| /* 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; |
| struct xfrm6_protocol __rcu **head = proto_handlers(protocol); |
| |
| if (!head) |
| return 0; |
| |
| 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 int 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)) |
| return 0; |
| |
| return -ENOENT; |
| } |
| |
| 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 int 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)) |
| return 0; |
| |
| return -ENOENT; |
| } |
| |
| 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 int 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)) |
| return 0; |
| |
| return -ENOENT; |
| } |
| |
| 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 const struct xfrm_input_afinfo xfrm6_input_afinfo = { |
| .family = AF_INET6, |
| .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; |
| |
| if (!proto_handlers(protocol) || !netproto(protocol)) |
| return -EINVAL; |
| |
| 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; |
| |
| if (!proto_handlers(protocol) || !netproto(protocol)) |
| return -EINVAL; |
| |
| 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); |
| } |