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authorEric Dumazet <eric.dumazet@gmail.com>2011-04-21 09:45:37 +0000
committerDavid S. Miller <davem@davemloft.net>2011-04-28 13:16:35 -0700
commitf6d8bd051c391c1c0458a30b2a7abcd939329259 (patch)
tree1dc4daecdeb0b42c2c6b59d7d6b41e091c11db5f /include/net/ip.h
parent0a14842f5a3c0e88a1e59fac5c3025db39721f74 (diff)
inet: add RCU protection to inet->opt
We lack proper synchronization to manipulate inet->opt ip_options Problem is ip_make_skb() calls ip_setup_cork() and ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options), without any protection against another thread manipulating inet->opt. Another thread can change inet->opt pointer and free old one under us. Use RCU to protect inet->opt (changed to inet->inet_opt). Instead of handling atomic refcounts, just copy ip_options when necessary, to avoid cache line dirtying. We cant insert an rcu_head in struct ip_options since its included in skb->cb[], so this patch is large because I had to introduce a new ip_options_rcu structure. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/ip.h')
-rw-r--r--include/net/ip.h11
1 files changed, 6 insertions, 5 deletions
diff --git a/include/net/ip.h b/include/net/ip.h
index 7c416583b710..3a59bf99aa3a 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -52,7 +52,7 @@ static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
struct ipcm_cookie {
__be32 addr;
int oif;
- struct ip_options *opt;
+ struct ip_options_rcu *opt;
__u8 tx_flags;
};
@@ -92,7 +92,7 @@ extern int igmp_mc_proc_init(void);
extern int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk,
__be32 saddr, __be32 daddr,
- struct ip_options *opt);
+ struct ip_options_rcu *opt);
extern int ip_rcv(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev);
extern int ip_local_deliver(struct sk_buff *skb);
@@ -416,14 +416,15 @@ extern int ip_forward(struct sk_buff *skb);
* Functions provided by ip_options.c
*/
-extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt, __be32 daddr, struct rtable *rt, int is_frag);
+extern void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
+ __be32 daddr, struct rtable *rt, int is_frag);
extern int ip_options_echo(struct ip_options *dopt, struct sk_buff *skb);
extern void ip_options_fragment(struct sk_buff *skb);
extern int ip_options_compile(struct net *net,
struct ip_options *opt, struct sk_buff *skb);
-extern int ip_options_get(struct net *net, struct ip_options **optp,
+extern int ip_options_get(struct net *net, struct ip_options_rcu **optp,
unsigned char *data, int optlen);
-extern int ip_options_get_from_user(struct net *net, struct ip_options **optp,
+extern int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
unsigned char __user *data, int optlen);
extern void ip_options_undo(struct ip_options * opt);
extern void ip_forward_options(struct sk_buff *skb);

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