diff options
Diffstat (limited to 'net/ipv4/tunnel4.c')
| -rw-r--r-- | net/ipv4/tunnel4.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c new file mode 100644 index 000000000..0d0171830 --- /dev/null +++ b/net/ipv4/tunnel4.c @@ -0,0 +1,192 @@ +/* tunnel4.c: Generic IP tunnel transformer. + * + * Copyright (C) 2003 David S. Miller (davem@redhat.com) + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <net/icmp.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/xfrm.h> + +static struct xfrm_tunnel __rcu *tunnel4_handlers __read_mostly; +static struct xfrm_tunnel __rcu *tunnel64_handlers __read_mostly; +static DEFINE_MUTEX(tunnel4_mutex); + +static inline struct xfrm_tunnel __rcu **fam_handlers(unsigned short family) +{ + return (family == AF_INET) ? &tunnel4_handlers : &tunnel64_handlers; +} + +int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family) +{ + struct xfrm_tunnel __rcu **pprev; + struct xfrm_tunnel *t; + + int ret = -EEXIST; + int priority = handler->priority; + + mutex_lock(&tunnel4_mutex); + + for (pprev = fam_handlers(family); + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&tunnel4_mutex))) != NULL; + pprev = &t->next) { + if (t->priority > priority) + break; + if (t->priority == priority) + goto err; + } + + handler->next = *pprev; + rcu_assign_pointer(*pprev, handler); + + ret = 0; + +err: + mutex_unlock(&tunnel4_mutex); + + return ret; +} +EXPORT_SYMBOL(xfrm4_tunnel_register); + +int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family) +{ + struct xfrm_tunnel __rcu **pprev; + struct xfrm_tunnel *t; + int ret = -ENOENT; + + mutex_lock(&tunnel4_mutex); + + for (pprev = fam_handlers(family); + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&tunnel4_mutex))) != NULL; + pprev = &t->next) { + if (t == handler) { + *pprev = handler->next; + ret = 0; + break; + } + } + + mutex_unlock(&tunnel4_mutex); + + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL(xfrm4_tunnel_deregister); + +#define for_each_tunnel_rcu(head, handler) \ + for (handler = rcu_dereference(head); \ + handler != NULL; \ + handler = rcu_dereference(handler->next)) \ + +static int tunnel4_rcv(struct sk_buff *skb) +{ + struct xfrm_tunnel *handler; + + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + goto drop; + + for_each_tunnel_rcu(tunnel4_handlers, handler) + if (!handler->handler(skb)) + return 0; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + kfree_skb(skb); + return 0; +} + +#if IS_ENABLED(CONFIG_IPV6) +static int tunnel64_rcv(struct sk_buff *skb) +{ + struct xfrm_tunnel *handler; + + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) + goto drop; + + for_each_tunnel_rcu(tunnel64_handlers, handler) + if (!handler->handler(skb)) + return 0; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + kfree_skb(skb); + return 0; +} +#endif + +static void tunnel4_err(struct sk_buff *skb, u32 info) +{ + struct xfrm_tunnel *handler; + + for_each_tunnel_rcu(tunnel4_handlers, handler) + if (!handler->err_handler(skb, info)) + break; +} + +#if IS_ENABLED(CONFIG_IPV6) +static void tunnel64_err(struct sk_buff *skb, u32 info) +{ + struct xfrm_tunnel *handler; + + for_each_tunnel_rcu(tunnel64_handlers, handler) + if (!handler->err_handler(skb, info)) + break; +} +#endif + +static const struct net_protocol tunnel4_protocol = { + .handler = tunnel4_rcv, + .err_handler = tunnel4_err, + .no_policy = 1, + .netns_ok = 1, +}; + +#if IS_ENABLED(CONFIG_IPV6) +static const struct net_protocol tunnel64_protocol = { + .handler = tunnel64_rcv, + .err_handler = tunnel64_err, + .no_policy = 1, + .netns_ok = 1, +}; +#endif + +static int __init tunnel4_init(void) +{ + if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) { + pr_err("%s: can't add protocol\n", __func__); + return -EAGAIN; + } +#if IS_ENABLED(CONFIG_IPV6) + if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) { + pr_err("tunnel64 init: can't add protocol\n"); + inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP); + return -EAGAIN; + } +#endif + return 0; +} + +static void __exit tunnel4_fini(void) +{ +#if IS_ENABLED(CONFIG_IPV6) + if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6)) + pr_err("tunnel64 close: can't remove protocol\n"); +#endif + if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP)) + pr_err("tunnel4 close: can't remove protocol\n"); +} + +module_init(tunnel4_init); +module_exit(tunnel4_fini); +MODULE_LICENSE("GPL"); |