route: add support for getting permanent mac address of link

#404

doc/route.txt

@@ -394,6 +394,17 @@ void rtnl_link_set_addr(struct rtnl_link *link, struct nl_addr *addr);
 struct nl_addr *rtnl_link_get_addr(struct rtnl_link *link);
 -----
 
+[[link_attr_permaddr]]
+==== Permanent address
+The permanent link layer address (e.g. MAC address).
+
+[source,c]
+-----
+#include <netlink/route/link.h>
+
+struct nl_addr *rtnl_link_get_perm_addr(struct rtnl_link *link);
+-----
+
 [[link_attr_broadcast]]
 ==== Broadcast Address
 The link layer broadcast address

include/netlink/route/link.h

@@ -183,6 +183,8 @@ extern unsigned int rtnl_link_get_arptype(struct rtnl_link *);
 extern void rtnl_link_set_addr(struct rtnl_link *, struct nl_addr *);
 extern struct nl_addr *rtnl_link_get_addr(struct rtnl_link *);
 
+extern struct nl_addr *rtnl_link_get_perm_addr(struct rtnl_link *);
+
 extern void rtnl_link_set_broadcast(struct rtnl_link *, struct nl_addr *);
 extern struct nl_addr *rtnl_link_get_broadcast(struct rtnl_link *);
 

lib/route/link.c

@@ -73,6 +73,7 @@
 #define LINK_ATTR_GSO_MAX_SEGS ((uint64_t) 1 << 37)
 #define LINK_ATTR_GSO_MAX_SIZE ((uint64_t) 1 << 38)
 #define LINK_ATTR_LINKINFO_SLAVE_KIND ((uint64_t) 1 << 39)
+#define LINK_ATTR_PERMANENT_ADDR ((uint64_t) 1 << 40)
 
 static struct nl_cache_ops rtnl_link_ops;
 static struct nl_object_ops link_obj_ops;
@@ -271,6 +272,7 @@ static void link_free_data(struct nl_object *c)
 
  nl_addr_put(link->l_addr);
  nl_addr_put(link->l_bcast);
+ nl_addr_put(link->l_paddr);
 
  free(link->l_ifalias);
  free(link->l_info_kind);
@@ -294,6 +296,7 @@ static int link_clone(struct nl_object *_dst, struct nl_object *_src)
 
  dst->l_addr = NULL;
  dst->l_bcast = NULL;
+ dst->l_paddr = NULL;
  dst->l_info_kind = NULL;
  dst->l_info_slave_kind = NULL;
  dst->l_info_ops = NULL;
@@ -313,6 +316,10 @@ static int link_clone(struct nl_object *_dst, struct nl_object *_src)
  if (!(dst->l_bcast = nl_addr_clone(src->l_bcast)))
  return -NLE_NOMEM;
 
+ if (src->l_paddr)
+ if (!(dst->l_paddr = nl_addr_clone(src->l_paddr)))
+ return -NLE_NOMEM;
+
  if (src->l_ifalias)
  if (!(dst->l_ifalias = strdup(src->l_ifalias)))
  return -NLE_NOMEM;
@@ -514,6 +521,15 @@ int rtnl_link_info_parse(struct rtnl_link *link, struct nlattr **tb)
  link->ce_mask |= LINK_ATTR_ADDR;
  }
 
+ if (tb[IFLA_PERM_ADDRESS]) {
+ link->l_paddr = nl_addr_alloc_attr(tb[IFLA_PERM_ADDRESS], AF_UNSPEC);
+ if (link->l_paddr == NULL)
+ return -NLE_NOMEM;
+ nl_addr_set_family(link->l_paddr,
+ nl_addr_guess_family(link->l_paddr));
+ link->ce_mask |= LINK_ATTR_PERMANENT_ADDR;
+ }
+
  if (tb[IFLA_BROADCAST]) {
  link->l_bcast = nl_addr_alloc_attr(tb[IFLA_BROADCAST],
  AF_UNSPEC);
@@ -863,6 +879,9 @@ static void link_dump_line(struct nl_object *obj, struct nl_dump_params *p)
  if (link->l_addr && !nl_addr_iszero(link->l_addr))
  nl_dump(p, "%s ", nl_addr2str(link->l_addr, buf, sizeof(buf)));
 
+ if (link->l_paddr && !nl_addr_iszero(link->l_paddr))
+ nl_dump(p, "permanent address %s ", nl_addr2str(link->l_paddr, buf, sizeof(buf)));
+
  if (link->ce_mask & LINK_ATTR_MASTER) {
  if (cache) {
  _nl_auto_rtnl_link struct rtnl_link *master = rtnl_link_get(cache, link->l_master);
@@ -1130,6 +1149,7 @@ static uint64_t link_compare(struct nl_object *_a, struct nl_object *_b,
  diff |= _DIFF(LINK_ATTR_IFNAME, strcmp(a->l_name, b->l_name));
  diff |= _DIFF(LINK_ATTR_ADDR, nl_addr_cmp(a->l_addr, b->l_addr));
  diff |= _DIFF(LINK_ATTR_BRD, nl_addr_cmp(a->l_bcast, b->l_bcast));
+ diff |= _DIFF(LINK_ATTR_PERMANENT_ADDR, nl_addr_cmp(a->l_paddr, b->l_paddr));
  diff |= _DIFF(LINK_ATTR_IFALIAS, strcmp(a->l_ifalias, b->l_ifalias));
  diff |= _DIFF(LINK_ATTR_NUM_VF, a->l_num_vf != b->l_num_vf);
  diff |= _DIFF(LINK_ATTR_PROMISCUITY,
@@ -2024,6 +2044,19 @@ struct nl_addr *rtnl_link_get_addr(struct rtnl_link *link)
  return link->ce_mask & LINK_ATTR_ADDR ? link->l_addr : NULL;
 }
 
+/**
+ * Return permanent link layer adress of link object
+ * @arg link Link object
+ *
+ * @copydoc pointer_lifetime_warning
+ * @route_doc{link_attr_permaddr, Permanent Link Layer Address}
+ * @return Permanent link layer address or NULL if not set.
+ */
+struct nl_addr *rtnl_link_get_perm_addr(struct rtnl_link *link)
+{
+ return link->ce_mask & LINK_ATTR_PERMANENT_ADDR ? link->l_paddr : NULL;
+}
+
 /**
  * Set link layer broadcast address of link object
  * @arg link Link object

lib/route/nl-route.h

@@ -43,6 +43,7 @@ struct rtnl_link {
  uint32_t l_master;
  struct nl_addr *l_addr;
  struct nl_addr *l_bcast;
+ struct nl_addr *l_paddr;
  char l_qdisc[IFQDISCSIZ];
  struct rtnl_link_map l_map;
  uint64_t l_stats[RTNL_LINK_STATS_MAX + 1];

libnl-route-3.sym

@@ -1340,4 +1340,5 @@ global:
  rtnl_link_bond_get_miimon;
  rtnl_link_bond_get_min_links;
  rtnl_link_bond_get_mode;
+ rtnl_link_get_perm_addr;
 } libnl_3_10;