[IRDA] sem2mutex: drivers/net/irda
[linux-2.6.git] / net / netfilter / nf_sockopt.c
1 #include <linux/config.h>
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/module.h>
5 #include <linux/skbuff.h>
6 #include <linux/netfilter.h>
7 #include <net/sock.h>
8
9 #include "nf_internals.h"
10
11 /* Sockopts only registered and called from user context, so
12    net locking would be overkill.  Also, [gs]etsockopt calls may
13    sleep. */
14 static DECLARE_MUTEX(nf_sockopt_mutex);
15 static LIST_HEAD(nf_sockopts);
16
17 /* Do exclusive ranges overlap? */
18 static inline int overlap(int min1, int max1, int min2, int max2)
19 {
20         return max1 > min2 && min1 < max2;
21 }
22
23 /* Functions to register sockopt ranges (exclusive). */
24 int nf_register_sockopt(struct nf_sockopt_ops *reg)
25 {
26         struct list_head *i;
27         int ret = 0;
28
29         if (down_interruptible(&nf_sockopt_mutex) != 0)
30                 return -EINTR;
31
32         list_for_each(i, &nf_sockopts) {
33                 struct nf_sockopt_ops *ops = (struct nf_sockopt_ops *)i;
34                 if (ops->pf == reg->pf
35                     && (overlap(ops->set_optmin, ops->set_optmax, 
36                                 reg->set_optmin, reg->set_optmax)
37                         || overlap(ops->get_optmin, ops->get_optmax, 
38                                    reg->get_optmin, reg->get_optmax))) {
39                         NFDEBUG("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n",
40                                 ops->set_optmin, ops->set_optmax, 
41                                 ops->get_optmin, ops->get_optmax, 
42                                 reg->set_optmin, reg->set_optmax,
43                                 reg->get_optmin, reg->get_optmax);
44                         ret = -EBUSY;
45                         goto out;
46                 }
47         }
48
49         list_add(&reg->list, &nf_sockopts);
50 out:
51         up(&nf_sockopt_mutex);
52         return ret;
53 }
54 EXPORT_SYMBOL(nf_register_sockopt);
55
56 void nf_unregister_sockopt(struct nf_sockopt_ops *reg)
57 {
58         /* No point being interruptible: we're probably in cleanup_module() */
59  restart:
60         down(&nf_sockopt_mutex);
61         if (reg->use != 0) {
62                 /* To be woken by nf_sockopt call... */
63                 /* FIXME: Stuart Young's name appears gratuitously. */
64                 set_current_state(TASK_UNINTERRUPTIBLE);
65                 reg->cleanup_task = current;
66                 up(&nf_sockopt_mutex);
67                 schedule();
68                 goto restart;
69         }
70         list_del(&reg->list);
71         up(&nf_sockopt_mutex);
72 }
73 EXPORT_SYMBOL(nf_unregister_sockopt);
74
75 /* Call get/setsockopt() */
76 static int nf_sockopt(struct sock *sk, int pf, int val, 
77                       char __user *opt, int *len, int get)
78 {
79         struct list_head *i;
80         struct nf_sockopt_ops *ops;
81         int ret;
82
83         if (down_interruptible(&nf_sockopt_mutex) != 0)
84                 return -EINTR;
85
86         list_for_each(i, &nf_sockopts) {
87                 ops = (struct nf_sockopt_ops *)i;
88                 if (ops->pf == pf) {
89                         if (get) {
90                                 if (val >= ops->get_optmin
91                                     && val < ops->get_optmax) {
92                                         ops->use++;
93                                         up(&nf_sockopt_mutex);
94                                         ret = ops->get(sk, val, opt, len);
95                                         goto out;
96                                 }
97                         } else {
98                                 if (val >= ops->set_optmin
99                                     && val < ops->set_optmax) {
100                                         ops->use++;
101                                         up(&nf_sockopt_mutex);
102                                         ret = ops->set(sk, val, opt, *len);
103                                         goto out;
104                                 }
105                         }
106                 }
107         }
108         up(&nf_sockopt_mutex);
109         return -ENOPROTOOPT;
110         
111  out:
112         down(&nf_sockopt_mutex);
113         ops->use--;
114         if (ops->cleanup_task)
115                 wake_up_process(ops->cleanup_task);
116         up(&nf_sockopt_mutex);
117         return ret;
118 }
119
120 int nf_setsockopt(struct sock *sk, int pf, int val, char __user *opt,
121                   int len)
122 {
123         return nf_sockopt(sk, pf, val, opt, &len, 0);
124 }
125 EXPORT_SYMBOL(nf_setsockopt);
126
127 int nf_getsockopt(struct sock *sk, int pf, int val, char __user *opt, int *len)
128 {
129         return nf_sockopt(sk, pf, val, opt, len, 1);
130 }
131 EXPORT_SYMBOL(nf_getsockopt);
132