diff options
Diffstat (limited to 'net/netfilter/nf_sockopt.c')
| -rw-r--r-- | net/netfilter/nf_sockopt.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/net/netfilter/nf_sockopt.c b/net/netfilter/nf_sockopt.c new file mode 100644 index 0000000..8ab829f --- /dev/null +++ b/net/netfilter/nf_sockopt.c @@ -0,0 +1,169 @@ +#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 nf_sockopt_ops *ops; + int ret = 0; + + if (mutex_lock_interruptible(&nf_sockopt_mutex) != 0) + return -EINTR; + + list_for_each_entry(ops, &nf_sockopts, list) { + 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) +{ + mutex_lock(&nf_sockopt_mutex); + list_del(®->list); + mutex_unlock(&nf_sockopt_mutex); +} +EXPORT_SYMBOL(nf_unregister_sockopt); + +static struct nf_sockopt_ops *nf_sockopt_find(struct sock *sk, u_int8_t pf, + int val, int get) +{ + struct nf_sockopt_ops *ops; + + if (mutex_lock_interruptible(&nf_sockopt_mutex) != 0) + return ERR_PTR(-EINTR); + + list_for_each_entry(ops, &nf_sockopts, list) { + if (ops->pf == pf) { + if (!try_module_get(ops->owner)) + goto out_nosup; + + if (get) { + if (val >= ops->get_optmin && + val < ops->get_optmax) + goto out; + } else { + if (val >= ops->set_optmin && + val < ops->set_optmax) + goto out; + } + module_put(ops->owner); + } + } +out_nosup: + ops = ERR_PTR(-ENOPROTOOPT); +out: + mutex_unlock(&nf_sockopt_mutex); + return ops; +} + +/* Call get/setsockopt() */ +static int nf_sockopt(struct sock *sk, u_int8_t pf, int val, + char __user *opt, int *len, int get) +{ + struct nf_sockopt_ops *ops; + int ret; + + ops = nf_sockopt_find(sk, pf, val, get); + if (IS_ERR(ops)) + return PTR_ERR(ops); + + if (get) + ret = ops->get(sk, val, opt, len); + else + ret = ops->set(sk, val, opt, *len); + + module_put(ops->owner); + return ret; +} + +int nf_setsockopt(struct sock *sk, u_int8_t 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, u_int8_t pf, int val, char __user *opt, + int *len) +{ + return nf_sockopt(sk, pf, val, opt, len, 1); +} +EXPORT_SYMBOL(nf_getsockopt); + +#ifdef CONFIG_COMPAT +static int compat_nf_sockopt(struct sock *sk, u_int8_t pf, int val, + char __user *opt, int *len, int get) +{ + struct nf_sockopt_ops *ops; + int ret; + + ops = nf_sockopt_find(sk, pf, val, get); + if (IS_ERR(ops)) + return PTR_ERR(ops); + + if (get) { + if (ops->compat_get) + ret = ops->compat_get(sk, val, opt, len); + else + ret = ops->get(sk, val, opt, len); + } else { + if (ops->compat_set) + ret = ops->compat_set(sk, val, opt, *len); + else + ret = ops->set(sk, val, opt, *len); + } + + module_put(ops->owner); + return ret; +} + +int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, + int val, char __user *opt, int len) +{ + return compat_nf_sockopt(sk, pf, val, opt, &len, 0); +} +EXPORT_SYMBOL(compat_nf_setsockopt); + +int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, + int val, char __user *opt, int *len) +{ + return compat_nf_sockopt(sk, pf, val, opt, len, 1); +} +EXPORT_SYMBOL(compat_nf_getsockopt); +#endif |
