code review 174030043: x/net/ipv4: add support for source-specific multicast

x/net/ipv4: add support for source-specific multicast

This CL introduces methods for the manipulation of source-specifc
group into both PacketConn and RawConn as follows:

JoinSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error
LeaveSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error
ExcludeSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error
IncludeSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error

Fixes issue 8266.

[mikio, 2014-11-12 13:28:55]

Hello iant@golang.org (cc: golang-codereviews@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go.net

[iant, 2014-11-12 21:39:59]

Consider writing some examples of using these features for real-world uses,
perhaps in some other CL.

https://codereview.appspot.com/174030043/diff/100001/ipv4/dgramopt_posix.go
File ipv4/dgramopt_posix.go (right):

https://codereview.appspot.com/174030043/diff/100001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:131: // SubscribeChannel subscribes the channel consists
of the
This first sentence doesn't make sense to me.  I don't know what "subscribes the
channel consists of" means.

Looking at the ip(7) man page, it looks like this means something like "Join  a 
multicast  group."  If that is the usual terminology, then that is what the
documentation should say.  Where does the "channel subscribe" terminology come
from?

My feeling is that this is so obscure that we need to be using the same
terminology as everybody else.  Otherwise nobody will understand how to use
these methods.

https://codereview.appspot.com/174030043/diff/100001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:178: // BlockChannel blocks transmitted data from source
to the
blocks multicast packets whose source address matches source.  You must already
have joined group.

[mikio, 2014-11-12 21:57:55]

On Thu, Nov 13, 2014 at 6:39 AM,  <iant@golang.org> wrote:

> Looking at the ip(7) man page, it looks like this means something like
> "Join  a  multicast  group."  If that is the usual terminology, then
> that is what the documentation should say.  Where does the "channel
> subscribe" terminology come from?

??? it just comes from rfc 4607; http://tools.ietf.org/html/rfc4607#section-3

> My feeling is that this is so obscure that we need to be using the same
> terminology as everybody else.  Otherwise nobody will understand how to
> use these methods.

i'm not sure what do you mean by "as everybody else", but suggestions
for better names are welcome.

[iant, 2014-11-12 23:24:14]

On Wed, Nov 12, 2014 at 1:57 PM, Mikio Hara <mikioh.mikioh@gmail.com> wrote:
> On Thu, Nov 13, 2014 at 6:39 AM,  <iant@golang.org> wrote:
>
>> Looking at the ip(7) man page, it looks like this means something like
>> "Join  a  multicast  group."  If that is the usual terminology, then
>> that is what the documentation should say.  Where does the "channel
>> subscribe" terminology come from?
>
> ??? it just comes from rfc 4607; http://tools.ietf.org/html/rfc4607#section-3
>
>> My feeling is that this is so obscure that we need to be using the same
>> terminology as everybody else.  Otherwise nobody will understand how to
>> use these methods.
>
> i'm not sure what do you mean by "as everybody else", but suggestions
> for better names are welcome.

When I search for "multicast channel subscribe" I don't come up with
anything.

The options you are using are using are named things like
MCAST_JOIN_SOURCE_GROUP.  When I search for that I find pages
discussing multicast groups.  The RFC may take about channels but I
think other people seem to talk about groups.

Of course I could be wrong.  Do you see other documentation that talks
about multicast channels?

Suppose instead of SubscribeChannel you use JoinGroup or JoinMulticastGroup?

Ian

[mikio, 2014-11-13 00:04:55]

> When I search for "multicast channel subscribe" I don't come up with
> anything.

:)

> Suppose instead of SubscribeChannel you use JoinGroup or JoinMulticastGroup?

Join/LeaveSourceSpecificGroup, and Block/UnblockSourceSpecificGroup or
Exclude/InclueSourceSpecificGroup make sense?

[iant, 2014-11-13 00:11:16]

On Wed, Nov 12, 2014 at 4:04 PM,  <mikioh.mikioh@gmail.com> wrote:
>> When I search for "multicast channel subscribe" I don't come up with
>> anything.
>
>
> :)
>
>> Suppose instead of SubscribeChannel you use JoinGroup or
>
> JoinMulticastGroup?
>
> Join/LeaveSourceSpecificGroup, and Block/UnblockSourceSpecificGroup or
> Exclude/InclueSourceSpecificGroup make sense?

Sure, I guess so.

Ian

[mikio, 2014-11-13 02:38:54]

ptal

> Consider writing some examples of using these features for real-world uses,
perhaps in some other CL.

will do in a separate cl

https://codereview.appspot.com/174030043/diff/100001/ipv4/dgramopt_posix.go
File ipv4/dgramopt_posix.go (right):

https://codereview.appspot.com/174030043/diff/100001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:131: // SubscribeChannel subscribes the channel consists
of the
changed

https://codereview.appspot.com/174030043/diff/100001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:178: // BlockChannel blocks transmitted data from source
to the
changed from block to exclude, so it actually tries to mute the sender using
igmpv2/3 signalling+pim.

[iant, 2014-11-13 05:17:41]

LGTM

https://codereview.appspot.com/174030043/diff/160001/ipv4/dgramopt_posix.go
File ipv4/dgramopt_posix.go (right):

https://codereview.appspot.com/174030043/diff/160001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:98: // possible to mute and unmute data transmission from
a spcific source
s/spcific/specific/

https://codereview.appspot.com/174030043/diff/160001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:136: // JoinSourceSpecificGroup joins the source-specific
group consists of
I'm not sure what the first sentence mean.  Do you mean s/consists/consisting/ ?

[mikio, 2014-11-13 06:17:18]

will submit with a few nitpicks in test found by vet.

On Thu, Nov 13, 2014 at 2:17 PM,  <iant@golang.org> wrote:

> ipv4/dgramopt_posix.go:136: // JoinSourceSpecificGroup joins the
> source-specific group consists of
> I'm not sure what the first sentence mean.  Do you mean
> s/consists/consisting/ ?

yup, consisting or "is comprised of", thanks

[mikio, 2014-11-13 08:23:53]

*** Submitted as
https://code.google.com/p/go/source/detail?r=8fd8d3a0313c&repo=net ***

x/net/ipv4: add support for source-specific multicast

This CL introduces methods for the manipulation of source-specifc
group into both PacketConn and RawConn as follows:

JoinSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error
LeaveSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error
ExcludeSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error
IncludeSourceSpecificGroup(*net.Interface, net.Addr, net.Addr) error

Fixes issue 8266.

LGTM=iant
R=iant
CC=golang-codereviews
https://codereview.appspot.com/174030043

https://codereview.appspot.com/174030043/diff/160001/ipv4/dgramopt_posix.go
File ipv4/dgramopt_posix.go (right):

https://codereview.appspot.com/174030043/diff/160001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:98: // possible to mute and unmute data transmission from
a spcific source
On 2014/11/13 05:17:40, iant wrote:
> s/spcific/specific/

Done.

https://codereview.appspot.com/174030043/diff/160001/ipv4/dgramopt_posix.go#n...
ipv4/dgramopt_posix.go:136: // JoinSourceSpecificGroup joins the source-specific
group consists of
On 2014/11/13 05:17:40, iant wrote:
> I'm not sure what the first sentence mean.  Do you mean s/consists/consisting/
?

Done.