* [PATCH net-next] net: drop_monitor: support drop reason
@ 2022-01-24 7:59 menglong8.dong
2022-01-26 3:38 ` Jakub Kicinski
0 siblings, 1 reply; 3+ messages in thread
From: menglong8.dong @ 2022-01-24 7:59 UTC (permalink / raw)
To: kuba
Cc: nhorman, davem, netdev, linux-kernel, dsahern, rostedt, Menglong Dong
From: Menglong Dong <imagedong@tencent.com>
In the commit c504e5c2f964 ("net: skb: introduce kfree_skb_reason()")
drop reason is introduced to the tracepoint of kfree_skb. Therefore,
drop_monitor is able to report the drop reason to users by netlink.
For now, the number of drop reason is passed to users ( seems it's
a little troublesome to pass the drop reason as string ). Therefore,
users can do some customized description of the reason.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
---
include/uapi/linux/net_dropmon.h | 1 +
net/core/drop_monitor.c | 6 ++++++
2 files changed, 7 insertions(+)
diff --git a/include/uapi/linux/net_dropmon.h b/include/uapi/linux/net_dropmon.h
index 66048cc5d7b3..b2815166dbc2 100644
--- a/include/uapi/linux/net_dropmon.h
+++ b/include/uapi/linux/net_dropmon.h
@@ -93,6 +93,7 @@ enum net_dm_attr {
NET_DM_ATTR_SW_DROPS, /* flag */
NET_DM_ATTR_HW_DROPS, /* flag */
NET_DM_ATTR_FLOW_ACTION_COOKIE, /* binary */
+ NET_DM_ATTR_REASON, /* u32 */
__NET_DM_ATTR_MAX,
NET_DM_ATTR_MAX = __NET_DM_ATTR_MAX - 1
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 7b288a121a41..4aed0e583770 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -126,6 +126,7 @@ struct net_dm_skb_cb {
struct devlink_trap_metadata *hw_metadata;
void *pc;
};
+ enum skb_drop_reason reason;
};
#define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0]))
@@ -508,6 +509,7 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
if (!nskb)
return;
+ NET_DM_SKB_CB(nskb)->reason = reason;
NET_DM_SKB_CB(nskb)->pc = location;
/* Override the timestamp because we care about the time when the
* packet was dropped.
@@ -606,6 +608,7 @@ static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
size_t payload_len)
{
+ enum skb_drop_reason reason = NET_DM_SKB_CB(skb)->reason;
u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
char buf[NET_DM_MAX_SYMBOL_LEN];
struct nlattr *attr;
@@ -623,6 +626,9 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
goto nla_put_failure;
+ if (nla_put_u32(msg, NET_DM_ATTR_REASON, reason))
+ goto nla_put_failure;
+
snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc);
if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
goto nla_put_failure;
--
2.27.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] net: drop_monitor: support drop reason
2022-01-24 7:59 [PATCH net-next] net: drop_monitor: support drop reason menglong8.dong
@ 2022-01-26 3:38 ` Jakub Kicinski
2022-01-26 3:38 ` Menglong Dong
0 siblings, 1 reply; 3+ messages in thread
From: Jakub Kicinski @ 2022-01-26 3:38 UTC (permalink / raw)
To: menglong8.dong
Cc: nhorman, davem, netdev, linux-kernel, dsahern, rostedt, Menglong Dong
On Mon, 24 Jan 2022 15:59:55 +0800 menglong8.dong@gmail.com wrote:
> @@ -606,6 +608,7 @@ static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
> static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
> size_t payload_len)
> {
> + enum skb_drop_reason reason = NET_DM_SKB_CB(skb)->reason;
> u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
nit: maybe it's better to get a pointer to struct net_dm_skb_cb here
instead of local var for each field?
> char buf[NET_DM_MAX_SYMBOL_LEN];
> struct nlattr *attr;
> @@ -623,6 +626,9 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
> if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
> goto nla_put_failure;
>
> + if (nla_put_u32(msg, NET_DM_ATTR_REASON, reason))
> + goto nla_put_failure;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net-next] net: drop_monitor: support drop reason
2022-01-26 3:38 ` Jakub Kicinski
@ 2022-01-26 3:38 ` Menglong Dong
0 siblings, 0 replies; 3+ messages in thread
From: Menglong Dong @ 2022-01-26 3:38 UTC (permalink / raw)
To: Jakub Kicinski
Cc: Neil Horman, David Miller, netdev, LKML, David Ahern,
Steven Rostedt, Menglong Dong
On Wed, Jan 26, 2022 at 11:38 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Mon, 24 Jan 2022 15:59:55 +0800 menglong8.dong@gmail.com wrote:
> > @@ -606,6 +608,7 @@ static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex,
> > static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
> > size_t payload_len)
> > {
> > + enum skb_drop_reason reason = NET_DM_SKB_CB(skb)->reason;
> > u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
>
> nit: maybe it's better to get a pointer to struct net_dm_skb_cb here
> instead of local var for each field?
Yeah, I think it's a good idea :/
>
> > char buf[NET_DM_MAX_SYMBOL_LEN];
> > struct nlattr *attr;
> > @@ -623,6 +626,9 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
> > if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
> > goto nla_put_failure;
> >
> > + if (nla_put_u32(msg, NET_DM_ATTR_REASON, reason))
> > + goto nla_put_failure;
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-01-26 3:43 UTC | newest]
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2022-01-24 7:59 [PATCH net-next] net: drop_monitor: support drop reason menglong8.dong
2022-01-26 3:38 ` Jakub Kicinski
2022-01-26 3:38 ` Menglong Dong
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