diff options
Diffstat (limited to 'net/mpls/af_mpls.c')
| -rw-r--r-- | net/mpls/af_mpls.c | 2808 |
1 files changed, 2808 insertions, 0 deletions
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c new file mode 100644 index 000000000..1dcbdab93 --- /dev/null +++ b/net/mpls/af_mpls.c @@ -0,0 +1,2808 @@ +// 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; + + /* 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_irq(&p->syncp); + local = p->stats; + } while (u64_stats_fetch_retry_irq(&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: + mdev->sysctl = NULL; + 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; + + if (!mdev->sysctl) + return; + + 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 int mpls_ifdown(struct net_device *dev, int event) +{ + struct mpls_route __rcu **platform_label; + struct net *net = dev_net(dev); + 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]); + bool nh_del = false; + u8 alive = 0; + + if (!rt) + continue; + + if (event == NETDEV_UNREGISTER) { + u8 deleted = 0; + + for_nexthops(rt) { + struct net_device *nh_dev = + rtnl_dereference(nh->nh_dev); + + if (!nh_dev || nh_dev == dev) + deleted++; + if (nh_dev == dev) + nh_del = true; + } endfor_nexthops(rt); + + /* if there are no more nexthops, delete the route */ + if (deleted == rt->rt_nhn) { + mpls_route_update(net, index, NULL, NULL); + continue; + } + + if (nh_del) { + size_t size = sizeof(*rt) + rt->rt_nhn * + rt->rt_nh_size; + struct mpls_route *orig = rt; + + rt = kmalloc(size, GFP_KERNEL); + if (!rt) + return -ENOMEM; + memcpy(rt, orig, size); + } + } + + 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++; + } endfor_nexthops(rt); + + WRITE_ONCE(rt->rt_nhn_alive, alive); + + if (nh_del) + mpls_route_update(net, index, rt, NULL); + } + + return 0; +} + +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) { + int err; + + case NETDEV_DOWN: + err = mpls_ifdown(dev, event); + if (err) + return notifier_from_errno(err); + 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 { + err = mpls_ifdown(dev, event); + if (err) + return notifier_from_errno(err); + } + break; + case NETDEV_UNREGISTER: + err = mpls_ifdown(dev, event); + if (err) + return notifier_from_errno(err); + 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) { + 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); |