RDMA/ucma: Support query resolved service records

Enable user-space to query resolved service records through a ucma
command when a RDMA_CM_EVENT_ADDRINFO_RESOLVED event is received.

Signed-off-by: Or Har-Toov <[e-mail]>
Signed-off-by: Mark Zhang <[e-mail]>
Reviewed-by: Vlad Dumitrescu <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Leon Romanovsky <[e-mail]>

drivers/infiniband/core/ucma.c

···
 	return ret;
 }
 
+static ssize_t ucma_query_ib_service(struct ucma_context *ctx,
+				     void __user *response, int out_len)
+{
+	struct rdma_ucm_query_ib_service_resp *resp;
+	int n, ret = 0;
+
+	if (out_len < sizeof(struct rdma_ucm_query_ib_service_resp))
+		return -ENOSPC;
+
+	if (!ctx->cm_id->route.service_recs)
+		return -ENODATA;
+
+	resp = kzalloc(out_len, GFP_KERNEL);
+	if (!resp)
+		return -ENOMEM;
+
+	resp->num_service_recs = ctx->cm_id->route.num_service_recs;
+
+	n = (out_len - sizeof(struct rdma_ucm_query_ib_service_resp)) /
+		sizeof(struct ib_user_service_rec);
+
+	if (!n)
+		goto out;
+
+	if (n > ctx->cm_id->route.num_service_recs)
+		n = ctx->cm_id->route.num_service_recs;
+
+	memcpy(resp->recs, ctx->cm_id->route.service_recs,
+	       sizeof(*resp->recs) * n);
+	if (copy_to_user(response, resp, struct_size(resp, recs, n)))
+		ret = -EFAULT;
+
+out:
+	kfree(resp);
+	return ret;
+}
+
 static ssize_t ucma_query(struct ucma_file *file,
 			  const char __user *inbuf,
 			  int in_len, int out_len)
···
 		break;
 	case RDMA_USER_CM_QUERY_GID:
 		ret = ucma_query_gid(ctx, response, out_len);
+		break;
+	case RDMA_USER_CM_QUERY_IB_SERVICE:
+		ret = ucma_query_ib_service(ctx, response, out_len);
 		break;
 	default:
 		ret = -ENOSYS;

include/uapi/rdma/ib_user_sa.h

···
 	__u8	preference;
 };
 
+struct ib_user_service_rec {
+	__be64	id;
+	__u8	gid[16];
+	__be16	pkey;
+	__u8	reserved[2];
+	__be32	lease;
+	__u8	key[16];
+	__u8	name[64];
+	__u8	data_8[16];
+	__be16	data_16[8];
+	__be32	data_32[4];
+	__be64	data_64[2];
+};
+
 #endif /* IB_USER_SA_H */

include/uapi/rdma/rdma_user_cm.h

···
 enum {
 	RDMA_USER_CM_QUERY_ADDR,
 	RDMA_USER_CM_QUERY_PATH,
-	RDMA_USER_CM_QUERY_GID
+	RDMA_USER_CM_QUERY_GID,
+	RDMA_USER_CM_QUERY_IB_SERVICE
 };
 
 struct rdma_ucm_query {
···
 	__u32 num_paths;
 	__u32 reserved;
 	struct ib_path_rec_data path_data[];
+};
+
+struct rdma_ucm_query_ib_service_resp {
+	__u32 num_service_recs;
+	struct ib_user_service_rec recs[];
 };
 
 struct rdma_ucm_conn_param {