v4.19.13 snapshot.
diff --git a/net/rxrpc/utils.c b/net/rxrpc/utils.c
new file mode 100644
index 0000000..e801171
--- /dev/null
+++ b/net/rxrpc/utils.c
@@ -0,0 +1,59 @@
+/* Utility routines
+ *
+ * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+#include "ar-internal.h"
+
+/*
+ * Fill out a peer address from a socket buffer containing a packet.
+ */
+int rxrpc_extract_addr_from_skb(struct rxrpc_local *local,
+ struct sockaddr_rxrpc *srx,
+ struct sk_buff *skb)
+{
+ memset(srx, 0, sizeof(*srx));
+
+ switch (ntohs(skb->protocol)) {
+ case ETH_P_IP:
+ if (local->srx.transport.family == AF_INET6) {
+ srx->transport_type = SOCK_DGRAM;
+ srx->transport_len = sizeof(srx->transport.sin6);
+ srx->transport.sin6.sin6_family = AF_INET6;
+ srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
+ srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
+ srx->transport.sin6.sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
+ } else {
+ srx->transport_type = SOCK_DGRAM;
+ srx->transport_len = sizeof(srx->transport.sin);
+ srx->transport.sin.sin_family = AF_INET;
+ srx->transport.sin.sin_port = udp_hdr(skb)->source;
+ srx->transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
+ }
+ return 0;
+
+#ifdef CONFIG_AF_RXRPC_IPV6
+ case ETH_P_IPV6:
+ srx->transport_type = SOCK_DGRAM;
+ srx->transport_len = sizeof(srx->transport.sin6);
+ srx->transport.sin6.sin6_family = AF_INET6;
+ srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
+ srx->transport.sin6.sin6_addr = ipv6_hdr(skb)->saddr;
+ return 0;
+#endif
+
+ default:
+ pr_warn_ratelimited("AF_RXRPC: Unknown eth protocol %u\n",
+ ntohs(skb->protocol));
+ return -EAFNOSUPPORT;
+ }
+}