+++ /dev/null
-/*
- * DNS lookup for SMTP sender
- *
- * Copyright (c) 1987-2017 by the citadel.org team
- *
- * This program is open source software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, version 3.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include "sysdep.h"
-#include <stdio.h>
-#include <syslog.h>
-#ifdef HAVE_RESOLV_H
-#include <arpa/nameser.h>
-#ifdef HAVE_ARPA_NAMESER_COMPAT_H
-#include <arpa/nameser_compat.h>
-#endif
-#include <resolv.h>
-#endif
-#include <libcitadel.h>
-#include "sysdep_decls.h"
-#include "citadel.h"
-#include "domain.h"
-#include "internet_addressing.h"
-
-
-/*
- * get_hosts() checks the Internet configuration for various types of
- * entries and returns them in the same format as getmx() does -- fill the
- * buffer with a delimited list of hosts and return the number of hosts.
- *
- * This is used to fetch MX smarthosts, SpamAssassin hosts, etc.
- */
-int get_hosts(char *mxbuf, char *rectype) {
- int config_lines;
- int i;
- char buf[256];
- char host[256], type[256];
- int total_smarthosts = 0;
-
- if (inetcfg == NULL) return(0);
- strcpy(mxbuf, "");
-
- config_lines = num_tokens(inetcfg, '\n');
- for (i=0; i<config_lines; ++i) {
- extract_token(buf, inetcfg, i, '\n', sizeof buf);
- extract_token(host, buf, 0, '|', sizeof host);
- extract_token(type, buf, 1, '|', sizeof type);
-
- if (!strcasecmp(type, rectype)) {
- strcat(mxbuf, host);
- strcat(mxbuf, "|");
- ++total_smarthosts;
- }
- }
-
- return(total_smarthosts);
-}
-
-
-/*
- * Compare the preference of two MX records. First check by the actual
- * number listed in the MX record. If they're identical, randomize the
- * result.
- */
-int mx_compare_pref(const void *mx1, const void *mx2) {
- int pref1;
- int pref2;
-
- pref1 = ((const struct mx *)mx1)->pref;
- pref2 = ((const struct mx *)mx2)->pref;
-
- if (pref1 > pref2) {
- return(1);
- }
- else if (pref1 < pref2) {
- return(0);
- }
- else {
- return(rand() % 2);
- }
-}
-
-
-/*
- * getmx()
- *
- * Return one or more MX's for a mail destination.
- *
- * Upon success, it fills 'mxbuf' with one or more MX hosts, separated by
- * vertical bar characters, and returns the number of hosts as its return
- * value. If no MX's are found, it returns 0.
- *
- */
-int getmx(char *mxbuf, char *dest) {
-
-#ifdef HAVE_RESOLV_H
- union {
- u_char bytes[1024];
- HEADER header;
- } answer;
-#endif
-
- int ret;
- unsigned char *startptr, *endptr, *ptr;
- char expanded_buf[1024];
- unsigned short pref, type;
- int n = 0;
- int qdcount;
-
- struct mx *mxrecs = NULL;
- int num_mxrecs = 0;
-
- /* If we're configured to send all mail to a smart-host, then our
- * job here is really easy.
- */
- n = get_hosts(mxbuf, "smarthost");
- if (n > 0) return(n);
-
- /*
- * No smart-host? Look up the best MX for a site.
- * Make a call to the resolver library.
- */
-
- ret = res_query(dest, C_IN, T_MX, (unsigned char *)answer.bytes, sizeof(answer));
-
- if (ret < 0) {
- mxrecs = malloc(sizeof(struct mx));
- mxrecs[0].pref = 0;
- strcpy(mxrecs[0].host, dest);
- num_mxrecs = 1;
- }
- else {
-
- /* If we had to truncate, shrink the number to avoid fireworks */
- if (ret > sizeof(answer)) {
- ret = sizeof(answer);
- }
-
- startptr = &answer.bytes[0]; // start and end of buffer
- endptr = &answer.bytes[ret];
- ptr = startptr + HFIXEDSZ; // advance past header
-
- for (qdcount = ntohs(answer.header.qdcount); qdcount--; ptr += ret + QFIXEDSZ) {
- if ((ret = dn_skipname(ptr, endptr)) < 0) {
- syslog(LOG_DEBUG, "dn_skipname error\n");
- return(0);
- }
- }
-
- while(1) {
- memset(expanded_buf, 0, sizeof(expanded_buf));
- ret = dn_expand(startptr, endptr, ptr, expanded_buf, sizeof(expanded_buf));
- if (ret < 0) break;
- ptr += ret;
-
- GETSHORT(type, ptr);
- ptr += INT16SZ + INT32SZ;
- GETSHORT(n, ptr);
-
- if (type != T_MX) {
- ptr += n;
- }
-
- else {
- GETSHORT(pref, ptr);
- ret = dn_expand(startptr, endptr, ptr, expanded_buf, sizeof(expanded_buf));
- ptr += ret;
-
- ++num_mxrecs;
- if (mxrecs == NULL) {
- mxrecs = malloc(sizeof(struct mx));
- }
- else {
- mxrecs = realloc(mxrecs, (sizeof(struct mx) * num_mxrecs) );
- }
-
- mxrecs[num_mxrecs - 1].pref = pref;
- strcpy(mxrecs[num_mxrecs - 1].host, expanded_buf);
- }
- }
- }
-
- /* Sort the MX records by preference */
- if (num_mxrecs > 1) {
- qsort(mxrecs, num_mxrecs, sizeof(struct mx), mx_compare_pref);
- }
-
- strcpy(mxbuf, "");
- for (n=0; n<num_mxrecs; ++n) {
- strcat(mxbuf, mxrecs[n].host);
- strcat(mxbuf, "|");
- }
- free(mxrecs);
-
- /*
- * Append any fallback smart hosts we have configured.
- */
- num_mxrecs += get_hosts(&mxbuf[strlen(mxbuf)], "fallbackhost");
- return(num_mxrecs);
-}
projects / citadel.git / blobdiff