static void verify_query_service(VSTREAM *client_stream)
{
VSTRING *addr = vstring_alloc(10);
VSTRING *get_buf = 0;
VSTRING *put_buf = 0;
const char *raw_data;
int addr_status;
long probed;
long updated;
char *text;
if (attr_scan(client_stream, ATTR_FLAG_STRICT,
RECV_ATTR_STR(MAIL_ATTR_ADDR, addr),
ATTR_TYPE_END) == 1) {
long now = (long) time((time_t *) 0);
/*
* Produce a default record when no usable record exists.
*
* If negative caching is disabled, purge an expired record from the
* database.
*
* XXX Assume that a probe is lost if no response is received in 1000
* seconds. If this number is too small the queue will slowly fill up
* with delayed probes.
*
* XXX Maintain a moving average for the probe turnaround time, and
* allow probe "retransmission" when a probe is outstanding for, say
* some minimal amount of time (1000 sec) plus several times the
* observed probe turnaround time. This causes probing to back off
* when the mail system becomes congested.
*/
#define POSITIVE_ENTRY_EXPIRED(addr_status, updated) \
(addr_status == DEL_RCPT_STAT_OK && updated + var_verify_pos_exp < now)
#define NEGATIVE_ENTRY_EXPIRED(addr_status, updated) \
(addr_status != DEL_RCPT_STAT_OK && updated + var_verify_neg_exp < now)
#define PROBE_TTL 1000
/* FIX 200501 IPv6 patch did not neuter ":" in address literals. */
translit(STR(addr), ":", "_");
if ((raw_data = dict_cache_lookup(verify_map, STR(addr))) == 0 /* not found */
|| ((get_buf = vstring_alloc(10)),
vstring_strcpy(get_buf, raw_data), /* malformed */
verify_parse_entry(STR(get_buf), &addr_status, &probed,
&updated, &text) < 0)
|| (now - probed > PROBE_TTL /* safe to probe */
&& (POSITIVE_ENTRY_EXPIRED(addr_status, updated)
|| NEGATIVE_ENTRY_EXPIRED(addr_status, updated)))) {
addr_status = DEL_RCPT_STAT_TODO;
probed = 0;
updated = 0;
text = "Address verification in progress";
if (raw_data != 0 && var_verify_neg_cache == 0)
dict_cache_delete(verify_map, STR(addr));
}
if (msg_verbose)
msg_info("GOT %s status=%d probed=%ld updated=%ld text=%s",
STR(addr), addr_status, probed, updated, text);
/*
* Respond to the client.
*/
attr_print(client_stream, ATTR_FLAG_NONE,
SEND_ATTR_INT(MAIL_ATTR_STATUS, VRFY_STAT_OK),
SEND_ATTR_INT(MAIL_ATTR_ADDR_STATUS, addr_status),
SEND_ATTR_STR(MAIL_ATTR_WHY, text),
ATTR_TYPE_END);
/*
* Send a new probe when the information needs to be refreshed.
*
* XXX For an initial proof of concept implementation, use synchronous
* mail submission. This needs to be made async for high-volume
* sites, which makes it even more interesting to eliminate duplicate
* queries while a probe is being built.
*
* If negative caching is turned off, update the database only when
* refreshing an existing entry.
*/
#define POSITIVE_REFRESH_NEEDED(addr_status, updated) \
(addr_status == DEL_RCPT_STAT_OK && updated + var_verify_pos_try < now)
#define NEGATIVE_REFRESH_NEEDED(addr_status, updated) \
(addr_status != DEL_RCPT_STAT_OK && updated + var_verify_neg_try < now)
if (now - probed > PROBE_TTL
&& (POSITIVE_REFRESH_NEEDED(addr_status, updated)
|| NEGATIVE_REFRESH_NEEDED(addr_status, updated))) {
if (msg_verbose)
msg_info("PROBE %s status=%d probed=%ld updated=%ld",
STR(addr), addr_status, now, updated);
post_mail_fopen_async(make_verify_sender_addr(), STR(addr),
MAIL_SRC_MASK_VERIFY,
DEL_REQ_FLAG_MTA_VRFY,
SMTPUTF8_FLAG_NONE,
(VSTRING *) 0,
verify_post_mail_action,
(void *) 0);
if (updated != 0 || var_verify_neg_cache != 0) {
put_buf = vstring_alloc(10);
verify_make_entry(put_buf, addr_status, now, updated, text);
if (msg_verbose)
msg_info("PUT %s status=%d probed=%ld updated=%ld text=%s",
STR(addr), addr_status, now, updated, text);
dict_cache_update(verify_map, STR(addr), STR(put_buf));
}
}
}
vstring_free(addr);
if (get_buf)
vstring_free(get_buf);
if (put_buf)
vstring_free(put_buf);
}
int main(int argc, char **argv)
{
const char *verify_sender;
const char *valid_sender;
msg_vstream_init(argv[0], VSTREAM_ERR);
/*
* Prepare to talk to the address rewriting service.
*/
mail_conf_read();
vstream_printf("using config files in %s\n", var_config_dir);
if (chdir(var_queue_dir) < 0)
msg_fatal("chdir %s: %m", var_queue_dir);
/*
* Parse JCL.
*/
if (argc != 3)
msg_fatal("usage: %s address_verify_sender address_verify_sender_ttl",
argv[0]);
var_verify_sender = argv[1];
if (conv_time(argv[2], &var_verify_sender_ttl, 's') == 0)
msg_fatal("bad time value: %s", argv[2]);
verify_time = time((time_t *) 0);
/*
* Compute the current probe sender address.
*/
verify_sender = make_verify_sender_addr();
/*
* Check two past time slots.
*/
if (var_verify_sender_ttl > 0) {
verify_time -= 2 * var_verify_sender_ttl;
vstream_printf("\"%s\" matches prev2: \"%s\"\n", verify_sender,
(valid_sender = valid_verify_sender_addr(verify_sender)) != 0 ?
valid_sender : "nope");
verify_time += var_verify_sender_ttl;
vstream_printf("\"%s\" matches prev1: \"%s\"\n", verify_sender,
(valid_sender = valid_verify_sender_addr(verify_sender)) != 0 ?
valid_sender : "nope");
verify_time += var_verify_sender_ttl;
}
/*
* Check the current time slot.
*/
vstream_printf("\"%s\" matches self: \"%s\"\n", verify_sender,
(valid_sender = valid_verify_sender_addr(verify_sender)) != 0 ?
valid_sender : "nope");
/*
* Check two future time slots.
*/
if (var_verify_sender_ttl > 0) {
verify_time += var_verify_sender_ttl;
vstream_printf("\"%s\" matches next1: \"%s\"\n", verify_sender,
(valid_sender = valid_verify_sender_addr(verify_sender)) != 0 ?
valid_sender : "nope");
verify_time += var_verify_sender_ttl;
vstream_printf("\"%s\" matches next2: \"%s\"\n", verify_sender,
(valid_sender = valid_verify_sender_addr(verify_sender)) != 0 ?
valid_sender : "nope");
}
vstream_fflush(VSTREAM_OUT);
exit(0);
}
