net: ipv4: use kfree_skb_reason() in ip_rcv_core()

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@tencent.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Menglong Dong 2022-02-05 15:47:35 +08:00 committed by David S. Miller
parent 2df3041ba3
commit 33cba42985
3 changed files with 22 additions and 2 deletions

View File

@ -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,
};

View File

@ -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

View File

@ -436,13 +436,16 @@ 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;
/* 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);
@ -452,6 +455,7 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
goto out;
}
drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto inhdr_error;
@ -488,6 +492,7 @@ 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 +521,14 @@ 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:
if (drop_reason == SKB_DROP_REASON_NOT_SPECIFIED)
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;
}