
+	struct mbox_save_context *ctx = MBOX_SAVECTX(_ctx);
+
+	if (!ctx->finished)
+		mbox_save_cancel(&ctx->ctx);
+
+	mbox_save_truncate(ctx);
+	mbox_transaction_save_deinit(ctx);
+	i_free(ctx);
+}