+++ /dev/null
-/*
- * $Id$
- *
- * DNS lookup for SMTP sender
- *
- */
-
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <netinet/in.h>
-#include <stdio.h>
-#include <arpa/nameser.h>
-#include <resolv.h>
-#include "sysdep_decls.h"
-#include "citadel.h"
-#include "domain.h"
-#include "server.h"
-#include "tools.h"
-#include "internet_addressing.h"
-
-
-/*
- * get_smarthosts() checks the Internet configuration for "smarthost"
- * 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.
- */
-int get_smarthosts(char *mxbuf) {
- int config_lines;
- int i;
- char buf[SIZ];
- char host[SIZ], type[SIZ];
- 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');
- extract_token(host, buf, 0, '|');
- extract_token(type, buf, 1, '|');
-
- if (!strcasecmp(type, "smarthost")) {
- strcat(mxbuf, host);
- strcat(mxbuf, "|");
- ++total_smarthosts;
- }
- }
-
- return(total_smarthosts);
-}
-
-
-
-
-/*
- * sort_mxrecs()
- *
- * Sort a pile of MX records (struct mx, definted in domain.h) by preference
- *
- */
-void sort_mxrecs(struct mx *mxrecs, int num_mxrecs) {
- int a, b;
- struct mx hold1, hold2;
-
- if (num_mxrecs < 2) return;
-
- /* do the sort */
- for (a = num_mxrecs - 2; a >= 0; --a) {
- for (b = 0; b <= a; ++b) {
- if (mxrecs[b].pref > mxrecs[b+1].pref) {
-
- memcpy(&hold1, &mxrecs[b], sizeof(struct mx));
- memcpy(&hold2, &mxrecs[b+1], sizeof(struct mx));
- memcpy(&mxrecs[b], &hold2, sizeof(struct mx));
- memcpy(&mxrecs[b+1], &hold1, sizeof(struct mx));
- }
- }
- }
-}
-
-
-
-/*
- * 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) {
- union {
- u_char bytes[1024];
- HEADER header;
- } answer;
- 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_smarthosts(mxbuf);
- if (n > 0) return(n);
-
- /*
- * No smart-host? Look up the best MX for a site.
- */
- ret = res_query(
- dest,
- C_IN, T_MX, (unsigned char *)answer.bytes, sizeof(answer) );
-
- if (ret < 0) {
- mxrecs = mallok(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) {
- lprintf(9, "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 = mallok(sizeof(struct mx));
- }
- else {
- mxrecs = reallok(mxrecs,
- (sizeof(struct mx) * num_mxrecs) );
- }
-
- mxrecs[num_mxrecs - 1].pref = pref;
- strcpy(mxrecs[num_mxrecs - 1].host,
- expanded_buf);
- }
- }
- }
-
- sort_mxrecs(mxrecs, num_mxrecs);
-
- strcpy(mxbuf, "");
- for (n=0; n<num_mxrecs; ++n) {
- strcat(mxbuf, mxrecs[n].host);
- strcat(mxbuf, "|");
- }
- phree(mxrecs);
- return(num_mxrecs);
-}