milter.h   [plain text]

#ifndef _MILTER_H_INCLUDED_
#define _MILTER_H_INCLUDED_

/*++
/* NAME
/*	milter 3h
/* SUMMARY
/*	smtp server
/* SYNOPSIS
/*	Postfix MTA-side Milter implementation
/* DESCRIPTION
/* .nf

 /*
  * Utility library.
  */
#include <vstring.h>
#include <vstream.h>
#include <argv.h>

 /*
  * Global library.
  */
#include <attr.h>

 /*
  * Each Milter handle is an element of a null-terminated linked list. The
  * functions are virtual so that we can support multiple MTA-side Milter
  * implementations. The Sendmail 8 and Sendmail X Milter-side APIs are too
  * different to implement the MTA side as a single hybrid.
  */
typedef struct MILTER {
    char   *name;			/* full name including transport */
    int     flags;			/* see below */
    struct MILTER *next;		/* linkage */
    struct MILTERS *parent;		/* parent information */
    struct MILTER_MACROS *macros;	/* private macros */
    const char *(*conn_event) (struct MILTER *, const char *, const char *, const char *, unsigned, ARGV *);
    const char *(*helo_event) (struct MILTER *, const char *, int, ARGV *);
    const char *(*mail_event) (struct MILTER *, const char **, ARGV *);
    const char *(*rcpt_event) (struct MILTER *, const char **, ARGV *);
    const char *(*data_event) (struct MILTER *, ARGV *);
    const char *(*message) (struct MILTER *, VSTREAM *, off_t, ARGV *, ARGV *);
    const char *(*unknown_event) (struct MILTER *, const char *, ARGV *);
    const char *(*other_event) (struct MILTER *);
    void    (*abort) (struct MILTER *);
    void    (*disc_event) (struct MILTER *);
    int     (*active) (struct MILTER *);
    int     (*send) (struct MILTER *, VSTREAM *);
    void    (*free) (struct MILTER *);
} MILTER;

#define MILTER_FLAG_NONE		(0)
#define MILTER_FLAG_WANT_RCPT_REJ	(1<<0)	/* see S8_RCPT_MAILER_ERROR */

extern MILTER *milter8_create(const char *, int, int, int, const char *, const char *, struct MILTERS *);
extern MILTER *milter8_receive(VSTREAM *, struct MILTERS *);

 /*
  * As of Sendmail 8.14 each milter can override the default macro list. If a
  * Milter has its own macro list, a null member means use the global
  * definition.
  */
typedef struct MILTER_MACROS {
    char   *conn_macros;		/* macros for connect event */
    char   *helo_macros;		/* macros for HELO/EHLO command */
    char   *mail_macros;		/* macros for MAIL FROM command */
    char   *rcpt_macros;		/* macros for RCPT TO command */
    char   *data_macros;		/* macros for DATA command */
    char   *eoh_macros;			/* macros for end-of-headers */
    char   *eod_macros;			/* macros for END-OF-DATA command */
    char   *unk_macros;			/* macros for unknown command */
} MILTER_MACROS;

extern MILTER_MACROS *milter_macros_create(const char *, const char *,
					         const char *, const char *,
					         const char *, const char *,
					        const char *, const char *);
extern MILTER_MACROS *milter_macros_alloc(int);
extern void milter_macros_free(MILTER_MACROS *);
extern int milter_macros_print(ATTR_PRINT_MASTER_FN, VSTREAM *, int, void *);
extern int milter_macros_scan(ATTR_SCAN_MASTER_FN, VSTREAM *, int, void *);

#define MILTER_MACROS_ALLOC_ZERO	1	/* null pointer */
#define MILTER_MACROS_ALLOC_EMPTY	2	/* mystrdup(""); */

 /*
  * A bunch of Milters.
  */
typedef const char *(*MILTER_MAC_LOOKUP_FN) (const char *, void *);
typedef const char *(*MILTER_ADD_HEADER_FN) (void *, const char *, const char *, const char *);
typedef const char *(*MILTER_EDIT_HEADER_FN) (void *, ssize_t, const char *, const char *, const char *);
typedef const char *(*MILTER_DEL_HEADER_FN) (void *, ssize_t, const char *);
typedef const char *(*MILTER_EDIT_FROM_FN) (void *, const char *, const char *);
typedef const char *(*MILTER_EDIT_RCPT_FN) (void *, const char *);
typedef const char *(*MILTER_EDIT_RCPT_PAR_FN) (void *, const char *, const char *);
typedef const char *(*MILTER_EDIT_BODY_FN) (void *, int, VSTRING *);

typedef struct MILTERS {
    MILTER *milter_list;		/* linked list of Milters */
    MILTER_MAC_LOOKUP_FN mac_lookup;
    void   *mac_context;		/* macro lookup context */
    struct MILTER_MACROS *macros;
    void   *chg_context;		/* context for queue file changes */
    MILTER_ADD_HEADER_FN add_header;
    MILTER_EDIT_HEADER_FN upd_header;
    MILTER_DEL_HEADER_FN del_header;
    MILTER_EDIT_HEADER_FN ins_header;
    MILTER_EDIT_FROM_FN chg_from;
    MILTER_EDIT_RCPT_FN add_rcpt;
    MILTER_EDIT_RCPT_PAR_FN add_rcpt_par;
    MILTER_EDIT_RCPT_FN del_rcpt;
    MILTER_EDIT_BODY_FN repl_body;
} MILTERS;

#define milter_create(milter_names, conn_timeout, cmd_timeout, msg_timeout, \
			protocol, def_action, conn_macros, helo_macros, \
			mail_macros, rcpt_macros, data_macros, eoh_macros, \
			eod_macros, unk_macros) \
	milter_new(milter_names, conn_timeout, cmd_timeout, msg_timeout, \
		    protocol, def_action, milter_macros_create(conn_macros, \
		    helo_macros, mail_macros, rcpt_macros, data_macros, \
		    eoh_macros, eod_macros, unk_macros))

extern MILTERS *milter_new(const char *, int, int, int, const char *,
			           const char *, MILTER_MACROS *);
extern void milter_macro_callback(MILTERS *, MILTER_MAC_LOOKUP_FN, void *);
extern void milter_edit_callback(MILTERS *milters, MILTER_ADD_HEADER_FN,
		               MILTER_EDIT_HEADER_FN, MILTER_EDIT_HEADER_FN,
			          MILTER_DEL_HEADER_FN, MILTER_EDIT_FROM_FN,
		               MILTER_EDIT_RCPT_FN, MILTER_EDIT_RCPT_PAR_FN,
			           MILTER_EDIT_RCPT_FN, MILTER_EDIT_BODY_FN,
				         void *);
extern const char *milter_conn_event(MILTERS *, const char *, const char *, const char *, unsigned);
extern const char *milter_helo_event(MILTERS *, const char *, int);
extern const char *milter_mail_event(MILTERS *, const char **);
extern const char *milter_rcpt_event(MILTERS *, int, const char **);
extern const char *milter_data_event(MILTERS *);
extern const char *milter_message(MILTERS *, VSTREAM *, off_t);
extern const char *milter_unknown_event(MILTERS *, const char *);
extern const char *milter_other_event(MILTERS *);
extern void milter_abort(MILTERS *);
extern void milter_disc_event(MILTERS *);
extern int milter_dummy(MILTERS *, VSTREAM *);
extern int milter_send(MILTERS *, VSTREAM *);
extern MILTERS *milter_receive(VSTREAM *, int);
extern void milter_free(MILTERS *);

 /*
  * Milter body edit commands.
  */
#define MILTER_BODY_START	1	/* start message body */
#define MILTER_BODY_LINE	2	/* message body line */
#define MILTER_BODY_END		3	/* end message body */

 /*
  * Sendmail 8 macro names. We support forms with and without the {}.
  */
#define S8_MAC__		"{_}"	/* sender resolve */
#define S8_MAC_J		"{j}"	/* myhostname */
#define S8_MAC_V		"{v}"	/* mail_name + mail_version */

#define S8_MAC_DAEMON_NAME	"{daemon_name}"
#define S8_MAC_IF_NAME		"{if_name}"
#define S8_MAC_IF_ADDR		"{if_addr}"

#define S8_MAC_CLIENT_ADDR	"{client_addr}"
#define S8_MAC_CLIENT_CONN	"{client_connections}"
#define S8_MAC_CLIENT_NAME	"{client_name}"
#define S8_MAC_CLIENT_PORT	"{client_port}"
#define S8_MAC_CLIENT_PTR	"{client_ptr}"
#define S8_MAC_CLIENT_RES	"{client_resolve}"

#define S8_MAC_TLS_VERSION	"{tls_version}"
#define S8_MAC_CIPHER		"{cipher}"
#define S8_MAC_CIPHER_BITS	"{cipher_bits}"
#define S8_MAC_CERT_SUBJECT	"{cert_subject}"
#define S8_MAC_CERT_ISSUER	"{cert_issuer}"

#define S8_MAC_I		"{i}"	/* queue ID */
#define S8_MAC_AUTH_TYPE	"{auth_type}"	/* SASL method */
#define S8_MAC_AUTH_AUTHEN	"{auth_authen}"	/* SASL username */
#define S8_MAC_AUTH_AUTHOR	"{auth_author}"	/* SASL sender */

#define S8_MAC_MAIL_MAILER	"{mail_mailer}"	/* sender transport */
#define S8_MAC_MAIL_HOST	"{mail_host}"	/* sender nexthop */
#define S8_MAC_MAIL_ADDR	"{mail_addr}"	/* sender address */

#define S8_MAC_RCPT_MAILER	"{rcpt_mailer}"	/* recip transport */
#define S8_MAC_RCPT_HOST	"{rcpt_host}"	/* recip nexthop */
#define S8_MAC_RCPT_ADDR	"{rcpt_addr}"	/* recip address */

#define S8_RCPT_MAILER_ERROR	"error"	/* see MILTER_FLAG_WANT_RCPT_REJ */

/* LICENSE
/* .ad
/* .fi
/*	The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*	Wietse Venema
/*	IBM T.J. Watson Research
/*	P.O. Box 704
/*	Yorktown Heights, NY 10598, USA
/*--*/

#endif