From: Eric Dumazet <eduma...@google.com>
1) gre_parse_header() can be called from gre_err()
At this point transport header points to ICMP header, not the inner
header.
2) We can not really change transport header as ipgre_err() will later
assume transport header still points to ICMP header.
3) pskb_may_pull() logic in gre_parse_header() really works
if we are interested at zone pointed by skb->data
So this fix :
A) changes gre_parse_header() to use skb->data instead of
skb_transport_header()
B) changes gre_err() to pull the IPv4 header immediately following
the ICMP header that was already pulled earlier.
C) remove obsolete IPV6 includes
Signed-off-by: Eric Dumazet <eduma...@google.com>
Cc: Tom Herbert <t...@herbertland.com>
Cc: Maciej Żenczykowski <m...@google.com>
---
net/ipv4/gre_demux.c | 4 ++--
net/ipv4/ip_gre.c | 9 +++------
2 files changed, 5 insertions(+), 8 deletions(-)
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 4c39f4fd332a..0ba26ad9809d 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -71,7 +71,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info
*tpi,
if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
return -EINVAL;
- greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ greh = (struct gre_base_hdr *)skb->data;
if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
return -EINVAL;
@@ -81,7 +81,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info
*tpi,
if (!pskb_may_pull(skb, hdr_len))
return -EINVAL;
- greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ greh = (struct gre_base_hdr *)skb->data;
tpi->proto = greh->protocol;
options = (__be32 *)(greh + 1);
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 4d2025f7ec57..454832bc2897 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -49,12 +49,6 @@
#include <net/gre.h>
#include <net/dst_metadata.h>
-#if IS_ENABLED(CONFIG_IPV6)
-#include <net/ipv6.h>
-#include <net/ip6_fib.h>
-#include <net/ip6_route.h>
-#endif
-
/*
Problems & solutions
--------------------
@@ -217,11 +211,14 @@ static void gre_err(struct sk_buff *skb, u32 info)
* by themselves???
*/
+ const struct iphdr *iph = (struct iphdr *)skb->data;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
struct tnl_ptk_info tpi;
bool csum_err = false;
+ pskb_pull(skb, iph->ihl * 4);
+
if (gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP)) < 0) {
if (!csum_err) /* ignore csum errors. */
return;
