Commit | Line | Data |
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e4fc408e DB |
1 | #include <linux/module.h> |
2 | #include <linux/kernel.h> | |
3 | #include <linux/netdevice.h> | |
4 | #include <linux/netlink.h> | |
5 | #include <net/net_namespace.h> | |
6 | #include <linux/if_arp.h> | |
7e6d4da8 | 7 | #include <net/rtnetlink.h> |
e4fc408e DB |
8 | |
9 | struct pcpu_lstats { | |
10 | u64 packets; | |
11 | u64 bytes; | |
12 | struct u64_stats_sync syncp; | |
13 | }; | |
14 | ||
15 | static netdev_tx_t nlmon_xmit(struct sk_buff *skb, struct net_device *dev) | |
16 | { | |
17 | int len = skb->len; | |
18 | struct pcpu_lstats *stats = this_cpu_ptr(dev->lstats); | |
19 | ||
20 | u64_stats_update_begin(&stats->syncp); | |
21 | stats->bytes += len; | |
22 | stats->packets++; | |
23 | u64_stats_update_end(&stats->syncp); | |
24 | ||
25 | dev_kfree_skb(skb); | |
26 | ||
27 | return NETDEV_TX_OK; | |
28 | } | |
29 | ||
30 | static int nlmon_is_valid_mtu(int new_mtu) | |
31 | { | |
3b233fe0 DB |
32 | /* Note that in netlink we do not really have an upper limit. On |
33 | * default, we use NLMSG_GOODSIZE. Here at least we should make | |
34 | * sure that it's at least the header size. | |
35 | */ | |
36 | return new_mtu >= (int) sizeof(struct nlmsghdr); | |
e4fc408e DB |
37 | } |
38 | ||
39 | static int nlmon_change_mtu(struct net_device *dev, int new_mtu) | |
40 | { | |
41 | if (!nlmon_is_valid_mtu(new_mtu)) | |
42 | return -EINVAL; | |
43 | ||
44 | dev->mtu = new_mtu; | |
45 | return 0; | |
46 | } | |
47 | ||
48 | static int nlmon_dev_init(struct net_device *dev) | |
49 | { | |
1c213bd2 | 50 | dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats); |
e4fc408e DB |
51 | return dev->lstats == NULL ? -ENOMEM : 0; |
52 | } | |
53 | ||
54 | static void nlmon_dev_uninit(struct net_device *dev) | |
55 | { | |
56 | free_percpu(dev->lstats); | |
57 | } | |
58 | ||
7e6d4da8 JP |
59 | struct nlmon { |
60 | struct netlink_tap nt; | |
61 | }; | |
e4fc408e DB |
62 | |
63 | static int nlmon_open(struct net_device *dev) | |
64 | { | |
7e6d4da8 JP |
65 | struct nlmon *nlmon = netdev_priv(dev); |
66 | ||
67 | nlmon->nt.dev = dev; | |
68 | nlmon->nt.module = THIS_MODULE; | |
69 | return netlink_add_tap(&nlmon->nt); | |
e4fc408e DB |
70 | } |
71 | ||
72 | static int nlmon_close(struct net_device *dev) | |
73 | { | |
7e6d4da8 JP |
74 | struct nlmon *nlmon = netdev_priv(dev); |
75 | ||
76 | return netlink_remove_tap(&nlmon->nt); | |
e4fc408e DB |
77 | } |
78 | ||
79 | static struct rtnl_link_stats64 * | |
80 | nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) | |
81 | { | |
82 | int i; | |
83 | u64 bytes = 0, packets = 0; | |
84 | ||
85 | for_each_possible_cpu(i) { | |
86 | const struct pcpu_lstats *nl_stats; | |
87 | u64 tbytes, tpackets; | |
88 | unsigned int start; | |
89 | ||
90 | nl_stats = per_cpu_ptr(dev->lstats, i); | |
91 | ||
92 | do { | |
57a7744e | 93 | start = u64_stats_fetch_begin_irq(&nl_stats->syncp); |
e4fc408e DB |
94 | tbytes = nl_stats->bytes; |
95 | tpackets = nl_stats->packets; | |
57a7744e | 96 | } while (u64_stats_fetch_retry_irq(&nl_stats->syncp, start)); |
e4fc408e DB |
97 | |
98 | packets += tpackets; | |
99 | bytes += tbytes; | |
100 | } | |
101 | ||
102 | stats->rx_packets = packets; | |
103 | stats->tx_packets = 0; | |
104 | ||
105 | stats->rx_bytes = bytes; | |
106 | stats->tx_bytes = 0; | |
107 | ||
108 | return stats; | |
109 | } | |
110 | ||
111 | static u32 always_on(struct net_device *dev) | |
112 | { | |
113 | return 1; | |
114 | } | |
115 | ||
116 | static const struct ethtool_ops nlmon_ethtool_ops = { | |
117 | .get_link = always_on, | |
118 | }; | |
119 | ||
120 | static const struct net_device_ops nlmon_ops = { | |
121 | .ndo_init = nlmon_dev_init, | |
122 | .ndo_uninit = nlmon_dev_uninit, | |
123 | .ndo_open = nlmon_open, | |
124 | .ndo_stop = nlmon_close, | |
125 | .ndo_start_xmit = nlmon_xmit, | |
126 | .ndo_get_stats64 = nlmon_get_stats64, | |
127 | .ndo_change_mtu = nlmon_change_mtu, | |
128 | }; | |
129 | ||
e4fc408e DB |
130 | static void nlmon_setup(struct net_device *dev) |
131 | { | |
132 | dev->type = ARPHRD_NETLINK; | |
133 | dev->tx_queue_len = 0; | |
134 | ||
135 | dev->netdev_ops = &nlmon_ops; | |
136 | dev->ethtool_ops = &nlmon_ethtool_ops; | |
137 | dev->destructor = free_netdev; | |
138 | ||
b7d47ca2 DB |
139 | dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | |
140 | NETIF_F_HIGHDMA | NETIF_F_LLTX; | |
e4fc408e DB |
141 | dev->flags = IFF_NOARP; |
142 | ||
143 | /* That's rather a softlimit here, which, of course, | |
144 | * can be altered. Not a real MTU, but what is to be | |
145 | * expected in most cases. | |
146 | */ | |
147 | dev->mtu = NLMSG_GOODSIZE; | |
148 | } | |
149 | ||
7e6d4da8 | 150 | static int nlmon_validate(struct nlattr *tb[], struct nlattr *data[]) |
e4fc408e | 151 | { |
7e6d4da8 JP |
152 | if (tb[IFLA_ADDRESS]) |
153 | return -EINVAL; | |
154 | return 0; | |
155 | } | |
e4fc408e | 156 | |
7e6d4da8 JP |
157 | static struct rtnl_link_ops nlmon_link_ops __read_mostly = { |
158 | .kind = "nlmon", | |
159 | .priv_size = sizeof(struct nlmon), | |
160 | .setup = nlmon_setup, | |
161 | .validate = nlmon_validate, | |
162 | }; | |
e4fc408e | 163 | |
7e6d4da8 JP |
164 | static __init int nlmon_register(void) |
165 | { | |
166 | return rtnl_link_register(&nlmon_link_ops); | |
e4fc408e DB |
167 | } |
168 | ||
169 | static __exit void nlmon_unregister(void) | |
170 | { | |
7e6d4da8 | 171 | rtnl_link_unregister(&nlmon_link_ops); |
e4fc408e DB |
172 | } |
173 | ||
174 | module_init(nlmon_register); | |
175 | module_exit(nlmon_unregister); | |
176 | ||
177 | MODULE_LICENSE("GPL v2"); | |
178 | MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>"); | |
179 | MODULE_AUTHOR("Mathieu Geli <geli@enseirb.fr>"); | |
180 | MODULE_DESCRIPTION("Netlink monitoring device"); | |
7e6d4da8 | 181 | MODULE_ALIAS_RTNL_LINK("nlmon"); |