static ssize_t i_stream_file_read(struct istream_private *stream)
{
	struct file_istream *fstream = (struct file_istream *) stream;
	uoff_t offset;
	size_t size;
	ssize_t ret;

	if (!i_stream_try_alloc(stream, 1, &size))
		return -2;

	if (stream->fd == -1) {
		if (i_stream_file_open(stream) < 0)
			return -1;
	}

	offset = stream->istream.v_offset + (stream->pos - stream->skip);
	do {
		if (fstream->file) {
			ret = pread(stream->fd, stream->w_buffer + stream->pos,
				    size, offset);
		} else if (fstream->seen_eof) {
			/* don't try to read() again. EOF from keyboard (^D)
			   requires this to work right. */
			ret = 0;
		} else {
			ret = read(stream->fd, stream->w_buffer + stream->pos,
				   size);
		}
	} while (unlikely(ret < 0 && errno == EINTR &&
			  stream->istream.blocking));

	if (ret == 0) {
		/* EOF */
		stream->istream.eof = TRUE;
		fstream->seen_eof = TRUE;
		return -1;
	}

	if (unlikely(ret < 0)) {
		if (errno == EINTR || errno == EAGAIN) {
			i_assert(!stream->istream.blocking);
			ret = 0;
		} else {
			i_assert(errno != 0);
			/* if we get EBADF for a valid fd, it means something's
			   really wrong and we'd better just crash. */
			i_assert(errno != EBADF);
			if (fstream->file) {
				io_stream_set_error(&stream->iostream,
					"pread(size=%"PRIuSIZE_T
					" offset=%"PRIuUOFF_T") failed: %m",
					size, offset);
			} else {
				io_stream_set_error(&stream->iostream,
					"read(size=%"PRIuSIZE_T") failed: %m",
					size);
			}
			stream->istream.stream_errno = errno;
			return -1;
		}
	}

	if (ret > 0 && fstream->skip_left > 0) {
		i_assert(!fstream->file);
		i_assert(stream->skip == stream->pos);

		if (fstream->skip_left >= (size_t)ret) {
			fstream->skip_left -= ret;
			ret = 0;
		} else {
			ret -= fstream->skip_left;
			stream->pos += fstream->skip_left;
			stream->skip += fstream->skip_left;
			fstream->skip_left = 0;
		}
	}

	stream->pos += ret;
	i_assert(ret != 0 || !fstream->file);
	i_assert(ret != -1);
	return ret;
}

struct service_process *service_process_create(struct service *service)
{
	static unsigned int uid_counter = 0;
	struct service_process *process;
	unsigned int uid = ++uid_counter;
	const char *hostdomain;
	pid_t pid;
	bool process_forked;

	i_assert(service->status_fd[0] != -1);

	if (service->to_throttle != NULL) {
		/* throttling service, don't create new processes */
		return NULL;
	}
	if (service->list->destroying) {
		/* these services are being destroyed, no point in creating
		   new processes now */
		return NULL;
	}
	/* look this up before fork()ing so that it gets cached for all the
	   future lookups. */
	hostdomain = my_hostdomain();

	if (service->type == SERVICE_TYPE_ANVIL &&
	    service_anvil_global->pid != 0) {
		pid = service_anvil_global->pid;
		uid = service_anvil_global->uid;
		process_forked = FALSE;
	} else {
		pid = fork();
		process_forked = TRUE;
		service->list->fork_counter++;
	}

	if (pid < 0) {
		service_error(service, "fork() failed: %m");
		return NULL;
	}
	if (pid == 0) {
		/* child */
		service_process_setup_environment(service, uid, hostdomain);
		service_reopen_inet_listeners(service);
		service_dup_fds(service);
		drop_privileges(service);
		process_exec(service->executable, NULL);
	}
	i_assert(hash_table_lookup(service_pids, POINTER_CAST(pid)) == NULL);

	process = i_new(struct service_process, 1);
	process->service = service;
	process->refcount = 1;
	process->pid = pid;
	process->uid = uid;
	if (process_forked) {
		process->to_status =
			timeout_add(SERVICE_FIRST_STATUS_TIMEOUT_SECS * 1000,
				    service_process_status_timeout, process);
	}

	process->available_count = service->client_limit;
	service->process_count++;
	service->process_avail++;
	DLLIST_PREPEND(&service->processes, process);

	service_list_ref(service->list);
	hash_table_insert(service_pids, POINTER_CAST(process->pid), process);

	if (service->type == SERVICE_TYPE_ANVIL && process_forked)
		service_anvil_process_created(process);
	return process;
}

static void
service_dup_fds(struct service *service)
{
	struct service_listener *const *listeners;
	ARRAY_TYPE(dup2) dups;
	string_t *listener_settings;
	int fd = MASTER_LISTEN_FD_FIRST;
	unsigned int i, count, socket_listener_count;

	/* stdin/stdout is already redirected to /dev/null. Other master fds
	   should have been opened with fd_close_on_exec() so we don't have to
	   worry about them.

	   because the destination fd might be another one's source fd we have
	   to be careful not to overwrite anything. dup() the fd when needed */

        socket_listener_count = 0;
	listeners = array_get(&service->listeners, &count);
	t_array_init(&dups, count + 10);

	switch (service->type) {
	case SERVICE_TYPE_LOG:
		i_assert(fd == MASTER_LISTEN_FD_FIRST);
		services_log_dup2(&dups, service->list, fd,
				  &socket_listener_count);
		fd += socket_listener_count;
		break;
	case SERVICE_TYPE_ANVIL:
		dup2_append(&dups, service_anvil_global->log_fdpass_fd[0],
			    MASTER_ANVIL_LOG_FDPASS_FD);
		/* nonblocking anvil fd must be the first one. anvil treats it
		   as the master's fd */
		dup2_append(&dups, service_anvil_global->nonblocking_fd[0], fd++);
		dup2_append(&dups, service_anvil_global->blocking_fd[0], fd++);
		socket_listener_count += 2;
		break;
	default:
		break;
	}

	/* add listeners */
	listener_settings = t_str_new(256);
	for (i = 0; i < count; i++) {
		if (listeners[i]->fd != -1) {
			str_truncate(listener_settings, 0);
			str_append_tabescaped(listener_settings, listeners[i]->name);

			if (listeners[i]->type == SERVICE_LISTENER_INET) {
				if (listeners[i]->set.inetset.set->ssl)
					str_append(listener_settings, "\tssl");
				if (listeners[i]->set.inetset.set->haproxy)
					str_append(listener_settings, "\thaproxy");
			}
			
			dup2_append(&dups, listeners[i]->fd, fd++);

			env_put(t_strdup_printf("SOCKET%d_SETTINGS=%s",
				socket_listener_count, str_c(listener_settings)));
			socket_listener_count++;
		}
	}

	if (service->login_notify_fd != -1) {
		dup2_append(&dups, service->login_notify_fd,
			    MASTER_LOGIN_NOTIFY_FD);
	}
	switch (service->type) {
	case SERVICE_TYPE_LOG:
	case SERVICE_TYPE_ANVIL:
	case SERVICE_TYPE_CONFIG:
		dup2_append(&dups, dev_null_fd, MASTER_ANVIL_FD);
		break;
	case SERVICE_TYPE_UNKNOWN:
	case SERVICE_TYPE_LOGIN:
	case SERVICE_TYPE_STARTUP:
		dup2_append(&dups, service_anvil_global->blocking_fd[1],
			    MASTER_ANVIL_FD);
		break;
	}
	dup2_append(&dups, service->status_fd[1], MASTER_STATUS_FD);
	if (service->type != SERVICE_TYPE_ANVIL) {
		dup2_append(&dups, service->master_dead_pipe_fd[1],
			    MASTER_DEAD_FD);
	} else {
		dup2_append(&dups, global_master_dead_pipe_fd[1],
			    MASTER_DEAD_FD);
	}

	if (service->type == SERVICE_TYPE_LOG) {
		/* keep stderr as-is. this is especially important when
		   log_path=/dev/stderr, but might be helpful even in other
		   situations for logging startup errors */
	} else {
		/* set log file to stderr. dup2() here immediately so that
		   we can set up logging to it without causing any log messages
		   to be lost. */
		i_assert(service->log_fd[1] != -1);

		env_put("LOG_SERVICE=1");
		if (dup2(service->log_fd[1], STDERR_FILENO) < 0)
//.........这里部分代码省略.........

struct client *
client_create(int fd, bool ssl, pool_t pool,
	      const struct master_service_connection *conn,
	      const struct login_settings *set,
	      const struct master_service_ssl_settings *ssl_set,
	      void **other_sets)
{
	struct client *client;

	i_assert(fd != -1);

	client = login_binary->client_vfuncs->alloc(pool);
	client->v = *login_binary->client_vfuncs;
	if (client->v.auth_send_challenge == NULL)
		client->v.auth_send_challenge = client_auth_send_challenge;
	if (client->v.auth_parse_response == NULL)
		client->v.auth_parse_response = client_auth_parse_response;

	client->created = ioloop_time;
	client->refcount = 1;

	client->pool = pool;
	client->set = set;
	client->ssl_set = ssl_set;

	client->fd = fd;
	client->tls = ssl;

	client->local_ip = conn->local_ip;
	client->local_port = conn->local_port;
	client->ip = conn->remote_ip;
	client->remote_port = conn->remote_port;
	client->real_local_ip = conn->real_local_ip;
	client->real_local_port = conn->real_local_port;
	client->real_remote_ip = conn->real_remote_ip;
	client->real_remote_port = conn->real_remote_port;
	client->listener_name = p_strdup(client->pool, conn->name);

	client->trusted = client_is_trusted(client);
	client->secured = ssl || client->trusted ||
		net_ip_compare(&conn->real_remote_ip, &conn->real_local_ip);
	client->proxy_ttl = LOGIN_PROXY_TTL;

	if (last_client == NULL)
		last_client = client;
	DLLIST_PREPEND(&clients, client);
	clients_count++;

	client->to_disconnect =
		timeout_add(CLIENT_LOGIN_TIMEOUT_MSECS,
			    client_idle_disconnect_timeout, client);
	client_open_streams(client);

	client->v.create(client, other_sets);

	if (auth_client_is_connected(auth_client))
		client_notify_auth_ready(client);
	else
		client_set_auth_waiting(client);

	login_refresh_proctitle();
	return client;
}

static ssize_t i_stream_lzma_read(struct istream_private *stream)
{
	struct lzma_istream *zstream = (struct lzma_istream *)stream;
	const unsigned char *data;
	uoff_t high_offset;
	size_t size, out_size;
	lzma_ret ret;

	high_offset = stream->istream.v_offset + (stream->pos - stream->skip);
	if (zstream->eof_offset == high_offset) {
		i_assert(zstream->high_pos == 0 ||
			 zstream->high_pos == stream->pos);
		stream->istream.eof = TRUE;
		return -1;
	}

	if (stream->pos < zstream->high_pos) {
		/* we're here because we seeked back within the read buffer. */
		ret = zstream->high_pos - stream->pos;
		stream->pos = zstream->high_pos;
		zstream->high_pos = 0;

		if (zstream->eof_offset != (uoff_t)-1) {
			high_offset = stream->istream.v_offset +
				(stream->pos - stream->skip);
			i_assert(zstream->eof_offset == high_offset);
			stream->istream.eof = TRUE;
		}
		return ret;
	}
	zstream->high_pos = 0;

	if (stream->pos + CHUNK_SIZE > stream->buffer_size) {
		/* try to keep at least CHUNK_SIZE available */
		if (!zstream->marked && stream->skip > 0) {
			/* don't try to keep anything cached if we don't
			   have a seek mark. */
			i_stream_compress(stream);
		}
		if (stream->max_buffer_size == 0 ||
		    stream->buffer_size < stream->max_buffer_size)
			i_stream_grow_buffer(stream, CHUNK_SIZE);

		if (stream->pos == stream->buffer_size) {
			if (stream->skip > 0) {
				/* lose our buffer cache */
				i_stream_compress(stream);
			}

			if (stream->pos == stream->buffer_size)
				return -2; /* buffer full */
		}
	}

	if (i_stream_read_data(stream->parent, &data, &size, 0) < 0) {
		if (stream->parent->stream_errno != 0) {
			stream->istream.stream_errno =
				stream->parent->stream_errno;
		} else {
			i_assert(stream->parent->eof);
			lzma_stream_end(zstream);
			stream->istream.eof = TRUE;
		}
		return -1;
	}
	if (size == 0) {
		/* no more input */
		i_assert(!stream->istream.blocking);
		return 0;
	}

	zstream->strm.next_in = data;
	zstream->strm.avail_in = size;

	out_size = stream->buffer_size - stream->pos;
	zstream->strm.next_out = stream->w_buffer + stream->pos;
	zstream->strm.avail_out = out_size;
	ret = lzma_code(&zstream->strm, LZMA_RUN);

	out_size -= zstream->strm.avail_out;
	stream->pos += out_size;

	i_stream_skip(stream->parent, size - zstream->strm.avail_in);

	switch (ret) {
	case LZMA_OK:
		break;
	case LZMA_DATA_ERROR:
	case LZMA_BUF_ERROR:
		lzma_read_error(zstream, "corrupted data");
		stream->istream.stream_errno = EINVAL;
		return -1;
	case LZMA_FORMAT_ERROR:
		lzma_read_error(zstream, "wrong magic in header (not xz file?)");
		stream->istream.stream_errno = EINVAL;
		return -1;
	case LZMA_OPTIONS_ERROR:
		lzma_read_error(zstream, "Unsupported xz options");
		stream->istream.stream_errno = EINVAL;
		return -1;
//.........这里部分代码省略.........

static void imap_urlauth_fetch_ref(struct imap_urlauth_fetch *ufetch)
{
	i_assert(ufetch->refcount > 0);
	ufetch->refcount++;
}

static int parse_next_header(struct message_parser_ctx *ctx,
			     struct message_block *block_r)
{
	struct message_part *part = ctx->part;
	struct message_header_line *hdr;
	struct message_boundary *boundary;
	bool full;
	int ret;

	if ((ret = message_parser_read_more(ctx, block_r, &full)) == 0)
		return ret;

	if (ret > 0 && block_is_at_eoh(block_r) &&
	    ctx->last_boundary != NULL &&
	    (part->flags & MESSAGE_PART_FLAG_IS_MIME) != 0) {
		/* we are at the end of headers and we've determined that we're
		   going to start a multipart. add the boundary already here
		   at this point so we can reliably determine whether the
		   "\n--boundary" belongs to us or to a previous boundary.
		   this is a problem if the boundary prefixes are identical,
		   because MIME requires only the prefix to match. */
		parse_next_body_multipart_init(ctx);
		ctx->multipart = TRUE;
	}

	/* before parsing the header see if we can find a --boundary from here.
	   we're guaranteed to be at the beginning of the line here. */
	if (ret > 0) {
		ret = ctx->boundaries == NULL ? -1 :
			boundary_line_find(ctx, block_r->data,
					   block_r->size, full, &boundary);
		if (ret > 0 && boundary->part == ctx->part) {
			/* our own body begins with our own --boundary.
			   we don't want to handle that yet. */
			ret = -1;
		}
	}
	if (ret < 0) {
		/* no boundary */
		ret = message_parse_header_next(ctx->hdr_parser_ctx, &hdr);
		if (ret == 0 || (ret < 0 && ctx->input->stream_errno != 0)) {
			ctx->want_count = i_stream_get_data_size(ctx->input) + 1;
			return ret;
		}
	} else if (ret == 0) {
		/* need more data */
		return 0;
	} else {
		/* boundary found. stop parsing headers here. The previous
		   [CR]LF belongs to the MIME boundary though. */
		if (ctx->prev_hdr_newline_size > 0) {
			i_assert(ctx->part->header_size.lines > 0);
			/* remove the newline size from the MIME header */
			ctx->part->header_size.lines--;
			ctx->part->header_size.physical_size -=
				ctx->prev_hdr_newline_size;
			ctx->part->header_size.virtual_size -= 2;
			/* add the newline size to the parent's body */
			ctx->part->parent->body_size.lines++;
			ctx->part->parent->body_size.physical_size +=
				ctx->prev_hdr_newline_size;
			ctx->part->parent->body_size.virtual_size += 2;
		}
		hdr = NULL;
	}

	if (hdr != NULL) {
		if (hdr->eoh)
			;
		else if (strcasecmp(hdr->name, "Mime-Version") == 0) {
			/* it's MIME. Content-* headers are valid */
			part->flags |= MESSAGE_PART_FLAG_IS_MIME;
		} else if (strcasecmp(hdr->name, "Content-Type") == 0) {
			if ((ctx->flags &
			     MESSAGE_PARSER_FLAG_MIME_VERSION_STRICT) == 0)
				part->flags |= MESSAGE_PART_FLAG_IS_MIME;

			if (hdr->continues)
				hdr->use_full_value = TRUE;
			else T_BEGIN {
				parse_content_type(ctx, hdr);
			} T_END;
		}

		block_r->hdr = hdr;
		block_r->size = 0;
		ctx->prev_hdr_newline_size = hdr->no_newline ? 0 :
			(hdr->crlf_newline ? 2 : 1);
		return 1;
	}

	/* end of headers */
	if ((part->flags & MESSAGE_PART_FLAG_IS_MIME) == 0) {
		/* It's not MIME. Reset everything we found from
		   Content-Type. */
		i_assert(!ctx->multipart);
		part->flags = 0;
	}
	ctx->last_boundary = NULL;

//.........这里部分代码省略.........

static void
dsync_brain_mailbox_tree_add_delete(struct dsync_mailbox_tree *tree,
				    struct dsync_mailbox_tree *other_tree,
				    const struct dsync_mailbox_delete *other_del)
{
	const struct dsync_mailbox_node *node;
	struct dsync_mailbox_node *other_node, *old_node;
	const char *name;

	/* see if we can find the deletion based on mailbox tree that should
	   still have the mailbox */
	node = dsync_mailbox_tree_find_delete(tree, other_del);
	if (node == NULL)
		return;

	switch (other_del->type) {
	case DSYNC_MAILBOX_DELETE_TYPE_MAILBOX:
		/* mailbox is always deleted */
		break;
	case DSYNC_MAILBOX_DELETE_TYPE_DIR:
		if (other_del->timestamp <= node->last_renamed_or_created) {
			/* we don't want to delete this directory, we already
			   have a newer timestamp for it */
			return;
		}
		break;
	case DSYNC_MAILBOX_DELETE_TYPE_UNSUBSCRIBE:
		if (other_del->timestamp <= node->last_subscription_change) {
			/* we don't want to unsubscribe, since we already have
			   a newer subscription timestamp */
			return;
		}
		break;
	}

	/* make a node for it in the other mailbox tree */
	name = dsync_mailbox_node_get_full_name(tree, node);
	other_node = dsync_mailbox_tree_get(other_tree, name);

	if (other_node->existence == DSYNC_MAILBOX_NODE_EXISTS &&
	    (!guid_128_is_empty(other_node->mailbox_guid) ||
	     other_del->type != DSYNC_MAILBOX_DELETE_TYPE_MAILBOX)) {
		/* other side has already created a new mailbox or
		   directory with this name, we can't delete it */
		return;
	}

	/* ok, mark the other node deleted */
	if (other_del->type == DSYNC_MAILBOX_DELETE_TYPE_MAILBOX) {
		memcpy(other_node->mailbox_guid, node->mailbox_guid,
		       sizeof(other_node->mailbox_guid));
	}
	i_assert(other_node->ns == NULL || other_node->ns == node->ns);
	other_node->ns = node->ns;
	if (other_del->type != DSYNC_MAILBOX_DELETE_TYPE_UNSUBSCRIBE)
		other_node->existence = DSYNC_MAILBOX_NODE_DELETED;
	else {
		other_node->last_subscription_change = other_del->timestamp;
		other_node->subscribed = FALSE;
	}

	if (dsync_mailbox_tree_guid_hash_add(other_tree, other_node,
					     &old_node) < 0)
		i_unreached();
}

int dsync_brain_mailbox_tree_sync_change(struct dsync_brain *brain,
			const struct dsync_mailbox_tree_sync_change *change,
			enum mail_error *error_r)
{
	struct mailbox *box = NULL, *destbox;
	const char *errstr, *func_name = NULL, *storage_name;
	enum mail_error error;
	int ret = -1;

	if (brain->backup_send) {
		i_assert(brain->no_backup_overwrite);
		return 0;
	}

	switch (change->type) {
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_DELETE_BOX:
		/* make sure we're deleting the correct mailbox */
		ret = dsync_brain_mailbox_alloc(brain, change->mailbox_guid,
						&box, &errstr, error_r);
		if (ret < 0) {
			i_error("Mailbox sync: Couldn't allocate mailbox GUID %s: %s",
				guid_128_to_string(change->mailbox_guid), errstr);
			return -1;
		}
		if (ret == 0) {
			if (brain->debug) {
				i_debug("brain %c: Change during sync: "
					"Mailbox GUID %s deletion conflict: %s",
					brain->master_brain ? 'M' : 'S',
					guid_128_to_string(change->mailbox_guid), errstr);
			}
			brain->changes_during_sync = TRUE;
			return 0;
		}
		break;
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_DELETE_DIR:
		storage_name = mailbox_list_get_storage_name(change->ns->list,
							     change->full_name);
		if (mailbox_list_delete_dir(change->ns->list, storage_name) == 0)
			return 0;

		errstr = mailbox_list_get_last_error(change->ns->list, &error);
		if (error == MAIL_ERROR_NOTFOUND ||
		    error == MAIL_ERROR_EXISTS) {
			if (brain->debug) {
				i_debug("brain %c: Change during sync: "
					"Mailbox %s mailbox_list_delete_dir conflict: %s",
					brain->master_brain ? 'M' : 'S',
					change->full_name, errstr);
			}
			brain->changes_during_sync = TRUE;
			return 0;
		} else {
			i_error("Mailbox sync: mailbox_list_delete_dir failed: %s",
				errstr);
			*error_r = error;
			return -1;
		}
	default:
		box = mailbox_alloc(change->ns->list, change->full_name, 0);
		break;
	}
	switch (change->type) {
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_CREATE_BOX:
		ret = sync_create_box(brain, box, change->mailbox_guid,
				      change->uid_validity, error_r);
		mailbox_free(&box);
		return ret;
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_CREATE_DIR:
		ret = mailbox_create(box, NULL, TRUE);
		if (ret < 0 &&
		    mailbox_get_last_mail_error(box) == MAIL_ERROR_EXISTS) {
			/* it doesn't matter if somebody else created this
			   directory or we automatically did while creating its
			   child mailbox. it's there now anyway and we don't
			   gain anything by treating this failure any
			   differently from success. */
			ret = 0;
		}
		func_name = "mailbox_create";
		break;
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_DELETE_BOX:
		ret = mailbox_delete(box);
		func_name = "mailbox_delete";
		break;
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_DELETE_DIR:
		i_unreached();
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_RENAME:
		destbox = mailbox_alloc(change->ns->list,
					change->rename_dest_name, 0);
		ret = mailbox_rename(box, destbox);
		func_name = "mailbox_rename";
		mailbox_free(&destbox);
		break;
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_SUBSCRIBE:
		ret = mailbox_set_subscribed(box, TRUE);
		func_name = "mailbox_set_subscribed";
		break;
	case DSYNC_MAILBOX_TREE_SYNC_TYPE_UNSUBSCRIBE:
		ret = mailbox_set_subscribed(box, FALSE);
//.........这里部分代码省略.........

static int driver_mysql_connect(struct sql_db *_db)
{
	struct mysql_db *db = (struct mysql_db *)_db;
	const char *unix_socket, *host;
	unsigned long client_flags = db->client_flags;
	unsigned int secs_used;
	bool failed;

	i_assert(db->api.state == SQL_DB_STATE_DISCONNECTED);

	sql_db_set_state(&db->api, SQL_DB_STATE_CONNECTING);

	if (*db->host == '/') {
		unix_socket = db->host;
		host = NULL;
	} else {
		unix_socket = NULL;
		host = db->host;
	}

	if (db->option_file != NULL) {
		mysql_options(db->mysql, MYSQL_READ_DEFAULT_FILE,
			      db->option_file);
	}

	mysql_options(db->mysql, MYSQL_READ_DEFAULT_GROUP,
		      db->option_group != NULL ? db->option_group : "client");

	if (!db->ssl_set && (db->ssl_ca != NULL || db->ssl_ca_path != NULL)) {
#ifdef HAVE_MYSQL_SSL
		mysql_ssl_set(db->mysql, db->ssl_key, db->ssl_cert,
			      db->ssl_ca, db->ssl_ca_path
#ifdef HAVE_MYSQL_SSL_CIPHER
			      , db->ssl_cipher
#endif
			     );
		db->ssl_set = TRUE;
#else
		i_fatal("mysql: SSL support not compiled in "
			"(remove ssl_ca and ssl_ca_path settings)");
#endif
	}

	alarm(SQL_CONNECT_TIMEOUT_SECS);
#ifdef CLIENT_MULTI_RESULTS
	client_flags |= CLIENT_MULTI_RESULTS;
#endif
	/* CLIENT_MULTI_RESULTS allows the use of stored procedures */
	failed = mysql_real_connect(db->mysql, host, db->user, db->password,
				    db->dbname, db->port, unix_socket,
				    client_flags) == NULL;
	secs_used = SQL_CONNECT_TIMEOUT_SECS - alarm(0);
	if (failed) {
		/* connecting could have taken a while. make sure that any
		   timeouts that get added soon will get a refreshed
		   timestamp. */
		io_loop_time_refresh();

		if (db->api.connect_delay < secs_used)
			db->api.connect_delay = secs_used;
		sql_db_set_state(&db->api, SQL_DB_STATE_DISCONNECTED);
		i_error("%s: Connect failed to database (%s): %s - "
			"waiting for %u seconds before retry",
			mysql_prefix(db), db->dbname,
			mysql_error(db->mysql), db->api.connect_delay);
		return -1;
	} else {
		db->last_success = ioloop_time;
		sql_db_set_state(&db->api, SQL_DB_STATE_IDLE);
		return 1;
	}
}

void io_remove_closed(struct io **io)
{
	i_assert(((*io)->condition & IO_NOTIFY) == 0);

	io_remove_full(io, TRUE);
}

static bool client_command_input(struct client_command_context *cmd)
{
	struct client *client = cmd->client;
	struct command *command;

        if (cmd->func != NULL) {
		/* command is being executed - continue it */
		if (command_exec(cmd)) {
			/* command execution was finished */
			client_command_free(&cmd);
			client_add_missing_io(client);
			return TRUE;
		}

		return client_handle_unfinished_cmd(cmd);
	}

	if (cmd->tag == NULL) {
                cmd->tag = imap_parser_read_word(cmd->parser);
		if (cmd->tag == NULL)
			return FALSE; /* need more data */
		cmd->tag = p_strdup(cmd->pool, cmd->tag);
	}

	if (cmd->name == NULL) {
		cmd->name = imap_parser_read_word(cmd->parser);
		if (cmd->name == NULL)
			return FALSE; /* need more data */

		/* UID commands are a special case. better to handle them
		   here. */
		if (!cmd->uid && strcasecmp(cmd->name, "UID") == 0) {
			cmd->uid = TRUE;
			cmd->name = imap_parser_read_word(cmd->parser);
			if (cmd->name == NULL)
				return FALSE; /* need more data */
		}
		cmd->name = !cmd->uid ? p_strdup(cmd->pool, cmd->name) :
			p_strconcat(cmd->pool, "UID ", cmd->name, NULL);
		imap_refresh_proctitle();
	}

	client->input_skip_line = TRUE;

	if (cmd->name[0] == '\0') {
		/* command not given - cmd->func is already NULL. */
	} else if ((command = command_find(cmd->name)) != NULL) {
		cmd->func = command->func;
		cmd->cmd_flags = command->flags;
		if (client_command_is_ambiguous(cmd)) {
			/* do nothing until existing commands are finished */
			i_assert(cmd->state == CLIENT_COMMAND_STATE_WAIT_INPUT);
			cmd->state = CLIENT_COMMAND_STATE_WAIT_UNAMBIGUITY;
			io_remove(&client->io);
			return FALSE;
		}
	}

	if (cmd->func == NULL) {
		/* unknown command */
		client_send_command_error(cmd, "Unknown command.");
		cmd->param_error = TRUE;
		client_command_free(&cmd);
		return TRUE;
	} else {
		i_assert(!client->disconnected);

		return client_command_input(cmd);
	}
}

void client_command_free(struct client_command_context **_cmd)
{
	struct client_command_context *cmd = *_cmd;
	struct client *client = cmd->client;
	enum client_command_state state = cmd->state;

	*_cmd = NULL;

	i_assert(client->output_cmd_lock == NULL);

	/* reset input idle time because command output might have taken a
	   long time and we don't want to disconnect client immediately then */
	client->last_input = ioloop_time;
	timeout_reset(client->to_idle);

	if (cmd->cancel) {
		cmd->cancel = FALSE;
		client_send_tagline(cmd, "NO Command cancelled.");
	}

	if (!cmd->param_error)
		client->bad_counter = 0;

	if (client->input_lock == cmd)
		client->input_lock = NULL;
	if (client->mailbox_change_lock == cmd)
		client->mailbox_change_lock = NULL;

	if (cmd->parser != NULL) {
		if (client->free_parser == NULL) {
			imap_parser_reset(cmd->parser);
			client->free_parser = cmd->parser;
		} else {
			imap_parser_unref(&cmd->parser);
		}
	}

	client->command_queue_size--;
	DLLIST_REMOVE(&client->command_queue, cmd);
	cmd = NULL;

	if (client->command_queue == NULL) {
		/* no commands left in the queue, we can clear the pool */
		p_clear(client->command_pool);
		if (client->to_idle_output != NULL)
			timeout_remove(&client->to_idle_output);
	}
	imap_client_notify_command_freed(client);
	imap_refresh_proctitle();

	/* if command finished from external event, check input for more
	   unhandled commands since we may not be executing from client_input
	   or client_output. */
	if (state == CLIENT_COMMAND_STATE_WAIT_EXTERNAL &&
	    !client->disconnected) {
		client_add_missing_io(client);
		if (client->to_delayed_input == NULL) {
			client->to_delayed_input =
				timeout_add(0, client_input, client);
		}
	}
}

static void client_default_destroy(struct client *client, const char *reason)
{
	struct client_command_context *cmd;
	const char *cmd_status = "";

	i_assert(!client->destroyed);
	client->destroyed = TRUE;

	if (!client->disconnected) {
		client->disconnected = TRUE;
		if (reason == NULL) {
			reason = io_stream_get_disconnect_reason(client->input,
								 client->output);
			cmd_status = client_get_commands_status(client);
		}
		i_info("%s%s %s", reason, cmd_status, client_stats(client));
	}

	i_stream_close(client->input);
	o_stream_close(client->output);

	/* finish off all the queued commands. */
	if (client->output_cmd_lock != NULL)
		client_command_cancel(&client->output_cmd_lock);
	while (client->command_queue != NULL) {
		cmd = client->command_queue;
		client_command_cancel(&cmd);
	}
	/* handle the input_lock command last. it might have been waiting on
	   other queued commands (although we probably should just drop the
	   command at that point since it hasn't started running. but this may
	   change in future). */
	if (client->input_lock != NULL)
		client_command_cancel(&client->input_lock);

	if (client->mailbox != NULL) {
		client_search_updates_free(client);
		mailbox_free(&client->mailbox);
	}
	if (client->notify_ctx != NULL)
		imap_notify_deinit(&client->notify_ctx);
	if (client->urlauth_ctx != NULL)
		imap_urlauth_deinit(&client->urlauth_ctx);
	if (client->anvil_sent) {
		master_service_anvil_send(master_service, t_strconcat(
			"DISCONNECT\t", my_pid, "\timap/",
			mail_user_get_anvil_userip_ident(client->user),
			"\n", NULL));
	}
	mail_user_unref(&client->user);

	if (client->free_parser != NULL)
		imap_parser_unref(&client->free_parser);
	if (client->io != NULL)
		io_remove(&client->io);
	if (client->to_idle_output != NULL)
		timeout_remove(&client->to_idle_output);
	if (client->to_delayed_input != NULL)
		timeout_remove(&client->to_delayed_input);
	timeout_remove(&client->to_idle);

	i_stream_destroy(&client->input);
	o_stream_destroy(&client->output);

	net_disconnect(client->fd_in);
	if (client->fd_in != client->fd_out)
		net_disconnect(client->fd_out);

	if (array_is_created(&client->search_saved_uidset))
		array_free(&client->search_saved_uidset);
	if (array_is_created(&client->search_updates))
		array_free(&client->search_updates);
	pool_unref(&client->command_pool);
	mail_storage_service_user_free(&client->service_user);

	imap_client_count--;
	DLLIST_REMOVE(&imap_clients, client);
	pool_unref(&client->pool);

	master_service_client_connection_destroyed(master_service);
	imap_refresh_proctitle();
}

void index_storage_get_open_status(struct mailbox *box,
				   enum mailbox_status_items items,
				   struct mailbox_status *status_r)
{
	const struct mail_index_header *hdr;

	/* we can get most of the status items without any trouble */
	hdr = mail_index_get_header(box->view);
	status_r->messages = hdr->messages_count;
	if ((items & STATUS_RECENT) != 0) {
		if ((box->flags & MAILBOX_FLAG_DROP_RECENT) != 0) {
			/* recent flags are set and dropped by the previous
			   sync while index was locked. if we updated the
			   recent flags here we'd have a race condition. */
			i_assert(box->synced);
		} else {
			/* make sure recent count is set, in case we haven't
			   synced yet */
			index_sync_update_recent_count(box);
		}
		status_r->recent = index_mailbox_get_recent_count(box);
		i_assert(status_r->recent <= status_r->messages);
	}
	if ((items & STATUS_UNSEEN) != 0) {
		if (box->view_pvt == NULL ||
		    (mailbox_get_private_flags_mask(box) & MAIL_SEEN) == 0) {
			status_r->unseen = hdr->messages_count -
				hdr->seen_messages_count;
		} else {
			status_r->unseen = index_storage_count_pvt_unseen(box);
		}
	}
	status_r->uidvalidity = hdr->uid_validity;
	status_r->uidnext = hdr->next_uid;
	status_r->first_recent_uid = hdr->first_recent_uid;
	if ((items & STATUS_HIGHESTMODSEQ) != 0) {
		status_r->nonpermanent_modseqs =
			mail_index_is_in_memory(box->index);
		status_r->no_modseq_tracking =
			!mail_index_have_modseq_tracking(box->index);
		status_r->highest_modseq =
			mail_index_modseq_get_highest(box->view);
		if (status_r->highest_modseq == 0) {
			/* modseqs not enabled yet, but we can't return 0 */
			status_r->highest_modseq = 1;
		}
	}
	if ((items & STATUS_HIGHESTPVTMODSEQ) != 0 && box->view_pvt != NULL) {
		status_r->highest_pvt_modseq =
			mail_index_modseq_get_highest(box->view_pvt);
		if (status_r->highest_pvt_modseq == 0) {
			/* modseqs not enabled yet, but we can't return 0 */
			status_r->highest_pvt_modseq = 1;
		}
	}

	if ((items & STATUS_FIRST_UNSEEN_SEQ) != 0) {
		if (box->view_pvt == NULL ||
		    (mailbox_get_private_flags_mask(box) & MAIL_SEEN) == 0) {
			mail_index_lookup_first(box->view, 0, MAIL_SEEN,
						&status_r->first_unseen_seq);
		} else {
			status_r->first_unseen_seq =
				index_storage_find_first_pvt_unseen_seq(box);
		}
	}
	if ((items & STATUS_LAST_CACHED_SEQ) != 0)
		get_last_cached_seq(box, &status_r->last_cached_seq);

	if ((items & STATUS_KEYWORDS) != 0)
		status_r->keywords = mail_index_get_keywords(box->index);
	if ((items & STATUS_PERMANENT_FLAGS) != 0) {
		if (!mailbox_is_readonly(box)) {
			status_r->permanent_flags = MAIL_FLAGS_NONRECENT;
			status_r->permanent_keywords = TRUE;
			status_r->allow_new_keywords =
				!box->disallow_new_keywords;
		}
	}
}

bool auth_request_handler_auth_begin(struct auth_request_handler *handler,
				     const char *args)
{
	const struct mech_module *mech;
	struct auth_request *request;
	const char *const *list, *name, *arg, *initial_resp;
	void *initial_resp_data;
	unsigned int id;
	buffer_t *buf;

	i_assert(!handler->destroyed);

	/* <id> <mechanism> [...] */
	list = t_strsplit_tab(args);
	if (list[0] == NULL || list[1] == NULL ||
	    str_to_uint(list[0], &id) < 0) {
		i_error("BUG: Authentication client %u "
			"sent broken AUTH request", handler->client_pid);
		return FALSE;
	}

	if (handler->token_auth) {
		mech = &mech_dovecot_token;
		if (strcmp(list[1], mech->mech_name) != 0) {
			/* unsupported mechanism */
			i_error("BUG: Authentication client %u requested invalid "
				"authentication mechanism %s (DOVECOT-TOKEN required)",
				handler->client_pid, str_sanitize(list[1], MAX_MECH_NAME_LEN));
			return FALSE;
		}
	} else {		 
		mech = mech_module_find(list[1]);
		if (mech == NULL) {
			/* unsupported mechanism */
			i_error("BUG: Authentication client %u requested unsupported "
				"authentication mechanism %s", handler->client_pid,
				str_sanitize(list[1], MAX_MECH_NAME_LEN));
			return FALSE;
		}
	}

	request = auth_request_new(mech);
	request->handler = handler;
	request->connect_uid = handler->connect_uid;
	request->client_pid = handler->client_pid;
	request->id = id;
	request->auth_only = handler->master_callback == NULL;

	/* parse optional parameters */
	initial_resp = NULL;
	for (list += 2; *list != NULL; list++) {
		arg = strchr(*list, '=');
		if (arg == NULL) {
			name = *list;
			arg = "";
		} else {
			name = t_strdup_until(*list, arg);
			arg++;
		}

		if (auth_request_import_auth(request, name, arg))
			;
		else if (strcmp(name, "resp") == 0) {
			initial_resp = arg;
			/* this must be the last parameter */
			list++;
			break;
		}
	}

	if (*list != NULL) {
		i_error("BUG: Authentication client %u "
			"sent AUTH parameters after 'resp'",
			handler->client_pid);
		auth_request_unref(&request);
		return FALSE;
	}

	if (request->service == NULL) {
		i_error("BUG: Authentication client %u "
			"didn't specify service in request",
			handler->client_pid);
		auth_request_unref(&request);
		return FALSE;
	}
	if (hash_table_lookup(handler->requests, POINTER_CAST(id)) != NULL) {
		i_error("BUG: Authentication client %u "
			"sent a duplicate ID %u", handler->client_pid, id);
		auth_request_unref(&request);
		return FALSE;
	}
	auth_request_init(request);

	request->to_abort = timeout_add(MASTER_AUTH_SERVER_TIMEOUT_SECS * 1000,
					auth_request_timeout, request);
	hash_table_insert(handler->requests, POINTER_CAST(id), request);

	if (request->set->ssl_require_client_cert &&
	    !request->valid_client_cert) {
		/* we fail without valid certificate */
//.........这里部分代码省略.........

bool imap_fetch_binary_init(struct imap_fetch_init_context *ctx)
{
	struct imap_fetch_body_data *body;
	const struct imap_arg *list_args;
	unsigned int list_count;
	const char *str, *p, *error;

	i_assert(strncmp(ctx->name, "BINARY", 6) == 0);
	p = ctx->name + 6;

	body = p_new(ctx->pool, struct imap_fetch_body_data, 1);
	body->binary = TRUE;

	if (strncmp(p, ".SIZE", 5) == 0) {
		/* fetch decoded size of the section */
		p += 5;
		body->binary_size = TRUE;
	} else if (strncmp(p, ".PEEK", 5) == 0) {
		p += 5;
	} else {
		ctx->fetch_ctx->flags_update_seen = TRUE;
	}
	if (*p != '[') {
		ctx->error = "Invalid BINARY[..] parameter: Missing '['";
		return FALSE;
	}

	if (imap_arg_get_list_full(&ctx->args[0], &list_args, &list_count)) {
		/* BINARY[HEADER.FIELDS.. (headers list)] */
		if (!imap_arg_get_atom(&ctx->args[1], &str) ||
		    str[0] != ']') {
			ctx->error = "Invalid BINARY[..] parameter: Missing ']'";
			return FALSE;
		}
		if (body_header_fields_parse(ctx, body, p+1,
					     list_args, list_count) < 0)
			return FALSE;
		p = str+1;
		ctx->args += 2;
	} else {
		/* no headers list */
		body->section = p+1;
		p = strchr(body->section, ']');
		if (p == NULL) {
			ctx->error = "Invalid BINARY[..] parameter: Missing ']'";
			return FALSE;
		}
		body->section = p_strdup_until(ctx->pool, body->section, p);
		p++;
	}
	if (imap_msgpart_parse(body->section, &body->msgpart) < 0) {
		ctx->error = "Invalid BINARY[..] section";
		return FALSE;
	}
	imap_msgpart_set_decode_to_binary(body->msgpart);
	ctx->fetch_ctx->fetch_data |=
		imap_msgpart_get_fetch_data(body->msgpart);

	if (!body->binary_size) {
		if (body_parse_partial(body, p, &error) < 0) {
			ctx->error = p_strdup_printf(ctx->pool,
				"Invalid BINARY[..] parameter: %s", error);
			return FALSE;
		}
	}

	/* update the section name for the imap_fetch_add_handler() */
	ctx->name = p_strdup(ctx->pool, get_body_name(body));
	if (body->binary_size) {
		imap_fetch_add_handler(ctx, IMAP_FETCH_HANDLER_FLAG_WANT_DEINIT,
				       "0", fetch_binary_size, body);
	} else {
		imap_fetch_add_handler(ctx, IMAP_FETCH_HANDLER_FLAG_WANT_DEINIT,
				       "NIL", fetch_body_msgpart, body);
	}
	return TRUE;
}