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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-04-21 09:45:37 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-04-28 13:16:35 -0700 |
| commit | f6d8bd051c391c1c0458a30b2a7abcd939329259 (patch) | |
| tree | 1dc4daecdeb0b42c2c6b59d7d6b41e091c11db5f /include/net | |
| parent | 0a14842f5a3c0e88a1e59fac5c3025db39721f74 (diff) | |
| download | linux-f6d8bd051c391c1c0458a30b2a7abcd939329259.tar.gz linux-f6d8bd051c391c1c0458a30b2a7abcd939329259.tar.bz2 linux-f6d8bd051c391c1c0458a30b2a7abcd939329259.zip | |
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')
| -rw-r--r-- | include/net/inet_sock.h | 14 | ||||
| -rw-r--r-- | include/net/ip.h | 11 |
2 files changed, 17 insertions, 8 deletions
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index 7a37369f8ea3..ed2ba6eca724 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -57,7 +57,15 @@ struct ip_options { unsigned char __data[0]; }; -#define optlength(opt) (sizeof(struct ip_options) + opt->optlen) +struct ip_options_rcu { + struct rcu_head rcu; + struct ip_options opt; +}; + +struct ip_options_data { + struct ip_options_rcu opt; + char data[40]; +}; struct inet_request_sock { struct request_sock req; @@ -78,7 +86,7 @@ struct inet_request_sock { acked : 1, no_srccheck: 1; kmemcheck_bitfield_end(flags); - struct ip_options *opt; + struct ip_options_rcu *opt; }; static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk) @@ -140,7 +148,7 @@ struct inet_sock { __be16 inet_sport; __u16 inet_id; - struct ip_options *opt; + struct ip_options_rcu __rcu *inet_opt; __u8 tos; __u8 min_ttl; __u8 mc_ttl; 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); |