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Date: Fri, 29 Apr 2016 17:12:16 -0700
From: Tom Herbert <tom@...bertland.com>
To: <davem@...emloft.net>, <netdev@...r.kernel.org>
CC: <kernel-team@...com>
Subject: [PATCH next-next 2/7] gre: Move utility functions to common headers
Several of the GRE functions defined in net/ipv4/ip_gre.c are usable
for IPv6 GRE implementation (that is they are protocol agnostic).
These include:
- GRE flag handling functions are move to gre.h
- GRE build_header is moved to gre.h and renamed gre_build_header
- parse_gre_header is moved to gre_demux.c and renamed gre_parse_header
- iptunnel_pull_header is taken out of gre_parse_header. This is now
done by caller. The header length is returned from gre_parse_header
in an int* argument.
Signed-off-by: Tom Herbert <tom@...bertland.com>
---
include/net/gre.h | 60 +++++++++++++++++++++
net/ipv4/gre_demux.c | 64 ++++++++++++++++++++++
net/ipv4/ip_gre.c | 149 +++++++--------------------------------------------
3 files changed, 144 insertions(+), 129 deletions(-)
diff --git a/include/net/gre.h b/include/net/gre.h
index 97eafdc..3959158 100644
--- a/include/net/gre.h
+++ b/include/net/gre.h
@@ -25,4 +25,64 @@ 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);
+
+static inline int gre_calc_hlen(__be16 o_flags)
+{
+ int addend = 4;
+
+ if (o_flags & TUNNEL_CSUM)
+ addend += 4;
+ if (o_flags & TUNNEL_KEY)
+ addend += 4;
+ if (o_flags & TUNNEL_SEQ)
+ addend += 4;
+ return addend;
+}
+
+static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
+{
+ __be16 tflags = 0;
+
+ if (flags & GRE_CSUM)
+ tflags |= TUNNEL_CSUM;
+ if (flags & GRE_ROUTING)
+ tflags |= TUNNEL_ROUTING;
+ if (flags & GRE_KEY)
+ tflags |= TUNNEL_KEY;
+ if (flags & GRE_SEQ)
+ tflags |= TUNNEL_SEQ;
+ if (flags & GRE_STRICT)
+ tflags |= TUNNEL_STRICT;
+ if (flags & GRE_REC)
+ tflags |= TUNNEL_REC;
+ if (flags & GRE_VERSION)
+ tflags |= TUNNEL_VERSION;
+
+ return tflags;
+}
+
+static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags)
+{
+ __be16 flags = 0;
+
+ if (tflags & TUNNEL_CSUM)
+ flags |= GRE_CSUM;
+ if (tflags & TUNNEL_ROUTING)
+ flags |= GRE_ROUTING;
+ if (tflags & TUNNEL_KEY)
+ flags |= GRE_KEY;
+ if (tflags & TUNNEL_SEQ)
+ flags |= GRE_SEQ;
+ if (tflags & TUNNEL_STRICT)
+ flags |= GRE_STRICT;
+ if (tflags & TUNNEL_REC)
+ flags |= GRE_REC;
+ if (tflags & TUNNEL_VERSION)
+ flags |= GRE_VERSION;
+
+ return flags;
+}
+
#endif
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index d9c552a..37167480 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -60,6 +60,70 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version)
}
EXPORT_SYMBOL_GPL(gre_del_protocol);
+int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
+ bool *csum_err, int *ret_hdr_len)
+{
+ const struct gre_base_hdr *greh;
+ __be32 *options;
+ int hdr_len;
+
+ if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
+ return -EINVAL;
+
+ greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
+ return -EINVAL;
+
+ tpi->flags = gre_flags_to_tnl_flags(greh->flags);
+ hdr_len = gre_calc_hlen(tpi->flags);
+
+ if (!pskb_may_pull(skb, hdr_len))
+ return -EINVAL;
+
+ greh = (struct gre_base_hdr *)skb_transport_header(skb);
+ tpi->proto = greh->protocol;
+
+ options = (__be32 *)(greh + 1);
+ if (greh->flags & GRE_CSUM) {
+ if (skb_checksum_simple_validate(skb)) {
+ *csum_err = true;
+ return -EINVAL;
+ }
+
+ skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
+ null_compute_pseudo);
+ options++;
+ }
+
+ if (greh->flags & GRE_KEY) {
+ tpi->key = *options;
+ options++;
+ } else {
+ tpi->key = 0;
+ }
+ if (unlikely(greh->flags & GRE_SEQ)) {
+ tpi->seq = *options;
+ options++;
+ } else {
+ tpi->seq = 0;
+ }
+ /* WCCP version 1 and 2 protocol decoding.
+ * - Change protocol to IP
+ * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
+ */
+ if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
+ tpi->proto = htons(ETH_P_IP);
+ if ((*(u8 *)options & 0xF0) != 0x40) {
+ hdr_len += 4;
+ if (!pskb_may_pull(skb, hdr_len))
+ return -EINVAL;
+ }
+ }
+ *ret_hdr_len = hdr_len;
+ return 0;
+}
+EXPORT_SYMBOL(gre_parse_header);
+
static int gre_rcv(struct sk_buff *skb)
{
const struct gre_protocol *proto;
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index eedd829..f6db3d6 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -122,125 +122,6 @@ static int ipgre_tunnel_init(struct net_device *dev);
static int ipgre_net_id __read_mostly;
static int gre_tap_net_id __read_mostly;
-static int ip_gre_calc_hlen(__be16 o_flags)
-{
- int addend = 4;
-
- if (o_flags & TUNNEL_CSUM)
- addend += 4;
- if (o_flags & TUNNEL_KEY)
- addend += 4;
- if (o_flags & TUNNEL_SEQ)
- addend += 4;
- return addend;
-}
-
-static __be16 gre_flags_to_tnl_flags(__be16 flags)
-{
- __be16 tflags = 0;
-
- if (flags & GRE_CSUM)
- tflags |= TUNNEL_CSUM;
- if (flags & GRE_ROUTING)
- tflags |= TUNNEL_ROUTING;
- if (flags & GRE_KEY)
- tflags |= TUNNEL_KEY;
- if (flags & GRE_SEQ)
- tflags |= TUNNEL_SEQ;
- if (flags & GRE_STRICT)
- tflags |= TUNNEL_STRICT;
- if (flags & GRE_REC)
- tflags |= TUNNEL_REC;
- if (flags & GRE_VERSION)
- tflags |= TUNNEL_VERSION;
-
- return tflags;
-}
-
-static __be16 tnl_flags_to_gre_flags(__be16 tflags)
-{
- __be16 flags = 0;
-
- if (tflags & TUNNEL_CSUM)
- flags |= GRE_CSUM;
- if (tflags & TUNNEL_ROUTING)
- flags |= GRE_ROUTING;
- if (tflags & TUNNEL_KEY)
- flags |= GRE_KEY;
- if (tflags & TUNNEL_SEQ)
- flags |= GRE_SEQ;
- if (tflags & TUNNEL_STRICT)
- flags |= GRE_STRICT;
- if (tflags & TUNNEL_REC)
- flags |= GRE_REC;
- if (tflags & TUNNEL_VERSION)
- flags |= GRE_VERSION;
-
- return flags;
-}
-
-static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
- bool *csum_err)
-{
- const struct gre_base_hdr *greh;
- __be32 *options;
- int hdr_len;
-
- if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
- return -EINVAL;
-
- greh = (struct gre_base_hdr *)skb_transport_header(skb);
- if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
- return -EINVAL;
-
- tpi->flags = gre_flags_to_tnl_flags(greh->flags);
- hdr_len = ip_gre_calc_hlen(tpi->flags);
-
- if (!pskb_may_pull(skb, hdr_len))
- return -EINVAL;
-
- greh = (struct gre_base_hdr *)skb_transport_header(skb);
- tpi->proto = greh->protocol;
-
- options = (__be32 *)(greh + 1);
- if (greh->flags & GRE_CSUM) {
- if (skb_checksum_simple_validate(skb)) {
- *csum_err = true;
- return -EINVAL;
- }
-
- skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
- null_compute_pseudo);
- options++;
- }
-
- if (greh->flags & GRE_KEY) {
- tpi->key = *options;
- options++;
- } else {
- tpi->key = 0;
- }
- if (unlikely(greh->flags & GRE_SEQ)) {
- tpi->seq = *options;
- options++;
- } else {
- tpi->seq = 0;
- }
- /* WCCP version 1 and 2 protocol decoding.
- * - Change protocol to IP
- * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
- */
- if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
- tpi->proto = htons(ETH_P_IP);
- if ((*(u8 *)options & 0xF0) != 0x40) {
- hdr_len += 4;
- if (!pskb_may_pull(skb, hdr_len))
- return -EINVAL;
- }
- }
- return iptunnel_pull_header(skb, hdr_len, tpi->proto, false);
-}
-
static void ipgre_err(struct sk_buff *skb, u32 info,
const struct tnl_ptk_info *tpi)
{
@@ -340,12 +221,16 @@ 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 (parse_gre_header(skb, &tpi, &csum_err)) {
+ if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len)) {
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);
@@ -419,6 +304,7 @@ static int gre_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
bool csum_err = false;
+ int hdr_len;
#ifdef CONFIG_NET_IPGRE_BROADCAST
if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
@@ -428,7 +314,10 @@ static int gre_rcv(struct sk_buff *skb)
}
#endif
- if (parse_gre_header(skb, &tpi, &csum_err) < 0)
+ if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
+ goto drop;
+
+ if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
goto drop;
if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
@@ -460,7 +349,7 @@ static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,
skb_reset_transport_header(skb);
greh = (struct gre_base_hdr *)skb->data;
- greh->flags = tnl_flags_to_gre_flags(flags);
+ greh->flags = gre_tnl_flags_to_gre_flags(flags);
greh->protocol = proto;
if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {
@@ -552,7 +441,7 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
fl.saddr);
}
- tunnel_hlen = ip_gre_calc_hlen(key->tun_flags);
+ tunnel_hlen = gre_calc_hlen(key->tun_flags);
min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
+ tunnel_hlen + sizeof(struct iphdr);
@@ -694,8 +583,8 @@ static int ipgre_tunnel_ioctl(struct net_device *dev,
if (err)
return err;
- p.i_flags = tnl_flags_to_gre_flags(p.i_flags);
- p.o_flags = tnl_flags_to_gre_flags(p.o_flags);
+ p.i_flags = gre_tnl_flags_to_gre_flags(p.i_flags);
+ p.o_flags = gre_tnl_flags_to_gre_flags(p.o_flags);
if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
return -EFAULT;
@@ -739,7 +628,7 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
iph = (struct iphdr *)skb_push(skb, t->hlen + sizeof(*iph));
greh = (struct gre_base_hdr *)(iph+1);
- greh->flags = tnl_flags_to_gre_flags(t->parms.o_flags);
+ greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
greh->protocol = htons(type);
memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
@@ -840,7 +729,7 @@ static void __gre_tunnel_init(struct net_device *dev)
int t_hlen;
tunnel = netdev_priv(dev);
- tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
+ tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
tunnel->parms.iph.protocol = IPPROTO_GRE;
tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
@@ -1155,8 +1044,10 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
struct ip_tunnel_parm *p = &t->parms;
if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
- nla_put_be16(skb, IFLA_GRE_IFLAGS, tnl_flags_to_gre_flags(p->i_flags)) ||
- nla_put_be16(skb, IFLA_GRE_OFLAGS, tnl_flags_to_gre_flags(p->o_flags)) ||
+ nla_put_be16(skb, IFLA_GRE_IFLAGS,
+ gre_tnl_flags_to_gre_flags(p->i_flags)) ||
+ nla_put_be16(skb, IFLA_GRE_OFLAGS,
+ gre_tnl_flags_to_gre_flags(p->o_flags)) ||
nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
--
2.8.0.rc2
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