[PATCH 4.19 81/95] vti4: eliminated some duplicate code.

From: Greg Kroah-Hartman
Date: Mon Jun 01 2020 - 14:06:58 EST


From: Jeremy Sowden <jeremy@xxxxxxxxxx>

commit f981c57ffd2d7cf2dd4b6d6f8fcb3965df42f54c upstream.

The ipip tunnel introduced in commit dd9ee3444014 ("vti4: Fix a ipip
packet processing bug in 'IPCOMP' virtual tunnel") largely duplicated
the existing vti_input and vti_recv functions. Refactored to
deduplicate the common code.

Signed-off-by: Jeremy Sowden <jeremy@xxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/ipv4/ip_vti.c | 60 +++++++++++++++++++-----------------------------------
1 file changed, 22 insertions(+), 38 deletions(-)

--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -50,7 +50,7 @@ static unsigned int vti_net_id __read_mo
static int vti_tunnel_init(struct net_device *dev);

static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
- int encap_type)
+ int encap_type, bool update_skb_dev)
{
struct ip_tunnel *tunnel;
const struct iphdr *iph = ip_hdr(skb);
@@ -65,6 +65,9 @@ static int vti_input(struct sk_buff *skb

XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;

+ if (update_skb_dev)
+ skb->dev = tunnel->dev;
+
return xfrm_input(skb, nexthdr, spi, encap_type);
}

@@ -74,47 +77,28 @@ drop:
return 0;
}

-static int vti_input_ipip(struct sk_buff *skb, int nexthdr, __be32 spi,
- int encap_type)
+static int vti_input_proto(struct sk_buff *skb, int nexthdr, __be32 spi,
+ int encap_type)
{
- struct ip_tunnel *tunnel;
- const struct iphdr *iph = ip_hdr(skb);
- struct net *net = dev_net(skb->dev);
- struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
-
- tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
- iph->saddr, iph->daddr, 0);
- if (tunnel) {
- if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
- goto drop;
-
- XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
-
- skb->dev = tunnel->dev;
-
- return xfrm_input(skb, nexthdr, spi, encap_type);
- }
-
- return -EINVAL;
-drop:
- kfree_skb(skb);
- return 0;
+ return vti_input(skb, nexthdr, spi, encap_type, false);
}

-static int vti_rcv(struct sk_buff *skb)
+static int vti_rcv(struct sk_buff *skb, __be32 spi, bool update_skb_dev)
{
XFRM_SPI_SKB_CB(skb)->family = AF_INET;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);

- return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
+ return vti_input(skb, ip_hdr(skb)->protocol, spi, 0, update_skb_dev);
}

-static int vti_rcv_ipip(struct sk_buff *skb)
+static int vti_rcv_proto(struct sk_buff *skb)
{
- XFRM_SPI_SKB_CB(skb)->family = AF_INET;
- XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
+ return vti_rcv(skb, 0, false);
+}

- return vti_input_ipip(skb, ip_hdr(skb)->protocol, ip_hdr(skb)->saddr, 0);
+static int vti_rcv_tunnel(struct sk_buff *skb)
+{
+ return vti_rcv(skb, ip_hdr(skb)->saddr, true);
}

static int vti_rcv_cb(struct sk_buff *skb, int err)
@@ -478,31 +462,31 @@ static void __net_init vti_fb_tunnel_ini
}

static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
- .handler = vti_rcv,
- .input_handler = vti_input,
+ .handler = vti_rcv_proto,
+ .input_handler = vti_input_proto,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};

static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
- .handler = vti_rcv,
- .input_handler = vti_input,
+ .handler = vti_rcv_proto,
+ .input_handler = vti_input_proto,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};

static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
- .handler = vti_rcv,
- .input_handler = vti_input,
+ .handler = vti_rcv_proto,
+ .input_handler = vti_input_proto,
.cb_handler = vti_rcv_cb,
.err_handler = vti4_err,
.priority = 100,
};

static struct xfrm_tunnel ipip_handler __read_mostly = {
- .handler = vti_rcv_ipip,
+ .handler = vti_rcv_tunnel,
.err_handler = vti4_err,
.priority = 0,
};