On Thu, May 21, 2015 at 07:52:36AM -0600, Wan, Kaike wrote:
>
> The general format of the request and response will be the same:
>
> ------------------
> | netlink header |
> ------------------
> | Data header |
> ------------------
> | Data |
> ------------------
>
> The data header contains information about the type of request/response, the status (for response),
> the type (format) of the data, the total length of the data header + data, and a flags field about
> the request/response or data.
>
> Based on the type of the data, the data section may be in different format: a string about the host
> name to resolve, an IP4/IP6 address, a pathrecord, a user pathrecord (struct ib_user_path_rec),
> or simply a MAD (like our posted patches), etc.
I think given the new plans this is not really necessary.
>
> Essentially it can be of any format based on the
> data type. The key is to document the format so that the kernel and user space can communicate
> correctly.
>
> The details are described below:
>
> #define IB_NL_VERSION 0x01
Change all "IB" to "RDMA"
>
> #define IB_NL_OP_MASK 0x0F
> #define IB_NL_OP_RESOLVE 0x01
> #define IB_NL_OP_QUERY_PATH 0x02
> #define IB_NL_OP_SET_TIMEOUT 0x03
> #define IB_NL_OP_ACK 0x80
>
> #define IB_NL_STATUS_SUCCESS 0x0000
> #define IB_NL_STATUS_ENODATA 0x0001
If we do what Doug suggested should we just make OP 16bits with the high bit
ACK/NACK?
Then use the other u8 as a detailed status if needed.
>
> #define IB_NL_DATA_TYPE_INVALID 0x0000
> #define IB_NL_DATA_TYPE_NAME 0x0001
> #define IB_NL_DATA_TYPE_ADDRESS_IP 0x0002
> #define IB_NL_DATA_TYPE_ADDRESS_IP6 0x0003
> #define IB_NL_DATA_TYPE_PATH_RECORD 0x0004
> #define IB_NL_DATA_TYPE_USER_PATH_REC 0x0005
Do we need both PATH_RECORD and USER_PATH_REC?
I'm having trouble determining when the OP == QUERY_PATH and the DATA_TYPE !=
PATH_RECORD.
Why don't we remove "QUERY_PATH" above and allow OP == RESOLVE and DATA_TYPE ==
PATH_RECORD be a "query for path record"?
> #define IB_NL_DATA_TYPE_MAD 0x0006
I would drop this for now.
>
> #define IB_NL_FLAGS_PATH_GMP 1
> #define IB_NL_FLAGS_PATH_PRIMARY (1<<1)
> #define IB_NL_FLAGS_PATH_ALTERNATE (1<<2)
> #define IB_NL_FLAGS_PATH_OUTBOUND (1<<3)
> #define IB_NL_FLAGS_PATH_INBOUND (1<<4)
> #define IB_NL_FLAGS_PATH_INBOUND_REVERSE (1<<5)
> #define IB_NL_FLAGS_PATH_BIDIRECTIONAL (IB_PATH_OUTBOUND | IB_PATH_INBOUND_REVERSE)
> #define IB_NL_FLAGS_QUERY_SA (1<<31)
> #define IB_NL_FLAGS_NODELAY (1<<30)
>
> struct ib_nl_data_hdr {
> __u8 version;
> __u8 opcode;
> __u16 status;
> __u16 type;
> __u16 reserved;
> __u32 flags;
> __u32 length;
The overall message length is in the netlink header. So keeping in mind Jasons
comments regarding returning multiple data records.
I think this should be the length of individual records with a "num records"
also specified. I would much prefer this over the yucky IBTA RMPP method of
implicit record sizes needing to be divided into the overall message size.
> };
Should we have a "class" value in the header somewhere? With multiple user
space listeners it could be easier to mux messages with such a value. The
class/seq would then differentiate the message.
>
> struct ib_nl_data {
> struct ib_nl_data_hdr hdr;
> __u8 data[0];
> };
>
>
> These defines and structures can be added to file include/upai/rdma/rdma_netlink.h (replace with
> RDMA_NL prefix) or contained in a seperate file (include/upai/rdma/ib_netlink.h ???).
This is not as important as getting the protocol down.
Ira
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