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>

include/net/sock.h

@@ -2249,6 +2249,8 @@ static inline struct sock *skb_steal_sock(struct sk_buff *skb)
 extern void sock_enable_timestamp(struct sock *sk, int flag);
 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
 extern int sock_get_timestampns(struct sock *, struct timespec __user *);
+extern int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
+ int level, int type);
 
 /*
  * Enable debug/info messages

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.
  *

net/packet/af_packet.c

@@ -2638,51 +2638,6 @@ static int packet_create(struct net *net, struct socket *sock, int protocol,
  return err;
 }
 
-static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
-{
- 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, SOL_PACKET, PACKET_TX_TIMESTAMP,
- 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;
-}
-
 /*
  * Pull a packet from our receive queue and hand it to the user.
  * If necessary we block.
@@ -2708,7 +2663,8 @@ static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
 #endif
 
  if (flags & MSG_ERRQUEUE) {
- err = packet_recv_error(sk, msg, len);
+ err = sock_recv_errqueue(sk, msg, len,
+ SOL_PACKET, PACKET_TX_TIMESTAMP);
  goto out;
  }