1 files changed, 61 insertions, 3 deletions

diff --git a/net/socket.c b/net/socket.c
index 2c1e8677ff2d..c2564eb25c6b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -652,6 +652,16 @@ int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 }
 EXPORT_SYMBOL(kernel_sendmsg);
 
+static bool skb_is_err_queue(const struct sk_buff *skb)
+{
+	/* pkt_type of skbs enqueued on the error queue are set to
+	 * PACKET_OUTGOING in skb_set_err_queue(). This is only safe to do
+	 * in recvmsg, since skbs received on a local socket will never
+	 * have a pkt_type of PACKET_OUTGOING.
+	 */
+	return skb->pkt_type == PACKET_OUTGOING;
+}
+
 /*
  * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP)
  */
@@ -695,7 +705,8 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
 		put_cmsg(msg, SOL_SOCKET,
 			 SCM_TIMESTAMPING, sizeof(tss), &tss);
 
-		if (skb->len && (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_STATS))
+		if (skb_is_err_queue(skb) && skb->len &&
+		    SKB_EXT_ERR(skb)->opt_stats)
 			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_OPT_STATS,
 				 skb->len, skb->data);
 	}
@@ -1506,7 +1517,7 @@ SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
 	if (err)
 		goto out_fd;
 
-	err = sock->ops->accept(sock, newsock, sock->file->f_flags);
+	err = sock->ops->accept(sock, newsock, sock->file->f_flags, false);
 	if (err < 0)
 		goto out_fd;
 
@@ -1731,6 +1742,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
 	/* We assume all kernel code knows the size of sockaddr_storage */
 	msg.msg_namelen = 0;
 	msg.msg_iocb = NULL;
+	msg.msg_flags = 0;
 	if (sock->file->f_flags & O_NONBLOCK)
 		flags |= MSG_DONTWAIT;
 	err = sock_recvmsg(sock, &msg, flags);
@@ -3238,7 +3250,7 @@ int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
 	if (err < 0)
 		goto done;
 
-	err = sock->ops->accept(sock, *newsock, flags);
+	err = sock->ops->accept(sock, *newsock, flags, true);
 	if (err < 0) {
 		sock_release(*newsock);
 		*newsock = NULL;
@@ -3344,3 +3356,49 @@ int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
 	return sock->ops->shutdown(sock, how);
 }
 EXPORT_SYMBOL(kernel_sock_shutdown);
+
+/* This routine returns the IP overhead imposed by a socket i.e.
+ * the length of the underlying IP header, depending on whether
+ * this is an IPv4 or IPv6 socket and the length from IP options turned
+ * on at the socket. Assumes that the caller has a lock on the socket.
+ */
+u32 kernel_sock_ip_overhead(struct sock *sk)
+{
+	struct inet_sock *inet;
+	struct ip_options_rcu *opt;
+	u32 overhead = 0;
+	bool owned_by_user;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct ipv6_pinfo *np;
+	struct ipv6_txoptions *optv6 = NULL;
+#endif /* IS_ENABLED(CONFIG_IPV6) */
+
+	if (!sk)
+		return overhead;
+
+	owned_by_user = sock_owned_by_user(sk);
+	switch (sk->sk_family) {
+	case AF_INET:
+		inet = inet_sk(sk);
+		overhead += sizeof(struct iphdr);
+		opt = rcu_dereference_protected(inet->inet_opt,
+						owned_by_user);
+		if (opt)
+			overhead += opt->opt.optlen;
+		return overhead;
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		np = inet6_sk(sk);
+		overhead += sizeof(struct ipv6hdr);
+		if (np)
+			optv6 = rcu_dereference_protected(np->opt,
+							  owned_by_user);
+		if (optv6)
+			overhead += (optv6->opt_flen + optv6->opt_nflen);
+		return overhead;
+#endif /* IS_ENABLED(CONFIG_IPV6) */
+	default: /* Returns 0 overhead if the socket is not ipv4 or ipv6 */
+		return overhead;
+	}
+}
+EXPORT_SYMBOL(kernel_sock_ip_overhead);