X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/1dc92d5af0dddcee977aab6da545951c051b2c58..8e0130284ead48da81351d4d2c22fe7eb23703d6:/src/src/dns.c diff --git a/src/src/dns.c b/src/src/dns.c index 66633f741..24f3522c7 100644 --- a/src/src/dns.c +++ b/src/src/dns.c @@ -10,16 +10,6 @@ #include "exim.h" -/* Function declaration needed for mutual recursion when A6 records -are supported. */ - -#if HAVE_IPV6 -#ifdef SUPPORT_A6 -static void dns_complete_a6(dns_address ***, dns_answer *, dns_record *, - int, uschar *); -#endif -#endif - /************************************************* * Fake DNS resolver * @@ -33,7 +23,7 @@ If not, it passes its arguments on to res_search(). The fake nameserver may also return a code specifying that the name should be passed on. Background: the original test suite required a real nameserver to carry the -test zones, whereas the new test suit has the fake server for portability. This +test zones, whereas the new test suite has the fake server for portability. This code supports both. Arguments: @@ -139,6 +129,10 @@ if (stat(CS utilname, &statbuf) >= 0) DEBUG(D_dns) debug_printf("fakens returned PASS_ON\n"); } } +else + { + DEBUG(D_dns) debug_printf("fakens (%s) not found\n", utilname); + } /* fakens utility not found, or it returned "pass on" */ @@ -257,9 +251,9 @@ Returns: nothing */ void -dns_build_reverse(uschar *string, uschar *buffer) +dns_build_reverse(const uschar *string, uschar *buffer) { -uschar *p = string + Ustrlen(string); +const uschar *p = string + Ustrlen(string); uschar *pp = buffer; /* Handle IPv4 address */ @@ -271,7 +265,7 @@ if (Ustrchr(string, ':') == NULL) int i; for (i = 0; i < 4; i++) { - uschar *ppp = p; + const uschar *ppp = p; while (ppp > string && ppp[-1] != '.') ppp--; Ustrncpy(pp, ppp, p - ppp); pp += p - ppp; @@ -443,7 +437,7 @@ Returns: bool indicating presence of AD bit */ BOOL -dns_is_secure(const dns_answer *dnsa) +dns_is_secure(const dns_answer * dnsa) { #ifdef DISABLE_DNSSEC DEBUG(D_dns) @@ -455,6 +449,13 @@ return h->ad ? TRUE : FALSE; #endif } +static void +dns_set_insecure(dns_answer * dnsa) +{ +HEADER * h = (HEADER *)dnsa->answer; +h->ad = 0; +} + @@ -553,7 +554,7 @@ dns_basic_lookup(dns_answer *dnsa, const uschar *name, int type) { #ifndef STAND_ALONE int rc = -1; -uschar *save; +const uschar *save_domain; #endif res_state resp = os_get_dns_resolver_res(); @@ -579,6 +580,25 @@ if (previous != NULL) return previous->data.val; } +#ifdef EXPERIMENTAL_INTERNATIONAL +/* Convert all names to a-label form before doing lookup */ + { + uschar * alabel; + uschar * errstr = NULL; + DEBUG(D_dns) if (string_is_utf8(name)) + debug_printf("convert utf8 '%s' to alabel for for lookup\n", name); + if ((alabel = string_domain_utf8_to_alabel(name, &errstr)), errstr) + { + DEBUG(D_dns) + debug_printf("DNS name '%s' utf8 conversion to alabel failed: %s\n", name, + errstr); + host_find_failed_syntax = TRUE; + return DNS_NOMATCH; + } + name = alabel; + } +#endif + /* If configured, check the hygene of the name passed to lookup. Otherwise, although DNS lookups may give REFUSED at the lower level, some resolvers turn this into TRY_AGAIN, which is silly. Give a NOMATCH return, since such @@ -600,9 +620,7 @@ if (check_dns_names_pattern[0] != 0 && type != T_PTR && type != T_TXT) const uschar *checkname = name; int ovector[3*(EXPAND_MAXN+1)]; - if (regex_check_dns_names == NULL) - regex_check_dns_names = - regex_must_compile(check_dns_names_pattern, FALSE, TRUE); + dns_pattern_init(); /* For an SRV lookup, skip over the first two components (the service and protocol names, which both start with an underscore). */ @@ -635,22 +653,16 @@ the IP address instead of returning -1 with h_error=HOST_NOT_FOUND. Some nameservers are also believed to do this. It is, of course, contrary to the specification of the DNS, so we lock it out. */ -if (( - #ifdef SUPPORT_A6 - type == T_A6 || - #endif - type == T_A || type == T_AAAA) && - string_is_ip_address(name, NULL) != 0) +if ((type == T_A || type == T_AAAA) && string_is_ip_address(name, NULL) != 0) return DNS_NOMATCH; /* If we are running in the test harness, instead of calling the normal resolver (res_search), we call fakens_search(), which recognizes certain special domains, and interfaces to a fake nameserver for certain special zones. */ -if (running_in_test_harness) - dnsa->answerlen = fakens_search(name, type, dnsa->answer, MAXPACKET); -else - dnsa->answerlen = res_search(CCS name, C_IN, type, dnsa->answer, MAXPACKET); +dnsa->answerlen = running_in_test_harness + ? fakens_search(name, type, dnsa->answer, MAXPACKET) + : res_search(CCS name, C_IN, type, dnsa->answer, MAXPACKET); if (dnsa->answerlen > MAXPACKET) { @@ -672,11 +684,11 @@ if (dnsa->answerlen < 0) switch (h_errno) /* Cut this out for various test programs */ #ifndef STAND_ALONE - save = deliver_domain; + save_domain = deliver_domain; deliver_domain = string_copy(name); /* set $domain */ - rc = match_isinlist(name, &dns_again_means_nonexist, 0, NULL, NULL, + rc = match_isinlist(name, (const uschar **)&dns_again_means_nonexist, 0, NULL, NULL, MCL_DOMAIN, TRUE, NULL); - deliver_domain = save; + deliver_domain = save_domain; if (rc != OK) { DEBUG(D_dns) debug_printf("returning DNS_AGAIN\n"); @@ -732,7 +744,8 @@ won't return any. If fully_qualified_name is not NULL, set it to point to the full name returned by the resolver, if this is different to what it is given, unless the returned name starts with "*" as some nameservers seem to be returning -wildcards in this form. +wildcards in this form. In international mode "different" means "alabel +forms are different". Arguments: dnsa pointer to dns_answer structure @@ -750,10 +763,11 @@ Returns: DNS_SUCCEED successful lookup int dns_lookup(dns_answer *dnsa, const uschar *name, int type, - uschar **fully_qualified_name) + const uschar **fully_qualified_name) { int i; const uschar *orig_name = name; +BOOL secure_so_far = TRUE; /* Loop to follow CNAME chains so far, but no further... */ @@ -792,23 +806,29 @@ for (i = 0; i < 10; i++) if (i == 0 && fully_qualified_name != NULL) { - if (cname_rr.data != NULL) - { - if (Ustrcmp(cname_rr.name, *fully_qualified_name) != 0 && - cname_rr.name[0] != '*') - *fully_qualified_name = string_copy_dnsdomain(cname_rr.name); - } - else if (type_rr.data != NULL) - { - if (Ustrcmp(type_rr.name, *fully_qualified_name) != 0 && - type_rr.name[0] != '*') - *fully_qualified_name = string_copy_dnsdomain(type_rr.name); - } + uschar * rr_name = cname_rr.data ? cname_rr.name + : type_rr.data ? type_rr.name : NULL; + if ( rr_name + && Ustrcmp(rr_name, *fully_qualified_name) != 0 + && rr_name[0] != '*' +#ifdef EXPERIMENTAL_INTERNATIONAL + && ( !string_is_utf8(*fully_qualified_name) + || Ustrcmp(rr_name, + string_domain_utf8_to_alabel(*fully_qualified_name, NULL)) != 0 + ) +#endif + ) + *fully_qualified_name = string_copy_dnsdomain(rr_name); } /* If any data records of the correct type were found, we are done. */ - if (type_rr.data != NULL) return DNS_SUCCEED; + if (type_rr.data != NULL) + { + if (!secure_so_far) /* mark insecure if any element of CNAME chain was */ + dns_set_insecure(dnsa); + return DNS_SUCCEED; + } /* If there are no data records, we need to re-scan the DNS using the domain given in the CNAME record, which should exist (otherwise we should @@ -821,6 +841,9 @@ for (i = 0; i < 10; i++) if (datalen < 0) return DNS_FAIL; name = data; + if (!dns_is_secure(dnsa)) + secure_so_far = FALSE; + DEBUG(D_dns) debug_printf("CNAME found: change to %s\n", name); } /* Loop back to do another lookup */ @@ -860,175 +883,181 @@ Returns: DNS_SUCCEED successful lookup int dns_special_lookup(dns_answer *dnsa, const uschar *name, int type, - uschar **fully_qualified_name) + const uschar **fully_qualified_name) { -if (type >= 0) return dns_lookup(dnsa, name, type, fully_qualified_name); - -/* The "mx hosts only" type doesn't require any special action here */ - -if (type == T_MXH) return dns_lookup(dnsa, name, T_MX, fully_qualified_name); - -/* Find nameservers for the domain or the nearest enclosing zone, excluding the -root servers. */ - -if (type == T_ZNS) +switch (type) { - const uschar *d = name; - while (d != 0) - { - int rc = dns_lookup(dnsa, d, T_NS, fully_qualified_name); - if (rc != DNS_NOMATCH && rc != DNS_NODATA) return rc; - while (*d != 0 && *d != '.') d++; - if (*d++ == 0) break; - } - return DNS_NOMATCH; - } - -/* Try to look up the Client SMTP Authorization SRV record for the name. If -there isn't one, search from the top downwards for a CSA record in a parent -domain, which might be making assertions about subdomains. If we find a record -we set fully_qualified_name to whichever lookup succeeded, so that the caller -can tell whether to look at the explicit authorization field or the subdomain -assertion field. */ - -if (type == T_CSA) - { - uschar *srvname, *namesuff, *tld, *p; - int priority, weight, port; - int limit, rc, i; - BOOL ipv6; - dns_record *rr; - dns_scan dnss; - - DEBUG(D_dns) debug_printf("CSA lookup of %s\n", name); - - srvname = string_sprintf("_client._smtp.%s", name); - rc = dns_lookup(dnsa, srvname, T_SRV, NULL); - if (rc == DNS_SUCCEED || rc == DNS_AGAIN) - { - if (rc == DNS_SUCCEED) *fully_qualified_name = string_copy(name); - return rc; - } - - /* Search for CSA subdomain assertion SRV records from the top downwards, - starting with the 2nd level domain. This order maximizes cache-friendliness. - We skip the top level domains to avoid loading their nameservers and because - we know they'll never have CSA SRV records. */ - - namesuff = Ustrrchr(name, '.'); - if (namesuff == NULL) return DNS_NOMATCH; - tld = namesuff + 1; - ipv6 = FALSE; - limit = dns_csa_search_limit; - - /* Use more appropriate search parameters if we are in the reverse DNS. */ - - if (strcmpic(namesuff, US".arpa") == 0) - { - if (namesuff - 8 > name && strcmpic(namesuff - 8, US".in-addr.arpa") == 0) - { - namesuff -= 8; - tld = namesuff + 1; - limit = 3; - } - else if (namesuff - 4 > name && strcmpic(namesuff - 4, US".ip6.arpa") == 0) - { - namesuff -= 4; - tld = namesuff + 1; - ipv6 = TRUE; - limit = 3; - } - } - - DEBUG(D_dns) debug_printf("CSA TLD %s\n", tld); - - /* Do not perform the search if the top level or 2nd level domains do not - exist. This is quite common, and when it occurs all the search queries would - go to the root or TLD name servers, which is not friendly. So we check the - AUTHORITY section; if it contains the root's SOA record or the TLD's SOA then - the TLD or the 2LD (respectively) doesn't exist and we can skip the search. - If the TLD and the 2LD exist but the explicit CSA record lookup failed, then - the AUTHORITY SOA will be the 2LD's or a subdomain thereof. */ - - if (rc == DNS_NOMATCH) - { - /* This is really gross. The successful return value from res_search() is - the packet length, which is stored in dnsa->answerlen. If we get a - negative DNS reply then res_search() returns -1, which causes the bounds - checks for name decompression to fail when it is treated as a packet - length, which in turn causes the authority search to fail. The correct - packet length has been lost inside libresolv, so we have to guess a - replacement value. (The only way to fix this properly would be to - re-implement res_search() and res_query() so that they don't muddle their - success and packet length return values.) For added safety we only reset - the packet length if the packet header looks plausible. */ - - HEADER *h = (HEADER *)dnsa->answer; - if (h->qr == 1 && h->opcode == QUERY && h->tc == 0 - && (h->rcode == NOERROR || h->rcode == NXDOMAIN) - && ntohs(h->qdcount) == 1 && ntohs(h->ancount) == 0 - && ntohs(h->nscount) >= 1) - dnsa->answerlen = MAXPACKET; - - for (rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY); - rr != NULL; - rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) - if (rr->type != T_SOA) continue; - else if (strcmpic(rr->name, US"") == 0 || - strcmpic(rr->name, tld) == 0) return DNS_NOMATCH; - else break; - } - - for (i = 0; i < limit; i++) - { - if (ipv6) - { - /* Scan through the IPv6 reverse DNS in chunks of 16 bits worth of IP - address, i.e. 4 hex chars and 4 dots, i.e. 8 chars. */ - namesuff -= 8; - if (namesuff <= name) return DNS_NOMATCH; - } - else - /* Find the start of the preceding domain name label. */ - do - if (--namesuff <= name) return DNS_NOMATCH; - while (*namesuff != '.'); - - DEBUG(D_dns) debug_printf("CSA parent search at %s\n", namesuff + 1); + /* The "mx hosts only" type doesn't require any special action here */ + case T_MXH: + return dns_lookup(dnsa, name, T_MX, fully_qualified_name); + + /* Find nameservers for the domain or the nearest enclosing zone, excluding + the root servers. */ + case T_ZNS: + type = T_NS; + /* FALLTHROUGH */ + case T_SOA: + { + const uschar *d = name; + while (d != 0) + { + int rc = dns_lookup(dnsa, d, type, fully_qualified_name); + if (rc != DNS_NOMATCH && rc != DNS_NODATA) return rc; + while (*d != 0 && *d != '.') d++; + if (*d++ == 0) break; + } + return DNS_NOMATCH; + } + + /* Try to look up the Client SMTP Authorization SRV record for the name. If + there isn't one, search from the top downwards for a CSA record in a parent + domain, which might be making assertions about subdomains. If we find a record + we set fully_qualified_name to whichever lookup succeeded, so that the caller + can tell whether to look at the explicit authorization field or the subdomain + assertion field. */ + case T_CSA: + { + uschar *srvname, *namesuff, *tld, *p; + int priority, weight, port; + int limit, rc, i; + BOOL ipv6; + dns_record *rr; + dns_scan dnss; + + DEBUG(D_dns) debug_printf("CSA lookup of %s\n", name); + + srvname = string_sprintf("_client._smtp.%s", name); + rc = dns_lookup(dnsa, srvname, T_SRV, NULL); + if (rc == DNS_SUCCEED || rc == DNS_AGAIN) + { + if (rc == DNS_SUCCEED) *fully_qualified_name = string_copy(name); + return rc; + } + + /* Search for CSA subdomain assertion SRV records from the top downwards, + starting with the 2nd level domain. This order maximizes cache-friendliness. + We skip the top level domains to avoid loading their nameservers and because + we know they'll never have CSA SRV records. */ + + namesuff = Ustrrchr(name, '.'); + if (namesuff == NULL) return DNS_NOMATCH; + tld = namesuff + 1; + ipv6 = FALSE; + limit = dns_csa_search_limit; + + /* Use more appropriate search parameters if we are in the reverse DNS. */ + + if (strcmpic(namesuff, US".arpa") == 0) + { + if (namesuff - 8 > name && strcmpic(namesuff - 8, US".in-addr.arpa") == 0) + { + namesuff -= 8; + tld = namesuff + 1; + limit = 3; + } + else if (namesuff - 4 > name && strcmpic(namesuff - 4, US".ip6.arpa") == 0) + { + namesuff -= 4; + tld = namesuff + 1; + ipv6 = TRUE; + limit = 3; + } + } + + DEBUG(D_dns) debug_printf("CSA TLD %s\n", tld); + + /* Do not perform the search if the top level or 2nd level domains do not + exist. This is quite common, and when it occurs all the search queries would + go to the root or TLD name servers, which is not friendly. So we check the + AUTHORITY section; if it contains the root's SOA record or the TLD's SOA then + the TLD or the 2LD (respectively) doesn't exist and we can skip the search. + If the TLD and the 2LD exist but the explicit CSA record lookup failed, then + the AUTHORITY SOA will be the 2LD's or a subdomain thereof. */ + + if (rc == DNS_NOMATCH) + { + /* This is really gross. The successful return value from res_search() is + the packet length, which is stored in dnsa->answerlen. If we get a + negative DNS reply then res_search() returns -1, which causes the bounds + checks for name decompression to fail when it is treated as a packet + length, which in turn causes the authority search to fail. The correct + packet length has been lost inside libresolv, so we have to guess a + replacement value. (The only way to fix this properly would be to + re-implement res_search() and res_query() so that they don't muddle their + success and packet length return values.) For added safety we only reset + the packet length if the packet header looks plausible. */ + + HEADER *h = (HEADER *)dnsa->answer; + if (h->qr == 1 && h->opcode == QUERY && h->tc == 0 + && (h->rcode == NOERROR || h->rcode == NXDOMAIN) + && ntohs(h->qdcount) == 1 && ntohs(h->ancount) == 0 + && ntohs(h->nscount) >= 1) + dnsa->answerlen = MAXPACKET; + + for (rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY); + rr != NULL; + rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) + if (rr->type != T_SOA) continue; + else if (strcmpic(rr->name, US"") == 0 || + strcmpic(rr->name, tld) == 0) return DNS_NOMATCH; + else break; + } + + for (i = 0; i < limit; i++) + { + if (ipv6) + { + /* Scan through the IPv6 reverse DNS in chunks of 16 bits worth of IP + address, i.e. 4 hex chars and 4 dots, i.e. 8 chars. */ + namesuff -= 8; + if (namesuff <= name) return DNS_NOMATCH; + } + else + /* Find the start of the preceding domain name label. */ + do + if (--namesuff <= name) return DNS_NOMATCH; + while (*namesuff != '.'); + + DEBUG(D_dns) debug_printf("CSA parent search at %s\n", namesuff + 1); + + srvname = string_sprintf("_client._smtp.%s", namesuff + 1); + rc = dns_lookup(dnsa, srvname, T_SRV, NULL); + if (rc == DNS_AGAIN) return rc; + if (rc != DNS_SUCCEED) continue; + + /* Check that the SRV record we have found is worth returning. We don't + just return the first one we find, because some lower level SRV record + might make stricter assertions than its parent domain. */ + + for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); + rr != NULL; + rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) + { + if (rr->type != T_SRV) continue; + + /* Extract the numerical SRV fields (p is incremented) */ + p = rr->data; + GETSHORT(priority, p); + GETSHORT(weight, p); weight = weight; /* compiler quietening */ + GETSHORT(port, p); + + /* Check the CSA version number */ + if (priority != 1) continue; + + /* If it's making an interesting assertion, return this response. */ + if (port & 1) + { + *fully_qualified_name = namesuff + 1; + return DNS_SUCCEED; + } + } + } + return DNS_NOMATCH; + } - srvname = string_sprintf("_client._smtp.%s", namesuff + 1); - rc = dns_lookup(dnsa, srvname, T_SRV, NULL); - if (rc == DNS_AGAIN) return rc; - if (rc != DNS_SUCCEED) continue; - - /* Check that the SRV record we have found is worth returning. We don't - just return the first one we find, because some lower level SRV record - might make stricter assertions than its parent domain. */ - - for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); - rr != NULL; - rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) - { - if (rr->type != T_SRV) continue; - - /* Extract the numerical SRV fields (p is incremented) */ - p = rr->data; - GETSHORT(priority, p); - GETSHORT(weight, p); - GETSHORT(port, p); - - /* Check the CSA version number */ - if (priority != 1) continue; - - /* If it's making an interesting assertion, return this response. */ - if (port & 1) - { - *fully_qualified_name = namesuff + 1; - return DNS_SUCCEED; - } - } - } - return DNS_NOMATCH; + default: + if (type >= 0) + return dns_lookup(dnsa, name, type, fully_qualified_name); } /* Control should never reach here */ @@ -1038,164 +1067,6 @@ return DNS_FAIL; -/* Support for A6 records has been commented out since they were demoted to -experimental status at IETF 51. */ - -#if HAVE_IPV6 && defined(SUPPORT_A6) - -/************************************************* -* Search DNS block for prefix RRs * -*************************************************/ - -/* Called from dns_complete_a6() to search an additional section or a main -answer section for required prefix records to complete an IPv6 address obtained -from an A6 record. For each prefix record, a recursive call to dns_complete_a6 -is made, with a new copy of the address so far. - -Arguments: - dnsa the DNS answer block - which RESET_ADDITIONAL or RESET_ANSWERS - name name of prefix record - yptrptr pointer to the pointer that points to where to hang the next - dns_address structure - bits number of bits we have already got - bitvec the bits we have already got - -Returns: TRUE if any records were found -*/ - -static BOOL -dns_find_prefix(dns_answer *dnsa, int which, uschar *name, dns_address - ***yptrptr, int bits, uschar *bitvec) -{ -BOOL yield = FALSE; -dns_record *rr; -dns_scan dnss; - -for (rr = dns_next_rr(dnsa, &dnss, which); - rr != NULL; - rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) - { - uschar cbitvec[16]; - if (rr->type != T_A6 || strcmpic(rr->name, name) != 0) continue; - yield = TRUE; - memcpy(cbitvec, bitvec, sizeof(cbitvec)); - dns_complete_a6(yptrptr, dnsa, rr, bits, cbitvec); - } - -return yield; -} - - - -/************************************************* -* Follow chains of A6 records * -*************************************************/ - -/* A6 records may be incomplete, with pointers to other records containing more -bits of the address. There can be a tree structure, leading to a number of -addresses originating from a single initial A6 record. - -Arguments: - yptrptr pointer to the pointer that points to where to hang the next - dns_address structure - dnsa the current DNS answer block - rr the RR we have at present - bits number of bits we have already got - bitvec the bits we have already got - -Returns: nothing -*/ - -static void -dns_complete_a6(dns_address ***yptrptr, dns_answer *dnsa, dns_record *rr, - int bits, uschar *bitvec) -{ -static uschar bitmask[] = { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 }; -uschar *p = (uschar *)(rr->data); -int prefix_len, suffix_len; -int i, j, k; -uschar *chainptr; -uschar chain[264]; -dns_answer cdnsa; - -/* The prefix length is the first byte. It defines the prefix which is missing -from the data in this record as a number of bits. Zero means this is the end of -a chain. The suffix is the data in this record; only sufficient bytes to hold -it are supplied. There may be zero bytes. We have to ignore trailing bits that -we have already obtained from earlier RRs in the chain. */ - -prefix_len = *p++; /* bits */ -suffix_len = (128 - prefix_len + 7)/8; /* bytes */ - -/* If the prefix in this record is greater than the prefix in the previous -record in the chain, we have to ignore the record (RFC 2874). */ - -if (prefix_len > 128 - bits) return; - -/* In this little loop, the number of bits up to and including the current byte -is held in k. If we have none of the bits in this byte, we can just or it into -the current data. If we have all of the bits in this byte, we skip it. -Otherwise, some masking has to be done. */ - -for (i = suffix_len - 1, j = 15, k = 8; i >= 0; i--) - { - int required = k - bits; - if (required >= 8) bitvec[j] |= p[i]; - else if (required > 0) bitvec[j] |= p[i] & bitmask[required]; - j--; /* I tried putting these in the "for" statement, but gcc muttered */ - k += 8; /* about computed values not being used. */ - } - -/* If the prefix_length is zero, we are at the end of a chain. Build a -dns_address item with the current data, hang it onto the end of the chain, -adjust the hanging pointer, and we are done. */ - -if (prefix_len == 0) - { - dns_address *new = store_get(sizeof(dns_address) + 50); - inet_ntop(AF_INET6, bitvec, CS new->address, 50); - new->next = NULL; - **yptrptr = new; - *yptrptr = &(new->next); - return; - } - -/* Prefix length is not zero. Reset the number of bits that we have collected -so far, and extract the chain name. */ - -bits = 128 - prefix_len; -p += suffix_len; - -chainptr = chain; -while ((i = *p++) != 0) - { - if (chainptr != chain) *chainptr++ = '.'; - memcpy(chainptr, p, i); - chainptr += i; - p += i; - } -*chainptr = 0; -chainptr = chain; - -/* Now scan the current DNS response record to see if the additional section -contains the records we want. This processing can be cut out for testing -purposes. */ - -if (dns_find_prefix(dnsa, RESET_ADDITIONAL, chainptr, yptrptr, bits, bitvec)) - return; - -/* No chain records were found in the current DNS response block. Do a new DNS -lookup to try to find these records. This opens up the possibility of DNS -failures. We ignore them at this point; if all branches of the tree fail, there -will be no addresses at the end. */ - -if (dns_lookup(&cdnsa, chainptr, T_A6, NULL) == DNS_SUCCEED) - (void)dns_find_prefix(&cdnsa, RESET_ANSWERS, chainptr, yptrptr, bits, bitvec); -} -#endif /* HAVE_IPV6 && defined(SUPPORT_A6) */ - - /************************************************* @@ -1203,16 +1074,13 @@ if (dns_lookup(&cdnsa, chainptr, T_A6, NULL) == DNS_SUCCEED) *************************************************/ /* The record type is either T_A for an IPv4 address or T_AAAA (or T_A6 when -supported) for an IPv6 address. In the A6 case, there may be several addresses, -generated by following chains. A recursive function does all the hard work. A6 -records now look like passing into history, so the code is only included when -explicitly asked for. +supported) for an IPv6 address. Argument: dnsa the DNS answer block rr the RR -Returns: pointer a chain of dns_address items +Returns: pointer to a chain of dns_address items */ dns_address * @@ -1220,16 +1088,11 @@ dns_address_from_rr(dns_answer *dnsa, dns_record *rr) { dns_address *yield = NULL; -#if HAVE_IPV6 && defined(SUPPORT_A6) -dns_address **yieldptr = &yield; -uschar bitvec[16]; -#else dnsa = dnsa; /* Stop picky compilers warning */ -#endif if (rr->type == T_A) { - uschar *p = (uschar *)(rr->data); + uschar *p = US rr->data; yield = store_get(sizeof(dns_address) + 20); (void)sprintf(CS yield->address, "%d.%d.%d.%d", p[0], p[1], p[2], p[3]); yield->next = NULL; @@ -1237,18 +1100,10 @@ if (rr->type == T_A) #if HAVE_IPV6 -#ifdef SUPPORT_A6 -else if (rr->type == T_A6) - { - memset(bitvec, 0, sizeof(bitvec)); - dns_complete_a6(&yieldptr, dnsa, rr, 0, bitvec); - } -#endif /* SUPPORT_A6 */ - else { yield = store_get(sizeof(dns_address) + 50); - inet_ntop(AF_INET6, (uschar *)(rr->data), CS yield->address, 50); + inet_ntop(AF_INET6, US rr->data, CS yield->address, 50); yield->next = NULL; } #endif /* HAVE_IPV6 */ @@ -1256,6 +1111,16 @@ else return yield; } + + +void +dns_pattern_init(void) +{ +if (check_dns_names_pattern[0] != 0 && !regex_check_dns_names) + regex_check_dns_names = + regex_must_compile(check_dns_names_pattern, FALSE, TRUE); +} + /* vi: aw ai sw=2 */ /* End of dns.c */