#include <net/xfrm.h>
static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;
-static struct gre_cisco_protocol __rcu *gre_cisco_proto_list[GRE_IP_PROTO_MAX];
int gre_add_protocol(const struct gre_protocol *proto, u8 version)
{
}
EXPORT_SYMBOL_GPL(gre_del_protocol);
-void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
- int hdr_len)
-{
- struct gre_base_hdr *greh;
-
- skb_push(skb, hdr_len);
-
- skb_reset_transport_header(skb);
- greh = (struct gre_base_hdr *)skb->data;
- greh->flags = tnl_flags_to_gre_flags(tpi->flags);
- greh->protocol = tpi->proto;
-
- if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) {
- __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
-
- if (tpi->flags&TUNNEL_SEQ) {
- *ptr = tpi->seq;
- ptr--;
- }
- if (tpi->flags&TUNNEL_KEY) {
- *ptr = tpi->key;
- ptr--;
- }
- if (tpi->flags&TUNNEL_CSUM &&
- !(skb_shinfo(skb)->gso_type &
- (SKB_GSO_GRE|SKB_GSO_GRE_CSUM))) {
- *ptr = 0;
- *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,
- skb->len, 0));
- }
- }
-}
-EXPORT_SYMBOL_GPL(gre_build_header);
-
-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 iptunnel_pull_header(skb, hdr_len, tpi->proto);
-}
-
-static int gre_cisco_rcv(struct sk_buff *skb)
-{
- struct tnl_ptk_info tpi;
- int i;
- bool csum_err = false;
-
-#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
-
- 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 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_rcv(struct sk_buff *skb)
{
const struct gre_protocol *proto;
.netns_ok = 1,
};
-static const struct gre_protocol ipgre_protocol = {
- .handler = gre_cisco_rcv,
- .err_handler = gre_cisco_err,
-};
-
-int gre_cisco_register(struct gre_cisco_protocol *newp)
-{
- struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **)
- &gre_cisco_proto_list[newp->priority];
-
- return (cmpxchg(proto, NULL, newp) == NULL) ? 0 : -EBUSY;
-}
-EXPORT_SYMBOL_GPL(gre_cisco_register);
-
-int gre_cisco_unregister(struct gre_cisco_protocol *del_proto)
-{
- struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **)
- &gre_cisco_proto_list[del_proto->priority];
- int ret;
-
- ret = (cmpxchg(proto, del_proto, NULL) == del_proto) ? 0 : -EINVAL;
-
- if (ret)
- return ret;
-
- synchronize_net();
- return 0;
-}
-EXPORT_SYMBOL_GPL(gre_cisco_unregister);
-
static int __init gre_init(void)
{
pr_info("GRE over IPv4 demultiplexor driver\n");
if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) {
pr_err("can't add protocol\n");
- goto err;
- }
-
- if (gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) {
- pr_info("%s: can't add ipgre handler\n", __func__);
- goto err_gre;
+ return -EAGAIN;
}
-
return 0;
-err_gre:
- inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
-err:
- return -EAGAIN;
}
static void __exit gre_exit(void)
{
- gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
}
Code Review / kvmfornfv.git / blobdiff