1 .\" Licensed under the OpenIB.org BSD license (FreeBSD Variant) - See COPYING.md
2 .TH "RDMA_JOIN_MULTICAST" 3 "2008-01-02" "librdmacm" "Librdmacm Programmer's Manual" librdmacm
4 rdma_join_multicast \- Joins a multicast group.
6 .B "#include <rdma/rdma_cma.h>"
8 .B "int" rdma_join_multicast
9 .BI "(struct rdma_cm_id *" id ","
10 .BI "struct sockaddr *" addr ","
11 .BI "void *" context ");"
14 Communication identifier associated with the request.
16 Multicast address identifying the group to join.
18 User-defined context associated with the join request.
20 Joins a multicast group and attaches an associated QP to the group.
22 Returns 0 on success, or -1 on error. If an error occurs, errno will be
23 set to indicate the failure reason.
25 Before joining a multicast group, the rdma_cm_id must be bound to
26 an RDMA device by calling rdma_bind_addr or rdma_resolve_addr. Use of
27 rdma_resolve_addr requires the local routing tables to resolve the
28 multicast address to an RDMA device, unless a specific source address
29 is provided. The user must call rdma_leave_multicast to leave the
30 multicast group and release any multicast resources. After the join
31 operation completes, if a QP is associated with the rdma_cm_id,
32 it is automatically attached to the multicast group when the multicast
33 event is retrieved by the user. Otherwise, the user is responsible
34 for calling ibv_attach_mcast to bind the QP to the multicast group.
35 The join context is returned to the user through the private_data
36 field in the rdma_cm_event.
38 rdma_leave_multicast(3), rdma_bind_addr(3), rdma_resolve_addr(3), rdma_create_qp(3),