![Robert Shearman](/assets/img/avatar_default.png)
Modules implementing lwtunnel ops should not be allowed to unload while there is state alive using those ops, so specify the owning module for all lwtunnel ops. Signed-off-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net>
437 lines
9.5 KiB
C
437 lines
9.5 KiB
C
/*
|
|
* SR-IPv6 implementation
|
|
*
|
|
* Author:
|
|
* David Lebrun <david.lebrun@uclouvain.be>
|
|
*
|
|
*
|
|
* 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 <net/ip.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/seg6.h>
|
|
#include <linux/seg6.h>
|
|
#include <linux/seg6_iptunnel.h>
|
|
#include <net/addrconf.h>
|
|
#include <net/ip6_route.h>
|
|
#ifdef CONFIG_DST_CACHE
|
|
#include <net/dst_cache.h>
|
|
#endif
|
|
#ifdef CONFIG_IPV6_SEG6_HMAC
|
|
#include <net/seg6_hmac.h>
|
|
#endif
|
|
|
|
struct seg6_lwt {
|
|
#ifdef CONFIG_DST_CACHE
|
|
struct dst_cache cache;
|
|
#endif
|
|
struct seg6_iptunnel_encap tuninfo[0];
|
|
};
|
|
|
|
static inline struct seg6_lwt *seg6_lwt_lwtunnel(struct lwtunnel_state *lwt)
|
|
{
|
|
return (struct seg6_lwt *)lwt->data;
|
|
}
|
|
|
|
static inline struct seg6_iptunnel_encap *
|
|
seg6_encap_lwtunnel(struct lwtunnel_state *lwt)
|
|
{
|
|
return seg6_lwt_lwtunnel(lwt)->tuninfo;
|
|
}
|
|
|
|
static const struct nla_policy seg6_iptunnel_policy[SEG6_IPTUNNEL_MAX + 1] = {
|
|
[SEG6_IPTUNNEL_SRH] = { .type = NLA_BINARY },
|
|
};
|
|
|
|
int nla_put_srh(struct sk_buff *skb, int attrtype,
|
|
struct seg6_iptunnel_encap *tuninfo)
|
|
{
|
|
struct seg6_iptunnel_encap *data;
|
|
struct nlattr *nla;
|
|
int len;
|
|
|
|
len = SEG6_IPTUN_ENCAP_SIZE(tuninfo);
|
|
|
|
nla = nla_reserve(skb, attrtype, len);
|
|
if (!nla)
|
|
return -EMSGSIZE;
|
|
|
|
data = nla_data(nla);
|
|
memcpy(data, tuninfo, len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void set_tun_src(struct net *net, struct net_device *dev,
|
|
struct in6_addr *daddr, struct in6_addr *saddr)
|
|
{
|
|
struct seg6_pernet_data *sdata = seg6_pernet(net);
|
|
struct in6_addr *tun_src;
|
|
|
|
rcu_read_lock();
|
|
|
|
tun_src = rcu_dereference(sdata->tun_src);
|
|
|
|
if (!ipv6_addr_any(tun_src)) {
|
|
memcpy(saddr, tun_src, sizeof(struct in6_addr));
|
|
} else {
|
|
ipv6_dev_get_saddr(net, dev, daddr, IPV6_PREFER_SRC_PUBLIC,
|
|
saddr);
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/* encapsulate an IPv6 packet within an outer IPv6 header with a given SRH */
|
|
static int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh)
|
|
{
|
|
struct net *net = dev_net(skb_dst(skb)->dev);
|
|
struct ipv6hdr *hdr, *inner_hdr;
|
|
struct ipv6_sr_hdr *isrh;
|
|
int hdrlen, tot_len, err;
|
|
|
|
hdrlen = (osrh->hdrlen + 1) << 3;
|
|
tot_len = hdrlen + sizeof(*hdr);
|
|
|
|
err = pskb_expand_head(skb, tot_len, 0, GFP_ATOMIC);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
inner_hdr = ipv6_hdr(skb);
|
|
|
|
skb_push(skb, tot_len);
|
|
skb_reset_network_header(skb);
|
|
skb_mac_header_rebuild(skb);
|
|
hdr = ipv6_hdr(skb);
|
|
|
|
/* inherit tc, flowlabel and hlim
|
|
* hlim will be decremented in ip6_forward() afterwards and
|
|
* decapsulation will overwrite inner hlim with outer hlim
|
|
*/
|
|
ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)),
|
|
ip6_flowlabel(inner_hdr));
|
|
hdr->hop_limit = inner_hdr->hop_limit;
|
|
hdr->nexthdr = NEXTHDR_ROUTING;
|
|
|
|
isrh = (void *)hdr + sizeof(*hdr);
|
|
memcpy(isrh, osrh, hdrlen);
|
|
|
|
isrh->nexthdr = NEXTHDR_IPV6;
|
|
|
|
hdr->daddr = isrh->segments[isrh->first_segment];
|
|
set_tun_src(net, skb->dev, &hdr->daddr, &hdr->saddr);
|
|
|
|
#ifdef CONFIG_IPV6_SEG6_HMAC
|
|
if (sr_has_hmac(isrh)) {
|
|
err = seg6_push_hmac(net, &hdr->saddr, isrh);
|
|
if (unlikely(err))
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
skb_postpush_rcsum(skb, hdr, tot_len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* insert an SRH within an IPv6 packet, just after the IPv6 header */
|
|
#ifdef CONFIG_IPV6_SEG6_INLINE
|
|
static int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh)
|
|
{
|
|
struct ipv6hdr *hdr, *oldhdr;
|
|
struct ipv6_sr_hdr *isrh;
|
|
int hdrlen, err;
|
|
|
|
hdrlen = (osrh->hdrlen + 1) << 3;
|
|
|
|
err = pskb_expand_head(skb, hdrlen, 0, GFP_ATOMIC);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
oldhdr = ipv6_hdr(skb);
|
|
|
|
skb_pull(skb, sizeof(struct ipv6hdr));
|
|
skb_postpull_rcsum(skb, skb_network_header(skb),
|
|
sizeof(struct ipv6hdr));
|
|
|
|
skb_push(skb, sizeof(struct ipv6hdr) + hdrlen);
|
|
skb_reset_network_header(skb);
|
|
skb_mac_header_rebuild(skb);
|
|
|
|
hdr = ipv6_hdr(skb);
|
|
|
|
memmove(hdr, oldhdr, sizeof(*hdr));
|
|
|
|
isrh = (void *)hdr + sizeof(*hdr);
|
|
memcpy(isrh, osrh, hdrlen);
|
|
|
|
isrh->nexthdr = hdr->nexthdr;
|
|
hdr->nexthdr = NEXTHDR_ROUTING;
|
|
|
|
isrh->segments[0] = hdr->daddr;
|
|
hdr->daddr = isrh->segments[isrh->first_segment];
|
|
|
|
#ifdef CONFIG_IPV6_SEG6_HMAC
|
|
if (sr_has_hmac(isrh)) {
|
|
struct net *net = dev_net(skb_dst(skb)->dev);
|
|
|
|
err = seg6_push_hmac(net, &hdr->saddr, isrh);
|
|
if (unlikely(err))
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static int seg6_do_srh(struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
struct seg6_iptunnel_encap *tinfo;
|
|
int err = 0;
|
|
|
|
tinfo = seg6_encap_lwtunnel(dst->lwtstate);
|
|
|
|
if (likely(!skb->encapsulation)) {
|
|
skb_reset_inner_headers(skb);
|
|
skb->encapsulation = 1;
|
|
}
|
|
|
|
switch (tinfo->mode) {
|
|
#ifdef CONFIG_IPV6_SEG6_INLINE
|
|
case SEG6_IPTUN_MODE_INLINE:
|
|
err = seg6_do_srh_inline(skb, tinfo->srh);
|
|
skb_reset_inner_headers(skb);
|
|
break;
|
|
#endif
|
|
case SEG6_IPTUN_MODE_ENCAP:
|
|
err = seg6_do_srh_encap(skb, tinfo->srh);
|
|
break;
|
|
}
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
|
|
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
|
|
|
|
skb_set_inner_protocol(skb, skb->protocol);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int seg6_input(struct sk_buff *skb)
|
|
{
|
|
int err;
|
|
|
|
err = seg6_do_srh(skb);
|
|
if (unlikely(err)) {
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
skb_dst_drop(skb);
|
|
ip6_route_input(skb);
|
|
|
|
return dst_input(skb);
|
|
}
|
|
|
|
int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *orig_dst = skb_dst(skb);
|
|
struct dst_entry *dst = NULL;
|
|
struct seg6_lwt *slwt;
|
|
int err = -EINVAL;
|
|
|
|
err = seg6_do_srh(skb);
|
|
if (unlikely(err))
|
|
goto drop;
|
|
|
|
slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
|
|
|
|
#ifdef CONFIG_DST_CACHE
|
|
preempt_disable();
|
|
dst = dst_cache_get(&slwt->cache);
|
|
preempt_enable();
|
|
#endif
|
|
|
|
if (unlikely(!dst)) {
|
|
struct ipv6hdr *hdr = ipv6_hdr(skb);
|
|
struct flowi6 fl6;
|
|
|
|
fl6.daddr = hdr->daddr;
|
|
fl6.saddr = hdr->saddr;
|
|
fl6.flowlabel = ip6_flowinfo(hdr);
|
|
fl6.flowi6_mark = skb->mark;
|
|
fl6.flowi6_proto = hdr->nexthdr;
|
|
|
|
dst = ip6_route_output(net, NULL, &fl6);
|
|
if (dst->error) {
|
|
err = dst->error;
|
|
dst_release(dst);
|
|
goto drop;
|
|
}
|
|
|
|
#ifdef CONFIG_DST_CACHE
|
|
preempt_disable();
|
|
dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr);
|
|
preempt_enable();
|
|
#endif
|
|
}
|
|
|
|
skb_dst_drop(skb);
|
|
skb_dst_set(skb, dst);
|
|
|
|
return dst_output(net, sk, skb);
|
|
drop:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
static int seg6_build_state(struct net_device *dev, struct nlattr *nla,
|
|
unsigned int family, const void *cfg,
|
|
struct lwtunnel_state **ts)
|
|
{
|
|
struct nlattr *tb[SEG6_IPTUNNEL_MAX + 1];
|
|
struct seg6_iptunnel_encap *tuninfo;
|
|
struct lwtunnel_state *newts;
|
|
int tuninfo_len, min_size;
|
|
struct seg6_lwt *slwt;
|
|
int err;
|
|
|
|
err = nla_parse_nested(tb, SEG6_IPTUNNEL_MAX, nla,
|
|
seg6_iptunnel_policy);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (!tb[SEG6_IPTUNNEL_SRH])
|
|
return -EINVAL;
|
|
|
|
tuninfo = nla_data(tb[SEG6_IPTUNNEL_SRH]);
|
|
tuninfo_len = nla_len(tb[SEG6_IPTUNNEL_SRH]);
|
|
|
|
/* tuninfo must contain at least the iptunnel encap structure,
|
|
* the SRH and one segment
|
|
*/
|
|
min_size = sizeof(*tuninfo) + sizeof(struct ipv6_sr_hdr) +
|
|
sizeof(struct in6_addr);
|
|
if (tuninfo_len < min_size)
|
|
return -EINVAL;
|
|
|
|
switch (tuninfo->mode) {
|
|
#ifdef CONFIG_IPV6_SEG6_INLINE
|
|
case SEG6_IPTUN_MODE_INLINE:
|
|
break;
|
|
#endif
|
|
case SEG6_IPTUN_MODE_ENCAP:
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* verify that SRH is consistent */
|
|
if (!seg6_validate_srh(tuninfo->srh, tuninfo_len - sizeof(*tuninfo)))
|
|
return -EINVAL;
|
|
|
|
newts = lwtunnel_state_alloc(tuninfo_len + sizeof(*slwt));
|
|
if (!newts)
|
|
return -ENOMEM;
|
|
|
|
slwt = seg6_lwt_lwtunnel(newts);
|
|
|
|
#ifdef CONFIG_DST_CACHE
|
|
err = dst_cache_init(&slwt->cache, GFP_KERNEL);
|
|
if (err) {
|
|
kfree(newts);
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
memcpy(&slwt->tuninfo, tuninfo, tuninfo_len);
|
|
|
|
newts->type = LWTUNNEL_ENCAP_SEG6;
|
|
newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
|
|
LWTUNNEL_STATE_INPUT_REDIRECT;
|
|
newts->headroom = seg6_lwt_headroom(tuninfo);
|
|
|
|
*ts = newts;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_DST_CACHE
|
|
static void seg6_destroy_state(struct lwtunnel_state *lwt)
|
|
{
|
|
dst_cache_destroy(&seg6_lwt_lwtunnel(lwt)->cache);
|
|
}
|
|
#endif
|
|
|
|
static int seg6_fill_encap_info(struct sk_buff *skb,
|
|
struct lwtunnel_state *lwtstate)
|
|
{
|
|
struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate);
|
|
|
|
if (nla_put_srh(skb, SEG6_IPTUNNEL_SRH, tuninfo))
|
|
return -EMSGSIZE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int seg6_encap_nlsize(struct lwtunnel_state *lwtstate)
|
|
{
|
|
struct seg6_iptunnel_encap *tuninfo = seg6_encap_lwtunnel(lwtstate);
|
|
|
|
return nla_total_size(SEG6_IPTUN_ENCAP_SIZE(tuninfo));
|
|
}
|
|
|
|
static int seg6_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
|
|
{
|
|
struct seg6_iptunnel_encap *a_hdr = seg6_encap_lwtunnel(a);
|
|
struct seg6_iptunnel_encap *b_hdr = seg6_encap_lwtunnel(b);
|
|
int len = SEG6_IPTUN_ENCAP_SIZE(a_hdr);
|
|
|
|
if (len != SEG6_IPTUN_ENCAP_SIZE(b_hdr))
|
|
return 1;
|
|
|
|
return memcmp(a_hdr, b_hdr, len);
|
|
}
|
|
|
|
static const struct lwtunnel_encap_ops seg6_iptun_ops = {
|
|
.build_state = seg6_build_state,
|
|
#ifdef CONFIG_DST_CACHE
|
|
.destroy_state = seg6_destroy_state,
|
|
#endif
|
|
.output = seg6_output,
|
|
.input = seg6_input,
|
|
.fill_encap = seg6_fill_encap_info,
|
|
.get_encap_size = seg6_encap_nlsize,
|
|
.cmp_encap = seg6_encap_cmp,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
int __init seg6_iptunnel_init(void)
|
|
{
|
|
return lwtunnel_encap_add_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6);
|
|
}
|
|
|
|
void seg6_iptunnel_exit(void)
|
|
{
|
|
lwtunnel_encap_del_ops(&seg6_iptun_ops, LWTUNNEL_ENCAP_SEG6);
|
|
}
|