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_map_header *map_header = (void *)skb->data;
  16         struct rmnet_endpoint *ep;
  17         struct net_device *vnd;
  18         u8 mux_id;
  19         int r;
  20
  21         mux_id = map_header->mux_id;
  22
  23         if (mux_id >= RMNET_MAX_LOGICAL_EP) {
  24                 kfree_skb(skb);
  25                 return RX_HANDLER_CONSUMED;
  26         }
  27
  28         ep = rmnet_get_endpoint(port, mux_id);
  29         if (!ep) {
  30                 kfree_skb(skb);
  31                 return RX_HANDLER_CONSUMED;
  32         }
  33
  34         vnd = ep->egress_dev;
  35
  36         /* Ignore the ip family and pass the sequence number for both v4 and v6
  37          * sequence. User space does not support creating dedicated flows for
  38          * the 2 protocols
  39          */
  40         r = rmnet_vnd_do_flow_control(vnd, enable);
  41         if (r) {
  42                 kfree_skb(skb);
  43                 return RMNET_MAP_COMMAND_UNSUPPORTED;
  44         } else {
  45                 return RMNET_MAP_COMMAND_ACK;
  46         }
  47 }
  48
  49 static void rmnet_map_send_ack(struct sk_buff *skb,
  50                                unsigned char type,
  51                                struct rmnet_port *port)
  52 {
  53         struct rmnet_map_header *map_header = (void *)skb->data;
  54         struct rmnet_map_control_command *cmd;
  55         struct net_device *dev = skb->dev;
  56
  57         if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
  58                 skb_trim(skb,
  59                          skb->len - sizeof(struct rmnet_map_dl_csum_trailer));
  60
  61         skb->protocol = htons(ETH_P_MAP);
  62
  63         /* Command data immediately follows the MAP header */
  64         cmd = (struct rmnet_map_control_command *)(map_header + 1);
  65         cmd->cmd_type = type & 0x03;
  66
  67         netif_tx_lock(dev);
  68         dev->netdev_ops->ndo_start_xmit(skb, dev);
  69         netif_tx_unlock(dev);
  70 }
  71
  72 /* Process MAP command frame and send N/ACK message as appropriate. Message cmd
  73  * name is decoded here and appropriate handler is called.
  74  */
  75 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port)
  76 {
  77         struct rmnet_map_header *map_header = (void *)skb->data;
  78         struct rmnet_map_control_command *cmd;
  79         unsigned char command_name;
  80         unsigned char rc = 0;
  81
  82         /* Command data immediately follows the MAP header */
  83         cmd = (struct rmnet_map_control_command *)(map_header + 1);
  84         command_name = cmd->command_name;
  85
  86         switch (command_name) {
  87         case RMNET_MAP_COMMAND_FLOW_ENABLE:
  88                 rc = rmnet_map_do_flow_control(skb, port, 1);
  89                 break;
  90
  91         case RMNET_MAP_COMMAND_FLOW_DISABLE:
  92                 rc = rmnet_map_do_flow_control(skb, port, 0);
  93                 break;
  94
  95         default:
  96                 rc = RMNET_MAP_COMMAND_UNSUPPORTED;
  97                 kfree_skb(skb);
  98                 break;
  99         }
 100         if (rc == RMNET_MAP_COMMAND_ACK)
 101                 rmnet_map_send_ack(skb, rc, port);
 102 }