1/* AS regular expression routine
2   Copyright (C) 1999 Kunihiro Ishiguro
3
4This file is part of GNU Zebra.
5
6GNU Zebra is free software; you can redistribute it and/or modify it
7under the terms of the GNU General Public License as published by the
8Free Software Foundation; either version 2, or (at your option) any
9later version.
10
11GNU Zebra is distributed in the hope that it will be useful, but
12WITHOUT ANY WARRANTY; without even the implied warranty of
13MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14General Public License for more details.
15
16You should have received a copy of the GNU General Public License
17along with GNU Zebra; see the file COPYING.  If not, write to the Free
18Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
1902111-1307, USA.  */
20
21#include <zebra.h>
22
23#include "log.h"
24#include "command.h"
25#include "memory.h"
26
27#include "bgpd.h"
28#include "bgp_aspath.h"
29#include "bgp_regex.h"
30
31/* Character `_' has special mean.  It represents [,{}() ] and the
32   beginning of the line(^) and the end of the line ($).
33
34   (^|[,{}() ]|$) */
35
36regex_t *
37bgp_regcomp (const char *regstr)
38{
39  /* Convert _ character to generic regular expression. */
40  int i, j;
41  int len;
42  int magic = 0;
43  char *magic_str;
44  char magic_regexp[] = "(^|[,{}() ]|$)";
45  int ret;
46  regex_t *regex;
47
48  len = strlen (regstr);
49  for (i = 0; i < len; i++)
50    if (regstr[i] == '_')
51      magic++;
52
53  magic_str = XMALLOC (MTYPE_TMP, len + (14 * magic) + 1);
54
55  for (i = 0, j = 0; i < len; i++)
56    {
57      if (regstr[i] == '_')
58	{
59	  memcpy (magic_str + j, magic_regexp, strlen (magic_regexp));
60	  j += strlen (magic_regexp);
61	}
62      else
63	magic_str[j++] = regstr[i];
64    }
65  magic_str[j] = '\0';
66
67  regex = XMALLOC (MTYPE_BGP_REGEXP, sizeof (regex_t));
68
69  ret = regcomp (regex, magic_str, REG_EXTENDED|REG_NOSUB);
70
71  XFREE (MTYPE_TMP, magic_str);
72
73  if (ret != 0)
74    {
75      XFREE (MTYPE_BGP_REGEXP, regex);
76      return NULL;
77    }
78
79  return regex;
80}
81
82int
83bgp_regexec (regex_t *regex, struct aspath *aspath)
84{
85  return regexec (regex, aspath->str, 0, NULL, 0);
86}
87
88void
89bgp_regex_free (regex_t *regex)
90{
91  regfree (regex);
92  XFREE (MTYPE_BGP_REGEXP, regex);
93}
94