1 files changed, 611 insertions, 0 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
new file mode 100644
index 000000000000..563e7d612706
--- /dev/null
+++ b/net/ipv4/fib_frontend.c
@@ -0,0 +1,611 @@
+/*
+ * INET         An implementation of the TCP/IP protocol suite for the LINUX
+ *              operating system.  INET is implemented using the  BSD Socket
+ *              interface as the means of communication with the user level.
+ *
+ *              IPv4 Forwarding Information Base: FIB frontend.
+ *
+ * Version:     $Id: fib_frontend.c,v 1.26 2001/10/31 21:55:54 davem Exp $
+ *
+ * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *              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.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+#include <linux/init.h>
+
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/sock.h>
+#include <net/icmp.h>
+#include <net/arp.h>
+#include <net/ip_fib.h>
+
+#define FFprint(a...) printk(KERN_DEBUG a)
+
+#ifndef CONFIG_IP_MULTIPLE_TABLES
+
+#define RT_TABLE_MIN RT_TABLE_MAIN
+
+struct fib_table *ip_fib_local_table;
+struct fib_table *ip_fib_main_table;
+
+#else
+
+#define RT_TABLE_MIN 1
+
+struct fib_table *fib_tables[RT_TABLE_MAX+1];
+
+struct fib_table *__fib_new_table(int id)
+{
+        struct fib_table *tb;
+
+        tb = fib_hash_init(id);
+        if (!tb)
+                return NULL;
+        fib_tables[id] = tb;
+        return tb;
+}
+
+
+#endif /* CONFIG_IP_MULTIPLE_TABLES */
+
+
+static void fib_flush(void)
+{
+        int flushed = 0;
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+        struct fib_table *tb;
+        int id;
+
+        for (id = RT_TABLE_MAX; id>0; id--) {
+                if ((tb = fib_get_table(id))==NULL)
+                        continue;
+                flushed += tb->tb_flush(tb);
+        }
+#else /* CONFIG_IP_MULTIPLE_TABLES */
+        flushed += ip_fib_main_table->tb_flush(ip_fib_main_table);
+        flushed += ip_fib_local_table->tb_flush(ip_fib_local_table);
+#endif /* CONFIG_IP_MULTIPLE_TABLES */
+
+        if (flushed)
+                rt_cache_flush(-1);
+}
+
+/*
+ *      Find the first device with a given source address.
+ */
+
+struct net_device * ip_dev_find(u32 addr)
+{
+        struct flowi fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
+        struct fib_result res;
+        struct net_device *dev = NULL;
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+        res.r = NULL;
+#endif
+
+        if (!ip_fib_local_table ||
+            ip_fib_local_table->tb_lookup(ip_fib_local_table, &fl, &res))
+                return NULL;
+        if (res.type != RTN_LOCAL)
+                goto out;
+        dev = FIB_RES_DEV(res);
+
+        if (dev)
+                dev_hold(dev);
+out:
+        fib_res_put(&res);
+        return dev;
+}
+
+unsigned inet_addr_type(u32 addr)
+{
+        struct flowi            fl = { .nl_u = { .ip4_u = { .daddr = addr } } };
+        struct fib_result       res;
+        unsigned ret = RTN_BROADCAST;
+
+        if (ZERONET(addr) || BADCLASS(addr))
+                return RTN_BROADCAST;
+        if (MULTICAST(addr))
+                return RTN_MULTICAST;
+
+#ifdef CONFIG_IP_MULTIPLE_TABLES
+        res.r = NULL;
+#endif
+        
+        if (ip_fib_local_table) {
+                ret = RTN_UNICAST;
+                if (!ip_fib_local_table->tb_lookup(ip_fib_local_table,
+                                                   &fl, &res)) {
+                        ret = res.type;
+                        fib_res_put(&res);
+                }
+        }
+        return ret;
+}
+
+/* Given (packet source, input interface) and optional (dst, oif, tos):
+   - (main) check, that source is valid i.e. not broadcast or our local
+     address.
+   - figure out what "logical" interface this packet arrived
+     and calculate "specific destination" address.
+   - check, that packet arrived from expected physical interface.
+ */
+
+int fib_validate_source(u32 src, u32 dst, u8 tos, int oif,
+                        struct net_device *dev, u32 *spec_dst, u32 *itag)
+{
+        struct in_device *in_dev;
+        struct flowi fl = { .nl_u = { .ip4_u =
+                                      { .daddr = src,
+                                        .saddr = dst,
+                                        .tos = tos } },
+                            .iif = oif };
+        struct fib_result res;
+        int no_addr, rpf;
+        int ret;
+
+        no_addr = rpf = 0;
+        rcu_read_lock();
+        in_dev = __in_dev_get(dev);
+        if (in_dev) {
+                no_addr = in_dev->ifa_list == NULL;
+                rpf = IN_DEV_RPFILTER(in_dev);
+        }
+        rcu_read_unlock();
+
+        if (in_dev == NULL)
+                goto e_inval;
+
+        if (fib_lookup(&fl, &res))
+                goto last_resort;
+        if (res.type != RTN_UNICAST)
+                goto e_inval_res;
+        *spec_dst = FIB_RES_PREFSRC(res);
+        fib_combine_itag(itag, &res);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+        if (FIB_RES_DEV(res) == dev || res.fi->fib_nhs > 1)
+#else
+        if (FIB_RES_DEV(res) == dev)
+#endif
+        {
+                ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
+                fib_res_put(&res);
+                return ret;
+        }
+        fib_res_put(&res);
+        if (no_addr)
+                goto last_resort;
+        if (rpf)
+                goto e_inval;
+        fl.oif = dev->ifindex;
+
+        ret = 0;
+        if (fib_lookup(&fl, &res) == 0) {
+                if (res.type == RTN_UNICAST) {
+                        *spec_dst = FIB_RES_PREFSRC(res);
+                        ret = FIB_RES_NH(res).nh_scope >= RT_SCOPE_HOST;
+                }
+                fib_res_put(&res);
+        }
+        return ret;
+
+last_resort:
+        if (rpf)
+                goto e_inval;
+        *spec_dst = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE);
+        *itag = 0;
+        return 0;
+
+e_inval_res:
+        fib_res_put(&res);
+e_inval:
+        return -EINVAL;
+}
+
+#ifndef CONFIG_IP_NOSIOCRT
+
+/*
+ *      Handle IP routing ioctl calls. These are used to manipulate the routing tables
+ */
+ 
+int ip_rt_ioctl(unsigned int cmd, void __user *arg)
+{
+        int err;
+        struct kern_rta rta;
+        struct rtentry  r;
+        struct {
+                struct nlmsghdr nlh;
+                struct rtmsg    rtm;
+        } req;
+
+        switch (cmd) {
+        case SIOCADDRT:         /* Add a route */
+        case SIOCDELRT:         /* Delete a route */
+                if (!capable(CAP_NET_ADMIN))
+                        return -EPERM;
+                if (copy_from_user(&r, arg, sizeof(struct rtentry)))
+                        return -EFAULT;
+                rtnl_lock();
+                err = fib_convert_rtentry(cmd, &req.nlh, &req.rtm, &rta, &r);
+                if (err == 0) {
+                        if (cmd == SIOCDELRT) {
+                                struct fib_table *tb = fib_get_table(req.rtm.rtm_table);
+                                err = -ESRCH;
+                                if (tb)
+                                        err = tb->tb_delete(tb, &req.rtm, &rta, &req.nlh, NULL);
+                        } else {
+                                struct fib_table *tb = fib_new_table(req.rtm.rtm_table);
+                                err = -ENOBUFS;
+                                if (tb)
+                                        err = tb->tb_insert(tb, &req.rtm, &rta, &req.nlh, NULL);
+                        }
+                        if (rta.rta_mx)
+                                kfree(rta.rta_mx);
+                }
+                rtnl_unlock();
+                return err;
+        }
+        return -EINVAL;
+}
+
+#else
+
+int ip_rt_ioctl(unsigned int cmd, void *arg)
+{
+        return -EINVAL;
+}
+
+#endif
+
+static int inet_check_attr(struct rtmsg *r, struct rtattr **rta)
+{
+        int i;
+
+        for (i=1; i<=RTA_MAX; i++) {
+                struct rtattr *attr = rta[i-1];
+                if (attr) {
+                        if (RTA_PAYLOAD(attr) < 4)
+                                return -EINVAL;
+                        if (i != RTA_MULTIPATH && i != RTA_METRICS)
+                                rta[i-1] = (struct rtattr*)RTA_DATA(attr);
+                }
+        }
+        return 0;
+}
+
+int inet_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
+{
+        struct fib_table * tb;
+        struct rtattr **rta = arg;
+        struct rtmsg *r = NLMSG_DATA(nlh);
+
+        if (inet_check_attr(r, rta))
+                return -EINVAL;
+
+        tb = fib_get_table(r->rtm_table);
+        if (tb)
+                return tb->tb_delete(tb, r, (struct kern_rta*)rta, nlh, &NETLINK_CB(skb));
+        return -ESRCH;
+}
+
+int inet_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
+{
+        struct fib_table * tb;
+        struct rtattr **rta = arg;
+        struct rtmsg *r = NLMSG_DATA(nlh);
+
+        if (inet_check_attr(r, rta))
+                return -EINVAL;
+
+        tb = fib_new_table(r->rtm_table);
+        if (tb)
+                return tb->tb_insert(tb, r, (struct kern_rta*)rta, nlh, &NETLINK_CB(skb));
+        return -ENOBUFS;
+}
+
+int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        int t;
+        int s_t;
+        struct fib_table *tb;
+
+        if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
+            ((struct rtmsg*)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
+                return ip_rt_dump(skb, cb);
+
+        s_t = cb->args[0];
+        if (s_t == 0)
+                s_t = cb->args[0] = RT_TABLE_MIN;
+
+        for (t=s_t; t<=RT_TABLE_MAX; t++) {
+                if (t < s_t) continue;
+                if (t > s_t)
+                        memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(cb->args[0]));
+                if ((tb = fib_get_table(t))==NULL)
+                        continue;
+                if (tb->tb_dump(tb, skb, cb) < 0) 
+                        break;
+        }
+
+        cb->args[0] = t;
+
+        return skb->len;
+}
+
+/* Prepare and feed intra-kernel routing request.
+   Really, it should be netlink message, but :-( netlink
+   can be not configured, so that we feed it directly
+   to fib engine. It is legal, because all events occur
+   only when netlink is already locked.
+ */
+
+static void fib_magic(int cmd, int type, u32 dst, int dst_len, struct in_ifaddr *ifa)
+{
+        struct fib_table * tb;
+        struct {
+                struct nlmsghdr nlh;
+                struct rtmsg    rtm;
+        } req;
+        struct kern_rta rta;
+
+        memset(&req.rtm, 0, sizeof(req.rtm));
+        memset(&rta, 0, sizeof(rta));
+
+        if (type == RTN_UNICAST)
+                tb = fib_new_table(RT_TABLE_MAIN);
+        else
+                tb = fib_new_table(RT_TABLE_LOCAL);
+
+        if (tb == NULL)
+                return;
+
+        req.nlh.nlmsg_len = sizeof(req);
+        req.nlh.nlmsg_type = cmd;
+        req.nlh.nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE|NLM_F_APPEND;
+        req.nlh.nlmsg_pid = 0;
+        req.nlh.nlmsg_seq = 0;
+
+        req.rtm.rtm_dst_len = dst_len;
+        req.rtm.rtm_table = tb->tb_id;
+        req.rtm.rtm_protocol = RTPROT_KERNEL;
+        req.rtm.rtm_scope = (type != RTN_LOCAL ? RT_SCOPE_LINK : RT_SCOPE_HOST);
+        req.rtm.rtm_type = type;
+
+        rta.rta_dst = &dst;
+        rta.rta_prefsrc = &ifa->ifa_local;
+        rta.rta_oif = &ifa->ifa_dev->dev->ifindex;
+
+        if (cmd == RTM_NEWROUTE)
+                tb->tb_insert(tb, &req.rtm, &rta, &req.nlh, NULL);
+        else
+                tb->tb_delete(tb, &req.rtm, &rta, &req.nlh, NULL);
+}
+
+static void fib_add_ifaddr(struct in_ifaddr *ifa)
+{
+        struct in_device *in_dev = ifa->ifa_dev;
+        struct net_device *dev = in_dev->dev;
+        struct in_ifaddr *prim = ifa;
+        u32 mask = ifa->ifa_mask;
+        u32 addr = ifa->ifa_local;
+        u32 prefix = ifa->ifa_address&mask;
+
+        if (ifa->ifa_flags&IFA_F_SECONDARY) {
+                prim = inet_ifa_byprefix(in_dev, prefix, mask);
+                if (prim == NULL) {
+                        printk(KERN_DEBUG "fib_add_ifaddr: bug: prim == NULL\n");
+                        return;
+                }
+        }
+
+        fib_magic(RTM_NEWROUTE, RTN_LOCAL, addr, 32, prim);
+
+        if (!(dev->flags&IFF_UP))
+                return;
+
+        /* Add broadcast address, if it is explicitly assigned. */
+        if (ifa->ifa_broadcast && ifa->ifa_broadcast != 0xFFFFFFFF)
+                fib_magic(RTM_NEWROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
+
+        if (!ZERONET(prefix) && !(ifa->ifa_flags&IFA_F_SECONDARY) &&
+            (prefix != addr || ifa->ifa_prefixlen < 32)) {
+                fib_magic(RTM_NEWROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL :
+                          RTN_UNICAST, prefix, ifa->ifa_prefixlen, prim);
+
+                /* Add network specific broadcasts, when it takes a sense */
+                if (ifa->ifa_prefixlen < 31) {
+                        fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix, 32, prim);
+                        fib_magic(RTM_NEWROUTE, RTN_BROADCAST, prefix|~mask, 32, prim);
+                }
+        }
+}
+
+static void fib_del_ifaddr(struct in_ifaddr *ifa)
+{
+        struct in_device *in_dev = ifa->ifa_dev;
+        struct net_device *dev = in_dev->dev;
+        struct in_ifaddr *ifa1;
+        struct in_ifaddr *prim = ifa;
+        u32 brd = ifa->ifa_address|~ifa->ifa_mask;
+        u32 any = ifa->ifa_address&ifa->ifa_mask;
+#define LOCAL_OK        1
+#define BRD_OK          2
+#define BRD0_OK         4
+#define BRD1_OK         8
+        unsigned ok = 0;
+
+        if (!(ifa->ifa_flags&IFA_F_SECONDARY))
+                fib_magic(RTM_DELROUTE, dev->flags&IFF_LOOPBACK ? RTN_LOCAL :
+                          RTN_UNICAST, any, ifa->ifa_prefixlen, prim);
+        else {
+                prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
+                if (prim == NULL) {
+                        printk(KERN_DEBUG "fib_del_ifaddr: bug: prim == NULL\n");
+                        return;
+                }
+        }
+
+        /* Deletion is more complicated than add.
+           We should take care of not to delete too much :-)
+
+           Scan address list to be sure that addresses are really gone.
+         */
+
+        for (ifa1 = in_dev->ifa_list; ifa1; ifa1 = ifa1->ifa_next) {
+                if (ifa->ifa_local == ifa1->ifa_local)
+                        ok |= LOCAL_OK;
+                if (ifa->ifa_broadcast == ifa1->ifa_broadcast)
+                        ok |= BRD_OK;
+                if (brd == ifa1->ifa_broadcast)
+                        ok |= BRD1_OK;
+                if (any == ifa1->ifa_broadcast)
+                        ok |= BRD0_OK;
+        }
+
+        if (!(ok&BRD_OK))
+                fib_magic(RTM_DELROUTE, RTN_BROADCAST, ifa->ifa_broadcast, 32, prim);
+        if (!(ok&BRD1_OK))
+                fib_magic(RTM_DELROUTE, RTN_BROADCAST, brd, 32, prim);
+        if (!(ok&BRD0_OK))
+                fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
+        if (!(ok&LOCAL_OK)) {
+                fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
+
+                /* Check, that this local address finally disappeared. */
+                if (inet_addr_type(ifa->ifa_local) != RTN_LOCAL) {
+                        /* And the last, but not the least thing.
+                           We must flush stray FIB entries.
+
+                           First of all, we scan fib_info list searching
+                           for stray nexthop entries, then ignite fib_flush.
+                        */
+                        if (fib_sync_down(ifa->ifa_local, NULL, 0))
+                                fib_flush();
+                }
+        }
+#undef LOCAL_OK
+#undef BRD_OK
+#undef BRD0_OK
+#undef BRD1_OK
+}
+
+static void fib_disable_ip(struct net_device *dev, int force)
+{
+        if (fib_sync_down(0, dev, force))
+                fib_flush();
+        rt_cache_flush(0);
+        arp_ifdown(dev);
+}
+
+static int fib_inetaddr_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+        struct in_ifaddr *ifa = (struct in_ifaddr*)ptr;
+
+        switch (event) {
+        case NETDEV_UP:
+                fib_add_ifaddr(ifa);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+                fib_sync_up(ifa->ifa_dev->dev);
+#endif
+                rt_cache_flush(-1);
+                break;
+        case NETDEV_DOWN:
+                fib_del_ifaddr(ifa);
+                if (ifa->ifa_dev && ifa->ifa_dev->ifa_list == NULL) {
+                        /* Last address was deleted from this interface.
+                           Disable IP.
+                         */
+                        fib_disable_ip(ifa->ifa_dev->dev, 1);
+                } else {
+                        rt_cache_flush(-1);
+                }
+                break;
+        }
+        return NOTIFY_DONE;
+}
+
+static int fib_netdev_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+        struct net_device *dev = ptr;
+        struct in_device *in_dev = __in_dev_get(dev);
+
+        if (event == NETDEV_UNREGISTER) {
+                fib_disable_ip(dev, 2);
+                return NOTIFY_DONE;
+        }
+
+        if (!in_dev)
+                return NOTIFY_DONE;
+
+        switch (event) {
+        case NETDEV_UP:
+                for_ifa(in_dev) {
+                        fib_add_ifaddr(ifa);
+                } endfor_ifa(in_dev);
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+                fib_sync_up(dev);
+#endif
+                rt_cache_flush(-1);
+                break;
+        case NETDEV_DOWN:
+                fib_disable_ip(dev, 0);
+                break;
+        case NETDEV_CHANGEMTU:
+        case NETDEV_CHANGE:
+                rt_cache_flush(0);
+                break;
+        }
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block fib_inetaddr_notifier = {
+        .notifier_call =fib_inetaddr_event,
+};
+
+static struct notifier_block fib_netdev_notifier = {
+        .notifier_call =fib_netdev_event,
+};
+
+void __init ip_fib_init(void)
+{
+#ifndef CONFIG_IP_MULTIPLE_TABLES
+        ip_fib_local_table = fib_hash_init(RT_TABLE_LOCAL);
+        ip_fib_main_table  = fib_hash_init(RT_TABLE_MAIN);
+#else
+        fib_rules_init();
+#endif
+
+        register_netdevice_notifier(&fib_netdev_notifier);
+        register_inetaddr_notifier(&fib_inetaddr_notifier);
+}
+
+EXPORT_SYMBOL(inet_addr_type);
+EXPORT_SYMBOL(ip_dev_find);
+EXPORT_SYMBOL(ip_rt_ioctl);