rdma_join_multicast_ex(3) — Linux manual page


RDMA_JOIN_MULTICAST_EX(3)rdmacm Programmer's Manual_JOIN_MULTICAST_EX(3)

NAME         top

       rdma_join_multicast_ex - Joins a multicast group with extended

SYNOPSIS         top

       #include <rdma/rdma_cma.h>

       int rdma_join_multicast_ex (struct rdma_cm_id *id, struct
       rdma_cm_join_mc_attr_ex *mc_join_attr, void *context);

ARGUMENTS         top

       id                  Communication identifier associated with the

       mc_join_attr        Is an rdma_cm_join_mc_attr_ex struct, as
                           defined in <rdma/rdma_cma.h>.

       context             User-defined context associated with the join

DESCRIPTION         top

       Joins a multicast group (MCG) with extended options.  Currently
       supporting MC join with a specified join flag.

       struct rdma_cm_join_mc_attr_ex {
               uint32_t                comp_mask;      /* Bitwise OR between "rdma_cm_join_mc_attr_mask" enum */
               uint32_t                join_flags;     /* Use a single flag from "rdma_cm_mc_join_flags" enum */
               struct sockaddr         *addr;          /* Multicast address identifying the group to join */

       The supported join flags are:

       RDMA_MC_JOIN_FLAG_FULLMEMBER - Create multicast group, Send
       multicast messages to MCG, Receive multicast messages from MCG.

       RDMA_MC_JOIN_FLAG_SENDONLY_FULLMEMBER - Create multicast group,
       Send multicast messages to MCG, Don't receive multicast messages
       from MCG (send-only).

       Initiating a MC join as "Send Only Full Member" on InfiniBand
       requires SM support, otherwise joining will fail.

       Initiating a MC join as "Send Only Full Member" on RoCEv2/ETH
       will not send any IGMP messages unlike a Full Member MC join.
       When "Send Only Full Member" is used the QP will not be attached
       to the MCG.

RETURN VALUE         top

       Returns 0 on success, or -1 on error.  If an error occurs, errno
       will be set to indicate the failure reason.

NOTES         top

       Before joining a multicast group, the rdma_cm_id must be bound to
       an RDMA device by calling rdma_bind_addr or rdma_resolve_addr.
       Use of rdma_resolve_addr requires the local routing tables to
       resolve the multicast address to an RDMA device, unless a
       specific source address is provided.  The user must call
       rdma_leave_multicast to leave the multicast group and release any
       multicast resources.  After the join operation completes, if a QP
       is associated with the rdma_cm_id, it is automatically attached
       to the multicast group when the multicast event is retrieved by
       the user.  Otherwise, the user is responsible for calling
       ibv_attach_mcast to bind the QP to the multicast group.  The join
       context is returned to the user through the private_data field in
       the rdma_cm_event.

SEE ALSO         top

       rdma_join_multicast(3), rdma_leave_multicast(3),
       rdma_bind_addr(3), rdma_resolve_addr(3), rdma_create_qp(3),

AUTHORS         top

       Alex Vesker <valex@mellanox.com>

COLOPHON         top

       This page is part of the rdma-core (RDMA Core Userspace Libraries
       and Daemons) project.  Information about the project can be found
       at ⟨https://github.com/linux-rdma/rdma-core⟩.  If you have a bug
       report for this manual page, send it to
       linux-rdma@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2021-08-27.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-08-18.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

librdmacm                      2017-11-17      RDMA_JOIN_MULTICAST_EX(3)