From: Menglong Dong <imagedong@xxxxxxxxxxx>
Replace kfree_skb() with kfree_skb_reason() in ip_rcv_core(). Three new
drop reasons are introduced:
SKB_DROP_REASON_OTHERHOST
SKB_DROP_REASON_IP_CSUM
SKB_DROP_REASON_IP_INHDR
Signed-off-by: Menglong Dong <imagedong@xxxxxxxxxxx>
---
v3:
- add a path to SKB_DROP_REASON_PKT_TOO_SMALL
v2:
- remove unrelated cleanup
- add document for introduced drop reasons
---
include/linux/skbuff.h | 9 +++++++++
include/trace/events/skb.h | 3 +++
net/ipv4/ip_input.c | 12 ++++++++++--
3 files changed, 22 insertions(+), 2 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 786ea2c2334e..2e87da91424f 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -321,6 +321,15 @@ enum skb_drop_reason {
SKB_DROP_REASON_SOCKET_FILTER, /* dropped by socket filter */
SKB_DROP_REASON_UDP_CSUM, /* UDP checksum error */
SKB_DROP_REASON_NETFILTER_DROP, /* dropped by netfilter */
+ SKB_DROP_REASON_OTHERHOST, /* packet don't belong to current
+ * host (interface is in promisc
+ * mode)
+ */
+ SKB_DROP_REASON_IP_CSUM, /* IP checksum error */
+ SKB_DROP_REASON_IP_INHDR, /* there is something wrong with
+ * IP header (see
+ * IPSTATS_MIB_INHDRERRORS)
+ */
SKB_DROP_REASON_MAX,
};
diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h
index 3d89f7b09a43..f2b1778485f0 100644
--- a/include/trace/events/skb.h
+++ b/include/trace/events/skb.h
@@ -17,6 +17,9 @@
EM(SKB_DROP_REASON_SOCKET_FILTER, SOCKET_FILTER) \
EM(SKB_DROP_REASON_UDP_CSUM, UDP_CSUM) \
EM(SKB_DROP_REASON_NETFILTER_DROP, NETFILTER_DROP) \
+ EM(SKB_DROP_REASON_OTHERHOST, OTHERHOST) \
+ EM(SKB_DROP_REASON_IP_CSUM, IP_CSUM) \
+ EM(SKB_DROP_REASON_IP_INHDR, IP_INHDR) \
EMe(SKB_DROP_REASON_MAX, MAX)
#undef EM
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 3a025c011971..627fad437593 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -436,13 +436,18 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
{
const struct iphdr *iph;
+ int drop_reason;
u32 len;
+ drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
+
/* When the interface is in promisc. mode, drop all the crap
* that it receives, do not try to analyse it.
*/
- if (skb->pkt_type == PACKET_OTHERHOST)
+ if (skb->pkt_type == PACKET_OTHERHOST) {
+ drop_reason = SKB_DROP_REASON_OTHERHOST;
goto drop;
+ }
__IP_UPD_PO_STATS(net, IPSTATS_MIB_IN, skb->len);
@@ -488,6 +493,7 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
len = ntohs(iph->tot_len);
if (skb->len < len) {
+ drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
__IP_INC_STATS(net, IPSTATS_MIB_INTRUNCATEDPKTS);
goto drop;
} else if (len < (iph->ihl*4))
@@ -516,11 +522,13 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
return skb;
csum_error:
+ drop_reason = SKB_DROP_REASON_IP_CSUM;
__IP_INC_STATS(net, IPSTATS_MIB_CSUMERRORS);
inhdr_error:
+ drop_reason = drop_reason ?: SKB_DROP_REASON_IP_INHDR;
__IP_INC_STATS(net, IPSTATS_MIB_INHDRERRORS);
drop:
- kfree_skb(skb);
+ kfree_skb_reason(skb, drop_reason);
out:
return NULL;
}
--
2.34.1
