Viewing file:  dn_rules.c (8.86 KB) -rw-r--r--
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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/config.h>
#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 <asm/atomic.h>
#include <asm/uaccess.h>
#include <net/neighbour.h>
#include <net/dst.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 dn_fib_rule *r_next;
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;
dn_address r_src;
dn_address r_srcmask;
dn_address r_dst;
dn_address r_dstmask;
u8 r_flags;
#ifdef CONFIG_DECNET_ROUTE_FWMARK
u32 r_fwmark;
#endif
int r_ifindex;
char r_ifname[IFNAMSIZ];
int r_dead;
};
static struct dn_fib_rule default_rule = {
r_clntref: ATOMIC_INIT(2),
r_preference: 0x7fff,
r_table: DN_DEFAULT_TABLE,
r_action: RTN_UNICAST
};
static struct dn_fib_rule *dn_fib_rules = &default_rule;
static rwlock_t dn_fib_rules_lock = RW_LOCK_UNLOCKED;
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, **rp;
int err = -ESRCH;
for(rp=&dn_fib_rules; (r=*rp) != NULL; rp = &r->r_next) {
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] || strcmp(RTA_DATA(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;
write_lock_bh(&dn_fib_rules_lock);
*rp = r->r_next;
r->r_dead = 1;
write_unlock_bh(&dn_fib_rules_lock);
dn_fib_rule_put(r);
err = 0;
break;
}
}
return err;
}
void dn_fib_rule_put(struct dn_fib_rule *r)
{
if (atomic_dec_and_test(&r->r_clntref)) {
if (r->r_dead)
kfree(r);
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, **rp;
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 = kmalloc(sizeof(*new_r), GFP_KERNEL);
if (!new_r)
return -ENOMEM;
memset(new_r, 0, sizeof(*new_r));
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);
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;
memcpy(new_r->r_ifname, RTA_DATA(rta[RTA_IIF-1]), IFNAMSIZ);
new_r->r_ifname[IFNAMSIZ-1] = 0;
new_r->r_ifindex = -1;
dev = __dev_get_by_name(new_r->r_ifname);
if (dev)
new_r->r_ifindex = dev->ifindex;
}
rp = &dn_fib_rules;
if (!new_r->r_preference) {
r = dn_fib_rules;
if (r && (r = r->r_next) != NULL) {
rp = &dn_fib_rules->r_next;
if (r->r_preference)
new_r->r_preference = r->r_preference - 1;
}
}
while((r=*rp) != NULL) {
if (r->r_preference > new_r->r_preference)
break;
rp = &r->r_next;
}
new_r->r_next = r;
atomic_inc(&new_r->r_clntref);
write_lock_bh(&dn_fib_rules_lock);
*rp = new_r;
write_unlock_bh(&dn_fib_rules_lock);
return 0;
}
int dn_fib_lookup(struct dn_fib_key *key, struct dn_fib_res *res)
{
struct dn_fib_rule *r, *policy;
struct dn_fib_table *tb;
dn_address saddr = key->src;
dn_address daddr = key->dst;
int err;
read_lock(&dn_fib_rules_lock);
for(r = dn_fib_rules; r; r = r->r_next) {
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 != key->fwmark) ||
#endif
(r->r_ifindex && r->r_ifindex != key->iif))
continue;
switch(r->r_action) {
case RTN_UNICAST:
policy = r;
break;
case RTN_UNREACHABLE:
read_unlock(&dn_fib_rules_lock);
return -ENETUNREACH;
default:
case RTN_BLACKHOLE:
read_unlock(&dn_fib_rules_lock);
return -EINVAL;
case RTN_PROHIBIT:
read_unlock(&dn_fib_rules_lock);
return -EACCES;
}
if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL)
continue;
err = tb->lookup(tb, key, res);
if (err == 0) {
res->r = policy;
if (policy)
atomic_inc(&policy->r_clntref);
read_unlock(&dn_fib_rules_lock);
return 0;
}
if (err < 0 && err != -EAGAIN) {
read_unlock(&dn_fib_rules_lock);
return err;
}
}
read_unlock(&dn_fib_rules_lock);
return -ESRCH;
}
static void dn_fib_rules_detach(struct net_device *dev)
{
struct dn_fib_rule *r;
for(r = dn_fib_rules; r; r = r->r_next) {
if (r->r_ifindex == dev->ifindex) {
write_lock_bh(&dn_fib_rules_lock);
r->r_ifindex = -1;
write_unlock_bh(&dn_fib_rules_lock);
}
}
}
static void dn_fib_rules_attach(struct net_device *dev)
{
struct dn_fib_rule *r;
for(r = dn_fib_rules; r; r = r->r_next) {
if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) {
write_lock_bh(&dn_fib_rules_lock);
r->r_ifindex = dev->ifindex;
write_unlock_bh(&dn_fib_rules_lock);
}
}
}
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)
{
struct rtmsg *rtm;
struct nlmsghdr *nlh;
unsigned char *b = skb->tail;
nlh = NLMSG_PUT(skb, NETLINK_CREDS(cb->skb)->pid, cb->nlh->nlmsg_seq, RTM_NEWRULE, sizeof(*rtm));
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);
nlh->nlmsg_len = skb->tail - b;
return skb->len;
nlmsg_failure:
rtattr_failure:
skb_put(skb, b - skb->tail);
return -1;
}
int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx;
int s_idx = cb->args[0];
struct dn_fib_rule *r;
read_lock(&dn_fib_rules_lock);
for(r = dn_fib_rules, idx = 0; r; r = r->r_next, idx++) {
if (idx < s_idx)
continue;
if (dn_fib_fill_rule(skb, r, cb) < 0)
break;
}
read_unlock(&dn_fib_rules_lock);
cb->args[0] = idx;
return skb->len;
}
void __init dn_fib_rules_init(void)
{
register_netdevice_notifier(&dn_fib_rules_notifier);
}
void __exit dn_fib_rules_cleanup(void)
{
unregister_netdevice_notifier(&dn_fib_rules_notifier);
}
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