mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Roopa Prabhu](/assets/img/avatar_default.png)
Today mpls iptunnel lwtunnel_output redirect expects the tunnel output function to handle fragmentation. This is ok but can be avoided if we did not do the mpls output redirect too early. ie we could wait until ip fragmentation is done and then call mpls output for each ip fragment. To make this work we will need, 1) the lwtunnel state to carry encap headroom 2) and do the redirect to the encap output handler on the ip fragment (essentially do the output redirect after fragmentation) This patch adds tunnel headroom in lwtstate to make sure we account for tunnel data in mtu calculations during fragmentation and adds new xmit redirect handler to redirect to lwtunnel xmit func after ip fragmentation. This includes IPV6 and some mtu fixes and testing from David Ahern. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
233 lines
5.6 KiB
C
233 lines
5.6 KiB
C
/*
|
|
* mpls tunnels An implementation mpls tunnels using the light weight tunnel
|
|
* infrastructure
|
|
*
|
|
* Authors: Roopa Prabhu, <roopa@cumulusnetworks.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*
|
|
*/
|
|
#include <linux/types.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/net.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mpls.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <net/ip.h>
|
|
#include <net/dst.h>
|
|
#include <net/lwtunnel.h>
|
|
#include <net/netevent.h>
|
|
#include <net/netns/generic.h>
|
|
#include <net/ip6_fib.h>
|
|
#include <net/route.h>
|
|
#include <net/mpls_iptunnel.h>
|
|
#include <linux/mpls_iptunnel.h>
|
|
#include "internal.h"
|
|
|
|
static const struct nla_policy mpls_iptunnel_policy[MPLS_IPTUNNEL_MAX + 1] = {
|
|
[MPLS_IPTUNNEL_DST] = { .type = NLA_U32 },
|
|
};
|
|
|
|
static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en)
|
|
{
|
|
/* The size of the layer 2.5 labels to be added for this route */
|
|
return en->labels * sizeof(struct mpls_shim_hdr);
|
|
}
|
|
|
|
static int mpls_xmit(struct sk_buff *skb)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
struct mpls_shim_hdr *hdr;
|
|
struct net_device *out_dev;
|
|
unsigned int hh_len;
|
|
unsigned int new_header_size;
|
|
unsigned int mtu;
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
struct rtable *rt = NULL;
|
|
struct rt6_info *rt6 = NULL;
|
|
int err = 0;
|
|
bool bos;
|
|
int i;
|
|
unsigned int ttl;
|
|
|
|
/* Obtain the ttl */
|
|
if (dst->ops->family == AF_INET) {
|
|
ttl = ip_hdr(skb)->ttl;
|
|
rt = (struct rtable *)dst;
|
|
} else if (dst->ops->family == AF_INET6) {
|
|
ttl = ipv6_hdr(skb)->hop_limit;
|
|
rt6 = (struct rt6_info *)dst;
|
|
} else {
|
|
goto drop;
|
|
}
|
|
|
|
skb_orphan(skb);
|
|
|
|
/* Find the output device */
|
|
out_dev = dst->dev;
|
|
if (!mpls_output_possible(out_dev) ||
|
|
!dst->lwtstate || skb_warn_if_lro(skb))
|
|
goto drop;
|
|
|
|
skb_forward_csum(skb);
|
|
|
|
tun_encap_info = mpls_lwtunnel_encap(dst->lwtstate);
|
|
|
|
/* Verify the destination can hold the packet */
|
|
new_header_size = mpls_encap_size(tun_encap_info);
|
|
mtu = mpls_dev_mtu(out_dev);
|
|
if (mpls_pkt_too_big(skb, mtu - new_header_size))
|
|
goto drop;
|
|
|
|
hh_len = LL_RESERVED_SPACE(out_dev);
|
|
if (!out_dev->header_ops)
|
|
hh_len = 0;
|
|
|
|
/* Ensure there is enough space for the headers in the skb */
|
|
if (skb_cow(skb, hh_len + new_header_size))
|
|
goto drop;
|
|
|
|
skb_push(skb, new_header_size);
|
|
skb_reset_network_header(skb);
|
|
|
|
skb->dev = out_dev;
|
|
skb->protocol = htons(ETH_P_MPLS_UC);
|
|
|
|
/* Push the new labels */
|
|
hdr = mpls_hdr(skb);
|
|
bos = true;
|
|
for (i = tun_encap_info->labels - 1; i >= 0; i--) {
|
|
hdr[i] = mpls_entry_encode(tun_encap_info->label[i],
|
|
ttl, 0, bos);
|
|
bos = false;
|
|
}
|
|
|
|
if (rt)
|
|
err = neigh_xmit(NEIGH_ARP_TABLE, out_dev, &rt->rt_gateway,
|
|
skb);
|
|
else if (rt6)
|
|
err = neigh_xmit(NEIGH_ND_TABLE, out_dev, &rt6->rt6i_gateway,
|
|
skb);
|
|
if (err)
|
|
net_dbg_ratelimited("%s: packet transmission failed: %d\n",
|
|
__func__, err);
|
|
|
|
return LWTUNNEL_XMIT_DONE;
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int mpls_build_state(struct net_device *dev, struct nlattr *nla,
|
|
unsigned int family, const void *cfg,
|
|
struct lwtunnel_state **ts)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
struct nlattr *tb[MPLS_IPTUNNEL_MAX + 1];
|
|
struct lwtunnel_state *newts;
|
|
int tun_encap_info_len;
|
|
int ret;
|
|
|
|
ret = nla_parse_nested(tb, MPLS_IPTUNNEL_MAX, nla,
|
|
mpls_iptunnel_policy);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!tb[MPLS_IPTUNNEL_DST])
|
|
return -EINVAL;
|
|
|
|
tun_encap_info_len = sizeof(*tun_encap_info);
|
|
|
|
newts = lwtunnel_state_alloc(tun_encap_info_len);
|
|
if (!newts)
|
|
return -ENOMEM;
|
|
|
|
newts->len = tun_encap_info_len;
|
|
tun_encap_info = mpls_lwtunnel_encap(newts);
|
|
ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
|
|
&tun_encap_info->labels, tun_encap_info->label);
|
|
if (ret)
|
|
goto errout;
|
|
newts->type = LWTUNNEL_ENCAP_MPLS;
|
|
newts->flags |= LWTUNNEL_STATE_XMIT_REDIRECT;
|
|
newts->headroom = mpls_encap_size(tun_encap_info);
|
|
|
|
*ts = newts;
|
|
|
|
return 0;
|
|
|
|
errout:
|
|
kfree(newts);
|
|
*ts = NULL;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int mpls_fill_encap_info(struct sk_buff *skb,
|
|
struct lwtunnel_state *lwtstate)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
|
|
tun_encap_info = mpls_lwtunnel_encap(lwtstate);
|
|
|
|
if (nla_put_labels(skb, MPLS_IPTUNNEL_DST, tun_encap_info->labels,
|
|
tun_encap_info->label))
|
|
goto nla_put_failure;
|
|
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int mpls_encap_nlsize(struct lwtunnel_state *lwtstate)
|
|
{
|
|
struct mpls_iptunnel_encap *tun_encap_info;
|
|
|
|
tun_encap_info = mpls_lwtunnel_encap(lwtstate);
|
|
|
|
return nla_total_size(tun_encap_info->labels * 4);
|
|
}
|
|
|
|
static int mpls_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
|
|
{
|
|
struct mpls_iptunnel_encap *a_hdr = mpls_lwtunnel_encap(a);
|
|
struct mpls_iptunnel_encap *b_hdr = mpls_lwtunnel_encap(b);
|
|
int l;
|
|
|
|
if (a_hdr->labels != b_hdr->labels)
|
|
return 1;
|
|
|
|
for (l = 0; l < MAX_NEW_LABELS; l++)
|
|
if (a_hdr->label[l] != b_hdr->label[l])
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static const struct lwtunnel_encap_ops mpls_iptun_ops = {
|
|
.build_state = mpls_build_state,
|
|
.xmit = mpls_xmit,
|
|
.fill_encap = mpls_fill_encap_info,
|
|
.get_encap_size = mpls_encap_nlsize,
|
|
.cmp_encap = mpls_encap_cmp,
|
|
};
|
|
|
|
static int __init mpls_iptunnel_init(void)
|
|
{
|
|
return lwtunnel_encap_add_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
|
|
}
|
|
module_init(mpls_iptunnel_init);
|
|
|
|
static void __exit mpls_iptunnel_exit(void)
|
|
{
|
|
lwtunnel_encap_del_ops(&mpls_iptun_ops, LWTUNNEL_ENCAP_MPLS);
|
|
}
|
|
module_exit(mpls_iptunnel_exit);
|
|
|
|
MODULE_ALIAS_RTNL_LWT(MPLS);
|
|
MODULE_DESCRIPTION("MultiProtocol Label Switching IP Tunnels");
|
|
MODULE_LICENSE("GPL v2");
|