1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) The Exim Maintainers 2020 - 2022 */
6 /* Copyright (c) University of Cambridge 1995 - 2018 */
7 /* See the file NOTICE for conditions of use and distribution. */
8 /* SPDX-License-Identifier: GPL-2.0-or-later */
10 /* Functions for finding hosts, either by gethostbyname(), gethostbyaddr(), or
11 directly via the DNS. When IPv6 is supported, getipnodebyname() and
12 getipnodebyaddr() may be used instead of gethostbyname() and gethostbyaddr(),
13 if the newer functions are available. This module also contains various other
14 functions concerned with hosts and addresses, and a random number function,
15 used for randomizing hosts with equal MXs but available for use in other parts
22 /* Static variable for preserving the list of interface addresses in case it is
23 used more than once. */
25 static ip_address_item *local_interface_data = NULL;
28 #ifdef USE_INET_NTOA_FIX
29 /*************************************************
30 * Replacement for broken inet_ntoa() *
31 *************************************************/
33 /* On IRIX systems, gcc uses a different structure passing convention to the
34 native libraries. This causes inet_ntoa() to always yield 0.0.0.0 or
35 255.255.255.255. To get round this, we provide a private version of the
36 function here. It is used only if USE_INET_NTOA_FIX is set, which should happen
37 only when gcc is in use on an IRIX system. Code send to me by J.T. Breitner,
41 as seen in comp.sys.sgi.admin
43 August 2005: Apparently this is also needed for AIX systems; USE_INET_NTOA_FIX
44 should now be set for them as well.
46 Arguments: sa an in_addr structure
47 Returns: pointer to static text string
51 inet_ntoa(struct in_addr sa)
53 static uschar addr[20];
54 sprintf(addr, "%d.%d.%d.%d",
65 /*************************************************
66 * Random number generator *
67 *************************************************/
69 /* This is a simple pseudo-random number generator. It does not have to be
70 very good for the uses to which it is put. When running the regression tests,
71 start with a fixed seed.
73 If you need better, see vaguely_random_number() which is potentially stronger,
74 if a crypto library is available, but might end up just calling this instead.
77 limit: one more than the largest number required
79 Returns: a pseudo-random number in the range 0 to limit-1
83 random_number(int limit)
88 if (f.running_in_test_harness)
92 int p = (int)getpid();
93 random_seed = (int)time(NULL) ^ ((p << 16) | p);
95 random_seed = 1103515245 * random_seed + 12345;
96 return (unsigned int)(random_seed >> 16) % limit;
99 /*************************************************
100 * Wrappers for logging lookup times *
101 *************************************************/
103 /* When the 'slow_lookup_log' variable is enabled, these wrappers will
104 write to the log file all (potential) dns lookups that take more than
105 slow_lookup_log milliseconds
109 log_long_lookup(const uschar * type, const uschar * data, unsigned long msec)
111 log_write(0, LOG_MAIN, "Long %s lookup for '%s': %lu msec",
116 /* returns the current system epoch time in milliseconds. */
120 struct timeval tmp_time;
121 unsigned long seconds, microseconds;
123 gettimeofday(&tmp_time, NULL);
124 seconds = (unsigned long) tmp_time.tv_sec;
125 microseconds = (unsigned long) tmp_time.tv_usec;
126 return seconds*1000 + microseconds/1000;
131 dns_lookup_timerwrap(dns_answer *dnsa, const uschar *name, int type,
132 const uschar **fully_qualified_name)
135 unsigned long time_msec;
137 if (!slow_lookup_log)
138 return dns_lookup(dnsa, name, type, fully_qualified_name);
140 time_msec = get_time_in_ms();
141 retval = dns_lookup(dnsa, name, type, fully_qualified_name);
142 if ((time_msec = get_time_in_ms() - time_msec) > slow_lookup_log)
143 log_long_lookup(dns_text_type(type), name, time_msec);
148 /*************************************************
149 * Replace gethostbyname() when testing *
150 *************************************************/
152 /* This function is called instead of gethostbyname(), gethostbyname2(), or
153 getipnodebyname() when running in the test harness. . It also
154 recognizes an unqualified "localhost" and forces it to the appropriate loopback
155 address. IP addresses are treated as literals. For other names, it uses the DNS
156 to find the host name. In the test harness, this means it will access only the
160 name the host name or a textual IP address
161 af AF_INET or AF_INET6
162 error_num where to put an error code:
163 HOST_NOT_FOUND/TRY_AGAIN/NO_RECOVERY/NO_DATA
165 Returns: a hostent structure or NULL for an error
168 static struct hostent *
169 host_fake_gethostbyname(const uschar *name, int af, int *error_num)
172 int alen = (af == AF_INET)? sizeof(struct in_addr):sizeof(struct in6_addr);
174 int alen = sizeof(struct in_addr);
178 const uschar *lname = name;
181 struct hostent *yield;
182 dns_answer * dnsa = store_get_dns_answer();
186 debug_printf("using host_fake_gethostbyname for %s (%s)\n", name,
187 af == AF_INET ? "IPv4" : "IPv6");
189 /* Handle unqualified "localhost" */
191 if (Ustrcmp(name, "localhost") == 0)
192 lname = af == AF_INET ? US"127.0.0.1" : US"::1";
194 /* Handle a literal IP address */
196 if ((ipa = string_is_ip_address(lname, NULL)) != 0)
197 if ( ipa == 4 && af == AF_INET
198 || ipa == 6 && af == AF_INET6)
201 yield = store_get(sizeof(struct hostent), GET_UNTAINTED);
202 alist = store_get(2 * sizeof(char *), GET_UNTAINTED);
203 adds = store_get(alen, GET_UNTAINTED);
204 yield->h_name = CS name;
205 yield->h_aliases = NULL;
206 yield->h_addrtype = af;
207 yield->h_length = alen;
208 yield->h_addr_list = CSS alist;
210 for (int n = host_aton(lname, x), i = 0; i < n; i++)
213 *adds++ = (y >> 24) & 255;
214 *adds++ = (y >> 16) & 255;
215 *adds++ = (y >> 8) & 255;
221 /* Wrong kind of literal address */
225 *error_num = HOST_NOT_FOUND;
230 /* Handle a host name */
234 int type = af == AF_INET ? T_A:T_AAAA;
235 int rc = dns_lookup_timerwrap(dnsa, lname, type, NULL);
238 lookup_dnssec_authenticated = NULL;
242 case DNS_SUCCEED: break;
243 case DNS_NOMATCH: *error_num = HOST_NOT_FOUND; yield = NULL; goto out;
244 case DNS_NODATA: *error_num = NO_DATA; yield = NULL; goto out;
245 case DNS_AGAIN: *error_num = TRY_AGAIN; yield = NULL; goto out;
247 case DNS_FAIL: *error_num = NO_RECOVERY; yield = NULL; goto out;
250 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
252 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == type)
255 yield = store_get(sizeof(struct hostent), GET_UNTAINTED);
256 alist = store_get((count + 1) * sizeof(char *), GET_UNTAINTED);
257 adds = store_get(count *alen, GET_UNTAINTED);
259 yield->h_name = CS name;
260 yield->h_aliases = NULL;
261 yield->h_addrtype = af;
262 yield->h_length = alen;
263 yield->h_addr_list = CSS alist;
265 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
267 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == type)
271 if (!(da = dns_address_from_rr(dnsa, rr))) break;
273 for (int n = host_aton(da->address, x), i = 0; i < n; i++)
276 *adds++ = (y >> 24) & 255;
277 *adds++ = (y >> 16) & 255;
278 *adds++ = (y >> 8) & 255;
287 store_free_dns_answer(dnsa);
293 /*************************************************
294 * Build chain of host items from list *
295 *************************************************/
297 /* This function builds a chain of host items from a textual list of host
298 names. It does not do any lookups. If randomize is true, the chain is build in
299 a randomized order. There may be multiple groups of independently randomized
300 hosts; they are delimited by a host name consisting of just "+".
303 anchor anchor for the chain
305 randomize TRUE for randomizing
311 host_build_hostlist(host_item **anchor, const uschar *list, BOOL randomize)
314 int fake_mx = MX_NONE; /* This value is actually -1 */
318 if (randomize) fake_mx--; /* Start at -2 for randomizing */
322 while ((name = string_nextinlist(&list, &sep, NULL, 0)))
326 if (name[0] == '+' && name[1] == 0) /* "+" delimits a randomized group */
327 { /* ignore if not randomizing */
328 if (randomize) fake_mx--;
332 h = store_get(sizeof(host_item), GET_UNTAINTED);
337 h->sort_key = randomize ? (-fake_mx)*1000 + random_number(1000) : 0;
338 h->status = hstatus_unknown;
339 h->why = hwhy_unknown;
349 host_item *hh = *anchor;
350 if (h->sort_key < hh->sort_key)
357 while (hh->next && h->sort_key >= hh->next->sort_key)
367 /*************************************************
368 * Get port from a host item's name *
369 *************************************************/
371 /* This function is called when finding the IP address for a host that is in a
372 list of hosts explicitly configured, such as in the manualroute router, or in a
373 fallback hosts list. We see if there is a port specification at the end of the
374 host name, and if so, remove it. A minimum length of 3 is required for the
375 original name; nothing shorter is recognized as having a port.
377 We test for a name ending with a sequence of digits; if preceded by colon we
378 have a port if the character before the colon is ] and the name starts with [
379 or if there are no other colons in the name (i.e. it's not an IPv6 address).
381 Arguments: pointer to the host item
382 Returns: a port number or PORT_NONE
386 host_item_get_port(host_item *h)
390 int len = Ustrlen(h->name);
392 if (len < 3 || (p = h->name + len - 1, !isdigit(*p))) return PORT_NONE;
394 /* Extract potential port number */
399 while (p > h->name + 1 && isdigit(*p))
401 port += (*p-- - '0') * x;
405 /* The smallest value of p at this point is h->name + 1. */
407 if (*p != ':') return PORT_NONE;
409 if (p[-1] == ']' && h->name[0] == '[')
410 h->name = string_copyn(h->name + 1, p - h->name - 2);
411 else if (Ustrchr(h->name, ':') == p)
412 h->name = string_copyn(h->name, p - h->name);
413 else return PORT_NONE;
415 DEBUG(D_route|D_host_lookup) debug_printf("host=%s port=%d\n", h->name, port);
421 #ifndef STAND_ALONE /* Omit when standalone testing */
423 /*************************************************
424 * Build sender_fullhost and sender_rcvhost *
425 *************************************************/
427 /* This function is called when sender_host_name and/or sender_helo_name
428 have been set. Or might have been set - for a local message read off the spool
429 they won't be. In that case, do nothing. Otherwise, set up the fullhost string
432 (a) No sender_host_name or sender_helo_name: "[ip address]"
433 (b) Just sender_host_name: "host_name [ip address]"
434 (c) Just sender_helo_name: "(helo_name) [ip address]" unless helo is IP
435 in which case: "[ip address}"
436 (d) The two are identical: "host_name [ip address]" includes helo = IP
437 (e) The two are different: "host_name (helo_name) [ip address]"
439 If log_incoming_port is set, the sending host's port number is added to the IP
442 This function also builds sender_rcvhost for use in Received: lines, whose
443 syntax is a bit different. This value also includes the RFC 1413 identity.
444 There wouldn't be two different variables if I had got all this right in the
447 Because this data may survive over more than one incoming SMTP message, it has
448 to be in permanent store. However, STARTTLS has to be forgotten and redone
449 on a multi-message conn, so this will be called once per message then. Hence
450 we use malloc, so we can free.
457 host_build_sender_fullhost(void)
459 BOOL show_helo = TRUE;
460 uschar * address, * fullhost, * rcvhost;
464 if (!sender_host_address) return;
466 reset_point = store_mark();
468 /* Set up address, with or without the port. After discussion, it seems that
469 the only format that doesn't cause trouble is [aaaa]:pppp. However, we can't
470 use this directly as the first item for Received: because it ain't an RFC 2822
473 address = string_sprintf("[%s]:%d", sender_host_address, sender_host_port);
474 if (!LOGGING(incoming_port) || sender_host_port <= 0)
475 *(Ustrrchr(address, ':')) = 0;
477 /* If there's no EHLO/HELO data, we can't show it. */
479 if (!sender_helo_name) show_helo = FALSE;
481 /* If HELO/EHLO was followed by an IP literal, it's messy because of two
482 features of IPv6. Firstly, there's the "IPv6:" prefix (Exim is liberal and
483 doesn't require this, for historical reasons). Secondly, IPv6 addresses may not
484 be given in canonical form, so we have to canonicalize them before comparing. As
485 it happens, the code works for both IPv4 and IPv6. */
487 else if (sender_helo_name[0] == '[' &&
488 sender_helo_name[(len=Ustrlen(sender_helo_name))-1] == ']')
493 if (strncmpic(sender_helo_name + 1, US"IPv6:", 5) == 0) offset += 5;
494 if (strncmpic(sender_helo_name + 1, US"IPv4:", 5) == 0) offset += 5;
496 helo_ip = string_copyn(sender_helo_name + offset, len - offset - 1);
498 if (string_is_ip_address(helo_ip, NULL) != 0)
502 uschar ipx[48], ipy[48]; /* large enough for full IPv6 */
504 sizex = host_aton(helo_ip, x);
505 sizey = host_aton(sender_host_address, y);
507 (void)host_nmtoa(sizex, x, -1, ipx, ':');
508 (void)host_nmtoa(sizey, y, -1, ipy, ':');
510 if (strcmpic(ipx, ipy) == 0) show_helo = FALSE;
514 /* Host name is not verified */
516 if (!sender_host_name)
518 uschar *portptr = Ustrstr(address, "]:");
520 int adlen; /* Sun compiler doesn't like ++ in initializers */
522 adlen = portptr ? (++portptr - address) : Ustrlen(address);
523 fullhost = sender_helo_name
524 ? string_sprintf("(%s) %s", sender_helo_name, address)
527 g = string_catn(NULL, address, adlen);
529 if (sender_ident || show_helo || portptr)
532 g = string_catn(g, US" (", 2);
536 g = string_append(g, 2, US"port=", portptr + 1);
539 g = string_append(g, 2,
540 firstptr == g->ptr ? US"helo=" : US" helo=", sender_helo_name);
543 g = string_append(g, 2,
544 firstptr == g->ptr ? US"ident=" : US" ident=", sender_ident);
546 g = string_catn(g, US")", 1);
549 rcvhost = string_from_gstring(g);
552 /* Host name is known and verified. Unless we've already found that the HELO
553 data matches the IP address, compare it with the name. */
557 if (show_helo && strcmpic(sender_host_name, sender_helo_name) == 0)
562 fullhost = string_sprintf("%s (%s) %s", sender_host_name,
563 sender_helo_name, address);
564 rcvhost = sender_ident
565 ? string_sprintf("%s\n\t(%s helo=%s ident=%s)", sender_host_name,
566 address, sender_helo_name, sender_ident)
567 : string_sprintf("%s (%s helo=%s)", sender_host_name,
568 address, sender_helo_name);
572 fullhost = string_sprintf("%s %s", sender_host_name, address);
573 rcvhost = sender_ident
574 ? string_sprintf("%s (%s ident=%s)", sender_host_name, address,
576 : string_sprintf("%s (%s)", sender_host_name, address);
580 sender_fullhost = string_copy_perm(fullhost, TRUE);
581 sender_rcvhost = string_copy_perm(rcvhost, TRUE);
583 store_reset(reset_point);
585 DEBUG(D_host_lookup) debug_printf("sender_fullhost = %s\n", sender_fullhost);
586 DEBUG(D_host_lookup) debug_printf("sender_rcvhost = %s\n", sender_rcvhost);
591 /*************************************************
592 * Build host+ident message *
593 *************************************************/
595 /* Used when logging rejections and various ACL and SMTP incidents. The text
596 return depends on whether sender_fullhost and sender_ident are set or not:
598 no ident, no host => U=unknown
599 no ident, host set => H=sender_fullhost
600 ident set, no host => U=ident
601 ident set, host set => H=sender_fullhost U=ident
604 useflag TRUE if first item to be flagged (H= or U=); if there are two
605 items, the second is always flagged
607 Returns: pointer to an allocated string
611 host_and_ident(BOOL useflag)
615 if (!sender_fullhost)
618 g = string_catn(g, US"U=", 2);
619 g = string_cat(g, sender_ident ? sender_ident : US"unknown");
624 g = string_catn(g, US"H=", 2);
625 g = string_cat(g, sender_fullhost);
626 if (LOGGING(incoming_interface) && interface_address)
627 g = string_fmt_append(g, " I=[%s]:%d", interface_address, interface_port);
629 g = string_fmt_append(g, " U=%s", sender_ident);
631 gstring_release_unused(g);
632 return string_from_gstring(g);
635 #endif /* STAND_ALONE */
640 /*************************************************
641 * Build list of local interfaces *
642 *************************************************/
644 /* This function interprets the contents of the local_interfaces or
645 extra_local_interfaces options, and creates an ip_address_item block for each
646 item on the list. There is no special interpretation of any IP addresses; in
647 particular, 0.0.0.0 and ::0 are returned without modification. If any address
648 includes a port, it is set in the block. Otherwise the port value is set to
653 name the name of the option being expanded
655 Returns: a chain of ip_address_items, each containing to a textual
656 version of an IP address, and a port number (host order) or
657 zero if no port was given with the address
661 host_build_ifacelist(const uschar *list, uschar *name)
665 ip_address_item * yield = NULL, * last = NULL, * next;
667 while ((s = string_nextinlist(&list, &sep, NULL, 0)))
670 int port = host_address_extract_port(s); /* Leaves just the IP address */
672 if (!(ipv = string_is_ip_address(s, NULL)))
673 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Malformed IP address \"%s\" in %s",
676 /* Skip IPv6 addresses if IPv6 is disabled. */
678 if (disable_ipv6 && ipv == 6) continue;
680 /* This use of strcpy() is OK because we have checked that s is a valid IP
681 address above. The field in the ip_address_item is large enough to hold an
684 next = store_get(sizeof(ip_address_item), list);
686 Ustrcpy(next->address, s);
688 next->v6_include_v4 = FALSE;
707 /*************************************************
708 * Find addresses on local interfaces *
709 *************************************************/
711 /* This function finds the addresses of local IP interfaces. These are used
712 when testing for routing to the local host. As the function may be called more
713 than once, the list is preserved in permanent store, pointed to by a static
714 variable, to save doing the work more than once per process.
716 The generic list of interfaces is obtained by calling host_build_ifacelist()
717 for local_interfaces and extra_local_interfaces. This list scanned to remove
718 duplicates (which may exist with different ports - not relevant here). If
719 either of the wildcard IP addresses (0.0.0.0 and ::0) are encountered, they are
720 replaced by the appropriate (IPv4 or IPv6) list of actual local interfaces,
721 obtained from os_find_running_interfaces().
724 Returns: a chain of ip_address_items, each containing to a textual
725 version of an IP address; the port numbers are not relevant
729 /* First, a local subfunction to add an interface to a list in permanent store,
730 but only if there isn't a previous copy of that address on the list. */
732 static ip_address_item *
733 add_unique_interface(ip_address_item *list, ip_address_item *ipa)
735 ip_address_item *ipa2;
736 for (ipa2 = list; ipa2; ipa2 = ipa2->next)
737 if (Ustrcmp(ipa2->address, ipa->address) == 0) return list;
738 ipa2 = store_get_perm(sizeof(ip_address_item), FALSE);
745 /* This is the globally visible function */
748 host_find_interfaces(void)
750 ip_address_item *running_interfaces = NULL;
752 if (!local_interface_data)
754 void *reset_item = store_mark();
755 ip_address_item *dlist = host_build_ifacelist(CUS local_interfaces,
756 US"local_interfaces");
757 ip_address_item *xlist = host_build_ifacelist(CUS extra_local_interfaces,
758 US"extra_local_interfaces");
759 ip_address_item *ipa;
761 if (!dlist) dlist = xlist;
764 for (ipa = dlist; ipa->next; ipa = ipa->next) ;
768 for (ipa = dlist; ipa; ipa = ipa->next)
770 if (Ustrcmp(ipa->address, "0.0.0.0") == 0 ||
771 Ustrcmp(ipa->address, "::0") == 0)
773 BOOL ipv6 = ipa->address[0] == ':';
774 if (!running_interfaces)
775 running_interfaces = os_find_running_interfaces();
776 for (ip_address_item * ipa2 = running_interfaces; ipa2; ipa2 = ipa2->next)
777 if ((Ustrchr(ipa2->address, ':') != NULL) == ipv6)
778 local_interface_data = add_unique_interface(local_interface_data,
783 local_interface_data = add_unique_interface(local_interface_data, ipa);
786 debug_printf("Configured local interface: address=%s", ipa->address);
787 if (ipa->port != 0) debug_printf(" port=%d", ipa->port);
792 store_reset(reset_item);
795 return local_interface_data;
802 /*************************************************
803 * Convert network IP address to text *
804 *************************************************/
806 /* Given an IPv4 or IPv6 address in binary, convert it to a text
807 string and return the result in a piece of new store. The address can
808 either be given directly, or passed over in a sockaddr structure. Note
809 that this isn't the converse of host_aton() because of byte ordering
810 differences. See host_nmtoa() below.
813 type if < 0 then arg points to a sockaddr, else
814 either AF_INET or AF_INET6
815 arg points to a sockaddr if type is < 0, or
816 points to an IPv4 address (32 bits), or
817 points to an IPv6 address (128 bits),
818 in both cases, in network byte order
819 buffer if NULL, the result is returned in gotten store;
820 else points to a buffer to hold the answer
821 portptr points to where to put the port number, if non NULL; only
824 Returns: pointer to character string
828 host_ntoa(int type, const void * arg, uschar * buffer, int * portptr)
832 /* The new world. It is annoying that we have to fish out the address from
833 different places in the block, depending on what kind of address it is. It
834 is also a pain that inet_ntop() returns a const uschar *, whereas the IPv4
835 function inet_ntoa() returns just uschar *, and some picky compilers insist
836 on warning if one assigns a const uschar * to a uschar *. Hence the casts. */
839 uschar addr_buffer[46];
842 int family = ((struct sockaddr *)arg)->sa_family;
843 if (family == AF_INET6)
845 struct sockaddr_in6 *sk = (struct sockaddr_in6 *)arg;
846 yield = US inet_ntop(family, &(sk->sin6_addr), CS addr_buffer,
847 sizeof(addr_buffer));
848 if (portptr) *portptr = ntohs(sk->sin6_port);
852 struct sockaddr_in *sk = (struct sockaddr_in *)arg;
853 yield = US inet_ntop(family, &(sk->sin_addr), CS addr_buffer,
854 sizeof(addr_buffer));
855 if (portptr) *portptr = ntohs(sk->sin_port);
860 yield = US inet_ntop(type, arg, CS addr_buffer, sizeof(addr_buffer));
863 /* If the result is a mapped IPv4 address, show it in V4 format. */
865 if (Ustrncmp(yield, "::ffff:", 7) == 0) yield += 7;
867 #else /* HAVE_IPV6 */
873 yield = US inet_ntoa(((struct sockaddr_in *)arg)->sin_addr);
874 if (portptr) *portptr = ntohs(((struct sockaddr_in *)arg)->sin_port);
877 yield = US inet_ntoa(*((struct in_addr *)arg));
880 /* If there is no buffer, put the string into some new store. */
882 if (!buffer) buffer = store_get(46, GET_UNTAINTED);
884 /* Callers of this function with a non-NULL buffer must ensure that it is
885 large enough to hold an IPv6 address, namely, at least 46 bytes. That's what
886 makes this use of strcpy() OK.
887 If the library returned apparently an apparently tainted string, clean it;
888 we trust IP addresses. */
890 string_format_nt(buffer, 46, "%s", yield);
897 /*************************************************
898 * Convert address text to binary *
899 *************************************************/
901 /* Given the textual form of an IP address, convert it to binary in an
902 array of ints. IPv4 addresses occupy one int; IPv6 addresses occupy 4 ints.
903 The result has the first byte in the most significant byte of the first int. In
904 other words, the result is not in network byte order, but in host byte order.
905 As a result, this is not the converse of host_ntoa(), which expects network
906 byte order. See host_nmtoa() below.
909 address points to the textual address, checked for syntax
910 bin points to an array of 4 ints
912 Returns: the number of ints used
916 host_aton(const uschar * address, int * bin)
921 /* Handle IPv6 address, which may end with an IPv4 address. It may also end
922 with a "scope", introduced by a percent sign. This code is NOT enclosed in #if
923 HAVE_IPV6 in order that IPv6 addresses are recognized even if IPv6 is not
926 if (Ustrchr(address, ':') != NULL)
928 const uschar * p = address;
929 const uschar * component[8];
930 BOOL ipv4_ends = FALSE;
931 int ci = 0, nulloffset = 0, v6count = 8, i;
933 /* If the address starts with a colon, it will start with two colons.
934 Just lose the first one, which will leave a null first component. */
938 /* Split the address into components separated by colons. The input address
939 is supposed to be checked for syntax. There was a case where this was
940 overlooked; to guard against that happening again, check here and crash if
941 there are too many components. */
943 while (*p && *p != '%')
945 int len = Ustrcspn(p, ":%");
946 if (len == 0) nulloffset = ci;
947 if (ci > 7) log_write(0, LOG_MAIN|LOG_PANIC_DIE,
948 "Internal error: invalid IPv6 address \"%s\" passed to host_aton()",
955 /* If the final component contains a dot, it is a trailing v4 address.
956 As the syntax is known to be checked, just set up for a trailing
957 v4 address and restrict the v6 part to 6 components. */
959 if (Ustrchr(component[ci-1], '.') != NULL)
961 address = component[--ci];
967 /* If there are fewer than 6 or 8 components, we have to insert some
968 more empty ones in the middle. */
972 int insert_count = v6count - ci;
973 for (i = v6count-1; i > nulloffset + insert_count; i--)
974 component[i] = component[i - insert_count];
975 while (i > nulloffset) component[i--] = US"";
978 /* Now turn the components into binary in pairs and bung them
979 into the vector of ints. */
981 for (i = 0; i < v6count; i += 2)
982 bin[i/2] = (Ustrtol(component[i], NULL, 16) << 16) +
983 Ustrtol(component[i+1], NULL, 16);
985 /* If there was no terminating v4 component, we are done. */
987 if (!ipv4_ends) return 4;
990 /* Handle IPv4 address */
992 (void)sscanf(CS address, "%d.%d.%d.%d", x, x+1, x+2, x+3);
993 bin[v4offset] = ((uint)x[0] << 24) + (x[1] << 16) + (x[2] << 8) + x[3];
998 /*************************************************
999 * Apply mask to an IP address *
1000 *************************************************/
1002 /* Mask an address held in 1 or 4 ints, with the ms bit in the ms bit of the
1006 count the number of ints
1007 binary points to the ints to be masked
1008 mask the count of ms bits to leave, or -1 if no masking
1014 host_mask(int count, int *binary, int mask)
1016 if (mask < 0) mask = 99999;
1017 for (int i = 0; i < count; i++)
1020 if (mask == 0) wordmask = 0;
1023 wordmask = (uint)(-1) << (32 - mask);
1031 binary[i] &= wordmask;
1038 /*************************************************
1039 * Convert masked IP address in ints to text *
1040 *************************************************/
1042 /* We can't use host_ntoa() because it assumes the binary values are in network
1043 byte order, and these are the result of host_aton(), which puts them in ints in
1044 host byte order. Also, we really want IPv6 addresses to be in a canonical
1045 format, so we output them with no abbreviation. In a number of cases we can't
1046 use the normal colon separator in them because it terminates keys in lsearch
1047 files, so we want to use dot instead. There's an argument that specifies what
1048 to use for IPv6 addresses.
1051 count 1 or 4 (number of ints)
1052 binary points to the ints
1053 mask mask value; if < 0 don't add to result
1054 buffer big enough to hold the result
1055 sep component separator character for IPv6 addresses
1057 Returns: the number of characters placed in buffer, not counting
1062 host_nmtoa(int count, int *binary, int mask, uschar *buffer, int sep)
1065 uschar *tt = buffer;
1070 for (int i = 24; i >= 0; i -= 8)
1071 tt += sprintf(CS tt, "%d.", (j >> i) & 255);
1074 for (int i = 0; i < 4; i++)
1077 tt += sprintf(CS tt, "%04x%c%04x%c", (j >> 16) & 0xffff, sep, j & 0xffff, sep);
1080 tt--; /* lose final separator */
1085 tt += sprintf(CS tt, "/%d", mask);
1091 /* Like host_nmtoa() but: ipv6-only, canonical output, no mask
1094 binary points to the ints
1095 buffer big enough to hold the result
1097 Returns: the number of characters placed in buffer, not counting
1102 ipv6_nmtoa(int * binary, uschar * buffer)
1105 uschar * c = buffer;
1106 uschar * d = NULL; /* shut insufficiently "clever" compiler up */
1108 for (i = 0; i < 4; i++)
1109 { /* expand to text */
1111 c += sprintf(CS c, "%x:%x:", (j >> 16) & 0xffff, j & 0xffff);
1114 for (c = buffer, k = -1, i = 0; i < 8; i++)
1115 { /* find longest 0-group sequence */
1116 if (*c == '0') /* must be "0:" */
1120 while (c[2] == '0') i++, c += 2;
1123 k = i-j; /* length of sequence */
1124 d = s; /* start of sequence */
1127 while (*++c != ':') ;
1131 *--c = '\0'; /* drop trailing colon */
1133 /* debug_printf("%s: D k %d <%s> <%s>\n", __FUNCTION__, k, buffer, buffer + 2*(k+1)); */
1137 if (d == buffer) c--; /* need extra colon */
1138 *d++ = ':'; /* 1st 0 */
1139 while ((*d++ = *c++)) ;
1149 /*************************************************
1150 * Check port for tls_on_connect *
1151 *************************************************/
1153 /* This function checks whether a given incoming port is configured for tls-
1154 on-connect. It is called from the daemon and from inetd handling. If the global
1155 option tls_on_connect is already set, all ports operate this way. Otherwise, we
1156 check the tls_on_connect_ports option for a list of ports.
1158 Argument: a port number
1159 Returns: TRUE or FALSE
1163 host_is_tls_on_connect_port(int port)
1166 const uschar * list = tls_in.on_connect_ports;
1168 if (tls_in.on_connect) return TRUE;
1170 for (uschar * s, * end; s = string_nextinlist(&list, &sep, NULL, 0); )
1171 if (Ustrtol(s, &end, 10) == port)
1179 /*************************************************
1180 * Check whether host is in a network *
1181 *************************************************/
1183 /* This function checks whether a given IP address matches a pattern that
1184 represents either a single host, or a network (using CIDR notation). The caller
1185 of this function must check the syntax of the arguments before calling it.
1188 host string representation of the ip-address to check
1189 net string representation of the network, with optional CIDR mask
1190 maskoffset offset to the / that introduces the mask in the key
1191 zero if there is no mask
1194 TRUE the host is inside the network
1195 FALSE the host is NOT inside the network
1199 host_is_in_net(const uschar *host, const uschar *net, int maskoffset)
1204 int size = host_aton(net, address);
1207 /* No mask => all bits to be checked */
1209 if (maskoffset == 0) mlen = 99999; /* Big number */
1210 else mlen = Uatoi(net + maskoffset + 1);
1212 /* Convert the incoming address to binary. */
1214 insize = host_aton(host, incoming);
1216 /* Convert IPv4 addresses given in IPv6 compatible mode, which represent
1217 connections from IPv4 hosts to IPv6 hosts, that is, addresses of the form
1218 ::ffff:<v4address>, to IPv4 format. */
1220 if (insize == 4 && incoming[0] == 0 && incoming[1] == 0 &&
1221 incoming[2] == 0xffff)
1224 incoming[0] = incoming[3];
1227 /* No match if the sizes don't agree. */
1229 if (insize != size) return FALSE;
1231 /* Else do the masked comparison. */
1233 for (int i = 0; i < size; i++)
1236 if (mlen == 0) mask = 0;
1239 mask = (uint)(-1) << (32 - mlen);
1247 if ((incoming[i] & mask) != (address[i] & mask)) return FALSE;
1255 /*************************************************
1256 * Scan host list for local hosts *
1257 *************************************************/
1259 /* Scan through a chain of addresses and check whether any of them is the
1260 address of an interface on the local machine. If so, remove that address and
1261 any previous ones with the same MX value, and all subsequent ones (which will
1262 have greater or equal MX values) from the chain. Note: marking them as unusable
1263 is NOT the right thing to do because it causes the hosts not to be used for
1264 other domains, for which they may well be correct.
1266 The hosts may be part of a longer chain; we only process those between the
1267 initial pointer and the "last" pointer.
1269 There is also a list of "pseudo-local" host names which are checked against the
1270 host names. Any match causes that host item to be treated the same as one which
1271 matches a local IP address.
1273 If the very first host is a local host, then all MX records had a precedence
1274 greater than or equal to that of the local host. Either there's a problem in
1275 the DNS, or an apparently remote name turned out to be an abbreviation for the
1276 local host. Give a specific return code, and let the caller decide what to do.
1277 Otherwise, give a success code if at least one host address has been found.
1280 host pointer to the first host in the chain
1281 lastptr pointer to pointer to the last host in the chain (may be updated)
1282 removed if not NULL, set TRUE if some local addresses were removed
1286 HOST_FOUND if there is at least one host with an IP address on the chain
1287 and an MX value less than any MX value associated with the
1289 HOST_FOUND_LOCAL if a local host is among the lowest-numbered MX hosts; when
1290 the host addresses were obtained from A records or
1291 gethostbyname(), the MX values are set to -1.
1292 HOST_FIND_FAILED if no valid hosts with set IP addresses were found
1296 host_scan_for_local_hosts(host_item *host, host_item **lastptr, BOOL *removed)
1298 int yield = HOST_FIND_FAILED;
1299 host_item *last = *lastptr;
1300 host_item *prev = NULL;
1303 if (removed != NULL) *removed = FALSE;
1305 if (local_interface_data == NULL) local_interface_data = host_find_interfaces();
1307 for (h = host; h != last->next; h = h->next)
1310 if (hosts_treat_as_local != NULL)
1313 const uschar *save = deliver_domain;
1314 deliver_domain = h->name; /* set $domain */
1315 rc = match_isinlist(string_copylc(h->name), CUSS &hosts_treat_as_local, 0,
1316 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL);
1317 deliver_domain = save;
1318 if (rc == OK) goto FOUND_LOCAL;
1322 /* It seems that on many operating systems, 0.0.0.0 is treated as a synonym
1323 for 127.0.0.1 and refers to the local host. We therefore force it always to
1324 be treated as local. */
1326 if (h->address != NULL)
1328 if (Ustrcmp(h->address, "0.0.0.0") == 0) goto FOUND_LOCAL;
1329 for (ip_address_item * ip = local_interface_data; ip; ip = ip->next)
1330 if (Ustrcmp(h->address, ip->address) == 0) goto FOUND_LOCAL;
1331 yield = HOST_FOUND; /* At least one remote address has been found */
1334 /* Update prev to point to the last host item before any that have
1335 the same MX value as the one we have just considered. */
1337 if (h->next == NULL || h->next->mx != h->mx) prev = h;
1340 return yield; /* No local hosts found: return HOST_FOUND or HOST_FIND_FAILED */
1342 /* A host whose IP address matches a local IP address, or whose name matches
1343 something in hosts_treat_as_local has been found. */
1349 HDEBUG(D_host_lookup) debug_printf((h->mx >= 0)?
1350 "local host has lowest MX\n" :
1351 "local host found for non-MX address\n");
1352 return HOST_FOUND_LOCAL;
1355 HDEBUG(D_host_lookup)
1357 debug_printf("local host in host list - removed hosts:\n");
1358 for (h = prev->next; h != last->next; h = h->next)
1359 debug_printf(" %s %s %d\n", h->name, h->address, h->mx);
1362 if (removed != NULL) *removed = TRUE;
1363 prev->next = last->next;
1371 /*************************************************
1372 * Remove duplicate IPs in host list *
1373 *************************************************/
1375 /* You would think that administrators could set up their DNS records so that
1376 one ended up with a list of unique IP addresses after looking up A or MX
1377 records, but apparently duplication is common. So we scan such lists and
1378 remove the later duplicates. Note that we may get lists in which some host
1379 addresses are not set.
1382 host pointer to the first host in the chain
1383 lastptr pointer to pointer to the last host in the chain (may be updated)
1389 host_remove_duplicates(host_item *host, host_item **lastptr)
1391 while (host != *lastptr)
1393 if (host->address != NULL)
1395 host_item *h = host;
1396 while (h != *lastptr)
1398 if (h->next->address != NULL &&
1399 Ustrcmp(h->next->address, host->address) == 0)
1401 DEBUG(D_host_lookup) debug_printf("duplicate IP address %s (MX=%d) "
1402 "removed\n", host->address, h->next->mx);
1403 if (h->next == *lastptr) *lastptr = h;
1404 h->next = h->next->next;
1409 /* If the last item was removed, host may have become == *lastptr */
1410 if (host != *lastptr) host = host->next;
1417 /*************************************************
1418 * Find sender host name by gethostbyaddr() *
1419 *************************************************/
1421 /* This used to be the only way it was done, but it turns out that not all
1422 systems give aliases for calls to gethostbyaddr() - or one of the modern
1423 equivalents like getipnodebyaddr(). Fortunately, multiple PTR records are rare,
1424 but they can still exist. This function is now used only when a DNS lookup of
1425 the IP address fails, in order to give access to /etc/hosts.
1428 Returns: OK, DEFER, FAIL
1432 host_name_lookup_byaddr(void)
1434 struct hostent * hosts;
1435 struct in_addr addr;
1436 unsigned long time_msec = 0; /* init to quieten dumb static analysis */
1438 if (slow_lookup_log) time_msec = get_time_in_ms();
1440 /* Lookup on IPv6 system */
1443 if (Ustrchr(sender_host_address, ':') != NULL)
1445 struct in6_addr addr6;
1446 if (inet_pton(AF_INET6, CS sender_host_address, &addr6) != 1)
1447 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an "
1448 "IPv6 address", sender_host_address);
1449 #if HAVE_GETIPNODEBYADDR
1450 hosts = getipnodebyaddr(CS &addr6, sizeof(addr6), AF_INET6, &h_errno);
1452 hosts = gethostbyaddr(CS &addr6, sizeof(addr6), AF_INET6);
1457 if (inet_pton(AF_INET, CS sender_host_address, &addr) != 1)
1458 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an "
1459 "IPv4 address", sender_host_address);
1460 #if HAVE_GETIPNODEBYADDR
1461 hosts = getipnodebyaddr(CS &addr, sizeof(addr), AF_INET, &h_errno);
1463 hosts = gethostbyaddr(CS &addr, sizeof(addr), AF_INET);
1467 /* Do lookup on IPv4 system */
1470 addr.s_addr = (S_ADDR_TYPE)inet_addr(CS sender_host_address);
1471 hosts = gethostbyaddr(CS(&addr), sizeof(addr), AF_INET);
1474 if ( slow_lookup_log
1475 && (time_msec = get_time_in_ms() - time_msec) > slow_lookup_log
1477 log_long_lookup(US"gethostbyaddr", sender_host_address, time_msec);
1479 /* Failed to look up the host. */
1483 HDEBUG(D_host_lookup) debug_printf("IP address lookup failed: h_errno=%d\n",
1485 return (h_errno == TRY_AGAIN || h_errno == NO_RECOVERY) ? DEFER : FAIL;
1488 /* It seems there are some records in the DNS that yield an empty name. We
1489 treat this as non-existent. In some operating systems, this is returned as an
1490 empty string; in others as a single dot. */
1492 if (!hosts->h_name || !hosts->h_name[0] || hosts->h_name[0] == '.')
1494 HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an empty name: "
1495 "treated as non-existent host name\n");
1499 /* Copy and lowercase the name, which is in static storage in many systems.
1500 Put it in permanent memory. */
1503 int old_pool = store_pool;
1504 store_pool = POOL_TAINT_PERM; /* names are tainted */
1506 sender_host_name = string_copylc(US hosts->h_name);
1508 /* If the host has aliases, build a copy of the alias list */
1510 if (hosts->h_aliases)
1512 int count = 1; /* need 1 more for terminating NULL */
1515 for (uschar ** aliases = USS hosts->h_aliases; *aliases; aliases++) count++;
1516 store_pool = POOL_PERM;
1517 ptr = sender_host_aliases = store_get(count * sizeof(uschar *), GET_UNTAINTED);
1518 store_pool = POOL_TAINT_PERM;
1520 for (uschar ** aliases = USS hosts->h_aliases; *aliases; aliases++)
1521 *ptr++ = string_copylc(*aliases);
1524 store_pool = old_pool;
1532 /*************************************************
1533 * Find host name for incoming call *
1534 *************************************************/
1536 /* Put the name in permanent store, pointed to by sender_host_name. We also set
1537 up a list of alias names, pointed to by sender_host_alias. The list is
1538 NULL-terminated. The incoming address is in sender_host_address, either in
1539 dotted-quad form for IPv4 or in colon-separated form for IPv6.
1541 This function does a thorough check that the names it finds point back to the
1542 incoming IP address. Any that do not are discarded. Note that this is relied on
1543 by the ACL reverse_host_lookup check.
1545 On some systems, get{host,ipnode}byaddr() appears to do this internally, but
1546 this it not universally true. Also, for release 4.30, this function was changed
1547 to do a direct DNS lookup first, by default[1], because it turns out that that
1548 is the only guaranteed way to find all the aliases on some systems. My
1549 experiments indicate that Solaris gethostbyaddr() gives the aliases for but
1552 [1] The actual order is controlled by the host_lookup_order option.
1555 Returns: OK on success, the answer being placed in the global variable
1556 sender_host_name, with any aliases in a list hung off
1558 FAIL if no host name can be found
1559 DEFER if a temporary error was encountered
1561 The variable host_lookup_msg is set to an empty string on success, or to a
1562 reason for the failure otherwise, in a form suitable for tagging onto an error
1563 message, and also host_lookup_failed is set TRUE if the lookup failed. If there
1564 was a defer, host_lookup_deferred is set TRUE.
1566 Any dynamically constructed string for host_lookup_msg must be in permanent
1567 store, because it might be used for several incoming messages on the same SMTP
1571 host_name_lookup(void)
1575 uschar *save_hostname;
1578 const uschar *list = host_lookup_order;
1579 dns_answer * dnsa = store_get_dns_answer();
1582 sender_host_dnssec = host_lookup_deferred = host_lookup_failed = FALSE;
1584 HDEBUG(D_host_lookup)
1585 debug_printf("looking up host name for %s\n", sender_host_address);
1587 /* For testing the case when a lookup does not complete, we have a special
1588 reserved IP address. */
1590 if (f.running_in_test_harness &&
1591 Ustrcmp(sender_host_address, "99.99.99.99") == 0)
1593 HDEBUG(D_host_lookup)
1594 debug_printf("Test harness: host name lookup returns DEFER\n");
1595 host_lookup_deferred = TRUE;
1599 /* Do lookups directly in the DNS or via gethostbyaddr() (or equivalent), in
1600 the order specified by the host_lookup_order option. */
1602 while ((ordername = string_nextinlist(&list, &sep, NULL, 0)))
1604 if (strcmpic(ordername, US"bydns") == 0)
1606 uschar * name = dns_build_reverse(sender_host_address);
1608 dns_init(FALSE, FALSE, FALSE); /* dnssec ctrl by dns_dnssec_ok glbl */
1609 rc = dns_lookup_timerwrap(dnsa, name, T_PTR, NULL);
1611 /* The first record we come across is used for the name; others are
1612 considered to be aliases. We have to scan twice, in order to find out the
1613 number of aliases. However, if all the names are empty, we will behave as
1614 if failure. (PTR records that yield empty names have been encountered in
1617 if (rc == DNS_SUCCEED)
1619 uschar **aptr = NULL;
1621 int count = 1; /* need 1 more for terminating NULL */
1622 int old_pool = store_pool;
1624 sender_host_dnssec = dns_is_secure(dnsa);
1626 debug_printf("Reverse DNS security status: %s\n",
1627 sender_host_dnssec ? "DNSSEC verified (AD)" : "unverified");
1629 store_pool = POOL_PERM; /* Save names in permanent storage */
1631 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1633 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_PTR)
1636 /* Get store for the list of aliases. For compatibility with
1637 gethostbyaddr, we make an empty list if there are none. */
1639 aptr = sender_host_aliases = store_get(count * sizeof(uschar *), GET_UNTAINTED);
1641 /* Re-scan and extract the names */
1643 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
1645 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == T_PTR)
1647 uschar * s = store_get(ssize, GET_TAINTED); /* names are tainted */
1650 /* If an overlong response was received, the data will have been
1651 truncated and dn_expand may fail. */
1653 if (dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen,
1654 US (rr->data), (DN_EXPAND_ARG4_TYPE)(s), ssize) < 0)
1656 log_write(0, LOG_MAIN, "host name alias list truncated for %s",
1657 sender_host_address);
1661 store_release_above(s + (slen = Ustrlen(s)) + 1);
1664 HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an "
1665 "empty name: treated as non-existent host name\n");
1668 if (Ustrspn(s, letter_digit_hyphen_dot) != slen)
1670 HDEBUG(D_host_lookup) debug_printf("IP address lookup yielded an "
1671 "illegal name (bad char): treated as non-existent host name\n");
1674 if (!sender_host_name) sender_host_name = s;
1676 while (*s) { *s = tolower(*s); s++; }
1679 *aptr = NULL; /* End of alias list */
1680 store_pool = old_pool; /* Reset store pool */
1682 /* If we've found a name, break out of the "order" loop */
1684 if (sender_host_name) break;
1687 /* If the DNS lookup deferred, we must also defer. */
1689 if (rc == DNS_AGAIN)
1691 HDEBUG(D_host_lookup)
1692 debug_printf("IP address PTR lookup gave temporary error\n");
1693 host_lookup_deferred = TRUE;
1698 /* Do a lookup using gethostbyaddr() - or equivalent */
1700 else if (strcmpic(ordername, US"byaddr") == 0)
1702 HDEBUG(D_host_lookup)
1703 debug_printf("IP address lookup using gethostbyaddr()\n");
1704 rc = host_name_lookup_byaddr();
1707 host_lookup_deferred = TRUE;
1708 return rc; /* Can't carry on */
1710 if (rc == OK) break; /* Found a name */
1712 } /* Loop for bydns/byaddr scanning */
1714 /* If we have failed to find a name, return FAIL and log when required.
1715 NB host_lookup_msg must be in permanent store. */
1717 if (!sender_host_name)
1719 if (host_checking || !f.log_testing_mode)
1720 log_write(L_host_lookup_failed, LOG_MAIN, "no host name found for IP "
1721 "address %s", sender_host_address);
1722 host_lookup_msg = US" (failed to find host name from IP address)";
1723 host_lookup_failed = TRUE;
1727 HDEBUG(D_host_lookup)
1729 uschar **aliases = sender_host_aliases;
1730 debug_printf("IP address lookup yielded \"%s\"\n", sender_host_name);
1731 while (*aliases) debug_printf(" alias \"%s\"\n", *aliases++);
1734 /* We need to verify that a forward lookup on the name we found does indeed
1735 correspond to the address. This is for security: in principle a malefactor who
1736 happened to own a reverse zone could set it to point to any names at all.
1738 This code was present in versions of Exim before 3.20. At that point I took it
1739 out because I thought that gethostbyaddr() did the check anyway. It turns out
1740 that this isn't always the case, so it's coming back in at 4.01. This version
1741 is actually better, because it also checks aliases.
1743 The code was made more robust at release 4.21. Prior to that, it accepted all
1744 the names if any of them had the correct IP address. Now the code checks all
1745 the names, and accepts only those that have the correct IP address. */
1747 save_hostname = sender_host_name; /* Save for error messages */
1748 aliases = sender_host_aliases;
1749 for (uschar * hname = sender_host_name; hname; hname = *aliases++)
1753 host_item h = { .next = NULL, .name = hname, .mx = MX_NONE, .address = NULL };
1755 { .request = sender_host_dnssec ? US"*" : NULL, .require = NULL };
1757 if ( (rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A | HOST_FIND_BY_AAAA,
1758 NULL, NULL, NULL, &d, NULL, NULL)) == HOST_FOUND
1759 || rc == HOST_FOUND_LOCAL
1762 HDEBUG(D_host_lookup) debug_printf("checking addresses for %s\n", hname);
1764 /* If the forward lookup was not secure we cancel the is-secure variable */
1766 DEBUG(D_dns) debug_printf("Forward DNS security status: %s\n",
1767 h.dnssec == DS_YES ? "DNSSEC verified (AD)" : "unverified");
1768 if (h.dnssec != DS_YES) sender_host_dnssec = FALSE;
1770 for (host_item * hh = &h; hh; hh = hh->next)
1771 if (host_is_in_net(hh->address, sender_host_address, 0))
1773 HDEBUG(D_host_lookup) debug_printf(" %s OK\n", hh->address);
1778 HDEBUG(D_host_lookup) debug_printf(" %s\n", hh->address);
1780 if (!ok) HDEBUG(D_host_lookup)
1781 debug_printf("no IP address for %s matched %s\n", hname,
1782 sender_host_address);
1784 else if (rc == HOST_FIND_AGAIN)
1786 HDEBUG(D_host_lookup) debug_printf("temporary error for host name lookup\n");
1787 host_lookup_deferred = TRUE;
1788 sender_host_name = NULL;
1792 HDEBUG(D_host_lookup) debug_printf("no IP addresses found for %s\n", hname);
1794 /* If this name is no good, and it's the sender name, set it null pro tem;
1795 if it's an alias, just remove it from the list. */
1799 if (hname == sender_host_name) sender_host_name = NULL; else
1801 uschar **a; /* Don't amalgamate - some */
1802 a = --aliases; /* compilers grumble */
1803 while (*a != NULL) { *a = a[1]; a++; }
1808 /* If sender_host_name == NULL, it means we didn't like the name. Replace
1809 it with the first alias, if there is one. */
1811 if (sender_host_name == NULL && *sender_host_aliases != NULL)
1812 sender_host_name = *sender_host_aliases++;
1814 /* If we now have a main name, all is well. */
1816 if (sender_host_name != NULL) return OK;
1818 /* We have failed to find an address that matches. */
1820 HDEBUG(D_host_lookup)
1821 debug_printf("%s does not match any IP address for %s\n",
1822 sender_host_address, save_hostname);
1824 /* This message must be in permanent store */
1826 old_pool = store_pool;
1827 store_pool = POOL_PERM;
1828 host_lookup_msg = string_sprintf(" (%s does not match any IP address for %s)",
1829 sender_host_address, save_hostname);
1830 store_pool = old_pool;
1831 host_lookup_failed = TRUE;
1838 /*************************************************
1839 * Find IP address(es) for host by name *
1840 *************************************************/
1842 /* The input is a host_item structure with the name filled in and the address
1843 field set to NULL. We use gethostbyname() or getipnodebyname() or
1844 gethostbyname2(), as appropriate. Of course, these functions may use the DNS,
1845 but they do not do MX processing. It appears, however, that in some systems the
1846 current setting of resolver options is used when one of these functions calls
1847 the resolver. For this reason, we call dns_init() at the start, with arguments
1848 influenced by bits in "flags", just as we do for host_find_bydns().
1850 The second argument provides a host list (usually an IP list) of hosts to
1851 ignore. This makes it possible to ignore IPv6 link-local addresses or loopback
1852 addresses in unreasonable places.
1854 The lookup may result in a change of name. For compatibility with the dns
1855 lookup, return this via fully_qualified_name as well as updating the host item.
1856 The lookup may also yield more than one IP address, in which case chain on
1857 subsequent host_item structures.
1860 host a host item with the name and MX filled in;
1861 the address is to be filled in;
1862 multiple IP addresses cause other host items to be
1864 ignore_target_hosts a list of hosts to ignore
1865 flags HOST_FIND_QUALIFY_SINGLE ) passed to
1866 HOST_FIND_SEARCH_PARENTS ) dns_init()
1867 fully_qualified_name if not NULL, set to point to host name for
1868 compatibility with host_find_bydns
1869 local_host_check TRUE if a check for the local host is wanted
1871 Returns: HOST_FIND_FAILED Failed to find the host or domain
1872 HOST_FIND_AGAIN Try again later
1873 HOST_FOUND Host found - data filled in
1874 HOST_FOUND_LOCAL Host found and is the local host
1878 host_find_byname(host_item *host, const uschar *ignore_target_hosts, int flags,
1879 const uschar **fully_qualified_name, BOOL local_host_check)
1882 host_item *last = NULL;
1883 BOOL temp_error = FALSE;
1887 /* Copy the host name at this point to the value which is used for
1888 TLS certificate name checking, before anything modifies it. */
1890 host->certname = host->name;
1893 /* Make sure DNS options are set as required. This appears to be necessary in
1894 some circumstances when the get..byname() function actually calls the DNS. */
1896 dns_init((flags & HOST_FIND_QUALIFY_SINGLE) != 0,
1897 (flags & HOST_FIND_SEARCH_PARENTS) != 0,
1898 FALSE); /* Cannot retrieve dnssec status so do not request */
1900 /* In an IPv6 world, unless IPv6 has been disabled, we need to scan for both
1901 kinds of address, so go round the loop twice. Note that we have ensured that
1902 AF_INET6 is defined even in an IPv4 world, which makes for slightly tidier
1903 code. However, if dns_ipv4_lookup matches the domain, we also just do IPv4
1904 lookups here (except when testing standalone). */
1912 && match_isinlist(host->name, CUSS &dns_ipv4_lookup, 0,
1913 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK)
1916 { af = AF_INET; times = 1; }
1918 { af = AF_INET6; times = 2; }
1920 /* No IPv6 support */
1922 #else /* HAVE_IPV6 */
1923 af = AF_INET; times = 1;
1924 #endif /* HAVE_IPV6 */
1926 /* Initialize the flag that gets set for DNS syntax check errors, so that the
1927 interface to this function can be similar to host_find_bydns. */
1929 f.host_find_failed_syntax = FALSE;
1931 /* Loop to look up both kinds of address in an IPv6 world */
1933 for (int i = 1; i <= times;
1935 af = AF_INET, /* If 2 passes, IPv4 on the second */
1941 struct hostent *hostdata;
1942 unsigned long time_msec = 0; /* compiler quietening */
1945 printf("Looking up: %s\n", host->name);
1948 if (slow_lookup_log) time_msec = get_time_in_ms();
1951 if (f.running_in_test_harness)
1952 hostdata = host_fake_gethostbyname(host->name, af, &error_num);
1955 #if HAVE_GETIPNODEBYNAME
1956 hostdata = getipnodebyname(CS host->name, af, 0, &error_num);
1958 hostdata = gethostbyname2(CS host->name, af);
1959 error_num = h_errno;
1963 #else /* not HAVE_IPV6 */
1964 if (f.running_in_test_harness)
1965 hostdata = host_fake_gethostbyname(host->name, af, &error_num);
1968 hostdata = gethostbyname(CS host->name);
1969 error_num = h_errno;
1971 #endif /* HAVE_IPV6 */
1973 if ( slow_lookup_log
1974 && (time_msec = get_time_in_ms() - time_msec) > slow_lookup_log)
1975 log_long_lookup(US"gethostbyname", host->name, time_msec);
1982 case HOST_NOT_FOUND: error = US"HOST_NOT_FOUND"; break;
1983 case TRY_AGAIN: error = US"TRY_AGAIN"; temp_error = TRUE; break;
1984 case NO_RECOVERY: error = US"NO_RECOVERY"; temp_error = TRUE; break;
1985 case NO_DATA: error = US"NO_DATA"; break;
1986 #if NO_DATA != NO_ADDRESS
1987 case NO_ADDRESS: error = US"NO_ADDRESS"; break;
1989 default: error = US"?"; break;
1992 DEBUG(D_host_lookup) debug_printf("%s(af=%s) returned %d (%s)\n",
1993 f.running_in_test_harness ? "host_fake_gethostbyname" :
1995 # if HAVE_GETIPNODEBYNAME
2003 af == AF_INET ? "inet" : "inet6", error_num, error);
2007 if (!(hostdata->h_addr_list)[0]) continue;
2009 /* Replace the name with the fully qualified one if necessary, and fill in
2010 the fully_qualified_name pointer. */
2012 if (hostdata->h_name[0] && Ustrcmp(host->name, hostdata->h_name) != 0)
2013 host->name = string_copy_dnsdomain(US hostdata->h_name);
2014 if (fully_qualified_name) *fully_qualified_name = host->name;
2016 /* Get the list of addresses. IPv4 and IPv6 addresses can be distinguished
2017 by their different lengths. Scan the list, ignoring any that are to be
2018 ignored, and build a chain from the rest. */
2020 ipv4_addr = hostdata->h_length == sizeof(struct in_addr);
2022 for (uschar ** addrlist = USS hostdata->h_addr_list; *addrlist; addrlist++)
2024 uschar *text_address =
2025 host_ntoa(ipv4_addr? AF_INET:AF_INET6, *addrlist, NULL, NULL);
2028 if ( ignore_target_hosts
2029 && verify_check_this_host(&ignore_target_hosts, NULL, host->name,
2030 text_address, NULL) == OK)
2032 DEBUG(D_host_lookup)
2033 debug_printf("ignored host %s [%s]\n", host->name, text_address);
2038 /* If this is the first address, last is NULL and we put the data in the
2043 host->address = text_address;
2044 host->port = PORT_NONE;
2045 host->status = hstatus_unknown;
2046 host->why = hwhy_unknown;
2047 host->dnssec = DS_UNK;
2051 /* Else add further host item blocks for any other addresses, keeping
2056 host_item *next = store_get(sizeof(host_item), GET_UNTAINTED);
2057 next->name = host->name;
2059 next->certname = host->certname;
2061 next->mx = host->mx;
2062 next->address = text_address;
2063 next->port = PORT_NONE;
2064 next->status = hstatus_unknown;
2065 next->why = hwhy_unknown;
2066 next->dnssec = DS_UNK;
2068 next->next = last->next;
2075 /* If no hosts were found, the address field in the original host block will be
2076 NULL. If temp_error is set, at least one of the lookups gave a temporary error,
2077 so we pass that back. */
2083 !message_id[0] && smtp_in
2084 ? string_sprintf("no IP address found for host %s (during %s)", host->name,
2085 smtp_get_connection_info()) :
2087 string_sprintf("no IP address found for host %s", host->name);
2089 HDEBUG(D_host_lookup) debug_printf("%s\n", msg);
2090 if (temp_error) goto RETURN_AGAIN;
2091 if (host_checking || !f.log_testing_mode)
2092 log_write(L_host_lookup_failed, LOG_MAIN, "%s", msg);
2093 return HOST_FIND_FAILED;
2096 /* Remove any duplicate IP addresses, then check to see if this is the local
2097 host if required. */
2099 host_remove_duplicates(host, &last);
2100 yield = local_host_check?
2101 host_scan_for_local_hosts(host, &last, NULL) : HOST_FOUND;
2103 HDEBUG(D_host_lookup)
2105 if (fully_qualified_name)
2106 debug_printf("fully qualified name = %s\n", *fully_qualified_name);
2107 debug_printf("%s looked up these IP addresses:\n",
2109 #if HAVE_GETIPNODEBYNAME
2118 for (const host_item * h = host; h != last->next; h = h->next)
2119 debug_printf(" name=%s address=%s\n", h->name,
2120 h->address ? h->address : US"<null>");
2123 /* Return the found status. */
2127 /* Handle the case when there is a temporary error. If the name matches
2128 dns_again_means_nonexist, return permanent rather than temporary failure. */
2134 const uschar *save = deliver_domain;
2135 deliver_domain = host->name; /* set $domain */
2136 rc = match_isinlist(host->name, CUSS &dns_again_means_nonexist, 0,
2137 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL);
2138 deliver_domain = save;
2141 DEBUG(D_host_lookup) debug_printf("%s is in dns_again_means_nonexist: "
2142 "returning HOST_FIND_FAILED\n", host->name);
2143 return HOST_FIND_FAILED;
2146 return HOST_FIND_AGAIN;
2152 /*************************************************
2153 * Fill in a host address from the DNS *
2154 *************************************************/
2156 /* Given a host item, with its name, port and mx fields set, and its address
2157 field set to NULL, fill in its IP address from the DNS. If it is multi-homed,
2158 create additional host items for the additional addresses, copying all the
2159 other fields, and randomizing the order.
2161 On IPv6 systems, AAAA records are sought first, then A records.
2163 The host name may be changed if the DNS returns a different name - e.g. fully
2164 qualified or changed via CNAME. If fully_qualified_name is not NULL, dns_lookup
2165 ensures that it points to the fully qualified name. However, this is the fully
2166 qualified version of the original name; if a CNAME is involved, the actual
2167 canonical host name may be different again, and so we get it directly from the
2168 relevant RR. Note that we do NOT change the mx field of the host item in this
2169 function as it may be called to set the addresses of hosts taken from MX
2173 host points to the host item we're filling in
2174 lastptr points to pointer to last host item in a chain of
2175 host items (may be updated if host is last and gets
2176 extended because multihomed)
2177 ignore_target_hosts list of hosts to ignore
2178 allow_ip if TRUE, recognize an IP address and return it
2179 fully_qualified_name if not NULL, return fully qualified name here if
2180 the contents are different (i.e. it must be preset
2182 dnssec_request if TRUE request the AD bit
2183 dnssec_require if TRUE require the AD bit
2184 whichrrs select ipv4, ipv6 results
2186 Returns: HOST_FIND_FAILED couldn't find A record
2187 HOST_FIND_AGAIN try again later
2188 HOST_FIND_SECURITY dnssec required but not acheived
2189 HOST_FOUND found AAAA and/or A record(s)
2190 HOST_IGNORED found, but all IPs ignored
2194 set_address_from_dns(host_item *host, host_item **lastptr,
2195 const uschar *ignore_target_hosts, BOOL allow_ip,
2196 const uschar **fully_qualified_name,
2197 BOOL dnssec_request, BOOL dnssec_require, int whichrrs)
2199 host_item *thishostlast = NULL; /* Indicates not yet filled in anything */
2200 BOOL v6_find_again = FALSE;
2201 BOOL dnssec_fail = FALSE;
2206 /* Copy the host name at this point to the value which is used for
2207 TLS certificate name checking, before any CNAME-following modifies it. */
2209 host->certname = host->name;
2212 /* If allow_ip is set, a name which is an IP address returns that value
2213 as its address. This is used for MX records when allow_mx_to_ip is set, for
2214 those sites that feel they have to flaunt the RFC rules. */
2216 if (allow_ip && string_is_ip_address(host->name, NULL) != 0)
2219 if ( ignore_target_hosts
2220 && verify_check_this_host(&ignore_target_hosts, NULL, host->name,
2221 host->name, NULL) == OK)
2222 return HOST_IGNORED;
2225 host->address = host->name;
2229 dnsa = store_get_dns_answer();
2231 /* On an IPv6 system, unless IPv6 is disabled, go round the loop up to twice,
2232 looking for AAAA records the first time. However, unless doing standalone
2233 testing, we force an IPv4 lookup if the domain matches dns_ipv4_lookup global.
2234 On an IPv4 system, go round the loop once only, looking only for A records. */
2239 || !(whichrrs & HOST_FIND_BY_AAAA)
2241 && match_isinlist(host->name, CUSS &dns_ipv4_lookup, 0,
2242 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK
2244 i = 0; /* look up A records only */
2246 #endif /* STAND_ALONE */
2248 i = 1; /* look up AAAA and A records */
2250 /* The IPv4 world */
2252 #else /* HAVE_IPV6 */
2253 i = 0; /* look up A records only */
2254 #endif /* HAVE_IPV6 */
2258 static int types[] = { T_A, T_AAAA };
2259 int type = types[i];
2260 int randoffset = i == (whichrrs & HOST_FIND_IPV4_FIRST ? 1 : 0)
2261 ? 500 : 0; /* Ensures v6/4 sort order */
2264 int rc = dns_lookup_timerwrap(dnsa, host->name, type, fully_qualified_name);
2265 lookup_dnssec_authenticated = !dnssec_request ? NULL
2266 : dns_is_secure(dnsa) ? US"yes" : US"no";
2269 if ( (dnssec_request || dnssec_require)
2270 && !dns_is_secure(dnsa)
2273 debug_printf("DNS lookup of %.256s (A/AAAA) requested AD, but got AA\n", host->name);
2275 /* We want to return HOST_FIND_AGAIN if one of the A or AAAA lookups
2276 fails or times out, but not if another one succeeds. (In the early
2277 IPv6 days there are name servers that always fail on AAAA, but are happy
2278 to give out an A record. We want to proceed with that A record.) */
2280 if (rc != DNS_SUCCEED)
2282 if (i == 0) /* Just tried for an A record, i.e. end of loop */
2284 if (host->address != NULL)
2285 i = HOST_FOUND; /* AAAA was found */
2286 else if (rc == DNS_AGAIN || rc == DNS_FAIL || v6_find_again)
2287 i = HOST_FIND_AGAIN;
2289 i = HOST_FIND_FAILED; /* DNS_NOMATCH or DNS_NODATA */
2293 /* Tried for an AAAA record: remember if this was a temporary
2294 error, and look for the next record type. */
2296 if (rc != DNS_NOMATCH && rc != DNS_NODATA) v6_find_again = TRUE;
2302 if (dns_is_secure(dnsa))
2304 DEBUG(D_host_lookup) debug_printf("%s A DNSSEC\n", host->name);
2305 if (host->dnssec == DS_UNK) /* set in host_find_bydns() */
2306 host->dnssec = DS_YES;
2313 DEBUG(D_host_lookup) debug_printf("dnssec fail on %s for %.256s",
2314 i>0 ? "AAAA" : "A", host->name);
2317 if (host->dnssec == DS_YES) /* set in host_find_bydns() */
2319 DEBUG(D_host_lookup) debug_printf("%s A cancel DNSSEC\n", host->name);
2320 host->dnssec = DS_NO;
2321 lookup_dnssec_authenticated = US"no";
2326 /* Lookup succeeded: fill in the given host item with the first non-ignored
2327 address found; create additional items for any others. A single A6 record
2328 may generate more than one address. The lookup had a chance to update the
2329 fqdn; we do not want any later times round the loop to do so. */
2331 fully_qualified_name = NULL;
2333 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
2335 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == type)
2337 dns_address * da = dns_address_from_rr(dnsa, rr);
2339 DEBUG(D_host_lookup)
2340 if (!da) debug_printf("no addresses extracted from A6 RR for %s\n",
2343 /* This loop runs only once for A and AAAA records, but may run
2344 several times for an A6 record that generated multiple addresses. */
2346 for (; da; da = da->next)
2349 if (ignore_target_hosts != NULL &&
2350 verify_check_this_host(&ignore_target_hosts, NULL,
2351 host->name, da->address, NULL) == OK)
2353 DEBUG(D_host_lookup)
2354 debug_printf("ignored host %s [%s]\n", host->name, da->address);
2359 /* If this is the first address, stick it in the given host block,
2360 and change the name if the returned RR has a different name. */
2362 if (thishostlast == NULL)
2364 if (strcmpic(host->name, rr->name) != 0)
2365 host->name = string_copy_dnsdomain(rr->name);
2366 host->address = da->address;
2367 host->sort_key = host->mx * 1000 + random_number(500) + randoffset;
2368 host->status = hstatus_unknown;
2369 host->why = hwhy_unknown;
2370 thishostlast = host;
2373 /* Not the first address. Check for, and ignore, duplicates. Then
2374 insert in the chain at a random point. */
2381 /* End of our local chain is specified by "thishostlast". */
2383 for (next = host;; next = next->next)
2385 if (Ustrcmp(CS da->address, next->address) == 0) break;
2386 if (next == thishostlast) { next = NULL; break; }
2388 if (next != NULL) continue; /* With loop for next address */
2390 /* Not a duplicate */
2392 new_sort_key = host->mx * 1000 + random_number(500) + randoffset;
2393 next = store_get(sizeof(host_item), GET_UNTAINTED);
2395 /* New address goes first: insert the new block after the first one
2396 (so as not to disturb the original pointer) but put the new address
2397 in the original block. */
2399 if (new_sort_key < host->sort_key)
2401 *next = *host; /* Copies port */
2403 host->address = da->address;
2404 host->sort_key = new_sort_key;
2405 if (thishostlast == host) thishostlast = next; /* Local last */
2406 if (*lastptr == host) *lastptr = next; /* Global last */
2409 /* Otherwise scan down the addresses for this host to find the
2410 one to insert after. */
2414 host_item *h = host;
2415 while (h != thishostlast)
2417 if (new_sort_key < h->next->sort_key) break;
2420 *next = *h; /* Copies port */
2422 next->address = da->address;
2423 next->sort_key = new_sort_key;
2424 if (h == thishostlast) thishostlast = next; /* Local last */
2425 if (h == *lastptr) *lastptr = next; /* Global last */
2432 /* Control gets here only if the second lookup (the A record) succeeded.
2433 However, the address may not be filled in if it was ignored. */
2438 ? HOST_FIND_SECURITY
2442 store_free_dns_answer(dnsa);
2449 /*************************************************
2450 * Find IP addresses and host names via DNS *
2451 *************************************************/
2453 /* The input is a host_item structure with the name field filled in and the
2454 address field set to NULL. This may be in a chain of other host items. The
2455 lookup may result in more than one IP address, in which case we must created
2456 new host blocks for the additional addresses, and insert them into the chain.
2457 The original name may not be fully qualified. Use the fully_qualified_name
2458 argument to return the official name, as returned by the resolver.
2461 host point to initial host item
2462 ignore_target_hosts a list of hosts to ignore
2463 whichrrs flags indicating which RRs to look for:
2464 HOST_FIND_BY_SRV => look for SRV
2465 HOST_FIND_BY_MX => look for MX
2466 HOST_FIND_BY_A => look for A
2467 HOST_FIND_BY_AAAA => look for AAAA
2468 also flags indicating how the lookup is done
2469 HOST_FIND_QUALIFY_SINGLE ) passed to the
2470 HOST_FIND_SEARCH_PARENTS ) resolver
2471 HOST_FIND_IPV4_FIRST => reverse usual result ordering
2472 HOST_FIND_IPV4_ONLY => MX results elide ipv6
2473 srv_service when SRV used, the service name
2474 srv_fail_domains DNS errors for these domains => assume nonexist
2475 mx_fail_domains DNS errors for these domains => assume nonexist
2476 dnssec_d.request => make dnssec request: domainlist
2477 dnssec_d.require => ditto and nonexist failures
2478 fully_qualified_name if not NULL, return fully-qualified name
2479 removed set TRUE if local host was removed from the list
2481 Returns: HOST_FIND_FAILED Failed to find the host or domain;
2482 if there was a syntax error,
2483 host_find_failed_syntax is set.
2484 HOST_FIND_AGAIN Could not resolve at this time
2485 HOST_FIND_SECURITY dnsssec required but not acheived
2486 HOST_FOUND Host found
2487 HOST_FOUND_LOCAL The lowest MX record points to this
2488 machine, if MX records were found, or
2489 an A record that was found contains
2490 an address of the local host
2494 host_find_bydns(host_item *host, const uschar *ignore_target_hosts, int whichrrs,
2495 uschar *srv_service, uschar *srv_fail_domains, uschar *mx_fail_domains,
2496 const dnssec_domains *dnssec_d,
2497 const uschar **fully_qualified_name, BOOL *removed)
2499 host_item *h, *last;
2503 dns_answer * dnsa = store_get_dns_answer();
2505 BOOL dnssec_require = dnssec_d
2506 && match_isinlist(host->name, CUSS &dnssec_d->require,
2507 0, &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK;
2508 BOOL dnssec_request = dnssec_require
2510 && match_isinlist(host->name, CUSS &dnssec_d->request,
2511 0, &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK);
2512 dnssec_status_t dnssec;
2514 /* Set the default fully qualified name to the incoming name, initialize the
2515 resolver if necessary, set up the relevant options, and initialize the flag
2516 that gets set for DNS syntax check errors. */
2518 if (fully_qualified_name != NULL) *fully_qualified_name = host->name;
2519 dns_init((whichrrs & HOST_FIND_QUALIFY_SINGLE) != 0,
2520 (whichrrs & HOST_FIND_SEARCH_PARENTS) != 0,
2522 f.host_find_failed_syntax = FALSE;
2524 /* First, if requested, look for SRV records. The service name is given; we
2525 assume TCP protocol. DNS domain names are constrained to a maximum of 256
2526 characters, so the code below should be safe. */
2528 if (whichrrs & HOST_FIND_BY_SRV)
2531 uschar * temp_fully_qualified_name;
2534 g = string_fmt_append(NULL, "_%s._tcp.%n%.256s",
2535 srv_service, &prefix_length, host->name);
2536 temp_fully_qualified_name = string_from_gstring(g);
2539 /* Search for SRV records. If the fully qualified name is different to
2540 the input name, pass back the new original domain, without the prepended
2544 lookup_dnssec_authenticated = NULL;
2545 rc = dns_lookup_timerwrap(dnsa, temp_fully_qualified_name, ind_type,
2546 CUSS &temp_fully_qualified_name);
2549 if ((dnssec_request || dnssec_require)
2550 && !dns_is_secure(dnsa)
2552 debug_printf("DNS lookup of %.256s (SRV) requested AD, but got AA\n", host->name);
2556 if (dns_is_secure(dnsa))
2557 { dnssec = DS_YES; lookup_dnssec_authenticated = US"yes"; }
2559 { dnssec = DS_NO; lookup_dnssec_authenticated = US"no"; }
2562 if (temp_fully_qualified_name != g->s && fully_qualified_name != NULL)
2563 *fully_qualified_name = temp_fully_qualified_name + prefix_length;
2565 /* On DNS failures, we give the "try again" error unless the domain is
2566 listed as one for which we continue. */
2568 if (rc == DNS_SUCCEED && dnssec_require && !dns_is_secure(dnsa))
2570 log_write(L_host_lookup_failed, LOG_MAIN,
2571 "dnssec fail on SRV for %.256s", host->name);
2574 if (rc == DNS_FAIL || rc == DNS_AGAIN)
2577 if (match_isinlist(host->name, CUSS &srv_fail_domains, 0,
2578 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) != OK)
2580 { yield = HOST_FIND_AGAIN; goto out; }
2581 DEBUG(D_host_lookup) debug_printf("DNS_%s treated as DNS_NODATA "
2582 "(domain in srv_fail_domains)\n", rc == DNS_FAIL ? "FAIL":"AGAIN");
2586 /* If we did not find any SRV records, search the DNS for MX records, if
2587 requested to do so. If the result is DNS_NOMATCH, it means there is no such
2588 domain, and there's no point in going on to look for address records with the
2589 same domain. The result will be DNS_NODATA if the domain exists but has no MX
2590 records. On DNS failures, we give the "try again" error unless the domain is
2591 listed as one for which we continue. */
2593 if (rc != DNS_SUCCEED && whichrrs & HOST_FIND_BY_MX)
2597 lookup_dnssec_authenticated = NULL;
2598 rc = dns_lookup_timerwrap(dnsa, host->name, ind_type, fully_qualified_name);
2601 if ( (dnssec_request || dnssec_require)
2602 && !dns_is_secure(dnsa)
2604 debug_printf("DNS lookup of %.256s (MX) requested AD, but got AA\n", host->name);
2607 if (dns_is_secure(dnsa))
2609 DEBUG(D_host_lookup) debug_printf("%s (MX resp) DNSSEC\n", host->name);
2610 dnssec = DS_YES; lookup_dnssec_authenticated = US"yes";
2614 dnssec = DS_NO; lookup_dnssec_authenticated = US"no";
2620 yield = HOST_FIND_FAILED; goto out;
2623 if (!dnssec_require || dns_is_secure(dnsa))
2625 DEBUG(D_host_lookup)
2626 debug_printf("dnssec fail on MX for %.256s", host->name);
2628 if (match_isinlist(host->name, CUSS &mx_fail_domains, 0,
2629 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) != OK)
2630 { yield = HOST_FIND_SECURITY; goto out; }
2638 if (match_isinlist(host->name, CUSS &mx_fail_domains, 0,
2639 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) != OK)
2641 { yield = HOST_FIND_AGAIN; goto out; }
2642 DEBUG(D_host_lookup) debug_printf("DNS_%s treated as DNS_NODATA "
2643 "(domain in mx_fail_domains)\n", (rc == DNS_FAIL)? "FAIL":"AGAIN");
2648 /* If we haven't found anything yet, and we are requested to do so, try for an
2649 A or AAAA record. If we find it (or them) check to see that it isn't the local
2652 if (rc != DNS_SUCCEED)
2654 if (!(whichrrs & (HOST_FIND_BY_A | HOST_FIND_BY_AAAA)))
2656 DEBUG(D_host_lookup) debug_printf("Address records are not being sought\n");
2657 yield = HOST_FIND_FAILED;
2661 last = host; /* End of local chainlet */
2663 host->port = PORT_NONE;
2664 host->dnssec = DS_UNK;
2665 lookup_dnssec_authenticated = NULL;
2666 rc = set_address_from_dns(host, &last, ignore_target_hosts, FALSE,
2667 fully_qualified_name, dnssec_request, dnssec_require, whichrrs);
2669 /* If one or more address records have been found, check that none of them
2670 are local. Since we know the host items all have their IP addresses
2671 inserted, host_scan_for_local_hosts() can only return HOST_FOUND or
2672 HOST_FOUND_LOCAL. We do not need to scan for duplicate IP addresses here,
2673 because set_address_from_dns() removes them. */
2675 if (rc == HOST_FOUND)
2676 rc = host_scan_for_local_hosts(host, &last, removed);
2678 if (rc == HOST_IGNORED) rc = HOST_FIND_FAILED; /* No special action */
2680 DEBUG(D_host_lookup)
2683 if (fully_qualified_name)
2684 debug_printf("fully qualified name = %s\n", *fully_qualified_name);
2685 for (host_item * h = host; h != last->next; h = h->next)
2686 debug_printf("%s %s mx=%d sort=%d %s\n", h->name,
2687 h->address ? h->address : US"<null>", h->mx, h->sort_key,
2688 h->status >= hstatus_unusable ? US"*" : US"");
2695 /* We have found one or more MX or SRV records. Sort them according to
2696 precedence. Put the data for the first one into the existing host block, and
2697 insert new host_item blocks into the chain for the remainder. For equal
2698 precedences one is supposed to randomize the order. To make this happen, the
2699 sorting is actually done on the MX value * 1000 + a random number. This is put
2700 into a host field called sort_key.
2702 In the case of hosts with both IPv6 and IPv4 addresses, we want to choose the
2703 IPv6 address in preference. At this stage, we don't know what kind of address
2704 the host has. We choose a random number < 500; if later we find an A record
2705 first, we add 500 to the random number. Then for any other address records, we
2706 use random numbers in the range 0-499 for AAAA records and 500-999 for A
2709 At this point we remove any duplicates that point to the same host, retaining
2710 only the one with the lowest precedence. We cannot yet check for precedence
2711 greater than that of the local host, because that test cannot be properly done
2712 until the addresses have been found - an MX record may point to a name for this
2713 host which is not the primary hostname. */
2715 last = NULL; /* Indicates that not even the first item is filled yet */
2717 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
2719 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == ind_type)
2721 int precedence, weight;
2722 int port = PORT_NONE;
2723 const uschar * s = rr->data; /* MUST be unsigned for GETSHORT */
2726 GETSHORT(precedence, s); /* Pointer s is advanced */
2728 /* For MX records, we use a random "weight" which causes multiple records of
2729 the same precedence to sort randomly. */
2731 if (ind_type == T_MX)
2732 weight = random_number(500);
2735 /* SRV records are specified with a port and a weight. The weight is used
2736 in a special algorithm. However, to start with, we just use it to order the
2737 records of equal priority (precedence). */
2738 GETSHORT(weight, s);
2742 /* Get the name of the host pointed to. */
2744 (void)dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, s,
2745 (DN_EXPAND_ARG4_TYPE)data, sizeof(data));
2747 /* Check that we haven't already got this host on the chain; if we have,
2748 keep only the lower precedence. This situation shouldn't occur, but you
2749 never know what junk might get into the DNS (and this case has been seen on
2750 more than one occasion). */
2752 if (last) /* This is not the first record */
2754 host_item *prev = NULL;
2756 for (h = host; h != last->next; prev = h, h = h->next)
2757 if (strcmpic(h->name, data) == 0)
2759 DEBUG(D_host_lookup)
2760 debug_printf("discarded duplicate host %s (MX=%d)\n", data,
2761 precedence > h->mx ? precedence : h->mx);
2762 if (precedence >= h->mx) goto NEXT_MX_RR; /* Skip greater precedence */
2763 if (h == host) /* Override first item */
2766 host->sort_key = precedence * 1000 + weight;
2770 /* Unwanted host item is not the first in the chain, so we can get
2771 get rid of it by cutting it out. */
2773 prev->next = h->next;
2774 if (h == last) last = prev;
2779 /* If this is the first MX or SRV record, put the data into the existing host
2780 block. Otherwise, add a new block in the correct place; if it has to be
2781 before the first block, copy the first block's data to a new second block. */
2785 host->name = string_copy_dnsdomain(data);
2786 host->address = NULL;
2788 host->mx = precedence;
2789 host->sort_key = precedence * 1000 + weight;
2790 host->status = hstatus_unknown;
2791 host->why = hwhy_unknown;
2792 host->dnssec = dnssec;
2797 /* Make a new host item and seek the correct insertion place */
2799 int sort_key = precedence * 1000 + weight;
2800 host_item * next = store_get(sizeof(host_item), GET_UNTAINTED);
2801 next->name = string_copy_dnsdomain(data);
2802 next->address = NULL;
2804 next->mx = precedence;
2805 next->sort_key = sort_key;
2806 next->status = hstatus_unknown;
2807 next->why = hwhy_unknown;
2808 next->dnssec = dnssec;
2811 /* Handle the case when we have to insert before the first item. */
2813 if (sort_key < host->sort_key)
2820 if (last == host) last = next;
2824 /* Else scan down the items we have inserted as part of this exercise;
2825 don't go further. */
2827 for (h = host; h != last; h = h->next)
2828 if (sort_key < h->next->sort_key)
2830 next->next = h->next;
2835 /* Join on after the last host item that's part of this
2836 processing if we haven't stopped sooner. */
2840 next->next = last->next;
2847 NEXT_MX_RR: continue;
2850 if (!last) /* No rr of correct type; give up */
2852 yield = HOST_FIND_FAILED;
2856 /* If the list of hosts was obtained from SRV records, there are two things to
2857 do. First, if there is only one host, and it's name is ".", it means there is
2858 no SMTP service at this domain. Otherwise, we have to sort the hosts of equal
2859 priority according to their weights, using an algorithm that is defined in RFC
2860 2782. The hosts are currently sorted by priority and weight. For each priority
2861 group we have to pick off one host and put it first, and then repeat for any
2862 remaining in the same priority group. */
2864 if (ind_type == T_SRV)
2868 if (host == last && host->name[0] == 0)
2870 DEBUG(D_host_lookup) debug_printf("the single SRV record is \".\"\n");
2871 yield = HOST_FIND_FAILED;
2875 DEBUG(D_host_lookup)
2877 debug_printf("original ordering of hosts from SRV records:\n");
2878 for (h = host; h != last->next; h = h->next)
2879 debug_printf(" %s P=%d W=%d\n", h->name, h->mx, h->sort_key % 1000);
2882 for (pptr = &host, h = host; h != last; pptr = &h->next, h = h->next)
2887 /* Find the last following host that has the same precedence. At the same
2888 time, compute the sum of the weights and the running totals. These can be
2889 stored in the sort_key field. */
2891 for (hh = h; hh != last; hh = hh->next)
2893 int weight = hh->sort_key % 1000; /* was precedence * 1000 + weight */
2896 if (hh->mx != hh->next->mx) break;
2899 /* If there's more than one host at this precedence (priority), we need to
2900 pick one to go first. */
2906 int randomizer = random_number(sum + 1);
2908 for (ppptr = pptr, hhh = h;
2910 ppptr = &hhh->next, hhh = hhh->next)
2911 if (hhh->sort_key >= randomizer)
2914 /* hhh now points to the host that should go first; ppptr points to the
2915 place that points to it. Unfortunately, if the start of the minilist is
2916 the start of the entire list, we can't just swap the items over, because
2917 we must not change the value of host, since it is passed in from outside.
2918 One day, this could perhaps be changed.
2920 The special case is fudged by putting the new item *second* in the chain,
2921 and then transferring the data between the first and second items. We
2922 can't just swap the first and the chosen item, because that would mean
2923 that an item with zero weight might no longer be first. */
2927 *ppptr = hhh->next; /* Cuts it out of the chain */
2931 host_item temp = *h;
2934 hhh->next = temp.next;
2939 hhh->next = h; /* The rest of the chain follows it */
2940 *pptr = hhh; /* It takes the place of h */
2941 h = hhh; /* It's now the start of this minilist */
2946 /* A host has been chosen to be first at this priority and h now points
2947 to this host. There may be others at the same priority, or others at a
2948 different priority. Before we leave this host, we need to put back a sort
2949 key of the traditional MX kind, in case this host is multihomed, because
2950 the sort key is used for ordering the multiple IP addresses. We do not need
2951 to ensure that these new sort keys actually reflect the order of the hosts,
2954 h->sort_key = h->mx * 1000 + random_number(500);
2955 } /* Move on to the next host */
2958 /* Now we have to find IP addresses for all the hosts. We have ensured above
2959 that the names in all the host items are unique. Before release 4.61 we used to
2960 process records from the additional section in the DNS packet that returned the
2961 MX or SRV records. However, a DNS name server is free to drop any resource
2962 records from the additional section. In theory, this has always been a
2963 potential problem, but it is exacerbated by the advent of IPv6. If a host had
2964 several IPv4 addresses and some were not in the additional section, at least
2965 Exim would try the others. However, if a host had both IPv4 and IPv6 addresses
2966 and all the IPv4 (say) addresses were absent, Exim would try only for a IPv6
2967 connection, and never try an IPv4 address. When there was only IPv4
2968 connectivity, this was a disaster that did in practice occur.
2970 So, from release 4.61 onwards, we always search for A and AAAA records
2971 explicitly. The names shouldn't point to CNAMES, but we use the general lookup
2972 function that handles them, just in case. If any lookup gives a soft error,
2973 change the default yield.
2975 For these DNS lookups, we must disable qualify_single and search_parents;
2976 otherwise invalid host names obtained from MX or SRV records can cause trouble
2977 if they happen to match something local. */
2979 yield = HOST_FIND_FAILED; /* Default yield */
2980 dns_init(FALSE, FALSE, /* Disable qualify_single and search_parents */
2981 dnssec_request || dnssec_require);
2983 for (h = host; h != last->next; h = h->next)
2985 if (h->address) continue; /* Inserted by a multihomed host */
2987 rc = set_address_from_dns(h, &last, ignore_target_hosts, allow_mx_to_ip,
2988 NULL, dnssec_request, dnssec_require,
2989 whichrrs & HOST_FIND_IPV4_ONLY
2990 ? HOST_FIND_BY_A : HOST_FIND_BY_A | HOST_FIND_BY_AAAA);
2991 if (rc != HOST_FOUND)
2993 h->status = hstatus_unusable;
2996 case HOST_FIND_AGAIN: yield = rc; h->why = hwhy_deferred; break;
2997 case HOST_FIND_SECURITY: yield = rc; h->why = hwhy_insecure; break;
2998 case HOST_IGNORED: h->why = hwhy_ignored; break;
2999 default: h->why = hwhy_failed; break;
3004 /* Scan the list for any hosts that are marked unusable because they have
3005 been explicitly ignored, and remove them from the list, as if they did not
3006 exist. If we end up with just a single, ignored host, flatten its fields as if
3007 nothing was found. */
3009 if (ignore_target_hosts)
3011 host_item *prev = NULL;
3012 for (h = host; h != last->next; h = h->next)
3015 if (h->why != hwhy_ignored) /* Non ignored host, just continue */
3017 else if (prev == NULL) /* First host is ignored */
3019 if (h != last) /* First is not last */
3021 if (h->next == last) last = h; /* Overwrite it with next */
3022 *h = *(h->next); /* and reprocess it. */
3023 goto REDO; /* C should have redo, like Perl */
3026 else /* Ignored host is not first - */
3028 prev->next = h->next;
3029 if (h == last) last = prev;
3033 if (host->why == hwhy_ignored) host->address = NULL;
3036 /* There is still one complication in the case of IPv6. Although the code above
3037 arranges that IPv6 addresses take precedence over IPv4 addresses for multihomed
3038 hosts, it doesn't do this for addresses that apply to different hosts with the
3039 same MX precedence, because the sorting on MX precedence happens first. So we
3040 have to make another pass to check for this case. We ensure that, within a
3041 single MX preference value, IPv6 addresses come first. This can separate the
3042 addresses of a multihomed host, but that should not matter. */
3045 if (h != last && !disable_ipv6) for (h = host; h != last; h = h->next)
3048 host_item *next = h->next;
3050 if ( h->mx != next->mx /* If next is different MX */
3051 || !h->address /* OR this one is unset */
3053 continue; /* move on to next */
3055 if ( whichrrs & HOST_FIND_IPV4_FIRST
3056 ? !Ustrchr(h->address, ':') /* OR this one is IPv4 */
3058 && Ustrchr(next->address, ':') /* OR next is IPv6 */
3060 : Ustrchr(h->address, ':') /* OR this one is IPv6 */
3062 && !Ustrchr(next->address, ':') /* OR next is IPv4 */
3064 continue; /* move on to next */
3066 temp = *h; /* otherwise, swap */
3067 temp.next = next->next;
3074 /* Remove any duplicate IP addresses and then scan the list of hosts for any
3075 whose IP addresses are on the local host. If any are found, all hosts with the
3076 same or higher MX values are removed. However, if the local host has the lowest
3077 numbered MX, then HOST_FOUND_LOCAL is returned. Otherwise, if at least one host
3078 with an IP address is on the list, HOST_FOUND is returned. Otherwise,
3079 HOST_FIND_FAILED is returned, but in this case do not update the yield, as it
3080 might have been set to HOST_FIND_AGAIN just above here. If not, it will already
3081 be HOST_FIND_FAILED. */
3083 host_remove_duplicates(host, &last);
3084 rc = host_scan_for_local_hosts(host, &last, removed);
3085 if (rc != HOST_FIND_FAILED) yield = rc;
3087 DEBUG(D_host_lookup)
3089 if (fully_qualified_name)
3090 debug_printf("fully qualified name = %s\n", *fully_qualified_name);
3091 debug_printf("host_find_bydns yield = %s (%d); returned hosts:\n",
3092 yield == HOST_FOUND ? "HOST_FOUND" :
3093 yield == HOST_FOUND_LOCAL ? "HOST_FOUND_LOCAL" :
3094 yield == HOST_FIND_SECURITY ? "HOST_FIND_SECURITY" :
3095 yield == HOST_FIND_AGAIN ? "HOST_FIND_AGAIN" :
3096 yield == HOST_FIND_FAILED ? "HOST_FIND_FAILED" : "?",
3098 for (h = host; h != last->next; h = h->next)
3100 debug_printf(" %s %s MX=%d %s", h->name,
3101 !h->address ? US"<null>" : h->address, h->mx,
3102 h->dnssec == DS_YES ? US"DNSSEC " : US"");
3103 if (h->port != PORT_NONE) debug_printf("port=%d ", h->port);
3104 if (h->status >= hstatus_unusable) debug_printf("*");
3111 dns_init(FALSE, FALSE, FALSE); /* clear the dnssec bit for getaddrbyname */
3112 store_free_dns_answer(dnsa);
3120 /* Lookup TLSA record for host/port.
3121 Return: OK success with dnssec; DANE mode
3122 DEFER Do not use this host now, may retry later
3123 FAIL_FORCED No TLSA record; DANE not usable
3124 FAIL Do not use this connection
3128 tlsa_lookup(const host_item * host, dns_answer * dnsa, BOOL dane_required)
3131 const uschar * fullname = buffer;
3135 /* TLSA lookup string */
3136 (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name);
3138 rc = dns_lookup_timerwrap(dnsa, buffer, T_TLSA, &fullname);
3139 sec = dns_is_secure(dnsa);
3141 debug_printf("TLSA lookup ret %s %sDNSSEC\n", dns_rc_names[rc], sec ? "" : "not ");
3146 return DEFER; /* just defer this TLS'd conn */
3154 for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
3155 rr = dns_next_rr(dnsa, &dnss, RESET_NEXT))
3156 if (rr->type == T_TLSA && rr->size > 3)
3158 uint16_t payload_length = rr->size - 3;
3159 uschar s[MAX_TLSA_EXPANDED_SIZE], * sp = s, * p = US rr->data;
3161 sp += sprintf(CS sp, "%d ", *p++); /* usage */
3162 sp += sprintf(CS sp, "%d ", *p++); /* selector */
3163 sp += sprintf(CS sp, "%d ", *p++); /* matchtype */
3164 while (payload_length-- > 0 && sp-s < (MAX_TLSA_EXPANDED_SIZE - 4))
3165 sp += sprintf(CS sp, "%02x", *p++);
3167 debug_printf(" %s\n", s);
3172 log_write(0, LOG_MAIN,
3173 "DANE error: TLSA lookup for %s not DNSSEC", host->name);
3176 case DNS_NODATA: /* no TLSA RR for this lookup */
3177 case DNS_NOMATCH: /* no records at all for this lookup */
3178 return dane_required ? FAIL : FAIL_FORCED;
3182 return dane_required ? FAIL : DEFER;
3185 #endif /*SUPPORT_DANE*/
3189 /*************************************************
3190 **************************************************
3191 * Stand-alone test program *
3192 **************************************************
3193 *************************************************/
3197 int main(int argc, char **cargv)
3200 int whichrrs = HOST_FIND_BY_MX | HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
3201 BOOL byname = FALSE;
3202 BOOL qualify_single = TRUE;
3203 BOOL search_parents = FALSE;
3204 BOOL request_dnssec = FALSE;
3205 BOOL require_dnssec = FALSE;
3206 uschar **argv = USS cargv;
3209 disable_ipv6 = FALSE;
3210 primary_hostname = US"";
3212 store_pool = POOL_MAIN;
3213 debug_selector = D_host_lookup|D_interface;
3214 debug_file = stdout;
3215 debug_fd = fileno(debug_file);
3217 printf("Exim stand-alone host functions test\n");
3219 host_find_interfaces();
3220 debug_selector = D_host_lookup | D_dns;
3222 if (argc > 1) primary_hostname = argv[1];
3224 /* So that debug level changes can be done first */
3226 dns_init(qualify_single, search_parents, FALSE);
3228 printf("Testing host lookup\n");
3230 while (Ufgets(buffer, 256, stdin) != NULL)
3233 int len = Ustrlen(buffer);
3234 uschar *fully_qualified_name;
3236 while (len > 0 && isspace(buffer[len-1])) len--;
3239 if (Ustrcmp(buffer, "q") == 0) break;
3241 if (Ustrcmp(buffer, "byname") == 0) byname = TRUE;
3242 else if (Ustrcmp(buffer, "no_byname") == 0) byname = FALSE;
3243 else if (Ustrcmp(buffer, "a_only") == 0) whichrrs = HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
3244 else if (Ustrcmp(buffer, "mx_only") == 0) whichrrs = HOST_FIND_BY_MX;
3245 else if (Ustrcmp(buffer, "srv_only") == 0) whichrrs = HOST_FIND_BY_SRV;
3246 else if (Ustrcmp(buffer, "srv+a") == 0)
3247 whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
3248 else if (Ustrcmp(buffer, "srv+mx") == 0)
3249 whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_MX;
3250 else if (Ustrcmp(buffer, "srv+mx+a") == 0)
3251 whichrrs = HOST_FIND_BY_SRV | HOST_FIND_BY_MX | HOST_FIND_BY_A | HOST_FIND_BY_AAAA;
3252 else if (Ustrcmp(buffer, "qualify_single") == 0) qualify_single = TRUE;
3253 else if (Ustrcmp(buffer, "no_qualify_single") == 0) qualify_single = FALSE;
3254 else if (Ustrcmp(buffer, "search_parents") == 0) search_parents = TRUE;
3255 else if (Ustrcmp(buffer, "no_search_parents") == 0) search_parents = FALSE;
3256 else if (Ustrcmp(buffer, "request_dnssec") == 0) request_dnssec = TRUE;
3257 else if (Ustrcmp(buffer, "no_request_dnssec") == 0) request_dnssec = FALSE;
3258 else if (Ustrcmp(buffer, "require_dnssec") == 0) require_dnssec = TRUE;
3259 else if (Ustrcmp(buffer, "no_require_dnssec") == 0) require_dnssec = FALSE;
3260 else if (Ustrcmp(buffer, "test_harness") == 0)
3261 f.running_in_test_harness = !f.running_in_test_harness;
3262 else if (Ustrcmp(buffer, "ipv6") == 0) disable_ipv6 = !disable_ipv6;
3263 else if (Ustrcmp(buffer, "res_debug") == 0)
3265 _res.options ^= RES_DEBUG;
3267 else if (Ustrncmp(buffer, "retrans", 7) == 0)
3269 (void)sscanf(CS(buffer+8), "%d", &dns_retrans);
3270 _res.retrans = dns_retrans;
3272 else if (Ustrncmp(buffer, "retry", 5) == 0)
3274 (void)sscanf(CS(buffer+6), "%d", &dns_retry);
3275 _res.retry = dns_retry;
3279 int flags = whichrrs;
3286 h.status = hstatus_unknown;
3287 h.why = hwhy_unknown;
3290 if (qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
3291 if (search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
3293 d.request = request_dnssec ? &h.name : NULL;
3294 d.require = require_dnssec ? &h.name : NULL;
3297 ? host_find_byname(&h, NULL, flags, &fully_qualified_name, TRUE)
3298 : host_find_bydns(&h, NULL, flags, US"smtp", NULL, NULL,
3299 &d, &fully_qualified_name, NULL);
3303 case HOST_FIND_FAILED: printf("Failed\n"); break;
3304 case HOST_FIND_AGAIN: printf("Again\n"); break;
3305 case HOST_FIND_SECURITY: printf("Security\n"); break;
3306 case HOST_FOUND_LOCAL: printf("Local\n"); break;
3313 printf("Testing host_aton\n");
3315 while (Ufgets(buffer, 256, stdin) != NULL)
3318 int len = Ustrlen(buffer);
3320 while (len > 0 && isspace(buffer[len-1])) len--;
3323 if (Ustrcmp(buffer, "q") == 0) break;
3325 len = host_aton(buffer, x);
3326 printf("length = %d ", len);
3327 for (int i = 0; i < len; i++)
3329 printf("%04x ", (x[i] >> 16) & 0xffff);
3330 printf("%04x ", x[i] & 0xffff);
3337 printf("Testing host_name_lookup\n");
3339 while (Ufgets(buffer, 256, stdin) != NULL)
3341 int len = Ustrlen(buffer);
3342 while (len > 0 && isspace(buffer[len-1])) len--;
3344 if (Ustrcmp(buffer, "q") == 0) break;
3345 sender_host_address = buffer;
3346 sender_host_name = NULL;
3347 sender_host_aliases = NULL;
3348 host_lookup_msg = US"";
3349 host_lookup_failed = FALSE;
3350 if (host_name_lookup() == FAIL) /* Debug causes printing */
3351 printf("Lookup failed:%s\n", host_lookup_msg);
3359 #endif /* STAND_ALONE */