[PATCH (repost) net-next] sched: add extack for tfilter_notify

Hangbin Liu
2022-09-29T03:35:28Z

In commit 81c7288b170a ("sched: cls: enable verbose logging") Marcelo
made cls could log verbose info for offloading failures, which helps
improving Open vSwitch debuggability when using flower offloading.

It would also be helpful if "tc monitor" could log this message, as it
doesn't require vswitchd log level adjusment. Let's add the extack message
in tfilter_notify so the monitor program could receive the failures.
e.g.

# tc monitor
added chain dev enp3s0f1np1 parent ffff: chain 0
added filter dev enp3s0f1np1 ingress protocol all pref 49152 flower chain 0 handle 0x1
ct_state +trk+new
not_in_hw
action order 1: gact action drop
random type none pass val 0
index 1 ref 1 bind 1

Warning: mlx5_core: matching on ct_state +new isn't supported.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---

Rebase the patch to latest net-next as the previous could not
apply to net-next.

---
net/sched/cls_api.c | 45 ++++++++++++++++++++++++++++++---------------
1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 50566db45949..7994dfdbd312 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1816,13 +1816,15 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
struct tcf_proto *tp, struct tcf_block *block,
struct Qdisc *q, u32 parent, void *fh,
u32 portid, u32 seq, u16 flags, int event,
- bool terse_dump, bool rtnl_held)
+ bool terse_dump, bool rtnl_held,
+ struct netlink_ext_ack *extack)
{
struct tcmsg *tcm;
struct nlmsghdr *nlh;
unsigned char *b = skb_tail_pointer(skb);

- nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
+ nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm),
+ (extack && extack->_msg) ? flags | NLM_F_MULTI : flags);
if (!nlh)
goto out_nlmsg_trim;
tcm = nlmsg_data(nlh);
@@ -1857,6 +1859,18 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,
goto nla_put_failure;
}
nlh->nlmsg_len = skb_tail_pointer(skb) - b;
+
+ if (extack && extack->_msg) {
+ nlh = nlmsg_put(skb, portid, seq, NLMSG_DONE, 0, flags | NLM_F_ACK_TLVS);
+ if (!nlh)
+ goto out_nlmsg_trim;
+
+ if (nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ }
+
return skb->len;

out_nlmsg_trim:
@@ -1870,7 +1884,7 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,
struct nlmsghdr *n, struct tcf_proto *tp,
struct tcf_block *block, struct Qdisc *q,
u32 parent, void *fh, int event, bool unicast,
- bool rtnl_held)
+ bool rtnl_held, struct netlink_ext_ack *extack)
{
struct sk_buff *skb;
u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
@@ -1882,7 +1896,7 @@ static int tfilter_notify(struct net *net, struct sk_buff *oskb,

if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
n->nlmsg_seq, n->nlmsg_flags, event,
- false, rtnl_held) <= 0) {
+ false, rtnl_held, extack) <= 0) {
kfree_skb(skb);
return -EINVAL;
}
@@ -1911,7 +1925,7 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,

if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
- false, rtnl_held) <= 0) {
+ false, rtnl_held, extack) <= 0) {
NL_SET_ERR_MSG(extack, "Failed to build del event notification");
kfree_skb(skb);
return -EINVAL;
@@ -1937,14 +1951,15 @@ static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
struct tcf_block *block, struct Qdisc *q,
u32 parent, struct nlmsghdr *n,
- struct tcf_chain *chain, int event)
+ struct tcf_chain *chain, int event,
+ struct netlink_ext_ack *extack)
{
struct tcf_proto *tp;

for (tp = tcf_get_next_proto(chain, NULL);
tp; tp = tcf_get_next_proto(chain, tp))
- tfilter_notify(net, oskb, n, tp, block,
- q, parent, NULL, event, false, true);
+ tfilter_notify(net, oskb, n, tp, block, q, parent, NULL,
+ event, false, true, extack);
}

static void tfilter_put(struct tcf_proto *tp, void *fh)
@@ -2148,7 +2163,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
flags, extack);
if (err == 0) {
tfilter_notify(net, skb, n, tp, block, q, parent, fh,
- RTM_NEWTFILTER, false, rtnl_held);
+ RTM_NEWTFILTER, false, rtnl_held, extack);
tfilter_put(tp, fh);
/* q pointer is NULL for shared blocks */
if (q)
@@ -2276,7 +2291,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,

if (prio == 0) {
tfilter_notify_chain(net, skb, block, q, parent, n,
- chain, RTM_DELTFILTER);
+ chain, RTM_DELTFILTER, extack);
tcf_chain_flush(chain, rtnl_held);
err = 0;
goto errout;
@@ -2300,7 +2315,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,

tcf_proto_put(tp, rtnl_held, NULL);
tfilter_notify(net, skb, n, tp, block, q, parent, fh,
- RTM_DELTFILTER, false, rtnl_held);
+ RTM_DELTFILTER, false, rtnl_held, extack);
err = 0;
goto errout;
}
@@ -2444,7 +2459,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
err = -ENOENT;
} else {
err = tfilter_notify(net, skb, n, tp, block, q, parent,
- fh, RTM_NEWTFILTER, true, rtnl_held);
+ fh, RTM_NEWTFILTER, true, rtnl_held, extack);
if (err < 0)
NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
}
@@ -2482,7 +2497,7 @@ static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
n, NETLINK_CB(a->cb->skb).portid,
a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
- RTM_NEWTFILTER, a->terse_dump, true);
+ RTM_NEWTFILTER, a->terse_dump, true, NULL);
}

static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
@@ -2516,7 +2531,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
- RTM_NEWTFILTER, false, true) <= 0)
+ RTM_NEWTFILTER, false, true, NULL) <= 0)
goto errout;
cb->args[1] = 1;
}
@@ -2904,7 +2919,7 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
break;
case RTM_DELCHAIN:
tfilter_notify_chain(net, skb, block, q, parent, n,
- chain, RTM_DELTFILTER);
+ chain, RTM_DELTFILTER, extack);
/* Flush the chain first as the user requested chain removal. */
tcf_chain_flush(chain, true);
/* In case the chain was successfully deleted, put a reference
--
2.37.2