1 /* Copyright (c) 2013-2018, 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 * port,int enable)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 if (!ep) {
42 kfree_skb(skb);
43 return RX_HANDLER_CONSUMED;
44 }
45
46 vnd = ep->egress_dev;
47
48 ip_family = cmd->flow_control.ip_family;
49 fc_seq = ntohs(cmd->flow_control.flow_control_seq_num);
50 qos_id = ntohl(cmd->flow_control.qos_id);
51
52 /* Ignore the ip family and pass the sequence number for both v4 and v6
53 * sequence. User space does not support creating dedicated flows for
54 * the 2 protocols
55 */
56 r = rmnet_vnd_do_flow_control(vnd, enable);
57 if (r) {
58 kfree_skb(skb);
59 return RMNET_MAP_COMMAND_UNSUPPORTED;
60 } else {
61 return RMNET_MAP_COMMAND_ACK;
62 }
63 }
64
rmnet_map_send_ack(struct sk_buff * skb,unsigned char type,struct rmnet_port * port)65 static void rmnet_map_send_ack(struct sk_buff *skb,
66 unsigned char type,
67 struct rmnet_port *port)
68 {
69 struct rmnet_map_control_command *cmd;
70 struct net_device *dev = skb->dev;
71
72 if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4)
73 skb_trim(skb,
74 skb->len - sizeof(struct rmnet_map_dl_csum_trailer));
75
76 skb->protocol = htons(ETH_P_MAP);
77
78 cmd = RMNET_MAP_GET_CMD_START(skb);
79 cmd->cmd_type = type & 0x03;
80
81 netif_tx_lock(dev);
82 dev->netdev_ops->ndo_start_xmit(skb, dev);
83 netif_tx_unlock(dev);
84 }
85
86 /* Process MAP command frame and send N/ACK message as appropriate. Message cmd
87 * name is decoded here and appropriate handler is called.
88 */
rmnet_map_command(struct sk_buff * skb,struct rmnet_port * port)89 void rmnet_map_command(struct sk_buff *skb, struct rmnet_port *port)
90 {
91 struct rmnet_map_control_command *cmd;
92 unsigned char command_name;
93 unsigned char rc = 0;
94
95 cmd = RMNET_MAP_GET_CMD_START(skb);
96 command_name = cmd->command_name;
97
98 switch (command_name) {
99 case RMNET_MAP_COMMAND_FLOW_ENABLE:
100 rc = rmnet_map_do_flow_control(skb, port, 1);
101 break;
102
103 case RMNET_MAP_COMMAND_FLOW_DISABLE:
104 rc = rmnet_map_do_flow_control(skb, port, 0);
105 break;
106
107 default:
108 rc = RMNET_MAP_COMMAND_UNSUPPORTED;
109 kfree_skb(skb);
110 break;
111 }
112 if (rc == RMNET_MAP_COMMAND_ACK)
113 rmnet_map_send_ack(skb, rc, port);
114 }
115