On Fri, 14 Aug 2020 10:46:26 +0200
Sascha Hauer <s.ha...@pengutronix.de> wrote:
> ip maddress add|del takes a MAC address as argument, so insist on
> getting a length of ETH_ALEN bytes. This makes sure the passed argument
> is actually a MAC address and especially not an IPv4 address which
> was previously accepted and silently taken as a MAC address.
>
> While at it, do not print *argv in the error path as this has been
> modified by ll_addr_a2n() and doesn't contain the full string anymore,
> which can lead to misleading error messages.
>
> Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de>
> ---
> ip/ipmaddr.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/ip/ipmaddr.c b/ip/ipmaddr.c
> index 3400e055..9979ed58 100644
> --- a/ip/ipmaddr.c
> +++ b/ip/ipmaddr.c
> @@ -291,7 +291,7 @@ static int multiaddr_modify(int cmd, int argc, char
> **argv)
> {
> struct ifreq ifr = {};
> int family;
> - int fd;
> + int fd, len;
>
> if (cmd == RTM_NEWADDR)
> cmd = SIOCADDMULTI;
> @@ -313,9 +313,12 @@ static int multiaddr_modify(int cmd, int argc, char
> **argv)
> usage();
> if (ifr.ifr_hwaddr.sa_data[0])
> duparg("address", *argv);
> - if (ll_addr_a2n(ifr.ifr_hwaddr.sa_data,
> - 14, *argv) < 0) {
> - fprintf(stderr, "Error: \"%s\" is not a legal
> ll address.\n", *argv);
> + len = ll_addr_a2n(ifr.ifr_hwaddr.sa_data, 14, *argv);
While you are at it, get rid of the hard code 14 here and use
sizeof(ifr.ifr_hwaddr.sa_data)?
