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The C and C++ Include Header Files

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