Commit 140f04c3 authored by David Lebrun's avatar David Lebrun Committed by David S. Miller

ipv6: sr: implement several seg6local actions

This patch implements the following seg6local actions.

- SEG6_LOCAL_ACTION_END: regular SRH processing. The DA of the packet
  is updated to the next segment and forwarded accordingly.

- SEG6_LOCAL_ACTION_END_X: same as above, except that the packet is
  forwarded to the specified IPv6 next-hop.

- SEG6_LOCAL_ACTION_END_DX6: decapsulate the packet and forward to
  inner IPv6 packet to the specified IPv6 next-hop.

- SEG6_LOCAL_ACTION_END_B6: insert the specified SRH directly after
  the IPv6 header of the packet.

- SEG6_LOCAL_ACTION_END_B6_ENCAP: encapsulate the packet within
  an outer IPv6 header, containing the specified SRH.
Signed-off-by: default avatarDavid Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2d9cc60a
......@@ -58,11 +58,282 @@ static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
return (struct seg6_local_lwt *)lwt->data;
}
static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
struct ipv6hdr *hdr;
int len;
hdr = ipv6_hdr(skb);
if (hdr->nexthdr != IPPROTO_ROUTING)
return NULL;
srh = (struct ipv6_sr_hdr *)(hdr + 1);
len = (srh->hdrlen + 1) << 3;
if (!pskb_may_pull(skb, sizeof(*hdr) + len))
return NULL;
if (!seg6_validate_srh(srh, len))
return NULL;
return srh;
}
static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
srh = get_srh(skb);
if (!srh)
return NULL;
if (srh->segments_left == 0)
return NULL;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (!seg6_hmac_validate_skb(skb))
return NULL;
#endif
return srh;
}
/* regular endpoint function */
static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
struct in6_addr *addr;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
ipv6_hdr(skb)->daddr = *addr;
skb_dst_drop(skb);
ip6_route_input(skb);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* regular endpoint, and forward to specified nexthop */
static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct net *net = dev_net(skb->dev);
struct ipv6_sr_hdr *srh;
struct dst_entry *dst;
struct in6_addr *addr;
struct ipv6hdr *hdr;
struct flowi6 fl6;
int flags;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
hdr = ipv6_hdr(skb);
hdr->daddr = *addr;
skb_dst_drop(skb);
fl6.flowi6_iif = skb->dev->ifindex;
fl6.daddr = slwt->nh6;
fl6.saddr = hdr->saddr;
fl6.flowlabel = ip6_flowinfo(hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;
flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE |
RT6_LOOKUP_F_REACHABLE;
dst = ip6_route_input_lookup(net, skb->dev, &fl6, flags);
if (dst->dev->flags & IFF_LOOPBACK)
goto drop;
skb_dst_set(skb, dst);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* decapsulate and forward to specified nexthop */
static int input_action_end_dx6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct net *net = dev_net(skb->dev);
struct ipv6hdr *inner_hdr;
struct ipv6_sr_hdr *srh;
struct dst_entry *dst;
unsigned int off = 0;
struct flowi6 fl6;
bool use_nh;
int flags;
/* this function accepts IPv6 encapsulated packets, with either
* an SRH with SL=0, or no SRH.
*/
srh = get_srh(skb);
if (srh && srh->segments_left > 0)
goto drop;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
goto drop;
#endif
if (ipv6_find_hdr(skb, &off, IPPROTO_IPV6, NULL, NULL) < 0)
goto drop;
if (!pskb_pull(skb, off))
goto drop;
skb_postpull_rcsum(skb, skb_network_header(skb), off);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
skb->encapsulation = 0;
inner_hdr = ipv6_hdr(skb);
/* The inner packet is not associated to any local interface,
* so we do not call netif_rx().
*
* If slwt->nh6 is set to ::, then lookup the nexthop for the
* inner packet's DA. Otherwise, use the specified nexthop.
*/
use_nh = !ipv6_addr_any(&slwt->nh6);
skb_dst_drop(skb);
fl6.flowi6_iif = skb->dev->ifindex;
fl6.daddr = use_nh ? slwt->nh6 : inner_hdr->daddr;
fl6.saddr = inner_hdr->saddr;
fl6.flowlabel = ip6_flowinfo(inner_hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = inner_hdr->nexthdr;
flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_REACHABLE;
if (use_nh)
flags |= RT6_LOOKUP_F_IFACE;
dst = ip6_route_input_lookup(net, skb->dev, &fl6, flags);
if (dst->dev->flags & IFF_LOOPBACK)
goto drop;
skb_dst_set(skb, dst);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* push an SRH on top of the current one */
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
err = seg6_do_srh_inline(skb, slwt->srh);
if (err)
goto drop;
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
skb_dst_drop(skb);
ip6_route_input(skb);
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
/* encapsulate within an outer IPv6 header and a specified SRH */
static int input_action_end_b6_encap(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
struct in6_addr *addr;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
ipv6_hdr(skb)->daddr = *addr;
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
err = seg6_do_srh_encap(skb, slwt->srh);
if (err)
goto drop;
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
skb_dst_drop(skb);
ip6_route_input(skb);
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
static struct seg6_action_desc seg6_action_table[] = {
{
.action = SEG6_LOCAL_ACTION_END,
.attrs = 0,
.input = input_action_end,
},
{
.action = SEG6_LOCAL_ACTION_END_X,
.attrs = (1 << SEG6_LOCAL_NH6),
.input = input_action_end_x,
},
{
.action = SEG6_LOCAL_ACTION_END_DX6,
.attrs = (1 << SEG6_LOCAL_NH6),
.input = input_action_end_dx6,
},
{
.action = SEG6_LOCAL_ACTION_END_B6,
.attrs = (1 << SEG6_LOCAL_SRH),
.input = input_action_end_b6,
},
{
.action = SEG6_LOCAL_ACTION_END_B6_ENCAP,
.attrs = (1 << SEG6_LOCAL_SRH),
.input = input_action_end_b6_encap,
.static_headroom = sizeof(struct ipv6hdr),
}
};
static struct seg6_action_desc *__get_action_desc(int action)
......
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