Same as ip_gre, use gre_parse_header to parse gre header in gre error
handler code.
Signed-off-by: Haishuang Yan <[email protected]>
---
net/ipv6/ip6_gre.c | 29 +++++++----------------------
1 file changed, 7 insertions(+), 22 deletions(-)
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 18a3794..505d891 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -427,35 +427,20 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
u8 type, u8 code, int offset, __be32 info)
{
struct net *net = dev_net(skb->dev);
- const struct gre_base_hdr *greh;
const struct ipv6hdr *ipv6h;
- int grehlen = sizeof(*greh);
+ struct tnl_ptk_info tpi;
+ bool csum_err = false;
struct ip6_tnl *t;
- int key_off = 0;
- __be16 flags;
- __be32 key;
- if (!pskb_may_pull(skb, offset + grehlen))
- return;
- greh = (const struct gre_base_hdr *)(skb->data + offset);
- flags = greh->flags;
- if (flags & (GRE_VERSION | GRE_ROUTING))
- return;
- if (flags & GRE_CSUM)
- grehlen += 4;
- if (flags & GRE_KEY) {
- key_off = grehlen + offset;
- grehlen += 4;
+ if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6),
+ offset) < 0) {
+ if (!csum_err) /* ignore csum errors. */
+ return;
}
- if (!pskb_may_pull(skb, offset + grehlen))
- return;
ipv6h = (const struct ipv6hdr *)skb->data;
- greh = (const struct gre_base_hdr *)(skb->data + offset);
- key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
-
t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
- key, greh->protocol);
+ tpi.key, tpi.proto);
if (!t)
return;
--
1.8.3.1
On Mon, 10 Sep 2018 16:25:09 +0800, Haishuang Yan wrote:
> + if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6),
> + offset) < 0) {
> + if (!csum_err) /* ignore csum errors. */
> + return;
> }
gre_parse_header stops parsing when csum_err is encountered. Which
means tpi.key is undefined...
>
> - if (!pskb_may_pull(skb, offset + grehlen))
> - return;
> ipv6h = (const struct ipv6hdr *)skb->data;
> - greh = (const struct gre_base_hdr *)(skb->data + offset);
> - key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
> -
> t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
> - key, greh->protocol);
> + tpi.key, tpi.proto);
...and can't be used here.
Jiri
> On 2018??9??10??, at ????11:36, Jiri Benc <[email protected]> wrote:
>
> On Mon, 10 Sep 2018 16:25:09 +0800, Haishuang Yan wrote:
>> + if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6),
>> + offset) < 0) {
>> + if (!csum_err) /* ignore csum errors. */
>> + return;
>> }
>
> gre_parse_header stops parsing when csum_err is encountered. Which
> means tpi.key is undefined...
>
>>
>> - if (!pskb_may_pull(skb, offset + grehlen))
>> - return;
>> ipv6h = (const struct ipv6hdr *)skb->data;
>> - greh = (const struct gre_base_hdr *)(skb->data + offset);
>> - key = key_off ? *(__be32 *)(skb->data + key_off) : 0;
>> -
>> t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr,
>> - key, greh->protocol);
>> + tpi.key, tpi.proto);
>
> ...and can't be used here.
>
> Jiri
>
You are right. Thanks for reviewing. So the same problem also arise in ipgre_err code:
187 iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
188 t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
189 iph->daddr, iph->saddr, tpi->key);
Since csum_err may not be used outside, how about refactoring gre_parse_header function like this:
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -86,7 +86,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
options = (__be32 *)(greh + 1);
if (greh->flags & GRE_CSUM) {
- if (skb_checksum_simple_validate(skb)) {
+ if (csum_err && skb_checksum_simple_validate(skb)) {
*csum_err = true;
return -EINVAL;
}
And in gre_err function, we can call gre_parse_header(skb, &tpi, NULL, **) like this:
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -234,11 +234,9 @@ static void gre_err(struct sk_buff *skb, u32 info)
struct tnl_ptk_info tpi;
bool csum_err = false;
- if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP),
- iph->ihl * 4) < 0) {
- if (!csum_err) /* ignore csum errors. */
+ if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
+ iph->ihl * 4) < 0)
return;
- }
On Tue, 11 Sep 2018 10:19:31 +0800, Haishuang Yan wrote:
> Since csum_err may not be used outside, how about refactoring gre_parse_header function like this:
>
> --- a/net/ipv4/gre_demux.c
> +++ b/net/ipv4/gre_demux.c
> @@ -86,7 +86,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
>
> options = (__be32 *)(greh + 1);
> if (greh->flags & GRE_CSUM) {
> - if (skb_checksum_simple_validate(skb)) {
> + if (csum_err && skb_checksum_simple_validate(skb)) {
Something like this, yes.
Thanks!
Jiri