include/uapi/linux/netfilter/nfnetlink_compat.h

   1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2 #ifndef _NFNETLINK_COMPAT_H
   3 #define _NFNETLINK_COMPAT_H
   4
   5 #include <linux/types.h>
   6
   7 #ifndef __KERNEL__
   8 /* Old nfnetlink macros for userspace */
   9
  10 /* nfnetlink groups: Up to 32 maximum */
  11 #define NF_NETLINK_CONNTRACK_NEW                0x00000001
  12 #define NF_NETLINK_CONNTRACK_UPDATE             0x00000002
  13 #define NF_NETLINK_CONNTRACK_DESTROY            0x00000004
  14 #define NF_NETLINK_CONNTRACK_EXP_NEW            0x00000008
  15 #define NF_NETLINK_CONNTRACK_EXP_UPDATE         0x00000010
  16 #define NF_NETLINK_CONNTRACK_EXP_DESTROY        0x00000020
  17
  18 /* Generic structure for encapsulation optional netfilter information.
  19  * It is reminiscent of sockaddr, but with sa_family replaced
  20  * with attribute type.
  21  * ! This should someday be put somewhere generic as now rtnetlink and
  22  * ! nfnetlink use the same attributes methods. - J. Schulist.
  23  */
  24
  25 struct nfattr {
  26         __u16 nfa_len;
  27         __u16 nfa_type; /* we use 15 bits for the type, and the highest
  28                                  * bit to indicate whether the payload is nested */
  29 };
  30
  31 /* FIXME: Apart from NFNL_NFA_NESTED shamelessly copy and pasted from
  32  * rtnetlink.h, it's time to put this in a generic file */
  33
  34 #define NFNL_NFA_NEST   0x8000
  35 #define NFA_TYPE(attr)  ((attr)->nfa_type & 0x7fff)
  36
  37 #define NFA_ALIGNTO     4
  38 #define NFA_ALIGN(len)  (((len) + NFA_ALIGNTO - 1) & ~(NFA_ALIGNTO - 1))
  39 #define NFA_OK(nfa,len) ((len) > 0 && (nfa)->nfa_len >= sizeof(struct nfattr) \
  40         && (nfa)->nfa_len <= (len))
  41 #define NFA_NEXT(nfa,attrlen)   ((attrlen) -= NFA_ALIGN((nfa)->nfa_len), \
  42         (struct nfattr *)(((char *)(nfa)) + NFA_ALIGN((nfa)->nfa_len)))
  43 #define NFA_LENGTH(len) (NFA_ALIGN(sizeof(struct nfattr)) + (len))
  44 #define NFA_SPACE(len)  NFA_ALIGN(NFA_LENGTH(len))
  45 #define NFA_DATA(nfa)   ((void *)(((char *)(nfa)) + NFA_LENGTH(0)))
  46 #define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0))
  47 #define NFA_NEST(skb, type) \
  48 ({      struct nfattr *__start = (struct nfattr *)skb_tail_pointer(skb); \
  49         NFA_PUT(skb, (NFNL_NFA_NEST | type), 0, NULL); \
  50         __start;  })
  51 #define NFA_NEST_END(skb, start) \
  52 ({      (start)->nfa_len = skb_tail_pointer(skb) - (unsigned char *)(start); \
  53         (skb)->len; })
  54 #define NFA_NEST_CANCEL(skb, start) \
  55 ({      if (start) \
  56                 skb_trim(skb, (unsigned char *) (start) - (skb)->data); \
  57         -1; })
  58
  59 #define NFM_NFA(n)      ((struct nfattr *)(((char *)(n)) \
  60         + NLMSG_ALIGN(sizeof(struct nfgenmsg))))
  61 #define NFM_PAYLOAD(n)  NLMSG_PAYLOAD(n, sizeof(struct nfgenmsg))
  62
  63 #endif /* ! __KERNEL__ */
  64 #endif /* _NFNETLINK_COMPAT_H */