diff options
Diffstat (limited to 'kernel/net/bridge/netfilter/ebt_ip.c')
-rw-r--r-- | kernel/net/bridge/netfilter/ebt_ip.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/kernel/net/bridge/netfilter/ebt_ip.c b/kernel/net/bridge/netfilter/ebt_ip.c new file mode 100644 index 000000000..23bca62d5 --- /dev/null +++ b/kernel/net/bridge/netfilter/ebt_ip.c @@ -0,0 +1,130 @@ +/* + * ebt_ip + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2002 + * + * Changes: + * added ip-sport and ip-dport + * Innominate Security Technologies AG <mhopf@innominate.com> + * September, 2002 + */ +#include <linux/ip.h> +#include <net/ip.h> +#include <linux/in.h> +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_ip.h> + +struct tcpudphdr { + __be16 src; + __be16 dst; +}; + +static bool +ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_ip_info *info = par->matchinfo; + const struct iphdr *ih; + struct iphdr _iph; + const struct tcpudphdr *pptr; + struct tcpudphdr _ports; + + ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (ih == NULL) + return false; + if (info->bitmask & EBT_IP_TOS && + FWINV(info->tos != ih->tos, EBT_IP_TOS)) + return false; + if (info->bitmask & EBT_IP_SOURCE && + FWINV((ih->saddr & info->smsk) != + info->saddr, EBT_IP_SOURCE)) + return false; + if ((info->bitmask & EBT_IP_DEST) && + FWINV((ih->daddr & info->dmsk) != + info->daddr, EBT_IP_DEST)) + return false; + if (info->bitmask & EBT_IP_PROTO) { + if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO)) + return false; + if (!(info->bitmask & EBT_IP_DPORT) && + !(info->bitmask & EBT_IP_SPORT)) + return true; + if (ntohs(ih->frag_off) & IP_OFFSET) + return false; + pptr = skb_header_pointer(skb, ih->ihl*4, + sizeof(_ports), &_ports); + if (pptr == NULL) + return false; + if (info->bitmask & EBT_IP_DPORT) { + u32 dst = ntohs(pptr->dst); + if (FWINV(dst < info->dport[0] || + dst > info->dport[1], + EBT_IP_DPORT)) + return false; + } + if (info->bitmask & EBT_IP_SPORT) { + u32 src = ntohs(pptr->src); + if (FWINV(src < info->sport[0] || + src > info->sport[1], + EBT_IP_SPORT)) + return false; + } + } + return true; +} + +static int ebt_ip_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_ip_info *info = par->matchinfo; + const struct ebt_entry *e = par->entryinfo; + + if (e->ethproto != htons(ETH_P_IP) || + e->invflags & EBT_IPROTO) + return -EINVAL; + if (info->bitmask & ~EBT_IP_MASK || info->invflags & ~EBT_IP_MASK) + return -EINVAL; + if (info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT)) { + if (info->invflags & EBT_IP_PROTO) + return -EINVAL; + if (info->protocol != IPPROTO_TCP && + info->protocol != IPPROTO_UDP && + info->protocol != IPPROTO_UDPLITE && + info->protocol != IPPROTO_SCTP && + info->protocol != IPPROTO_DCCP) + return -EINVAL; + } + if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1]) + return -EINVAL; + if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1]) + return -EINVAL; + return 0; +} + +static struct xt_match ebt_ip_mt_reg __read_mostly = { + .name = "ip", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_ip_mt, + .checkentry = ebt_ip_mt_check, + .matchsize = sizeof(struct ebt_ip_info), + .me = THIS_MODULE, +}; + +static int __init ebt_ip_init(void) +{ + return xt_register_match(&ebt_ip_mt_reg); +} + +static void __exit ebt_ip_fini(void) +{ + xt_unregister_match(&ebt_ip_mt_reg); +} + +module_init(ebt_ip_init); +module_exit(ebt_ip_fini); +MODULE_DESCRIPTION("Ebtables: IPv4 protocol packet match"); +MODULE_LICENSE("GPL"); |