[master] Merge branch 'trac1957'

Conflicts:
	src/lib/dhcp/iface_mgr.cc

src/lib/dhcp/iface_mgr.cc

@@ -19,11 +19,14 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <sys/select.h>
+#include <asio.hpp>
 
 #include <dhcp/dhcp4.h>
 #include <dhcp/dhcp6.h>
 #include <dhcp/iface_mgr.h>
 #include <exceptions/exceptions.h>
+#include <asiolink/udp_endpoint.h>
+#include <asiolink/io_error.h>
 #include <util/io/pktinfo_utilities.h>
 
 using namespace std;
@@ -197,7 +200,7 @@ void IfaceMgr::stubDetectIfaces() {
         iface.flag_up_ = true;
         iface.flag_running_ = true;
 
-        // note that we claim that this is not a loopback. iface_mgr tries to open a
+        // Note that we claim that this is not a loopback. iface_mgr tries to open a
         // socket on all interaces that are up, running and not loopback. As this is
         // the only interface we were able to detect, let's pretend this is a normal
         // interface.
@@ -228,8 +231,8 @@ bool IfaceMgr::openSockets4(const uint16_t port) {
     int sock;
     int count = 0;
 
-    for (IfaceCollection::iterator iface=ifaces_.begin();
-         iface!=ifaces_.end();
+    for (IfaceCollection::iterator iface = ifaces_.begin();
+         iface != ifaces_.end();
          ++iface) {
 
         cout << "Trying opening socket on interface " << iface->getFullName() << endl;
@@ -243,18 +246,17 @@ bool IfaceMgr::openSockets4(const uint16_t port) {
         }
 
         AddressCollection addrs = iface->getAddresses();
-
-        for (AddressCollection::iterator addr= addrs.begin();
+        for (AddressCollection::iterator addr = addrs.begin();
              addr != addrs.end();
              ++addr) {
 
-            // skip IPv6 addresses
+            // Skip IPv6 addresses
             if (addr->getFamily() != AF_INET) {
                 continue;
             }
 
             sock = openSocket(iface->getName(), *addr, port);
-            if (sock<0) {
+            if (sock < 0) {
                 cout << "Failed to open unicast socket." << endl;
                 return (false);
             }
@@ -270,8 +272,8 @@ bool IfaceMgr::openSockets6(const uint16_t port) {
     int sock;
     int count = 0;
 
-    for (IfaceCollection::iterator iface=ifaces_.begin();
-         iface!=ifaces_.end();
+    for (IfaceCollection::iterator iface = ifaces_.begin();
+         iface != ifaces_.end();
          ++iface) {
 
         if (iface->flag_loopback_ ||
@@ -281,8 +283,7 @@ bool IfaceMgr::openSockets6(const uint16_t port) {
         }
 
         AddressCollection addrs = iface->getAddresses();
-
-        for (AddressCollection::iterator addr= addrs.begin();
+        for (AddressCollection::iterator addr = addrs.begin();
              addr != addrs.end();
              ++addr) {
 
@@ -292,7 +293,7 @@ bool IfaceMgr::openSockets6(const uint16_t port) {
             }
 
             sock = openSocket(iface->getName(), *addr, port);
-            if (sock<0) {
+            if (sock < 0) {
                 cout << "Failed to open unicast socket." << endl;
                 return (false);
             }
@@ -301,7 +302,7 @@ bool IfaceMgr::openSockets6(const uint16_t port) {
             // works well on Mac OS (and possibly other BSDs), but does not work
             // on Linux.
             if ( !joinMulticast(sock, iface->getName(),
-                                string(ALL_DHCP_RELAY_AGENTS_AND_SERVERS) ) ) {
+                                string(ALL_DHCP_RELAY_AGENTS_AND_SERVERS))) {
                 close(sock);
                 isc_throw(Unexpected, "Failed to join " << ALL_DHCP_RELAY_AGENTS_AND_SERVERS
                           << " multicast group.");
@@ -317,7 +318,7 @@ bool IfaceMgr::openSockets6(const uint16_t port) {
             int sock2 = openSocket(iface->getName(),
                                    IOAddress(ALL_DHCP_RELAY_AGENTS_AND_SERVERS),
                                    port);
-            if (sock2<0) {
+            if (sock2 < 0) {
                 isc_throw(Unexpected, "Failed to open multicast socket on "
                           << " interface " << iface->getFullName());
                 iface->delSocket(sock); // delete previously opened socket
@@ -397,6 +398,117 @@ int IfaceMgr::openSocket(const std::string& ifname, const IOAddress& addr,
     }
 }
 
+int IfaceMgr::openSocketFromIface(const std::string& ifname,
+                                  const uint16_t port,
+                                  const uint8_t family) {
+    // Search for specified interface among detected interfaces.
+    for (IfaceCollection::iterator iface = ifaces_.begin();
+         iface != ifaces_.end();
+         ++iface) {
+
+        if ((iface->getFullName() != ifname) &&
+            (iface->getName() != ifname)) {
+            continue;
+        }
+
+        // Interface is now detected. Search for address on interface
+        // that matches address family (v6 or v4).
+        AddressCollection addrs = iface->getAddresses();
+        AddressCollection::iterator addr_it = addrs.begin();
+        while (addr_it != addrs.end()) {
+            if (addr_it->getFamily() == family) {
+                // We have interface and address so let's open socket.
+                // This may cause isc::Unexpected exception.
+                return (openSocket(iface->getName(), *addr_it, port));
+            }
+            ++addr_it;
+        }
+        // If we are at the end of address collection it means that we found
+        // interface but there is no address for family specified.
+        if (addr_it == addrs.end()) {
+            // Stringify the family value to append it to exception string.
+            std::string family_name("AF_INET");
+            if (family == AF_INET6) {
+                family_name = "AF_INET6";
+            }
+            // We did not find address on the interface.
+            isc_throw(BadValue, "There is no address for interface: "
+                      << ifname << ", port: " << port << ", address "
+                      " family: " << family_name);
+        }
+    }
+    // If we got here it means that we had not found the specified interface.
+    // Otherwise we would have returned from previous exist points.
+    isc_throw(BadValue, "There is no " << ifname << " interface present.");
+}
+
+int IfaceMgr::openSocketFromAddress(const IOAddress& addr,
+                                    const uint16_t port) {
+    // Search through detected interfaces and addresses to match
+    // local address we got.
+    for (IfaceCollection::iterator iface = ifaces_.begin();
+         iface != ifaces_.end();
+         ++iface) {
+
+        AddressCollection addrs = iface->getAddresses();
+
+        for (AddressCollection::iterator addr_it = addrs.begin();
+             addr_it != addrs.end();
+             ++addr_it) {
+
+            // Local address must match one of the addresses
+            // on detected interfaces. If it does, we have
+            // address and interface detected so we can open
+            // socket.
+            if (*addr_it == addr) {
+                // Open socket using local interface, address and port.
+                // This may cause isc::Unexpected exception.
+                return (openSocket(iface->getName(), *addr_it, port));
+            }
+        }
+    }
+    // If we got here it means that we did not find specified address
+    // on any available interface.
+    isc_throw(BadValue, "There is no such address " << addr.toText());
+}
+
+int IfaceMgr::openSocketFromRemoteAddress(const IOAddress& remote_addr,
+                                          const uint16_t port) {
+    // Get local address to be used to connect to remote location.
+    IOAddress local_address(getLocalAddress(remote_addr, port).getAddress());
+    return openSocketFromAddress(local_address, port);
+}
+
+isc::asiolink::IOAddress
+IfaceMgr::getLocalAddress(const IOAddress& remote_addr, const uint16_t port) {
+    // Create remote endpoint, we will be connecting to it.
+    boost::scoped_ptr<const UDPEndpoint>
+        remote_endpoint(static_cast<const UDPEndpoint*>
+                        (UDPEndpoint::create(IPPROTO_UDP, remote_addr, port)));
+    if (!remote_endpoint) {
+        isc_throw(Unexpected, "Unable to create remote endpoint");
+    }
+
+    // Create socket that will be used to connect to remote endpoint.
+    asio::io_service io_service;
+    asio::ip::udp::socket sock(io_service);
+
+    // Try to connect to remote endpoint and check if attempt is successful.
+    asio::error_code err_code;
+    sock.connect(remote_endpoint->getASIOEndpoint(), err_code);
+    if (err_code) {
+        isc_throw(Unexpected,"Failed to connect to remote endpoint.");
+    }
+
+    // Once we are connected socket object holds local endpoint.
+    asio::ip::udp::socket::endpoint_type local_endpoint =
+        sock.local_endpoint();
+    asio::ip::address local_address(local_endpoint.address());
+
+    // Return address of local endpoint.
+    return IOAddress(local_address);
+}
+
 int IfaceMgr::openSocket4(Iface& iface, const IOAddress& addr, uint16_t port) {
 
     cout << "Creating UDP4 socket on " << iface.getFullName()

src/lib/dhcp/iface_mgr.h

@@ -374,7 +374,58 @@ public:
     /// @return socket descriptor, if socket creation, binding and multicast
     /// group join were all successful.
     int openSocket(const std::string& ifname,
-                   const isc::asiolink::IOAddress& addr, const uint16_t port);
+                   const isc::asiolink::IOAddress& addr,
+                   const uint16_t port);
+
+    /// @brief Opens UDP/IP socket and binds it to interface specified.
+    ///
+    /// This method differs from \ref openSocket in that it does not require
+    /// the specification of a local address to which socket will be bound.
+    /// Instead, the method searches through the addresses on the specified
+    /// interface and selects one that matches the address family.
+    ///
+    /// @param ifname name of the interface
+    /// @param port UDP port
+    /// @param family address family (AF_INET or AF_INET6)
+    /// @return socket descriptor, if socket creation, binding and multicast
+    /// group join were all successful.
+    /// @throw isc::Unexpected if failed to create and bind socket.
+    /// @throw isc::BadValue if there is no address on specified interface
+    /// that belongs to given family.
+    int openSocketFromIface(const std::string& ifname,
+                            const uint16_t port,
+                            const uint8_t family);
+
+    /// @brief Opens UDP/IP socket and binds to address specified
+    ///
+    /// This methods differs from \ref openSocket in that it does not require
+    /// the specification of the interface to which the socket will be bound.
+    ///
+    /// @param addr address to be bound
+    /// @param port UDP port
+    /// @return socket descriptor, if socket creation, binding and multicast
+    /// group join were all successful.
+    /// @throw isc::Unexpected if failed to create and bind socket
+    /// @throw isc::BadValue if specified address is not available on
+    /// any interface
+    int openSocketFromAddress(const isc::asiolink::IOAddress& addr,
+                              const uint16_t port);
+
+    /// @brief Opens UDP/IP socket to be used to connect to remote address
+    ///
+    /// This method identifies the local address to be used to connect to the
+    /// remote address specified as argument.  Once the local address is
+    /// identified, \ref openSocket is called to open a socket and bind it to
+    /// the interface, address and port.
+    ///
+    /// @param remote_addr remote address to connect to
+    /// @param port UDP port
+    /// @return socket descriptor, if socket creation, binding and multicast
+    /// group join were all successful.
+    /// @throw isc::Unexpected if failed to create and bind socket
+    int openSocketFromRemoteAddress(const isc::asiolink::IOAddress& remote_addr,
+                                    const uint16_t port);
+
 
     /// Opens IPv6 sockets on detected interfaces.
     ///
@@ -548,6 +599,23 @@ private:
     joinMulticast(int sock, const std::string& ifname,
                   const std::string& mcast);
 
+    /// @brief Identifies local network address to be used to
+    /// connect to remote address.
+    ///
+    /// This method identifies local network address that can be used
+    /// to connect to remote address specified.
+    /// It first creates socket and makes attempt to connect
+    /// to remote location via this socket. If connection
+    /// is established successfully, the local address to which
+    /// socket is bound is returned.
+    ///
+    /// @param remote_addr remote address to connect to
+    /// @param port port to be used
+    /// @return local address to be used to connect to remote address
+    /// @throw isc::Unexpected if unable to indentify local address
+    isc::asiolink::IOAddress
+    getLocalAddress(const isc::asiolink::IOAddress& remote_addr,
+                    const uint16_t port);
 };
 
 }; // namespace isc::dhcp

src/lib/dhcp/tests/iface_mgr_unittest.cc

@@ -19,6 +19,7 @@
 
 #include <unistd.h>
 #include <arpa/inet.h>
+#include <boost/scoped_ptr.hpp>
 #include <gtest/gtest.h>
 
 #include <asiolink/io_address.h>
@@ -31,12 +32,17 @@ using namespace isc;
 using namespace isc::asiolink;
 using namespace isc::dhcp;
 
-// name of loopback interface detection
-const size_t buf_size = 32;
-char LOOPBACK[buf_size] = "lo";
-
 namespace {
 
+// Name of loopback interface detection
+const size_t BUF_SIZE = 32;
+char LOOPBACK[BUF_SIZE] = "lo";
+
+// Ports used during testing
+const uint16_t PORT1 = 10547;   // V6 socket
+const uint16_t PORT2 = 10548;   // V4 socket
+
+
 class NakedIfaceMgr: public IfaceMgr {
     // "naked" Interface Manager, exposes internal fields
 public:
@@ -69,10 +75,10 @@ TEST_F(IfaceMgrTest, loDetect) {
     // is implemented
     if (if_nametoindex("lo") > 0) {
         cout << "This is Linux, using lo as loopback." << endl;
-        snprintf(LOOPBACK, buf_size - 1, "lo");
+        snprintf(LOOPBACK, BUF_SIZE - 1, "lo");
     } else if (if_nametoindex("lo0") > 0) {
         cout << "This is BSD, using lo0 as loopback." << endl;
-        snprintf(LOOPBACK, buf_size - 1, "lo0");
+        snprintf(LOOPBACK, BUF_SIZE - 1, "lo0");
     } else {
         cout << "Failed to detect loopback interface. Neither "
              << "lo nor lo0 worked. I give up." << endl;
@@ -80,7 +86,7 @@ TEST_F(IfaceMgrTest, loDetect) {
     }
 }
 
-// uncomment this test to create packet writer. It will
+// Uncomment this test to create packet writer. It will
 // write incoming DHCPv6 packets as C arrays. That is useful
 // for generating test sequences based on actual traffic
 //
@@ -241,6 +247,78 @@ TEST_F(IfaceMgrTest, sockets6) {
     delete ifacemgr;
 }
 
+TEST_F(IfaceMgrTest, socketsFromIface) {
+    boost::scoped_ptr<NakedIfaceMgr> ifacemgr(new NakedIfaceMgr());
+
+    // Open v6 socket on loopback interface and bind to port
+    int socket1 = 0;
+    EXPECT_NO_THROW(
+        socket1 = ifacemgr->openSocketFromIface(LOOPBACK, PORT1, AF_INET6);
+    );
+    // Socket descriptor must be positive integer
+    EXPECT_GT(socket1, 0);
+    close(socket1);
+
+    // Open v4 socket on loopback interface and bind to different port
+    int socket2 = 0;
+    EXPECT_NO_THROW(
+        socket2 = ifacemgr->openSocketFromIface(LOOPBACK, PORT2, AF_INET);
+    );
+    // socket descriptor must be positive integer
+    EXPECT_GT(socket2, 0);
+    close(socket2);
+
+}
+
+
+TEST_F(IfaceMgrTest, socketsFromAddress) {
+    boost::scoped_ptr<NakedIfaceMgr> ifacemgr(new NakedIfaceMgr());
+
+    // Open v6 socket on loopback interface and bind to port
+    int socket1 = 0;
+    IOAddress loAddr6("::1");
+    EXPECT_NO_THROW(
+        socket1 = ifacemgr->openSocketFromAddress(loAddr6, PORT1);
+    );
+    // socket descriptor must be positive integer
+    EXPECT_GT(socket1, 0);
+    close(socket1);
+
+    // Open v4 socket on loopback interface and bind to different port
+    int socket2 = 0;
+    IOAddress loAddr("127.0.0.1");
+    EXPECT_NO_THROW(
+        socket2 = ifacemgr->openSocketFromAddress(loAddr, PORT2);
+    );
+    // socket descriptor must be positive integer
+    EXPECT_GT(socket2, 0);
+    close(socket2);
+}
+
+TEST_F(IfaceMgrTest, socketsFromRemoteAddress) {
+    boost::scoped_ptr<NakedIfaceMgr> ifacemgr(new NakedIfaceMgr());
+
+    // Open v6 socket to connect to remote address.
+    // Loopback address is the only one that we know
+    // so let's treat it as remote address.
+    int socket1 = 0;
+    IOAddress loAddr6("::1");
+    EXPECT_NO_THROW(
+        socket1 = ifacemgr->openSocketFromRemoteAddress(loAddr6, PORT1);
+    );
+    EXPECT_GT(socket1, 0);
+    close(socket1);
+
+    // Open v4 socket to connect to remote address.
+    int socket2 = 0;
+    IOAddress loAddr("127.0.0.1");
+    EXPECT_NO_THROW(
+        socket2 = ifacemgr->openSocketFromRemoteAddress(loAddr, PORT2);
+    );
+    EXPECT_GT(socket2, 0);
+    close(socket2);
+}
+
 // TODO: disabled due to other naming on various systems
 // (lo in Linux, lo0 in BSD systems)
 TEST_F(IfaceMgrTest, DISABLED_sockets6Mcast) {