From ba8de796baf4bdc03530774fb284fe3c97875566 Mon Sep 17 00:00:00 2001 From: Yan Zhai Date: Mon, 17 Jun 2024 11:09:09 -0700 Subject: net: introduce sk_skb_reason_drop function Long used destructors kfree_skb and kfree_skb_reason do not pass receiving socket to packet drop tracepoints trace_kfree_skb. This makes it hard to track packet drops of a certain netns (container) or a socket (user application). The naming of these destructors are also not consistent with most sk/skb operating functions, i.e. functions named "sk_xxx" or "skb_xxx". Introduce a new functions sk_skb_reason_drop as drop-in replacement for kfree_skb_reason on local receiving path. Callers can now pass receiving sockets to the tracepoints. kfree_skb and kfree_skb_reason are still usable but they are now just inline helpers that call sk_skb_reason_drop. Note it is not feasible to do the same to consume_skb. Packets not dropped can flow through multiple receive handlers, and have multiple receiving sockets. Leave it untouched for now. Suggested-by: Eric Dumazet Signed-off-by: Yan Zhai Acked-by: Jesper Dangaard Brouer Signed-off-by: David S. Miller --- net/core/skbuff.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) (limited to 'net') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 8973db4eabd4..2315c088e91d 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1190,7 +1190,8 @@ void __kfree_skb(struct sk_buff *skb) EXPORT_SYMBOL(__kfree_skb); static __always_inline -bool __kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) +bool __sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb, + enum skb_drop_reason reason) { if (unlikely(!skb_unref(skb))) return false; @@ -1203,26 +1204,27 @@ 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, NULL); + trace_kfree_skb(skb, __builtin_return_address(0), reason, sk); return true; } /** - * kfree_skb_reason - free an sk_buff with special reason + * sk_skb_reason_drop - free an sk_buff with special reason + * @sk: the socket to receive @skb, or NULL if not applicable * @skb: buffer to free * @reason: reason why this skb is dropped * - * Drop a reference to the buffer and free it if the usage count has - * hit zero. Meanwhile, pass the drop reason to 'kfree_skb' - * tracepoint. + * Drop a reference to the buffer and free it if the usage count has hit + * zero. Meanwhile, pass the receiving socket and drop reason to + * 'kfree_skb' tracepoint. */ void __fix_address -kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason) +sk_skb_reason_drop(struct sock *sk, struct sk_buff *skb, enum skb_drop_reason reason) { - if (__kfree_skb_reason(skb, reason)) + if (__sk_skb_reason_drop(sk, skb, reason)) __kfree_skb(skb); } -EXPORT_SYMBOL(kfree_skb_reason); +EXPORT_SYMBOL(sk_skb_reason_drop); #define KFREE_SKB_BULK_SIZE 16 @@ -1261,7 +1263,7 @@ kfree_skb_list_reason(struct sk_buff *segs, enum skb_drop_reason reason) while (segs) { struct sk_buff *next = segs->next; - if (__kfree_skb_reason(segs, reason)) { + if (__sk_skb_reason_drop(NULL, segs, reason)) { skb_poison_list(segs); kfree_skb_add_bulk(segs, &sa, reason); } -- cgit v1.2.3-58-ga151