X-Git-Url: https://git.netwichtig.de/gitweb/?a=blobdiff_plain;f=src%2Fsrc%2Fdns.c;h=6ef6b7784b03343bff3a2b3fae635577d8300d37;hb=87abcb247b4444bab5fd0bcb212ddb26d5fd9191;hp=cb1766618ba26bc29cf2cf8ede723e34da7edecc;hpb=d8d9f9301c9a31c826635bbdd334bb4be99ea05a;p=user%2Fhenk%2Fcode%2Fexim.git diff --git a/src/src/dns.c b/src/src/dns.c index cb1766618..6ef6b7784 100644 --- a/src/src/dns.c +++ b/src/src/dns.c @@ -240,8 +240,7 @@ uschar *pp = buffer; if (Ustrchr(string, ':') == NULL) #endif { - int i; - for (i = 0; i < 4; i++) + for (int i = 0; i < 4; i++) { const uschar *ppp = p; while (ppp > string && ppp[-1] != '.') ppp--; @@ -259,7 +258,6 @@ abbreviation in the textual form. */ #if HAVE_IPV6 else { - int i; int v6[4]; (void)host_aton(string, v6); @@ -267,12 +265,9 @@ else nibble, and look in the ip6.int domain. The domain was subsequently changed to ip6.arpa. */ - for (i = 3; i >= 0; i--) - { - int j; - for (j = 0; j < 32; j += 4) + for (int i = 3; i >= 0; i--) + for (int j = 0; j < 32; j += 4) pp += sprintf(CS pp, "%x.", (v6[i] >> j) & 15); - } Ustrcpy(pp, "ip6.arpa."); /* Another way of doing IPv6 reverse lookups was proposed in conjunction @@ -287,7 +282,7 @@ else Ustrcpy(pp, "\\[x"); pp += 3; - for (i = 0; i < 4; i++) + for (int i = 0; i < 4; i++) { sprintf(pp, "%08X", v6[i]); pp += 8; @@ -467,11 +462,10 @@ static const uschar * dns_extract_auth_name(const dns_answer * dnsa) /* FIXME: const dns_answer */ { dns_scan dnss; -dns_record * rr; const HEADER * h = (const HEADER *) dnsa->answer; if (h->nscount && h->aa) - for (rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY); + for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY); rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == (h->ancount ? T_NS : T_SOA)) return string_copy(rr->name); @@ -639,6 +633,10 @@ up nameservers that produce this error continually, so there is the option of providing a list of domains for which this is treated as a non-existent host. +The dns_answer structure is pretty big; enough to hold a max-sized DNS message +- so best allocated from fast-release memory. As of writing, all our callers +use a stack-auto variable. + Arguments: dnsa pointer to dns_answer structure name name to look up @@ -693,7 +691,7 @@ if ((previous = tree_search(tree_dns_fails, node_name))) DEBUG(D_dns) debug_printf("DNS name '%s' utf8 conversion to alabel failed: %s\n", name, errstr); - host_find_failed_syntax = TRUE; + f.host_find_failed_syntax = TRUE; return DNS_NOMATCH; } name = alabel; @@ -712,7 +710,11 @@ lookup, which constructs the names itself, so they should be OK. Besides, bitstring labels don't conform to normal name syntax. (But the aren't used any more.) -For SRV records, we omit the initial _smtp._tcp. components at the start. */ +For SRV records, we omit the initial _smtp._tcp. components at the start. +The check has been seen to bite on the destination of a SRV lookup that +initiall hit a CNAME, for which the next name had only two components. +RFC2782 makes no mention of the possibiility of CNAMES, but the Wikipedia +article on SRV says they are not a valid configuration. */ #ifndef STAND_ALONE /* Omit this for stand-alone tests */ @@ -728,8 +730,8 @@ if (check_dns_names_pattern[0] != 0 && type != T_PTR && type != T_TXT) if (type == T_SRV || type == T_TLSA) { - while (*checkname++ != '.'); - while (*checkname++ != '.'); + while (*checkname && *checkname++ != '.') ; + while (*checkname && *checkname++ != '.') ; } if (pcre_exec(regex_check_dns_names, NULL, CCS checkname, Ustrlen(checkname), @@ -738,7 +740,7 @@ if (check_dns_names_pattern[0] != 0 && type != T_PTR && type != T_TXT) DEBUG(D_dns) debug_printf("DNS name syntax check failed: %s (%s)\n", name, dns_text_type(type)); - host_find_failed_syntax = TRUE; + f.host_find_failed_syntax = TRUE; return DNS_NOMATCH; } } @@ -761,7 +763,7 @@ if ((type == T_A || type == T_AAAA) && string_is_ip_address(name, NULL) != 0) (res_search), we call fakens_search(), which recognizes certain special domains, and interfaces to a fake nameserver for certain special zones. */ -dnsa->answerlen = running_in_test_harness +dnsa->answerlen = f.running_in_test_harness ? fakens_search(name, type, dnsa->answer, sizeof(dnsa->answer)) : res_search(CCS name, C_IN, type, dnsa->answer, sizeof(dnsa->answer)); @@ -869,7 +871,6 @@ int dns_lookup(dns_answer *dnsa, const uschar *name, int type, const uschar **fully_qualified_name) { -int i; const uschar *orig_name = name; BOOL secure_so_far = TRUE; @@ -880,12 +881,12 @@ resolvers hiding behind a config variable. Loop to follow CNAME chains so far, but no further... The testsuite tests the latter case, mostly assuming that the former will work. */ -for (i = 0; i <= dns_cname_loops; i++) +for (int i = 0; i <= dns_cname_loops; i++) { uschar * data; - dns_record *rr, cname_rr, type_rr; + dns_record cname_rr, type_rr; dns_scan dnss; - int datalen, rc; + int rc; /* DNS lookup failures get passed straight back. */ @@ -899,7 +900,7 @@ for (i = 0; i <= dns_cname_loops; i++) area in the dnsa block. */ cname_rr.data = type_rr.data = NULL; - for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); + for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) if (rr->type == type) { @@ -947,8 +948,8 @@ for (i = 0; i <= dns_cname_loops; i++) return DNS_FAIL; data = store_get(256); - if ((datalen = dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, - cname_rr.data, (DN_EXPAND_ARG4_TYPE)data, 256)) < 0) + if (dn_expand(dnsa->answer, dnsa->answer + dnsa->answerlen, + cname_rr.data, (DN_EXPAND_ARG4_TYPE)data, 256) < 0) return DNS_FAIL; name = data; @@ -1101,7 +1102,7 @@ switch (type) && (h->rcode == NOERROR || h->rcode == NXDOMAIN) && ntohs(h->qdcount) == 1 && ntohs(h->ancount) == 0 && ntohs(h->nscount) >= 1) - dnsa->answerlen = MAXPACKET; + dnsa->answerlen = sizeof(dnsa->answer); for (rr = dns_next_rr(dnsa, &dnss, RESET_AUTHORITY); rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) @@ -1213,8 +1214,7 @@ else if (rr->data + 16 <= dnsa_lim) { struct in6_addr in6; - int i; - for (i = 0; i < 16; i++) in6.s6_addr[i] = rr->data[i]; + for (int i = 0; i < 16; i++) in6.s6_addr[i] = rr->data[i]; yield = store_get(sizeof(dns_address) + 50); inet_ntop(AF_INET6, &in6, CS yield->address, 50); yield->next = NULL;