mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 02:09:42 +00:00
1222 lines
28 KiB
C
1222 lines
28 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* 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 <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/inetdevice.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/if_arp.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/init.h>
|
|
|
|
#include <net/arp.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/netlink.h>
|
|
#include <net/nexthop.h>
|
|
|
|
#include "fib_lookup.h"
|
|
|
|
static DEFINE_SPINLOCK(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 const struct
|
|
{
|
|
int error;
|
|
u8 scope;
|
|
} fib_props[RTN_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(KERN_WARNING "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--;
|
|
release_net(fi->fib_net);
|
|
kfree(fi);
|
|
}
|
|
|
|
void fib_release_info(struct fib_info *fi)
|
|
{
|
|
spin_lock_bh(&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);
|
|
}
|
|
spin_unlock_bh(&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_devindex_hashfn(unsigned int val)
|
|
{
|
|
unsigned int mask = DEVINDEX_HASHSIZE - 1;
|
|
|
|
return (val ^
|
|
(val >> DEVINDEX_HASHBITS) ^
|
|
(val >> (DEVINDEX_HASHBITS * 2))) & mask;
|
|
}
|
|
|
|
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 ^= (__force u32)fi->fib_prefsrc;
|
|
val ^= fi->fib_priority;
|
|
for_nexthops(fi) {
|
|
val ^= fib_devindex_hashfn(nh->nh_oif);
|
|
} endfor_nexthops(fi)
|
|
|
|
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_net != nfi->fib_net)
|
|
continue;
|
|
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;
|
|
}
|
|
|
|
/* Check, that the gateway is already configured.
|
|
Used only by redirect accept routine.
|
|
*/
|
|
|
|
int ip_fib_check_default(__be32 gw, struct net_device *dev)
|
|
{
|
|
struct hlist_head *head;
|
|
struct hlist_node *node;
|
|
struct fib_nh *nh;
|
|
unsigned int hash;
|
|
|
|
spin_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)) {
|
|
spin_unlock(&fib_info_lock);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
spin_unlock(&fib_info_lock);
|
|
|
|
return -1;
|
|
}
|
|
|
|
static inline size_t fib_nlmsg_size(struct fib_info *fi)
|
|
{
|
|
size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
|
|
+ nla_total_size(4) /* RTA_TABLE */
|
|
+ nla_total_size(4) /* RTA_DST */
|
|
+ nla_total_size(4) /* RTA_PRIORITY */
|
|
+ nla_total_size(4); /* RTA_PREFSRC */
|
|
|
|
/* space for nested metrics */
|
|
payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
|
|
|
|
if (fi->fib_nhs) {
|
|
/* Also handles the special case fib_nhs == 1 */
|
|
|
|
/* each nexthop is packed in an attribute */
|
|
size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
|
|
|
|
/* may contain flow and gateway attribute */
|
|
nhsize += 2 * nla_total_size(4);
|
|
|
|
/* all nexthops are packed in a nested attribute */
|
|
payload += nla_total_size(fi->fib_nhs * nhsize);
|
|
}
|
|
|
|
return payload;
|
|
}
|
|
|
|
void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
|
|
int dst_len, u32 tb_id, struct nl_info *info,
|
|
unsigned int nlm_flags)
|
|
{
|
|
struct sk_buff *skb;
|
|
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
|
|
int err = -ENOBUFS;
|
|
|
|
skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
|
|
if (skb == NULL)
|
|
goto errout;
|
|
|
|
err = fib_dump_info(skb, info->pid, seq, event, tb_id,
|
|
fa->fa_type, fa->fa_scope, key, dst_len,
|
|
fa->fa_tos, fa->fa_info, nlm_flags);
|
|
if (err < 0) {
|
|
/* -EMSGSIZE implies BUG in fib_nlmsg_size() */
|
|
WARN_ON(err == -EMSGSIZE);
|
|
kfree_skb(skb);
|
|
goto errout;
|
|
}
|
|
err = rtnl_notify(skb, info->nl_net, info->pid, RTNLGRP_IPV4_ROUTE,
|
|
info->nlh, GFP_KERNEL);
|
|
errout:
|
|
if (err < 0)
|
|
rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
|
|
}
|
|
|
|
/* 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 int fib_count_nexthops(struct rtnexthop *rtnh, int remaining)
|
|
{
|
|
int nhs = 0;
|
|
|
|
while (rtnh_ok(rtnh, remaining)) {
|
|
nhs++;
|
|
rtnh = rtnh_next(rtnh, &remaining);
|
|
}
|
|
|
|
/* leftover implies invalid nexthop configuration, discard it */
|
|
return remaining > 0 ? 0 : nhs;
|
|
}
|
|
|
|
static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
|
|
int remaining, struct fib_config *cfg)
|
|
{
|
|
change_nexthops(fi) {
|
|
int attrlen;
|
|
|
|
if (!rtnh_ok(rtnh, remaining))
|
|
return -EINVAL;
|
|
|
|
nh->nh_flags = (cfg->fc_flags & ~0xFF) | rtnh->rtnh_flags;
|
|
nh->nh_oif = rtnh->rtnh_ifindex;
|
|
nh->nh_weight = rtnh->rtnh_hops + 1;
|
|
|
|
attrlen = rtnh_attrlen(rtnh);
|
|
if (attrlen > 0) {
|
|
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
|
|
|
|
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
|
|
nh->nh_gw = nla ? nla_get_be32(nla) : 0;
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
nla = nla_find(attrs, attrlen, RTA_FLOW);
|
|
nh->nh_tclassid = nla ? nla_get_u32(nla) : 0;
|
|
#endif
|
|
}
|
|
|
|
rtnh = rtnh_next(rtnh, &remaining);
|
|
} endfor_nexthops(fi);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)
|
|
{
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
struct rtnexthop *rtnh;
|
|
int remaining;
|
|
#endif
|
|
|
|
if (cfg->fc_priority && cfg->fc_priority != fi->fib_priority)
|
|
return 1;
|
|
|
|
if (cfg->fc_oif || cfg->fc_gw) {
|
|
if ((!cfg->fc_oif || cfg->fc_oif == fi->fib_nh->nh_oif) &&
|
|
(!cfg->fc_gw || cfg->fc_gw == fi->fib_nh->nh_gw))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (cfg->fc_mp == NULL)
|
|
return 0;
|
|
|
|
rtnh = cfg->fc_mp;
|
|
remaining = cfg->fc_mp_len;
|
|
|
|
for_nexthops(fi) {
|
|
int attrlen;
|
|
|
|
if (!rtnh_ok(rtnh, remaining))
|
|
return -EINVAL;
|
|
|
|
if (rtnh->rtnh_ifindex && rtnh->rtnh_ifindex != nh->nh_oif)
|
|
return 1;
|
|
|
|
attrlen = rtnh_attrlen(rtnh);
|
|
if (attrlen < 0) {
|
|
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
|
|
|
|
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
|
|
if (nla && nla_get_be32(nla) != nh->nh_gw)
|
|
return 1;
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
nla = nla_find(attrs, attrlen, RTA_FLOW);
|
|
if (nla && nla_get_u32(nla) != nh->nh_tclassid)
|
|
return 1;
|
|
#endif
|
|
}
|
|
|
|
rtnh = rtnh_next(rtnh, &remaining);
|
|
} 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(struct fib_config *cfg, struct fib_info *fi,
|
|
struct fib_nh *nh)
|
|
{
|
|
int err;
|
|
struct net *net;
|
|
|
|
net = cfg->fc_nlinfo.nl_net;
|
|
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 (cfg->fc_scope >= RT_SCOPE_LINK)
|
|
return -EINVAL;
|
|
if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST)
|
|
return -EINVAL;
|
|
if ((dev = __dev_get_by_index(net, 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 = cfg->fc_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(net, &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(net, 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(__be32 val)
|
|
{
|
|
unsigned int mask = (fib_hash_size - 1);
|
|
|
|
return ((__force u32)val ^ ((__force u32)val >> 7) ^ ((__force u32)val >> 14)) & mask;
|
|
}
|
|
|
|
static struct hlist_head *fib_hash_alloc(int bytes)
|
|
{
|
|
if (bytes <= PAGE_SIZE)
|
|
return kzalloc(bytes, GFP_KERNEL);
|
|
else
|
|
return (struct hlist_head *)
|
|
__get_free_pages(GFP_KERNEL | __GFP_ZERO, 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)
|
|
{
|
|
struct hlist_head *old_info_hash, *old_laddrhash;
|
|
unsigned int old_size = fib_hash_size;
|
|
unsigned int i, bytes;
|
|
|
|
spin_lock_bh(&fib_info_lock);
|
|
old_info_hash = fib_info_hash;
|
|
old_laddrhash = fib_info_laddrhash;
|
|
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;
|
|
|
|
spin_unlock_bh(&fib_info_lock);
|
|
|
|
bytes = old_size * sizeof(struct hlist_head *);
|
|
fib_hash_free(old_info_hash, bytes);
|
|
fib_hash_free(old_laddrhash, bytes);
|
|
}
|
|
|
|
struct fib_info *fib_create_info(struct fib_config *cfg)
|
|
{
|
|
int err;
|
|
struct fib_info *fi = NULL;
|
|
struct fib_info *ofi;
|
|
int nhs = 1;
|
|
struct net *net = cfg->fc_nlinfo.nl_net;
|
|
|
|
/* Fast check to catch the most weird cases */
|
|
if (fib_props[cfg->fc_type].scope > cfg->fc_scope)
|
|
goto err_inval;
|
|
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (cfg->fc_mp) {
|
|
nhs = fib_count_nexthops(cfg->fc_mp, cfg->fc_mp_len);
|
|
if (nhs == 0)
|
|
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
|
|
fib_hash_move(new_info_hash, new_laddrhash, new_size);
|
|
|
|
if (!fib_hash_size)
|
|
goto failure;
|
|
}
|
|
|
|
fi = kzalloc(sizeof(*fi)+nhs*sizeof(struct fib_nh), GFP_KERNEL);
|
|
if (fi == NULL)
|
|
goto failure;
|
|
fib_info_cnt++;
|
|
|
|
fi->fib_net = hold_net(net);
|
|
fi->fib_protocol = cfg->fc_protocol;
|
|
fi->fib_flags = cfg->fc_flags;
|
|
fi->fib_priority = cfg->fc_priority;
|
|
fi->fib_prefsrc = cfg->fc_prefsrc;
|
|
|
|
fi->fib_nhs = nhs;
|
|
change_nexthops(fi) {
|
|
nh->nh_parent = fi;
|
|
} endfor_nexthops(fi)
|
|
|
|
if (cfg->fc_mx) {
|
|
struct nlattr *nla;
|
|
int remaining;
|
|
|
|
nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
|
|
int type = nla_type(nla);
|
|
|
|
if (type) {
|
|
if (type > RTAX_MAX)
|
|
goto err_inval;
|
|
fi->fib_metrics[type - 1] = nla_get_u32(nla);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (cfg->fc_mp) {
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg);
|
|
if (err != 0)
|
|
goto failure;
|
|
if (cfg->fc_oif && fi->fib_nh->nh_oif != cfg->fc_oif)
|
|
goto err_inval;
|
|
if (cfg->fc_gw && fi->fib_nh->nh_gw != cfg->fc_gw)
|
|
goto err_inval;
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (cfg->fc_flow && fi->fib_nh->nh_tclassid != cfg->fc_flow)
|
|
goto err_inval;
|
|
#endif
|
|
#else
|
|
goto err_inval;
|
|
#endif
|
|
} else {
|
|
struct fib_nh *nh = fi->fib_nh;
|
|
|
|
nh->nh_oif = cfg->fc_oif;
|
|
nh->nh_gw = cfg->fc_gw;
|
|
nh->nh_flags = cfg->fc_flags;
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
nh->nh_tclassid = cfg->fc_flow;
|
|
#endif
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
nh->nh_weight = 1;
|
|
#endif
|
|
}
|
|
|
|
if (fib_props[cfg->fc_type].error) {
|
|
if (cfg->fc_gw || cfg->fc_oif || cfg->fc_mp)
|
|
goto err_inval;
|
|
goto link_it;
|
|
}
|
|
|
|
if (cfg->fc_scope > RT_SCOPE_HOST)
|
|
goto err_inval;
|
|
|
|
if (cfg->fc_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(net, fi->fib_nh->nh_oif);
|
|
err = -ENODEV;
|
|
if (nh->nh_dev == NULL)
|
|
goto failure;
|
|
} else {
|
|
change_nexthops(fi) {
|
|
if ((err = fib_check_nh(cfg, fi, nh)) != 0)
|
|
goto failure;
|
|
} endfor_nexthops(fi)
|
|
}
|
|
|
|
if (fi->fib_prefsrc) {
|
|
if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
|
|
fi->fib_prefsrc != cfg->fc_dst)
|
|
if (inet_addr_type(net, 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);
|
|
spin_lock_bh(&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)
|
|
spin_unlock_bh(&fib_info_lock);
|
|
return fi;
|
|
|
|
err_inval:
|
|
err = -EINVAL;
|
|
|
|
failure:
|
|
if (fi) {
|
|
fi->fib_dead = 1;
|
|
free_fib_info(fi);
|
|
}
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/* Note! fib_semantic_match intentionally uses RCU list functions. */
|
|
int fib_semantic_match(struct list_head *head, const struct flowi *flp,
|
|
struct fib_result *res, __be32 zone, __be32 mask,
|
|
int prefixlen)
|
|
{
|
|
struct fib_alias *fa;
|
|
int nh_sel = 0;
|
|
|
|
list_for_each_entry_rcu(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_WARNING "fib_semantic_match bad type %#x\n",
|
|
fa->fa_type);
|
|
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;
|
|
atomic_inc(&res->fi->fib_clntref);
|
|
return 0;
|
|
}
|
|
|
|
/* Find appropriate source address to this destination */
|
|
|
|
__be32 __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,
|
|
u32 tb_id, u8 type, u8 scope, __be32 dst, int dst_len, u8 tos,
|
|
struct fib_info *fi, unsigned int flags)
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
struct rtmsg *rtm;
|
|
|
|
nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), flags);
|
|
if (nlh == NULL)
|
|
return -EMSGSIZE;
|
|
|
|
rtm = nlmsg_data(nlh);
|
|
rtm->rtm_family = AF_INET;
|
|
rtm->rtm_dst_len = dst_len;
|
|
rtm->rtm_src_len = 0;
|
|
rtm->rtm_tos = tos;
|
|
if (tb_id < 256)
|
|
rtm->rtm_table = tb_id;
|
|
else
|
|
rtm->rtm_table = RT_TABLE_COMPAT;
|
|
NLA_PUT_U32(skb, RTA_TABLE, tb_id);
|
|
rtm->rtm_type = type;
|
|
rtm->rtm_flags = fi->fib_flags;
|
|
rtm->rtm_scope = scope;
|
|
rtm->rtm_protocol = fi->fib_protocol;
|
|
|
|
if (rtm->rtm_dst_len)
|
|
NLA_PUT_BE32(skb, RTA_DST, dst);
|
|
|
|
if (fi->fib_priority)
|
|
NLA_PUT_U32(skb, RTA_PRIORITY, fi->fib_priority);
|
|
|
|
if (rtnetlink_put_metrics(skb, fi->fib_metrics) < 0)
|
|
goto nla_put_failure;
|
|
|
|
if (fi->fib_prefsrc)
|
|
NLA_PUT_BE32(skb, RTA_PREFSRC, fi->fib_prefsrc);
|
|
|
|
if (fi->fib_nhs == 1) {
|
|
if (fi->fib_nh->nh_gw)
|
|
NLA_PUT_BE32(skb, RTA_GATEWAY, fi->fib_nh->nh_gw);
|
|
|
|
if (fi->fib_nh->nh_oif)
|
|
NLA_PUT_U32(skb, RTA_OIF, fi->fib_nh->nh_oif);
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (fi->fib_nh[0].nh_tclassid)
|
|
NLA_PUT_U32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid);
|
|
#endif
|
|
}
|
|
#ifdef CONFIG_IP_ROUTE_MULTIPATH
|
|
if (fi->fib_nhs > 1) {
|
|
struct rtnexthop *rtnh;
|
|
struct nlattr *mp;
|
|
|
|
mp = nla_nest_start(skb, RTA_MULTIPATH);
|
|
if (mp == NULL)
|
|
goto nla_put_failure;
|
|
|
|
for_nexthops(fi) {
|
|
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
|
|
if (rtnh == NULL)
|
|
goto nla_put_failure;
|
|
|
|
rtnh->rtnh_flags = nh->nh_flags & 0xFF;
|
|
rtnh->rtnh_hops = nh->nh_weight - 1;
|
|
rtnh->rtnh_ifindex = nh->nh_oif;
|
|
|
|
if (nh->nh_gw)
|
|
NLA_PUT_BE32(skb, RTA_GATEWAY, nh->nh_gw);
|
|
#ifdef CONFIG_NET_CLS_ROUTE
|
|
if (nh->nh_tclassid)
|
|
NLA_PUT_U32(skb, RTA_FLOW, nh->nh_tclassid);
|
|
#endif
|
|
/* length of rtnetlink header + attributes */
|
|
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
|
|
} endfor_nexthops(fi);
|
|
|
|
nla_nest_end(skb, mp);
|
|
}
|
|
#endif
|
|
return nlmsg_end(skb, nlh);
|
|
|
|
nla_put_failure:
|
|
nlmsg_cancel(skb, nlh);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
/*
|
|
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_addr(struct net *net, __be32 local)
|
|
{
|
|
int ret = 0;
|
|
unsigned int hash = fib_laddr_hashfn(local);
|
|
struct hlist_head *head = &fib_info_laddrhash[hash];
|
|
struct hlist_node *node;
|
|
struct fib_info *fi;
|
|
|
|
if (fib_info_laddrhash == NULL || local == 0)
|
|
return 0;
|
|
|
|
hlist_for_each_entry(fi, node, head, fib_lhash) {
|
|
if (fi->fib_net != net)
|
|
continue;
|
|
if (fi->fib_prefsrc == local) {
|
|
fi->fib_flags |= RTNH_F_DEAD;
|
|
ret++;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int fib_sync_down_dev(struct net_device *dev, int force)
|
|
{
|
|
int ret = 0;
|
|
int scope = RT_SCOPE_NOWHERE;
|
|
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;
|
|
|
|
if (force)
|
|
scope = -1;
|
|
|
|
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_rtnl(dev))
|
|
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
|