1 files changed, 278 insertions, 0 deletions
diff --git a/src/lib/dhcpsrv/dhcp4o6_ipc.cc b/src/lib/dhcpsrv/dhcp4o6_ipc.cc
new file mode 100644
index 0000000..742b954
--- /dev/null
+++ b/src/lib/dhcpsrv/dhcp4o6_ipc.cc
@@ -0,0 +1,278 @@
+// Copyright (C) 2015-2019 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#include <config.h>
+
+#include <dhcp/dhcp6.h>
+#include <dhcp/iface_mgr.h>
+#include <dhcp/option6_addrlst.h>
+#include <dhcp/option_custom.h>
+#include <dhcp/option_int.h>
+#include <dhcp/option_string.h>
+#include <dhcp/option_vendor.h>
+#include <dhcpsrv/dhcp4o6_ipc.h>
+#include <dhcpsrv/dhcpsrv_log.h>
+
+#include <boost/pointer_cast.hpp>
+
+#include <errno.h>
+#include <netinet/in.h>
+#include <fcntl.h>
+#include <string>
+
+using namespace isc::asiolink;
+using namespace isc::util;
+using namespace std;
+
+namespace isc {
+namespace dhcp {
+
+Dhcp4o6IpcBase::Dhcp4o6IpcBase() : port_(0), socket_fd_(-1) {}
+
+Dhcp4o6IpcBase::~Dhcp4o6IpcBase() {
+    close();
+}
+
+int Dhcp4o6IpcBase::open(uint16_t port, EndpointType endpoint_type) {
+    // Don't check if the value is greater than 65534 as it is done
+    // by callers before they cast the value to 16 bits.
+
+    if (port == port_) {
+        // No change: nothing to do
+        return (socket_fd_);
+    }
+
+    // Open socket
+    int sock = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
+    if (sock < 0) {
+        isc_throw(Dhcp4o6IpcError, "Failed to create DHCP4o6 socket.");
+    }
+
+    // Set no blocking
+    if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
+        ::close(sock);
+        isc_throw(Dhcp4o6IpcError,
+                  "Failed to set O_NONBLOCK on DHCP4o6 socket.");
+    }
+
+    // Bind to the local address
+    struct sockaddr_in6 local6;
+    memset(&local6, 0, sizeof(local6));
+    local6.sin6_family = AF_INET6;
+#ifdef HAVE_SA_LEN
+    local6.sin6_len = sizeof(local6);
+#endif
+    if (endpoint_type == ENDPOINT_TYPE_V6) {
+        local6.sin6_port = htons(port);
+    } else {
+        local6.sin6_port = htons(port + 1);
+    }
+    // We'll connect to the loopback address so bind to it too.
+    local6.sin6_addr.s6_addr[15] = 1;
+    if (::bind(sock, (struct sockaddr *)&local6, sizeof(local6)) < 0) {
+        ::close(sock);
+        isc_throw(Dhcp4o6IpcError, "Failed to bind DHCP4o6 socket.");
+    }
+
+    // Connect to the remote address
+    struct sockaddr_in6 remote6;
+    memset(&remote6, 0, sizeof(remote6));
+    remote6.sin6_family = AF_INET6;
+#ifdef HAVE_SA_LEN
+    remote6.sin6_len = sizeof(remote6);
+#endif
+    if (endpoint_type == ENDPOINT_TYPE_V6) {
+        remote6.sin6_port = htons(port + 1);
+    } else {
+        remote6.sin6_port = htons(port);
+    }
+    // At least OpenBSD requires the remote address to not be left
+    // unspecified, so we set it to the loopback address.
+    remote6.sin6_addr.s6_addr[15] = 1;
+    if (connect(sock, reinterpret_cast<const struct sockaddr*>(&remote6),
+                sizeof(remote6)) < 0) {
+        ::close(sock);
+        isc_throw(Dhcp4o6IpcError, "Failed to connect DHCP4o6 socket.");
+    }
+
+    if (socket_fd_ != -1) {
+        if (dup2(sock, socket_fd_) == -1) {
+            ::close(sock);
+            isc_throw(Dhcp4o6IpcError, "Failed to duplicate DHCP4o6 socket.");
+        }
+        if (sock != socket_fd_) {
+            ::close(sock);
+            sock = socket_fd_;
+        }
+    }
+
+    // Success
+    port_ = port;
+    socket_fd_ = sock;
+    return (socket_fd_);
+}
+
+void Dhcp4o6IpcBase::close() {
+    port_ = 0;
+    if (socket_fd_ != -1) {
+        IfaceMgr::instance().deleteExternalSocket(socket_fd_);
+        ::close(socket_fd_);
+        socket_fd_ = -1;
+    }
+}
+
+Pkt6Ptr Dhcp4o6IpcBase::receive() {
+    uint8_t buf[65536];
+    ssize_t cc = recv(socket_fd_, buf, sizeof(buf), 0);
+    if (cc < 0) {
+        isc_throw(Dhcp4o6IpcError, "Failed to receive on DHCP4o6 socket.");
+    }
+    Pkt6Ptr pkt = Pkt6Ptr(new Pkt6(buf, cc));
+    pkt->updateTimestamp();
+
+    // Get interface name and remote address
+    pkt->unpack();
+
+    // Vendor option is initially NULL. If we find the instance of the vendor
+    // option with the ISC enterprise id this pointer will point to it.
+    OptionVendorPtr option_vendor;
+
+    // Get all vendor option and look for the one with the ISC enterprise id.
+    OptionCollection vendor_options = pkt->getOptions(D6O_VENDOR_OPTS);
+    for (OptionCollection::const_iterator opt = vendor_options.begin();
+         opt != vendor_options.end(); ++opt) {
+        option_vendor = boost::dynamic_pointer_cast<OptionVendor>(opt->second);
+        if (option_vendor) {
+            if (option_vendor->getVendorId() == ENTERPRISE_ID_ISC) {
+                break;
+            }
+            option_vendor.reset();
+        }
+    }
+
+    // Vendor option must exist.
+    if (!option_vendor) {
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+            .arg("no ISC vendor option");
+        isc_throw(Dhcp4o6IpcError, "malformed packet (no ISC vendor option)");
+    }
+
+    // The option carrying interface name is required.
+    OptionStringPtr ifname = boost::dynamic_pointer_cast<
+        OptionString>(option_vendor->getOption(ISC_V6_4O6_INTERFACE));
+    if (!ifname) {
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+            .arg("no interface suboption");
+        isc_throw(Dhcp4o6IpcError,
+                  "malformed packet (interface suboption missing "
+                  "or has incorrect type)");
+    }
+
+    // Check if this interface is present in the system.
+    IfacePtr iface = IfaceMgr::instance().getIface(ifname->getValue());
+    if (!iface) {
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+            .arg("can't get interface " + ifname->getValue());
+        isc_throw(Dhcp4o6IpcError,
+                  "malformed packet (unknown interface "
+                  + ifname->getValue() + ")");
+    }
+
+    // Get the option holding source IPv6 address.
+    OptionCustomPtr srcs = boost::dynamic_pointer_cast<
+        OptionCustom>(option_vendor->getOption(ISC_V6_4O6_SRC_ADDRESS));
+    if (!srcs) {
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+            .arg("no source address suboption");
+        isc_throw(Dhcp4o6IpcError,
+                  "malformed packet (source address suboption missing "
+                  "or has incorrect type)");
+    }
+
+    // Get the option holding source port.
+    OptionUint16Ptr sport = boost::dynamic_pointer_cast<
+        OptionUint16>(option_vendor->getOption(ISC_V6_4O6_SRC_PORT));
+    if (!sport) {
+        LOG_WARN(dhcpsrv_logger, DHCPSRV_DHCP4O6_RECEIVED_BAD_PACKET)
+            .arg("no source port suboption");
+        isc_throw(Dhcp4o6IpcError,
+                  "malformed packet (source port suboption missing "
+                  "or has incorrect type)");
+    }
+
+    // Update the packet.
+    pkt->setRemoteAddr(srcs->readAddress());
+    pkt->setRemotePort(sport->getValue());
+    pkt->setIface(iface->getName());
+    pkt->setIndex(iface->getIndex());
+
+    // Remove options that have been added by the IPC sender.
+    static_cast<void>(option_vendor->delOption(ISC_V6_4O6_INTERFACE));
+    static_cast<void>(option_vendor->delOption(ISC_V6_4O6_SRC_ADDRESS));
+    static_cast<void>(option_vendor->delOption(ISC_V6_4O6_SRC_PORT));
+
+    // If there are no more options, the IPC sender has probably created the
+    // vendor option, in which case we should remove it here.
+    if (option_vendor->getOptions().empty()) {
+        static_cast<void>(pkt->delOption(D6O_VENDOR_OPTS));
+    }
+
+    return (pkt);
+}
+
+void Dhcp4o6IpcBase::send(const Pkt6Ptr& pkt) {
+    // This shouldn't happen, i.e. send() shouldn't be called if there is
+    // no message.
+    if (!pkt) {
+        isc_throw(Dhcp4o6IpcError, "DHCP4o6 message must not be NULL while"
+                  " trying to send it over the IPC");
+    }
+
+    // Disabled: nowhere to send
+    if (socket_fd_ == -1) {
+        isc_throw(Dhcp4o6IpcError, "unable to send DHCP4o6 message because"
+                  " IPC socket is closed");
+    }
+
+    // Check if vendor option exists.
+    OptionVendorPtr option_vendor = boost::dynamic_pointer_cast<
+        OptionVendor>(pkt->getOption(D6O_VENDOR_OPTS));
+
+    // If vendor option doesn't exist or its enterprise id is not ISC's
+    // enterprise id, let's create it.
+    if (!option_vendor ||
+        (option_vendor->getVendorId() != ENTERPRISE_ID_ISC)) {
+        option_vendor.reset(new OptionVendor(Option::V6, ENTERPRISE_ID_ISC));
+        pkt->addOption(option_vendor);
+
+    }
+
+    // Push interface name and source address in it
+    option_vendor->addOption(OptionStringPtr(new OptionString(Option::V6,
+                                                       ISC_V6_4O6_INTERFACE,
+                                                       pkt->getIface())));
+    option_vendor->addOption(Option6AddrLstPtr(new Option6AddrLst(
+                                                       ISC_V6_4O6_SRC_ADDRESS,
+                                                       pkt->getRemoteAddr())));
+    option_vendor->addOption(OptionUint16Ptr(new OptionUint16(Option::V6,
+                                                       ISC_V6_4O6_SRC_PORT,
+                                                       pkt->getRemotePort())));
+    // Get packet content
+    OutputBuffer& buf = pkt->getBuffer();
+    buf.clear();
+    pkt->pack();
+
+    // Try to send the message.
+   if (::send(socket_fd_, buf.getData(), buf.getLength(), 0) < 0) {
+       isc_throw(Dhcp4o6IpcError,
+                 "failed to send DHCP4o6 message over the IPC: "
+                 << strerror(errno));
+   }
+}
+
+};  // namespace dhcp
+
+};  // namespace isc