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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 /net/ipv4/icmp.c
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 'net/ipv4/icmp.c')
-rw-r--r--net/ipv4/icmp.c23
1 files changed, 11 insertions, 12 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 74e35e5736e2..cfeca3c2152d 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -108,8 +108,7 @@ struct icmp_bxm {
__be32 times[3];
} data;
int head_len;
- struct ip_options replyopts;
- unsigned char optbuf[40];
+ struct ip_options_data replyopts;
};
/* An array of errno for error messages from dest unreach. */
@@ -333,7 +332,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
struct inet_sock *inet;
__be32 daddr;
- if (ip_options_echo(&icmp_param->replyopts, skb))
+ if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb))
return;
sk = icmp_xmit_lock(net);
@@ -347,10 +346,10 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
daddr = ipc.addr = rt->rt_src;
ipc.opt = NULL;
ipc.tx_flags = 0;
- if (icmp_param->replyopts.optlen) {
- ipc.opt = &icmp_param->replyopts;
- if (ipc.opt->srr)
- daddr = icmp_param->replyopts.faddr;
+ if (icmp_param->replyopts.opt.opt.optlen) {
+ ipc.opt = &icmp_param->replyopts.opt;
+ if (ipc.opt->opt.srr)
+ daddr = icmp_param->replyopts.opt.opt.faddr;
}
{
struct flowi4 fl4 = {
@@ -379,8 +378,8 @@ static struct rtable *icmp_route_lookup(struct net *net, struct sk_buff *skb_in,
struct icmp_bxm *param)
{
struct flowi4 fl4 = {
- .daddr = (param->replyopts.srr ?
- param->replyopts.faddr : iph->saddr),
+ .daddr = (param->replyopts.opt.opt.srr ?
+ param->replyopts.opt.opt.faddr : iph->saddr),
.saddr = saddr,
.flowi4_tos = RT_TOS(tos),
.flowi4_proto = IPPROTO_ICMP,
@@ -581,7 +580,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
IPTOS_PREC_INTERNETCONTROL) :
iph->tos;
- if (ip_options_echo(&icmp_param.replyopts, skb_in))
+ if (ip_options_echo(&icmp_param.replyopts.opt.opt, skb_in))
goto out_unlock;
@@ -597,7 +596,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
icmp_param.offset = skb_network_offset(skb_in);
inet_sk(sk)->tos = tos;
ipc.addr = iph->saddr;
- ipc.opt = &icmp_param.replyopts;
+ ipc.opt = &icmp_param.replyopts.opt;
ipc.tx_flags = 0;
rt = icmp_route_lookup(net, skb_in, iph, saddr, tos,
@@ -613,7 +612,7 @@ void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
room = dst_mtu(&rt->dst);
if (room > 576)
room = 576;
- room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
+ room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen;
room -= sizeof(struct icmphdr);
icmp_param.data_len = skb_in->len - icmp_param.offset;

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