static void smtp_connect_inet(SMTP_STATE *state, const char *nexthop,
char *def_service)
{
DELIVER_REQUEST *request = state->request;
SMTP_ITERATOR *iter = state->iterator;
ARGV *sites;
char *dest;
char **cpp;
int non_fallback_sites;
int retry_plain = 0;
DSN_BUF *why = state->why;
/*
* For sanity, require that at least one of INET or INET6 is enabled.
* Otherwise, we can't look up interface information, and we can't
* convert names or addresses.
*/
if (inet_proto_info()->ai_family_list[0] == 0) {
dsb_simple(why, "4.4.4", "all network protocols are disabled");
return;
}
/*
* Future proofing: do a null destination sanity check in case we allow
* the primary destination to be a list (it could be just separators).
*/
sites = argv_alloc(1);
argv_add(sites, nexthop, (char *) 0);
if (sites->argc == 0)
msg_panic("null destination: \"%s\"", nexthop);
non_fallback_sites = sites->argc;
argv_split_append(sites, var_fallback_relay, CHARS_COMMA_SP);
/*
* Don't give up after a hard host lookup error until we have tried the
* fallback relay servers.
*
* Don't bounce mail after a host lookup problem with a relayhost or with a
* fallback relay.
*
* Don't give up after a qualifying soft error until we have tried all
* qualifying backup mail servers.
*
* All this means that error handling and error reporting depends on whether
* the error qualifies for trying to deliver to a backup mail server, or
* whether we're looking up a relayhost or fallback relay. The challenge
* then is to build this into the pre-existing SMTP client without
* getting lost in the complexity.
*/
#define IS_FALLBACK_RELAY(cpp, sites, non_fallback_sites) \
(*(cpp) && (cpp) >= (sites)->argv + (non_fallback_sites))
for (cpp = sites->argv, (state->misc_flags |= SMTP_MISC_FLAG_FIRST_NEXTHOP);
SMTP_RCPT_LEFT(state) > 0 && (dest = *cpp) != 0;
cpp++, (state->misc_flags &= ~SMTP_MISC_FLAG_FIRST_NEXTHOP)) {
char *dest_buf;
char *domain;
unsigned port;
DNS_RR *addr_list;
DNS_RR *addr;
DNS_RR *next;
int addr_count;
int sess_count;
SMTP_SESSION *session;
int lookup_mx;
unsigned domain_best_pref;
MAI_HOSTADDR_STR hostaddr;
if (cpp[1] == 0)
state->misc_flags |= SMTP_MISC_FLAG_FINAL_NEXTHOP;
/*
* Parse the destination. If no TCP port is specified, use the port
* that is reserved for the protocol (SMTP or LMTP).
*/
dest_buf = smtp_parse_destination(dest, def_service, &domain, &port);
if (var_helpful_warnings && var_smtp_tls_wrappermode == 0
&& ntohs(port) == 465) {
msg_info("SMTPS wrappermode (TCP port 465) requires setting "
"\"%s = yes\", and \"%s = encrypt\" (or stronger)",
VAR_LMTP_SMTP(TLS_WRAPPER), VAR_LMTP_SMTP(TLS_LEVEL));
}
#define NO_HOST "" /* safety */
#define NO_ADDR "" /* safety */
SMTP_ITER_INIT(iter, dest, NO_HOST, NO_ADDR, port, state);
/*
* Resolve an SMTP or LMTP server. In the case of SMTP, skip mail
* exchanger lookups when a quoted host is specified or when DNS
* lookups are disabled.
*/
if (msg_verbose)
msg_info("connecting to %s port %d", domain, ntohs(port));
if (smtp_mode) {
if (ntohs(port) == IPPORT_SMTP)
state->misc_flags |= SMTP_MISC_FLAG_LOOP_DETECT;
else
state->misc_flags &= ~SMTP_MISC_FLAG_LOOP_DETECT;
lookup_mx = (smtp_dns_support != SMTP_DNS_DISABLED && *dest != '[');
} else
lookup_mx = 0;
if (!lookup_mx) {
addr_list = smtp_host_addr(domain, state->misc_flags, why);
/* XXX We could be an MX host for this destination... */
} else {
int i_am_mx = 0;
addr_list = smtp_domain_addr(domain, &iter->mx, state->misc_flags,
why, &i_am_mx);
/* If we're MX host, don't connect to non-MX backups. */
if (i_am_mx)
state->misc_flags |= SMTP_MISC_FLAG_FINAL_NEXTHOP;
}
/*
* Don't try fall-back hosts if mail loops to myself. That would just
* make the problem worse.
*/
if (addr_list == 0 && SMTP_HAS_LOOP_DSN(why))
state->misc_flags |= SMTP_MISC_FLAG_FINAL_NEXTHOP;
/*
* No early loop exit or we have a memory leak with dest_buf.
*/
if (addr_list)
domain_best_pref = addr_list->pref;
/*
* When session caching is enabled, store the first good session for
* this delivery request under the next-hop destination name. All
* good sessions will be stored under their specific server IP
* address.
*
* XXX smtp_session_cache_destinations specifies domain names without
* :port, because : is already used for maptype:mapname. Because of
* this limitation we use the bare domain without the optional [] or
* non-default TCP port.
*
* Opportunistic (a.k.a. on-demand) session caching on request by the
* queue manager. This is turned temporarily when a destination has a
* high volume of mail in the active queue. When the surge reaches
* its end, the queue manager requests that connections be retrieved
* but not stored.
*/
if (addr_list && (state->misc_flags & SMTP_MISC_FLAG_FIRST_NEXTHOP)) {
smtp_cache_policy(state, domain);
if (state->misc_flags & SMTP_MISC_FLAG_CONN_CACHE_MASK)
SET_NEXTHOP_STATE(state, dest);
}
/*
* Delete visited cached hosts from the address list.
*
* Optionally search the connection cache by domain name or by primary
* MX address before we try to create new connections.
*
* Enforce the MX session and MX address counts per next-hop or
* fall-back destination. smtp_reuse_session() will truncate the
* address list when either limit is reached.
*/
if (addr_list && (state->misc_flags & SMTP_MISC_FLAG_CONN_LOAD)) {
if (state->cache_used->used > 0)
smtp_scrub_addr_list(state->cache_used, &addr_list);
sess_count = addr_count =
smtp_reuse_session(state, &addr_list, domain_best_pref);
} else
sess_count = addr_count = 0;
/*
* Connect to an SMTP server: create primary MX connections, and
* reuse or create backup MX connections.
*
* At the start of an SMTP session, all recipients are unmarked. In the
* course of an SMTP session, recipients are marked as KEEP (deliver
* to alternate mail server) or DROP (remove from recipient list). At
* the end of an SMTP session, weed out the recipient list. Unmark
* any left-over recipients and try to deliver them to a backup mail
* server.
*
* Cache the first good session under the next-hop destination name.
* Cache all good sessions under their physical endpoint.
*
* Don't query the session cache for primary MX hosts. We already did
* that in smtp_reuse_session(), and if any were found in the cache,
* they were already deleted from the address list.
*
* Currently, we use smtp_reuse_addr() only for SASL-unauthenticated
* connections. Furthermore, we rely on smtp_reuse_addr() to look up
* an existing SASL-unauthenticated connection only when a new
* connection would be guaranteed not to require SASL authentication.
*
* In addition, we rely on smtp_reuse_addr() to look up an existing
* plaintext connection only when a new connection would be
* guaranteed not to use TLS.
*/
for (addr = addr_list; SMTP_RCPT_LEFT(state) > 0 && addr; addr = next) {
next = addr->next;
if (++addr_count == var_smtp_mxaddr_limit)
next = 0;
if (dns_rr_to_pa(addr, &hostaddr) == 0) {
msg_warn("cannot convert type %s record to printable address",
dns_strtype(addr->type));
/* XXX Assume there is no code at the end of this loop. */
continue;
}
vstring_strcpy(iter->addr, hostaddr.buf);
vstring_strcpy(iter->host, SMTP_HNAME(addr));
iter->rr = addr;
#ifdef USE_TLS
if (!smtp_tls_policy_cache_query(why, state->tls, iter)) {
msg_warn("TLS policy lookup for %s/%s: %s",
STR(iter->dest), STR(iter->host), STR(why->reason));
continue;
/* XXX Assume there is no code at the end of this loop. */
}
if (var_smtp_tls_wrappermode
&& state->tls->level < TLS_LEV_ENCRYPT) {
msg_warn("%s requires \"%s = encrypt\" (or stronger)",
VAR_LMTP_SMTP(TLS_WRAPPER), VAR_LMTP_SMTP(TLS_LEVEL));
continue;
/* XXX Assume there is no code at the end of this loop. */
}
/* Disable TLS when retrying after a handshake failure */
if (retry_plain) {
state->tls->level = TLS_LEV_NONE;
retry_plain = 0;
}
#endif
if ((state->misc_flags & SMTP_MISC_FLAG_CONN_LOAD) == 0
|| addr->pref == domain_best_pref
|| !(session = smtp_reuse_addr(state,
SMTP_KEY_MASK_SCACHE_ENDP_LABEL)))
session = smtp_connect_addr(iter, why, state->misc_flags);
if ((state->session = session) != 0) {
session->state = state;
#ifdef USE_TLS
session->tls_nexthop = domain;
#endif
if (addr->pref == domain_best_pref)
session->features |= SMTP_FEATURE_BEST_MX;
/* Don't count handshake errors towards the session limit. */
if ((state->misc_flags & SMTP_MISC_FLAG_FINAL_NEXTHOP)
&& next == 0)
state->misc_flags |= SMTP_MISC_FLAG_FINAL_SERVER;
if ((session->features & SMTP_FEATURE_FROM_CACHE) == 0
&& smtp_helo(state) != 0) {
#ifdef USE_TLS
/*
* When an opportunistic TLS handshake fails, try the
* same address again, with TLS disabled. See also the
* RETRY_AS_PLAINTEXT macro.
*/
if ((retry_plain = session->tls_retry_plain) != 0) {
--addr_count;
next = addr;
}
#endif
/*
* When a TLS handshake fails, the stream is marked
* "dead" to avoid further I/O over a broken channel.
*/
if (!THIS_SESSION_IS_FORBIDDEN
&& vstream_ferror(session->stream) == 0
&& vstream_feof(session->stream) == 0)
smtp_quit(state);
} else {
/* Do count delivery errors towards the session limit. */
if (++sess_count == var_smtp_mxsess_limit)
next = 0;
if ((state->misc_flags & SMTP_MISC_FLAG_FINAL_NEXTHOP)
&& next == 0)
state->misc_flags |= SMTP_MISC_FLAG_FINAL_SERVER;
smtp_xfer(state);
#ifdef USE_TLS
/*
* When opportunistic TLS fails after the STARTTLS
* handshake, try the same address again, with TLS
* disabled. See also the RETRY_AS_PLAINTEXT macro.
*/
if ((retry_plain = session->tls_retry_plain) != 0) {
--sess_count;
--addr_count;
next = addr;
}
#endif
}
smtp_cleanup_session(state);
} else {
/* The reason already includes the IP address and TCP port. */
msg_info("%s", STR(why->reason));
}
/* XXX Code above assumes there is no code at this loop ending. */
}
dns_rr_free(addr_list);
if (iter->mx) {
dns_rr_free(iter->mx);
iter->mx = 0; /* Just in case */
}
myfree(dest_buf);
if (state->misc_flags & SMTP_MISC_FLAG_FINAL_NEXTHOP)
break;
}
/*
* We still need to deliver, bounce or defer some left-over recipients:
* either mail loops or some backup mail server was unavailable.
*/
if (SMTP_RCPT_LEFT(state) > 0) {
/*
* In case of a "no error" indication we make up an excuse: we did
* find the host address, but we did not attempt to connect to it.
* This can happen when the fall-back relay was already tried via a
* cached connection, so that the address list scrubber left behind
* an empty list.
*/
if (!SMTP_HAS_DSN(why)) {
dsb_simple(why, "4.3.0",
"server unavailable or unable to receive mail");
}
/*
* Pay attention to what could be configuration problems, and pretend
* that these are recoverable rather than bouncing the mail.
*/
else if (!SMTP_HAS_SOFT_DSN(why)) {
/*
* The fall-back destination did not resolve as expected, or it
* is refusing to talk to us, or mail for it loops back to us.
*/
if (IS_FALLBACK_RELAY(cpp, sites, non_fallback_sites)) {
msg_warn("%s configuration problem", VAR_SMTP_FALLBACK);
vstring_strcpy(why->status, "4.3.5");
/* XXX Keep the diagnostic code and MTA. */
}
/*
* The next-hop relayhost did not resolve as expected, or it is
* refusing to talk to us, or mail for it loops back to us.
*
* XXX There is no equivalent safety net for mis-configured
* sender-dependent relay hosts. The trivial-rewrite resolver
* would have to flag the result, and the queue manager would
* have to provide that information to delivery agents.
*/
else if (smtp_mode && strcmp(sites->argv[0], var_relayhost) == 0) {
msg_warn("%s configuration problem", VAR_RELAYHOST);
vstring_strcpy(why->status, "4.3.5");
/* XXX Keep the diagnostic code and MTA. */
}
/*
* Mail for the next-hop destination loops back to myself. Pass
* the mail to the best_mx_transport or bounce it.
*/
else if (smtp_mode && SMTP_HAS_LOOP_DSN(why) && *var_bestmx_transp) {
dsb_reset(why); /* XXX */
state->status = deliver_pass_all(MAIL_CLASS_PRIVATE,
var_bestmx_transp,
request);
SMTP_RCPT_LEFT(state) = 0; /* XXX */
}
}
}
/*
* Cleanup.
*/
if (HAVE_NEXTHOP_STATE(state))
FREE_NEXTHOP_STATE(state);
argv_free(sites);
}
static SMTP_SESSION *smtp_connect_addr(SMTP_ITERATOR *iter, DSN_BUF *why,
int sess_flags)
{
const char *myname = "smtp_connect_addr";
struct sockaddr_storage ss; /* remote */
struct sockaddr *sa = (struct sockaddr *) &ss;
SOCKADDR_SIZE salen = sizeof(ss);
MAI_HOSTADDR_STR hostaddr;
DNS_RR *addr = iter->rr;
unsigned port = iter->port;
int sock;
char *bind_addr;
char *bind_var;
dsb_reset(why); /* Paranoia */
/*
* Sanity checks.
*/
if (dns_rr_to_sa(addr, port, sa, &salen) != 0) {
msg_warn("%s: skip address type %s: %m",
myname, dns_strtype(addr->type));
dsb_simple(why, "4.4.0", "network address conversion failed: %m");
return (0);
}
/*
* Initialize.
*/
if ((sock = socket(sa->sa_family, SOCK_STREAM, 0)) < 0)
msg_fatal("%s: socket: %m", myname);
if (inet_windowsize > 0)
set_inet_windowsize(sock, inet_windowsize);
/*
* Allow the sysadmin to specify the source address, for example, as "-o
* smtp_bind_address=x.x.x.x" in the master.cf file.
*/
#ifdef HAS_IPV6
if (sa->sa_family == AF_INET6) {
bind_addr = var_smtp_bind_addr6;
bind_var = VAR_LMTP_SMTP(BIND_ADDR6);
} else
#endif
if (sa->sa_family == AF_INET) {
bind_addr = var_smtp_bind_addr;
bind_var = VAR_LMTP_SMTP(BIND_ADDR);
} else
bind_var = bind_addr = "";
if (*bind_addr) {
int aierr;
struct addrinfo *res0;
if ((aierr = hostaddr_to_sockaddr(bind_addr, (char *) 0, 0, &res0)) != 0)
msg_fatal("%s: bad %s parameter: %s: %s",
myname, bind_var, bind_addr, MAI_STRERROR(aierr));
if (bind(sock, res0->ai_addr, res0->ai_addrlen) < 0)
msg_warn("%s: bind %s: %m", myname, bind_addr);
else if (msg_verbose)
msg_info("%s: bind %s", myname, bind_addr);
freeaddrinfo(res0);
}
/*
* When running as a virtual host, bind to the virtual interface so that
* the mail appears to come from the "right" machine address.
*
* XXX The IPv6 patch expands the null host (as client endpoint) and uses
* the result as the loopback address list.
*/
else {
int count = 0;
struct sockaddr *own_addr = 0;
INET_ADDR_LIST *addr_list = own_inet_addr_list();
struct sockaddr_storage *s;
for (s = addr_list->addrs; s < addr_list->addrs + addr_list->used; s++) {
if (SOCK_ADDR_FAMILY(s) == sa->sa_family) {
if (count++ > 0)
break;
own_addr = SOCK_ADDR_PTR(s);
}
}
if (count == 1 && !sock_addr_in_loopback(own_addr)) {
if (bind(sock, own_addr, SOCK_ADDR_LEN(own_addr)) < 0) {
SOCKADDR_TO_HOSTADDR(own_addr, SOCK_ADDR_LEN(own_addr),
&hostaddr, (MAI_SERVPORT_STR *) 0, 0);
msg_warn("%s: bind %s: %m", myname, hostaddr.buf);
} else if (msg_verbose) {
SOCKADDR_TO_HOSTADDR(own_addr, SOCK_ADDR_LEN(own_addr),
&hostaddr, (MAI_SERVPORT_STR *) 0, 0);
msg_info("%s: bind %s", myname, hostaddr.buf);
}
}
}
/*
* Connect to the server.
*/
if (msg_verbose)
msg_info("%s: trying: %s[%s] port %d...",
myname, STR(iter->host), STR(iter->addr), ntohs(port));
return (smtp_connect_sock(sock, sa, salen, iter, why, sess_flags));
}
static void pre_init(char *unused_name, char **unused_argv)
{
int use_tls;
static const NAME_CODE addr_pref_map[] = {
INET_PROTO_NAME_IPV6, SMTP_MISC_FLAG_PREF_IPV6,
INET_PROTO_NAME_IPV4, SMTP_MISC_FLAG_PREF_IPV4,
INET_PROTO_NAME_ANY, 0,
0, -1,
};
/*
* Turn on per-peer debugging.
*/
debug_peer_init();
/*
* SASL initialization.
*/
if (var_smtp_sasl_enable)
#ifdef USE_SASL_AUTH
smtp_sasl_initialize();
#else
msg_warn("%s is true, but SASL support is not compiled in",
VAR_LMTP_SMTP(SASL_ENABLE));
#endif
if (*var_smtp_tls_level != 0)
switch (tls_level_lookup(var_smtp_tls_level)) {
case TLS_LEV_SECURE:
case TLS_LEV_VERIFY:
case TLS_LEV_DANE_ONLY:
case TLS_LEV_FPRINT:
case TLS_LEV_ENCRYPT:
var_smtp_use_tls = var_smtp_enforce_tls = 1;
break;
case TLS_LEV_DANE:
case TLS_LEV_MAY:
var_smtp_use_tls = 1;
var_smtp_enforce_tls = 0;
break;
case TLS_LEV_NONE:
var_smtp_use_tls = var_smtp_enforce_tls = 0;
break;
default:
/* tls_level_lookup() logs no warning. */
/* session_tls_init() assumes that var_smtp_tls_level is sane. */
msg_fatal("Invalid TLS level \"%s\"", var_smtp_tls_level);
}
use_tls = (var_smtp_use_tls || var_smtp_enforce_tls);
/*
* Initialize the TLS data before entering the chroot jail
*/
if (use_tls || var_smtp_tls_per_site[0] || var_smtp_tls_policy[0]) {
#ifdef USE_TLS
TLS_CLIENT_INIT_PROPS props;
/*
* We get stronger type safety and a cleaner interface by combining
* the various parameters into a single tls_client_props structure.
*
* Large parameter lists are error-prone, so we emulate a language
* feature that C does not have natively: named parameter lists.
*/
smtp_tls_ctx =
TLS_CLIENT_INIT(&props,
log_param = VAR_LMTP_SMTP(TLS_LOGLEVEL),
log_level = var_smtp_tls_loglevel,
verifydepth = var_smtp_tls_scert_vd,
cache_type = LMTP_SMTP_SUFFIX(TLS_MGR_SCACHE),
cert_file = var_smtp_tls_cert_file,
key_file = var_smtp_tls_key_file,
dcert_file = var_smtp_tls_dcert_file,
dkey_file = var_smtp_tls_dkey_file,
eccert_file = var_smtp_tls_eccert_file,
eckey_file = var_smtp_tls_eckey_file,
CAfile = var_smtp_tls_CAfile,
CApath = var_smtp_tls_CApath,
mdalg = var_smtp_tls_fpt_dgst);
smtp_tls_list_init();
#else
msg_warn("TLS has been selected, but TLS support is not compiled in");
#endif
}
/*
* Flush client.
*/
flush_init();
/*
* Session cache domain list.
*/
if (*var_smtp_cache_dest)
smtp_cache_dest = string_list_init(MATCH_FLAG_RETURN, var_smtp_cache_dest);
/*
* EHLO keyword filter.
*/
if (*var_smtp_ehlo_dis_maps)
smtp_ehlo_dis_maps = maps_create(VAR_LMTP_SMTP(EHLO_DIS_MAPS),
var_smtp_ehlo_dis_maps,
DICT_FLAG_LOCK);
/*
* PIX bug workarounds.
*/
if (*var_smtp_pix_bug_maps)
smtp_pix_bug_maps = maps_create(VAR_LMTP_SMTP(PIX_BUG_MAPS),
var_smtp_pix_bug_maps,
DICT_FLAG_LOCK);
/*
* Generic maps.
*/
if (*var_prop_extension)
smtp_ext_prop_mask =
ext_prop_mask(VAR_PROP_EXTENSION, var_prop_extension);
if (*var_smtp_generic_maps)
smtp_generic_maps =
maps_create(VAR_LMTP_SMTP(GENERIC_MAPS), var_smtp_generic_maps,
DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX);
/*
* Header/body checks.
*/
smtp_header_checks = hbc_header_checks_create(
VAR_LMTP_SMTP(HEAD_CHKS), var_smtp_head_chks,
VAR_LMTP_SMTP(MIME_CHKS), var_smtp_mime_chks,
VAR_LMTP_SMTP(NEST_CHKS), var_smtp_nest_chks,
smtp_hbc_callbacks);
smtp_body_checks = hbc_body_checks_create(
VAR_LMTP_SMTP(BODY_CHKS), var_smtp_body_chks,
smtp_hbc_callbacks);
/*
* Server reply filter.
*/
if (*var_smtp_resp_filter)
smtp_chat_resp_filter =
dict_open(var_smtp_resp_filter, O_RDONLY,
DICT_FLAG_LOCK | DICT_FLAG_FOLD_FIX);
/*
* Address family preference.
*/
if (*var_smtp_addr_pref) {
smtp_addr_pref = name_code(addr_pref_map, NAME_CODE_FLAG_NONE,
var_smtp_addr_pref);
if (smtp_addr_pref < 0)
msg_fatal("bad %s value: %s", VAR_LMTP_SMTP(ADDR_PREF),
var_smtp_addr_pref);
}
}
SMTP_RESP *smtp_chat_resp(SMTP_SESSION *session)
{
static SMTP_RESP rdata;
char *cp;
int last_char;
int three_digs = 0;
size_t len;
const char *new_reply;
int chat_append_flag;
int chat_append_skipped = 0;
/*
* Initialize the response data buffer.
*/
if (rdata.str_buf == 0) {
rdata.dsn_buf = vstring_alloc(10);
rdata.str_buf = vstring_alloc(100);
}
/*
* Censor out non-printable characters in server responses. Concatenate
* multi-line server responses. Separate the status code from the text.
* Leave further parsing up to the application.
*
* We can't parse or store input that exceeds var_line_limit, so we just
* skip over it to simplify the remainder of the code below.
*/
VSTRING_RESET(rdata.str_buf);
for (;;) {
last_char = smtp_get(session->buffer, session->stream, var_line_limit,
SMTP_GET_FLAG_SKIP);
/* XXX Update the per-line time limit. */
printable(STR(session->buffer), '?');
if (last_char != '\n')
msg_warn("%s: response longer than %d: %.30s...",
session->namaddrport, var_line_limit, STR(session->buffer));
if (msg_verbose)
msg_info("< %s: %.100s", session->namaddrport, STR(session->buffer));
/*
* Defend against a denial of service attack by limiting the amount
* of multi-line text that we are willing to store.
*/
chat_append_flag = (LEN(rdata.str_buf) < var_line_limit);
if (chat_append_flag)
smtp_chat_append(session, "In: ", STR(session->buffer));
else {
if (chat_append_skipped == 0)
msg_warn("%s: multi-line response longer than %d %.30s...",
session->namaddrport, var_line_limit, STR(rdata.str_buf));
if (chat_append_skipped < INT_MAX)
chat_append_skipped++;
}
/*
* Server reply substitution, for fault-injection testing, or for
* working around broken systems. Use with care.
*/
if (smtp_chat_resp_filter != 0) {
new_reply = dict_get(smtp_chat_resp_filter, STR(session->buffer));
if (new_reply != 0) {
msg_info("%s: replacing server reply \"%s\" with \"%s\"",
session->namaddrport, STR(session->buffer), new_reply);
vstring_strcpy(session->buffer, new_reply);
if (chat_append_flag) {
smtp_chat_append(session, "Replaced-by: ", "");
smtp_chat_append(session, " ", new_reply);
}
} else if (smtp_chat_resp_filter->error != 0) {
msg_warn("%s: table %s:%s lookup error for %s",
session->state->request->queue_id,
smtp_chat_resp_filter->type,
smtp_chat_resp_filter->name,
printable(STR(session->buffer), '?'));
vstream_longjmp(session->stream, SMTP_ERR_DATA);
}
}
if (chat_append_flag) {
if (LEN(rdata.str_buf))
VSTRING_ADDCH(rdata.str_buf, '\n');
vstring_strcat(rdata.str_buf, STR(session->buffer));
}
/*
* Parse into code and text. Do not ignore garbage (see below).
*/
for (cp = STR(session->buffer); *cp && ISDIGIT(*cp); cp++)
/* void */ ;
if ((three_digs = (cp - STR(session->buffer) == 3)) != 0) {
if (*cp == '-')
continue;
if (*cp == ' ' || *cp == 0)
break;
}
/*
* XXX Do not simply ignore garbage in the server reply when ESMTP
* command pipelining is turned on. For example, after sending
* ".<CR><LF>QUIT<CR><LF>" and receiving garbage followed by a
* legitimate 2XX reply, Postfix recognizes the server's QUIT reply
* as the END-OF-DATA reply after garbage, causing mail to be lost.
*
* Without the ability to store per-domain status information in queue
* files, automatic workarounds are problematic:
*
* - Automatically deferring delivery creates a "repeated delivery"
* problem when garbage arrives after the DATA stage. Without the
* workaround, Postfix delivers only once.
*
* - Automatically deferring delivery creates a "no delivery" problem
* when the garbage arrives before the DATA stage. Without the
* workaround, mail might still get through.
*
* - Automatically turning off pipelining for delayed mail affects
* deliveries to correctly implemented servers, and may also affect
* delivery of large mailing lists.
*
* So we leave the decision with the administrator, but we don't force
* them to take action, like we would with automatic deferral. If
* loss of mail is not acceptable then they can turn off pipelining
* for specific sites, or they can turn off pipelining globally when
* they find that there are just too many broken sites.
*/
session->error_mask |= MAIL_ERROR_PROTOCOL;
if (session->features & SMTP_FEATURE_PIPELINING) {
msg_warn("%s: non-%s response from %s: %.100s",
session->state->request->queue_id,
smtp_mode ? "ESMTP" : "LMTP",
session->namaddrport, STR(session->buffer));
if (var_helpful_warnings)
msg_warn("to prevent loss of mail, turn off command pipelining "
"for %s with the %s parameter",
STR(session->iterator->addr),
VAR_LMTP_SMTP(EHLO_DIS_MAPS));
}
}
/*
* Extract RFC 821 reply code and RFC 2034 detail. Use a default detail
* code if none was given.
*
* Ignore out-of-protocol enhanced status codes: codes that accompany 3XX
* replies, or codes whose initial digit is out of sync with the reply
* code.
*
* XXX Potential stability problem. In order to save memory, the queue
* manager stores DSNs in a compact manner:
*
* - empty strings are represented by null pointers,
*
* - the status and reason are required to be non-empty.
*
* Other Postfix daemons inherit this behavior, because they use the same
* DSN support code. This means that everything that receives DSNs must
* cope with null pointers for the optional DSN attributes, and that
* everything that provides DSN information must provide a non-empty
* status and reason, otherwise the DSN support code wil panic().
*
* Thus, when the remote server sends a malformed reply (or 3XX out of
* context) we should not panic() in DSN_COPY() just because we don't
* have a status. Robustness suggests that we supply a status here, and
* that we leave it up to the down-stream code to override the
* server-supplied status in case of an error we can't detect here, such
* as an out-of-order server reply.
*/
VSTRING_TERMINATE(rdata.str_buf);
vstring_strcpy(rdata.dsn_buf, "5.5.0"); /* SAFETY! protocol error */
if (three_digs != 0) {
rdata.code = atoi(STR(session->buffer));
if (strchr("245", STR(session->buffer)[0]) != 0) {
for (cp = STR(session->buffer) + 4; *cp == ' '; cp++)
/* void */ ;
if ((len = dsn_valid(cp)) > 0 && *cp == *STR(session->buffer)) {
vstring_strncpy(rdata.dsn_buf, cp, len);
} else {
vstring_strcpy(rdata.dsn_buf, "0.0.0");
STR(rdata.dsn_buf)[0] = STR(session->buffer)[0];
}
}
} else {
rdata.code = 0;
}
rdata.dsn = STR(rdata.dsn_buf);
rdata.str = STR(rdata.str_buf);
return (&rdata);
}
static void post_init(char *unused_name, char **unused_argv)
{
static const NAME_MASK lookup_masks[] = {
SMTP_HOST_LOOKUP_DNS, SMTP_HOST_FLAG_DNS,
SMTP_HOST_LOOKUP_NATIVE, SMTP_HOST_FLAG_NATIVE,
0,
};
static const NAME_MASK dns_res_opt_masks[] = {
SMTP_DNS_RES_OPT_DEFNAMES, RES_DEFNAMES,
SMTP_DNS_RES_OPT_DNSRCH, RES_DNSRCH,
0,
};
static const NAME_CODE dns_support[] = {
SMTP_DNS_SUPPORT_DISABLED, SMTP_DNS_DISABLED,
SMTP_DNS_SUPPORT_ENABLED, SMTP_DNS_ENABLED,
#if (RES_USE_DNSSEC != 0) && (RES_USE_EDNS0 != 0)
SMTP_DNS_SUPPORT_DNSSEC, SMTP_DNS_DNSSEC,
#endif
0, SMTP_DNS_INVALID,
};
if (*var_smtp_dns_support == 0) {
/* Backwards compatible empty setting */
smtp_dns_support =
var_disable_dns ? SMTP_DNS_DISABLED : SMTP_DNS_ENABLED;
} else {
smtp_dns_support =
name_code(dns_support, NAME_CODE_FLAG_NONE, var_smtp_dns_support);
if (smtp_dns_support == SMTP_DNS_INVALID)
msg_fatal("invalid %s: \"%s\"", VAR_LMTP_SMTP(DNS_SUPPORT),
var_smtp_dns_support);
var_disable_dns = (smtp_dns_support == SMTP_DNS_DISABLED);
}
/*
* Select hostname lookup mechanisms.
*/
if (smtp_dns_support == SMTP_DNS_DISABLED)
smtp_host_lookup_mask = SMTP_HOST_FLAG_NATIVE;
else
smtp_host_lookup_mask =
name_mask(VAR_LMTP_SMTP(HOST_LOOKUP), lookup_masks,
var_smtp_host_lookup);
if (msg_verbose)
msg_info("host name lookup methods: %s",
str_name_mask(VAR_LMTP_SMTP(HOST_LOOKUP), lookup_masks,
smtp_host_lookup_mask));
/*
* Session cache instance.
*/
if (*var_smtp_cache_dest || var_smtp_cache_demand)
#if 0
smtp_scache = scache_multi_create();
#else
smtp_scache = scache_clnt_create(var_scache_service,
var_scache_proto_tmout,
var_ipc_idle_limit,
var_ipc_ttl_limit);
#endif
/*
* Select DNS query flags.
*/
smtp_dns_res_opt = name_mask(VAR_LMTP_SMTP(DNS_RES_OPT), dns_res_opt_masks,
var_smtp_dns_res_opt);
}
