/*
- * $Id$
- *
* DNS lookup for SMTP sender
*
+ * Copyright (c) 1987-2021 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 <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <netinet/in.h>
#include <stdio.h>
-
+#include <syslog.h>
#ifdef HAVE_RESOLV_H
#include <arpa/nameser.h>
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
#endif
#include <resolv.h>
#endif
-
+#include <libcitadel.h>
#include "sysdep_decls.h"
#include "citadel.h"
#include "domain.h"
-#include "server.h"
-#include "tools.h"
#include "internet_addressing.h"
int get_hosts(char *mxbuf, char *rectype) {
int config_lines;
int i;
- char buf[SIZ];
- char host[SIZ], type[SIZ];
+ char buf[256];
+ char host[256], type[256];
int total_smarthosts = 0;
if (inetcfg == NULL) return(0);
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, '|');
+ 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);
u_char bytes[1024];
HEADER header;
} answer;
-#else
- char buf[SIZ];
- FILE *fp;
#endif
int ret;
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);
+ if (n > 0) {
+ return(n);
+ }
/*
* No smart-host? Look up the best MX for a site.
+ * Make a call to the resolver library.
*/
-#ifndef HAVE_RESOLV_H
-
- /*
- * On systems with b0rken or non-standard resolver libraries, learn
- * the MX records by calling "nslookup" from the command line.
- *
- * Someday.
- *
- */
-
- return(0);
-
-#else /* HAVE_RESOLV_H */
-
- /*
- * Make a call to the standard resolver library.
- */
-
- ret = res_query(
- dest,
- C_IN, T_MX, (unsigned char *)answer.bytes, sizeof(answer) );
+ ret = res_query(dest, C_IN, T_MX, (unsigned char *)answer.bytes, sizeof(answer));
if (ret < 0) {
- mxrecs = mallok(sizeof(struct mx));
+ 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))
+ if (ret > sizeof(answer)) {
ret = sizeof(answer);
+ }
- startptr = &answer.bytes[0]; /* start and end of buffer */
+ startptr = &answer.bytes[0]; // start and end of buffer
endptr = &answer.bytes[ret];
- ptr = startptr + HFIXEDSZ; /* advance past header */
+ 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");
+ syslog(LOG_DEBUG, "domain: dn_skipname error");
return(0);
}
}
while(1) {
memset(expanded_buf, 0, sizeof(expanded_buf));
- ret = dn_expand(startptr,
- endptr,
- ptr,
- expanded_buf,
- sizeof(expanded_buf)
- );
+ ret = dn_expand(startptr, endptr, ptr, expanded_buf, sizeof(expanded_buf));
if (ret < 0) break;
ptr += ret;
else {
GETSHORT(pref, ptr);
- ret = dn_expand(startptr,
- endptr,
- ptr,
- expanded_buf,
- sizeof(expanded_buf)
- );
+ 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) );
- }
+ // If there are no MX records for the domain, resolv will give us a single one with zero length.
+ // Make sure we only record actual MX records and not the blank.
+ if (strlen(expanded_buf) > 0) {
+ ++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);
+ mxrecs[num_mxrecs - 1].pref = pref;
+ strcpy(mxrecs[num_mxrecs - 1].host, expanded_buf);
+ }
}
}
}
-#endif /* HAVE_RESOLV_H */
/* Sort the MX records by preference */
if (num_mxrecs > 1) {
strcat(mxbuf, mxrecs[n].host);
strcat(mxbuf, "|");
}
- phree(mxrecs);
+ 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