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gre: add collect_md mode to ERSPAN tunnel

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Similar to gre, vxlan, geneve, ipip tunnels, allow ERSPAN tunnels to
operate in 'collect metadata' mode.  bpf_skb_[gs]et_tunnel_key() helpers
can make use of it right away.  OVS can use it as well in the future.

Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
William Tu 2017-08-25 09:21:28 -07:00 committed by David S. Miller
parent 862a03c35e
commit 1a66a836da
2 changed files with 101 additions and 5 deletions
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4
include/net/ip_tunnels.h
View file

@ -154,8 +154,10 @@ struct ip_tunnel {
#define TUNNEL_GENEVE_OPT __cpu_to_be16(0x0800)
#define TUNNEL_VXLAN_OPT __cpu_to_be16(0x1000)
#define TUNNEL_NOCACHE __cpu_to_be16(0x2000)
#define TUNNEL_ERSPAN_OPT __cpu_to_be16(0x4000)
#define TUNNEL_OPTIONS_PRESENT (TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT)
#define TUNNEL_OPTIONS_PRESENT \
(TUNNEL_GENEVE_OPT | TUNNEL_VXLAN_OPT | TUNNEL_ERSPAN_OPT)
struct tnl_ptk_info {
__be16 flags;

102
net/ipv4/ip_gre.c
View file

@ -113,6 +113,8 @@ MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
static struct rtnl_link_ops ipgre_link_ops __read_mostly;
static int ipgre_tunnel_init(struct net_device *dev);
static void erspan_build_header(struct sk_buff *skb,
__be32 id, u32 index, bool truncate);
static unsigned int ipgre_net_id __read_mostly;
static unsigned int gre_tap_net_id __read_mostly;
@ -287,7 +289,33 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
false, false) < 0)
goto drop;
tunnel->index = ntohl(index);
if (tunnel->collect_md) {
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 = ip_tun_rx_dst(skb, flags,
tun_id, sizeof(*md));
if (!tun_dst)
return PACKET_REJECT;
md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
if (!md)
return PACKET_REJECT;
md->index = index;
info = &tun_dst->u.tun_info;
info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
info->options_len = sizeof(*md);
} else {
tunnel->index = ntohl(index);
}
skb_reset_mac_header(skb);
ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
return PACKET_RCVD;
@ -523,6 +551,64 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
dev->stats.tx_dropped++;
}
static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
__be16 proto)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct erspan_metadata *md;
struct rtable *rt = NULL;
bool truncate = false;
struct flowi4 fl;
int tunnel_hlen;
__be16 df;
tun_info = skb_tunnel_info(skb);
if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
ip_tunnel_info_af(tun_info) != AF_INET))
goto err_free_skb;
key = &tun_info->key;
/* ERSPAN has fixed 8 byte GRE header */
tunnel_hlen = 8 + sizeof(struct erspanhdr);
rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen);
if (!rt)
return;
if (gre_handle_offloads(skb, false))
goto err_free_rt;
if (skb->len > dev->mtu) {
pskb_trim(skb, dev->mtu);
truncate = true;
}
md = ip_tunnel_info_opts(tun_info);
if (!md)
goto err_free_rt;
erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
ntohl(md->index), truncate);
gre_build_header(skb, 8, TUNNEL_SEQ,
htons(ETH_P_ERSPAN), 0, htonl(tunnel->o_seqno++));
df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE,
key->tos, key->ttl, df, false);
return;
err_free_rt:
ip_rt_put(rt);
err_free_skb:
kfree_skb(skb);
dev->stats.tx_dropped++;
}
static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
{
struct ip_tunnel_info *info = skb_tunnel_info(skb);
@ -636,6 +722,11 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
struct ip_tunnel *tunnel = netdev_priv(dev);
bool truncate = false;
if (tunnel->collect_md) {
erspan_fb_xmit(skb, dev, skb->protocol);
return NETDEV_TX_OK;
}
if (gre_handle_offloads(skb, false))
goto free_skb;
@ -998,9 +1089,12 @@ static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
return ret;
/* ERSPAN should only have GRE sequence and key flag */
flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
if (flags != (GRE_SEQ | GRE_KEY))
if (data[IFLA_GRE_OFLAGS])
flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
if (data[IFLA_GRE_IFLAGS])
flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
if (!data[IFLA_GRE_COLLECT_METADATA] &&
flags != (GRE_SEQ | GRE_KEY))
return -EINVAL;
/* ERSPAN Session ID only has 10-bit. Since we reuse