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#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netfilter.h>
#include <linux/mutex.h>
#include <net/sock.h>
#include "nf_internals.h"
/* Sockopts only registered and called from user context, so
net locking would be overkill. Also, [gs]etsockopt calls may
sleep. */
static DEFINE_MUTEX(nf_sockopt_mutex);
static LIST_HEAD(nf_sockopts);
/* Do exclusive ranges overlap? */
static inline int overlap(int min1, int max1, int min2, int max2)
{
return max1 > min2 && min1 < max2;
}
/* Functions to register sockopt ranges (exclusive). */
int nf_register_sockopt(struct nf_sockopt_ops *reg)
{
struct list_head *i;
int ret = 0;
if (mutex_lock_interruptible(&nf_sockopt_mutex) != 0)
return -EINTR;
list_for_each(i, &nf_sockopts) {
struct nf_sockopt_ops *ops = (struct nf_sockopt_ops *)i;
if (ops->pf == reg->pf
&& (overlap(ops->set_optmin, ops->set_optmax,
reg->set_optmin, reg->set_optmax)
|| overlap(ops->get_optmin, ops->get_optmax,
reg->get_optmin, reg->get_optmax))) {
NFDEBUG("nf_sock overlap: %u-%u/%u-%u v %u-%u/%u-%u\n",
ops->set_optmin, ops->set_optmax,
ops->get_optmin, ops->get_optmax,
reg->set_optmin, reg->set_optmax,
reg->get_optmin, reg->get_optmax);
ret = -EBUSY;
goto out;
}
}
list_add(®->list, &nf_sockopts);
out:
mutex_unlock(&nf_sockopt_mutex);
return ret;
}
EXPORT_SYMBOL(nf_register_sockopt);
void nf_unregister_sockopt(struct nf_sockopt_ops *reg)
{
/* No point being interruptible: we're probably in cleanup_module() */
restart:
mutex_lock(&nf_sockopt_mutex);
if (reg->use != 0) {
/* To be woken by nf_sockopt call... */
/* FIXME: Stuart Young's name appears gratuitously. */
set_current_state(TASK_UNINTERRUPTIBLE);
reg->cleanup_task = current;
mutex_unlock(&nf_sockopt_mutex);
schedule();
goto restart;
}
list_del(®->list);
mutex_unlock(&nf_sockopt_mutex);
}
EXPORT_SYMBOL(nf_unregister_sockopt);
/* Call get/setsockopt() */
static int nf_sockopt(struct sock *sk, int pf, int val,
char __user *opt, int *len, int get)
{
struct list_head *i;
struct nf_sockopt_ops *ops;
int ret;
if (mutex_lock_interruptible(&nf_sockopt_mutex) != 0)
return -EINTR;
list_for_each(i, &nf_sockopts) {
ops = (struct nf_sockopt_ops *)i;
if (ops->pf == pf) {
if (get) {
if (val >= ops->get_optmin
&& val < ops->get_optmax) {
ops->use++;
mutex_unlock(&nf_sockopt_mutex);
ret = ops->get(sk, val, opt, len);
goto out;
}
} else {
if (val >= ops->set_optmin
&& val < ops->set_optmax) {
ops->use++;
mutex_unlock(&nf_sockopt_mutex);
ret = ops->set(sk, val, opt, *len);
goto out;
}
}
}
}
mutex_unlock(&nf_sockopt_mutex);
return -ENOPROTOOPT;
out:
mutex_lock(&nf_sockopt_mutex);
ops->use--;
if (ops->cleanup_task)
wake_up_process(ops->cleanup_task);
mutex_unlock(&nf_sockopt_mutex);
return ret;
}
int nf_setsockopt(struct sock *sk, int pf, int val, char __user *opt,
int len)
{
return nf_sockopt(sk, pf, val, opt, &len, 0);
}
EXPORT_SYMBOL(nf_setsockopt);
int nf_getsockopt(struct sock *sk, int pf, int val, char __user *opt, int *len)
{
return nf_sockopt(sk, pf, val, opt, len, 1);
}
EXPORT_SYMBOL(nf_getsockopt);
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