Support IPv4-compatible IPv6 addresses on IPv4 sockets.
Bug: 2194581
Change-Id: I825835280e9d7d88a4db3fa817dfb4234fc19039
diff --git a/libcore/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp b/libcore/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp
index 12c3dd9..1a8f3a4 100644
--- a/libcore/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp
+++ b/libcore/luni/src/main/native/org_apache_harmony_luni_platform_OSNetworkSystem.cpp
@@ -331,38 +331,70 @@
return byteArrayToInetAddress(env, byteArray);
}
-/**
- * Converts an IPv4 address to an IPv4-mapped IPv6 address if fd is an IPv6
- * socket.
- * @param fd the socket.
- * @param sin_ss the address.
- * @param sin6_ss scratch space where we can store the mapped address if necessary.
- * @param mapUnspecified if true, convert 0.0.0.0 to ::ffff:0:0; if false, to ::
- * @return either sin_ss or sin6_ss, depending on which the caller should use.
- */
-static const sockaddr* convertIpv4ToMapped(int fd,
- const sockaddr_storage* sin_ss, sockaddr_storage* sin6_ss, bool mapUnspecified) {
- // We need to map if we have an IPv4 address but an IPv6 socket.
- bool needsMapping = (sin_ss->ss_family == AF_INET && getSocketAddressFamily(fd) == AF_INET6);
- if (!needsMapping) {
- return reinterpret_cast<const sockaddr*>(sin_ss);
+// Handles translating between IPv4 and IPv6 addresses so -- where possible --
+// we can use either class of address with either an IPv4 or IPv6 socket.
+class CompatibleSocketAddress {
+public:
+ // Constructs an address corresponding to 'ss' that's compatible with 'fd'.
+ CompatibleSocketAddress(int fd, const sockaddr_storage& ss, bool mapUnspecified) {
+ const int desiredFamily = getSocketAddressFamily(fd);
+ if (ss.ss_family == AF_INET6) {
+ if (desiredFamily == AF_INET6) {
+ // Nothing to do.
+ mCompatibleAddress = reinterpret_cast<const sockaddr*>(&ss);
+ } else {
+ sockaddr_in* sin = reinterpret_cast<sockaddr_in*>(&mTmp);
+ const sockaddr_in6* sin6 = reinterpret_cast<const sockaddr_in6*>(&ss);
+ memset(sin, 0, sizeof(*sin));
+ sin->sin_family = AF_INET;
+ sin->sin_port = sin6->sin6_port;
+ if (IN6_IS_ADDR_V4COMPAT(&sin6->sin6_addr)) {
+ // We have an IPv6-mapped IPv4 address, but need plain old IPv4.
+ // Unmap the mapped address in ss into an IPv6 address in mTmp.
+ memcpy(&sin->sin_addr.s_addr, &sin6->sin6_addr.s6_addr[12], 4);
+ mCompatibleAddress = reinterpret_cast<const sockaddr*>(&mTmp);
+ } else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) {
+ // Translate the IPv6 loopback address to the IPv4 one.
+ sin->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+ mCompatibleAddress = reinterpret_cast<const sockaddr*>(&mTmp);
+ } else {
+ // We can't help you. We return what you gave us, and assume you'll
+ // get a sensible error when you use the address.
+ mCompatibleAddress = reinterpret_cast<const sockaddr*>(&ss);
+ }
+ }
+ } else /* ss.ss_family == AF_INET */ {
+ if (desiredFamily == AF_INET) {
+ // Nothing to do.
+ mCompatibleAddress = reinterpret_cast<const sockaddr*>(&ss);
+ } else {
+ // We have IPv4 and need IPv6.
+ // Map the IPv4 address in ss into an IPv6 address in mTmp.
+ const sockaddr_in* sin = reinterpret_cast<const sockaddr_in*>(&ss);
+ sockaddr_in6* sin6 = reinterpret_cast<sockaddr_in6*>(&mTmp);
+ memset(sin6, 0, sizeof(*sin6));
+ sin6->sin6_family = AF_INET6;
+ sin6->sin6_port = sin->sin_port;
+ // TODO: mapUnspecified was introduced because kernels < 2.6.31 don't allow
+ // you to bind to ::ffff:0.0.0.0. When we move to something >= 2.6.31, we
+ // should make the code behave as if mapUnspecified were always true, and
+ // remove the parameter.
+ if (sin->sin_addr.s_addr != 0 || mapUnspecified) {
+ memset(&(sin6->sin6_addr.s6_addr[10]), 0xff, 2);
+ }
+ memcpy(&sin6->sin6_addr.s6_addr[12], &sin->sin_addr.s_addr, 4);
+ mCompatibleAddress = reinterpret_cast<const sockaddr*>(&mTmp);
+ }
+ }
}
- // Map the IPv4 address in sin_ss into an IPv6 address in sin6_ss.
- const sockaddr_in* sin = reinterpret_cast<const sockaddr_in*>(sin_ss);
- sockaddr_in6* sin6 = reinterpret_cast<sockaddr_in6*>(sin6_ss);
- memset(sin6, 0, sizeof(*sin6));
- sin6->sin6_family = AF_INET6;
- sin6->sin6_port = sin->sin_port;
- // TODO: mapUnspecified was introduced because kernels < 2.6.31 don't allow
- // you to bind to ::ffff:0.0.0.0. When we move to something >= 2.6.31, we
- // should make the code behave as if mapUnspecified were always true, and
- // remove the parameter.
- if (sin->sin_addr.s_addr != 0 || mapUnspecified) {
- memset(&(sin6->sin6_addr.s6_addr[10]), 0xff, 2);
+ // Returns a pointer to an address compatible with the socket.
+ const sockaddr* get() const {
+ return mCompatibleAddress;
}
- memcpy(&sin6->sin6_addr.s6_addr[12], &sin->sin_addr.s_addr, 4);
- return reinterpret_cast<const sockaddr*>(sin6_ss);
-}
+private:
+ const sockaddr* mCompatibleAddress;
+ sockaddr_storage mTmp;
+};
/**
* Converts an InetAddress object and port number to a native address structure.
@@ -926,9 +958,8 @@
* @param socketAddress the address to connect to
*/
static int doConnect(int fd, const sockaddr_storage* socketAddress) {
- sockaddr_storage tmp;
- const sockaddr* realAddress = convertIpv4ToMapped(fd, socketAddress, &tmp, true);
- return TEMP_FAILURE_RETRY(connect(fd, realAddress, sizeof(sockaddr_storage)));
+ const CompatibleSocketAddress compatibleAddress(fd, *socketAddress, true);
+ return TEMP_FAILURE_RETRY(connect(fd, compatibleAddress.get(), sizeof(sockaddr_storage)));
}
/**
@@ -1442,12 +1473,12 @@
return -1;
}
- int sock;
- sock = socket(PF_INET6, type, 0);
- if (sock < 0 && errno == EAFNOSUPPORT) {
+ // Try IPv6 but fall back to IPv4...
+ int sock = socket(PF_INET6, type, 0);
+ if (sock == -1 && errno == EAFNOSUPPORT) {
sock = socket(PF_INET, type, 0);
}
- if (sock < 0) {
+ if (sock == -1) {
jniThrowSocketException(env, errno);
return sock;
}
@@ -1774,9 +1805,8 @@
return;
}
- sockaddr_storage tmp;
- const sockaddr* realAddress = convertIpv4ToMapped(fd, &socketAddress, &tmp, false);
- int rc = TEMP_FAILURE_RETRY(bind(fd, realAddress, sizeof(sockaddr_storage)));
+ const CompatibleSocketAddress compatibleAddress(fd, socketAddress, false);
+ int rc = TEMP_FAILURE_RETRY(bind(fd, compatibleAddress.get(), sizeof(sockaddr_storage)));
if (rc == -1) {
jniThrowBindException(env, errno);
}
@@ -1936,12 +1966,14 @@
return;
}
- sockaddr_storage sockAddr;
- memset(&sockAddr, 0, sizeof(sockAddr));
- sockAddr.ss_family = AF_UNSPEC;
-
- int result = doConnect(fd, &sockAddr);
- if (result < 0) {
+ // To disconnect a datagram socket, we connect to a bogus address with
+ // the family AF_UNSPEC.
+ sockaddr_storage ss;
+ memset(&ss, 0, sizeof(ss));
+ ss.ss_family = AF_UNSPEC;
+ const sockaddr* sa = reinterpret_cast<const sockaddr*>(&ss);
+ int rc = TEMP_FAILURE_RETRY(connect(fd, sa, sizeof(ss)));
+ if (rc == -1) {
jniThrowSocketException(env, errno);
}
}
