LXR linux/net/mpls/internal.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef MPLS_INTERNAL_H
   3#define MPLS_INTERNAL_H
   4#include <net/mpls.h>
   5
   6/* put a reasonable limit on the number of labels
   7 * we will accept from userspace
   8 */
   9#define MAX_NEW_LABELS 30
  10
  11struct mpls_entry_decoded {
  12        u32 label;
  13        u8 ttl;
  14        u8 tc;
  15        u8 bos;
  16};
  17
  18struct mpls_pcpu_stats {
  19        struct mpls_link_stats  stats;
  20        struct u64_stats_sync   syncp;
  21};
  22
  23struct mpls_dev {
  24        int                             input_enabled;
  25        struct net_device               *dev;
  26        struct mpls_pcpu_stats __percpu *stats;
  27
  28        struct ctl_table_header         *sysctl;
  29        struct rcu_head                 rcu;
  30};
  31
  32#if BITS_PER_LONG == 32
  33
  34#define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)          \
  35        do {                                                            \
  36                __typeof__(*(mdev)->stats) *ptr =                       \
  37                        raw_cpu_ptr((mdev)->stats);                     \
  38                local_bh_disable();                                     \
  39                u64_stats_update_begin(&ptr->syncp);                    \
  40                ptr->stats.pkts_field++;                                \
  41                ptr->stats.bytes_field += (len);                        \
  42                u64_stats_update_end(&ptr->syncp);                      \
  43                local_bh_enable();                                      \
  44        } while (0)
  45
  46#define MPLS_INC_STATS(mdev, field)                                     \
  47        do {                                                            \
  48                __typeof__(*(mdev)->stats) *ptr =                       \
  49                        raw_cpu_ptr((mdev)->stats);                     \
  50                local_bh_disable();                                     \
  51                u64_stats_update_begin(&ptr->syncp);                    \
  52                ptr->stats.field++;                                     \
  53                u64_stats_update_end(&ptr->syncp);                      \
  54                local_bh_enable();                                      \
  55        } while (0)
  56
  57#else
  58
  59#define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)          \
  60        do {                                                            \
  61                this_cpu_inc((mdev)->stats->stats.pkts_field);          \
  62                this_cpu_add((mdev)->stats->stats.bytes_field, (len));  \
  63        } while (0)
  64
  65#define MPLS_INC_STATS(mdev, field)                     \
  66        this_cpu_inc((mdev)->stats->stats.field)
  67
  68#endif
  69
  70struct sk_buff;
  71
  72#define LABEL_NOT_SPECIFIED (1 << 20)
  73
  74/* This maximum ha length copied from the definition of struct neighbour */
  75#define VIA_ALEN_ALIGN sizeof(unsigned long)
  76#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
  77
  78enum mpls_payload_type {
  79        MPT_UNSPEC, /* IPv4 or IPv6 */
  80        MPT_IPV4 = 4,
  81        MPT_IPV6 = 6,
  82
  83        /* Other types not implemented:
  84         *  - Pseudo-wire with or without control word (RFC4385)
  85         *  - GAL (RFC5586)
  86         */
  87};
  88
  89struct mpls_nh { /* next hop label forwarding entry */
  90        struct net_device __rcu *nh_dev;
  91
  92        /* nh_flags is accessed under RCU in the packet path; it is
  93         * modified handling netdev events with rtnl lock held
  94         */
  95        unsigned int            nh_flags;
  96        u8                      nh_labels;
  97        u8                      nh_via_alen;
  98        u8                      nh_via_table;
  99        u8                      nh_reserved1;
 100
 101        u32                     nh_label[];
 102};
 103
 104/* offset of via from beginning of mpls_nh */
 105#define MPLS_NH_VIA_OFF(num_labels) \
 106                ALIGN(sizeof(struct mpls_nh) + (num_labels) * sizeof(u32), \
 107                      VIA_ALEN_ALIGN)
 108
 109/* all nexthops within a route have the same size based on the
 110 * max number of labels and max via length across all nexthops
 111 */
 112#define MPLS_NH_SIZE(num_labels, max_via_alen)          \
 113                (MPLS_NH_VIA_OFF((num_labels)) +        \
 114                ALIGN((max_via_alen), VIA_ALEN_ALIGN))
 115
 116enum mpls_ttl_propagation {
 117        MPLS_TTL_PROP_DEFAULT,
 118        MPLS_TTL_PROP_ENABLED,
 119        MPLS_TTL_PROP_DISABLED,
 120};
 121
 122/* The route, nexthops and vias are stored together in the same memory
 123 * block:
 124 *
 125 * +----------------------+
 126 * | mpls_route           |
 127 * +----------------------+
 128 * | mpls_nh 0            |
 129 * +----------------------+
 130 * | alignment padding    |   4 bytes for odd number of labels
 131 * +----------------------+
 132 * | via[rt_max_alen] 0   |
 133 * +----------------------+
 134 * | alignment padding    |   via's aligned on sizeof(unsigned long)
 135 * +----------------------+
 136 * | ...                  |
 137 * +----------------------+
 138 * | mpls_nh n-1          |
 139 * +----------------------+
 140 * | via[rt_max_alen] n-1 |
 141 * +----------------------+
 142 */
 143struct mpls_route { /* next hop label forwarding entry */
 144        struct rcu_head         rt_rcu;
 145        u8                      rt_protocol;
 146        u8                      rt_payload_type;
 147        u8                      rt_max_alen;
 148        u8                      rt_ttl_propagate;
 149        u8                      rt_nhn;
 150        /* rt_nhn_alive is accessed under RCU in the packet path; it
 151         * is modified handling netdev events with rtnl lock held
 152         */
 153        u8                      rt_nhn_alive;
 154        u8                      rt_nh_size;
 155        u8                      rt_via_offset;
 156        u8                      rt_reserved1;
 157        struct mpls_nh          rt_nh[];
 158};
 159
 160#define for_nexthops(rt) {                                              \
 161        int nhsel; struct mpls_nh *nh;  u8 *__nh;                       \
 162        for (nhsel = 0, nh = (rt)->rt_nh, __nh = (u8 *)((rt)->rt_nh);   \
 163             nhsel < (rt)->rt_nhn;                                      \
 164             __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)
 165
 166#define change_nexthops(rt) {                                           \
 167        int nhsel; struct mpls_nh *nh; u8 *__nh;                        \
 168        for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh),           \
 169                        __nh = (u8 *)((rt)->rt_nh);                     \
 170             nhsel < (rt)->rt_nhn;                                      \
 171             __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)
 172
 173#define endfor_nexthops(rt) }
 174
 175static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
 176{
 177        struct mpls_entry_decoded result;
 178        unsigned entry = be32_to_cpu(hdr->label_stack_entry);
 179
 180        result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 181        result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
 182        result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
 183        result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
 184
 185        return result;
 186}
 187
 188static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
 189{
 190        return rcu_dereference_rtnl(dev->mpls_ptr);
 191}
 192
 193int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
 194                   const u32 label[]);
 195int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
 196                   u32 label[], struct netlink_ext_ack *extack);
 197bool mpls_output_possible(const struct net_device *dev);
 198unsigned int mpls_dev_mtu(const struct net_device *dev);
 199bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
 200void mpls_stats_inc_outucastpkts(struct net_device *dev,
 201                                 const struct sk_buff *skb);
 202
 203#endif /* MPLS_INTERNAL_H */
 204