xfrm: introduce xfrm_trans_queue_net

This will be used by TCP encapsulation to write packets to the encap
socket without holding the user socket's lock. Without this reinjection,
we're already holding the lock of the user socket, and then try to lock
the encap socket as well when we enqueue the encrypted packet.

While at it, add a BUILD_BUG_ON like we usually do for skb->cb, since
it's missing for struct xfrm_trans_cb.

Co-developed-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index dda3c025452e0a6666ddf5c837aebd0404411984..56ff86621bb42dd2992b1e6dc0007d84d39caab7 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1547,6 +1547,9 @@ int __xfrm_init_state(struct xfrm_state *x, bool init_replay, bool offload);
 int xfrm_init_state(struct xfrm_state *x);
 int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type);
 int xfrm_input_resume(struct sk_buff *skb, int nexthdr);
+int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
+                        int (*finish)(struct net *, struct sock *,
+                                      struct sk_buff *));
 int xfrm_trans_queue(struct sk_buff *skb,
                     int (*finish)(struct net *, struct sock *,
                                   struct sk_buff *));

diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 2c86a2fc3915437c7b7935d25774939fb9976994..aa35f23c491292f362858660e14d9a9e786c7445 100644 (file)
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -36,6 +36,7 @@ struct xfrm_trans_cb {
 #endif
        } header;
        int (*finish)(struct net *net, struct sock *sk, struct sk_buff *skb);
+       struct net *net;
 };
 
 #define XFRM_TRANS_SKB_CB(__skb) ((struct xfrm_trans_cb *)&((__skb)->cb[0]))
@@ -766,12 +767,13 @@ static void xfrm_trans_reinject(unsigned long data)
        skb_queue_splice_init(&trans->queue, &queue);
 
        while ((skb = __skb_dequeue(&queue)))
-               XFRM_TRANS_SKB_CB(skb)->finish(dev_net(skb->dev), NULL, skb);
+               XFRM_TRANS_SKB_CB(skb)->finish(XFRM_TRANS_SKB_CB(skb)->net,
+                                              NULL, skb);
 }
 
-int xfrm_trans_queue(struct sk_buff *skb,
-                    int (*finish)(struct net *, struct sock *,
-                                  struct sk_buff *))
+int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb,
+                        int (*finish)(struct net *, struct sock *,
+                                      struct sk_buff *))
 {
        struct xfrm_trans_tasklet *trans;
 
@@ -780,11 +782,22 @@ int xfrm_trans_queue(struct sk_buff *skb,
        if (skb_queue_len(&trans->queue) >= netdev_max_backlog)
                return -ENOBUFS;
 
+       BUILD_BUG_ON(sizeof(struct xfrm_trans_cb) > sizeof(skb->cb));
+
        XFRM_TRANS_SKB_CB(skb)->finish = finish;
+       XFRM_TRANS_SKB_CB(skb)->net = net;
        __skb_queue_tail(&trans->queue, skb);
        tasklet_schedule(&trans->tasklet);
        return 0;
 }
+EXPORT_SYMBOL(xfrm_trans_queue_net);
+
+int xfrm_trans_queue(struct sk_buff *skb,
+                    int (*finish)(struct net *, struct sock *,
+                                  struct sk_buff *))
+{
+       return xfrm_trans_queue_net(dev_net(skb->dev), skb, finish);
+}
 EXPORT_SYMBOL(xfrm_trans_queue);
 
 void __init xfrm_input_init(void)