BIND 10 trac3251, updated. cef44a4094cac6272f1a85c485b23fd047107fe0 [3251] Addressed review comments.
BIND 10 source code commits
bind10-changes at lists.isc.org
Thu Dec 19 15:57:10 UTC 2013
The branch, trac3251 has been updated
via cef44a4094cac6272f1a85c485b23fd047107fe0 (commit)
from 9139b19b6220b270e2442731f258ba85c7877526 (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.
- Log -----------------------------------------------------------------
commit cef44a4094cac6272f1a85c485b23fd047107fe0
Author: Marcin Siodelski <marcin at isc.org>
Date: Thu Dec 19 16:56:57 2013 +0100
[3251] Addressed review comments.
-----------------------------------------------------------------------
Summary of changes:
src/lib/dhcp/iface_mgr.cc | 48 ++++-----
src/lib/dhcp/iface_mgr.h | 6 +-
src/lib/dhcp/pkt_filter6.cc | 2 +
src/lib/dhcp/pkt_filter6.h | 18 +++-
src/lib/dhcp/pkt_filter_inet6.cc | 26 ++---
src/lib/dhcp/pkt_filter_inet6.h | 13 ++-
src/lib/dhcp/pkt_filter_lpf.h | 9 +-
src/lib/dhcp/tests/iface_mgr_unittest.cc | 154 +++++++++++++++++++++++++--
src/lib/dhcp/tests/pkt_filter6_test_utils.h | 2 +-
9 files changed, 217 insertions(+), 61 deletions(-)
-----------------------------------------------------------------------
diff --git a/src/lib/dhcp/iface_mgr.cc b/src/lib/dhcp/iface_mgr.cc
index 56e347f..94c7ab9 100644
--- a/src/lib/dhcp/iface_mgr.cc
+++ b/src/lib/dhcp/iface_mgr.cc
@@ -477,41 +477,41 @@ bool IfaceMgr::openSockets6(const uint16_t port) {
continue;
}
- sock = openSocket(iface->getName(), *addr, port);
+ // Open socket and join multicast group only if the interface
+ // is multicast-capable.
+ // @todo The DHCPv6 requires multicast so we may want to think
+ // whether we want to open the socket on a multicast-incapable
+ // interface or not. For now, we prefer to be liberal and allow
+ // 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 "
+ isc_throw(SocketConfigError, "failed to open link-local"
+ " socket on " << addr->toText() << " on interface "
<< iface->getName() << ", reason: " << errstr);
}
- /* // Binding socket to unicast address and then joining multicast group
- // works well on Mac OS (and possibly other BSDs), but does not work
- // on Linux.
- if ( !PktFilter6::joinMulticast(sock, iface->getName(),
- string(ALL_DHCP_RELAY_AGENTS_AND_SERVERS))) {
- close(sock);
- isc_throw(SocketConfigError, "Failed to join "
- << ALL_DHCP_RELAY_AGENTS_AND_SERVERS
- << " multicast group.");
- } */
-
count++;
/// @todo: Remove this ifdef once we start supporting BSD systems.
#if defined(OS_LINUX)
// To receive multicast traffic, Linux requires binding socket to
// a multicast group. That in turn doesn't work on NetBSD.
-
- int sock2 = 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
+ if (iface->flag_multicast_) {
+ int sock2 =
+ 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
+ }
}
#endif
}
diff --git a/src/lib/dhcp/iface_mgr.h b/src/lib/dhcp/iface_mgr.h
index a253564..2a220b8 100644
--- a/src/lib/dhcp/iface_mgr.h
+++ b/src/lib/dhcp/iface_mgr.h
@@ -976,13 +976,17 @@ private:
/// Holds instance of a class derived from PktFilter, used by the
/// IfaceMgr to open sockets and send/receive packets through these
/// sockets. It is possible to supply custom object using
- /// setPacketFilter class. Various Packet Filters differ mainly by using
+ /// setPacketFilter method. Various Packet Filters differ mainly by using
/// different types of sockets, e.g. SOCK_DGRAM, SOCK_RAW and different
/// families, e.g. AF_INET, AF_PACKET etc. Another possible type of
/// Packet Filter is the one used for unit testing, which doesn't
/// open sockets but rather mimics their behavior (mock object).
PktFilterPtr packet_filter_;
+ /// Holds instance of a class derived from PktFilter6, used by the
+ /// IfaceMgr to manage sockets used to send and receive DHCPv6
+ /// messages. It is possible to supply a custom object using
+ /// setPacketFilter method.
PktFilter6Ptr packet_filter6_;
};
diff --git a/src/lib/dhcp/pkt_filter6.cc b/src/lib/dhcp/pkt_filter6.cc
index 7ba9212..03927fb 100644
--- a/src/lib/dhcp/pkt_filter6.cc
+++ b/src/lib/dhcp/pkt_filter6.cc
@@ -22,6 +22,8 @@ PktFilter6::joinMulticast(int sock, const std::string& ifname,
const std::string & mcast) {
struct ipv6_mreq mreq;
+ memset(&mreq, 0, sizeof(ipv6_mreq));
+
// Convert the multicast address to a binary form.
if (inet_pton(AF_INET6, mcast.c_str(), &mreq.ipv6mr_multiaddr) <= 0) {
return (false);
diff --git a/src/lib/dhcp/pkt_filter6.h b/src/lib/dhcp/pkt_filter6.h
index 1cd5e5b..dcddf6c 100644
--- a/src/lib/dhcp/pkt_filter6.h
+++ b/src/lib/dhcp/pkt_filter6.h
@@ -65,16 +65,26 @@ class Iface;
/// but simply create a pool of fake interfaces which configuration
/// can be freely modified by a test. This however implies that operations
/// on sockets must be simulated.
+///
+/// @note This class is named after @c PktFilter abstract class which exposes
+/// similar interface for DHVPv4. However, the PktFilter class is devoted to
+/// solve the problem of sending DHCPv4 messages to the hosts which don't have
+/// an IP address yet (a.k.a. direct DHCPv4 traffic). Where required, the
+/// custom implementations of @c PktFilter are provided to send and receive
+/// messages through raw sockets. In order to filter out the desired traffic
+/// Linux Packet Filtering or Berkeley Packet Filtering is used, hence the
+/// name of the class. In case of DHCPv6 regular IPv6/UDPv6 sockets are used
+/// and derived classes do not use Linux or Berkeley Packet Filtering.
class PktFilter6 {
public:
/// @brief Virtual Destructor.
virtual ~PktFilter6() { }
- /// @brief Open a socket.
+ /// @brief Opens a socket.
///
/// This function open an IPv6 socket on an interface and binds it to a
- /// specified UDP port and IP address.
+ /// specified UDP port and IPv6 address.
///
/// @param iface Interface descriptor.
/// @param addr Address on the interface to be used to send packets.
@@ -89,7 +99,7 @@ public:
const uint16_t port,
const bool join_multicast) = 0;
- /// @brief Receive DHCPv6 message on the interface.
+ /// @brief Receives DHCPv6 message on the interface.
///
/// This function receives a single DHCPv6 message through using a socket
/// open on a specified interface.
@@ -99,7 +109,7 @@ public:
/// @return A pointer to received message.
virtual Pkt6Ptr receive(const SocketInfo& socket_info) = 0;
- /// @brief Send DHCPv6 message through a specified interface and socket.
+ /// @brief Sends DHCPv6 message through a specified interface and socket.
///
/// This function sends a DHCPv6 message through a specified interface and
/// socket. In general, there may be multiple sockets open on a single
diff --git a/src/lib/dhcp/pkt_filter_inet6.cc b/src/lib/dhcp/pkt_filter_inet6.cc
index b0ff557..1ec75f3 100644
--- a/src/lib/dhcp/pkt_filter_inet6.cc
+++ b/src/lib/dhcp/pkt_filter_inet6.cc
@@ -47,7 +47,7 @@ PktFilterInet6::openSocket(const Iface& iface,
addr6.sin6_len = sizeof(addr6);
#endif
- // TODO: use sockcreator once it becomes available
+ // @todo use sockcreator once it becomes available
// make a socket
int sock = socket(AF_INET6, SOCK_DGRAM, 0);
@@ -55,8 +55,7 @@ PktFilterInet6::openSocket(const Iface& iface,
isc_throw(SocketConfigError, "Failed to create UDP6 socket.");
}
- // Set the REUSEADDR option so that we don't fail to start if
- // we're being restarted.
+ // Set SO_REUSEADDR option.
int flag = 1;
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(char *)&flag, sizeof(flag)) < 0) {
@@ -85,18 +84,15 @@ PktFilterInet6::openSocket(const Iface& iface,
}
#endif
- // multicast stuff
- if (addr.getAddress().to_v6().is_multicast()) {
- // both mcast (ALL_DHCP_RELAY_AGENTS_AND_SERVERS and ALL_DHCP_SERVERS)
- // are link and site-scoped, so there is no sense to join those groups
- // with global addresses.
-
- if (join_multicast && !joinMulticast(sock, iface.getName(),
- std::string(ALL_DHCP_RELAY_AGENTS_AND_SERVERS))) {
- close(sock);
- isc_throw(SocketConfigError, "Failed to join " << ALL_DHCP_RELAY_AGENTS_AND_SERVERS
- << " multicast group.");
- }
+ // Join All_DHCP_Relay_Agents_and_Servers multicast group if
+ // requested.
+ if (join_multicast &&
+ !joinMulticast(sock, iface.getName(),
+ std::string(ALL_DHCP_RELAY_AGENTS_AND_SERVERS))) {
+ close(sock);
+ isc_throw(SocketConfigError, "Failed to join "
+ << ALL_DHCP_RELAY_AGENTS_AND_SERVERS
+ << " multicast group.");
}
return (SocketInfo(addr, port, sock));
diff --git a/src/lib/dhcp/pkt_filter_inet6.h b/src/lib/dhcp/pkt_filter_inet6.h
index e4b879c..c475cf5 100644
--- a/src/lib/dhcp/pkt_filter_inet6.h
+++ b/src/lib/dhcp/pkt_filter_inet6.h
@@ -34,7 +34,7 @@ public:
/// Initializes a control buffer used in the message transmission.
PktFilterInet6();
- /// @brief Open a socket.
+ /// @brief Opens a socket.
///
/// This function open an IPv6 socket on an interface and binds it to a
/// specified UDP port and IP address.
@@ -54,10 +54,13 @@ public:
const uint16_t port,
const bool join_multicast);
- /// @brief Receive DHCPv6 message on the interface.
+ /// @brief Receives DHCPv6 message on the interface.
///
- /// This function receives a single DHCPv6 message through using a socket
- /// open on a specified interface.
+ /// This function receives a single DHCPv6 message through a socket
+ /// open on a specified interface. This function will block if there is
+ /// no message waiting on the specified socket. Therefore the @c IfaceMgr
+ /// must first check that there is any message on the socket (using
+ /// select function) prior to calling this function.
///
/// @param socket_info A structure holding socket information.
///
@@ -66,7 +69,7 @@ public:
/// reception.
virtual Pkt6Ptr receive(const SocketInfo& socket_info);
- /// @brief Send DHCPv6 message through a specified interface and socket.
+ /// @brief Sends DHCPv6 message through a specified interface and socket.
///
/// Thie function sends a DHCPv6 message through a specified interface and
/// socket. In general, there may be multiple sockets open on a single
diff --git a/src/lib/dhcp/pkt_filter_lpf.h b/src/lib/dhcp/pkt_filter_lpf.h
index 279c864..1815dda 100644
--- a/src/lib/dhcp/pkt_filter_lpf.h
+++ b/src/lib/dhcp/pkt_filter_lpf.h
@@ -24,11 +24,10 @@ namespace dhcp {
/// @brief Packet handling class using Linux Packet Filtering
///
-/// This class provides methods to send and recive packet using raw sockets
-/// and Linux Packet Filtering.
-///
-/// @warning This class is not implemented yet. Therefore all functions
-/// currently throw isc::NotImplemented exception.
+/// This class provides methods to send and recive DHCPv4 messages using raw
+/// sockets and Linux Packet Filtering. It is used by @c isc::dhcp::IfaceMgr
+/// to send DHCPv4 messages to the hosts which don't have an IPv4 address
+/// assigned yet.
class PktFilterLPF : public PktFilter {
public:
diff --git a/src/lib/dhcp/tests/iface_mgr_unittest.cc b/src/lib/dhcp/tests/iface_mgr_unittest.cc
index 83fbe99..0469b86 100644
--- a/src/lib/dhcp/tests/iface_mgr_unittest.cc
+++ b/src/lib/dhcp/tests/iface_mgr_unittest.cc
@@ -158,7 +158,7 @@ public:
/// @brief Returns the collection of existing interfaces.
IfaceCollection& getIfacesLst() { return (ifaces_); }
- /// @brief This function creates fictious interfaces with fictious
+ /// @brief This function creates fictitious interfaces with fictious
/// addresses.
///
/// These interfaces can be used in tests that don't actually try
@@ -195,6 +195,8 @@ public:
/// - up always true
/// - running always true
/// - inactive always to false
+ /// - multicast always to true
+ /// - broadcast always to true
///
/// If one needs to modify the default flag settings, the setIfaceFlags
/// function should be used.
@@ -208,9 +210,12 @@ public:
if (name == "lo") {
iface.flag_loopback_ = true;
}
+ iface.flag_multicast_ = true;
+ iface.flag_broadcast_ = true;
iface.flag_up_ = true;
iface.flag_running_ = true;
iface.inactive4_ = false;
+ iface.inactive6_ = false;
return (iface);
}
@@ -288,7 +293,9 @@ public:
///
/// @param iface An interface on which sockets are open.
/// @param unicast_num A number of unicast addresses bound.
- void checkSocketsCount6(const Iface& iface, const int unicast_num) {
+ /// @param link_local_num A number of link local addresses bound.
+ void checkSocketsCount6(const Iface& iface, const int unicast_num,
+ const int link_local_num = 1) {
// On local-loopback interface, there should be no sockets.
if (iface.flag_loopback_) {
ASSERT_TRUE(iface.getSockets().empty())
@@ -297,13 +304,16 @@ public:
return;
}
#if defined OS_LINUX
- // On Linux, there is an additional socket bound to ff02::1:2.
- ASSERT_EQ(unicast_num + 2, iface.getSockets().size())
+ // On Linux, for each link-local address there may be an
+ // additional socket opened and bound to ff02::1:2. This socket
+ // is only opened if the interface is multicast-capable.
+ ASSERT_EQ(unicast_num + (iface.flag_multicast_ ? link_local_num : 0)
+ + link_local_num, iface.getSockets().size())
<< "invalid number of sockets on interface "
<< iface.getName();
#else
// On non-Linux, there is no additional socket.
- ASSERT_EQ(unicast_num + 1, iface.getSockets().size())
+ ASSERT_EQ(unicast_num + link_local_num, iface.getSockets().size())
<< "invalid number of sockets on interface "
<< iface.getName();
@@ -1505,6 +1515,92 @@ TEST_F(IfaceMgrTest, openSockets6LinkLocal) {
#endif
}
+// This test checks that socket is not open on the interface which doesn't
+// have a link-local address.
+TEST_F(IfaceMgrTest, openSockets6NoLinkLocal) {
+ 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));
+
+ // Remove a link local address from eth0. If there is no link-local
+ // address, the socket should not open.
+ ASSERT_TRUE(ifacemgr.getIface("eth0")->
+ delAddress(IOAddress("fe80::3a60:77ff:fed5:cdef")));
+
+ // Simulate opening sockets using the dummy packet filter.
+ bool success = false;
+ ASSERT_NO_THROW(success = ifacemgr.openSockets6(DHCP6_SERVER_PORT));
+ EXPECT_TRUE(success);
+
+ // Check that the number of sockets is correct on each interface.
+ checkSocketsCount6(*ifacemgr.getIface("lo"), 0);
+ // The thrid parameter specifies that the number of link-local
+ // addresses for eth0 is equal to 0.
+ checkSocketsCount6(*ifacemgr.getIface("eth0"), 0, 0);
+ checkSocketsCount6(*ifacemgr.getIface("eth1"), 0, 1);
+
+ // There should be no sockets open on eth0 because it neither has
+ // link-local nor global unicast addresses.
+ EXPECT_FALSE(ifacemgr.isBound("eth0", "fe80::3a60:77ff:fed5:cdef"));
+ EXPECT_FALSE(ifacemgr.isBound("eth0", "2001:db8:1::1"));
+ // Socket on eth1 should be bound to link local only.
+ EXPECT_TRUE(ifacemgr.isBound("eth1", "fe80::3a60:77ff:fed5:abcd"));
+
+ // If we are on Linux, there is one more socket bound to ff02::1:2
+#if defined OS_LINUX
+ EXPECT_FALSE(ifacemgr.isBound("eth0", ALL_DHCP_RELAY_AGENTS_AND_SERVERS));
+#endif
+
+}
+
+// This test checks that socket is open on the non-muticast-capable
+// interface. This socket simply doesn't join multicast group.
+TEST_F(IfaceMgrTest, openSockets6NotMulticast) {
+ 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));
+
+ // Make eth0 multicast-incapable.
+ ifacemgr.getIface("eth0")->flag_multicast_ = false;
+
+ // Simulate opening sockets using the dummy packet filter.
+ bool success = false;
+ ASSERT_NO_THROW(success = ifacemgr.openSockets6(DHCP6_SERVER_PORT));
+ EXPECT_TRUE(success);
+
+ // Check that the number of sockets is correct on each interface.
+ checkSocketsCount6(*ifacemgr.getIface("lo"), 0);
+ checkSocketsCount6(*ifacemgr.getIface("eth0"), 0);
+ checkSocketsCount6(*ifacemgr.getIface("eth1"), 0);
+
+ // Sockets on eth0 should be bound to link-local and should not be bound
+ // to global unicast address, even though this address is configured on
+ // the eth0.
+ EXPECT_TRUE(ifacemgr.isBound("eth0", "fe80::3a60:77ff:fed5:cdef"));
+ EXPECT_FALSE(ifacemgr.isBound("eth0", "2001:db8:1::1"));
+ // The eth0 is not a multicast-capable interface, so the socket should
+ // not be bound to the multicast address.
+ EXPECT_FALSE(ifacemgr.isBound("eth0", ALL_DHCP_RELAY_AGENTS_AND_SERVERS));
+ // Socket on eth1 should be bound to link local only.
+ EXPECT_TRUE(ifacemgr.isBound("eth1", "fe80::3a60:77ff:fed5:abcd"));
+
+ // If we are on Linux, there is one more socket bound to ff02::1:2
+ // on eth1.
+#if defined OS_LINUX
+ EXPECT_TRUE(ifacemgr.isBound("eth1", ALL_DHCP_RELAY_AGENTS_AND_SERVERS));
+#endif
+}
+
// This test checks that the sockets are opened and bound to link local
// and unicast addresses which have been explicitly specified.
TEST_F(IfaceMgrTest, openSockets6Unicast) {
@@ -1546,6 +1642,52 @@ TEST_F(IfaceMgrTest, openSockets6Unicast) {
}
+// This test checks that the socket is open and bound to a global unicast
+// address if the link-local address does not exist for the particular
+// interface.
+TEST_F(IfaceMgrTest, openSockets6UnicastOnly) {
+ 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));
+
+ // Configure the eth0 to open socket on the unicast address, apart
+ // from link-local address.
+ ifacemgr.getIface("eth0")->addUnicast(IOAddress("2001:db8:1::1"));
+ // Explicitly remove the link-local address from eth0.
+ ASSERT_TRUE(ifacemgr.getIface("eth0")->
+ delAddress(IOAddress("fe80::3a60:77ff:fed5:cdef")));
+
+ // Simulate opening sockets using the dummy packet filter.
+ bool success = false;
+ ASSERT_NO_THROW(success = ifacemgr.openSockets6(DHCP6_SERVER_PORT));
+ EXPECT_TRUE(success);
+
+ // Check that we have correct number of sockets on each interface.
+ checkSocketsCount6(*ifacemgr.getIface("lo"), 0);
+ checkSocketsCount6(*ifacemgr.getIface("eth0"), 1, 0);
+ checkSocketsCount6(*ifacemgr.getIface("eth1"), 0);
+
+ // The link-local address is not present on eth0. Therefore, no socket
+ // must be bound to this address, nor to multicast address.
+ EXPECT_FALSE(ifacemgr.isBound("eth0", "fe80::3a60:77ff:fed5:cdef"));
+ EXPECT_FALSE(ifacemgr.isBound("eth0", ALL_DHCP_RELAY_AGENTS_AND_SERVERS));
+ // There should be one socket bound to unicast address.
+ EXPECT_TRUE(ifacemgr.isBound("eth0", "2001:db8:1::1"));
+ // eth1 should have one socket, bound to link-local address.
+ EXPECT_TRUE(ifacemgr.isBound("eth1", "fe80::3a60:77ff:fed5:abcd"));
+
+ // If we are on Linux, there is one more socket bound to ff02::1:2
+#if defined OS_LINUX
+ EXPECT_TRUE(ifacemgr.isBound("eth1", ALL_DHCP_RELAY_AGENTS_AND_SERVERS));
+#endif
+
+}
+
// This test checks that no sockets are open for the interface which is down.
TEST_F(IfaceMgrTest, openSockets6IfaceDown) {
NakedIfaceMgr ifacemgr;
@@ -1645,7 +1787,7 @@ TEST_F(IfaceMgrTest, openSockets6IfaceInactive) {
}
-// That that the openSockets6 function does not throw if there are no interfaces
+// Test that the openSockets6 function does not throw if there are no interfaces
// detected. This function is expected to return false.
TEST_F(IfaceMgrTest, openSockets6NoIfaces) {
NakedIfaceMgr ifacemgr;
diff --git a/src/lib/dhcp/tests/pkt_filter6_test_utils.h b/src/lib/dhcp/tests/pkt_filter6_test_utils.h
index 8c399f0..a0fb1b8 100644
--- a/src/lib/dhcp/tests/pkt_filter6_test_utils.h
+++ b/src/lib/dhcp/tests/pkt_filter6_test_utils.h
@@ -81,7 +81,7 @@ public:
/// @param rcvd_msg An instance of the message to be tested.
void testRcvdMessage(const Pkt6Ptr& rcvd_msg) const;
- std::string ifname_; ///< Loopback interface name
+ std::string ifname_; ///< Loopback interface name.
uint16_t ifindex_; ///< Loopback interface index.
uint16_t port_; ///< A port number used for the test.
isc::dhcp::SocketInfo sock_info_; ///< A structure holding socket info.
More information about the bind10-changes
mailing list