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diff --git a/src/verify.c b/src/verify.c
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+++ b/src/verify.c
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+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+/* Functions concerned with verifying things. The original code for callout
+caching was contributed by Kevin Fleming (but I hacked it around a bit). */
+
+
+#include "exim.h"
+#include "transports/smtp.h"
+
+#define CUTTHROUGH_CMD_TIMEOUT 30 /* timeout for cutthrough-routing calls */
+#define CUTTHROUGH_DATA_TIMEOUT 60 /* timeout for cutthrough-routing calls */
+static smtp_context ctctx;
+uschar ctbuffer[8192];
+
+
+/* Structure for caching DNSBL lookups */
+
+typedef struct dnsbl_cache_block {
+ time_t expiry;
+ dns_address *rhs;
+ uschar *text;
+ int rc;
+ BOOL text_set;
+} dnsbl_cache_block;
+
+
+/* Anchor for DNSBL cache */
+
+static tree_node *dnsbl_cache = NULL;
+
+
+/* Bits for match_type in one_check_dnsbl() */
+
+#define MT_NOT 1
+#define MT_ALL 2
+
+static uschar cutthrough_response(client_conn_ctx *, char, uschar **, int);
+
+
+
+/*************************************************
+* Retrieve a callout cache record *
+*************************************************/
+
+/* If a record exists, check whether it has expired.
+
+Arguments:
+ dbm_file an open hints file
+ key the record key
+ type "address" or "domain"
+ positive_expire expire time for positive records
+ negative_expire expire time for negative records
+
+Returns: the cache record if a non-expired one exists, else NULL
+*/
+
+static dbdata_callout_cache *
+get_callout_cache_record(open_db *dbm_file, const uschar *key, uschar *type,
+ int positive_expire, int negative_expire)
+{
+BOOL negative;
+int length, expire;
+time_t now;
+dbdata_callout_cache *cache_record;
+
+if (!(cache_record = dbfn_read_with_length(dbm_file, key, &length)))
+ {
+ HDEBUG(D_verify) debug_printf("callout cache: no %s record found for %s\n", type, key);
+ return NULL;
+ }
+
+/* We treat a record as "negative" if its result field is not positive, or if
+it is a domain record and the postmaster field is negative. */
+
+negative = cache_record->result != ccache_accept ||
+ (type[0] == 'd' && cache_record->postmaster_result == ccache_reject);
+expire = negative? negative_expire : positive_expire;
+now = time(NULL);
+
+if (now - cache_record->time_stamp > expire)
+ {
+ HDEBUG(D_verify) debug_printf("callout cache: %s record expired for %s\n", type, key);
+ return NULL;
+ }
+
+/* If this is a non-reject domain record, check for the obsolete format version
+that doesn't have the postmaster and random timestamps, by looking at the
+length. If so, copy it to a new-style block, replicating the record's
+timestamp. Then check the additional timestamps. (There's no point wasting
+effort if connections are rejected.) */
+
+if (type[0] == 'd' && cache_record->result != ccache_reject)
+ {
+ if (length == sizeof(dbdata_callout_cache_obs))
+ {
+ dbdata_callout_cache *new = store_get(sizeof(dbdata_callout_cache), FALSE);
+ memcpy(new, cache_record, length);
+ new->postmaster_stamp = new->random_stamp = new->time_stamp;
+ cache_record = new;
+ }
+
+ if (now - cache_record->postmaster_stamp > expire)
+ cache_record->postmaster_result = ccache_unknown;
+
+ if (now - cache_record->random_stamp > expire)
+ cache_record->random_result = ccache_unknown;
+ }
+
+HDEBUG(D_verify) debug_printf("callout cache: found %s record for %s\n", type, key);
+return cache_record;
+}
+
+
+
+/* Check the callout cache.
+Options * pm_mailfrom may be modified by cache partial results.
+
+Return: TRUE if result found
+*/
+
+static BOOL
+cached_callout_lookup(address_item * addr, uschar * address_key,
+ uschar * from_address, int * opt_ptr, uschar ** pm_ptr,
+ int * yield, uschar ** failure_ptr,
+ dbdata_callout_cache * new_domain_record, int * old_domain_res)
+{
+int options = *opt_ptr;
+open_db dbblock;
+open_db *dbm_file = NULL;
+
+/* Open the callout cache database, it it exists, for reading only at this
+stage, unless caching has been disabled. */
+
+if (options & vopt_callout_no_cache)
+ {
+ HDEBUG(D_verify) debug_printf("callout cache: disabled by no_cache\n");
+ }
+else if (!(dbm_file = dbfn_open(US"callout", O_RDWR, &dbblock, FALSE, TRUE)))
+ {
+ HDEBUG(D_verify) debug_printf("callout cache: not available\n");
+ }
+else
+ {
+ /* If a cache database is available see if we can avoid the need to do an
+ actual callout by making use of previously-obtained data. */
+
+ dbdata_callout_cache_address * cache_address_record;
+ dbdata_callout_cache * cache_record = get_callout_cache_record(dbm_file,
+ addr->domain, US"domain",
+ callout_cache_domain_positive_expire, callout_cache_domain_negative_expire);
+
+ /* If an unexpired cache record was found for this domain, see if the callout
+ process can be short-circuited. */
+
+ if (cache_record)
+ {
+ /* In most cases, if an early command (up to and including MAIL FROM:<>)
+ was rejected, there is no point carrying on. The callout fails. However, if
+ we are doing a recipient verification with use_sender or use_postmaster
+ set, a previous failure of MAIL FROM:<> doesn't count, because this time we
+ will be using a non-empty sender. We have to remember this situation so as
+ not to disturb the cached domain value if this whole verification succeeds
+ (we don't want it turning into "accept"). */
+
+ *old_domain_res = cache_record->result;
+
+ if ( cache_record->result == ccache_reject
+ || *from_address == 0 && cache_record->result == ccache_reject_mfnull)
+ {
+ HDEBUG(D_verify)
+ debug_printf("callout cache: domain gave initial rejection, or "
+ "does not accept HELO or MAIL FROM:<>\n");
+ setflag(addr, af_verify_nsfail);
+ addr->user_message = US"(result of an earlier callout reused).";
+ *yield = FAIL;
+ *failure_ptr = US"mail";
+ dbfn_close(dbm_file);
+ return TRUE;
+ }
+
+ /* If a previous check on a "random" local part was accepted, we assume
+ that the server does not do any checking on local parts. There is therefore
+ no point in doing the callout, because it will always be successful. If a
+ random check previously failed, arrange not to do it again, but preserve
+ the data in the new record. If a random check is required but hasn't been
+ done, skip the remaining cache processing. */
+
+ if (options & vopt_callout_random) switch(cache_record->random_result)
+ {
+ case ccache_accept:
+ HDEBUG(D_verify)
+ debug_printf("callout cache: domain accepts random addresses\n");
+ *failure_ptr = US"random";
+ dbfn_close(dbm_file);
+ return TRUE; /* Default yield is OK */
+
+ case ccache_reject:
+ HDEBUG(D_verify)
+ debug_printf("callout cache: domain rejects random addresses\n");
+ *opt_ptr = options & ~vopt_callout_random;
+ new_domain_record->random_result = ccache_reject;
+ new_domain_record->random_stamp = cache_record->random_stamp;
+ break;
+
+ default:
+ HDEBUG(D_verify)
+ debug_printf("callout cache: need to check random address handling "
+ "(not cached or cache expired)\n");
+ dbfn_close(dbm_file);
+ return FALSE;
+ }
+
+ /* If a postmaster check is requested, but there was a previous failure,
+ there is again no point in carrying on. If a postmaster check is required,
+ but has not been done before, we are going to have to do a callout, so skip
+ remaining cache processing. */
+
+ if (*pm_ptr)
+ {
+ if (cache_record->postmaster_result == ccache_reject)
+ {
+ setflag(addr, af_verify_pmfail);
+ HDEBUG(D_verify)
+ debug_printf("callout cache: domain does not accept "
+ "RCPT TO:<postmaster@domain>\n");
+ *yield = FAIL;
+ *failure_ptr = US"postmaster";
+ setflag(addr, af_verify_pmfail);
+ addr->user_message = US"(result of earlier verification reused).";
+ dbfn_close(dbm_file);
+ return TRUE;
+ }
+ if (cache_record->postmaster_result == ccache_unknown)
+ {
+ HDEBUG(D_verify)
+ debug_printf("callout cache: need to check RCPT "
+ "TO:<postmaster@domain> (not cached or cache expired)\n");
+ dbfn_close(dbm_file);
+ return FALSE;
+ }
+
+ /* If cache says OK, set pm_mailfrom NULL to prevent a redundant
+ postmaster check if the address itself has to be checked. Also ensure
+ that the value in the cache record is preserved (with its old timestamp).
+ */
+
+ HDEBUG(D_verify) debug_printf("callout cache: domain accepts RCPT "
+ "TO:<postmaster@domain>\n");
+ *pm_ptr = NULL;
+ new_domain_record->postmaster_result = ccache_accept;
+ new_domain_record->postmaster_stamp = cache_record->postmaster_stamp;
+ }
+ }
+
+ /* We can't give a result based on information about the domain. See if there
+ is an unexpired cache record for this specific address (combined with the
+ sender address if we are doing a recipient callout with a non-empty sender).
+ */
+
+ if (!(cache_address_record = (dbdata_callout_cache_address *)
+ get_callout_cache_record(dbm_file, address_key, US"address",
+ callout_cache_positive_expire, callout_cache_negative_expire)))
+ {
+ dbfn_close(dbm_file);
+ return FALSE;
+ }
+
+ if (cache_address_record->result == ccache_accept)
+ {
+ HDEBUG(D_verify)
+ debug_printf("callout cache: address record is positive\n");
+ }
+ else
+ {
+ HDEBUG(D_verify)
+ debug_printf("callout cache: address record is negative\n");
+ addr->user_message = US"Previous (cached) callout verification failure";
+ *failure_ptr = US"recipient";
+ *yield = FAIL;
+ }
+
+ /* Close the cache database while we actually do the callout for real. */
+
+ dbfn_close(dbm_file);
+ return TRUE;
+ }
+return FALSE;
+}
+
+
+/* Write results to callout cache
+*/
+static void
+cache_callout_write(dbdata_callout_cache * dom_rec, const uschar * domain,
+ int done, dbdata_callout_cache_address * addr_rec, uschar * address_key)
+{
+open_db dbblock;
+open_db *dbm_file = NULL;
+
+/* If we get here with done == TRUE, a successful callout happened, and yield
+will be set OK or FAIL according to the response to the RCPT command.
+Otherwise, we looped through the hosts but couldn't complete the business.
+However, there may be domain-specific information to cache in both cases.
+
+The value of the result field in the new_domain record is ccache_unknown if
+there was an error before or with MAIL FROM:, and errno was not zero,
+implying some kind of I/O error. We don't want to write the cache in that case.
+Otherwise the value is ccache_accept, ccache_reject, or ccache_reject_mfnull. */
+
+if (dom_rec->result != ccache_unknown)
+ if (!(dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE, TRUE)))
+ {
+ HDEBUG(D_verify) debug_printf("callout cache: not available\n");
+ }
+ else
+ {
+ (void)dbfn_write(dbm_file, domain, dom_rec,
+ (int)sizeof(dbdata_callout_cache));
+ HDEBUG(D_verify) debug_printf("wrote callout cache domain record for %s:\n"
+ " result=%d postmaster=%d random=%d\n",
+ domain,
+ dom_rec->result,
+ dom_rec->postmaster_result,
+ dom_rec->random_result);
+ }
+
+/* If a definite result was obtained for the callout, cache it unless caching
+is disabled. */
+
+if (done && addr_rec->result != ccache_unknown)
+ {
+ if (!dbm_file)
+ dbm_file = dbfn_open(US"callout", O_RDWR|O_CREAT, &dbblock, FALSE, TRUE);
+ if (!dbm_file)
+ {
+ HDEBUG(D_verify) debug_printf("no callout cache available\n");
+ }
+ else
+ {
+ (void)dbfn_write(dbm_file, address_key, addr_rec,
+ (int)sizeof(dbdata_callout_cache_address));
+ HDEBUG(D_verify) debug_printf("wrote %s callout cache address record for %s\n",
+ addr_rec->result == ccache_accept ? "positive" : "negative",
+ address_key);
+ }
+ }
+
+if (dbm_file) dbfn_close(dbm_file);
+}
+
+
+/* Cutthrough-multi. If the existing cached cutthrough connection matches
+the one we would make for a subsequent recipient, use it. Send the RCPT TO
+and check the result, nonpipelined as it may be wanted immediately for
+recipient-verification.
+
+It seems simpler to deal with this case separately from the main callout loop.
+We will need to remember it has sent, or not, so that rcpt-acl tail code
+can do it there for the non-rcpt-verify case. For this we keep an addresscount.
+
+Return: TRUE for a definitive result for the recipient
+*/
+static int
+cutthrough_multi(address_item * addr, host_item * host_list,
+ transport_feedback * tf, int * yield)
+{
+BOOL done = FALSE;
+
+if (addr->transport == cutthrough.addr.transport)
+ for (host_item * host = host_list; host; host = host->next)
+ if (Ustrcmp(host->address, cutthrough.host.address) == 0)
+ {
+ int host_af;
+ uschar *interface = NULL; /* Outgoing interface to use; NULL => any */
+ int port = 25;
+
+ deliver_host = host->name;
+ deliver_host_address = host->address;
+ deliver_host_port = host->port;
+ deliver_domain = addr->domain;
+ transport_name = addr->transport->name;
+
+ host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
+
+ if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
+ US"callout")
+ || !smtp_get_port(tf->port, addr, &port, US"callout")
+ )
+ log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
+ addr->message);
+
+ smtp_port_for_connect(host, port);
+
+ if ( ( interface == cutthrough.interface
+ || ( interface
+ && cutthrough.interface
+ && Ustrcmp(interface, cutthrough.interface) == 0
+ ) )
+ && host->port == cutthrough.host.port
+ )
+ {
+ uschar * resp = NULL;
+
+ /* Match! Send the RCPT TO, set done from the response */
+ done =
+ smtp_write_command(&ctctx, SCMD_FLUSH, "RCPT TO:<%.1000s>\r\n",
+ transport_rcpt_address(addr,
+ addr->transport->rcpt_include_affixes)) >= 0
+ && cutthrough_response(&cutthrough.cctx, '2', &resp,
+ CUTTHROUGH_DATA_TIMEOUT) == '2';
+
+ /* This would go horribly wrong if a callout fail was ignored by ACL.
+ We punt by abandoning cutthrough on a reject, like the
+ first-rcpt does. */
+
+ if (done)
+ {
+ address_item * na = store_get(sizeof(address_item), FALSE);
+ *na = cutthrough.addr;
+ cutthrough.addr = *addr;
+ cutthrough.addr.host_used = &cutthrough.host;
+ cutthrough.addr.next = na;
+
+ cutthrough.nrcpt++;
+ }
+ else
+ {
+ cancel_cutthrough_connection(TRUE, US"recipient rejected");
+ if (!resp || errno == ETIMEDOUT)
+ {
+ HDEBUG(D_verify) debug_printf("SMTP timeout\n");
+ }
+ else if (errno == 0)
+ {
+ if (*resp == 0)
+ Ustrcpy(resp, US"connection dropped");
+
+ addr->message =
+ string_sprintf("response to \"%s\" was: %s",
+ big_buffer, string_printing(resp));
+
+ addr->user_message =
+ string_sprintf("Callout verification failed:\n%s", resp);
+
+ /* Hard rejection ends the process */
+
+ if (resp[0] == '5') /* Address rejected */
+ {
+ *yield = FAIL;
+ done = TRUE;
+ }
+ }
+ }
+ }
+ break; /* host_list */
+ }
+if (!done)
+ cancel_cutthrough_connection(TRUE, US"incompatible connection");
+return done;
+}
+
+
+/*************************************************
+* Do callout verification for an address *
+*************************************************/
+
+/* This function is called from verify_address() when the address has routed to
+a host list, and a callout has been requested. Callouts are expensive; that is
+why a cache is used to improve the efficiency.
+
+Arguments:
+ addr the address that's been routed
+ host_list the list of hosts to try
+ tf the transport feedback block
+
+ ifstring "interface" option from transport, or NULL
+ portstring "port" option from transport, or NULL
+ protocolstring "protocol" option from transport, or NULL
+ callout the per-command callout timeout
+ callout_overall the overall callout timeout (if < 0 use 4*callout)
+ callout_connect the callout connection timeout (if < 0 use callout)
+ options the verification options - these bits are used:
+ vopt_is_recipient => this is a recipient address
+ vopt_callout_no_cache => don't use callout cache
+ vopt_callout_fullpm => if postmaster check, do full one
+ vopt_callout_random => do the "random" thing
+ vopt_callout_recipsender => use real sender for recipient
+ vopt_callout_recippmaster => use postmaster for recipient
+ vopt_callout_hold => lazy close connection
+ se_mailfrom MAIL FROM address for sender verify; NULL => ""
+ pm_mailfrom if non-NULL, do the postmaster check with this sender
+
+Returns: OK/FAIL/DEFER
+*/
+
+static int
+do_callout(address_item *addr, host_item *host_list, transport_feedback *tf,
+ int callout, int callout_overall, int callout_connect, int options,
+ uschar *se_mailfrom, uschar *pm_mailfrom)
+{
+int yield = OK;
+int old_domain_cache_result = ccache_accept;
+BOOL done = FALSE;
+uschar *address_key;
+uschar *from_address;
+uschar *random_local_part = NULL;
+const uschar *save_deliver_domain = deliver_domain;
+uschar **failure_ptr = options & vopt_is_recipient
+ ? &recipient_verify_failure : &sender_verify_failure;
+dbdata_callout_cache new_domain_record;
+dbdata_callout_cache_address new_address_record;
+time_t callout_start_time;
+
+new_domain_record.result = ccache_unknown;
+new_domain_record.postmaster_result = ccache_unknown;
+new_domain_record.random_result = ccache_unknown;
+
+memset(&new_address_record, 0, sizeof(new_address_record));
+
+/* For a recipient callout, the key used for the address cache record must
+include the sender address if we are using the real sender in the callout,
+because that may influence the result of the callout. */
+
+if (options & vopt_is_recipient)
+ if (options & vopt_callout_recipsender)
+ {
+ from_address = sender_address;
+ address_key = string_sprintf("%s/<%s>", addr->address, sender_address);
+ if (cutthrough.delivery) options |= vopt_callout_no_cache;
+ }
+ else if (options & vopt_callout_recippmaster)
+ {
+ from_address = string_sprintf("postmaster@%s", qualify_domain_sender);
+ address_key = string_sprintf("%s/<postmaster@%s>", addr->address,
+ qualify_domain_sender);
+ }
+ else
+ {
+ from_address = US"";
+ address_key = addr->address;
+ }
+
+/* For a sender callout, we must adjust the key if the mailfrom address is not
+empty. */
+
+else
+ {
+ from_address = se_mailfrom ? se_mailfrom : US"";
+ address_key = *from_address
+ ? string_sprintf("%s/<%s>", addr->address, from_address) : addr->address;
+ }
+
+if (cached_callout_lookup(addr, address_key, from_address,
+ &options, &pm_mailfrom, &yield, failure_ptr,
+ &new_domain_record, &old_domain_cache_result))
+ {
+ cancel_cutthrough_connection(TRUE, US"cache-hit");
+ goto END_CALLOUT;
+ }
+
+if (!addr->transport)
+ {
+ HDEBUG(D_verify) debug_printf("cannot callout via null transport\n");
+ }
+else if (Ustrcmp(addr->transport->driver_name, "smtp") != 0)
+ log_write(0, LOG_MAIN|LOG_PANIC|LOG_CONFIG_FOR, "callout transport '%s': %s is non-smtp",
+ addr->transport->name, addr->transport->driver_name);
+else
+ {
+ smtp_transport_options_block *ob =
+ (smtp_transport_options_block *)addr->transport->options_block;
+ smtp_context * sx = NULL;
+
+ /* The information wasn't available in the cache, so we have to do a real
+ callout and save the result in the cache for next time, unless no_cache is set,
+ or unless we have a previously cached negative random result. If we are to test
+ with a random local part, ensure that such a local part is available. If not,
+ log the fact, but carry on without randomising. */
+
+ if (options & vopt_callout_random && callout_random_local_part)
+ if (!(random_local_part = expand_string(callout_random_local_part)))
+ log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand "
+ "callout_random_local_part: %s", expand_string_message);
+
+ /* Compile regex' used by client-side smtp */
+
+ smtp_deliver_init();
+
+ /* Default the connect and overall callout timeouts if not set, and record the
+ time we are starting so that we can enforce it. */
+
+ if (callout_overall < 0) callout_overall = 4 * callout;
+ if (callout_connect < 0) callout_connect = callout;
+ callout_start_time = time(NULL);
+
+ /* Before doing a real callout, if this is an SMTP connection, flush the SMTP
+ output because a callout might take some time. When PIPELINING is active and
+ there are many recipients, the total time for doing lots of callouts can add up
+ and cause the client to time out. So in this case we forgo the PIPELINING
+ optimization. */
+
+ if (smtp_out && !f.disable_callout_flush) mac_smtp_fflush();
+
+ clearflag(addr, af_verify_pmfail); /* postmaster callout flag */
+ clearflag(addr, af_verify_nsfail); /* null sender callout flag */
+
+/* cutthrough-multi: if a nonfirst rcpt has the same routing as the first,
+and we are holding a cutthrough conn open, we can just append the rcpt to
+that conn for verification purposes (and later delivery also). Simplest
+coding means skipping this whole loop and doing the append separately. */
+
+ /* Can we re-use an open cutthrough connection? */
+ if ( cutthrough.cctx.sock >= 0
+ && (options & (vopt_callout_recipsender | vopt_callout_recippmaster))
+ == vopt_callout_recipsender
+ && !random_local_part
+ && !pm_mailfrom
+ )
+ done = cutthrough_multi(addr, host_list, tf, &yield);
+
+ /* If we did not use a cached connection, make connections to the hosts
+ and do real callouts. The list of hosts is passed in as an argument. */
+
+ for (host_item * host = host_list; host && !done; host = host->next)
+ {
+ int host_af;
+ int port = 25;
+ uschar * interface = NULL; /* Outgoing interface to use; NULL => any */
+
+ if (!host->address)
+ {
+ DEBUG(D_verify) debug_printf("no IP address for host name %s: skipping\n",
+ host->name);
+ continue;
+ }
+
+ /* Check the overall callout timeout */
+
+ if (time(NULL) - callout_start_time >= callout_overall)
+ {
+ HDEBUG(D_verify) debug_printf("overall timeout for callout exceeded\n");
+ break;
+ }
+
+ /* Set IPv4 or IPv6 */
+
+ host_af = Ustrchr(host->address, ':') ? AF_INET6 : AF_INET;
+
+ /* Expand and interpret the interface and port strings. The latter will not
+ be used if there is a host-specific port (e.g. from a manualroute router).
+ This has to be delayed till now, because they may expand differently for
+ different hosts. If there's a failure, log it, but carry on with the
+ defaults. */
+
+ deliver_host = host->name;
+ deliver_host_address = host->address;
+ deliver_host_port = host->port;
+ deliver_domain = addr->domain;
+ transport_name = addr->transport->name;
+
+ if ( !smtp_get_interface(tf->interface, host_af, addr, &interface,
+ US"callout")
+ || !smtp_get_port(tf->port, addr, &port, US"callout")
+ )
+ log_write(0, LOG_MAIN|LOG_PANIC, "<%s>: %s", addr->address,
+ addr->message);
+
+ if (!sx) sx = store_get(sizeof(*sx), TRUE); /* tainted buffers */
+ memset(sx, 0, sizeof(*sx));
+
+ sx->addrlist = sx->first_addr = addr;
+ sx->conn_args.host = host;
+ sx->conn_args.host_af = host_af,
+ sx->port = port;
+ sx->conn_args.interface = interface;
+ sx->helo_data = tf->helo_data;
+ sx->conn_args.tblock = addr->transport;
+ sx->verify = TRUE;
+
+tls_retry_connection:
+ /* Set the address state so that errors are recorded in it */
+
+ addr->transport_return = PENDING_DEFER;
+ ob->connect_timeout = callout_connect;
+ ob->command_timeout = callout;
+
+ /* Get the channel set up ready for a message (MAIL FROM being the next
+ SMTP command to send. If we tried TLS but it failed, try again without
+ if permitted */
+
+ yield = smtp_setup_conn(sx, FALSE);
+#ifndef DISABLE_TLS
+ if ( yield == DEFER
+ && addr->basic_errno == ERRNO_TLSFAILURE
+ && ob->tls_tempfail_tryclear
+ && verify_check_given_host(CUSS &ob->hosts_require_tls, host) != OK
+ )
+ {
+ log_write(0, LOG_MAIN,
+ "%s: callout unencrypted to %s [%s] (not in hosts_require_tls)",
+ addr->message, host->name, host->address);
+ addr->transport_return = PENDING_DEFER;
+ yield = smtp_setup_conn(sx, TRUE);
+ }
+#endif
+ if (yield != OK)
+ {
+ errno = addr->basic_errno;
+ transport_name = NULL;
+ deliver_host = deliver_host_address = NULL;
+ deliver_domain = save_deliver_domain;
+
+ /* Failure to accept HELO is cached; this blocks the whole domain for all
+ senders. I/O errors and defer responses are not cached. */
+
+ if (yield == FAIL && (errno == 0 || errno == ERRNO_SMTPCLOSED))
+ {
+ setflag(addr, af_verify_nsfail);
+ new_domain_record.result = ccache_reject;
+ done = TRUE;
+ }
+ else
+ done = FALSE;
+ goto no_conn;
+ }
+
+ /* If we needed to authenticate, smtp_setup_conn() did that. Copy
+ the AUTH info for logging */
+
+ addr->authenticator = client_authenticator;
+ addr->auth_id = client_authenticated_id;
+
+ sx->from_addr = from_address;
+ sx->first_addr = sx->sync_addr = addr;
+ sx->ok = FALSE; /*XXX these 3 last might not be needed for verify? */
+ sx->send_rset = TRUE;
+ sx->completed_addr = FALSE;
+
+ new_domain_record.result = old_domain_cache_result == ccache_reject_mfnull
+ ? ccache_reject_mfnull : ccache_accept;
+
+ /* Do the random local part check first. Temporarily replace the recipient
+ with the "random" value */
+
+ if (random_local_part)
+ {
+ uschar * main_address = addr->address;
+ const uschar * rcpt_domain = addr->domain;
+
+#ifdef SUPPORT_I18N
+ uschar * errstr = NULL;
+ if ( testflag(addr, af_utf8_downcvt)
+ && (rcpt_domain = string_domain_utf8_to_alabel(rcpt_domain,
+ &errstr), errstr)
+ )
+ {
+ addr->message = errstr;
+ errno = ERRNO_EXPANDFAIL;
+ setflag(addr, af_verify_nsfail);
+ done = FALSE;
+ rcpt_domain = US""; /*XXX errorhandling! */
+ }
+#endif
+
+ /* This would be ok for 1st rcpt of a cutthrough (the case handled here;
+ subsequents are done in cutthrough_multi()), but no way to
+ handle a subsequent because of the RSET vaporising the MAIL FROM.
+ So refuse to support any. Most cutthrough use will not involve
+ random_local_part, so no loss. */
+ cancel_cutthrough_connection(TRUE, US"random-recipient");
+
+ addr->address = string_sprintf("%s@%.1000s",
+ random_local_part, rcpt_domain);
+ done = FALSE;
+
+ /* If accepted, we aren't going to do any further tests below.
+ Otherwise, cache a real negative response, and get back to the right
+ state to send RCPT. Unless there's some problem such as a dropped
+ connection, we expect to succeed, because the commands succeeded above.
+ However, some servers drop the connection after responding to an
+ invalid recipient, so on (any) error we drop and remake the connection.
+ XXX We don't care about that for postmaster_full. Should we?
+
+ XXX could we add another flag to the context, and have the common
+ code emit the RSET too? Even pipelined after the RCPT...
+ Then the main-verify call could use it if there's to be a subsequent
+ postmaster-verify.
+ The sync_responses() would need to be taught about it and we'd
+ need another return code filtering out to here.
+
+ Avoid using a SIZE option on the MAIL for all random-rcpt checks.
+ */
+
+ sx->avoid_option = OPTION_SIZE;
+
+ /* Remember when we last did a random test */
+ new_domain_record.random_stamp = time(NULL);
+
+ if (smtp_write_mail_and_rcpt_cmds(sx, &yield) == 0)
+ switch(addr->transport_return)
+ {
+ case PENDING_OK: /* random was accepted, unfortunately */
+ new_domain_record.random_result = ccache_accept;
+ yield = OK; /* Only usable verify result we can return */
+ done = TRUE;
+ *failure_ptr = US"random";
+ goto no_conn;
+ case FAIL: /* rejected: the preferred result */
+ new_domain_record.random_result = ccache_reject;
+ sx->avoid_option = 0;
+
+ /* Between each check, issue RSET, because some servers accept only
+ one recipient after MAIL FROM:<>.
+ XXX We don't care about that for postmaster_full. Should we? */
+
+ if ((done =
+ smtp_write_command(sx, SCMD_FLUSH, "RSET\r\n") >= 0 &&
+ smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', callout)))
+ break;
+
+ HDEBUG(D_acl|D_v)
+ debug_printf_indent("problem after random/rset/mfrom; reopen conn\n");
+ random_local_part = NULL;
+#ifndef DISABLE_TLS
+ tls_close(sx->cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
+#endif
+ HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
+ (void)close(sx->cctx.sock);
+ sx->cctx.sock = -1;
+#ifndef DISABLE_EVENT
+ (void) event_raise(addr->transport->event_action,
+ US"tcp:close", NULL);
+#endif
+ addr->address = main_address;
+ addr->transport_return = PENDING_DEFER;
+ sx->first_addr = sx->sync_addr = addr;
+ sx->ok = FALSE;
+ sx->send_rset = TRUE;
+ sx->completed_addr = FALSE;
+ goto tls_retry_connection;
+ case DEFER: /* 4xx response to random */
+ break; /* Just to be clear. ccache_unknown, !done. */
+ }
+
+ /* Re-setup for main verify, or for the error message when failing */
+ addr->address = main_address;
+ addr->transport_return = PENDING_DEFER;
+ sx->first_addr = sx->sync_addr = addr;
+ sx->ok = FALSE;
+ sx->send_rset = TRUE;
+ sx->completed_addr = FALSE;
+ }
+ else
+ done = TRUE;
+
+ /* Main verify. For rcpt-verify use SIZE if we know it and we're not cacheing;
+ for sndr-verify never use it. */
+
+ if (done)
+ {
+ if (!(options & vopt_is_recipient && options & vopt_callout_no_cache))
+ sx->avoid_option = OPTION_SIZE;
+
+ done = FALSE;
+ switch(smtp_write_mail_and_rcpt_cmds(sx, &yield))
+ {
+ case 0: switch(addr->transport_return) /* ok so far */
+ {
+ case PENDING_OK: done = TRUE;
+ new_address_record.result = ccache_accept;
+ break;
+ case FAIL: done = TRUE;
+ yield = FAIL;
+ *failure_ptr = US"recipient";
+ new_address_record.result = ccache_reject;
+ break;
+ default: break;
+ }
+ break;
+
+ case -1: /* MAIL response error */
+ *failure_ptr = US"mail";
+ if (errno == 0 && sx->buffer[0] == '5')
+ {
+ setflag(addr, af_verify_nsfail);
+ if (from_address[0] == 0)
+ new_domain_record.result = ccache_reject_mfnull;
+ }
+ break;
+ /* non-MAIL read i/o error */
+ /* non-MAIL response timeout */
+ /* internal error; channel still usable */
+ default: break; /* transmit failed */
+ }
+ }
+
+ addr->auth_sndr = client_authenticated_sender;
+
+ deliver_host = deliver_host_address = NULL;
+ deliver_domain = save_deliver_domain;
+
+ /* Do postmaster check if requested; if a full check is required, we
+ check for RCPT TO:<postmaster> (no domain) in accordance with RFC 821. */
+
+ if (done && pm_mailfrom)
+ {
+ /* Could possibly shift before main verify, just above, and be ok
+ for cutthrough. But no way to handle a subsequent rcpt, so just
+ refuse any */
+ cancel_cutthrough_connection(TRUE, US"postmaster verify");
+ HDEBUG(D_acl|D_v) debug_printf_indent("Cutthrough cancelled by presence of postmaster verify\n");
+
+ done = smtp_write_command(sx, SCMD_FLUSH, "RSET\r\n") >= 0
+ && smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', callout);
+
+ if (done)
+ {
+ uschar * main_address = addr->address;
+
+ /*XXX oops, affixes */
+ addr->address = string_sprintf("postmaster@%.1000s", addr->domain);
+ addr->transport_return = PENDING_DEFER;
+
+ sx->from_addr = pm_mailfrom;
+ sx->first_addr = sx->sync_addr = addr;
+ sx->ok = FALSE;
+ sx->send_rset = TRUE;
+ sx->completed_addr = FALSE;
+ sx->avoid_option = OPTION_SIZE;
+
+ if( smtp_write_mail_and_rcpt_cmds(sx, &yield) == 0
+ && addr->transport_return == PENDING_OK
+ )
+ done = TRUE;
+ else
+ done = (options & vopt_callout_fullpm) != 0
+ && smtp_write_command(sx, SCMD_FLUSH,
+ "RCPT TO:<postmaster>\r\n") >= 0
+ && smtp_read_response(sx, sx->buffer,
+ sizeof(sx->buffer), '2', callout);
+
+ /* Sort out the cache record */
+
+ new_domain_record.postmaster_stamp = time(NULL);
+
+ if (done)
+ new_domain_record.postmaster_result = ccache_accept;
+ else if (errno == 0 && sx->buffer[0] == '5')
+ {
+ *failure_ptr = US"postmaster";
+ setflag(addr, af_verify_pmfail);
+ new_domain_record.postmaster_result = ccache_reject;
+ }
+
+ addr->address = main_address;
+ }
+ }
+ /* For any failure of the main check, other than a negative response, we just
+ close the connection and carry on. We can identify a negative response by the
+ fact that errno is zero. For I/O errors it will be non-zero
+
+ Set up different error texts for logging and for sending back to the caller
+ as an SMTP response. Log in all cases, using a one-line format. For sender
+ callouts, give a full response to the caller, but for recipient callouts,
+ don't give the IP address because this may be an internal host whose identity
+ is not to be widely broadcast. */
+
+no_conn:
+ switch(errno)
+ {
+ case ETIMEDOUT:
+ HDEBUG(D_verify) debug_printf("SMTP timeout\n");
+ sx->send_quit = FALSE;
+ break;
+
+#ifdef SUPPORT_I18N
+ case ERRNO_UTF8_FWD:
+ {
+ extern int acl_where; /* src/acl.c */
+ errno = 0;
+ addr->message = US"response to \"EHLO\" did not include SMTPUTF8";
+ addr->user_message = acl_where == ACL_WHERE_RCPT
+ ? US"533 no support for internationalised mailbox name"
+ : US"550 mailbox unavailable";
+ yield = FAIL;
+ done = TRUE;
+ }
+ break;
+#endif
+ case ECONNREFUSED:
+ sx->send_quit = FALSE;
+ break;
+
+ case 0:
+ if (*sx->buffer == 0) Ustrcpy(sx->buffer, US"connection dropped");
+
+ /*XXX test here is ugly; seem to have a split of responsibility for
+ building this message. Need to rationalise. Where is it done
+ before here, and when not?
+ Not == 5xx resp to MAIL on main-verify
+ */
+ if (!addr->message) addr->message =
+ string_sprintf("response to \"%s\" was: %s",
+ big_buffer, string_printing(sx->buffer));
+
+ /* RFC 5321 section 4.2: the text portion of the response may have only
+ HT, SP, Printable US-ASCII. Deal with awkward chars by cutting the
+ received message off before passing it onward. Newlines are ok; they
+ just become a multiline response (but wrapped in the error code we
+ produce). */
+
+ for (uschar * s = sx->buffer;
+ *s && s < sx->buffer + sizeof(sx->buffer);
+ s++)
+ {
+ uschar c = *s;
+ if (c != '\t' && c != '\n' && (c < ' ' || c > '~'))
+ {
+ if (s - sx->buffer < sizeof(sx->buffer) - 12)
+ memcpy(s, "(truncated)", 12);
+ else
+ *s = '\0';
+ break;
+ }
+ }
+ addr->user_message = options & vopt_is_recipient
+ ? string_sprintf("Callout verification failed:\n%s", sx->buffer)
+ : string_sprintf("Called: %s\nSent: %s\nResponse: %s",
+ host->address, big_buffer, sx->buffer);
+
+ /* Hard rejection ends the process */
+
+ if (sx->buffer[0] == '5') /* Address rejected */
+ {
+ yield = FAIL;
+ done = TRUE;
+ }
+ break;
+ }
+
+ /* End the SMTP conversation and close the connection. */
+
+ /* Cutthrough - on a successful connect and recipient-verify with
+ use-sender and we are 1st rcpt and have no cutthrough conn so far
+ here is where we want to leave the conn open. Ditto for a lazy-close
+ verify. */
+
+ if (cutthrough.delivery)
+ {
+ if (addr->transport->filter_command)
+ {
+ cutthrough.delivery= FALSE;
+ HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of transport filter\n");
+ }
+#ifndef DISABLE_DKIM
+ if (ob->dkim.dkim_domain)
+ {
+ cutthrough.delivery= FALSE;
+ HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of DKIM signing\n");
+ }
+#endif
+#ifdef EXPERIMENTAL_ARC
+ if (ob->arc_sign)
+ {
+ cutthrough.delivery= FALSE;
+ HDEBUG(D_acl|D_v) debug_printf("Cutthrough cancelled by presence of ARC signing\n");
+ }
+#endif
+ }
+
+ if ( (cutthrough.delivery || options & vopt_callout_hold)
+ && rcpt_count == 1
+ && done
+ && yield == OK
+ && (options & (vopt_callout_recipsender|vopt_callout_recippmaster|vopt_success_on_redirect))
+ == vopt_callout_recipsender
+ && !random_local_part
+ && !pm_mailfrom
+ && cutthrough.cctx.sock < 0
+ && !sx->lmtp
+ )
+ {
+ HDEBUG(D_acl|D_v) debug_printf_indent("holding verify callout open for %s\n",
+ cutthrough.delivery
+ ? "cutthrough delivery" : "potential further verifies and delivery");
+
+ cutthrough.callout_hold_only = !cutthrough.delivery;
+ cutthrough.is_tls = tls_out.active.sock >= 0;
+ /* We assume no buffer in use in the outblock */
+ cutthrough.cctx = sx->cctx;
+ cutthrough.nrcpt = 1;
+ cutthrough.transport = addr->transport->name;
+ cutthrough.interface = interface;
+ cutthrough.snd_port = sending_port;
+ cutthrough.peer_options = smtp_peer_options;
+ cutthrough.host = *host;
+ {
+ int oldpool = store_pool;
+ store_pool = POOL_PERM;
+ cutthrough.snd_ip = string_copy(sending_ip_address);
+ cutthrough.host.name = string_copy(host->name);
+ cutthrough.host.address = string_copy(host->address);
+ store_pool = oldpool;
+ }
+
+ /* Save the address_item and parent chain for later logging */
+ cutthrough.addr = *addr;
+ cutthrough.addr.next = NULL;
+ cutthrough.addr.host_used = &cutthrough.host;
+ for (address_item * caddr = &cutthrough.addr, * parent = addr->parent;
+ parent;
+ caddr = caddr->parent, parent = parent->parent)
+ *(caddr->parent = store_get(sizeof(address_item), FALSE)) = *parent;
+
+ ctctx.outblock.buffer = ctbuffer;
+ ctctx.outblock.buffersize = sizeof(ctbuffer);
+ ctctx.outblock.ptr = ctbuffer;
+ /* ctctx.outblock.cmd_count = 0; ctctx.outblock.authenticating = FALSE; */
+ ctctx.outblock.cctx = &cutthrough.cctx;
+ }
+ else
+ {
+ /* Ensure no cutthrough on multiple verifies that were incompatible */
+ if (options & vopt_callout_recipsender)
+ cancel_cutthrough_connection(TRUE, US"not usable for cutthrough");
+ if (sx->send_quit)
+ if (smtp_write_command(sx, SCMD_FLUSH, "QUIT\r\n") != -1)
+ /* Wait a short time for response, and discard it */
+ smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', 1);
+
+ if (sx->cctx.sock >= 0)
+ {
+#ifndef DISABLE_TLS
+ if (sx->cctx.tls_ctx)
+ {
+ tls_close(sx->cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
+ sx->cctx.tls_ctx = NULL;
+ }
+#endif
+ HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
+ (void)close(sx->cctx.sock);
+ sx->cctx.sock = -1;
+#ifndef DISABLE_EVENT
+ (void) event_raise(addr->transport->event_action, US"tcp:close", NULL);
+#endif
+ }
+ }
+
+ if (!done || yield != OK)
+ addr->message = string_sprintf("%s [%s] : %s", host->name, host->address,
+ addr->message);
+ } /* Loop through all hosts, while !done */
+ }
+
+/* If we get here with done == TRUE, a successful callout happened, and yield
+will be set OK or FAIL according to the response to the RCPT command.
+Otherwise, we looped through the hosts but couldn't complete the business.
+However, there may be domain-specific information to cache in both cases. */
+
+if (!(options & vopt_callout_no_cache))
+ cache_callout_write(&new_domain_record, addr->domain,
+ done, &new_address_record, address_key);
+
+/* Failure to connect to any host, or any response other than 2xx or 5xx is a
+temporary error. If there was only one host, and a response was received, leave
+it alone if supplying details. Otherwise, give a generic response. */
+
+if (!done)
+ {
+ uschar * dullmsg = string_sprintf("Could not complete %s verify callout",
+ options & vopt_is_recipient ? "recipient" : "sender");
+ yield = DEFER;
+
+ addr->message = host_list->next || !addr->message
+ ? dullmsg : string_sprintf("%s: %s", dullmsg, addr->message);
+
+ addr->user_message = smtp_return_error_details
+ ? string_sprintf("%s for <%s>.\n"
+ "The mail server(s) for the domain may be temporarily unreachable, or\n"
+ "they may be permanently unreachable from this server. In the latter case,\n%s",
+ dullmsg, addr->address,
+ options & vopt_is_recipient
+ ? "the address will never be accepted."
+ : "you need to change the address or create an MX record for its domain\n"
+ "if it is supposed to be generally accessible from the Internet.\n"
+ "Talk to your mail administrator for details.")
+ : dullmsg;
+
+ /* Force a specific error code */
+
+ addr->basic_errno = ERRNO_CALLOUTDEFER;
+ }
+
+/* Come here from within the cache-reading code on fast-track exit. */
+
+END_CALLOUT:
+tls_modify_variables(&tls_in); /* return variables to inbound values */
+return yield;
+}
+
+
+
+/* Called after recipient-acl to get a cutthrough connection open when
+ one was requested and a recipient-verify wasn't subsequently done.
+*/
+int
+open_cutthrough_connection(address_item * addr)
+{
+address_item addr2;
+int rc;
+
+/* Use a recipient-verify-callout to set up the cutthrough connection. */
+/* We must use a copy of the address for verification, because it might
+get rewritten. */
+
+addr2 = *addr;
+HDEBUG(D_acl) debug_printf_indent("----------- %s cutthrough setup ------------\n",
+ rcpt_count > 1 ? "more" : "start");
+rc = verify_address(&addr2, NULL,
+ vopt_is_recipient | vopt_callout_recipsender | vopt_callout_no_cache,
+ CUTTHROUGH_CMD_TIMEOUT, -1, -1,
+ NULL, NULL, NULL);
+addr->message = addr2.message;
+addr->user_message = addr2.user_message;
+HDEBUG(D_acl) debug_printf_indent("----------- end cutthrough setup ------------\n");
+return rc;
+}
+
+
+
+/* Send given number of bytes from the buffer */
+static BOOL
+cutthrough_send(int n)
+{
+if(cutthrough.cctx.sock < 0)
+ return TRUE;
+
+if(
+#ifndef DISABLE_TLS
+ cutthrough.is_tls
+ ? tls_write(cutthrough.cctx.tls_ctx, ctctx.outblock.buffer, n, FALSE)
+ :
+#endif
+ send(cutthrough.cctx.sock, ctctx.outblock.buffer, n, 0) > 0
+ )
+{
+ transport_count += n;
+ ctctx.outblock.ptr= ctctx.outblock.buffer;
+ return TRUE;
+}
+
+HDEBUG(D_transport|D_acl) debug_printf_indent("cutthrough_send failed: %s\n", strerror(errno));
+return FALSE;
+}
+
+
+
+static BOOL
+_cutthrough_puts(uschar * cp, int n)
+{
+while(n--)
+ {
+ if(ctctx.outblock.ptr >= ctctx.outblock.buffer+ctctx.outblock.buffersize)
+ if(!cutthrough_send(ctctx.outblock.buffersize))
+ return FALSE;
+
+ *ctctx.outblock.ptr++ = *cp++;
+ }
+return TRUE;
+}
+
+/* Buffered output of counted data block. Return boolean success */
+static BOOL
+cutthrough_puts(uschar * cp, int n)
+{
+if (cutthrough.cctx.sock < 0) return TRUE;
+if (_cutthrough_puts(cp, n)) return TRUE;
+cancel_cutthrough_connection(TRUE, US"transmit failed");
+return FALSE;
+}
+
+void
+cutthrough_data_puts(uschar * cp, int n)
+{
+if (cutthrough.delivery) (void) cutthrough_puts(cp, n);
+return;
+}
+
+
+static BOOL
+_cutthrough_flush_send(void)
+{
+int n = ctctx.outblock.ptr - ctctx.outblock.buffer;
+
+if(n>0)
+ if(!cutthrough_send(n))
+ return FALSE;
+return TRUE;
+}
+
+
+/* Send out any bufferred output. Return boolean success. */
+BOOL
+cutthrough_flush_send(void)
+{
+if (_cutthrough_flush_send()) return TRUE;
+cancel_cutthrough_connection(TRUE, US"transmit failed");
+return FALSE;
+}
+
+
+static BOOL
+cutthrough_put_nl(void)
+{
+return cutthrough_puts(US"\r\n", 2);
+}
+
+
+void
+cutthrough_data_put_nl(void)
+{
+cutthrough_data_puts(US"\r\n", 2);
+}
+
+
+/* Get and check response from cutthrough target */
+static uschar
+cutthrough_response(client_conn_ctx * cctx, char expect, uschar ** copy, int timeout)
+{
+smtp_context sx = {0};
+uschar inbuffer[4096];
+uschar responsebuffer[4096];
+
+sx.inblock.buffer = inbuffer;
+sx.inblock.buffersize = sizeof(inbuffer);
+sx.inblock.ptr = inbuffer;
+sx.inblock.ptrend = inbuffer;
+sx.inblock.cctx = cctx;
+if(!smtp_read_response(&sx, responsebuffer, sizeof(responsebuffer), expect, timeout))
+ cancel_cutthrough_connection(TRUE, US"target timeout on read");
+
+if(copy)
+ {
+ uschar * cp;
+ *copy = cp = string_copy(responsebuffer);
+ /* Trim the trailing end of line */
+ cp += Ustrlen(responsebuffer);
+ if(cp > *copy && cp[-1] == '\n') *--cp = '\0';
+ if(cp > *copy && cp[-1] == '\r') *--cp = '\0';
+ }
+
+return responsebuffer[0];
+}
+
+
+/* Negotiate dataphase with the cutthrough target, returning success boolean */
+BOOL
+cutthrough_predata(void)
+{
+if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
+ return FALSE;
+
+HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> DATA\n");
+cutthrough_puts(US"DATA\r\n", 6);
+cutthrough_flush_send();
+
+/* Assume nothing buffered. If it was it gets ignored. */
+return cutthrough_response(&cutthrough.cctx, '3', NULL, CUTTHROUGH_DATA_TIMEOUT) == '3';
+}
+
+
+/* tctx arg only to match write_chunk() */
+static BOOL
+cutthrough_write_chunk(transport_ctx * tctx, uschar * s, int len)
+{
+uschar * s2;
+while(s && (s2 = Ustrchr(s, '\n')))
+ {
+ if(!cutthrough_puts(s, s2-s) || !cutthrough_put_nl())
+ return FALSE;
+ s = s2+1;
+ }
+return TRUE;
+}
+
+
+/* Buffered send of headers. Return success boolean. */
+/* Expands newlines to wire format (CR,NL). */
+/* Also sends header-terminating blank line. */
+BOOL
+cutthrough_headers_send(void)
+{
+transport_ctx tctx;
+
+if(cutthrough.cctx.sock < 0 || cutthrough.callout_hold_only)
+ return FALSE;
+
+/* We share a routine with the mainline transport to handle header add/remove/rewrites,
+ but having a separate buffered-output function (for now)
+*/
+HDEBUG(D_acl) debug_printf_indent("----------- start cutthrough headers send -----------\n");
+
+tctx.u.fd = cutthrough.cctx.sock;
+tctx.tblock = cutthrough.addr.transport;
+tctx.addr = &cutthrough.addr;
+tctx.check_string = US".";
+tctx.escape_string = US"..";
+/*XXX check under spool_files_wireformat. Might be irrelevant */
+tctx.options = topt_use_crlf;
+
+if (!transport_headers_send(&tctx, &cutthrough_write_chunk))
+ return FALSE;
+
+HDEBUG(D_acl) debug_printf_indent("----------- done cutthrough headers send ------------\n");
+return TRUE;
+}
+
+
+static void
+close_cutthrough_connection(const uschar * why)
+{
+int fd = cutthrough.cctx.sock;
+if(fd >= 0)
+ {
+ /* We could be sending this after a bunch of data, but that is ok as
+ the only way to cancel the transfer in dataphase is to drop the tcp
+ conn before the final dot.
+ */
+ client_conn_ctx tmp_ctx = cutthrough.cctx;
+ ctctx.outblock.ptr = ctbuffer;
+ HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> QUIT\n");
+ _cutthrough_puts(US"QUIT\r\n", 6); /* avoid recursion */
+ _cutthrough_flush_send();
+ cutthrough.cctx.sock = -1; /* avoid recursion via read timeout */
+ cutthrough.nrcpt = 0; /* permit re-cutthrough on subsequent message */
+
+ /* Wait a short time for response, and discard it */
+ cutthrough_response(&tmp_ctx, '2', NULL, 1);
+
+#ifndef DISABLE_TLS
+ if (cutthrough.is_tls)
+ {
+ tls_close(cutthrough.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT);
+ cutthrough.cctx.tls_ctx = NULL;
+ cutthrough.is_tls = FALSE;
+ }
+#endif
+ HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
+ (void)close(fd);
+ HDEBUG(D_acl) debug_printf_indent("----------- cutthrough shutdown (%s) ------------\n", why);
+ }
+ctctx.outblock.ptr = ctbuffer;
+}
+
+void
+cancel_cutthrough_connection(BOOL close_noncutthrough_verifies, const uschar * why)
+{
+if (cutthrough.delivery || close_noncutthrough_verifies)
+ close_cutthrough_connection(why);
+cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
+}
+
+
+void
+release_cutthrough_connection(const uschar * why)
+{
+if (cutthrough.cctx.sock < 0) return;
+HDEBUG(D_acl) debug_printf_indent("release cutthrough conn: %s\n", why);
+cutthrough.cctx.sock = -1;
+cutthrough.cctx.tls_ctx = NULL;
+cutthrough.delivery = cutthrough.callout_hold_only = FALSE;
+}
+
+
+
+
+/* Have senders final-dot. Send one to cutthrough target, and grab the response.
+ Log an OK response as a transmission.
+ Close the connection.
+ Return smtp response-class digit.
+*/
+uschar *
+cutthrough_finaldot(void)
+{
+uschar res;
+HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> .\n");
+
+/* Assume data finshed with new-line */
+if( !cutthrough_puts(US".", 1)
+ || !cutthrough_put_nl()
+ || !cutthrough_flush_send()
+ )
+ return cutthrough.addr.message;
+
+res = cutthrough_response(&cutthrough.cctx, '2', &cutthrough.addr.message,
+ CUTTHROUGH_DATA_TIMEOUT);
+for (address_item * addr = &cutthrough.addr; addr; addr = addr->next)
+ {
+ addr->message = cutthrough.addr.message;
+ switch(res)
+ {
+ case '2':
+ delivery_log(LOG_MAIN, addr, (int)'>', NULL);
+ close_cutthrough_connection(US"delivered");
+ break;
+
+ case '4':
+ delivery_log(LOG_MAIN, addr, 0,
+ US"tmp-reject from cutthrough after DATA:");
+ break;
+
+ case '5':
+ delivery_log(LOG_MAIN|LOG_REJECT, addr, 0,
+ US"rejected after DATA:");
+ break;
+
+ default:
+ break;
+ }
+ }
+return cutthrough.addr.message;
+}
+
+
+
+/*************************************************
+* Copy error to toplevel address *
+*************************************************/
+
+/* This function is used when a verify fails or defers, to ensure that the
+failure or defer information is in the original toplevel address. This applies
+when an address is redirected to a single new address, and the failure or
+deferral happens to the child address.
+
+Arguments:
+ vaddr the verify address item
+ addr the final address item
+ yield FAIL or DEFER
+
+Returns: the value of YIELD
+*/
+
+static int
+copy_error(address_item *vaddr, address_item *addr, int yield)
+{
+if (addr != vaddr)
+ {
+ vaddr->message = addr->message;
+ vaddr->user_message = addr->user_message;
+ vaddr->basic_errno = addr->basic_errno;
+ vaddr->more_errno = addr->more_errno;
+ vaddr->prop.address_data = addr->prop.address_data;
+ vaddr->prop.variables = NULL;
+ tree_dup((tree_node **)&vaddr->prop.variables, addr->prop.variables);
+ copyflag(vaddr, addr, af_pass_message);
+ }
+return yield;
+}
+
+
+
+
+/**************************************************
+* printf that automatically handles TLS if needed *
+***************************************************/
+
+/* This function is used by verify_address() as a substitute for all fprintf()
+calls; a direct fprintf() will not produce output in a TLS SMTP session, such
+as a response to an EXPN command. smtp_in.c makes smtp_printf available but
+that assumes that we always use the smtp_out FILE* when not using TLS or the
+ssl buffer when we are. Instead we take a FILE* parameter and check to see if
+that is smtp_out; if so, smtp_printf() with TLS support, otherwise regular
+fprintf().
+
+Arguments:
+ f the candidate FILE* to write to
+ format format string
+ ... optional arguments
+
+Returns:
+ nothing
+*/
+
+static void PRINTF_FUNCTION(2,3)
+respond_printf(FILE *f, const char *format, ...)
+{
+va_list ap;
+
+va_start(ap, format);
+if (smtp_out && (f == smtp_out))
+ smtp_vprintf(format, FALSE, ap);
+else
+ vfprintf(f, format, ap);
+va_end(ap);
+}
+
+
+
+/*************************************************
+* Verify an email address *
+*************************************************/
+
+/* This function is used both for verification (-bv and at other times) and
+address testing (-bt), which is indicated by address_test_mode being set.
+
+Arguments:
+ vaddr contains the address to verify; the next field in this block
+ must be NULL
+ f if not NULL, write the result to this file
+ options various option bits:
+ vopt_fake_sender => this sender verify is not for the real
+ sender (it was verify=sender=xxxx or an address from a
+ header line) - rewriting must not change sender_address
+ vopt_is_recipient => this is a recipient address, otherwise
+ it's a sender address - this affects qualification and
+ rewriting and messages from callouts
+ vopt_qualify => qualify an unqualified address; else error
+ vopt_expn => called from SMTP EXPN command
+ vopt_success_on_redirect => when a new address is generated
+ the verification instantly succeeds
+
+ These ones are used by do_callout() -- the options variable
+ is passed to it.
+
+ vopt_callout_fullpm => if postmaster check, do full one
+ vopt_callout_no_cache => don't use callout cache
+ vopt_callout_random => do the "random" thing
+ vopt_callout_recipsender => use real sender for recipient
+ vopt_callout_recippmaster => use postmaster for recipient
+
+ callout if > 0, specifies that callout is required, and gives timeout
+ for individual commands
+ callout_overall if > 0, gives overall timeout for the callout function;
+ if < 0, a default is used (see do_callout())
+ callout_connect the connection timeout for callouts
+ se_mailfrom when callout is requested to verify a sender, use this
+ in MAIL FROM; NULL => ""
+ pm_mailfrom when callout is requested, if non-NULL, do the postmaster
+ thing and use this as the sender address (may be "")
+
+ routed if not NULL, set TRUE if routing succeeded, so we can
+ distinguish between routing failed and callout failed
+
+Returns: OK address verified
+ FAIL address failed to verify
+ DEFER can't tell at present
+*/
+
+int
+verify_address(address_item * vaddr, FILE * fp, int options, int callout,
+ int callout_overall, int callout_connect, uschar * se_mailfrom,
+ uschar *pm_mailfrom, BOOL *routed)
+{
+BOOL allok = TRUE;
+BOOL full_info = fp ? debug_selector != 0 : FALSE;
+BOOL expn = (options & vopt_expn) != 0;
+BOOL success_on_redirect = (options & vopt_success_on_redirect) != 0;
+int i;
+int yield = OK;
+int verify_type = expn? v_expn :
+ f.address_test_mode? v_none :
+ options & vopt_is_recipient? v_recipient : v_sender;
+address_item *addr_list;
+address_item *addr_new = NULL;
+address_item *addr_remote = NULL;
+address_item *addr_local = NULL;
+address_item *addr_succeed = NULL;
+uschar **failure_ptr = options & vopt_is_recipient
+ ? &recipient_verify_failure : &sender_verify_failure;
+uschar *ko_prefix, *cr;
+uschar *address = vaddr->address;
+uschar *save_sender;
+uschar null_sender[] = { 0 }; /* Ensure writeable memory */
+
+/* Clear, just in case */
+
+*failure_ptr = NULL;
+
+/* Set up a prefix and suffix for error message which allow us to use the same
+output statements both in EXPN mode (where an SMTP response is needed) and when
+debugging with an output file. */
+
+if (expn)
+ {
+ ko_prefix = US"553 ";
+ cr = US"\r";
+ }
+else ko_prefix = cr = US"";
+
+/* Add qualify domain if permitted; otherwise an unqualified address fails. */
+
+if (parse_find_at(address) == NULL)
+ {
+ if (!(options & vopt_qualify))
+ {
+ if (fp)
+ respond_printf(fp, "%sA domain is required for \"%s\"%s\n",
+ ko_prefix, address, cr);
+ *failure_ptr = US"qualify";
+ return FAIL;
+ }
+ /* deconst ok as address was not const */
+ address = US rewrite_address_qualify(address, options & vopt_is_recipient);
+ }
+
+DEBUG(D_verify)
+ {
+ debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ debug_printf("%s %s\n", f.address_test_mode? "Testing" : "Verifying", address);
+ }
+
+/* Rewrite and report on it. Clear the domain and local part caches - these
+may have been set by domains and local part tests during an ACL. */
+
+if (global_rewrite_rules)
+ {
+ uschar *old = address;
+ /* deconst ok as address was not const */
+ address = US rewrite_address(address, options & vopt_is_recipient, FALSE,
+ global_rewrite_rules, rewrite_existflags);
+ if (address != old)
+ {
+ for (int i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->localpart_cache[i] = 0;
+ for (int i = 0; i < (MAX_NAMED_LIST * 2)/32; i++) vaddr->domain_cache[i] = 0;
+ if (fp && !expn) fprintf(fp, "Address rewritten as: %s\n", address);
+ }
+ }
+
+/* If this is the real sender address, we must update sender_address at
+this point, because it may be referred to in the routers. */
+
+if (!(options & (vopt_fake_sender|vopt_is_recipient)))
+ sender_address = address;
+
+/* If the address was rewritten to <> no verification can be done, and we have
+to return OK. This rewriting is permitted only for sender addresses; for other
+addresses, such rewriting fails. */
+
+if (!address[0]) return OK;
+
+/* Flip the legacy TLS-related variables over to the outbound set in case
+they're used in the context of a transport used by verification. Reset them
+at exit from this routine (so no returns allowed from here on). */
+
+tls_modify_variables(&tls_out);
+
+/* Save a copy of the sender address for re-instating if we change it to <>
+while verifying a sender address (a nice bit of self-reference there). */
+
+save_sender = sender_address;
+
+/* Observability variable for router/transport use */
+
+verify_mode = options & vopt_is_recipient ? US"R" : US"S";
+
+/* Update the address structure with the possibly qualified and rewritten
+address. Set it up as the starting address on the chain of new addresses. */
+
+vaddr->address = address;
+addr_new = vaddr;
+
+/* We need a loop, because an address can generate new addresses. We must also
+cope with generated pipes and files at the top level. (See also the code and
+comment in deliver.c.) However, it is usually the case that the router for
+user's .forward files has its verify flag turned off.
+
+If an address generates more than one child, the loop is used only when
+full_info is set, and this can only be set locally. Remote enquiries just get
+information about the top level address, not anything that it generated. */
+
+while (addr_new)
+ {
+ int rc;
+ address_item *addr = addr_new;
+
+ addr_new = addr->next;
+ addr->next = NULL;
+
+ DEBUG(D_verify)
+ {
+ debug_printf(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
+ debug_printf("Considering %s\n", addr->address);
+ }
+
+ /* Handle generated pipe, file or reply addresses. We don't get these
+ when handling EXPN, as it does only one level of expansion. */
+
+ if (testflag(addr, af_pfr))
+ {
+ allok = FALSE;
+ if (fp)
+ {
+ BOOL allow;
+
+ if (addr->address[0] == '>')
+ {
+ allow = testflag(addr, af_allow_reply);
+ fprintf(fp, "%s -> mail %s", addr->parent->address, addr->address + 1);
+ }
+ else
+ {
+ allow = addr->address[0] == '|'
+ ? testflag(addr, af_allow_pipe) : testflag(addr, af_allow_file);
+ fprintf(fp, "%s -> %s", addr->parent->address, addr->address);
+ }
+
+ if (addr->basic_errno == ERRNO_BADTRANSPORT)
+ fprintf(fp, "\n*** Error in setting up pipe, file, or autoreply:\n"
+ "%s\n", addr->message);
+ else if (allow)
+ fprintf(fp, "\n transport = %s\n", addr->transport->name);
+ else
+ fprintf(fp, " *** forbidden ***\n");
+ }
+ continue;
+ }
+
+ /* Just in case some router parameter refers to it. */
+
+ return_path = addr->prop.errors_address
+ ? addr->prop.errors_address : sender_address;
+
+ /* Split the address into domain and local part, handling the %-hack if
+ necessary, and then route it. While routing a sender address, set
+ $sender_address to <> because that is what it will be if we were trying to
+ send a bounce to the sender. */
+
+ if (routed) *routed = FALSE;
+ if ((rc = deliver_split_address(addr)) == OK)
+ {
+ if (!(options & vopt_is_recipient)) sender_address = null_sender;
+ rc = route_address(addr, &addr_local, &addr_remote, &addr_new,
+ &addr_succeed, verify_type);
+ sender_address = save_sender; /* Put back the real sender */
+ }
+
+ /* If routing an address succeeded, set the flag that remembers, for use when
+ an ACL cached a sender verify (in case a callout fails). Then if routing set
+ up a list of hosts or the transport has a host list, and the callout option
+ is set, and we aren't in a host checking run, do the callout verification,
+ and set another flag that notes that a callout happened. */
+
+ if (rc == OK)
+ {
+ if (routed) *routed = TRUE;
+ if (callout > 0)
+ {
+ transport_instance * tp;
+ host_item * host_list = addr->host_list;
+
+ /* Make up some data for use in the case where there is no remote
+ transport. */
+
+ transport_feedback tf = {
+ .interface = NULL, /* interface (=> any) */
+ .port = US"smtp",
+ .protocol = US"smtp",
+ .hosts = NULL,
+ .helo_data = US"$smtp_active_hostname",
+ .hosts_override = FALSE,
+ .hosts_randomize = FALSE,
+ .gethostbyname = FALSE,
+ .qualify_single = TRUE,
+ .search_parents = FALSE
+ };
+
+ /* If verification yielded a remote transport, we want to use that
+ transport's options, so as to mimic what would happen if we were really
+ sending a message to this address. */
+
+ if ((tp = addr->transport) && !tp->info->local)
+ {
+ (void)(tp->setup)(tp, addr, &tf, 0, 0, NULL);
+
+ /* If the transport has hosts and the router does not, or if the
+ transport is configured to override the router's hosts, we must build a
+ host list of the transport's hosts, and find the IP addresses */
+
+ if (tf.hosts && (!host_list || tf.hosts_override))
+ {
+ uschar *s;
+ const uschar *save_deliver_domain = deliver_domain;
+ uschar *save_deliver_localpart = deliver_localpart;
+
+ host_list = NULL; /* Ignore the router's hosts */
+
+ deliver_domain = addr->domain;
+ deliver_localpart = addr->local_part;
+ s = expand_string(tf.hosts);
+ deliver_domain = save_deliver_domain;
+ deliver_localpart = save_deliver_localpart;
+
+ if (!s)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand list of hosts "
+ "\"%s\" in %s transport for callout: %s", tf.hosts,
+ tp->name, expand_string_message);
+ }
+ else
+ {
+ int flags;
+ host_build_hostlist(&host_list, s, tf.hosts_randomize);
+
+ /* Just ignore failures to find a host address. If we don't manage
+ to find any addresses, the callout will defer. Note that more than
+ one address may be found for a single host, which will result in
+ additional host items being inserted into the chain. Hence we must
+ save the next host first. */
+
+ flags = HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
+ if (tf.qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
+ if (tf.search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
+
+ for (host_item * host = host_list, * nexthost; host; host = nexthost)
+ {
+ nexthost = host->next;
+ if (tf.gethostbyname ||
+ string_is_ip_address(host->name, NULL) != 0)
+ (void)host_find_byname(host, NULL, flags, NULL, TRUE);
+ else
+ {
+ const dnssec_domains * dsp = NULL;
+ if (Ustrcmp(tp->driver_name, "smtp") == 0)
+ {
+ smtp_transport_options_block * ob =
+ (smtp_transport_options_block *) tp->options_block;
+ dsp = &ob->dnssec;
+ }
+
+ (void) host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
+ dsp, NULL, NULL);
+ }
+ }
+ }
+ }
+ }
+
+ /* Can only do a callout if we have at least one host! If the callout
+ fails, it will have set ${sender,recipient}_verify_failure. */
+
+ if (host_list)
+ {
+ HDEBUG(D_verify) debug_printf("Attempting full verification using callout\n");
+ if (host_checking && !f.host_checking_callout)
+ {
+ HDEBUG(D_verify)
+ debug_printf("... callout omitted by default when host testing\n"
+ "(Use -bhc if you want the callouts to happen.)\n");
+ }
+ else
+ {
+#ifndef DISABLE_TLS
+ deliver_set_expansions(addr);
+#endif
+ rc = do_callout(addr, host_list, &tf, callout, callout_overall,
+ callout_connect, options, se_mailfrom, pm_mailfrom);
+#ifndef DISABLE_TLS
+ deliver_set_expansions(NULL);
+#endif
+ }
+ }
+ else
+ {
+ HDEBUG(D_verify) debug_printf("Cannot do callout: neither router nor "
+ "transport provided a host list, or transport is not smtp\n");
+ }
+ }
+ }
+
+ /* Otherwise, any failure is a routing failure */
+
+ else *failure_ptr = US"route";
+
+ /* A router may return REROUTED if it has set up a child address as a result
+ of a change of domain name (typically from widening). In this case we always
+ want to continue to verify the new child. */
+
+ if (rc == REROUTED) continue;
+
+ /* Handle hard failures */
+
+ if (rc == FAIL)
+ {
+ allok = FALSE;
+ if (fp)
+ {
+ address_item *p = addr->parent;
+
+ respond_printf(fp, "%s%s %s", ko_prefix,
+ full_info ? addr->address : address,
+ f.address_test_mode ? "is undeliverable" : "failed to verify");
+ if (!expn && f.admin_user)
+ {
+ if (addr->basic_errno > 0)
+ respond_printf(fp, ": %s", strerror(addr->basic_errno));
+ if (addr->message)
+ respond_printf(fp, ": %s", addr->message);
+ }
+
+ /* Show parents iff doing full info */
+
+ if (full_info) while (p)
+ {
+ respond_printf(fp, "%s\n <-- %s", cr, p->address);
+ p = p->parent;
+ }
+ respond_printf(fp, "%s\n", cr);
+ }
+ cancel_cutthrough_connection(TRUE, US"routing hard fail");
+
+ if (!full_info)
+ {
+ yield = copy_error(vaddr, addr, FAIL);
+ goto out;
+ }
+ yield = FAIL;
+ }
+
+ /* Soft failure */
+
+ else if (rc == DEFER)
+ {
+ allok = FALSE;
+ if (fp)
+ {
+ address_item *p = addr->parent;
+ respond_printf(fp, "%s%s cannot be resolved at this time", ko_prefix,
+ full_info? addr->address : address);
+ if (!expn && f.admin_user)
+ {
+ if (addr->basic_errno > 0)
+ respond_printf(fp, ": %s", strerror(addr->basic_errno));
+ if (addr->message)
+ respond_printf(fp, ": %s", addr->message);
+ else if (addr->basic_errno <= 0)
+ respond_printf(fp, ": unknown error");
+ }
+
+ /* Show parents iff doing full info */
+
+ if (full_info) while (p)
+ {
+ respond_printf(fp, "%s\n <-- %s", cr, p->address);
+ p = p->parent;
+ }
+ respond_printf(fp, "%s\n", cr);
+ }
+ cancel_cutthrough_connection(TRUE, US"routing soft fail");
+
+ if (!full_info)
+ {
+ yield = copy_error(vaddr, addr, DEFER);
+ goto out;
+ }
+ if (yield == OK) yield = DEFER;
+ }
+
+ /* If we are handling EXPN, we do not want to continue to route beyond
+ the top level (whose address is in "address"). */
+
+ else if (expn)
+ {
+ uschar *ok_prefix = US"250-";
+
+ if (!addr_new)
+ if (!addr_local && !addr_remote)
+ respond_printf(fp, "250 mail to <%s> is discarded\r\n", address);
+ else
+ respond_printf(fp, "250 <%s>\r\n", address);
+
+ else do
+ {
+ address_item *addr2 = addr_new;
+ addr_new = addr2->next;
+ if (!addr_new) ok_prefix = US"250 ";
+ respond_printf(fp, "%s<%s>\r\n", ok_prefix, addr2->address);
+ } while (addr_new);
+ yield = OK;
+ goto out;
+ }
+
+ /* Successful routing other than EXPN. */
+
+ else
+ {
+ /* Handle successful routing when short info wanted. Otherwise continue for
+ other (generated) addresses. Short info is the operational case. Full info
+ can be requested only when debug_selector != 0 and a file is supplied.
+
+ There is a conflict between the use of aliasing as an alternate email
+ address, and as a sort of mailing list. If an alias turns the incoming
+ address into just one address (e.g. J.Caesar->jc44) you may well want to
+ carry on verifying the generated address to ensure it is valid when
+ checking incoming mail. If aliasing generates multiple addresses, you
+ probably don't want to do this. Exim therefore treats the generation of
+ just a single new address as a special case, and continues on to verify the
+ generated address. */
+
+ if ( !full_info /* Stop if short info wanted AND */
+ && ( ( !addr_new /* No new address OR */
+ || addr_new->next /* More than one new address OR */
+ || testflag(addr_new, af_pfr) /* New address is pfr */
+ )
+ || /* OR */
+ ( addr_new /* At least one new address AND */
+ && success_on_redirect /* success_on_redirect is set */
+ ) )
+ )
+ {
+ if (fp) fprintf(fp, "%s %s\n",
+ address, f.address_test_mode ? "is deliverable" : "verified");
+
+ /* If we have carried on to verify a child address, we want the value
+ of $address_data to be that of the child */
+
+ vaddr->prop.address_data = addr->prop.address_data;
+ vaddr->prop.variables = NULL;
+ tree_dup((tree_node **)&vaddr->prop.variables, addr->prop.variables);
+
+ /* If stopped because more than one new address, cannot cutthrough */
+
+ if (addr_new && addr_new->next)
+ cancel_cutthrough_connection(TRUE, US"multiple addresses from routing");
+
+ yield = OK;
+ goto out;
+ }
+ }
+ } /* Loop for generated addresses */
+
+/* Display the full results of the successful routing, including any generated
+addresses. Control gets here only when full_info is set, which requires fp not
+to be NULL, and this occurs only when a top-level verify is called with the
+debugging switch on.
+
+If there are no local and no remote addresses, and there were no pipes, files,
+or autoreplies, and there were no errors or deferments, the message is to be
+discarded, usually because of the use of :blackhole: in an alias file. */
+
+if (allok && !addr_local && !addr_remote)
+ {
+ fprintf(fp, "mail to %s is discarded\n", address);
+ goto out;
+ }
+
+for (addr_list = addr_local, i = 0; i < 2; addr_list = addr_remote, i++)
+ while (addr_list)
+ {
+ address_item *addr = addr_list;
+ transport_instance * tp = addr->transport;
+
+ addr_list = addr->next;
+
+ fprintf(fp, "%s", CS addr->address);
+#ifdef EXPERIMENTAL_SRS
+ if(addr->prop.srs_sender)
+ fprintf(fp, " [srs = %s]", addr->prop.srs_sender);
+#endif
+
+ /* If the address is a duplicate, show something about it. */
+
+ if (!testflag(addr, af_pfr))
+ {
+ tree_node *tnode;
+ if ((tnode = tree_search(tree_duplicates, addr->unique)))
+ fprintf(fp, " [duplicate, would not be delivered]");
+ else tree_add_duplicate(addr->unique, addr);
+ }
+
+ /* Now show its parents */
+
+ for (address_item * p = addr->parent; p; p = p->parent)
+ fprintf(fp, "\n <-- %s", p->address);
+ fprintf(fp, "\n ");
+
+ /* Show router, and transport */
+
+ fprintf(fp, "router = %s, transport = %s\n",
+ addr->router->name, tp ? tp->name : US"unset");
+
+ /* Show any hosts that are set up by a router unless the transport
+ is going to override them; fiddle a bit to get a nice format. */
+
+ if (addr->host_list && tp && !tp->overrides_hosts)
+ {
+ int maxlen = 0;
+ int maxaddlen = 0;
+ for (host_item * h = addr->host_list; h; h = h->next)
+ { /* get max lengths of host names, addrs */
+ int len = Ustrlen(h->name);
+ if (len > maxlen) maxlen = len;
+ len = h->address ? Ustrlen(h->address) : 7;
+ if (len > maxaddlen) maxaddlen = len;
+ }
+ for (host_item * h = addr->host_list; h; h = h->next)
+ {
+ fprintf(fp, " host %-*s ", maxlen, h->name);
+
+ if (h->address)
+ fprintf(fp, "[%s%-*c", h->address, maxaddlen+1 - Ustrlen(h->address), ']');
+ else if (tp->info->local)
+ fprintf(fp, " %-*s ", maxaddlen, ""); /* Omit [unknown] for local */
+ else
+ fprintf(fp, "[%s%-*c", "unknown", maxaddlen+1 - 7, ']');
+
+ if (h->mx >= 0) fprintf(fp, " MX=%d", h->mx);
+ if (h->port != PORT_NONE) fprintf(fp, " port=%d", h->port);
+ if (f.running_in_test_harness && h->dnssec == DS_YES) fputs(" AD", fp);
+ if (h->status == hstatus_unusable) fputs(" ** unusable **", fp);
+ fputc('\n', fp);
+ }
+ }
+ }
+
+/* Yield will be DEFER or FAIL if any one address has, only for full_info (which is
+the -bv or -bt case). */
+
+out:
+verify_mode = NULL;
+tls_modify_variables(&tls_in); /* return variables to inbound values */
+
+return yield;
+}
+
+
+
+
+/*************************************************
+* Check headers for syntax errors *
+*************************************************/
+
+/* This function checks those header lines that contain addresses, and verifies
+that all the addresses therein are 5322-syntactially correct.
+
+Arguments:
+ msgptr where to put an error message
+
+Returns: OK
+ FAIL
+*/
+
+int
+verify_check_headers(uschar **msgptr)
+{
+uschar *colon, *s;
+int yield = OK;
+
+for (header_line * h = header_list; h && yield == OK; h = h->next)
+ {
+ if (h->type != htype_from &&
+ h->type != htype_reply_to &&
+ h->type != htype_sender &&
+ h->type != htype_to &&
+ h->type != htype_cc &&
+ h->type != htype_bcc)
+ continue;
+
+ colon = Ustrchr(h->text, ':');
+ s = colon + 1;
+ Uskip_whitespace(&s);
+
+ /* Loop for multiple addresses in the header, enabling group syntax. Note
+ that we have to reset this after the header has been scanned. */
+
+ f.parse_allow_group = TRUE;
+
+ while (*s)
+ {
+ uschar *ss = parse_find_address_end(s, FALSE);
+ uschar *recipient, *errmess;
+ int terminator = *ss;
+ int start, end, domain;
+
+ /* Temporarily terminate the string at this point, and extract the
+ operative address within, allowing group syntax. */
+
+ *ss = 0;
+ recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
+ *ss = terminator;
+
+ /* Permit an unqualified address only if the message is local, or if the
+ sending host is configured to be permitted to send them. */
+
+ if (recipient && !domain)
+ {
+ if (h->type == htype_from || h->type == htype_sender)
+ {
+ if (!f.allow_unqualified_sender) recipient = NULL;
+ }
+ else
+ {
+ if (!f.allow_unqualified_recipient) recipient = NULL;
+ }
+ if (!recipient) errmess = US"unqualified address not permitted";
+ }
+
+ /* It's an error if no address could be extracted, except for the special
+ case of an empty address. */
+
+ if (!recipient && Ustrcmp(errmess, "empty address") != 0)
+ {
+ uschar *verb = US"is";
+ uschar *t = ss;
+ uschar *tt = colon;
+ int len;
+
+ /* Arrange not to include any white space at the end in the
+ error message or the header name. */
+
+ while (t > s && isspace(t[-1])) t--;
+ while (tt > h->text && isspace(tt[-1])) tt--;
+
+ /* Add the address that failed to the error message, since in a
+ header with very many addresses it is sometimes hard to spot
+ which one is at fault. However, limit the amount of address to
+ quote - cases have been seen where, for example, a missing double
+ quote in a humungous To: header creates an "address" that is longer
+ than string_sprintf can handle. */
+
+ len = t - s;
+ if (len > 1024)
+ {
+ len = 1024;
+ verb = US"begins";
+ }
+
+ /* deconst cast ok as we're passing a non-const to string_printing() */
+ *msgptr = US string_printing(
+ string_sprintf("%s: failing address in \"%.*s:\" header %s: %.*s",
+ errmess, (int)(tt - h->text), h->text, verb, len, s));
+
+ yield = FAIL;
+ break; /* Out of address loop */
+ }
+
+ /* Advance to the next address */
+
+ s = ss + (terminator ? 1 : 0);
+ Uskip_whitespace(&s);
+ } /* Next address */
+
+ f.parse_allow_group = FALSE;
+ f.parse_found_group = FALSE;
+ } /* Next header unless yield has been set FALSE */
+
+return yield;
+}
+
+
+/*************************************************
+* Check header names for 8-bit characters *
+*************************************************/
+
+/* This function checks for invalid characters in header names. See
+RFC 5322, 2.2. and RFC 6532, 3.
+
+Arguments:
+ msgptr where to put an error message
+
+Returns: OK
+ FAIL
+*/
+
+int
+verify_check_header_names_ascii(uschar **msgptr)
+{
+uschar *colon;
+
+for (header_line * h = header_list; h; h = h->next)
+ {
+ colon = Ustrchr(h->text, ':');
+ for(uschar * s = h->text; s < colon; s++)
+ if ((*s < 33) || (*s > 126))
+ {
+ *msgptr = string_sprintf("Invalid character in header \"%.*s\" found",
+ (int)(colon - h->text), h->text);
+ return FAIL;
+ }
+ }
+return OK;
+}
+
+/*************************************************
+* Check for blind recipients *
+*************************************************/
+
+/* This function checks that every (envelope) recipient is mentioned in either
+the To: or Cc: header lines, thus detecting blind carbon copies.
+
+There are two ways of scanning that could be used: either scan the header lines
+and tick off the recipients, or scan the recipients and check the header lines.
+The original proposed patch did the former, but I have chosen to do the latter,
+because (a) it requires no memory and (b) will use fewer resources when there
+are many addresses in To: and/or Cc: and only one or two envelope recipients.
+
+Arguments: case_sensitive true if case sensitive matching should be used
+Returns: OK if there are no blind recipients
+ FAIL if there is at least one blind recipient
+*/
+
+int
+verify_check_notblind(BOOL case_sensitive)
+{
+for (int i = 0; i < recipients_count; i++)
+ {
+ BOOL found = FALSE;
+ uschar *address = recipients_list[i].address;
+
+ for (header_line * h = header_list; !found && h; h = h->next)
+ {
+ uschar *colon, *s;
+
+ if (h->type != htype_to && h->type != htype_cc) continue;
+
+ colon = Ustrchr(h->text, ':');
+ s = colon + 1;
+ Uskip_whitespace(&s);
+
+ /* Loop for multiple addresses in the header, enabling group syntax. Note
+ that we have to reset this after the header has been scanned. */
+
+ f.parse_allow_group = TRUE;
+
+ while (*s)
+ {
+ uschar * ss = parse_find_address_end(s, FALSE);
+ uschar * recipient, * errmess;
+ int terminator = *ss;
+ int start, end, domain;
+
+ /* Temporarily terminate the string at this point, and extract the
+ operative address within, allowing group syntax. */
+
+ *ss = 0;
+ recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE);
+ *ss = terminator;
+
+ /* If we found a valid recipient that has a domain, compare it with the
+ envelope recipient. Local parts are compared with case-sensitivity
+ according to the routine arg, domains case-insensitively.
+ By comparing from the start with length "domain", we include the "@" at
+ the end, which ensures that we are comparing the whole local part of each
+ address. */
+
+ if (recipient && domain != 0)
+ if ((found = (case_sensitive
+ ? Ustrncmp(recipient, address, domain) == 0
+ : strncmpic(recipient, address, domain) == 0)
+ && strcmpic(recipient + domain, address + domain) == 0))
+ break;
+
+ /* Advance to the next address */
+
+ s = ss + (terminator ? 1:0);
+ Uskip_whitespace(&s);
+ } /* Next address */
+
+ f.parse_allow_group = FALSE;
+ f.parse_found_group = FALSE;
+ } /* Next header (if found is false) */
+
+ if (!found) return FAIL;
+ } /* Next recipient */
+
+return OK;
+}
+
+
+
+/*************************************************
+* Find if verified sender *
+*************************************************/
+
+/* Usually, just a single address is verified as the sender of the message.
+However, Exim can be made to verify other addresses as well (often related in
+some way), and this is useful in some environments. There may therefore be a
+chain of such addresses that have previously been tested. This function finds
+whether a given address is on the chain.
+
+Arguments: the address to be verified
+Returns: pointer to an address item, or NULL
+*/
+
+address_item *
+verify_checked_sender(uschar *sender)
+{
+for (address_item * addr = sender_verified_list; addr; addr = addr->next)
+ if (Ustrcmp(sender, addr->address) == 0) return addr;
+return NULL;
+}
+
+
+
+
+
+/*************************************************
+* Get valid header address *
+*************************************************/
+
+/* Scan the originator headers of the message, looking for an address that
+verifies successfully. RFC 822 says:
+
+ o The "Sender" field mailbox should be sent notices of
+ any problems in transport or delivery of the original
+ messages. If there is no "Sender" field, then the
+ "From" field mailbox should be used.
+
+ o If the "Reply-To" field exists, then the reply should
+ go to the addresses indicated in that field and not to
+ the address(es) indicated in the "From" field.
+
+So we check a Sender field if there is one, else a Reply_to field, else a From
+field. As some strange messages may have more than one of these fields,
+especially if they are resent- fields, check all of them if there is more than
+one.
+
+Arguments:
+ user_msgptr points to where to put a user error message
+ log_msgptr points to where to put a log error message
+ callout timeout for callout check (passed to verify_address())
+ callout_overall overall callout timeout (ditto)
+ callout_connect connect callout timeout (ditto)
+ se_mailfrom mailfrom for verify; NULL => ""
+ pm_mailfrom sender for pm callout check (passed to verify_address())
+ options callout options (passed to verify_address())
+ verrno where to put the address basic_errno
+
+If log_msgptr is set to something without setting user_msgptr, the caller
+normally uses log_msgptr for both things.
+
+Returns: result of the verification attempt: OK, FAIL, or DEFER;
+ FAIL is given if no appropriate headers are found
+*/
+
+int
+verify_check_header_address(uschar **user_msgptr, uschar **log_msgptr,
+ int callout, int callout_overall, int callout_connect, uschar *se_mailfrom,
+ uschar *pm_mailfrom, int options, int *verrno)
+{
+static int header_types[] = { htype_sender, htype_reply_to, htype_from };
+BOOL done = FALSE;
+int yield = FAIL;
+
+for (int i = 0; i < 3 && !done; i++)
+ for (header_line * h = header_list; h != NULL && !done; h = h->next)
+ {
+ int terminator, new_ok;
+ uschar *s, *ss, *endname;
+
+ if (h->type != header_types[i]) continue;
+ s = endname = Ustrchr(h->text, ':') + 1;
+
+ /* Scan the addresses in the header, enabling group syntax. Note that we
+ have to reset this after the header has been scanned. */
+
+ f.parse_allow_group = TRUE;
+
+ while (*s != 0)
+ {
+ address_item *vaddr;
+
+ while (isspace(*s) || *s == ',') s++;
+ if (*s == 0) break; /* End of header */
+
+ ss = parse_find_address_end(s, FALSE);
+
+ /* The terminator is a comma or end of header, but there may be white
+ space preceding it (including newline for the last address). Move back
+ past any white space so we can check against any cached envelope sender
+ address verifications. */
+
+ while (isspace(ss[-1])) ss--;
+ terminator = *ss;
+ *ss = 0;
+
+ HDEBUG(D_verify) debug_printf("verifying %.*s header address %s\n",
+ (int)(endname - h->text), h->text, s);
+
+ /* See if we have already verified this address as an envelope sender,
+ and if so, use the previous answer. */
+
+ vaddr = verify_checked_sender(s);
+
+ if (vaddr != NULL && /* Previously checked */
+ (callout <= 0 || /* No callout needed; OR */
+ vaddr->special_action > 256)) /* Callout was done */
+ {
+ new_ok = vaddr->special_action & 255;
+ HDEBUG(D_verify) debug_printf("previously checked as envelope sender\n");
+ *ss = terminator; /* Restore shortened string */
+ }
+
+ /* Otherwise we run the verification now. We must restore the shortened
+ string before running the verification, so the headers are correct, in
+ case there is any rewriting. */
+
+ else
+ {
+ int start, end, domain;
+ uschar *address = parse_extract_address(s, log_msgptr, &start, &end,
+ &domain, FALSE);
+
+ *ss = terminator;
+
+ /* If we found an empty address, just carry on with the next one, but
+ kill the message. */
+
+ if (!address && Ustrcmp(*log_msgptr, "empty address") == 0)
+ {
+ *log_msgptr = NULL;
+ s = ss;
+ continue;
+ }
+
+ /* If verification failed because of a syntax error, fail this
+ function, and ensure that the failing address gets added to the error
+ message. */
+
+ if (!address)
+ {
+ new_ok = FAIL;
+ while (ss > s && isspace(ss[-1])) ss--;
+ *log_msgptr = string_sprintf("syntax error in '%.*s' header when "
+ "scanning for sender: %s in \"%.*s\"",
+ (int)(endname - h->text), h->text, *log_msgptr, (int)(ss - s), s);
+ yield = FAIL;
+ done = TRUE;
+ break;
+ }
+
+ /* Else go ahead with the sender verification. But it isn't *the*
+ sender of the message, so set vopt_fake_sender to stop sender_address
+ being replaced after rewriting or qualification. */
+
+ else
+ {
+ vaddr = deliver_make_addr(address, FALSE);
+ new_ok = verify_address(vaddr, NULL, options | vopt_fake_sender,
+ callout, callout_overall, callout_connect, se_mailfrom,
+ pm_mailfrom, NULL);
+ }
+ }
+
+ /* We now have the result, either newly found, or cached. If we are
+ giving out error details, set a specific user error. This means that the
+ last of these will be returned to the user if all three fail. We do not
+ set a log message - the generic one below will be used. */
+
+ if (new_ok != OK)
+ {
+ *verrno = vaddr->basic_errno;
+ if (smtp_return_error_details)
+ *user_msgptr = string_sprintf("Rejected after DATA: "
+ "could not verify \"%.*s\" header address\n%s: %s",
+ (int)(endname - h->text), h->text, vaddr->address, vaddr->message);
+ }
+
+ /* Success or defer */
+
+ if (new_ok == OK)
+ {
+ yield = OK;
+ done = TRUE;
+ break;
+ }
+
+ if (new_ok == DEFER) yield = DEFER;
+
+ /* Move on to any more addresses in the header */
+
+ s = ss;
+ } /* Next address */
+
+ f.parse_allow_group = FALSE;
+ f.parse_found_group = FALSE;
+ } /* Next header, unless done */
+ /* Next header type unless done */
+
+if (yield == FAIL && *log_msgptr == NULL)
+ *log_msgptr = US"there is no valid sender in any header line";
+
+if (yield == DEFER && *log_msgptr == NULL)
+ *log_msgptr = US"all attempts to verify a sender in a header line deferred";
+
+return yield;
+}
+
+
+
+
+/*************************************************
+* Get RFC 1413 identification *
+*************************************************/
+
+/* Attempt to get an id from the sending machine via the RFC 1413 protocol. If
+the timeout is set to zero, then the query is not done. There may also be lists
+of hosts and nets which are exempt. To guard against malefactors sending
+non-printing characters which could, for example, disrupt a message's headers,
+make sure the string consists of printing characters only.
+
+Argument:
+ port the port to connect to; usually this is IDENT_PORT (113), but when
+ running in the test harness with -bh a different value is used.
+
+Returns: nothing
+
+Side effect: any received ident value is put in sender_ident (NULL otherwise)
+*/
+
+void
+verify_get_ident(int port)
+{
+client_conn_ctx ident_conn_ctx = {0};
+int host_af, qlen;
+int received_sender_port, received_interface_port, n;
+uschar *p;
+blob early_data;
+uschar buffer[2048];
+
+/* Default is no ident. Check whether we want to do an ident check for this
+host. */
+
+sender_ident = NULL;
+if (rfc1413_query_timeout <= 0 || verify_check_host(&rfc1413_hosts) != OK)
+ return;
+
+DEBUG(D_ident) debug_printf("doing ident callback\n");
+
+/* Set up a connection to the ident port of the remote host. Bind the local end
+to the incoming interface address. If the sender host address is an IPv6
+address, the incoming interface address will also be IPv6. */
+
+host_af = Ustrchr(sender_host_address, ':') == NULL ? AF_INET : AF_INET6;
+if ((ident_conn_ctx.sock = ip_socket(SOCK_STREAM, host_af)) < 0) return;
+
+if (ip_bind(ident_conn_ctx.sock, host_af, interface_address, 0) < 0)
+ {
+ DEBUG(D_ident) debug_printf("bind socket for ident failed: %s\n",
+ strerror(errno));
+ goto END_OFF;
+ }
+
+/* Construct and send the query. */
+
+qlen = snprintf(CS buffer, sizeof(buffer), "%d , %d\r\n",
+ sender_host_port, interface_port);
+early_data.data = buffer;
+early_data.len = qlen;
+
+/*XXX we trust that the query is idempotent */
+if (ip_connect(ident_conn_ctx.sock, host_af, sender_host_address, port,
+ rfc1413_query_timeout, &early_data) < 0)
+ {
+ if (errno == ETIMEDOUT && LOGGING(ident_timeout))
+ log_write(0, LOG_MAIN, "ident connection to %s timed out",
+ sender_host_address);
+ else
+ DEBUG(D_ident) debug_printf("ident connection to %s failed: %s\n",
+ sender_host_address, strerror(errno));
+ goto END_OFF;
+ }
+
+/* Read a response line. We put it into the rest of the buffer, using several
+recv() calls if necessary. */
+
+p = buffer + qlen;
+
+for (;;)
+ {
+ uschar *pp;
+ int count;
+ int size = sizeof(buffer) - (p - buffer);
+
+ if (size <= 0) goto END_OFF; /* Buffer filled without seeing \n. */
+ count = ip_recv(&ident_conn_ctx, p, size, time(NULL) + rfc1413_query_timeout);
+ if (count <= 0) goto END_OFF; /* Read error or EOF */
+
+ /* Scan what we just read, to see if we have reached the terminating \r\n. Be
+ generous, and accept a plain \n terminator as well. The only illegal
+ character is 0. */
+
+ for (pp = p; pp < p + count; pp++)
+ {
+ if (*pp == 0) goto END_OFF; /* Zero octet not allowed */
+ if (*pp == '\n')
+ {
+ if (pp[-1] == '\r') pp--;
+ *pp = 0;
+ goto GOT_DATA; /* Break out of both loops */
+ }
+ }
+
+ /* Reached the end of the data without finding \n. Let the loop continue to
+ read some more, if there is room. */
+
+ p = pp;
+ }
+
+GOT_DATA:
+
+/* We have received a line of data. Check it carefully. It must start with the
+same two port numbers that we sent, followed by data as defined by the RFC. For
+example,
+
+ 12345 , 25 : USERID : UNIX :root
+
+However, the amount of white space may be different to what we sent. In the
+"osname" field there may be several sub-fields, comma separated. The data we
+actually want to save follows the third colon. Some systems put leading spaces
+in it - we discard those. */
+
+if (sscanf(CS buffer + qlen, "%d , %d%n", &received_sender_port,
+ &received_interface_port, &n) != 2 ||
+ received_sender_port != sender_host_port ||
+ received_interface_port != interface_port)
+ goto END_OFF;
+
+p = buffer + qlen + n;
+while(isspace(*p)) p++;
+if (*p++ != ':') goto END_OFF;
+while(isspace(*p)) p++;
+if (Ustrncmp(p, "USERID", 6) != 0) goto END_OFF;
+p += 6;
+while(isspace(*p)) p++;
+if (*p++ != ':') goto END_OFF;
+while (*p != 0 && *p != ':') p++;
+if (*p++ == 0) goto END_OFF;
+while(isspace(*p)) p++;
+if (*p == 0) goto END_OFF;
+
+/* The rest of the line is the data we want. We turn it into printing
+characters when we save it, so that it cannot mess up the format of any logging
+or Received: lines into which it gets inserted. We keep a maximum of 127
+characters. The deconst cast is ok as we fed a nonconst to string_printing() */
+
+sender_ident = US string_printing(string_copyn(p, 127));
+DEBUG(D_ident) debug_printf("sender_ident = %s\n", sender_ident);
+
+END_OFF:
+(void)close(ident_conn_ctx.sock);
+return;
+}
+
+
+
+
+/*************************************************
+* Match host to a single host-list item *
+*************************************************/
+
+/* This function compares a host (name or address) against a single item
+from a host list. The host name gets looked up if it is needed and is not
+already known. The function is called from verify_check_this_host() via
+match_check_list(), which is why most of its arguments are in a single block.
+
+Arguments:
+ arg the argument block (see below)
+ ss the host-list item
+ valueptr where to pass back looked up data, or NULL
+ error for error message when returning ERROR
+
+The block contains:
+ host_name (a) the host name, or
+ (b) NULL, implying use sender_host_name and
+ sender_host_aliases, looking them up if required, or
+ (c) the empty string, meaning that only IP address matches
+ are permitted
+ host_address the host address
+ host_ipv4 the IPv4 address taken from an IPv6 one
+
+Returns: OK matched
+ FAIL did not match
+ DEFER lookup deferred
+ ERROR (a) failed to find the host name or IP address, or
+ (b) unknown lookup type specified, or
+ (c) host name encountered when only IP addresses are
+ being matched
+*/
+
+int
+check_host(void *arg, const uschar *ss, const uschar **valueptr, uschar **error)
+{
+check_host_block *cb = (check_host_block *)arg;
+int mlen = -1;
+int maskoffset;
+BOOL iplookup = FALSE;
+BOOL isquery = FALSE;
+BOOL isiponly = cb->host_name != NULL && cb->host_name[0] == 0;
+const uschar *t;
+uschar * semicolon, * endname, * opts;
+uschar **aliases;
+
+/* Optimize for the special case when the pattern is "*". */
+
+if (*ss == '*' && ss[1] == 0) return OK;
+
+/* If the pattern is empty, it matches only in the case when there is no host -
+this can occur in ACL checking for SMTP input using the -bs option. In this
+situation, the host address is the empty string. */
+
+if (cb->host_address[0] == 0) return (*ss == 0)? OK : FAIL;
+if (*ss == 0) return FAIL;
+
+/* If the pattern is precisely "@" then match against the primary host name,
+provided that host name matching is permitted; if it's "@[]" match against the
+local host's IP addresses. */
+
+if (*ss == '@')
+ if (ss[1] == 0)
+ {
+ if (isiponly) return ERROR;
+ ss = primary_hostname;
+ }
+ else if (Ustrcmp(ss, "@[]") == 0)
+ {
+ for (ip_address_item * ip = host_find_interfaces(); ip; ip = ip->next)
+ if (Ustrcmp(ip->address, cb->host_address) == 0) return OK;
+ return FAIL;
+ }
+
+/* If the pattern is an IP address, optionally followed by a bitmask count, do
+a (possibly masked) comparison with the current IP address. */
+
+if (string_is_ip_address(ss, &maskoffset) != 0)
+ return (host_is_in_net(cb->host_address, ss, maskoffset)? OK : FAIL);
+
+/* The pattern is not an IP address. A common error that people make is to omit
+one component of an IPv4 address, either by accident, or believing that, for
+example, 1.2.3/24 is the same as 1.2.3.0/24, or 1.2.3 is the same as 1.2.3.0,
+which it isn't. (Those applications that do accept 1.2.3 as an IP address
+interpret it as 1.2.0.3 because the final component becomes 16-bit - this is an
+ancient specification.) To aid in debugging these cases, we give a specific
+error if the pattern contains only digits and dots or contains a slash preceded
+only by digits and dots (a slash at the start indicates a file name and of
+course slashes may be present in lookups, but not preceded only by digits and
+dots). */
+
+for (t = ss; isdigit(*t) || *t == '.'; ) t++;
+if (*t == 0 || (*t == '/' && t != ss))
+ {
+ *error = US"malformed IPv4 address or address mask";
+ return ERROR;
+ }
+
+/* See if there is a semicolon in the pattern, separating a searchtype
+prefix. If there is one then check for comma-sep options. */
+
+if ((semicolon = Ustrchr(ss, ';')))
+ if ((opts = Ustrchr(ss, ',')) && opts < semicolon)
+ {
+ endname = opts++;
+ opts = string_copyn(opts, semicolon - opts);
+ }
+ else
+ {
+ endname = semicolon;
+ opts = NULL;
+ }
+
+/* If we are doing an IP address only match, then all lookups must be IP
+address lookups, even if there is no "net-". */
+
+if (isiponly)
+ iplookup = semicolon != NULL;
+
+/* Otherwise, if the item is of the form net[n]-lookup;<file|query> then it is
+a lookup on a masked IP network, in textual form. We obey this code even if we
+have already set iplookup, so as to skip over the "net-" prefix and to set the
+mask length. The net- stuff really only applies to single-key lookups where the
+key is implicit. For query-style lookups the key is specified in the query.
+From release 4.30, the use of net- for query style is no longer needed, but we
+retain it for backward compatibility. */
+
+if (Ustrncmp(ss, "net", 3) == 0 && semicolon)
+ {
+ mlen = 0;
+ for (t = ss + 3; isdigit(*t); t++) mlen = mlen * 10 + *t - '0';
+ if (mlen == 0 && t == ss+3) mlen = -1; /* No mask supplied */
+ iplookup = *t++ == '-';
+ }
+else
+ t = ss;
+
+/* Do the IP address lookup if that is indeed what we have */
+
+if (iplookup)
+ {
+ int insize;
+ int search_type;
+ int incoming[4];
+ void *handle;
+ uschar *filename, *key, *result;
+ uschar buffer[64];
+
+ /* Find the search type */
+
+ search_type = search_findtype(t, endname - t);
+
+ if (search_type < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s",
+ search_error_message);
+
+ /* Adjust parameters for the type of lookup. For a query-style lookup, there
+ is no file name, and the "key" is just the query. For query-style with a file
+ name, we have to fish the file off the start of the query. For a single-key
+ lookup, the key is the current IP address, masked appropriately, and
+ reconverted to text form, with the mask appended. For IPv6 addresses, specify
+ dot separators instead of colons, except when the lookup type is "iplsearch".
+ */
+
+ if (mac_islookup(search_type, lookup_absfilequery))
+ {
+ filename = semicolon + 1;
+ key = filename;
+ while (*key != 0 && !isspace(*key)) key++;
+ filename = string_copyn(filename, key - filename);
+ while (isspace(*key)) key++;
+ }
+ else if (mac_islookup(search_type, lookup_querystyle))
+ {
+ filename = NULL;
+ key = semicolon + 1;
+ }
+ else /* Single-key style */
+ {
+ int sep = (Ustrcmp(lookup_list[search_type]->name, "iplsearch") == 0)?
+ ':' : '.';
+ insize = host_aton(cb->host_address, incoming);
+ host_mask(insize, incoming, mlen);
+ (void)host_nmtoa(insize, incoming, mlen, buffer, sep);
+ key = buffer;
+ filename = semicolon + 1;
+ }
+
+ /* Now do the actual lookup; note that there is no search_close() because
+ of the caching arrangements. */
+
+ if (!(handle = search_open(filename, search_type, 0, NULL, NULL)))
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "%s", search_error_message);
+
+ result = search_find(handle, filename, key, -1, NULL, 0, 0, NULL, opts);
+ if (valueptr) *valueptr = result;
+ return result ? OK : f.search_find_defer ? DEFER: FAIL;
+ }
+
+/* The pattern is not an IP address or network reference of any kind. That is,
+it is a host name pattern. If this is an IP only match, there's an error in the
+host list. */
+
+if (isiponly)
+ {
+ *error = US"cannot match host name in match_ip list";
+ return ERROR;
+ }
+
+/* Check the characters of the pattern to see if they comprise only letters,
+digits, full stops, and hyphens (the constituents of domain names). Allow
+underscores, as they are all too commonly found. Sigh. Also, if
+allow_utf8_domains is set, allow top-bit characters. */
+
+for (t = ss; *t != 0; t++)
+ if (!isalnum(*t) && *t != '.' && *t != '-' && *t != '_' &&
+ (!allow_utf8_domains || *t < 128)) break;
+
+/* If the pattern is a complete domain name, with no fancy characters, look up
+its IP address and match against that. Note that a multi-homed host will add
+items to the chain. */
+
+if (*t == 0)
+ {
+ int rc;
+ host_item h;
+ h.next = NULL;
+ h.name = ss;
+ h.address = NULL;
+ h.mx = MX_NONE;
+
+ /* Using byname rather than bydns here means we cannot determine dnssec
+ status. On the other hand it is unclear how that could be either
+ propagated up or enforced. */
+
+ rc = host_find_byname(&h, NULL, HOST_FIND_QUALIFY_SINGLE, NULL, FALSE);
+ if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
+ {
+ for (host_item * hh = &h; hh; hh = hh->next)
+ if (host_is_in_net(hh->address, cb->host_address, 0)) return OK;
+ return FAIL;
+ }
+ if (rc == HOST_FIND_AGAIN) return DEFER;
+ *error = string_sprintf("failed to find IP address for %s", ss);
+ return ERROR;
+ }
+
+/* Almost all subsequent comparisons require the host name, and can be done
+using the general string matching function. When this function is called for
+outgoing hosts, the name is always given explicitly. If it is NULL, it means we
+must use sender_host_name and its aliases, looking them up if necessary. */
+
+if (cb->host_name) /* Explicit host name given */
+ return match_check_string(cb->host_name, ss, -1, TRUE, TRUE, TRUE,
+ valueptr);
+
+/* Host name not given; in principle we need the sender host name and its
+aliases. However, for query-style lookups, we do not need the name if the
+query does not contain $sender_host_name. From release 4.23, a reference to
+$sender_host_name causes it to be looked up, so we don't need to do the lookup
+on spec. */
+
+if ((semicolon = Ustrchr(ss, ';')))
+ {
+ const uschar * affix, * opts;
+ int partial, affixlen, starflags, id;
+
+ *semicolon = 0;
+ id = search_findtype_partial(ss, &partial, &affix, &affixlen, &starflags,
+ &opts);
+ *semicolon=';';
+
+ if (id < 0) /* Unknown lookup type */
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "%s in host list item \"%s\"",
+ search_error_message, ss);
+ return DEFER;
+ }
+ isquery = mac_islookup(id, lookup_querystyle|lookup_absfilequery);
+ }
+
+if (isquery)
+ {
+ switch(match_check_string(US"", ss, -1, TRUE, TRUE, TRUE, valueptr))
+ {
+ case OK: return OK;
+ case DEFER: return DEFER;
+ default: return FAIL;
+ }
+ }
+
+/* Not a query-style lookup; must ensure the host name is present, and then we
+do a check on the name and all its aliases. */
+
+if (!sender_host_name)
+ {
+ HDEBUG(D_host_lookup)
+ debug_printf("sender host name required, to match against %s\n", ss);
+ if (host_lookup_failed || host_name_lookup() != OK)
+ {
+ *error = string_sprintf("failed to find host name for %s",
+ sender_host_address);;
+ return ERROR;
+ }
+ host_build_sender_fullhost();
+ }
+
+/* Match on the sender host name, using the general matching function */
+
+switch(match_check_string(sender_host_name, ss, -1, TRUE, TRUE, TRUE, valueptr))
+ {
+ case OK: return OK;
+ case DEFER: return DEFER;
+ }
+
+/* If there are aliases, try matching on them. */
+
+aliases = sender_host_aliases;
+while (*aliases)
+ switch(match_check_string(*aliases++, ss, -1, TRUE, TRUE, TRUE, valueptr))
+ {
+ case OK: return OK;
+ case DEFER: return DEFER;
+ }
+return FAIL;
+}
+
+
+
+
+/*************************************************
+* Check a specific host matches a host list *
+*************************************************/
+
+/* This function is passed a host list containing items in a number of
+different formats and the identity of a host. Its job is to determine whether
+the given host is in the set of hosts defined by the list. The host name is
+passed as a pointer so that it can be looked up if needed and not already
+known. This is commonly the case when called from verify_check_host() to check
+an incoming connection. When called from elsewhere the host name should usually
+be set.
+
+This function is now just a front end to match_check_list(), which runs common
+code for scanning a list. We pass it the check_host() function to perform a
+single test.
+
+Arguments:
+ listptr pointer to the host list
+ cache_bits pointer to cache for named lists, or NULL
+ host_name the host name or NULL, implying use sender_host_name and
+ sender_host_aliases, looking them up if required
+ host_address the IP address
+ valueptr if not NULL, data from a lookup is passed back here
+
+Returns: OK if the host is in the defined set
+ FAIL if the host is not in the defined set,
+ DEFER if a data lookup deferred (not a host lookup)
+
+If the host name was needed in order to make a comparison, and could not be
+determined from the IP address, the result is FAIL unless the item
+"+allow_unknown" was met earlier in the list, in which case OK is returned. */
+
+int
+verify_check_this_host(const uschar **listptr, unsigned int *cache_bits,
+ const uschar *host_name, const uschar *host_address, const uschar **valueptr)
+{
+int rc;
+unsigned int *local_cache_bits = cache_bits;
+const uschar *save_host_address = deliver_host_address;
+check_host_block cb = { .host_name = host_name, .host_address = host_address };
+
+if (valueptr) *valueptr = NULL;
+
+/* If the host address starts off ::ffff: it is an IPv6 address in
+IPv4-compatible mode. Find the IPv4 part for checking against IPv4
+addresses. */
+
+cb.host_ipv4 = Ustrncmp(host_address, "::ffff:", 7) == 0
+ ? host_address + 7 : host_address;
+
+/* During the running of the check, put the IP address into $host_address. In
+the case of calls from the smtp transport, it will already be there. However,
+in other calls (e.g. when testing ignore_target_hosts), it won't. Just to be on
+the safe side, any existing setting is preserved, though as I write this
+(November 2004) I can't see any cases where it is actually needed. */
+
+deliver_host_address = host_address;
+rc = match_check_list(
+ listptr, /* the list */
+ 0, /* separator character */
+ &hostlist_anchor, /* anchor pointer */
+ &local_cache_bits, /* cache pointer */
+ check_host, /* function for testing */
+ &cb, /* argument for function */
+ MCL_HOST, /* type of check */
+ (host_address == sender_host_address)?
+ US"host" : host_address, /* text for debugging */
+ valueptr); /* where to pass back data */
+deliver_host_address = save_host_address;
+return rc;
+}
+
+
+
+
+/*************************************************
+* Check the given host item matches a list *
+*************************************************/
+int
+verify_check_given_host(const uschar **listptr, const host_item *host)
+{
+return verify_check_this_host(listptr, NULL, host->name, host->address, NULL);
+}
+
+/*************************************************
+* Check the remote host matches a list *
+*************************************************/
+
+/* This is a front end to verify_check_this_host(), created because checking
+the remote host is a common occurrence. With luck, a good compiler will spot
+the tail recursion and optimize it. If there's no host address, this is
+command-line SMTP input - check against an empty string for the address.
+
+Arguments:
+ listptr pointer to the host list
+
+Returns: the yield of verify_check_this_host(),
+ i.e. OK, FAIL, or DEFER
+*/
+
+int
+verify_check_host(uschar **listptr)
+{
+return verify_check_this_host(CUSS listptr, sender_host_cache, NULL,
+ sender_host_address ? sender_host_address : US"", NULL);
+}
+
+
+
+
+
+/*************************************************
+* Invert an IP address *
+*************************************************/
+
+/* Originally just used for DNS xBL lists, now also used for the
+reverse_ip expansion operator.
+
+Arguments:
+ buffer where to put the answer
+ address the address to invert
+*/
+
+void
+invert_address(uschar *buffer, uschar *address)
+{
+int bin[4];
+uschar *bptr = buffer;
+
+/* If this is an IPv4 address mapped into IPv6 format, adjust the pointer
+to the IPv4 part only. */
+
+if (Ustrncmp(address, "::ffff:", 7) == 0) address += 7;
+
+/* Handle IPv4 address: when HAVE_IPV6 is false, the result of host_aton() is
+always 1. */
+
+if (host_aton(address, bin) == 1)
+ {
+ int x = bin[0];
+ for (int i = 0; i < 4; i++)
+ {
+ sprintf(CS bptr, "%d.", x & 255);
+ while (*bptr) bptr++;
+ x >>= 8;
+ }
+ }
+
+/* Handle IPv6 address. Actually, as far as I know, there are no IPv6 addresses
+in any DNS black lists, and the format in which they will be looked up is
+unknown. This is just a guess. */
+
+#if HAVE_IPV6
+else
+ for (int j = 3; j >= 0; j--)
+ {
+ int x = bin[j];
+ for (int i = 0; i < 8; i++)
+ {
+ sprintf(CS bptr, "%x.", x & 15);
+ while (*bptr) bptr++;
+ x >>= 4;
+ }
+ }
+#endif
+
+/* Remove trailing period -- this is needed so that both arbitrary
+dnsbl keydomains and inverted addresses may be combined with the
+same format string, "%s.%s" */
+
+*(--bptr) = 0;
+}
+
+
+
+/*************************************************
+* Perform a single dnsbl lookup *
+*************************************************/
+
+/* This function is called from verify_check_dnsbl() below. It is also called
+recursively from within itself when domain and domain_txt are different
+pointers, in order to get the TXT record from the alternate domain.
+
+Arguments:
+ domain the outer dnsbl domain
+ domain_txt alternate domain to lookup TXT record on success; when the
+ same domain is to be used, domain_txt == domain (that is,
+ the pointers must be identical, not just the text)
+ keydomain the current keydomain (for debug message)
+ prepend subdomain to lookup (like keydomain, but
+ reversed if IP address)
+ iplist the list of matching IP addresses, or NULL for "any"
+ bitmask true if bitmask matching is wanted
+ match_type condition for 'succeed' result
+ 0 => Any RR in iplist (=)
+ 1 => No RR in iplist (!=)
+ 2 => All RRs in iplist (==)
+ 3 => Some RRs not in iplist (!==)
+ the two bits are defined as MT_NOT and MT_ALL
+ defer_return what to return for a defer
+
+Returns: OK if lookup succeeded
+ FAIL if not
+*/
+
+static int
+one_check_dnsbl(uschar *domain, uschar *domain_txt, uschar *keydomain,
+ uschar *prepend, uschar *iplist, BOOL bitmask, int match_type,
+ int defer_return)
+{
+dns_answer * dnsa = store_get_dns_answer();
+dns_scan dnss;
+tree_node *t;
+dnsbl_cache_block *cb;
+int old_pool = store_pool;
+uschar * query;
+int qlen;
+
+/* Construct the specific query domainname */
+
+query = string_sprintf("%s.%s", prepend, domain);
+if ((qlen = Ustrlen(query)) >= 256)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "dnslist query is too long "
+ "(ignored): %s...", query);
+ return FAIL;
+ }
+
+/* Look for this query in the cache. */
+
+if ( (t = tree_search(dnsbl_cache, query))
+ && (cb = t->data.ptr)->expiry > time(NULL)
+ )
+
+/* Previous lookup was cached */
+
+ {
+ HDEBUG(D_dnsbl) debug_printf("dnslists: using result of previous lookup\n");
+ }
+
+/* If not cached from a previous lookup, we must do a DNS lookup, and
+cache the result in permanent memory. */
+
+else
+ {
+ uint ttl = 3600; /* max TTL for positive cache entries */
+
+ store_pool = POOL_PERM;
+
+ if (t)
+ {
+ HDEBUG(D_dnsbl) debug_printf("cached data found but past valid time; ");
+ }
+
+ else
+ { /* Set up a tree entry to cache the lookup */
+ t = store_get(sizeof(tree_node) + qlen + 1 + 1, is_tainted(query));
+ Ustrcpy(t->name, query);
+ t->data.ptr = cb = store_get(sizeof(dnsbl_cache_block), FALSE);
+ (void)tree_insertnode(&dnsbl_cache, t);
+ }
+
+ /* Do the DNS lookup . */
+
+ HDEBUG(D_dnsbl) debug_printf("new DNS lookup for %s\n", query);
+ cb->rc = dns_basic_lookup(dnsa, query, T_A);
+ cb->text_set = FALSE;
+ cb->text = NULL;
+ cb->rhs = NULL;
+
+ /* If the lookup succeeded, cache the RHS address. The code allows for
+ more than one address - this was for complete generality and the possible
+ use of A6 records. However, A6 records are no longer supported. Leave the code
+ here, just in case.
+
+ Quite apart from one A6 RR generating multiple addresses, there are DNS
+ lists that return more than one A record, so we must handle multiple
+ addresses generated in that way as well.
+
+ Mark the cache entry with the "now" plus the minimum of the address TTLs,
+ or the RFC 2308 negative-cache value from the SOA if none were found. */
+
+ switch (cb->rc)
+ {
+ case DNS_SUCCEED:
+ {
+ dns_address ** addrp = &cb->rhs;
+ dns_address * da;
+ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
+ if (rr->type == T_A && (da = dns_address_from_rr(dnsa, rr)))
+ {
+ *addrp = da;
+ while (da->next) da = da->next;
+ addrp = &da->next;
+ if (ttl > rr->ttl) ttl = rr->ttl;
+ }
+
+ if (cb->rhs)
+ {
+ cb->expiry = time(NULL) + ttl;
+ break;
+ }
+
+ /* If we didn't find any A records, change the return code. This can
+ happen when there is a CNAME record but there are no A records for what
+ it points to. */
+
+ cb->rc = DNS_NODATA;
+ }
+ /*FALLTHROUGH*/
+
+ case DNS_NOMATCH:
+ case DNS_NODATA:
+ {
+ /* Although there already is a neg-cache layer maintained by
+ dns_basic_lookup(), we have a dnslist cache entry allocated and
+ tree-inserted. So we may as well use it. */
+
+ time_t soa_negttl = dns_expire_from_soa(dnsa, T_A);
+ cb->expiry = soa_negttl ? soa_negttl : time(NULL) + ttl;
+ break;
+ }
+
+ default:
+ cb->expiry = time(NULL) + ttl;
+ break;
+ }
+
+ store_pool = old_pool;
+ HDEBUG(D_dnsbl) debug_printf("dnslists: wrote cache entry, ttl=%d\n",
+ (int)(cb->expiry - time(NULL)));
+ }
+
+/* We now have the result of the DNS lookup, either newly done, or cached
+from a previous call. If the lookup succeeded, check against the address
+list if there is one. This may be a positive equality list (introduced by
+"="), a negative equality list (introduced by "!="), a positive bitmask
+list (introduced by "&"), or a negative bitmask list (introduced by "!&").*/
+
+if (cb->rc == DNS_SUCCEED)
+ {
+ dns_address * da = NULL;
+ uschar *addlist = cb->rhs->address;
+
+ /* For A and AAAA records, there may be multiple addresses from multiple
+ records. For A6 records (currently not expected to be used) there may be
+ multiple addresses from a single record. */
+
+ for (da = cb->rhs->next; da; da = da->next)
+ addlist = string_sprintf("%s, %s", addlist, da->address);
+
+ HDEBUG(D_dnsbl) debug_printf("DNS lookup for %s succeeded (yielding %s)\n",
+ query, addlist);
+
+ /* Address list check; this can be either for equality, or via a bitmask.
+ In the latter case, all the bits must match. */
+
+ if (iplist)
+ {
+ for (da = cb->rhs; da; da = da->next)
+ {
+ int ipsep = ',';
+ const uschar *ptr = iplist;
+ uschar *res;
+
+ /* Handle exact matching */
+
+ if (!bitmask)
+ {
+ while ((res = string_nextinlist(&ptr, &ipsep, NULL, 0)))
+ if (Ustrcmp(CS da->address, res) == 0)
+ break;
+ }
+
+ /* Handle bitmask matching */
+
+ else
+ {
+ int address[4];
+ int mask = 0;
+
+ /* At present, all known DNS blocking lists use A records, with
+ IPv4 addresses on the RHS encoding the information they return. I
+ wonder if this will linger on as the last vestige of IPv4 when IPv6
+ is ubiquitous? Anyway, for now we use paranoia code to completely
+ ignore IPv6 addresses. The default mask is 0, which always matches.
+ We change this only for IPv4 addresses in the list. */
+
+ if (host_aton(da->address, address) == 1) mask = address[0];
+
+ /* Scan the returned addresses, skipping any that are IPv6 */
+
+ while ((res = string_nextinlist(&ptr, &ipsep, NULL, 0)))
+ {
+ if (host_aton(res, address) != 1) continue;
+ if ((address[0] & mask) == address[0]) break;
+ }
+ }
+
+ /* If either
+
+ (a) An IP address in an any ('=') list matched, or
+ (b) No IP address in an all ('==') list matched
+
+ then we're done searching. */
+
+ if (((match_type & MT_ALL) != 0) == (res == NULL)) break;
+ }
+
+ /* If da == NULL, either
+
+ (a) No IP address in an any ('=') list matched, or
+ (b) An IP address in an all ('==') list didn't match
+
+ so behave as if the DNSBL lookup had not succeeded, i.e. the host is not on
+ the list. */
+
+ if ((match_type == MT_NOT || match_type == MT_ALL) != (da == NULL))
+ {
+ HDEBUG(D_dnsbl)
+ {
+ uschar *res = NULL;
+ switch(match_type)
+ {
+ case 0:
+ res = US"was no match"; break;
+ case MT_NOT:
+ res = US"was an exclude match"; break;
+ case MT_ALL:
+ res = US"was an IP address that did not match"; break;
+ case MT_NOT|MT_ALL:
+ res = US"were no IP addresses that did not match"; break;
+ }
+ debug_printf("=> but we are not accepting this block class because\n");
+ debug_printf("=> there %s for %s%c%s\n",
+ res,
+ ((match_type & MT_ALL) == 0)? "" : "=",
+ bitmask? '&' : '=', iplist);
+ }
+ return FAIL;
+ }
+ }
+
+ /* Either there was no IP list, or the record matched, implying that the
+ domain is on the list. We now want to find a corresponding TXT record. If an
+ alternate domain is specified for the TXT record, call this function
+ recursively to look that up; this has the side effect of re-checking that
+ there is indeed an A record at the alternate domain. */
+
+ if (domain_txt != domain)
+ return one_check_dnsbl(domain_txt, domain_txt, keydomain, prepend, NULL,
+ FALSE, match_type, defer_return);
+
+ /* If there is no alternate domain, look up a TXT record in the main domain
+ if it has not previously been cached. */
+
+ if (!cb->text_set)
+ {
+ cb->text_set = TRUE;
+ if (dns_basic_lookup(dnsa, query, T_TXT) == DNS_SUCCEED)
+ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
+ if (rr->type == T_TXT)
+ {
+ int len = (rr->data)[0];
+ if (len > 511) len = 127;
+ store_pool = POOL_PERM;
+ cb->text = string_sprintf("%.*s", len, CUS (rr->data+1));
+ store_pool = old_pool;
+ break;
+ }
+ }
+
+ dnslist_value = addlist;
+ dnslist_text = cb->text;
+ return OK;
+ }
+
+/* There was a problem with the DNS lookup */
+
+if (cb->rc != DNS_NOMATCH && cb->rc != DNS_NODATA)
+ {
+ log_write(L_dnslist_defer, LOG_MAIN,
+ "DNS list lookup defer (probably timeout) for %s: %s", query,
+ (defer_return == OK)? US"assumed in list" :
+ (defer_return == FAIL)? US"assumed not in list" :
+ US"returned DEFER");
+ return defer_return;
+ }
+
+/* No entry was found in the DNS; continue for next domain */
+
+HDEBUG(D_dnsbl)
+ {
+ debug_printf("DNS lookup for %s failed\n", query);
+ debug_printf("=> that means %s is not listed at %s\n",
+ keydomain, domain);
+ }
+
+return FAIL;
+}
+
+
+
+
+/*************************************************
+* Check host against DNS black lists *
+*************************************************/
+
+/* This function runs checks against a list of DNS black lists, until one
+matches. Each item on the list can be of the form
+
+ domain=ip-address/key
+
+The domain is the right-most domain that is used for the query, for example,
+blackholes.mail-abuse.org. If the IP address is present, there is a match only
+if the DNS lookup returns a matching IP address. Several addresses may be
+given, comma-separated, for example: x.y.z=127.0.0.1,127.0.0.2.
+
+If no key is given, what is looked up in the domain is the inverted IP address
+of the current client host. If a key is given, it is used to construct the
+domain for the lookup. For example:
+
+ dsn.rfc-ignorant.org/$sender_address_domain
+
+After finding a match in the DNS, the domain is placed in $dnslist_domain, and
+then we check for a TXT record for an error message, and if found, save its
+value in $dnslist_text. We also cache everything in a tree, to optimize
+multiple lookups.
+
+The TXT record is normally looked up in the same domain as the A record, but
+when many lists are combined in a single DNS domain, this will not be a very
+specific message. It is possible to specify a different domain for looking up
+TXT records; this is given before the main domain, comma-separated. For
+example:
+
+ dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \
+ socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3
+
+The caching ensures that only one lookup in dnsbl.sorbs.net is done.
+
+Note: an address for testing RBL is 192.203.178.39
+Note: an address for testing DUL is 192.203.178.4
+Note: a domain for testing RFCI is example.tld.dsn.rfc-ignorant.org
+
+Arguments:
+ where the acl type
+ listptr the domain/address/data list
+ log_msgptr log message on error
+
+Returns: OK successful lookup (i.e. the address is on the list), or
+ lookup deferred after +include_unknown
+ FAIL name not found, or no data found for the given type, or
+ lookup deferred after +exclude_unknown (default)
+ DEFER lookup failure, if +defer_unknown was set
+*/
+
+int
+verify_check_dnsbl(int where, const uschar ** listptr, uschar ** log_msgptr)
+{
+int sep = 0;
+int defer_return = FAIL;
+const uschar *list = *listptr;
+uschar *domain;
+uschar revadd[128]; /* Long enough for IPv6 address */
+
+/* Indicate that the inverted IP address is not yet set up */
+
+revadd[0] = 0;
+
+/* In case this is the first time the DNS resolver is being used. */
+
+dns_init(FALSE, FALSE, FALSE); /*XXX dnssec? */
+
+/* Loop through all the domains supplied, until something matches */
+
+while ((domain = string_nextinlist(&list, &sep, NULL, 0)))
+ {
+ int rc;
+ BOOL bitmask = FALSE;
+ int match_type = 0;
+ uschar *domain_txt;
+ uschar *comma;
+ uschar *iplist;
+ uschar *key;
+
+ HDEBUG(D_dnsbl) debug_printf("dnslists check: %s\n", domain);
+
+ /* Deal with special values that change the behaviour on defer */
+
+ if (domain[0] == '+')
+ {
+ if (strcmpic(domain, US"+include_unknown") == 0) defer_return = OK;
+ else if (strcmpic(domain, US"+exclude_unknown") == 0) defer_return = FAIL;
+ else if (strcmpic(domain, US"+defer_unknown") == 0) defer_return = DEFER;
+ else
+ log_write(0, LOG_MAIN|LOG_PANIC, "unknown item in dnslist (ignored): %s",
+ domain);
+ continue;
+ }
+
+ /* See if there's explicit data to be looked up */
+
+ if ((key = Ustrchr(domain, '/'))) *key++ = 0;
+
+ /* See if there's a list of addresses supplied after the domain name. This is
+ introduced by an = or a & character; if preceded by = we require all matches
+ and if preceded by ! we invert the result. */
+
+ if (!(iplist = Ustrchr(domain, '=')))
+ {
+ bitmask = TRUE;
+ iplist = Ustrchr(domain, '&');
+ }
+
+ if (iplist) /* Found either = or & */
+ {
+ if (iplist > domain && iplist[-1] == '!') /* Handle preceding ! */
+ {
+ match_type |= MT_NOT;
+ iplist[-1] = 0;
+ }
+
+ *iplist++ = 0; /* Terminate domain, move on */
+
+ /* If we found = (bitmask == FALSE), check for == or =& */
+
+ if (!bitmask && (*iplist == '=' || *iplist == '&'))
+ {
+ bitmask = *iplist++ == '&';
+ match_type |= MT_ALL;
+ }
+ }
+
+
+ /* If there is a comma in the domain, it indicates that a second domain for
+ looking up TXT records is provided, before the main domain. Otherwise we must
+ set domain_txt == domain. */
+
+ domain_txt = domain;
+ if ((comma = Ustrchr(domain, ',')))
+ {
+ *comma++ = 0;
+ domain = comma;
+ }
+
+ /* Check that what we have left is a sensible domain name. There is no reason
+ why these domains should in fact use the same syntax as hosts and email
+ domains, but in practice they seem to. However, there is little point in
+ actually causing an error here, because that would no doubt hold up incoming
+ mail. Instead, I'll just log it. */
+
+ for (uschar * s = domain; *s; s++)
+ if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
+ {
+ log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
+ "strange characters - is this right?", domain);
+ break;
+ }
+
+ /* Check the alternate domain if present */
+
+ if (domain_txt != domain) for (uschar * s = domain_txt; *s; s++)
+ if (!isalnum(*s) && *s != '-' && *s != '.' && *s != '_')
+ {
+ log_write(0, LOG_MAIN, "dnslists domain \"%s\" contains "
+ "strange characters - is this right?", domain_txt);
+ break;
+ }
+
+ /* If there is no key string, construct the query by adding the domain name
+ onto the inverted host address, and perform a single DNS lookup. */
+
+ if (!key)
+ {
+ if (where == ACL_WHERE_NOTSMTP_START || where == ACL_WHERE_NOTSMTP)
+ {
+ *log_msgptr = string_sprintf
+ ("cannot test auto-keyed dnslists condition in %s ACL",
+ acl_wherenames[where]);
+ return ERROR;
+ }
+ if (!sender_host_address) return FAIL; /* can never match */
+ if (revadd[0] == 0) invert_address(revadd, sender_host_address);
+ rc = one_check_dnsbl(domain, domain_txt, sender_host_address, revadd,
+ iplist, bitmask, match_type, defer_return);
+ if (rc == OK)
+ {
+ dnslist_domain = string_copy(domain_txt);
+ dnslist_matched = string_copy(sender_host_address);
+ HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
+ sender_host_address, dnslist_domain);
+ }
+ if (rc != FAIL) return rc; /* OK or DEFER */
+ }
+
+ /* If there is a key string, it can be a list of domains or IP addresses to
+ be concatenated with the main domain. */
+
+ else
+ {
+ int keysep = 0;
+ BOOL defer = FALSE;
+ uschar *keydomain;
+ uschar keyrevadd[128];
+
+ while ((keydomain = string_nextinlist(CUSS &key, &keysep, NULL, 0)))
+ {
+ uschar *prepend = keydomain;
+
+ if (string_is_ip_address(keydomain, NULL) != 0)
+ {
+ invert_address(keyrevadd, keydomain);
+ prepend = keyrevadd;
+ }
+
+ rc = one_check_dnsbl(domain, domain_txt, keydomain, prepend, iplist,
+ bitmask, match_type, defer_return);
+ if (rc == OK)
+ {
+ dnslist_domain = string_copy(domain_txt);
+ dnslist_matched = string_copy(keydomain);
+ HDEBUG(D_dnsbl) debug_printf("=> that means %s is listed at %s\n",
+ keydomain, dnslist_domain);
+ return OK;
+ }
+
+ /* If the lookup deferred, remember this fact. We keep trying the rest
+ of the list to see if we get a useful result, and if we don't, we return
+ DEFER at the end. */
+
+ if (rc == DEFER) defer = TRUE;
+ } /* continue with next keystring domain/address */
+
+ if (defer) return DEFER;
+ }
+ } /* continue with next dnsdb outer domain */
+
+return FAIL;
+}
+
+/* vi: aw ai sw=2
+*/
+/* End of verify.c */