ipv4: ipmr: support multiple tables
This patch adds support for multiple independant multicast routing instances,
named "tables".
Userspace multicast routing daemons can bind to a specific table instance by
issuing a setsockopt call using a new option MRT_TABLE. The table number is
stored in the raw socket data and affects all following ipmr setsockopt(),
getsockopt() and ioctl() calls. By default, a single table (RT_TABLE_DEFAULT)
is created with a default routing rule pointing to it. Newly created pimreg
devices have the table number appended ("pimregX"), with the exception of
devices created in the default table, which are named just "pimreg" for
compatibility reasons.
Packets are directed to a specific table instance using routing rules,
similar to how regular routing rules work. Currently iif, oif and mark
are supported as keys, source and destination addresses could be supported
additionally.
Example usage:
- bind pimd/xorp/... to a specific table:
uint32_t table = 123;
setsockopt(fd, IPPROTO_IP, MRT_TABLE, &table, sizeof(table));
- create routing rules directing packets to the new table:
# ip mrule add iif eth0 lookup 123
# ip mrule add oif eth0 lookup 123
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 498f4e9..5df5fd7 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -63,12 +63,15 @@
#include <net/ipip.h>
#include <net/checksum.h>
#include <net/netlink.h>
+#include <net/fib_rules.h>
#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
#define CONFIG_IP_PIMSM 1
#endif
struct mr_table {
+ struct list_head list;
+ u32 id;
struct sock *mroute_sk;
struct timer_list ipmr_expire_timer;
struct list_head mfc_unres_queue;
@@ -83,6 +86,14 @@
#endif
};
+struct ipmr_rule {
+ struct fib_rule common;
+};
+
+struct ipmr_result {
+ struct mr_table *mrt;
+};
+
/* Big lock, protecting vif table, mrt cache and mroute socket state.
Note that the changes are semaphored via rtnl_lock.
*/
@@ -108,6 +119,7 @@
static struct kmem_cache *mrt_cachep __read_mostly;
+static struct mr_table *ipmr_new_table(struct net *net, u32 id);
static int ip_mr_forward(struct net *net, struct mr_table *mrt,
struct sk_buff *skb, struct mfc_cache *cache,
int local);
@@ -115,6 +127,206 @@
struct sk_buff *pkt, vifi_t vifi, int assert);
static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
struct mfc_cache *c, struct rtmsg *rtm);
+static void ipmr_expire_process(unsigned long arg);
+
+#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
+#define ipmr_for_each_table(mrt, net) \
+ list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
+
+static struct mr_table *ipmr_get_table(struct net *net, u32 id)
+{
+ struct mr_table *mrt;
+
+ ipmr_for_each_table(mrt, net) {
+ if (mrt->id == id)
+ return mrt;
+ }
+ return NULL;
+}
+
+static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
+ struct mr_table **mrt)
+{
+ struct ipmr_result res;
+ struct fib_lookup_arg arg = { .result = &res, };
+ int err;
+
+ err = fib_rules_lookup(net->ipv4.mr_rules_ops, flp, 0, &arg);
+ if (err < 0)
+ return err;
+ *mrt = res.mrt;
+ return 0;
+}
+
+static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
+ int flags, struct fib_lookup_arg *arg)
+{
+ struct ipmr_result *res = arg->result;
+ struct mr_table *mrt;
+
+ switch (rule->action) {
+ case FR_ACT_TO_TBL:
+ break;
+ case FR_ACT_UNREACHABLE:
+ return -ENETUNREACH;
+ case FR_ACT_PROHIBIT:
+ return -EACCES;
+ case FR_ACT_BLACKHOLE:
+ default:
+ return -EINVAL;
+ }
+
+ mrt = ipmr_get_table(rule->fr_net, rule->table);
+ if (mrt == NULL)
+ return -EAGAIN;
+ res->mrt = mrt;
+ return 0;
+}
+
+static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
+{
+ return 1;
+}
+
+static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
+ FRA_GENERIC_POLICY,
+};
+
+static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
+ struct fib_rule_hdr *frh, struct nlattr **tb)
+{
+ return 0;
+}
+
+static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
+ struct nlattr **tb)
+{
+ return 1;
+}
+
+static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
+ struct fib_rule_hdr *frh)
+{
+ frh->dst_len = 0;
+ frh->src_len = 0;
+ frh->tos = 0;
+ return 0;
+}
+
+static struct fib_rules_ops ipmr_rules_ops_template = {
+ .family = FIB_RULES_IPMR,
+ .rule_size = sizeof(struct ipmr_rule),
+ .addr_size = sizeof(u32),
+ .action = ipmr_rule_action,
+ .match = ipmr_rule_match,
+ .configure = ipmr_rule_configure,
+ .compare = ipmr_rule_compare,
+ .default_pref = fib_default_rule_pref,
+ .fill = ipmr_rule_fill,
+ .nlgroup = RTNLGRP_IPV4_RULE,
+ .policy = ipmr_rule_policy,
+ .owner = THIS_MODULE,
+};
+
+static int __net_init ipmr_rules_init(struct net *net)
+{
+ struct fib_rules_ops *ops;
+ struct mr_table *mrt;
+ int err;
+
+ ops = fib_rules_register(&ipmr_rules_ops_template, net);
+ if (IS_ERR(ops))
+ return PTR_ERR(ops);
+
+ INIT_LIST_HEAD(&net->ipv4.mr_tables);
+
+ mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
+ if (mrt == NULL) {
+ err = -ENOMEM;
+ goto err1;
+ }
+
+ err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
+ if (err < 0)
+ goto err2;
+
+ net->ipv4.mr_rules_ops = ops;
+ return 0;
+
+err2:
+ kfree(mrt);
+err1:
+ fib_rules_unregister(ops);
+ return err;
+}
+
+static void __net_exit ipmr_rules_exit(struct net *net)
+{
+ struct mr_table *mrt, *next;
+
+ list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list)
+ kfree(mrt);
+ fib_rules_unregister(net->ipv4.mr_rules_ops);
+}
+#else
+#define ipmr_for_each_table(mrt, net) \
+ for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
+
+static struct mr_table *ipmr_get_table(struct net *net, u32 id)
+{
+ return net->ipv4.mrt;
+}
+
+static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
+ struct mr_table **mrt)
+{
+ *mrt = net->ipv4.mrt;
+ return 0;
+}
+
+static int __net_init ipmr_rules_init(struct net *net)
+{
+ net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
+ return net->ipv4.mrt ? 0 : -ENOMEM;
+}
+
+static void __net_exit ipmr_rules_exit(struct net *net)
+{
+ kfree(net->ipv4.mrt);
+}
+#endif
+
+static struct mr_table *ipmr_new_table(struct net *net, u32 id)
+{
+ struct mr_table *mrt;
+ unsigned int i;
+
+ mrt = ipmr_get_table(net, id);
+ if (mrt != NULL)
+ return mrt;
+
+ mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
+ if (mrt == NULL)
+ return NULL;
+ mrt->id = id;
+
+ /* Forwarding cache */
+ for (i = 0; i < MFC_LINES; i++)
+ INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
+
+ INIT_LIST_HEAD(&mrt->mfc_unres_queue);
+
+ setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
+ (unsigned long)mrt);
+
+#ifdef CONFIG_IP_PIMSM
+ mrt->mroute_reg_vif_num = -1;
+#endif
+#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
+ list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
+#endif
+ return mrt;
+}
/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
@@ -215,7 +427,17 @@
static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct net *net = dev_net(dev);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
+ struct flowi fl = {
+ .oif = dev->ifindex,
+ .iif = skb->skb_iif,
+ .mark = skb->mark,
+ };
+ int err;
+
+ err = ipmr_fib_lookup(net, &fl, &mrt);
+ if (err < 0)
+ return err;
read_lock(&mrt_lock);
dev->stats.tx_bytes += skb->len;
@@ -240,12 +462,18 @@
dev->features |= NETIF_F_NETNS_LOCAL;
}
-static struct net_device *ipmr_reg_vif(struct net *net)
+static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
{
struct net_device *dev;
struct in_device *in_dev;
+ char name[IFNAMSIZ];
- dev = alloc_netdev(0, "pimreg", reg_vif_setup);
+ if (mrt->id == RT_TABLE_DEFAULT)
+ sprintf(name, "pimreg");
+ else
+ sprintf(name, "pimreg%u", mrt->id);
+
+ dev = alloc_netdev(0, name, reg_vif_setup);
if (dev == NULL)
return NULL;
@@ -461,7 +689,7 @@
*/
if (mrt->mroute_reg_vif_num >= 0)
return -EADDRINUSE;
- dev = ipmr_reg_vif(net);
+ dev = ipmr_reg_vif(net, mrt);
if (!dev)
return -ENOBUFS;
err = dev_set_allmulti(dev, 1);
@@ -928,17 +1156,19 @@
static void mrtsock_destruct(struct sock *sk)
{
struct net *net = sock_net(sk);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
rtnl_lock();
- if (sk == mrt->mroute_sk) {
- IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
+ ipmr_for_each_table(mrt, net) {
+ if (sk == mrt->mroute_sk) {
+ IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
- write_lock_bh(&mrt_lock);
- mrt->mroute_sk = NULL;
- write_unlock_bh(&mrt_lock);
+ write_lock_bh(&mrt_lock);
+ mrt->mroute_sk = NULL;
+ write_unlock_bh(&mrt_lock);
- mroute_clean_tables(mrt);
+ mroute_clean_tables(mrt);
+ }
}
rtnl_unlock();
}
@@ -956,7 +1186,11 @@
struct vifctl vif;
struct mfcctl mfc;
struct net *net = sock_net(sk);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
+
+ mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
+ if (mrt == NULL)
+ return -ENOENT;
if (optname != MRT_INIT) {
if (sk != mrt->mroute_sk && !capable(CAP_NET_ADMIN))
@@ -1055,6 +1289,27 @@
return ret;
}
#endif
+#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
+ case MRT_TABLE:
+ {
+ u32 v;
+
+ if (optlen != sizeof(u32))
+ return -EINVAL;
+ if (get_user(v, (u32 __user *)optval))
+ return -EFAULT;
+ if (sk == mrt->mroute_sk)
+ return -EBUSY;
+
+ rtnl_lock();
+ ret = 0;
+ if (!ipmr_new_table(net, v))
+ ret = -ENOMEM;
+ raw_sk(sk)->ipmr_table = v;
+ rtnl_unlock();
+ return ret;
+ }
+#endif
/*
* Spurious command, or MRT_VERSION which you cannot
* set.
@@ -1073,7 +1328,11 @@
int olr;
int val;
struct net *net = sock_net(sk);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
+
+ mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
+ if (mrt == NULL)
+ return -ENOENT;
if (optname != MRT_VERSION &&
#ifdef CONFIG_IP_PIMSM
@@ -1115,7 +1374,11 @@
struct vif_device *vif;
struct mfc_cache *c;
struct net *net = sock_net(sk);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
+
+ mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
+ if (mrt == NULL)
+ return -ENOENT;
switch (cmd) {
case SIOCGETVIFCNT:
@@ -1166,17 +1429,20 @@
{
struct net_device *dev = ptr;
struct net *net = dev_net(dev);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
struct vif_device *v;
int ct;
LIST_HEAD(list);
if (event != NETDEV_UNREGISTER)
return NOTIFY_DONE;
- v = &mrt->vif_table[0];
- for (ct = 0; ct < mrt->maxvif; ct++, v++) {
- if (v->dev == dev)
- vif_delete(mrt, ct, 1, &list);
+
+ ipmr_for_each_table(mrt, net) {
+ v = &mrt->vif_table[0];
+ for (ct = 0; ct < mrt->maxvif; ct++, v++) {
+ if (v->dev == dev)
+ vif_delete(mrt, ct, 1, &list);
+ }
}
unregister_netdevice_many(&list);
return NOTIFY_DONE;
@@ -1443,8 +1709,9 @@
{
struct mfc_cache *cache;
struct net *net = dev_net(skb->dev);
- struct mr_table *mrt = net->ipv4.mrt;
int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
+ struct mr_table *mrt;
+ int err;
/* Packet is looped back after forward, it should not be
forwarded second time, but still can be delivered locally.
@@ -1452,6 +1719,10 @@
if (IPCB(skb)->flags&IPSKB_FORWARDED)
goto dont_forward;
+ err = ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt);
+ if (err < 0)
+ return err;
+
if (!local) {
if (IPCB(skb)->opt.router_alert) {
if (ip_call_ra_chain(skb))
@@ -1522,12 +1793,11 @@
}
#ifdef CONFIG_IP_PIMSM
-static int __pim_rcv(struct sk_buff *skb, unsigned int pimlen)
+static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
+ unsigned int pimlen)
{
struct net_device *reg_dev = NULL;
struct iphdr *encap;
- struct net *net = dev_net(skb->dev);
- struct mr_table *mrt = net->ipv4.mrt;
encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
/*
@@ -1578,18 +1848,21 @@
{
struct igmphdr *pim;
struct net *net = dev_net(skb->dev);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
goto drop;
pim = igmp_hdr(skb);
+ if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
+ goto drop;
+
if (!mrt->mroute_do_pim ||
pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
goto drop;
- if (__pim_rcv(skb, sizeof(*pim))) {
+ if (__pim_rcv(mrt, skb, sizeof(*pim))) {
drop:
kfree_skb(skb);
}
@@ -1601,6 +1874,8 @@
static int pim_rcv(struct sk_buff * skb)
{
struct pimreghdr *pim;
+ struct net *net = dev_net(skb->dev);
+ struct mr_table *mrt;
if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
goto drop;
@@ -1612,7 +1887,10 @@
csum_fold(skb_checksum(skb, 0, skb->len, 0))))
goto drop;
- if (__pim_rcv(skb, sizeof(*pim))) {
+ if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
+ goto drop;
+
+ if (__pim_rcv(mrt, skb, sizeof(*pim))) {
drop:
kfree_skb(skb);
}
@@ -1663,10 +1941,14 @@
struct sk_buff *skb, struct rtmsg *rtm, int nowait)
{
int err;
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt;
struct mfc_cache *cache;
struct rtable *rt = skb_rtable(skb);
+ mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
+ if (mrt == NULL)
+ return -ENOENT;
+
read_lock(&mrt_lock);
cache = ipmr_cache_find(mrt, rt->rt_src, rt->rt_dst);
@@ -1717,6 +1999,7 @@
*/
struct ipmr_vif_iter {
struct seq_net_private p;
+ struct mr_table *mrt;
int ct;
};
@@ -1724,7 +2007,7 @@
struct ipmr_vif_iter *iter,
loff_t pos)
{
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt = iter->mrt;
for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
if (!VIF_EXISTS(mrt, iter->ct))
@@ -1738,7 +2021,15 @@
static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(mrt_lock)
{
+ struct ipmr_vif_iter *iter = seq->private;
struct net *net = seq_file_net(seq);
+ struct mr_table *mrt;
+
+ mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
+ if (mrt == NULL)
+ return ERR_PTR(-ENOENT);
+
+ iter->mrt = mrt;
read_lock(&mrt_lock);
return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
@@ -1749,7 +2040,7 @@
{
struct ipmr_vif_iter *iter = seq->private;
struct net *net = seq_file_net(seq);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt = iter->mrt;
++*pos;
if (v == SEQ_START_TOKEN)
@@ -1771,8 +2062,8 @@
static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
{
- struct net *net = seq_file_net(seq);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct ipmr_vif_iter *iter = seq->private;
+ struct mr_table *mrt = iter->mrt;
if (v == SEQ_START_TOKEN) {
seq_puts(seq,
@@ -1814,6 +2105,7 @@
struct ipmr_mfc_iter {
struct seq_net_private p;
+ struct mr_table *mrt;
struct list_head *cache;
int ct;
};
@@ -1822,7 +2114,7 @@
static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
struct ipmr_mfc_iter *it, loff_t pos)
{
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt = it->mrt;
struct mfc_cache *mfc;
read_lock(&mrt_lock);
@@ -1850,7 +2142,13 @@
{
struct ipmr_mfc_iter *it = seq->private;
struct net *net = seq_file_net(seq);
+ struct mr_table *mrt;
+ mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
+ if (mrt == NULL)
+ return ERR_PTR(-ENOENT);
+
+ it->mrt = mrt;
it->cache = NULL;
it->ct = 0;
return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
@@ -1862,7 +2160,7 @@
struct mfc_cache *mfc = v;
struct ipmr_mfc_iter *it = seq->private;
struct net *net = seq_file_net(seq);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt = it->mrt;
++*pos;
@@ -1903,8 +2201,7 @@
static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
{
struct ipmr_mfc_iter *it = seq->private;
- struct net *net = seq_file_net(seq);
- struct mr_table *mrt = net->ipv4.mrt;
+ struct mr_table *mrt = it->mrt;
if (it->cache == &mrt->mfc_unres_queue)
spin_unlock_bh(&mfc_unres_lock);
@@ -1915,8 +2212,6 @@
static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
{
int n;
- struct net *net = seq_file_net(seq);
- struct mr_table *mrt = net->ipv4.mrt;
if (v == SEQ_START_TOKEN) {
seq_puts(seq,
@@ -1924,6 +2219,7 @@
} else {
const struct mfc_cache *mfc = v;
const struct ipmr_mfc_iter *it = seq->private;
+ const struct mr_table *mrt = it->mrt;
seq_printf(seq, "%08lX %08lX %-3hd",
(unsigned long) mfc->mfc_mcastgrp,
@@ -1989,28 +2285,11 @@
*/
static int __net_init ipmr_net_init(struct net *net)
{
- struct mr_table *mrt;
- unsigned int i;
- int err = 0;
+ int err;
- mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
- if (mrt == NULL) {
- err = -ENOMEM;
+ err = ipmr_rules_init(net);
+ if (err < 0)
goto fail;
- }
-
- /* Forwarding cache */
- for (i = 0; i < MFC_LINES; i++)
- INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
-
- INIT_LIST_HEAD(&mrt->mfc_unres_queue);
-
- setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
- (unsigned long)net);
-
-#ifdef CONFIG_IP_PIMSM
- mrt->mroute_reg_vif_num = -1;
-#endif
#ifdef CONFIG_PROC_FS
err = -ENOMEM;
@@ -2019,15 +2298,13 @@
if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
goto proc_cache_fail;
#endif
-
- net->ipv4.mrt = mrt;
return 0;
#ifdef CONFIG_PROC_FS
proc_cache_fail:
proc_net_remove(net, "ip_mr_vif");
proc_vif_fail:
- kfree(mrt);
+ ipmr_rules_exit(net);
#endif
fail:
return err;
@@ -2039,7 +2316,7 @@
proc_net_remove(net, "ip_mr_cache");
proc_net_remove(net, "ip_mr_vif");
#endif
- kfree(net->ipv4.mrt);
+ ipmr_rules_exit(net);
}
static struct pernet_operations ipmr_net_ops = {
