sock_diag.c revision d594e987c6f5417cc63dd7e107a2a03a7eeee03f 
1#include <linux/mutex.h>
2#include <linux/socket.h>
3#include <linux/skbuff.h>
4#include <net/netlink.h>
5#include <net/net_namespace.h>
6#include <linux/module.h>
7#include <linux/rtnetlink.h>
8#include <net/sock.h>
9
10#include <linux/inet_diag.h>
11#include <linux/sock_diag.h>
12
13static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
14static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
15static DEFINE_MUTEX(sock_diag_table_mutex);
16
17int sock_diag_check_cookie(void *sk, __u32 *cookie)
18{
19	if ((cookie[0] != INET_DIAG_NOCOOKIE ||
20	     cookie[1] != INET_DIAG_NOCOOKIE) &&
21	    ((u32)(unsigned long)sk != cookie[0] ||
22	     (u32)((((unsigned long)sk) >> 31) >> 1) != cookie[1]))
23		return -ESTALE;
24	else
25		return 0;
26}
27EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
28
29void sock_diag_save_cookie(void *sk, __u32 *cookie)
30{
31	cookie[0] = (u32)(unsigned long)sk;
32	cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
33}
34EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
35
36int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
37{
38	__u32 *mem;
39
40	mem = RTA_DATA(__RTA_PUT(skb, attrtype, SK_MEMINFO_VARS * sizeof(__u32)));
41
42	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
43	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
44	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
45	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
46	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
47	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
48	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
49	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
50
51	return 0;
52
53rtattr_failure:
54	return -EMSGSIZE;
55}
56EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
57
58void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
59{
60	mutex_lock(&sock_diag_table_mutex);
61	inet_rcv_compat = fn;
62	mutex_unlock(&sock_diag_table_mutex);
63}
64EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
65
66void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
67{
68	mutex_lock(&sock_diag_table_mutex);
69	inet_rcv_compat = NULL;
70	mutex_unlock(&sock_diag_table_mutex);
71}
72EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
73
74int sock_diag_register(const struct sock_diag_handler *hndl)
75{
76	int err = 0;
77
78	if (hndl->family >= AF_MAX)
79		return -EINVAL;
80
81	mutex_lock(&sock_diag_table_mutex);
82	if (sock_diag_handlers[hndl->family])
83		err = -EBUSY;
84	else
85		sock_diag_handlers[hndl->family] = hndl;
86	mutex_unlock(&sock_diag_table_mutex);
87
88	return err;
89}
90EXPORT_SYMBOL_GPL(sock_diag_register);
91
92void sock_diag_unregister(const struct sock_diag_handler *hnld)
93{
94	int family = hnld->family;
95
96	if (family >= AF_MAX)
97		return;
98
99	mutex_lock(&sock_diag_table_mutex);
100	BUG_ON(sock_diag_handlers[family] != hnld);
101	sock_diag_handlers[family] = NULL;
102	mutex_unlock(&sock_diag_table_mutex);
103}
104EXPORT_SYMBOL_GPL(sock_diag_unregister);
105
106static const inline struct sock_diag_handler *sock_diag_lock_handler(int family)
107{
108	if (sock_diag_handlers[family] == NULL)
109		request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
110				NETLINK_SOCK_DIAG, family);
111
112	mutex_lock(&sock_diag_table_mutex);
113	return sock_diag_handlers[family];
114}
115
116static inline void sock_diag_unlock_handler(const struct sock_diag_handler *h)
117{
118	mutex_unlock(&sock_diag_table_mutex);
119}
120
121static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
122{
123	int err;
124	struct sock_diag_req *req = NLMSG_DATA(nlh);
125	const struct sock_diag_handler *hndl;
126
127	if (nlmsg_len(nlh) < sizeof(*req))
128		return -EINVAL;
129
130	hndl = sock_diag_lock_handler(req->sdiag_family);
131	if (hndl == NULL)
132		err = -ENOENT;
133	else
134		err = hndl->dump(skb, nlh);
135	sock_diag_unlock_handler(hndl);
136
137	return err;
138}
139
140static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
141{
142	int ret;
143
144	switch (nlh->nlmsg_type) {
145	case TCPDIAG_GETSOCK:
146	case DCCPDIAG_GETSOCK:
147		if (inet_rcv_compat == NULL)
148			request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
149					NETLINK_SOCK_DIAG, AF_INET);
150
151		mutex_lock(&sock_diag_table_mutex);
152		if (inet_rcv_compat != NULL)
153			ret = inet_rcv_compat(skb, nlh);
154		else
155			ret = -EOPNOTSUPP;
156		mutex_unlock(&sock_diag_table_mutex);
157
158		return ret;
159	case SOCK_DIAG_BY_FAMILY:
160		return __sock_diag_rcv_msg(skb, nlh);
161	default:
162		return -EINVAL;
163	}
164}
165
166static DEFINE_MUTEX(sock_diag_mutex);
167
168static void sock_diag_rcv(struct sk_buff *skb)
169{
170	mutex_lock(&sock_diag_mutex);
171	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
172	mutex_unlock(&sock_diag_mutex);
173}
174
175struct sock *sock_diag_nlsk;
176EXPORT_SYMBOL_GPL(sock_diag_nlsk);
177
178static int __init sock_diag_init(void)
179{
180	sock_diag_nlsk = netlink_kernel_create(&init_net, NETLINK_SOCK_DIAG, 0,
181					sock_diag_rcv, NULL, THIS_MODULE);
182	return sock_diag_nlsk == NULL ? -ENOMEM : 0;
183}
184
185static void __exit sock_diag_exit(void)
186{
187	netlink_kernel_release(sock_diag_nlsk);
188}
189
190module_init(sock_diag_init);
191module_exit(sock_diag_exit);
192MODULE_LICENSE("GPL");
193MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);
194