src/substitution.c

   1 /*
   2  * charybdis: an advanced ircd
   3  * substitution.c: parses substitution-keyword expansions
   4  *
   5  * Copyright (c) 2006-2007 William Pitcock <nenolod@nenolod.net>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions are
   9  * met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright notice,
  12  *    this list of conditions and the following disclaimer.
  13  *
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * 3. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  24  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  25  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  26  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  27  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  29  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  30  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  * $Id$
  34  */
  35
  36 #include "stdinc.h"
  37 #include "s_user.h"
  38 #include "snomask.h"
  39 #include "match.h"
  40 #include "substitution.h"
  41
  42 /*
  43  * Simple mappings for $foo -> 'bar'.
  44  * Everything is a string, so typing doesn't really matter too
  45  * horribly much right now.
  46  */
  47 struct substitution_variable
  48 {
  49         char *name;
  50         char *value;
  51 };
  52
  53 /*
  54  * substitution_append_var
  55  *
  56  * Inputs       - A variable list (rb_dlink_list), name -> value for mapping to make
  57  * Output       - none
  58  * Side Effects - Adds a name->value mapping to a list.
  59  */
  60 void substitution_append_var(rb_dlink_list *varlist, const char *name, const char *value)
  61 {
  62         struct substitution_variable *tmp = rb_malloc(sizeof(struct substitution_variable));
  63
  64         tmp->name = rb_strdup(name);
  65         tmp->value = rb_strdup(value);
  66
  67         rb_dlinkAddAlloc(tmp, varlist);
  68 }
  69
  70 /*
  71  * substitution_free
  72  *
  73  * Inputs       - A rb_dlink_list of markup variables to free.
  74  * Outputs      - none
  75  * Side Effects - Empties a list of markup variables.
  76  */
  77 void substitution_free(rb_dlink_list *varlist)
  78 {
  79         rb_dlink_node *nptr, *nptr2;
  80
  81         RB_DLINK_FOREACH_SAFE(nptr, nptr2, varlist->head)
  82         {
  83                 struct substitution_variable *tmp = (struct substitution_variable *) nptr->data;
  84
  85                 rb_dlinkDelete(nptr, varlist);
  86                 rb_free(tmp->name);
  87                 rb_free(tmp->value);
  88                 rb_free(tmp);
  89         }
  90 }
  91
  92 /*
  93  * substitution_parse
  94  *
  95  * Inputs       - A markup string, rb_dlink-list of markup values
  96  * Output       - A string which has been markup-replaced.
  97  * Side Effects - Strings larger than BUFSIZE are terminated.
  98  */
  99 char *substitution_parse(const char *fmt, rb_dlink_list *varlist)
 100 {
 101         static char buf[BUFSIZE];
 102         const char *ptr;
 103         char *bptr = buf;
 104
 105         for (ptr = fmt; *ptr != '\0' && bptr - buf < BUFSIZE; ptr++)
 106                 if (*ptr != '$')
 107                         *bptr++ = *ptr;
 108                 else if (*(ptr + 1) == '{')
 109                 {
 110                         static char varname[BUFSIZE];
 111                         char *vptr = varname;
 112                         const char *pptr;
 113                         rb_dlink_node *nptr;
 114
 115                         *vptr = '\0';
 116
 117                         /* break out ${var} */
 118                         for (pptr = ptr + 2; *pptr != '\0'; pptr++)
 119                         {
 120                                 if (*pptr != '}')
 121                                         *vptr++ = *pptr;
 122                                 else
 123                                 {
 124                                         *vptr++ = '\0';
 125                                         break;
 126                                 }
 127                         }
 128
 129                         s_assert(*varname != '\0');
 130                         s_assert(*pptr != '\0');
 131
 132                         /* advance ptr by length of variable */
 133                         ptr += (pptr - ptr);
 134
 135                         RB_DLINK_FOREACH(nptr, varlist->head)
 136                         {
 137                                 struct substitution_variable *val = (struct substitution_variable *) nptr->data;
 138
 139                                 if (!strcasecmp(varname, val->name))
 140                                 {
 141                                         rb_strlcpy(bptr, val->value, BUFSIZE - (bptr - buf));
 142                                         bptr += strlen(val->value);
 143                                         break;
 144                                 }
 145                         }
 146                 }
 147
 148         *bptr = '\0';
 149         return buf;
 150 }