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31#include <linux/module.h>
32#include <linux/kernel.h>
33#include <linux/netdevice.h>
34#include <linux/etherdevice.h>
35#include <linux/init.h>
36#include <linux/moduleparam.h>
37#include <linux/rtnetlink.h>
38#include <linux/net_tstamp.h>
39#include <net/rtnetlink.h>
40#include <linux/u64_stats_sync.h>
41
42#define DRV_NAME "dummy"
43#define DRV_VERSION "1.0"
44
45static int numdummies = 1;
46
47
48static void set_multicast_list(struct net_device *dev)
49{
50}
51
52struct pcpu_dstats {
53 u64 tx_packets;
54 u64 tx_bytes;
55 struct u64_stats_sync syncp;
56};
57
58static void dummy_get_stats64(struct net_device *dev,
59 struct rtnl_link_stats64 *stats)
60{
61 int i;
62
63 for_each_possible_cpu(i) {
64 const struct pcpu_dstats *dstats;
65 u64 tbytes, tpackets;
66 unsigned int start;
67
68 dstats = per_cpu_ptr(dev->dstats, i);
69 do {
70 start = u64_stats_fetch_begin_irq(&dstats->syncp);
71 tbytes = dstats->tx_bytes;
72 tpackets = dstats->tx_packets;
73 } while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
74 stats->tx_bytes += tbytes;
75 stats->tx_packets += tpackets;
76 }
77}
78
79static netdev_tx_t dummy_xmit(struct sk_buff *skb, struct net_device *dev)
80{
81 struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
82
83 u64_stats_update_begin(&dstats->syncp);
84 dstats->tx_packets++;
85 dstats->tx_bytes += skb->len;
86 u64_stats_update_end(&dstats->syncp);
87
88 skb_tx_timestamp(skb);
89 dev_kfree_skb(skb);
90 return NETDEV_TX_OK;
91}
92
93static int dummy_dev_init(struct net_device *dev)
94{
95 dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
96 if (!dev->dstats)
97 return -ENOMEM;
98
99 return 0;
100}
101
102static void dummy_dev_uninit(struct net_device *dev)
103{
104 free_percpu(dev->dstats);
105}
106
107static int dummy_change_carrier(struct net_device *dev, bool new_carrier)
108{
109 if (new_carrier)
110 netif_carrier_on(dev);
111 else
112 netif_carrier_off(dev);
113 return 0;
114}
115
116static const struct net_device_ops dummy_netdev_ops = {
117 .ndo_init = dummy_dev_init,
118 .ndo_uninit = dummy_dev_uninit,
119 .ndo_start_xmit = dummy_xmit,
120 .ndo_validate_addr = eth_validate_addr,
121 .ndo_set_rx_mode = set_multicast_list,
122 .ndo_set_mac_address = eth_mac_addr,
123 .ndo_get_stats64 = dummy_get_stats64,
124 .ndo_change_carrier = dummy_change_carrier,
125};
126
127static void dummy_get_drvinfo(struct net_device *dev,
128 struct ethtool_drvinfo *info)
129{
130 strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
131 strlcpy(info->version, DRV_VERSION, sizeof(info->version));
132}
133
134static int dummy_get_ts_info(struct net_device *dev,
135 struct ethtool_ts_info *ts_info)
136{
137 ts_info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
138 SOF_TIMESTAMPING_RX_SOFTWARE |
139 SOF_TIMESTAMPING_SOFTWARE;
140
141 ts_info->phc_index = -1;
142
143 return 0;
144};
145
146static const struct ethtool_ops dummy_ethtool_ops = {
147 .get_drvinfo = dummy_get_drvinfo,
148 .get_ts_info = dummy_get_ts_info,
149};
150
151static void dummy_setup(struct net_device *dev)
152{
153 ether_setup(dev);
154
155
156 dev->netdev_ops = &dummy_netdev_ops;
157 dev->ethtool_ops = &dummy_ethtool_ops;
158 dev->needs_free_netdev = true;
159
160
161 dev->flags |= IFF_NOARP;
162 dev->flags &= ~IFF_MULTICAST;
163 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
164 dev->features |= NETIF_F_SG | NETIF_F_FRAGLIST;
165 dev->features |= NETIF_F_ALL_TSO;
166 dev->features |= NETIF_F_HW_CSUM | NETIF_F_HIGHDMA | NETIF_F_LLTX;
167 dev->features |= NETIF_F_GSO_ENCAP_ALL;
168 dev->hw_features |= dev->features;
169 dev->hw_enc_features |= dev->features;
170 eth_hw_addr_random(dev);
171
172 dev->min_mtu = 0;
173 dev->max_mtu = 0;
174}
175
176static int dummy_validate(struct nlattr *tb[], struct nlattr *data[],
177 struct netlink_ext_ack *extack)
178{
179 if (tb[IFLA_ADDRESS]) {
180 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
181 return -EINVAL;
182 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
183 return -EADDRNOTAVAIL;
184 }
185 return 0;
186}
187
188static struct rtnl_link_ops dummy_link_ops __read_mostly = {
189 .kind = DRV_NAME,
190 .setup = dummy_setup,
191 .validate = dummy_validate,
192};
193
194
195module_param(numdummies, int, 0);
196MODULE_PARM_DESC(numdummies, "Number of dummy pseudo devices");
197
198static int __init dummy_init_one(void)
199{
200 struct net_device *dev_dummy;
201 int err;
202
203 dev_dummy = alloc_netdev(0, "dummy%d", NET_NAME_ENUM, dummy_setup);
204 if (!dev_dummy)
205 return -ENOMEM;
206
207 dev_dummy->rtnl_link_ops = &dummy_link_ops;
208 err = register_netdevice(dev_dummy);
209 if (err < 0)
210 goto err;
211 return 0;
212
213err:
214 free_netdev(dev_dummy);
215 return err;
216}
217
218static int __init dummy_init_module(void)
219{
220 int i, err = 0;
221
222 down_write(&pernet_ops_rwsem);
223 rtnl_lock();
224 err = __rtnl_link_register(&dummy_link_ops);
225 if (err < 0)
226 goto out;
227
228 for (i = 0; i < numdummies && !err; i++) {
229 err = dummy_init_one();
230 cond_resched();
231 }
232 if (err < 0)
233 __rtnl_link_unregister(&dummy_link_ops);
234
235out:
236 rtnl_unlock();
237 up_write(&pernet_ops_rwsem);
238
239 return err;
240}
241
242static void __exit dummy_cleanup_module(void)
243{
244 rtnl_link_unregister(&dummy_link_ops);
245}
246
247module_init(dummy_init_module);
248module_exit(dummy_cleanup_module);
249MODULE_LICENSE("GPL");
250MODULE_ALIAS_RTNL_LINK(DRV_NAME);
251MODULE_VERSION(DRV_VERSION);
252
