[PATCH net-next v2 07/12] net: vxlan: add skb drop reasons to vxlan_rcv()
From: Menglong Dong
Date: Thu Aug 29 2024 - 22:04:32 EST
Introduce skb drop reasons to the function vxlan_rcv(). Following new
vxlan drop reasons are added:
VXLAN_DROP_INVALID_HDR
VXLAN_DROP_VNI_NOT_FOUND
And Following core skb drop reason is added:
SKB_DROP_REASON_IP_TUNNEL_ECN
Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
---
v2:
- rename the drop reasons, as Ido advised.
- document the drop reasons
---
drivers/net/vxlan/drop.h | 10 ++++++++++
drivers/net/vxlan/vxlan_core.c | 35 +++++++++++++++++++++++++---------
include/net/dropreason-core.h | 6 ++++++
3 files changed, 42 insertions(+), 9 deletions(-)
diff --git a/drivers/net/vxlan/drop.h b/drivers/net/vxlan/drop.h
index 876b4a9de92f..416532633881 100644
--- a/drivers/net/vxlan/drop.h
+++ b/drivers/net/vxlan/drop.h
@@ -11,6 +11,8 @@
#define VXLAN_DROP_REASONS(R) \
R(VXLAN_DROP_INVALID_SMAC) \
R(VXLAN_DROP_ENTRY_EXISTS) \
+ R(VXLAN_DROP_INVALID_HDR) \
+ R(VXLAN_DROP_VNI_NOT_FOUND) \
/* deliberate comment for trailing \ */
enum vxlan_drop_reason {
@@ -23,6 +25,14 @@ enum vxlan_drop_reason {
* one pointing to a nexthop
*/
VXLAN_DROP_ENTRY_EXISTS,
+ /**
+ * @VXLAN_DROP_INVALID_HDR: the vxlan header is invalid, such as:
+ * 1) the reserved fields are not zero
+ * 2) the "I" flag is not set
+ */
+ VXLAN_DROP_INVALID_HDR,
+ /** @VXLAN_DROP_VNI_NOT_FOUND: no vxlan device found for the vni */
+ VXLAN_DROP_VNI_NOT_FOUND,
};
static inline void
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 58c175432a15..ab1c14a807f2 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1674,13 +1674,15 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
struct vxlan_metadata _md;
struct vxlan_metadata *md = &_md;
__be16 protocol = htons(ETH_P_TEB);
+ enum skb_drop_reason reason;
bool raw_proto = false;
void *oiph;
__be32 vni = 0;
int nh;
/* Need UDP and VXLAN header to be present */
- if (!pskb_may_pull(skb, VXLAN_HLEN))
+ reason = pskb_may_pull_reason(skb, VXLAN_HLEN);
+ if (reason)
goto drop;
unparsed = *vxlan_hdr(skb);
@@ -1689,6 +1691,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
netdev_dbg(skb->dev, "invalid vxlan flags=%#x vni=%#x\n",
ntohl(vxlan_hdr(skb)->vx_flags),
ntohl(vxlan_hdr(skb)->vx_vni));
+ reason = (u32)VXLAN_DROP_INVALID_HDR;
/* Return non vxlan pkt */
goto drop;
}
@@ -1702,8 +1705,10 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
vni = vxlan_vni(vxlan_hdr(skb)->vx_vni);
vxlan = vxlan_vs_find_vni(vs, skb->dev->ifindex, vni, &vninode);
- if (!vxlan)
+ if (!vxlan) {
+ reason = (u32)VXLAN_DROP_VNI_NOT_FOUND;
goto drop;
+ }
/* For backwards compatibility, only allow reserved fields to be
* used by VXLAN extensions if explicitly requested.
@@ -1716,12 +1721,16 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
}
if (__iptunnel_pull_header(skb, VXLAN_HLEN, protocol, raw_proto,
- !net_eq(vxlan->net, dev_net(vxlan->dev))))
+ !net_eq(vxlan->net, dev_net(vxlan->dev)))) {
+ reason = SKB_DROP_REASON_NOMEM;
goto drop;
+ }
- if (vs->flags & VXLAN_F_REMCSUM_RX)
- if (unlikely(!vxlan_remcsum(&unparsed, skb, vs->flags)))
+ if (vs->flags & VXLAN_F_REMCSUM_RX) {
+ reason = vxlan_remcsum(&unparsed, skb, vs->flags);
+ if (unlikely(reason))
goto drop;
+ }
if (vxlan_collect_metadata(vs)) {
IP_TUNNEL_DECLARE_FLAGS(flags) = { };
@@ -1731,8 +1740,10 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
tun_dst = udp_tun_rx_dst(skb, vxlan_get_sk_family(vs), flags,
key32_to_tunnel_id(vni), sizeof(*md));
- if (!tun_dst)
+ if (!tun_dst) {
+ reason = SKB_DROP_REASON_NOMEM;
goto drop;
+ }
md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
@@ -1756,11 +1767,13 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
* is more robust and provides a little more security in
* adding extensions to VXLAN.
*/
+ reason = (u32)VXLAN_DROP_INVALID_HDR;
goto drop;
}
if (!raw_proto) {
- if (!vxlan_set_mac(vxlan, vs, skb, vni))
+ reason = vxlan_set_mac(vxlan, vs, skb, vni);
+ if (reason)
goto drop;
} else {
skb_reset_mac_header(skb);
@@ -1776,7 +1789,8 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
skb_reset_network_header(skb);
- if (!pskb_inet_may_pull(skb)) {
+ reason = pskb_inet_may_pull_reason(skb);
+ if (reason) {
DEV_STATS_INC(vxlan->dev, rx_length_errors);
DEV_STATS_INC(vxlan->dev, rx_errors);
vxlan_vnifilter_count(vxlan, vni, vninode,
@@ -1788,6 +1802,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
oiph = skb->head + nh;
if (!vxlan_ecn_decapsulate(vs, oiph, skb)) {
+ reason = SKB_DROP_REASON_IP_TUNNEL_ECN;
DEV_STATS_INC(vxlan->dev, rx_frame_errors);
DEV_STATS_INC(vxlan->dev, rx_errors);
vxlan_vnifilter_count(vxlan, vni, vninode,
@@ -1802,6 +1817,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
dev_core_stats_rx_dropped_inc(vxlan->dev);
vxlan_vnifilter_count(vxlan, vni, vninode,
VXLAN_VNI_STATS_RX_DROPS, 0);
+ reason = SKB_DROP_REASON_DEV_READY;
goto drop;
}
@@ -1814,8 +1830,9 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
return 0;
drop:
+ reason = reason ?: SKB_DROP_REASON_NOT_SPECIFIED;
/* Consume bad packet */
- kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
return 0;
}
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 4748680e8c88..d38371f33e2b 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -92,6 +92,7 @@
FN(PACKET_SOCK_ERROR) \
FN(TC_CHAIN_NOTFOUND) \
FN(TC_RECLASSIFY_LOOP) \
+ FN(IP_TUNNEL_ECN) \
FNe(MAX)
/**
@@ -418,6 +419,11 @@ enum skb_drop_reason {
* iterations.
*/
SKB_DROP_REASON_TC_RECLASSIFY_LOOP,
+ /**
+ * @SKB_DROP_REASON_IP_TUNNEL_ECN: skb is dropped according to
+ * RFC 6040 4.2, see __INET_ECN_decapsulate() for detail.
+ */
+ SKB_DROP_REASON_IP_TUNNEL_ECN,
/**
* @SKB_DROP_REASON_MAX: the maximum of core drop reasons, which
* shouldn't be used as a real 'reason' - only for tracing code gen
--
2.39.2