drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c

   1 /* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  */
  12
  13 #include <linux/netdevice.h>
  14 #include "rmnet_config.h"
  15 #include "rmnet_map.h"
  16 #include "rmnet_private.h"
  17 #include "rmnet_vnd.h"
  18
  19 static u8 rmnet_map_do_flow_control(struct sk_buff *skb,
  20                                     struct rmnet_port *rdinfo,
  21                                     int enable)
  22 {
  23         struct rmnet_map_control_command *cmd;
  24         struct rmnet_endpoint *ep;
  25         struct net_device *vnd;
  26         u16 ip_family;
  27         u16 fc_seq;
  28         u32 qos_id;
  29         u8 mux_id;
  30         int r;
  31
  32         mux_id = RMNET_MAP_GET_MUX_ID(skb);
  33         cmd = RMNET_MAP_GET_CMD_START(skb);
  34
  35         if (mux_id >= RMNET_MAX_LOGICAL_EP) {
  36                 kfree_skb(skb);
  37                 return RX_HANDLER_CONSUMED;
  38         }
  39
  40         ep = &rdinfo->muxed_ep[mux_id];
  41         vnd = ep->egress_dev;
  42
  43         ip_family = cmd->flow_control.ip_family;
  44         fc_seq = ntohs(cmd->flow_control.flow_control_seq_num);
  45         qos_id = ntohl(cmd->flow_control.qos_id);
  46
  47         /* Ignore the ip family and pass the sequence number for both v4 and v6
  48          * sequence. User space does not support creating dedicated flows for
  49          * the 2 protocols
  50          */
  51         r = rmnet_vnd_do_flow_control(vnd, enable);
  52         if (r) {
  53                 kfree_skb(skb);
  54                 return RMNET_MAP_COMMAND_UNSUPPORTED;
  55         } else {
  56                 return RMNET_MAP_COMMAND_ACK;
  57         }
  58 }
  59
  60 static void rmnet_map_send_ack(struct sk_buff *skb,
  61                                unsigned char type)
  62 {
  63         struct rmnet_map_control_command *cmd;
  64         int xmit_status;
  65
  66         skb->protocol = htons(ETH_P_MAP);
  67
  68         cmd = RMNET_MAP_GET_CMD_START(skb);
  69         cmd->cmd_type = type & 0x03;
  70
  71         netif_tx_lock(skb->dev);
  72         xmit_status = skb->dev->netdev_ops->ndo_start_xmit(skb, skb->dev);
  73         netif_tx_unlock(skb->dev);
  74 }
  75
  76 /* Process MAP command frame and send N/ACK message as appropriate. Message cmd
  77  * name is decoded here and appropriate handler is called.
  78  */
  79 rx_handler_result_t rmnet_map_command(struct sk_buff *skb,
  80                                       struct rmnet_port *port)
  81 {
  82         struct rmnet_map_control_command *cmd;
  83         unsigned char command_name;
  84         unsigned char rc = 0;
  85
  86         cmd = RMNET_MAP_GET_CMD_START(skb);
  87         command_name = cmd->command_name;
  88
  89         switch (command_name) {
  90         case RMNET_MAP_COMMAND_FLOW_ENABLE:
  91                 rc = rmnet_map_do_flow_control(skb, port, 1);
  92                 break;
  93
  94         case RMNET_MAP_COMMAND_FLOW_DISABLE:
  95                 rc = rmnet_map_do_flow_control(skb, port, 0);
  96                 break;
  97
  98         default:
  99                 rc = RMNET_MAP_COMMAND_UNSUPPORTED;
 100                 kfree_skb(skb);
 101                 break;
 102         }
 103         if (rc == RMNET_MAP_COMMAND_ACK)
 104                 rmnet_map_send_ack(skb, rc);
 105         return RX_HANDLER_CONSUMED;
 106 }