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author | David Lebrun <david.lebrun@uclouvain.be> | 2016-11-08 14:57:41 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2016-11-09 20:40:06 -0500 |
commit | 6c8702c60b88651072460f3f4026c7dfe2521d12 (patch) | |
tree | 2ff901e3824bb605585e76c43739aa9b4b90ec39 /net/ipv6/seg6.c | |
parent | 915d7e5e5930b4f01d0971d93b9b25ed17d221aa (diff) | |
download | lwn-6c8702c60b88651072460f3f4026c7dfe2521d12.tar.gz lwn-6c8702c60b88651072460f3f4026c7dfe2521d12.zip |
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>
Diffstat (limited to 'net/ipv6/seg6.c')
-rw-r--r-- | net/ipv6/seg6.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c index e246b0ba12ac..9c78053e67e0 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); } |