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Message-Id: <20171218161656.40618-3-lorenzo@google.com>
Date: Tue, 19 Dec 2017 01:16:54 +0900
From: Lorenzo Colitti <lorenzo@...gle.com>
To: netdev@...r.kernel.org
Cc: steffen.klassert@...unet.com, subashab@...eaurora.org,
nharold@...gle.com, Lorenzo Colitti <lorenzo@...gle.com>
Subject: [RFC ipsec-next 2/4] net: xfrm: find VTI interfaces from xfrm_input
Currently, the VTI input path works by first looking up the VTI
by its IP addresses, then setting the tunnel pointer in the
XFRM_TUNNEL_SKB_CB, and then having xfrm_input override the mark
with the mark in the tunnel.
This patch changes the order so that the tunnel is found by a
callback from xfrm_input. Each tunnel type (currently only ip_vti
and ip6_vti) implements a lookup function pointer that finds the
tunnel and sets it in the CB, and also does a state lookup.
This has the advantage that much more information is available to
the tunnel lookup function, including the looked-up XFRM state.
This will be used in a future change to allow finding the tunnel
not just from the IP addresses, but also from the xfrm lookup.
The lookup function pointer occupies the same space in the
XFRM_TUNNEL_SKB_CB as the IPv4/IPv6 tunnel pointer. The semantics
of the field are:
- When not running a handler that uses tunnels: always null.
- At the beginning of xfrm_input: lookup function pointer.
- After xfrm_input calls the lookup function: tunnel if found,
else null.
Signed-off-by: Lorenzo Colitti <lorenzo@...gle.com>
---
include/net/xfrm.h | 2 ++
net/ipv4/ip_vti.c | 43 ++++++++++++++++++++++++++++++++++++----
net/ipv6/ip6_vti.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-----
net/ipv6/xfrm6_input.c | 1 -
net/xfrm/xfrm_input.c | 34 +++++++++++++++++++-------------
5 files changed, 109 insertions(+), 24 deletions(-)
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 9d3b7c0ac6e2..3d245f2f6f6c 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -653,6 +653,8 @@ struct xfrm_tunnel_skb_cb {
} header;
union {
+ int (*lookup)(struct sk_buff *skb, int nexthdr, __be32 spi,
+ __be32 seq, struct xfrm_state **x);
struct ip_tunnel *ip4;
struct ip6_tnl *ip6;
} tunnel;
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 949f432a5f04..850625598187 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -49,8 +49,8 @@ static struct rtnl_link_ops vti_link_ops __read_mostly;
static unsigned int vti_net_id __read_mostly;
static int vti_tunnel_init(struct net_device *dev);
-static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
- int encap_type)
+static struct ip_tunnel *
+vti4_find_tunnel(struct sk_buff *skb, __be32 spi, struct xfrm_state **x)
{
struct ip_tunnel *tunnel;
const struct iphdr *iph = ip_hdr(skb);
@@ -59,19 +59,52 @@ static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
iph->saddr, iph->daddr, 0);
+ if (tunnel) {
+ *x = xfrm_state_lookup(net, be32_to_cpu(tunnel->parms.i_key),
+ (xfrm_address_t *)&iph->daddr,
+ spi, iph->protocol, AF_INET);
+ }
+
+ return tunnel;
+}
+
+static int vti_lookup(struct sk_buff *skb, int nexthdr, __be32 spi, __be32 seq,
+ struct xfrm_state **x)
+{
+ struct net *net = dev_net(skb->dev);
+ struct ip_tunnel *tunnel;
+
+ tunnel = vti4_find_tunnel(skb, spi, x);
if (tunnel) {
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
goto drop;
+ if (!*x) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
+ xfrm_audit_state_notfound(skb, AF_INET, spi, seq);
+ tunnel->dev->stats.rx_errors++;
+ tunnel->dev->stats.rx_dropped++;
+ goto drop;
+ }
+
XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
- return xfrm_input(skb, nexthdr, spi, encap_type);
+ return 0;
}
return -EINVAL;
drop:
+ if (*x)
+ xfrm_state_put(*x);
kfree_skb(skb);
- return 0;
+ return -ESRCH;
+}
+
+static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
+ int encap_type)
+{
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.lookup = vti_lookup;
+ return xfrm_input(skb, nexthdr, spi, encap_type);
}
static int vti_rcv(struct sk_buff *skb)
@@ -93,6 +126,8 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
u32 orig_mark = skb->mark;
int ret;
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
+
if (!tunnel)
return 1;
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index dbb74f3c57a7..d0676f2f99eb 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -297,13 +297,33 @@ static void vti6_dev_uninit(struct net_device *dev)
dev_put(dev);
}
-static int vti6_rcv(struct sk_buff *skb)
+static struct ip6_tnl *
+vti6_find_tunnel(struct sk_buff *skb, __be32 spi, struct xfrm_state **x)
{
+ const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ struct net *net = dev_net(skb->dev);
struct ip6_tnl *t;
+
+ t = vti6_tnl_lookup(net, &ipv6h->saddr, &ipv6h->daddr);
+ if (t) {
+ *x = xfrm_state_lookup(net, be32_to_cpu(t->parms.i_key),
+ (xfrm_address_t *)&ipv6h->daddr,
+ spi, ipv6h->nexthdr, AF_INET6);
+ }
+
+ return t;
+}
+
+int
+vti6_lookup(struct sk_buff *skb, int nexthdr, __be32 spi, __be32 seq,
+ struct xfrm_state **x)
+{
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ struct net *net = dev_net(skb->dev);
+ struct ip6_tnl *t;
rcu_read_lock();
- t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
+ t = vti6_find_tunnel(skb, spi, x);
if (t) {
if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) {
rcu_read_unlock();
@@ -312,7 +332,7 @@ static int vti6_rcv(struct sk_buff *skb)
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
rcu_read_unlock();
- return 0;
+ goto discard;
}
if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
@@ -321,15 +341,36 @@ static int vti6_rcv(struct sk_buff *skb)
goto discard;
}
+ if (!*x) {
+ XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
+ xfrm_audit_state_notfound(skb, AF_INET6, spi, seq);
+ t->dev->stats.rx_errors++;
+ t->dev->stats.rx_dropped++;
+ rcu_read_unlock();
+ goto discard;
+ }
+
rcu_read_unlock();
- return xfrm6_rcv_tnl(skb, t);
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
+
+ return 0;
}
rcu_read_unlock();
return -EINVAL;
discard:
+ if (*x)
+ xfrm_state_put(*x);
kfree_skb(skb);
- return 0;
+ return -ESRCH;
+}
+
+static int vti6_rcv(struct sk_buff *skb)
+{
+ int nexthdr = skb_network_header(skb)[IP6CB(skb)->nhoff];
+
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.lookup = vti6_lookup;
+ return xfrm6_rcv_spi(skb, nexthdr, 0, NULL);
}
static int vti6_rcv_cb(struct sk_buff *skb, int err)
@@ -343,6 +384,8 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
u32 orig_mark = skb->mark;
int ret;
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
+
if (!t)
return 1;
diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c
index fe04e23af986..6d1b734fef8d 100644
--- a/net/ipv6/xfrm6_input.c
+++ b/net/ipv6/xfrm6_input.c
@@ -25,7 +25,6 @@ int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb)
int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi,
struct ip6_tnl *t)
{
- XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
XFRM_SPI_SKB_CB(skb)->family = AF_INET6;
XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr);
return xfrm_input(skb, nexthdr, spi, 0);
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index ac277b97e0d7..7b54f58454ee 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -267,18 +267,6 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
family = XFRM_SPI_SKB_CB(skb)->family;
- /* if tunnel is present override skb->mark value with tunnel i_key */
- switch (family) {
- case AF_INET:
- if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4)
- mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4->parms.i_key);
- break;
- case AF_INET6:
- if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6)
- mark = be32_to_cpu(XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6->parms.i_key);
- break;
- }
-
err = secpath_set(skb);
if (err) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMINERROR);
@@ -293,14 +281,29 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
daddr = (xfrm_address_t *)(skb_network_header(skb) +
XFRM_SPI_SKB_CB(skb)->daddroff);
+
+ if (XFRM_TUNNEL_SKB_CB(skb)->tunnel.lookup) {
+ err = XFRM_TUNNEL_SKB_CB(skb)->tunnel.lookup(skb, nexthdr,
+ spi, seq, &x);
+ if (err) {
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.lookup = NULL;
+ return err;
+ }
+ }
+
do {
if (skb->sp->len == XFRM_MAX_DEPTH) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMINBUFFERERROR);
+ if (x)
+ xfrm_state_put(x);
goto drop;
}
- x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr, family);
- if (x == NULL) {
+ if (!x)
+ x = xfrm_state_lookup(net, mark, daddr, spi, nexthdr,
+ family);
+
+ if (!x) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMINNOSTATES);
xfrm_audit_state_notfound(skb, family, spi, seq);
goto drop;
@@ -420,6 +423,9 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
goto drop;
}
+
+ if (!err)
+ x = NULL;
} while (!err);
err = xfrm_rcv_cb(skb, family, x->type->proto, 0);
--
2.15.1.504.g5279b80103-goog
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