Provided by: libopensmtpd0_0.7-2build1_amd64 
NAME
osmtpd_register_filter_connect, osmtpd_register_filter_helo, osmtpd_register_filter_ehlo,
osmtpd_register_filter_starttls, osmtpd_register_filter_auth,
osmtpd_register_filter_mailfrom, osmtpd_register_filter_rcptto,
osmtpd_register_filter_data, osmtpd_register_filter_dataline, osmtpd_register_filter_rset,
osmtpd_register_filter_quit, osmtpd_register_filter_noop, osmtpd_register_filter_help,
osmtpd_register_filter_wiz, osmtpd_register_filter_commit, osmtpd_register_report_connect,
osmtpd_register_report_disconnect, osmtpd_register_report_identify,
osmtpd_register_report_tls, osmtpd_register_report_begin, osmtpd_register_report_mail,
osmtpd_register_report_rcpt, osmtpd_register_report_envelope, osmtpd_register_report_data,
osmtpd_register_report_commit, osmtpd_register_report_rollback,
osmtpd_register_report_client, osmtpd_register_report_server,
osmtpd_register_report_response, osmtpd_register_report_timeout, osmtpd_local_session,
osmtpd_local_message, osmtpd_need, osmtpd_filter_proceed, osmtpd_filter_reject,
osmtpd_filter_disconnect, osmtpd_filter_rewrite, osmtpd_filter_dataline, osmtpd_run,
osmtpd_err, osmtpd_errx - C filter API for smtpd(8)
SYNOPSIS
#include <opensmtpd.h>
void
osmtpd_register_filter_connect(void (*cb)(struct osmtpd_ctx *ctx, const char *hostname, struct sockaddr_storage *ss));
void
osmtpd_register_filter_helo(void (cb*)(struct osmtpd_ctx *ctx, const char *helo));
void
osmtpd_register_filter_ehlo(void (*cb)(struct osmtpd_ctx *ctx, const char *ehlo));
void
osmtpd_register_filter_starttls(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_auth(void (*cb)(struct osmtpd_ctx *ctx, const char *auth));
void
osmtpd_register_filter_mailfrom(void (*cb)(struct osmtpd_ctx *ctx, const char *from));
void
osmtpd_register_filter_rcptto(void (*cb)(struct osmtpd_ctx *ctx, const char *rcpt));
void
osmtpd_register_filter_data(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_dataline(void (*cb)(struct osmtpd_ctx *ctx, const char *line));
void
osmtpd_register_filter_rset(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_quit(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_noop(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_help(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_wiz(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_filter_commit(void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_register_report_connect(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, const char *rdns, enum osmtpd_status fcrdns, struct sockaddr_storage *src, struct sockaddr_storage *dst));
void
osmtpd_register_report_disconnect(int incoming, void (*ctx)(struct osmtpd_ctx *ctx));
void
osmtpd_register_report_identify(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, const char *identity));
void
osmtpd_register_report_tls(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, const char *ciphers));
void
osmtpd_register_report_begin(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid));
void
osmtpd_register_report_mail(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid, const char *mailfrom, enum osmtpd_status status));
void
osmtpd_register_report_rcpt(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid, const char *rcptto, enum osmtpd_status status));
void
osmtpd_register_report_envelope(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid, uint64_t evpid));
void
osmtpd_register_report_data(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid, enum osmtpd_status status));
void
osmtpd_register_report_commit(int, incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid, size_t msgsz));
void
osmtpd_register_report_rollback(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, uint32_t msgid));
void
osmtpd_register_report_client(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, const char *cmd));
void
osmtpd_register_report_server(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, const char *resp));
void
osmtpd_register_report_response(int incoming,
void (*cb)(struct osmtpd_ctx *ctx, const char *resp));
void
osmtpd_register_report_timeout(int incoming, void (*cb)(struct osmtpd_ctx *ctx));
void
osmtpd_local_session(void *(*oncreate)(struct osmtpd_ctx *ctx),
void (*ondelete)(struct osmtpd_ctx *ctx, void *data));
void
osmtpd_local_message(void *(*oncreate)(struct osmtpd_ctx *ctx),
void (*ondelete)(struct osmtpd_ctx *ctx, void *data));
void
osmtpd_need(int needs);
void
osmtpd_filter_proceed(struct osmtpd_ctx *ctx);
void
osmtpd_filter_reject(struct osmtpd_ctx *ctx, int error, const char *msg, ...);
void
osmtpd_filter_disconnect(struct osmtpd_ctx *ctx, const char *msg, ...);
void
osmtpd_filter_rewrite(struct osmtpd_ctx *ctx, const char *value, ...);
void
osmtpd_filter_dataline(struct osmtpd_ctx *ctx, const char *line, ...);
void
osmtpd_run(void);
void
osmtpd_err(int eval, const char *fmt, ...);
void
osmtpd_errx(int eval, const char *fmt, ...);
DESCRIPTION
The osmtpd API is an event based interface for writing smtpd(8) filters. Filter and
report callbacks are registered via the osmtpd_register class of functions, followed by
osmtpd_run.
osmtpd_run starts the communication with the server and transforms network queries to
callbacks. Internally it uses event_dispatch(3), which allows filters to be written fully
asynchronously.
Each callback cb gets at least a pointer of the type struct, osmtpd_ctx. It contains the
following elements:
enum osmtpd_type type
The type of request being made. The possible values are OSMTPD_TYPE_FILTER and
OSMTPD_TYPE_REPORT.
enum osmtpd_phase phase
The phase in the transaction which triggered the callback. The following values
match their respective osmtpd_register function:
OSMTPD_PHASE_CONNECT osmtpd_register_filter_connect
OSMTPD_PHASE_HELO osmtpd_register_filter_helo
OSMTPD_PHASE_EHLO osmtpd_register_filter_ehlo
OSMTPD_PHASE_STARTTLS osmtpd_register_filter_starttls
OSMTPD_PHASE_AUTH osmtpd_register_filter_auth
OSMTPD_PHASE_MAIL_FROM osmtpd_register_filter_mailfrom
OSMTPD_PHASE_RCPT_TO osmtpd_register_filter_rcptto
OSMTPD_PHASE_DATA osmtpd_register_filter_data
OSMTPD_PHASE_DATA_LINE osmtpd_register_filter_dataline
OSMTPD_PHASE_RSET osmtpd_register_filter_rset
OSMTPD_PHASE_QUIT osmtpd_register_filter_quit
OSMTPD_PHASE_NOOP osmtpd_register_filter_noop
OSMTPD_PHASE_HELP osmtpd_register_filter_help
OSMTPD_PHASE_WIZ osmtpd_register_filter_wiz
OSMTPD_PHASE_COMMIT osmtpd_register_filter_commit
OSMTPD_PHASE_LINK_CONNECT osmtpd_register_report_connect
OSMTPD_PHASE_LINK_DISCONNECT osmtpd_register_report_disconnect
OSMTPD_PHASE_LINK_IDENTIFY osmtpd_register_report_identify
OSMTPD_PHASE_LINK_TLS osmtpd_register_report_tls
OSMTPD_PHASE_TX_BEGIN osmtpd_register_report_begin
OSMTPD_PHASE_TX_MAIL osmtpd_register_report_mail
OSMTPD_PHASE_TX_RCPT osmtpd_register_report_rcpt
OSMTPD_PHASE_TX_ENVELOPE osmtpd_register_report_envelope
OSMTPD_PHASE_TX_DATA osmtpd_register_report_data
OSMTPD_PHASE_TX_COMMIT osmtpd_register_report_commit
OSMTPD_PHASE_TX_ROLLBACK osmtpd_register_report_rollback
OSMTPD_PHASE_PROTOCOL_CLIENT osmtpd_register_report_client
OSMTPD_PHASE_PROTOCOL_SERVER osmtpd_register_report_server
OSMTPD_PHASE_FILTER_RESPONSE osmtpd_register_report_response
OSMTPD_PHASE_TIMEOUT. osmtpd_register_report_timeout
int version_major
The major version number of the protocol. Most filters don't need this
information.
int version_minor
The minor version number of the protocol. Most filters don't need this
information.
struct timespec tm
The time the event was triggered inside smtpd(8).
int incoming
Set to 1 if the event was based on an incoming connection, 0 if it's an outgoing
connection. The osmtpd_register_filter class of functions is always based on
incoming connections. osmtpd_register_report can be both incoming and outgoing.
uint64_t reqid
The request ID of the connection the event was issued on. This value can be
useful for logging. Filters in need of filter specific data can use
osmtpd_local_session and local_session.
uint64_t token
The filter specific token. Most filters don't need this information.
struct sockaddr_storage src
The source address and port of the connection. This needs to be cast to the
appropriate sockaddr type based on the ss_family attribute. It can have the
following families: AF_INET, AF_INET6 and AF_UNIX. To use this attribute,
initialize osmtpd_need with OSMTPD_NEED_SRC. If not available the entire
attribute is zeroed out.
struct sockaddr_storage dst
The destination address and port of the connection. This needs to be cast to the
appropriate sockaddr type based on the ss_family attribute. It can have the
following families: AF_INET, AF_INET6 and AF_UNIX. To use this attribute,
initialize osmtpd_need with OSMTPD_NEED_DST. If not available the entire
attribute is zeroed out.
char *rdns
The reverse DNS hostname of the connection. To use this attribute, initialize
osmtpd_need with OSMTPD_NEED_RDNS. If not available the attribute is set to NULL.
enum osmtpd_status fcrdns
Whether the reverse DNS hostname is forward confirmed. To use this attribute,
initialize osmtpd_need with OSMTPD_NEED_FCRDNS. If not available the attribute is
set to OSMTPD_STATUS_TEMPFAIL.
char *identity
The identity of the remote host as presented by the HELO or EHLO SMTP command. To
use this attribute, initialize osmtpd_need with OSMTPD_NEED_IDENTITY. If not
available the attribute is set to NULL.
char *ciphers
The ciphers used during (start)tls. To use this attribute, initialize osmtpd_need
with OSMTPD_NEED_CIPHERS. If not available the attribute is set to NULL.
uint32_t msgid
The message ID of the current message being handled in the SMTP transaction. This
value can be useful for logging. osmtpd_need needs to be initialized with
OSMTPD_NEED_MSGID. If not available the attribute is set to 0. Filters in need
of filter specific data can use osmtpd_local_message and local_message.
char *mailfrom
The envelope MAIL FROM address in the SMTP transaction. osmtpd_need needs to be
initialized with OSMTPD_NEED_MAILFROM. If not available the attribute is set to
NULL.
char **rcptto
The envelope RCPT TO address in the SMTP transaction. osmtpd_need needs to be
initialized with OSMTPD_NEED_RCPTTO. This attribute is a NULL-terminated array of
address strings. If not available the first element in the array is set to NULL.
uint64_t evpid
The envelope ID we're currently working on. osmtpd_need needs to be initialized
with OSMTPD_NEED_EVPID. If not available the attribute is set to 0.
void *local_session
Any filter specific data that needs to be stored during the session. This is
initialized on ctx creation by calling oncreate argument from
osmtpd_local_session.
void *local_message
Any filter specific data that needs to be stored during the message transaction.
This is initialized on ctx creation by calling oncreate argument from
osmtpd_local_message.
The osmtpd_register_filter class of functions must call one of osmtpd_filter_proceed,
osmtpd_filter_rewrite, osmtpd_filter_reject and osmtpd_filter_disconnect. This can be
done either in the callback function itself, or at a later moment through another
callback. Note that the session stalls until the osmtpd_filter has been called.
Exceptions to the above reply options are:
• osmtpd_register_filter_connect's and osmtpd_register_filter functions' callbacks
without argument can't use osmtpd_filter_rewrite.
• osmtpd_register_filter_dataline's callback can only use osmtpd_filter_dataline.
osmtpd_err and osmtpd_errx can be used as a standin for err(3) and errx(3) without
printing the program name to stderr.
SEE ALSO
event_init(3), smtpd.conf(5)
HISTORY
The osmtpd_run API first appeared in OpenBSD 6.6.
AUTHORS
Martijn van Duren <martijn@openbsd.org>