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, 20 insertions, 22 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 2b3ffc582d16..cbf127ae7c67 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1182,12 +1182,12 @@ static void ip6_append_data_mtu(unsigned int *mtu,
 }
 
 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
-			  struct inet6_cork *v6_cork,
-			  int hlimit, int tclass, struct ipv6_txoptions *opt,
+			  struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
 			  struct rt6_info *rt, struct flowi6 *fl6)
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	unsigned int mtu;
+	struct ipv6_txoptions *opt = ipc6->opt;
 
 	/*
 	 * setup for corking
@@ -1229,8 +1229,8 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 	dst_hold(&rt->dst);
 	cork->base.dst = &rt->dst;
 	cork->fl.u.ip6 = *fl6;
-	v6_cork->hop_limit = hlimit;
-	v6_cork->tclass = tclass;
+	v6_cork->hop_limit = ipc6->hlimit;
+	v6_cork->tclass = ipc6->tclass;
 	if (rt->dst.flags & DST_XFRM_TUNNEL)
 		mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ?
 		      rt->dst.dev->mtu : dst_mtu(&rt->dst);
@@ -1258,7 +1258,7 @@ static int __ip6_append_data(struct sock *sk,
 			     int getfrag(void *from, char *to, int offset,
 					 int len, int odd, struct sk_buff *skb),
 			     void *from, int length, int transhdrlen,
-			     unsigned int flags, int dontfrag,
+			     unsigned int flags, struct ipcm6_cookie *ipc6,
 			     const struct sockcm_cookie *sockc)
 {
 	struct sk_buff *skb, *skb_prev = NULL;
@@ -1298,7 +1298,7 @@ static int __ip6_append_data(struct sock *sk,
 		      sizeof(struct frag_hdr) : 0) +
 		     rt->rt6i_nfheader_len;
 
-	if (cork->length + length > mtu - headersize && dontfrag &&
+	if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
 	    (sk->sk_protocol == IPPROTO_UDP ||
 	     sk->sk_protocol == IPPROTO_RAW)) {
 		ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
@@ -1564,9 +1564,9 @@ error:
 int ip6_append_data(struct sock *sk,
 		    int getfrag(void *from, char *to, int offset, int len,
 				int odd, struct sk_buff *skb),
-		    void *from, int length, int transhdrlen, int hlimit,
-		    int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6,
-		    struct rt6_info *rt, unsigned int flags, int dontfrag,
+		    void *from, int length, int transhdrlen,
+		    struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
+		    struct rt6_info *rt, unsigned int flags,
 		    const struct sockcm_cookie *sockc)
 {
 	struct inet_sock *inet = inet_sk(sk);
@@ -1580,12 +1580,12 @@ int ip6_append_data(struct sock *sk,
 		/*
 		 * setup for corking
 		 */
-		err = ip6_setup_cork(sk, &inet->cork, &np->cork, hlimit,
-				     tclass, opt, rt, fl6);
+		err = ip6_setup_cork(sk, &inet->cork, &np->cork,
+				     ipc6, rt, fl6);
 		if (err)
 			return err;
 
-		exthdrlen = (opt ? opt->opt_flen : 0);
+		exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
 		length += exthdrlen;
 		transhdrlen += exthdrlen;
 	} else {
@@ -1595,8 +1595,7 @@ int ip6_append_data(struct sock *sk,
 
 	return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base,
 				 &np->cork, sk_page_frag(sk), getfrag,
-				 from, length, transhdrlen, flags, dontfrag,
-				 sockc);
+				 from, length, transhdrlen, flags, ipc6, sockc);
 }
 EXPORT_SYMBOL_GPL(ip6_append_data);
 
@@ -1752,15 +1751,14 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 			     int getfrag(void *from, char *to, int offset,
 					 int len, int odd, struct sk_buff *skb),
 			     void *from, int length, int transhdrlen,
-			     int hlimit, int tclass,
-			     struct ipv6_txoptions *opt, struct flowi6 *fl6,
+			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
 			     struct rt6_info *rt, unsigned int flags,
-			     int dontfrag, const struct sockcm_cookie *sockc)
+			     const struct sockcm_cookie *sockc)
 {
 	struct inet_cork_full cork;
 	struct inet6_cork v6_cork;
 	struct sk_buff_head queue;
-	int exthdrlen = (opt ? opt->opt_flen : 0);
+	int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
 	int err;
 
 	if (flags & MSG_PROBE)
@@ -1772,17 +1770,17 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 	cork.base.addr = 0;
 	cork.base.opt = NULL;
 	v6_cork.opt = NULL;
-	err = ip6_setup_cork(sk, &cork, &v6_cork, hlimit, tclass, opt, rt, fl6);
+	err = ip6_setup_cork(sk, &cork, &v6_cork, ipc6, rt, fl6);
 	if (err)
 		return ERR_PTR(err);
 
-	if (dontfrag < 0)
-		dontfrag = inet6_sk(sk)->dontfrag;
+	if (ipc6->dontfrag < 0)
+		ipc6->dontfrag = inet6_sk(sk)->dontfrag;
 
 	err = __ip6_append_data(sk, fl6, &queue, &cork.base, &v6_cork,
 				&current->task_frag, getfrag, from,
 				length + exthdrlen, transhdrlen + exthdrlen,
-				flags, dontfrag, sockc);
+				flags, ipc6, sockc);
 	if (err) {
 		__ip6_flush_pending_frames(sk, &queue, &cork, &v6_cork);
 		return ERR_PTR(err);