linux/net/decnet/dn_rules.c

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/*
* DECnet An implementation of the DECnet protocol suite for the LINUX
* operating system. DECnet is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* DECnet Routing Forwarding Information Base (Rules)
*
* Author: Steve Whitehouse <SteveW@ACM.org>
* Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c
*
*
* Changes:
*
*/
#include <linux/string.h>
#include <linux/net.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/proc_fs.h>
#include <linux/netdevice.h>
#include <linux/timer.h>
#include <linux/spinlock.h>
#include <linux/in_route.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <asm/atomic.h>
#include <asm/uaccess.h>
#include <net/neighbour.h>
#include <net/dst.h>
#include <net/flow.h>
#include <net/dn.h>
#include <net/dn_fib.h>
#include <net/dn_neigh.h>
#include <net/dn_dev.h>
struct dn_fib_rule
{
struct hlist_node r_hlist;
atomic_t r_clntref;
u32 r_preference;
unsigned char r_table;
unsigned char r_action;
unsigned char r_dst_len;
unsigned char r_src_len;
__le16 r_src;
__le16 r_srcmask;
__le16 r_dst;
__le16 r_dstmask;
__le16 r_srcmap;
u8 r_flags;
#ifdef CONFIG_DECNET_ROUTE_FWMARK
u32 r_fwmark;
#endif
int r_ifindex;
char r_ifname[IFNAMSIZ];
int r_dead;
struct rcu_head rcu;
};
static struct dn_fib_rule default_rule = {
.r_clntref = ATOMIC_INIT(2),
.r_preference = 0x7fff,
.r_table = RT_TABLE_MAIN,
.r_action = RTN_UNICAST
};
static struct hlist_head dn_fib_rules;
int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct rtattr **rta = arg;
struct rtmsg *rtm = NLMSG_DATA(nlh);
struct dn_fib_rule *r;
struct hlist_node *node;
int err = -ESRCH;
hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) &&
rtm->rtm_src_len == r->r_src_len &&
rtm->rtm_dst_len == r->r_dst_len &&
(!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) &&
#ifdef CONFIG_DECNET_ROUTE_FWMARK
(!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) &&
#endif
(!rtm->rtm_type || rtm->rtm_type == r->r_action) &&
(!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) &&
(!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) &&
(!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) {
err = -EPERM;
if (r == &default_rule)
break;
hlist_del_rcu(&r->r_hlist);
r->r_dead = 1;
dn_fib_rule_put(r);
err = 0;
break;
}
}
return err;
}
static inline void dn_fib_rule_put_rcu(struct rcu_head *head)
{
struct dn_fib_rule *r = container_of(head, struct dn_fib_rule, rcu);
kfree(r);
}
void dn_fib_rule_put(struct dn_fib_rule *r)
{
if (atomic_dec_and_test(&r->r_clntref)) {
if (r->r_dead)
call_rcu(&r->rcu, dn_fib_rule_put_rcu);
else
printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n");
}
}
int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
struct rtattr **rta = arg;
struct rtmsg *rtm = NLMSG_DATA(nlh);
struct dn_fib_rule *r, *new_r, *last = NULL;
struct hlist_node *node = NULL;
unsigned char table_id;
if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16)
return -EINVAL;
if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ)
return -EINVAL;
if (rtm->rtm_type == RTN_NAT)
return -EINVAL;
table_id = rtm->rtm_table;
if (table_id == RT_TABLE_UNSPEC) {
struct dn_fib_table *tb;
if (rtm->rtm_type == RTN_UNICAST) {
if ((tb = dn_fib_empty_table()) == NULL)
return -ENOBUFS;
table_id = tb->n;
}
}
new_r = kzalloc(sizeof(*new_r), GFP_KERNEL);
if (!new_r)
return -ENOMEM;
if (rta[RTA_SRC-1])
memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2);
if (rta[RTA_DST-1])
memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2);
if (rta[RTA_GATEWAY-1])
memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 2);
new_r->r_src_len = rtm->rtm_src_len;
new_r->r_dst_len = rtm->rtm_dst_len;
new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len);
new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len);
#ifdef CONFIG_DECNET_ROUTE_FWMARK
if (rta[RTA_PROTOINFO-1])
memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4);
#endif
new_r->r_action = rtm->rtm_type;
new_r->r_flags = rtm->rtm_flags;
if (rta[RTA_PRIORITY-1])
memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4);
new_r->r_table = table_id;
if (rta[RTA_IIF-1]) {
struct net_device *dev;
rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ);
new_r->r_ifindex = -1;
dev = dev_get_by_name(new_r->r_ifname);
if (dev) {
new_r->r_ifindex = dev->ifindex;
dev_put(dev);
}
}
r = container_of(dn_fib_rules.first, struct dn_fib_rule, r_hlist);
if (!new_r->r_preference) {
if (r && r->r_hlist.next != NULL) {
r = container_of(r->r_hlist.next, struct dn_fib_rule, r_hlist);
if (r->r_preference)
new_r->r_preference = r->r_preference - 1;
}
}
hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if (r->r_preference > new_r->r_preference)
break;
last = r;
}
atomic_inc(&new_r->r_clntref);
if (last)
hlist_add_after_rcu(&last->r_hlist, &new_r->r_hlist);
else
hlist_add_before_rcu(&new_r->r_hlist, &r->r_hlist);
return 0;
}
int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res)
{
struct dn_fib_rule *r, *policy;
struct dn_fib_table *tb;
__le16 saddr = flp->fld_src;
__le16 daddr = flp->fld_dst;
struct hlist_node *node;
int err;
rcu_read_lock();
hlist_for_each_entry_rcu(r, node, &dn_fib_rules, r_hlist) {
if (((saddr^r->r_src) & r->r_srcmask) ||
((daddr^r->r_dst) & r->r_dstmask) ||
#ifdef CONFIG_DECNET_ROUTE_FWMARK
(r->r_fwmark && r->r_fwmark != flp->fld_fwmark) ||
#endif
(r->r_ifindex && r->r_ifindex != flp->iif))
continue;
switch(r->r_action) {
case RTN_UNICAST:
case RTN_NAT:
policy = r;
break;
case RTN_UNREACHABLE:
rcu_read_unlock();
return -ENETUNREACH;
default:
case RTN_BLACKHOLE:
rcu_read_unlock();
return -EINVAL;
case RTN_PROHIBIT:
rcu_read_unlock();
return -EACCES;
}
if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL)
continue;
err = tb->lookup(tb, flp, res);
if (err == 0) {
res->r = policy;
if (policy)
atomic_inc(&policy->r_clntref);
rcu_read_unlock();
return 0;
}
if (err < 0 && err != -EAGAIN) {
rcu_read_unlock();
return err;
}
}
rcu_read_unlock();
return -ESRCH;
}
unsigned dnet_addr_type(__le16 addr)
{
struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } };
struct dn_fib_res res;
unsigned ret = RTN_UNICAST;
struct dn_fib_table *tb = dn_fib_tables[RT_TABLE_LOCAL];
res.r = NULL;
if (tb) {
if (!tb->lookup(tb, &fl, &res)) {
ret = res.type;
dn_fib_res_put(&res);
}
}
return ret;
}
__le16 dn_fib_rules_policy(__le16 saddr, struct dn_fib_res *res, unsigned *flags)
{
struct dn_fib_rule *r = res->r;
if (r->r_action == RTN_NAT) {
int addrtype = dnet_addr_type(r->r_srcmap);
if (addrtype == RTN_NAT) {
saddr = (saddr&~r->r_srcmask)|r->r_srcmap;
*flags |= RTCF_SNAT;
} else if (addrtype == RTN_LOCAL || r->r_srcmap == 0) {
saddr = r->r_srcmap;
*flags |= RTCF_MASQ;
}
}
return saddr;
}
static void dn_fib_rules_detach(struct net_device *dev)
{
struct hlist_node *node;
struct dn_fib_rule *r;
hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if (r->r_ifindex == dev->ifindex)
r->r_ifindex = -1;
}
}
static void dn_fib_rules_attach(struct net_device *dev)
{
struct hlist_node *node;
struct dn_fib_rule *r;
hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0)
r->r_ifindex = dev->ifindex;
}
}
static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
switch(event) {
case NETDEV_UNREGISTER:
dn_fib_rules_detach(dev);
dn_fib_sync_down(0, dev, 1);
case NETDEV_REGISTER:
dn_fib_rules_attach(dev);
dn_fib_sync_up(dev);
}
return NOTIFY_DONE;
}
static struct notifier_block dn_fib_rules_notifier = {
.notifier_call = dn_fib_rules_event,
};
static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r,
struct netlink_callback *cb, unsigned int flags)
{
struct rtmsg *rtm;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags);
rtm = NLMSG_DATA(nlh);
rtm->rtm_family = AF_DECnet;
rtm->rtm_dst_len = r->r_dst_len;
rtm->rtm_src_len = r->r_src_len;
rtm->rtm_tos = 0;
#ifdef CONFIG_DECNET_ROUTE_FWMARK
if (r->r_fwmark)
RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark);
#endif
rtm->rtm_table = r->r_table;
rtm->rtm_protocol = 0;
rtm->rtm_scope = 0;
rtm->rtm_type = r->r_action;
rtm->rtm_flags = r->r_flags;
if (r->r_dst_len)
RTA_PUT(skb, RTA_DST, 2, &r->r_dst);
if (r->r_src_len)
RTA_PUT(skb, RTA_SRC, 2, &r->r_src);
if (r->r_ifname[0])
RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname);
if (r->r_preference)
RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference);
if (r->r_srcmap)
RTA_PUT(skb, RTA_GATEWAY, 2, &r->r_srcmap);
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx = 0;
int s_idx = cb->args[0];
struct dn_fib_rule *r;
struct hlist_node *node;
rcu_read_lock();
hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) {
if (idx < s_idx)
goto next;
if (dn_fib_fill_rule(skb, r, cb, NLM_F_MULTI) < 0)
break;
next:
idx++;
}
rcu_read_unlock();
cb->args[0] = idx;
return skb->len;
}
void __init dn_fib_rules_init(void)
{
INIT_HLIST_HEAD(&dn_fib_rules);
hlist_add_head(&default_rule.r_hlist, &dn_fib_rules);
register_netdevice_notifier(&dn_fib_rules_notifier);
}
void __exit dn_fib_rules_cleanup(void)
{
unregister_netdevice_notifier(&dn_fib_rules_notifier);
}