+/*
+ * $Id$
+ *
+ * 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));
+ }
+ }
+ }
+}
+
-#define SMART_HOST "gatekeeper.wdcs.com"
/*
* getmx()
int getmx(char *mxbuf, char *dest) {
char answer[1024];
int ret;
+ unsigned char *startptr, *endptr, *ptr;
+ char expanded_buf[1024];
+ unsigned short pref, type;
+ int n = 0;
+ HEADER *hp;
+ 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.
*/
- if (1) { /* FIX */
- strcpy(mxbuf, SMART_HOST);
- return(1);
- }
+ n = get_smarthosts(mxbuf);
+ if (n > 0) return(n);
- /* No smart-host? Look up the best MX for a site.
+ /*
+ * No smart-host? Look up the best MX for a site.
*/
ret = res_query(
dest,
- C_IN, T_MX, answer, sizeof(answer) );
+ C_IN, T_MX, (unsigned char *)answer, sizeof(answer) );
+
+ if (ret < 0) {
+ mxrecs = mallok(sizeof(struct mx));
+ mxrecs[0].pref = 0;
+ strcpy(mxrecs[0].host, dest);
+ num_mxrecs = 1;
+ }
+ else {
- lprintf(9, "res_query() returned %d\n", ret);
- return(0); /* FIX not yet working!! */
+ /* If we had to truncate, shrink the number to avoid fireworks */
+ if (ret > sizeof(answer))
+ ret = sizeof(answer);
+
+ hp = (HEADER *)&answer[0];
+ startptr = &answer[0]; /* start and end of buffer */
+ endptr = &answer[ret];
+ ptr = startptr + HFIXEDSZ; /* advance past header */
+
+ for (qdcount = ntohs(hp->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);
}