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Diffstat (limited to 'net/ipv6/ip6_output.c')
-rw-r--r--net/ipv6/ip6_output.c30
1 files changed, 21 insertions, 9 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 291a07b..60c5653 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -150,14 +150,16 @@ int ip6_output(struct sock *sk, struct sk_buff *skb)
}
/*
- * xmit an sk_buff (used by TCP, SCTP and DCCP)
+ * xmit an sk_buff (used by TCP, SCTP and DCCP)
+ * Note : socket lock is not held for SYNACK packets, but might be modified
+ * by calls to skb_set_owner_w() and ipv6_local_error(),
+ * which are using proper atomic operations or spinlocks.
*/
-
-int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
+int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
struct ipv6_txoptions *opt, int tclass)
{
struct net *net = sock_net(sk);
- struct ipv6_pinfo *np = inet6_sk(sk);
+ const struct ipv6_pinfo *np = inet6_sk(sk);
struct in6_addr *first_hop = &fl6->daddr;
struct dst_entry *dst = skb_dst(skb);
struct ipv6hdr *hdr;
@@ -186,7 +188,10 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
}
consume_skb(skb);
skb = skb2;
- skb_set_owner_w(skb, sk);
+ /* skb_set_owner_w() changes sk->sk_wmem_alloc atomically,
+ * it is safe to call in our context (socket lock not held)
+ */
+ skb_set_owner_w(skb, (struct sock *)sk);
}
if (opt->opt_flen)
ipv6_push_frag_opts(skb, opt, &proto);
@@ -224,13 +229,20 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) {
IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_OUT, skb->len);
+ /* hooks should never assume socket lock is held.
+ * we promote our socket to non const
+ */
return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT,
- net, sk, skb, NULL, dst->dev,
+ net, (struct sock *)sk, skb, NULL, dst->dev,
dst_output_okfn);
}
skb->dev = dst->dev;
- ipv6_local_error(sk, EMSGSIZE, fl6, mtu);
+ /* ipv6_local_error() does not require socket lock,
+ * we promote our socket to non const
+ */
+ ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu);
+
IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS);
kfree_skb(skb);
return -EMSGSIZE;
@@ -883,7 +895,7 @@ out:
return dst;
}
-static int ip6_dst_lookup_tail(struct net *net, struct sock *sk,
+static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk,
struct dst_entry **dst, struct flowi6 *fl6)
{
#ifdef CONFIG_IPV6_OPTIMISTIC_DAD
@@ -1014,7 +1026,7 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup);
* It returns a valid dst pointer on success, or a pointer encoded
* error code.
*/
-struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
+struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6,
const struct in6_addr *final_dst)
{
struct dst_entry *dst = NULL;
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