Linux Kernel  3.7.1
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sock_diag.c
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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 
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 }
27 
29 {
30  cookie[0] = (u32)(unsigned long)sk;
31  cookie[1] = (u32)(((unsigned long)sk >> 31) >> 1);
32 }
34 
35 int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
36 {
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;
46  mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
47 
48  return nla_put(skb, attrtype, sizeof(mem), &mem);
49 }
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 }
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 }
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 }
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 }
99 
100 static const inline struct sock_diag_handler *sock_diag_lock_handler(int family)
101 {
102  if (sock_diag_handlers[family] == NULL)
103  request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
104  NETLINK_SOCK_DIAG, family);
105 
106  mutex_lock(&sock_diag_table_mutex);
107  return sock_diag_handlers[family];
108 }
109 
110 static inline void sock_diag_unlock_handler(const struct sock_diag_handler *h)
111 {
112  mutex_unlock(&sock_diag_table_mutex);
113 }
114 
115 static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
116 {
117  int err;
118  struct sock_diag_req *req = nlmsg_data(nlh);
119  const struct sock_diag_handler *hndl;
120 
121  if (nlmsg_len(nlh) < sizeof(*req))
122  return -EINVAL;
123 
124  hndl = sock_diag_lock_handler(req->sdiag_family);
125  if (hndl == NULL)
126  err = -ENOENT;
127  else
128  err = hndl->dump(skb, nlh);
129  sock_diag_unlock_handler(hndl);
130 
131  return err;
132 }
133 
134 static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
135 {
136  int ret;
137 
138  switch (nlh->nlmsg_type) {
139  case TCPDIAG_GETSOCK:
140  case DCCPDIAG_GETSOCK:
141  if (inet_rcv_compat == NULL)
142  request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
144 
145  mutex_lock(&sock_diag_table_mutex);
146  if (inet_rcv_compat != NULL)
147  ret = inet_rcv_compat(skb, nlh);
148  else
149  ret = -EOPNOTSUPP;
150  mutex_unlock(&sock_diag_table_mutex);
151 
152  return ret;
153  case SOCK_DIAG_BY_FAMILY:
154  return __sock_diag_rcv_msg(skb, nlh);
155  default:
156  return -EINVAL;
157  }
158 }
159 
160 static DEFINE_MUTEX(sock_diag_mutex);
161 
162 static void sock_diag_rcv(struct sk_buff *skb)
163 {
164  mutex_lock(&sock_diag_mutex);
165  netlink_rcv_skb(skb, &sock_diag_rcv_msg);
166  mutex_unlock(&sock_diag_mutex);
167 }
168 
169 static int __net_init diag_net_init(struct net *net)
170 {
171  struct netlink_kernel_cfg cfg = {
172  .input = sock_diag_rcv,
173  };
174 
175  net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
176  return net->diag_nlsk == NULL ? -ENOMEM : 0;
177 }
178 
179 static void __net_exit diag_net_exit(struct net *net)
180 {
182  net->diag_nlsk = NULL;
183 }
184 
185 static struct pernet_operations diag_net_ops = {
186  .init = diag_net_init,
187  .exit = diag_net_exit,
188 };
189 
190 static int __init sock_diag_init(void)
191 {
192  return register_pernet_subsys(&diag_net_ops);
193 }
194 
195 static void __exit sock_diag_exit(void)
196 {
197  unregister_pernet_subsys(&diag_net_ops);
198 }
199 
200 module_init(sock_diag_init);
201 module_exit(sock_diag_exit);
202 MODULE_LICENSE("GPL");