libnm: add internal nmc_client_has_{version_info_v,version_info_capability,capability}() helper

In the end, it turned out I don't need them. They still seem useful,
because they show how to use this API. In particular for how the
bitfield should be parsed.

src/libnm-client-aux-extern/nm-libnm-aux.c

@@ -135,3 +135,64 @@ nmc_client_new_waitsync(GCancellable *cancellable,
     }
     return TRUE;
 }
+
+/*****************************************************************************/
+
+guint32
+nmc_client_has_version_info_v(NMClient *nmc)
+{
+    const guint32 *ver;
+    gsize          len;
+
+    ver = nm_client_get_version_info(nmc, &len);
+    if (len < 1)
+        return 0;
+    return ver[0];
+}
+
+gboolean
+nmc_client_has_version_info_capability(NMClient *nmc, NMVersionInfoCapability capability)
+{
+    const guint32 *ver;
+    gsize          len;
+    gsize          idx;
+    gsize          idx_hi;
+    gsize          idx_lo;
+
+    ver = nm_client_get_version_info(nmc, &len);
+
+    if (len < 2)
+        return FALSE;
+
+    len--;
+    ver++;
+
+    idx = (gsize) capability;
+    if (idx >= G_MAXSIZE - 31u)
+        return FALSE;
+
+    idx_hi = ((idx + 31u) / 32u);
+    idx_lo = (idx % 32u);
+
+    if (idx_hi > len)
+        return FALSE;
+
+    return NM_FLAGS_ANY(ver[idx_hi], (1ull << idx_lo));
+}
+
+gboolean
+nmc_client_has_capability(NMClient *nmc, NMCapability capability)
+{
+    const guint32 *caps;
+    gsize          len;
+    gsize          i;
+
+    caps = nm_client_get_capabilities(nmc, &len);
+
+    for (i = 0; i < len; i++) {
+        if (caps[i] == capability)
+            return TRUE;
+    }
+
+    return FALSE;
+}

src/libnm-client-aux-extern/nm-libnm-aux.h

@@ -21,4 +21,8 @@ gboolean nmc_client_new_waitsync(GCancellable *cancellable,
                                  const char   *first_property_name,
                                  ...);
 
+guint32  nmc_client_has_version_info_v(NMClient *nmc);
+gboolean nmc_client_has_version_info_capability(NMClient *nmc, NMVersionInfoCapability capability);
+gboolean nmc_client_has_capability(NMClient *nmc, NMCapability capability);
+
 #endif /* __NM_LIBNM_AUX_H__ */