Re: [PATCH iproute2] iplink: display the value of IFLA_PROMISCUITY

Re: [PATCH iproute2] iplink: display the value of IFLA_PROMISCUITY

[Stephen Hemminger]

On Mon, 28 Jan 2013 06:47:56 -0800
Nicolas Dichtel <nicolas.dichtel@6wind.com> wrote:

> This is usefull to know the 'real' status of an interface (the flag IFF_PROMISC
> is exported by the kernel only when the user set it explicitly, for example it
> will not be exported when a tcpdump is running).
> 
> Note that I add a space after qlen (instead of before promiscuity) to be
> coherent with the rest of the code.
> 
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> ---
>  ip/ipaddress.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

The idea is good, but I can't accept in the current form.
The problem with this is that it violates the unwritten assumption that the output
of ip command should be the arguments used to setup that interface. There were even
some VPN's that depended on that.

Re: [PATCH iproute2] iplink: display the value of IFLA_PROMISCUITY

[Nicolas Dichtel]

Le 04/02/2013 18:04, Stephen Hemminger a écrit :
> On Mon, 28 Jan 2013 06:47:56 -0800
> Nicolas Dichtel <nicolas.dichtel@6wind.com> wrote:
>
>> This is usefull to know the 'real' status of an interface (the flag IFF_PROMISC
>> is exported by the kernel only when the user set it explicitly, for example it
>> will not be exported when a tcpdump is running).
>>
>> Note that I add a space after qlen (instead of before promiscuity) to be
>> coherent with the rest of the code.
>>
>> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
>> ---
>>   ip/ipaddress.c | 5 ++++-
>>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> The idea is good, but I can't accept in the current form.
> The problem with this is that it violates the unwritten assumption that the output
> of ip command should be the arguments used to setup that interface. There were even
> some VPN's that depended on that.
>
Would it be acceptable to display this information when '-d' (ip -details link) 
is provided by the user?

Re: [PATCH iproute2] iplink: display the value of IFLA_PROMISCUITY

[Stephen Hemminger]

On Mon, 04 Feb 2013 18:27:51 +0100
Nicolas Dichtel <nicolas.dichtel@6wind.com> wrote:

> Le 04/02/2013 18:04, Stephen Hemminger a écrit :
> > On Mon, 28 Jan 2013 06:47:56 -0800
> > Nicolas Dichtel <nicolas.dichtel@6wind.com> wrote:
> >
> >> This is usefull to know the 'real' status of an interface (the flag IFF_PROMISC
> >> is exported by the kernel only when the user set it explicitly, for example it
> >> will not be exported when a tcpdump is running).
> >>
> >> Note that I add a space after qlen (instead of before promiscuity) to be
> >> coherent with the rest of the code.
> >>
> >> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> >> ---
> >>   ip/ipaddress.c | 5 ++++-
> >>   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > The idea is good, but I can't accept in the current form.
> > The problem with this is that it violates the unwritten assumption that the output
> > of ip command should be the arguments used to setup that interface. There were even
> > some VPN's that depended on that.
> >
> Would it be acceptable to display this information when '-d' (ip -details link) 
> is provided by the user?

Yeah, that seems to be where such things end up.

[PATCH iproute2 v2] iplink: display the value of IFLA_PROMISCUITY

[Nicolas Dichtel]

This is useful to know the 'real' status of an interface (the flag IFF_PROMISC
is exported by the kernel only when the user set it explicitly, for example it
will not be exported when a tcpdump is running).

This information will be displayed when '-details' is provided by the user.

Example:
$ ip -d l l tun10
6: tun10: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN mode DEFAULT
    link/sit 10.16.0.249 peer 10.16.0.121
    sit remote 10.16.0.121 local 10.16.0.249 ttl inherit pmtudisc 6rd-prefix 2002::/16
    promiscuity 2

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
v2: because IFLA_PROMISCUITY is read only, display it only when '-details' is
    provided (and even if the value is zero)

 ip/ipaddress.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 2eb1a0a..e8cab40 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -464,6 +464,10 @@ int print_linkinfo(const struct sockaddr_nl *who,
 	if (do_link && tb[IFLA_LINKINFO] && show_details)
 		print_linktype(fp, tb[IFLA_LINKINFO]);
 
+	if (do_link && tb[IFLA_PROMISCUITY] && show_details)
+		fprintf(fp, "\n    promiscuity %u ",
+			*(int*)RTA_DATA(tb[IFLA_PROMISCUITY]));
+
 	if (do_link && tb[IFLA_IFALIAS])
 		fprintf(fp,"\n    alias %s", 
 			rta_getattr_str(tb[IFLA_IFALIAS]));
-- 
1.8.0.1

[PATCH iproute2] iplink: display the value of IFLA_PROMISCUITY

[Nicolas Dichtel]

This is usefull to know the 'real' status of an interface (the flag IFF_PROMISC
is exported by the kernel only when the user set it explicitly, for example it
will not be exported when a tcpdump is running).

Note that I add a space after qlen (instead of before promiscuity) to be
coherent with the rest of the code.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
---
 ip/ipaddress.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 5498f46..0d988ae 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -171,7 +171,7 @@ static void print_queuelen(FILE *f, struct rtattr *tb[IFLA_MAX + 1])
 		qlen = ifr.ifr_qlen;
 	}
 	if (qlen)
-		fprintf(f, "qlen %d", qlen);
+		fprintf(f, "qlen %d ", qlen);
 }
 
 static const char *link_modes[] = {
@@ -438,6 +438,9 @@ int print_linkinfo(const struct sockaddr_nl *who,
 	if (filter.showqueue)
 		print_queuelen(fp, tb);
 
+	if (tb[IFLA_PROMISCUITY] && *(int*)RTA_DATA(tb[IFLA_PROMISCUITY]) > 0)
+		fprintf(fp, "promiscuity %u ", *(int*)RTA_DATA(tb[IFLA_PROMISCUITY]));
+
 	if (!filter.family || filter.family == AF_PACKET) {
 		SPRINT_BUF(b1);
 		fprintf(fp, "%s", _SL_);
-- 
1.8.0.1