1 /*
2  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
3  * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *	- Redistributions of source code must retain the above
16  *	  copyright notice, this list of conditions and the following
17  *	  disclaimer.
18  *
19  *	- Redistributions in binary form must reproduce the above
20  *	  copyright notice, this list of conditions and the following
21  *	  disclaimer in the documentation and/or other materials
22  *	  provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include "rxe.h"
35 #include "rxe_loc.h"
36 
37 /* Compute a partial ICRC for all the IB transport headers. */
38 u32 rxe_icrc_hdr(struct rxe_pkt_info *pkt, struct sk_buff *skb)
39 {
40 	unsigned int bth_offset = 0;
41 	struct iphdr *ip4h = NULL;
42 	struct ipv6hdr *ip6h = NULL;
43 	struct udphdr *udph;
44 	struct rxe_bth *bth;
45 	int crc;
46 	int length;
47 	int hdr_size = sizeof(struct udphdr) +
48 		(skb->protocol == htons(ETH_P_IP) ?
49 		sizeof(struct iphdr) : sizeof(struct ipv6hdr));
50 	/* pseudo header buffer size is calculate using ipv6 header size since
51 	 * it is bigger than ipv4
52 	 */
53 	u8 pshdr[sizeof(struct udphdr) +
54 		sizeof(struct ipv6hdr) +
55 		RXE_BTH_BYTES];
56 
57 	/* This seed is the result of computing a CRC with a seed of
58 	 * 0xfffffff and 8 bytes of 0xff representing a masked LRH.
59 	 */
60 	crc = 0xdebb20e3;
61 
62 	if (skb->protocol == htons(ETH_P_IP)) { /* IPv4 */
63 		memcpy(pshdr, ip_hdr(skb), hdr_size);
64 		ip4h = (struct iphdr *)pshdr;
65 		udph = (struct udphdr *)(ip4h + 1);
66 
67 		ip4h->ttl = 0xff;
68 		ip4h->check = CSUM_MANGLED_0;
69 		ip4h->tos = 0xff;
70 	} else {				/* IPv6 */
71 		memcpy(pshdr, ipv6_hdr(skb), hdr_size);
72 		ip6h = (struct ipv6hdr *)pshdr;
73 		udph = (struct udphdr *)(ip6h + 1);
74 
75 		memset(ip6h->flow_lbl, 0xff, sizeof(ip6h->flow_lbl));
76 		ip6h->priority = 0xf;
77 		ip6h->hop_limit = 0xff;
78 	}
79 	udph->check = CSUM_MANGLED_0;
80 
81 	bth_offset += hdr_size;
82 
83 	memcpy(&pshdr[bth_offset], pkt->hdr, RXE_BTH_BYTES);
84 	bth = (struct rxe_bth *)&pshdr[bth_offset];
85 
86 	/* exclude bth.resv8a */
87 	bth->qpn |= cpu_to_be32(~BTH_QPN_MASK);
88 
89 	length = hdr_size + RXE_BTH_BYTES;
90 	crc = crc32_le(crc, pshdr, length);
91 
92 	/* And finish to compute the CRC on the remainder of the headers. */
93 	crc = crc32_le(crc, pkt->hdr + RXE_BTH_BYTES,
94 		       rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES);
95 	return crc;
96 }
97