ipv4: New multicast-all socket option
After some discussion offline with Christoph Lameter and David Stevens
regarding multicast behaviour in Linux, I'm submitting a slightly
modified patch from the one Christoph submitted earlier.
This patch provides a new socket option IP_MULTICAST_ALL.
In this case, default behaviour is _unchanged_ from the current
Linux standard. The socket option is set by default to provide
original behaviour. Sockets wishing to receive data only from
multicast groups they join explicitly will need to clear this
socket option.
Signed-off-by: Nivedita Singhvi <niv@us.ibm.com>
Signed-off-by: Christoph Lameter<cl@linux.com>
Acked-by: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/in.h b/include/linux/in.h
index d60122a..cf196da 100644
--- a/include/linux/in.h
+++ b/include/linux/in.h
@@ -107,6 +107,7 @@
#define MCAST_JOIN_SOURCE_GROUP 46
#define MCAST_LEAVE_SOURCE_GROUP 47
#define MCAST_MSFILTER 48
+#define IP_MULTICAST_ALL 49
#define MCAST_EXCLUDE 0
#define MCAST_INCLUDE 1
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index de0ecc7..20a6957 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -130,7 +130,8 @@
freebind:1,
hdrincl:1,
mc_loop:1,
- transparent:1;
+ transparent:1,
+ mc_all:1;
int mc_index;
__be32 mc_addr;
struct ip_mc_socklist *mc_list;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5abee4c..d873621 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -375,6 +375,7 @@
inet->uc_ttl = -1;
inet->mc_loop = 1;
inet->mc_ttl = 1;
+ inet->mc_all = 1;
inet->mc_index = 0;
inet->mc_list = NULL;
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 9eb6219..e6058a5 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2196,7 +2196,7 @@
break;
}
if (!pmc)
- return 1;
+ return inet->mc_all;
psl = pmc->sflist;
if (!psl)
return pmc->sfmode == MCAST_EXCLUDE;
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 21b0187..cb49936 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -453,6 +453,7 @@
(1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
(1<<IP_PASSSEC) | (1<<IP_TRANSPARENT))) ||
optname == IP_MULTICAST_TTL ||
+ optname == IP_MULTICAST_ALL ||
optname == IP_MULTICAST_LOOP ||
optname == IP_RECVORIGDSTADDR) {
if (optlen >= sizeof(int)) {
@@ -898,6 +899,13 @@
kfree(gsf);
break;
}
+ case IP_MULTICAST_ALL:
+ if (optlen < 1)
+ goto e_inval;
+ if (val != 0 && val != 1)
+ goto e_inval;
+ inet->mc_all = val;
+ break;
case IP_ROUTER_ALERT:
err = ip_ra_control(sk, val ? 1 : 0, NULL);
break;
@@ -1151,6 +1159,9 @@
release_sock(sk);
return err;
}
+ case IP_MULTICAST_ALL:
+ val = inet->mc_all;
+ break;
case IP_PKTOPTIONS:
{
struct msghdr msg;