[PATCH net-next,v5 03/12] flow_offload: add flow action infrastructure

Pablo Neira Ayuso
2018-12-06T22:40:32Z

This new infrastructure defines the nic actions that you can perform
from existing network drivers. This infrastructure allows us to avoid a
direct dependency with the native software TC action representation.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
v5: rebase on top of net-next head.

include/net/flow_offload.h | 69 +++++++++++++++++++++++++++++++++++++++++++++-
include/net/pkt_cls.h | 2 ++
net/core/flow_offload.c | 14 ++++++++--
net/sched/cls_api.c | 17 ++++++++++++
net/sched/cls_flower.c | 7 +++--
5 files changed, 103 insertions(+), 6 deletions(-)

diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
index 461c66595763..dabc819b6cc9 100644
--- a/include/net/flow_offload.h
+++ b/include/net/flow_offload.h
@@ -100,11 +100,78 @@ void flow_rule_match_enc_keyid(const struct flow_rule *rule,
void flow_rule_match_enc_opts(const struct flow_rule *rule,
struct flow_match_enc_opts *out);

+enum flow_action_id {
+ FLOW_ACTION_ACCEPT = 0,
+ FLOW_ACTION_DROP,
+ FLOW_ACTION_TRAP,
+ FLOW_ACTION_GOTO,
+ FLOW_ACTION_REDIRECT,
+ FLOW_ACTION_MIRRED,
+ FLOW_ACTION_VLAN_PUSH,
+ FLOW_ACTION_VLAN_POP,
+ FLOW_ACTION_VLAN_MANGLE,
+ FLOW_ACTION_TUNNEL_ENCAP,
+ FLOW_ACTION_TUNNEL_DECAP,
+ FLOW_ACTION_MANGLE,
+ FLOW_ACTION_ADD,
+ FLOW_ACTION_CSUM,
+ FLOW_ACTION_MARK,
+};
+
+/* This is mirroring enum pedit_header_type definition for easy mapping between
+ * tc pedit action. Legacy TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK is mapped to
+ * FLOW_ACT_MANGLE_UNSPEC, which is supported by no driver.
+ */
+enum flow_action_mangle_base {
+ FLOW_ACT_MANGLE_UNSPEC = 0,
+ FLOW_ACT_MANGLE_HDR_TYPE_ETH,
+ FLOW_ACT_MANGLE_HDR_TYPE_IP4,
+ FLOW_ACT_MANGLE_HDR_TYPE_IP6,
+ FLOW_ACT_MANGLE_HDR_TYPE_TCP,
+ FLOW_ACT_MANGLE_HDR_TYPE_UDP,
+};
+
+struct flow_action_entry {
+ enum flow_action_id id;
+ union {
+ u32 chain_index; /* FLOW_ACTION_GOTO */
+ struct net_device *dev; /* FLOW_ACTION_REDIRECT */
+ struct { /* FLOW_ACTION_VLAN */
+ u16 vid;
+ __be16 proto;
+ u8 prio;
+ } vlan;
+ struct { /* FLOW_ACTION_PACKET_EDIT */
+ enum flow_action_mangle_base htype;
+ u32 offset;
+ u32 mask;
+ u32 val;
+ } mangle;
+ const struct ip_tunnel_info *tunnel; /* FLOW_ACTION_TUNNEL_ENCAP */
+ u32 csum_flags; /* FLOW_ACTION_CSUM */
+ u32 mark; /* FLOW_ACTION_MARK */
+ };
+};
+
+struct flow_action {
+ unsigned int num_entries;
+ struct flow_action_entry entries[0];
+};
+
+static inline bool flow_action_has_entries(const struct flow_action *action)
+{
+ return action->num_entries;
+}
+
+#define flow_action_for_each(__i, __act, __actions) \
+ for (__i = 0, __act = &(__actions)->entries[0]; __i < (__actions)->num_entries; __act = &(__actions)->entries[__i++])
+
struct flow_rule {
struct flow_match match;
+ struct flow_action action;
};

-struct flow_rule *flow_rule_alloc(void);
+struct flow_rule *flow_rule_alloc(unsigned int num_actions);

static inline bool flow_rule_match_key(const struct flow_rule *rule,
enum flow_dissector_key_id key)
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 359876ee32be..9ceac97e5eff 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -620,6 +620,8 @@ tcf_match_indev(struct sk_buff *skb, int ifindex)
}
#endif /* CONFIG_NET_CLS_IND */

+unsigned int tcf_exts_num_actions(struct tcf_exts *exts);
+
int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts,
enum tc_setup_type type, void *type_data, bool err_stop);

diff --git a/net/core/flow_offload.c b/net/core/flow_offload.c
index 2fbf6903d2f6..c3a00eac4804 100644
--- a/net/core/flow_offload.c
+++ b/net/core/flow_offload.c
@@ -3,9 +3,19 @@
#include <linux/slab.h>
#include <net/flow_offload.h>

-struct flow_rule *flow_rule_alloc(void)
+struct flow_rule *flow_rule_alloc(unsigned int num_actions)
{
- return kzalloc(sizeof(struct flow_rule), GFP_KERNEL);
+ struct flow_rule *rule;
+
+ rule = kzalloc(sizeof(struct flow_rule) +
+ sizeof(struct flow_action_entry) * num_actions,
+ GFP_KERNEL);
+ if (!rule)
+ return NULL;
+
+ rule->action.num_entries = num_actions;
+
+ return rule;
}
EXPORT_SYMBOL(flow_rule_alloc);

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index d92f44ac4c39..3a4d36072fd5 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -31,6 +31,7 @@
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
+#include <net/tc_act/tc_pedit.h>

extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];

@@ -2567,6 +2568,22 @@ int tc_setup_cb_call(struct tcf_block *block, struct tcf_exts *exts,
}
EXPORT_SYMBOL(tc_setup_cb_call);

+unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
+{
+ unsigned int num_acts = 0;
+ struct tc_action *act;
+ int i;
+
+ tcf_exts_for_each_action(i, act, exts) {
+ if (is_tcf_pedit(act))
+ num_acts += tcf_pedit_nkeys(act);
+ else
+ num_acts++;
+ }
+ return num_acts;
+}
+EXPORT_SYMBOL(tcf_exts_num_actions);
+
static __net_init int tcf_net_init(struct net *net)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index bd6c40fea627..89fcf01c04f9 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -382,7 +382,7 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
bool skip_sw = tc_skip_sw(f->flags);
int err;

- cls_flower.rule = flow_rule_alloc();
+ cls_flower.rule = flow_rule_alloc(tcf_exts_num_actions(&f->exts));
if (!cls_flower.rule)
return -ENOMEM;

@@ -1467,7 +1467,8 @@ static int fl_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb,
if (tc_skip_hw(f->flags))
continue;

- cls_flower.rule = flow_rule_alloc();
+ cls_flower.rule =
+ flow_rule_alloc(tcf_exts_num_actions(&f->exts));
if (!cls_flower.rule)
return -ENOMEM;

@@ -1506,7 +1507,7 @@ static int fl_hw_create_tmplt(struct tcf_chain *chain,
struct tcf_block *block = chain->block;
struct tcf_exts dummy_exts = { 0, };

- cls_flower.rule = flow_rule_alloc();
+ cls_flower.rule = flow_rule_alloc(0);
if (!cls_flower.rule)
return -ENOMEM;

--
2.11.0