contrib/ipfilter/lib/var.c

   1 /*      $FreeBSD$       */
   2
   3 #include <ctype.h>
   4
   5 #include "ipf.h"
   6
   7 typedef struct  variable        {
   8         struct  variable        *v_next;
   9         char    *v_name;
  10         char    *v_value;
  11 } variable_t;
  12
  13 static  variable_t      *vtop = NULL;
  14
  15 static variable_t *find_var __P((char *));
  16 static char *expand_string __P((char *, int));
  17
  18
  19 static variable_t *find_var(name)
  20 char *name;
  21 {
  22         variable_t *v;
  23
  24         for (v = vtop; v != NULL; v = v->v_next)
  25                 if (!strcmp(name, v->v_name))
  26                         return v;
  27         return NULL;
  28 }
  29
  30
  31 char *get_variable(string, after, line)
  32 char *string, **after;
  33 int line;
  34 {
  35         char c, *s, *t, *value;
  36         variable_t *v;
  37
  38         s = string;
  39
  40         if (*s == '{') {
  41                 s++;
  42                 for (t = s; *t != '\0'; t++)
  43                         if (*t == '}')
  44                                 break;
  45                 if (*t == '\0') {
  46                         fprintf(stderr, "%d: { without }\n", line);
  47                         return NULL;
  48                 }
  49         } else if (ISALPHA(*s)) {
  50                 for (t = s + 1; *t != '\0'; t++)
  51                         if (!ISALPHA(*t) && !ISDIGIT(*t) && (*t != '_'))
  52                                 break;
  53         } else {
  54                 fprintf(stderr, "%d: variables cannot start with '%c'\n",
  55                         line, *s);
  56                 return NULL;
  57         }
  58
  59         if (after != NULL)
  60                 *after = t;
  61         c = *t;
  62         *t = '\0';
  63         v = find_var(s);
  64         *t = c;
  65         if (v == NULL) {
  66                 fprintf(stderr, "%d: unknown variable '%s'\n", line, s);
  67                 return NULL;
  68         }
  69
  70         s = strdup(v->v_value);
  71         value = expand_string(s, line);
  72         if (value != s)
  73                 free(s);
  74         return value;
  75 }
  76
  77
  78 static char *expand_string(oldstring, line)
  79 char *oldstring;
  80 int line;
  81 {
  82         char c, *s, *p1, *p2, *p3, *newstring, *value;
  83         int len;
  84
  85         p3 = NULL;
  86         newstring = oldstring;
  87
  88         for (s = oldstring; *s != '\0'; s++)
  89                 if (*s == '$') {
  90                         *s = '\0';
  91                         s++;
  92
  93                         switch (*s)
  94                         {
  95                         case '$' :
  96                                 bcopy(s, s - 1, strlen(s));
  97                                 break;
  98                         default :
  99                                 c = *s;
 100                                 if (c == '\0')
 101                                         return newstring;
 102
 103                                 value = get_variable(s, &p3, line);
 104                                 if (value == NULL)
 105                                         return NULL;
 106
 107                                 p2 = expand_string(value, line);
 108                                 if (p2 == NULL)
 109                                         return NULL;
 110
 111                                 len = strlen(newstring) + strlen(p2);
 112                                 if (p3 != NULL) {
 113                                         if (c == '{' && *p3 == '}')
 114                                                 p3++;
 115                                         len += strlen(p3);
 116                                 }
 117                                 p1 = malloc(len + 1);
 118                                 if (p1 == NULL)
 119                                         return NULL;
 120
 121                                 *(s - 1) = '\0';
 122                                 strcpy(p1, newstring);
 123                                 strcat(p1, p2);
 124                                 if (p3 != NULL)
 125                                         strcat(p1, p3);
 126
 127                                 s = p1 + len - strlen(p3) - 1;
 128                                 if (newstring != oldstring)
 129                                         free(newstring);
 130                                 newstring = p1;
 131                                 break;
 132                         }
 133                 }
 134         return newstring;
 135 }
 136
 137
 138 void set_variable(name, value)
 139 char *name;
 140 char *value;
 141 {
 142         variable_t *v;
 143         int len;
 144
 145         if (name == NULL || value == NULL || *name == '\0')
 146                 return;
 147
 148         v = find_var(name);
 149         if (v != NULL) {
 150                 free(v->v_value);
 151                 v->v_value = strdup(value);
 152                 return;
 153         }
 154
 155         len = strlen(value);
 156
 157         if ((*value == '"' && value[len - 1] == '"') ||
 158             (*value == '\'' && value[len - 1] == '\'')) {
 159                 value[len - 1] = '\0';
 160                 value++;
 161                 len -=2;
 162         }
 163
 164         v = (variable_t *)malloc(sizeof(*v));
 165         if (v == NULL)
 166                 return;
 167         v->v_name = strdup(name);
 168         v->v_value = strdup(value);
 169         v->v_next = vtop;
 170         vtop = v;
 171 }