ipv6: Append sending data to arbitrary queue

Add the ability to append data to arbitrary queue.  This
will be needed later to implement lockless UDP sends.

Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index f9f08c43c6e153ec5659b5741dafb9502db4c2c5..1b66453a695d12ea84830108dda13dcf0fe8bb5b 100644 (file)
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1041,6 +1041,7 @@ struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow);
 
 static inline int ip6_ufo_append_data(struct sock *sk,
+                       struct sk_buff_head *queue,
                        int getfrag(void *from, char *to, int offset, int len,
                        int odd, struct sk_buff *skb),
                        void *from, int length, int hh_len, int fragheaderlen,
@@ -1056,7 +1057,7 @@ static inline int ip6_ufo_append_data(struct sock *sk,
         * device, so create one single skb packet containing complete
         * udp datagram
         */
-       skb = skb_peek_tail(&sk->sk_write_queue);
+       skb = skb_peek_tail(queue);
        if (skb == NULL) {
                skb = sock_alloc_send_skb(sk,
                        hh_len + fragheaderlen + transhdrlen + 20,
@@ -1079,7 +1080,7 @@ static inline int ip6_ufo_append_data(struct sock *sk,
                skb->protocol = htons(ETH_P_IPV6);
                skb->csum = 0;
 
-               __skb_queue_tail(&sk->sk_write_queue, skb);
+               __skb_queue_tail(queue, skb);
        } else if (skb_is_gso(skb)) {
                goto append;
        }
@@ -1203,49 +1204,36 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
        return 0;
 }
 
-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)
+static int __ip6_append_data(struct sock *sk,
+                            struct flowi6 *fl6,
+                            struct sk_buff_head *queue,
+                            struct inet_cork *cork,
+                            struct inet6_cork *v6_cork,
+                            struct page_frag *pfrag,
+                            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)
 {
-       struct inet_sock *inet = inet_sk(sk);
-       struct ipv6_pinfo *np = inet6_sk(sk);
-       struct inet_cork *cork;
        struct sk_buff *skb, *skb_prev = NULL;
        unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
-       int exthdrlen;
-       int dst_exthdrlen;
+       int exthdrlen = 0;
+       int dst_exthdrlen = 0;
        int hh_len;
        int copy;
        int err;
        int offset = 0;
        __u8 tx_flags = 0;
        u32 tskey = 0;
+       struct rt6_info *rt = (struct rt6_info *)cork->dst;
+       struct ipv6_txoptions *opt = v6_cork->opt;
 
-       if (flags&MSG_PROBE)
-               return 0;
-       cork = &inet->cork.base;
-       if (skb_queue_empty(&sk->sk_write_queue)) {
-               /*
-                * setup for corking
-                */
-               err = ip6_setup_cork(sk, &inet->cork, &np->cork, hlimit,
-                                    tclass, opt, rt, fl6);
-               if (err)
-                       return err;
-               exthdrlen = (opt ? opt->opt_flen : 0);
-               length += exthdrlen;
-               transhdrlen += exthdrlen;
+       skb = skb_peek_tail(queue);
+       if (!skb) {
+               exthdrlen = opt ? opt->opt_flen : 0;
                dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
-       } else {
-               rt = (struct rt6_info *)cork->dst;
-               fl6 = &inet->cork.fl.u.ip6;
-               opt = np->cork.opt;
-               transhdrlen = 0;
-               exthdrlen = 0;
-               dst_exthdrlen = 0;
        }
+
        mtu = cork->fragsize;
        orig_mtu = mtu;
 
@@ -1311,13 +1299,12 @@ emsgsize:
         * --yoshfuji
         */
 
-       skb = skb_peek_tail(&sk->sk_write_queue);
        cork->length += length;
        if (((length > mtu) ||
             (skb && skb_is_gso(skb))) &&
            (sk->sk_protocol == IPPROTO_UDP) &&
            (rt->dst.dev->features & NETIF_F_UFO)) {
-               err = ip6_ufo_append_data(sk, getfrag, from, length,
+               err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
                                          hh_len, fragheaderlen,
                                          transhdrlen, mtu, flags, rt);
                if (err)
@@ -1458,7 +1445,7 @@ alloc_new_skb:
                        /*
                         * Put the packet on the pending queue
                         */
-                       __skb_queue_tail(&sk->sk_write_queue, skb);
+                       __skb_queue_tail(queue, skb);
                        continue;
                }
 
@@ -1477,7 +1464,6 @@ alloc_new_skb:
                        }
                } else {
                        int i = skb_shinfo(skb)->nr_frags;
-                       struct page_frag *pfrag = sk_page_frag(sk);
 
                        err = -ENOMEM;
                        if (!sk_page_frag_refill(sk, pfrag))
@@ -1520,6 +1506,42 @@ error:
        IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
        return err;
 }
+
+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)
+{
+       struct inet_sock *inet = inet_sk(sk);
+       struct ipv6_pinfo *np = inet6_sk(sk);
+       int exthdrlen;
+       int err;
+
+       if (flags&MSG_PROBE)
+               return 0;
+       if (skb_queue_empty(&sk->sk_write_queue)) {
+               /*
+                * setup for corking
+                */
+               err = ip6_setup_cork(sk, &inet->cork, &np->cork, hlimit,
+                                    tclass, opt, rt, fl6);
+               if (err)
+                       return err;
+
+               exthdrlen = (opt ? opt->opt_flen : 0);
+               length += exthdrlen;
+               transhdrlen += exthdrlen;
+       } else {
+               fl6 = &inet->cork.fl.u.ip6;
+               transhdrlen = 0;
+       }
+
+       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);
+}
 EXPORT_SYMBOL_GPL(ip6_append_data);
 
 static void ip6_cork_release(struct inet_cork_full *cork,
@@ -1627,11 +1649,12 @@ error:
 }
 EXPORT_SYMBOL_GPL(ip6_push_pending_frames);
 
-void ip6_flush_pending_frames(struct sock *sk)
+static void __ip6_flush_pending_frames(struct sock *sk,
+                                      struct sk_buff_head *queue)
 {
        struct sk_buff *skb;
 
-       while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) {
+       while ((skb = __skb_dequeue_tail(queue)) != NULL) {
                if (skb_dst(skb))
                        IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)),
                                      IPSTATS_MIB_OUTDISCARDS);
@@ -1640,4 +1663,9 @@ void ip6_flush_pending_frames(struct sock *sk)
 
        ip6_cork_release(&inet_sk(sk)->cork, &inet6_sk(sk)->cork);
 }
+
+void ip6_flush_pending_frames(struct sock *sk)
+{
+       __ip6_flush_pending_frames(sk, &sk->sk_write_queue);
+}
 EXPORT_SYMBOL_GPL(ip6_flush_pending_frames);