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authorJoe Stringer <joe@wand.net.nz>2020-03-29 15:53:39 -0700
committerAlexei Starovoitov <ast@kernel.org>2020-03-30 13:45:04 -0700
commit71489e21d720a09388b565d60ef87ae993c10528 (patch)
tree0ebc9f8445150e0cf11c71c628ba69f7ae50da15 /net
parentcf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 (diff)
downloadlinux-71489e21d720a09388b565d60ef87ae993c10528.tar.bz2
net: Track socket refcounts in skb_steal_sock()
Refactor the UDP/TCP handlers slightly to allow skb_steal_sock() to make the determination of whether the socket is reference counted in the case where it is prefetched by earlier logic such as early_demux. Signed-off-by: Joe Stringer <joe@wand.net.nz> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200329225342.16317-3-joe@wand.net.nz
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/udp.c6
-rw-r--r--net/ipv6/udp.c9
2 files changed, 10 insertions, 5 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 2633fc231593..b4035021bbd3 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2288,6 +2288,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
struct rtable *rt = skb_rtable(skb);
__be32 saddr, daddr;
struct net *net = dev_net(skb->dev);
+ bool refcounted;
/*
* Validate the packet.
@@ -2313,7 +2314,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
if (udp4_csum_init(skb, uh, proto))
goto csum_error;
- sk = skb_steal_sock(skb);
+ sk = skb_steal_sock(skb, &refcounted);
if (sk) {
struct dst_entry *dst = skb_dst(skb);
int ret;
@@ -2322,7 +2323,8 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
udp_sk_rx_dst_set(sk, dst);
ret = udp_unicast_rcv_skb(sk, skb, uh);
- sock_put(sk);
+ if (refcounted)
+ sock_put(sk);
return ret;
}
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 5dc439a391fe..7d4151747340 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -843,6 +843,7 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
struct net *net = dev_net(skb->dev);
struct udphdr *uh;
struct sock *sk;
+ bool refcounted;
u32 ulen = 0;
if (!pskb_may_pull(skb, sizeof(struct udphdr)))
@@ -879,7 +880,7 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
goto csum_error;
/* Check if the socket is already available, e.g. due to early demux */
- sk = skb_steal_sock(skb);
+ sk = skb_steal_sock(skb, &refcounted);
if (sk) {
struct dst_entry *dst = skb_dst(skb);
int ret;
@@ -888,12 +889,14 @@ int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable,
udp6_sk_rx_dst_set(sk, dst);
if (!uh->check && !udp_sk(sk)->no_check6_rx) {
- sock_put(sk);
+ if (refcounted)
+ sock_put(sk);
goto report_csum_error;
}
ret = udp6_unicast_rcv_skb(sk, skb, uh);
- sock_put(sk);
+ if (refcounted)
+ sock_put(sk);
return ret;
}