From f132ae7c46370c981412a68ccec9f2145812a9b6 Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Tue, 3 May 2016 15:00:21 +0200 Subject: [PATCH] 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 Acked-by: Tom Herbert Signed-off-by: David S. Miller --- include/net/gre.h | 2 +- net/ipv4/gre_demux.c | 6 +++--- net/ipv4/ip_gre.c | 9 +++------ net/ipv6/ip6_gre.c | 3 ++- 4 files changed, 9 insertions(+), 11 deletions(-) diff --git a/include/net/gre.h b/include/net/gre.h index 29e37322c06e..a14093c70eab 100644 --- a/include/net/gre.h +++ b/include/net/gre.h @@ -26,7 +26,7 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version); 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 371674801e84..a41e73ab1369 100644 --- a/net/ipv4/gre_demux.c +++ b/net/ipv4/gre_demux.c @@ -60,8 +60,9 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version) } 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 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, 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 b99213c46aac..8260a707b9b8 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -221,16 +221,12 @@ static void gre_err(struct sk_buff *skb, u32 info) 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 @@ static int gre_rcv(struct sk_buff *skb) } #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 10127741a60d..47b671a46dc4 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -468,7 +468,8 @@ static int gre_rcv(struct sk_buff *skb) 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)) -- 2.20.1