[dpdk-dev] [PATCH v3 2/3] net: replace htons with rte_cpu_to_be_16

[Morten Brørup]

> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Fady Bader
> Sent: Wednesday, July 8, 2020 10:25 AM
> 
> htons wasn't defined in Windows for the minGW compiler.
> htons was replaced with rte_cpu_to_be_16 in order to compile
> under Windows.
> 
> Signed-off-by: Fady Bader <fady at mellanox.com>
> ---
>  lib/librte_net/rte_arp.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/librte_net/rte_arp.c b/lib/librte_net/rte_arp.c
> index 784b7f48fa..227a6396de 100644
> --- a/lib/librte_net/rte_arp.c
> +++ b/lib/librte_net/rte_arp.c
> @@ -2,9 +2,12 @@
>   * Copyright(c) 2018 Intel Corporation
>   */
> 
> +#ifndef RTE_EXEC_ENV_WINDOWS
>  #include <arpa/inet.h>
> +#endif
> 
>  #include <rte_arp.h>
> +#include <rte_byteorder.h>
> 
>  #define RARP_PKT_SIZE	64
>  struct rte_mbuf *
> @@ -32,15 +35,15 @@ rte_net_make_rarp_packet(struct rte_mempool *mpool,
>  	/* Ethernet header. */
>  	memset(eth_hdr->d_addr.addr_bytes, 0xff, RTE_ETHER_ADDR_LEN);
>  	rte_ether_addr_copy(mac, &eth_hdr->s_addr);
> -	eth_hdr->ether_type = htons(RTE_ETHER_TYPE_RARP);
> +	eth_hdr->ether_type = rte_cpu_to_be_16(RTE_ETHER_TYPE_RARP);
> 
>  	/* RARP header. */
>  	rarp = (struct rte_arp_hdr *)(eth_hdr + 1);
> -	rarp->arp_hardware = htons(RTE_ARP_HRD_ETHER);
> -	rarp->arp_protocol = htons(RTE_ETHER_TYPE_IPV4);
> +	rarp->arp_hardware = rte_cpu_to_be_16(RTE_ARP_HRD_ETHER);
> +	rarp->arp_protocol = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4);
>  	rarp->arp_hlen = RTE_ETHER_ADDR_LEN;
>  	rarp->arp_plen = 4;
> -	rarp->arp_opcode  = htons(RTE_ARP_OP_REVREQUEST);
> +	rarp->arp_opcode  = rte_cpu_to_be_16(RTE_ARP_OP_REVREQUEST);
> 
>  	rte_ether_addr_copy(mac, &rarp->arp_data.arp_sha);
>  	rte_ether_addr_copy(mac, &rarp->arp_data.arp_tha);
> --
> 2.16.1.windows.4
> 

The way I read rte_byteorder.h, you should use RTE_BE16() for compile time integers and rte_cpu_to_be_16() for runtime variable integers.

<rant>
I guess that the resulting compiler output is the same with a modern compiler; but since the API exposes different functions for different purposes, we should use them as instructed by the documentation.

Otherwise the obsolete (duplicate) functions should be deprecated and eventually removed.
</rant>