ip6_gre: add ip6 erspan collect_md mode

Similar to ip6 gretap and ip4 gretap, the patch allows
erspan tunnel to operate in collect metadata mode.
bpf_skb_[gs]et_tunnel_key() helpers can make use of
it right away.

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
William Tu 2017-12-05 15:15:44 -08:00 committed by David S. Miller
parent 92425c4067
commit ef7baf5e08

View file

@ -524,8 +524,37 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
false, false) < 0)
return PACKET_REJECT;
tunnel->parms.index = ntohl(index);
ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
if (tunnel->parms.collect_md) {
struct metadata_dst *tun_dst;
struct ip_tunnel_info *info;
struct erspan_metadata *md;
__be64 tun_id;
__be16 flags;
tpi->flags |= TUNNEL_KEY;
flags = tpi->flags;
tun_id = key32_to_tunnel_id(tpi->key);
tun_dst = ipv6_tun_rx_dst(skb, flags, tun_id,
sizeof(*md));
if (!tun_dst)
return PACKET_REJECT;
info = &tun_dst->u.tun_info;
md = ip_tunnel_info_opts(info);
if (!md)
return PACKET_REJECT;
md->index = index;
info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
info->options_len = sizeof(*md);
ip6_tnl_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
} else {
tunnel->parms.index = ntohl(index);
ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
}
return PACKET_RCVD;
}
@ -857,42 +886,73 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
if (gre_handle_offloads(skb, false))
goto tx_err;
switch (skb->protocol) {
case htons(ETH_P_IP):
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
&dsfield, &encap_limit);
break;
case htons(ETH_P_IPV6):
if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
goto tx_err;
if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
&dsfield, &encap_limit))
goto tx_err;
break;
default:
memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
break;
}
if (skb->len > dev->mtu + dev->hard_header_len) {
pskb_trim(skb, dev->mtu + dev->hard_header_len);
truncate = true;
}
erspan_build_header(skb, t->parms.o_key, t->parms.index,
truncate, false);
t->parms.o_flags &= ~TUNNEL_KEY;
IPCB(skb)->flags = 0;
fl6.daddr = t->parms.raddr;
/* For collect_md mode, derive fl6 from the tunnel key,
* for native mode, call prepare_ip6gre_xmit_{ipv4,ipv6}.
*/
if (t->parms.collect_md) {
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct erspan_metadata *md;
tun_info = skb_tunnel_info(skb);
if (unlikely(!tun_info ||
!(tun_info->mode & IP_TUNNEL_INFO_TX) ||
ip_tunnel_info_af(tun_info) != AF_INET6))
return -EINVAL;
key = &tun_info->key;
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_proto = IPPROTO_GRE;
fl6.daddr = key->u.ipv6.dst;
fl6.flowlabel = key->label;
fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
dsfield = key->tos;
md = ip_tunnel_info_opts(tun_info);
if (!md)
goto tx_err;
erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
ntohl(md->index), truncate, false);
} else {
switch (skb->protocol) {
case htons(ETH_P_IP):
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
prepare_ip6gre_xmit_ipv4(skb, dev, &fl6,
&dsfield, &encap_limit);
break;
case htons(ETH_P_IPV6):
if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr))
goto tx_err;
if (prepare_ip6gre_xmit_ipv6(skb, dev, &fl6,
&dsfield, &encap_limit))
goto tx_err;
break;
default:
memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
break;
}
erspan_build_header(skb, t->parms.o_key, t->parms.index,
truncate, false);
fl6.daddr = t->parms.raddr;
}
/* Push GRE header. */
gre_build_header(skb, 8, TUNNEL_SEQ,
htons(ETH_P_ERSPAN), 0, htonl(t->o_seqno++));
/* TooBig packet may have updated dst->dev's mtu */
if (dst && dst_mtu(dst) > dst->dev->mtu)
if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu)
dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu);
err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,