The branch stable/15 has been updated by pouria: URL: https://cgit.FreeBSD.org/src/commit/?id=49ab036fc48a4dd5f3f3d47b3d7d604df1235724
commit 49ab036fc48a4dd5f3f3d47b3d7d604df1235724 Author: Pouria Mousavizadeh Tehrani <[email protected]> AuthorDate: 2026-02-12 23:06:15 +0000 Commit: Pouria Mousavizadeh Tehrani <[email protected]> CommitDate: 2026-02-23 20:30:10 +0000 multicast.4: Fix disabling multicast forwarding Reviewed by: markj, glebius MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D55266 (cherry picked from commit f2c2e5b0bf9def01b10651b9802fa38d07d9d265) --- share/man/man4/multicast.4 | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/share/man/man4/multicast.4 b/share/man/man4/multicast.4 index aa3293e107eb..84c6c5c4199b 100644 --- a/share/man/man4/multicast.4 +++ b/share/man/man4/multicast.4 @@ -23,7 +23,7 @@ .\" FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER .\" DEALINGS IN THE SOFTWARE. .\" -.Dd May 27, 2009 +.Dd February 13, 2026 .Dt MULTICAST 4 .Os .\" @@ -124,15 +124,15 @@ Therefore, for portability reason the multicast routing socket should be reused for IGMP and MLD messages as well. .Pp After the multicast routing socket is open, it can be used to enable -or disable multicast forwarding in the kernel: +multicast forwarding in the kernel: .Bd -literal /* IPv4 */ -int v = 1; /* 1 to enable, or 0 to disable */ +int v = 1; setsockopt(mrouter_s4, IPPROTO_IP, MRT_INIT, (void *)&v, sizeof(v)); .Ed .Bd -literal /* IPv6 */ -int v = 1; /* 1 to enable, or 0 to disable */ +int v = 1; setsockopt(mrouter_s6, IPPROTO_IPV6, MRT6_INIT, (void *)&v, sizeof(v)); \&... /* If necessary, filter all ICMPv6 messages */ @@ -142,6 +142,24 @@ setsockopt(mrouter_s6, IPPROTO_ICMPV6, ICMP6_FILTER, (void *)&filter, sizeof(filter)); .Ed .Pp +When applied to the multicast routing socket, the +.Dv MRT_DONE +and +.Dv MRT6_DONE +socket options disable multicast forwarding in the kernel: +.Bd -literal +/* IPv4 */ +int v = 1; +setsockopt(mrouter_s4, IPPROTO_IP, MRT_DONE, (void *)&v, sizeof(v)); +.Ed +.Bd -literal +/* IPv6 */ +int v = 1; +setsockopt(mrouter_s6, IPPROTO_IPV6, MRT6_DONE, (void *)&v, sizeof(v)); +.Ed +.Pp +Closing the socket has the same effect. +.Pp After multicast forwarding is enabled, the multicast routing socket can be used to enable PIM processing in the kernel if we are running PIM-SM or PIM-DM
