From: menglong8.dong@gmail.com
To: kuba@kernel.org
Cc: nhorman@tuxdriver.com, davem@davemloft.net,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
dsahern@kernel.org, rostedt@goodmis.org,
Menglong Dong <imagedong@tencent.com>
Subject: [PATCH v3 net-next] net: drop_monitor: support drop reason
Date: Thu, 27 Jan 2022 11:33:56 +0800 [thread overview]
Message-ID: <20220127033356.4050072-1-imagedong@tencent.com> (raw)
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>
---
v3:
- referring to cb->reason and cb->pc directly in
net_dm_packet_report_fill()
v2:
- get a pointer to struct net_dm_skb_cb instead of local var for
each field
---
include/uapi/linux/net_dropmon.h | 1 +
net/core/drop_monitor.c | 16 ++++++++++++----
2 files changed, 13 insertions(+), 4 deletions(-)
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..11448110f65d 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]))
@@ -498,6 +499,7 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
{
ktime_t tstamp = ktime_get_real();
struct per_cpu_dm_data *data;
+ struct net_dm_skb_cb *cb;
struct sk_buff *nskb;
unsigned long flags;
@@ -508,7 +510,9 @@ static void net_dm_packet_trace_kfree_skb_hit(void *ignore,
if (!nskb)
return;
- NET_DM_SKB_CB(nskb)->pc = location;
+ cb = NET_DM_SKB_CB(nskb);
+ cb->reason = reason;
+ cb->pc = location;
/* Override the timestamp because we care about the time when the
* packet was dropped.
*/
@@ -606,7 +610,7 @@ 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)
{
- u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc;
+ struct net_dm_skb_cb *cb = NET_DM_SKB_CB(skb);
char buf[NET_DM_MAX_SYMBOL_LEN];
struct nlattr *attr;
void *hdr;
@@ -620,10 +624,14 @@ static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb,
if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW))
goto nla_put_failure;
- if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD))
+ if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, (u64)(uintptr_t)cb->pc,
+ NET_DM_ATTR_PAD))
goto nla_put_failure;
- snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc);
+ if (nla_put_u32(msg, NET_DM_ATTR_REASON, cb->reason))
+ goto nla_put_failure;
+
+ snprintf(buf, sizeof(buf), "%pS", cb->pc);
if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf))
goto nla_put_failure;
--
2.34.1
next reply other threads:[~2022-01-27 3:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-27 3:33 menglong8.dong [this message]
2022-01-27 15:53 ` [PATCH v3 net-next] net: drop_monitor: support drop reason David Ahern
2022-01-27 16:02 ` Ido Schimmel
2022-01-28 2:56 ` Menglong Dong
2022-02-15 0:48 ` Cong Wang
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