Commit | Line | Data |
---|---|---|
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 | { | |
50 | dev->lstats = alloc_percpu(struct pcpu_lstats); | |
51 | ||
52 | return dev->lstats == NULL ? -ENOMEM : 0; | |
53 | } | |
54 | ||
55 | static void nlmon_dev_uninit(struct net_device *dev) | |
56 | { | |
57 | free_percpu(dev->lstats); | |
58 | } | |
59 | ||
7e6d4da8 JP |
60 | struct nlmon { |
61 | struct netlink_tap nt; | |
62 | }; | |
e4fc408e DB |
63 | |
64 | static int nlmon_open(struct net_device *dev) | |
65 | { | |
7e6d4da8 JP |
66 | struct nlmon *nlmon = netdev_priv(dev); |
67 | ||
68 | nlmon->nt.dev = dev; | |
69 | nlmon->nt.module = THIS_MODULE; | |
70 | return netlink_add_tap(&nlmon->nt); | |
e4fc408e DB |
71 | } |
72 | ||
73 | static int nlmon_close(struct net_device *dev) | |
74 | { | |
7e6d4da8 JP |
75 | struct nlmon *nlmon = netdev_priv(dev); |
76 | ||
77 | return netlink_remove_tap(&nlmon->nt); | |
e4fc408e DB |
78 | } |
79 | ||
80 | static struct rtnl_link_stats64 * | |
81 | nlmon_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) | |
82 | { | |
83 | int i; | |
84 | u64 bytes = 0, packets = 0; | |
85 | ||
86 | for_each_possible_cpu(i) { | |
87 | const struct pcpu_lstats *nl_stats; | |
88 | u64 tbytes, tpackets; | |
89 | unsigned int start; | |
90 | ||
91 | nl_stats = per_cpu_ptr(dev->lstats, i); | |
92 | ||
93 | do { | |
94 | start = u64_stats_fetch_begin_bh(&nl_stats->syncp); | |
95 | tbytes = nl_stats->bytes; | |
96 | tpackets = nl_stats->packets; | |
97 | } while (u64_stats_fetch_retry_bh(&nl_stats->syncp, start)); | |
98 | ||
99 | packets += tpackets; | |
100 | bytes += tbytes; | |
101 | } | |
102 | ||
103 | stats->rx_packets = packets; | |
104 | stats->tx_packets = 0; | |
105 | ||
106 | stats->rx_bytes = bytes; | |
107 | stats->tx_bytes = 0; | |
108 | ||
109 | return stats; | |
110 | } | |
111 | ||
112 | static u32 always_on(struct net_device *dev) | |
113 | { | |
114 | return 1; | |
115 | } | |
116 | ||
117 | static const struct ethtool_ops nlmon_ethtool_ops = { | |
118 | .get_link = always_on, | |
119 | }; | |
120 | ||
121 | static const struct net_device_ops nlmon_ops = { | |
122 | .ndo_init = nlmon_dev_init, | |
123 | .ndo_uninit = nlmon_dev_uninit, | |
124 | .ndo_open = nlmon_open, | |
125 | .ndo_stop = nlmon_close, | |
126 | .ndo_start_xmit = nlmon_xmit, | |
127 | .ndo_get_stats64 = nlmon_get_stats64, | |
128 | .ndo_change_mtu = nlmon_change_mtu, | |
129 | }; | |
130 | ||
e4fc408e DB |
131 | static void nlmon_setup(struct net_device *dev) |
132 | { | |
133 | dev->type = ARPHRD_NETLINK; | |
134 | dev->tx_queue_len = 0; | |
135 | ||
136 | dev->netdev_ops = &nlmon_ops; | |
137 | dev->ethtool_ops = &nlmon_ethtool_ops; | |
138 | dev->destructor = free_netdev; | |
139 | ||
140 | dev->features = NETIF_F_FRAGLIST | NETIF_F_HIGHDMA; | |
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"); |