diff options
Diffstat (limited to 'net/ipv6/netfilter/ip6table_filter.c')
-rw-r--r-- | net/ipv6/netfilter/ip6table_filter.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6table_filter.c b/net/ipv6/netfilter/ip6table_filter.c new file mode 100644 index 000000000..88337b51f --- /dev/null +++ b/net/ipv6/netfilter/ip6table_filter.c @@ -0,0 +1,119 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This is the 1999 rewrite of IP Firewalling, aiming for kernel 2.3.x. + * + * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling + * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> + */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/netfilter_ipv6/ip6_tables.h> +#include <linux/slab.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("ip6tables filter table"); + +#define FILTER_VALID_HOOKS ((1 << NF_INET_LOCAL_IN) | \ + (1 << NF_INET_FORWARD) | \ + (1 << NF_INET_LOCAL_OUT)) + +static int __net_init ip6table_filter_table_init(struct net *net); + +static const struct xt_table packet_filter = { + .name = "filter", + .valid_hooks = FILTER_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV6, + .priority = NF_IP6_PRI_FILTER, + .table_init = ip6table_filter_table_init, +}; + +/* The work comes in here from netfilter.c. */ +static unsigned int +ip6table_filter_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + return ip6t_do_table(skb, state, state->net->ipv6.ip6table_filter); +} + +static struct nf_hook_ops *filter_ops __read_mostly; + +/* Default to forward because I got too much mail already. */ +static bool forward = true; +module_param(forward, bool, 0000); + +static int __net_init ip6table_filter_table_init(struct net *net) +{ + struct ip6t_replace *repl; + int err; + + if (net->ipv6.ip6table_filter) + return 0; + + repl = ip6t_alloc_initial_table(&packet_filter); + if (repl == NULL) + return -ENOMEM; + /* Entry 1 is the FORWARD hook */ + ((struct ip6t_standard *)repl->entries)[1].target.verdict = + forward ? -NF_ACCEPT - 1 : -NF_DROP - 1; + + err = ip6t_register_table(net, &packet_filter, repl, filter_ops, + &net->ipv6.ip6table_filter); + kfree(repl); + return err; +} + +static int __net_init ip6table_filter_net_init(struct net *net) +{ + if (net == &init_net || !forward) + return ip6table_filter_table_init(net); + + return 0; +} + +static void __net_exit ip6table_filter_net_pre_exit(struct net *net) +{ + if (net->ipv6.ip6table_filter) + ip6t_unregister_table_pre_exit(net, net->ipv6.ip6table_filter, + filter_ops); +} + +static void __net_exit ip6table_filter_net_exit(struct net *net) +{ + if (!net->ipv6.ip6table_filter) + return; + ip6t_unregister_table_exit(net, net->ipv6.ip6table_filter); + net->ipv6.ip6table_filter = NULL; +} + +static struct pernet_operations ip6table_filter_net_ops = { + .init = ip6table_filter_net_init, + .pre_exit = ip6table_filter_net_pre_exit, + .exit = ip6table_filter_net_exit, +}; + +static int __init ip6table_filter_init(void) +{ + int ret; + + filter_ops = xt_hook_ops_alloc(&packet_filter, ip6table_filter_hook); + if (IS_ERR(filter_ops)) + return PTR_ERR(filter_ops); + + ret = register_pernet_subsys(&ip6table_filter_net_ops); + if (ret < 0) + kfree(filter_ops); + + return ret; +} + +static void __exit ip6table_filter_fini(void) +{ + unregister_pernet_subsys(&ip6table_filter_net_ops); + kfree(filter_ops); +} + +module_init(ip6table_filter_init); +module_exit(ip6table_filter_fini); |