From d2681e93b0ab7afe01d07f8c96f14afaccdcea4c Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 8 Oct 2020 12:45:16 +0200 Subject: netlink: policy: refactor per-attr policy writing Refactor the per-attribute policy writing into a new helper function, to be used later for dumping out the policy of a rejected attribute. v2: - fix some indentation v3: - change variable order in netlink_policy_dump_write() Reviewed-by: Jakub Kicinski Signed-off-by: Johannes Berg Signed-off-by: Jakub Kicinski --- net/netlink/policy.c | 79 +++++++++++++++++++++++++++++++++------------------- 1 file changed, 51 insertions(+), 28 deletions(-) (limited to 'net/netlink') diff --git a/net/netlink/policy.c b/net/netlink/policy.c index ee26d01328ee..4383436759e2 100644 --- a/net/netlink/policy.c +++ b/net/netlink/policy.c @@ -196,49 +196,33 @@ bool netlink_policy_dump_loop(struct netlink_policy_dump_state *state) return !netlink_policy_dump_finished(state); } -/** - * netlink_policy_dump_write - write current policy dump attributes - * @skb: the message skb to write to - * @state: the policy dump state - * - * Returns: 0 on success, an error code otherwise - */ -int netlink_policy_dump_write(struct sk_buff *skb, - struct netlink_policy_dump_state *state) +static int +__netlink_policy_dump_write_attr(struct netlink_policy_dump_state *state, + struct sk_buff *skb, + const struct nla_policy *pt, + int nestattr) { - const struct nla_policy *pt; - struct nlattr *policy, *attr; enum netlink_attribute_type type; - bool again; - -send_attribute: - again = false; - - pt = &state->policies[state->policy_idx].policy[state->attr_idx]; + struct nlattr *attr; - policy = nla_nest_start(skb, state->policy_idx); - if (!policy) - return -ENOBUFS; - - attr = nla_nest_start(skb, state->attr_idx); + attr = nla_nest_start(skb, nestattr); if (!attr) - goto nla_put_failure; + return -ENOBUFS; switch (pt->type) { default: case NLA_UNSPEC: case NLA_REJECT: /* skip - use NLA_MIN_LEN to advertise such */ - nla_nest_cancel(skb, policy); - again = true; - goto next; + nla_nest_cancel(skb, attr); + return -ENODATA; case NLA_NESTED: type = NL_ATTR_TYPE_NESTED; fallthrough; case NLA_NESTED_ARRAY: if (pt->type == NLA_NESTED_ARRAY) type = NL_ATTR_TYPE_NESTED_ARRAY; - if (pt->nested_policy && pt->len && + if (state && pt->nested_policy && pt->len && (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_POLICY_IDX, netlink_policy_dump_get_policy_idx(state, pt->nested_policy, @@ -349,8 +333,47 @@ send_attribute: if (nla_put_u32(skb, NL_POLICY_TYPE_ATTR_TYPE, type)) goto nla_put_failure; - /* finish and move state to next attribute */ nla_nest_end(skb, attr); + return 0; +nla_put_failure: + nla_nest_cancel(skb, attr); + return -ENOBUFS; +} + +/** + * netlink_policy_dump_write - write current policy dump attributes + * @skb: the message skb to write to + * @state: the policy dump state + * + * Returns: 0 on success, an error code otherwise + */ +int netlink_policy_dump_write(struct sk_buff *skb, + struct netlink_policy_dump_state *state) +{ + const struct nla_policy *pt; + struct nlattr *policy; + bool again; + int err; + +send_attribute: + again = false; + + pt = &state->policies[state->policy_idx].policy[state->attr_idx]; + + policy = nla_nest_start(skb, state->policy_idx); + if (!policy) + return -ENOBUFS; + + err = __netlink_policy_dump_write_attr(state, skb, pt, state->attr_idx); + if (err == -ENODATA) { + nla_nest_cancel(skb, policy); + again = true; + goto next; + } else if (err) { + goto nla_put_failure; + } + + /* finish and move state to next attribute */ nla_nest_end(skb, policy); next: -- cgit v1.2.3