[PATCH iproute2] ipmaddr: use preferred_family when given

[PATCH iproute2] ipmaddr: use preferred_family when given

[Mahesh Bandewar]

From: Mahesh Bandewar <maheshb@google.com>

When creating socket() AF_INET is used irrespective of the family
that is given at the command-line (with -4, -6, or -0). This change
will open the socket with the preferred family.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
---
 ip/ipmaddr.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/ip/ipmaddr.c b/ip/ipmaddr.c
index a48499029e17..abf83784d0df 100644
--- a/ip/ipmaddr.c
+++ b/ip/ipmaddr.c
@@ -289,6 +289,7 @@ static int multiaddr_list(int argc, char **argv)
 static int multiaddr_modify(int cmd, int argc, char **argv)
 {
 	struct ifreq ifr = {};
+	int family;
 	int fd;
 
 	if (cmd == RTM_NEWADDR)
@@ -324,7 +325,17 @@ static int multiaddr_modify(int cmd, int argc, char **argv)
 		exit(-1);
 	}
 
-	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	switch (preferred_family) {
+	case AF_INET6:
+	case AF_PACKET:
+	case AF_INET:
+		family = preferred_family;
+		break;
+	default:
+		family = AF_INET;
+	}
+
+	fd = socket(family, SOCK_DGRAM, 0);
 	if (fd < 0) {
 		perror("Cannot create socket");
 		exit(1);
-- 
2.18.0.865.gffc8e1a3cd6-goog

Re: [PATCH iproute2] ipmaddr: use preferred_family when given

[Stephen Hemminger]

On Wed, 15 Aug 2018 16:08:55 -0700
Mahesh Bandewar <mahesh@bandewar.net> wrote:

> From: Mahesh Bandewar <maheshb@google.com>
> 
> When creating socket() AF_INET is used irrespective of the family
> that is given at the command-line (with -4, -6, or -0). This change
> will open the socket with the preferred family.
> 
> Signed-off-by: Mahesh Bandewar <maheshb@google.com>
> ---
>  ip/ipmaddr.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)

What is impact of this? Does ip multicast address changes not work on IPv6?
Or is it just doing the right thing?

Re: [PATCH iproute2] ipmaddr: use preferred_family when given

[Mahesh Bandewar (महेश बंडेवार)]

On Fri, Aug 17, 2018 at 9:29 AM, Stephen Hemminger
<stephen@networkplumber.org> wrote:
> On Wed, 15 Aug 2018 16:08:55 -0700
> Mahesh Bandewar <mahesh@bandewar.net> wrote:
>
>> From: Mahesh Bandewar <maheshb@google.com>
>>
>> When creating socket() AF_INET is used irrespective of the family
>> that is given at the command-line (with -4, -6, or -0). This change
>> will open the socket with the preferred family.
>>
>> Signed-off-by: Mahesh Bandewar <maheshb@google.com>
>> ---
>>  ip/ipmaddr.c | 13 ++++++++++++-
>>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> What is impact of this? Does ip multicast address changes not work on IPv6?
> Or is it just doing the right thing?
Essentially a no-op. Just doing the right thing. :)