On 5/8/18 1:48 PM, 吉藤英明 wrote: > Hi, > > 2018-05-08 15:41 GMT+09:00 Andre Naujoks <nauts...@gmail.com>: >> On 08.05.2018 08:31, 吉藤英明 wrote: >>> Hi, >>> >>> 2018-05-08 15:03 GMT+09:00 Andre Naujoks <nauts...@gmail.com>: >>>> On 11.04.2018 13:02, Andre Naujoks wrote: >>>>> Hi. >>>> >>>> Hi again. >>>> >>>> Since it has been a month now, I'd like to send a little "ping" on this >>>> subject. >>>> >>>> Is anything wrong with this? Or was it just bad timing?
Hi. Anything new about this? I still think, this is a very useful addition. If this is not wanted/needed, then I'll stop pinging this topic. Regards Andre >>> >>> I'm just curious... What kind of behaviour do you expect? >>> >>> Unless you explicitly join the group, you cannot get traffic for the group >>> because of multicast filtering at device level (multicast fitlering) or at >>> the >>> switch level (MLD). >>> >>> If an application is interested in (several) multicast groups, it should >>> explicitly join the group. So I cannot find valid (or meaningful) use-case. >> >> I expect only to receive the multicast traffic of groups I explicitly joined >> on that >> socket. This is was the IPv4 version of this socket option already does. The >> problem >> only exists if multiple groups are joined and the socket therefore has to be >> bound >> to the "any"-address. Then we get traffic from all multicast groups joined >> by any(!) >> process on the system (plus anything else on that IP-port). > > Okay I agree that we should be able NOT to get such traffic. > > Acked-By: YOSHIFUJI Hideaki <yoshf...@linux-ipv6.org> > > --yoshfuji > >> >> Regards >> Andre >> >>> >>> --yoshfuji >>> >>>> >>>> Regards >>>> Andre >>>> >>>>> >>>>> I was running into a problem, when trying to join multiple multicast >>>>> groups >>>>> on a single socket and thus binding to the any-address on said socket. I >>>>> received traffic from multicast groups, I did not join on that socket and >>>>> was at first surprised by that. After reading some old e-mails/threads, >>>>> which came to the conclusion "It is, as it is." >>>>> (e.g https://marc.info/?l=linux-kernel&m=115815686626791&w=2), I >>>>> discovered >>>>> the IPv4 socketoption IP_MULTICAST_ALL, which, when disabled, does exactly >>>>> what I would expect from a socket by default. >>>>> >>>>> I propose a socket option for IPv6, which does the same and has the same >>>>> default as the IPv4 version. My first thought was, to just apply >>>>> IP_MULTICAST_ALL to a ipv6 socket, but that would change the behavior of >>>>> current applications and would probably be a big no-no. >>>>> >>>>> Regards >>>>> Andre >>>>> >>>>> >>>>> From 473653086c05a3de839c3504885053f6254c7bc5 Mon Sep 17 00:00:00 2001 >>>>> From: Andre Naujoks <nauts...@gmail.com> >>>>> Date: Wed, 11 Apr 2018 12:38:28 +0200 >>>>> Subject: [PATCH] Add a socketoption IPV6_MULTICAST_ALL analogue to the >>>>> IPV4 >>>>> version >>>>> >>>>> The socket option will be enabled by default to ensure current behaviour >>>>> is not changed. This is the same for the IPv4 version. >>>>> >>>>> A socket bound to in6addr_any and a specific port will receive all traffic >>>>> on that port. Analogue to IP_MULTICAST_ALL, disable this behaviour, if >>>>> one or more multicast groups were joined (using said socket) and only >>>>> pass on multicast traffic from groups, which were explicitly joined via >>>>> this socket. >>>>> >>>>> Without this option disabled a socket (system even) joined to multiple >>>>> multicast groups is very hard to get right. Filtering by destination >>>>> address has to take place in user space to avoid receiving multicast >>>>> traffic from other multicast groups, which might have traffic on the same >>>>> port. >>>>> >>>>> The extension of the IP_MULTICAST_ALL socketoption to just apply to ipv6, >>>>> too, is not done to avoid changing the behaviour of current applications. >>>>> >>>>> Signed-off-by: Andre Naujoks <nauts...@gmail.com> >>>>> --- >>>>> include/linux/ipv6.h | 3 ++- >>>>> include/uapi/linux/in6.h | 1 + >>>>> net/ipv6/af_inet6.c | 1 + >>>>> net/ipv6/ipv6_sockglue.c | 11 +++++++++++ >>>>> net/ipv6/mcast.c | 2 +- >>>>> 5 files changed, 16 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h >>>>> index 8415bf1a9776..495e834c1367 100644 >>>>> --- a/include/linux/ipv6.h >>>>> +++ b/include/linux/ipv6.h >>>>> @@ -274,7 +274,8 @@ struct ipv6_pinfo { >>>>> */ >>>>> dontfrag:1, >>>>> autoflowlabel:1, >>>>> - autoflowlabel_set:1; >>>>> + autoflowlabel_set:1, >>>>> + mc_all:1; >>>>> __u8 min_hopcount; >>>>> __u8 tclass; >>>>> __be32 rcv_flowinfo; >>>>> diff --git a/include/uapi/linux/in6.h b/include/uapi/linux/in6.h >>>>> index ed291e55f024..71d82fe15b03 100644 >>>>> --- a/include/uapi/linux/in6.h >>>>> +++ b/include/uapi/linux/in6.h >>>>> @@ -177,6 +177,7 @@ struct in6_flowlabel_req { >>>>> #define IPV6_V6ONLY 26 >>>>> #define IPV6_JOIN_ANYCAST 27 >>>>> #define IPV6_LEAVE_ANYCAST 28 >>>>> +#define IPV6_MULTICAST_ALL 29 >>>>> >>>>> /* IPV6_MTU_DISCOVER values */ >>>>> #define IPV6_PMTUDISC_DONT 0 >>>>> diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c >>>>> index 8da0b513f188..7844cd9d2f10 100644 >>>>> --- a/net/ipv6/af_inet6.c >>>>> +++ b/net/ipv6/af_inet6.c >>>>> @@ -209,6 +209,7 @@ static int inet6_create(struct net *net, struct >>>>> socket *sock, int protocol, >>>>> np->hop_limit = -1; >>>>> np->mcast_hops = IPV6_DEFAULT_MCASTHOPS; >>>>> np->mc_loop = 1; >>>>> + np->mc_all = 1; >>>>> np->pmtudisc = IPV6_PMTUDISC_WANT; >>>>> np->repflow = net->ipv6.sysctl.flowlabel_reflect; >>>>> sk->sk_ipv6only = net->ipv6.sysctl.bindv6only; >>>>> diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c >>>>> index 4d780c7f0130..b2bc1942a2ee 100644 >>>>> --- a/net/ipv6/ipv6_sockglue.c >>>>> +++ b/net/ipv6/ipv6_sockglue.c >>>>> @@ -664,6 +664,13 @@ static int do_ipv6_setsockopt(struct sock *sk, int >>>>> level, int optname, >>>>> retv = ipv6_sock_ac_drop(sk, mreq.ipv6mr_ifindex, >>>>> &mreq.ipv6mr_acaddr); >>>>> break; >>>>> } >>>>> + case IPV6_MULTICAST_ALL: >>>>> + if (optlen < sizeof(int)) >>>>> + goto e_inval; >>>>> + np->mc_all = valbool; >>>>> + retv = 0; >>>>> + break; >>>>> + >>>>> case MCAST_JOIN_GROUP: >>>>> case MCAST_LEAVE_GROUP: >>>>> { >>>>> @@ -1255,6 +1262,10 @@ static int do_ipv6_getsockopt(struct sock *sk, int >>>>> level, int optname, >>>>> val = np->mcast_oif; >>>>> break; >>>>> >>>>> + case IPV6_MULTICAST_ALL: >>>>> + val = np->mc_all; >>>>> + break; >>>>> + >>>>> case IPV6_UNICAST_IF: >>>>> val = (__force int)htonl((__u32) np->ucast_oif); >>>>> break; >>>>> diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c >>>>> index 793159d77d8a..623ad00eb3c2 100644 >>>>> --- a/net/ipv6/mcast.c >>>>> +++ b/net/ipv6/mcast.c >>>>> @@ -622,7 +622,7 @@ bool inet6_mc_check(struct sock *sk, const struct >>>>> in6_addr *mc_addr, >>>>> } >>>>> if (!mc) { >>>>> rcu_read_unlock(); >>>>> - return true; >>>>> + return np->mc_all; >>>>> } >>>>> read_lock(&mc->sflock); >>>>> psl = mc->sflist; >>>>> >>>> >>
