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af_mpls.c
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#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/sysctl.h>
#include <linux/net.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/ipv6.h>
#include <linux/mpls.h>
#include <linux/vmalloc.h>
#include <net/ip.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/arp.h>
#include <net/ip_fib.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
#include "internal.h"
#define LABEL_NOT_SPECIFIED (1<<20)
#define MAX_NEW_LABELS 2
/* This maximum ha length copied from the definition of struct neighbour */
#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
struct mpls_route { /* next hop label forwarding entry */
struct net_device __rcu *rt_dev;
struct rcu_head rt_rcu;
u32 rt_label[MAX_NEW_LABELS];
u8 rt_protocol; /* routing protocol that set this entry */
u8 rt_labels;
u8 rt_via_alen;
u8 rt_via_table;
u8 rt_via[0];
};
static int zero = 0;
static int label_limit = (1 << 20) - 1;
static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
struct nlmsghdr *nlh, struct net *net, u32 portid,
unsigned int nlm_flags);
static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
{
struct mpls_route *rt = NULL;
if (index < net->mpls.platform_labels) {
struct mpls_route __rcu **platform_label =
rcu_dereference(net->mpls.platform_label);
rt = rcu_dereference(platform_label[index]);
}
return rt;
}
static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
{
return rcu_dereference_rtnl(dev->mpls_ptr);
}
static bool mpls_output_possible(const struct net_device *dev)
{
return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
}
static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
{
/* The size of the layer 2.5 labels to be added for this route */
return rt->rt_labels * sizeof(struct mpls_shim_hdr);
}
static unsigned int mpls_dev_mtu(const struct net_device *dev)
{
/* The amount of data the layer 2 frame can hold */
return dev->mtu;
}
static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
{
if (skb->len <= mtu)
return false;
if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
return false;
return true;
}
static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
struct mpls_entry_decoded dec)
{
/* RFC4385 and RFC5586 encode other packets in mpls such that
* they don't conflict with the ip version number, making
* decoding by examining the ip version correct in everything
* except for the strangest cases.
*
* The strange cases if we choose to support them will require
* manual configuration.
*/
struct iphdr *hdr4;
bool success = true;
/* The IPv4 code below accesses through the IPv4 header
* checksum, which is 12 bytes into the packet.
* The IPv6 code below accesses through the IPv6 hop limit
* which is 8 bytes into the packet.
*
* For all supported cases there should always be at least 12
* bytes of packet data present. The IPv4 header is 20 bytes
* without options and the IPv6 header is always 40 bytes
* long.
*/
if (!pskb_may_pull(skb, 12))
return false;
/* Use ip_hdr to find the ip protocol version */
hdr4 = ip_hdr(skb);
if (hdr4->version == 4) {
skb->protocol = htons(ETH_P_IP);
csum_replace2(&hdr4->check,
htons(hdr4->ttl << 8),
htons(dec.ttl << 8));
hdr4->ttl = dec.ttl;
}
else if (hdr4->version == 6) {
struct ipv6hdr *hdr6 = ipv6_hdr(skb);
skb->protocol = htons(ETH_P_IPV6);
hdr6->hop_limit = dec.ttl;
}
else
/* version 0 and version 1 are used by pseudo wires */
success = false;
return success;
}
static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct net *net = dev_net(dev);
struct mpls_shim_hdr *hdr;
struct mpls_route *rt;
struct mpls_entry_decoded dec;
struct net_device *out_dev;
struct mpls_dev *mdev;
unsigned int hh_len;
unsigned int new_header_size;
unsigned int mtu;
int err;
/* Careful this entire function runs inside of an rcu critical section */
mdev = mpls_dev_get(dev);
if (!mdev || !mdev->input_enabled)
goto drop;
if (skb->pkt_type != PACKET_HOST)
goto drop;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
goto drop;
if (!pskb_may_pull(skb, sizeof(*hdr)))
goto drop;
/* Read and decode the label */
hdr = mpls_hdr(skb);
dec = mpls_entry_decode(hdr);
/* Pop the label */
skb_pull(skb, sizeof(*hdr));
skb_reset_network_header(skb);
skb_orphan(skb);
rt = mpls_route_input_rcu(net, dec.label);
if (!rt)
goto drop;
/* Find the output device */
out_dev = rcu_dereference(rt->rt_dev);
if (!mpls_output_possible(out_dev))
goto drop;
if (skb_warn_if_lro(skb))
goto drop;
skb_forward_csum(skb);
/* Verify ttl is valid */
if (dec.ttl <= 1)
goto drop;
dec.ttl -= 1;
/* Verify the destination can hold the packet */
new_header_size = mpls_rt_header_size(rt);
mtu = mpls_dev_mtu(out_dev);
if (mpls_pkt_too_big(skb, mtu - new_header_size))
goto drop;
hh_len = LL_RESERVED_SPACE(out_dev);
if (!out_dev->header_ops)
hh_len = 0;
/* Ensure there is enough space for the headers in the skb */
if (skb_cow(skb, hh_len + new_header_size))
goto drop;
skb->dev = out_dev;
skb->protocol = htons(ETH_P_MPLS_UC);
if (unlikely(!new_header_size && dec.bos)) {
/* Penultimate hop popping */
if (!mpls_egress(rt, skb, dec))
goto drop;
} else {
bool bos;
int i;
skb_push(skb, new_header_size);
skb_reset_network_header(skb);
/* Push the new labels */
hdr = mpls_hdr(skb);
bos = dec.bos;
for (i = rt->rt_labels - 1; i >= 0; i--) {
hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos);
bos = false;
}
}
err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb);
if (err)
net_dbg_ratelimited("%s: packet transmission failed: %d\n",
__func__, err);
return 0;
drop:
kfree_skb(skb);
return NET_RX_DROP;
}
static struct packet_type mpls_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_MPLS_UC),
.func = mpls_forward,
};
static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
[RTA_DST] = { .type = NLA_U32 },
[RTA_OIF] = { .type = NLA_U32 },
};
struct mpls_route_config {
u32 rc_protocol;
u32 rc_ifindex;
u16 rc_via_table;
u16 rc_via_alen;
u8 rc_via[MAX_VIA_ALEN];
u32 rc_label;
u32 rc_output_labels;
u32 rc_output_label[MAX_NEW_LABELS];
u32 rc_nlflags;
struct nl_info rc_nlinfo;
};
static struct mpls_route *mpls_rt_alloc(size_t alen)
{
struct mpls_route *rt;
rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL);
if (rt)
rt->rt_via_alen = alen;
return rt;
}
static void mpls_rt_free(struct mpls_route *rt)
{
if (rt)
kfree_rcu(rt, rt_rcu);
}
static void mpls_notify_route(struct net *net, unsigned index,
struct mpls_route *old, struct mpls_route *new,
const struct nl_info *info)
{
struct nlmsghdr *nlh = info ? info->nlh : NULL;
unsigned portid = info ? info->portid : 0;
int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
struct mpls_route *rt = new ? new : old;
unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
/* Ignore reserved labels for now */
if (rt && (index >= 16))
rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
}
static void mpls_route_update(struct net *net, unsigned index,
struct net_device *dev, struct mpls_route *new,
const struct nl_info *info)
{
struct mpls_route __rcu **platform_label;
struct mpls_route *rt, *old = NULL;
ASSERT_RTNL();
platform_label = rtnl_dereference(net->mpls.platform_label);
rt = rtnl_dereference(platform_label[index]);
if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) {
rcu_assign_pointer(platform_label[index], new);
old = rt;
}
mpls_notify_route(net, index, old, new, info);
/* If we removed a route free it now */
mpls_rt_free(old);
}
static unsigned find_free_label(struct net *net)
{
struct mpls_route __rcu **platform_label;
size_t platform_labels;
unsigned index;
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
for (index = 16; index < platform_labels; index++) {
if (!rtnl_dereference(platform_label[index]))
return index;
}
return LABEL_NOT_SPECIFIED;
}
static int mpls_route_add(struct mpls_route_config *cfg)
{
struct mpls_route __rcu **platform_label;
struct net *net = cfg->rc_nlinfo.nl_net;
struct net_device *dev = NULL;
struct mpls_route *rt, *old;
unsigned index;
int i;
int err = -EINVAL;
index = cfg->rc_label;
/* If a label was not specified during insert pick one */
if ((index == LABEL_NOT_SPECIFIED) &&
(cfg->rc_nlflags & NLM_F_CREATE)) {
index = find_free_label(net);
}
/* The first 16 labels are reserved, and may not be set */
if (index < 16)
goto errout;
/* The full 20 bit range may not be supported. */
if (index >= net->mpls.platform_labels)
goto errout;
/* Ensure only a supported number of labels are present */
if (cfg->rc_output_labels > MAX_NEW_LABELS)
goto errout;
err = -ENODEV;
dev = dev_get_by_index(net, cfg->rc_ifindex);
if (!dev)
goto errout;
/* Ensure this is a supported device */
err = -EINVAL;
if (!mpls_dev_get(dev))
goto errout;
err = -EINVAL;
if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
(dev->addr_len != cfg->rc_via_alen))
goto errout;
/* Append makes no sense with mpls */
err = -EOPNOTSUPP;
if (cfg->rc_nlflags & NLM_F_APPEND)
goto errout;
err = -EEXIST;
platform_label = rtnl_dereference(net->mpls.platform_label);
old = rtnl_dereference(platform_label[index]);
if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
goto errout;
err = -EEXIST;
if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
goto errout;
err = -ENOENT;
if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
goto errout;
err = -ENOMEM;
rt = mpls_rt_alloc(cfg->rc_via_alen);
if (!rt)
goto errout;
rt->rt_labels = cfg->rc_output_labels;
for (i = 0; i < rt->rt_labels; i++)
rt->rt_label[i] = cfg->rc_output_label[i];
rt->rt_protocol = cfg->rc_protocol;
RCU_INIT_POINTER(rt->rt_dev, dev);
rt->rt_via_table = cfg->rc_via_table;
memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
dev_put(dev);
return 0;
errout:
if (dev)
dev_put(dev);
return err;
}
static int mpls_route_del(struct mpls_route_config *cfg)
{
struct net *net = cfg->rc_nlinfo.nl_net;
unsigned index;
int err = -EINVAL;
index = cfg->rc_label;
/* The first 16 labels are reserved, and may not be removed */
if (index < 16)
goto errout;
/* The full 20 bit range may not be supported */
if (index >= net->mpls.platform_labels)
goto errout;
mpls_route_update(net, index, NULL, NULL, &cfg->rc_nlinfo);
err = 0;
errout:
return err;
}
#define MPLS_PERDEV_SYSCTL_OFFSET(field) \
(&((struct mpls_dev *)0)->field)
static const struct ctl_table mpls_dev_table[] = {
{
.procname = "input",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
.data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
},
{ }
};
static int mpls_dev_sysctl_register(struct net_device *dev,
struct mpls_dev *mdev)
{
char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
struct ctl_table *table;
int i;
table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
if (!table)
goto out;
/* Table data contains only offsets relative to the base of
* the mdev at this point, so make them absolute.
*/
for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
table[i].data = (char *)mdev + (uintptr_t)table[i].data;
snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
if (!mdev->sysctl)
goto free;
return 0;
free:
kfree(table);
out:
return -ENOBUFS;
}
static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
{
struct ctl_table *table;
table = mdev->sysctl->ctl_table_arg;
unregister_net_sysctl_table(mdev->sysctl);
kfree(table);
}
static struct mpls_dev *mpls_add_dev(struct net_device *dev)
{
struct mpls_dev *mdev;
int err = -ENOMEM;
ASSERT_RTNL();
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev)
return ERR_PTR(err);
err = mpls_dev_sysctl_register(dev, mdev);
if (err)
goto free;
rcu_assign_pointer(dev->mpls_ptr, mdev);
return mdev;
free:
kfree(mdev);
return ERR_PTR(err);
}
static void mpls_ifdown(struct net_device *dev)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
struct mpls_dev *mdev;
unsigned index;
platform_label = rtnl_dereference(net->mpls.platform_label);
for (index = 0; index < net->mpls.platform_labels; index++) {
struct mpls_route *rt = rtnl_dereference(platform_label[index]);
if (!rt)
continue;
if (rtnl_dereference(rt->rt_dev) != dev)
continue;
rt->rt_dev = NULL;
}
mdev = mpls_dev_get(dev);
if (!mdev)
return;
mpls_dev_sysctl_unregister(mdev);
RCU_INIT_POINTER(dev->mpls_ptr, NULL);
kfree_rcu(mdev, rcu);
}
static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct mpls_dev *mdev;
switch(event) {
case NETDEV_REGISTER:
/* For now just support ethernet devices */
if ((dev->type == ARPHRD_ETHER) ||
(dev->type == ARPHRD_LOOPBACK)) {
mdev = mpls_add_dev(dev);
if (IS_ERR(mdev))
return notifier_from_errno(PTR_ERR(mdev));
}
break;
case NETDEV_UNREGISTER:
mpls_ifdown(dev);
break;
}
return NOTIFY_OK;
}
static struct notifier_block mpls_dev_notifier = {
.notifier_call = mpls_dev_notify,
};
static int nla_put_via(struct sk_buff *skb,
u8 table, const void *addr, int alen)
{
static const int table_to_family[NEIGH_NR_TABLES + 1] = {
AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
};
struct nlattr *nla;
struct rtvia *via;
int family = AF_UNSPEC;
nla = nla_reserve(skb, RTA_VIA, alen + 2);
if (!nla)
return -EMSGSIZE;
if (table <= NEIGH_NR_TABLES)
family = table_to_family[table];
via = nla_data(nla);
via->rtvia_family = family;
memcpy(via->rtvia_addr, addr, alen);
return 0;
}
int nla_put_labels(struct sk_buff *skb, int attrtype,
u8 labels, const u32 label[])
{
struct nlattr *nla;
struct mpls_shim_hdr *nla_label;
bool bos;
int i;
nla = nla_reserve(skb, attrtype, labels*4);
if (!nla)
return -EMSGSIZE;
nla_label = nla_data(nla);
bos = true;
for (i = labels - 1; i >= 0; i--) {
nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
bos = false;
}
return 0;
}
int nla_get_labels(const struct nlattr *nla,
u32 max_labels, u32 *labels, u32 label[])
{
unsigned len = nla_len(nla);
unsigned nla_labels;
struct mpls_shim_hdr *nla_label;
bool bos;
int i;
/* len needs to be an even multiple of 4 (the label size) */
if (len & 3)
return -EINVAL;
/* Limit the number of new labels allowed */
nla_labels = len/4;
if (nla_labels > max_labels)
return -EINVAL;
nla_label = nla_data(nla);
bos = true;
for (i = nla_labels - 1; i >= 0; i--, bos = false) {
struct mpls_entry_decoded dec;
dec = mpls_entry_decode(nla_label + i);
/* Ensure the bottom of stack flag is properly set
* and ttl and tc are both clear.
*/
if ((dec.bos != bos) || dec.ttl || dec.tc)
return -EINVAL;
switch (dec.label) {
case MPLS_LABEL_IMPLNULL:
/* RFC3032: This is a label that an LSR may
* assign and distribute, but which never
* actually appears in the encapsulation.
*/
return -EINVAL;
}
label[i] = dec.label;
}
*labels = nla_labels;
return 0;
}
static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
struct mpls_route_config *cfg)
{
struct rtmsg *rtm;
struct nlattr *tb[RTA_MAX+1];
int index;
int err;
err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy);
if (err < 0)
goto errout;
err = -EINVAL;
rtm = nlmsg_data(nlh);
memset(cfg, 0, sizeof(*cfg));
if (rtm->rtm_family != AF_MPLS)
goto errout;
if (rtm->rtm_dst_len != 20)
goto errout;
if (rtm->rtm_src_len != 0)
goto errout;
if (rtm->rtm_tos != 0)
goto errout;
if (rtm->rtm_table != RT_TABLE_MAIN)
goto errout;
/* Any value is acceptable for rtm_protocol */
/* As mpls uses destination specific addresses
* (or source specific address in the case of multicast)
* all addresses have universal scope.
*/
if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
goto errout;
if (rtm->rtm_type != RTN_UNICAST)
goto errout;
if (rtm->rtm_flags != 0)
goto errout;
cfg->rc_label = LABEL_NOT_SPECIFIED;
cfg->rc_protocol = rtm->rtm_protocol;
cfg->rc_nlflags = nlh->nlmsg_flags;
cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
cfg->rc_nlinfo.nlh = nlh;
cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
for (index = 0; index <= RTA_MAX; index++) {
struct nlattr *nla = tb[index];
if (!nla)
continue;
switch(index) {
case RTA_OIF:
cfg->rc_ifindex = nla_get_u32(nla);
break;
case RTA_NEWDST:
if (nla_get_labels(nla, MAX_NEW_LABELS,
&cfg->rc_output_labels,
cfg->rc_output_label))
goto errout;
break;
case RTA_DST:
{
u32 label_count;
if (nla_get_labels(nla, 1, &label_count,
&cfg->rc_label))
goto errout;
/* The first 16 labels are reserved, and may not be set */
if (cfg->rc_label < 16)
goto errout;
break;
}
case RTA_VIA:
{
struct rtvia *via = nla_data(nla);
if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
goto errout;
cfg->rc_via_alen = nla_len(nla) -
offsetof(struct rtvia, rtvia_addr);
if (cfg->rc_via_alen > MAX_VIA_ALEN)
goto errout;
/* Validate the address family */
switch(via->rtvia_family) {
case AF_PACKET:
cfg->rc_via_table = NEIGH_LINK_TABLE;
break;
case AF_INET:
cfg->rc_via_table = NEIGH_ARP_TABLE;
if (cfg->rc_via_alen != 4)
goto errout;
break;
case AF_INET6:
cfg->rc_via_table = NEIGH_ND_TABLE;
if (cfg->rc_via_alen != 16)
goto errout;
break;
default:
/* Unsupported address family */
goto errout;
}
memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen);
break;
}
default:
/* Unsupported attribute */
goto errout;
}
}
err = 0;
errout:
return err;
}
static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct mpls_route_config cfg;
int err;
err = rtm_to_route_config(skb, nlh, &cfg);
if (err < 0)
return err;
return mpls_route_del(&cfg);
}
static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
{
struct mpls_route_config cfg;
int err;
err = rtm_to_route_config(skb, nlh, &cfg);
if (err < 0)
return err;
return mpls_route_add(&cfg);
}
static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
u32 label, struct mpls_route *rt, int flags)
{
struct net_device *dev;
struct nlmsghdr *nlh;
struct rtmsg *rtm;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
if (nlh == NULL)
return -EMSGSIZE;
rtm = nlmsg_data(nlh);
rtm->rtm_family = AF_MPLS;
rtm->rtm_dst_len = 20;
rtm->rtm_src_len = 0;
rtm->rtm_tos = 0;
rtm->rtm_table = RT_TABLE_MAIN;
rtm->rtm_protocol = rt->rt_protocol;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
rtm->rtm_type = RTN_UNICAST;
rtm->rtm_flags = 0;
if (rt->rt_labels &&
nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
goto nla_put_failure;
if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(rt->rt_dev);
if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
goto nla_put_failure;
if (nla_put_labels(skb, RTA_DST, 1, &label))
goto nla_put_failure;
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct mpls_route __rcu **platform_label;
size_t platform_labels;
unsigned int index;
ASSERT_RTNL();
index = cb->args[0];
if (index < 16)
index = 16;
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
for (; index < platform_labels; index++) {
struct mpls_route *rt;
rt = rtnl_dereference(platform_label[index]);
if (!rt)
continue;
if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, RTM_NEWROUTE,
index, rt, NLM_F_MULTI) < 0)
break;
}
cb->args[0] = index;
return skb->len;
}
static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
{
size_t payload =
NLMSG_ALIGN(sizeof(struct rtmsg))
+ nla_total_size(2 + rt->rt_via_alen) /* RTA_VIA */
+ nla_total_size(4); /* RTA_DST */
if (rt->rt_labels) /* RTA_NEWDST */
payload += nla_total_size(rt->rt_labels * 4);
if (rt->rt_dev) /* RTA_OIF */
payload += nla_total_size(4);
return payload;
}
static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
struct nlmsghdr *nlh, struct net *net, u32 portid,
unsigned int nlm_flags)
{
struct sk_buff *skb;
u32 seq = nlh ? nlh->nlmsg_seq : 0;
int err = -ENOBUFS;
skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
if (skb == NULL)
goto errout;
err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
if (err < 0) {
/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
return;
errout:
if (err < 0)
rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
}
static int resize_platform_label_table(struct net *net, size_t limit)
{
size_t size = sizeof(struct mpls_route *) * limit;
size_t old_limit;
size_t cp_size;
struct mpls_route __rcu **labels = NULL, **old;
struct mpls_route *rt0 = NULL, *rt2 = NULL;
unsigned index;
if (size) {
labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
if (!labels)
labels = vzalloc(size);
if (!labels)
goto nolabels;
}
/* In case the predefined labels need to be populated */
if (limit > MPLS_LABEL_IPV4NULL) {
struct net_device *lo = net->loopback_dev;
rt0 = mpls_rt_alloc(lo->addr_len);
if (!rt0)
goto nort0;
RCU_INIT_POINTER(rt0->rt_dev, lo);
rt0->rt_protocol = RTPROT_KERNEL;
rt0->rt_via_table = NEIGH_LINK_TABLE;
memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
}
if (limit > MPLS_LABEL_IPV6NULL) {
struct net_device *lo = net->loopback_dev;
rt2 = mpls_rt_alloc(lo->addr_len);
if (!rt2)
goto nort2;
RCU_INIT_POINTER(rt2->rt_dev, lo);
rt2->rt_protocol = RTPROT_KERNEL;
rt2->rt_via_table = NEIGH_LINK_TABLE;
memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
}
rtnl_lock();
/* Remember the original table */
old = rtnl_dereference(net->mpls.platform_label);
old_limit = net->mpls.platform_labels;
/* Free any labels beyond the new table */
for (index = limit; index < old_limit; index++)
mpls_route_update(net, index, NULL, NULL, NULL);
/* Copy over the old labels */
cp_size = size;
if (old_limit < limit)
cp_size = old_limit * sizeof(struct mpls_route *);
memcpy(labels, old, cp_size);
/* If needed set the predefined labels */
if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
(limit > MPLS_LABEL_IPV6NULL)) {
RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
rt2 = NULL;
}
if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
(limit > MPLS_LABEL_IPV4NULL)) {
RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
rt0 = NULL;
}
/* Update the global pointers */
net->mpls.platform_labels = limit;
rcu_assign_pointer(net->mpls.platform_label, labels);
rtnl_unlock();
mpls_rt_free(rt2);
mpls_rt_free(rt0);
if (old) {
synchronize_rcu();
kvfree(old);
}