--- /dev/null
+/* xfrm6_protocol.c - Generic xfrm protocol multiplexer for ipv6.
+ *
+ * Copyright (C) 2013 secunet Security Networks AG
+ *
+ * Author:
+ * Steffen Klassert <steffen.klassert@secunet.com>
+ *
+ * Based on:
+ * net/ipv4/xfrm4_protocol.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/skbuff.h>
+#include <linux/icmpv6.h>
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/xfrm.h>
+
+static struct xfrm6_protocol __rcu *esp6_handlers __read_mostly;
+static struct xfrm6_protocol __rcu *ah6_handlers __read_mostly;
+static struct xfrm6_protocol __rcu *ipcomp6_handlers __read_mostly;
+static DEFINE_MUTEX(xfrm6_protocol_mutex);
+
+static inline struct xfrm6_protocol __rcu **proto_handlers(u8 protocol)
+{
+ switch (protocol) {
+ case IPPROTO_ESP:
+ return &esp6_handlers;
+ case IPPROTO_AH:
+ return &ah6_handlers;
+ case IPPROTO_COMP:
+ return &ipcomp6_handlers;
+ }
+
+ return NULL;
+}
+
+#define for_each_protocol_rcu(head, handler) \
+ for (handler = rcu_dereference(head); \
+ handler != NULL; \
+ handler = rcu_dereference(handler->next)) \
+
+int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
+{
+ int ret;
+ struct xfrm6_protocol *handler;
+
+ for_each_protocol_rcu(*proto_handlers(protocol), handler)
+ if ((ret = handler->cb_handler(skb, err)) <= 0)
+ return ret;
+
+ return 0;
+}
+EXPORT_SYMBOL(xfrm6_rcv_cb);
+
+static int xfrm6_esp_rcv(struct sk_buff *skb)
+{
+ int ret;
+ struct xfrm6_protocol *handler;
+
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
+
+ for_each_protocol_rcu(esp6_handlers, handler)
+ if ((ret = handler->handler(skb)) != -EINVAL)
+ return ret;
+
+ icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+ kfree_skb(skb);
+ return 0;
+}
+
+static void xfrm6_esp_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ struct xfrm6_protocol *handler;
+
+ for_each_protocol_rcu(esp6_handlers, handler)
+ if (!handler->err_handler(skb, opt, type, code, offset, info))
+ break;
+}
+
+static int xfrm6_ah_rcv(struct sk_buff *skb)
+{
+ int ret;
+ struct xfrm6_protocol *handler;
+
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
+
+ for_each_protocol_rcu(ah6_handlers, handler)
+ if ((ret = handler->handler(skb)) != -EINVAL)
+ return ret;
+
+ icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+ kfree_skb(skb);
+ return 0;
+}
+
+static void xfrm6_ah_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ struct xfrm6_protocol *handler;
+
+ for_each_protocol_rcu(ah6_handlers, handler)
+ if (!handler->err_handler(skb, opt, type, code, offset, info))
+ break;
+}
+
+static int xfrm6_ipcomp_rcv(struct sk_buff *skb)
+{
+ int ret;
+ struct xfrm6_protocol *handler;
+
+ XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL;
+
+ for_each_protocol_rcu(ipcomp6_handlers, handler)
+ if ((ret = handler->handler(skb)) != -EINVAL)
+ return ret;
+
+ icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
+
+ kfree_skb(skb);
+ return 0;
+}
+
+static void xfrm6_ipcomp_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ struct xfrm6_protocol *handler;
+
+ for_each_protocol_rcu(ipcomp6_handlers, handler)
+ if (!handler->err_handler(skb, opt, type, code, offset, info))
+ break;
+}
+
+static const struct inet6_protocol esp6_protocol = {
+ .handler = xfrm6_esp_rcv,
+ .err_handler = xfrm6_esp_err,
+ .flags = INET6_PROTO_NOPOLICY,
+};
+
+static const struct inet6_protocol ah6_protocol = {
+ .handler = xfrm6_ah_rcv,
+ .err_handler = xfrm6_ah_err,
+ .flags = INET6_PROTO_NOPOLICY,
+};
+
+static const struct inet6_protocol ipcomp6_protocol = {
+ .handler = xfrm6_ipcomp_rcv,
+ .err_handler = xfrm6_ipcomp_err,
+ .flags = INET6_PROTO_NOPOLICY,
+};
+
+static struct xfrm_input_afinfo xfrm6_input_afinfo = {
+ .family = AF_INET6,
+ .owner = THIS_MODULE,
+ .callback = xfrm6_rcv_cb,
+};
+
+static inline const struct inet6_protocol *netproto(unsigned char protocol)
+{
+ switch (protocol) {
+ case IPPROTO_ESP:
+ return &esp6_protocol;
+ case IPPROTO_AH:
+ return &ah6_protocol;
+ case IPPROTO_COMP:
+ return &ipcomp6_protocol;
+ }
+
+ return NULL;
+}
+
+int xfrm6_protocol_register(struct xfrm6_protocol *handler,
+ unsigned char protocol)
+{
+ struct xfrm6_protocol __rcu **pprev;
+ struct xfrm6_protocol *t;
+ bool add_netproto = false;
+
+ int ret = -EEXIST;
+ int priority = handler->priority;
+
+ mutex_lock(&xfrm6_protocol_mutex);
+
+ if (!rcu_dereference_protected(*proto_handlers(protocol),
+ lockdep_is_held(&xfrm6_protocol_mutex)))
+ add_netproto = true;
+
+ for (pprev = proto_handlers(protocol);
+ (t = rcu_dereference_protected(*pprev,
+ lockdep_is_held(&xfrm6_protocol_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(&xfrm6_protocol_mutex);
+
+ if (add_netproto) {
+ if (inet6_add_protocol(netproto(protocol), protocol)) {
+ pr_err("%s: can't add protocol\n", __func__);
+ ret = -EAGAIN;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(xfrm6_protocol_register);
+
+int xfrm6_protocol_deregister(struct xfrm6_protocol *handler,
+ unsigned char protocol)
+{
+ struct xfrm6_protocol __rcu **pprev;
+ struct xfrm6_protocol *t;
+ int ret = -ENOENT;
+
+ mutex_lock(&xfrm6_protocol_mutex);
+
+ for (pprev = proto_handlers(protocol);
+ (t = rcu_dereference_protected(*pprev,
+ lockdep_is_held(&xfrm6_protocol_mutex))) != NULL;
+ pprev = &t->next) {
+ if (t == handler) {
+ *pprev = handler->next;
+ ret = 0;
+ break;
+ }
+ }
+
+ if (!rcu_dereference_protected(*proto_handlers(protocol),
+ lockdep_is_held(&xfrm6_protocol_mutex))) {
+ if (inet6_del_protocol(netproto(protocol), protocol) < 0) {
+ pr_err("%s: can't remove protocol\n", __func__);
+ ret = -EAGAIN;
+ }
+ }
+
+ mutex_unlock(&xfrm6_protocol_mutex);
+
+ synchronize_net();
+
+ return ret;
+}
+EXPORT_SYMBOL(xfrm6_protocol_deregister);
+
+int __init xfrm6_protocol_init(void)
+{
+ return xfrm_input_register_afinfo(&xfrm6_input_afinfo);
+}
+
+void xfrm6_protocol_fini(void)
+{
+ xfrm_input_unregister_afinfo(&xfrm6_input_afinfo);
+}
projects / mirror_ubuntu-artful-kernel.git / blobdiff