tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1#include <linux/kernel.h>
2#include <linux/init.h>
3#include <linux/module.h>
4#include <linux/skbuff.h>
5#include <linux/netfilter.h>
6#include <linux/mutex.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. */
14static DEFINE_MUTEX(nf_sockopt_mutex);
15static LIST_HEAD(nf_sockopts);
16
17/* Do exclusive ranges overlap? */
18static 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). */
24int nf_register_sockopt(struct nf_sockopt_ops *reg)
25{
26 struct nf_sockopt_ops *ops;
27 int ret = 0;
28
29 if (mutex_lock_interruptible(&nf_sockopt_mutex) != 0)
30 return -EINTR;
31
32 list_for_each_entry(ops, &nf_sockopts, list) {
33 if (ops->pf == reg->pf
34 && (overlap(ops->set_optmin, ops->set_optmax,
35 reg->set_optmin, reg->set_optmax)
36 || overlap(ops->get_optmin, ops->get_optmax,
37 reg->get_optmin, reg->get_optmax))) {
38 NFDEBUG("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n",
39 ops->set_optmin, ops->set_optmax,
40 ops->get_optmin, ops->get_optmax,
41 reg->set_optmin, reg->set_optmax,
42 reg->get_optmin, reg->get_optmax);
43 ret = -EBUSY;
44 goto out;
45 }
46 }
47
48 list_add(®->list, &nf_sockopts);
49out:
50 mutex_unlock(&nf_sockopt_mutex);
51 return ret;
52}
53EXPORT_SYMBOL(nf_register_sockopt);
54
55void nf_unregister_sockopt(struct nf_sockopt_ops *reg)
56{
57 mutex_lock(&nf_sockopt_mutex);
58 list_del(®->list);
59 mutex_unlock(&nf_sockopt_mutex);
60}
61EXPORT_SYMBOL(nf_unregister_sockopt);
62
63static struct nf_sockopt_ops *nf_sockopt_find(struct sock *sk, int pf,
64 int val, int get)
65{
66 struct nf_sockopt_ops *ops;
67
68 if (sock_net(sk) != &init_net)
69 return ERR_PTR(-ENOPROTOOPT);
70
71 if (mutex_lock_interruptible(&nf_sockopt_mutex) != 0)
72 return ERR_PTR(-EINTR);
73
74 list_for_each_entry(ops, &nf_sockopts, list) {
75 if (ops->pf == pf) {
76 if (!try_module_get(ops->owner))
77 goto out_nosup;
78
79 if (get) {
80 if (val >= ops->get_optmin &&
81 val < ops->get_optmax)
82 goto out;
83 } else {
84 if (val >= ops->set_optmin &&
85 val < ops->set_optmax)
86 goto out;
87 }
88 module_put(ops->owner);
89 }
90 }
91out_nosup:
92 ops = ERR_PTR(-ENOPROTOOPT);
93out:
94 mutex_unlock(&nf_sockopt_mutex);
95 return ops;
96}
97
98/* Call get/setsockopt() */
99static int nf_sockopt(struct sock *sk, int pf, int val,
100 char __user *opt, int *len, int get)
101{
102 struct nf_sockopt_ops *ops;
103 int ret;
104
105 ops = nf_sockopt_find(sk, pf, val, get);
106 if (IS_ERR(ops))
107 return PTR_ERR(ops);
108
109 if (get)
110 ret = ops->get(sk, val, opt, len);
111 else
112 ret = ops->set(sk, val, opt, *len);
113
114 module_put(ops->owner);
115 return ret;
116}
117
118int nf_setsockopt(struct sock *sk, int pf, int val, char __user *opt,
119 int len)
120{
121 return nf_sockopt(sk, pf, val, opt, &len, 0);
122}
123EXPORT_SYMBOL(nf_setsockopt);
124
125int nf_getsockopt(struct sock *sk, int pf, int val, char __user *opt, int *len)
126{
127 return nf_sockopt(sk, pf, val, opt, len, 1);
128}
129EXPORT_SYMBOL(nf_getsockopt);
130
131#ifdef CONFIG_COMPAT
132static int compat_nf_sockopt(struct sock *sk, int pf, int val,
133 char __user *opt, int *len, int get)
134{
135 struct nf_sockopt_ops *ops;
136 int ret;
137
138 ops = nf_sockopt_find(sk, pf, val, get);
139 if (IS_ERR(ops))
140 return PTR_ERR(ops);
141
142 if (get) {
143 if (ops->compat_get)
144 ret = ops->compat_get(sk, val, opt, len);
145 else
146 ret = ops->get(sk, val, opt, len);
147 } else {
148 if (ops->compat_set)
149 ret = ops->compat_set(sk, val, opt, *len);
150 else
151 ret = ops->set(sk, val, opt, *len);
152 }
153
154 module_put(ops->owner);
155 return ret;
156}
157
158int compat_nf_setsockopt(struct sock *sk, int pf,
159 int val, char __user *opt, int len)
160{
161 return compat_nf_sockopt(sk, pf, val, opt, &len, 0);
162}
163EXPORT_SYMBOL(compat_nf_setsockopt);
164
165int compat_nf_getsockopt(struct sock *sk, int pf,
166 int val, char __user *opt, int *len)
167{
168 return compat_nf_sockopt(sk, pf, val, opt, len, 1);
169}
170EXPORT_SYMBOL(compat_nf_getsockopt);
171#endif