face: make EthernetFace more robust against errors.
We now call .fail() instead of throwing an exception.
Also modernize the code with some C++11 features.
In particular, std::unique_ptr is now used to manage
the pcap instance.
Change-Id: I91200ff9ab64ddb2d86f082647043e42ca85f538
Refs: #1984
diff --git a/daemon/face/ethernet-face.cpp b/daemon/face/ethernet-face.cpp
index 4ffb9db..0e13844 100644
--- a/daemon/face/ethernet-face.cpp
+++ b/daemon/face/ethernet-face.cpp
@@ -64,6 +64,7 @@
const NetworkInterfaceInfo& interface,
const ethernet::Address& address)
: Face(FaceUri(address), FaceUri::fromDev(interface.name))
+ , m_pcap(nullptr, pcap_close)
, m_socket(socket)
#if defined(__linux__)
, m_interfaceIndex(interface.index)
@@ -76,7 +77,7 @@
<< m_srcAddress << " <--> " << m_destAddress);
pcapInit();
- int fd = pcap_get_selectable_fd(m_pcap);
+ int fd = pcap_get_selectable_fd(m_pcap.get());
if (fd < 0)
throw Error("pcap_get_selectable_fd() failed");
@@ -107,8 +108,6 @@
EthernetFace::~EthernetFace()
{
- onFail.clear(); // no reason to call onFail anymore
- close();
}
void
@@ -128,23 +127,25 @@
void
EthernetFace::close()
{
- if (m_pcap)
- {
- boost::system::error_code error;
- m_socket->close(error); // ignore errors
- pcap_close(m_pcap);
- m_pcap = 0;
+ if (!m_pcap)
+ return;
- fail("Face closed");
- }
+ NFD_LOG_INFO("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] Closing face");
+
+ boost::system::error_code error;
+ m_socket->cancel(error); // ignore errors
+ m_socket->close(error); // ignore errors
+ m_pcap.reset(nullptr);
+
+ fail("Face closed");
}
void
EthernetFace::pcapInit()
{
- char errbuf[PCAP_ERRBUF_SIZE];
- errbuf[0] = '\0';
- m_pcap = pcap_create(m_interfaceName.c_str(), errbuf);
+ char errbuf[PCAP_ERRBUF_SIZE] = {};
+ m_pcap.reset(pcap_create(m_interfaceName.c_str(), errbuf));
if (!m_pcap)
throw Error("pcap_create(): " + std::string(errbuf));
@@ -153,31 +154,31 @@
// This corresponds to the BIOCIMMEDIATE ioctl on BSD-like systems (including OS X)
// where libpcap uses a BPF device. On Linux this forces libpcap not to use TPACKET_V3,
// even if the kernel supports it, thus preventing bug #1511.
- pcap_set_immediate_mode(m_pcap, 1);
+ pcap_set_immediate_mode(m_pcap.get(), 1);
#endif
- if (pcap_activate(m_pcap) < 0)
+ if (pcap_activate(m_pcap.get()) < 0)
throw Error("pcap_activate() failed");
- if (pcap_set_datalink(m_pcap, DLT_EN10MB) < 0)
- throw Error("pcap_set_datalink(): " + std::string(pcap_geterr(m_pcap)));
+ if (pcap_set_datalink(m_pcap.get(), DLT_EN10MB) < 0)
+ throw Error("pcap_set_datalink(): " + std::string(pcap_geterr(m_pcap.get())));
- if (pcap_setdirection(m_pcap, PCAP_D_IN) < 0)
+ if (pcap_setdirection(m_pcap.get(), PCAP_D_IN) < 0)
// no need to throw on failure, BPF will filter unwanted packets anyway
- NFD_LOG_WARN("pcap_setdirection(): " << pcap_geterr(m_pcap));
+ NFD_LOG_WARN("pcap_setdirection(): " << pcap_geterr(m_pcap.get()));
}
void
EthernetFace::setPacketFilter(const char* filterString)
{
bpf_program filter;
- if (pcap_compile(m_pcap, &filter, filterString, 1, PCAP_NETMASK_UNKNOWN) < 0)
- throw Error("pcap_compile(): " + std::string(pcap_geterr(m_pcap)));
+ if (pcap_compile(m_pcap.get(), &filter, filterString, 1, PCAP_NETMASK_UNKNOWN) < 0)
+ throw Error("pcap_compile(): " + std::string(pcap_geterr(m_pcap.get())));
- int ret = pcap_setfilter(m_pcap, &filter);
+ int ret = pcap_setfilter(m_pcap.get(), &filter);
pcap_freecode(&filter);
if (ret < 0)
- throw Error("pcap_setfilter(): " + std::string(pcap_geterr(m_pcap)));
+ throw Error("pcap_setfilter(): " + std::string(pcap_geterr(m_pcap.get())));
}
void
@@ -242,7 +243,7 @@
{
NFD_LOG_DEBUG("[id:" << getId() << ",endpoint:" << m_interfaceName
<< "] Falling back to promiscuous mode");
- pcap_set_promisc(m_pcap, 1);
+ pcap_set_promisc(m_pcap.get(), 1);
}
}
@@ -253,8 +254,7 @@
{
NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
<< "] Trying to send on closed face");
- fail("Face closed");
- return;
+ return fail("Face closed");
}
/// \todo Fragmentation
@@ -283,14 +283,14 @@
buffer.prependByteArray(m_destAddress.data(), m_destAddress.size());
// send the packet
- int sent = pcap_inject(m_pcap, buffer.buf(), buffer.size());
+ int sent = pcap_inject(m_pcap.get(), buffer.buf(), buffer.size());
if (sent < 0)
{
- throw Error("pcap_inject(): " + std::string(pcap_geterr(m_pcap)));
+ return fail("pcap_inject(): " + std::string(pcap_geterr(m_pcap.get())));
}
else if (static_cast<size_t>(sent) < buffer.size())
{
- throw Error("Failed to send packet");
+ return fail("Failed to inject frame");
}
NFD_LOG_TRACE("[id:" << getId() << ",endpoint:" << m_interfaceName
@@ -301,56 +301,26 @@
void
EthernetFace::handleRead(const boost::system::error_code& error, size_t)
{
+ if (!m_pcap)
+ return fail("Face closed");
+
if (error)
return processErrorCode(error);
- pcap_pkthdr* pktHeader;
+ pcap_pkthdr* header;
const uint8_t* packet;
- int ret = pcap_next_ex(m_pcap, &pktHeader, &packet);
+ int ret = pcap_next_ex(m_pcap.get(), &header, &packet);
if (ret < 0)
{
- throw Error("pcap_next_ex(): " + std::string(pcap_geterr(m_pcap)));
+ return fail("pcap_next_ex(): " + std::string(pcap_geterr(m_pcap.get())));
}
else if (ret == 0)
{
- NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
- << "] pcap_next_ex() timed out");
+ NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName << "] Read timeout");
}
else
{
- size_t length = pktHeader->caplen;
- if (length < ethernet::HDR_LEN + ethernet::MIN_DATA_LEN)
- throw Error("Received packet is too short");
-
- const ether_header* eh = reinterpret_cast<const ether_header*>(packet);
- if (ntohs(eh->ether_type) != ethernet::ETHERTYPE_NDN)
- throw Error("Unrecognized ethertype");
-
- packet += ethernet::HDR_LEN;
- length -= ethernet::HDR_LEN;
-
- /// \todo Reserve space in front and at the back
- /// of the underlying buffer
- Block element;
- bool isOk = Block::fromBuffer(packet, length, element);
- if (isOk)
- {
- NFD_LOG_TRACE("[id:" << getId() << ",endpoint:" << m_interfaceName
- << "] Received: " << element.size() << " bytes");
- this->getMutableCounters().getNInBytes() += element.size();
-
- if (!decodeAndDispatchInput(element))
- {
- NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
- << "] Received unrecognized block of type " << element.type());
- // ignore unknown packet
- }
- }
- else
- {
- NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
- << "] Received block is invalid or too large to process");
- }
+ processIncomingPacket(header, packet);
}
m_socket->async_read_some(boost::asio::null_buffers(),
@@ -360,18 +330,58 @@
}
void
-EthernetFace::processErrorCode(const boost::system::error_code& error)
+EthernetFace::processIncomingPacket(const pcap_pkthdr* header, const uint8_t* packet)
{
- if (error == boost::system::errc::operation_canceled)
- // when socket is closed by someone
- return;
-
- if (!m_pcap)
+ size_t length = header->caplen;
+ if (length < ethernet::HDR_LEN + ethernet::MIN_DATA_LEN)
{
- fail("Face closed");
+ NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] Received frame is too short (" << length << " bytes)");
return;
}
+ const ether_header* eh = reinterpret_cast<const ether_header*>(packet);
+
+ // assert in case BPF fails to filter unwanted frames
+ BOOST_ASSERT_MSG(ethernet::Address(eh->ether_dhost) == m_destAddress,
+ "Received frame addressed to a different multicast group");
+ BOOST_ASSERT_MSG(ethernet::Address(eh->ether_shost) != m_srcAddress,
+ "Received frame sent by this host");
+ BOOST_ASSERT_MSG(ntohs(eh->ether_type) == ethernet::ETHERTYPE_NDN,
+ "Received frame with unrecognized ethertype");
+
+ packet += ethernet::HDR_LEN;
+ length -= ethernet::HDR_LEN;
+
+ /// \todo Reserve space in front and at the back of the underlying buffer
+ Block element;
+ bool isOk = Block::fromBuffer(packet, length, element);
+ if (isOk)
+ {
+ NFD_LOG_TRACE("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] Received: " << element.size() << " bytes");
+ this->getMutableCounters().getNInBytes() += element.size();
+
+ if (!decodeAndDispatchInput(element))
+ {
+ NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] Received unrecognized block of type " << element.type());
+ }
+ }
+ else
+ {
+ NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] Received block is invalid or too large to process");
+ }
+}
+
+void
+EthernetFace::processErrorCode(const boost::system::error_code& error)
+{
+ if (error == boost::asio::error::operation_aborted)
+ // cancel() has been called on the socket
+ return;
+
std::string msg;
if (error == boost::asio::error::eof)
{
@@ -380,11 +390,9 @@
}
else
{
- msg = "Receive operation failed, closing face: " + error.message();
+ msg = "Receive operation failed: " + error.message();
NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName << "] " << msg);
}
-
- close();
fail(msg);
}
diff --git a/daemon/face/ethernet-face.hpp b/daemon/face/ethernet-face.hpp
index 0c673c3..1dd6593 100644
--- a/daemon/face/ethernet-face.hpp
+++ b/daemon/face/ethernet-face.hpp
@@ -26,7 +26,7 @@
#ifndef NFD_DAEMON_FACE_ETHERNET_FACE_HPP
#define NFD_DAEMON_FACE_ETHERNET_FACE_HPP
-#include "config.hpp"
+#include "common.hpp"
#include "face.hpp"
#include "core/network-interface.hpp"
@@ -37,18 +37,19 @@
// forward declarations
struct pcap;
typedef pcap pcap_t;
+struct pcap_pkthdr;
namespace nfd {
/**
- * \brief Implementation of Face abstraction that uses raw
+ * @brief Implementation of Face abstraction that uses raw
* Ethernet frames as underlying transport mechanism
*/
class EthernetFace : public Face
{
public:
/**
- * \brief EthernetFace-related error
+ * @brief EthernetFace-related error
*/
struct Error : public Face::Error
{
@@ -71,39 +72,73 @@
sendData(const Data& data);
/**
- * \brief Close the face
+ * @brief Closes the face
*
- * This terminates all communication on the face and cause
- * onFail() method event to be invoked
+ * This terminates all communication on the face and triggers the onFail() event.
*/
virtual void
close();
private:
+ /**
+ * @brief Allocates and initializes a libpcap context for live capture
+ */
void
pcapInit();
+ /**
+ * @brief Installs a BPF filter on the receiving socket
+ *
+ * @param filterString string containing the source BPF program
+ */
void
setPacketFilter(const char* filterString);
+ /**
+ * @brief Enables receiving frames addressed to our MAC multicast group
+ */
void
joinMulticastGroup();
+ /**
+ * @brief Sends the specified TLV block on the network wrapped in an Ethernet frame
+ */
void
sendPacket(const ndn::Block& block);
+ /**
+ * @brief Receive callback
+ */
void
- handleRead(const boost::system::error_code& error,
- size_t nBytesRead);
+ handleRead(const boost::system::error_code& error, size_t nBytesRead);
+PUBLIC_WITH_TESTS_ELSE_PRIVATE:
+ /**
+ * @brief Processes an incoming frame as captured by libpcap
+ *
+ * @param header pointer to capture metadata
+ * @param packet pointer to the received frame, including the link-layer header
+ */
+ void
+ processIncomingPacket(const pcap_pkthdr* header, const uint8_t* packet);
+
+private:
+ /**
+ * @brief Handles errors encountered by Boost.Asio on the receive path
+ */
void
processErrorCode(const boost::system::error_code& error);
+ /**
+ * @brief Returns the MTU of the underlying network interface
+ */
size_t
getInterfaceMtu() const;
private:
+ unique_ptr<pcap_t, void(*)(pcap_t*)> m_pcap;
shared_ptr<boost::asio::posix::stream_descriptor> m_socket;
+
#if defined(__linux__)
int m_interfaceIndex;
#endif
@@ -111,7 +146,6 @@
ethernet::Address m_srcAddress;
ethernet::Address m_destAddress;
size_t m_interfaceMtu;
- pcap_t* m_pcap;
};
} // namespace nfd
diff --git a/daemon/face/ethernet-factory.cpp b/daemon/face/ethernet-factory.cpp
index 314614e..d9f1612 100644
--- a/daemon/face/ethernet-factory.cpp
+++ b/daemon/face/ethernet-factory.cpp
@@ -27,9 +27,6 @@
#include "core/logger.hpp"
#include "core/global-io.hpp"
-#include <boost/algorithm/string/predicate.hpp>
-#include <pcap/pcap.h>
-
namespace nfd {
NFD_LOG_INIT("EthernetFactory");
@@ -45,35 +42,27 @@
if (face)
return face;
- shared_ptr<boost::asio::posix::stream_descriptor> socket =
- make_shared<boost::asio::posix::stream_descriptor>(ref(getGlobalIoService()));
-
+ auto socket = make_shared<boost::asio::posix::stream_descriptor>(ref(getGlobalIoService()));
face = make_shared<EthernetFace>(socket, interface, address);
- face->onFail += bind(&EthernetFactory::afterFaceFailed,
- this, interface.name, address);
- m_multicastFaces[std::make_pair(interface.name, address)] = face;
+
+ auto key = std::make_pair(interface.name, address);
+ face->onFail += [this, key] (const std::string& reason) {
+ m_multicastFaces.erase(key);
+ };
+ m_multicastFaces.insert({key, face});
return face;
}
-void
-EthernetFactory::afterFaceFailed(const std::string& interfaceName,
- const ethernet::Address& address)
-{
- NFD_LOG_DEBUG("afterFaceFailed: " << interfaceName << "/" << address);
- m_multicastFaces.erase(std::make_pair(interfaceName, address));
-}
-
shared_ptr<EthernetFace>
EthernetFactory::findMulticastFace(const std::string& interfaceName,
const ethernet::Address& address) const
{
- MulticastFaceMap::const_iterator i =
- m_multicastFaces.find(std::make_pair(interfaceName, address));
- if (i != m_multicastFaces.end())
- return i->second;
+ auto it = m_multicastFaces.find({interfaceName, address});
+ if (it != m_multicastFaces.end())
+ return it->second;
else
- return shared_ptr<EthernetFace>();
+ return {};
}
void
@@ -84,10 +73,10 @@
throw Error("EthernetFactory does not support 'createFace' operation");
}
-std::list<shared_ptr<const Channel> >
+std::list<shared_ptr<const Channel>>
EthernetFactory::getChannels() const
{
- return std::list<shared_ptr<const Channel> >();
+ return {};
}
} // namespace nfd
diff --git a/daemon/face/ethernet-factory.hpp b/daemon/face/ethernet-factory.hpp
index b7d5ec0..cc8516a 100644
--- a/daemon/face/ethernet-factory.hpp
+++ b/daemon/face/ethernet-factory.hpp
@@ -47,8 +47,8 @@
}
};
- typedef std::map< std::pair<std::string, ethernet::Address>,
- shared_ptr<EthernetFace> > MulticastFaceMap;
+ typedef std::map<std::pair<std::string, ethernet::Address>,
+ shared_ptr<EthernetFace>> MulticastFaceMap;
// from ProtocolFactory
virtual void
@@ -81,14 +81,10 @@
const MulticastFaceMap&
getMulticastFaces() const;
- virtual std::list<shared_ptr<const Channel> >
+ virtual std::list<shared_ptr<const Channel>>
getChannels() const;
private:
- void
- afterFaceFailed(const std::string& interfaceName,
- const ethernet::Address& address);
-
/**
* \brief Look up EthernetFace using specified interface and address
*
@@ -105,14 +101,12 @@
MulticastFaceMap m_multicastFaces;
};
-
inline const EthernetFactory::MulticastFaceMap&
EthernetFactory::getMulticastFaces() const
{
return m_multicastFaces;
}
-
} // namespace nfd
#endif // NFD_DAEMON_FACE_ETHERNET_FACTORY_HPP