tcp: do not mess with cloned skbs in tcp_add_backlog()

[linux-2.6-microblaze.git] / net / ipv4 / tcp_ipv4.c

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 595dcc3..4e82745 100644 (file)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1445,9 +1445,15 @@ static void tcp_v4_init_req(struct request_sock *req,
 }
 
 static struct dst_entry *tcp_v4_route_req(const struct sock *sk,
+                                         struct sk_buff *skb,
                                          struct flowi *fl,
-                                         const struct request_sock *req)
+                                         struct request_sock *req)
 {
+       tcp_v4_init_req(req, sk, skb);
+
+       if (security_inet_conn_request(sk, skb, req))
+               return NULL;
+
        return inet_csk_route_req(sk, &fl->u.ip4, req);
 }
 
@@ -1467,7 +1473,6 @@ const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
        .req_md5_lookup =       tcp_v4_md5_lookup,
        .calc_md5_hash  =       tcp_v4_md5_hash_skb,
 #endif
-       .init_req       =       tcp_v4_init_req,
 #ifdef CONFIG_SYN_COOKIES
        .cookie_init_seq =      cookie_v4_init_sequence,
 #endif
@@ -1755,6 +1760,7 @@ int tcp_v4_early_demux(struct sk_buff *skb)
 bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
 {
        u32 limit = READ_ONCE(sk->sk_rcvbuf) + READ_ONCE(sk->sk_sndbuf);
+       u32 tail_gso_size, tail_gso_segs;
        struct skb_shared_info *shinfo;
        const struct tcphdr *th;
        struct tcphdr *thtail;
@@ -1762,6 +1768,7 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
        unsigned int hdrlen;
        bool fragstolen;
        u32 gso_segs;
+       u32 gso_size;
        int delta;
 
        /* In case all data was pulled from skb frags (in __pskb_pull_tail()),
@@ -1787,13 +1794,6 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
         */
        th = (const struct tcphdr *)skb->data;
        hdrlen = th->doff * 4;
-       shinfo = skb_shinfo(skb);
-
-       if (!shinfo->gso_size)
-               shinfo->gso_size = skb->len - hdrlen;
-
-       if (!shinfo->gso_segs)
-               shinfo->gso_segs = 1;
 
        tail = sk->sk_backlog.tail;
        if (!tail)
@@ -1816,6 +1816,15 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
                goto no_coalesce;
 
        __skb_pull(skb, hdrlen);
+
+       shinfo = skb_shinfo(skb);
+       gso_size = shinfo->gso_size ?: skb->len;
+       gso_segs = shinfo->gso_segs ?: 1;
+
+       shinfo = skb_shinfo(tail);
+       tail_gso_size = shinfo->gso_size ?: (tail->len - hdrlen);
+       tail_gso_segs = shinfo->gso_segs ?: 1;
+
        if (skb_try_coalesce(tail, skb, &fragstolen, &delta)) {
                TCP_SKB_CB(tail)->end_seq = TCP_SKB_CB(skb)->end_seq;
 
@@ -1842,11 +1851,8 @@ bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
                }
 
                /* Not as strict as GRO. We only need to carry mss max value */
-               skb_shinfo(tail)->gso_size = max(shinfo->gso_size,
-                                                skb_shinfo(tail)->gso_size);
-
-               gso_segs = skb_shinfo(tail)->gso_segs + shinfo->gso_segs;
-               skb_shinfo(tail)->gso_segs = min_t(u32, gso_segs, 0xFFFF);
+               shinfo->gso_size = max(gso_size, tail_gso_size);
+               shinfo->gso_segs = min_t(u32, gso_segs + tail_gso_segs, 0xFFFF);
 
                sk->sk_backlog.len += delta;
                __NET_INC_STATS(sock_net(sk),
@@ -2759,6 +2765,20 @@ void tcp4_proc_exit(void)
 }
 #endif /* CONFIG_PROC_FS */
 
+/* @wake is one when sk_stream_write_space() calls us.
+ * This sends EPOLLOUT only if notsent_bytes is half the limit.
+ * This mimics the strategy used in sock_def_write_space().
+ */
+bool tcp_stream_memory_free(const struct sock *sk, int wake)
+{
+       const struct tcp_sock *tp = tcp_sk(sk);
+       u32 notsent_bytes = READ_ONCE(tp->write_seq) -
+                           READ_ONCE(tp->snd_nxt);
+
+       return (notsent_bytes << wake) < tcp_notsent_lowat(tp);
+}
+EXPORT_SYMBOL(tcp_stream_memory_free);
+
 struct proto tcp_prot = {
        .name                   = "TCP",
        .owner                  = THIS_MODULE,