base: add nm_net_aux_rtnl_rtntype_{n2a,a2n}() helpers

src/libnm-base/nm-net-aux.c

@@ -4,4 +4,76 @@
 
 #include "nm-net-aux.h"
 
+#include <linux/rtnetlink.h>
+#include <linux/fib_rules.h>
+
 /*****************************************************************************/
+
+G_STATIC_ASSERT((int) FR_ACT_UNSPEC == RTN_UNSPEC);
+G_STATIC_ASSERT((int) FR_ACT_TO_TBL == RTN_UNICAST);
+G_STATIC_ASSERT((int) FR_ACT_GOTO == RTN_LOCAL);
+G_STATIC_ASSERT((int) FR_ACT_NOP == RTN_BROADCAST);
+G_STATIC_ASSERT((int) FR_ACT_RES3 == RTN_ANYCAST);
+G_STATIC_ASSERT((int) FR_ACT_RES4 == RTN_MULTICAST);
+G_STATIC_ASSERT((int) FR_ACT_BLACKHOLE == RTN_BLACKHOLE);
+G_STATIC_ASSERT((int) FR_ACT_UNREACHABLE == RTN_UNREACHABLE);
+G_STATIC_ASSERT((int) FR_ACT_PROHIBIT == RTN_PROHIBIT);
+
+/* see iproute2's rtnl_rtntype_a2n() */
+NM_UTILS_STRING_TABLE_LOOKUP_DEFINE(
+    nm_net_aux_rtnl_rtntype_a2n,
+    int,
+    { nm_assert(name); },
+    {
+        NM_AUTO_PROTECT_ERRNO(errsv);
+        return _nm_utils_ascii_str_to_int64(name, 0, 0, 255, -1);
+    },
+    {"anycast", RTN_ANYCAST},
+    {"blackhole", RTN_BLACKHOLE},
+    {"brd", RTN_BROADCAST},
+    {"broadcast", RTN_BROADCAST},
+    {"local", RTN_LOCAL},
+    {"multicast", RTN_MULTICAST},
+    {"nat", RTN_NAT},
+    {"prohibit", RTN_PROHIBIT},
+    {"throw", RTN_THROW},
+    {"unicast", RTN_UNICAST},
+    {"unreachable", RTN_UNREACHABLE},
+    {"xresolve", RTN_XRESOLVE}, );
+
+const char *
+nm_net_aux_rtnl_rtntype_n2a(guint8 v)
+{
+    /* see iproute2's rtnl_rtntype_n2a(). */
+
+    switch (v) {
+    case RTN_UNSPEC:
+        return "none";
+    case RTN_UNICAST:
+        return "unicast";
+    case RTN_LOCAL:
+        return "local";
+    case RTN_BROADCAST:
+        return "broadcast";
+    case RTN_ANYCAST:
+        return "anycast";
+    case RTN_MULTICAST:
+        return "multicast";
+    case RTN_BLACKHOLE:
+        return "blackhole";
+    case RTN_UNREACHABLE:
+        return "unreachable";
+    case RTN_PROHIBIT:
+        return "prohibit";
+    case RTN_THROW:
+        return "throw";
+    case RTN_NAT:
+        return "nat";
+    case RTN_XRESOLVE:
+        return "xresolve";
+    }
+
+    /* unlike the iproute2 code, this returns %NULL for unknown values.
+     * You may represent this value as "%d" integer, but do it yourself. */
+    return NULL;
+}

src/libnm-base/nm-net-aux.h

@@ -3,4 +3,19 @@
 #ifndef __NM_NET_AUX_H__
 #define __NM_NET_AUX_H__
 
+const char *nm_net_aux_rtnl_rtntype_n2a(guint8 v);
+int         nm_net_aux_rtnl_rtntype_a2n(const char *name);
+
+#define nm_net_aux_rtnl_rtntype_n2a_maybe_buf(v, buf)                      \
+    ({                                                                     \
+        const guint8 _v = (v);                                             \
+                                                                           \
+        /* Warning: this will only touch/initialize @buf if necessary.
+         * That means, don't assume that @buf was initialized after calling
+         * this macro. */     \
+        nm_net_aux_rtnl_rtntype_n2a(v) ?: nm_sprintf_buf((buf), "%u", _v); \
+    })
+
+/*****************************************************************************/
+
 #endif /* __NM_NET_AUX_H__ */