gre: change gre_parse_header to return the header length
It's easier for gre_parse_header to return the header length instead of
filing it into a parameter. That way, the callers that don't care about the
header length can just check whether the returned value is lower than zero.
In gre_err, the tunnel header must not be pulled. See commit b7f8fe251e46
("gre: do not pull header in ICMP error processing") for details.
This patch reduces the conflict between the mentioned commit and commit
95f5c64c3c13 ("gre: Move utility functions to common headers").
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/gre.h b/include/net/gre.h
index 29e3732..a14093c 100644
--- a/include/net/gre.h
+++ b/include/net/gre.h
@@ -26,7 +26,7 @@
struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
u8 name_assign_type);
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
- bool *csum_err, int *hdr_len);
+ bool *csum_err);
static inline int gre_calc_hlen(__be16 o_flags)
{
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 37167480..a41e73a 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -60,8 +60,9 @@
}
EXPORT_SYMBOL_GPL(gre_del_protocol);
+/* Fills in tpi and returns header length to be pulled. */
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
- bool *csum_err, int *ret_hdr_len)
+ bool *csum_err)
{
const struct gre_base_hdr *greh;
__be32 *options;
@@ -119,8 +120,7 @@
return -EINVAL;
}
}
- *ret_hdr_len = hdr_len;
- return 0;
+ return hdr_len;
}
EXPORT_SYMBOL(gre_parse_header);
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index b99213c..8260a70 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -221,16 +221,12 @@
const int code = icmp_hdr(skb)->code;
struct tnl_ptk_info tpi;
bool csum_err = false;
- int hdr_len;
- if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len)) {
+ if (gre_parse_header(skb, &tpi, &csum_err) < 0) {
if (!csum_err) /* ignore csum errors. */
return;
}
- if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
- return;
-
if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
ipv4_update_pmtu(skb, dev_net(skb->dev), info,
skb->dev->ifindex, 0, IPPROTO_GRE, 0);
@@ -314,7 +310,8 @@
}
#endif
- if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
+ hdr_len = gre_parse_header(skb, &tpi, &csum_err);
+ if (hdr_len < 0)
goto drop;
if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 1012774..47b671a 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -468,7 +468,8 @@
bool csum_err = false;
int hdr_len;
- if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
+ hdr_len = gre_parse_header(skb, &tpi, &csum_err);
+ if (hdr_len < 0)
goto drop;
if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))