From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 18 Sep 2023 12:22:07 +0000 (+0200)
Subject: dnsdist: Small cleanup of the XSK code
X-Git-Tag: dnsdist-1.9.0-rc1^2~40
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ce2e13280ae62de8f93602738bac12968ee313fa;p=thirdparty%2Fpdns.git

dnsdist: Small cleanup of the XSK code
---

diff --git a/pdns/dnsdist-lua-bindings.cc b/pdns/dnsdist-lua-bindings.cc
index 6a3644d672..5a6d8f4e95 100644
--- a/pdns/dnsdist-lua-bindings.cc
+++ b/pdns/dnsdist-lua-bindings.cc
@@ -759,7 +759,7 @@ void setupLuaBindings(LuaContext& luaCtx, bool client, bool configCheck)
     }
     extern std::vector<std::shared_ptr<XskSocket>> g_xsk;
     auto socket = std::make_shared<XskSocket>(frameNums, ifName, queue_id, path, poolName);
-    g_xsk.push_back(socket); 
+    g_xsk.push_back(socket);
     return socket;
   });
   luaCtx.registerFunction<std::string(std::shared_ptr<XskSocket>::*)()const>("getMetrics", [](const std::shared_ptr<XskSocket>& xsk) {
diff --git a/pdns/dnsdist.hh b/pdns/dnsdist.hh
index 34d4600dac..9b5d33e38c 100644
--- a/pdns/dnsdist.hh
+++ b/pdns/dnsdist.hh
@@ -986,7 +986,7 @@ public:
       throw runtime_error("invalid source addr");
     }
     xsk->addWorker(xskInfo, d_config.sourceAddr, getProtocol() != dnsdist::Protocol::DoUDP);
-    memcpy(d_config.sourceMACAddr, xsk->source, sizeof(MACAddr));
+    d_config.sourceMACAddr = xsk->source;
     xskInfo->sharedEmptyFrameOffset = xsk->sharedEmptyFrameOffset;
   }
 #endif /* HAVE_XSK */
diff --git a/pdns/dnsdistdist/dnsdist-healthchecks.hh b/pdns/dnsdistdist/dnsdist-healthchecks.hh
index 4f1940643e..2c5fc6015c 100644
--- a/pdns/dnsdistdist/dnsdist-healthchecks.hh
+++ b/pdns/dnsdistdist/dnsdist-healthchecks.hh
@@ -67,4 +67,3 @@ struct HealthCheckData
 PacketBuffer getHealthCheckPacket(const std::shared_ptr<DownstreamState>& ds, FDMultiplexer* mplexer, std::shared_ptr<HealthCheckData>& data);
 void setHealthCheckTime(const std::shared_ptr<DownstreamState>& ds, const std::shared_ptr<HealthCheckData>& data);
 bool handleResponse(std::shared_ptr<HealthCheckData>& data);
-
diff --git a/pdns/iputils.hh b/pdns/iputils.hh
index 7d8b2e4c2d..6bcac3256b 100644
--- a/pdns/iputils.hh
+++ b/pdns/iputils.hh
@@ -83,7 +83,6 @@
 #undef IP_PKTINFO
 #endif
 
-using MACAddr = uint8_t[6];
 union ComboAddress {
   struct sockaddr_in sin4;
   struct sockaddr_in6 sin6;
diff --git a/pdns/xsk.cc b/pdns/xsk.cc
index f8c73d8c88..c57f97f367 100644
--- a/pdns/xsk.cc
+++ b/pdns/xsk.cc
@@ -42,6 +42,7 @@
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <net/if.h>
+#include <net/if_arp.h>
 #include <netinet/in.h>
 #include <poll.h>
 #include <stdexcept>
@@ -781,14 +782,22 @@ void XskWorker::notifyWorker() noexcept
 }
 void XskSocket::getMACFromIfName()
 {
-  ifreq ifr;
-  auto fd = ::socket(AF_INET, SOCK_DGRAM, 0);
+  ifreq ifr{};
+  auto fd = FDWrapper(::socket(AF_INET, SOCK_DGRAM, 0));
+  if (fd < 0) {
+    throw std::runtime_error("Error creating a socket to get the MAC address of interface " + ifName);
+  }
+
+  if (ifName.size() >= IFNAMSIZ) {
+    throw std::runtime_error("Unable to get MAC address for interface " + ifName + ": name too long");
+  }
+
   strncpy(ifr.ifr_name, ifName.c_str(), ifName.length() + 1);
-  if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
-    throw runtime_error("Error getting MAC addr");
+  if (ioctl(fd.getHandle(), SIOCGIFHWADDR, &ifr) < 0 || ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
+    throw std::runtime_error("Error getting MAC address for interface " + ifName);
   }
-  memcpy(source, ifr.ifr_hwaddr.sa_data, sizeof(source));
-  close(fd);
+  static_assert(sizeof(ifr.ifr_hwaddr.sa_data) >= std::tuple_size<decltype(source)>{}, "The size of an ARPHRD_ETHER MAC address is smaller than expected");
+  memcpy(source.data(), ifr.ifr_hwaddr.sa_data, source.size());
 }
 [[nodiscard]] int XskSocket::timeDifference(const timespec& t1, const timespec& t2) noexcept
 {
diff --git a/pdns/xsk.hh b/pdns/xsk.hh
index 026417d6f3..b4e10c6eee 100644
--- a/pdns/xsk.hh
+++ b/pdns/xsk.hh
@@ -52,6 +52,8 @@ class XskPacket;
 class XskWorker;
 class XskSocket;
 
+using MACAddr = std::array<uint8_t,6>;
+
 #ifdef HAVE_XSK
 using XskPacketPtr = std::unique_ptr<XskPacket>;