1 /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
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.
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.
12 * RMNET Data ingress/egress handler
16 #include <linux/netdevice.h>
17 #include <linux/netdev_features.h>
18 #include <linux/if_arp.h>
20 #include "rmnet_private.h"
21 #include "rmnet_config.h"
22 #include "rmnet_vnd.h"
23 #include "rmnet_map.h"
24 #include "rmnet_handlers.h"
26 #define RMNET_IP_VERSION_4 0x40
27 #define RMNET_IP_VERSION_6 0x60
29 /* Helper Functions */
31 static void rmnet_set_skb_proto(struct sk_buff *skb)
33 switch (skb->data[0] & 0xF0) {
34 case RMNET_IP_VERSION_4:
35 skb->protocol = htons(ETH_P_IP);
37 case RMNET_IP_VERSION_6:
38 skb->protocol = htons(ETH_P_IPV6);
41 skb->protocol = htons(ETH_P_MAP);
49 rmnet_deliver_skb(struct sk_buff *skb)
51 struct rmnet_priv *priv = netdev_priv(skb->dev);
53 skb_reset_transport_header(skb);
54 skb_reset_network_header(skb);
55 rmnet_vnd_rx_fixup(skb, skb->dev);
57 skb->pkt_type = PACKET_HOST;
58 skb_set_mac_header(skb, 0);
59 gro_cells_receive(&priv->gro_cells, skb);
65 __rmnet_map_ingress_handler(struct sk_buff *skb,
66 struct rmnet_port *port)
68 struct rmnet_endpoint *ep;
72 if (RMNET_MAP_GET_CD_BIT(skb)) {
73 if (port->data_format & RMNET_FLAGS_INGRESS_MAP_COMMANDS)
74 return rmnet_map_command(skb, port);
79 mux_id = RMNET_MAP_GET_MUX_ID(skb);
80 pad = RMNET_MAP_GET_PAD(skb);
81 len = RMNET_MAP_GET_LENGTH(skb) - pad;
83 if (mux_id >= RMNET_MAX_LOGICAL_EP)
86 ep = rmnet_get_endpoint(port, mux_id);
90 skb->dev = ep->egress_dev;
92 /* Subtract MAP header */
93 skb_pull(skb, sizeof(struct rmnet_map_header));
94 rmnet_set_skb_proto(skb);
96 if (port->data_format & RMNET_FLAGS_INGRESS_MAP_CKSUMV4) {
97 if (!rmnet_map_checksum_downlink_packet(skb, len + pad))
98 skb->ip_summed = CHECKSUM_UNNECESSARY;
102 rmnet_deliver_skb(skb);
110 rmnet_map_ingress_handler(struct sk_buff *skb,
111 struct rmnet_port *port)
113 struct sk_buff *skbn;
115 if (skb->dev->type == ARPHRD_ETHER) {
116 if (pskb_expand_head(skb, ETH_HLEN, 0, GFP_ATOMIC)) {
121 skb_push(skb, ETH_HLEN);
124 if (port->data_format & RMNET_FLAGS_INGRESS_DEAGGREGATION) {
125 while ((skbn = rmnet_map_deaggregate(skb, port)) != NULL)
126 __rmnet_map_ingress_handler(skbn, port);
130 __rmnet_map_ingress_handler(skb, port);
134 static int rmnet_map_egress_handler(struct sk_buff *skb,
135 struct rmnet_port *port, u8 mux_id,
136 struct net_device *orig_dev)
138 int required_headroom, additional_header_len;
139 struct rmnet_map_header *map_header;
141 additional_header_len = 0;
142 required_headroom = sizeof(struct rmnet_map_header);
144 if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4) {
145 additional_header_len = sizeof(struct rmnet_map_ul_csum_header);
146 required_headroom += additional_header_len;
149 if (skb_headroom(skb) < required_headroom) {
150 if (pskb_expand_head(skb, required_headroom, 0, GFP_ATOMIC))
154 if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
155 rmnet_map_checksum_uplink_packet(skb, orig_dev);
157 map_header = rmnet_map_add_map_header(skb, additional_header_len, 0);
161 map_header->mux_id = mux_id;
163 skb->protocol = htons(ETH_P_MAP);
169 rmnet_bridge_handler(struct sk_buff *skb, struct net_device *bridge_dev)
171 if (skb_mac_header_was_set(skb))
172 skb_push(skb, skb->mac_len);
175 skb->dev = bridge_dev;
180 /* Ingress / Egress Entry Points */
182 /* Processes packet as per ingress data format for receiving device. Logical
183 * endpoint is determined from packet inspection. Packet is then sent to the
184 * egress device listed in the logical endpoint configuration.
186 rx_handler_result_t rmnet_rx_handler(struct sk_buff **pskb)
188 struct sk_buff *skb = *pskb;
189 struct rmnet_port *port;
190 struct net_device *dev;
195 if (skb->pkt_type == PACKET_LOOPBACK)
196 return RX_HANDLER_PASS;
199 port = rmnet_get_port_rcu(dev);
200 if (unlikely(!port)) {
201 atomic_long_inc(&skb->dev->rx_nohandler);
206 switch (port->rmnet_mode) {
207 case RMNET_EPMODE_VND:
208 rmnet_map_ingress_handler(skb, port);
210 case RMNET_EPMODE_BRIDGE:
211 rmnet_bridge_handler(skb, port->bridge_ep);
216 return RX_HANDLER_CONSUMED;
219 /* Modifies packet as per logical endpoint configuration and egress data format
220 * for egress device configured in logical endpoint. Packet is then transmitted
221 * on the egress device.
223 void rmnet_egress_handler(struct sk_buff *skb)
225 struct net_device *orig_dev;
226 struct rmnet_port *port;
227 struct rmnet_priv *priv;
230 sk_pacing_shift_update(skb->sk, 8);
233 priv = netdev_priv(orig_dev);
234 skb->dev = priv->real_dev;
235 mux_id = priv->mux_id;
237 port = rmnet_get_port_rcu(skb->dev);
241 if (rmnet_map_egress_handler(skb, port, mux_id, orig_dev))
244 rmnet_vnd_tx_fixup(skb, orig_dev);
250 this_cpu_inc(priv->pcpu_stats->stats.tx_drops);