int smtpd_proxy_create(SMTPD_STATE *state, int flags, const char *service,
int timeout, const char *ehlo_name,
const char *mail_from)
{
SMTPD_PROXY *proxy;
/*
* When an operation has many arguments it is safer to use named
* parameters, and have the compiler enforce the argument count.
*/
#define SMTPD_PROXY_ALLOC(p, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12) \
((p) = (SMTPD_PROXY *) mymalloc(sizeof(*(p))), (p)->a1, (p)->a2, \
(p)->a3, (p)->a4, (p)->a5, (p)->a6, (p)->a7, (p)->a8, (p)->a9, \
(p)->a10, (p)->a11, (p)->a12, (p))
/*
* Sanity check.
*/
if (state->proxy != 0)
msg_panic("smtpd_proxy_create: handle still exists");
/*
* Connect to the before-queue filter immediately.
*/
if ((flags & SMTPD_PROXY_FLAG_SPEED_ADJUST) == 0) {
state->proxy =
SMTPD_PROXY_ALLOC(proxy, stream = 0, request = vstring_alloc(10),
reply = vstring_alloc(10),
cmd = smtpd_proxy_cmd,
rec_fprintf = smtpd_proxy_rec_fprintf,
rec_put = smtpd_proxy_rec_put,
flags = flags, service_stream = 0,
service_name = service, timeout = timeout,
ehlo_name = ehlo_name, mail_from = mail_from);
if (smtpd_proxy_connect(state) < 0) {
/* NOT: smtpd_proxy_free(state); we still need proxy->reply. */
return (-1);
}
proxy->stream = proxy->service_stream;
return (0);
}
/*
* Connect to the before-queue filter after we receive the entire
* message. Open the replay logfile early to simplify code. The file is
* reused for multiple mail transactions, so there is no need to minimize
* its life time.
*/
else {
#ifdef NO_TRUNCATE
msg_panic("smtpd_proxy_create: speed-adjust support is not available");
#else
if (smtpd_proxy_replay_setup(state) < 0)
return (-1);
state->proxy =
SMTPD_PROXY_ALLOC(proxy, stream = smtpd_proxy_replay_stream,
request = vstring_alloc(10),
reply = vstring_alloc(10),
cmd = smtpd_proxy_save_cmd,
rec_fprintf = smtpd_proxy_save_rec_fprintf,
rec_put = smtpd_proxy_save_rec_put,
flags = flags, service_stream = 0,
service_name = service, timeout = timeout,
ehlo_name = ehlo_name, mail_from = mail_from);
return (0);
#endif
}
}
static int smtpd_proxy_replay_send(SMTPD_STATE *state)
{
const char *myname = "smtpd_proxy_replay_send";
static VSTRING *replay_buf = 0;
SMTPD_PROXY *proxy = state->proxy;
int rec_type;
int expect = SMTPD_PROX_WANT_BAD;
/*
* Sanity check.
*/
if (smtpd_proxy_replay_stream == 0)
msg_panic("%s: no before-queue filter speed-adjust log", myname);
/*
* Errors first.
*/
if (vstream_ferror(smtpd_proxy_replay_stream)
|| vstream_feof(smtpd_proxy_replay_stream)
|| rec_put(smtpd_proxy_replay_stream, REC_TYPE_END, "", 0) != REC_TYPE_END
|| vstream_fflush(smtpd_proxy_replay_stream))
/* NOT: fsync(vstream_fileno(smtpd_proxy_replay_stream)) */
return (smtpd_proxy_replay_rdwr_error(state));
/*
* Delayed connection to the before-queue filter.
*/
if (smtpd_proxy_connect(state) < 0)
return (-1);
/*
* Replay the speed-match log. We do sanity check record content, but we
* don't implement a protocol state engine here, since we are reading
* from a file that we just wrote ourselves.
*
* This is different than the MailChannels patented solution that
* multiplexes a large number of slowed-down inbound connections over a
* small number of fast connections to a local MTA.
*
* - MailChannels receives mail directly from the Internet. It uses one
* connection to the local MTA to reject invalid recipients before
* receiving the entire email message at reduced bit rates, and then uses
* a different connection to quickly deliver the message to the local
* MTA.
*
* - Postfix receives mail directly from the Internet. The Postfix SMTP
* server rejects invalid recipients before receiving the entire message
* over the Internet, and then delivers the message quickly to a local
* SMTP-based content filter.
*/
if (replay_buf == 0)
replay_buf = vstring_alloc(100);
if (vstream_fseek(smtpd_proxy_replay_stream, (off_t) 0, SEEK_SET) < 0)
return (smtpd_proxy_replay_rdwr_error(state));
for (;;) {
switch (rec_type = rec_get(smtpd_proxy_replay_stream, replay_buf,
REC_FLAG_NONE)) {
/*
* Message content.
*/
case REC_TYPE_NORM:
case REC_TYPE_CONT:
if (smtpd_proxy_rec_put(proxy->service_stream, rec_type,
STR(replay_buf), LEN(replay_buf)) < 0)
return (-1);
break;
/*
* Expected server reply type.
*/
case REC_TYPE_RCPT:
if (!alldig(STR(replay_buf))
|| (expect = atoi(STR(replay_buf))) == SMTPD_PROX_WANT_BAD)
msg_panic("%s: malformed server reply type: %s",
myname, STR(replay_buf));
break;
/*
* Client command, or void. Bail out on the first negative proxy
* response. This is OK, because the filter must use the same
* reply code for all recipients of a multi-recipient message.
*/
case REC_TYPE_FROM:
if (expect == SMTPD_PROX_WANT_BAD)
msg_panic("%s: missing server reply type", myname);
if (smtpd_proxy_cmd(state, expect, *STR(replay_buf) ? "%s" :
SMTPD_PROXY_CONN_FMT, STR(replay_buf)) < 0)
return (-1);
expect = SMTPD_PROX_WANT_BAD;
break;
/*
* Explicit end marker, instead of implicit EOF.
*/
case REC_TYPE_END:
return (0);
/*
* Errors.
*/
case REC_TYPE_ERROR:
return (smtpd_proxy_replay_rdwr_error(state));
default:
msg_panic("%s: unexpected record type; %d", myname, rec_type);
}
}
}
static int smtpd_proxy_replay_send(SMTPD_STATE *state)
{
const char *myname = "smtpd_proxy_replay_send";
static VSTRING *replay_buf = 0;
SMTPD_PROXY *proxy = state->proxy;
int rec_type;
int expect = SMTPD_PROX_WANT_BAD;
/*
* Sanity check.
*/
if (smtpd_proxy_replay_stream == 0)
msg_panic("%s: no before-queue filter speed-adjust log", myname);
/*
* Errors first.
*/
if (vstream_ferror(smtpd_proxy_replay_stream)
|| vstream_feof(smtpd_proxy_replay_stream)
|| rec_put(smtpd_proxy_replay_stream, REC_TYPE_END, "", 0) != REC_TYPE_END
|| vstream_fflush(smtpd_proxy_replay_stream))
/* NOT: fsync(vstream_fileno(smtpd_proxy_replay_stream)) */
return (smtpd_proxy_replay_rdwr_error(state));
/*
* Delayed connection to the before-queue filter.
*/
if (smtpd_proxy_connect(state) < 0)
return (-1);
/*
* Replay the speed-match log. We do sanity check record content, but we
* don't implement a protocol state engine here, since we are reading
* from a file that we just wrote ourselves.
*/
if (replay_buf == 0)
replay_buf = vstring_alloc(100);
if (vstream_fseek(smtpd_proxy_replay_stream, (off_t) 0, SEEK_SET) < 0)
return (smtpd_proxy_replay_rdwr_error(state));
for (;;) {
switch (rec_type = rec_get(smtpd_proxy_replay_stream, replay_buf,
REC_FLAG_NONE)) {
/*
* Message content.
*/
case REC_TYPE_NORM:
case REC_TYPE_CONT:
if (smtpd_proxy_rec_put(proxy->service_stream, rec_type,
STR(replay_buf), LEN(replay_buf)) < 0)
return (-1);
break;
/*
* Expected server reply type.
*/
case REC_TYPE_RCPT:
if (!alldig(STR(replay_buf))
|| (expect = atoi(STR(replay_buf))) == SMTPD_PROX_WANT_BAD)
msg_panic("%s: malformed server reply type: %s",
myname, STR(replay_buf));
break;
/*
* Client command, or void. Bail out on the first negative proxy
* response. This is OK, because the filter must use the same
* reply code for all recipients of a multi-recipient message.
*/
case REC_TYPE_FROM:
if (expect == SMTPD_PROX_WANT_BAD)
msg_panic("%s: missing server reply type", myname);
if (smtpd_proxy_cmd(state, expect, *STR(replay_buf) ? "%s" :
SMTPD_PROXY_CONN_FMT, STR(replay_buf)) < 0)
return (-1);
expect = SMTPD_PROX_WANT_BAD;
break;
/*
* Explicit end marker, instead of implicit EOF.
*/
case REC_TYPE_END:
return (0);
/*
* Errors.
*/
case REC_TYPE_ERROR:
return (smtpd_proxy_replay_rdwr_error(state));
default:
msg_panic("%s: unexpected record type; %d", myname, rec_type);
}
}
}
