From 6c8702c60b88651072460f3f4026c7dfe2521d12 Mon Sep 17 00:00:00 2001
From: David Lebrun <david.lebrun@uclouvain.be>
Date: Tue, 8 Nov 2016 14:57:41 +0100
Subject: ipv6: sr: add support for SRH encapsulation and injection with
lwtunnels
This patch creates a new type of interfaceless lightweight tunnel (SEG6),
enabling the encapsulation and injection of SRH within locally emitted
packets and forwarded packets.
>From a configuration viewpoint, a seg6 tunnel would be configured as follows:
ip -6 ro ad fc00::1/128 encap seg6 mode encap segs fc42::1,fc42::2,fc42::3 dev eth0
Any packet whose destination address is fc00::1 would thus be encapsulated
within an outer IPv6 header containing the SRH with three segments, and would
actually be routed to the first segment of the list. If `mode inline' was
specified instead of `mode encap', then the SRH would be directly inserted
after the IPv6 header without outer encapsulation.
The inline mode is only available if CONFIG_IPV6_SEG6_INLINE is enabled. This
feature was made configurable because direct header insertion may break
several mechanisms such as PMTUD or IPSec AH.
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv6/seg6.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)
(limited to 'net/ipv6/seg6.c')
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index e246b0b..9c78053 100644
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -26,6 +26,43 @@
#include <linux/seg6.h>
#include <linux/seg6_genl.h>
+bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len)
+{
+ int trailing;
+ unsigned int tlv_offset;
+
+ if (srh->type != IPV6_SRCRT_TYPE_4)
+ return false;
+
+ if (((srh->hdrlen + 1) << 3) != len)
+ return false;
+
+ if (srh->segments_left != srh->first_segment)
+ return false;
+
+ tlv_offset = sizeof(*srh) + ((srh->first_segment + 1) << 4);
+
+ trailing = len - tlv_offset;
+ if (trailing < 0)
+ return false;
+
+ while (trailing) {
+ struct sr6_tlv *tlv;
+ unsigned int tlv_len;
+
+ tlv = (struct sr6_tlv *)((unsigned char *)srh + tlv_offset);
+ tlv_len = sizeof(*tlv) + tlv->len;
+
+ trailing -= tlv_len;
+ if (trailing < 0)
+ return false;
+
+ tlv_offset += tlv_len;
+ }
+
+ return true;
+}
+
static struct genl_family seg6_genl_family;
static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = {
@@ -198,10 +235,16 @@ int __init seg6_init(void)
if (err)
goto out_unregister_genl;
+ err = seg6_iptunnel_init();
+ if (err)
+ goto out_unregister_pernet;
+
pr_info("Segment Routing with IPv6\n");
out:
return err;
+out_unregister_pernet:
+ unregister_pernet_subsys(&ip6_segments_ops);
out_unregister_genl:
genl_unregister_family(&seg6_genl_family);
goto out;
@@ -209,6 +252,7 @@ out_unregister_genl:
void seg6_exit(void)
{
+ seg6_iptunnel_exit();
unregister_pernet_subsys(&ip6_segments_ops);
genl_unregister_family(&seg6_genl_family);
}
--
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