/* SPDX-License-Identifier: GPL-2.0 */

  #ifndef MPLS_INTERNAL_H
  #define MPLS_INTERNAL_H

  #include <net/mpls.h>

  /* put a reasonable limit on the number of labels
   * we will accept from userspace
   */
  #define MAX_NEW_LABELS 30

  struct mpls_entry_decoded {
  	u32 label;
  	u8 ttl;
  	u8 tc;
  	u8 bos;
  };

  struct mpls_pcpu_stats {
  	struct mpls_link_stats	stats;
  	struct u64_stats_sync	syncp;
  };

  struct mpls_dev {

  	int				input_enabled;

  	struct net_device		*dev;

  	struct mpls_pcpu_stats __percpu	*stats;
  
  	struct ctl_table_header		*sysctl;
  	struct rcu_head			rcu;

  };

  #if BITS_PER_LONG == 32
  
  #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
  	do {								\
  		__typeof__(*(mdev)->stats) *ptr =			\
  			raw_cpu_ptr((mdev)->stats);			\
  		local_bh_disable();					\
  		u64_stats_update_begin(&ptr->syncp);			\
  		ptr->stats.pkts_field++;				\
  		ptr->stats.bytes_field += (len);			\
  		u64_stats_update_end(&ptr->syncp);			\
  		local_bh_enable();					\
  	} while (0)
  
  #define MPLS_INC_STATS(mdev, field)					\
  	do {								\
  		__typeof__(*(mdev)->stats) *ptr =			\
  			raw_cpu_ptr((mdev)->stats);			\
  		local_bh_disable();					\
  		u64_stats_update_begin(&ptr->syncp);			\
  		ptr->stats.field++;					\
  		u64_stats_update_end(&ptr->syncp);			\
  		local_bh_enable();					\
  	} while (0)
  
  #else
  
  #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
  	do {								\
  		this_cpu_inc((mdev)->stats->stats.pkts_field);		\
  		this_cpu_add((mdev)->stats->stats.bytes_field, (len));	\
  	} while (0)
  
  #define MPLS_INC_STATS(mdev, field)			\
  	this_cpu_inc((mdev)->stats->stats.field)
  
  #endif

  struct sk_buff;

  #define LABEL_NOT_SPECIFIED (1 << 20)

  
  /* This maximum ha length copied from the definition of struct neighbour */

  #define VIA_ALEN_ALIGN sizeof(unsigned long)
  #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))

  
  enum mpls_payload_type {
  	MPT_UNSPEC, /* IPv4 or IPv6 */
  	MPT_IPV4 = 4,
  	MPT_IPV6 = 6,
  
  	/* Other types not implemented:
  	 *  - Pseudo-wire with or without control word (RFC4385)
  	 *  - GAL (RFC5586)
  	 */
  };
  
  struct mpls_nh { /* next hop label forwarding entry */
  	struct net_device __rcu *nh_dev;

  
  	/* nh_flags is accessed under RCU in the packet path; it is
  	 * modified handling netdev events with rtnl lock held
  	 */

  	unsigned int		nh_flags;

  	u8			nh_labels;
  	u8			nh_via_alen;
  	u8			nh_via_table;

  	u8			nh_reserved1;
  
  	u32			nh_label[0];

  };

  /* offset of via from beginning of mpls_nh */
  #define MPLS_NH_VIA_OFF(num_labels) \
  		ALIGN(sizeof(struct mpls_nh) + (num_labels) * sizeof(u32), \
  		      VIA_ALEN_ALIGN)
  
  /* all nexthops within a route have the same size based on the
   * max number of labels and max via length across all nexthops
   */
  #define MPLS_NH_SIZE(num_labels, max_via_alen)		\
  		(MPLS_NH_VIA_OFF((num_labels)) +	\
  		ALIGN((max_via_alen), VIA_ALEN_ALIGN))

  enum mpls_ttl_propagation {
  	MPLS_TTL_PROP_DEFAULT,
  	MPLS_TTL_PROP_ENABLED,
  	MPLS_TTL_PROP_DISABLED,
  };

  /* The route, nexthops and vias are stored together in the same memory
   * block:
   *
   * +----------------------+
   * | mpls_route           |
   * +----------------------+
   * | mpls_nh 0            |
   * +----------------------+

   * | alignment padding    |   4 bytes for odd number of labels

   * +----------------------+
   * | via[rt_max_alen] 0   |
   * +----------------------+

   * | alignment padding    |   via's aligned on sizeof(unsigned long)
   * +----------------------+

   * | ...                  |
   * +----------------------+

   * | mpls_nh n-1          |
   * +----------------------+

   * | via[rt_max_alen] n-1 |
   * +----------------------+
   */

  struct mpls_route { /* next hop label forwarding entry */
  	struct rcu_head		rt_rcu;
  	u8			rt_protocol;
  	u8			rt_payload_type;

  	u8			rt_max_alen;

  	u8			rt_ttl_propagate;

  	u8			rt_nhn;

  	/* rt_nhn_alive is accessed under RCU in the packet path; it
  	 * is modified handling netdev events with rtnl lock held
  	 */

  	u8			rt_nhn_alive;

  	u8			rt_nh_size;
  	u8			rt_via_offset;
  	u8			rt_reserved1;

  	struct mpls_nh		rt_nh[0];
  };
  
  #define for_nexthops(rt) {						\

  	int nhsel; struct mpls_nh *nh;  u8 *__nh;			\
  	for (nhsel = 0, nh = (rt)->rt_nh, __nh = (u8 *)((rt)->rt_nh);	\

  	     nhsel < (rt)->rt_nhn;					\

  	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)

  
  #define change_nexthops(rt) {						\

  	int nhsel; struct mpls_nh *nh; u8 *__nh;			\
  	for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh),		\
  			__nh = (u8 *)((rt)->rt_nh);			\

  	     nhsel < (rt)->rt_nhn;					\

  	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)

  
  #define endfor_nexthops(rt) }

  static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
  {
  	struct mpls_shim_hdr result;
  	result.label_stack_entry =
  		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
  			    (tc << MPLS_LS_TC_SHIFT) |
  			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
  			    (ttl << MPLS_LS_TTL_SHIFT));
  	return result;
  }
  
  static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
  {
  	struct mpls_entry_decoded result;
  	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
  
  	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
  	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
  	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
  	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
  
  	return result;
  }

  static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
  {
  	return rcu_dereference_rtnl(dev->mpls_ptr);
  }

  int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
  		   const u32 label[]);

  int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,

  		   u32 label[], struct netlink_ext_ack *extack);

  bool mpls_output_possible(const struct net_device *dev);
  unsigned int mpls_dev_mtu(const struct net_device *dev);
  bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);

  void mpls_stats_inc_outucastpkts(struct net_device *dev,
  				 const struct sk_buff *skb);

  #endif /* MPLS_INTERNAL_H */