static int gre_cisco_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
int i;
bool csum_err = false;
if (parse_gre_header(skb, &tpi, &csum_err) < 0)
goto drop;
rcu_read_lock();
for (i = 0; i < GRE_IP_PROTO_MAX; i++) {
struct gre_cisco_protocol *proto;
int ret;
proto = rcu_dereference(gre_cisco_proto_list[i]);
if (!proto)
continue;
ret = proto->handler(skb, &tpi);
if (ret == PACKET_RCVD) {
rcu_read_unlock();
return 0;
}
}
rcu_read_unlock();
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
drop:
kfree_skb(skb);
return 0;
}
static int ipgre_rcv(struct sk_buff *skb)
{
struct net *net = dev_net(skb->dev);
struct ip_tunnel_net *itn;
const struct iphdr *iph;
struct ip_tunnel *tunnel;
struct tnl_ptk_info tpi;
int hdr_len;
bool csum_err = false;
if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len) < 0)
goto drop;
if (tpi.proto == htons(ETH_P_TEB))
itn = net_generic(net, gre_tap_net_id);
else
itn = net_generic(net, ipgre_net_id);
iph = ip_hdr(skb);
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags,
iph->saddr, iph->daddr, tpi.key);
if (tunnel) {
skb_pop_mac_header(skb);
ip_tunnel_rcv(tunnel, skb, &tpi, hdr_len, log_ecn_error);
return 0;
}
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
drop:
kfree_skb(skb);
return 0;
}
static int gre_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
bool csum_err = false;
int hdr_len;
#ifdef CONFIG_NET_IPGRE_BROADCAST
if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
/* Looped back packet, drop it! */
if (rt_is_output_route(skb_rtable(skb)))
goto drop;
}
#endif
hdr_len = parse_gre_header(skb, &tpi, &csum_err);
if (hdr_len < 0)
goto drop;
if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false) < 0)
goto drop;
if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
return 0;
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
drop:
kfree_skb(skb);
return 0;
}
static void gre_cisco_err(struct sk_buff *skb, u32 info)
{
/* All the routers (except for Linux) return only
* 8 bytes of packet payload. It means, that precise relaying of
* ICMP in the real Internet is absolutely infeasible.
*
* Moreover, Cisco "wise men" put GRE key to the third word
* in GRE header. It makes impossible maintaining even soft
* state for keyed
* GRE tunnels with enabled checksum. Tell them "thank you".
*
* Well, I wonder, rfc1812 was written by Cisco employee,
* what the hell these idiots break standards established
* by themselves???
*/
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
struct tnl_ptk_info tpi;
bool csum_err = false;
int i;
if (parse_gre_header(skb, &tpi, &csum_err)) {
if (!csum_err) /* ignore csum errors. */
return;
}
if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
ipv4_update_pmtu(skb, dev_net(skb->dev), info,
skb->dev->ifindex, 0, IPPROTO_GRE, 0);
return;
}
if (type == ICMP_REDIRECT) {
ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0,
IPPROTO_GRE, 0);
return;
}
rcu_read_lock();
for (i = 0; i < GRE_IP_PROTO_MAX; i++) {
struct gre_cisco_protocol *proto;
proto = rcu_dereference(gre_cisco_proto_list[i]);
if (!proto)
continue;
if (proto->err_handler(skb, info, &tpi) == PACKET_RCVD)
goto out;
}
out:
rcu_read_unlock();
}
static int gre_cisco_rcv(struct sk_buff *skb)
{
struct tnl_ptk_info tpi;
bool csum_err = false;
struct gre_cisco_protocol *proto;
rcu_read_lock();
proto = rcu_dereference(gre_cisco_proto);
if (!proto)
goto drop;
if (parse_gre_header(skb, &tpi, &csum_err) < 0)
goto drop;
proto->handler(skb, &tpi);
rcu_read_unlock();
return 0;
drop:
rcu_read_unlock();
kfree_skb(skb);
return 0;
}
static void ipgre_err(struct sk_buff *skb, u32 info)
{
/* All the routers (except for Linux) return only
8 bytes of packet payload. It means, that precise relaying of
ICMP in the real Internet is absolutely infeasible.
Moreover, Cisco "wise men" put GRE key to the third word
in GRE header. It makes impossible maintaining even soft
state for keyed GRE tunnels with enabled checksum. Tell
them "thank you".
Well, I wonder, rfc1812 was written by Cisco employee,
what the hell these idiots break standards established
by themselves???
*/
struct net *net = dev_net(skb->dev);
struct ip_tunnel_net *itn;
const struct iphdr *iph;
const int type = icmp_hdr(skb)->type;
const int code = icmp_hdr(skb)->code;
struct ip_tunnel *t;
struct tnl_ptk_info tpi;
int hdr_len;
bool csum_err = false;
if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len)) {
if (!csum_err) /* ignore csum errors. */
return;
}
switch (type) {
default:
case ICMP_PARAMETERPROB:
return;
case ICMP_DEST_UNREACH:
switch (code) {
case ICMP_SR_FAILED:
case ICMP_PORT_UNREACH:
/* Impossible event. */
return;
default:
/* All others are translated to HOST_UNREACH.
rfc2003 contains "deep thoughts" about NET_UNREACH,
I believe they are just ether pollution. --ANK
*/
break;
}
break;
case ICMP_TIME_EXCEEDED:
if (code != ICMP_EXC_TTL)
return;
break;
case ICMP_REDIRECT:
break;
}
if (tpi.proto == htons(ETH_P_TEB))
itn = net_generic(net, gre_tap_net_id);
else
itn = net_generic(net, ipgre_net_id);
iph = (const struct iphdr *)skb->data;
t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags,
iph->daddr, iph->saddr, tpi.key);
if (t == NULL)
return;
if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
ipv4_update_pmtu(skb, dev_net(skb->dev), info,
t->parms.link, 0, IPPROTO_GRE, 0);
return;
}
if (type == ICMP_REDIRECT) {
ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
IPPROTO_GRE, 0);
return;
}
if (t->parms.iph.daddr == 0 ||
ipv4_is_multicast(t->parms.iph.daddr))
return;
if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
return;
if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
t->err_count++;
else
t->err_count = 1;
t->err_time = jiffies;
}