1 | // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB |
2 | /* |
3 | * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved. |
4 | * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved. |
5 | */ |
6 | |
7 | #include <linux/crc32.h> |
8 | |
9 | #include "rxe.h" |
10 | #include "rxe_loc.h" |
11 | |
12 | /** |
13 | * rxe_icrc_init() - Initialize crypto function for computing crc32 |
14 | * @rxe: rdma_rxe device object |
15 | * |
16 | * Return: 0 on success else an error |
17 | */ |
18 | int rxe_icrc_init(struct rxe_dev *rxe) |
19 | { |
20 | struct crypto_shash *tfm; |
21 | |
22 | tfm = crypto_alloc_shash(alg_name: "crc32" , type: 0, mask: 0); |
23 | if (IS_ERR(ptr: tfm)) { |
24 | rxe_dbg_dev(rxe, "failed to init crc32 algorithm err: %ld\n" , |
25 | PTR_ERR(tfm)); |
26 | return PTR_ERR(ptr: tfm); |
27 | } |
28 | |
29 | rxe->tfm = tfm; |
30 | |
31 | return 0; |
32 | } |
33 | |
34 | /** |
35 | * rxe_crc32() - Compute cumulative crc32 for a contiguous segment |
36 | * @rxe: rdma_rxe device object |
37 | * @crc: starting crc32 value from previous segments |
38 | * @next: starting address of current segment |
39 | * @len: length of current segment |
40 | * |
41 | * Return: the cumulative crc32 checksum |
42 | */ |
43 | static __be32 rxe_crc32(struct rxe_dev *rxe, __be32 crc, void *next, size_t len) |
44 | { |
45 | __be32 icrc; |
46 | int err; |
47 | |
48 | SHASH_DESC_ON_STACK(shash, rxe->tfm); |
49 | |
50 | shash->tfm = rxe->tfm; |
51 | *(__be32 *)shash_desc_ctx(desc: shash) = crc; |
52 | err = crypto_shash_update(desc: shash, data: next, len); |
53 | if (unlikely(err)) { |
54 | rxe_dbg_dev(rxe, "failed crc calculation, err: %d\n" , err); |
55 | return (__force __be32)crc32_le(crc: (__force u32)crc, p: next, len); |
56 | } |
57 | |
58 | icrc = *(__be32 *)shash_desc_ctx(desc: shash); |
59 | barrier_data(shash_desc_ctx(shash)); |
60 | |
61 | return icrc; |
62 | } |
63 | |
64 | /** |
65 | * rxe_icrc_hdr() - Compute the partial ICRC for the network and transport |
66 | * headers of a packet. |
67 | * @skb: packet buffer |
68 | * @pkt: packet information |
69 | * |
70 | * Return: the partial ICRC |
71 | */ |
72 | static __be32 rxe_icrc_hdr(struct sk_buff *skb, struct rxe_pkt_info *pkt) |
73 | { |
74 | unsigned int bth_offset = 0; |
75 | struct iphdr *ip4h = NULL; |
76 | struct ipv6hdr *ip6h = NULL; |
77 | struct udphdr *udph; |
78 | struct rxe_bth *bth; |
79 | __be32 crc; |
80 | int length; |
81 | int hdr_size = sizeof(struct udphdr) + |
82 | (skb->protocol == htons(ETH_P_IP) ? |
83 | sizeof(struct iphdr) : sizeof(struct ipv6hdr)); |
84 | /* pseudo header buffer size is calculate using ipv6 header size since |
85 | * it is bigger than ipv4 |
86 | */ |
87 | u8 pshdr[sizeof(struct udphdr) + |
88 | sizeof(struct ipv6hdr) + |
89 | RXE_BTH_BYTES]; |
90 | |
91 | /* This seed is the result of computing a CRC with a seed of |
92 | * 0xfffffff and 8 bytes of 0xff representing a masked LRH. |
93 | */ |
94 | crc = (__force __be32)0xdebb20e3; |
95 | |
96 | if (skb->protocol == htons(ETH_P_IP)) { /* IPv4 */ |
97 | memcpy(pshdr, ip_hdr(skb), hdr_size); |
98 | ip4h = (struct iphdr *)pshdr; |
99 | udph = (struct udphdr *)(ip4h + 1); |
100 | |
101 | ip4h->ttl = 0xff; |
102 | ip4h->check = CSUM_MANGLED_0; |
103 | ip4h->tos = 0xff; |
104 | } else { /* IPv6 */ |
105 | memcpy(pshdr, ipv6_hdr(skb), hdr_size); |
106 | ip6h = (struct ipv6hdr *)pshdr; |
107 | udph = (struct udphdr *)(ip6h + 1); |
108 | |
109 | memset(ip6h->flow_lbl, 0xff, sizeof(ip6h->flow_lbl)); |
110 | ip6h->priority = 0xf; |
111 | ip6h->hop_limit = 0xff; |
112 | } |
113 | udph->check = CSUM_MANGLED_0; |
114 | |
115 | bth_offset += hdr_size; |
116 | |
117 | memcpy(&pshdr[bth_offset], pkt->hdr, RXE_BTH_BYTES); |
118 | bth = (struct rxe_bth *)&pshdr[bth_offset]; |
119 | |
120 | /* exclude bth.resv8a */ |
121 | bth->qpn |= cpu_to_be32(~BTH_QPN_MASK); |
122 | |
123 | length = hdr_size + RXE_BTH_BYTES; |
124 | crc = rxe_crc32(rxe: pkt->rxe, crc, next: pshdr, len: length); |
125 | |
126 | /* And finish to compute the CRC on the remainder of the headers. */ |
127 | crc = rxe_crc32(rxe: pkt->rxe, crc, next: pkt->hdr + RXE_BTH_BYTES, |
128 | len: rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES); |
129 | return crc; |
130 | } |
131 | |
132 | /** |
133 | * rxe_icrc_check() - Compute ICRC for a packet and compare to the ICRC |
134 | * delivered in the packet. |
135 | * @skb: packet buffer |
136 | * @pkt: packet information |
137 | * |
138 | * Return: 0 if the values match else an error |
139 | */ |
140 | int rxe_icrc_check(struct sk_buff *skb, struct rxe_pkt_info *pkt) |
141 | { |
142 | __be32 *icrcp; |
143 | __be32 pkt_icrc; |
144 | __be32 icrc; |
145 | |
146 | icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE); |
147 | pkt_icrc = *icrcp; |
148 | |
149 | icrc = rxe_icrc_hdr(skb, pkt); |
150 | icrc = rxe_crc32(rxe: pkt->rxe, crc: icrc, next: (u8 *)payload_addr(pkt), |
151 | len: payload_size(pkt) + bth_pad(pkt)); |
152 | icrc = ~icrc; |
153 | |
154 | if (unlikely(icrc != pkt_icrc)) |
155 | return -EINVAL; |
156 | |
157 | return 0; |
158 | } |
159 | |
160 | /** |
161 | * rxe_icrc_generate() - compute ICRC for a packet. |
162 | * @skb: packet buffer |
163 | * @pkt: packet information |
164 | */ |
165 | void rxe_icrc_generate(struct sk_buff *skb, struct rxe_pkt_info *pkt) |
166 | { |
167 | __be32 *icrcp; |
168 | __be32 icrc; |
169 | |
170 | icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE); |
171 | icrc = rxe_icrc_hdr(skb, pkt); |
172 | icrc = rxe_crc32(rxe: pkt->rxe, crc: icrc, next: (u8 *)payload_addr(pkt), |
173 | len: payload_size(pkt) + bth_pad(pkt)); |
174 | *icrcp = ~icrc; |
175 | } |
176 | |