commit d36151441870bba3fac0e29d5913e71195192f9e
author William A. Kennington III <wak@google.com> Sat Nov 12 01:28:33 2022 -0800
committer William A. Kennington III <wak@google.com> Mon Nov 21 02:34:37 2022 -0800
tree cd4f9190c5474932c2e3c1f3d8f2442df1d20a5d
parent be1af44cf61f535bebcc7bbff0190d044aae8d1c

rtnetlink: Return neighbor even if addr is missing

There are valid configurations that return these type of messages from
the kernel and we don't want to fail for them

Change-Id: I74a0fd519e553c2e4bc3e114e7563fe93d8facf6
Signed-off-by: William A. Kennington III <wak@google.com>

src/ethernet_interface.cpp

diff --git a/src/ethernet_interface.cpp b/src/ethernet_interface.cpp
index b15f598..4f71a46 100644
--- a/src/ethernet_interface.cpp
+++ b/src/ethernet_interface.cpp
@@ -219,17 +219,16 @@
     {
         return;
     }
-    if (!info.mac)
+    if (!info.mac || !info.addr)
     {
-        auto msg = fmt::format("Missing neighbor mac for `{}` on {}\n",
-                               info.addr, interfaceName());
+        auto msg = fmt::format("Missing neighbor mac on {}\n", interfaceName());
         log<level::ERR>(msg.c_str());
         return;
     }
     staticNeighbors.emplace(
-        info.addr, std::make_unique<Neighbor>(bus, std::string_view(objPath),
-                                              *this, info.addr, *info.mac,
-                                              Neighbor::State::Permanent));
+        *info.addr, std::make_unique<Neighbor>(bus, std::string_view(objPath),
+                                               *this, *info.addr, *info.mac,
+                                               Neighbor::State::Permanent));
 }
 
 void EthernetInterface::createStaticNeighborObjects()

src/rtnetlink.cpp

diff --git a/src/rtnetlink.cpp b/src/rtnetlink.cpp
index 6b456b7..febc305 100644
--- a/src/rtnetlink.cpp
+++ b/src/rtnetlink.cpp
@@ -88,7 +88,6 @@
     NeighborInfo ret;
     ret.ifidx = ndm.ndm_ifindex;
     ret.state = ndm.ndm_state;
-    bool set_addr = false;
     while (!msg.empty())
     {
         auto [hdr, data] = netlink::extractRtAttr(msg);
@@ -99,13 +98,8 @@
         else if (hdr.rta_type == NDA_DST)
         {
             ret.addr = addrFromBuf(ndm.ndm_family, data);
-            set_addr = true;
         }
     }
-    if (!set_addr)
-    {
-        throw std::runtime_error("Missing address");
-    }
     return ret;
 }
 

src/rtnetlink_server.cpp

diff --git a/src/rtnetlink_server.cpp b/src/rtnetlink_server.cpp
index 4645367..5afe637 100644
--- a/src/rtnetlink_server.cpp
+++ b/src/rtnetlink_server.cpp
@@ -123,9 +123,9 @@
     {
         it->second->addStaticNeigh(info);
     }
-    else
+    else if (info.addr)
     {
-        it->second->staticNeighbors.erase(info.addr);
+        it->second->staticNeighbors.erase(*info.addr);
     }
 }
 

src/types.hpp

diff --git a/src/types.hpp b/src/types.hpp
index 9262623..709874c 100644
--- a/src/types.hpp
+++ b/src/types.hpp
@@ -138,7 +138,7 @@
 {
     unsigned ifidx;
     uint16_t state;
-    InAddrAny addr;
+    std::optional<InAddrAny> addr;
     std::optional<ether_addr> mac;
 
     constexpr bool operator==(const NeighborInfo& rhs) const noexcept

test/test_rtnetlink.cpp

diff --git a/test/test_rtnetlink.cpp b/test/test_rtnetlink.cpp
index 8bf2a1e..7b60072 100644
--- a/test/test_rtnetlink.cpp
+++ b/test/test_rtnetlink.cpp
@@ -69,8 +69,8 @@
     {
         alignas(NLMSG_ALIGNTO) ndmsg ndm = {};
     } msg;
-    EXPECT_THROW(neighFromRtm(stdplus::raw::asView<char>(msg)),
-                 std::runtime_error);
+
+    EXPECT_EQ((NeighborInfo{}), neighFromRtm(stdplus::raw::asView<char>(msg)));
 }
 
 TEST(NeighFromRtm, NoMac)