From eb8637cd4a0d651cf4fcc1559231facee829a0ac Mon Sep 17 00:00:00 2001 From: Saurabh Date: Tue, 17 Jul 2012 09:44:49 +0000 Subject: [PATCH] net/ipv4: VTI support rx-path hook in xfrm4_mode_tunnel. Incorporated David and Steffen's comments. Add hook for rx-path xfmr4_mode_tunnel for VTI tunnel module. Signed-off-by: Saurabh Mohan Reviewed-by: Stephen Hemminger Signed-off-by: David S. Miller --- include/net/xfrm.h | 2 ++ net/ipv4/xfrm4_mode_tunnel.c | 68 ++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/include/net/xfrm.h b/include/net/xfrm.h index 17acbc92476d..d9509eb29b80 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1475,6 +1475,8 @@ extern int xfrm4_output(struct sk_buff *skb); extern int xfrm4_output_finish(struct sk_buff *skb); extern int xfrm4_tunnel_register(struct xfrm_tunnel *handler, unsigned short family); extern int xfrm4_tunnel_deregister(struct xfrm_tunnel *handler, unsigned short family); +extern int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel *handler); +extern int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel *handler); extern int xfrm6_extract_header(struct sk_buff *skb); extern int xfrm6_extract_input(struct xfrm_state *x, struct sk_buff *skb); extern int xfrm6_rcv_spi(struct sk_buff *skb, int nexthdr, __be32 spi); diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c index ed4bf11ef9f4..ddee0a099a2c 100644 --- a/net/ipv4/xfrm4_mode_tunnel.c +++ b/net/ipv4/xfrm4_mode_tunnel.c @@ -15,6 +15,65 @@ #include #include +/* Informational hook. The decap is still done here. */ +static struct xfrm_tunnel __rcu *rcv_notify_handlers __read_mostly; +static DEFINE_MUTEX(xfrm4_mode_tunnel_input_mutex); + +int xfrm4_mode_tunnel_input_register(struct xfrm_tunnel *handler) +{ + struct xfrm_tunnel __rcu **pprev; + struct xfrm_tunnel *t; + int ret = -EEXIST; + int priority = handler->priority; + + mutex_lock(&xfrm4_mode_tunnel_input_mutex); + + for (pprev = &rcv_notify_handlers; + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&xfrm4_mode_tunnel_input_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(&xfrm4_mode_tunnel_input_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(xfrm4_mode_tunnel_input_register); + +int xfrm4_mode_tunnel_input_deregister(struct xfrm_tunnel *handler) +{ + struct xfrm_tunnel __rcu **pprev; + struct xfrm_tunnel *t; + int ret = -ENOENT; + + mutex_lock(&xfrm4_mode_tunnel_input_mutex); + for (pprev = &rcv_notify_handlers; + (t = rcu_dereference_protected(*pprev, + lockdep_is_held(&xfrm4_mode_tunnel_input_mutex))) != NULL; + pprev = &t->next) { + if (t == handler) { + *pprev = handler->next; + ret = 0; + break; + } + } + mutex_unlock(&xfrm4_mode_tunnel_input_mutex); + synchronize_net(); + + return ret; +} +EXPORT_SYMBOL_GPL(xfrm4_mode_tunnel_input_deregister); + static inline void ipip_ecn_decapsulate(struct sk_buff *skb) { struct iphdr *inner_iph = ipip_hdr(skb); @@ -64,8 +123,14 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb) return 0; } +#define for_each_input_rcu(head, handler) \ + for (handler = rcu_dereference(head); \ + handler != NULL; \ + handler = rcu_dereference(handler->next)) + static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) { + struct xfrm_tunnel *handler; int err = -EINVAL; if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP) @@ -74,6 +139,9 @@ static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb) if (!pskb_may_pull(skb, sizeof(struct iphdr))) goto out; + for_each_input_rcu(rcv_notify_handlers, handler) + handler->handler(skb); + if (skb_cloned(skb) && (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC))) goto out; -- 2.20.1