routing_table: Parse v6 routes

Since we ultimately handle all of the routes as strings it is safe to
include v6 routes into the table so that we can later support using
those. This has no effect on observed behavior.

Tested:
    Used a future change to validate that this was parsing the default
    gateway for ipv6 and that old ipv4 parsing still works as expected.

Change-Id: I0fec5788ab31f7b1c4f7f0d7a34023ccdb15d9ba
Signed-off-by: William A. Kennington III <wak@google.com>

1 files changed, 25 insertions, 14 deletions

diff --git a/routing_table.cpp b/routing_table.cpp
index ff5e3f4..6aa237a 100644
--- a/routing_table.cpp
+++ b/routing_table.cpp
@@ -11,9 +11,11 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <optional>
 #include <phosphor-logging/elog-errors.hpp>
 #include <phosphor-logging/log.hpp>
 #include <stdexcept>
+#include <string_view>
 #include <xyz/openbmc_project/Common/error.hpp>
 
 namespace phosphor
@@ -99,15 +101,16 @@ void Table::parseRoutes(const nlmsghdr* nlHdr)
     rtmsg* rtMsg = nullptr;
     rtattr* rtAttr = nullptr;
     int rtLen{};
-    in_addr dstAddr{};
-    in_addr gateWayAddr{};
+    std::optional<InAddrAny> dstAddr;
+    std::optional<InAddrAny> gateWayAddr;
     char ifName[IF_NAMESIZE] = {};
 
     rtMsg = reinterpret_cast<rtmsg*>(NLMSG_DATA(nlHdr));
 
-    // If the route is not for AF_INET or does not belong to main routing table
-    // then return.
-    if ((rtMsg->rtm_family != AF_INET) || (rtMsg->rtm_table != RT_TABLE_MAIN))
+    // If the route is not for AF_INET{,6} or does not belong to main routing
+    // table then return.
+    if ((rtMsg->rtm_family != AF_INET && rtMsg->rtm_family != AF_INET6) ||
+        rtMsg->rtm_table != RT_TABLE_MAIN)
     {
         return;
     }
@@ -119,6 +122,8 @@ void Table::parseRoutes(const nlmsghdr* nlHdr)
 
     for (; RTA_OK(rtAttr, rtLen); rtAttr = RTA_NEXT(rtAttr, rtLen))
     {
+        std::string_view attrData(reinterpret_cast<char*>(RTA_DATA(rtAttr)),
+                                  RTA_PAYLOAD(rtAttr));
         switch (rtAttr->rta_type)
         {
             case RTA_OIF:
@@ -126,25 +131,31 @@ void Table::parseRoutes(const nlmsghdr* nlHdr)
                                ifName);
                 break;
             case RTA_GATEWAY:
-                gateWayAddr.s_addr =
-                    *reinterpret_cast<u_int*>(RTA_DATA(rtAttr));
+                gateWayAddr = addrFromBuf(rtMsg->rtm_family, attrData);
                 break;
             case RTA_DST:
-                dstAddr.s_addr = *reinterpret_cast<u_int*>(RTA_DATA(rtAttr));
+                dstAddr = addrFromBuf(rtMsg->rtm_family, attrData);
                 break;
         }
     }
 
     std::string dstStr;
+    if (dstAddr)
+    {
+        dstStr = toString(*dstAddr);
+    }
     std::string gatewayStr;
-
-    if (dstAddr.s_addr == 0 && gateWayAddr.s_addr != 0)
+    if (gateWayAddr)
     {
-        defaultGateway = reinterpret_cast<char*>(inet_ntoa(gateWayAddr));
+        gatewayStr = toString(*gateWayAddr);
+    }
+    if (!dstAddr && gateWayAddr)
+    {
+        if (rtMsg->rtm_family == AF_INET)
+        {
+            defaultGateway = gatewayStr;
+        }
     }
-
-    dstStr = inet_ntoa(dstAddr);
-    gatewayStr = inet_ntoa(gateWayAddr);
 
     Entry route(dstStr, gatewayStr, ifName);
     // if there is already existing route for this network