diff options
| -rw-r--r-- | include/net/genetlink.h | 10 | ||||
| -rw-r--r-- | net/netlink/genetlink.c | 23 |
2 files changed, 32 insertions, 1 deletions
diff --git a/include/net/genetlink.h b/include/net/genetlink.h index 3d08e67b3cfc..9f97f73615b6 100644 --- a/include/net/genetlink.h +++ b/include/net/genetlink.h @@ -41,13 +41,21 @@ struct genl_info; * @mcgrps: multicast groups used by this family * @n_mcgrps: number of multicast groups * @resv_start_op: first operation for which reserved fields of the header - * can be validated, new families should leave this field at zero + * can be validated and policies are required (see below); + * new families should leave this field at zero * @mcgrp_offset: starting number of multicast group IDs in this family * (private) * @ops: the operations supported by this family * @n_ops: number of operations supported by this family * @small_ops: the small-struct operations supported by this family * @n_small_ops: number of small-struct operations supported by this family + * + * Attribute policies (the combination of @policy and @maxattr fields) + * can be attached at the family level or at the operation level. + * If both are present the per-operation policy takes precedence. + * For operations before @resv_start_op lack of policy means that the core + * will perform no attribute parsing or validation. For newer operations + * if policy is not provided core will reject all TLV attributes. */ struct genl_family { int id; /* private */ diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 39b7c00e4cef..b1fd059c9992 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -78,10 +78,29 @@ static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) | static unsigned long *mc_groups = &mc_group_start; static unsigned long mc_groups_longs = 1; +/* We need the last attribute with non-zero ID therefore a 2-entry array */ +static struct nla_policy genl_policy_reject_all[] = { + { .type = NLA_REJECT }, + { .type = NLA_REJECT }, +}; + static int genl_ctrl_event(int event, const struct genl_family *family, const struct genl_multicast_group *grp, int grp_id); +static void +genl_op_fill_in_reject_policy(const struct genl_family *family, + struct genl_ops *op) +{ + BUILD_BUG_ON(ARRAY_SIZE(genl_policy_reject_all) - 1 != 1); + + if (op->policy || op->cmd < family->resv_start_op) + return; + + op->policy = genl_policy_reject_all; + op->maxattr = 1; +} + static const struct genl_family *genl_family_find_byid(unsigned int id) { return idr_find(&genl_fam_idr, id); @@ -113,6 +132,8 @@ static void genl_op_from_full(const struct genl_family *family, op->maxattr = family->maxattr; if (!op->policy) op->policy = family->policy; + + genl_op_fill_in_reject_policy(family, op); } static int genl_get_cmd_full(u32 cmd, const struct genl_family *family, @@ -142,6 +163,8 @@ static void genl_op_from_small(const struct genl_family *family, op->maxattr = family->maxattr; op->policy = family->policy; + + genl_op_fill_in_reject_policy(family, op); } static int genl_get_cmd_small(u32 cmd, const struct genl_family *family, |