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
rmnet_map_do_flow_control(struct sk_buff * skb,struct rmnet_port * rdinfo,int enable)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
rmnet_map_send_ack(struct sk_buff * skb,unsigned char type)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 */
rmnet_map_command(struct sk_buff * skb,struct rmnet_port * port)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 }
107