4238. [bug] Don't send to servers on net zero (0.0.0.0/8).

[RT #40947]

CHANGES

@@ -1,3 +1,6 @@
+4238.	[bug]		Don't send to servers on net zero (0.0.0.0/8).
+			[RT #40947]
+
 4237.	[doc]		Upgraded documentation toolchain to use DocBook 5
 			and dblatex. [RT #40766]
 

lib/dns/resolver.c

@@ -3489,6 +3489,9 @@ possibly_mark(fetchctx_t *fctx, dns_adbaddrinfo_t *addr) {
 	if (aborted) {
 		addr->flags |= FCTX_ADDRINFO_MARK;
 		msg = "ignoring blackholed / bogus server: ";
+	} else if (isc_sockaddr_isnetzero(sa)) {
+		addr->flags |= FCTX_ADDRINFO_MARK;
+		msg = "ignoring net zero address: ";
 	} else if (isc_sockaddr_ismulticast(sa)) {
 		addr->flags |= FCTX_ADDRINFO_MARK;
 		msg = "ignoring multicast address: ";

lib/isc/httpd.c

@@ -378,8 +378,10 @@ static isc_result_t
 process_request(isc_httpd_t *httpd, int length) {
 	char *s;
 	char *p;
+#ifdef HAVE_ZLIB
 	char *e;
 	char *v;
+#endif
 	int delim;
 
 	ENTER("request");

lib/isc/include/isc/netaddr.h

@@ -155,6 +155,12 @@ isc_netaddr_issitelocal(isc_netaddr_t *na);
  * Returns #ISC_TRUE if the address is a site local address.
  */
 
+isc_boolean_t
+isc_netaddr_isnetzero(isc_netaddr_t *na);
+/*%<
+ * Returns #ISC_TRUE if the address is in net zero.
+ */
+
 void
 isc_netaddr_fromv4mapped(isc_netaddr_t *t, const isc_netaddr_t *s);
 /*%<

lib/isc/include/isc/sockaddr.h

@@ -220,6 +220,12 @@ isc_sockaddr_issitelocal(const isc_sockaddr_t *sa);
  * Returns ISC_TRUE if the address is a sitelocal address.
  */
 
+isc_boolean_t
+isc_sockaddr_isnetzero(const isc_sockaddr_t *sa);
+/*%<
+ * Returns ISC_TRUE if the address is in net zero.
+ */
+
 isc_result_t
 isc_sockaddr_frompath(isc_sockaddr_t *sockaddr, const char *path);
 /*

lib/isc/netaddr.c

@@ -419,6 +419,22 @@ isc_netaddr_issitelocal(isc_netaddr_t *na) {
 	}
 }
 
+#ifndef IN_ZERONET
+#define IN_ZERONET(x) (((x) & htonl(0xff000000U)) == 0)
+#endif
+
+isc_boolean_t
+isc_netaddr_isnetzero(isc_netaddr_t *na) {
+	switch (na->family) {
+	case AF_INET:
+		return (ISC_TF(IN_ZERONET(na->type.in.s_addr)));
+	case AF_INET6:
+		return (ISC_FALSE);
+	default:
+		return (ISC_FALSE);
+	}
+}
+
 void
 isc_netaddr_fromv4mapped(isc_netaddr_t *t, const isc_netaddr_t *s) {
 	isc_netaddr_t *src;

lib/isc/sockaddr.c

@@ -483,6 +483,17 @@ isc_sockaddr_islinklocal(const isc_sockaddr_t *sockaddr) {
 	return (ISC_FALSE);
 }
 
+isc_boolean_t
+isc_sockaddr_isnetzero(const isc_sockaddr_t *sockaddr) {
+	isc_netaddr_t netaddr;
+
+	if (sockaddr->type.sa.sa_family == AF_INET) {
+		isc_netaddr_fromsockaddr(&netaddr, sockaddr);
+		return (isc_netaddr_isnetzero(&netaddr));
+	}
+	return (ISC_FALSE);
+}
+
 isc_result_t
 isc_sockaddr_frompath(isc_sockaddr_t *sockaddr, const char *path) {
 #ifdef ISC_PLATFORM_HAVESYSUNH

lib/isc/tests/sockaddr_test.c

@@ -67,11 +67,70 @@ ATF_TC_BODY(sockaddr_hash, tc) {
 	isc_test_end();
 }
 
+ATF_TC(sockaddr_isnetzero);
+ATF_TC_HEAD(sockaddr_isnetzero, tc) {
+	atf_tc_set_md_var(tc, "descr", "sockaddr is net zero");
+}
+ATF_TC_BODY(sockaddr_isnetzero, tc) {
+	isc_sockaddr_t addr;
+	struct in_addr in;
+	struct in6_addr in6;
+	isc_boolean_t r;
+	int ret;
+	size_t i;
+	struct {
+		const char *string;
+		isc_boolean_t expect;
+	} data4[] = {
+		{ "0.0.0.0", ISC_TRUE },
+		{ "0.0.0.1", ISC_TRUE },
+		{ "0.0.1.0", ISC_TRUE },
+		{ "0.1.0.0", ISC_TRUE },
+		{ "1.0.0.0", ISC_FALSE },
+		{ "0.0.0.127", ISC_TRUE },
+		{ "0.0.0.255", ISC_TRUE },
+		{ "127.0.0.1", ISC_FALSE },
+		{ "255.255.255.255", ISC_FALSE },
+	};
+	/*
+	 * Mapped addresses are currently not netzero.
+	 */
+	struct {
+		const char *string;
+		isc_boolean_t expect;
+	} data6[] = {
+		{ "::ffff:0.0.0.0", ISC_FALSE },
+		{ "::ffff:0.0.0.1", ISC_FALSE },
+		{ "::ffff:0.0.0.127", ISC_FALSE },
+		{ "::ffff:0.0.0.255", ISC_FALSE },
+		{ "::ffff:127.0.0.1", ISC_FALSE },
+		{ "::ffff:255.255.255.255", ISC_FALSE },
+	};
+
+	UNUSED(tc);
+
+	for (i = 0; i < sizeof(data4)/sizeof(data4[0]); i++) {
+		in.s_addr = inet_addr(data4[0].string);
+		isc_sockaddr_fromin(&addr, &in, 1);
+		r = isc_sockaddr_isnetzero(&addr);
+		ATF_CHECK_EQ(r, data4[0].expect);
+	}
+
+	for (i = 0; i < sizeof(data6)/sizeof(data6[0]); i++) {
+		ret = inet_pton(AF_INET6, "::ffff:127.0.0.1", &in6);
+		ATF_CHECK_EQ(ret, 1);
+		isc_sockaddr_fromin6(&addr, &in6, 1);
+		r = isc_sockaddr_isnetzero(&addr);
+		ATF_CHECK_EQ(r, data6[0].expect);
+	}
+}
+
 /*
  * Main
  */
 ATF_TP_ADD_TCS(tp) {
 	ATF_TP_ADD_TC(tp, sockaddr_hash);
+	ATF_TP_ADD_TC(tp, sockaddr_isnetzero);
 
 	return (atf_no_error());
 }

lib/isc/win32/libisc.def.in

@@ -458,6 +458,7 @@ isc_netaddr_getzone
 isc_netaddr_isexperimental
 isc_netaddr_islinklocal
 isc_netaddr_ismulticast
+isc_netaddr_isnetzero
 isc_netaddr_issitelocal
 isc_netaddr_masktoprefixlen
 isc_netaddr_prefixok
@@ -582,6 +583,7 @@ isc_sockaddr_hash
 isc_sockaddr_isexperimental
 isc_sockaddr_islinklocal
 isc_sockaddr_ismulticast
+isc_sockaddr_isnetzero
 isc_sockaddr_issitelocal
 isc_sockaddr_pf
 isc_sockaddr_setport