net: Make enabling of zero UDP6 csums more restrictive
RFC 6935 permits zero checksums to be used in IPv6 however this is
recommended only for certain tunnel protocols, it does not make
checksums completely optional like they are in IPv4.
This patch restricts the use of IPv6 zero checksums that was previously
intoduced. no_check6_tx and no_check6_rx have been added to control
the use of checksums in UDP6 RX and TX path. The normal
sk_no_check_{rx,tx} settings are not used (this avoids ambiguity when
dealing with a dual stack socket).
A helper function has been added (udp_set_no_check6) which can be
called by tunnel impelmentations to all zero checksums (send on the
socket, and accept them as valid).
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/udp.h b/include/linux/udp.h
index 42278bb..247cfdc 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -47,7 +47,9 @@
#define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node
int pending; /* Any pending frames ? */
unsigned int corkflag; /* Cork is required */
- __u16 encap_type; /* Is this an Encapsulation socket? */
+ __u8 encap_type; /* Is this an Encapsulation socket? */
+ unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
+ no_check6_rx:1;/* Allow zero UDP6 checksums on RX? */
/*
* Following member retains the information to create a UDP header
* when the socket is uncorked.
@@ -76,6 +78,26 @@
return (struct udp_sock *)sk;
}
+static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
+{
+ udp_sk(sk)->no_check6_tx = val;
+}
+
+static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
+{
+ udp_sk(sk)->no_check6_rx = val;
+}
+
+static inline bool udp_get_no_check6_tx(struct sock *sk)
+{
+ return udp_sk(sk)->no_check6_tx;
+}
+
+static inline bool udp_get_no_check6_rx(struct sock *sk)
+{
+ return udp_sk(sk)->no_check6_rx;
+}
+
#define udp_portaddr_for_each_entry(__sk, node, list) \
hlist_nulls_for_each_entry(__sk, node, list, __sk_common.skc_portaddr_node)