drivers/infiniband/sw/rxe/rxe_icrc.c

   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 "rxe.h"
   8 #include "rxe_loc.h"
   9
  10 /* Compute a partial ICRC for all the IB transport headers. */
  11 u32 rxe_icrc_hdr(struct rxe_pkt_info *pkt, struct sk_buff *skb)
  12 {
  13         unsigned int bth_offset = 0;
  14         struct iphdr *ip4h = NULL;
  15         struct ipv6hdr *ip6h = NULL;
  16         struct udphdr *udph;
  17         struct rxe_bth *bth;
  18         int crc;
  19         int length;
  20         int hdr_size = sizeof(struct udphdr) +
  21                 (skb->protocol == htons(ETH_P_IP) ?
  22                 sizeof(struct iphdr) : sizeof(struct ipv6hdr));
  23         /* pseudo header buffer size is calculate using ipv6 header size since
  24          * it is bigger than ipv4
  25          */
  26         u8 pshdr[sizeof(struct udphdr) +
  27                 sizeof(struct ipv6hdr) +
  28                 RXE_BTH_BYTES];
  29
  30         /* This seed is the result of computing a CRC with a seed of
  31          * 0xfffffff and 8 bytes of 0xff representing a masked LRH.
  32          */
  33         crc = 0xdebb20e3;
  34
  35         if (skb->protocol == htons(ETH_P_IP)) { /* IPv4 */
  36                 memcpy(pshdr, ip_hdr(skb), hdr_size);
  37                 ip4h = (struct iphdr *)pshdr;
  38                 udph = (struct udphdr *)(ip4h + 1);
  39
  40                 ip4h->ttl = 0xff;
  41                 ip4h->check = CSUM_MANGLED_0;
  42                 ip4h->tos = 0xff;
  43         } else {                                /* IPv6 */
  44                 memcpy(pshdr, ipv6_hdr(skb), hdr_size);
  45                 ip6h = (struct ipv6hdr *)pshdr;
  46                 udph = (struct udphdr *)(ip6h + 1);
  47
  48                 memset(ip6h->flow_lbl, 0xff, sizeof(ip6h->flow_lbl));
  49                 ip6h->priority = 0xf;
  50                 ip6h->hop_limit = 0xff;
  51         }
  52         udph->check = CSUM_MANGLED_0;
  53
  54         bth_offset += hdr_size;
  55
  56         memcpy(&pshdr[bth_offset], pkt->hdr, RXE_BTH_BYTES);
  57         bth = (struct rxe_bth *)&pshdr[bth_offset];
  58
  59         /* exclude bth.resv8a */
  60         bth->qpn |= cpu_to_be32(~BTH_QPN_MASK);
  61
  62         length = hdr_size + RXE_BTH_BYTES;
  63         crc = rxe_crc32(pkt->rxe, crc, pshdr, length);
  64
  65         /* And finish to compute the CRC on the remainder of the headers. */
  66         crc = rxe_crc32(pkt->rxe, crc, pkt->hdr + RXE_BTH_BYTES,
  67                         rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES);
  68         return crc;
  69 }