| /* |
| * iptables module to match inet_addr_type() of an ip. |
| * |
| * Copyright (c) 2004 Patrick McHardy <kaber@trash.net> |
| * (C) 2007 Laszlo Attila Toth <panther@balabit.hu> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/netdevice.h> |
| #include <linux/ip.h> |
| #include <net/route.h> |
| |
| #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
| #include <net/ipv6.h> |
| #include <net/ip6_route.h> |
| #include <net/ip6_fib.h> |
| #endif |
| |
| #include <linux/netfilter_ipv6.h> |
| #include <linux/netfilter/xt_addrtype.h> |
| #include <linux/netfilter/x_tables.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| MODULE_DESCRIPTION("Xtables: address type match"); |
| MODULE_ALIAS("ipt_addrtype"); |
| MODULE_ALIAS("ip6t_addrtype"); |
| |
| #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
| static u32 match_lookup_rt6(struct net *net, const struct net_device *dev, |
| const struct in6_addr *addr, u16 mask) |
| { |
| const struct nf_afinfo *afinfo; |
| struct flowi6 flow; |
| struct rt6_info *rt; |
| u32 ret = 0; |
| int route_err; |
| |
| memset(&flow, 0, sizeof(flow)); |
| flow.daddr = *addr; |
| if (dev) |
| flow.flowi6_oif = dev->ifindex; |
| |
| afinfo = nf_get_afinfo(NFPROTO_IPV6); |
| if (afinfo != NULL) { |
| const struct nf_ipv6_ops *v6ops; |
| |
| if (dev && (mask & XT_ADDRTYPE_LOCAL)) { |
| v6ops = nf_get_ipv6_ops(); |
| if (v6ops && v6ops->chk_addr(net, addr, dev, true)) |
| ret = XT_ADDRTYPE_LOCAL; |
| } |
| route_err = afinfo->route(net, (struct dst_entry **)&rt, |
| flowi6_to_flowi(&flow), false); |
| } else { |
| route_err = 1; |
| } |
| |
| if (route_err) |
| return XT_ADDRTYPE_UNREACHABLE; |
| |
| if (rt->rt6i_flags & RTF_REJECT) |
| ret = XT_ADDRTYPE_UNREACHABLE; |
| |
| if (dev == NULL && rt->rt6i_flags & RTF_LOCAL) |
| ret |= XT_ADDRTYPE_LOCAL; |
| if (ipv6_anycast_destination((struct dst_entry *)rt, addr)) |
| ret |= XT_ADDRTYPE_ANYCAST; |
| |
| dst_release(&rt->dst); |
| return ret; |
| } |
| |
| static bool match_type6(struct net *net, const struct net_device *dev, |
| const struct in6_addr *addr, u16 mask) |
| { |
| int addr_type = ipv6_addr_type(addr); |
| |
| if ((mask & XT_ADDRTYPE_MULTICAST) && |
| !(addr_type & IPV6_ADDR_MULTICAST)) |
| return false; |
| if ((mask & XT_ADDRTYPE_UNICAST) && !(addr_type & IPV6_ADDR_UNICAST)) |
| return false; |
| if ((mask & XT_ADDRTYPE_UNSPEC) && addr_type != IPV6_ADDR_ANY) |
| return false; |
| |
| if ((XT_ADDRTYPE_LOCAL | XT_ADDRTYPE_ANYCAST | |
| XT_ADDRTYPE_UNREACHABLE) & mask) |
| return !!(mask & match_lookup_rt6(net, dev, addr, mask)); |
| return true; |
| } |
| |
| static bool |
| addrtype_mt6(struct net *net, const struct net_device *dev, |
| const struct sk_buff *skb, const struct xt_addrtype_info_v1 *info) |
| { |
| const struct ipv6hdr *iph = ipv6_hdr(skb); |
| bool ret = true; |
| |
| if (info->source) |
| ret &= match_type6(net, dev, &iph->saddr, info->source) ^ |
| (info->flags & XT_ADDRTYPE_INVERT_SOURCE); |
| if (ret && info->dest) |
| ret &= match_type6(net, dev, &iph->daddr, info->dest) ^ |
| !!(info->flags & XT_ADDRTYPE_INVERT_DEST); |
| return ret; |
| } |
| #endif |
| |
| static inline bool match_type(struct net *net, const struct net_device *dev, |
| __be32 addr, u_int16_t mask) |
| { |
| return !!(mask & (1 << inet_dev_addr_type(net, dev, addr))); |
| } |
| |
| static bool |
| addrtype_mt_v0(const struct sk_buff *skb, struct xt_action_param *par) |
| { |
| struct net *net = xt_net(par); |
| const struct xt_addrtype_info *info = par->matchinfo; |
| const struct iphdr *iph = ip_hdr(skb); |
| bool ret = true; |
| |
| if (info->source) |
| ret &= match_type(net, NULL, iph->saddr, info->source) ^ |
| info->invert_source; |
| if (info->dest) |
| ret &= match_type(net, NULL, iph->daddr, info->dest) ^ |
| info->invert_dest; |
| |
| return ret; |
| } |
| |
| static bool |
| addrtype_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) |
| { |
| struct net *net = xt_net(par); |
| const struct xt_addrtype_info_v1 *info = par->matchinfo; |
| const struct iphdr *iph; |
| const struct net_device *dev = NULL; |
| bool ret = true; |
| |
| if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) |
| dev = xt_in(par); |
| else if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) |
| dev = xt_out(par); |
| |
| #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
| if (xt_family(par) == NFPROTO_IPV6) |
| return addrtype_mt6(net, dev, skb, info); |
| #endif |
| iph = ip_hdr(skb); |
| if (info->source) |
| ret &= match_type(net, dev, iph->saddr, info->source) ^ |
| (info->flags & XT_ADDRTYPE_INVERT_SOURCE); |
| if (ret && info->dest) |
| ret &= match_type(net, dev, iph->daddr, info->dest) ^ |
| !!(info->flags & XT_ADDRTYPE_INVERT_DEST); |
| return ret; |
| } |
| |
| static int addrtype_mt_checkentry_v1(const struct xt_mtchk_param *par) |
| { |
| struct xt_addrtype_info_v1 *info = par->matchinfo; |
| |
| if (info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN && |
| info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) { |
| pr_info("both incoming and outgoing " |
| "interface limitation cannot be selected\n"); |
| return -EINVAL; |
| } |
| |
| if (par->hook_mask & ((1 << NF_INET_PRE_ROUTING) | |
| (1 << NF_INET_LOCAL_IN)) && |
| info->flags & XT_ADDRTYPE_LIMIT_IFACE_OUT) { |
| pr_info("output interface limitation " |
| "not valid in PREROUTING and INPUT\n"); |
| return -EINVAL; |
| } |
| |
| if (par->hook_mask & ((1 << NF_INET_POST_ROUTING) | |
| (1 << NF_INET_LOCAL_OUT)) && |
| info->flags & XT_ADDRTYPE_LIMIT_IFACE_IN) { |
| pr_info("input interface limitation " |
| "not valid in POSTROUTING and OUTPUT\n"); |
| return -EINVAL; |
| } |
| |
| #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
| if (par->family == NFPROTO_IPV6) { |
| if ((info->source | info->dest) & XT_ADDRTYPE_BLACKHOLE) { |
| pr_err("ipv6 BLACKHOLE matching not supported\n"); |
| return -EINVAL; |
| } |
| if ((info->source | info->dest) >= XT_ADDRTYPE_PROHIBIT) { |
| pr_err("ipv6 PROHIBIT (THROW, NAT ..) matching not supported\n"); |
| return -EINVAL; |
| } |
| if ((info->source | info->dest) & XT_ADDRTYPE_BROADCAST) { |
| pr_err("ipv6 does not support BROADCAST matching\n"); |
| return -EINVAL; |
| } |
| } |
| #endif |
| return 0; |
| } |
| |
| static struct xt_match addrtype_mt_reg[] __read_mostly = { |
| { |
| .name = "addrtype", |
| .family = NFPROTO_IPV4, |
| .match = addrtype_mt_v0, |
| .matchsize = sizeof(struct xt_addrtype_info), |
| .me = THIS_MODULE |
| }, |
| { |
| .name = "addrtype", |
| .family = NFPROTO_UNSPEC, |
| .revision = 1, |
| .match = addrtype_mt_v1, |
| .checkentry = addrtype_mt_checkentry_v1, |
| .matchsize = sizeof(struct xt_addrtype_info_v1), |
| .me = THIS_MODULE |
| } |
| }; |
| |
| static int __init addrtype_mt_init(void) |
| { |
| return xt_register_matches(addrtype_mt_reg, |
| ARRAY_SIZE(addrtype_mt_reg)); |
| } |
| |
| static void __exit addrtype_mt_exit(void) |
| { |
| xt_unregister_matches(addrtype_mt_reg, ARRAY_SIZE(addrtype_mt_reg)); |
| } |
| |
| module_init(addrtype_mt_init); |
| module_exit(addrtype_mt_exit); |