--- /dev/null
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/socket.h>
+#include <linux/sysctl.h>
+#include <linux/net.h>
+#include <linux/module.h>
+#include <linux/if_arp.h>
+#include <linux/ipv6.h>
+#include <linux/mpls.h>
+#include <linux/vmalloc.h>
+#include <net/ip.h>
+#include <net/dst.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#include <net/ip_fib.h>
+#include <net/netevent.h>
+#include <net/netns/generic.h>
+#include "internal.h"
+
+#define LABEL_NOT_SPECIFIED (1<<20)
+#define MAX_NEW_LABELS 2
+
+/* This maximum ha length copied from the definition of struct neighbour */
+#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
+
+struct mpls_route { /* next hop label forwarding entry */
+ struct net_device __rcu *rt_dev;
+ struct rcu_head rt_rcu;
+ u32 rt_label[MAX_NEW_LABELS];
+ u8 rt_protocol; /* routing protocol that set this entry */
+ u8 rt_labels;
+ u8 rt_via_alen;
+ u8 rt_via_table;
+ u8 rt_via[0];
+};
+
+static int zero = 0;
+static int label_limit = (1 << 20) - 1;
+
+static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
+ struct nlmsghdr *nlh, struct net *net, u32 portid,
+ unsigned int nlm_flags);
+
+static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
+{
+ struct mpls_route *rt = NULL;
+
+ if (index < net->mpls.platform_labels) {
+ struct mpls_route __rcu **platform_label =
+ rcu_dereference(net->mpls.platform_label);
+ rt = rcu_dereference(platform_label[index]);
+ }
+ return rt;
+}
+
+static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
+{
+ return rcu_dereference_rtnl(dev->mpls_ptr);
+}
+
+static bool mpls_output_possible(const struct net_device *dev)
+{
+ return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
+}
+
+static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
+{
+ /* The size of the layer 2.5 labels to be added for this route */
+ return rt->rt_labels * sizeof(struct mpls_shim_hdr);
+}
+
+static unsigned int mpls_dev_mtu(const struct net_device *dev)
+{
+ /* The amount of data the layer 2 frame can hold */
+ return dev->mtu;
+}
+
+static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
+{
+ if (skb->len <= mtu)
+ return false;
+
+ if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
+ return false;
+
+ return true;
+}
+
+static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
+ struct mpls_entry_decoded dec)
+{
+ /* RFC4385 and RFC5586 encode other packets in mpls such that
+ * they don't conflict with the ip version number, making
+ * decoding by examining the ip version correct in everything
+ * except for the strangest cases.
+ *
+ * The strange cases if we choose to support them will require
+ * manual configuration.
+ */
+ struct iphdr *hdr4;
+ bool success = true;
+
+ /* The IPv4 code below accesses through the IPv4 header
+ * checksum, which is 12 bytes into the packet.
+ * The IPv6 code below accesses through the IPv6 hop limit
+ * which is 8 bytes into the packet.
+ *
+ * For all supported cases there should always be at least 12
+ * bytes of packet data present. The IPv4 header is 20 bytes
+ * without options and the IPv6 header is always 40 bytes
+ * long.
+ */
+ if (!pskb_may_pull(skb, 12))
+ return false;
+
+ /* Use ip_hdr to find the ip protocol version */
+ hdr4 = ip_hdr(skb);
+ if (hdr4->version == 4) {
+ skb->protocol = htons(ETH_P_IP);
+ csum_replace2(&hdr4->check,
+ htons(hdr4->ttl << 8),
+ htons(dec.ttl << 8));
+ hdr4->ttl = dec.ttl;
+ }
+ else if (hdr4->version == 6) {
+ struct ipv6hdr *hdr6 = ipv6_hdr(skb);
+ skb->protocol = htons(ETH_P_IPV6);
+ hdr6->hop_limit = dec.ttl;
+ }
+ else
+ /* version 0 and version 1 are used by pseudo wires */
+ success = false;
+ return success;
+}
+
+static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct net *net = dev_net(dev);
+ struct mpls_shim_hdr *hdr;
+ struct mpls_route *rt;
+ struct mpls_entry_decoded dec;
+ struct net_device *out_dev;
+ struct mpls_dev *mdev;
+ unsigned int hh_len;
+ unsigned int new_header_size;
+ unsigned int mtu;
+ int err;
+
+ /* Careful this entire function runs inside of an rcu critical section */
+
+ mdev = mpls_dev_get(dev);
+ if (!mdev || !mdev->input_enabled)
+ goto drop;
+
+ if (skb->pkt_type != PACKET_HOST)
+ goto drop;
+
+ if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
+ goto drop;
+
+ if (!pskb_may_pull(skb, sizeof(*hdr)))
+ goto drop;
+
+ /* Read and decode the label */
+ hdr = mpls_hdr(skb);
+ dec = mpls_entry_decode(hdr);
+
+ /* Pop the label */
+ skb_pull(skb, sizeof(*hdr));
+ skb_reset_network_header(skb);
+
+ skb_orphan(skb);
+
+ rt = mpls_route_input_rcu(net, dec.label);
+ if (!rt)
+ goto drop;
+
+ /* Find the output device */
+ out_dev = rcu_dereference(rt->rt_dev);
+ if (!mpls_output_possible(out_dev))
+ goto drop;
+
+ if (skb_warn_if_lro(skb))
+ goto drop;
+
+ skb_forward_csum(skb);
+
+ /* Verify ttl is valid */
+ if (dec.ttl <= 1)
+ goto drop;
+ dec.ttl -= 1;
+
+ /* Verify the destination can hold the packet */
+ new_header_size = mpls_rt_header_size(rt);
+ mtu = mpls_dev_mtu(out_dev);
+ if (mpls_pkt_too_big(skb, mtu - new_header_size))
+ goto drop;
+
+ hh_len = LL_RESERVED_SPACE(out_dev);
+ if (!out_dev->header_ops)
+ hh_len = 0;
+
+ /* Ensure there is enough space for the headers in the skb */
+ if (skb_cow(skb, hh_len + new_header_size))
+ goto drop;
+
+ skb->dev = out_dev;
+ skb->protocol = htons(ETH_P_MPLS_UC);
+
+ if (unlikely(!new_header_size && dec.bos)) {
+ /* Penultimate hop popping */
+ if (!mpls_egress(rt, skb, dec))
+ goto drop;
+ } else {
+ bool bos;
+ int i;
+ skb_push(skb, new_header_size);
+ skb_reset_network_header(skb);
+ /* Push the new labels */
+ hdr = mpls_hdr(skb);
+ bos = dec.bos;
+ for (i = rt->rt_labels - 1; i >= 0; i--) {
+ hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos);
+ bos = false;
+ }
+ }
+
+ err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb);
+ if (err)
+ net_dbg_ratelimited("%s: packet transmission failed: %d\n",
+ __func__, err);
+ return 0;
+
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+static struct packet_type mpls_packet_type __read_mostly = {
+ .type = cpu_to_be16(ETH_P_MPLS_UC),
+ .func = mpls_forward,
+};
+
+static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
+ [RTA_DST] = { .type = NLA_U32 },
+ [RTA_OIF] = { .type = NLA_U32 },
+};
+
+struct mpls_route_config {
+ u32 rc_protocol;
+ u32 rc_ifindex;
+ u16 rc_via_table;
+ u16 rc_via_alen;
+ u8 rc_via[MAX_VIA_ALEN];
+ u32 rc_label;
+ u32 rc_output_labels;
+ u32 rc_output_label[MAX_NEW_LABELS];
+ u32 rc_nlflags;
+ struct nl_info rc_nlinfo;
+};
+
+static struct mpls_route *mpls_rt_alloc(size_t alen)
+{
+ struct mpls_route *rt;
+
+ rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL);
+ if (rt)
+ rt->rt_via_alen = alen;
+ return rt;
+}
+
+static void mpls_rt_free(struct mpls_route *rt)
+{
+ if (rt)
+ kfree_rcu(rt, rt_rcu);
+}
+
+static void mpls_notify_route(struct net *net, unsigned index,
+ struct mpls_route *old, struct mpls_route *new,
+ const struct nl_info *info)
+{
+ struct nlmsghdr *nlh = info ? info->nlh : NULL;
+ unsigned portid = info ? info->portid : 0;
+ int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
+ struct mpls_route *rt = new ? new : old;
+ unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
+ /* Ignore reserved labels for now */
+ if (rt && (index >= 16))
+ rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
+}
+
+static void mpls_route_update(struct net *net, unsigned index,
+ struct net_device *dev, struct mpls_route *new,
+ const struct nl_info *info)
+{
+ struct mpls_route __rcu **platform_label;
+ struct mpls_route *rt, *old = NULL;
+
+ ASSERT_RTNL();
+
+ platform_label = rtnl_dereference(net->mpls.platform_label);
+ rt = rtnl_dereference(platform_label[index]);
+ if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) {
+ rcu_assign_pointer(platform_label[index], new);
+ old = rt;
+ }
+
+ mpls_notify_route(net, index, old, new, info);
+
+ /* If we removed a route free it now */
+ mpls_rt_free(old);
+}
+
+static unsigned find_free_label(struct net *net)
+{
+ struct mpls_route __rcu **platform_label;
+ size_t platform_labels;
+ unsigned index;
+
+ platform_label = rtnl_dereference(net->mpls.platform_label);
+ platform_labels = net->mpls.platform_labels;
+ for (index = 16; index < platform_labels; index++) {
+ if (!rtnl_dereference(platform_label[index]))
+ return index;
+ }
+ return LABEL_NOT_SPECIFIED;
+}
+
+static int mpls_route_add(struct mpls_route_config *cfg)
+{
+ struct mpls_route __rcu **platform_label;
+ struct net *net = cfg->rc_nlinfo.nl_net;
+ struct net_device *dev = NULL;
+ struct mpls_route *rt, *old;
+ unsigned index;
+ int i;
+ int err = -EINVAL;
+
+ index = cfg->rc_label;
+
+ /* If a label was not specified during insert pick one */
+ if ((index == LABEL_NOT_SPECIFIED) &&
+ (cfg->rc_nlflags & NLM_F_CREATE)) {
+ index = find_free_label(net);
+ }
+
+ /* The first 16 labels are reserved, and may not be set */
+ if (index < 16)
+ goto errout;
+
+ /* The full 20 bit range may not be supported. */
+ if (index >= net->mpls.platform_labels)
+ goto errout;
+
+ /* Ensure only a supported number of labels are present */
+ if (cfg->rc_output_labels > MAX_NEW_LABELS)
+ goto errout;
+
+ err = -ENODEV;
+ dev = dev_get_by_index(net, cfg->rc_ifindex);
+ if (!dev)
+ goto errout;
+
+ /* Ensure this is a supported device */
+ err = -EINVAL;
+ if (!mpls_dev_get(dev))
+ goto errout;
+
+ err = -EINVAL;
+ if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
+ (dev->addr_len != cfg->rc_via_alen))
+ goto errout;
+
+ /* Append makes no sense with mpls */
+ err = -EOPNOTSUPP;
+ if (cfg->rc_nlflags & NLM_F_APPEND)
+ goto errout;
+
+ err = -EEXIST;
+ platform_label = rtnl_dereference(net->mpls.platform_label);
+ old = rtnl_dereference(platform_label[index]);
+ if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
+ goto errout;
+
+ err = -EEXIST;
+ if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
+ goto errout;
+
+ err = -ENOENT;
+ if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
+ goto errout;
+
+ err = -ENOMEM;
+ rt = mpls_rt_alloc(cfg->rc_via_alen);
+ if (!rt)
+ goto errout;
+
+ rt->rt_labels = cfg->rc_output_labels;
+ for (i = 0; i < rt->rt_labels; i++)
+ rt->rt_label[i] = cfg->rc_output_label[i];
+ rt->rt_protocol = cfg->rc_protocol;
+ RCU_INIT_POINTER(rt->rt_dev, dev);
+ rt->rt_via_table = cfg->rc_via_table;
+ memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
+
+ mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
+
+ dev_put(dev);
+ return 0;
+
+errout:
+ if (dev)
+ dev_put(dev);
+ return err;
+}
+
+static int mpls_route_del(struct mpls_route_config *cfg)
+{
+ struct net *net = cfg->rc_nlinfo.nl_net;
+ unsigned index;
+ int err = -EINVAL;
+
+ index = cfg->rc_label;
+
+ /* The first 16 labels are reserved, and may not be removed */
+ if (index < 16)
+ goto errout;
+
+ /* The full 20 bit range may not be supported */
+ if (index >= net->mpls.platform_labels)
+ goto errout;
+
+ mpls_route_update(net, index, NULL, NULL, &cfg->rc_nlinfo);
+
+ err = 0;
+errout:
+ return err;
+}
+
+#define MPLS_PERDEV_SYSCTL_OFFSET(field) \
+ (&((struct mpls_dev *)0)->field)
+
+static const struct ctl_table mpls_dev_table[] = {
+ {
+ .procname = "input",
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
+ },
+ { }
+};
+
+static int mpls_dev_sysctl_register(struct net_device *dev,
+ struct mpls_dev *mdev)
+{
+ char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
+ struct ctl_table *table;
+ int i;
+
+ table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
+ if (!table)
+ goto out;
+
+ /* Table data contains only offsets relative to the base of
+ * the mdev at this point, so make them absolute.
+ */
+ for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
+ table[i].data = (char *)mdev + (uintptr_t)table[i].data;
+
+ snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
+
+ mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
+ if (!mdev->sysctl)
+ goto free;
+
+ return 0;
+
+free:
+ kfree(table);
+out:
+ return -ENOBUFS;
+}
+
+static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
+{
+ struct ctl_table *table;
+
+ table = mdev->sysctl->ctl_table_arg;
+ unregister_net_sysctl_table(mdev->sysctl);
+ kfree(table);
+}
+
+static struct mpls_dev *mpls_add_dev(struct net_device *dev)
+{
+ struct mpls_dev *mdev;
+ int err = -ENOMEM;
+
+ ASSERT_RTNL();
+
+ mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+ if (!mdev)
+ return ERR_PTR(err);
+
+ err = mpls_dev_sysctl_register(dev, mdev);
+ if (err)
+ goto free;
+
+ rcu_assign_pointer(dev->mpls_ptr, mdev);
+
+ return mdev;
+
+free:
+ kfree(mdev);
+ return ERR_PTR(err);
+}
+
+static void mpls_ifdown(struct net_device *dev)
+{
+ struct mpls_route __rcu **platform_label;
+ struct net *net = dev_net(dev);
+ struct mpls_dev *mdev;
+ unsigned index;
+
+ platform_label = rtnl_dereference(net->mpls.platform_label);
+ for (index = 0; index < net->mpls.platform_labels; index++) {
+ struct mpls_route *rt = rtnl_dereference(platform_label[index]);
+ if (!rt)
+ continue;
+ if (rtnl_dereference(rt->rt_dev) != dev)
+ continue;
+ rt->rt_dev = NULL;
+ }
+
+ mdev = mpls_dev_get(dev);
+ if (!mdev)
+ return;
+
+ mpls_dev_sysctl_unregister(mdev);
+
+ RCU_INIT_POINTER(dev->mpls_ptr, NULL);
+
+ kfree_rcu(mdev, rcu);
+}
+
+static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
+ void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct mpls_dev *mdev;
+
+ switch(event) {
+ case NETDEV_REGISTER:
+ /* For now just support ethernet devices */
+ if ((dev->type == ARPHRD_ETHER) ||
+ (dev->type == ARPHRD_LOOPBACK)) {
+ mdev = mpls_add_dev(dev);
+ if (IS_ERR(mdev))
+ return notifier_from_errno(PTR_ERR(mdev));
+ }
+ break;
+
+ case NETDEV_UNREGISTER:
+ mpls_ifdown(dev);
+ break;
+ case NETDEV_CHANGENAME:
+ mdev = mpls_dev_get(dev);
+ if (mdev) {
+ int err;
+
+ mpls_dev_sysctl_unregister(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;
+}
+
+int nla_get_labels(const struct nlattr *nla,
+ u32 max_labels, u32 *labels, u32 label[])
+{
+ unsigned len = nla_len(nla);
+ unsigned nla_labels;
+ struct mpls_shim_hdr *nla_label;
+ bool bos;
+ int i;
+
+ /* len needs to be an even multiple of 4 (the label size) */
+ if (len & 3)
+ return -EINVAL;
+
+ /* Limit the number of new labels allowed */
+ nla_labels = len/4;
+ if (nla_labels > max_labels)
+ return -EINVAL;
+
+ nla_label = nla_data(nla);
+ bos = true;
+ for (i = nla_labels - 1; i >= 0; i--, bos = false) {
+ struct mpls_entry_decoded dec;
+ dec = mpls_entry_decode(nla_label + i);
+
+ /* Ensure the bottom of stack flag is properly set
+ * and ttl and tc are both clear.
+ */
+ if ((dec.bos != bos) || dec.ttl || dec.tc)
+ return -EINVAL;
+
+ switch (dec.label) {
+ case MPLS_LABEL_IMPLNULL:
+ /* RFC3032: This is a label that an LSR may
+ * assign and distribute, but which never
+ * actually appears in the encapsulation.
+ */
+ return -EINVAL;
+ }
+
+ label[i] = dec.label;
+ }
+ *labels = nla_labels;
+ return 0;
+}
+
+static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct mpls_route_config *cfg)
+{
+ struct rtmsg *rtm;
+ struct nlattr *tb[RTA_MAX+1];
+ int index;
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy);
+ if (err < 0)
+ goto errout;
+
+ err = -EINVAL;
+ rtm = nlmsg_data(nlh);
+ memset(cfg, 0, sizeof(*cfg));
+
+ if (rtm->rtm_family != AF_MPLS)
+ goto errout;
+ if (rtm->rtm_dst_len != 20)
+ goto errout;
+ if (rtm->rtm_src_len != 0)
+ goto errout;
+ if (rtm->rtm_tos != 0)
+ goto errout;
+ if (rtm->rtm_table != RT_TABLE_MAIN)
+ goto errout;
+ /* Any value is acceptable for rtm_protocol */
+
+ /* As mpls uses destination specific addresses
+ * (or source specific address in the case of multicast)
+ * all addresses have universal scope.
+ */
+ if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
+ goto errout;
+ if (rtm->rtm_type != RTN_UNICAST)
+ goto errout;
+ if (rtm->rtm_flags != 0)
+ goto errout;
+
+ cfg->rc_label = LABEL_NOT_SPECIFIED;
+ cfg->rc_protocol = rtm->rtm_protocol;
+ cfg->rc_nlflags = nlh->nlmsg_flags;
+ cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
+ cfg->rc_nlinfo.nlh = nlh;
+ cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
+
+ for (index = 0; index <= RTA_MAX; index++) {
+ struct nlattr *nla = tb[index];
+ if (!nla)
+ continue;
+
+ switch(index) {
+ case RTA_OIF:
+ cfg->rc_ifindex = nla_get_u32(nla);
+ break;
+ case RTA_NEWDST:
+ if (nla_get_labels(nla, MAX_NEW_LABELS,
+ &cfg->rc_output_labels,
+ cfg->rc_output_label))
+ goto errout;
+ break;
+ case RTA_DST:
+ {
+ u32 label_count;
+ if (nla_get_labels(nla, 1, &label_count,
+ &cfg->rc_label))
+ goto errout;
+
+ /* The first 16 labels are reserved, and may not be set */
+ if (cfg->rc_label < 16)
+ goto errout;
+
+ break;
+ }
+ case RTA_VIA:
+ {
+ struct rtvia *via = nla_data(nla);
+ if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
+ goto errout;
+ cfg->rc_via_alen = nla_len(nla) -
+ offsetof(struct rtvia, rtvia_addr);
+ if (cfg->rc_via_alen > MAX_VIA_ALEN)
+ goto errout;
+
+ /* Validate the address family */
+ switch(via->rtvia_family) {
+ case AF_PACKET:
+ cfg->rc_via_table = NEIGH_LINK_TABLE;
+ break;
+ case AF_INET:
+ cfg->rc_via_table = NEIGH_ARP_TABLE;
+ if (cfg->rc_via_alen != 4)
+ goto errout;
+ break;
+ case AF_INET6:
+ cfg->rc_via_table = NEIGH_ND_TABLE;
+ if (cfg->rc_via_alen != 16)
+ goto errout;
+ break;
+ default:
+ /* Unsupported address family */
+ goto errout;
+ }
+
+ memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen);
+ break;
+ }
+ default:
+ /* Unsupported attribute */
+ goto errout;
+ }
+ }
+
+ err = 0;
+errout:
+ return err;
+}
+
+static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ struct mpls_route_config cfg;
+ int err;
+
+ err = rtm_to_route_config(skb, nlh, &cfg);
+ if (err < 0)
+ return err;
+
+ return mpls_route_del(&cfg);
+}
+
+
+static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ struct mpls_route_config cfg;
+ int err;
+
+ err = rtm_to_route_config(skb, nlh, &cfg);
+ if (err < 0)
+ return err;
+
+ return mpls_route_add(&cfg);
+}
+
+static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
+ u32 label, struct mpls_route *rt, int flags)
+{
+ struct net_device *dev;
+ struct nlmsghdr *nlh;
+ struct rtmsg *rtm;
+
+ nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
+ if (nlh == NULL)
+ return -EMSGSIZE;
+
+ rtm = nlmsg_data(nlh);
+ rtm->rtm_family = AF_MPLS;
+ rtm->rtm_dst_len = 20;
+ rtm->rtm_src_len = 0;
+ rtm->rtm_tos = 0;
+ rtm->rtm_table = RT_TABLE_MAIN;
+ rtm->rtm_protocol = rt->rt_protocol;
+ rtm->rtm_scope = RT_SCOPE_UNIVERSE;
+ rtm->rtm_type = RTN_UNICAST;
+ rtm->rtm_flags = 0;
+
+ if (rt->rt_labels &&
+ nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
+ goto nla_put_failure;
+ if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen))
+ goto nla_put_failure;
+ dev = rtnl_dereference(rt->rt_dev);
+ if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
+ goto nla_put_failure;
+ if (nla_put_labels(skb, RTA_DST, 1, &label))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct net *net = sock_net(skb->sk);
+ struct mpls_route __rcu **platform_label;
+ size_t platform_labels;
+ unsigned int index;
+
+ ASSERT_RTNL();
+
+ index = cb->args[0];
+ if (index < 16)
+ index = 16;
+
+ platform_label = rtnl_dereference(net->mpls.platform_label);
+ platform_labels = net->mpls.platform_labels;
+ for (; index < platform_labels; index++) {
+ struct mpls_route *rt;
+ rt = rtnl_dereference(platform_label[index]);
+ if (!rt)
+ continue;
+
+ if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, RTM_NEWROUTE,
+ index, rt, NLM_F_MULTI) < 0)
+ break;
+ }
+ cb->args[0] = index;
+
+ return skb->len;
+}
+
+static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
+{
+ size_t payload =
+ NLMSG_ALIGN(sizeof(struct rtmsg))
+ + nla_total_size(2 + rt->rt_via_alen) /* RTA_VIA */
+ + nla_total_size(4); /* RTA_DST */
+ if (rt->rt_labels) /* RTA_NEWDST */
+ payload += nla_total_size(rt->rt_labels * 4);
+ if (rt->rt_dev) /* RTA_OIF */
+ payload += nla_total_size(4);
+ return payload;
+}
+
+static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
+ struct nlmsghdr *nlh, struct net *net, u32 portid,
+ unsigned int nlm_flags)
+{
+ struct sk_buff *skb;
+ u32 seq = nlh ? nlh->nlmsg_seq : 0;
+ int err = -ENOBUFS;
+
+ skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
+ if (skb == NULL)
+ goto errout;
+
+ err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
+ rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
+
+ return;
+errout:
+ if (err < 0)
+ rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
+}
+
+static int resize_platform_label_table(struct net *net, size_t limit)
+{
+ size_t size = sizeof(struct mpls_route *) * limit;
+ size_t old_limit;
+ size_t cp_size;
+ struct mpls_route __rcu **labels = NULL, **old;
+ struct mpls_route *rt0 = NULL, *rt2 = NULL;
+ unsigned index;
+
+ if (size) {
+ labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
+ if (!labels)
+ labels = vzalloc(size);
+
+ if (!labels)
+ goto nolabels;
+ }
+
+ /* In case the predefined labels need to be populated */
+ if (limit > MPLS_LABEL_IPV4NULL) {
+ struct net_device *lo = net->loopback_dev;
+ rt0 = mpls_rt_alloc(lo->addr_len);
+ if (!rt0)
+ goto nort0;
+ RCU_INIT_POINTER(rt0->rt_dev, lo);
+ rt0->rt_protocol = RTPROT_KERNEL;
+ rt0->rt_via_table = NEIGH_LINK_TABLE;
+ memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
+ }
+ if (limit > MPLS_LABEL_IPV6NULL) {
+ struct net_device *lo = net->loopback_dev;
+ rt2 = mpls_rt_alloc(lo->addr_len);
+ if (!rt2)
+ goto nort2;
+ RCU_INIT_POINTER(rt2->rt_dev, lo);
+ rt2->rt_protocol = RTPROT_KERNEL;
+ rt2->rt_via_table = NEIGH_LINK_TABLE;
+ memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
+ }
+
+ rtnl_lock();
+ /* Remember the original table */
+ old = rtnl_dereference(net->mpls.platform_label);
+ old_limit = net->mpls.platform_labels;
+
+ /* Free any labels beyond the new table */
+ for (index = limit; index < old_limit; index++)
+ mpls_route_update(net, index, NULL, NULL, NULL);
+
+ /* Copy over the old labels */
+ cp_size = size;
+ if (old_limit < limit)
+ cp_size = old_limit * sizeof(struct mpls_route *);
+
+ memcpy(labels, old, cp_size);
+
+ /* If needed set the predefined labels */
+ if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
+ (limit > MPLS_LABEL_IPV6NULL)) {
+ RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
+ rt2 = NULL;
+ }
+
+ if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
+ (limit > MPLS_LABEL_IPV4NULL)) {
+ RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
+ rt0 = NULL;
+ }
+
+ /* Update the global pointers */
+ net->mpls.platform_labels = limit;
+ rcu_assign_pointer(net->mpls.platform_label, labels);
+
+ rtnl_unlock();
+
+ mpls_rt_free(rt2);
+ mpls_rt_free(rt0);
+
+ if (old) {
+ synchronize_rcu();
+ kvfree(old);
+ }
+ 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 __user *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 = &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;
+}
+
+static const struct ctl_table mpls_table[] = {
+ {
+ .procname = "platform_labels",
+ .data = NULL,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = mpls_platform_labels,
+ },
+ { }
+};
+
+static int mpls_net_init(struct net *net)
+{
+ struct ctl_table *table;
+
+ net->mpls.platform_labels = 0;
+ net->mpls.platform_label = NULL;
+
+ table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
+ if (table == NULL)
+ return -ENOMEM;
+
+ table[0].data = net;
+ net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
+ if (net->mpls.ctl == NULL)
+ 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_rt_free(rt);
+ }
+ rtnl_unlock();
+
+ kvfree(platform_label);
+}
+
+static struct pernet_operations mpls_net_ops = {
+ .init = mpls_net_init,
+ .exit = mpls_net_exit,
+};
+
+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_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL);
+ rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL);
+ rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL);
+ 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);
+ dev_remove_pack(&mpls_packet_type);
+ unregister_netdevice_notifier(&mpls_dev_notifier);
+ unregister_pernet_subsys(&mpls_net_ops);
+}
+module_exit(mpls_exit);
+
+MODULE_DESCRIPTION("MultiProtocol Label Switching");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_NETPROTO(PF_MPLS);
Code Review / kvmfornfv.git / blobdiff