cidr_match.h

[詳解]

#ifndef _CIDR_MATCH_H_INCLUDED_
#define _CIDR_MATCH_H_INCLUDED_

/*++
/* NAME
/*  dict_cidr 3h
/* SUMMARY
/*  CIDR-style pattern matching
/* SYNOPSIS
/*  #include <cidr_match.h>
/* DESCRIPTION
/* .nf

 /*
  * System library.
  */
#include <limits.h>         /* CHAR_BIT */

 /*
  * Utility library.
  */
#include <myaddrinfo.h>         /* MAI_V6ADDR_BYTES etc. */
#include <vstring.h>

 /*
  * External interface.
  * 
  * Address length is protocol dependent. Find out how large our address byte
  * strings should be.
  */
#ifdef HAS_IPV6
# define CIDR_MATCH_ABYTES  MAI_V6ADDR_BYTES
#else
# define CIDR_MATCH_ABYTES  MAI_V4ADDR_BYTES
#endif

 /*
  * Each parsed CIDR pattern can be member of a linked list.
  */
typedef struct CIDR_MATCH {
    int     op;             /* operation, match or control flow */
    int     match;          /* positive or negative match */
    unsigned char net_bytes[CIDR_MATCH_ABYTES]; /* network portion */
    unsigned char mask_bytes[CIDR_MATCH_ABYTES];    /* network mask */
    unsigned char addr_family;      /* AF_XXX */
    unsigned char addr_byte_count;  /* typically, 4 or 16 */
    unsigned char addr_bit_count;   /* optimization */
    unsigned char mask_shift;       /* optimization */
    struct CIDR_MATCH *next;        /* next entry */
    struct CIDR_MATCH *block_end;   /* block terminator */
} CIDR_MATCH;

#define CIDR_MATCH_OP_MATCH 1   /* Match this pattern */
#define CIDR_MATCH_OP_IF    2   /* Increase if/endif nesting on match */
#define CIDR_MATCH_OP_ENDIF 3   /* Decrease if/endif nesting on match */

#define CIDR_MATCH_TRUE     1   /* Request positive match */
#define CIDR_MATCH_FALSE    0   /* Request negative match */

extern VSTRING *cidr_match_parse(CIDR_MATCH *, char *, int, VSTRING *);
extern VSTRING *cidr_match_parse_if(CIDR_MATCH *, char *, int, VSTRING *);
extern void cidr_match_endif(CIDR_MATCH *);

extern CIDR_MATCH *cidr_match_execute(CIDR_MATCH *, const char *);

/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*
/*  Wietse Venema
/*  Google, Inc.
/*  111 8th Avenue
/*  New York, NY 10011, USA
/*--*/

#endif