Re: [PATCH] alfred: add more verbose error message

[Sven Eckelmann <sven@narfation.org>]

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On Sunday, 8 September 2024 22:46:05 CEST noahbpeterson1997@gmail.com wrote:
> diff --git a/netsock.c b/netsock.c
> index feed21d..04f95c7 100644
> --- a/netsock.c
> +++ b/netsock.c
> @@ -322,7 +322,23 @@ static int netsock_open(struct globals *globals, struct interface *interface)
>         enable_raw_bind_capability(0);
>  
>         if (bind(sock, (struct sockaddr *)&sin6, sizeof(sin6)) < 0) {
> -               perror("can't bind");
> +               if (errno == EADDRNOTAVAIL)
> +                       fprintf(stderr, "can't bind to interface %s; "
> +                               "expected ipv6 address not found: "
> +                               "%02x%02x::%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
> +                               interface->interface,
> +                               (int)interface->address.ipv6.s6_addr[0],
> +                               (int)interface->address.ipv6.s6_addr[1],
> +                               (int)interface->address.ipv6.s6_addr[8],
> +                               (int)interface->address.ipv6.s6_addr[9],
> +                               (int)interface->address.ipv6.s6_addr[10],
> +                               (int)interface->address.ipv6.s6_addr[11],
> +                               (int)interface->address.ipv6.s6_addr[12],
> +                               (int)interface->address.ipv6.s6_addr[13],
> +                               (int)interface->address.ipv6.s6_addr[14],
> +                               (int)interface->address.ipv6.s6_addr[15]);
> +               else
> +                       perror("can't bind");
>                 goto err;
>         }

Ehrm, no - this is not a valid way to print IPv6 addresses and it makes to 
many assumptions about the IPv6 address - which will then lead to more 
problems in the future. For creating the ip address string:

    		char ipstr_buf[INET6_ADDRSTRLEN];
    		const char *ipstr;
    		....
    		ipstr = inet_ntop(AF_INET6, &interface->address.ipv6.s6_addr,
    				  ipstr_buf, INET6_ADDRSTRLEN);


Kind regards,
	Sven

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