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_crc32() - Compute cumulative crc32 for a contiguous segment 14 * @rxe: rdma_rxe device object 15 * @crc: starting crc32 value from previous segments 16 * @next: starting address of current segment 17 * @len: length of current segment 18 * 19 * Return: the cumulative crc32 checksum 20 */ 21 static __be32 rxe_crc32(struct rxe_dev *rxe, __be32 crc, void *next, size_t len) 22 { 23 return (__force __be32)crc32_le((__force u32)crc, next, len); 24 } 25 26 /** 27 * rxe_icrc_hdr() - Compute the partial ICRC for the network and transport 28 * headers of a packet. 29 * @skb: packet buffer 30 * @pkt: packet information 31 * 32 * Return: the partial ICRC 33 */ 34 static __be32 rxe_icrc_hdr(struct sk_buff *skb, struct rxe_pkt_info *pkt) 35 { 36 unsigned int bth_offset = 0; 37 struct iphdr *ip4h = NULL; 38 struct ipv6hdr *ip6h = NULL; 39 struct udphdr *udph; 40 struct rxe_bth *bth; 41 __be32 crc; 42 int length; 43 int hdr_size = sizeof(struct udphdr) + 44 (skb->protocol == htons(ETH_P_IP) ? 45 sizeof(struct iphdr) : sizeof(struct ipv6hdr)); 46 /* pseudo header buffer size is calculate using ipv6 header size since 47 * it is bigger than ipv4 48 */ 49 u8 pshdr[sizeof(struct udphdr) + 50 sizeof(struct ipv6hdr) + 51 RXE_BTH_BYTES]; 52 53 /* This seed is the result of computing a CRC with a seed of 54 * 0xfffffff and 8 bytes of 0xff representing a masked LRH. 55 */ 56 crc = (__force __be32)0xdebb20e3; 57 58 if (skb->protocol == htons(ETH_P_IP)) { /* IPv4 */ 59 memcpy(pshdr, ip_hdr(skb), hdr_size); 60 ip4h = (struct iphdr *)pshdr; 61 udph = (struct udphdr *)(ip4h + 1); 62 63 ip4h->ttl = 0xff; 64 ip4h->check = CSUM_MANGLED_0; 65 ip4h->tos = 0xff; 66 } else { /* IPv6 */ 67 memcpy(pshdr, ipv6_hdr(skb), hdr_size); 68 ip6h = (struct ipv6hdr *)pshdr; 69 udph = (struct udphdr *)(ip6h + 1); 70 71 memset(ip6h->flow_lbl, 0xff, sizeof(ip6h->flow_lbl)); 72 ip6h->priority = 0xf; 73 ip6h->hop_limit = 0xff; 74 } 75 udph->check = CSUM_MANGLED_0; 76 77 bth_offset += hdr_size; 78 79 memcpy(&pshdr[bth_offset], pkt->hdr, RXE_BTH_BYTES); 80 bth = (struct rxe_bth *)&pshdr[bth_offset]; 81 82 /* exclude bth.resv8a */ 83 bth->qpn |= cpu_to_be32(~BTH_QPN_MASK); 84 85 length = hdr_size + RXE_BTH_BYTES; 86 crc = rxe_crc32(pkt->rxe, crc, pshdr, length); 87 88 /* And finish to compute the CRC on the remainder of the headers. */ 89 crc = rxe_crc32(pkt->rxe, crc, pkt->hdr + RXE_BTH_BYTES, 90 rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES); 91 return crc; 92 } 93 94 /** 95 * rxe_icrc_check() - Compute ICRC for a packet and compare to the ICRC 96 * delivered in the packet. 97 * @skb: packet buffer 98 * @pkt: packet information 99 * 100 * Return: 0 if the values match else an error 101 */ 102 int rxe_icrc_check(struct sk_buff *skb, struct rxe_pkt_info *pkt) 103 { 104 __be32 *icrcp; 105 __be32 pkt_icrc; 106 __be32 icrc; 107 108 icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE); 109 pkt_icrc = *icrcp; 110 111 icrc = rxe_icrc_hdr(skb, pkt); 112 icrc = rxe_crc32(pkt->rxe, icrc, (u8 *)payload_addr(pkt), 113 payload_size(pkt) + bth_pad(pkt)); 114 icrc = ~icrc; 115 116 if (unlikely(icrc != pkt_icrc)) 117 return -EINVAL; 118 119 return 0; 120 } 121 122 /** 123 * rxe_icrc_generate() - compute ICRC for a packet. 124 * @skb: packet buffer 125 * @pkt: packet information 126 */ 127 void rxe_icrc_generate(struct sk_buff *skb, struct rxe_pkt_info *pkt) 128 { 129 __be32 *icrcp; 130 __be32 icrc; 131 132 icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE); 133 icrc = rxe_icrc_hdr(skb, pkt); 134 icrc = rxe_crc32(pkt->rxe, icrc, (u8 *)payload_addr(pkt), 135 payload_size(pkt) + bth_pad(pkt)); 136 *icrcp = ~icrc; 137 } 138