xref: /linux/net/core/sock_diag.c (revision c75c5ab575af7db707689cdbb5a5c458e9a034bb)
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 <net/sock.h>
8 
9 #include <linux/inet_diag.h>
10 #include <linux/sock_diag.h>
11 
12 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
13 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
14 static DEFINE_MUTEX(sock_diag_table_mutex);
15 
16 int sock_diag_check_cookie(void *sk, __u32 *cookie)
17 {
18 	if ((cookie[0] != INET_DIAG_NOCOOKIE ||
19 	     cookie[1] != INET_DIAG_NOCOOKIE) &&
20 	    ((u32)(unsigned long)sk != cookie[0] ||
21 	     (u32)((((unsigned long)sk) >> 31) >> 1) != cookie[1]))
22 		return -ESTALE;
23 	else
24 		return 0;
25 }
26 EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
27 
28 void sock_diag_save_cookie(void *sk, __u32 *cookie)
29 {
30 	cookie[0] = (u32)(unsigned long)sk;
31 	cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
32 }
33 EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
34 
35 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
36 {
37 	u32 mem[SK_MEMINFO_VARS];
38 
39 	mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
40 	mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
41 	mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
42 	mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
43 	mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
44 	mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
45 	mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
46 	mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
47 
48 	return nla_put(skb, attrtype, sizeof(mem), &mem);
49 }
50 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
51 
52 void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
53 {
54 	mutex_lock(&sock_diag_table_mutex);
55 	inet_rcv_compat = fn;
56 	mutex_unlock(&sock_diag_table_mutex);
57 }
58 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
59 
60 void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
61 {
62 	mutex_lock(&sock_diag_table_mutex);
63 	inet_rcv_compat = NULL;
64 	mutex_unlock(&sock_diag_table_mutex);
65 }
66 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
67 
68 int sock_diag_register(const struct sock_diag_handler *hndl)
69 {
70 	int err = 0;
71 
72 	if (hndl->family >= AF_MAX)
73 		return -EINVAL;
74 
75 	mutex_lock(&sock_diag_table_mutex);
76 	if (sock_diag_handlers[hndl->family])
77 		err = -EBUSY;
78 	else
79 		sock_diag_handlers[hndl->family] = hndl;
80 	mutex_unlock(&sock_diag_table_mutex);
81 
82 	return err;
83 }
84 EXPORT_SYMBOL_GPL(sock_diag_register);
85 
86 void sock_diag_unregister(const struct sock_diag_handler *hnld)
87 {
88 	int family = hnld->family;
89 
90 	if (family >= AF_MAX)
91 		return;
92 
93 	mutex_lock(&sock_diag_table_mutex);
94 	BUG_ON(sock_diag_handlers[family] != hnld);
95 	sock_diag_handlers[family] = NULL;
96 	mutex_unlock(&sock_diag_table_mutex);
97 }
98 EXPORT_SYMBOL_GPL(sock_diag_unregister);
99 
100 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
101 {
102 	int err;
103 	struct sock_diag_req *req = nlmsg_data(nlh);
104 	const struct sock_diag_handler *hndl;
105 
106 	if (nlmsg_len(nlh) < sizeof(*req))
107 		return -EINVAL;
108 
109 	if (req->sdiag_family >= AF_MAX)
110 		return -EINVAL;
111 
112 	if (sock_diag_handlers[req->sdiag_family] == NULL)
113 		request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
114 				NETLINK_SOCK_DIAG, req->sdiag_family);
115 
116 	mutex_lock(&sock_diag_table_mutex);
117 	hndl = sock_diag_handlers[req->sdiag_family];
118 	if (hndl == NULL)
119 		err = -ENOENT;
120 	else
121 		err = hndl->dump(skb, nlh);
122 	mutex_unlock(&sock_diag_table_mutex);
123 
124 	return err;
125 }
126 
127 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
128 {
129 	int ret;
130 
131 	switch (nlh->nlmsg_type) {
132 	case TCPDIAG_GETSOCK:
133 	case DCCPDIAG_GETSOCK:
134 		if (inet_rcv_compat == NULL)
135 			request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
136 					NETLINK_SOCK_DIAG, AF_INET);
137 
138 		mutex_lock(&sock_diag_table_mutex);
139 		if (inet_rcv_compat != NULL)
140 			ret = inet_rcv_compat(skb, nlh);
141 		else
142 			ret = -EOPNOTSUPP;
143 		mutex_unlock(&sock_diag_table_mutex);
144 
145 		return ret;
146 	case SOCK_DIAG_BY_FAMILY:
147 		return __sock_diag_rcv_msg(skb, nlh);
148 	default:
149 		return -EINVAL;
150 	}
151 }
152 
153 static DEFINE_MUTEX(sock_diag_mutex);
154 
155 static void sock_diag_rcv(struct sk_buff *skb)
156 {
157 	mutex_lock(&sock_diag_mutex);
158 	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
159 	mutex_unlock(&sock_diag_mutex);
160 }
161 
162 static int __net_init diag_net_init(struct net *net)
163 {
164 	struct netlink_kernel_cfg cfg = {
165 		.input	= sock_diag_rcv,
166 	};
167 
168 	net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
169 	return net->diag_nlsk == NULL ? -ENOMEM : 0;
170 }
171 
172 static void __net_exit diag_net_exit(struct net *net)
173 {
174 	netlink_kernel_release(net->diag_nlsk);
175 	net->diag_nlsk = NULL;
176 }
177 
178 static struct pernet_operations diag_net_ops = {
179 	.init = diag_net_init,
180 	.exit = diag_net_exit,
181 };
182 
183 static int __init sock_diag_init(void)
184 {
185 	return register_pernet_subsys(&diag_net_ops);
186 }
187 
188 static void __exit sock_diag_exit(void)
189 {
190 	unregister_pernet_subsys(&diag_net_ops);
191 }
192 
193 module_init(sock_diag_init);
194 module_exit(sock_diag_exit);
195 MODULE_LICENSE("GPL");
196 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);
197