/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) The Exim Maintainers 2020 - 2026 */
/* Copyright (c) University of Cambridge 1995 - 2018 */
/* See the file NOTICE for conditions of use and distribution. */
/* SPDX-License-Identifier: GPL-2.0-or-later */

#define DELIVER_BUFFER_SIZE 4096

#define PENDING          256
#define PENDING_DEFER   (PENDING + DEFER)
#define PENDING_OK      (PENDING + OK)


#ifndef DISABLE_TLS
/* Flags structure for validity of TLS configuration */

typedef struct {
  BOOL conn_certs:1;		/* certificates etc. loaded */
  BOOL cabundle:1;		/* CA certificates loaded */
  BOOL crl:1;			/* CRL loaded */
  BOOL pri_string:1;		/* cipher priority-string cache loaded */
  BOOL dh:1;			/* Diffie-Helman params loaded */
  BOOL ecdh:1;			/* EC Diffie-Helman params loaded */

  BOOL ca_rdn_emulate:1;	/* do not advertise usable-cert list */
  BOOL ocsp_hook:1;		/* need hshake callback on session */

  void * libdata0;		/* library-dependent preloaded data */
  void * libdata1;		/* library-dependent preloaded data */
} exim_tlslib_state;
#endif


/* Private structure for the private options and other private data. */

typedef struct {
  uschar	*hosts;
  uschar	*fallback_hosts;
  host_item	*hostlist;
  host_item	*fallback_hostlist;
  uschar	*authenticated_sender;
  uschar	*helo_data;
  uschar	*interface;
  uschar	*port;
  uschar	*protocol;
  uschar	*dscp;
  uschar	*serialize_hosts;
  uschar	*hosts_try_auth;
  uschar	*hosts_require_alpn;
  uschar	*hosts_require_auth;
  uschar	*hosts_try_chunking;
#ifdef SUPPORT_DANE
  uschar	*hosts_try_dane;
  uschar	*hosts_require_dane;
  uschar	*dane_require_tls_ciphers;
#endif
  uschar	*hosts_try_fastopen;
#ifndef DISABLE_PRDR
  uschar	*hosts_try_prdr;
#endif
#ifndef DISABLE_OCSP
  uschar	*hosts_request_ocsp;
  uschar	*hosts_require_ocsp;
#endif
  uschar	*hosts_require_tls;
  uschar	*hosts_avoid_tls;
  uschar	*hosts_verify_avoid_tls;
  uschar	*hosts_avoid_pipelining;
#ifndef DISABLE_PIPE_CONNECT
  uschar	*hosts_pipe_connect;
#endif
  uschar	*hosts_avoid_esmtp;
#ifndef DISABLE_TLS
  uschar	*hosts_nopass_tls;
  uschar	*hosts_noproxy_tls;
#endif
  int		command_timeout;
  int		connect_timeout;
  int		data_timeout;
  int		final_timeout;
  int		size_addition;
  int		hosts_max_try;
  int		hosts_max_try_hardlimit;
  int		message_linelength_limit;
  BOOL		address_retry_include_sender;
  BOOL		allow_localhost;
  BOOL		authenticated_sender_force;
  BOOL		gethostbyname;
  BOOL		dns_qualify_single;
  BOOL		dns_search_parents;
  dnssec_domains dnssec;
  BOOL		delay_after_cutoff;
  BOOL		hosts_override;
  BOOL		hosts_randomize;
  uschar *	expand_hosts_randomize;
  BOOL		keepalive;
  BOOL		lmtp_ignore_quota;
  uschar	*expand_retry_include_ip_address;
  BOOL		retry_include_ip_address;
#ifdef SUPPORT_SOCKS
  uschar	*socks_proxy;
#endif
#ifndef DISABLE_TLS
  uschar	*tls_alpn;
  uschar	*tls_certificate;
  uschar	*tls_crl;
  uschar	*tls_eccurve;
  uschar	*tls_privatekey;
  uschar	*tls_require_ciphers;
# ifndef DISABLE_TLS_RESUME
#  define HNE_DEFAULT US"${if and {{match{$host}{.outlook.com\\$}} {match{$item}{\\N^250-([\\w.]+)\\s\\N}}} {$1}}"
  uschar	*host_name_extract;
  uschar	*tls_resumption_hosts;
# endif
  const uschar	*tls_sni;
  uschar	*tls_verify_certificates;
  int		tls_dh_min_bits;
  BOOL		tls_tempfail_tryclear;
  uschar	*tls_verify_hosts;
  uschar	*tls_try_verify_hosts;
  uschar	*tls_verify_cert_hostnames;
#endif
#ifdef SUPPORT_I18N
  uschar	*utf8_downconvert;
#endif
#ifndef DISABLE_DKIM
  struct ob_dkim dkim;
#endif
#ifdef EXPERIMENTAL_ARC
  uschar	*arc_sign;
#endif
#ifndef DISABLE_TLS
  exim_tlslib_state tls_preload;
#endif
} smtp_transport_options_block;

#define SOB (smtp_transport_options_block *)


/* smtp connect context */
typedef struct {
  const uschar *	from_addr;
  address_item *	addrlist;

  smtp_connect_args	conn_args;	/* Large (if DANE supported) */
  int			port;

  BOOL verify:1;
  BOOL lmtp:1;
  BOOL smtps:1;
#ifdef EXPERIMENTAL_SRV_SMTPS
  BOOL require_tls:1;
#endif

  BOOL ok:1;
  BOOL setting_up:1;
#ifndef DISABLE_PIPE_CONNECT
  BOOL early_pipe_ok:1;
  BOOL early_pipe_active:1;
#endif
  BOOL esmtp:1;
  BOOL esmtp_sent:1;
  BOOL pipelining_used:1;
#ifndef DISABLE_PRDR
  BOOL prdr_active:1;
#endif
#ifdef SUPPORT_I18N
  BOOL utf8_needed:1;
#endif
  BOOL dsn_all_lasthop:1;
#if !defined(DISABLE_TLS) && defined(SUPPORT_DANE)
  BOOL dane_required:1;		/* required by transport option */
#endif
#ifndef DISABLE_PIPE_CONNECT
  BOOL pending_BANNER:1;
  BOOL pending_EHLO:1;
#endif
  BOOL pending_MAIL:1;
  BOOL pending_BDAT:1;
  BOOL RCPT_452:1;
  BOOL good_RCPT:1;
#ifndef DISABLE_ESMTP_LIMITS
  BOOL single_rcpt_domain:1;
#endif
  BOOL completed_addr:1;
  BOOL send_rset:1;
  BOOL send_quit:1;
  BOOL send_tlsclose:1;

  unsigned	peer_offered;
#ifndef DISABLE_ESMTP_LIMITS
  unsigned	peer_limit_mail;
  unsigned	peer_limit_rcpt;
  unsigned	peer_limit_rcptdom;
#endif

  unsigned	max_mail;
  int		max_rcpt;
  int		cmd_count;

  unsigned	avoid_option;
  uschar *	igquotstr;
  const uschar * helo_data;
#ifdef EXPERIMENTAL_DSN_INFO
  uschar *	smtp_greeting;
  uschar *	helo_response;
#endif
#ifndef DISABLE_PIPE_CONNECT
  /* Info about the EHLO response stored to / retrieved from cache.  When
  operating early-pipe, we use the cached values.  For each of plaintext and
  crypted we store bitmaps for ESMTP features and AUTH methods.  If the LIMITS
  extension is built and usable them at least one of the limits values cached
  is nonzero, and we use the values to constrain the connection. */
  ehlo_resp_precis	ehlo_resp;
#endif

  struct timeval	delivery_start;
  address_item *	first_addr;
  address_item *	next_addr;
  address_item *	sync_addr;

  client_conn_ctx	cctx;
  smtp_inblock		inblock;
  smtp_outblock		outblock;
  uschar	buffer[DELIVER_BUFFER_SIZE];
  uschar	inbuffer[4096];
  uschar	outbuffer[4096];
} smtp_context;

extern int smtp_setup_conn(smtp_context *, BOOL);
extern sw_mrc_t smtp_write_mail_and_rcpt_cmds(smtp_context *, int *);
extern int smtp_reap_early_pipe(smtp_context *, int *);


/* Data for reading the private options. */

extern optionlist smtp_transport_options[];
extern int smtp_transport_options_count;

/* Block containing default values. */

extern smtp_transport_options_block smtp_transport_option_defaults;

/* The main, init, and closedown entry points for the transport */

extern void smtp_transport_init(driver_instance *);
extern BOOL smtp_transport_entry(transport_instance *, address_item *);
extern void smtp_transport_closedown(transport_instance *);


/* End of transports/smtp.h */
