ipv6: add new struct ipcm6_cookie

In the sendmsg function of UDP, raw, ICMP and l2tp sockets, we use local
variables like hlimits, tclass, opt and dontfrag and pass them to corresponding
functions like ip6_make_skb, ip6_append_data and xxx_push_pending_frames.
This is not a good practice and makes it hard to add new parameters.
This fix introduces a new struct ipcm6_cookie similar to ipcm_cookie in
ipv4 and include the above mentioned variables. And we only pass the
pointer to this structure to corresponding functions. This makes it easier
to add new parameters in the future and makes the function cleaner.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 12 deletions

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 23b9a4cc418e..9554b99a8508 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -401,10 +401,10 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
 	struct flowi6 fl6;
 	struct icmpv6_msg msg;
 	struct sockcm_cookie sockc_unused = {0};
+	struct ipcm6_cookie ipc6;
 	int iif = 0;
 	int addr_type = 0;
 	int len;
-	int hlimit;
 	int err = 0;
 	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 
@@ -507,7 +507,10 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
 	if (IS_ERR(dst))
 		goto out;
 
-	hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+	ipc6.tclass = np->tclass;
+	ipc6.dontfrag = np->dontfrag;
+	ipc6.opt = NULL;
 
 	msg.skb = skb;
 	msg.offset = skb_network_offset(skb);
@@ -526,9 +529,9 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
 
 	err = ip6_append_data(sk, icmpv6_getfrag, &msg,
 			      len + sizeof(struct icmp6hdr),
-			      sizeof(struct icmp6hdr), hlimit,
-			      np->tclass, NULL, &fl6, (struct rt6_info *)dst,
-			      MSG_DONTWAIT, np->dontfrag, &sockc_unused);
+			      sizeof(struct icmp6hdr),
+			      &ipc6, &fl6, (struct rt6_info *)dst,
+			      MSG_DONTWAIT, &sockc_unused);
 	if (err) {
 		ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
 		ip6_flush_pending_frames(sk);
@@ -563,9 +566,8 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	struct flowi6 fl6;
 	struct icmpv6_msg msg;
 	struct dst_entry *dst;
+	struct ipcm6_cookie ipc6;
 	int err = 0;
-	int hlimit;
-	u8 tclass;
 	u32 mark = IP6_REPLY_MARK(net, skb->mark);
 	struct sockcm_cookie sockc_unused = {0};
 
@@ -607,19 +609,21 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	if (IS_ERR(dst))
 		goto out;
 
-	hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
-
 	idev = __in6_dev_get(skb->dev);
 
 	msg.skb = skb;
 	msg.offset = 0;
 	msg.type = ICMPV6_ECHO_REPLY;
 
-	tclass = ipv6_get_dsfield(ipv6_hdr(skb));
+	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+	ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb));
+	ipc6.dontfrag = np->dontfrag;
+	ipc6.opt = NULL;
+
 	err = ip6_append_data(sk, icmpv6_getfrag, &msg, skb->len + sizeof(struct icmp6hdr),
-				sizeof(struct icmp6hdr), hlimit, tclass, NULL, &fl6,
+				sizeof(struct icmp6hdr), &ipc6, &fl6,
 				(struct rt6_info *)dst, MSG_DONTWAIT,
-				np->dontfrag, &sockc_unused);
+				&sockc_unused);
 
 	if (err) {
 		__ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);