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Message-Id: <20061206203537.2e5ba9ec.kazunori@miyazawa.org>
Date: Wed, 6 Dec 2006 20:35:37 +0900
From: Kazunori MIYAZAWA <kazunori@...azawa.org>
To: Kazunori MIYAZAWA <kazunori@...azawa.org>
Cc: davem@...emloft.net, miika@....fi, Diego.Beltrami@...t.fi,
herbert@...dor.apana.org.au, netdev@...r.kernel.org,
usagi-core@...ux-ipv6.org
Subject: Re: [PATCH][IPSEC][4/7] inter address family ipsec tunnel
On Fri, 01 Dec 2006 13:41:39 +0900
Kazunori MIYAZAWA <kazunori@...azawa.org> wrote:
> David Miller wrote:
> > From: Kazunori MIYAZAWA <kazunori@...azawa.org>
> > Date: Fri, 24 Nov 2006 14:38:39 +0900
> >
> > What is going on here?
> >
> >> + /* Without this, the atomic inc below segfaults */
> >> + if (encap_family == AF_INET6) {
> >> + rt->peer = NULL;
> >> + rt_bind_peer(rt,1);
> >> + }
> > ...
> >> - dst_prev->output = xfrm4_output;
> >> + if (dst_prev->xfrm->props.family == AF_INET)
> >> + dst_prev->output = xfrm4_output;
> >> +#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
> >> + else
> >> + dst_prev->output = xfrm6_output;
> >> +#endif
> >> if (rt->peer)
> >> atomic_inc(&rt->peer->refcnt);
> >
> > If it's non-NULL and you get a segfault for atomic_inc() that
> > means there is garbage here, and it seems that if you're
> > setting it to NULL explicitly then it's just a workaround
> > for whatever problem is causing it to be non-NULL to begin
> > with.
> >
> > What is putting a non-valid pointer value there? Is this an IPV6 or
> > IPSEC dst route by chance? If so, that makes this change really
> > wrong, and we are corrupting the route by running rt_bind_peer() on
> > it. rt_bind_peer() is only valid on ipv4 route entries.
>
> Thank you for your good catch.
> I think atomic_inc must be done in case of props.family == AF_INET.
> And we probably should manage reference count of the device in case of
> AF_INET6.
>
> Anyway I'll check and fix it.
>
> Thank you.
>
Hello David,
Sorry, I mixed up changes in the patches. I described that [4/7] will add
"IPv6 over IPv4 IPsec tunnel". However I send a patch for "IPv4 over IPv6"
as a reply because it includes the discussing item.
So this patch adds IPv4 over IPv6 IPsec tunnel. It's complicated.
I deleted subustituting NULL for rt->peer and moved atomic_inc stuff
under the "if" section.
BTW, I have a question about descrementing the reference count of rt->peer.
The reference cound in normal "dst" structure is decremented by calling
inet_putpeer from ipv4_dst_destroy. But xfrm4_dst_destroy does not call inet_putpeer.
Where do we decrement the count? Should xfrm4_dst_destroy do that?
Signed-off-by: Miika Komu <miika@....fi>
Signed-off-by: Diego Beltrami <Diego.Beltrami@...t.fi>
Signed-off-by: Kazunori Miyazawa <miyazawa@...ux-ipv6.org>
---
net/ipv4/xfrm4_policy.c | 68 ++++++++++++++++++++++++++++++++----------
net/ipv6/xfrm6_mode_tunnel.c | 42 ++++++++++++++++++++------
2 files changed, 83 insertions(+), 27 deletions(-)
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index d4107bb..37b14e8 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -72,17 +72,20 @@ __xfrm4_bundle_create(struct xfrm_policy
struct dst_entry *dst, *dst_prev;
struct rtable *rt0 = (struct rtable*)(*dst_p);
struct rtable *rt = rt0;
- __be32 remote = fl->fl4_dst;
- __be32 local = fl->fl4_src;
struct flowi fl_tunnel = {
.nl_u = {
.ip4_u = {
- .saddr = local,
- .daddr = remote,
+ .saddr = fl->fl4_src,
+ .daddr = fl->fl4_dst,
.tos = fl->fl4_tos
}
}
};
+ union {
+ struct in6_addr *in6;
+ struct in_addr *in;
+ } remote, local;
+ unsigned short encap_family = 0;
int i;
int err;
int header_len = 0;
@@ -94,7 +97,6 @@ __xfrm4_bundle_create(struct xfrm_policy
for (i = 0; i < nx; i++) {
struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
struct xfrm_dst *xdst;
- int tunnel = 0;
if (unlikely(dst1 == NULL)) {
err = -ENOBUFS;
@@ -116,19 +118,45 @@ __xfrm4_bundle_create(struct xfrm_policy
dst1->next = dst_prev;
dst_prev = dst1;
- if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
- remote = xfrm[i]->id.daddr.a4;
- local = xfrm[i]->props.saddr.a4;
- tunnel = 1;
+
+ if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) {
+ encap_family = xfrm[i]->props.family;
+
+ switch(encap_family) {
+ case AF_INET:
+ remote.in = (struct in_addr*)&xfrm[i]->id.daddr;
+ local.in = (struct in_addr*)&xfrm[i]->props.saddr;
+ break;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+ case AF_INET6:
+ remote.in6 = (struct in6_addr*)&xfrm[i]->id.daddr;
+ local.in6 = (struct in6_addr*)&xfrm[i]->props.saddr;
+ break;
+#endif
+ default:
+ BUG_ON(1);
+ }
}
header_len += xfrm[i]->props.header_len;
trailer_len += xfrm[i]->props.trailer_len;
- if (tunnel) {
- fl_tunnel.fl4_src = local;
- fl_tunnel.fl4_dst = remote;
+ if (encap_family) {
+ switch(encap_family) {
+ case AF_INET:
+ fl_tunnel.fl4_dst = remote.in->s_addr;
+ fl_tunnel.fl4_src = local.in->s_addr;
+ break;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+ case AF_INET6:
+ ipv6_addr_copy(&fl_tunnel.fl6_dst, remote.in6);
+ ipv6_addr_copy(&fl_tunnel.fl6_src, local.in6);
+ break;
+#endif
+ default:
+ BUG_ON(1);
+ }
err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
- &fl_tunnel, AF_INET);
+ &fl_tunnel, encap_family);
if (err)
goto error;
} else
@@ -162,10 +190,16 @@ __xfrm4_bundle_create(struct xfrm_policy
/* Copy neighbout for reachability confirmation */
dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour);
dst_prev->input = rt->u.dst.input;
- dst_prev->output = xfrm4_output;
- if (rt->peer)
- atomic_inc(&rt->peer->refcnt);
- x->u.rt.peer = rt->peer;
+ if (dst_prev->xfrm->props.family == AF_INET) {
+ dst_prev->output = xfrm4_output;
+ if (rt->peer)
+ atomic_inc(&rt->peer->refcnt);
+ x->u.rt.peer = rt->peer;
+ }
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+ else
+ dst_prev->output = xfrm6_output;
+#endif
/* Sheit... I remember I did this right. Apparently,
* it was magically lost, so this code needs audit */
x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 5e7d8a7..51eb59d 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -25,6 +25,12 @@ static inline void ipip6_ecn_decapsulate
IP6_ECN_set_ce(inner_iph);
}
+static inline void ip6ip_ecn_decapsulate(struct sk_buff *skb)
+{
+ if (INET_ECN_is_ce(ipv6_get_dsfield(skb->nh.ipv6h)))
+ IP_ECN_set_ce(skb->h.ipiph);
+}
+
/* Add encapsulation header.
*
* The top IP header will be constructed per RFC 2401. The following fields
@@ -40,6 +46,7 @@ static inline void ipip6_ecn_decapsulate
static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
struct dst_entry *dst = skb->dst;
+ struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
struct ipv6hdr *iph, *top_iph;
int dsfield;
@@ -52,16 +59,24 @@ static int xfrm6_tunnel_output(struct xf
skb->h.ipv6h = top_iph + 1;
top_iph->version = 6;
- top_iph->priority = iph->priority;
- top_iph->flow_lbl[0] = iph->flow_lbl[0];
- top_iph->flow_lbl[1] = iph->flow_lbl[1];
- top_iph->flow_lbl[2] = iph->flow_lbl[2];
+ if (xdst->route->ops->family == AF_INET6) {
+ top_iph->priority = iph->priority;
+ top_iph->flow_lbl[0] = iph->flow_lbl[0];
+ top_iph->flow_lbl[1] = iph->flow_lbl[1];
+ top_iph->flow_lbl[2] = iph->flow_lbl[2];
+ top_iph->nexthdr = IPPROTO_IPV6;
+ } else {
+ top_iph->priority = 0;
+ top_iph->flow_lbl[0] = 0;
+ top_iph->flow_lbl[1] = 0;
+ top_iph->flow_lbl[2] = 0;
+ top_iph->nexthdr = IPPROTO_IPIP;
+ }
dsfield = ipv6_get_dsfield(top_iph);
dsfield = INET_ECN_encapsulate(dsfield, dsfield);
if (x->props.flags & XFRM_STATE_NOECN)
dsfield &= ~INET_ECN_MASK;
ipv6_change_dsfield(top_iph, 0, dsfield);
- top_iph->nexthdr = IPPROTO_IPV6;
top_iph->hop_limit = dst_metric(dst->child, RTAX_HOPLIMIT);
ipv6_addr_copy(&top_iph->saddr, (struct in6_addr *)&x->props.saddr);
ipv6_addr_copy(&top_iph->daddr, (struct in6_addr *)&x->id.daddr);
@@ -72,7 +87,8 @@ static int xfrm6_tunnel_input(struct xfr
{
int err = -EINVAL;
- if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6)
+ if (skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPV6
+ && skb->nh.raw[IP6CB(skb)->nhoff] != IPPROTO_IPIP)
goto out;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto out;
@@ -81,10 +97,16 @@ static int xfrm6_tunnel_input(struct xfr
(err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
goto out;
- if (x->props.flags & XFRM_STATE_DECAP_DSCP)
- ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
- if (!(x->props.flags & XFRM_STATE_NOECN))
- ipip6_ecn_decapsulate(skb);
+ if (skb->nh.raw[IP6CB(skb)->nhoff] == IPPROTO_IPV6) {
+ if (x->props.flags & XFRM_STATE_DECAP_DSCP)
+ ipv6_copy_dscp(skb->nh.ipv6h, skb->h.ipv6h);
+ if (!(x->props.flags & XFRM_STATE_NOECN))
+ ipip6_ecn_decapsulate(skb);
+ } else {
+ if (!(x->props.flags & XFRM_STATE_NOECN))
+ ip6ip_ecn_decapsulate(skb);
+ skb->protocol = htons(ETH_P_IP);
+ }
skb->mac.raw = memmove(skb->data - skb->mac_len,
skb->mac.raw, skb->mac_len);
skb->nh.raw = skb->data;
--
1.4.1
-
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