struct seg6_action_desc {
int action;
unsigned long attrs;
+
+ /* The optattrs field is used for specifying all the optional
+ * attributes supported by a specific behavior.
+ * It means that if one of these attributes is not provided in the
+ * netlink message during the behavior creation, no errors will be
+ * returned to the userspace.
+ *
+ * Each attribute can be only of two types (mutually exclusive):
+ * 1) required or 2) optional.
+ * Every user MUST obey to this rule! If you set an attribute as
+ * required the same attribute CANNOT be set as optional and vice
+ * versa.
+ */
+ unsigned long optattrs;
+
int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int static_headroom;
};
int headroom;
struct seg6_action_desc *desc;
+ /* unlike the required attrs, we have to track the optional attributes
+ * that have been effectively parsed.
+ */
+ unsigned long parsed_optattrs;
};
static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
};
/* call the destroy() callback (if available) for each set attribute in
- * @slwt, starting from the first attribute up to the @max_parsed (excluded)
- * attribute.
+ * @parsed_attrs, starting from the first attribute up to the @max_parsed
+ * (excluded) attribute.
*/
-static void __destroy_attrs(int max_parsed, struct seg6_local_lwt *slwt)
+static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed,
+ struct seg6_local_lwt *slwt)
{
- unsigned long attrs = slwt->desc->attrs;
struct seg6_action_param *param;
int i;
/* Every required seg6local attribute is identified by an ID which is
* encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask;
*
- * We scan the 'attrs' bitmask, starting from the first attribute
+ * We scan the 'parsed_attrs' bitmask, starting from the first attribute
* up to the @max_parsed (excluded) attribute.
* For each set attribute, we retrieve the corresponding destroy()
* callback. If the callback is not available, then we skip to the next
* attribute; otherwise, we call the destroy() callback.
*/
for (i = 0; i < max_parsed; ++i) {
- if (!(attrs & (1 << i)))
+ if (!(parsed_attrs & (1 << i)))
continue;
param = &seg6_action_params[i];
*/
static void destroy_attrs(struct seg6_local_lwt *slwt)
{
- __destroy_attrs(SEG6_LOCAL_MAX + 1, slwt);
+ unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs;
+
+ __destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt);
+}
+
+static int parse_nla_optional_attrs(struct nlattr **attrs,
+ struct seg6_local_lwt *slwt)
+{
+ struct seg6_action_desc *desc = slwt->desc;
+ unsigned long parsed_optattrs = 0;
+ struct seg6_action_param *param;
+ int err, i;
+
+ for (i = 0; i < SEG6_LOCAL_MAX + 1; ++i) {
+ if (!(desc->optattrs & (1 << i)) || !attrs[i])
+ continue;
+
+ /* once here, the i-th attribute is provided by the
+ * userspace AND it is identified optional as well.
+ */
+ param = &seg6_action_params[i];
+
+ err = param->parse(attrs, slwt);
+ if (err < 0)
+ goto parse_optattrs_err;
+
+ /* current attribute has been correctly parsed */
+ parsed_optattrs |= (1 << i);
+ }
+
+ /* store in the tunnel state all the optional attributed successfully
+ * parsed.
+ */
+ slwt->parsed_optattrs = parsed_optattrs;
+
+ return 0;
+
+parse_optattrs_err:
+ __destroy_attrs(parsed_optattrs, i, slwt);
+
+ return err;
}
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
{
struct seg6_action_param *param;
struct seg6_action_desc *desc;
+ unsigned long invalid_attrs;
int i, err;
desc = __get_action_desc(slwt->action);
slwt->desc = desc;
slwt->headroom += desc->static_headroom;
+ /* Forcing the desc->optattrs *set* and the desc->attrs *set* to be
+ * disjoined, this allow us to release acquired resources by optional
+ * attributes and by required attributes independently from each other
+ * without any interfarence.
+ * In other terms, we are sure that we do not release some the acquired
+ * resources twice.
+ *
+ * Note that if an attribute is configured both as required and as
+ * optional, it means that the user has messed something up in the
+ * seg6_action_table. Therefore, this check is required for SRv6
+ * behaviors to work properly.
+ */
+ invalid_attrs = desc->attrs & desc->optattrs;
+ if (invalid_attrs) {
+ WARN_ONCE(1,
+ "An attribute cannot be both required AND optional");
+ return -EINVAL;
+ }
+
+ /* parse the required attributes */
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
if (desc->attrs & (1 << i)) {
if (!attrs[i])
err = param->parse(attrs, slwt);
if (err < 0)
- goto parse_err;
+ goto parse_attrs_err;
}
}
+ /* parse the optional attributes, if any */
+ err = parse_nla_optional_attrs(attrs, slwt);
+ if (err < 0)
+ goto parse_attrs_err;
+
return 0;
-parse_err:
+parse_attrs_err:
/* release any resource that may have been acquired during the i-1
* parse() operations.
*/
- __destroy_attrs(i, slwt);
+ __destroy_attrs(desc->attrs, i, slwt);
return err;
}
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
struct seg6_action_param *param;
+ unsigned long attrs;
int i, err;
if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
return -EMSGSIZE;
+ attrs = slwt->desc->attrs | slwt->parsed_optattrs;
+
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
- if (slwt->desc->attrs & (1 << i)) {
+ if (attrs & (1 << i)) {
param = &seg6_action_params[i];
err = param->put(skb, slwt);
if (err < 0)
nlsize = nla_total_size(4); /* action */
- attrs = slwt->desc->attrs;
+ attrs = slwt->desc->attrs | slwt->parsed_optattrs;
if (attrs & (1 << SEG6_LOCAL_SRH))
nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
{
struct seg6_local_lwt *slwt_a, *slwt_b;
struct seg6_action_param *param;
+ unsigned long attrs_a, attrs_b;
int i;
slwt_a = seg6_local_lwtunnel(a);
if (slwt_a->action != slwt_b->action)
return 1;
- if (slwt_a->desc->attrs != slwt_b->desc->attrs)
+ attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs;
+ attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs;
+
+ if (attrs_a != attrs_b)
return 1;
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
- if (slwt_a->desc->attrs & (1 << i)) {
+ if (attrs_a & (1 << i)) {
param = &seg6_action_params[i];
if (param->cmp(slwt_a, slwt_b))
return 1;