dnsbl: src/dnsbl.cpp comparison

comparison src/dnsbl.cpp @ 414:d5a1ed33d3ae

spf code now handles mx,exists,ptr tags, multiple A records, %{i} macro

author	Carl Byington <carl@five-ten-sg.com>
date	Tue, 25 Apr 2017 14:48:19 -0700
parents	6b03435868cb
children	16451edcb962

comparison

equal deleted inserted replaced

-:54809ee70bb8
+:d5a1ed33d3ae
 ////////////////////////////////////////////////
 //  Ask a dns question and get an A record answer in network byte order.
 //  We don't try very hard, just using the default resolver retry settings.
 //  If we cannot get an answer, we just accept the mail.
-//  If the qtype is ns_t_txt, the answer is placed in txt_answer which
+//  If the qtype is ns_t_txt, the answer is placed in my_answer which
 //  must be non-null, and the return value can be ignored.
-//  A null string is returned in txt_answer in the case of errors.
+//  A null string is returned in my_answer in the case of errors.
-//  If the qtype is ns_t_a, the ip address is returned in network byte order.
+//  If the qtype is ns_t_a, one of the ip addresses is returned in network byte order,
+//  and if my_answer is non-null, all the ip addresses are returned in
+//  my_answer (in network byte order), prepended with the count.
 //  IP address 0 is returned in case of errors.
 //
-uint32_t dns_interface(mlfiPriv &priv, const char *question, int qtype, bool maybe_ip, ns_map *nameservers, char *txt_answer, size_t txt_size) {
+uint32_t dns_interface(mlfiPriv &priv, const char *question, int qtype, bool maybe_ip, ns_map *nameservers, char *my_answer, size_t my_size) {
-if (txt_answer) txt_answer[0] = '\0';   // return null string if there are no txt answers
+if (my_answer) my_answer[0] = '\0';   // return null string if there are no txt answers
 // tell sendmail we are still working
 #if _FFR_SMFI_PROGRESS
 if (priv.eom) smfi_progress(priv.ctx);
 #endif
 }
 }
 }
 int rrnum = 0;
 if (qtype == ns_t_a) {
+uint32_t *ans = (uint32_t *)my_answer;
+size_t c = 0;
+size_t m = my_size/4;   // 1 + max ipv4 addresses that will fit in the answer buffer
 while (ns_parserr(&handle, ns_s_an, rrnum++, &rr) == 0) {
 if (ns_rr_type(rr) == qtype) {
 uint32_t address;
 memcpy(&address, ns_rr_rdata(rr), sizeof(address));
 ret_address = address;
+if (ans && (c < m-1)) {
+c++;
+ans[c] = address;
+}
 }
 }
-}
+if (ans && (c < m)) ans[0] = c;
-if ((qtype == ns_t_txt) && (txt_answer) && (txt_size > 7)) {
+}
-txt_answer[0] = '\0';  // return null string if there are no txt answers
+if ((qtype == ns_t_mx) && (my_answer) && (my_size > 1)) {
-txt_size--; // allow room for terminating null;
+uint32_t c = 0;
+while (ns_parserr(&handle, ns_s_an, rrnum++, &rr) == 0) {
+if (ns_rr_type(rr) == qtype) {
+char exchange[NS_MAXDNAME];
+size_t rdlen = ns_rr_rdlen(rr);
+const unsigned char *rdata = ns_rr_rdata(rr);
+const uint16_t pri = ns_get16(rdata);
+int len = dn_expand(glom.answer, glom.answer+glom.length, rdata + 2, exchange, sizeof(exchange));
+if ((len > 0) && (my_size > len+2)) {
+strcpy(my_answer, exchange);
+my_answer += len + 1;
+my_size   -= len + 1;
+c++;
+}
+}
+}
+*my_answer = '\0';    // final trailing null
+ret_address = htonl(c);
+}
+if ((qtype == ns_t_txt) && (my_answer) && (my_size > 7)) {
+my_answer[0] = '\0';  // return null string if there are no txt answers
+my_size--; // allow room for terminating null;
 while (ns_parserr(&handle, ns_s_an, rrnum++, &rr) == 0) {
 if (ns_rr_type(rr) == qtype) {
 size_t offset = 0;
 size_t rdlen = ns_rr_rdlen(rr);
 const unsigned char *rdata = ns_rr_rdata(rr);
 #ifdef RESOLVER_DEBUG
 char text[1000];
 snprintf(text, sizeof(text), "found txt record rdlen = %d", rdlen);
 my_syslog(text);
 #endif
-while ((offset < txt_size) && rdlen) {
+while ((offset < my_size) && rdlen) {
 size_t slen = size_t(*(rdata++));
 rdlen--;
 size_t m = min(slen, rdlen);
-m = min(m, txt_size-offset);
+m = min(m, my_size-offset);
-memcpy(txt_answer+offset, rdata, m);
+memcpy(my_answer+offset, rdata, m);
 offset += m;
 rdata  += m;
 rdlen  -= m;
 }
-txt_answer[offset] = '\0';  // trailing null
+my_answer[offset] = '\0';  // trailing null
 #ifdef RESOLVER_DEBUG
-snprintf(text, sizeof(text), "found txt record %s", txt_answer);
+snprintf(text, sizeof(text), "found txt record %s", my_answer);
 my_syslog(text);
 #endif
-if (strncasecmp(txt_answer, "v=spf1 ", 7) == 0) break;
+if (strncasecmp(my_answer, "v=spf1 ", 7) == 0) break;
 }
 }
-if (strncasecmp(txt_answer, "v=spf1 ", 7) != 0) {
+if (strncasecmp(my_answer, "v=spf1 ", 7) != 0) {
-txt_answer[0] = '\0';  // return null string if there are no spf1 txt answers
+my_answer[0] = '\0';  // return null string if there are no spf1 txt answers
 }
 }
 }
 pthread_mutex_unlock(&resolve_mutex);
 #ifdef RESOLVER_DEBUG

Mercurial > dnsbl

comparison src/dnsbl.cpp @ 414:d5a1ed33d3ae