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, 18 insertions, 15 deletions

diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index b07ce21983aa..896350df6423 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -746,10 +746,8 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
         struct raw6_frag_vec rfv;
         struct flowi6 fl6;
         struct sockcm_cookie sockc;
+        struct ipcm6_cookie ipc6;
         int addr_len = msg->msg_namelen;
-        int hlimit = -1;
-        int tclass = -1;
-        int dontfrag = -1;
         u16 proto;
         int err;
 
@@ -770,6 +768,11 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
         fl6.flowi6_mark = sk->sk_mark;
 
+        ipc6.hlimit = -1;
+        ipc6.tclass = -1;
+        ipc6.dontfrag = -1;
+        ipc6.opt = NULL;
+
         if (sin6) {
                 if (addr_len < SIN6_LEN_RFC2133)
                         return -EINVAL;
@@ -827,10 +830,9 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
                 opt = &opt_space;
                 memset(opt, 0, sizeof(struct ipv6_txoptions));
                 opt->tot_len = sizeof(struct ipv6_txoptions);
+                ipc6.opt = opt;
 
-                err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, opt,
-                                            &hlimit, &tclass, &dontfrag,
-                                            &sockc);
+                err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc);
                 if (err < 0) {
                         fl6_sock_release(flowlabel);
                         return err;
@@ -846,7 +848,7 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
         if (!opt) {
                 opt = txopt_get(np);
                 opt_to_free = opt;
-                }
+        }
         if (flowlabel)
                 opt = fl6_merge_options(&opt_space, flowlabel, opt);
         opt = ipv6_fixup_options(&opt_space, opt);
@@ -881,14 +883,14 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
                 err = PTR_ERR(dst);
                 goto out;
         }
-        if (hlimit < 0)
-                hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+        if (ipc6.hlimit < 0)
+                ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 
-        if (tclass < 0)
-                tclass = np->tclass;
+        if (ipc6.tclass < 0)
+                ipc6.tclass = np->tclass;
 
-        if (dontfrag < 0)
-                dontfrag = np->dontfrag;
+        if (ipc6.dontfrag < 0)
+                ipc6.dontfrag = np->dontfrag;
 
         if (msg->msg_flags&MSG_CONFIRM)
                 goto do_confirm;
@@ -897,10 +899,11 @@ back_from_confirm:
         if (inet->hdrincl)
                 err = rawv6_send_hdrinc(sk, msg, len, &fl6, &dst, msg->msg_flags);
         else {
+                ipc6.opt = opt;
                 lock_sock(sk);
                 err = ip6_append_data(sk, raw6_getfrag, &rfv,
-                        len, 0, hlimit, tclass, opt, &fl6, (struct rt6_info *)dst,
-                        msg->msg_flags, dontfrag, &sockc);
+                        len, 0, &ipc6, &fl6, (struct rt6_info *)dst,
+                        msg->msg_flags, &sockc);
 
                 if (err)
                         ip6_flush_pending_frames(sk);