diff options
-rw-r--r-- | net/ipv6/seg6_local.c | 120 |
1 files changed, 106 insertions, 14 deletions
diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index aef39eab9be2..3b5657c622a0 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -36,6 +36,21 @@ struct seg6_local_lwt; 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; }; @@ -57,6 +72,10 @@ struct seg6_local_lwt { 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) @@ -959,26 +978,26 @@ static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = { }; /* 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]; @@ -993,13 +1012,54 @@ static void __destroy_attrs(int max_parsed, struct seg6_local_lwt *slwt) */ 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); @@ -1012,6 +1072,26 @@ static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt) 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]) @@ -1021,17 +1101,22 @@ static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt) 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; } @@ -1096,13 +1181,16 @@ static int seg6_local_fill_encap(struct sk_buff *skb, { 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) @@ -1121,7 +1209,7 @@ static int seg6_local_get_encap_size(struct lwtunnel_state *lwt) 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); @@ -1154,6 +1242,7 @@ static int seg6_local_cmp_encap(struct lwtunnel_state *a, { 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); @@ -1162,11 +1251,14 @@ static int seg6_local_cmp_encap(struct lwtunnel_state *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; |