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
 50	return 0;
 51
 52rtattr_failure:
 53	return -EMSGSIZE;
 54}
 55EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
 56
 57void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
 58{
 59	mutex_lock(&sock_diag_table_mutex);
 60	inet_rcv_compat = fn;
 61	mutex_unlock(&sock_diag_table_mutex);
 62}
 63EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
 64
 65void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
 66{
 67	mutex_lock(&sock_diag_table_mutex);
 68	inet_rcv_compat = NULL;
 69	mutex_unlock(&sock_diag_table_mutex);
 70}
 71EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
 72
 73int sock_diag_register(const struct sock_diag_handler *hndl)
 74{
 75	int err = 0;
 76
 77	if (hndl->family >= AF_MAX)
 78		return -EINVAL;
 79
 80	mutex_lock(&sock_diag_table_mutex);
 81	if (sock_diag_handlers[hndl->family])
 82		err = -EBUSY;
 83	else
 84		sock_diag_handlers[hndl->family] = hndl;
 85	mutex_unlock(&sock_diag_table_mutex);
 86
 87	return err;
 88}
 89EXPORT_SYMBOL_GPL(sock_diag_register);
 90
 91void sock_diag_unregister(const struct sock_diag_handler *hnld)
 92{
 93	int family = hnld->family;
 94
 95	if (family >= AF_MAX)
 96		return;
 97
 98	mutex_lock(&sock_diag_table_mutex);
 99	BUG_ON(sock_diag_handlers[family] != hnld);
100	sock_diag_handlers[family] = NULL;
101	mutex_unlock(&sock_diag_table_mutex);
102}
103EXPORT_SYMBOL_GPL(sock_diag_unregister);
104
105static const inline struct sock_diag_handler *sock_diag_lock_handler(int family)
106{
107	if (sock_diag_handlers[family] == NULL)
108		request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
109				NETLINK_SOCK_DIAG, family);
110
111	mutex_lock(&sock_diag_table_mutex);
112	return sock_diag_handlers[family];
113}
114
115static inline void sock_diag_unlock_handler(const struct sock_diag_handler *h)
116{
117	mutex_unlock(&sock_diag_table_mutex);
118}
119
120static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
121{
122	int err;
123	struct sock_diag_req *req = NLMSG_DATA(nlh);
124	const struct sock_diag_handler *hndl;
125
126	if (nlmsg_len(nlh) < sizeof(*req))
127		return -EINVAL;
128
129	hndl = sock_diag_lock_handler(req->sdiag_family);
130	if (hndl == NULL)
131		err = -ENOENT;
132	else
133		err = hndl->dump(skb, nlh);
134	sock_diag_unlock_handler(hndl);
135
136	return err;
137}
138
139static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
140{
141	int ret;
142
143	switch (nlh->nlmsg_type) {
144	case TCPDIAG_GETSOCK:
145	case DCCPDIAG_GETSOCK:
146		if (inet_rcv_compat == NULL)
147			request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
148					NETLINK_SOCK_DIAG, AF_INET);
149
150		mutex_lock(&sock_diag_table_mutex);
151		if (inet_rcv_compat != NULL)
152			ret = inet_rcv_compat(skb, nlh);
153		else
154			ret = -EOPNOTSUPP;
155		mutex_unlock(&sock_diag_table_mutex);
156
157		return ret;
158	case SOCK_DIAG_BY_FAMILY:
159		return __sock_diag_rcv_msg(skb, nlh);
160	default:
161		return -EINVAL;
162	}
163}
164
165static DEFINE_MUTEX(sock_diag_mutex);
166
167static void sock_diag_rcv(struct sk_buff *skb)
168{
169	mutex_lock(&sock_diag_mutex);
170	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
171	mutex_unlock(&sock_diag_mutex);
172}
173
174struct sock *sock_diag_nlsk;
175EXPORT_SYMBOL_GPL(sock_diag_nlsk);
176
177static int __init sock_diag_init(void)
178{
179	sock_diag_nlsk = netlink_kernel_create(&init_net, NETLINK_SOCK_DIAG, 0,
180					sock_diag_rcv, NULL, THIS_MODULE);
181	return sock_diag_nlsk == NULL ? -ENOMEM : 0;
182}
183
184static void __exit sock_diag_exit(void)
185{
186	netlink_kernel_release(sock_diag_nlsk);
187}
188
189module_init(sock_diag_init);
190module_exit(sock_diag_exit);
191MODULE_LICENSE("GPL");
192MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);