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 *port, 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 = rmnet_get_endpoint(port, 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 struct rmnet_port *port) 63 { 64 struct rmnet_map_control_command *cmd; 65 int xmit_status; 66 67 if (port->data_format & RMNET_INGRESS_FORMAT_MAP_CKSUMV4) { 68 if (skb->len < sizeof(struct rmnet_map_header) + 69 RMNET_MAP_GET_LENGTH(skb) + 70 sizeof(struct rmnet_map_dl_csum_trailer)) { 71 kfree_skb(skb); 72 return; 73 } 74 75 skb_trim(skb, skb->len - 76 sizeof(struct rmnet_map_dl_csum_trailer)); 77 } 78 79 skb->protocol = htons(ETH_P_MAP); 80 81 cmd = RMNET_MAP_GET_CMD_START(skb); 82 cmd->cmd_type = type & 0x03; 83 84 netif_tx_lock(skb->dev); 85 xmit_status = skb->dev->netdev_ops->ndo_start_xmit(skb, skb->dev); 86 netif_tx_unlock(skb->dev); 87 } 88 89 /* Process MAP command frame and send N/ACK message as appropriate. Message cmd 90 * name is decoded here and appropriate handler is called. 91 */ 92 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port) 93 { 94 struct rmnet_map_control_command *cmd; 95 unsigned char command_name; 96 unsigned char rc = 0; 97 98 cmd = RMNET_MAP_GET_CMD_START(skb); 99 command_name = cmd->command_name; 100 101 switch (command_name) { 102 case RMNET_MAP_COMMAND_FLOW_ENABLE: 103 rc = rmnet_map_do_flow_control(skb, port, 1); 104 break; 105 106 case RMNET_MAP_COMMAND_FLOW_DISABLE: 107 rc = rmnet_map_do_flow_control(skb, port, 0); 108 break; 109 110 default: 111 rc = RMNET_MAP_COMMAND_UNSUPPORTED; 112 kfree_skb(skb); 113 break; 114 } 115 if (rc == RMNET_MAP_COMMAND_ACK) 116 rmnet_map_send_ack(skb, rc, port); 117 } 118