EthernetFace: avoid putting the NIC in promiscuous mode if possible.
Try to use the PACKET_ADD_MEMBERSHIP socket option and the
SIOCADDMULTI ioctl, and only if they fail or are not available
we fall back to promiscuous mode.
Change-Id: Ib534e161ff86ca855e084240b94a166bc4d33ce1
Refs: #1278
diff --git a/daemon/face/ethernet-face.cpp b/daemon/face/ethernet-face.cpp
index ea9e522..4ffb9db 100644
--- a/daemon/face/ethernet-face.cpp
+++ b/daemon/face/ethernet-face.cpp
@@ -28,14 +28,26 @@
#include <pcap/pcap.h>
-#include <cstring> // for std::strncpy()
+#include <cerrno> // for errno
+#include <cstdio> // for std::snprintf()
+#include <cstring> // for std::strerror() and std::strncpy()
#include <arpa/inet.h> // for htons() and ntohs()
#include <net/ethernet.h> // for struct ether_header
#include <net/if.h> // for struct ifreq
-#include <stdio.h> // for snprintf()
#include <sys/ioctl.h> // for ioctl()
#include <unistd.h> // for dup()
+#if defined(__linux__)
+#include <netpacket/packet.h> // for struct packet_mreq
+#include <sys/socket.h> // for setsockopt()
+#endif
+
+#ifdef SIOCADDMULTI
+#if defined(__APPLE__) || defined(__FreeBSD__)
+#include <net/if_dl.h> // for struct sockaddr_dl
+#endif
+#endif
+
#if !defined(PCAP_NETMASK_UNKNOWN)
/*
* Value to pass to pcap_compile() as the netmask if you don't know what
@@ -53,6 +65,9 @@
const ethernet::Address& address)
: Face(FaceUri(address), FaceUri::fromDev(interface.name))
, m_socket(socket)
+#if defined(__linux__)
+ , m_interfaceIndex(interface.index)
+#endif
, m_interfaceName(interface.name)
, m_srcAddress(interface.etherAddress)
, m_destAddress(address)
@@ -75,13 +90,15 @@
<< "] Interface MTU is: " << m_interfaceMtu);
char filter[100];
- ::snprintf(filter, sizeof(filter),
- "(ether proto 0x%x) && (ether dst %s) && (not ether src %s)",
- ethernet::ETHERTYPE_NDN,
- m_destAddress.toString().c_str(),
- m_srcAddress.toString().c_str());
+ std::snprintf(filter, sizeof(filter),
+ "(ether proto 0x%x) && (ether dst %s) && (not ether src %s)",
+ ethernet::ETHERTYPE_NDN,
+ m_destAddress.toString().c_str(),
+ m_srcAddress.toString().c_str());
setPacketFilter(filter);
+ joinMulticastGroup();
+
m_socket->async_read_some(boost::asio::null_buffers(),
bind(&EthernetFace::handleRead, this,
boost::asio::placeholders::error,
@@ -139,10 +156,6 @@
pcap_set_immediate_mode(m_pcap, 1);
#endif
- /// \todo Do not rely on promisc mode, see task #1278
- if (!m_destAddress.isBroadcast())
- pcap_set_promisc(m_pcap, 1);
-
if (pcap_activate(m_pcap) < 0)
throw Error("pcap_activate() failed");
@@ -168,6 +181,72 @@
}
void
+EthernetFace::joinMulticastGroup()
+{
+#if defined(__linux__)
+ packet_mreq mr{};
+ mr.mr_ifindex = m_interfaceIndex;
+ mr.mr_type = PACKET_MR_MULTICAST;
+ mr.mr_alen = m_destAddress.size();
+ std::copy(m_destAddress.begin(), m_destAddress.end(), mr.mr_address);
+
+ if (::setsockopt(m_socket->native_handle(), SOL_PACKET,
+ PACKET_ADD_MEMBERSHIP, &mr, sizeof(mr)) == 0)
+ return; // success
+
+ NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] setsockopt(PACKET_ADD_MEMBERSHIP) failed: " << std::strerror(errno));
+#endif
+
+#if defined(SIOCADDMULTI)
+ ifreq ifr{};
+ std::strncpy(ifr.ifr_name, m_interfaceName.c_str(), sizeof(ifr.ifr_name) - 1);
+
+#if defined(__APPLE__) || defined(__FreeBSD__)
+ /*
+ * Differences between Linux and the BSDs (including OS X):
+ * o BSD does not have ifr_hwaddr; use ifr_addr instead.
+ * o While OS X seems to accept both AF_LINK and AF_UNSPEC as the address
+ * family, FreeBSD explicitly requires AF_LINK, so we have to use AF_LINK
+ * and sockaddr_dl instead of the generic sockaddr structure.
+ * o BSD's sockaddr (and sockaddr_dl in particular) contains an additional
+ * field, sa_len (sdl_len), which must be set to the total length of the
+ * structure, including the length field itself.
+ * o We do not specify the interface name, thus sdl_nlen is left at 0 and
+ * LLADDR is effectively the same as sdl_data.
+ */
+ sockaddr_dl* sdl = reinterpret_cast<sockaddr_dl*>(&ifr.ifr_addr);
+ sdl->sdl_len = sizeof(ifr.ifr_addr);
+ sdl->sdl_family = AF_LINK;
+ sdl->sdl_alen = m_destAddress.size();
+ std::copy(m_destAddress.begin(), m_destAddress.end(), LLADDR(sdl));
+
+ static_assert(sizeof(ifr.ifr_addr) >= offsetof(sockaddr_dl, sdl_data) + ethernet::ADDR_LEN,
+ "ifr_addr in struct ifreq is too small on this platform");
+#else
+ ifr.ifr_hwaddr.sa_family = AF_UNSPEC;
+ std::copy(m_destAddress.begin(), m_destAddress.end(), ifr.ifr_hwaddr.sa_data);
+
+ static_assert(sizeof(ifr.ifr_hwaddr) >= offsetof(sockaddr, sa_data) + ethernet::ADDR_LEN,
+ "ifr_hwaddr in struct ifreq is too small on this platform");
+#endif
+
+ if (::ioctl(m_socket->native_handle(), SIOCADDMULTI, &ifr) >= 0)
+ return; // success
+
+ NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] ioctl(SIOCADDMULTI) failed: " << std::strerror(errno));
+#endif
+
+ if (!m_destAddress.isBroadcast())
+ {
+ NFD_LOG_DEBUG("[id:" << getId() << ",endpoint:" << m_interfaceName
+ << "] Falling back to promiscuous mode");
+ pcap_set_promisc(m_pcap, 1);
+ }
+}
+
+void
EthernetFace::sendPacket(const ndn::Block& block)
{
if (!m_pcap)
@@ -315,13 +394,13 @@
size_t mtu = ethernet::MAX_DATA_LEN;
#ifdef SIOCGIFMTU
- ifreq ifr = boost::initialized_value;
+ ifreq ifr{};
std::strncpy(ifr.ifr_name, m_interfaceName.c_str(), sizeof(ifr.ifr_name) - 1);
if (::ioctl(m_socket->native_handle(), SIOCGIFMTU, &ifr) < 0)
{
NFD_LOG_WARN("[id:" << getId() << ",endpoint:" << m_interfaceName
- << "] Failed to get interface MTU, assuming " << mtu);
+ << "] Failed to get interface MTU: " << std::strerror(errno));
}
else
{
diff --git a/daemon/face/ethernet-face.hpp b/daemon/face/ethernet-face.hpp
index 4383246..0c673c3 100644
--- a/daemon/face/ethernet-face.hpp
+++ b/daemon/face/ethernet-face.hpp
@@ -87,6 +87,9 @@
setPacketFilter(const char* filterString);
void
+ joinMulticastGroup();
+
+ void
sendPacket(const ndn::Block& block);
void
@@ -101,6 +104,9 @@
private:
shared_ptr<boost::asio::posix::stream_descriptor> m_socket;
+#if defined(__linux__)
+ int m_interfaceIndex;
+#endif
std::string m_interfaceName;
ethernet::Address m_srcAddress;
ethernet::Address m_destAddress;