1 // SPDX-License-Identifier: GPL-2.0
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 <linux/mutex.h>
10 #include "nf_internals.h"
12 /* Sockopts only registered and called from user context, so
13 net locking would be overkill. Also, [gs]etsockopt calls may
15 static DEFINE_MUTEX(nf_sockopt_mutex);
16 static LIST_HEAD(nf_sockopts);
18 /* Do exclusive ranges overlap? */
19 static inline int overlap(int min1, int max1, int min2, int max2)
21 return max1 > min2 && min1 < max2;
24 /* Functions to register sockopt ranges (exclusive). */
25 int nf_register_sockopt(struct nf_sockopt_ops *reg)
27 struct nf_sockopt_ops *ops;
30 mutex_lock(&nf_sockopt_mutex);
31 list_for_each_entry(ops, &nf_sockopts, list) {
32 if (ops->pf == reg->pf
33 && (overlap(ops->set_optmin, ops->set_optmax,
34 reg->set_optmin, reg->set_optmax)
35 || overlap(ops->get_optmin, ops->get_optmax,
36 reg->get_optmin, reg->get_optmax))) {
37 pr_debug("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n",
38 ops->set_optmin, ops->set_optmax,
39 ops->get_optmin, ops->get_optmax,
40 reg->set_optmin, reg->set_optmax,
41 reg->get_optmin, reg->get_optmax);
47 list_add(®->list, &nf_sockopts);
49 mutex_unlock(&nf_sockopt_mutex);
52 EXPORT_SYMBOL(nf_register_sockopt);
54 void nf_unregister_sockopt(struct nf_sockopt_ops *reg)
56 mutex_lock(&nf_sockopt_mutex);
58 mutex_unlock(&nf_sockopt_mutex);
60 EXPORT_SYMBOL(nf_unregister_sockopt);
62 static struct nf_sockopt_ops *nf_sockopt_find(struct sock *sk, u_int8_t pf,
65 struct nf_sockopt_ops *ops;
67 mutex_lock(&nf_sockopt_mutex);
68 list_for_each_entry(ops, &nf_sockopts, list) {
70 if (!try_module_get(ops->owner))
74 if (val >= ops->get_optmin &&
75 val < ops->get_optmax)
78 if (val >= ops->set_optmin &&
79 val < ops->set_optmax)
82 module_put(ops->owner);
86 ops = ERR_PTR(-ENOPROTOOPT);
88 mutex_unlock(&nf_sockopt_mutex);
92 int nf_setsockopt(struct sock *sk, u_int8_t pf, int val, sockptr_t opt,
95 struct nf_sockopt_ops *ops;
98 ops = nf_sockopt_find(sk, pf, val, 0);
101 ret = ops->set(sk, val, opt, len);
102 module_put(ops->owner);
105 EXPORT_SYMBOL(nf_setsockopt);
107 int nf_getsockopt(struct sock *sk, u_int8_t pf, int val, char __user *opt,
110 struct nf_sockopt_ops *ops;
113 ops = nf_sockopt_find(sk, pf, val, 1);
116 ret = ops->get(sk, val, opt, len);
117 module_put(ops->owner);
120 EXPORT_SYMBOL(nf_getsockopt);