From: Harlan Stenn <stenn@ntp.org>
Date: Wed, 2 Mar 2005 21:18:07 +0000 (-0500)
Subject: [Bug 389] Fix from Remi Demis-Courmont, via Loic Minier (http://bugs.debian.org/293793
X-Git-Tag: NTP_4_2_0B_RC1~11^2~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9114195231144bd6d3fd5b3cd87a1e75e7a79a12;p=thirdparty%2Fntp.git

[Bug 389] Fix from Remi Demis-Courmont, via Loic Minier (http://bugs.debian.org/293793

bk: 42262d8fH2lVb1ZYI2YAIe5BLM-BqQ
---

diff --git a/ntpdate/ntpdate.c b/ntpdate/ntpdate.c
index 0408d7472..9ce701b04 100644
--- a/ntpdate/ntpdate.c
+++ b/ntpdate/ntpdate.c
@@ -1321,6 +1321,30 @@ clock_adjust(void)
 }
 
 
+/*
+ * is_unreachable - check to see if we have a route to given destination
+ *		    (non-blocking).
+ */
+static int
+is_reachable (struct sockaddr_storage *dst)
+{
+	SOCKET sockfd;
+
+	sockfd = socket(dst->ss_family, SOCK_DGRAM, 0);
+	if (sockfd == -1) {
+		return 0;
+	}
+
+	if(connect(sockfd, (struct sockaddr *)dst, SOCKLEN(dst))) {
+		closesocket(sockfd);
+		return 0;
+	}
+	closesocket(sockfd);
+	return 1;
+}
+
+
+
 /* XXX ELIMINATE: merge BIG slew into adj_systime in lib/systime.c */
 /*
  * addserver - determine a server's address and allocate a new structure
@@ -1333,7 +1357,7 @@ addserver(
 {
 	register struct server *server;
 	/* Address infos structure to store result of getaddrinfo */
-	struct addrinfo *addrResult;
+	struct addrinfo *addrResult, *ptr;
 	/* Address infos structure to store hints for getaddrinfo */
 	struct addrinfo hints;
 	/* Error variable for getaddrinfo */
@@ -1364,22 +1388,28 @@ addserver(
 	}
 #endif
 
-	server = (struct server *)emalloc(sizeof(struct server));
-	memset((char *)server, 0, sizeof(struct server));
-
-	/* For now we only get the first returned server of the addrinfo list */
-	memset(&(server->srcadr), 0, sizeof(struct sockaddr_storage));
-	memcpy(&(server->srcadr), addrResult->ai_addr, addrResult->ai_addrlen);
-	server->event_time = ++sys_numservers;
-	if (sys_servers == NULL)
-		sys_servers = server;
-	else {
-		struct server *sp;
+	/* We must get all returned server in case the first one fails */
+	for (ptr = addrResult; ptr != NULL; ptr = ptr->ai_next) {
+		if (is_reachable ((struct sockaddr_storage *)ptr->ai_addr)) {
+			server = (struct server *)emalloc(sizeof(struct server));
+			memset((char *)server, 0, sizeof(struct server));
+
+			memset(&(server->srcadr), 0, sizeof(struct sockaddr_storage));
+			memcpy(&(server->srcadr), ptr->ai_addr, ptr->ai_addrlen);
+			server->event_time = ++sys_numservers;
+			if (sys_servers == NULL)
+				sys_servers = server;
+			else {
+				struct server *sp;
 
-		for (sp = sys_servers; sp->next_server != NULL;
-		     sp = sp->next_server) ;
-		sp->next_server = server;
+				for (sp = sys_servers; sp->next_server != NULL;
+				     sp = sp->next_server) ;
+				sp->next_server = server;
+			}
+		}
 	}
+
+	freeaddrinfo(addrResult);
 }