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-rw-r--r--net/ipv4/fib_semantics.c1332
1 files changed, 1332 insertions, 0 deletions
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
new file mode 100644
index 00000000000..029362d6613
--- /dev/null
+++ b/net/ipv4/fib_semantics.c
@@ -0,0 +1,1332 @@
+/*
+ * 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: semantics.
+ *
+ * Version: $Id: fib_semantics.c,v 1.19 2002/01/12 07:54:56 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 <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.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/proc_fs.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/ip_fib.h>
+#include <net/ip_mp_alg.h>
+
+#include "fib_lookup.h"
+
+#define FSprintk(a...)
+
+static DEFINE_RWLOCK(fib_info_lock);
+static struct hlist_head *fib_info_hash;
+static struct hlist_head *fib_info_laddrhash;
+static unsigned int fib_hash_size;
+static unsigned int fib_info_cnt;
+
+#define DEVINDEX_HASHBITS 8
+#define DEVINDEX_HASHSIZE (1U << DEVINDEX_HASHBITS)
+static struct hlist_head fib_info_devhash[DEVINDEX_HASHSIZE];
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+
+static DEFINE_SPINLOCK(fib_multipath_lock);
+
+#define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \
+for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
+
+#define change_nexthops(fi) { int nhsel; struct fib_nh * nh; \
+for (nhsel=0, nh = (struct fib_nh*)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
+
+#else /* CONFIG_IP_ROUTE_MULTIPATH */
+
+/* Hope, that gcc will optimize it to get rid of dummy loop */
+
+#define for_nexthops(fi) { int nhsel=0; const struct fib_nh * nh = (fi)->fib_nh; \
+for (nhsel=0; nhsel < 1; nhsel++)
+
+#define change_nexthops(fi) { int nhsel=0; struct fib_nh * nh = (struct fib_nh*)((fi)->fib_nh); \
+for (nhsel=0; nhsel < 1; nhsel++)
+
+#endif /* CONFIG_IP_ROUTE_MULTIPATH */
+
+#define endfor_nexthops(fi) }
+
+
+static struct
+{
+ int error;
+ u8 scope;
+} fib_props[RTA_MAX + 1] = {
+ {
+ .error = 0,
+ .scope = RT_SCOPE_NOWHERE,
+ }, /* RTN_UNSPEC */
+ {
+ .error = 0,
+ .scope = RT_SCOPE_UNIVERSE,
+ }, /* RTN_UNICAST */
+ {
+ .error = 0,
+ .scope = RT_SCOPE_HOST,
+ }, /* RTN_LOCAL */
+ {
+ .error = 0,
+ .scope = RT_SCOPE_LINK,
+ }, /* RTN_BROADCAST */
+ {
+ .error = 0,
+ .scope = RT_SCOPE_LINK,
+ }, /* RTN_ANYCAST */
+ {
+ .error = 0,
+ .scope = RT_SCOPE_UNIVERSE,
+ }, /* RTN_MULTICAST */
+ {
+ .error = -EINVAL,
+ .scope = RT_SCOPE_UNIVERSE,
+ }, /* RTN_BLACKHOLE */
+ {
+ .error = -EHOSTUNREACH,
+ .scope = RT_SCOPE_UNIVERSE,
+ }, /* RTN_UNREACHABLE */
+ {
+ .error = -EACCES,
+ .scope = RT_SCOPE_UNIVERSE,
+ }, /* RTN_PROHIBIT */
+ {
+ .error = -EAGAIN,
+ .scope = RT_SCOPE_UNIVERSE,
+ }, /* RTN_THROW */
+ {
+ .error = -EINVAL,
+ .scope = RT_SCOPE_NOWHERE,
+ }, /* RTN_NAT */
+ {
+ .error = -EINVAL,
+ .scope = RT_SCOPE_NOWHERE,
+ }, /* RTN_XRESOLVE */
+};
+
+
+/* Release a nexthop info record */
+
+void free_fib_info(struct fib_info *fi)
+{
+ if (fi->fib_dead == 0) {
+ printk("Freeing alive fib_info %p\n", fi);
+ return;
+ }
+ change_nexthops(fi) {
+ if (nh->nh_dev)
+ dev_put(nh->nh_dev);
+ nh->nh_dev = NULL;
+ } endfor_nexthops(fi);
+ fib_info_cnt--;
+ kfree(fi);
+}
+
+void fib_release_info(struct fib_info *fi)
+{
+ write_lock(&fib_info_lock);
+ if (fi && --fi->fib_treeref == 0) {
+ hlist_del(&fi->fib_hash);
+ if (fi->fib_prefsrc)
+ hlist_del(&fi->fib_lhash);
+ change_nexthops(fi) {
+ if (!nh->nh_dev)
+ continue;
+ hlist_del(&nh->nh_hash);
+ } endfor_nexthops(fi)
+ fi->fib_dead = 1;
+ fib_info_put(fi);
+ }
+ write_unlock(&fib_info_lock);
+}
+
+static __inline__ int nh_comp(const struct fib_info *fi, const struct fib_info *ofi)
+{
+ const struct fib_nh *onh = ofi->fib_nh;
+
+ for_nexthops(fi) {
+ if (nh->nh_oif != onh->nh_oif ||
+ nh->nh_gw != onh->nh_gw ||
+ nh->nh_scope != onh->nh_scope ||
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ nh->nh_weight != onh->nh_weight ||
+#endif
+#ifdef CONFIG_NET_CLS_ROUTE
+ nh->nh_tclassid != onh->nh_tclassid ||
+#endif
+ ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
+ return -1;
+ onh++;
+ } endfor_nexthops(fi);
+ return 0;
+}
+
+static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
+{
+ unsigned int mask = (fib_hash_size - 1);
+ unsigned int val = fi->fib_nhs;
+
+ val ^= fi->fib_protocol;
+ val ^= fi->fib_prefsrc;
+ val ^= fi->fib_priority;
+
+ return (val ^ (val >> 7) ^ (val >> 12)) & mask;
+}
+
+static struct fib_info *fib_find_info(const struct fib_info *nfi)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct fib_info *fi;
+ unsigned int hash;
+
+ hash = fib_info_hashfn(nfi);
+ head = &fib_info_hash[hash];
+
+ hlist_for_each_entry(fi, node, head, fib_hash) {
+ if (fi->fib_nhs != nfi->fib_nhs)
+ continue;
+ if (nfi->fib_protocol == fi->fib_protocol &&
+ nfi->fib_prefsrc == fi->fib_prefsrc &&
+ nfi->fib_priority == fi->fib_priority &&
+ memcmp(nfi->fib_metrics, fi->fib_metrics,
+ sizeof(fi->fib_metrics)) == 0 &&
+ ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
+ (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
+ return fi;
+ }
+
+ return NULL;
+}
+
+static inline unsigned int fib_devindex_hashfn(unsigned int val)
+{
+ unsigned int mask = DEVINDEX_HASHSIZE - 1;
+
+ return (val ^
+ (val >> DEVINDEX_HASHBITS) ^
+ (val >> (DEVINDEX_HASHBITS * 2))) & mask;
+}
+
+/* Check, that the gateway is already configured.
+ Used only by redirect accept routine.
+ */
+
+int ip_fib_check_default(u32 gw, struct net_device *dev)
+{
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct fib_nh *nh;
+ unsigned int hash;
+
+ read_lock(&fib_info_lock);
+
+ hash = fib_devindex_hashfn(dev->ifindex);
+ head = &fib_info_devhash[hash];
+ hlist_for_each_entry(nh, node, head, nh_hash) {
+ if (nh->nh_dev == dev &&
+ nh->nh_gw == gw &&
+ !(nh->nh_flags&RTNH_F_DEAD)) {
+ read_unlock(&fib_info_lock);
+ return 0;
+ }
+ }
+
+ read_unlock(&fib_info_lock);
+
+ return -1;
+}
+
+void rtmsg_fib(int event, u32 key, struct fib_alias *fa,
+ int z, int tb_id,
+ struct nlmsghdr *n, struct netlink_skb_parms *req)
+{
+ struct sk_buff *skb;
+ u32 pid = req ? req->pid : 0;
+ int size = NLMSG_SPACE(sizeof(struct rtmsg)+256);
+
+ skb = alloc_skb(size, GFP_KERNEL);
+ if (!skb)
+ return;
+
+ if (fib_dump_info(skb, pid, n->nlmsg_seq, event, tb_id,
+ fa->fa_type, fa->fa_scope, &key, z,
+ fa->fa_tos,
+ fa->fa_info) < 0) {
+ kfree_skb(skb);
+ return;
+ }
+ NETLINK_CB(skb).dst_groups = RTMGRP_IPV4_ROUTE;
+ if (n->nlmsg_flags&NLM_F_ECHO)
+ atomic_inc(&skb->users);
+ netlink_broadcast(rtnl, skb, pid, RTMGRP_IPV4_ROUTE, GFP_KERNEL);
+ if (n->nlmsg_flags&NLM_F_ECHO)
+ netlink_unicast(rtnl, skb, pid, MSG_DONTWAIT);
+}
+
+/* Return the first fib alias matching TOS with
+ * priority less than or equal to PRIO.
+ */
+struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
+{
+ if (fah) {
+ struct fib_alias *fa;
+ list_for_each_entry(fa, fah, fa_list) {
+ if (fa->fa_tos > tos)
+ continue;
+ if (fa->fa_info->fib_priority >= prio ||
+ fa->fa_tos < tos)
+ return fa;
+ }
+ }
+ return NULL;
+}
+
+int fib_detect_death(struct fib_info *fi, int order,
+ struct fib_info **last_resort, int *last_idx, int *dflt)
+{
+ struct neighbour *n;
+ int state = NUD_NONE;
+
+ n = neigh_lookup(&arp_tbl, &fi->fib_nh[0].nh_gw, fi->fib_dev);
+ if (n) {
+ state = n->nud_state;
+ neigh_release(n);
+ }
+ if (state==NUD_REACHABLE)
+ return 0;
+ if ((state&NUD_VALID) && order != *dflt)
+ return 0;
+ if ((state&NUD_VALID) ||
+ (*last_idx<0 && order > *dflt)) {
+ *last_resort = fi;
+ *last_idx = order;
+ }
+ return 1;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+
+static u32 fib_get_attr32(struct rtattr *attr, int attrlen, int type)
+{
+ while (RTA_OK(attr,attrlen)) {
+ if (attr->rta_type == type)
+ return *(u32*)RTA_DATA(attr);
+ attr = RTA_NEXT(attr, attrlen);
+ }
+ return 0;
+}
+
+static int
+fib_count_nexthops(struct rtattr *rta)
+{
+ int nhs = 0;
+ struct rtnexthop *nhp = RTA_DATA(rta);
+ int nhlen = RTA_PAYLOAD(rta);
+
+ while (nhlen >= (int)sizeof(struct rtnexthop)) {
+ if ((nhlen -= nhp->rtnh_len) < 0)
+ return 0;
+ nhs++;
+ nhp = RTNH_NEXT(nhp);
+ };
+ return nhs;
+}
+
+static int
+fib_get_nhs(struct fib_info *fi, const struct rtattr *rta, const struct rtmsg *r)
+{
+ struct rtnexthop *nhp = RTA_DATA(rta);
+ int nhlen = RTA_PAYLOAD(rta);
+
+ change_nexthops(fi) {
+ int attrlen = nhlen - sizeof(struct rtnexthop);
+ if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
+ return -EINVAL;
+ nh->nh_flags = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
+ nh->nh_oif = nhp->rtnh_ifindex;
+ nh->nh_weight = nhp->rtnh_hops + 1;
+ if (attrlen) {
+ nh->nh_gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
+#ifdef CONFIG_NET_CLS_ROUTE
+ nh->nh_tclassid = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_FLOW);
+#endif
+ }
+ nhp = RTNH_NEXT(nhp);
+ } endfor_nexthops(fi);
+ return 0;
+}
+
+#endif
+
+int fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct kern_rta *rta,
+ struct fib_info *fi)
+{
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ struct rtnexthop *nhp;
+ int nhlen;
+#endif
+
+ if (rta->rta_priority &&
+ *rta->rta_priority != fi->fib_priority)
+ return 1;
+
+ if (rta->rta_oif || rta->rta_gw) {
+ if ((!rta->rta_oif || *rta->rta_oif == fi->fib_nh->nh_oif) &&
+ (!rta->rta_gw || memcmp(rta->rta_gw, &fi->fib_nh->nh_gw, 4) == 0))
+ return 0;
+ return 1;
+ }
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (rta->rta_mp == NULL)
+ return 0;
+ nhp = RTA_DATA(rta->rta_mp);
+ nhlen = RTA_PAYLOAD(rta->rta_mp);
+
+ for_nexthops(fi) {
+ int attrlen = nhlen - sizeof(struct rtnexthop);
+ u32 gw;
+
+ if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
+ return -EINVAL;
+ if (nhp->rtnh_ifindex && nhp->rtnh_ifindex != nh->nh_oif)
+ return 1;
+ if (attrlen) {
+ gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
+ if (gw && gw != nh->nh_gw)
+ return 1;
+#ifdef CONFIG_NET_CLS_ROUTE
+ gw = fib_get_attr32(RTNH_DATA(nhp), attrlen, RTA_FLOW);
+ if (gw && gw != nh->nh_tclassid)
+ return 1;
+#endif
+ }
+ nhp = RTNH_NEXT(nhp);
+ } endfor_nexthops(fi);
+#endif
+ return 0;
+}
+
+
+/*
+ Picture
+ -------
+
+ Semantics of nexthop is very messy by historical reasons.
+ We have to take into account, that:
+ a) gateway can be actually local interface address,
+ so that gatewayed route is direct.
+ b) gateway must be on-link address, possibly
+ described not by an ifaddr, but also by a direct route.
+ c) If both gateway and interface are specified, they should not
+ contradict.
+ d) If we use tunnel routes, gateway could be not on-link.
+
+ Attempt to reconcile all of these (alas, self-contradictory) conditions
+ results in pretty ugly and hairy code with obscure logic.
+
+ I chose to generalized it instead, so that the size
+ of code does not increase practically, but it becomes
+ much more general.
+ Every prefix is assigned a "scope" value: "host" is local address,
+ "link" is direct route,
+ [ ... "site" ... "interior" ... ]
+ and "universe" is true gateway route with global meaning.
+
+ Every prefix refers to a set of "nexthop"s (gw, oif),
+ where gw must have narrower scope. This recursion stops
+ when gw has LOCAL scope or if "nexthop" is declared ONLINK,
+ which means that gw is forced to be on link.
+
+ Code is still hairy, but now it is apparently logically
+ consistent and very flexible. F.e. as by-product it allows
+ to co-exists in peace independent exterior and interior
+ routing processes.
+
+ Normally it looks as following.
+
+ {universe prefix} -> (gw, oif) [scope link]
+ |
+ |-> {link prefix} -> (gw, oif) [scope local]
+ |
+ |-> {local prefix} (terminal node)
+ */
+
+static int fib_check_nh(const struct rtmsg *r, struct fib_info *fi, struct fib_nh *nh)
+{
+ int err;
+
+ if (nh->nh_gw) {
+ struct fib_result res;
+
+#ifdef CONFIG_IP_ROUTE_PERVASIVE
+ if (nh->nh_flags&RTNH_F_PERVASIVE)
+ return 0;
+#endif
+ if (nh->nh_flags&RTNH_F_ONLINK) {
+ struct net_device *dev;
+
+ if (r->rtm_scope >= RT_SCOPE_LINK)
+ return -EINVAL;
+ if (inet_addr_type(nh->nh_gw) != RTN_UNICAST)
+ return -EINVAL;
+ if ((dev = __dev_get_by_index(nh->nh_oif)) == NULL)
+ return -ENODEV;
+ if (!(dev->flags&IFF_UP))
+ return -ENETDOWN;
+ nh->nh_dev = dev;
+ dev_hold(dev);
+ nh->nh_scope = RT_SCOPE_LINK;
+ return 0;
+ }
+ {
+ struct flowi fl = { .nl_u = { .ip4_u =
+ { .daddr = nh->nh_gw,
+ .scope = r->rtm_scope + 1 } },
+ .oif = nh->nh_oif };
+
+ /* It is not necessary, but requires a bit of thinking */
+ if (fl.fl4_scope < RT_SCOPE_LINK)
+ fl.fl4_scope = RT_SCOPE_LINK;
+ if ((err = fib_lookup(&fl, &res)) != 0)
+ return err;
+ }
+ err = -EINVAL;
+ if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
+ goto out;
+ nh->nh_scope = res.scope;
+ nh->nh_oif = FIB_RES_OIF(res);
+ if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
+ goto out;
+ dev_hold(nh->nh_dev);
+ err = -ENETDOWN;
+ if (!(nh->nh_dev->flags & IFF_UP))
+ goto out;
+ err = 0;
+out:
+ fib_res_put(&res);
+ return err;
+ } else {
+ struct in_device *in_dev;
+
+ if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
+ return -EINVAL;
+
+ in_dev = inetdev_by_index(nh->nh_oif);
+ if (in_dev == NULL)
+ return -ENODEV;
+ if (!(in_dev->dev->flags&IFF_UP)) {
+ in_dev_put(in_dev);
+ return -ENETDOWN;
+ }
+ nh->nh_dev = in_dev->dev;
+ dev_hold(nh->nh_dev);
+ nh->nh_scope = RT_SCOPE_HOST;
+ in_dev_put(in_dev);
+ }
+ return 0;
+}
+
+static inline unsigned int fib_laddr_hashfn(u32 val)
+{
+ unsigned int mask = (fib_hash_size - 1);
+
+ return (val ^ (val >> 7) ^ (val >> 14)) & mask;
+}
+
+static struct hlist_head *fib_hash_alloc(int bytes)
+{
+ if (bytes <= PAGE_SIZE)
+ return kmalloc(bytes, GFP_KERNEL);
+ else
+ return (struct hlist_head *)
+ __get_free_pages(GFP_KERNEL, get_order(bytes));
+}
+
+static void fib_hash_free(struct hlist_head *hash, int bytes)
+{
+ if (!hash)
+ return;
+
+ if (bytes <= PAGE_SIZE)
+ kfree(hash);
+ else
+ free_pages((unsigned long) hash, get_order(bytes));
+}
+
+static void fib_hash_move(struct hlist_head *new_info_hash,
+ struct hlist_head *new_laddrhash,
+ unsigned int new_size)
+{
+ unsigned int old_size = fib_hash_size;
+ unsigned int i;
+
+ write_lock(&fib_info_lock);
+ fib_hash_size = new_size;
+
+ for (i = 0; i < old_size; i++) {
+ struct hlist_head *head = &fib_info_hash[i];
+ struct hlist_node *node, *n;
+ struct fib_info *fi;
+
+ hlist_for_each_entry_safe(fi, node, n, head, fib_hash) {
+ struct hlist_head *dest;
+ unsigned int new_hash;
+
+ hlist_del(&fi->fib_hash);
+
+ new_hash = fib_info_hashfn(fi);
+ dest = &new_info_hash[new_hash];
+ hlist_add_head(&fi->fib_hash, dest);
+ }
+ }
+ fib_info_hash = new_info_hash;
+
+ for (i = 0; i < old_size; i++) {
+ struct hlist_head *lhead = &fib_info_laddrhash[i];
+ struct hlist_node *node, *n;
+ struct fib_info *fi;
+
+ hlist_for_each_entry_safe(fi, node, n, lhead, fib_lhash) {
+ struct hlist_head *ldest;
+ unsigned int new_hash;
+
+ hlist_del(&fi->fib_lhash);
+
+ new_hash = fib_laddr_hashfn(fi->fib_prefsrc);
+ ldest = &new_laddrhash[new_hash];
+ hlist_add_head(&fi->fib_lhash, ldest);
+ }
+ }
+ fib_info_laddrhash = new_laddrhash;
+
+ write_unlock(&fib_info_lock);
+}
+
+struct fib_info *
+fib_create_info(const struct rtmsg *r, struct kern_rta *rta,
+ const struct nlmsghdr *nlh, int *errp)
+{
+ int err;
+ struct fib_info *fi = NULL;
+ struct fib_info *ofi;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ int nhs = 1;
+#else
+ const int nhs = 1;
+#endif
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ u32 mp_alg = IP_MP_ALG_NONE;
+#endif
+
+ /* Fast check to catch the most weird cases */
+ if (fib_props[r->rtm_type].scope > r->rtm_scope)
+ goto err_inval;
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (rta->rta_mp) {
+ nhs = fib_count_nexthops(rta->rta_mp);
+ if (nhs == 0)
+ goto err_inval;
+ }
+#endif
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ if (rta->rta_mp_alg) {
+ mp_alg = *rta->rta_mp_alg;
+
+ if (mp_alg < IP_MP_ALG_NONE ||
+ mp_alg > IP_MP_ALG_MAX)
+ goto err_inval;
+ }
+#endif
+
+ err = -ENOBUFS;
+ if (fib_info_cnt >= fib_hash_size) {
+ unsigned int new_size = fib_hash_size << 1;
+ struct hlist_head *new_info_hash;
+ struct hlist_head *new_laddrhash;
+ unsigned int bytes;
+
+ if (!new_size)
+ new_size = 1;
+ bytes = new_size * sizeof(struct hlist_head *);
+ new_info_hash = fib_hash_alloc(bytes);
+ new_laddrhash = fib_hash_alloc(bytes);
+ if (!new_info_hash || !new_laddrhash) {
+ fib_hash_free(new_info_hash, bytes);
+ fib_hash_free(new_laddrhash, bytes);
+ } else {
+ memset(new_info_hash, 0, bytes);
+ memset(new_laddrhash, 0, bytes);
+
+ fib_hash_move(new_info_hash, new_laddrhash, new_size);
+ }
+
+ if (!fib_hash_size)
+ goto failure;
+ }
+
+ fi = kmalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
+ if (fi == NULL)
+ goto failure;
+ fib_info_cnt++;
+ memset(fi, 0, sizeof(*fi)+nhs*sizeof(struct fib_nh));
+
+ fi->fib_protocol = r->rtm_protocol;
+
+ fi->fib_nhs = nhs;
+ change_nexthops(fi) {
+ nh->nh_parent = fi;
+ } endfor_nexthops(fi)
+
+ fi->fib_flags = r->rtm_flags;
+ if (rta->rta_priority)
+ fi->fib_priority = *rta->rta_priority;
+ if (rta->rta_mx) {
+ int attrlen = RTA_PAYLOAD(rta->rta_mx);
+ struct rtattr *attr = RTA_DATA(rta->rta_mx);
+
+ while (RTA_OK(attr, attrlen)) {
+ unsigned flavor = attr->rta_type;
+ if (flavor) {
+ if (flavor > RTAX_MAX)
+ goto err_inval;
+ fi->fib_metrics[flavor-1] = *(unsigned*)RTA_DATA(attr);
+ }
+ attr = RTA_NEXT(attr, attrlen);
+ }
+ }
+ if (rta->rta_prefsrc)
+ memcpy(&fi->fib_prefsrc, rta->rta_prefsrc, 4);
+
+ if (rta->rta_mp) {
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if ((err = fib_get_nhs(fi, rta->rta_mp, r)) != 0)
+ goto failure;
+ if (rta->rta_oif && fi->fib_nh->nh_oif != *rta->rta_oif)
+ goto err_inval;
+ if (rta->rta_gw && memcmp(&fi->fib_nh->nh_gw, rta->rta_gw, 4))
+ goto err_inval;
+#ifdef CONFIG_NET_CLS_ROUTE
+ if (rta->rta_flow && memcmp(&fi->fib_nh->nh_tclassid, rta->rta_flow, 4))
+ goto err_inval;
+#endif
+#else
+ goto err_inval;
+#endif
+ } else {
+ struct fib_nh *nh = fi->fib_nh;
+ if (rta->rta_oif)
+ nh->nh_oif = *rta->rta_oif;
+ if (rta->rta_gw)
+ memcpy(&nh->nh_gw, rta->rta_gw, 4);
+#ifdef CONFIG_NET_CLS_ROUTE
+ if (rta->rta_flow)
+ memcpy(&nh->nh_tclassid, rta->rta_flow, 4);
+#endif
+ nh->nh_flags = r->rtm_flags;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ nh->nh_weight = 1;
+#endif
+ }
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ fi->fib_mp_alg = mp_alg;
+#endif
+
+ if (fib_props[r->rtm_type].error) {
+ if (rta->rta_gw || rta->rta_oif || rta->rta_mp)
+ goto err_inval;
+ goto link_it;
+ }
+
+ if (r->rtm_scope > RT_SCOPE_HOST)
+ goto err_inval;
+
+ if (r->rtm_scope == RT_SCOPE_HOST) {
+ struct fib_nh *nh = fi->fib_nh;
+
+ /* Local address is added. */
+ if (nhs != 1 || nh->nh_gw)
+ goto err_inval;
+ nh->nh_scope = RT_SCOPE_NOWHERE;
+ nh->nh_dev = dev_get_by_index(fi->fib_nh->nh_oif);
+ err = -ENODEV;
+ if (nh->nh_dev == NULL)
+ goto failure;
+ } else {
+ change_nexthops(fi) {
+ if ((err = fib_check_nh(r, fi, nh)) != 0)
+ goto failure;
+ } endfor_nexthops(fi)
+ }
+
+ if (fi->fib_prefsrc) {
+ if (r->rtm_type != RTN_LOCAL || rta->rta_dst == NULL ||
+ memcmp(&fi->fib_prefsrc, rta->rta_dst, 4))
+ if (inet_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
+ goto err_inval;
+ }
+
+link_it:
+ if ((ofi = fib_find_info(fi)) != NULL) {
+ fi->fib_dead = 1;
+ free_fib_info(fi);
+ ofi->fib_treeref++;
+ return ofi;
+ }
+
+ fi->fib_treeref++;
+ atomic_inc(&fi->fib_clntref);
+ write_lock(&fib_info_lock);
+ hlist_add_head(&fi->fib_hash,
+ &fib_info_hash[fib_info_hashfn(fi)]);
+ if (fi->fib_prefsrc) {
+ struct hlist_head *head;
+
+ head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
+ hlist_add_head(&fi->fib_lhash, head);
+ }
+ change_nexthops(fi) {
+ struct hlist_head *head;
+ unsigned int hash;
+
+ if (!nh->nh_dev)
+ continue;
+ hash = fib_devindex_hashfn(nh->nh_dev->ifindex);
+ head = &fib_info_devhash[hash];
+ hlist_add_head(&nh->nh_hash, head);
+ } endfor_nexthops(fi)
+ write_unlock(&fib_info_lock);
+ return fi;
+
+err_inval:
+ err = -EINVAL;
+
+failure:
+ *errp = err;
+ if (fi) {
+ fi->fib_dead = 1;
+ free_fib_info(fi);
+ }
+ return NULL;
+}
+
+int fib_semantic_match(struct list_head *head, const struct flowi *flp,
+ struct fib_result *res, __u32 zone, __u32 mask,
+ int prefixlen)
+{
+ struct fib_alias *fa;
+ int nh_sel = 0;
+
+ list_for_each_entry(fa, head, fa_list) {
+ int err;
+
+ if (fa->fa_tos &&
+ fa->fa_tos != flp->fl4_tos)
+ continue;
+
+ if (fa->fa_scope < flp->fl4_scope)
+ continue;
+
+ fa->fa_state |= FA_S_ACCESSED;
+
+ err = fib_props[fa->fa_type].error;
+ if (err == 0) {
+ struct fib_info *fi = fa->fa_info;
+
+ if (fi->fib_flags & RTNH_F_DEAD)
+ continue;
+
+ switch (fa->fa_type) {
+ case RTN_UNICAST:
+ case RTN_LOCAL:
+ case RTN_BROADCAST:
+ case RTN_ANYCAST:
+ case RTN_MULTICAST:
+ for_nexthops(fi) {
+ if (nh->nh_flags&RTNH_F_DEAD)
+ continue;
+ if (!flp->oif || flp->oif == nh->nh_oif)
+ break;
+ }
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (nhsel < fi->fib_nhs) {
+ nh_sel = nhsel;
+ goto out_fill_res;
+ }
+#else
+ if (nhsel < 1) {
+ goto out_fill_res;
+ }
+#endif
+ endfor_nexthops(fi);
+ continue;
+
+ default:
+ printk(KERN_DEBUG "impossible 102\n");
+ return -EINVAL;
+ };
+ }
+ return err;
+ }
+ return 1;
+
+out_fill_res:
+ res->prefixlen = prefixlen;
+ res->nh_sel = nh_sel;
+ res->type = fa->fa_type;
+ res->scope = fa->fa_scope;
+ res->fi = fa->fa_info;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
+ res->netmask = mask;
+ res->network = zone &
+ (0xFFFFFFFF >> (32 - prefixlen));
+#endif
+ atomic_inc(&res->fi->fib_clntref);
+ return 0;
+}
+
+/* Find appropriate source address to this destination */
+
+u32 __fib_res_prefsrc(struct fib_result *res)
+{
+ return inet_select_addr(FIB_RES_DEV(*res), FIB_RES_GW(*res), res->scope);
+}
+
+int
+fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
+ u8 tb_id, u8 type, u8 scope, void *dst, int dst_len, u8 tos,
+ struct fib_info *fi)
+{
+ struct rtmsg *rtm;
+ struct nlmsghdr *nlh;
+ unsigned char *b = skb->tail;
+
+ nlh = NLMSG_PUT(skb, pid, seq, event, sizeof(*rtm));
+ rtm = NLMSG_DATA(nlh);
+ rtm->rtm_family = AF_INET;
+ rtm->rtm_dst_len = dst_len;
+ rtm->rtm_src_len = 0;
+ rtm->rtm_tos = tos;
+ rtm->rtm_table = tb_id;
+ rtm->rtm_type = type;
+ rtm->rtm_flags = fi->fib_flags;
+ rtm->rtm_scope = scope;
+ if (rtm->rtm_dst_len)
+ RTA_PUT(skb, RTA_DST, 4, dst);
+ rtm->rtm_protocol = fi->fib_protocol;
+ if (fi->fib_priority)
+ RTA_PUT(skb, RTA_PRIORITY, 4, &fi->fib_priority);
+#ifdef CONFIG_NET_CLS_ROUTE
+ if (fi->fib_nh[0].nh_tclassid)
+ RTA_PUT(skb, RTA_FLOW, 4, &fi->fib_nh[0].nh_tclassid);
+#endif
+ if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
+ goto rtattr_failure;
+ if (fi->fib_prefsrc)
+ RTA_PUT(skb, RTA_PREFSRC, 4, &fi->fib_prefsrc);
+ if (fi->fib_nhs == 1) {
+ if (fi->fib_nh->nh_gw)
+ RTA_PUT(skb, RTA_GATEWAY, 4, &fi->fib_nh->nh_gw);
+ if (fi->fib_nh->nh_oif)
+ RTA_PUT(skb, RTA_OIF, sizeof(int), &fi->fib_nh->nh_oif);
+ }
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (fi->fib_nhs > 1) {
+ struct rtnexthop *nhp;
+ struct rtattr *mp_head;
+ if (skb_tailroom(skb) <= RTA_SPACE(0))
+ goto rtattr_failure;
+ mp_head = (struct rtattr*)skb_put(skb, RTA_SPACE(0));
+
+ for_nexthops(fi) {
+ if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
+ goto rtattr_failure;
+ nhp = (struct rtnexthop*)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
+ nhp->rtnh_flags = nh->nh_flags & 0xFF;
+ nhp->rtnh_hops = nh->nh_weight-1;
+ nhp->rtnh_ifindex = nh->nh_oif;
+ if (nh->nh_gw)
+ RTA_PUT(skb, RTA_GATEWAY, 4, &nh->nh_gw);
+ nhp->rtnh_len = skb->tail - (unsigned char*)nhp;
+ } endfor_nexthops(fi);
+ mp_head->rta_type = RTA_MULTIPATH;
+ mp_head->rta_len = skb->tail - (u8*)mp_head;
+ }
+#endif
+ nlh->nlmsg_len = skb->tail - b;
+ return skb->len;
+
+nlmsg_failure:
+rtattr_failure:
+ skb_trim(skb, b - skb->data);
+ return -1;
+}
+
+#ifndef CONFIG_IP_NOSIOCRT
+
+int
+fib_convert_rtentry(int cmd, struct nlmsghdr *nl, struct rtmsg *rtm,
+ struct kern_rta *rta, struct rtentry *r)
+{
+ int plen;
+ u32 *ptr;
+
+ memset(rtm, 0, sizeof(*rtm));
+ memset(rta, 0, sizeof(*rta));
+
+ if (r->rt_dst.sa_family != AF_INET)
+ return -EAFNOSUPPORT;
+
+ /* Check mask for validity:
+ a) it must be contiguous.
+ b) destination must have all host bits clear.
+ c) if application forgot to set correct family (AF_INET),
+ reject request unless it is absolutely clear i.e.
+ both family and mask are zero.
+ */
+ plen = 32;
+ ptr = &((struct sockaddr_in*)&r->rt_dst)->sin_addr.s_addr;
+ if (!(r->rt_flags&RTF_HOST)) {
+ u32 mask = ((struct sockaddr_in*)&r->rt_genmask)->sin_addr.s_addr;
+ if (r->rt_genmask.sa_family != AF_INET) {
+ if (mask || r->rt_genmask.sa_family)
+ return -EAFNOSUPPORT;
+ }
+ if (bad_mask(mask, *ptr))
+ return -EINVAL;
+ plen = inet_mask_len(mask);
+ }
+
+ nl->nlmsg_flags = NLM_F_REQUEST;
+ nl->nlmsg_pid = 0;
+ nl->nlmsg_seq = 0;
+ nl->nlmsg_len = NLMSG_LENGTH(sizeof(*rtm));
+ if (cmd == SIOCDELRT) {
+ nl->nlmsg_type = RTM_DELROUTE;
+ nl->nlmsg_flags = 0;
+ } else {
+ nl->nlmsg_type = RTM_NEWROUTE;
+ nl->nlmsg_flags = NLM_F_REQUEST|NLM_F_CREATE;
+ rtm->rtm_protocol = RTPROT_BOOT;
+ }
+
+ rtm->rtm_dst_len = plen;
+ rta->rta_dst = ptr;
+
+ if (r->rt_metric) {
+ *(u32*)&r->rt_pad3 = r->rt_metric - 1;
+ rta->rta_priority = (u32*)&r->rt_pad3;
+ }
+ if (r->rt_flags&RTF_REJECT) {
+ rtm->rtm_scope = RT_SCOPE_HOST;
+ rtm->rtm_type = RTN_UNREACHABLE;
+ return 0;
+ }
+ rtm->rtm_scope = RT_SCOPE_NOWHERE;
+ rtm->rtm_type = RTN_UNICAST;
+
+ if (r->rt_dev) {
+ char *colon;
+ struct net_device *dev;
+ char devname[IFNAMSIZ];
+
+ if (copy_from_user(devname, r->rt_dev, IFNAMSIZ-1))
+ return -EFAULT;
+ devname[IFNAMSIZ-1] = 0;
+ colon = strchr(devname, ':');
+ if (colon)
+ *colon = 0;
+ dev = __dev_get_by_name(devname);
+ if (!dev)
+ return -ENODEV;
+ rta->rta_oif = &dev->ifindex;
+ if (colon) {
+ struct in_ifaddr *ifa;
+ struct in_device *in_dev = __in_dev_get(dev);
+ if (!in_dev)
+ return -ENODEV;
+ *colon = ':';
+ for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
+ if (strcmp(ifa->ifa_label, devname) == 0)
+ break;
+ if (ifa == NULL)
+ return -ENODEV;
+ rta->rta_prefsrc = &ifa->ifa_local;
+ }
+ }
+
+ ptr = &((struct sockaddr_in*)&r->rt_gateway)->sin_addr.s_addr;
+ if (r->rt_gateway.sa_family == AF_INET && *ptr) {
+ rta->rta_gw = ptr;
+ if (r->rt_flags&RTF_GATEWAY && inet_addr_type(*ptr) == RTN_UNICAST)
+ rtm->rtm_scope = RT_SCOPE_UNIVERSE;
+ }
+
+ if (cmd == SIOCDELRT)
+ return 0;
+
+ if (r->rt_flags&RTF_GATEWAY && rta->rta_gw == NULL)
+ return -EINVAL;
+
+ if (rtm->rtm_scope == RT_SCOPE_NOWHERE)
+ rtm->rtm_scope = RT_SCOPE_LINK;
+
+ if (r->rt_flags&(RTF_MTU|RTF_WINDOW|RTF_IRTT)) {
+ struct rtattr *rec;
+ struct rtattr *mx = kmalloc(RTA_LENGTH(3*RTA_LENGTH(4)), GFP_KERNEL);
+ if (mx == NULL)
+ return -ENOMEM;
+ rta->rta_mx = mx;
+ mx->rta_type = RTA_METRICS;
+ mx->rta_len = RTA_LENGTH(0);
+ if (r->rt_flags&RTF_MTU) {
+ rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
+ rec->rta_type = RTAX_ADVMSS;
+ rec->rta_len = RTA_LENGTH(4);
+ mx->rta_len += RTA_LENGTH(4);
+ *(u32*)RTA_DATA(rec) = r->rt_mtu - 40;
+ }
+ if (r->rt_flags&RTF_WINDOW) {
+ rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
+ rec->rta_type = RTAX_WINDOW;
+ rec->rta_len = RTA_LENGTH(4);
+ mx->rta_len += RTA_LENGTH(4);
+ *(u32*)RTA_DATA(rec) = r->rt_window;
+ }
+ if (r->rt_flags&RTF_IRTT) {
+ rec = (void*)((char*)mx + RTA_ALIGN(mx->rta_len));
+ rec->rta_type = RTAX_RTT;
+ rec->rta_len = RTA_LENGTH(4);
+ mx->rta_len += RTA_LENGTH(4);
+ *(u32*)RTA_DATA(rec) = r->rt_irtt<<3;
+ }
+ }
+ return 0;
+}
+
+#endif
+
+/*
+ Update FIB if:
+ - local address disappeared -> we must delete all the entries
+ referring to it.
+ - device went down -> we must shutdown all nexthops going via it.
+ */
+
+int fib_sync_down(u32 local, struct net_device *dev, int force)
+{
+ int ret = 0;
+ int scope = RT_SCOPE_NOWHERE;
+
+ if (force)
+ scope = -1;
+
+ if (local && fib_info_laddrhash) {
+ unsigned int hash = fib_laddr_hashfn(local);
+ struct hlist_head *head = &fib_info_laddrhash[hash];
+ struct hlist_node *node;
+ struct fib_info *fi;
+
+ hlist_for_each_entry(fi, node, head, fib_lhash) {
+ if (fi->fib_prefsrc == local) {
+ fi->fib_flags |= RTNH_F_DEAD;
+ ret++;
+ }
+ }
+ }
+
+ if (dev) {
+ struct fib_info *prev_fi = NULL;
+ unsigned int hash = fib_devindex_hashfn(dev->ifindex);
+ struct hlist_head *head = &fib_info_devhash[hash];
+ struct hlist_node *node;
+ struct fib_nh *nh;
+
+ hlist_for_each_entry(nh, node, head, nh_hash) {
+ struct fib_info *fi = nh->nh_parent;
+ int dead;
+
+ BUG_ON(!fi->fib_nhs);
+ if (nh->nh_dev != dev || fi == prev_fi)
+ continue;
+ prev_fi = fi;
+ dead = 0;
+ change_nexthops(fi) {
+ if (nh->nh_flags&RTNH_F_DEAD)
+ dead++;
+ else if (nh->nh_dev == dev &&
+ nh->nh_scope != scope) {
+ nh->nh_flags |= RTNH_F_DEAD;
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ spin_lock_bh(&fib_multipath_lock);
+ fi->fib_power -= nh->nh_power;
+ nh->nh_power = 0;
+ spin_unlock_bh(&fib_multipath_lock);
+#endif
+ dead++;
+ }
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+ if (force > 1 && nh->nh_dev == dev) {
+ dead = fi->fib_nhs;
+ break;
+ }
+#endif
+ } endfor_nexthops(fi)
+ if (dead == fi->fib_nhs) {
+ fi->fib_flags |= RTNH_F_DEAD;
+ ret++;
+ }
+ }
+ }
+
+ return ret;
+}
+
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+
+/*
+ Dead device goes up. We wake up dead nexthops.
+ It takes sense only on multipath routes.
+ */
+
+int fib_sync_up(struct net_device *dev)
+{
+ struct fib_info *prev_fi;
+ unsigned int hash;
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct fib_nh *nh;
+ int ret;
+
+ if (!(dev->flags&IFF_UP))
+ return 0;
+
+ prev_fi = NULL;
+ hash = fib_devindex_hashfn(dev->ifindex);
+ head = &fib_info_devhash[hash];
+ ret = 0;
+
+ hlist_for_each_entry(nh, node, head, nh_hash) {
+ struct fib_info *fi = nh->nh_parent;
+ int alive;
+
+ BUG_ON(!fi->fib_nhs);
+ if (nh->nh_dev != dev || fi == prev_fi)
+ continue;
+
+ prev_fi = fi;
+ alive = 0;
+ change_nexthops(fi) {
+ if (!(nh->nh_flags&RTNH_F_DEAD)) {
+ alive++;
+ continue;
+ }
+ if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
+ continue;
+ if (nh->nh_dev != dev || __in_dev_get(dev) == NULL)
+ continue;
+ alive++;
+ spin_lock_bh(&fib_multipath_lock);
+ nh->nh_power = 0;
+ nh->nh_flags &= ~RTNH_F_DEAD;
+ spin_unlock_bh(&fib_multipath_lock);
+ } endfor_nexthops(fi)
+
+ if (alive > 0) {
+ fi->fib_flags &= ~RTNH_F_DEAD;
+ ret++;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ The algorithm is suboptimal, but it provides really
+ fair weighted route distribution.
+ */
+
+void fib_select_multipath(const struct flowi *flp, struct fib_result *res)
+{
+ struct fib_info *fi = res->fi;
+ int w;
+
+ spin_lock_bh(&fib_multipath_lock);
+ if (fi->fib_power <= 0) {
+ int power = 0;
+ change_nexthops(fi) {
+ if (!(nh->nh_flags&RTNH_F_DEAD)) {
+ power += nh->nh_weight;
+ nh->nh_power = nh->nh_weight;
+ }
+ } endfor_nexthops(fi);
+ fi->fib_power = power;
+ if (power <= 0) {
+ spin_unlock_bh(&fib_multipath_lock);
+ /* Race condition: route has just become dead. */
+ res->nh_sel = 0;
+ return;
+ }
+ }
+
+
+ /* w should be random number [0..fi->fib_power-1],
+ it is pretty bad approximation.
+ */
+
+ w = jiffies % fi->fib_power;
+
+ change_nexthops(fi) {
+ if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
+ if ((w -= nh->nh_power) <= 0) {
+ nh->nh_power--;
+ fi->fib_power--;
+ res->nh_sel = nhsel;
+ spin_unlock_bh(&fib_multipath_lock);
+ return;
+ }
+ }
+ } endfor_nexthops(fi);
+
+ /* Race condition: route has just become dead. */
+ res->nh_sel = 0;
+ spin_unlock_bh(&fib_multipath_lock);
+}
+#endif