xref: /linux/net/rxrpc/utils.c (revision 74ce1896c6c65b2f8cccbf59162d542988835835)
1 /* Utility routines
2  *
3  * Copyright (C) 2015 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public Licence
8  * as published by the Free Software Foundation; either version
9  * 2 of the Licence, or (at your option) any later version.
10  */
11 
12 #include <linux/ip.h>
13 #include <linux/ipv6.h>
14 #include <linux/udp.h>
15 #include "ar-internal.h"
16 
17 /*
18  * Fill out a peer address from a socket buffer containing a packet.
19  */
20 int rxrpc_extract_addr_from_skb(struct rxrpc_local *local,
21 				struct sockaddr_rxrpc *srx,
22 				struct sk_buff *skb)
23 {
24 	memset(srx, 0, sizeof(*srx));
25 
26 	switch (ntohs(skb->protocol)) {
27 	case ETH_P_IP:
28 		if (local->srx.transport.family == AF_INET6) {
29 			srx->transport_type = SOCK_DGRAM;
30 			srx->transport_len = sizeof(srx->transport.sin6);
31 			srx->transport.sin6.sin6_family = AF_INET6;
32 			srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
33 			srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
34 			srx->transport.sin6.sin6_addr.s6_addr32[3] = ip_hdr(skb)->saddr;
35 		} else {
36 			srx->transport_type = SOCK_DGRAM;
37 			srx->transport_len = sizeof(srx->transport.sin);
38 			srx->transport.sin.sin_family = AF_INET;
39 			srx->transport.sin.sin_port = udp_hdr(skb)->source;
40 			srx->transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
41 		}
42 		return 0;
43 
44 #ifdef CONFIG_AF_RXRPC_IPV6
45 	case ETH_P_IPV6:
46 		srx->transport_type = SOCK_DGRAM;
47 		srx->transport_len = sizeof(srx->transport.sin6);
48 		srx->transport.sin6.sin6_family = AF_INET6;
49 		srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
50 		srx->transport.sin6.sin6_addr = ipv6_hdr(skb)->saddr;
51 		return 0;
52 #endif
53 
54 	default:
55 		pr_warn_ratelimited("AF_RXRPC: Unknown eth protocol %u\n",
56 				    ntohs(skb->protocol));
57 		return -EAFNOSUPPORT;
58 	}
59 }
60