qualcomm/rmnet/rmnet_map_command.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
0003  */
0004
0005 #include <linux/netdevice.h>
0006 #include "rmnet_config.h"
0007 #include "rmnet_map.h"
0008 #include "rmnet_private.h"
0009 #include "rmnet_vnd.h"
0010
0011 static u8 rmnet_map_do_flow_control(struct sk_buff *skb,
0012                     struct rmnet_port *port,
0013                     int enable)
0014 {
0015     struct rmnet_map_header *map_header = (void *)skb->data;
0016     struct rmnet_endpoint *ep;
0017     struct net_device *vnd;
0018     u8 mux_id;
0019     int r;
0020
0021     mux_id = map_header->mux_id;
0022
0023     if (mux_id >= RMNET_MAX_LOGICAL_EP) {
0024         kfree_skb(skb);
0025         return RX_HANDLER_CONSUMED;
0026     }
0027
0028     ep = rmnet_get_endpoint(port, mux_id);
0029     if (!ep) {
0030         kfree_skb(skb);
0031         return RX_HANDLER_CONSUMED;
0032     }
0033
0034     vnd = ep->egress_dev;
0035
0036     /* Ignore the ip family and pass the sequence number for both v4 and v6
0037      * sequence. User space does not support creating dedicated flows for
0038      * the 2 protocols
0039      */
0040     r = rmnet_vnd_do_flow_control(vnd, enable);
0041     if (r) {
0042         kfree_skb(skb);
0043         return RMNET_MAP_COMMAND_UNSUPPORTED;
0044     } else {
0045         return RMNET_MAP_COMMAND_ACK;
0046     }
0047 }
0048
0049 static void rmnet_map_send_ack(struct sk_buff *skb,
0050                    unsigned char type,
0051                    struct rmnet_port *port)
0052 {
0053     struct rmnet_map_header *map_header = (void *)skb->data;
0054     struct rmnet_map_control_command *cmd;
0055     struct net_device *dev = skb->dev;
0056
0057     if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
0058         skb_trim(skb,
0059              skb->len - sizeof(struct rmnet_map_dl_csum_trailer));
0060
0061     skb->protocol = htons(ETH_P_MAP);
0062
0063     /* Command data immediately follows the MAP header */
0064     cmd = (struct rmnet_map_control_command *)(map_header + 1);
0065     cmd->cmd_type = type & 0x03;
0066
0067     netif_tx_lock(dev);
0068     dev->netdev_ops->ndo_start_xmit(skb, dev);
0069     netif_tx_unlock(dev);
0070 }
0071
0072 /* Process MAP command frame and send N/ACK message as appropriate. Message cmd
0073  * name is decoded here and appropriate handler is called.
0074  */
0075 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port)
0076 {
0077     struct rmnet_map_header *map_header = (void *)skb->data;
0078     struct rmnet_map_control_command *cmd;
0079     unsigned char command_name;
0080     unsigned char rc = 0;
0081
0082     /* Command data immediately follows the MAP header */
0083     cmd = (struct rmnet_map_control_command *)(map_header + 1);
0084     command_name = cmd->command_name;
0085
0086     switch (command_name) {
0087     case RMNET_MAP_COMMAND_FLOW_ENABLE:
0088         rc = rmnet_map_do_flow_control(skb, port, 1);
0089         break;
0090
0091     case RMNET_MAP_COMMAND_FLOW_DISABLE:
0092         rc = rmnet_map_do_flow_control(skb, port, 0);
0093         break;
0094
0095     default:
0096         rc = RMNET_MAP_COMMAND_UNSUPPORTED;
0097         kfree_skb(skb);
0098         break;
0099     }
0100     if (rc == RMNET_MAP_COMMAND_ACK)
0101         rmnet_map_send_ack(skb, rc, port);
0102 }