static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
bool *csum_err)
{
unsigned int ip_hlen = ip_hdrlen(skb);
const struct gre_base_hdr *greh;
__be32 *options;
int hdr_len;
if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
return -EINVAL;
greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
return -EINVAL;
tpi->flags = gre_flags_to_tnl_flags(greh->flags);
hdr_len = ip_gre_calc_hlen(tpi->flags);
if (!pskb_may_pull(skb, hdr_len))
return -EINVAL;
greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
tpi->proto = greh->protocol;
options = (__be32 *)(greh + 1);
if (greh->flags & GRE_CSUM) {
if (check_checksum(skb)) {
*csum_err = true;
return -EINVAL;
}
options++;
}
if (greh->flags & GRE_KEY) {
tpi->key = *options;
options++;
} else
tpi->key = 0;
if (unlikely(greh->flags & GRE_SEQ)) {
tpi->seq = *options;
options++;
} else
tpi->seq = 0;
/* WCCP version 1 and 2 protocol decoding.
* - Change protocol to IP
* - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
*/
if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
tpi->proto = htons(ETH_P_IP);
if ((*(u8 *)options & 0xF0) != 0x40) {
hdr_len += 4;
if (!pskb_may_pull(skb, hdr_len))
return -EINVAL;
}
}
return iptunnel_pull_header(skb, hdr_len, tpi->proto);
}
static void __gre_tunnel_init(struct net_device *dev)
{
struct ip_tunnel *tunnel;
int t_hlen;
tunnel = netdev_priv(dev);
tunnel->tun_hlen = ip_gre_calc_hlen(tunnel->parms.o_flags);
tunnel->parms.iph.protocol = IPPROTO_GRE;
tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
t_hlen = tunnel->hlen + sizeof(struct iphdr);
dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4;
dev->mtu = ETH_DATA_LEN - t_hlen - 4;
dev->features |= GRE_FEATURES;
dev->hw_features |= GRE_FEATURES;
if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
/* TCP offload with GRE SEQ is not supported. */
dev->features |= NETIF_F_GSO_SOFTWARE;
dev->hw_features |= NETIF_F_GSO_SOFTWARE;
/* Can use a lockless transmit, unless we generate
* output sequences
*/
dev->features |= NETIF_F_LLTX;
}
}
static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct flowi4 fl;
struct rtable *rt;
int min_headroom;
int tunnel_hlen;
__be16 df, flags;
int err;
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;
rt = gre_get_rt(skb, dev, &fl, key);
if (IS_ERR(rt))
goto err_free_skb;
tunnel_hlen = ip_gre_calc_hlen(key->tun_flags);
min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
+ tunnel_hlen + sizeof(struct iphdr);
if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
int head_delta = SKB_DATA_ALIGN(min_headroom -
skb_headroom(skb) +
16);
err = pskb_expand_head(skb, max_t(int, head_delta, 0),
0, GFP_ATOMIC);
if (unlikely(err))
goto err_free_rt;
}
static int gre_tnl_send(struct vport *vport, struct sk_buff *skb)
{
struct net *net = ovs_dp_get_net(vport->dp);
struct ovs_key_ipv4_tunnel *tun_key;
struct flowi4 fl;
struct rtable *rt;
int min_headroom;
int tunnel_hlen;
__be16 df;
int err;
if (unlikely(!OVS_CB(skb)->egress_tun_key)) {
err = -EINVAL;
goto error;
}
tun_key = OVS_CB(skb)->egress_tun_key;
/* Route lookup */
memset(&fl, 0, sizeof(fl));
fl.daddr = tun_key->ipv4_dst;
fl.saddr = tun_key->ipv4_src;
fl.flowi4_tos = RT_TOS(tun_key->ipv4_tos);
fl.flowi4_mark = skb->mark;
fl.flowi4_proto = IPPROTO_GRE;
rt = ip_route_output_key(net, &fl);
if (IS_ERR(rt))
return PTR_ERR(rt);
tunnel_hlen = ip_gre_calc_hlen(tun_key->tun_flags);
min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
+ tunnel_hlen + sizeof(struct iphdr)
+ (vlan_tx_tag_present(skb) ? VLAN_HLEN : 0);
if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
int head_delta = SKB_DATA_ALIGN(min_headroom -
skb_headroom(skb) +
16);
err = pskb_expand_head(skb, max_t(int, head_delta, 0),
0, GFP_ATOMIC);
if (unlikely(err))
goto err_free_rt;
}
static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ip_tunnel_info *tun_info;
struct net *net = dev_net(dev);
const struct ip_tunnel_key *key;
struct flowi4 fl;
struct rtable *rt;
int min_headroom;
int tunnel_hlen;
__be16 df, flags;
int err;
tun_info = skb_tunnel_info(skb, AF_INET);
if (unlikely(!tun_info || tun_info->mode != IP_TUNNEL_INFO_TX))
goto err_free_skb;
key = &tun_info->key;
memset(&fl, 0, sizeof(fl));
fl.daddr = key->ipv4_dst;
fl.saddr = key->ipv4_src;
fl.flowi4_tos = RT_TOS(key->ipv4_tos);
fl.flowi4_mark = skb->mark;
fl.flowi4_proto = IPPROTO_GRE;
rt = ip_route_output_key(net, &fl);
if (IS_ERR(rt))
goto err_free_skb;
tunnel_hlen = ip_gre_calc_hlen(key->tun_flags);
min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len
+ tunnel_hlen + sizeof(struct iphdr);
if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
int head_delta = SKB_DATA_ALIGN(min_headroom -
skb_headroom(skb) +
16);
err = pskb_expand_head(skb, max_t(int, head_delta, 0),
0, GFP_ATOMIC);
if (unlikely(err))
goto err_free_rt;
}
/* Fills in tpi and returns header length to be pulled. */
static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
bool *csum_err)
{
const struct gre_base_hdr *greh;
__be32 *options;
int hdr_len;
if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
return -EINVAL;
greh = (struct gre_base_hdr *)skb_transport_header(skb);
if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
return -EINVAL;
tpi->flags = gre_flags_to_tnl_flags(greh->flags);
hdr_len = ip_gre_calc_hlen(tpi->flags);
if (!pskb_may_pull(skb, hdr_len))
return -EINVAL;
greh = (struct gre_base_hdr *)skb_transport_header(skb);
tpi->proto = greh->protocol;
options = (__be32 *)(greh + 1);
if (greh->flags & GRE_CSUM) {
if (skb_checksum_simple_validate(skb)) {
*csum_err = true;
return -EINVAL;
}
skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
null_compute_pseudo);
options++;
}
if (greh->flags & GRE_KEY) {
tpi->key = *options;
options++;
} else {
tpi->key = 0;
}
if (unlikely(greh->flags & GRE_SEQ)) {
tpi->seq = *options;
options++;
} else {
tpi->seq = 0;
}
/* WCCP version 1 and 2 protocol decoding.
* - Change protocol to IP
* - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
*/
if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
tpi->proto = htons(ETH_P_IP);
if ((*(u8 *)options & 0xF0) != 0x40) {
hdr_len += 4;
if (!pskb_may_pull(skb, hdr_len))
return -EINVAL;
}
}
return hdr_len;
}
