diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index 5117e4d2ddfa..be378cf47fcc 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -167,6 +167,7 @@ struct xt_match { const char *table; unsigned int matchsize; + unsigned int usersize; #ifdef CONFIG_COMPAT unsigned int compatsize; #endif @@ -207,6 +208,7 @@ struct xt_target { const char *table; unsigned int targetsize; + unsigned int usersize; #ifdef CONFIG_COMPAT unsigned int compatsize; #endif @@ -287,6 +289,13 @@ int xt_check_match(struct xt_mtchk_param *, unsigned int size, u_int8_t proto, int xt_check_target(struct xt_tgchk_param *, unsigned int size, u_int8_t proto, bool inv_proto); +int xt_match_to_user(const struct xt_entry_match *m, + struct xt_entry_match __user *u); +int xt_target_to_user(const struct xt_entry_target *t, + struct xt_entry_target __user *u); +int xt_data_to_user(void __user *dst, const void *src, + int usersize, int size); + void *xt_copy_counters_from_user(const void __user *user, unsigned int len, struct xt_counters_info *info, bool compat); diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 2ff499680cc6..feccf527abdd 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -262,6 +262,60 @@ struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision) } EXPORT_SYMBOL_GPL(xt_request_find_target); + +static int xt_obj_to_user(u16 __user *psize, u16 size, + void __user *pname, const char *name, + u8 __user *prev, u8 rev) +{ + if (put_user(size, psize)) + return -EFAULT; + if (copy_to_user(pname, name, strlen(name) + 1)) + return -EFAULT; + if (put_user(rev, prev)) + return -EFAULT; + + return 0; +} + +#define XT_OBJ_TO_USER(U, K, TYPE, C_SIZE) \ + xt_obj_to_user(&U->u.TYPE##_size, C_SIZE ? : K->u.TYPE##_size, \ + U->u.user.name, K->u.kernel.TYPE->name, \ + &U->u.user.revision, K->u.kernel.TYPE->revision) + +int xt_data_to_user(void __user *dst, const void *src, + int usersize, int size) +{ + usersize = usersize ? : size; + if (copy_to_user(dst, src, usersize)) + return -EFAULT; + if (usersize != size && clear_user(dst + usersize, size - usersize)) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL_GPL(xt_data_to_user); + +#define XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \ + xt_data_to_user(U->data, K->data, \ + K->u.kernel.TYPE->usersize, \ + C_SIZE ? : K->u.kernel.TYPE->TYPE##size) + +int xt_match_to_user(const struct xt_entry_match *m, + struct xt_entry_match __user *u) +{ + return XT_OBJ_TO_USER(u, m, match, 0) || + XT_DATA_TO_USER(u, m, match, 0); +} +EXPORT_SYMBOL_GPL(xt_match_to_user); + +int xt_target_to_user(const struct xt_entry_target *t, + struct xt_entry_target __user *u) +{ + return XT_OBJ_TO_USER(u, t, target, 0) || + XT_DATA_TO_USER(u, t, target, 0); +} +EXPORT_SYMBOL_GPL(xt_target_to_user); + static int match_revfn(u8 af, const char *name, u8 revision, int *bestp) { const struct xt_match *m;