Re: [PATCHv4 bpf-next] samples/bpf: add xdp program on egress for xdp_redirect_map

From: Daniel Borkmann <daniel@iogearbox.net>
To: Hangbin Liu <liuhangbin@gmail.com>, bpf@vger.kernel.org
Cc: netdev@vger.kernel.org,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	"John Fastabend" <john.fastabend@gmail.com>,
	"Yonghong Song" <yhs@fb.com>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>
Subject: Re: [PATCHv4 bpf-next] samples/bpf: add xdp program on egress for xdp_redirect_map
Date: Fri, 11 Dec 2020 01:15:05 +0100	[thread overview]
Message-ID: <fea564b7-8c6f-fa61-48e5-76eaaf9cbe91@iogearbox.net> (raw)
In-Reply-To: <20201208120159.2278277-1-liuhangbin@gmail.com>

On 12/8/20 1:01 PM, Hangbin Liu wrote:
[...]
>   
> +static int get_mac_addr(unsigned int ifindex_out, void *mac_addr)
> +{
> +	struct ifreq ifr;
> +	char ifname[IF_NAMESIZE];
> +	int fd = socket(AF_INET, SOCK_DGRAM, 0);
> +
> +	if (fd < 0)
> +		return -1;
> +
> +	if (!if_indextoname(ifindex_out, ifname))
> +		return -1;
> +
> +	strcpy(ifr.ifr_name, ifname);
> +
> +	if (ioctl(fd, SIOCGIFHWADDR, &ifr) != 0)
> +		return -1;
> +
> +	memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
> +	close(fd);

Given we do bother to close the socket fd here, we should also close it in above
error cases..

> +	return 0;
> +}
> +