[PATCH v6 net-core] net-core
From: Jeffrey Ji <hidden>
Date: 2022-02-01 21:43:24
Also in:
lkml
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: jeffreyji <redacted>
Increment InMacErrors counter when packet dropped due to incorrect dest
MAC addr.
An example when this drop can occur is when manually crafting raw
packets that will be consumed by a user space application via a tap
device. For testing purposes local traffic was generated using trafgen
for the client and netcat to start a server
example output from nstat:
\~# nstat -a | grep InMac
Ip6InMacErrors 0 0.0
IpExtInMacErrors 1 0.0
Tested: Created 2 netns, sent 1 packet using trafgen from 1 to the other
with "{eth(daddr=$INCORRECT_MAC...}", verified that nstat showed the
counter was incremented.
changelog:
v6: rebase onto net-next
v5:
Change from SKB_DROP_REASON_BAD_DEST_MAC to SKB_DROP_REASON_OTHERHOST
v3-4:
Remove Change-Id
v2:
Use skb_free_reason() for tracing
Add real-life example in patch msg
Signed-off-by: jeffreyji <redacted>
---
include/linux/skbuff.h | 1 +
include/uapi/linux/snmp.h | 1 +
net/ipv4/ip_input.c | 7 +++++--
net/ipv4/proc.c | 1 +
net/ipv6/ip6_input.c | 12 +++++++-----
net/ipv6/proc.c | 1 +
6 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index a27bcc4f7e9a..1b1114f5c68e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h@@ -320,6 +320,7 @@ enum skb_drop_reason { SKB_DROP_REASON_TCP_CSUM, SKB_DROP_REASON_SOCKET_FILTER, SKB_DROP_REASON_UDP_CSUM, + SKB_DROP_REASON_OTHERHOST, SKB_DROP_REASON_MAX, };
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 904909d020e2..ac2fac12dd7d 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h@@ -57,6 +57,7 @@ enum IPSTATS_MIB_ECT0PKTS, /* InECT0Pkts */ IPSTATS_MIB_CEPKTS, /* InCEPkts */ IPSTATS_MIB_REASM_OVERLAPS, /* ReasmOverlaps */ + IPSTATS_MIB_INMACERRORS, /* InMacErrors */ __IPSTATS_MIB_MAX };
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 3a025c011971..780892526166 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c@@ -441,8 +441,11 @@ static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net) /* 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) - goto drop; + if (skb->pkt_type == PACKET_OTHERHOST) { + __IP_INC_STATS(net, IPSTATS_MIB_INMACERRORS); + kfree_skb_reason(skb, SKB_DROP_REASON_OTHERHOST); + return NULL; + } __IP_UPD_PO_STATS(net, IPSTATS_MIB_IN, skb->len);
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 28836071f0a6..2be4189197f3 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c@@ -117,6 +117,7 @@ static const struct snmp_mib snmp4_ipextstats_list[] = { SNMP_MIB_ITEM("InECT0Pkts", IPSTATS_MIB_ECT0PKTS), SNMP_MIB_ITEM("InCEPkts", IPSTATS_MIB_CEPKTS), SNMP_MIB_ITEM("ReasmOverlaps", IPSTATS_MIB_REASM_OVERLAPS), + SNMP_MIB_ITEM("InMacErrors", IPSTATS_MIB_INMACERRORS), SNMP_MIB_SENTINEL };
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 80256717868e..da18d9159647 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c@@ -149,15 +149,17 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, u32 pkt_len; struct inet6_dev *idev; - if (skb->pkt_type == PACKET_OTHERHOST) { - kfree_skb(skb); - return NULL; - } - rcu_read_lock(); idev = __in6_dev_get(skb->dev); + if (skb->pkt_type == PACKET_OTHERHOST) { + __IP6_INC_STATS(net, idev, IPSTATS_MIB_INMACERRORS); + rcu_read_unlock(); + kfree_skb_reason(skb, SKB_DROP_REASON_OTHERHOST); + return NULL; + } + __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len); if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index d6306aa46bb1..76e6119ba558 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c@@ -84,6 +84,7 @@ static const struct snmp_mib snmp6_ipstats_list[] = { SNMP_MIB_ITEM("Ip6InECT1Pkts", IPSTATS_MIB_ECT1PKTS), SNMP_MIB_ITEM("Ip6InECT0Pkts", IPSTATS_MIB_ECT0PKTS), SNMP_MIB_ITEM("Ip6InCEPkts", IPSTATS_MIB_CEPKTS), + SNMP_MIB_ITEM("Ip6InMacErrors", IPSTATS_MIB_INMACERRORS), SNMP_MIB_SENTINEL };
--
2.35.0.rc2.247.g8bbb082509-goog