#include <string.h>
#include <sys/select.h>
+/// @brief A macro which handles an error in IfaceMgr.
+///
+/// There are certain cases when IfaceMgr may hit an error which shouldn't
+/// result in interruption of the function processing. A typical case is
+/// the function which opens sockets on available interfaces for a DHCP
+/// server. If this function fails to open a socket on a specific interface
+/// (for example, there is another socket already open on this interface
+/// and bound to the same address and port), it is desired that the server
+/// logs a warning but will try to open sockets on other interfaces. In order
+/// to log an error, the IfaceMgr will use the error handler function provided
+/// by the server and pass an error string to it. When the handler function
+/// returns, the IfaceMgr will proceed to open other sockets. It is allowed
+/// that the error handler function is not installed (is NULL). In these
+/// cases it is expected that the exception is thrown instead. A possible
+/// solution would be to enclose this conditional behavior in a function.
+/// However, despite the hate for macros, the macro seems to be a bit
+/// better solution in this case as it allows to convenietly pass an
+/// error string in a stream (not as a string).
+///
+/// @param ex_type Exception to be thrown if error_handler is NULL.
+/// @param handler Error handler function to be called or NULL to indicate
+/// that exception should be thrown instead.
+/// @param stream stream object holding an error string.
+#define ifacemgr_error(ex_type, handler, stream) \
+ std::ostringstream oss__; \
+ oss__ << stream; \
+ if (handler) { \
+ handler(oss__.str()); \
+ } else { \
+ isc_throw(ex_type, oss__); \
+ }
+
using namespace std;
using namespace isc::asiolink;
using namespace isc::util::io::internal;
return (count > 0);
}
-bool IfaceMgr::openSockets6(const uint16_t port) {
- int sock;
+bool
+IfaceMgr::openSockets6(const uint16_t port,
+ IfaceMgrErrorMsgCallback error_handler) {
int count = 0;
for (IfaceCollection::iterator iface = ifaces_.begin();
for (Iface::AddressCollection::iterator addr = unicasts.begin();
addr != unicasts.end(); ++addr) {
- sock = openSocket(iface->getName(), *addr, port);
- if (sock < 0) {
- const char* errstr = strerror(errno);
- isc_throw(SocketConfigError, "failed to open unicast socket on "
- << addr->toText() << " on interface " << iface->getName()
- << ", reason: " << errstr);
+ try {
+ openSocket(iface->getName(), *addr, port);
+
+ } catch (const Exception& ex) {
+ ifacemgr_error(SocketConfigError, error_handler,
+ "Failed to open unicast socket on interface "
+ << iface->getName() << ", reason: "
+ << ex.what());
+ continue;
}
count++;
// it for some odd use cases which may utilize non-multicast
// interfaces. Perhaps a warning should be emitted if the
// interface is not a multicast one.
- sock = openSocket(iface->getName(), *addr, port,
- iface->flag_multicast_);
- if (sock < 0) {
- const char* errstr = strerror(errno);
- isc_throw(SocketConfigError, "failed to open link-local"
- " socket on " << addr->toText() << " on interface "
- << iface->getName() << ", reason: " << errstr);
+ int sock;
+ try {
+ sock = openSocket(iface->getName(), *addr, port,
+ iface->flag_multicast_);
+
+ } catch (const Exception& ex) {
+ ifacemgr_error(SocketConfigError, error_handler,
+ "Failed to open link-local socket on "
+ " interface " << iface->getName() << ": "
+ << ex.what());
+ continue;
+
}
count++;
// To receive multicast traffic, Linux requires binding socket to
// a multicast group. That in turn doesn't work on NetBSD.
if (iface->flag_multicast_) {
- int sock2 =
+ try {
openSocket(iface->getName(),
IOAddress(ALL_DHCP_RELAY_AGENTS_AND_SERVERS),
port);
- if (sock2 < 0) {
- const char* errstr = strerror(errno);
- isc_throw(SocketConfigError, "Failed to open multicast"
- " socket on interface " << iface->getFullName()
- << ", reason:" << errstr);
- iface->delSocket(sock); // delete previously opened socket
+ } catch (const Exception& ex) {
+ // Delete previously opened socket.
+ iface->delSocket(sock);
+ ifacemgr_error(SocketConfigError, error_handler,
+ "Failed to open multicast socket on"
+ " interface " << iface->getFullName()
+ << ", reason: " << ex.what());
+ continue;
}
}
#endif
/// implementation is hardcoded in the openSocket6.
///
/// @param port specifies port number (usually DHCP6_SERVER_PORT)
+ /// @param error_handler A pointer to an error handler function which is
+ /// called by the openSockets6 when it fails to open a socket. This
+ /// parameter can be NULL to indicate that the callback should not be used.
///
/// @throw SocketOpenFailure if tried and failed to open socket.
/// @return true if any sockets were open
- bool openSockets6(const uint16_t port = DHCP6_SERVER_PORT);
+ bool openSockets6(const uint16_t port = DHCP6_SERVER_PORT,
+ IfaceMgrErrorMsgCallback error_handler = NULL);
/// @brief Opens IPv4 sockets on detected interfaces.
///
// Test that the external error handler is called when trying to bind a new
// socket to the address and port being in use. The sockets on the other
-// interfaces should open just fine..
+// interfaces should open just fine.
TEST_F(IfaceMgrTest, openSocket4ErrorHandler) {
NakedIfaceMgr ifacemgr;
EXPECT_FALSE(socket_open);
}
+// Test that exception is thrown when trying to bind a new socket to the port
+// and address which is already in use by another socket.
+TEST_F(IfaceMgrTest, openSockets6NoErrorHandler) {
+ NakedIfaceMgr ifacemgr;
+
+ // Remove all real interfaces and create a set of dummy interfaces.
+ ifacemgr.createIfaces();
+
+ boost::shared_ptr<PktFilter6Stub> filter(new PktFilter6Stub());
+ ASSERT_TRUE(filter);
+ ASSERT_NO_THROW(ifacemgr.setPacketFilter(filter));
+
+ // Open socket on eth0. The openSockets6 should detect that this
+ // socket has been already open and an attempt to open another socket
+ // and bind to this address and port should fail.
+ ASSERT_NO_THROW(ifacemgr.openSocket("eth0",
+ IOAddress("fe80::3a60:77ff:fed5:cdef"),
+ DHCP6_SERVER_PORT));
+
+ // The function throws an exception when it tries to open a socket
+ // and bind it to the address in use.
+ EXPECT_THROW(ifacemgr.openSockets6(DHCP6_SERVER_PORT),
+ isc::dhcp::SocketConfigError);
+
+}
+
+// Test that the external error handler is called when trying to bind a new
+// socket to the address and port being in use. The sockets on the other
+// interfaces should open just fine.
+TEST_F(IfaceMgrTest, openSocket6ErrorHandler) {
+ NakedIfaceMgr ifacemgr;
+
+ // Remove all real interfaces and create a set of dummy interfaces.
+ ifacemgr.createIfaces();
+
+ boost::shared_ptr<PktFilter6Stub> filter(new PktFilter6Stub());
+ ASSERT_TRUE(filter);
+ ASSERT_NO_THROW(ifacemgr.setPacketFilter(filter));
+
+ // Open socket on eth0. The openSockets6 should detect that this
+ // socket has been already open and an attempt to open another socket
+ // and bind to this address and port should fail.
+ ASSERT_NO_THROW(ifacemgr.openSocket("eth0",
+ IOAddress("fe80::3a60:77ff:fed5:cdef"),
+ DHCP6_SERVER_PORT));
+
+ // Install an error handler before trying to open sockets. This handler
+ // should be called when the IfaceMgr fails to open socket on eth0.
+ isc::dhcp::IfaceMgrErrorMsgCallback error_handler =
+ boost::bind(&IfaceMgrTest::ifaceMgrErrorHandler, this, _1);
+ // ASSERT_NO_THROW(ifacemgr.openSockets6(DHCP6_SERVER_PORT, error_handler));
+ try {
+ ifacemgr.openSockets6(DHCP6_SERVER_PORT, error_handler);
+ } catch (const Exception& ex) {
+ std::cout << ex.what() << std::endl;
+ }
+ // We expect that an error occured when we tried to open a socket on
+ // eth0, but the socket on eth1 should open just fine.
+ EXPECT_EQ(1, errors_count_);
+
+ // Reset errors count.
+ errors_count_ = 0;
+
+ // Now that we have two sockets open, we can try this again but this time
+ // we should get two errors: one when opening a socket on eth0, another one
+ // when opening a socket on eth1.
+ ASSERT_NO_THROW(ifacemgr.openSockets6(DHCP6_SERVER_PORT, error_handler));
+ EXPECT_EQ(2, errors_count_);
+
+}
+
// Test the Iface structure itself
TEST_F(IfaceMgrTest, iface) {
boost::scoped_ptr<Iface> iface;
}
SocketInfo
-PktFilter6Stub::openSocket(const Iface&, const isc::asiolink::IOAddress& addr,
+PktFilter6Stub::openSocket(const Iface& iface, const isc::asiolink::IOAddress& addr,
const uint16_t port, const bool) {
+ // Check if there is any other socket bound to the specified address
+ // and port on this interface.
+ const Iface::SocketCollection& sockets = iface.getSockets();
+ for (Iface::SocketCollection::const_iterator socket = sockets.begin();
+ socket != sockets.end(); ++socket) {
+ if ((socket->addr_ == addr) && (socket->port_ == port)) {
+ isc_throw(SocketConfigError, "test socket bind error");
+ }
+ }
++open_socket_count_;
return (SocketInfo(addr, port, 0));
}
/// always set to 0. On each call to this function, the counter of
/// invocations is increased by one. This is useful to check if packet
/// filter object has been correctly installed and is used by @c IfaceMgr.
+ /// As in the case of opening a real socket, this function will check
+ /// if there is another fake socket "bound" to the same address and port.
+ /// If there is, it will throw an exception. This allows to simulate the
+ /// conditions when one of the sockets can't be open because there is
+ /// a socket already open and test how IfaceMgr will handle it.
///
/// @param iface Interface descriptor.
/// @param addr Address on the interface to be used to send packets.
projects / thirdparty / kea.git / commitdiff
