Commit | Line | Data |
---|---|---|
531b3748 GG |
1 | /* |
2 | * Tap functions for AF_VSOCK sockets. | |
3 | * | |
4 | * Code based on net/netlink/af_netlink.c tap functions. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | #include <net/sock.h> | |
14 | #include <net/af_vsock.h> | |
15 | #include <linux/if_arp.h> | |
16 | ||
17 | static DEFINE_SPINLOCK(vsock_tap_lock); | |
18 | static struct list_head vsock_tap_all __read_mostly = | |
19 | LIST_HEAD_INIT(vsock_tap_all); | |
20 | ||
21 | int vsock_add_tap(struct vsock_tap *vt) | |
22 | { | |
23 | if (unlikely(vt->dev->type != ARPHRD_VSOCKMON)) | |
24 | return -EINVAL; | |
25 | ||
26 | __module_get(vt->module); | |
27 | ||
28 | spin_lock(&vsock_tap_lock); | |
29 | list_add_rcu(&vt->list, &vsock_tap_all); | |
30 | spin_unlock(&vsock_tap_lock); | |
31 | ||
32 | return 0; | |
33 | } | |
34 | EXPORT_SYMBOL_GPL(vsock_add_tap); | |
35 | ||
36 | int vsock_remove_tap(struct vsock_tap *vt) | |
37 | { | |
38 | struct vsock_tap *tmp; | |
39 | bool found = false; | |
40 | ||
41 | spin_lock(&vsock_tap_lock); | |
42 | ||
43 | list_for_each_entry(tmp, &vsock_tap_all, list) { | |
44 | if (vt == tmp) { | |
45 | list_del_rcu(&vt->list); | |
46 | found = true; | |
47 | goto out; | |
48 | } | |
49 | } | |
50 | ||
51 | pr_warn("vsock_remove_tap: %p not found\n", vt); | |
52 | out: | |
53 | spin_unlock(&vsock_tap_lock); | |
54 | ||
55 | synchronize_net(); | |
56 | ||
57 | if (found) | |
58 | module_put(vt->module); | |
59 | ||
60 | return found ? 0 : -ENODEV; | |
61 | } | |
62 | EXPORT_SYMBOL_GPL(vsock_remove_tap); | |
63 | ||
64 | static int __vsock_deliver_tap_skb(struct sk_buff *skb, | |
65 | struct net_device *dev) | |
66 | { | |
67 | int ret = 0; | |
68 | struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC); | |
69 | ||
70 | if (nskb) { | |
71 | dev_hold(dev); | |
72 | ||
73 | nskb->dev = dev; | |
74 | ret = dev_queue_xmit(nskb); | |
75 | if (unlikely(ret > 0)) | |
76 | ret = net_xmit_errno(ret); | |
77 | ||
78 | dev_put(dev); | |
79 | } | |
80 | ||
81 | return ret; | |
82 | } | |
83 | ||
84 | static void __vsock_deliver_tap(struct sk_buff *skb) | |
85 | { | |
86 | int ret; | |
87 | struct vsock_tap *tmp; | |
88 | ||
89 | list_for_each_entry_rcu(tmp, &vsock_tap_all, list) { | |
90 | ret = __vsock_deliver_tap_skb(skb, tmp->dev); | |
91 | if (unlikely(ret)) | |
92 | break; | |
93 | } | |
94 | } | |
95 | ||
96 | void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque) | |
97 | { | |
98 | struct sk_buff *skb; | |
99 | ||
100 | rcu_read_lock(); | |
101 | ||
102 | if (likely(list_empty(&vsock_tap_all))) | |
103 | goto out; | |
104 | ||
105 | skb = build_skb(opaque); | |
106 | if (skb) { | |
107 | __vsock_deliver_tap(skb); | |
108 | consume_skb(skb); | |
109 | } | |
110 | ||
111 | out: | |
112 | rcu_read_unlock(); | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(vsock_deliver_tap); |