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("crc32", 0, 0); 23 if (IS_ERR(tfm)) { 24 pr_warn("failed to init crc32 algorithm err:%ld\n", 25 PTR_ERR(tfm)); 26 return PTR_ERR(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(shash) = crc; 52 err = crypto_shash_update(shash, next, len); 53 if (unlikely(err)) { 54 pr_warn_ratelimited("failed crc calculation, err: %d\n", err); 55 return (__force __be32)crc32_le((__force u32)crc, next, len); 56 } 57 58 icrc = *(__be32 *)shash_desc_ctx(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(pkt->rxe, crc, pshdr, length); 125 126 /* And finish to compute the CRC on the remainder of the headers. */ 127 crc = rxe_crc32(pkt->rxe, crc, pkt->hdr + RXE_BTH_BYTES, 128 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(pkt->rxe, icrc, (u8 *)payload_addr(pkt), 151 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(pkt->rxe, icrc, (u8 *)payload_addr(pkt), 173 payload_size(pkt) + bth_pad(pkt)); 174 *icrcp = ~icrc; 175 } 176