Only cls_bpf and act_bpf can safely use such value. If a generic
action is configured by user space to return TC_ACT_REDIRECT,
the usually visible behavior is passing the skb up the stack - as
for unknown action, but, with complex configuration, more random
results can be obtained.
This patch forcefully converts TC_ACT_REDIRECT to TC_ACT_LAST + 1
at action init time, making the kernel behavior more consistent.
Signed-off-by: Paolo Abeni <pab...@redhat.com>
---
include/uapi/linux/pkt_cls.h | 1 +
net/sched/act_api.c | 5 +++++
2 files changed, 6 insertions(+)
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index c4262d911596..7cdd62b51106 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -45,6 +45,7 @@ enum {
* the skb and act like everything
* is alright.
*/
+#define TC_ACT_LAST TC_ACT_TRAP
/* There is a special kind of actions called "extended actions",
* which need a value parameter. These have a local opcode located in
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 148a89ab789b..f6438f246dab 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -895,6 +895,11 @@ struct tc_action *tcf_action_init_1(struct net *net,
struct tcf_proto *tp,
}
}
+ if (a->tcfa_action == TC_ACT_REDIRECT) {
+ net_warn_ratelimited("TC_ACT_REDIRECT can't be used directly");
+ a->tcfa_action = TC_ACT_LAST + 1;
+ }
+
return a;
err_mod:
--
2.17.1
