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path: root/net/bridge/netfilter/ebt_ip.c
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Diffstat (limited to 'net/bridge/netfilter/ebt_ip.c')
-rw-r--r--net/bridge/netfilter/ebt_ip.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/net/bridge/netfilter/ebt_ip.c b/net/bridge/netfilter/ebt_ip.c
new file mode 100644
index 00000000000..7323805b972
--- /dev/null
+++ b/net/bridge/netfilter/ebt_ip.c
@@ -0,0 +1,122 @@
+/*
+ * 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/netfilter_bridge/ebtables.h>
+#include <linux/netfilter_bridge/ebt_ip.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/module.h>
+
+struct tcpudphdr {
+ uint16_t src;
+ uint16_t dst;
+};
+
+static int ebt_filter_ip(const struct sk_buff *skb, const struct net_device *in,
+ const struct net_device *out, const void *data,
+ unsigned int datalen)
+{
+ struct ebt_ip_info *info = (struct ebt_ip_info *)data;
+ struct iphdr _iph, *ih;
+ struct tcpudphdr _ports, *pptr;
+
+ ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
+ if (ih == NULL)
+ return EBT_NOMATCH;
+ if (info->bitmask & EBT_IP_TOS &&
+ FWINV(info->tos != ih->tos, EBT_IP_TOS))
+ return EBT_NOMATCH;
+ if (info->bitmask & EBT_IP_SOURCE &&
+ FWINV((ih->saddr & info->smsk) !=
+ info->saddr, EBT_IP_SOURCE))
+ return EBT_NOMATCH;
+ if ((info->bitmask & EBT_IP_DEST) &&
+ FWINV((ih->daddr & info->dmsk) !=
+ info->daddr, EBT_IP_DEST))
+ return EBT_NOMATCH;
+ if (info->bitmask & EBT_IP_PROTO) {
+ if (FWINV(info->protocol != ih->protocol, EBT_IP_PROTO))
+ return EBT_NOMATCH;
+ if (!(info->bitmask & EBT_IP_DPORT) &&
+ !(info->bitmask & EBT_IP_SPORT))
+ return EBT_MATCH;
+ pptr = skb_header_pointer(skb, ih->ihl*4,
+ sizeof(_ports), &_ports);
+ if (pptr == NULL)
+ return EBT_NOMATCH;
+ 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 EBT_NOMATCH;
+ }
+ 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 EBT_NOMATCH;
+ }
+ }
+ return EBT_MATCH;
+}
+
+static int ebt_ip_check(const char *tablename, unsigned int hookmask,
+ const struct ebt_entry *e, void *data, unsigned int datalen)
+{
+ struct ebt_ip_info *info = (struct ebt_ip_info *)data;
+
+ if (datalen != EBT_ALIGN(sizeof(struct ebt_ip_info)))
+ return -EINVAL;
+ 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)
+ 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 ebt_match filter_ip =
+{
+ .name = EBT_IP_MATCH,
+ .match = ebt_filter_ip,
+ .check = ebt_ip_check,
+ .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+ return ebt_register_match(&filter_ip);
+}
+
+static void __exit fini(void)
+{
+ ebt_unregister_match(&filter_ip);
+}
+
+module_init(init);
+module_exit(fini);
+MODULE_LICENSE("GPL");