gre: Remove support for sharing GRE protocol hook.

Support for sharing GREPROTO_CISCO port was added so that
OVS gre port and kernel GRE devices can co-exist. After
flow-based tunneling patches OVS GRE protocol processing
is completely moved to ip_gre module. so there is no need
for GRE protocol hook. Following patch consolidates
GRE protocol related functions into ip_gre module.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pravin B Shelar
2015-08-07 23:51:52 -07:00
committed by David S. Miller
parent b2acd1dc39
commit 9f57c67c37
3 changed files with 206 additions and 290 deletions

View File

@@ -123,8 +123,127 @@ 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 ipgre_err(struct sk_buff *skb, u32 info,
const struct tnl_ptk_info *tpi)
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);
}
static void ipgre_err(struct sk_buff *skb, u32 info,
const struct tnl_ptk_info *tpi)
{
/* All the routers (except for Linux) return only
@@ -150,14 +269,14 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
switch (type) {
default:
case ICMP_PARAMETERPROB:
return PACKET_RCVD;
return;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
case ICMP_PORT_UNREACH:
/* Impossible event. */
return PACKET_RCVD;
return;
default:
/* All others are translated to HOST_UNREACH.
rfc2003 contains "deep thoughts" about NET_UNREACH,
@@ -166,9 +285,10 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
break;
}
break;
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return PACKET_RCVD;
return;
break;
case ICMP_REDIRECT:
@@ -185,21 +305,60 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
iph->daddr, iph->saddr, tpi->key);
if (!t)
return PACKET_REJECT;
return;
if (t->parms.iph.daddr == 0 ||
ipv4_is_multicast(t->parms.iph.daddr))
return PACKET_RCVD;
return;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
return PACKET_RCVD;
return;
if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
return PACKET_RCVD;
}
static void gre_err(struct sk_buff *skb, u32 info)
{
/* All the routers (except for Linux) return only
* 8 bytes of packet payload. It means, that precise relaying of
* ICMP in the real Internet is absolutely infeasible.
*
* Moreover, Cisco "wise men" put GRE key to the third word
* in GRE header. It makes impossible maintaining even soft
* state for keyed
* GRE tunnels with enabled checksum. Tell them "thank you".
*
* Well, I wonder, rfc1812 was written by Cisco employee,
* what the hell these idiots break standards established
* by themselves???
*/
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
struct tnl_ptk_info tpi;
bool csum_err = false;
if (parse_gre_header(skb, &tpi, &csum_err)) {
if (!csum_err) /* ignore csum errors. */
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);
return;
}
if (type == ICMP_REDIRECT) {
ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0,
IPPROTO_GRE, 0);
return;
}
ipgre_err(skb, info, &tpi);
}
static __be64 key_to_tunnel_id(__be32 key)
@@ -268,6 +427,31 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
return PACKET_REJECT;
}
static int gre_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
bool csum_err = false;
#ifdef CONFIG_NET_IPGRE_BROADCAST
if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
/* Looped back packet, drop it! */
if (rt_is_output_route(skb_rtable(skb)))
goto drop;
}
#endif
if (parse_gre_header(skb, &tpi, &csum_err) < 0)
goto drop;
if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
return 0;
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
drop:
kfree_skb(skb);
return 0;
}
static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,
__be16 proto, __be32 key, __be32 seq)
{
@@ -684,10 +868,9 @@ static int ipgre_tunnel_init(struct net_device *dev)
return ip_tunnel_init(dev);
}
static struct gre_cisco_protocol ipgre_protocol = {
.handler = ipgre_rcv,
.err_handler = ipgre_err,
.priority = 0,
static const struct gre_protocol ipgre_protocol = {
.handler = gre_rcv,
.err_handler = gre_err,
};
static int __net_init ipgre_init_net(struct net *net)
@@ -1080,7 +1263,7 @@ static int __init ipgre_init(void)
if (err < 0)
goto pnet_tap_faied;
err = gre_cisco_register(&ipgre_protocol);
err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
if (err < 0) {
pr_info("%s: can't add protocol\n", __func__);
goto add_proto_failed;
@@ -1099,7 +1282,7 @@ static int __init ipgre_init(void)
tap_ops_failed:
rtnl_link_unregister(&ipgre_link_ops);
rtnl_link_failed:
gre_cisco_unregister(&ipgre_protocol);
gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
add_proto_failed:
unregister_pernet_device(&ipgre_tap_net_ops);
pnet_tap_faied:
@@ -1111,7 +1294,7 @@ static void __exit ipgre_fini(void)
{
rtnl_link_unregister(&ipgre_tap_ops);
rtnl_link_unregister(&ipgre_link_ops);
gre_cisco_unregister(&ipgre_protocol);
gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
unregister_pernet_device(&ipgre_tap_net_ops);
unregister_pernet_device(&ipgre_net_ops);
}