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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
   3  */
   4
   5 #include <linux/netdevice.h>
   6 #include "rmnet_config.h"
   7 #include "rmnet_map.h"
   8 #include "rmnet_private.h"
   9 #include "rmnet_vnd.h"
  10
  11 static u8 rmnet_map_do_flow_control(struct sk_buff *skb,
  12                                     struct rmnet_port *port,
  13                                     int enable)
  14 {
  15         struct rmnet_endpoint *ep;
  16         struct net_device *vnd;
  17         u8 mux_id;
  18         int r;
  19
  20         mux_id = RMNET_MAP_GET_MUX_ID(skb);
  21
  22         if (mux_id >= RMNET_MAX_LOGICAL_EP) {
  23                 kfree_skb(skb);
  24                 return RX_HANDLER_CONSUMED;
  25         }
  26
  27         ep = rmnet_get_endpoint(port, mux_id);
  28         if (!ep) {
  29                 kfree_skb(skb);
  30                 return RX_HANDLER_CONSUMED;
  31         }
  32
  33         vnd = ep->egress_dev;
  34
  35         /* Ignore the ip family and pass the sequence number for both v4 and v6
  36          * sequence. User space does not support creating dedicated flows for
  37          * the 2 protocols
  38          */
  39         r = rmnet_vnd_do_flow_control(vnd, enable);
  40         if (r) {
  41                 kfree_skb(skb);
  42                 return RMNET_MAP_COMMAND_UNSUPPORTED;
  43         } else {
  44                 return RMNET_MAP_COMMAND_ACK;
  45         }
  46 }
  47
  48 static void rmnet_map_send_ack(struct sk_buff *skb,
  49                                unsigned char type,
  50                                struct rmnet_port *port)
  51 {
  52         struct rmnet_map_control_command *cmd;
  53         struct net_device *dev = skb->dev;
  54
  55         if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
  56                 skb_trim(skb,
  57                          skb->len - sizeof(struct rmnet_map_dl_csum_trailer));
  58
  59         skb->protocol = htons(ETH_P_MAP);
  60
  61         cmd = RMNET_MAP_GET_CMD_START(skb);
  62         cmd->cmd_type = type & 0x03;
  63
  64         netif_tx_lock(dev);
  65         dev->netdev_ops->ndo_start_xmit(skb, dev);
  66         netif_tx_unlock(dev);
  67 }
  68
  69 /* Process MAP command frame and send N/ACK message as appropriate. Message cmd
  70  * name is decoded here and appropriate handler is called.
  71  */
  72 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port)
  73 {
  74         struct rmnet_map_control_command *cmd;
  75         unsigned char command_name;
  76         unsigned char rc = 0;
  77
  78         cmd = RMNET_MAP_GET_CMD_START(skb);
  79         command_name = cmd->command_name;
  80
  81         switch (command_name) {
  82         case RMNET_MAP_COMMAND_FLOW_ENABLE:
  83                 rc = rmnet_map_do_flow_control(skb, port, 1);
  84                 break;
  85
  86         case RMNET_MAP_COMMAND_FLOW_DISABLE:
  87                 rc = rmnet_map_do_flow_control(skb, port, 0);
  88                 break;
  89
  90         default:
  91                 rc = RMNET_MAP_COMMAND_UNSUPPORTED;
  92                 kfree_skb(skb);
  93                 break;
  94         }
  95         if (rc == RMNET_MAP_COMMAND_ACK)
  96                 rmnet_map_send_ack(skb, rc, port);
  97 }