diff options
Diffstat (limited to 'br-nf-bds/patches/bridge-nf-0.0.7-bds-against-2.4.18.diff')
| -rw-r--r-- | br-nf-bds/patches/bridge-nf-0.0.7-bds-against-2.4.18.diff | 975 |
1 files changed, 975 insertions, 0 deletions
diff --git a/br-nf-bds/patches/bridge-nf-0.0.7-bds-against-2.4.18.diff b/br-nf-bds/patches/bridge-nf-0.0.7-bds-against-2.4.18.diff new file mode 100644 index 0000000..eb33426 --- /dev/null +++ b/br-nf-bds/patches/bridge-nf-0.0.7-bds-against-2.4.18.diff @@ -0,0 +1,975 @@ +All patches are the same as Lennert's 0.0.6 except the last patch +(br_netfilter.c). + +--- linux-2.4.18/include/linux/netfilter.h Thu Nov 22 20:47:48 2001 ++++ linux-2.4.18-brnf0.0.6/include/linux/netfilter.h Tue Feb 26 04:53:26 2002 +@@ -117,17 +117,23 @@ + /* This is gross, but inline doesn't cut it for avoiding the function + call in fast path: gcc doesn't inline (needs value tracking?). --RR */ + #ifdef CONFIG_NETFILTER_DEBUG +-#define NF_HOOK nf_hook_slow ++#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ ++ nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn), INT_MIN) ++#define NF_HOOK_THRESH nf_hook_slow + #else + #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ + (list_empty(&nf_hooks[(pf)][(hook)]) \ + ? (okfn)(skb) \ +- : nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn))) ++ : nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn), INT_MIN)) ++#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ ++(list_empty(&nf_hooks[(pf)][(hook)]) \ ++ ? (okfn)(skb) \ ++ : nf_hook_slow((pf), (hook), (skb), (indev), (outdev), (okfn), (thresh))) + #endif + + int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb, + struct net_device *indev, struct net_device *outdev, +- int (*okfn)(struct sk_buff *)); ++ int (*okfn)(struct sk_buff *), int thresh); + + /* Call setsockopt() */ + int nf_setsockopt(struct sock *sk, int pf, int optval, char *opt, +--- linux-2.4.18/include/linux/netfilter_ipv4.h Mon Feb 25 20:38:13 2002 ++++ linux-2.4.18-brnf0.0.6/include/linux/netfilter_ipv4.h Tue Feb 26 04:53:57 2002 +@@ -54,6 +54,7 @@ + NF_IP_PRI_CONNTRACK = -200, + NF_IP_PRI_MANGLE = -150, + NF_IP_PRI_NAT_DST = -100, ++ NF_IP_PRI_BRIDGE_SABOTAGE = -50, + NF_IP_PRI_FILTER = 0, + NF_IP_PRI_NAT_SRC = 100, + NF_IP_PRI_LAST = INT_MAX, +--- linux-2.4.18/include/linux/skbuff.h Thu Nov 22 20:46:26 2001 ++++ linux-2.4.18-brnf0.0.6/include/linux/skbuff.h Tue Feb 26 04:53:47 2002 +@@ -135,6 +135,8 @@ + struct sock *sk; /* Socket we are owned by */ + struct timeval stamp; /* Time we arrived */ + struct net_device *dev; /* Device we arrived on/are leaving by */ ++ struct net_device *physindev; /* Physical device we arrived on */ ++ struct net_device *physoutdev; /* Physical device we will leave by */ + + /* Transport layer header */ + union +--- linux-2.4.18/net/bridge/br.c Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/bridge/br.c Tue Feb 26 04:54:47 2002 +@@ -42,6 +42,11 @@ + { + printk(KERN_INFO "NET4: Ethernet Bridge 008 for NET4.0\n"); + ++#ifdef CONFIG_BRIDGE_NF ++ if (br_netfilter_init()) ++ return 1; ++#endif ++ + br_handle_frame_hook = br_handle_frame; + br_ioctl_hook = br_ioctl_deviceless_stub; + #if defined(CONFIG_ATM_LANE) || defined(CONFIG_ATM_LANE_MODULE) +@@ -65,6 +70,9 @@ + + static void __exit br_deinit(void) + { ++#ifdef CONFIG_BRIDGE_NF ++ br_netfilter_fini(); ++#endif + unregister_netdevice_notifier(&br_device_notifier); + br_call_ioctl_atomic(__br_clear_ioctl_hook); + net_call_rx_atomic(__br_clear_frame_hook); +--- linux-2.4.18/net/bridge/br_forward.c Wed Aug 15 10:54:35 2001 ++++ linux-2.4.18-brnf0.0.6/net/bridge/br_forward.c Tue Feb 26 04:54:15 2002 +@@ -30,7 +30,7 @@ + return 1; + } + +-static int __dev_queue_push_xmit(struct sk_buff *skb) ++int br_dev_queue_push_xmit(struct sk_buff *skb) + { + skb_push(skb, ETH_HLEN); + dev_queue_xmit(skb); +@@ -38,10 +38,10 @@ + return 0; + } + +-static int __br_forward_finish(struct sk_buff *skb) ++int br_forward_finish(struct sk_buff *skb) + { + NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, +- __dev_queue_push_xmit); ++ br_dev_queue_push_xmit); + + return 0; + } +@@ -54,7 +54,7 @@ + skb->dev = to->dev; + + NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, indev, skb->dev, +- __br_forward_finish); ++ br_forward_finish); + } + + static void __br_forward(struct net_bridge_port *to, struct sk_buff *skb) +@@ -65,7 +65,7 @@ + skb->dev = to->dev; + + NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, +- __br_forward_finish); ++ br_forward_finish); + } + + /* called under bridge lock */ +--- linux-2.4.18/net/bridge/br_input.c Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/bridge/br_input.c Tue Feb 26 04:54:24 2002 +@@ -46,7 +46,7 @@ + br_pass_frame_up_finish); + } + +-static int br_handle_frame_finish(struct sk_buff *skb) ++int br_handle_frame_finish(struct sk_buff *skb) + { + struct net_bridge *br; + unsigned char *dest; +--- linux-2.4.18/net/bridge/br_private.h Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/bridge/br_private.h Tue Feb 26 04:54:47 2002 +@@ -120,6 +120,7 @@ + extern void br_inc_use_count(void); + + /* br_device.c */ ++extern int br_dev_xmit(struct sk_buff *skb, struct net_device *dev); + extern void br_dev_setup(struct net_device *dev); + extern int br_dev_xmit(struct sk_buff *skb, struct net_device *dev); + +@@ -144,8 +145,10 @@ + /* br_forward.c */ + extern void br_deliver(struct net_bridge_port *to, + struct sk_buff *skb); ++extern int br_dev_queue_push_xmit(struct sk_buff *skb); + extern void br_forward(struct net_bridge_port *to, + struct sk_buff *skb); ++extern int br_forward_finish(struct sk_buff *skb); + extern void br_flood_deliver(struct net_bridge *br, + struct sk_buff *skb, + int clone); +@@ -166,6 +169,7 @@ + int *ifindices); + + /* br_input.c */ ++extern int br_handle_frame_finish(struct sk_buff *skb); + extern void br_handle_frame(struct sk_buff *skb); + + /* br_ioctl.c */ +@@ -177,6 +181,10 @@ + unsigned long arg2); + extern int br_ioctl_deviceless_stub(unsigned long arg); + ++/* br_netfilter.c */ ++extern int br_netfilter_init(void); ++extern void br_netfilter_fini(void); ++ + /* br_stp.c */ + extern int br_is_root_bridge(struct net_bridge *br); + extern struct net_bridge_port *br_get_port(struct net_bridge *br, +--- linux-2.4.18/net/bridge/Makefile Fri Dec 29 23:07:24 2000 ++++ linux-2.4.18-brnf0.0.6/net/bridge/Makefile Tue Feb 26 04:54:47 2002 +@@ -13,4 +13,6 @@ + br_stp_if.o br_stp_timer.o + obj-m := $(O_TARGET) + ++obj-$(CONFIG_BRIDGE_NF) += br_netfilter.o ++ + include $(TOPDIR)/Rules.make +--- linux-2.4.18/net/Config.in Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/Config.in Tue Feb 26 04:54:47 2002 +@@ -61,6 +61,9 @@ + fi + dep_tristate '802.1d Ethernet Bridging' CONFIG_BRIDGE $CONFIG_INET + if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then ++ if [ "$CONFIG_BRIDGE" != "n" -a "$CONFIG_NETFILTER" != "n" ]; then ++ bool ' netfilter (firewalling) support' CONFIG_BRIDGE_NF ++ fi + tristate 'CCITT X.25 Packet Layer (EXPERIMENTAL)' CONFIG_X25 + tristate 'LAPB Data Link Driver (EXPERIMENTAL)' CONFIG_LAPB + bool '802.2 LLC (EXPERIMENTAL)' CONFIG_LLC +--- linux-2.4.18/net/core/netfilter.c Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/core/netfilter.c Tue Feb 26 04:53:47 2002 +@@ -343,10 +343,15 @@ + const struct net_device *indev, + const struct net_device *outdev, + struct list_head **i, +- int (*okfn)(struct sk_buff *)) ++ int (*okfn)(struct sk_buff *), ++ int hook_thresh) + { + for (*i = (*i)->next; *i != head; *i = (*i)->next) { + struct nf_hook_ops *elem = (struct nf_hook_ops *)*i; ++ ++ if (hook_thresh > elem->priority) ++ continue; ++ + switch (elem->hook(hook, skb, indev, outdev, okfn)) { + case NF_QUEUE: + return NF_QUEUE; +@@ -414,6 +419,8 @@ + { + int status; + struct nf_info *info; ++ struct net_device *physindev; ++ struct net_device *physoutdev; + + if (!queue_handler[pf].outfn) { + kfree_skb(skb); +@@ -436,11 +443,16 @@ + if (indev) dev_hold(indev); + if (outdev) dev_hold(outdev); + ++ if ((physindev = skb->physindev)) dev_hold(physindev); ++ if ((physoutdev = skb->physoutdev)) dev_hold(physoutdev); ++ + status = queue_handler[pf].outfn(skb, info, queue_handler[pf].data); + if (status < 0) { + /* James M doesn't say fuck enough. */ + if (indev) dev_put(indev); + if (outdev) dev_put(outdev); ++ if (physindev) dev_put(physindev); ++ if (physoutdev) dev_put(physoutdev); + kfree(info); + kfree_skb(skb); + return; +@@ -450,7 +462,8 @@ + int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb, + struct net_device *indev, + struct net_device *outdev, +- int (*okfn)(struct sk_buff *)) ++ int (*okfn)(struct sk_buff *), ++ int hook_thresh) + { + struct list_head *elem; + unsigned int verdict; +@@ -482,7 +495,7 @@ + + elem = &nf_hooks[pf][hook]; + verdict = nf_iterate(&nf_hooks[pf][hook], &skb, hook, indev, +- outdev, &elem, okfn); ++ outdev, &elem, okfn, hook_thresh); + if (verdict == NF_QUEUE) { + NFDEBUG("nf_hook: Verdict = QUEUE.\n"); + nf_queue(skb, elem, pf, hook, indev, outdev, okfn); +@@ -531,7 +544,7 @@ + verdict = nf_iterate(&nf_hooks[info->pf][info->hook], + &skb, info->hook, + info->indev, info->outdev, &elem, +- info->okfn); ++ info->okfn, INT_MIN); + } + + switch (verdict) { +--- linux-2.4.18/net/core/skbuff.c Fri Dec 21 18:42:05 2001 ++++ linux-2.4.18-brnf0.0.6/net/core/skbuff.c Tue Feb 26 04:53:47 2002 +@@ -231,6 +231,8 @@ + skb->sk = NULL; + skb->stamp.tv_sec=0; /* No idea about time */ + skb->dev = NULL; ++ skb->physindev = NULL; ++ skb->physoutdev = NULL; + skb->dst = NULL; + memset(skb->cb, 0, sizeof(skb->cb)); + skb->pkt_type = PACKET_HOST; /* Default type */ +@@ -362,6 +364,8 @@ + n->sk = NULL; + C(stamp); + C(dev); ++ C(physindev); ++ C(physoutdev); + C(h); + C(nh); + C(mac); +@@ -417,6 +421,8 @@ + new->list=NULL; + new->sk=NULL; + new->dev=old->dev; ++ new->physindev=old->physindev; ++ new->physoutdev=old->physoutdev; + new->priority=old->priority; + new->protocol=old->protocol; + new->dst=dst_clone(old->dst); +--- linux-2.4.18/net/ipv4/ip_output.c Tue Feb 26 04:52:58 2002 ++++ linux-2.4.18-brnf0.0.6/net/ipv4/ip_output.c Tue Feb 26 04:53:47 2002 +@@ -819,6 +819,8 @@ + skb_set_owner_w(skb2, skb->sk); + skb2->dst = dst_clone(skb->dst); + skb2->dev = skb->dev; ++ skb2->physindev = skb->physindev; ++ skb2->physoutdev = skb->physoutdev; + + /* + * Copy the packet header into the new buffer. +@@ -882,6 +884,7 @@ + iph->tot_len = htons(len + hlen); + + ip_send_check(iph); ++ memcpy(skb2->data - 16, skb->data - 16, 16); + + err = output(skb2); + if (err) +--- linux-2.4.18/net/ipv4/netfilter/ip_tables.c Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/ipv4/netfilter/ip_tables.c Tue Feb 26 04:53:52 2002 +@@ -121,12 +121,15 @@ + static inline int + ip_packet_match(const struct iphdr *ip, + const char *indev, ++ const char *physindev, + const char *outdev, ++ const char *physoutdev, + const struct ipt_ip *ipinfo, + int isfrag) + { + size_t i; + unsigned long ret; ++ unsigned long ret2; + + #define FWINV(bool,invflg) ((bool) ^ !!(ipinfo->invflags & invflg)) + +@@ -156,7 +159,13 @@ + & ((const unsigned long *)ipinfo->iniface_mask)[i]; + } + +- if (FWINV(ret != 0, IPT_INV_VIA_IN)) { ++ for (i = 0, ret2 = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { ++ ret2 |= (((const unsigned long *)physindev)[i] ++ ^ ((const unsigned long *)ipinfo->iniface)[i]) ++ & ((const unsigned long *)ipinfo->iniface_mask)[i]; ++ } ++ ++ if (FWINV(ret != 0 && ret2 != 0, IPT_INV_VIA_IN)) { + dprintf("VIA in mismatch (%s vs %s).%s\n", + indev, ipinfo->iniface, + ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":""); +@@ -169,7 +178,13 @@ + & ((const unsigned long *)ipinfo->outiface_mask)[i]; + } + +- if (FWINV(ret != 0, IPT_INV_VIA_OUT)) { ++ for (i = 0, ret2 = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { ++ ret2 |= (((const unsigned long *)physoutdev)[i] ++ ^ ((const unsigned long *)ipinfo->outiface)[i]) ++ & ((const unsigned long *)ipinfo->outiface_mask)[i]; ++ } ++ ++ if (FWINV(ret != 0 && ret2 != 0, IPT_INV_VIA_OUT)) { + dprintf("VIA out mismatch (%s vs %s).%s\n", + outdev, ipinfo->outiface, + ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":""); +@@ -268,6 +283,7 @@ + /* Initializing verdict to NF_DROP keeps gcc happy. */ + unsigned int verdict = NF_DROP; + const char *indev, *outdev; ++ const char *physindev, *physoutdev; + void *table_base; + struct ipt_entry *e, *back; + +@@ -277,6 +293,9 @@ + datalen = (*pskb)->len - ip->ihl * 4; + indev = in ? in->name : nulldevname; + outdev = out ? out->name : nulldevname; ++ physindev = (*pskb)->physindev ? (*pskb)->physindev->name : nulldevname; ++ physoutdev = (*pskb)->physoutdev ? (*pskb)->physoutdev->name : nulldevname; ++ + /* We handle fragments by dealing with the first fragment as + * if it was a normal packet. All other fragments are treated + * normally, except that they will NEVER match rules that ask +@@ -312,7 +331,7 @@ + IP_NF_ASSERT(e); + IP_NF_ASSERT(back); + (*pskb)->nfcache |= e->nfcache; +- if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) { ++ if (ip_packet_match(ip, indev, physindev, outdev, physoutdev, &e->ip, offset)) { + struct ipt_entry_target *t; + + if (IPT_MATCH_ITERATE(e, do_match, +--- linux-2.4.18/net/ipv4/netfilter/ipt_LOG.c Mon Feb 25 20:38:14 2002 ++++ linux-2.4.18-brnf0.0.6/net/ipv4/netfilter/ipt_LOG.c Tue Feb 26 04:54:03 2002 +@@ -285,10 +285,13 @@ + level_string[1] = '0' + (loginfo->level % 8); + spin_lock_bh(&log_lock); + printk(level_string); +- printk("%sIN=%s OUT=%s ", +- loginfo->prefix, +- in ? in->name : "", +- out ? out->name : ""); ++ printk("%sIN=%s ", loginfo->prefix, in ? in->name : ""); ++ if ((*pskb)->physindev && in != (*pskb)->physindev) ++ printk("PHYSIN=%s ", (*pskb)->physindev->name); ++ printk("OUT=%s ", out ? out->name : ""); ++ if ((*pskb)->physoutdev && out != (*pskb)->physoutdev) ++ printk("PHYSOUT=%s ", (*pskb)->physoutdev->name); ++ + if (in && !out) { + /* MAC logging for input chain only. */ + printk("MAC="); +--- /dev/null Thu Aug 24 11:00:32 2000 ++++ bridge-nf-0.0.7-bds/net/bridge/br_netfilter.c Fri Apr 26 22:56:26 2002 +@@ -0,0 +1,565 @@ ++/* ++ * Handle firewalling ++ * Linux ethernet bridge ++ * ++ * Authors: ++ * Lennert Buytenhek <buytenh@gnu.org> ++ * Bart De Schuymer <bart.de.schuymer@pandora.be> ++ * ++ * $Id: bridge-nf-0.0.7-bds-against-2.4.18.diff,v 1.1 2002/06/01 19:23:59 bdschuym Exp $ ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public License ++ * as published by the Free Software Foundation; either version ++ * 2 of the License, or (at your option) any later version. ++ * ++ * Lennert dedicates this file to Kerstin Wurdinger. ++ */ ++ ++#include <linux/module.h> ++#include <linux/kernel.h> ++#include <linux/ip.h> ++#include <linux/netdevice.h> ++#include <linux/skbuff.h> ++#include <linux/if_ether.h> ++#include <linux/netfilter_bridge.h> ++#include <linux/netfilter_ipv4.h> ++#include <linux/in_route.h> ++#include <net/ip.h> ++#include <net/tcp.h> ++#include <asm/uaccess.h> ++#include <asm/checksum.h> ++#include "br_private.h" ++ ++ ++#ifndef WE_REALLY_INSIST_ON_NOT_HAVING_NAT_SUPPORT ++/* As the original source/destination addresses are variables private to this ++ * file, we store them in unused space at the end of the control buffer. ++ * On 64-bit platforms the TCP control buffer size still leaves us 8 bytes ++ * of space at the end, so that fits. Usage of the original source address ++ * and the original destination address never overlaps (daddr is needed ++ * around PRE_ROUTING, and saddr around POST_ROUTING), so that's okay as ++ * well. ++ */ ++#define skb_origaddr(skb) (*((u32 *)((skb)->cb + sizeof((skb)->cb) - 4))) ++ ++#define store_orig_dstaddr(skb) (skb_origaddr(skb) = (skb)->nh.iph->daddr) ++#define store_orig_srcaddr(skb) (skb_origaddr(skb) = (skb)->nh.iph->saddr) ++#define dnat_took_place(skb) (skb_origaddr(skb) != (skb)->nh.iph->daddr) ++#define snat_took_place(skb) (skb_origaddr(skb) != (skb)->nh.iph->saddr) ++#else ++#define store_orig_dstaddr(skb) ++#define store_orig_srcaddr(skb) ++#define dnat_took_place(skb) (0) ++#define snat_took_place(skb) (0) ++#endif ++ ++ ++#define has_bridge_parent(device) ((device)->br_port != NULL) ++#define bridge_parent(device) (&((device)->br_port->br->dev)) ++ ++ ++/* As opposed to the DNAT case, for the SNAT case it's not quite ++ * clear what we should do with ethernet addresses in NAT'ed ++ * packets. Use this heuristic for now. ++ */ ++static inline void __maybe_fixup_src_address(struct sk_buff *skb) ++{ ++ if (snat_took_place(skb) && ++ inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) { ++ memcpy(skb->mac.ethernet->h_source, ++ bridge_parent(skb->dev)->dev_addr, ++ ETH_ALEN); ++ } ++} ++ ++ ++/* We need these fake structures to make netfilter happy -- ++ * lots of places assume that skb->dst != NULL, which isn't ++ * all that unreasonable. ++ * ++ * Currently, we fill in the PMTU entry because netfilter ++ * refragmentation needs it, and the rt_flags entry because ++ * ipt_REJECT needs it. Future netfilter modules might ++ * require us to fill additional fields. ++ */ ++static struct net_device __fake_net_device = { ++ hard_header_len: ETH_HLEN ++}; ++ ++static struct rtable __fake_rtable = { ++ u: { ++ dst: { ++ __refcnt: ATOMIC_INIT(1), ++ dev: &__fake_net_device, ++ pmtu: 1500 ++ } ++ }, ++ ++ rt_flags: 0 ++}; ++ ++ ++/* PF_BRIDGE/PRE_ROUTING *********************************************/ ++static void __br_dnat_complain(void) ++{ ++ static unsigned long last_complaint = 0; ++ ++ if (jiffies - last_complaint >= 5 * HZ) { ++ printk(KERN_WARNING "Performing cross-bridge DNAT requires IP " ++ "forwarding to be enabled\n"); ++ last_complaint = jiffies; ++ } ++} ++ ++ ++static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) ++{ ++ skb->dev = bridge_parent(skb->dev); ++ skb->dst->output(skb); ++ return 0; ++} ++ ++/* This requires some explaining. If DNAT has taken place, ++ * we will need to fix up the destination ethernet address, ++ * and this is a tricky process. ++ * ++ * There are two cases to consider: ++ * 1. The packet was DNAT'ed to a device in the same bridge ++ * port group as it was received on. We can still bridge ++ * the packet. ++ * 2. The packet was DNAT'ed to a different device, either ++ * a non-bridged device or another bridge port group. ++ * The packet will need to be routed. ++ * ++ * The way to distinguish between the two is by calling ip_route_input() ++ * and looking at skb->dst->dev, which it changed to the destination device ++ * if ip_route_input() succeeds. ++ * ++ * Let us first consider ip_route_input() succeeds: ++ * ++ * If skb->dst->dev equals the logical bridge device the packet came in on, ++ * we can consider this bridging. We then call skb->dst->output() which will ++ * make the packet enter br_nf_local_out() not much later. In that function ++ * it is assured that the iptables FORWARD chain is traversed for the packet. ++ * ++ * Else, the packet is considered to be routed and we just change the ++ * destination MAC address so that the packet will later be passed up to the ip ++ * stack to be routed. ++ * ++ * Let us now consider ip_route_input() fails: ++ * ++ * After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input() will ++ * fail, while ip_route_output() will return success. The source address for ++ * for ip_route_output() is set to zero, so ip_route_output() ++ * thinks we're handling a locally generated packet and won't care if ++ * ip forwarding is allowed. We send a warning message to the users's log ++ * telling her to put ip forwarding on. ++ * ++ * ip_route_input() will also fail if there is no route available. Then we just ++ * drop the packet. ++ * ++ * The other special thing happening here is putting skb->physoutdev on ++ * &__fake_net_device (resp. NULL) for bridged (resp. routed) packets. This is ++ * needed so that br_nf_local_out() can know that it has to give the packets to ++ * the BR_NF_FORWARD (resp. BR_NF_LOCAL_OUT) bridge hook. See that function. ++ * --Lennert, 20020411 ++ * --Bart, 20020416 (updated) ++ */ ++ ++static int br_nf_pre_routing_finish(struct sk_buff *skb) ++{ ++ struct net_device *dev = skb->dev; ++ struct iphdr *iph = skb->nh.iph; ++ ++ if (dnat_took_place(skb)) { ++ if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev)) { ++ struct rtable *rt; ++ ++ if (!ip_route_output(&rt, iph->daddr, 0, iph->tos, 0)) { ++ // bridged dnated traffic isn't dependent on ++ // disabled ip_forwarding ++ if (((struct dst_entry *)rt)->dev == dev) { ++ skb->dst = (struct dst_entry *)rt; ++ goto bridged_dnat; ++ } ++ __br_dnat_complain(); ++ dst_release((struct dst_entry *)rt); ++ } ++ kfree_skb(skb); ++ return 0; ++ } else { ++ if (skb->dst->dev == dev) { ++bridged_dnat: ++ // tell br_nf_local_out this is a bridged frame ++ skb->physoutdev = &__fake_net_device; ++ skb->dev = skb->physindev; ++ NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, ++ br_nf_pre_routing_finish_bridge, 1); ++ return 0; ++ } ++ // tell br_nf_local_out this is a routed frame ++ skb->physoutdev = NULL; ++ memcpy(skb->mac.ethernet->h_dest, dev->dev_addr, ETH_ALEN); ++ } ++ } else { ++ skb->dst = (struct dst_entry *)&__fake_rtable; ++ dst_hold(skb->dst); ++ } ++ ++ skb->dev = skb->physindev; ++ NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, ++ br_handle_frame_finish, 1); ++ ++ return 0; ++} ++ ++/* Replicate the checks that IPv4 does on packet reception. ++ * Set skb->dev to the bridge device (i.e. parent of the ++ * receiving device) to make netfilter happy, the REDIRECT ++ * target in particular. Save the original destination IP ++ * address to be able to detect DNAT afterwards. ++ */ ++static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) ++{ ++ struct iphdr *iph; ++ __u32 len; ++ struct sk_buff *skb; ++ ++ if ((*pskb)->protocol != __constant_htons(ETH_P_IP)) ++ return NF_ACCEPT; ++ ++ if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL) ++ goto out; ++ ++ if (!pskb_may_pull(skb, sizeof(struct iphdr))) ++ goto inhdr_error; ++ ++ iph = skb->nh.iph; ++ if (iph->ihl < 5 || iph->version != 4) ++ goto inhdr_error; ++ ++ if (!pskb_may_pull(skb, 4*iph->ihl)) ++ goto inhdr_error; ++ ++ iph = skb->nh.iph; ++ if (ip_fast_csum((__u8 *)iph, iph->ihl) != 0) ++ goto inhdr_error; ++ ++ len = ntohs(iph->tot_len); ++ if (skb->len < len || len < 4*iph->ihl) ++ goto inhdr_error; ++ ++ if (skb->len > len) { ++ __pskb_trim(skb, len); ++ if (skb->ip_summed == CHECKSUM_HW) ++ skb->ip_summed = CHECKSUM_NONE; ++ } ++ ++ skb->physindev = skb->dev; ++ skb->dev = bridge_parent(skb->dev); ++ if (skb->pkt_type == PACKET_OTHERHOST) ++ skb->pkt_type = PACKET_HOST; ++ store_orig_dstaddr(skb); ++ NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL, ++ br_nf_pre_routing_finish); ++ ++ return NF_STOLEN; ++ ++inhdr_error: ++// IP_INC_STATS_BH(IpInHdrErrors); ++out: ++ return NF_DROP; ++} ++ ++ ++/* PF_BRIDGE/LOCAL_IN ************************************************/ ++/* The packet is locally destined, which requires a real ++ * dst_entry, so detach the fake one. On the way up, the ++ * packet would pass through PRE_ROUTING again (which already ++ * took place when the packet entered the bridge), but we ++ * register an IPv4 PRE_ROUTING 'sabotage' hook that will ++ * prevent this from happening. ++ */ ++static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) ++{ ++ struct sk_buff *skb = *pskb; ++ ++ if (skb->protocol != __constant_htons(ETH_P_IP)) ++ return NF_ACCEPT; ++ ++ if (skb->dst == (struct dst_entry *)&__fake_rtable) { ++ dst_release(skb->dst); ++ skb->dst = NULL; ++ } ++ ++ return NF_ACCEPT; ++} ++ ++ ++/* PF_BRIDGE/FORWARD *************************************************/ ++static int br_nf_forward_finish(struct sk_buff *skb) ++{ ++ NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, skb->physindev, ++ skb->dev, br_forward_finish, 1); ++ ++ return 0; ++} ++ ++/* This is the 'purely bridged' case. We pass the packet to ++ * netfilter with indev and outdev set to the bridge device, ++ * but we are still able to filter on the 'real' indev/outdev ++ * because another bit of the bridge-nf patch overloads the ++ * '-i' and '-o' iptables interface checks to take ++ * skb->phys{in,out}dev into account as well (so both the real ++ * device and the bridge device will match). ++ */ ++static unsigned int br_nf_forward(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) ++{ ++ struct sk_buff *skb = *pskb; ++ ++ // don't mess with non-ip frames, also don't mess with the ip-packets ++ // when br_nf_local_out_finish explicitly says so. ++ if (skb->protocol != __constant_htons(ETH_P_IP) || skb->physindev == NULL) ++ return NF_ACCEPT; ++ ++ skb->physoutdev = skb->dev; ++ NF_HOOK(PF_INET, NF_IP_FORWARD, skb, bridge_parent(skb->physindev), ++ bridge_parent(skb->dev), br_nf_forward_finish); ++ ++ return NF_STOLEN; ++} ++ ++ ++/* PF_BRIDGE/LOCAL_OUT ***********************************************/ ++static int br_nf_local_out_finish_forward(struct sk_buff *skb) ++{ ++ struct net_device *dev; ++ ++ dev = skb->physindev; ++ // tell br_nf_forward to stay away ++ skb->physindev = NULL; ++ NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, dev, skb->dev, ++ br_forward_finish); ++ ++ return 0; ++} ++ ++static int br_nf_local_out_finish(struct sk_buff *skb) ++{ ++ NF_HOOK_THRESH(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, ++ br_forward_finish, INT_MIN + 1); ++ ++ return 0; ++} ++ ++ ++/* This hook sees both locally originated IP packets and forwarded ++ * IP packets (in both cases the destination device is a bridge ++ * device). For the sake of interface transparency (i.e. properly ++ * overloading the '-o' option), we steal packets destined to ++ * a bridge device away from the IPv4 FORWARD and OUTPUT hooks, ++ * and reinject them later, when we have determined the real ++ * output device. This reinjecting happens here. ++ * ++ * If skb->physindev is NULL, the bridge-nf code never touched ++ * this packet before, and so the packet was locally originated. ++ * We call the IPv4 LOCAL_OUT hook. ++ * ++ * If skb->physindev isn't NULL, there are two cases: ++ * 1. The packet was IP routed. ++ * 2. The packet was cross-bridge DNAT'ed (see the comment near ++ * PF_BRIDGE/PRE_ROUTING). ++ * In both cases, we call the IPv4 FORWARD hook. In case 1, ++ * if the packet originally came from a bridge device, and in ++ * case 2, skb->physindev will have a bridge device as parent, ++ * so we use that parent device as indev. Otherwise, we just ++ * use physindev. ++ * ++ * If skb->physoutdev == NULL the bridge code never touched the ++ * packet or the packet was routed in br_nf_pre_routing_finish(). ++ * We give the packet to the bridge NF_BR_LOCAL_OUT hook. ++ * If not, the packet is actually a bridged one so we give it to ++ * the NF_BR_FORWARD hook. ++ */ ++ ++static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*_okfn)(struct sk_buff *)) ++{ ++ int hookno; ++ int (*okfn)(struct sk_buff *skb); ++ struct net_device *realindev; ++ struct sk_buff *skb = *pskb; ++ ++ if (skb->protocol != __constant_htons(ETH_P_IP)) ++ return NF_ACCEPT; ++ ++ /* Sometimes we get packets with NULL ->dst here (for example, ++ * running a dhcp client daemon triggers this). ++ */ ++ if (skb->dst == NULL) ++ return NF_ACCEPT; ++ ++ // bridged, take forward ++ // (see big note in front of br_nf_pre_routing_finish) ++ if (skb->physoutdev == &__fake_net_device) { ++ okfn = br_nf_local_out_finish_forward; ++ } else if (skb->physoutdev == NULL) { ++ // non-bridged: routed or locally generated traffic, take local_out ++ // (see big note in front of br_nf_pre_routing_finish) ++ okfn = br_nf_local_out_finish; ++ } else { ++ printk("ARGH: bridge_or_routed hack doesn't work\n"); ++ okfn = br_nf_local_out_finish; ++ } ++ ++ skb->physoutdev = skb->dev; ++ ++ hookno = NF_IP_LOCAL_OUT; ++ if ((realindev = skb->physindev) != NULL) { ++ hookno = NF_IP_FORWARD; ++ if (has_bridge_parent(realindev)) ++ realindev = bridge_parent(realindev); ++ } ++ ++ NF_HOOK_THRESH(PF_INET, hookno, skb, realindev, ++ bridge_parent(skb->dev), ++ okfn, ++ NF_IP_PRI_BRIDGE_SABOTAGE + 1); ++ ++ return NF_STOLEN; ++} ++ ++ ++/* PF_BRIDGE/POST_ROUTING ********************************************/ ++static int br_nf_post_routing_finish(struct sk_buff *skb) ++{ ++ __maybe_fixup_src_address(skb); ++ NF_HOOK_THRESH(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, ++ bridge_parent(skb->dev), br_dev_queue_push_xmit, 1); ++ ++ return 0; ++} ++ ++static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) ++{ ++ struct sk_buff *skb = *pskb; ++ ++ /* Be very paranoid. */ ++ if (skb->mac.raw < skb->head || skb->mac.raw + ETH_HLEN > skb->data) { ++ printk(KERN_CRIT "Argh!! Fuck me harder with a chainsaw. "); ++ if (skb->dev != NULL) { ++ printk("[%s]", skb->dev->name); ++ if (has_bridge_parent(skb->dev)) ++ printk("[%s]", bridge_parent(skb->dev)->name); ++ } ++ printk("\n"); ++ return NF_ACCEPT; ++ } ++ ++ if (skb->protocol != __constant_htons(ETH_P_IP)) ++ return NF_ACCEPT; ++ ++ /* Sometimes we get packets with NULL ->dst here (for example, ++ * running a dhcp client daemon triggers this). ++ */ ++ if (skb->dst == NULL) ++ return NF_ACCEPT; ++ ++ store_orig_srcaddr(skb); ++ NF_HOOK(PF_INET, NF_IP_POST_ROUTING, skb, NULL, ++ bridge_parent(skb->dev), br_nf_post_routing_finish); ++ ++ return NF_STOLEN; ++} ++ ++ ++/* IPv4/SABOTAGE *****************************************************/ ++/* Don't hand locally destined packets to PF_INET/PRE_ROUTING ++ * for the second time. */ ++static unsigned int ipv4_sabotage_in(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) ++{ ++ if (in->hard_start_xmit == br_dev_xmit && ++ okfn != br_nf_pre_routing_finish) { ++ okfn(*pskb); ++ return NF_STOLEN; ++ } ++ ++ return NF_ACCEPT; ++} ++ ++/* Postpone execution of PF_INET/FORWARD, PF_INET/LOCAL_OUT ++ * and PF_INET/POST_ROUTING until we have done the forwarding ++ * decision in the bridge code and have determined skb->physoutdev. ++ */ ++static unsigned int ipv4_sabotage_out(unsigned int hook, struct sk_buff **pskb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) ++{ ++ if (out->hard_start_xmit == br_dev_xmit && ++ okfn != br_nf_forward_finish && ++ okfn != br_nf_local_out_finish && ++ okfn != br_nf_post_routing_finish) { ++ struct sk_buff *skb = *pskb; ++ ++ if (hook == NF_IP_FORWARD && skb->physindev == NULL) ++ skb->physindev = (struct net_device *)in; ++ okfn(skb); ++ return NF_STOLEN; ++ } ++ ++ return NF_ACCEPT; ++} ++ ++ ++static struct nf_hook_ops br_nf_ops[] = { ++ { { NULL, NULL }, br_nf_pre_routing, PF_BRIDGE, NF_BR_PRE_ROUTING, 0 }, ++ { { NULL, NULL }, br_nf_local_in, PF_BRIDGE, NF_BR_LOCAL_IN, 0 }, ++ { { NULL, NULL }, br_nf_forward, PF_BRIDGE, NF_BR_FORWARD, 0 }, ++ // we need INT_MIN, so innocent NF_BR_LOCAL_OUT functions don't ++ // get bridged traffic as input ++ { { NULL, NULL }, br_nf_local_out, PF_BRIDGE, NF_BR_LOCAL_OUT, INT_MIN }, ++ { { NULL, NULL }, br_nf_post_routing, PF_BRIDGE, NF_BR_POST_ROUTING, 0 }, ++ ++ { { NULL, NULL }, ipv4_sabotage_in, PF_INET, NF_IP_PRE_ROUTING, NF_IP_PRI_FIRST }, ++ ++ { { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_FORWARD, NF_IP_PRI_BRIDGE_SABOTAGE }, ++ { { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_LOCAL_OUT, NF_IP_PRI_BRIDGE_SABOTAGE }, ++ { { NULL, NULL }, ipv4_sabotage_out, PF_INET, NF_IP_POST_ROUTING, NF_IP_PRI_FIRST }, ++}; ++ ++#define NUMHOOKS (sizeof(br_nf_ops)/sizeof(br_nf_ops[0])) ++ ++ ++int br_netfilter_init(void) ++{ ++ int i; ++ ++#ifndef WE_REALLY_INSIST_ON_NOT_HAVING_NAT_SUPPORT ++ if (sizeof(struct tcp_skb_cb) + 4 >= sizeof(((struct sk_buff *)NULL)->cb)) { ++ extern int __too_little_space_in_control_buffer(void); ++ __too_little_space_in_control_buffer(); ++ } ++#endif ++ ++ for (i=0;i<NUMHOOKS;i++) { ++ int ret; ++ ++ if ((ret = nf_register_hook(&br_nf_ops[i])) >= 0) ++ continue; ++ ++ while (i--) ++ nf_unregister_hook(&br_nf_ops[i]); ++ ++ return ret; ++ } ++ ++ printk(KERN_NOTICE "Bridge firewalling registered\n"); ++ ++ return 0; ++} ++ ++void br_netfilter_fini(void) ++{ ++ int i; ++ ++ for (i=NUMHOOKS-1;i>=0;i--) ++ nf_unregister_hook(&br_nf_ops[i]); ++} |