[PATCH AUTOSEL 5.5 092/121] xfrm: add prep for esp beet mode offload

Sasha Levin
2020-04-11T23:35:32Z

From: Xin Long <lucien.xin@gmail.com>

[ Upstream commit 308491755f36c461ee67290af159fdba6be0169d ]

Like __xfrm_transport/mode_tunnel_prep(), this patch is to add
__xfrm_mode_beet_prep() to fix the transport_header for gso
segments, and reset skb mac_len, and pull skb data to the
proto inside esp.

This patch also fixes a panic, reported by ltp:

# modprobe esp4_offload
# runltp -f net_stress.ipsec_tcp

[ 2452.780511] kernel BUG at net/core/skbuff.c:109!
[ 2452.799851] Call Trace:
[ 2452.800298] <IRQ>
[ 2452.800705] skb_push.cold.98+0x14/0x20
[ 2452.801396] esp_xmit+0x17b/0x270 [esp4_offload]
[ 2452.802799] validate_xmit_xfrm+0x22f/0x2e0
[ 2452.804285] __dev_queue_xmit+0x589/0x910
[ 2452.806264] __neigh_update+0x3d7/0xa50
[ 2452.806958] arp_process+0x259/0x810
[ 2452.807589] arp_rcv+0x18a/0x1c

It was caused by the skb going to esp_xmit with a wrong transport
header.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/xfrm/xfrm_device.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
index 64486ad813411..0159de5ace90f 100644
--- a/net/xfrm/xfrm_device.c
+++ b/net/xfrm/xfrm_device.c
@@ -46,6 +46,25 @@ static void __xfrm_mode_tunnel_prep(struct xfrm_state *x, struct sk_buff *skb,
pskb_pull(skb, skb->mac_len + x->props.header_len);
}

+static void __xfrm_mode_beet_prep(struct xfrm_state *x, struct sk_buff *skb,
+ unsigned int hsize)
+{
+ struct xfrm_offload *xo = xfrm_offload(skb);
+ int phlen = 0;
+
+ if (xo->flags & XFRM_GSO_SEGMENT)
+ skb->transport_header = skb->network_header + hsize;
+
+ skb_reset_mac_len(skb);
+ if (x->sel.family != AF_INET6) {
+ phlen = IPV4_BEET_PHMAXLEN;
+ if (x->outer_mode.family == AF_INET6)
+ phlen += sizeof(struct ipv6hdr) - sizeof(struct iphdr);
+ }
+
+ pskb_pull(skb, skb->mac_len + hsize + (x->props.header_len - phlen));
+}
+
/* Adjust pointers into the packet when IPsec is done at layer2 */
static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
{
@@ -66,9 +85,16 @@ static void xfrm_outer_mode_prep(struct xfrm_state *x, struct sk_buff *skb)
return __xfrm_transport_prep(x, skb,
sizeof(struct ipv6hdr));
break;
+ case XFRM_MODE_BEET:
+ if (x->outer_mode.family == AF_INET)
+ return __xfrm_mode_beet_prep(x, skb,
+ sizeof(struct iphdr));
+ if (x->outer_mode.family == AF_INET6)
+ return __xfrm_mode_beet_prep(x, skb,
+ sizeof(struct ipv6hdr));
+ break;
case XFRM_MODE_ROUTEOPTIMIZATION:
case XFRM_MODE_IN_TRIGGER:
- case XFRM_MODE_BEET:
break;
}
}
--
2.20.1