Modify

Opened 12 years ago

Closed 11 years ago

Last modified 4 years ago

#595 closed enhancement (fixed)

patch-o-matic: ROUTE iptables module

Reported by: frop Owned by: florian
Priority: normal Milestone: Barrier Breaker 14.07
Component: kernel Version:
Keywords: Cc:

Description

lo
so far i've a patch file for the kernel tree (2.6.16) (under buildroot-ng r3943)
Problem remains in "config"
For ipv4, "Packet mangling" is needed. (the two modules can be insert as Module or Compiled in)

For ipv6 this TARGET works only if "compiled-in" (not as a module), so:

"The IPv6 protocol"

"IP6 tables support (required for filtering/masq/NAT)"

"Packet mangling"
"ROUTE target support"

need to be "compiled-in" the kernel.

here's a cat of it (150-netfilter_ROUTE.patch):

diff -u'rNF^function' linux-2.6.16.7/include/linux/netfilter_ipv4/ipt_ROUTE.h linux-2.6.16.7-ROUTE/include/linux/netfilter_ipv4/ipt_ROUTE.h
--- linux-2.6.16.7/include/linux/netfilter_ipv4/ipt_ROUTE.h     1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.16.7-ROUTE/include/linux/netfilter_ipv4/ipt_ROUTE.h       2006-06-14 16:40:49.000000000 +0200
@@ -0,0 +1,23 @@
+/* Header file for iptables ipt_ROUTE target
+ *
+ * (C) 2002 by Cédric de Launois <delaunois@info.ucl.ac.be>
+ *
+ * This software is distributed under GNU GPL v2, 1991
+ */
+#ifndef _IPT_ROUTE_H_target
+#define _IPT_ROUTE_H_target
+
+#define IPT_ROUTE_IFNAMSIZ 16
+
+struct ipt_route_target_info {
+       char      oif[IPT_ROUTE_IFNAMSIZ];      /* Output Interface Name */
+       char      iif[IPT_ROUTE_IFNAMSIZ];      /* Input Interface Name  */
+       u_int32_t gw;                           /* IP address of gateway */
+       u_int8_t  flags;
+};
+
+/* Values for "flags" field */
+#define IPT_ROUTE_CONTINUE        0x01
+#define IPT_ROUTE_TEE             0x02
+
+#endif /*_IPT_ROUTE_H_target*/
diff -u'rNF^function' linux-2.6.16.7/include/linux/netfilter_ipv6/ip6t_ROUTE.h linux-2.6.16.7-ROUTE/include/linux/netfilter_ipv6/ip6t_ROUTE.h
--- linux-2.6.16.7/include/linux/netfilter_ipv6/ip6t_ROUTE.h    1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.16.7-ROUTE/include/linux/netfilter_ipv6/ip6t_ROUTE.h      2006-06-14 16:41:08.000000000 +0200
@@ -0,0 +1,23 @@
+/* Header file for iptables ip6t_ROUTE target
+ *
+ * (C) 2003 by Cédric de Launois <delaunois@info.ucl.ac.be>
+ *
+ * This software is distributed under GNU GPL v2, 1991
+ */
+#ifndef _IPT_ROUTE_H_target
+#define _IPT_ROUTE_H_target
+
+#define IP6T_ROUTE_IFNAMSIZ 16
+
+struct ip6t_route_target_info {
+       char      oif[IP6T_ROUTE_IFNAMSIZ];     /* Output Interface Name */
+       char      iif[IP6T_ROUTE_IFNAMSIZ];     /* Input Interface Name  */
+       u_int32_t gw[4];                        /* IPv6 address of gateway */
+       u_int8_t  flags;
+};
+
+/* Values for "flags" field */
+#define IP6T_ROUTE_CONTINUE        0x01
+#define IP6T_ROUTE_TEE             0x02
+
+#endif /*_IP6T_ROUTE_H_target*/
diff -u'rNF^function' linux-2.6.16.7/net/ipv4/netfilter/Kconfig linux-2.6.16.7-ROUTE/net/ipv4/netfilter/Kconfig
--- linux-2.6.16.7/net/ipv4/netfilter/Kconfig   2006-06-14 16:05:44.000000000 +0200
+++ linux-2.6.16.7-ROUTE/net/ipv4/netfilter/Kconfig     2006-06-14 16:46:40.000000000 +0200
@@ -491,6 +491,23 @@

          To compile it as a module, choose M here.  If unsure, say N.

+config IP_NF_TARGET_ROUTE
+        tristate  'ROUTE target support'
+        depends on IP_NF_MANGLE
+        help
+          This option adds a `ROUTE' target, which enables you to setup unusual
+          routes. For example, the ROUTE lets you route a received packet through
+          an interface or towards a host, even if the regular destination of the
+          packet is the router itself. The ROUTE target is also able to change the
+          incoming interface of a packet.
+
+          The target can be or not a final target. It has to be used inside the
+          mangle table.
+
+          If you want to compile it as a module, say M here and read
+          Documentation/modules.txt.  The module will be called ipt_ROUTE.o.
+          If unsure, say `N'.
+
 config IP_NF_TARGET_NETMAP
        tristate "NETMAP target support"
        depends on IP_NF_NAT
diff -u'rNF^function' linux-2.6.16.7/net/ipv4/netfilter/Makefile linux-2.6.16.7-ROUTE/net/ipv4/netfilter/Makefile
--- linux-2.6.16.7/net/ipv4/netfilter/Makefile  2006-06-14 16:05:44.000000000 +0200
+++ linux-2.6.16.7-ROUTE/net/ipv4/netfilter/Makefile    2006-06-14 16:44:02.000000000 +0200
@@ -74,6 +74,7 @@
 obj-$(CONFIG_IP_NF_TARGET_IMQ) += ipt_IMQ.o
 obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
+obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
 obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
 obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
diff -u'rNF^function' linux-2.6.16.7/net/ipv4/netfilter/ipt_ROUTE.c linux-2.6.16.7-ROUTE/net/ipv4/netfilter/ipt_ROUTE.c
--- linux-2.6.16.7/net/ipv4/netfilter/ipt_ROUTE.c       1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.16.7-ROUTE/net/ipv4/netfilter/ipt_ROUTE.c 2006-06-14 16:42:23.000000000 +0200
@@ -0,0 +1,461 @@
+/*
+ * This implements the ROUTE target, which enables you to setup unusual
+ * routes not supported by the standard kernel routing table.
+ *
+ * Copyright (C) 2002 Cedric de Launois <delaunois@info.ucl.ac.be>
+ *
+ * v 1.11 2004/11/23
+ *
+ * This software is distributed under GNU GPL v2, 1991
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ipt_ROUTE.h>
+#include <linux/netdevice.h>
+#include <linux/route.h>
+#include <linux/if_arp.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/icmp.h>
+#include <net/checksum.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cedric de Launois <delaunois@info.ucl.ac.be>");
+MODULE_DESCRIPTION("iptables ROUTE target module");
+
+/* Try to route the packet according to the routing keys specified in
+ * route_info. Keys are :
+ *  - ifindex :
+ *      0 if no oif preferred,
+ *      otherwise set to the index of the desired oif
+ *  - route_info->gw :
+ *      0 if no gateway specified,
+ *      otherwise set to the next host to which the pkt must be routed
+ * If success, skb->dev is the output device to which the packet must
+ * be sent and skb->dst is not NULL
+ *
+ * RETURN: -1 if an error occured
+ *          1 if the packet was succesfully routed to the
+ *            destination desired
+ *          0 if the kernel routing table could not route the packet
+ *            according to the keys specified
+ */
+static int route(struct sk_buff *skb,
+                unsigned int ifindex,
+                const struct ipt_route_target_info *route_info)
+{
+       int err;
+       struct rtable *rt;
+       struct iphdr *iph = skb->nh.iph;
+       struct flowi fl = {
+               .oif = ifindex,
+               .nl_u = {
+                       .ip4_u = {
+                               .daddr = iph->daddr,
+                               .saddr = 0,
+                               .tos = RT_TOS(iph->tos),
+                               .scope = RT_SCOPE_UNIVERSE,
+                       }
+               }
+       };
+
+       /* The destination address may be overloaded by the target */
+       if (route_info->gw)
+               fl.fl4_dst = route_info->gw;
+
+       /* Trying to route the packet using the standard routing table. */
+       if ((err = ip_route_output_key(&rt, &fl))) {
+               if (net_ratelimit())
+                       DEBUGP("ipt_ROUTE: couldn't route pkt (err: %i)",err);
+               return -1;
+       }
+
+       /* Drop old route. */
+       dst_release(skb->dst);
+       skb->dst = NULL;
+
+       /* Success if no oif specified or if the oif correspond to the
+        * one desired */
+       if (!ifindex || rt->u.dst.dev->ifindex == ifindex) {
+               skb->dst = &rt->u.dst;
+               skb->dev = skb->dst->dev;
+               skb->protocol = htons(ETH_P_IP);
+               return 1;
+       }
+
+       /* The interface selected by the routing table is not the one
+        * specified by the user. This may happen because the dst address
+        * is one of our own addresses.
+        */
+       if (net_ratelimit())
+               DEBUGP("ipt_ROUTE: failed to route as desired gw=%u.%u.%u.%u oif=%i (got oif=%i)\n",
+                      NIPQUAD(route_info->gw), ifindex, rt->u.dst.dev->ifindex);
+
+       return 0;
+}
+
+
+/* Stolen from ip_finish_output2
+ * PRE : skb->dev is set to the device we are leaving by
+ *       skb->dst is not NULL
+ * POST: the packet is sent with the link layer header pushed
+ *       the packet is destroyed
+ */
+static void ip_direct_send(struct sk_buff *skb)
+{
+       struct dst_entry *dst = skb->dst;
+       struct hh_cache *hh = dst->hh;
+       struct net_device *dev = dst->dev;
+       int hh_len = LL_RESERVED_SPACE(dev);
+
+       /* Be paranoid, rather than too clever. */
+       if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
+               struct sk_buff *skb2;
+
+               skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
+               if (skb2 == NULL) {
+                       kfree_skb(skb);
+                       return;
+               }
+               if (skb->sk)
+                       skb_set_owner_w(skb2, skb->sk);
+               kfree_skb(skb);
+               skb = skb2;
+       }
+
+       if (hh) {
+               int hh_alen;
+
+               read_lock_bh(&hh->hh_lock);
+               hh_alen = HH_DATA_ALIGN(hh->hh_len);
+               memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
+               read_unlock_bh(&hh->hh_lock);
+               skb_push(skb, hh->hh_len);
+               hh->hh_output(skb);
+       } else if (dst->neighbour)
+               dst->neighbour->output(skb);
+       else {
+               if (net_ratelimit())
+                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no hdr & no neighbour cache!\n");
+               kfree_skb(skb);
+       }
+}
+
+
+/* PRE : skb->dev is set to the device we are leaving by
+ * POST: - the packet is directly sent to the skb->dev device, without
+ *         pushing the link layer header.
+ *       - the packet is destroyed
+ */
+static inline int dev_direct_send(struct sk_buff *skb)
+{
+       return dev_queue_xmit(skb);
+}
+
+
+static unsigned int route_oif(const struct ipt_route_target_info *route_info,
+                             struct sk_buff *skb)
+{
+       unsigned int ifindex = 0;
+       struct net_device *dev_out = NULL;
+
+       /* The user set the interface name to use.
+        * Getting the current interface index.
+        */
+       if ((dev_out = dev_get_by_name(route_info->oif))) {
+               ifindex = dev_out->ifindex;
+       } else {
+               /* Unknown interface name : packet dropped */
+               if (net_ratelimit())
+                       DEBUGP("ipt_ROUTE: oif interface %s not found\n", route_info->oif);
+               return NF_DROP;
+       }
+
+       /* Trying the standard way of routing packets */
+       switch (route(skb, ifindex, route_info)) {
+       case 1:
+               dev_put(dev_out);
+               if (route_info->flags & IPT_ROUTE_CONTINUE)
+                       return IPT_CONTINUE;
+
+               ip_direct_send(skb);
+               return NF_STOLEN;
+
+       case 0:
+               /* Failed to send to oif. Trying the hard way */
+               if (route_info->flags & IPT_ROUTE_CONTINUE)
+                       return NF_DROP;
+
+               if (net_ratelimit())
+                       DEBUGP("ipt_ROUTE: forcing the use of %i\n",
+                              ifindex);
+
+               /* We have to force the use of an interface.
+                * This interface must be a tunnel interface since
+                * otherwise we can't guess the hw address for
+                * the packet. For a tunnel interface, no hw address
+                * is needed.
+                */
+               if ((dev_out->type != ARPHRD_TUNNEL)
+                   && (dev_out->type != ARPHRD_IPGRE)) {
+                       if (net_ratelimit())
+                               DEBUGP("ipt_ROUTE: can't guess the hw addr !\n");
+                       dev_put(dev_out);
+                       return NF_DROP;
+               }
+
+               /* Send the packet. This will also free skb
+                * Do not go through the POST_ROUTING hook because
+                * skb->dst is not set and because it will probably
+                * get confused by the destination IP address.
+                */
+               skb->dev = dev_out;
+               dev_direct_send(skb);
+               dev_put(dev_out);
+               return NF_STOLEN;
+
+       default:
+               /* Unexpected error */
+               dev_put(dev_out);
+               return NF_DROP;
+       }
+}
+
+
+static unsigned int route_iif(const struct ipt_route_target_info *route_info,
+                             struct sk_buff *skb)
+{
+       struct net_device *dev_in = NULL;
+
+       /* Getting the current interface index. */
+       if (!(dev_in = dev_get_by_name(route_info->iif))) {
+               if (net_ratelimit())
+                       DEBUGP("ipt_ROUTE: iif interface %s not found\n", route_info->iif);
+               return NF_DROP;
+       }
+
+       skb->dev = dev_in;
+       dst_release(skb->dst);
+       skb->dst = NULL;
+
+       netif_rx(skb);
+       dev_put(dev_in);
+       return NF_STOLEN;
+}
+
+
+static unsigned int route_gw(const struct ipt_route_target_info *route_info,
+                            struct sk_buff *skb)
+{
+       if (route(skb, 0, route_info)!=1)
+               return NF_DROP;
+
+       if (route_info->flags & IPT_ROUTE_CONTINUE)
+               return IPT_CONTINUE;
+
+       ip_direct_send(skb);
+       return NF_STOLEN;
+}
+
+
+/* To detect and deter routed packet loopback when using the --tee option,
+ * we take a page out of the raw.patch book: on the copied skb, we set up
+ * a fake ->nfct entry, pointing to the local &route_tee_track. We skip
+ * routing packets when we see they already have that ->nfct.
+ */
+
+static struct ip_conntrack route_tee_track;
+
+static unsigned int ipt_route_target(struct sk_buff **pskb,
+                                    const struct net_device *in,
+                                    const struct net_device *out,
+                                    unsigned int hooknum,
+                                    const void *targinfo,
+                                    void *userinfo)
+{
+       const struct ipt_route_target_info *route_info = targinfo;
+       struct sk_buff *skb = *pskb;
+       unsigned int res;
+
+       if (skb->nfct == &route_tee_track.ct_general) {
+               /* Loopback - a packet we already routed, is to be
+                * routed another time. Avoid that, now.
+                */
+               if (net_ratelimit())
+                       DEBUGP(KERN_DEBUG "ipt_ROUTE: loopback - DROP!\n");
+               return NF_DROP;
+       }
+
+       /* If we are at PREROUTING or INPUT hook
+        * the TTL isn't decreased by the IP stack
+        */
+       if (hooknum == NF_IP_PRE_ROUTING ||
+           hooknum == NF_IP_LOCAL_IN) {
+
+               struct iphdr *iph = skb->nh.iph;
+
+               if (iph->ttl <= 1) {
+                       struct rtable *rt;
+                       struct flowi fl = {
+                               .oif = 0,
+                               .nl_u = {
+                                       .ip4_u = {
+                                               .daddr = iph->daddr,
+                                               .saddr = iph->saddr,
+                                               .tos = RT_TOS(iph->tos),
+                                               .scope = ((iph->tos & RTO_ONLINK) ?
+                                                         RT_SCOPE_LINK :
+                                                         RT_SCOPE_UNIVERSE)
+                                       }
+                               }
+                       };
+
+                       if (ip_route_output_key(&rt, &fl)) {
+                               return NF_DROP;
+                       }
+
+                       if (skb->dev == rt->u.dst.dev) {
+                               /* Drop old route. */
+                               dst_release(skb->dst);
+                               skb->dst = &rt->u.dst;
+
+                               /* this will traverse normal stack, and
+                                * thus call conntrack on the icmp packet */
+                               icmp_send(skb, ICMP_TIME_EXCEEDED,
+                                         ICMP_EXC_TTL, 0);
+                       }
+
+                       return NF_DROP;
+               }
+
+               /*
+                * If we are at INPUT the checksum must be recalculated since
+                * the length could change as the result of a defragmentation.
+                */
+               if(hooknum == NF_IP_LOCAL_IN) {
+                       iph->ttl = iph->ttl - 1;
+                       iph->check = 0;
+                       iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
+               } else {
+                       ip_decrease_ttl(iph);
+               }
+       }
+
+       if ((route_info->flags & IPT_ROUTE_TEE)) {
+               /*
+                * Copy the *pskb, and route the copy. Will later return
+                * IPT_CONTINUE for the original skb, which should continue
+                * on its way as if nothing happened. The copy should be
+                * independantly delivered to the ROUTE --gw.
+                */
+               skb = skb_copy(*pskb, GFP_ATOMIC);
+               if (!skb) {
+                       if (net_ratelimit())
+                               DEBUGP(KERN_DEBUG "ipt_ROUTE: copy failed!\n");
+                       return IPT_CONTINUE;
+               }
+       }
+
+       /* Tell conntrack to forget this packet since it may get confused
+        * when a packet is leaving with dst address == our address.
+        * Good idea ? Dunno. Need advice.
+        *
+        * NEW: mark the skb with our &route_tee_track, so we avoid looping
+        * on any already routed packet.
+        */
+       if (!(route_info->flags & IPT_ROUTE_CONTINUE)) {
+               nf_conntrack_put(skb->nfct);
+               skb->nfct = &route_tee_track.ct_general;
+               skb->nfctinfo = IP_CT_NEW;
+               nf_conntrack_get(skb->nfct);
+       }
+
+       if (route_info->oif[0] != '\0') {
+               res = route_oif(route_info, skb);
+       } else if (route_info->iif[0] != '\0') {
+               res = route_iif(route_info, skb);
+       } else if (route_info->gw) {
+               res = route_gw(route_info, skb);
+       } else {
+               if (net_ratelimit())
+                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no parameter !\n");
+               res = IPT_CONTINUE;
+       }
+
+       if ((route_info->flags & IPT_ROUTE_TEE))
+               res = IPT_CONTINUE;
+
+       return res;
+}
+
+
+static int ipt_route_checkentry(const char *tablename,
+                               const void *e,
+                               void *targinfo,
+                               unsigned int targinfosize,
+                               unsigned int hook_mask)
+{
+       if (strcmp(tablename, "mangle") != 0) {
+               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
+                      tablename);
+               return 0;
+       }
+
+       if (hook_mask & ~(  (1 << NF_IP_PRE_ROUTING)
+                           | (1 << NF_IP_LOCAL_IN)
+                           | (1 << NF_IP_FORWARD)
+                           | (1 << NF_IP_LOCAL_OUT)
+                           | (1 << NF_IP_POST_ROUTING))) {
+               printk("ipt_ROUTE: bad hook\n");
+               return 0;
+       }
+
+       if (targinfosize != IPT_ALIGN(sizeof(struct ipt_route_target_info))) {
+               printk(KERN_WARNING "ipt_ROUTE: targinfosize %u != %Zu\n",
+                      targinfosize,
+                      IPT_ALIGN(sizeof(struct ipt_route_target_info)));
+               return 0;
+       }
+
+       return 1;
+}
+
+
+static struct ipt_target ipt_route_reg = {
+       .name = "ROUTE",
+       .target = ipt_route_target,
+       .checkentry = ipt_route_checkentry,
+       .me = THIS_MODULE,
+};
+
+static int __init init(void)
+{
+       /* Set up fake conntrack (stolen from raw.patch):
+           - to never be deleted, not in any hashes */
+       atomic_set(&route_tee_track.ct_general.use, 1);
+       /*  - and look it like as a confirmed connection */
+       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
+       /* Initialize fake conntrack so that NAT will skip it */
+       route_tee_track.status |= IPS_NAT_DONE_MASK;
+
+       return ipt_register_target(&ipt_route_reg);
+}
+
+
+static void __exit fini(void)
+{
+       ipt_unregister_target(&ipt_route_reg);
+}
+
+module_init(init);
+module_exit(fini);
diff -u'rNF^function' linux-2.6.16.7/net/ipv6/ipv6_syms.c linux-2.6.16.7-ROUTE/net/ipv6/ipv6_syms.c
--- linux-2.6.16.7/net/ipv6/ipv6_syms.c 2006-04-17 23:53:25.000000000 +0200
+++ linux-2.6.16.7-ROUTE/net/ipv6/ipv6_syms.c   2006-06-14 17:02:32.000000000 +0200
@@ -12,6 +12,7 @@
 EXPORT_SYMBOL(icmpv6_statistics);
 EXPORT_SYMBOL(icmpv6_err_convert);
 EXPORT_SYMBOL(ndisc_mc_map);
+EXPORT_SYMBOL(nd_tbl);
 EXPORT_SYMBOL(register_inet6addr_notifier);
 EXPORT_SYMBOL(unregister_inet6addr_notifier);
 EXPORT_SYMBOL(ip6_route_output);
diff -u'rNF^function' linux-2.6.16.7/net/ipv6/netfilter/Kconfig linux-2.6.16.7-ROUTE/net/ipv6/netfilter/Kconfig
--- linux-2.6.16.7/net/ipv6/netfilter/Kconfig   2006-06-14 16:05:44.000000000 +0200
+++ linux-2.6.16.7-ROUTE/net/ipv6/netfilter/Kconfig     2006-06-14 16:45:45.000000000 +0200
@@ -182,6 +182,19 @@

          To compile it as a module, choose M here.  If unsure, say N.

+config IP6_NF_TARGET_ROUTE
+        tristate '    ROUTE target support'
+        depends on IP6_NF_MANGLE
+        help
+          This option adds a `ROUTE' target, which enables you to setup unusual
+          routes. The ROUTE target is also able to change the incoming interface
+          of a packet.
+
+          The target can be or not a final target. It has to be used inside the
+          mangle table.
+
+          Not working as a module.
+
 config IP6_NF_MANGLE
        tristate "Packet mangling"
        depends on IP6_NF_IPTABLES
diff -u'rNF^function' linux-2.6.16.7/net/ipv6/netfilter/Makefile linux-2.6.16.7-ROUTE/net/ipv6/netfilter/Makefile
--- linux-2.6.16.7/net/ipv6/netfilter/Makefile  2006-06-14 16:05:44.000000000 +0200
+++ linux-2.6.16.7-ROUTE/net/ipv6/netfilter/Makefile    2006-06-14 16:45:00.000000000 +0200
@@ -22,6 +22,7 @@
 obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
 obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
 obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
+obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o

 # objects for l3 independent conntrack
 nf_conntrack_ipv6-objs  :=  nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o nf_conntrack_reasm.o
diff -u'rNF^function' linux-2.6.16.7/net/ipv6/netfilter/ip6t_ROUTE.c linux-2.6.16.7-ROUTE/net/ipv6/netfilter/ip6t_ROUTE.c
--- linux-2.6.16.7/net/ipv6/netfilter/ip6t_ROUTE.c      1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.16.7-ROUTE/net/ipv6/netfilter/ip6t_ROUTE.c        2006-06-14 16:42:44.000000000 +0200
@@ -0,0 +1,308 @@
+/*
+ * This implements the ROUTE v6 target, which enables you to setup unusual
+ * routes not supported by the standard kernel routing table.
+ *
+ * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
+ *
+ * v 1.1 2004/11/23
+ *
+ * This software is distributed under GNU GPL v2, 1991
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ipv6.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
+#include <linux/netdevice.h>
+#include <net/ipv6.h>
+#include <net/ndisc.h>
+#include <net/ip6_route.h>
+#include <linux/icmpv6.h>
+
+#if 1
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+#define NIP6(addr) \
+       ntohs((addr).s6_addr16[0]), \
+       ntohs((addr).s6_addr16[1]), \
+       ntohs((addr).s6_addr16[2]), \
+       ntohs((addr).s6_addr16[3]), \
+       ntohs((addr).s6_addr16[4]), \
+       ntohs((addr).s6_addr16[5]), \
+       ntohs((addr).s6_addr16[6]), \
+       ntohs((addr).s6_addr16[7])
+
+/* Route the packet according to the routing keys specified in
+ * route_info. Keys are :
+ *  - ifindex :
+ *      0 if no oif preferred,
+ *      otherwise set to the index of the desired oif
+ *  - route_info->gw :
+ *      0 if no gateway specified,
+ *      otherwise set to the next host to which the pkt must be routed
+ * If success, skb->dev is the output device to which the packet must
+ * be sent and skb->dst is not NULL
+ *
+ * RETURN:  1 if the packet was succesfully routed to the
+ *            destination desired
+ *          0 if the kernel routing table could not route the packet
+ *            according to the keys specified
+ */
+static int
+route6(struct sk_buff *skb,
+       unsigned int ifindex,
+       const struct ip6t_route_target_info *route_info)
+{
+       struct rt6_info *rt = NULL;
+       struct ipv6hdr *ipv6h = skb->nh.ipv6h;
+       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
+
+       DEBUGP("ip6t_ROUTE: called with: ");
+       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
+       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
+       DEBUGP("OUT=%s\n", route_info->oif);
+
+       if (ipv6_addr_any(gw))
+               rt = rt6_lookup(&ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
+       else
+               rt = rt6_lookup(gw, &ipv6h->saddr, ifindex, 1);
+
+       if (!rt)
+               goto no_route;
+
+       DEBUGP("ip6t_ROUTE: routing gives: ");
+       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
+       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
+       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
+
+       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
+               goto wrong_route;
+
+       if (!rt->rt6i_nexthop) {
+               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
+               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
+       }
+
+       /* Drop old route. */
+       dst_release(skb->dst);
+       skb->dst = &rt->u.dst;
+       skb->dev = rt->rt6i_dev;
+       return 1;
+
+ wrong_route:
+       dst_release(&rt->u.dst);
+ no_route:
+       if (!net_ratelimit())
+               return 0;
+
+       printk("ip6t_ROUTE: no explicit route found ");
+       if (ifindex)
+               printk("via interface %s ", route_info->oif);
+       if (!ipv6_addr_any(gw))
+               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
+       printk("\n");
+       return 0;
+}
+
+
+/* Stolen from ip6_output_finish
+ * PRE : skb->dev is set to the device we are leaving by
+ *       skb->dst is not NULL
+ * POST: the packet is sent with the link layer header pushed
+ *       the packet is destroyed
+ */
+static void ip_direct_send(struct sk_buff *skb)
+{
+       struct dst_entry *dst = skb->dst;
+       struct hh_cache *hh = dst->hh;
+
+       if (hh) {
+               read_lock_bh(&hh->hh_lock);
+               memcpy(skb->data - 16, hh->hh_data, 16);
+               read_unlock_bh(&hh->hh_lock);
+               skb_push(skb, hh->hh_len);
+               hh->hh_output(skb);
+       } else if (dst->neighbour)
+               dst->neighbour->output(skb);
+       else {
+               if (net_ratelimit())
+                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
+               kfree_skb(skb);
+       }
+}
+
+
+static unsigned int
+route6_oif(const struct ip6t_route_target_info *route_info,
+          struct sk_buff *skb)
+{
+       unsigned int ifindex = 0;
+       struct net_device *dev_out = NULL;
+
+       /* The user set the interface name to use.
+        * Getting the current interface index.
+        */
+       if ((dev_out = dev_get_by_name(route_info->oif))) {
+               ifindex = dev_out->ifindex;
+       } else {
+               /* Unknown interface name : packet dropped */
+               if (net_ratelimit())
+                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
+
+               if (route_info->flags & IP6T_ROUTE_CONTINUE)
+                       return IP6T_CONTINUE;
+               else
+                       return NF_DROP;
+       }
+
+       /* Trying the standard way of routing packets */
+       if (route6(skb, ifindex, route_info)) {
+               dev_put(dev_out);
+               if (route_info->flags & IP6T_ROUTE_CONTINUE)
+                       return IP6T_CONTINUE;
+
+               ip_direct_send(skb);
+               return NF_STOLEN;
+       } else
+               return NF_DROP;
+}
+
+
+static unsigned int
+route6_gw(const struct ip6t_route_target_info *route_info,
+         struct sk_buff *skb)
+{
+       if (route6(skb, 0, route_info)) {
+               if (route_info->flags & IP6T_ROUTE_CONTINUE)
+                       return IP6T_CONTINUE;
+
+               ip_direct_send(skb);
+               return NF_STOLEN;
+       } else
+               return NF_DROP;
+}
+
+
+static unsigned int
+ip6t_route_target(struct sk_buff **pskb,
+                 const struct net_device *in,
+                 const struct net_device *out,
+                 unsigned int hooknum,
+                 const void *targinfo,
+                 void *userinfo)
+{
+       const struct ip6t_route_target_info *route_info = targinfo;
+       struct sk_buff *skb = *pskb;
+       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
+       unsigned int res;
+
+       if (route_info->flags & IP6T_ROUTE_CONTINUE)
+               goto do_it;
+
+       /* If we are at PREROUTING or INPUT hook
+        * the TTL isn't decreased by the IP stack
+        */
+       if (hooknum == NF_IP6_PRE_ROUTING ||
+           hooknum == NF_IP6_LOCAL_IN) {
+
+               struct ipv6hdr *ipv6h = skb->nh.ipv6h;
+
+               if (ipv6h->hop_limit <= 1) {
+                       /* Force OUTPUT device used as source address */
+                       skb->dev = skb->dst->dev;
+
+                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
+                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
+
+                       return NF_DROP;
+               }
+
+               ipv6h->hop_limit--;
+       }
+
+       if ((route_info->flags & IP6T_ROUTE_TEE)) {
+               /*
+                * Copy the *pskb, and route the copy. Will later return
+                * IP6T_CONTINUE for the original skb, which should continue
+                * on its way as if nothing happened. The copy should be
+                * independantly delivered to the ROUTE --gw.
+                */
+               skb = skb_copy(*pskb, GFP_ATOMIC);
+               if (!skb) {
+                       if (net_ratelimit())
+                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
+                       return IP6T_CONTINUE;
+               }
+       }
+
+do_it:
+       if (route_info->oif[0]) {
+               res = route6_oif(route_info, skb);
+       } else if (!ipv6_addr_any(gw)) {
+               res = route6_gw(route_info, skb);
+       } else {
+               if (net_ratelimit())
+                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
+               res = IP6T_CONTINUE;
+       }
+
+       if ((route_info->flags & IP6T_ROUTE_TEE))
+               res = IP6T_CONTINUE;
+
+       return res;
+}
+
+
+static int
+ip6t_route_checkentry(const char *tablename,
+                     const struct ip6t_entry *e,
+                     void *targinfo,
+                     unsigned int targinfosize,
+                     unsigned int hook_mask)
+{
+       if (strcmp(tablename, "mangle") != 0) {
+               printk("ip6t_ROUTE: can only be called from \"mangle\" table.\n");
+               return 0;
+       }
+
+       if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
+               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
+                      targinfosize,
+                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
+               return 0;
+       }
+
+       return 1;
+}
+
+
+static struct ip6t_target ip6t_route_reg = {
+       .name       = "ROUTE",
+       .target     = ip6t_route_target,
+       .checkentry = ip6t_route_checkentry,
+       .me         = THIS_MODULE
+};
+
+
+static int __init init(void)
+{
+       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
+       if (ip6t_register_target(&ip6t_route_reg))
+               return -EINVAL;
+
+       return 0;
+}
+
+
+static void __exit fini(void)
+{
+       ip6t_unregister_target(&ip6t_route_reg);
+}
+
+module_init(init);
+module_exit(fini);
+MODULE_LICENSE("GPL");

i wish you know how to do with this patch (throw it out of windowS?)

Attachments (0)

Change History (4)

comment:1 Changed 12 years ago by kaloz

  • Milestone set to 2.0

comment:2 Changed 12 years ago by florian

  • Owner changed from developers to florian
  • Status changed from new to assigned

comment:3 Changed 11 years ago by florian

  • Resolution set to fixed
  • Status changed from assigned to closed

Added in [4620], the kernel configuration has not been fully updated as you indicate (to have built-in route target for 2.6 kernels) because it depends on several other features that are compiled as modules yet.

comment:4 Changed 4 years ago by jow

  • Milestone changed from Attitude Adjustment 12.09 to Barrier Breaker 14.07

Milestone Attitude Adjustment 12.09 deleted

Add Comment

Modify Ticket

Action
as closed .
The resolution will be deleted. Next status will be 'reopened'.
Author


E-mail address and user name can be saved in the Preferences.

 
Note: See TracTickets for help on using tickets.