[PATCH net-next v2 7/9] netconsole: move netpoll_udp_checksum() from netpoll

[Breno Leitao <leitao@debian.org>]

netpoll_udp_checksum() computes the UDP checksum for netconsole's
packets. Move it into drivers/net/netconsole.c as a file-static
helper; drop its EXPORT_SYMBOL_GPL and remove the prototype from
include/linux/netpoll.h.

This was the last csum_ipv6_magic() consumer in net/core/netpoll.c,
so drop the now-stale <net/ip6_checksum.h> include there. Pull it
into netconsole.c so the moved code keeps building.

It was also the last udp_hdr() consumer in net/core/netpoll.c. The
file no longer needs anything from <net/udp.h> (the UDP socket-layer
helpers); MAX_SKB_SIZE only needs struct udphdr, which is provided
by the lighter <linux/udp.h>. Swap the include accordingly.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 drivers/net/netconsole.c | 26 ++++++++++++++++++++++++++
 include/linux/netpoll.h  |  1 -
 net/core/netpoll.c       | 29 +----------------------------
 3 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index e8d96e482fe05..48d2670bbdef5 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -38,6 +38,7 @@
 #include <linux/netpoll.h>
 #include <linux/inet.h>
 #include <linux/unaligned.h>
+#include <net/ip6_checksum.h>
 #include <linux/configfs.h>
 #include <linux/etherdevice.h>
 #include <linux/hex.h>
@@ -1652,6 +1653,31 @@ static struct notifier_block netconsole_netdev_notifier = {
 	.notifier_call  = netconsole_netdev_event,
 };
 
+static void netpoll_udp_checksum(struct netpoll *np, struct sk_buff *skb,
+				 int len)
+{
+	struct udphdr *udph;
+	int udp_len;
+
+	udp_len = len + sizeof(struct udphdr);
+	udph = udp_hdr(skb);
+
+	/* check needs to be set, since it will be consumed in csum_partial */
+	udph->check = 0;
+	if (np->ipv6)
+		udph->check = csum_ipv6_magic(&np->local_ip.in6,
+					      &np->remote_ip.in6,
+					      udp_len, IPPROTO_UDP,
+					      csum_partial(udph, udp_len, 0));
+	else
+		udph->check = csum_tcpudp_magic(np->local_ip.ip,
+						np->remote_ip.ip,
+						udp_len, IPPROTO_UDP,
+						csum_partial(udph, udp_len, 0));
+	if (udph->check == 0)
+		udph->check = CSUM_MANGLED_0;
+}
+
 static void push_udp(struct netpoll *np, struct sk_buff *skb, int len)
 {
 	struct udphdr *udph;
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 03a49953a3d8a..1877d42ccbccf 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -74,7 +74,6 @@ void netpoll_cleanup(struct netpoll *np);
 void do_netpoll_cleanup(struct netpoll *np);
 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb);
 struct sk_buff *find_skb(struct netpoll *np, int len, int reserve);
-void netpoll_udp_checksum(struct netpoll *np, struct sk_buff *skb, int len);
 
 #ifdef CONFIG_NETPOLL
 static inline void *netpoll_poll_lock(struct napi_struct *napi)
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 96c65625f4cbb..c148b3b68cec9 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -29,11 +29,10 @@
 #include <linux/slab.h>
 #include <linux/export.h>
 #include <linux/if_vlan.h>
+#include <linux/udp.h>
 #include <net/tcp.h>
-#include <net/udp.h>
 #include <net/addrconf.h>
 #include <net/ndisc.h>
-#include <net/ip6_checksum.h>
 #include <trace/events/napi.h>
 #include <linux/kconfig.h>
 
@@ -369,32 +368,6 @@ static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 	return ret;
 }
 
-void netpoll_udp_checksum(struct netpoll *np, struct sk_buff *skb,
-			  int len)
-{
-	struct udphdr *udph;
-	int udp_len;
-
-	udp_len = len + sizeof(struct udphdr);
-	udph = udp_hdr(skb);
-
-	/* check needs to be set, since it will be consumed in csum_partial */
-	udph->check = 0;
-	if (np->ipv6)
-		udph->check = csum_ipv6_magic(&np->local_ip.in6,
-					      &np->remote_ip.in6,
-					      udp_len, IPPROTO_UDP,
-					      csum_partial(udph, udp_len, 0));
-	else
-		udph->check = csum_tcpudp_magic(np->local_ip.ip,
-						np->remote_ip.ip,
-						udp_len, IPPROTO_UDP,
-						csum_partial(udph, udp_len, 0));
-	if (udph->check == 0)
-		udph->check = CSUM_MANGLED_0;
-}
-EXPORT_SYMBOL_GPL(netpoll_udp_checksum);
-
 netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 {
 	unsigned long flags;

-- 
2.53.0-Meta