/src/dovecot/src/lib-smtp/smtp-server-connection.c

Source
/* Copyright (c) Dovecot authors, see top-level COPYING file */

#include "lib.h"
#include "llist.h"
#include "array.h"
#include "str.h"
#include "guid.h"
#include "base64.h"
#include "ioloop.h"
#include "istream.h"
#include "ostream.h"
#include "iostream.h"
#include "connection.h"
#include "iostream-rawlog.h"
#include "iostream-ssl.h"
#include "settings.h"
#include "master-service.h"
#include "master-service-ssl.h"

#include "smtp-syntax.h"
#include "smtp-reply-parser.h"
#include "smtp-command-parser.h"
#include "smtp-server-private.h"
#include "ssl-settings.h"

const char *const smtp_server_state_names[] = {
  "GREETING",
  "XCLIENT",
  "HELO",
  "STARTTLS",
  "AUTH",
  "READY",
  "MAIL FROM",
  "RCPT TO",
  "DATA"
};

/*
 * Connection
 */

static void smtp_server_connection_input(struct connection *_conn);
static int smtp_server_connection_output(struct smtp_server_connection *conn);
static void
smtp_server_connection_disconnect(struct smtp_server_connection *conn,
          const char *reason) ATTR_NULL(2);

static void
smtp_server_connection_update_stats(struct smtp_server_connection *conn)
{
  if (conn->conn.input != NULL)
    conn->stats.input = conn->conn.input->v_offset;
  if (conn->conn.output != NULL)
    conn->stats.output = conn->conn.output->offset;
  connection_update_counters(&conn->conn);
}

const struct smtp_server_stats *
smtp_server_connection_get_stats(struct smtp_server_connection *conn)
{
  smtp_server_connection_update_stats(conn);
  return &conn->stats;
}

static bool
smtp_server_connection_check_pipeline(struct smtp_server_connection *conn)
{
  unsigned int pipeline = conn->command_queue_count;
  struct smtp_server_command *cmd;

  if (conn->command_queue_tail != NULL) {
    i_assert(pipeline > 0);
    if (conn->command_queue_tail->state ==
        SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY)
      pipeline--;
  }

  if (pipeline >= conn->set.max_pipelined_commands) {
    e_debug(conn->event, "Command pipeline is full "
      "(pipelined commands %u > limit %u)",
      pipeline, conn->set.max_pipelined_commands);
    return FALSE;
  }

  cmd = conn->command_queue_head;
  while (cmd != NULL) {
    if (cmd->pipeline_blocked)
      return FALSE;
    cmd = cmd->next;
  }
  return TRUE;
}

void smtp_server_connection_input_halt(struct smtp_server_connection *conn)
{
  connection_input_halt(&conn->conn);
}

void smtp_server_connection_input_resume(struct smtp_server_connection *conn)
{
  struct smtp_server_command *cmd;

  if (conn->conn.io == NULL) {
    /* Only resume when we actually can */
    if (conn->input_locked || conn->input_broken ||
      conn->disconnected)
      return;
    if (!smtp_server_connection_check_pipeline(conn)) {
      i_assert(conn->command_queue_tail != NULL);
      if (!conn->command_queue_tail->pipeline_blocked ||
          !smtp_server_connection_pending_command_data(conn))
        return;
    }

    /* Is queued command still blocking input? */
    cmd = conn->command_queue_head;
    while (cmd != NULL) {
      if (cmd->input_locked)
        return;
      cmd = cmd->next;
    }

    /* Restore input handler */
    connection_input_resume(&conn->conn);
  }

  if (conn->conn.io != NULL &&
    i_stream_have_bytes_left(conn->conn.input)) {
    io_set_pending(conn->conn.io);
  }
}

void smtp_server_connection_input_lock(struct smtp_server_connection *conn)
{
  conn->input_locked = TRUE;
  smtp_server_connection_input_halt(conn);
}

void smtp_server_connection_input_unlock(struct smtp_server_connection *conn)
{
  conn->input_locked = FALSE;
  smtp_server_connection_input_resume(conn);
}

#undef smtp_server_connection_input_capture
void smtp_server_connection_input_capture(
  struct smtp_server_connection *conn,
  smtp_server_input_callback_t *callback, void *context)
{
  i_assert(!conn->input_broken && !conn->disconnected);
  connection_input_halt(&conn->conn);
  i_stream_set_input_pending(conn->conn.input, TRUE);
  conn->conn.io = io_add_istream(conn->conn.input, *callback, context);
}

static void
smtp_server_connection_update_rawlog(struct smtp_server_connection *conn)
{
  struct stat st;

  if (conn->set.rawlog_dir == NULL)
    return;

  if (!conn->rawlog_checked) {
    conn->rawlog_checked = TRUE;
    if (stat(conn->set.rawlog_dir, &st) == 0)
      conn->rawlog_enabled = TRUE;
  }
  if (conn->rawlog_enabled) {
    /* FIXME: we don't know the setting name here */
    iostream_rawlog_create(conn->event, "smtp server rawlog",
               conn->set.rawlog_dir,
               &conn->conn.input, &conn->conn.output);
  }
}

static void
smtp_server_connection_streams_changed(struct smtp_server_connection *conn)
{
  smtp_server_connection_update_rawlog(conn);
  smtp_command_parser_set_stream(conn->smtp_parser, conn->conn.input);

  o_stream_set_flush_callback(conn->conn.output,
    smtp_server_connection_output, conn);
  o_stream_set_flush_pending(conn->conn.output, TRUE);
}

void smtp_server_connection_set_streams(struct smtp_server_connection *conn,
          struct istream *input,
          struct ostream *output)
{
  struct istream *old_input = conn->conn.input;
  struct ostream *old_output = conn->conn.output;

  i_assert(conn->created_from_streams);

  conn->conn.input = input;
  i_stream_ref(conn->conn.input);

  conn->conn.output = output;
  o_stream_ref(conn->conn.output);
  o_stream_set_no_error_handling(conn->conn.output, TRUE);

  i_stream_unref(&old_input);
  o_stream_unref(&old_output);

  smtp_server_connection_streams_changed(conn);
}

void smtp_server_connection_set_ssl_streams(struct smtp_server_connection *conn,
              struct istream *input,
              struct ostream *output)
{
  conn->ssl_secured = TRUE;
  conn->set.capabilities &= ENUM_NEGATE(SMTP_CAPABILITY_STARTTLS);

  smtp_server_connection_set_streams(conn, input, output);
}

static void
smtp_server_connection_idle_timeout(struct smtp_server_connection *conn)
{
  smtp_server_connection_terminate(
    &conn, "4.4.2", "Disconnected for inactivity");
}

void smtp_server_connection_timeout_stop(struct smtp_server_connection *conn)
{
  if (conn->to_idle != NULL) {
    e_debug(conn->event, "Timeout stop");

    timeout_remove(&conn->to_idle);
  }
}

void smtp_server_connection_timeout_start(struct smtp_server_connection *conn)
{
  if (conn->disconnected)
    return;

  if (conn->to_idle == NULL &&
    conn->set.max_client_idle_time_msecs > 0) {
    e_debug(conn->event, "Timeout start");

    conn->to_idle = timeout_add(
      conn->set.max_client_idle_time_msecs,
      smtp_server_connection_idle_timeout, conn);
  }
}

void smtp_server_connection_timeout_reset(struct smtp_server_connection *conn)
{
  if (conn->to_idle != NULL)
    timeout_reset(conn->to_idle);
}

static void
smtp_server_connection_timeout_update(struct smtp_server_connection *conn)
{
  struct smtp_server_command *cmd = conn->command_queue_head;

  if (cmd == NULL) {
    smtp_server_connection_timeout_start(conn);
    return;
  }

  switch (cmd->state) {
  case SMTP_SERVER_COMMAND_STATE_NEW:
    smtp_server_connection_timeout_start(conn);
    break;
  case SMTP_SERVER_COMMAND_STATE_PROCESSING:
    if (cmd->input_captured) {
      /* Command updates timeout internally */
      return;
    }
    smtp_server_connection_timeout_stop(conn);
    break;
  case SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY:
  case SMTP_SERVER_COMMAND_STATE_READY_TO_REPLY:
    smtp_server_connection_timeout_stop(conn);
    break;
  case SMTP_SERVER_COMMAND_STATE_FINISHED:
  case SMTP_SERVER_COMMAND_STATE_ABORTED:
    i_unreached();
  }
}

static void smtp_server_connection_ready(struct smtp_server_connection *conn)
{
  conn->raw_input = conn->conn.input;
  conn->raw_output = conn->conn.output;

  conn->connect_succeeded = TRUE;

  smtp_server_connection_update_rawlog(conn);

  conn->smtp_parser = smtp_command_parser_init(conn->conn.input,
                 &conn->set.command_limits);
  o_stream_set_flush_callback(conn->conn.output,
            smtp_server_connection_output, conn);

  o_stream_cork(conn->conn.output);
  if (conn->set.no_greeting) {
    /* Don't send greeting or login reply. */
  } else if (conn->authenticated) {
    /* RFC 4954, Section 4:
       Should the client successfully complete the exchange, the
       SMTP server issues a 235 reply. */
    smtp_server_connection_send_line(
      conn, "235 2.7.0 Logged in.");
  } else {
    smtp_server_connection_send_line(
      conn, "220 %s %s", conn->set.hostname,
      conn->set.login_greeting);
  }
  if (!conn->corked)
    o_stream_uncork(conn->conn.output);
}

static void smtp_server_connection_destroy(struct connection *_conn)
{
  struct smtp_server_connection *conn =
    (struct smtp_server_connection *)_conn;

  smtp_server_connection_disconnect(conn, NULL);
  smtp_server_connection_unref(&conn);
}

static bool
smtp_server_connection_handle_command(struct smtp_server_connection *conn,
              const char *cmd_name,
              const char *cmd_params)
{
  struct smtp_server_connection *tmp_conn = conn;
  struct smtp_server_command *cmd;
  bool finished;

  cmd = smtp_server_command_new(tmp_conn, cmd_name);

  smtp_server_command_ref(cmd);

  smtp_server_connection_ref(tmp_conn);
  smtp_server_command_execute(cmd, cmd_params);
  if (!smtp_server_connection_unref(&tmp_conn)) {
    /* The command start callback managed to get this connection
       destroyed */
    smtp_server_command_unref(&cmd);
    return FALSE;
  }

  if (conn->command_queue_head == cmd)
    (void)smtp_server_command_next_to_reply(&cmd);

  smtp_server_connection_timeout_update(conn);

  finished = !cmd->input_locked;
  return (!smtp_server_command_unref(&cmd) || finished);
}

static int
smtp_server_connection_sni_callback(const char *name, const char **error_r,
            void *context)
{
  struct smtp_server_connection *conn = context;
  struct ssl_iostream_context *ssl_ctx;
  const struct ssl_settings *ssl_set;
  const struct ssl_server_settings *ssl_server_set;

  event_add_str(conn->event, "local_name", name);
  i_free(conn->local_name);
  conn->local_name = i_strdup(name);
  if (ssl_server_settings_get(conn->event, &ssl_set, &ssl_server_set,
            error_r) < 0)
    return -1;
  if (conn->local_name != NULL && *conn->local_name != '\0')
    conn->set.hostname = conn->local_name;
  if (conn->callbacks->conn_tls_sni_callback != NULL &&
      conn->callbacks->conn_tls_sni_callback(conn->context, name,
               error_r) < 0) {
    settings_free(ssl_set);
    settings_free(ssl_server_set);
    return -1;
  }

  ssl_server_settings_to_iostream_set(ssl_set, ssl_server_set,
              &conn->set.ssl);

  int ret;
  if ((ret = ssl_iostream_server_context_cache_get(conn->set.ssl, &ssl_ctx,
               error_r)) < 0) {
    settings_free(ssl_set);
    settings_free(ssl_server_set);
    return -1;
  }
  settings_free(ssl_set);
  settings_free(ssl_server_set);
  if (ret == 1) {
    const char *application_protocol = smtp_protocol_name(conn->set.protocol);
    const char *const names[] = {
      application_protocol,
      NULL
    };
    ssl_iostream_context_set_application_protocols(ssl_ctx, names);
  }
  ssl_iostream_change_context(conn->ssl_iostream, ssl_ctx);
  ssl_iostream_context_unref(&ssl_ctx);
  return 0;
}

int smtp_server_connection_ssl_init(struct smtp_server_connection *conn)
{
  struct ssl_iostream_context *ssl_ctx;
  const char *error;
  int ret;

  e_debug(conn->event, "Starting SSL handshake");

  if (conn->raw_input != conn->conn.input) {
    /* Recreate rawlog after STARTTLS */
    i_stream_ref(conn->raw_input);
    o_stream_ref(conn->raw_output);
    i_stream_destroy(&conn->conn.input);
    o_stream_destroy(&conn->conn.output);
    conn->conn.input = conn->raw_input;
    conn->conn.output = conn->raw_output;
  }

  smtp_server_connection_input_halt(conn);
  if (conn->set.ssl == NULL) {
    const struct ssl_iostream_server_autocreate_parameters parameters = {
      .event_parent = conn->event,
    };
    ret = io_stream_autocreate_ssl_server(&parameters,
      &conn->conn.input, &conn->conn.output,
      &conn->ssl_iostream, &error);
  } else if (ssl_iostream_server_context_cache_get(conn->set.ssl,
               &ssl_ctx, &error) < 0)
    ret = -1;
  else {
    ret = io_stream_create_ssl_server(ssl_ctx, conn->event,
      &conn->conn.input, &conn->conn.output,
      &conn->ssl_iostream, &error);
    ssl_iostream_context_unref(&ssl_ctx);
  }
  if (ret < 0) {
    e_error(conn->event,
      "Couldn't initialize SSL server for %s: %s",
      conn->conn.name, error);
    return -1;
  }
  ssl_iostream_set_sni_callback(
    conn->ssl_iostream, smtp_server_connection_sni_callback, conn);
  smtp_server_connection_input_resume(conn);

  if (ssl_iostream_handshake(conn->ssl_iostream) < 0) {
    e_error(conn->event, "SSL handshake failed: %s",
      ssl_iostream_get_last_error(conn->ssl_iostream));
    return -1;
  }

  conn->ssl_secured = TRUE;
  conn->set.capabilities &= ENUM_NEGATE(SMTP_CAPABILITY_STARTTLS);

  if (conn->connect_succeeded)
    smtp_server_connection_streams_changed(conn);
  else if (conn->ssl_start &&
     ssl_iostream_is_handshaked(conn->ssl_iostream))
    smtp_server_connection_ready(conn);

  return 0;
}

static void
smtp_server_connection_handle_input(struct smtp_server_connection *conn,
            bool pipeline_blocked)
{
  struct smtp_server_command *pending_command;
  enum smtp_command_parse_error error_code;
  const char *cmd_name, *cmd_params, *error;
  int ret;

  /* Check whether we are continuing a command */
  pending_command = NULL;
  if (conn->command_queue_tail != NULL) {
    pending_command =
      ((conn->command_queue_tail->state ==
        SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY) ?
       conn->command_queue_tail : NULL);
  }

  smtp_server_connection_timeout_reset(conn);

  /* Parse commands */
  ret = 1;
  while (!conn->closing && !conn->input_locked && ret != 0) {
    while ((ret = smtp_command_parse_next(
      conn->smtp_parser, pipeline_blocked,
      &cmd_name, &cmd_params, &error_code, &error)) > 0) {

      if (pending_command != NULL) {
        /* Previous command is now fully read and ready
           to reply */
        smtp_server_command_ready_to_reply(pending_command);
        pending_command = NULL;
      }

      if (pipeline_blocked) {
        e_debug(conn->event,
          "Discarded remaining data for previous command");
        break;
      }

      e_debug(conn->event, "Received new command: %s %s",
        cmd_name, cmd_params);

      conn->stats.command_count++;

      /* Handle command (cmd may be destroyed after this) */
      if (!smtp_server_connection_handle_command(conn,
        cmd_name, cmd_params))
        return;

      if (conn->disconnected)
        return;
      /* Last command locked the input; stop trying to read
         more. */
      if (conn->input_locked)
        break;
      /* Client indicated it will close after this command;
         stop trying to read more. */
      if (conn->closing)
        break;

      if (!smtp_server_connection_check_pipeline(conn))
        pipeline_blocked = TRUE;
      if (pipeline_blocked &&
          !smtp_command_parser_pending_data(conn->smtp_parser)) {
        smtp_server_connection_input_halt(conn);
        return;
      }

      if (conn->command_queue_tail != NULL) {
        pending_command =
          ((conn->command_queue_tail->state ==
            SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY) ?
           conn->command_queue_tail : NULL);
      }
    }

    if (ret < 0 && conn->conn.input->eof) {
      const char *error =
        i_stream_get_disconnect_reason(conn->conn.input);
      e_debug(conn->event, "Remote closed connection: %s",
        error);

      if (conn->command_queue_head == NULL ||
          conn->command_queue_head->state <
          SMTP_SERVER_COMMAND_STATE_SUBMITTED_REPLY) {
        /* No pending commands or unfinished
           command; close */
        smtp_server_connection_close(&conn, error);
      } else {
        /* A command is still processing;
           only drop input io for now */
        conn->input_broken = TRUE;
        smtp_server_connection_input_halt(conn);
      }
      return;
    }

    if (ret < 0) {
      struct smtp_server_command *cmd;

      e_debug(conn->event,
        "Client sent invalid command: %s", error);

      switch (error_code) {
      case SMTP_COMMAND_PARSE_ERROR_BROKEN_COMMAND:
        conn->input_broken = TRUE;
        /* fall through */
      case SMTP_COMMAND_PARSE_ERROR_BAD_COMMAND:
        cmd = smtp_server_command_new_invalid(conn);
        smtp_server_command_fail(
          cmd, 500, "5.5.2",
          "Invalid command syntax");
        break;
      case SMTP_COMMAND_PARSE_ERROR_LINE_TOO_LONG:
        cmd = smtp_server_command_new_invalid(conn);
        smtp_server_command_fail(
          cmd, 500, "5.5.2", "Line too long");
        break;
      case SMTP_COMMAND_PARSE_ERROR_DATA_TOO_LARGE:
        /* Command data size exceeds the absolute limit;
           i.e. beyond which we don't even want to skip
           data anymore. The command error is usually
           already submitted by the application and sent
           to the client. */
        smtp_server_connection_close(&conn,
          "Command data size exceeds absolute limit");
        return;
      case SMTP_COMMAND_PARSE_ERROR_BROKEN_STREAM:
        smtp_server_connection_close(&conn, error);
        return;
      default:
        i_unreached();
      }
    }

    if (conn->disconnected)
      return;
    if (conn->input_broken || conn->closing) {
      smtp_server_connection_input_halt(conn);
      return;
    }

    if (ret == 0 && pending_command != NULL &&
        !smtp_command_parser_pending_data(conn->smtp_parser)) {
      /* Previous command is now fully read and ready to
         reply */
      smtp_server_command_ready_to_reply(pending_command);
    }

    if (pipeline_blocked &&
        !smtp_command_parser_pending_data(conn->smtp_parser)) {
      smtp_server_connection_input_halt(conn);
      return;
    }
  }
}

static void smtp_server_connection_input(struct connection *_conn)
{
  struct smtp_server_connection *conn =
    (struct smtp_server_connection *)_conn;
  int ret;

  i_assert(!conn->input_broken);

  if (conn->handling_input)
    return;

  smtp_server_connection_timeout_reset(conn);

  if (conn->ssl_start && conn->ssl_iostream == NULL) {
    if (smtp_server_connection_ssl_init(conn) < 0) {
      smtp_server_connection_close(&conn,
        "SSL Initialization failed");
      return;
    }
  }
  i_assert(!conn->halted);

  /* If connection is established over secure line, wait for TLS
     handshake to finish. */
  if (conn->ssl_iostream != NULL &&
      !ssl_iostream_is_handshaked(conn->ssl_iostream)) {
    /* Finish SSL negotiating by reading from input stream. */
    while ((ret = i_stream_read(conn->conn.input)) > 0 ||
           ret == -2) {
      if (ssl_iostream_is_handshaked(conn->ssl_iostream))
        break;
    }
    if (ret == -1) {
      int stream_errno = conn->conn.input->stream_errno;

      /* Failed somehow. */
      i_assert(ret != -2);
      const char *error = t_strdup_printf(
        "SSL handshaking with %s failed: "
        "read(%s) failed: %s",
        _conn->name,
        i_stream_get_name(conn->conn.input),
        (stream_errno != 0 ?
         i_stream_get_error(conn->conn.input) : "EOF"));
      e_error(conn->event, "%s", error);
      smtp_server_connection_close(&conn, error);
      return;
    }
    if (!ssl_iostream_is_handshaked(conn->ssl_iostream)) {
      /* Not finished. */
      i_assert(ret == 0);
      return;
    }
    if (conn->halted) {
      smtp_server_connection_input_lock(conn);
      return;
    }
  }

  if (!conn->connect_succeeded &&
      (conn->ssl_iostream == NULL ||
       ssl_iostream_is_handshaked(conn->ssl_iostream)))
    smtp_server_connection_ready(conn);

  bool pipeline_blocked = FALSE;
  if (!smtp_server_connection_check_pipeline(conn)) {
    /* Check whether the last command in the queue is blocking the
       pipeline and whether it still has pending input data. In that
       case we read/discard that first to possibly unblock the
       pipeline. */
    if (conn->command_queue_tail == NULL ||
        !conn->command_queue_tail->pipeline_blocked ||
        !smtp_server_connection_pending_command_data(conn)) {
      smtp_server_connection_input_halt(conn);
      return;
    }
    pipeline_blocked = TRUE;
  }

  smtp_server_connection_ref(conn);
  conn->handling_input = TRUE;
  if (conn->callbacks != NULL &&
      conn->callbacks->conn_cmd_input_pre != NULL)
    conn->callbacks->conn_cmd_input_pre(conn->context);
  smtp_server_connection_handle_input(conn, pipeline_blocked);
  if (conn->callbacks != NULL &&
      conn->callbacks->conn_cmd_input_post != NULL)
    conn->callbacks->conn_cmd_input_post(conn->context);
  conn->handling_input = FALSE;

  /* Handle output errors from immediate replies sent to client
     (normal replies are exclusively sent in output handler). */
  if (conn->conn.output != NULL && conn->conn.output->closed)
                smtp_server_connection_handle_output_error(conn);
  smtp_server_connection_unref(&conn);
}

bool smtp_server_connection_pending_command_data(
  struct smtp_server_connection *conn)
{
  if (conn->smtp_parser == NULL)
    return FALSE;
  return smtp_command_parser_pending_data(conn->smtp_parser);
}

/*
 * Command reply handling
 */

void smtp_server_connection_handle_output_error(
  struct smtp_server_connection *conn)
{
  smtp_server_connection_close(&conn,
    o_stream_get_disconnect_reason(conn->conn.output));
}

static bool
smtp_server_connection_next_reply(struct smtp_server_connection *conn)
{
  struct smtp_server_command *cmd;

  cmd = conn->command_queue_head;
  if (cmd == NULL) {
    /* No commands pending */
    e_debug(conn->event, "No more commands pending");
    return FALSE;
  }

  return smtp_server_command_send_replies(cmd);
}

void smtp_server_connection_cork(struct smtp_server_connection *conn)
{
  conn->corked = TRUE;
  if (conn->conn.output != NULL)
    o_stream_cork(conn->conn.output);
}

void smtp_server_connection_uncork(struct smtp_server_connection *conn)
{
  conn->corked = FALSE;
  if (!conn->conn.output->closed) {
    if (o_stream_uncork_flush(conn->conn.output) < 0) {
      smtp_server_connection_handle_output_error(conn);
      return;
    }
    smtp_server_connection_trigger_output(conn);
  }
}

static void
smtp_server_connection_send_replies(struct smtp_server_connection *conn)
{
  /* Send more replies until no more replies remain, the output
     blocks again, or the connection is closed */
  while (!conn->disconnected && smtp_server_connection_next_reply(conn));

  smtp_server_connection_timeout_update(conn);

  /* Accept more commands if possible */
  smtp_server_connection_input_resume(conn);
}

int smtp_server_connection_flush(struct smtp_server_connection *conn)
{
  struct ostream *output = conn->conn.output;
  int ret;

  if ((ret = o_stream_flush(output)) <= 0) {
    if (ret < 0)
      smtp_server_connection_handle_output_error(conn);
    return ret;
  }
  return 1;
}

static int smtp_server_connection_output(struct smtp_server_connection *conn)
{
  int ret;

  e_debug(conn->event, "Sending replies");

  smtp_server_connection_ref(conn);
  o_stream_cork(conn->conn.output);
  ret = smtp_server_connection_flush(conn);
  if (ret > 0) {
    smtp_server_connection_timeout_reset(conn);
    smtp_server_connection_send_replies(conn);
  }
  if (ret >= 0 && !conn->corked && conn->conn.output != NULL)
    ret = o_stream_uncork_flush(conn->conn.output);
  if (conn->conn.output != NULL && conn->conn.output->closed) {
    smtp_server_connection_handle_output_error(conn);
    ret = -1;
  }
  smtp_server_connection_unref(&conn);
  return ret;
}

void smtp_server_connection_trigger_output(struct smtp_server_connection *conn)
{
  if (conn->conn.output != NULL) {
    e_debug(conn->event, "Trigger output");
    o_stream_set_flush_pending(conn->conn.output, TRUE);
  }
}

/*
 *
 */

static struct connection_settings smtp_server_connection_set = {
  .input_max_size = SIZE_MAX,
  .output_max_size = SIZE_MAX,
  .client = FALSE,
  .log_connection_id = TRUE,
};

static const struct connection_vfuncs smtp_server_connection_vfuncs = {
  .destroy = smtp_server_connection_destroy,
  .input = smtp_server_connection_input,
};

struct connection_list *smtp_server_connection_list_init(void)
{
  return connection_list_init(&smtp_server_connection_set,
            &smtp_server_connection_vfuncs);
}

static struct event *
smtp_server_connection_event_create(struct smtp_server *server,
            const struct smtp_server_settings *set)
{
  struct event *conn_event;

  if (set != NULL && set->event_parent != NULL) {
    conn_event = event_create(set->event_parent);
    smtp_server_event_init(server, conn_event);
  } else
    conn_event = event_create(server->event);
  event_set_append_log_prefix(conn_event, t_strdup_printf(
    "%s-server: ", smtp_protocol_name(server->set.protocol)));
  event_set_forced_debug(conn_event, (set != NULL && set->debug));

  return conn_event;
}

static void
smtp_server_connection_update_event(struct smtp_server_connection *conn)
{
  event_add_str(conn->event, "connection_id", conn->session_id);
  event_add_str(conn->event, "session", conn->session_id);
}

static void
smtp_server_connection_init_session(struct smtp_server_connection *conn)
{
  guid_128_t guid;
  string_t *session_id;

  session_id = t_str_new(30);
  guid_128_generate(guid);
  base64_encode(guid, sizeof(guid), session_id);

  /* drop trailing "==" */
  i_assert(str_c(session_id)[str_len(session_id)-2] == '=');
  str_truncate(session_id, str_len(session_id)-2);

  conn->session_id = i_strdup(str_c(session_id));
}

static struct smtp_server_connection * ATTR_NULL(5, 6)
smtp_server_connection_alloc(struct smtp_server *server,
           const struct smtp_server_settings *set,
           int fd_in, int fd_out,
           const struct smtp_server_callbacks *callbacks,
           void *context)
{
  struct smtp_server_connection *conn;
  pool_t pool;

  pool = pool_alloconly_create("smtp server", 2048);
  conn = p_new(pool, struct smtp_server_connection, 1);
  conn->pool = pool;
  conn->refcount = 1;
  conn->server = server;
  conn->callbacks = callbacks;
  conn->context = context;

  /* Merge settings with global server settings */
  conn->set = server->set;
  if (set != NULL) {
    conn->set.protocol = server->set.protocol;
    if (set->rawlog_dir != NULL && *set->rawlog_dir != '\0')
      conn->set.rawlog_dir = p_strdup(pool, set->rawlog_dir);

    if (set->ssl != NULL) {
      conn->set.ssl = set->ssl;
      pool_ref(conn->set.ssl->pool);
    }

    if (set->hostname != NULL && *set->hostname != '\0')
      conn->set.hostname = p_strdup(pool, set->hostname);
    if (set->login_greeting != NULL &&
      *set->login_greeting != '\0') {
      conn->set.login_greeting =
        p_strdup(pool, set->login_greeting);
    }
    if (set->capabilities != 0)
      conn->set.capabilities = set->capabilities;
    conn->set.workarounds |= set->workarounds;

    if (set->max_client_idle_time_msecs > 0) {
      conn->set.max_client_idle_time_msecs =
        set->max_client_idle_time_msecs;
    }
    if (set->max_pipelined_commands > 0) {
      conn->set.max_pipelined_commands =
        set->max_pipelined_commands;
    }
    if (set->max_bad_commands > 0) {
      conn->set.max_bad_commands = set->max_bad_commands;
    }
    conn->set.max_recipients = set->max_recipients;
    i_assert(server->set.max_recipients != 0);
    smtp_command_limits_merge(&conn->set.command_limits,
            &set->command_limits);

    conn->set.max_message_size = set->max_message_size;
    if (set->max_message_size == 0 ||
        set->max_message_size == UOFF_T_MAX) {
      conn->set.command_limits.max_data_size = UOFF_T_MAX;
    } else if (conn->set.command_limits.max_data_size != 0) {
      /* Explicit limit given */
    } else if (set->max_message_size >
      (UOFF_T_MAX - SMTP_SERVER_DEFAULT_MAX_SIZE_EXCESS_LIMIT)) {
      /* Very high limit */
      conn->set.command_limits.max_data_size = UOFF_T_MAX;
    } else {
      /* Absolute maximum before connection is closed in DATA
         command */
      conn->set.command_limits.max_data_size =
        set->max_message_size +
          SMTP_SERVER_DEFAULT_MAX_SIZE_EXCESS_LIMIT;
    }

    if (set->mail_param_extensions != NULL) {
      conn->set.mail_param_extensions =
        p_strarray_dup(pool, set->mail_param_extensions);
    }
    if (set->rcpt_param_extensions != NULL) {
      conn->set.rcpt_param_extensions =
        p_strarray_dup(pool, set->rcpt_param_extensions);
    }
    if (set->xclient_extensions != NULL) {
      conn->set.xclient_extensions =
        p_strarray_dup(pool, set->xclient_extensions);
    }

    if (set->socket_send_buffer_size > 0) {
      conn->set.socket_send_buffer_size =
        set->socket_send_buffer_size;
    }
    if (set->socket_recv_buffer_size > 0) {
      conn->set.socket_recv_buffer_size =
        set->socket_recv_buffer_size;
    }

    conn->set.tls_required =
      conn->set.tls_required || set->tls_required;
    conn->set.auth_optional =
      conn->set.auth_optional || set->auth_optional;
    conn->set.mail_path_allow_broken =
      conn->set.mail_path_allow_broken ||
        set->mail_path_allow_broken;
    conn->set.rcpt_domain_optional =
      conn->set.rcpt_domain_optional ||
        set->rcpt_domain_optional;
    conn->set.no_greeting =
      conn->set.no_greeting || set->no_greeting;
    conn->set.debug = conn->set.debug || set->debug;
  }

  if (set != NULL && set->mail_param_extensions != NULL) {
    const char *const *extp;

    p_array_init(&conn->mail_param_extensions, pool,
           str_array_length(set->mail_param_extensions) + 8);
    for (extp = set->mail_param_extensions; *extp != NULL; extp++) {
      const char *ext = p_strdup(pool, *extp);
      array_push_back(&conn->mail_param_extensions, &ext);
    }
    array_append_zero(&conn->mail_param_extensions);
  }
  if (set != NULL && set->rcpt_param_extensions != NULL) {
    const char *const *extp;

    p_array_init(&conn->rcpt_param_extensions, pool,
           str_array_length(set->rcpt_param_extensions) + 8);
    for (extp = set->rcpt_param_extensions; *extp != NULL; extp++) {
      const char *ext = p_strdup(pool, *extp);
      array_push_back(&conn->rcpt_param_extensions, &ext);
    }
    array_append_zero(&conn->rcpt_param_extensions);
  }

  net_set_nonblock(fd_in, TRUE);
  if (fd_in != fd_out)
    net_set_nonblock(fd_out, TRUE);
  (void)net_set_tcp_nodelay(fd_out, TRUE);

  set = &conn->set;
  if (set->socket_send_buffer_size > 0 &&
      net_set_send_buffer_size(fd_out,
                   set->socket_send_buffer_size) < 0) {
    e_error(conn->event,
      "net_set_send_buffer_size(%zu) failed: %m",
      set->socket_send_buffer_size);
  }
  if (set->socket_recv_buffer_size > 0 &&
      net_set_recv_buffer_size(fd_in,
             set->socket_recv_buffer_size) < 0) {
    e_error(conn->event,
      "net_set_recv_buffer_size(%zu) failed: %m",
      set->socket_recv_buffer_size);
  }

  smtp_server_connection_init_session(conn);

  return conn;
}

static void smtp_server_connection_created(struct smtp_server_connection *conn)
{
  conn->raw_input = conn->conn.input;
  conn->raw_output = conn->conn.output;

  /* Halt input until started */
  smtp_server_connection_halt(conn);

  e_debug(conn->event, "Connection created");
}

struct smtp_server_connection *
smtp_server_connection_create(
  struct smtp_server *server, int fd_in, int fd_out,
  const struct ip_addr *local_ip, in_port_t local_port,
  const struct ip_addr *remote_ip, in_port_t remote_port,
  bool ssl_start, const struct smtp_server_settings *set,
  const struct smtp_server_callbacks *callbacks, void *context)
{
  struct smtp_server_connection *conn;
  struct event *conn_event;

  conn = smtp_server_connection_alloc(server, set, fd_in, fd_out,
              callbacks, context);
  conn_event = smtp_server_connection_event_create(server, set);
  conn->conn.event_parent = conn_event;
  connection_init_server_ip(server->conn_list, &conn->conn, NULL,
          fd_in, fd_out, remote_ip, remote_port);
  if (local_ip != NULL && local_ip->family != 0)
    conn->conn.local_ip = *local_ip;
  conn->conn.local_port = local_port;
  conn->event = conn->conn.event;
  smtp_server_connection_update_event(conn);
  event_unref(&conn_event);

  conn->ssl_start = ssl_start;
  if (ssl_start)
    conn->set.capabilities &= ENUM_NEGATE(SMTP_CAPABILITY_STARTTLS);

  smtp_server_connection_created(conn);

  return conn;
}

struct smtp_server_connection *
smtp_server_connection_create_from_streams(
  struct smtp_server *server,
  struct istream *input, struct ostream *output,
  const struct ip_addr *local_ip, in_port_t local_port,
  const struct ip_addr *remote_ip, in_port_t remote_port,
  const struct smtp_server_settings *set,
  const struct smtp_server_callbacks *callbacks, void *context)
{
  struct smtp_server_connection *conn;
  struct event *conn_event;
  int fd_in, fd_out;

  fd_in = i_stream_get_fd(input);
  fd_out = o_stream_get_fd(output);
  i_assert(fd_in >= 0);
  i_assert(fd_out >= 0);

  conn = smtp_server_connection_alloc(server, set, fd_in, fd_out,
              callbacks, context);
  if (local_ip != NULL && local_ip->family != 0)
    conn->conn.local_ip = *local_ip;
  conn->conn.local_port = local_port;
  if (remote_ip != NULL && remote_ip->family != 0)
    conn->conn.remote_ip = *remote_ip;
  if (remote_port != 0)
    conn->conn.remote_port = remote_port;
  conn_event = smtp_server_connection_event_create(server, set);
  conn->conn.event_parent = conn_event;
  connection_init_from_streams(server->conn_list, &conn->conn, NULL,
             input, output);
  conn->created_from_streams = TRUE;
  conn->event = conn->conn.event;
  smtp_server_connection_update_event(conn);
  event_unref(&conn_event);

  smtp_server_connection_created(conn);

  return conn;
}

void smtp_server_connection_ref(struct smtp_server_connection *conn)
{
  conn->refcount++;
}

static const char *
smtp_server_connection_get_disconnect_reason(
  struct smtp_server_connection *conn)
{
  const char *err;

  if (conn->ssl_iostream != NULL &&
      !ssl_iostream_is_handshaked(conn->ssl_iostream)) {
    err = ssl_iostream_get_last_error(conn->ssl_iostream);
    if (err != NULL) {
      return t_strdup_printf(
        "TLS handshaking failed: %s", err);
    }
  }

  return io_stream_get_disconnect_reason(conn->conn.input,
                 conn->conn.output);
}

static void
smtp_server_connection_disconnect(struct smtp_server_connection *conn,
          const char *reason)
{
  struct smtp_server_command *cmd, *cmd_next;

  if (conn->disconnected)
    return;
  conn->disconnected = TRUE;

  if (reason == NULL)
    reason = smtp_server_connection_get_disconnect_reason(conn);
  else
    reason = t_str_oneline(reason);

  cmd = conn->command_queue_head;
  if (cmd != NULL && cmd->reg != NULL) {
    /* Unfinished command - include it in the reason string */
    reason = t_strdup_printf("%s (unfinished %s command)",
      reason, cmd->reg->name);
  }
  if (!conn->set.no_state_in_reason) {
    reason = t_strdup_printf("%s (state=%s)", reason,
      smtp_server_state_names[conn->state.state]);
  }

  e_debug(conn->event, "Disconnected: %s", reason);

  /* Preserve statistics */
  smtp_server_connection_update_stats(conn);

  /* Drop transaction */
  smtp_server_connection_reset_state(conn);

  /* Clear command queue */
  cmd = conn->command_queue_head;
  while (cmd != NULL) {
    cmd_next = cmd->next;
    smtp_server_command_abort(&cmd);
    cmd = cmd_next;
  }

  smtp_server_connection_timeout_stop(conn);
  if (conn->conn.output != NULL)
    o_stream_uncork(conn->conn.output);
  if (conn->smtp_parser != NULL)
    smtp_command_parser_deinit(&conn->smtp_parser);
  ssl_iostream_destroy(&conn->ssl_iostream);
  settings_free(conn->set.ssl);

  if (conn->callbacks != NULL &&
      conn->callbacks->conn_disconnect != NULL) {
    /* The callback may close the fd, so remove IO before that */
    io_remove(&conn->conn.io);
    conn->callbacks->conn_disconnect(conn->context, reason);
  }

  if (!conn->created_from_streams)
    connection_disconnect(&conn->conn);
  else {
    conn->conn.fd_in = conn->conn.fd_out = -1;
    io_remove(&conn->conn.io);
    i_stream_unref(&conn->conn.input);
    o_stream_unref(&conn->conn.output);
  }
}

bool smtp_server_connection_unref(struct smtp_server_connection **_conn)
{
  struct smtp_server_connection *conn = *_conn;

  *_conn = NULL;

  i_assert(conn->refcount > 0);
  if (--conn->refcount > 0)
    return TRUE;

  smtp_server_connection_disconnect(conn, NULL);

  e_debug(conn->event, "Connection destroy");

  connection_deinit(&conn->conn);

  if (conn->callbacks != NULL && conn->callbacks->conn_free != NULL)
    conn->callbacks->conn_free(conn->context);

  i_free(conn->proxy_helo);
  i_free(conn->helo_domain);
  i_free(conn->username);
  i_free(conn->session_id);
  i_free(conn->client_transport);
  i_free(conn->local_name);
  event_unref(&conn->next_trans_event);
  pool_unref(&conn->pool);
  return FALSE;
}

void smtp_server_connection_send_line(struct smtp_server_connection *conn,
              const char *fmt, ...)
{
  va_list args;

  va_start(args, fmt);

  T_BEGIN {
    string_t *str;

    str = t_str_new(256);
    str_vprintfa(str, fmt, args);

    e_debug(conn->event, "Sent: %s", str_c(str));

    str_append(str, "\r\n");
    o_stream_nsend(conn->conn.output, str_data(str), str_len(str));
  } T_END;
  va_end(args);
}

void smtp_server_connection_reply_lines(struct smtp_server_connection *conn,
                unsigned int status,
          const char *enh_code,
          const char *const *text_lines)
{
  struct smtp_reply reply;

  i_zero(&reply);
  reply.status = status;
  reply.text_lines = text_lines;

  if (!smtp_reply_parse_enhanced_code(
    enh_code, &reply.enhanced_code, NULL))
    reply.enhanced_code = SMTP_REPLY_ENH_CODE(status / 100, 0, 0);

  T_BEGIN {
    string_t *str;

    e_debug(conn->event, "Sent: %s", smtp_reply_log(&reply));

    str = t_str_new(256);
    smtp_reply_write(str, &reply);
    o_stream_nsend(conn->conn.output, str_data(str), str_len(str));
  } T_END;
}

void smtp_server_connection_reply_immediate(
  struct smtp_server_connection *conn,
  unsigned int status, const char *fmt, ...)
{
  va_list args;

  va_start(args, fmt);
  T_BEGIN {
    string_t *str;

    str = t_str_new(256);
    str_printfa(str, "%03u ", status);
    str_vprintfa(str, fmt, args);

    e_debug(conn->event, "Sent: %s", str_c(str));

    str_append(str, "\r\n");
    o_stream_nsend(conn->conn.output, str_data(str), str_len(str));
  } T_END;
  va_end(args);

  /* Send immediately */
  if (o_stream_is_corked(conn->conn.output)) {
    o_stream_uncork(conn->conn.output);
    o_stream_cork(conn->conn.output);
  }
}

void smtp_server_connection_login(struct smtp_server_connection *conn,
          const char *username, const char *helo,
          const unsigned char *pdata,
          unsigned int pdata_len, bool ssl_secured)
{
  i_assert(!conn->started);

  conn->set.capabilities &= ENUM_NEGATE(SMTP_CAPABILITY_STARTTLS);
  i_free(conn->username);
  conn->username = i_strdup(username);
  if (helo != NULL && *helo != '\0') {
    i_free(conn->helo_domain);
    conn->helo_domain = i_strdup(helo);
    conn->helo.domain = conn->helo_domain;
    conn->helo.domain_valid = TRUE;
  }
  conn->authenticated = TRUE;
  conn->ssl_secured = ssl_secured;

  if (pdata_len > 0) {
    if (!i_stream_add_data(conn->conn.input, pdata, pdata_len))
      i_panic("Couldn't add client input to stream");
  }
}

void smtp_server_connection_start_pending(struct smtp_server_connection *conn)
{
  i_assert(!conn->started);
  conn->started = TRUE;

  e_debug(conn->event, "Connection started");

  if (!conn->ssl_start)
    smtp_server_connection_ready(conn);
  else if (conn->ssl_iostream == NULL)
    smtp_server_connection_input_unlock(conn);
}

void smtp_server_connection_start(struct smtp_server_connection *conn)
{
  smtp_server_connection_start_pending(conn);
  smtp_server_connection_resume(conn);
}

void smtp_server_connection_abort(struct smtp_server_connection **_conn,
          unsigned int status, const char *enh_code,
          const char *reason)
{
  struct smtp_server_connection *conn = *_conn;
  const char **reason_lines;

  if (conn == NULL)
    return;
  *_conn = NULL;

  i_assert(!conn->started);
  conn->started = TRUE;

  if (conn->authenticated) {
    reason_lines = t_strsplit_spaces(reason, "\r\n");
    smtp_server_connection_reply_lines(
      conn, status, enh_code, reason_lines);
    smtp_server_connection_terminate(
      &conn, "4.3.2", "Shutting down due to fatal error");
  } else {
    smtp_server_connection_terminate(&conn, enh_code, reason);
  }
}

void smtp_server_connection_halt(struct smtp_server_connection *conn)
{
  conn->halted = TRUE;
  smtp_server_connection_timeout_stop(conn);
  if (conn->ssl_start &&
      (conn->ssl_iostream == NULL ||
       !ssl_iostream_is_handshaked(conn->ssl_iostream)))
    return;

  smtp_server_connection_input_lock(conn);
}

void smtp_server_connection_resume(struct smtp_server_connection *conn)
{
  smtp_server_connection_input_unlock(conn);
  smtp_server_connection_timeout_update(conn);
  conn->halted = FALSE;
}

void smtp_server_connection_close(struct smtp_server_connection **_conn,
          const char *reason)
{
  struct smtp_server_connection *conn = *_conn;

  *_conn = NULL;

  if (conn->closed)
    return;
  conn->closed = TRUE;

  smtp_server_connection_disconnect(conn, reason);
  smtp_server_connection_unref(&conn);
}

void smtp_server_connection_terminate(struct smtp_server_connection **_conn,
              const char *enh_code, const char *reason)
{
  smtp_server_connection_terminate_full(_conn, enh_code, reason, reason);
}

void smtp_server_connection_terminate_full(
  struct smtp_server_connection **_conn, const char *enh_code,
  const char *reply_reason, const char *log_reason)
{
  struct smtp_server_connection *conn = *_conn;
  const char **reason_lines;

  *_conn = NULL;

  if (conn->closed)
    return;

  i_assert(enh_code[0] == '4' && enh_code[1] == '.');

  T_BEGIN {
    /* Add hostname prefix */
    reason_lines = t_strsplit_spaces(reply_reason, "\r\n");
    reason_lines[0] = t_strconcat(conn->set.hostname, " ",
                reason_lines[0], NULL);

    smtp_server_connection_reply_lines(conn, 421, enh_code,
               reason_lines);

    smtp_server_connection_close(&conn, log_reason);
  } T_END;
}

struct smtp_server_helo_data *
smtp_server_connection_get_helo_data(struct smtp_server_connection *conn)
{
  return &conn->helo;
}

enum smtp_server_state
smtp_server_connection_get_state(struct smtp_server_connection *conn,
         const char **args_r)
{
  if (args_r != NULL)
    *args_r = conn->state.args;
  return conn->state.state;
}

void smtp_server_connection_set_state(struct smtp_server_connection *conn,
              enum smtp_server_state state,
              const char *args)
{
  bool changed = FALSE;

  if (conn->state.state != state) {
    conn->state.state = state;
    changed = TRUE;
  }
  if (null_strcmp(args, conn->state.args) != 0) {
    i_free(conn->state.args);
    conn->state.args = i_strdup(args);
    changed = TRUE;
  }

  if (changed && conn->callbacks != NULL &&
      conn->callbacks->conn_state_changed != NULL)
    conn->callbacks->conn_state_changed(conn->context, state, args);
}

const char *
smtp_server_connection_get_security_string(struct smtp_server_connection *conn)
{
  if (conn->ssl_iostream == NULL)
    return NULL;
  return ssl_iostream_get_security_string(conn->ssl_iostream);
}

void smtp_server_connection_reset_state(struct smtp_server_connection *conn)
{
  e_debug(conn->event, "Connection state reset");

  i_free(conn->state.args);

  if (conn->state.trans != NULL)
    smtp_server_transaction_free(&conn->state.trans);

  /* RFC 3030, Section 2:
     The RSET command, when issued after the first BDAT and before the
     BDAT LAST, clears all segments sent during that transaction and
     resets the session.
   */
  i_stream_destroy(&conn->state.data_input);
  i_stream_destroy(&conn->state.data_chain_input);
  conn->state.data_chain = NULL;

  /* Reset state */
  i_zero(&conn->state);
  smtp_server_connection_set_state(conn, SMTP_SERVER_STATE_READY, NULL);
}

void smtp_server_connection_clear(struct smtp_server_connection *conn)
{
  e_debug(conn->event, "Connection clear");

  i_free(conn->helo_domain);
  i_zero(&conn->helo);
  smtp_server_connection_reset_state(conn);
}

void smtp_server_connection_set_capabilities(
  struct smtp_server_connection *conn, enum smtp_capability capabilities)
{
  conn->set.capabilities = capabilities;
}

void smtp_server_connection_set_greeting(struct smtp_server_connection *conn,
           const char *greeting)
{
  conn->set.login_greeting = p_strdup(conn->pool, greeting);
}

void smtp_server_connection_add_extra_capability(
  struct smtp_server_connection *conn,
  const struct smtp_capability_extra *cap)
{
  const struct smtp_capability_extra *cap_idx;
  struct smtp_capability_extra cap_new;
  unsigned int insert_idx;
  pool_t pool = conn->pool;

  /* Avoid committing protocol errors */
  i_assert(smtp_ehlo_keyword_is_valid(cap->name));
  i_assert(smtp_ehlo_params_are_valid(cap->params));

  /* Cannot override standard capabilities */
  i_assert(smtp_capability_find_by_name(cap->name)
     == SMTP_CAPABILITY_NONE);

  if (!array_is_created(&conn->extra_capabilities))
    p_array_init(&conn->extra_capabilities, pool, 4);

  /* Keep array sorted */
  insert_idx = array_count(&conn->extra_capabilities);
  array_foreach(&conn->extra_capabilities, cap_idx) {
    int cmp = strcasecmp(cap_idx->name, cap->name);

    /* Prohibit duplicates */
    i_assert(cmp != 0);

    if (cmp > 0) {
      insert_idx = array_foreach_idx(
        &conn->extra_capabilities, cap_idx);
      break;
    }
  }

  i_zero(&cap_new);
  cap_new.name = p_strdup(pool, cap->name);
  if (cap->params != NULL)
    cap_new.params = p_strarray_dup(pool, cap->params);

  array_insert(&conn->extra_capabilities, insert_idx, &cap_new, 1);
}

void *smtp_server_connection_get_context(struct smtp_server_connection *conn)
{
  return conn->context;
}

bool smtp_server_connection_is_ssl_secured(struct smtp_server_connection *conn)
{
  return conn->ssl_secured;
}

bool smtp_server_connection_is_trusted(struct smtp_server_connection *conn)
{
  if (conn->callbacks == NULL || conn->callbacks->conn_is_trusted == NULL)
    return FALSE;
  return conn->callbacks->conn_is_trusted(conn->context);
}

bool smtp_server_connection_is_started(struct smtp_server_connection *conn)
{
  return conn->started;
}

enum smtp_protocol
smtp_server_connection_get_protocol(struct smtp_server_connection *conn)
{
  return conn->set.protocol;
}

const char *
smtp_server_connection_get_protocol_name(struct smtp_server_connection *conn)
{
  string_t *pname = t_str_new(16);

  switch (conn->set.protocol) {
  case SMTP_PROTOCOL_SMTP:
    if (conn->helo.old_smtp)
      str_append(pname, "SMTP");
    else
      str_append(pname, "ESMTP");
    break;
  case SMTP_PROTOCOL_LMTP:
    str_append(pname, "LMTP");
    break;
  default:
    i_unreached();
  }
  if (conn->ssl_secured)
    str_append_c(pname, 'S');
  if (conn->authenticated)
    str_append_c(pname, 'A');
  return str_c(pname);
}

struct smtp_server_transaction *
smtp_server_connection_get_transaction(struct smtp_server_connection *conn)
{
  return conn->state.trans;
}

const char *
smtp_server_connection_get_transaction_id(struct smtp_server_connection *conn)
{
  if (conn->state.trans == NULL)
    return NULL;
  return conn->state.trans->id;
}

void smtp_server_connection_get_proxy_data(struct smtp_server_connection *conn,
             struct smtp_proxy_data *proxy_data)
{
  i_zero(proxy_data);
  proxy_data->source_ip = conn->conn.remote_ip;
  proxy_data->source_port = conn->conn.remote_port;
  proxy_data->dest_ip = conn->conn.local_ip;
  proxy_data->dest_port = conn->conn.local_port;
  if (conn->proxy_helo != NULL)
    proxy_data->helo = conn->proxy_helo;
  else if (conn->helo.domain_valid)
    proxy_data->helo = conn->helo.domain;
  proxy_data->login = conn->username;
  proxy_data->session = conn->session_id;
  proxy_data->client_transport = conn->client_transport;
  proxy_data->local_name = conn->local_name;

  if (conn->proxy_proto != SMTP_PROXY_PROTOCOL_UNKNOWN)
    proxy_data->proto = conn->proxy_proto;
  else if (conn->set.protocol == SMTP_PROTOCOL_LMTP)
    proxy_data->proto = SMTP_PROXY_PROTOCOL_LMTP;
  else if (conn->helo.old_smtp)
    proxy_data->proto = SMTP_PROXY_PROTOCOL_SMTP;
  else
    proxy_data->proto = SMTP_PROXY_PROTOCOL_ESMTP;

  proxy_data->ttl_plus_1 = conn->proxy_ttl_plus_1;
  proxy_data->timeout_secs = conn->proxy_timeout_secs;
}

void smtp_server_connection_set_proxy_data(
  struct smtp_server_connection *conn,
  const struct smtp_proxy_data *proxy_data)
{
  if (proxy_data->source_ip.family != 0)
    conn->conn.remote_ip = proxy_data->source_ip;
  if (proxy_data->source_port != 0)
    conn->conn.remote_port = proxy_data->source_port;
  if (proxy_data->helo != NULL) {
    i_free(conn->helo_domain);
    conn->helo_domain = i_strdup(proxy_data->helo);
    conn->helo.domain = conn->helo_domain;
    conn->helo.domain_valid = TRUE;
    if (conn->helo.domain_valid) {
      i_free(conn->proxy_helo);
      conn->proxy_helo = i_strdup(proxy_data->helo);
    }
  }
  if (proxy_data->login != NULL) {
    i_free(conn->username);
    conn->username = i_strdup(proxy_data->login);
  }
  if (proxy_data->proto != SMTP_PROXY_PROTOCOL_UNKNOWN)
    conn->proxy_proto = proxy_data->proto;
  if (proxy_data->session != NULL &&
      strcmp(proxy_data->session, conn->session_id) != 0) {
    e_debug(conn->event, "Updated session ID from %s to %s",
            conn->session_id, proxy_data->session);
    i_free(conn->session_id);
    conn->session_id = i_strdup(proxy_data->session);
  }
  if (proxy_data->client_transport != NULL) {
    i_free(conn->client_transport);
    conn->client_transport = i_strdup(proxy_data->client_transport);
  }
  if (proxy_data->local_name != NULL) {
    i_free(conn->local_name);
    conn->local_name = i_strdup(proxy_data->local_name);
  }
  if (proxy_data->ttl_plus_1 > 0)
    conn->proxy_ttl_plus_1 = proxy_data->ttl_plus_1;
  if (conn->proxy_timeout_secs > 0)
    conn->proxy_timeout_secs = proxy_data->timeout_secs;

  connection_update_properties(&conn->conn);
  smtp_server_connection_update_event(conn);

  if (conn->callbacks != NULL &&
      conn->callbacks->conn_proxy_data_updated != NULL) {
    struct smtp_proxy_data full_data;

    smtp_server_connection_get_proxy_data(conn, &full_data);

    conn->callbacks->
      conn_proxy_data_updated(conn->context, &full_data);
  }
}

void smtp_server_connection_register_mail_param(
  struct smtp_server_connection *conn, const char *param)
{
  param = p_strdup(conn->pool, param);

  if (!array_is_created(&conn->mail_param_extensions)) {
    p_array_init(&conn->mail_param_extensions, conn->pool, 8);
    array_push_back(&conn->mail_param_extensions, &param);
  } else {
    unsigned int count = array_count(&conn->mail_param_extensions);

    i_assert(count > 0);
    array_idx_set(&conn->mail_param_extensions,
            count - 1, &param);
  }
  array_append_zero(&conn->mail_param_extensions);
}

void smtp_server_connection_register_rcpt_param(
  struct smtp_server_connection *conn, const char *param)
{
  param = p_strdup(conn->pool, param);

  if (!array_is_created(&conn->rcpt_param_extensions)) {
    p_array_init(&conn->rcpt_param_extensions, conn->pool, 8);
    array_push_back(&conn->rcpt_param_extensions, &param);
  } else {
    unsigned int count = array_count(&conn->rcpt_param_extensions);

    i_assert(count > 0);
    array_idx_set(&conn->rcpt_param_extensions,
            count - 1, &param);
  }
  array_append_zero(&conn->rcpt_param_extensions);
}

void smtp_server_connection_switch_ioloop(struct smtp_server_connection *conn)
{
  if (conn->to_idle != NULL)
    conn->to_idle = io_loop_move_timeout(&conn->to_idle);
  connection_switch_ioloop(&conn->conn);
}

struct event_reason *
smtp_server_connection_reason_begin(struct smtp_server_connection *conn,
            const char *name)
{
  if (conn->set.reason_code_module == NULL)
    return NULL;
  const char *reason_code =
    event_reason_code(conn->set.reason_code_module, name);
  return event_reason_begin(reason_code);
}

const char *
smtp_server_connection_get_server_name(struct smtp_server_connection *conn)
{
  if (conn->ssl_iostream == NULL)
    return NULL;
  return ssl_iostream_get_server_name(conn->ssl_iostream);
}

Coverage Report

Created: 2026-07-30 06:31