X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=citadel%2Fdomain.c;h=2e16a20afe7855ec7bc699dbead29bda24163fab;hb=0fadbcbe2c27134ad71634b9c81d277d118eff17;hp=52d57665f6fb81e23aa57bd4dd591c6ffe6abbe9;hpb=85e09d9a91021c6522841569330bf2fdb0601208;p=citadel.git

diff --git a/citadel/domain.c b/citadel/domain.c
index 52d57665f..2e16a20af 100644
--- a/citadel/domain.c
+++ b/citadel/domain.c
@@ -1,30 +1,42 @@
 /*
- * $Id$
- *
  * 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 <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <netinet/in.h>
+#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 "server.h"
-#include "tools.h"
 #include "internet_addressing.h"
 
 
 /*
- * get_smarthosts() checks the Internet configuration for "smarthost"
+ * 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_smarthosts(char *mxbuf) {
+int get_hosts(char *mxbuf, char *rectype) {
 	int config_lines;
 	int i;
 	char buf[256];
@@ -36,11 +48,11 @@ int get_smarthosts(char *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, '|');
+		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, "smarthost")) {
+		if (!strcasecmp(type, rectype)) {
 			strcat(mxbuf, host);
 			strcat(mxbuf, "|");
 			++total_smarthosts;
@@ -51,36 +63,30 @@ int get_smarthosts(char *mxbuf) {
 }
 
 
-
-
 /*
- * sort_mxrecs()
- *
- * Sort a pile of MX records (struct mx, definted in domain.h) by preference
- *
+ * 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.
  */
-void sort_mxrecs(struct mx *mxrecs, int num_mxrecs) {
-	int a, b;
-	struct mx hold1, hold2;
-
-	if (num_mxrecs < 2) return;
+int mx_compare_pref(const void *mx1, const void *mx2) {
+	int pref1;
+	int pref2;
 
-	/* 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) {
+	pref1 = ((const struct mx *)mx1)->pref;
+	pref2 = ((const struct mx *)mx2)->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));
-			}
-		}
+	if (pref1 > pref2) {
+		return(1);
+	}
+	else if (pref1 < pref2) {
+		return(0);
+	}
+	else {
+		return(rand() % 2);
 	}
 }
 
 
-
 /* 
  * getmx()
  *
@@ -92,13 +98,19 @@ void sort_mxrecs(struct mx *mxrecs, int num_mxrecs) {
  *
  */
 int getmx(char *mxbuf, char *dest) {
-	char answer[1024];
+
+#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;
-	HEADER *hp;
 	int qdcount;
 
 	struct mx *mxrecs = NULL;
@@ -107,18 +119,18 @@ int getmx(char *mxbuf, char *dest) {
 	/* If we're configured to send all mail to a smart-host, then our
 	 * job here is really easy.
 	 */
-	n = get_smarthosts(mxbuf);
+	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, 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;
@@ -126,29 +138,24 @@ int getmx(char *mxbuf, char *dest) {
 	else {
 
 		/* If we had to truncate, shrink the number to avoid fireworks */
-		if (ret > sizeof(answer))
+		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 */
+		startptr = &answer.bytes[0];		// start and end of buffer
+		endptr = &answer.bytes[ret];
+		ptr = startptr + HFIXEDSZ;		// advance past header
 	
-		for (qdcount = ntohs(hp->qdcount); qdcount--; ptr += ret + QFIXEDSZ) {
+		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;
 	
@@ -162,37 +169,38 @@ int getmx(char *mxbuf, char *dest) {
 	
 			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));
+					mxrecs = malloc(sizeof(struct mx));
 				}
 				else {
-					mxrecs = reallok(mxrecs,
-					    (sizeof(struct mx) * num_mxrecs) );
+					mxrecs = realloc(mxrecs, (sizeof(struct mx) * num_mxrecs) );
 				}
 	
 				mxrecs[num_mxrecs - 1].pref = pref;
-				strcpy(mxrecs[num_mxrecs - 1].host,
-				       expanded_buf);
+				strcpy(mxrecs[num_mxrecs - 1].host, expanded_buf);
 			}
 		}
 	}
 
-	sort_mxrecs(mxrecs, num_mxrecs);
+	/* 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, "|");
 	}
-	phree(mxrecs);
+	free(mxrecs);
+
+	/*
+	 * Append any fallback smart hosts we have configured.
+	 */
+	num_mxrecs += get_hosts(&mxbuf[strlen(mxbuf)], "fallbackhost");
 	return(num_mxrecs);
 }