summaryrefslogtreecommitdiff
path: root/net/ipv4/ip_gre.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv4/ip_gre.c')
-rw-r--r--net/ipv4/ip_gre.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index a85ae2f7a21..303012adf9e 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -750,6 +750,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
int gre_hlen;
__be32 dst;
int mtu;
+ u8 ttl;
if (skb->ip_summed == CHECKSUM_PARTIAL &&
skb_checksum_help(skb))
@@ -760,7 +761,10 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
gre_hlen = 0;
- tiph = (const struct iphdr *)skb->data;
+ if (skb->protocol == htons(ETH_P_IP))
+ tiph = (const struct iphdr *)skb->data;
+ else
+ tiph = &tunnel->parms.iph;
} else {
gre_hlen = tunnel->hlen;
tiph = &tunnel->parms.iph;
@@ -812,6 +816,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
goto tx_error;
}
+ ttl = tiph->ttl;
tos = tiph->tos;
if (tos == 1) {
tos = 0;
@@ -904,11 +909,12 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
dev_kfree_skb(skb);
skb = new_skb;
old_iph = ip_hdr(skb);
+ /* Warning : tiph value might point to freed memory */
}
- skb_reset_transport_header(skb);
skb_push(skb, gre_hlen);
skb_reset_network_header(skb);
+ skb_set_transport_header(skb, sizeof(*iph));
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
IPSKB_REROUTED);
@@ -927,8 +933,9 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev
iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
iph->daddr = fl4.daddr;
iph->saddr = fl4.saddr;
+ iph->ttl = ttl;
- if ((iph->ttl = tiph->ttl) == 0) {
+ if (ttl == 0) {
if (skb->protocol == htons(ETH_P_IP))
iph->ttl = old_iph->ttl;
#if IS_ENABLED(CONFIG_IPV6)