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 #include "s_assert.h"
  42
  43 /*
  44  * Simple mappings for $foo -> 'bar'.
  45  * Everything is a string, so typing doesn't really matter too
  46  * horribly much right now.
  47  */
  48 struct substitution_variable
  49 {
  50         char *name;
  51         char *value;
  52 };
  53
  54 /*
  55  * substitution_append_var
  56  *
  57  * Inputs       - A variable list (rb_dlink_list), name -> value for mapping to make
  58  * Output       - none
  59  * Side Effects - Adds a name->value mapping to a list.
  60  */
  61 void substitution_append_var(rb_dlink_list *varlist, const char *name, const char *value)
  62 {
  63         struct substitution_variable *tmp = rb_malloc(sizeof(struct substitution_variable));
  64
  65         tmp->name = rb_strdup(name);
  66         tmp->value = rb_strdup(value);
  67
  68         rb_dlinkAddAlloc(tmp, varlist);
  69 }
  70
  71 /*
  72  * substitution_free
  73  *
  74  * Inputs       - A rb_dlink_list of markup variables to free.
  75  * Outputs      - none
  76  * Side Effects - Empties a list of markup variables.
  77  */
  78 void substitution_free(rb_dlink_list *varlist)
  79 {
  80         rb_dlink_node *nptr, *nptr2;
  81
  82         RB_DLINK_FOREACH_SAFE(nptr, nptr2, varlist->head)
  83         {
  84                 struct substitution_variable *tmp = (struct substitution_variable *) nptr->data;
  85
  86                 rb_dlinkDelete(nptr, varlist);
  87                 rb_free(tmp->name);
  88                 rb_free(tmp->value);
  89                 rb_free(tmp);
  90         }
  91 }
  92
  93 /*
  94  * substitution_parse
  95  *
  96  * Inputs       - A markup string, rb_dlink-list of markup values
  97  * Output       - A string which has been markup-replaced.
  98  * Side Effects - Strings larger than BUFSIZE are terminated.
  99  */
 100 char *substitution_parse(const char *fmt, rb_dlink_list *varlist)
 101 {
 102         static char buf[BUFSIZE];
 103         const char *ptr;
 104         char *bptr = buf;
 105
 106         for (ptr = fmt; *ptr != '\0' && bptr - buf < BUFSIZE; ptr++)
 107                 if (*ptr != '$')
 108                         *bptr++ = *ptr;
 109                 else if (*(ptr + 1) == '{')
 110                 {
 111                         static char varname[BUFSIZE];
 112                         char *vptr = varname;
 113                         const char *pptr;
 114                         rb_dlink_node *nptr;
 115
 116                         *vptr = '\0';
 117
 118                         /* break out ${var} */
 119                         for (pptr = ptr + 2; *pptr != '\0'; pptr++)
 120                         {
 121                                 if (*pptr != '}')
 122                                         *vptr++ = *pptr;
 123                                 else
 124                                 {
 125                                         *vptr++ = '\0';
 126                                         break;
 127                                 }
 128                         }
 129
 130                         s_assert(*varname != '\0');
 131                         s_assert(*pptr != '\0');
 132
 133                         /* advance ptr by length of variable */
 134                         ptr += (pptr - ptr);
 135
 136                         RB_DLINK_FOREACH(nptr, varlist->head)
 137                         {
 138                                 struct substitution_variable *val = (struct substitution_variable *) nptr->data;
 139
 140                                 if (!strcasecmp(varname, val->name))
 141                                 {
 142                                         rb_strlcpy(bptr, val->value, BUFSIZE - (bptr - buf));
 143                                         bptr += strlen(val->value);
 144                                         break;
 145                                 }
 146                         }
 147                 }
 148
 149         *bptr = '\0';
 150         return buf;
 151 }