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);
+ if (len < 0)
+ exit(1);
+
+ if (len != ETH_ALEN) {
+ fprintf(stderr, "Error: Invalid address length
%d - must be %d bytes\n", len, ETH_ALEN);
exit(1);
}
}
--
2.28.0
