src/submission/cmd-quit.c

/* Copyright (c) 2013-2018 Dovecot authors, see the included COPYING file */

#include "submission-common.h"
#include "smtp-client.h"
#include "smtp-client-connection.h"

#include "submission-commands.h"

/*
 * QUIT command
 */

struct cmd_quit_context {
    struct client *client;
    struct smtp_server_cmd_ctx *cmd;
    struct smtp_client_command *cmd_proxied;
};

static void cmd_quit_finish(struct cmd_quit_context *quit_cmd)
{
    struct client *client = quit_cmd->client;
    struct smtp_server_cmd_ctx *cmd = quit_cmd->cmd;

    timeout_remove(&client->to_quit);
    if (quit_cmd->cmd_proxied != NULL)
        smtp_client_command_abort(&quit_cmd->cmd_proxied);
    smtp_server_reply_quit(cmd);
}

static void cmd_quit_proxy_cb(
    const struct smtp_reply *proxy_reply ATTR_UNUSED,
    struct cmd_quit_context *quit_cmd)
{
    quit_cmd->cmd_proxied = NULL;
    cmd_quit_finish(quit_cmd);
}

static void cmd_quit_proxy(struct cmd_quit_context *quit_cmd)
{
    struct client *client = quit_cmd->client;
    struct smtp_server_cmd_ctx *cmd = quit_cmd->cmd;

    if (quit_cmd->cmd_proxied != NULL)
        return;

    if (smtp_client_connection_get_state(client->proxy_conn)
        < SMTP_CLIENT_CONNECTION_STATE_READY) {
        /* Don't bother proxying QUIT command when proxy is not
           fully initialized. */
        smtp_server_reply_quit(cmd);
        return;
    }

    /* RFC 5321, Section 4.1.1.10:

       The sender MUST NOT intentionally close the transmission channel
       until it sends a QUIT command, and it SHOULD wait until it receives
       the reply (even if there was an error response to a previous
       command). */
    quit_cmd->cmd_proxied =
        smtp_client_command_new(client->proxy_conn, 0,
                    cmd_quit_proxy_cb, quit_cmd);
    smtp_client_command_write(quit_cmd->cmd_proxied, "QUIT");
    smtp_client_command_submit(quit_cmd->cmd_proxied);
}

static void cmd_quit_next(struct smtp_server_cmd_ctx *cmd)
{
    struct cmd_quit_context *quit_cmd = cmd->context;
    struct client *client = quit_cmd->client;

    /* QUIT command is next to reply */

    cmd_quit_proxy(quit_cmd);

    if (quit_cmd->cmd_proxied != NULL) {
        /* give relay server brief interval to reply */
        client->to_quit = timeout_add(
            SUBMISSION_MAX_WAIT_QUIT_REPLY_MSECS,
            cmd_quit_finish, quit_cmd);
    }
}

int cmd_quit(void *conn_ctx, struct smtp_server_cmd_ctx *cmd)
{
    struct client *client = conn_ctx;
    struct cmd_quit_context *quit_cmd;

    quit_cmd = p_new(cmd->pool, struct cmd_quit_context, 1);
    quit_cmd->client = client;
    quit_cmd->cmd = cmd;

    cmd->hook_next = cmd_quit_next;
    cmd->context = quit_cmd;

    if (smtp_client_connection_get_state(client->proxy_conn)
        >= SMTP_CLIENT_CONNECTION_STATE_READY)
        cmd_quit_proxy(quit_cmd);
    return 0;
}