net: Provide a generic socket error queue delivery method for Tx time stamps.

This patch moves the private error queue delivery function from the
af_packet code to the core socket method. In this way, network layers
only needing the error queue for transmit time stamping can share common
code.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 47 insertions, 0 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 548d716c5f62..85e8de1bc7fd 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -93,6 +93,7 @@
 
 #include <linux/capability.h>
 #include <linux/errno.h>
+#include <linux/errqueue.h>
 #include <linux/types.h>
 #include <linux/socket.h>
 #include <linux/in.h>
@@ -2425,6 +2426,52 @@ void sock_enable_timestamp(struct sock *sk, int flag)
         }
 }
 
+int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
+                       int level, int type)
+{
+        struct sock_exterr_skb *serr;
+        struct sk_buff *skb, *skb2;
+        int copied, err;
+
+        err = -EAGAIN;
+        skb = skb_dequeue(&sk->sk_error_queue);
+        if (skb == NULL)
+                goto out;
+
+        copied = skb->len;
+        if (copied > len) {
+                msg->msg_flags |= MSG_TRUNC;
+                copied = len;
+        }
+        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+        if (err)
+                goto out_free_skb;
+
+        sock_recv_timestamp(msg, sk, skb);
+
+        serr = SKB_EXT_ERR(skb);
+        put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
+
+        msg->msg_flags |= MSG_ERRQUEUE;
+        err = copied;
+
+        /* Reset and regenerate socket error */
+        spin_lock_bh(&sk->sk_error_queue.lock);
+        sk->sk_err = 0;
+        if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
+                sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
+                spin_unlock_bh(&sk->sk_error_queue.lock);
+                sk->sk_error_report(sk);
+        } else
+                spin_unlock_bh(&sk->sk_error_queue.lock);
+
+out_free_skb:
+        kfree_skb(skb);
+out:
+        return err;
+}
+EXPORT_SYMBOL(sock_recv_errqueue);
+
 /*
  *      Get a socket option on an socket.
  *