[RFC v3 net-next 1/7] net: add rx_sk to trace_kfree_skb
From: Yan Zhai <hidden>
Date: 2024-06-04 21:47:42
Also in:
lkml, netdev
Subsystem:
network drop monitor, networking [general], the rest, tracing · Maintainers:
Neil Horman, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
skb does not include enough information to find out receiving sockets/services and netns/containers on packet drops. In theory skb->dev tells about netns, but it can get cleared/reused, e.g. by TCP stack for OOO packet lookup. Similarly, skb->sk often identifies a local sender, and tells nothing about a receiver. Allow passing an extra receiving socket to the tracepoint to improve the visibility on receiving drops. Signed-off-by: Yan Zhai <redacted> --- v2->v3: fixed drop_monitor function prototype --- include/trace/events/skb.h | 11 +++++++---- net/core/dev.c | 2 +- net/core/drop_monitor.c | 9 ++++++--- net/core/skbuff.c | 2 +- 4 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index 07e0715628ec..aa6b46b6172c 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h@@ -24,15 +24,16 @@ DEFINE_DROP_REASON(FN, FN) TRACE_EVENT(kfree_skb, TP_PROTO(struct sk_buff *skb, void *location, - enum skb_drop_reason reason), + enum skb_drop_reason reason, struct sock *rx_sk), - TP_ARGS(skb, location, reason), + TP_ARGS(skb, location, reason, rx_sk), TP_STRUCT__entry( __field(void *, skbaddr) __field(void *, location) __field(unsigned short, protocol) __field(enum skb_drop_reason, reason) + __field(void *, rx_skaddr) ), TP_fast_assign(
@@ -40,12 +41,14 @@ TRACE_EVENT(kfree_skb, __entry->location = location; __entry->protocol = ntohs(skb->protocol); __entry->reason = reason; + __entry->rx_skaddr = rx_sk; ), - TP_printk("skbaddr=%p protocol=%u location=%pS reason: %s", + TP_printk("skbaddr=%p protocol=%u location=%pS reason: %s rx_skaddr=%p", __entry->skbaddr, __entry->protocol, __entry->location, __print_symbolic(__entry->reason, - DEFINE_DROP_REASON(FN, FNe))) + DEFINE_DROP_REASON(FN, FNe)), + __entry->rx_skaddr) ); #undef FN
diff --git a/net/core/dev.c b/net/core/dev.c
index 85fe8138f3e4..7844227ecbfd 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -5233,7 +5233,7 @@ static __latent_entropy void net_tx_action(struct softirq_action *h) trace_consume_skb(skb, net_tx_action); else trace_kfree_skb(skb, net_tx_action, - get_kfree_skb_cb(skb)->reason); + get_kfree_skb_cb(skb)->reason, NULL); if (skb->fclone != SKB_FCLONE_UNAVAILABLE) __kfree_skb(skb);
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 430ed18f8584..2e0ae3328232 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c@@ -109,7 +109,8 @@ static u32 net_dm_queue_len = 1000; struct net_dm_alert_ops { void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb, void *location, - enum skb_drop_reason reason); + enum skb_drop_reason reason, + struct sock *rx_sk); void (*napi_poll_probe)(void *ignore, struct napi_struct *napi, int work, int budget); void (*work_item_func)(struct work_struct *work);
@@ -264,7 +265,8 @@ static void trace_drop_common(struct sk_buff *skb, void *location) static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location, - enum skb_drop_reason reason) + enum skb_drop_reason reason, + struct sock *rx_sk) { trace_drop_common(skb, location); }
@@ -491,7 +493,8 @@ static const struct net_dm_alert_ops net_dm_alert_summary_ops = { static void net_dm_packet_trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location, - enum skb_drop_reason reason) + enum skb_drop_reason reason, + struct sock *rx_sk) { ktime_t tstamp = ktime_get_real(); struct per_cpu_dm_data *data;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 466999a7515e..2854afdd713f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c@@ -1203,7 +1203,7 @@ bool __kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) if (reason == SKB_CONSUMED) trace_consume_skb(skb, __builtin_return_address(0)); else - trace_kfree_skb(skb, __builtin_return_address(0), reason); + trace_kfree_skb(skb, __builtin_return_address(0), reason, NULL); return true; }
--
2.30.2