1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (c) 2013-2018, The Linux Foundation. All rights reserved.
3 *
4 * RMNET Data virtual network driver
5 */
6
7 #include <linux/etherdevice.h>
8 #include <linux/ethtool.h>
9 #include <linux/if_arp.h>
10 #include <net/pkt_sched.h>
11 #include "rmnet_config.h"
12 #include "rmnet_handlers.h"
13 #include "rmnet_private.h"
14 #include "rmnet_map.h"
15 #include "rmnet_vnd.h"
16
17 /* RX/TX Fixup */
18
rmnet_vnd_rx_fixup(struct sk_buff * skb,struct net_device * dev)19 void rmnet_vnd_rx_fixup(struct sk_buff *skb, struct net_device *dev)
20 {
21 struct rmnet_priv *priv = netdev_priv(dev);
22 struct rmnet_pcpu_stats *pcpu_ptr;
23
24 pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
25
26 u64_stats_update_begin(&pcpu_ptr->syncp);
27 pcpu_ptr->stats.rx_pkts++;
28 pcpu_ptr->stats.rx_bytes += skb->len;
29 u64_stats_update_end(&pcpu_ptr->syncp);
30 }
31
rmnet_vnd_tx_fixup(struct sk_buff * skb,struct net_device * dev)32 void rmnet_vnd_tx_fixup(struct sk_buff *skb, struct net_device *dev)
33 {
34 struct rmnet_priv *priv = netdev_priv(dev);
35 struct rmnet_pcpu_stats *pcpu_ptr;
36
37 pcpu_ptr = this_cpu_ptr(priv->pcpu_stats);
38
39 u64_stats_update_begin(&pcpu_ptr->syncp);
40 pcpu_ptr->stats.tx_pkts++;
41 pcpu_ptr->stats.tx_bytes += skb->len;
42 u64_stats_update_end(&pcpu_ptr->syncp);
43 }
44
45 /* Network Device Operations */
46
rmnet_vnd_start_xmit(struct sk_buff * skb,struct net_device * dev)47 static netdev_tx_t rmnet_vnd_start_xmit(struct sk_buff *skb,
48 struct net_device *dev)
49 {
50 struct rmnet_priv *priv;
51
52 priv = netdev_priv(dev);
53 if (priv->real_dev) {
54 rmnet_egress_handler(skb);
55 } else {
56 this_cpu_inc(priv->pcpu_stats->stats.tx_drops);
57 kfree_skb(skb);
58 }
59 return NETDEV_TX_OK;
60 }
61
rmnet_vnd_headroom(struct rmnet_port * port)62 static int rmnet_vnd_headroom(struct rmnet_port *port)
63 {
64 u32 headroom;
65
66 headroom = sizeof(struct rmnet_map_header);
67
68 if (port->data_format & RMNET_FLAGS_EGRESS_MAP_CKSUMV4)
69 headroom += sizeof(struct rmnet_map_ul_csum_header);
70
71 return headroom;
72 }
73
rmnet_vnd_change_mtu(struct net_device * rmnet_dev,int new_mtu)74 static int rmnet_vnd_change_mtu(struct net_device *rmnet_dev, int new_mtu)
75 {
76 struct rmnet_priv *priv = netdev_priv(rmnet_dev);
77 struct rmnet_port *port;
78 u32 headroom;
79
80 port = rmnet_get_port_rtnl(priv->real_dev);
81
82 headroom = rmnet_vnd_headroom(port);
83
84 if (new_mtu < 0 || new_mtu > RMNET_MAX_PACKET_SIZE ||
85 new_mtu > (priv->real_dev->mtu - headroom))
86 return -EINVAL;
87
88 rmnet_dev->mtu = new_mtu;
89 return 0;
90 }
91
rmnet_vnd_get_iflink(const struct net_device * dev)92 static int rmnet_vnd_get_iflink(const struct net_device *dev)
93 {
94 struct rmnet_priv *priv = netdev_priv(dev);
95
96 return priv->real_dev->ifindex;
97 }
98
rmnet_vnd_init(struct net_device * dev)99 static int rmnet_vnd_init(struct net_device *dev)
100 {
101 struct rmnet_priv *priv = netdev_priv(dev);
102 int err;
103
104 priv->pcpu_stats = alloc_percpu(struct rmnet_pcpu_stats);
105 if (!priv->pcpu_stats)
106 return -ENOMEM;
107
108 err = gro_cells_init(&priv->gro_cells, dev);
109 if (err) {
110 free_percpu(priv->pcpu_stats);
111 return err;
112 }
113
114 return 0;
115 }
116
rmnet_vnd_uninit(struct net_device * dev)117 static void rmnet_vnd_uninit(struct net_device *dev)
118 {
119 struct rmnet_priv *priv = netdev_priv(dev);
120
121 gro_cells_destroy(&priv->gro_cells);
122 free_percpu(priv->pcpu_stats);
123 }
124
rmnet_get_stats64(struct net_device * dev,struct rtnl_link_stats64 * s)125 static void rmnet_get_stats64(struct net_device *dev,
126 struct rtnl_link_stats64 *s)
127 {
128 struct rmnet_priv *priv = netdev_priv(dev);
129 struct rmnet_vnd_stats total_stats;
130 struct rmnet_pcpu_stats *pcpu_ptr;
131 unsigned int cpu, start;
132
133 memset(&total_stats, 0, sizeof(struct rmnet_vnd_stats));
134
135 for_each_possible_cpu(cpu) {
136 pcpu_ptr = per_cpu_ptr(priv->pcpu_stats, cpu);
137
138 do {
139 start = u64_stats_fetch_begin_irq(&pcpu_ptr->syncp);
140 total_stats.rx_pkts += pcpu_ptr->stats.rx_pkts;
141 total_stats.rx_bytes += pcpu_ptr->stats.rx_bytes;
142 total_stats.tx_pkts += pcpu_ptr->stats.tx_pkts;
143 total_stats.tx_bytes += pcpu_ptr->stats.tx_bytes;
144 } while (u64_stats_fetch_retry_irq(&pcpu_ptr->syncp, start));
145
146 total_stats.tx_drops += pcpu_ptr->stats.tx_drops;
147 }
148
149 s->rx_packets = total_stats.rx_pkts;
150 s->rx_bytes = total_stats.rx_bytes;
151 s->tx_packets = total_stats.tx_pkts;
152 s->tx_bytes = total_stats.tx_bytes;
153 s->tx_dropped = total_stats.tx_drops;
154 }
155
156 static const struct net_device_ops rmnet_vnd_ops = {
157 .ndo_start_xmit = rmnet_vnd_start_xmit,
158 .ndo_change_mtu = rmnet_vnd_change_mtu,
159 .ndo_get_iflink = rmnet_vnd_get_iflink,
160 .ndo_add_slave = rmnet_add_bridge,
161 .ndo_del_slave = rmnet_del_bridge,
162 .ndo_init = rmnet_vnd_init,
163 .ndo_uninit = rmnet_vnd_uninit,
164 .ndo_get_stats64 = rmnet_get_stats64,
165 };
166
167 static const char rmnet_gstrings_stats[][ETH_GSTRING_LEN] = {
168 "Checksum ok",
169 "Checksum valid bit not set",
170 "Checksum validation failed",
171 "Checksum error bad buffer",
172 "Checksum error bad ip version",
173 "Checksum error bad transport",
174 "Checksum skipped on ip fragment",
175 "Checksum skipped",
176 "Checksum computed in software",
177 };
178
rmnet_get_strings(struct net_device * dev,u32 stringset,u8 * buf)179 static void rmnet_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
180 {
181 switch (stringset) {
182 case ETH_SS_STATS:
183 memcpy(buf, &rmnet_gstrings_stats,
184 sizeof(rmnet_gstrings_stats));
185 break;
186 }
187 }
188
rmnet_get_sset_count(struct net_device * dev,int sset)189 static int rmnet_get_sset_count(struct net_device *dev, int sset)
190 {
191 switch (sset) {
192 case ETH_SS_STATS:
193 return ARRAY_SIZE(rmnet_gstrings_stats);
194 default:
195 return -EOPNOTSUPP;
196 }
197 }
198
rmnet_get_ethtool_stats(struct net_device * dev,struct ethtool_stats * stats,u64 * data)199 static void rmnet_get_ethtool_stats(struct net_device *dev,
200 struct ethtool_stats *stats, u64 *data)
201 {
202 struct rmnet_priv *priv = netdev_priv(dev);
203 struct rmnet_priv_stats *st = &priv->stats;
204
205 if (!data)
206 return;
207
208 memcpy(data, st, ARRAY_SIZE(rmnet_gstrings_stats) * sizeof(u64));
209 }
210
211 static const struct ethtool_ops rmnet_ethtool_ops = {
212 .get_ethtool_stats = rmnet_get_ethtool_stats,
213 .get_strings = rmnet_get_strings,
214 .get_sset_count = rmnet_get_sset_count,
215 };
216
217 /* Called by kernel whenever a new rmnet<n> device is created. Sets MTU,
218 * flags, ARP type, needed headroom, etc...
219 */
rmnet_vnd_setup(struct net_device * rmnet_dev)220 void rmnet_vnd_setup(struct net_device *rmnet_dev)
221 {
222 rmnet_dev->netdev_ops = &rmnet_vnd_ops;
223 rmnet_dev->mtu = RMNET_DFLT_PACKET_SIZE;
224 rmnet_dev->needed_headroom = RMNET_NEEDED_HEADROOM;
225 eth_random_addr(rmnet_dev->dev_addr);
226 rmnet_dev->tx_queue_len = RMNET_TX_QUEUE_LEN;
227
228 /* Raw IP mode */
229 rmnet_dev->header_ops = NULL; /* No header */
230 rmnet_dev->type = ARPHRD_RAWIP;
231 rmnet_dev->hard_header_len = 0;
232 rmnet_dev->flags &= ~(IFF_BROADCAST | IFF_MULTICAST);
233
234 rmnet_dev->needs_free_netdev = true;
235 rmnet_dev->ethtool_ops = &rmnet_ethtool_ops;
236
237 rmnet_dev->features |= NETIF_F_LLTX;
238
239 /* This perm addr will be used as interface identifier by IPv6 */
240 rmnet_dev->addr_assign_type = NET_ADDR_RANDOM;
241 eth_random_addr(rmnet_dev->perm_addr);
242 }
243
244 /* Exposed API */
245
rmnet_vnd_newlink(u8 id,struct net_device * rmnet_dev,struct rmnet_port * port,struct net_device * real_dev,struct rmnet_endpoint * ep,struct netlink_ext_ack * extack)246 int rmnet_vnd_newlink(u8 id, struct net_device *rmnet_dev,
247 struct rmnet_port *port,
248 struct net_device *real_dev,
249 struct rmnet_endpoint *ep,
250 struct netlink_ext_ack *extack)
251
252 {
253 struct rmnet_priv *priv = netdev_priv(rmnet_dev);
254 u32 headroom;
255 int rc;
256
257 if (rmnet_get_endpoint(port, id)) {
258 NL_SET_ERR_MSG_MOD(extack, "MUX ID already exists");
259 return -EBUSY;
260 }
261
262 rmnet_dev->hw_features = NETIF_F_RXCSUM;
263 rmnet_dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
264 rmnet_dev->hw_features |= NETIF_F_SG;
265
266 priv->real_dev = real_dev;
267
268 headroom = rmnet_vnd_headroom(port);
269
270 if (rmnet_vnd_change_mtu(rmnet_dev, real_dev->mtu - headroom)) {
271 NL_SET_ERR_MSG_MOD(extack, "Invalid MTU on real dev");
272 return -EINVAL;
273 }
274
275 rc = register_netdevice(rmnet_dev);
276 if (!rc) {
277 ep->egress_dev = rmnet_dev;
278 ep->mux_id = id;
279 port->nr_rmnet_devs++;
280
281 rmnet_dev->rtnl_link_ops = &rmnet_link_ops;
282
283 priv->mux_id = id;
284
285 netdev_dbg(rmnet_dev, "rmnet dev created\n");
286 }
287
288 return rc;
289 }
290
rmnet_vnd_dellink(u8 id,struct rmnet_port * port,struct rmnet_endpoint * ep)291 int rmnet_vnd_dellink(u8 id, struct rmnet_port *port,
292 struct rmnet_endpoint *ep)
293 {
294 if (id >= RMNET_MAX_LOGICAL_EP || !ep->egress_dev)
295 return -EINVAL;
296
297 ep->egress_dev = NULL;
298 port->nr_rmnet_devs--;
299 return 0;
300 }
301
rmnet_vnd_do_flow_control(struct net_device * rmnet_dev,int enable)302 int rmnet_vnd_do_flow_control(struct net_device *rmnet_dev, int enable)
303 {
304 netdev_dbg(rmnet_dev, "Setting VND TX queue state to %d\n", enable);
305 /* Although we expect similar number of enable/disable
306 * commands, optimize for the disable. That is more
307 * latency sensitive than enable
308 */
309 if (unlikely(enable))
310 netif_wake_queue(rmnet_dev);
311 else
312 netif_stop_queue(rmnet_dev);
313
314 return 0;
315 }
316
rmnet_vnd_validate_real_dev_mtu(struct net_device * real_dev)317 int rmnet_vnd_validate_real_dev_mtu(struct net_device *real_dev)
318 {
319 struct hlist_node *tmp_ep;
320 struct rmnet_endpoint *ep;
321 struct rmnet_port *port;
322 unsigned long bkt_ep;
323 u32 headroom;
324
325 port = rmnet_get_port_rtnl(real_dev);
326
327 headroom = rmnet_vnd_headroom(port);
328
329 hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
330 if (ep->egress_dev->mtu > (real_dev->mtu - headroom))
331 return -1;
332 }
333
334 return 0;
335 }
336
rmnet_vnd_update_dev_mtu(struct rmnet_port * port,struct net_device * real_dev)337 int rmnet_vnd_update_dev_mtu(struct rmnet_port *port,
338 struct net_device *real_dev)
339 {
340 struct hlist_node *tmp_ep;
341 struct rmnet_endpoint *ep;
342 unsigned long bkt_ep;
343 u32 headroom;
344
345 headroom = rmnet_vnd_headroom(port);
346
347 hash_for_each_safe(port->muxed_ep, bkt_ep, tmp_ep, ep, hlnode) {
348 if (ep->egress_dev->mtu <= (real_dev->mtu - headroom))
349 continue;
350
351 if (rmnet_vnd_change_mtu(ep->egress_dev,
352 real_dev->mtu - headroom))
353 return -1;
354 }
355
356 return 0;
357 }