static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
__be16 proto)
{
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct rtable *rt = NULL;
struct flowi4 fl;
int min_headroom;
int tunnel_hlen;
__be16 df, flags;
bool use_cache;
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;
use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
if (use_cache)
rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl.saddr);
if (!rt) {
rt = gre_get_rt(skb, dev, &fl, key);
if (IS_ERR(rt))
goto err_free_skb;
if (use_cache)
dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
fl.saddr);
}
tunnel_hlen = 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 struct rtable *prepare_fb_xmit(struct sk_buff *skb,
struct net_device *dev,
struct flowi4 *fl,
int tunnel_hlen)
{
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct rtable *rt = NULL;
int min_headroom;
bool use_cache;
int err;
tun_info = skb_tunnel_info(skb);
key = &tun_info->key;
use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);
if (use_cache)
rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl->saddr);
if (!rt) {
rt = gre_get_rt(skb, dev, fl, key);
if (IS_ERR(rt))
goto err_free_skb;
if (use_cache)
dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,
fl->saddr);
}
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;
}
void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
const struct iphdr *tnl_params, u8 protocol)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
const struct iphdr *inner_iph;
struct flowi4 fl4;
u8 tos, ttl;
__be16 df;
struct rtable *rt; /* Route to the other host */
unsigned int max_headroom; /* The extra header space needed */
__be32 dst;
bool connected;
inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
connected = (tunnel->parms.iph.daddr != 0);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
dst = tnl_params->daddr;
if (dst == 0) {
/* NBMA tunnel */
if (!skb_dst(skb)) {
dev->stats.tx_fifo_errors++;
goto tx_error;
}
if (skb->protocol == htons(ETH_P_IP)) {
rt = skb_rtable(skb);
dst = rt_nexthop(rt, inner_iph->daddr);
}
#if IS_ENABLED(CONFIG_IPV6)
else if (skb->protocol == htons(ETH_P_IPV6)) {
const struct in6_addr *addr6;
struct neighbour *neigh;
bool do_tx_error_icmp;
int addr_type;
neigh = dst_neigh_lookup(skb_dst(skb),
&ipv6_hdr(skb)->daddr);
if (!neigh)
goto tx_error;
addr6 = (const struct in6_addr *)&neigh->primary_key;
addr_type = ipv6_addr_type(addr6);
if (addr_type == IPV6_ADDR_ANY) {
addr6 = &ipv6_hdr(skb)->daddr;
addr_type = ipv6_addr_type(addr6);
}
if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
do_tx_error_icmp = true;
else {
do_tx_error_icmp = false;
dst = addr6->s6_addr32[3];
}
neigh_release(neigh);
if (do_tx_error_icmp)
goto tx_error_icmp;
}
#endif
else
goto tx_error;
connected = false;
}
tos = tnl_params->tos;
if (tos & 0x1) {
tos &= ~0x1;
if (skb->protocol == htons(ETH_P_IP)) {
tos = inner_iph->tos;
connected = false;
} else if (skb->protocol == htons(ETH_P_IPV6)) {
tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
connected = false;
}
}
init_tunnel_flow(&fl4, protocol, dst, tnl_params->saddr,
tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link);
if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0)
goto tx_error;
rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr) :
NULL;
if (!rt) {
rt = ip_route_output_key(tunnel->net, &fl4);
if (IS_ERR(rt)) {
dev->stats.tx_carrier_errors++;
goto tx_error;
}
if (connected)
dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst,
fl4.saddr);
}
if (rt->dst.dev == dev) {
ip_rt_put(rt);
dev->stats.collisions++;
goto tx_error;
}
if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off, inner_iph)) {
ip_rt_put(rt);
goto tx_error;
}
if (tunnel->err_count > 0) {
if (time_before(jiffies,
tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
tunnel->err_count--;
dst_link_failure(skb);
} else
tunnel->err_count = 0;
}
tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
ttl = tnl_params->ttl;
if (ttl == 0) {
if (skb->protocol == htons(ETH_P_IP))
ttl = inner_iph->ttl;
#if IS_ENABLED(CONFIG_IPV6)
else if (skb->protocol == htons(ETH_P_IPV6))
ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
#endif
else
ttl = ip4_dst_hoplimit(&rt->dst);
}
df = tnl_params->frag_off;
if (skb->protocol == htons(ETH_P_IP))
df |= (inner_iph->frag_off&htons(IP_DF));
max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr)
+ rt->dst.header_len + ip_encap_hlen(&tunnel->encap);
if (max_headroom > dev->needed_headroom)
dev->needed_headroom = max_headroom;
if (skb_cow_head(skb, dev->needed_headroom)) {
ip_rt_put(rt);
dev->stats.tx_dropped++;
kfree_skb(skb);
return;
}
iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
df, !net_eq(tunnel->net, dev_net(dev)));
return;
#if IS_ENABLED(CONFIG_IPV6)
tx_error_icmp:
dst_link_failure(skb);
#endif
tx_error:
dev->stats.tx_errors++;
kfree_skb(skb);
}
