diff mbox series

[net-next,1/1] seg6: add support for SRv6 Headend Reduced Encapsulation

Message ID 4f26bfaf-3c91-fe19-ede1-d47d852c17f6@gmail.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series [net-next,1/1] seg6: add support for SRv6 Headend Reduced Encapsulation | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/apply fail Patch does not apply to net-next

Commit Message

Anton Makarov June 6, 2022, 6:41 p.m. UTC
This patch extends SRv6 Headend behaviors with reduced SRH encapsulation
accordingly to RFC 8986. Additional SRv6 Headend behaviors H.Encaps.Red and
H.Encaps.L2.Red optimize overhead of network traffic for SRv6 L2 and L3 
VPNs.

Signed-off-by: Anton Makarov <anton.makarov11235@gmail.com>
---
  include/net/seg6.h                 |  2 +
  include/uapi/linux/seg6_iptunnel.h |  2 +
  net/ipv6/seg6_iptunnel.c           | 95 +++++++++++++++++++++++++++++-
  3 files changed, 97 insertions(+), 2 deletions(-)


@@ -195,6 +197,81 @@ int seg6_do_srh_encap(struct sk_buff *skb, struct 
ipv6_sr_hdr *osrh, int proto)
  }
  EXPORT_SYMBOL_GPL(seg6_do_srh_encap);

+/* encapsulate an IPv6 packet within an outer IPv6 header with reduced 
SRH */
+int seg6_do_srh_encap_red(struct sk_buff *skb, struct ipv6_sr_hdr 
*osrh, int proto)
+{
+    struct dst_entry *dst = skb_dst(skb);
+    struct net *net = dev_net(dst->dev);
+    struct ipv6hdr *hdr, *inner_hdr6;
+    struct iphdr *inner_hdr4;
+    struct ipv6_sr_hdr *isrh;
+    int hdrlen = 0, tot_len, err;
+    __be32 flowlabel = 0;
+
+    if (osrh->first_segment > 0)
+        hdrlen = (osrh->hdrlen - 1) << 3;
+
+    tot_len = hdrlen + sizeof(struct ipv6hdr);
+
+    err = skb_cow_head(skb, tot_len + skb->mac_len);
+    if (unlikely(err))
+        return err;
+
+    inner_hdr6 = ipv6_hdr(skb);
+    inner_hdr4 = ip_hdr(skb);
+    flowlabel = seg6_make_flowlabel(net, skb, inner_hdr6);
+
+    skb_push(skb, tot_len);
+    skb_reset_network_header(skb);
+    skb_mac_header_rebuild(skb);
+    hdr = ipv6_hdr(skb);
+
+    memset(skb->cb, 0, 48);
+    IP6CB(skb)->iif = skb->skb_iif;
+
+    if (skb->protocol == htons(ETH_P_IPV6)) {
+        ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr6)),
+                 flowlabel);
+        hdr->hop_limit = inner_hdr6->hop_limit;
+    } else if (skb->protocol == htons(ETH_P_IP)) {
+        ip6_flow_hdr(hdr, ip6_tclass(inner_hdr4->tos), flowlabel);
+        hdr->hop_limit = inner_hdr4->ttl;
+    }
+
+    skb->protocol = htons(ETH_P_IPV6);
+
+    hdr->daddr = osrh->segments[osrh->first_segment];
+    hdr->version = 6;
+
+    if (osrh->first_segment > 0) {
+        hdr->nexthdr = NEXTHDR_ROUTING;
+
+        isrh = (void *)hdr + sizeof(struct ipv6hdr);
+        memcpy(isrh, osrh, hdrlen);
+
+        isrh->nexthdr = proto;
+        isrh->first_segment--;
+        isrh->hdrlen -= 2;
+    } else {
+        hdr->nexthdr = proto;
+    }
+
+    set_tun_src(net, dst->dev, &hdr->daddr, &hdr->saddr);
+
+#ifdef CONFIG_IPV6_SEG6_HMAC
+    if (osrh->first_segment > 0 && 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;
+}
+EXPORT_SYMBOL_GPL(seg6_do_srh_encap_red);
+
  /* insert an SRH within an IPv6 packet, just after the IPv6 header */
  int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh)
  {
@@ -265,6 +342,7 @@ static int seg6_do_srh(struct sk_buff *skb)
              return err;
          break;
      case SEG6_IPTUN_MODE_ENCAP:
+    case SEG6_IPTUN_MODE_ENCAP_RED:
          err = iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6);
          if (err)
              return err;
@@ -276,7 +354,11 @@ static int seg6_do_srh(struct sk_buff *skb)
          else
              return -EINVAL;

-        err = seg6_do_srh_encap(skb, tinfo->srh, proto);
+        if (tinfo->mode == SEG6_IPTUN_MODE_ENCAP)
+            err = seg6_do_srh_encap(skb, tinfo->srh, proto);
+        else
+            err = seg6_do_srh_encap_red(skb, tinfo->srh, proto);
+
          if (err)
              return err;

@@ -285,6 +367,7 @@ static int seg6_do_srh(struct sk_buff *skb)
          skb->protocol = htons(ETH_P_IPV6);
          break;
      case SEG6_IPTUN_MODE_L2ENCAP:
+    case SEG6_IPTUN_MODE_L2ENCAP_RED:
          if (!skb_mac_header_was_set(skb))
              return -EINVAL;

@@ -294,7 +377,11 @@ static int seg6_do_srh(struct sk_buff *skb)
          skb_mac_header_rebuild(skb);
          skb_push(skb, skb->mac_len);

-        err = seg6_do_srh_encap(skb, tinfo->srh, IPPROTO_ETHERNET);
+        if (tinfo->mode == SEG6_IPTUN_MODE_L2ENCAP)
+            err = seg6_do_srh_encap(skb, tinfo->srh, IPPROTO_ETHERNET);
+        else
+            err = seg6_do_srh_encap_red(skb, tinfo->srh, IPPROTO_ETHERNET);
+
          if (err)
              return err;

@@ -514,6 +601,10 @@ static int seg6_build_state(struct net *net, struct 
nlattr *nla,
          break;
      case SEG6_IPTUN_MODE_L2ENCAP:
          break;
+    case SEG6_IPTUN_MODE_ENCAP_RED:
+        break;
+    case SEG6_IPTUN_MODE_L2ENCAP_RED:
+        break;
      default:
          return -EINVAL;
      }

Comments

Jakub Kicinski June 8, 2022, 12:21 a.m. UTC | #1
On Mon, 6 Jun 2022 21:41:59 +0300 Anton Makarov wrote:
> This patch extends SRv6 Headend behaviors with reduced SRH encapsulation
> accordingly to RFC 8986. Additional SRv6 Headend behaviors H.Encaps.Red and
> H.Encaps.L2.Red optimize overhead of network traffic for SRv6 L2 and L3 
> VPNs.
> 
> Signed-off-by: Anton Makarov <anton.makarov11235@gmail.com>

Thurnderbird line-wrapped the patch contents. Could you try reposting
with git send-email?
diff mbox series

Patch

diff --git a/include/net/seg6.h b/include/net/seg6.h
index af668f17b398..8d0ce782f830 100644
--- a/include/net/seg6.h
+++ b/include/net/seg6.h
@@ -62,6 +62,8 @@  extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff 
*skb, int flags);
  extern void seg6_icmp_srh(struct sk_buff *skb, struct inet6_skb_parm 
*opt);
  extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr 
*osrh,
                   int proto);
+extern int seg6_do_srh_encap_red(struct sk_buff *skb, struct 
ipv6_sr_hdr *osrh,
+                 int proto);
  extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr 
*osrh);
  extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr 
*nhaddr,
                     u32 tbl_id);
diff --git a/include/uapi/linux/seg6_iptunnel.h 
b/include/uapi/linux/seg6_iptunnel.h
index eb815e0d0ac3..a9fa777f16de 100644
--- a/include/uapi/linux/seg6_iptunnel.h
+++ b/include/uapi/linux/seg6_iptunnel.h
@@ -35,6 +35,8 @@  enum {
      SEG6_IPTUN_MODE_INLINE,
      SEG6_IPTUN_MODE_ENCAP,
      SEG6_IPTUN_MODE_L2ENCAP,
+    SEG6_IPTUN_MODE_ENCAP_RED,
+    SEG6_IPTUN_MODE_L2ENCAP_RED,
  };

  #endif
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index d64855010948..430975b03597 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -36,9 +36,11 @@  static size_t seg6_lwt_headroom(struct 
seg6_iptunnel_encap *tuninfo)
      case SEG6_IPTUN_MODE_INLINE:
          break;
      case SEG6_IPTUN_MODE_ENCAP:
+    case SEG6_IPTUN_MODE_ENCAP_RED:
          head = sizeof(struct ipv6hdr);
          break;
      case SEG6_IPTUN_MODE_L2ENCAP:
+    case SEG6_IPTUN_MODE_L2ENCAP_RED:
          return 0;
      }