view src/doveadm/dsync/dsync-mail.c @ 22715:20415dd0b85a

dsync: Add per-mailbox sync lock that is always used. Both importing and exporting gets the lock before they even sync the mailbox. The lock is kept until the import/export finishes. This guarantees that no matter how dsync is run, two dsyncs can't be working on the same mailbox at the same time. This lock is in addition to the optional per-user lock enabled by the -l parameter. If the -l parameter is used, the same lock timeout is used for the per-mailbox lock. Otherwise 30s timeout is used. This should help to avoid email duplication when replication is enabled for public namespaces, and maybe in some other rare situations as well.
author Timo Sirainen <timo.sirainen@dovecot.fi>
date Thu, 28 Dec 2017 14:10:23 +0200
parents cb108f786fb4
children
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/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "hex-binary.h"
#include "md5.h"
#include "istream.h"
#include "istream-crlf.h"
#include "message-header-hash.h"
#include "message-size.h"
#include "mail-storage.h"
#include "dsync-mail.h"

struct mailbox_header_lookup_ctx *
dsync_mail_get_hash_headers(struct mailbox *box, const char *const *hashed_headers)
{
	return mailbox_header_lookup_init(box, hashed_headers);
}

int dsync_mail_get_hdr_hash(struct mail *mail, unsigned int version,
			    const char *const *hashed_headers, const char **hdr_hash_r)
{
	struct istream *hdr_input, *input;
	struct mailbox_header_lookup_ctx *hdr_ctx;
	struct message_header_hash_context hash_ctx;
	struct md5_context md5_ctx;
	unsigned char md5_result[MD5_RESULTLEN];
	const unsigned char *data;
	size_t size;
	ssize_t sret;
	int ret = 0;

	hdr_ctx = mailbox_header_lookup_init(mail->box, hashed_headers);
	ret = mail_get_header_stream(mail, hdr_ctx, &hdr_input);
	mailbox_header_lookup_unref(&hdr_ctx);
	if (ret < 0)
		return -1;

	input = i_stream_create_lf(hdr_input);

	md5_init(&md5_ctx);
	i_zero(&hash_ctx);
	while ((sret = i_stream_read_more(input, &data, &size)) > 0) {
		message_header_hash_more(&hash_ctx, &hash_method_md5, &md5_ctx,
					 version, data, size);
		i_stream_skip(input, size);
	}
	i_assert(sret == -1);
	if (input->stream_errno != 0)
		ret = -1;
	i_stream_unref(&input);

	md5_final(&md5_ctx, md5_result);
	*hdr_hash_r = binary_to_hex(md5_result, sizeof(md5_result));
	return ret;
}

int dsync_mail_fill(struct mail *mail, bool minimal_fill,
		    struct dsync_mail *dmail_r, const char **error_field_r)
{
	const char *guid;

	i_zero(dmail_r);

	if (mail_get_special(mail, MAIL_FETCH_GUID, &guid) < 0) {
		*error_field_r = "GUID";
		return -1;
	}
	dmail_r->guid = guid;
	dmail_r->uid = mail->uid;

	dmail_r->input_mail = mail;
	dmail_r->input_mail_uid = mail->uid;

	if (mail_get_save_date(mail, &dmail_r->saved_date) < 0) {
		*error_field_r = "saved-date";
		return -1;
	}
	if (!minimal_fill)
		return dsync_mail_fill_nonminimal(mail, dmail_r, error_field_r);
	dmail_r->minimal_fields = TRUE;
	return 0;
}

int dsync_mail_fill_nonminimal(struct mail *mail, struct dsync_mail *dmail_r,
			       const char **error_field_r)
{
	const char *str;

	if (mail_get_stream(mail, NULL, NULL, &dmail_r->input) < 0) {
		*error_field_r = "body";
		return -1;
	}

	if (mail_get_special(mail, MAIL_FETCH_UIDL_BACKEND, &dmail_r->pop3_uidl) < 0) {
		*error_field_r = "pop3-uidl";
		return -1;
	}
	if (mail_get_special(mail, MAIL_FETCH_POP3_ORDER, &str) < 0) {
		*error_field_r = "pop3-order";
		return -1;
	}
	if (*str != '\0') {
		if (str_to_uint(str, &dmail_r->pop3_order) < 0)
			i_unreached();
	}
	if (mail_get_received_date(mail, &dmail_r->received_date) < 0) {
		*error_field_r = "received-date";
		return -1;
	}
	return 0;
}

static void
const_string_array_dup(pool_t pool, const ARRAY_TYPE(const_string) *src,
		       ARRAY_TYPE(const_string) *dest)
{
	const char *const *strings, *str;
	unsigned int i, count;

	if (!array_is_created(src))
		return;

	strings = array_get(src, &count);
	if (count == 0)
		return;

	p_array_init(dest, pool, count);
	for (i = 0; i < count; i++) {
		str = p_strdup(pool, strings[i]);
		array_append(dest, &str, 1);
	}
}

void dsync_mail_change_dup(pool_t pool, const struct dsync_mail_change *src,
			   struct dsync_mail_change *dest_r)
{
	dest_r->type = src->type;
	dest_r->uid = src->uid;
	if (src->guid != NULL) {
		dest_r->guid = *src->guid == '\0' ? "" :
			p_strdup(pool, src->guid);
	}
	dest_r->hdr_hash = p_strdup(pool, src->hdr_hash);
	dest_r->modseq = src->modseq;
	dest_r->pvt_modseq = src->pvt_modseq;

	dest_r->add_flags = src->add_flags;
	dest_r->remove_flags = src->remove_flags;
	dest_r->final_flags = src->final_flags;
	dest_r->keywords_reset = src->keywords_reset;
	const_string_array_dup(pool, &src->keyword_changes,
			       &dest_r->keyword_changes);
	dest_r->received_timestamp = src->received_timestamp;
	dest_r->virtual_size = src->virtual_size;
}