This commit adds documentation for the IP_MULTICAST_ALL socket option.
The option was added to the Linux kernel in 2.6.31:
Author Nivedita Singhvi <niv@xxxxxxxxxx>
Commit f771bef98004d9d141b085d987a77d06669d4f4f
The description is based on a previous one [3] posted by the original
author of the code -- Nivedita, but it is slightly re-worded.
I tested it myself and it works as described.
References:
[1] http://lxr.free-electrons.com/source/net/ipv4/ip_sockglue.c#L972
[2] http://lxr.free-electrons.com/source/net/ipv4/igmp.c#L2267
[3] http://patchwork.ozlabs.org/patch/28902/
Signed-off-by: Radek Pazdera <rpazdera@xxxxxxxxxx>
---
man7/ip.7 | 14 +++++++++++---
1 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/man7/ip.7 b/man7/ip.7
index 9bef3bf..cc8eea6 100644
--- a/man7/ip.7
+++ b/man7/ip.7
@@ -29,9 +29,6 @@
.\" MCAST_JOIN_SOURCE_GROUP (2.4.22 / 2.6)
.\" MCAST_LEAVE_SOURCE_GROUP (2.4.22 / 2.6)
.\" MCAST_MSFILTER (2.4.22 / 2.6)
-.\" IP_MULTICAST_ALL (2.6.31)
-.\" commit f771bef98004d9d141b085d987a77d06669d4f4f
-.\" Author: Nivedita Singhvi <niv@xxxxxxxxxx>
.\" IP_UNICAST_IF (3.4)
.\" commit 76e21053b5bf33a07c76f99d27a74238310e3c71
.\" Author: Erich E. Hoover <ehoover@xxxxxxxxx>
@@ -525,6 +522,17 @@ This is also particularly useful for diagnostic tools such as
that wish to deliberately send probe packets larger than
the observed Path MTU.
.TP
+.BR IP_MULTICAST_ALL " (since Linux 2.6.31)"
+This option can be used to modify the delivery policy of multicast messages
+to sockets bound to the wildcard
+.B INADDR_ANY
+address. The argument is a boolean integer (defaults to 1). If set to 1,
+the socket will receive messages from all the groups that have been joined
+globally on the whole system. Otherwise, it will deliver only messages from
+the groups that have been explicitly joined (for example via the
+.B IP_ADD_MEMBERSHIP
+option) on this particular socket.
+.TP
.BR IP_MULTICAST_IF " (since Linux 1.2)"
Set the local device for a multicast socket.
Argument is an
--
1.7.7.6
--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
