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linux/net/mpls/af_mpls.c
Guillaume Nault 0992d67bc2 mpls: drop skb's dst in mpls_forward() 
Commit 394de110a7 ("net: Added pointer check for
dst->ops->neigh_lookup in dst_neigh_lookup_skb") added a test in
dst_neigh_lookup_skb() to avoid a NULL pointer dereference. The root
cause was the MPLS forwarding code, which doesn't call skb_dst_drop()
on incoming packets. That is, if the packet is received from a
collect_md device, it has a metadata_dst attached to it that doesn't
implement any dst_ops function.

To align the MPLS behaviour with IPv4 and IPv6, let's drop the dst in
mpls_forward(). This way, dst_neigh_lookup_skb() doesn't need to test
->neigh_lookup any more. Let's keep a WARN condition though, to
document the precondition and to ease detection of such problems in the
future.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/f8c2784c13faa54469a2aac339470b1049ca6b63.1604102750.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-03 12:55:53 -08:00

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// SPDX-License-Identifier: GPL-2.0-only
#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/netconf.h>
#include <linux/nospec.h>
#include <linux/vmalloc.h>
#include <linux/percpu.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/ip_tunnels.h>
#include <net/netns/generic.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#endif
#include <net/ipv6_stubs.h>
#include <net/rtnh.h>
#include "internal.h"
/* max memory we will use for mpls_route */
#define MAX_MPLS_ROUTE_MEM 4096
/* Maximum number of labels to look ahead at when selecting a path of
* a multipath route
*/
#define MAX_MP_SELECT_LABELS 4
#define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
static int label_limit = (1 << 20) - 1;
static int ttl_max = 255;
#if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
{
return sizeof(struct mpls_shim_hdr);
}
static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
.encap_hlen = ipgre_mpls_encap_hlen,
};
static int ipgre_tunnel_encap_add_mpls_ops(void)
{
return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
}
static void ipgre_tunnel_encap_del_mpls_ops(void)
{
ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
}
#else
static int ipgre_tunnel_encap_add_mpls_ops(void)
{
return 0;
}
static void ipgre_tunnel_encap_del_mpls_ops(void)
{
}
#endif
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;
}
bool mpls_output_possible(const struct net_device *dev)
{
return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
}
EXPORT_SYMBOL_GPL(mpls_output_possible);
static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
{
return (u8 *)nh + rt->rt_via_offset;
}
static const u8 *mpls_nh_via(const struct mpls_route *rt,
const struct mpls_nh *nh)
{
return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
}
static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
{
/* The size of the layer 2.5 labels to be added for this route */
return nh->nh_labels * sizeof(struct mpls_shim_hdr);
}
unsigned int mpls_dev_mtu(const struct net_device *dev)
{
/* The amount of data the layer 2 frame can hold */
return dev->mtu;
}
EXPORT_SYMBOL_GPL(mpls_dev_mtu);
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_validate_network_len(skb, mtu))
return false;
return true;
}
EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
void mpls_stats_inc_outucastpkts(struct net_device *dev,
const struct sk_buff *skb)
{
struct mpls_dev *mdev;
if (skb->protocol == htons(ETH_P_MPLS_UC)) {
mdev = mpls_dev_get(dev);
if (mdev)
MPLS_INC_STATS_LEN(mdev, skb->len,
tx_packets,
tx_bytes);
} else if (skb->protocol == htons(ETH_P_IP)) {
IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
#if IS_ENABLED(CONFIG_IPV6)
} else if (skb->protocol == htons(ETH_P_IPV6)) {
struct inet6_dev *in6dev = __in6_dev_get(dev);
if (in6dev)
IP6_UPD_PO_STATS(dev_net(dev), in6dev,
IPSTATS_MIB_OUT, skb->len);
#endif
}
}
EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
{
struct mpls_entry_decoded dec;
unsigned int mpls_hdr_len = 0;
struct mpls_shim_hdr *hdr;
bool eli_seen = false;
int label_index;
u32 hash = 0;
for (label_index = 0; label_index < MAX_MP_SELECT_LABELS;
label_index++) {
mpls_hdr_len += sizeof(*hdr);
if (!pskb_may_pull(skb, mpls_hdr_len))
break;
/* Read and decode the current label */
hdr = mpls_hdr(skb) + label_index;
dec = mpls_entry_decode(hdr);
/* RFC6790 - reserved labels MUST NOT be used as keys
* for the load-balancing function
*/
if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
hash = jhash_1word(dec.label, hash);
/* The entropy label follows the entropy label
* indicator, so this means that the entropy
* label was just added to the hash - no need to
* go any deeper either in the label stack or in the
* payload
*/
if (eli_seen)
break;
} else if (dec.label == MPLS_LABEL_ENTROPY) {
eli_seen = true;
}
if (!dec.bos)
continue;
/* found bottom label; does skb have room for a header? */
if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
const struct iphdr *v4hdr;
v4hdr = (const struct iphdr *)(hdr + 1);
if (v4hdr->version == 4) {
hash = jhash_3words(ntohl(v4hdr->saddr),
ntohl(v4hdr->daddr),
v4hdr->protocol, hash);
} else if (v4hdr->version == 6 &&
pskb_may_pull(skb, mpls_hdr_len +
sizeof(struct ipv6hdr))) {
const struct ipv6hdr *v6hdr;
v6hdr = (const struct ipv6hdr *)(hdr + 1);
hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
hash = jhash_1word(v6hdr->nexthdr, hash);
}
}
break;
}
return hash;
}
static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
{
return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
}
/* number of alive nexthops (rt->rt_nhn_alive) and the flags for
* a next hop (nh->nh_flags) are modified by netdev event handlers.
* Since those fields can change at any moment, use READ_ONCE to
* access both.
*/
static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
struct sk_buff *skb)
{
u32 hash = 0;
int nh_index = 0;
int n = 0;
u8 alive;
/* No need to look further into packet if there's only
* one path
*/
if (rt->rt_nhn == 1)
return rt->rt_nh;
alive = READ_ONCE(rt->rt_nhn_alive);
if (alive == 0)
return NULL;
hash = mpls_multipath_hash(rt, skb);
nh_index = hash % alive;
if (alive == rt->rt_nhn)
goto out;
for_nexthops(rt) {
unsigned int nh_flags = READ_ONCE(nh->nh_flags);
if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
continue;
if (n == nh_index)
return nh;
n++;
} endfor_nexthops(rt);
out:
return mpls_get_nexthop(rt, nh_index);
}
static bool mpls_egress(struct net *net, struct mpls_route *rt,
struct sk_buff *skb, struct mpls_entry_decoded dec)
{
enum mpls_payload_type payload_type;
bool success = false;
/* 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;
payload_type = rt->rt_payload_type;
if (payload_type == MPT_UNSPEC)
payload_type = ip_hdr(skb)->version;
switch (payload_type) {
case MPT_IPV4: {
struct iphdr *hdr4 = ip_hdr(skb);
u8 new_ttl;
skb->protocol = htons(ETH_P_IP);
/* If propagating TTL, take the decremented TTL from
* the incoming MPLS header, otherwise decrement the
* TTL, but only if not 0 to avoid underflow.
*/
if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
(rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
net->mpls.ip_ttl_propagate))
new_ttl = dec.ttl;
else
new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
csum_replace2(&hdr4->check,
htons(hdr4->ttl << 8),
htons(new_ttl << 8));
hdr4->ttl = new_ttl;
success = true;
break;
}
case MPT_IPV6: {
struct ipv6hdr *hdr6 = ipv6_hdr(skb);
skb->protocol = htons(ETH_P_IPV6);
/* If propagating TTL, take the decremented TTL from
* the incoming MPLS header, otherwise decrement the
* hop limit, but only if not 0 to avoid underflow.
*/
if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
(rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
net->mpls.ip_ttl_propagate))
hdr6->hop_limit = dec.ttl;
else if (hdr6->hop_limit)
hdr6->hop_limit = hdr6->hop_limit - 1;
success = true;
break;
}
case MPT_UNSPEC:
/* Should have decided which protocol it is by now */
break;
}
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_nh *nh;
struct mpls_entry_decoded dec;
struct net_device *out_dev;
struct mpls_dev *out_mdev;
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)
goto drop;
MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
rx_bytes);
if (!mdev->input_enabled) {
MPLS_INC_STATS(mdev, rx_dropped);
goto drop;
}
if (skb->pkt_type != PACKET_HOST)
goto err;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
goto err;
if (!pskb_may_pull(skb, sizeof(*hdr)))
goto err;
skb_dst_drop(skb);
/* Read and decode the label */
hdr = mpls_hdr(skb);
dec = mpls_entry_decode(hdr);
rt = mpls_route_input_rcu(net, dec.label);
if (!rt) {
MPLS_INC_STATS(mdev, rx_noroute);
goto drop;
}
nh = mpls_select_multipath(rt, skb);
if (!nh)
goto err;
/* Pop the label */
skb_pull(skb, sizeof(*hdr));
skb_reset_network_header(skb);
skb_orphan(skb);
if (skb_warn_if_lro(skb))
goto err;
skb_forward_csum(skb);
/* Verify ttl is valid */
if (dec.ttl <= 1)
goto err;
dec.ttl -= 1;
/* Find the output device */
out_dev = rcu_dereference(nh->nh_dev);
if (!mpls_output_possible(out_dev))
goto tx_err;
/* Verify the destination can hold the packet */
new_header_size = mpls_nh_header_size(nh);
mtu = mpls_dev_mtu(out_dev);
if (mpls_pkt_too_big(skb, mtu - new_header_size))
goto tx_err;
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 tx_err;
skb->dev = out_dev;
skb->protocol = htons(ETH_P_MPLS_UC);
if (unlikely(!new_header_size && dec.bos)) {
/* Penultimate hop popping */
if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
goto err;
} 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 = nh->nh_labels - 1; i >= 0; i--) {
hdr[i] = mpls_entry_encode(nh->nh_label[i],
dec.ttl, 0, bos);
bos = false;
}
}
mpls_stats_inc_outucastpkts(out_dev, skb);
/* If via wasn't specified then send out using device address */
if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
out_dev->dev_addr, skb);
else
err = neigh_xmit(nh->nh_via_table, out_dev,
mpls_nh_via(rt, nh), skb);
if (err)
net_dbg_ratelimited("%s: packet transmission failed: %d\n",
__func__, err);
return 0;
tx_err:
out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
if (out_mdev)
MPLS_INC_STATS(out_mdev, tx_errors);
goto drop;
err:
MPLS_INC_STATS(mdev, rx_errors);
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 },
[RTA_TTL_PROPAGATE] = { .type = NLA_U8 },
};
struct mpls_route_config {
u32 rc_protocol;
u32 rc_ifindex;
u8 rc_via_table;
u8 rc_via_alen;
u8 rc_via[MAX_VIA_ALEN];
u32 rc_label;
u8 rc_ttl_propagate;
u8 rc_output_labels;
u32 rc_output_label[MAX_NEW_LABELS];
u32 rc_nlflags;
enum mpls_payload_type rc_payload_type;
struct nl_info rc_nlinfo;
struct rtnexthop *rc_mp;
int rc_mp_len;
};
/* all nexthops within a route have the same size based on max
* number of labels and max via length for a hop
*/
static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
{
u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
struct mpls_route *rt;
size_t size;
size = sizeof(*rt) + num_nh * nh_size;
if (size > MAX_MPLS_ROUTE_MEM)
return ERR_PTR(-EINVAL);
rt = kzalloc(size, GFP_KERNEL);
if (!rt)
return ERR_PTR(-ENOMEM);
rt->rt_nhn = num_nh;
rt->rt_nhn_alive = num_nh;
rt->rt_nh_size = nh_size;
rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
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 >= MPLS_LABEL_FIRST_UNRESERVED))
rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
}
static void mpls_route_update(struct net *net, unsigned index,
struct mpls_route *new,
const struct nl_info *info)
{
struct mpls_route __rcu **platform_label;
struct mpls_route *rt;
ASSERT_RTNL();
platform_label = rtnl_dereference(net->mpls.platform_label);
rt = rtnl_dereference(platform_label[index]);
rcu_assign_pointer(platform_label[index], new);
mpls_notify_route(net, index, rt, new, info);
/* If we removed a route free it now */
mpls_rt_free(rt);
}
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 = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
index++) {
if (!rtnl_dereference(platform_label[index]))
return index;
}
return LABEL_NOT_SPECIFIED;
}
#if IS_ENABLED(CONFIG_INET)
static struct net_device *inet_fib_lookup_dev(struct net *net,
const void *addr)
{
struct net_device *dev;
struct rtable *rt;
struct in_addr daddr;
memcpy(&daddr, addr, sizeof(struct in_addr));
rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
if (IS_ERR(rt))
return ERR_CAST(rt);
dev = rt->dst.dev;
dev_hold(dev);
ip_rt_put(rt);
return dev;
}
#else
static struct net_device *inet_fib_lookup_dev(struct net *net,
const void *addr)
{
return ERR_PTR(-EAFNOSUPPORT);
}
#endif
#if IS_ENABLED(CONFIG_IPV6)
static struct net_device *inet6_fib_lookup_dev(struct net *net,
const void *addr)
{
struct net_device *dev;
struct dst_entry *dst;
struct flowi6 fl6;
if (!ipv6_stub)
return ERR_PTR(-EAFNOSUPPORT);
memset(&fl6, 0, sizeof(fl6));
memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
if (IS_ERR(dst))
return ERR_CAST(dst);
dev = dst->dev;
dev_hold(dev);
dst_release(dst);
return dev;
}
#else
static struct net_device *inet6_fib_lookup_dev(struct net *net,
const void *addr)
{
return ERR_PTR(-EAFNOSUPPORT);
}
#endif
static struct net_device *find_outdev(struct net *net,
struct mpls_route *rt,
struct mpls_nh *nh, int oif)
{
struct net_device *dev = NULL;
if (!oif) {
switch (nh->nh_via_table) {
case NEIGH_ARP_TABLE:
dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
break;
case NEIGH_ND_TABLE:
dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
break;
case NEIGH_LINK_TABLE:
break;
}
} else {
dev = dev_get_by_index(net, oif);
}
if (!dev)
return ERR_PTR(-ENODEV);
if (IS_ERR(dev))
return dev;
/* The caller is holding rtnl anyways, so release the dev reference */
dev_put(dev);
return dev;
}
static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
struct mpls_nh *nh, int oif)
{
struct net_device *dev = NULL;
int err = -ENODEV;
dev = find_outdev(net, rt, nh, oif);
if (IS_ERR(dev)) {
err = PTR_ERR(dev);
dev = NULL;
goto errout;
}
/* Ensure this is a supported device */
err = -EINVAL;
if (!mpls_dev_get(dev))
goto errout;
if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
(dev->addr_len != nh->nh_via_alen))
goto errout;
RCU_INIT_POINTER(nh->nh_dev, dev);
if (!(dev->flags & IFF_UP)) {
nh->nh_flags |= RTNH_F_DEAD;
} else {
unsigned int flags;
flags = dev_get_flags(dev);
if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
nh->nh_flags |= RTNH_F_LINKDOWN;
}
return 0;
errout:
return err;
}
static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
u8 via_addr[], struct netlink_ext_ack *extack)
{
struct rtvia *via = nla_data(nla);
int err = -EINVAL;
int alen;
if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"Invalid attribute length for RTA_VIA");
goto errout;
}
alen = nla_len(nla) -
offsetof(struct rtvia, rtvia_addr);
if (alen > MAX_VIA_ALEN) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"Invalid address length for RTA_VIA");
goto errout;
}
/* Validate the address family */
switch (via->rtvia_family) {
case AF_PACKET:
*via_table = NEIGH_LINK_TABLE;
break;
case AF_INET:
*via_table = NEIGH_ARP_TABLE;
if (alen != 4)
goto errout;
break;
case AF_INET6:
*via_table = NEIGH_ND_TABLE;
if (alen != 16)
goto errout;
break;
default:
/* Unsupported address family */
goto errout;
}
memcpy(via_addr, via->rtvia_addr, alen);
*via_alen = alen;
err = 0;
errout:
return err;
}
static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
struct mpls_route *rt)
{
struct net *net = cfg->rc_nlinfo.nl_net;
struct mpls_nh *nh = rt->rt_nh;
int err;
int i;
if (!nh)
return -ENOMEM;
nh->nh_labels = cfg->rc_output_labels;
for (i = 0; i < nh->nh_labels; i++)
nh->nh_label[i] = cfg->rc_output_label[i];
nh->nh_via_table = cfg->rc_via_table;
memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
nh->nh_via_alen = cfg->rc_via_alen;
err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
if (err)
goto errout;
if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
rt->rt_nhn_alive--;
return 0;
errout:
return err;
}
static int mpls_nh_build(struct net *net, struct mpls_route *rt,
struct mpls_nh *nh, int oif, struct nlattr *via,
struct nlattr *newdst, u8 max_labels,
struct netlink_ext_ack *extack)
{
int err = -ENOMEM;
if (!nh)
goto errout;
if (newdst) {
err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
nh->nh_label, extack);
if (err)
goto errout;
}
if (via) {
err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
__mpls_nh_via(rt, nh), extack);
if (err)
goto errout;
} else {
nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
}
err = mpls_nh_assign_dev(net, rt, nh, oif);
if (err)
goto errout;
return 0;
errout:
return err;
}
static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
u8 cfg_via_alen, u8 *max_via_alen,
u8 *max_labels)
{
int remaining = len;
u8 nhs = 0;
*max_via_alen = 0;
*max_labels = 0;
while (rtnh_ok(rtnh, remaining)) {
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
int attrlen;
u8 n_labels = 0;
attrlen = rtnh_attrlen(rtnh);
nla = nla_find(attrs, attrlen, RTA_VIA);
if (nla && nla_len(nla) >=
offsetof(struct rtvia, rtvia_addr)) {
int via_alen = nla_len(nla) -
offsetof(struct rtvia, rtvia_addr);
if (via_alen <= MAX_VIA_ALEN)
*max_via_alen = max_t(u16, *max_via_alen,
via_alen);
}
nla = nla_find(attrs, attrlen, RTA_NEWDST);
if (nla &&
nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
NULL, NULL) != 0)
return 0;
*max_labels = max_t(u8, *max_labels, n_labels);
/* number of nexthops is tracked by a u8.
* Check for overflow.
*/
if (nhs == 255)
return 0;
nhs++;
rtnh = rtnh_next(rtnh, &remaining);
}
/* leftover implies invalid nexthop configuration, discard it */
return remaining > 0 ? 0 : nhs;
}
static int mpls_nh_build_multi(struct mpls_route_config *cfg,
struct mpls_route *rt, u8 max_labels,
struct netlink_ext_ack *extack)
{
struct rtnexthop *rtnh = cfg->rc_mp;
struct nlattr *nla_via, *nla_newdst;
int remaining = cfg->rc_mp_len;
int err = 0;
u8 nhs = 0;
change_nexthops(rt) {
int attrlen;
nla_via = NULL;
nla_newdst = NULL;
err = -EINVAL;
if (!rtnh_ok(rtnh, remaining))
goto errout;
/* neither weighted multipath nor any flags
* are supported
*/
if (rtnh->rtnh_hops || rtnh->rtnh_flags)
goto errout;
attrlen = rtnh_attrlen(rtnh);
if (attrlen > 0) {
struct nlattr *attrs = rtnh_attrs(rtnh);
nla_via = nla_find(attrs, attrlen, RTA_VIA);
nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
}
err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
rtnh->rtnh_ifindex, nla_via, nla_newdst,
max_labels, extack);
if (err)
goto errout;
if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
rt->rt_nhn_alive--;
rtnh = rtnh_next(rtnh, &remaining);
nhs++;
} endfor_nexthops(rt);
rt->rt_nhn = nhs;
return 0;
errout:
return err;
}
static bool mpls_label_ok(struct net *net, unsigned int *index,
struct netlink_ext_ack *extack)
{
bool is_ok = true;
/* Reserved labels may not be set */
if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
NL_SET_ERR_MSG(extack,
"Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
is_ok = false;
}
/* The full 20 bit range may not be supported. */
if (is_ok && *index >= net->mpls.platform_labels) {
NL_SET_ERR_MSG(extack,
"Label >= configured maximum in platform_labels");
is_ok = false;
}
*index = array_index_nospec(*index, net->mpls.platform_labels);
return is_ok;
}
static int mpls_route_add(struct mpls_route_config *cfg,
struct netlink_ext_ack *extack)
{
struct mpls_route __rcu **platform_label;
struct net *net = cfg->rc_nlinfo.nl_net;
struct mpls_route *rt, *old;
int err = -EINVAL;
u8 max_via_alen;
unsigned index;
u8 max_labels;
u8 nhs;
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);
}
if (!mpls_label_ok(net, &index, extack))
goto errout;
/* Append makes no sense with mpls */
err = -EOPNOTSUPP;
if (cfg->rc_nlflags & NLM_F_APPEND) {
NL_SET_ERR_MSG(extack, "MPLS does not support route 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 = -EINVAL;
if (cfg->rc_mp) {
nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
cfg->rc_via_alen, &max_via_alen,
&max_labels);
} else {
max_via_alen = cfg->rc_via_alen;
max_labels = cfg->rc_output_labels;
nhs = 1;
}
if (nhs == 0) {
NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
goto errout;
}
err = -ENOMEM;
rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
goto errout;
}
rt->rt_protocol = cfg->rc_protocol;
rt->rt_payload_type = cfg->rc_payload_type;
rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
if (cfg->rc_mp)
err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
else
err = mpls_nh_build_from_cfg(cfg, rt);
if (err)
goto freert;
mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
return 0;
freert:
mpls_rt_free(rt);
errout:
return err;
}
static int mpls_route_del(struct mpls_route_config *cfg,
struct netlink_ext_ack *extack)
{
struct net *net = cfg->rc_nlinfo.nl_net;
unsigned index;
int err = -EINVAL;
index = cfg->rc_label;
if (!mpls_label_ok(net, &index, extack))
goto errout;
mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
err = 0;
errout:
return err;
}
static void mpls_get_stats(struct mpls_dev *mdev,
struct mpls_link_stats *stats)
{
struct mpls_pcpu_stats *p;
int i;
memset(stats, 0, sizeof(*stats));
for_each_possible_cpu(i) {
struct mpls_link_stats local;
unsigned int start;
p = per_cpu_ptr(mdev->stats, i);
do {
start = u64_stats_fetch_begin(&p->syncp);
local = p->stats;
} while (u64_stats_fetch_retry(&p->syncp, start));
stats->rx_packets += local.rx_packets;
stats->rx_bytes += local.rx_bytes;
stats->tx_packets += local.tx_packets;
stats->tx_bytes += local.tx_bytes;
stats->rx_errors += local.rx_errors;
stats->tx_errors += local.tx_errors;
stats->rx_dropped += local.rx_dropped;
stats->tx_dropped += local.tx_dropped;
stats->rx_noroute += local.rx_noroute;
}
}
static int mpls_fill_stats_af(struct sk_buff *skb,
const struct net_device *dev)
{
struct mpls_link_stats *stats;
struct mpls_dev *mdev;
struct nlattr *nla;
mdev = mpls_dev_get(dev);
if (!mdev)
return -ENODATA;
nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
sizeof(struct mpls_link_stats),
MPLS_STATS_UNSPEC);
if (!nla)
return -EMSGSIZE;
stats = nla_data(nla);
mpls_get_stats(mdev, stats);
return 0;
}
static size_t mpls_get_stats_af_size(const struct net_device *dev)
{
struct mpls_dev *mdev;
mdev = mpls_dev_get(dev);
if (!mdev)
return 0;
return nla_total_size_64bit(sizeof(struct mpls_link_stats));
}
static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
u32 portid, u32 seq, int event,
unsigned int flags, int type)
{
struct nlmsghdr *nlh;
struct netconfmsg *ncm;
bool all = false;
nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
flags);
if (!nlh)
return -EMSGSIZE;
if (type == NETCONFA_ALL)
all = true;
ncm = nlmsg_data(nlh);
ncm->ncm_family = AF_MPLS;
if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
goto nla_put_failure;
if ((all || type == NETCONFA_INPUT) &&
nla_put_s32(skb, NETCONFA_INPUT,
mdev->input_enabled) < 0)
goto nla_put_failure;
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int mpls_netconf_msgsize_devconf(int type)
{
int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
+ nla_total_size(4); /* NETCONFA_IFINDEX */
bool all = false;
if (type == NETCONFA_ALL)
all = true;
if (all || type == NETCONFA_INPUT)
size += nla_total_size(4);
return size;
}
static void mpls_netconf_notify_devconf(struct net *net, int event,
int type, struct mpls_dev *mdev)
{
struct sk_buff *skb;
int err = -ENOBUFS;
skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
if (!skb)
goto errout;
err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
if (err < 0) {
/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
return;
errout:
if (err < 0)
rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
}
static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
[NETCONFA_IFINDEX] = { .len = sizeof(int) },
};
static int mpls_netconf_valid_get_req(struct sk_buff *skb,
const struct nlmsghdr *nlh,
struct nlattr **tb,
struct netlink_ext_ack *extack)
{
int i, err;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
NL_SET_ERR_MSG_MOD(extack,
"Invalid header for netconf get request");
return -EINVAL;
}
if (!netlink_strict_get_check(skb))
return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
tb, NETCONFA_MAX,
devconf_mpls_policy, extack);
err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
tb, NETCONFA_MAX,
devconf_mpls_policy, extack);
if (err)
return err;
for (i = 0; i <= NETCONFA_MAX; i++) {
if (!tb[i])
continue;
switch (i) {
case NETCONFA_IFINDEX:
break;
default:
NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
return -EINVAL;
}
}
return 0;
}
static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(in_skb->sk);
struct nlattr *tb[NETCONFA_MAX + 1];
struct net_device *dev;
struct mpls_dev *mdev;
struct sk_buff *skb;
int ifindex;
int err;
err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
if (err < 0)
goto errout;
err = -EINVAL;
if (!tb[NETCONFA_IFINDEX])
goto errout;
ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
dev = __dev_get_by_index(net, ifindex);
if (!dev)
goto errout;
mdev = mpls_dev_get(dev);
if (!mdev)
goto errout;
err = -ENOBUFS;
skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
if (!skb)
goto errout;
err = mpls_netconf_fill_devconf(skb, mdev,
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
NETCONFA_ALL);
if (err < 0) {
/* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
errout:
return err;
}
static int mpls_netconf_dump_devconf(struct sk_buff *skb,
struct netlink_callback *cb)
{
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
struct hlist_head *head;
struct net_device *dev;
struct mpls_dev *mdev;
int idx, s_idx;
int h, s_h;
if (cb->strict_check) {
struct netlink_ext_ack *extack = cb->extack;
struct netconfmsg *ncm;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
return -EINVAL;
}
if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
return -EINVAL;
}
}
s_h = cb->args[0];
s_idx = idx = cb->args[1];
for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
idx = 0;
head = &net->dev_index_head[h];
rcu_read_lock();
cb->seq = net->dev_base_seq;
hlist_for_each_entry_rcu(dev, head, index_hlist) {
if (idx < s_idx)
goto cont;
mdev = mpls_dev_get(dev);
if (!mdev)
goto cont;
if (mpls_netconf_fill_devconf(skb, mdev,
NETLINK_CB(cb->skb).portid,
nlh->nlmsg_seq,
RTM_NEWNETCONF,
NLM_F_MULTI,
NETCONFA_ALL) < 0) {
rcu_read_unlock();
goto done;
}
nl_dump_check_consistent(cb, nlmsg_hdr(skb));
cont:
idx++;
}
rcu_read_unlock();
}
done:
cb->args[0] = h;
cb->args[1] = idx;
return skb->len;
}
#define MPLS_PERDEV_SYSCTL_OFFSET(field) \
(&((struct mpls_dev *)0)->field)
static int mpls_conf_proc(struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
int oval = *(int *)ctl->data;
int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (write) {
struct mpls_dev *mdev = ctl->extra1;
int i = (int *)ctl->data - (int *)mdev;
struct net *net = ctl->extra2;
int val = *(int *)ctl->data;
if (i == offsetof(struct mpls_dev, input_enabled) &&
val != oval) {
mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
NETCONFA_INPUT, mdev);
}
}
return ret;
}
static const struct ctl_table mpls_dev_table[] = {
{
.procname = "input",
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = mpls_conf_proc,
.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 net *net = dev_net(dev);
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;
table[i].extra1 = mdev;
table[i].extra2 = net;
}
snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
mdev->sysctl = register_net_sysctl(net, path, table);
if (!mdev->sysctl)
goto free;
mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
return 0;
free:
kfree(table);
out:
return -ENOBUFS;
}
static void mpls_dev_sysctl_unregister(struct net_device *dev,
struct mpls_dev *mdev)
{
struct net *net = dev_net(dev);
struct ctl_table *table;
table = mdev->sysctl->ctl_table_arg;
unregister_net_sysctl_table(mdev->sysctl);
kfree(table);
mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
}
static struct mpls_dev *mpls_add_dev(struct net_device *dev)
{
struct mpls_dev *mdev;
int err = -ENOMEM;
int i;
ASSERT_RTNL();
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev)
return ERR_PTR(err);
mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
if (!mdev->stats)
goto free;
for_each_possible_cpu(i) {
struct mpls_pcpu_stats *mpls_stats;
mpls_stats = per_cpu_ptr(mdev->stats, i);
u64_stats_init(&mpls_stats->syncp);
}
mdev->dev = dev;
err = mpls_dev_sysctl_register(dev, mdev);
if (err)
goto free;
rcu_assign_pointer(dev->mpls_ptr, mdev);
return mdev;
free:
free_percpu(mdev->stats);
kfree(mdev);
return ERR_PTR(err);
}
static void mpls_dev_destroy_rcu(struct rcu_head *head)
{
struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
free_percpu(mdev->stats);
kfree(mdev);
}
static void mpls_ifdown(struct net_device *dev, int event)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
u8 alive, deleted;
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;
alive = 0;
deleted = 0;
change_nexthops(rt) {
unsigned int nh_flags = nh->nh_flags;
if (rtnl_dereference(nh->nh_dev) != dev)
goto next;
switch (event) {
case NETDEV_DOWN:
case NETDEV_UNREGISTER:
nh_flags |= RTNH_F_DEAD;
fallthrough;
case NETDEV_CHANGE:
nh_flags |= RTNH_F_LINKDOWN;
break;
}
if (event == NETDEV_UNREGISTER)
RCU_INIT_POINTER(nh->nh_dev, NULL);
if (nh->nh_flags != nh_flags)
WRITE_ONCE(nh->nh_flags, nh_flags);
next:
if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
alive++;
if (!rtnl_dereference(nh->nh_dev))
deleted++;
} endfor_nexthops(rt);
WRITE_ONCE(rt->rt_nhn_alive, alive);
/* if there are no more nexthops, delete the route */
if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
mpls_route_update(net, index, NULL, NULL);
}
}
static void mpls_ifup(struct net_device *dev, unsigned int flags)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
unsigned index;
u8 alive;
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;
alive = 0;
change_nexthops(rt) {
unsigned int nh_flags = nh->nh_flags;
struct net_device *nh_dev =
rtnl_dereference(nh->nh_dev);
if (!(nh_flags & flags)) {
alive++;
continue;
}
if (nh_dev != dev)
continue;
alive++;
nh_flags &= ~flags;
WRITE_ONCE(nh->nh_flags, nh_flags);
} endfor_nexthops(rt);
WRITE_ONCE(rt->rt_nhn_alive, alive);
}
}
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;
unsigned int flags;
if (event == NETDEV_REGISTER) {
mdev = mpls_add_dev(dev);
if (IS_ERR(mdev))
return notifier_from_errno(PTR_ERR(mdev));
return NOTIFY_OK;
}
mdev = mpls_dev_get(dev);
if (!mdev)
return NOTIFY_OK;
switch (event) {
case NETDEV_DOWN:
mpls_ifdown(dev, event);
break;
case NETDEV_UP:
flags = dev_get_flags(dev);
if (flags & (IFF_RUNNING | IFF_LOWER_UP))
mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
else
mpls_ifup(dev, RTNH_F_DEAD);
break;
case NETDEV_CHANGE:
flags = dev_get_flags(dev);
if (flags & (IFF_RUNNING | IFF_LOWER_UP))
mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
else
mpls_ifdown(dev, event);
break;
case NETDEV_UNREGISTER:
mpls_ifdown(dev, event);
mdev = mpls_dev_get(dev);
if (mdev) {
mpls_dev_sysctl_unregister(dev, mdev);
RCU_INIT_POINTER(dev->mpls_ptr, NULL);
call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
}
break;
case NETDEV_CHANGENAME:
mdev = mpls_dev_get(dev);
if (mdev) {
int err;
mpls_dev_sysctl_unregister(dev, mdev);
err = mpls_dev_sysctl_register(dev, mdev);
if (err)
return notifier_from_errno(err);
}
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;
}
EXPORT_SYMBOL_GPL(nla_put_labels);
int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
u32 label[], struct netlink_ext_ack *extack)
{
unsigned len = nla_len(nla);
struct mpls_shim_hdr *nla_label;
u8 nla_labels;
bool bos;
int i;
/* len needs to be an even multiple of 4 (the label size). Number
* of labels is a u8 so check for overflow.
*/
if (len & 3 || len / 4 > 255) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"Invalid length for labels attribute");
return -EINVAL;
}
/* Limit the number of new labels allowed */
nla_labels = len/4;
if (nla_labels > max_labels) {
NL_SET_ERR_MSG(extack, "Too many labels");
return -EINVAL;
}
/* when label == NULL, caller wants number of labels */
if (!label)
goto out;
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.ttl) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"TTL in label must be 0");
return -EINVAL;
}
if (dec.tc) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"Traffic class in label must be 0");
return -EINVAL;
}
if (dec.bos != bos) {
NL_SET_BAD_ATTR(extack, nla);
if (bos) {
NL_SET_ERR_MSG(extack,
"BOS bit must be set in first label");
} else {
NL_SET_ERR_MSG(extack,
"BOS bit can only be set in first label");
}
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.
*/
NL_SET_ERR_MSG_ATTR(extack, nla,
"Implicit NULL Label (3) can not be used in encapsulation");
return -EINVAL;
}
label[i] = dec.label;
}
out:
*labels = nla_labels;
return 0;
}
EXPORT_SYMBOL_GPL(nla_get_labels);
static int rtm_to_route_config(struct sk_buff *skb,
struct nlmsghdr *nlh,
struct mpls_route_config *cfg,
struct netlink_ext_ack *extack)
{
struct rtmsg *rtm;
struct nlattr *tb[RTA_MAX+1];
int index;
int err;
err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_mpls_policy, extack);
if (err < 0)
goto errout;
err = -EINVAL;
rtm = nlmsg_data(nlh);
if (rtm->rtm_family != AF_MPLS) {
NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
goto errout;
}
if (rtm->rtm_dst_len != 20) {
NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
goto errout;
}
if (rtm->rtm_src_len != 0) {
NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
goto errout;
}
if (rtm->rtm_tos != 0) {
NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
goto errout;
}
if (rtm->rtm_table != RT_TABLE_MAIN) {
NL_SET_ERR_MSG(extack,
"MPLS only supports the main route table");
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) {
NL_SET_ERR_MSG(extack,
"Invalid route scope - MPLS only supports UNIVERSE");
goto errout;
}
if (rtm->rtm_type != RTN_UNICAST) {
NL_SET_ERR_MSG(extack,
"Invalid route type - MPLS only supports UNICAST");
goto errout;
}
if (rtm->rtm_flags != 0) {
NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
goto errout;
}
cfg->rc_label = LABEL_NOT_SPECIFIED;
cfg->rc_protocol = rtm->rtm_protocol;
cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC;
cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
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, extack))
goto errout;
break;
case RTA_DST:
{
u8 label_count;
if (nla_get_labels(nla, 1, &label_count,
&cfg->rc_label, extack))
goto errout;
if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
&cfg->rc_label, extack))
goto errout;
break;
}
case RTA_GATEWAY:
NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
goto errout;
case RTA_VIA:
{
if (nla_get_via(nla, &cfg->rc_via_alen,
&cfg->rc_via_table, cfg->rc_via,
extack))
goto errout;
break;
}
case RTA_MULTIPATH:
{
cfg->rc_mp = nla_data(nla);
cfg->rc_mp_len = nla_len(nla);
break;
}
case RTA_TTL_PROPAGATE:
{
u8 ttl_propagate = nla_get_u8(nla);
if (ttl_propagate > 1) {
NL_SET_ERR_MSG_ATTR(extack, nla,
"RTA_TTL_PROPAGATE can only be 0 or 1");
goto errout;
}
cfg->rc_ttl_propagate = ttl_propagate ?
MPLS_TTL_PROP_ENABLED :
MPLS_TTL_PROP_DISABLED;
break;
}
default:
NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
/* Unsupported attribute */
goto errout;
}
}
err = 0;
errout:
return err;
}
static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct mpls_route_config *cfg;
int err;
cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
if (!cfg)
return -ENOMEM;
err = rtm_to_route_config(skb, nlh, cfg, extack);
if (err < 0)
goto out;
err = mpls_route_del(cfg, extack);
out:
kfree(cfg);
return err;
}
static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct mpls_route_config *cfg;
int err;
cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
if (!cfg)
return -ENOMEM;
err = rtm_to_route_config(skb, nlh, cfg, extack);
if (err < 0)
goto out;
err = mpls_route_add(cfg, extack);
out:
kfree(cfg);
return err;
}
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 (nla_put_labels(skb, RTA_DST, 1, &label))
goto nla_put_failure;
if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
bool ttl_propagate =
rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
ttl_propagate))
goto nla_put_failure;
}
if (rt->rt_nhn == 1) {
const struct mpls_nh *nh = rt->rt_nh;
if (nh->nh_labels &&
nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
nh->nh_label))
goto nla_put_failure;
if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
goto nla_put_failure;
if (nh->nh_flags & RTNH_F_LINKDOWN)
rtm->rtm_flags |= RTNH_F_LINKDOWN;
if (nh->nh_flags & RTNH_F_DEAD)
rtm->rtm_flags |= RTNH_F_DEAD;
} else {
struct rtnexthop *rtnh;
struct nlattr *mp;
u8 linkdown = 0;
u8 dead = 0;
mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
if (!mp)
goto nla_put_failure;
for_nexthops(rt) {
dev = rtnl_dereference(nh->nh_dev);
if (!dev)
continue;
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
if (!rtnh)
goto nla_put_failure;
rtnh->rtnh_ifindex = dev->ifindex;
if (nh->nh_flags & RTNH_F_LINKDOWN) {
rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
linkdown++;
}
if (nh->nh_flags & RTNH_F_DEAD) {
rtnh->rtnh_flags |= RTNH_F_DEAD;
dead++;
}
if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
nh->nh_labels,
nh->nh_label))
goto nla_put_failure;
if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
nla_put_via(skb, nh->nh_via_table,
mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
/* length of rtnetlink header + attributes */
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
} endfor_nexthops(rt);
if (linkdown == rt->rt_nhn)
rtm->rtm_flags |= RTNH_F_LINKDOWN;
if (dead == rt->rt_nhn)
rtm->rtm_flags |= RTNH_F_DEAD;
nla_nest_end(skb, mp);
}
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
#if IS_ENABLED(CONFIG_INET)
static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
struct fib_dump_filter *filter,
struct netlink_callback *cb)
{
return ip_valid_fib_dump_req(net, nlh, filter, cb);
}
#else
static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
struct fib_dump_filter *filter,
struct netlink_callback *cb)
{
struct netlink_ext_ack *extack = cb->extack;
struct nlattr *tb[RTA_MAX + 1];
struct rtmsg *rtm;
int err, i;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
return -EINVAL;
}
rtm = nlmsg_data(nlh);
if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
rtm->rtm_table || rtm->rtm_scope || rtm->rtm_type ||
rtm->rtm_flags) {
NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
return -EINVAL;
}
if (rtm->rtm_protocol) {
filter->protocol = rtm->rtm_protocol;
filter->filter_set = 1;
cb->answer_flags = NLM_F_DUMP_FILTERED;
}
err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_mpls_policy, extack);
if (err < 0)
return err;
for (i = 0; i <= RTA_MAX; ++i) {
int ifindex;
if (i == RTA_OIF) {
ifindex = nla_get_u32(tb[i]);
filter->dev = __dev_get_by_index(net, ifindex);
if (!filter->dev)
return -ENODEV;
filter->filter_set = 1;
} else if (tb[i]) {
NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
return -EINVAL;
}
}
return 0;
}
#endif
static bool mpls_rt_uses_dev(struct mpls_route *rt,
const struct net_device *dev)
{
struct net_device *nh_dev;
if (rt->rt_nhn == 1) {
struct mpls_nh *nh = rt->rt_nh;
nh_dev = rtnl_dereference(nh->nh_dev);
if (dev == nh_dev)
return true;
} else {
for_nexthops(rt) {
nh_dev = rtnl_dereference(nh->nh_dev);
if (nh_dev == dev)
return true;
} endfor_nexthops(rt);
}
return false;
}
static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
{
const struct nlmsghdr *nlh = cb->nlh;
struct net *net = sock_net(skb->sk);
struct mpls_route __rcu **platform_label;
struct fib_dump_filter filter = {};
unsigned int flags = NLM_F_MULTI;
size_t platform_labels;
unsigned int index;
ASSERT_RTNL();
if (cb->strict_check) {
int err;
err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
if (err < 0)
return err;
/* for MPLS, there is only 1 table with fixed type and flags.
* If either are set in the filter then return nothing.
*/
if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
(filter.rt_type && filter.rt_type != RTN_UNICAST) ||
filter.flags)
return skb->len;
}
index = cb->args[0];
if (index < MPLS_LABEL_FIRST_UNRESERVED)
index = MPLS_LABEL_FIRST_UNRESERVED;
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
if (filter.filter_set)
flags |= NLM_F_DUMP_FILTERED;
for (; index < platform_labels; index++) {
struct mpls_route *rt;
rt = rtnl_dereference(platform_label[index]);
if (!rt)
continue;
if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
(filter.protocol && rt->rt_protocol != filter.protocol))
continue;
if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, RTM_NEWROUTE,
index, rt, flags) < 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(4) /* RTA_DST */
+ nla_total_size(1); /* RTA_TTL_PROPAGATE */
if (rt->rt_nhn == 1) {
struct mpls_nh *nh = rt->rt_nh;
if (nh->nh_dev)
payload += nla_total_size(4); /* RTA_OIF */
if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
payload += nla_total_size(2 + nh->nh_via_alen);
if (nh->nh_labels) /* RTA_NEWDST */
payload += nla_total_size(nh->nh_labels * 4);
} else {
/* each nexthop is packed in an attribute */
size_t nhsize = 0;
for_nexthops(rt) {
if (!rtnl_dereference(nh->nh_dev))
continue;
nhsize += nla_total_size(sizeof(struct rtnexthop));
/* RTA_VIA */
if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
nhsize += nla_total_size(2 + nh->nh_via_alen);
if (nh->nh_labels)
nhsize += nla_total_size(nh->nh_labels * 4);
} endfor_nexthops(rt);
/* nested attribute */
payload += nla_total_size(nhsize);
}
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 mpls_valid_getroute_req(struct sk_buff *skb,
const struct nlmsghdr *nlh,
struct nlattr **tb,
struct netlink_ext_ack *extack)
{
struct rtmsg *rtm;
int i, err;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
NL_SET_ERR_MSG_MOD(extack,
"Invalid header for get route request");
return -EINVAL;
}
if (!netlink_strict_get_check(skb))
return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_mpls_policy, extack);
rtm = nlmsg_data(nlh);
if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
return -EINVAL;
}
if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
NL_SET_ERR_MSG_MOD(extack,
"Invalid flags for get route request");
return -EINVAL;
}
err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_mpls_policy, extack);
if (err)
return err;
if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
return -EINVAL;
}
for (i = 0; i <= RTA_MAX; i++) {
if (!tb[i])
continue;
switch (i) {
case RTA_DST:
case RTA_NEWDST:
break;
default:
NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
return -EINVAL;
}
}
return 0;
}
static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(in_skb->sk);
u32 portid = NETLINK_CB(in_skb).portid;
u32 in_label = LABEL_NOT_SPECIFIED;
struct nlattr *tb[RTA_MAX + 1];
u32 labels[MAX_NEW_LABELS];
struct mpls_shim_hdr *hdr;
unsigned int hdr_size = 0;
struct net_device *dev;
struct mpls_route *rt;
struct rtmsg *rtm, *r;
struct nlmsghdr *nlh;
struct sk_buff *skb;
struct mpls_nh *nh;
u8 n_labels;
int err;
err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
if (err < 0)
goto errout;
rtm = nlmsg_data(in_nlh);
if (tb[RTA_DST]) {
u8 label_count;
if (nla_get_labels(tb[RTA_DST], 1, &label_count,
&in_label, extack)) {
err = -EINVAL;
goto errout;
}
if (!mpls_label_ok(net, &in_label, extack)) {
err = -EINVAL;
goto errout;
}
}
rt = mpls_route_input_rcu(net, in_label);
if (!rt) {
err = -ENETUNREACH;
goto errout;
}
if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
if (!skb) {
err = -ENOBUFS;
goto errout;
}
err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
RTM_NEWROUTE, in_label, rt, 0);
if (err < 0) {
/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
WARN_ON(err == -EMSGSIZE);
goto errout_free;
}
return rtnl_unicast(skb, net, portid);
}
if (tb[RTA_NEWDST]) {
if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
labels, extack) != 0) {
err = -EINVAL;
goto errout;
}
hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
}
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb) {
err = -ENOBUFS;
goto errout;
}
skb->protocol = htons(ETH_P_MPLS_UC);
if (hdr_size) {
bool bos;
int i;
if (skb_cow(skb, hdr_size)) {
err = -ENOBUFS;
goto errout_free;
}
skb_reserve(skb, hdr_size);
skb_push(skb, hdr_size);
skb_reset_network_header(skb);
/* Push new labels */
hdr = mpls_hdr(skb);
bos = true;
for (i = n_labels - 1; i >= 0; i--) {
hdr[i] = mpls_entry_encode(labels[i],
1, 0, bos);
bos = false;
}
}
nh = mpls_select_multipath(rt, skb);
if (!nh) {
err = -ENETUNREACH;
goto errout_free;
}
if (hdr_size) {
skb_pull(skb, hdr_size);
skb_reset_network_header(skb);
}
nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
RTM_NEWROUTE, sizeof(*r), 0);
if (!nlh) {
err = -EMSGSIZE;
goto errout_free;
}
r = nlmsg_data(nlh);
r->rtm_family = AF_MPLS;
r->rtm_dst_len = 20;
r->rtm_src_len = 0;
r->rtm_table = RT_TABLE_MAIN;
r->rtm_type = RTN_UNICAST;
r->rtm_scope = RT_SCOPE_UNIVERSE;
r->rtm_protocol = rt->rt_protocol;
r->rtm_flags = 0;
if (nla_put_labels(skb, RTA_DST, 1, &in_label))
goto nla_put_failure;
if (nh->nh_labels &&
nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
nh->nh_label))
goto nla_put_failure;
if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
goto nla_put_failure;
nlmsg_end(skb, nlh);
err = rtnl_unicast(skb, net, portid);
errout:
return err;
nla_put_failure:
nlmsg_cancel(skb, nlh);
err = -EMSGSIZE;
errout_free:
kfree_skb(skb);
return 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 = kvzalloc(size, GFP_KERNEL);
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(1, lo->addr_len, 0);
if (IS_ERR(rt0))
goto nort0;
RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
rt0->rt_protocol = RTPROT_KERNEL;
rt0->rt_payload_type = MPT_IPV4;
rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
rt0->rt_nh->nh_via_alen = lo->addr_len;
memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
lo->addr_len);
}
if (limit > MPLS_LABEL_IPV6NULL) {
struct net_device *lo = net->loopback_dev;
rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
if (IS_ERR(rt2))
goto nort2;
RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
rt2->rt_protocol = RTPROT_KERNEL;
rt2->rt_payload_type = MPT_IPV6;
rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
rt2->rt_nh->nh_via_alen = lo->addr_len;
memcpy(__mpls_nh_via(rt2, rt2->rt_nh), 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);
/* 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);
}
return 0;
nort2:
mpls_rt_free(rt0);
nort0:
kvfree(labels);
nolabels:
return -ENOMEM;
}
static int mpls_platform_labels(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net = table->data;
int platform_labels = net->mpls.platform_labels;
int ret;
struct ctl_table tmp = {
.procname = table->procname,
.data = &platform_labels,
.maxlen = sizeof(int),
.mode = table->mode,
.extra1 = SYSCTL_ZERO,
.extra2 = &label_limit,
};
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && ret == 0)
ret = resize_platform_label_table(net, platform_labels);
return ret;
}
#define MPLS_NS_SYSCTL_OFFSET(field) \
(&((struct net *)0)->field)
static const struct ctl_table mpls_table[] = {
{
.procname = "platform_labels",
.data = NULL,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = mpls_platform_labels,
},
{
.procname = "ip_ttl_propagate",
.data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
{
.procname = "default_ttl",
.data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ONE,
.extra2 = &ttl_max,
},
{ }
};
static int mpls_net_init(struct net *net)
{
struct ctl_table *table;
int i;
net->mpls.platform_labels = 0;
net->mpls.platform_label = NULL;
net->mpls.ip_ttl_propagate = 1;
net->mpls.default_ttl = 255;
table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
if (table == NULL)
return -ENOMEM;
/* 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_table) - 1; i++)
table[i].data = (char *)net + (uintptr_t)table[i].data;
net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
if (net->mpls.ctl == NULL) {
kfree(table);
return -ENOMEM;
}
return 0;
}
static void mpls_net_exit(struct net *net)
{
struct mpls_route __rcu **platform_label;
size_t platform_labels;
struct ctl_table *table;
unsigned int index;
table = net->mpls.ctl->ctl_table_arg;
unregister_net_sysctl_table(net->mpls.ctl);
kfree(table);
/* An rcu grace period has passed since there was a device in
* the network namespace (and thus the last in flight packet)
* left this network namespace. This is because
* unregister_netdevice_many and netdev_run_todo has completed
* for each network device that was in this network namespace.
*
* As such no additional rcu synchronization is necessary when
* freeing the platform_label table.
*/
rtnl_lock();
platform_label = rtnl_dereference(net->mpls.platform_label);
platform_labels = net->mpls.platform_labels;
for (index = 0; index < platform_labels; index++) {
struct mpls_route *rt = rtnl_dereference(platform_label[index]);
RCU_INIT_POINTER(platform_label[index], NULL);
mpls_notify_route(net, index, rt, NULL, NULL);
mpls_rt_free(rt);
}
rtnl_unlock();
kvfree(platform_label);
}
static struct pernet_operations mpls_net_ops = {
.init = mpls_net_init,
.exit = mpls_net_exit,
};
static struct rtnl_af_ops mpls_af_ops __read_mostly = {
.family = AF_MPLS,
.fill_stats_af = mpls_fill_stats_af,
.get_stats_af_size = mpls_get_stats_af_size,
};
static int __init mpls_init(void)
{
int err;
BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
err = register_pernet_subsys(&mpls_net_ops);
if (err)
goto out;
err = register_netdevice_notifier(&mpls_dev_notifier);
if (err)
goto out_unregister_pernet;
dev_add_pack(&mpls_packet_type);
rtnl_af_register(&mpls_af_ops);
rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
mpls_rtm_newroute, NULL, 0);
rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
mpls_rtm_delroute, NULL, 0);
rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
mpls_getroute, mpls_dump_routes, 0);
rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
mpls_netconf_get_devconf,
mpls_netconf_dump_devconf, 0);
err = ipgre_tunnel_encap_add_mpls_ops();
if (err)
pr_err("Can't add mpls over gre tunnel ops\n");
err = 0;
out:
return err;
out_unregister_pernet:
unregister_pernet_subsys(&mpls_net_ops);
goto out;
}
module_init(mpls_init);
static void __exit mpls_exit(void)
{
rtnl_unregister_all(PF_MPLS);
rtnl_af_unregister(&mpls_af_ops);
dev_remove_pack(&mpls_packet_type);
unregister_netdevice_notifier(&mpls_dev_notifier);
unregister_pernet_subsys(&mpls_net_ops);
ipgre_tunnel_encap_del_mpls_ops();
}
module_exit(mpls_exit);
MODULE_DESCRIPTION("MultiProtocol Label Switching");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_NETPROTO(PF_MPLS);
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