Commit 14c0b97d authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

[NET]: Protocol Independant Policy Routing Rules Framework



Derived from net/ipv/fib_rules.c
Signed-off-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c71099ac
#ifndef __LINUX_FIB_RULES_H
#define __LINUX_FIB_RULES_H
#include <linux/types.h>
#include <linux/rtnetlink.h>
/* rule is permanent, and cannot be deleted */
#define FIB_RULE_PERMANENT 1
struct fib_rule_hdr
{
__u8 family;
__u8 dst_len;
__u8 src_len;
__u8 tos;
__u8 table;
__u8 res1; /* reserved */
__u8 res2; /* reserved */
__u8 action;
__u32 flags;
};
enum
{
FRA_UNSPEC,
FRA_DST, /* destination address */
FRA_SRC, /* source address */
FRA_IFNAME, /* interface name */
FRA_UNUSED1,
FRA_UNUSED2,
FRA_PRIORITY, /* priority/preference */
FRA_UNUSED3,
FRA_UNUSED4,
FRA_UNUSED5,
FRA_FWMARK, /* netfilter mark (IPv4) */
FRA_FLOW, /* flow/class id */
__FRA_MAX
};
#define FRA_MAX (__FRA_MAX - 1)
enum
{
FR_ACT_UNSPEC,
FR_ACT_TO_TBL, /* Pass to fixed table */
FR_ACT_RES1,
FR_ACT_RES2,
FR_ACT_RES3,
FR_ACT_RES4,
FR_ACT_BLACKHOLE, /* Drop without notification */
FR_ACT_UNREACHABLE, /* Drop with ENETUNREACH */
FR_ACT_PROHIBIT, /* Drop with EACCES */
__FR_ACT_MAX,
};
#define FR_ACT_MAX (__FR_ACT_MAX - 1)
#endif
#ifndef __NET_FIB_RULES_H
#define __NET_FIB_RULES_H
#include <linux/types.h>
#include <linux/netdevice.h>
#include <linux/fib_rules.h>
#include <net/flow.h>
#include <net/netlink.h>
struct fib_rule
{
struct list_head list;
atomic_t refcnt;
int ifindex;
char ifname[IFNAMSIZ];
u32 pref;
u32 flags;
u32 table;
u8 action;
struct rcu_head rcu;
};
struct fib_lookup_arg
{
void *lookup_ptr;
void *result;
struct fib_rule *rule;
};
struct fib_rules_ops
{
int family;
struct list_head list;
int rule_size;
int (*action)(struct fib_rule *,
struct flowi *, int,
struct fib_lookup_arg *);
int (*match)(struct fib_rule *,
struct flowi *, int);
int (*configure)(struct fib_rule *,
struct sk_buff *,
struct nlmsghdr *,
struct fib_rule_hdr *,
struct nlattr **);
int (*compare)(struct fib_rule *,
struct fib_rule_hdr *,
struct nlattr **);
int (*fill)(struct fib_rule *, struct sk_buff *,
struct nlmsghdr *,
struct fib_rule_hdr *);
u32 (*default_pref)(void);
int nlgroup;
struct nla_policy *policy;
struct list_head *rules_list;
struct module *owner;
};
static inline void fib_rule_get(struct fib_rule *rule)
{
atomic_inc(&rule->refcnt);
}
static inline void fib_rule_put_rcu(struct rcu_head *head)
{
struct fib_rule *rule = container_of(head, struct fib_rule, rcu);
kfree(rule);
}
static inline void fib_rule_put(struct fib_rule *rule)
{
if (atomic_dec_and_test(&rule->refcnt))
call_rcu(&rule->rcu, fib_rule_put_rcu);
}
extern int fib_rules_register(struct fib_rules_ops *);
extern int fib_rules_unregister(struct fib_rules_ops *);
extern int fib_rules_lookup(struct fib_rules_ops *,
struct flowi *, int flags,
struct fib_lookup_arg *);
extern int fib_nl_newrule(struct sk_buff *,
struct nlmsghdr *, void *);
extern int fib_nl_delrule(struct sk_buff *,
struct nlmsghdr *, void *);
extern int fib_rules_dump(struct sk_buff *,
struct netlink_callback *, int);
#endif
......@@ -251,6 +251,9 @@ config WIRELESS_EXT
source "net/netlabel/Kconfig"
config FIB_RULES
bool
endif # if NET
endmenu # Networking
......@@ -17,3 +17,4 @@ obj-$(CONFIG_NET_PKTGEN) += pktgen.o
obj-$(CONFIG_WIRELESS_EXT) += wireless.o
obj-$(CONFIG_NETPOLL) += netpoll.o
obj-$(CONFIG_NET_DMA) += user_dma.o
obj-$(CONFIG_FIB_RULES) += fib_rules.o
/*
* net/core/fib_rules.c Generic Routing Rules
*
* 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, version 2.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <net/fib_rules.h>
static LIST_HEAD(rules_ops);
static DEFINE_SPINLOCK(rules_mod_lock);
static void notify_rule_change(int event, struct fib_rule *rule,
struct fib_rules_ops *ops);
static struct fib_rules_ops *lookup_rules_ops(int family)
{
struct fib_rules_ops *ops;
rcu_read_lock();
list_for_each_entry_rcu(ops, &rules_ops, list) {
if (ops->family == family) {
if (!try_module_get(ops->owner))
ops = NULL;
rcu_read_unlock();
return ops;
}
}
rcu_read_unlock();
return NULL;
}
static void rules_ops_put(struct fib_rules_ops *ops)
{
if (ops)
module_put(ops->owner);
}
int fib_rules_register(struct fib_rules_ops *ops)
{
int err = -EEXIST;
struct fib_rules_ops *o;
if (ops->rule_size < sizeof(struct fib_rule))
return -EINVAL;
if (ops->match == NULL || ops->configure == NULL ||
ops->compare == NULL || ops->fill == NULL ||
ops->action == NULL)
return -EINVAL;
spin_lock(&rules_mod_lock);
list_for_each_entry(o, &rules_ops, list)
if (ops->family == o->family)
goto errout;
list_add_tail_rcu(&ops->list, &rules_ops);
err = 0;
errout:
spin_unlock(&rules_mod_lock);
return err;
}
EXPORT_SYMBOL_GPL(fib_rules_register);
static void cleanup_ops(struct fib_rules_ops *ops)
{
struct fib_rule *rule, *tmp;
list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
list_del_rcu(&rule->list);
fib_rule_put(rule);
}
}
int fib_rules_unregister(struct fib_rules_ops *ops)
{
int err = 0;
struct fib_rules_ops *o;
spin_lock(&rules_mod_lock);
list_for_each_entry(o, &rules_ops, list) {
if (o == ops) {
list_del_rcu(&o->list);
cleanup_ops(ops);
goto out;
}
}
err = -ENOENT;
out:
spin_unlock(&rules_mod_lock);
synchronize_rcu();
return err;
}
EXPORT_SYMBOL_GPL(fib_rules_unregister);
int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
int flags, struct fib_lookup_arg *arg)
{
struct fib_rule *rule;
int err;
rcu_read_lock();
list_for_each_entry_rcu(rule, ops->rules_list, list) {
if (rule->ifindex && (rule->ifindex != fl->iif))
continue;
if (!ops->match(rule, fl, flags))
continue;
err = ops->action(rule, fl, flags, arg);
if (err != -EAGAIN) {
fib_rule_get(rule);
arg->rule = rule;
goto out;
}
}
err = -ENETUNREACH;
out:
rcu_read_unlock();
return err;
}
EXPORT_SYMBOL_GPL(fib_rules_lookup);
int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
struct fib_rule_hdr *frh = nlmsg_data(nlh);
struct fib_rules_ops *ops = NULL;
struct fib_rule *rule, *r, *last = NULL;
struct nlattr *tb[FRA_MAX+1];
int err = -EINVAL;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
goto errout;
ops = lookup_rules_ops(frh->family);
if (ops == NULL) {
err = EAFNOSUPPORT;
goto errout;
}
err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
if (err < 0)
goto errout;
if (tb[FRA_IFNAME] && nla_len(tb[FRA_IFNAME]) > IFNAMSIZ)
goto errout;
rule = kzalloc(ops->rule_size, GFP_KERNEL);
if (rule == NULL) {
err = -ENOMEM;
goto errout;
}
if (tb[FRA_PRIORITY])
rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
if (tb[FRA_IFNAME]) {
struct net_device *dev;
rule->ifindex = -1;
if (nla_strlcpy(rule->ifname, tb[FRA_IFNAME],
IFNAMSIZ) >= IFNAMSIZ)
goto errout_free;
dev = __dev_get_by_name(rule->ifname);
if (dev)
rule->ifindex = dev->ifindex;
}
rule->action = frh->action;
rule->flags = frh->flags;
rule->table = frh->table;
if (!rule->pref && ops->default_pref)
rule->pref = ops->default_pref();
err = ops->configure(rule, skb, nlh, frh, tb);
if (err < 0)
goto errout_free;
list_for_each_entry(r, ops->rules_list, list) {
if (r->pref > rule->pref)
break;
last = r;
}
fib_rule_get(rule);
if (last)
list_add_rcu(&rule->list, &last->list);
else
list_add_rcu(&rule->list, ops->rules_list);
notify_rule_change(RTM_NEWRULE, rule, ops);
rules_ops_put(ops);
return 0;
errout_free:
kfree(rule);
errout:
rules_ops_put(ops);
return err;
}
int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
struct fib_rule_hdr *frh = nlmsg_data(nlh);
struct fib_rules_ops *ops = NULL;
struct fib_rule *rule;
struct nlattr *tb[FRA_MAX+1];
int err = -EINVAL;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
goto errout;
ops = lookup_rules_ops(frh->family);
if (ops == NULL) {
err = EAFNOSUPPORT;
goto errout;
}
err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
if (err < 0)
goto errout;
list_for_each_entry(rule, ops->rules_list, list) {
if (frh->action && (frh->action != rule->action))
continue;
if (frh->table && (frh->table != rule->table))
continue;
if (tb[FRA_PRIORITY] &&
(rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
continue;
if (tb[FRA_IFNAME] &&
nla_strcmp(tb[FRA_IFNAME], rule->ifname))
continue;
if (!ops->compare(rule, frh, tb))
continue;
if (rule->flags & FIB_RULE_PERMANENT) {
err = -EPERM;
goto errout;
}
list_del_rcu(&rule->list);
synchronize_rcu();
notify_rule_change(RTM_DELRULE, rule, ops);
fib_rule_put(rule);
rules_ops_put(ops);
return 0;
}
err = -ENOENT;
errout:
rules_ops_put(ops);
return err;
}
static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
u32 pid, u32 seq, int type, int flags,
struct fib_rules_ops *ops)
{
struct nlmsghdr *nlh;
struct fib_rule_hdr *frh;
nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
if (nlh == NULL)
return -1;
frh = nlmsg_data(nlh);
frh->table = rule->table;
frh->res1 = 0;
frh->res2 = 0;
frh->action = rule->action;
frh->flags = rule->flags;
if (rule->ifname[0])
NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);
if (rule->pref)
NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
if (ops->fill(rule, skb, nlh, frh) < 0)
goto nla_put_failure;
return nlmsg_end(skb, nlh);
nla_put_failure:
return nlmsg_cancel(skb, nlh);
}
int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
{
int idx = 0;
struct fib_rule *rule;
struct fib_rules_ops *ops;
ops = lookup_rules_ops(family);
if (ops == NULL)
return -EAFNOSUPPORT;
rcu_read_lock();
list_for_each_entry(rule, ops->rules_list, list) {
if (idx < cb->args[0])
goto skip;
if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, RTM_NEWRULE,
NLM_F_MULTI, ops) < 0)
break;
skip:
idx++;
}
rcu_read_unlock();
cb->args[0] = idx;
rules_ops_put(ops);
return skb->len;
}
EXPORT_SYMBOL_GPL(fib_rules_dump);
static void notify_rule_change(int event, struct fib_rule *rule,
struct fib_rules_ops *ops)
{
int size = nlmsg_total_size(sizeof(struct fib_rule_hdr) + 128);
struct sk_buff *skb = alloc_skb(size, GFP_KERNEL);
if (skb == NULL)
netlink_set_err(rtnl, 0, ops->nlgroup, ENOBUFS);
else if (fib_nl_fill_rule(skb, rule, 0, 0, event, 0, ops) < 0) {
kfree_skb(skb);
netlink_set_err(rtnl, 0, ops->nlgroup, EINVAL);
} else
netlink_broadcast(rtnl, skb, 0, ops->nlgroup, GFP_KERNEL);
}
static void attach_rules(struct list_head *rules, struct net_device *dev)
{
struct fib_rule *rule;
list_for_each_entry(rule, rules, list) {
if (rule->ifindex == -1 &&
strcmp(dev->name, rule->ifname) == 0)
rule->ifindex = dev->ifindex;
}
}
static void detach_rules(struct list_head *rules, struct net_device *dev)
{
struct fib_rule *rule;
list_for_each_entry(rule, rules, list)
if (rule->ifindex == dev->ifindex)
rule->ifindex = -1;
}
static int fib_rules_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = ptr;
struct fib_rules_ops *ops;
ASSERT_RTNL();
rcu_read_lock();
switch (event) {
case NETDEV_REGISTER:
list_for_each_entry(ops, &rules_ops, list)
attach_rules(ops->rules_list, dev);
break;
case NETDEV_UNREGISTER:
list_for_each_entry(ops, &rules_ops, list)
detach_rules(ops->rules_list, dev);
break;
}
rcu_read_unlock();
return NOTIFY_DONE;
}
static struct notifier_block fib_rules_notifier = {
.notifier_call = fib_rules_event,
};
static int __init fib_rules_init(void)
{
return register_netdevice_notifier(&fib_rules_notifier);
}
subsys_initcall(fib_rules_init);
......@@ -49,6 +49,7 @@
#include <net/udp.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <net/fib_rules.h>
#include <net/netlink.h>
#ifdef CONFIG_NET_WIRELESS_RTNETLINK
#include <linux/wireless.h>
......@@ -103,7 +104,7 @@ static const int rtm_min[RTM_NR_FAMILIES] =
[RTM_FAM(RTM_NEWADDR)] = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
[RTM_FAM(RTM_NEWROUTE)] = NLMSG_LENGTH(sizeof(struct rtmsg)),
[RTM_FAM(RTM_NEWNEIGH)] = NLMSG_LENGTH(sizeof(struct ndmsg)),
[RTM_FAM(RTM_NEWRULE)] = NLMSG_LENGTH(sizeof(struct rtmsg)),
[RTM_FAM(RTM_NEWRULE)] = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
[RTM_FAM(RTM_NEWQDISC)] = NLMSG_LENGTH(sizeof(struct tcmsg)),
[RTM_FAM(RTM_NEWTCLASS)] = NLMSG_LENGTH(sizeof(struct tcmsg)),
[RTM_FAM(RTM_NEWTFILTER)] = NLMSG_LENGTH(sizeof(struct tcmsg)),
......@@ -120,7 +121,7 @@ static const int rta_max[RTM_NR_FAMILIES] =
[RTM_FAM(RTM_NEWADDR)] = IFA_MAX,
[RTM_FAM(RTM_NEWROUTE)] = RTA_MAX,
[RTM_FAM(RTM_NEWNEIGH)] = NDA_MAX,
[RTM_FAM(RTM_NEWRULE)] = RTA_MAX,
[RTM_FAM(RTM_NEWRULE)] = FRA_MAX,
[RTM_FAM(RTM_NEWQDISC)] = TCA_MAX,
[RTM_FAM(RTM_NEWTCLASS)] = TCA_MAX,
[RTM_FAM(RTM_NEWTFILTER)] = TCA_MAX,
......@@ -757,6 +758,10 @@ static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
[RTM_NEWNEIGH - RTM_BASE] = { .doit = neigh_add },
[RTM_DELNEIGH - RTM_BASE] = { .doit = neigh_delete },
[RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info },
#ifdef CONFIG_FIB_RULES
[RTM_NEWRULE - RTM_BASE] = { .doit = fib_nl_newrule },
[RTM_DELRULE - RTM_BASE] = { .doit = fib_nl_delrule },
#endif
[RTM_GETRULE - RTM_BASE] = { .dumpit = rtnetlink_dump_all },
[RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = neightbl_dump_info },
[RTM_SETNEIGHTBL - RTM_BASE] = { .doit = neightbl_set },
......
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