rtnetlink: Add public interface parser

This will be used by the rtnetlink server to parse new links.

Change-Id: Ibc0abc12ca58b78ffc22ac6f75822853d4b7bdc8
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/test/test_rtnetlink.cpp b/test/test_rtnetlink.cpp
index 7b60072..73a0f00 100644
--- a/test/test_rtnetlink.cpp
+++ b/test/test_rtnetlink.cpp
@@ -10,6 +10,54 @@
 namespace phosphor::network::netlink
 {
 
+TEST(IntfFromRtm, SmallMsg)
+{
+    EXPECT_THROW(intfFromRtm("1"), std::runtime_error);
+}
+
+TEST(IntfFromRtm, NoAttrs)
+{
+    struct
+    {
+        ifinfomsg hdr __attribute__((aligned(NLMSG_ALIGNTO)));
+    } msg;
+    msg.hdr.ifi_index = 1;
+    msg.hdr.ifi_flags = 2;
+    EXPECT_EQ(intfFromRtm(stdplus::raw::asView<char>(msg)),
+              (InterfaceInfo{.idx = 1, .flags = 2}));
+}
+
+TEST(IntfFromRtm, AllAttrs)
+{
+    struct
+    {
+        ifinfomsg hdr __attribute__((aligned(NLMSG_ALIGNTO)));
+        rtattr addr_hdr __attribute__((aligned((RTA_ALIGNTO))));
+        char addr[6]
+            __attribute__((aligned((RTA_ALIGNTO)))) = {0, 1, 2, 3, 4, 5};
+        rtattr name_hdr __attribute__((aligned((RTA_ALIGNTO))));
+        char name[5] __attribute__((aligned((RTA_ALIGNTO)))) = "eth0";
+        rtattr mtu_hdr __attribute__((aligned((RTA_ALIGNTO))));
+        unsigned mtu __attribute__((aligned((RTA_ALIGNTO)))) = 50;
+    } msg;
+    msg.hdr.ifi_index = 1;
+    msg.hdr.ifi_flags = 2;
+    msg.addr_hdr.rta_type = IFLA_ADDRESS;
+    msg.addr_hdr.rta_len = RTA_LENGTH(sizeof(msg.addr));
+    msg.name_hdr.rta_type = IFLA_IFNAME;
+    msg.name_hdr.rta_len = RTA_LENGTH(sizeof(msg.name));
+    msg.mtu_hdr.rta_type = IFLA_MTU;
+    msg.mtu_hdr.rta_len = RTA_LENGTH(sizeof(msg.mtu));
+
+    auto info = intfFromRtm(stdplus::raw::asView<char>(msg));
+    auto expected = InterfaceInfo{.idx = 1,
+                                  .flags = 2,
+                                  .name = "eth0",
+                                  .mac = ether_addr{0, 1, 2, 3, 4, 5},
+                                  .mtu = 50};
+    EXPECT_EQ(info, expected);
+}
+
 TEST(AddrFromRtm, MissingAddr)
 {
     struct
diff --git a/test/test_system_queries.cpp b/test/test_system_queries.cpp
index 5042cc6..e88c64b 100644
--- a/test/test_system_queries.cpp
+++ b/test/test_system_queries.cpp
@@ -1,87 +1,12 @@
 #include "system_queries.hpp"
 
-#include <linux/rtnetlink.h>
-#include <net/if.h>
-
-#include <stdplus/raw.hpp>
-
 #include <gtest/gtest.h>
 
-using std::literals::string_view_literals::operator""sv;
-
 namespace phosphor::network::system
 {
 namespace detail
 {
 
-TEST(ParseInterface, NotLinkType)
-{
-    nlmsghdr hdr{};
-    hdr.nlmsg_type = RTM_NEWADDR;
-
-    EXPECT_THROW(parseInterface(hdr, ""), std::runtime_error);
-}
-
-TEST(ParseInterface, SmallMsg)
-{
-    nlmsghdr hdr{};
-    hdr.nlmsg_type = RTM_NEWLINK;
-    auto data = "1"sv;
-
-    EXPECT_THROW(parseInterface(hdr, data), std::runtime_error);
-}
-
-TEST(ParseInterface, NoAttrs)
-{
-    nlmsghdr hdr{};
-    hdr.nlmsg_type = RTM_NEWLINK;
-    struct
-    {
-        ifinfomsg hdr __attribute__((aligned(NLMSG_ALIGNTO)));
-    } msg;
-    msg.hdr.ifi_index = 1;
-    msg.hdr.ifi_flags = 2;
-    auto data = stdplus::raw::asView<char>(msg);
-
-    auto info = parseInterface(hdr, data);
-    auto expected = InterfaceInfo{.idx = 1, .flags = 2};
-    EXPECT_EQ(info, expected);
-}
-
-TEST(ParseInterface, AllAttrs)
-{
-    nlmsghdr hdr{};
-    hdr.nlmsg_type = RTM_NEWLINK;
-    struct
-    {
-        ifinfomsg hdr __attribute__((aligned(NLMSG_ALIGNTO)));
-        rtattr addr_hdr __attribute__((aligned((RTA_ALIGNTO))));
-        char addr[6]
-            __attribute__((aligned((RTA_ALIGNTO)))) = {0, 1, 2, 3, 4, 5};
-        rtattr name_hdr __attribute__((aligned((RTA_ALIGNTO))));
-        char name[5] __attribute__((aligned((RTA_ALIGNTO)))) = "eth0";
-        rtattr mtu_hdr __attribute__((aligned((RTA_ALIGNTO))));
-        unsigned mtu __attribute__((aligned((RTA_ALIGNTO)))) = 50;
-    } msg;
-    msg.hdr.ifi_index = 1;
-    msg.hdr.ifi_flags = 2;
-    msg.addr_hdr.rta_type = IFLA_ADDRESS;
-    msg.addr_hdr.rta_len = RTA_LENGTH(sizeof(msg.addr));
-    msg.name_hdr.rta_type = IFLA_IFNAME;
-    msg.name_hdr.rta_len = RTA_LENGTH(sizeof(msg.name));
-    msg.mtu_hdr.rta_type = IFLA_MTU;
-    msg.mtu_hdr.rta_len = RTA_LENGTH(sizeof(msg.mtu));
-    auto data = stdplus::raw::asView<char>(msg);
-
-    auto info = parseInterface(hdr, data);
-    auto expected = InterfaceInfo{.idx = 1,
-                                  .flags = 2,
-                                  .name = "eth0",
-                                  .mac = ether_addr{0, 1, 2, 3, 4, 5},
-                                  .mtu = 50};
-    EXPECT_EQ(info, expected);
-}
-
 TEST(ValidateNewAddr, Filtering)
 {
     AddressInfo info = {};