[PATCH 1/2] ipv4: constify net_protocol structures

From: Julia Lawall
Date: Sat Jul 29 2017 - 02:42:51 EST


The net_protocol structures are only passed as the first argument to
inet_add_protocol, which is declared as const. Thus the net_protocol
structures themselves can be const.

Done with the help of Coccinelle.

// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct net_protocol i@p = { ... };

@ok1@
identifier r.i;
expression e1;
position p;
@@
inet_add_protocol(&i@p,...)

@bad@
position p != {r.p,ok1.p};
identifier r.i;
struct net_protocol e;
@@
e@i@p

@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct net_protocol i = { ... };
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

---
net/ipv4/af_inet.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5ce44fb..2e38624 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1594,7 +1594,7 @@ u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
};
#endif

-static struct net_protocol tcp_protocol = {
+static const struct net_protocol tcp_protocol = {
.early_demux = tcp_v4_early_demux,
.early_demux_handler = tcp_v4_early_demux,
.handler = tcp_v4_rcv,
@@ -1604,7 +1604,7 @@ u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
.icmp_strict_tag_validation = 1,
};

-static struct net_protocol udp_protocol = {
+static const struct net_protocol udp_protocol = {
.early_demux = udp_v4_early_demux,
.early_demux_handler = udp_v4_early_demux,
.handler = udp_rcv,