cpmodem_shim/include/cpmodem_wrapper.h

/*
 * FILE NAME cpmodem_wrapper.h
 *
 * BRIEF MODULE DESCRIPTION
 *  Header file indicating API requirements for interfacing to custom wrapper module
 *
 *  Author: CradlePoint Technology, Inc.  <source@cradlepoint.com>
 *          Ben Kendall <benk@cradlepoint.com>
 *          Cory Atkin <catkin@cradlepoint.com>
 *
 * Copyright 2012-2021, CradlePoint Technology, Inc.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 */

// OR'd mask bits for setting the log mask - these must match cpmodem_shim.h
#define LOG_DEBUG_LEVEL_ERROR	(1 << 0)
#define LOG_DEBUG_LEVEL_WARN	(1 << 1)
#define LOG_DEBUG_LEVEL_INFO	(1 << 2)
#define LOG_DEBUG_LEVEL_TRACE	(1 << 3)
#define LOG_DEBUG_LEVEL_PRINTF	(1 << 4)
// LOG_DEBUG_LEVEL_ASSERT is always on 


//Traffic control for wrappers
#define CP_LKM_WRAPPER_SRC_DATA        0x01   //data coming from the network
#define CP_LKM_WRAPPER_SRC_CTRL        0x02   //data coming from the cpcommon stack
#define CP_LKM_WRAPPER_DST_DATA        0x03   //data going to network stack
#define CP_LKM_WRAPPER_DST_CTRL        0x04   //data going to cpcommon stack
#define CP_LKM_WRAPPER_DST_FLOW_PAUSE  0x05   //pause tx traffic (i.e. SRC_DATA)
#define CP_LKM_WRAPPER_DST_FLOW_RESUME 0x06   //resume tx traffic
#define CP_LKM_WRAPPER_DST_UNKNOWN     0x07   //don't know what this is, drop it

//results for wrappers
#define CP_LKM_WRAPPER_RES_DONE   0x01   //Wrapper is done with success
#define CP_LKM_WRAPPER_RES_AGAIN  0x02   //Wrapper needs to be called again to continue processing
#define CP_LKM_WRAPPER_RES_ERROR  0x03   //Wrapper is done with an error

//state of the usb device as a whole
typedef enum{
   CP_LKM_WRAPPER_INIT =    0,  //ioctl created the object, but we haven't gotten the probe yet from USB
   CP_LKM_WRAPPER_CTRL =    1,  //got probe from usb, can now pass ctrl pkts between USB device and the app space driver
   CP_LKM_WRAPPER_ACTIVE =  2,  //ioctl told us the data connection is now active
	CP_LKM_WRAPPER_INVALID = 0xff
} cp_lkm_wrapper_state_t;

//These must match the cp_lkm_wrapper_t enum in cpmodem_shim.h
typedef enum
{
   CP_LKM_WRAPPER_TYPE_NONE = 0,
   CP_LKM_WRAPPER_TYPE_ASIX,
   CP_LKM_WRAPPER_TYPE_ASIX_88179,
   CP_LKM_WRAPPER_TYPE_LG,
   CP_LKM_WRAPPER_TYPE_DIRECT_IP,
   CP_LKM_WRAPPER_TYPE_MSRNDIS,
   CP_LKM_WRAPPER_TYPE_PEGASUS,
   CP_LKM_WRAPPER_TYPE_NCM,
	CP_LKM_WRAPPER_TYPE_QMAP,          //New Qualcomm muxing and aggregation protocol
   CP_LKM_WRAPPER_TYPE_NUM_WRAPPERS //NOTE: this one needs to always be last
} cp_lkm_wrapper_type_t;


/* 
   Alloc an opaque wrapper context
   wrapper_info is wrapper specific data sent down from the app space driver. cp_lkm retains
   ownership of the memory and frees it when the device unplugs, so the wrapper must copy any data it needs to hang onto.
*/
void* cp_lkm_wrapper_instance_alloc(cp_lkm_wrapper_type_t wrapper, void* wrapper_info, int len);
void cp_lkm_wrapper_instance_free(void* ctxt);

/*
 * Apply the wrapper to a send pkt before sending to USB 
 * ctxt    : wrapper ctxt from cp_lkm_wrapper_instance_alloc() 
 * src     : CP_LKM_WRAPPER_SRC_DATA or CP_LKM_WRAPPER_SRC_CTRL 
 * skb_in  : buffer with send data. This function takes ownership of skb_in and is responsible for freeing it when done. 
 * skb_out : pointer to skb to send to usb. If NULL, nothing to send, else send it. The calling function takes ownership 
 *           of skb_out and is responsbil for freeing it.
 * wrapper_state: CP_LKM_WRAPPER_ACTIVE if data connection is active, CP_LKM_WRAPPER_CTRL if no data connection. Some wrappers may 
 *            need to wrap differently depending on the state 
 *  
 * return value: CP_LKM_WRAPPER_RES_DONE  - Done processing skb_in. if skb_out is non NULL, send to usb.
 *               CP_LKM_WRAPPER_RES_AGAIN - Still processing skb_in. if skb_out is non NULL send to usb, call send again with
 *                                          skb_in set to NULL (since send took ownership on last call).
 *               CP_LKM_WRAPPER_RES_ERROR - There was an error with the buffer, update error pkt counts if needed.
 *                                          (send has taken ownership, and will free the skb).
 *  
 */
int cp_lkm_wrapper_send(void* ctxt, int src, int mux_id, struct sk_buff* skb_in, struct sk_buff** skb_out);

/*
 * Process the recv pkt before sending up to the app driver (ctrl) or to the network stack (data)  
 * ctxt    : wrapper ctxt from cp_lkm_wrapper_instance_alloc() 
 * skb_in  : buffer with recv data. This function takes ownership of skb_in and is responsible for freeing it when done. 
 * skb_out : pointer to skb to send to ctrl or data. If NULL, nothing to send. The calling function takes ownership 
 *           of skb_out and is responsible for freeing it.
 * wrapper_state: CP_LKM_WRAPPER_ACTIVE if data connection is active, CP_LKM_WRAPPER_CTRL if no data connection. Some wrappers may 
 *            need to wrap differently depending on the state
 *  
 * return value: The return value has the result and the destination OR'd into it. 
 *       result: 
 *               CP_LKM_WRAPPER_RES_DONE  - Done processing skb_in. if skb_out is non NULL, send to destination.
 *               CP_LKM_WRAPPER_RES_AGAIN - Still processing skb_in. if skb_out is non NULL send to destination, then call send again with
 *                                          skb_in set to NULL (since send took ownership on last call) to get the next result and dest.
 *               CP_LKM_WRAPPER_RES_ERROR - There was an error with the buffer, update error pkt counts if needed.
 *                                          (send has taken ownership, and will free the skb).
 *        dest:  CP_LKM_WRAPPER_DST_DATA - send to protocol stack
 *               CP_LKM_WRAPPER_DST_CTRL = send to app space driver
 *  
*/
int cp_lkm_wrapper_recv(void* ctxt, int* dst, int* mux_id, struct sk_buff* skb_in, struct sk_buff** skb_out);

/*
 * Let the wrapper know the state of the interface with unique identifier id 
 *  
*/
#define CP_LKM_WRAPPER_DEFAULT_ID 0
void cp_lkm_wrapper_set_state(void* ctxt, int id, cp_lkm_wrapper_state_t wrapper_state);

void cp_lkm_wrapper_set_log_level(int level);
int cp_lkm_wrapper_hdr_size(void* ctxt);