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