platform: add GRE links creation support

src/platform/nm-linux-platform.c

@@ -118,6 +118,8 @@
         } \
     } G_STMT_END
 
+#define LOG_FMT_IP_TUNNEL "adding %s '%s' parent %u local %s remote %s"
+
 /******************************************************************
  * Forward declarations and enums
  ******************************************************************/
@@ -821,10 +823,10 @@ _parse_lnk_gre (const char *kind, struct nlattr *info_data)
 	props = &obj->lnk_gre;
 
 	props->parent_ifindex = tb[IFLA_GRE_LINK] ? nla_get_u32 (tb[IFLA_GRE_LINK]) : 0;
-	props->input_flags = tb[IFLA_GRE_IFLAGS] ? nla_get_u16 (tb[IFLA_GRE_IFLAGS]) : 0;
+	props->input_flags = tb[IFLA_GRE_IFLAGS] ? ntohs (nla_get_u16 (tb[IFLA_GRE_IFLAGS])) : 0;
-	props->output_flags = tb[IFLA_GRE_OFLAGS] ? nla_get_u16 (tb[IFLA_GRE_OFLAGS]) : 0;
+	props->output_flags = tb[IFLA_GRE_OFLAGS] ? ntohs (nla_get_u16 (tb[IFLA_GRE_OFLAGS])) : 0;
-	props->input_key = (props->input_flags & GRE_KEY) && tb[IFLA_GRE_IKEY] ? nla_get_u32 (tb[IFLA_GRE_IKEY]) : 0;
+	props->input_key = tb[IFLA_GRE_IKEY] ? ntohl (nla_get_u32 (tb[IFLA_GRE_IKEY])) : 0;
-	props->output_key = (props->output_flags & GRE_KEY) && tb[IFLA_GRE_OKEY] ? nla_get_u32 (tb[IFLA_GRE_OKEY]) : 0;
+	props->output_key = tb[IFLA_GRE_OKEY] ? ntohl (nla_get_u32 (tb[IFLA_GRE_OKEY])) : 0;
 	props->local = tb[IFLA_GRE_LOCAL] ? nla_get_u32 (tb[IFLA_GRE_LOCAL]) : 0;
 	props->remote = tb[IFLA_GRE_REMOTE] ? nla_get_u32 (tb[IFLA_GRE_REMOTE]) : 0;
 	props->tos = tb[IFLA_GRE_TOS] ? nla_get_u8 (tb[IFLA_GRE_TOS]) : 0;
@@ -4034,6 +4036,61 @@ nla_put_failure:
 	g_return_val_if_reached (FALSE);
 }
 
+static int
+link_gre_add (NMPlatform *platform,
+              const char *name,
+              NMPlatformLnkGre *props,
+              NMPlatformLink *out_link)
+{
+	nm_auto_nlmsg struct nl_msg *nlmsg = NULL;
+	struct nlattr *info;
+	struct nlattr *data;
+	char buffer[INET_ADDRSTRLEN];
+
+	_LOGD (LOG_FMT_IP_TUNNEL,
+	       "gre",
+	       name,
+	       props->parent_ifindex,
+	       nm_utils_inet4_ntop (props->local, NULL),
+	       nm_utils_inet4_ntop (props->remote, buffer));
+
+	nlmsg = _nl_msg_new_link (RTM_NEWLINK,
+	                          NLM_F_CREATE,
+	                          0,
+	                          name,
+	                          0,
+	                          0);
+	if (!nlmsg)
+		return FALSE;
+
+	if (!(info = nla_nest_start (nlmsg, IFLA_LINKINFO)))
+		goto nla_put_failure;
+
+	NLA_PUT_STRING (nlmsg, IFLA_INFO_KIND, "gre");
+
+	if (!(data = nla_nest_start (nlmsg, IFLA_INFO_DATA)))
+		goto nla_put_failure;
+
+	if (props->parent_ifindex)
+		NLA_PUT_U32 (nlmsg, IFLA_GRE_LINK, props->parent_ifindex);
+	NLA_PUT_U32 (nlmsg, IFLA_GRE_LOCAL, props->local);
+	NLA_PUT_U32 (nlmsg, IFLA_GRE_REMOTE, props->remote);
+	NLA_PUT_U8 (nlmsg, IFLA_GRE_TTL, props->ttl);
+	NLA_PUT_U8 (nlmsg, IFLA_GRE_TOS, props->tos);
+	NLA_PUT_U8 (nlmsg, IFLA_GRE_PMTUDISC, !!props->path_mtu_discovery);
+	NLA_PUT_U32 (nlmsg, IFLA_GRE_IKEY, htonl (props->input_key));
+	NLA_PUT_U32 (nlmsg, IFLA_GRE_OKEY, htonl (props->output_key));
+	NLA_PUT_U32 (nlmsg, IFLA_GRE_IFLAGS, htons (props->input_flags));
+	NLA_PUT_U32 (nlmsg, IFLA_GRE_OFLAGS, htons (props->output_flags));
+
+	nla_nest_end (nlmsg, data);
+	nla_nest_end (nlmsg, info);
+
+	return do_add_link_with_lookup (platform, NM_LINK_TYPE_GRE, name, nlmsg, out_link);
+nla_put_failure:
+	g_return_val_if_reached (FALSE);
+}
+
 static void
 _vlan_change_vlan_qos_mapping_create (gboolean is_ingress_map,
                                       gboolean reset_all,
@@ -5487,6 +5544,8 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->mesh_set_channel = mesh_set_channel;
 	platform_class->mesh_set_ssid = mesh_set_ssid;
 
+	platform_class->link_gre_add = link_gre_add;
+
 	platform_class->ip4_address_get = ip4_address_get;
 	platform_class->ip6_address_get = ip6_address_get;
 	platform_class->ip4_address_get_all = ip4_address_get_all;

src/platform/nm-platform.c

@@ -71,6 +71,8 @@ G_STATIC_ASSERT (G_STRUCT_OFFSET (NMPlatformIPRoute, network_ptr) == G_STRUCT_OF
         } \
     } G_STMT_END
 
+#define LOG_FMT_IP_TUNNEL "adding %s '%s' parent %u local %s remote %s"
+
 /*****************************************************************************/
 
 #define NM_PLATFORM_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_PLATFORM, NMPlatformPrivate))
@@ -1709,6 +1711,45 @@ nm_platform_vlan_set_egress_map (NMPlatform *self, int ifindex, int from, int to
 	return nm_platform_link_vlan_change (self, ifindex, 0, 0, FALSE, NULL, 0, FALSE, &map, 1);
 }
 
+/**
+ * nm_platform_link_gre_add:
+ * @self: platform instance
+ * @name: name of the new interface
+ * @props: interface properties
+ * @out_link: on success, the link object
+ *
+ * Create a software GRE device.
+ */
+NMPlatformError
+nm_platform_link_gre_add (NMPlatform *self,
+                          const char *name,
+                          NMPlatformLnkGre *props,
+                          NMPlatformLink *out_link)
+{
+	NMPlatformError plerr;
+	char buffer[INET_ADDRSTRLEN];
+
+	_CHECK_SELF (self, klass, NM_PLATFORM_ERROR_BUG);
+
+	g_return_val_if_fail (props, NM_PLATFORM_ERROR_BUG);
+	g_return_val_if_fail (name, NM_PLATFORM_ERROR_BUG);
+
+	plerr = _link_add_check_existing (self, name, NM_LINK_TYPE_GRE, out_link);
+	if (plerr != NM_PLATFORM_ERROR_SUCCESS)
+		return plerr;
+
+	_LOGD (LOG_FMT_IP_TUNNEL,
+	       "gre",
+	       name,
+	       props->parent_ifindex,
+	       nm_utils_inet4_ntop (props->local, NULL),
+	       nm_utils_inet4_ntop (props->remote, buffer));
+
+	if (!klass->link_gre_add (self, name, props, out_link))
+		return NM_PLATFORM_ERROR_UNSPECIFIED;
+	return NM_PLATFORM_ERROR_SUCCESS;
+}
+
 NMPlatformError
 nm_platform_infiniband_partition_add (NMPlatform *self, int parent, int p_key, NMPlatformLink *out_link)
 {

src/platform/nm-platform.h

@@ -63,6 +63,9 @@ typedef struct _NMPlatform NMPlatform;
 
 #define NM_IFF_MULTI_QUEUE                     0x0100 /* IFF_MULTI_QUEUE */
 
+/* Redefine this in host's endianness */
+#define NM_GRE_KEY      0x2000
+
 typedef enum { /*< skip >*/
 
 	/* dummy value, to enforce that the enum type is signed and has a size
@@ -524,6 +527,9 @@ typedef struct {
 	                              const NMVlanQosMapping *egress_map,
 	                              gsize n_egress_map);
 
+	gboolean (*link_gre_add) (NMPlatform *, const char *name, NMPlatformLnkGre *props,
+	                          NMPlatformLink *out_link);
+
 	gboolean (*infiniband_partition_add) (NMPlatform *, int parent, int p_key, NMPlatformLink *out_link);
 
 	gboolean (*tun_add) (NMPlatform *platform, const char *name, gboolean tap, gint64 owner, gint64 group, gboolean pi,
@@ -762,6 +768,10 @@ void                   nm_platform_ip4_address_set_addr (NMPlatformIP4Address *a
 const struct in6_addr *nm_platform_ip6_address_get_peer (const NMPlatformIP6Address *addr);
 
 const NMPlatformIP4Address *nm_platform_ip4_address_get (NMPlatform *self, int ifindex, in_addr_t address, int plen, in_addr_t peer_address);
+
+NMPlatformError nm_platform_link_gre_add (NMPlatform *self, const char *name, NMPlatformLnkGre *props,
+                                          NMPlatformLink *out_link);
+
 const NMPlatformIP6Address *nm_platform_ip6_address_get (NMPlatform *self, int ifindex, struct in6_addr address, int plen);
 GArray *nm_platform_ip4_address_get_all (NMPlatform *self, int ifindex);
 GArray *nm_platform_ip6_address_get_all (NMPlatform *self, int ifindex);