Merge branch 'evutil_found_ifaddr-dev'

* evutil_found_ifaddr-dev: Cover evutil_v4addr_is_local_()/evutil_v6addr_is_local_() Split evutil_found_ifaddr() into helpers (evutil_v{4,6}addr_is_local()) Use INADDR_ANY over 0 in evutil_found_ifaddr() Replace EVUTIL_V4ADDR_IS_*() macroses with static inline functions Filter link-local IPv4 addresses in evutil_found_ifaddr()
superzgg · Oct 24, 2018 · b2667b7 · b2667b7
2 parents 0ec12bc + 32349ab
commit b2667b7
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Showing 3 changed files with 128 additions and 26 deletions.
diff --git a/evutil.c b/evutil.c
@@ -595,44 +595,56 @@ evutil_socket_finished_connecting_(evutil_socket_t fd)
    set by evutil_check_interfaces. */
 static int have_checked_interfaces, had_ipv4_address, had_ipv6_address;
 
-/* Macro: True iff the IPv4 address 'addr', in host order, is in 127.0.0.0/8
- */
-#define EVUTIL_V4ADDR_IS_LOCALHOST(addr) (((addr)>>24) == 127)
+/* True iff the IPv4 address 'addr', in host order, is in 127.0.0.0/8 */
+static inline int evutil_v4addr_is_localhost(ev_uint32_t addr)
+{ return addr>>24 == 127; }
 
-/* Macro: True iff the IPv4 address 'addr', in host order, is a class D
- * (multiclass) address.
- */
-#define EVUTIL_V4ADDR_IS_CLASSD(addr) ((((addr)>>24) & 0xf0) == 0xe0)
+/* True iff the IPv4 address 'addr', in host order, is link-local
+ * 169.254.0.0/16 (RFC3927) */
+static inline int evutil_v4addr_is_linklocal(ev_uint32_t addr)
+{ return ((addr & 0xffff0000U) == 0xa9fe0000U); }
+
+/* True iff the IPv4 address 'addr', in host order, is a class D
+ * (multiclass) address.  */
+static inline int evutil_v4addr_is_classd(ev_uint32_t addr)
+{ return ((addr>>24) & 0xf0) == 0xe0; }
+
+int
+evutil_v4addr_is_local_(const struct in_addr *in)
+{
+	const ev_uint32_t addr = ntohl(in->s_addr);
+	return addr == INADDR_ANY ||
+		evutil_v4addr_is_localhost(addr) ||
+		evutil_v4addr_is_linklocal(addr) ||
+		evutil_v4addr_is_classd(addr);
+}
+int
+evutil_v6addr_is_local_(const struct in6_addr *in)
+{
+	static const char ZEROES[] =
+		"\x00\x00\x00\x00\x00\x00\x00\x00"
+		"\x00\x00\x00\x00\x00\x00\x00\x00";
+
+	const unsigned char *addr = (const unsigned char *)in->s6_addr;
+	return !memcmp(addr, ZEROES, 8) ||
+		((addr[0] & 0xfe) == 0xfc) ||
+		(addr[0] == 0xfe && (addr[1] & 0xc0) == 0x80) ||
+		(addr[0] == 0xfe && (addr[1] & 0xc0) == 0xc0) ||
+		(addr[0] == 0xff);
+}
 
 static void
 evutil_found_ifaddr(const struct sockaddr *sa)
 {
-	const char ZEROES[] = "\x00\x00\x00\x00\x00\x00\x00\x00"
-	    "\x00\x00\x00\x00\x00\x00\x00\x00";
-
 	if (sa->sa_family == AF_INET) {
 		const struct sockaddr_in *sin = (struct sockaddr_in *)sa;
-		ev_uint32_t addr = ntohl(sin->sin_addr.s_addr);
-		if (addr == 0 ||
-		    EVUTIL_V4ADDR_IS_LOCALHOST(addr) ||
-		    EVUTIL_V4ADDR_IS_CLASSD(addr)) {
-			/* Not actually a usable external address. */
-		} else {
+		if (!evutil_v4addr_is_local_(&sin->sin_addr)) {
 			event_debug(("Detected an IPv4 interface"));
 			had_ipv4_address = 1;
 		}
 	} else if (sa->sa_family == AF_INET6) {
 		const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
-		const unsigned char *addr =
-		    (unsigned char*)sin6->sin6_addr.s6_addr;
-		if (!memcmp(addr, ZEROES, 8) ||
-		    ((addr[0] & 0xfe) == 0xfc) ||
-		    (addr[0] == 0xfe && (addr[1] & 0xc0) == 0x80) ||
-		    (addr[0] == 0xfe && (addr[1] & 0xc0) == 0xc0) ||
-		    (addr[0] == 0xff)) {
-			/* This is a reserved, ipv4compat, ipv4map, loopback,
-			 * link-local, multicast, or unspecified address. */
-		} else {
+		if (!evutil_v6addr_is_local_(&sin6->sin6_addr)) {
 			event_debug(("Detected an IPv6 interface"));
 			had_ipv6_address = 1;
 		}

diff --git a/test/regress_util.c b/test/regress_util.c
@@ -1455,6 +1455,83 @@ test_evutil_date_rfc1123(void *arg)
 	;
 }
 
+static void
+test_evutil_v4addr_is_local(void *arg)
+{
+	struct sockaddr_in sin;
+	sin.sin_family = AF_INET;
+
+	/* we use evutil_inet_pton() here to fill in network-byte order */
+#define LOCAL(str, yes) do {                                              \
+	tt_int_op(evutil_inet_pton(AF_INET, str, &sin.sin_addr), ==, 1);  \
+	tt_int_op(evutil_v4addr_is_local_(&sin.sin_addr), ==, yes);       \
+} while (0)
+
+	/** any */
+	sin.sin_addr.s_addr = INADDR_ANY;
+	tt_int_op(evutil_v4addr_is_local_(&sin.sin_addr), ==, 1);
+
+	/** loopback */
+	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	tt_int_op(evutil_v4addr_is_local_(&sin.sin_addr), ==, 1);
+	LOCAL("127.0.0.1", 1);
+	LOCAL("127.255.255.255", 1);
+	LOCAL("121.0.0.1", 0);
+
+	/** link-local */
+	LOCAL("169.254.0.1", 1);
+	LOCAL("169.254.255.255", 1);
+	LOCAL("170.0.0.0", 0);
+
+	/** Multicast */
+	LOCAL("224.0.0.0", 1);
+	LOCAL("239.255.255.255", 1);
+	LOCAL("240.0.0.0", 0);
+end:
+	;
+}
+
+static void
+test_evutil_v6addr_is_local(void *arg)
+{
+	struct sockaddr_in6 sin6;
+	struct in6_addr anyaddr = IN6ADDR_ANY_INIT;
+	struct in6_addr loopback = IN6ADDR_LOOPBACK_INIT;
+
+	sin6.sin6_family = AF_INET6;
+#define LOCAL6(str, yes) do {                                              \
+	tt_int_op(evutil_inet_pton(AF_INET6, str, &sin6.sin6_addr), ==, 1);\
+	tt_int_op(evutil_v6addr_is_local_(&sin6.sin6_addr), ==, yes);      \
+} while (0)
+
+	/** any */
+	tt_int_op(evutil_v6addr_is_local_(&anyaddr), ==, 1);
+	LOCAL6("::0", 1);
+
+	/** loopback */
+	tt_int_op(evutil_v6addr_is_local_(&loopback), ==, 1);
+	LOCAL6("::1", 1);
+
+	/** IPV4 mapped */
+	LOCAL6("::ffff:0:0", 1);
+	/** IPv4 translated */
+	LOCAL6("::ffff:0:0:0", 1);
+	/** IPv4/IPv6 translation */
+	LOCAL6("64:ff9b::", 0);
+	/** Link-local */
+	LOCAL6("fe80::", 1);
+	/** Multicast */
+	LOCAL6("ff00::", 1);
+	/** Unspecified */
+	LOCAL6("::", 1);
+
+	/** Global Internet */
+	LOCAL6("2001::", 0);
+	LOCAL6("2001:4860:4802:32::1b", 0);
+end:
+	;
+}
+
 struct testcase_t util_testcases[] = {
 	{ "ipv4_parse", regress_ipv4_parse, 0, NULL, NULL },
 	{ "ipv6_parse", regress_ipv6_parse, 0, NULL, NULL },
@@ -1486,6 +1563,8 @@ struct testcase_t util_testcases[] = {
 	{ "monotonic_prc_precise", test_evutil_monotonic_prc, 0, &basic_setup, (void*)"precise" },
 	{ "monotonic_prc_fallback", test_evutil_monotonic_prc, 0, &basic_setup, (void*)"fallback" },
 	{ "date_rfc1123", test_evutil_date_rfc1123, 0, NULL, NULL },
+	{ "evutil_v4addr_is_local", test_evutil_v4addr_is_local, 0, NULL, NULL },
+	{ "evutil_v6addr_is_local", test_evutil_v6addr_is_local, 0, NULL, NULL },
 	END_OF_TESTCASES,
 };
 
diff --git a/util-internal.h b/util-internal.h
@@ -527,6 +527,17 @@ evutil_socket_t evutil_eventfd_(unsigned initval, int flags);
 
 void evutil_memclear_(void *mem, size_t len);
 
+struct in_addr;
+struct in6_addr;
+
+/* This is a any, loopback, link-local, multicast */
+EVENT2_EXPORT_SYMBOL
+int evutil_v4addr_is_local_(const struct in_addr *in);
+/* This is a reserved, ipv4compat, ipv4map, loopback,
+ * link-local, multicast, or unspecified address. */
+EVENT2_EXPORT_SYMBOL
+int evutil_v6addr_is_local_(const struct in6_addr *in);
+
 #ifdef __cplusplus
 }
 #endif