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// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/*
* Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
* Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
*/
#include <linux/crc32.h>
#include "rxe.h"
#include "rxe_loc.h"
/**
* rxe_icrc_init() - Initialize crypto function for computing crc32
* @rxe: rdma_rxe device object
*
* Return: 0 on success else an error
*/
int rxe_icrc_init(struct rxe_dev *rxe)
{
struct crypto_shash *tfm;
tfm = crypto_alloc_shash("crc32", 0, 0);
if (IS_ERR(tfm)) {
pr_warn("failed to init crc32 algorithm err:%ld\n",
PTR_ERR(tfm));
return PTR_ERR(tfm);
}
rxe->tfm = tfm;
return 0;
}
/**
* rxe_crc32() - Compute cumulative crc32 for a contiguous segment
* @rxe: rdma_rxe device object
* @crc: starting crc32 value from previous segments
* @next: starting address of current segment
* @len: length of current segment
*
* Return: the cumulative crc32 checksum
*/
static __be32 rxe_crc32(struct rxe_dev *rxe, __be32 crc, void *next, size_t len)
{
__be32 icrc;
int err;
SHASH_DESC_ON_STACK(shash, rxe->tfm);
shash->tfm = rxe->tfm;
*(__be32 *)shash_desc_ctx(shash) = crc;
err = crypto_shash_update(shash, next, len);
if (unlikely(err)) {
pr_warn_ratelimited("failed crc calculation, err: %d\n", err);
return (__force __be32)crc32_le((__force u32)crc, next, len);
}
icrc = *(__be32 *)shash_desc_ctx(shash);
barrier_data(shash_desc_ctx(shash));
return icrc;
}
/**
* rxe_icrc_hdr() - Compute the partial ICRC for the network and transport
* headers of a packet.
* @skb: packet buffer
* @pkt: packet information
*
* Return: the partial ICRC
*/
static __be32 rxe_icrc_hdr(struct sk_buff *skb, struct rxe_pkt_info *pkt)
{
unsigned int bth_offset = 0;
struct iphdr *ip4h = NULL;
struct ipv6hdr *ip6h = NULL;
struct udphdr *udph;
struct rxe_bth *bth;
__be32 crc;
int length;
int hdr_size = sizeof(struct udphdr) +
(skb->protocol == htons(ETH_P_IP) ?
sizeof(struct iphdr) : sizeof(struct ipv6hdr));
/* pseudo header buffer size is calculate using ipv6 header size since
* it is bigger than ipv4
*/
u8 pshdr[sizeof(struct udphdr) +
sizeof(struct ipv6hdr) +
RXE_BTH_BYTES];
/* This seed is the result of computing a CRC with a seed of
* 0xfffffff and 8 bytes of 0xff representing a masked LRH.
*/
crc = (__force __be32)0xdebb20e3;
if (skb->protocol == htons(ETH_P_IP)) { /* IPv4 */
memcpy(pshdr, ip_hdr(skb), hdr_size);
ip4h = (struct iphdr *)pshdr;
udph = (struct udphdr *)(ip4h + 1);
ip4h->ttl = 0xff;
ip4h->check = CSUM_MANGLED_0;
ip4h->tos = 0xff;
} else { /* IPv6 */
memcpy(pshdr, ipv6_hdr(skb), hdr_size);
ip6h = (struct ipv6hdr *)pshdr;
udph = (struct udphdr *)(ip6h + 1);
memset(ip6h->flow_lbl, 0xff, sizeof(ip6h->flow_lbl));
ip6h->priority = 0xf;
ip6h->hop_limit = 0xff;
}
udph->check = CSUM_MANGLED_0;
bth_offset += hdr_size;
memcpy(&pshdr[bth_offset], pkt->hdr, RXE_BTH_BYTES);
bth = (struct rxe_bth *)&pshdr[bth_offset];
/* exclude bth.resv8a */
bth->qpn |= cpu_to_be32(~BTH_QPN_MASK);
length = hdr_size + RXE_BTH_BYTES;
crc = rxe_crc32(pkt->rxe, crc, pshdr, length);
/* And finish to compute the CRC on the remainder of the headers. */
crc = rxe_crc32(pkt->rxe, crc, pkt->hdr + RXE_BTH_BYTES,
rxe_opcode[pkt->opcode].length - RXE_BTH_BYTES);
return crc;
}
/**
* rxe_icrc_check() - Compute ICRC for a packet and compare to the ICRC
* delivered in the packet.
* @skb: packet buffer
* @pkt: packet information
*
* Return: 0 if the values match else an error
*/
int rxe_icrc_check(struct sk_buff *skb, struct rxe_pkt_info *pkt)
{
__be32 *icrcp;
__be32 pkt_icrc;
__be32 icrc;
icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
pkt_icrc = *icrcp;
icrc = rxe_icrc_hdr(skb, pkt);
icrc = rxe_crc32(pkt->rxe, icrc, (u8 *)payload_addr(pkt),
payload_size(pkt) + bth_pad(pkt));
icrc = ~icrc;
if (unlikely(icrc != pkt_icrc)) {
if (skb->protocol == htons(ETH_P_IPV6))
pr_warn_ratelimited("bad ICRC from %pI6c\n",
&ipv6_hdr(skb)->saddr);
else if (skb->protocol == htons(ETH_P_IP))
pr_warn_ratelimited("bad ICRC from %pI4\n",
&ip_hdr(skb)->saddr);
else
pr_warn_ratelimited("bad ICRC from unknown\n");
return -EINVAL;
}
return 0;
}
/**
* rxe_icrc_generate() - compute ICRC for a packet.
* @skb: packet buffer
* @pkt: packet information
*/
void rxe_icrc_generate(struct sk_buff *skb, struct rxe_pkt_info *pkt)
{
__be32 *icrcp;
__be32 icrc;
icrcp = (__be32 *)(pkt->hdr + pkt->paylen - RXE_ICRC_SIZE);
icrc = rxe_icrc_hdr(skb, pkt);
icrc = rxe_crc32(pkt->rxe, icrc, (u8 *)payload_addr(pkt),
payload_size(pkt) + bth_pad(pkt));
*icrcp = ~icrc;
}
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