| FILTER_API(3) | Library Functions Manual | FILTER_API(3) |
filter_api_loop,
filter_api_accept,
filter_api_reject,
filter_api_reject_code,
filter_api_writeln,
filter_api_on_connect,
filter_api_on_helo,
filter_api_on_mail,
filter_api_on_rcpt,
filter_api_on_data,
filter_api_on_dataline,
filter_api_on_eom,
filter_api_on_reset,
filter_api_on_disconnect,
filter_api_on_commit,
filter_api_on_rollback,
filter_api_setugid,
filter_api_set_chroot,
filter_api_no_chroot,
filter_api_set_udata,
filter_api_get_udata,
filter_api_sockaddr_to_text,
filter_api_mailaddr_to_text —
filter API for smtpd
#include
<smtpd-defines.h>
#include <smtpd-api.h>
void
filter_api_loop(void);
int
filter_api_accept(uint64_t
id);
int
filter_api_reject(uint64_t
id, enum filter_status
status);
int
filter_api_reject_code(uint64_t
id, enum filter_status
status, uint32_t
code, const char
*line);
void
filter_api_writeln(uint64_t
id, const char *
line);
void
filter_api_on_connect(int(*cb)(uint64_t,
struct filter_connect *));
void
filter_api_on_helo(int(*cb)(uint64_t,
const char *));
void
filter_api_on_mail(int(*cb)(uint64_t,
struct mailaddr *));
void
filter_api_on_rcpt(int(*cb)(uint64_t,
struct mailaddr *));
void
filter_api_on_data(int(*cb)(uint64_t));
void
filter_api_on_dataline(void(*cb)(uint64_t,
const char *));
void
filter_api_on_eom(int(*cb)(uint64_t,
size_t));
void
filter_api_on_reset(void(*cb)(uint64_t));
void
filter_api_on_disconnect(void(*cb)(uint64_t));
void
filter_api_on_commit(void(*cb)(uint64_t));
void
filter_api_on_rollback(void(*cb)(uint64_t));
void
filter_api_setugid(uid_t
uid, gid_t
gid);
void
filter_api_set_chroot(const
char *rootpath);
void
filter_api_no_chroot(void);
void
filter_api_set_udata(uint64_t
id, void
*data);
void *
filter_api_get_udata(uint64_t
id);
const char *
filter_api_sockaddr_to_text(const
struct sockaddr *sa);
const char *
filter_api_mailaddr_to_text(const
struct mailaddr *maddr);
filter_api is an interface intended to
provide filter capabilities for the smtpd(8) daemon.
filter_api is used in standalone filter programs,
which setup callback functions to hook into the SMTP dialog. For example,
each SMTP command can be intercepted with callback functions.
The function
filter_api_loop()
is used to enter the filter loop, waiting for callback functions to be
called.
The function
filter_api_accept()
can be called to accept the current message with the given
id from within a callback function.
The functions
filter_api_reject()
and filter_api_reject_code() can be called to reject
the current message with the given id from within a
callback function. Both expect the status to be
specified which should be one of the following values.
FILTER_FAILFILTER_CLOSEMorover, with the function
filter_api_reject_code()
a code and line can be
specified, to reject the current message with a custom SMTP reply code and
error message.
The function
filter_api_writeln()
is intended to write (received) SMTP DATA command lines (back) from within a
callback function. This might be used by a filter to add or modifiy DATA
lines.
The function
filter_api_on_connect()
is called on new SMTP connections. The callback can be used to accept or
reject messages based on the given connection information.
The function
filter_api_on_helo()
is called on SMTP HELO command. The callback can be used to accept or reject
messages based on the given HELO string.
The function
filter_api_on_mail()
is called on SMTP MAIL FROM command. The callback can be used to accept or
reject messages based on the given MAIL FROM address.
The function
filter_api_on_rcpt()
is called on SMTP RCPT TO command. The callback can be used to accept or
reject messages based on the given RCPT TO address.
The function
filter_api_on_data()
is called on SMTP DATA command. The callback might be used to setup data
structures for filtering the upcoming DATA lines.
The function
filter_api_on_dataline()
is called on each SMTP DATA line. The callback can be used to accept or
reject messaged based on the (header or body) content of the current
message.
The function
filter_api_on_eom()
is called on the end (of DATA command) of the current message. The callback
might be used to cleanup data structures and finalize the decision of
accepting or rejecting the message.
The function
filter_api_on_reset()
is called on SMTP RSET command. The callback might be used to reset the
current filter state.
The function
filter_api_on_disconnect()
is called on closed SMTP connections. The callback might be used to cleanup
earlier setup data structures.
The function
filter_api_on_commit()
is called on commit of the current message.
The function
filter_api_on_rollback()
is called on rollback of the SMTP session. The callback might be used to
cleanup earlier setup data structures.
The function
filter_api_setugid()
can be called using uid and gid
to set the running user and group of the filter.
The function
filter_api_set_chroot()
can be called using rootpath to set the chroot path of
the filter.
The function
filter_api_no_chroot()
can be called to disable chroot for the filter.
The function
filter_api_set_udata()
can be called for the current message with the given
id to set a user data pointer
data from within a callback function.
The function
filter_api_get_udata()
can be called to get the user data pointer for the current message with the
given id from within a callback function.
The function
filter_api_sockaddr_to_text()
can be called to convert a socket address sa to a
string.
The function
filter_api_mailaddr_to_text()
can be called to convert a mail address maddr to a
string.
The functions filter_api_accept(),
filter_api_reject(), and
filter_api_reject_code(), return 1, intended to be
used in a return statement of a callback function.
The function filter_api_get_udata()
returns a pointer to the user data set for the current message.
The functions
filter_api_sockaddr_to_text() and
filter_api_mailaddr_to_text() return a pointer to a
static buffer containing the string representation. The buffer remains valid
until the next call to the conversion functions. In case of error, the
function filter_api_sockaddr_to_text() returns the
static string “(unknown)” and the
function filter_api_mailaddr_to_text() returns
NULL.
The function filter_api_sockaddr_to_text()
may fail for any of the errors specified for the routine
getnameinfo(3) and listed in
gai_strerror(3).
filter-stub(8) which ships with OpenSMTPD-extras is intended to provide an example code template.
| June 11, 2015 | Debian |