usr/src/cmd/ipf/lib/common/var.c

   1 /*
   2  * Copyright (C) 1993-2005  by Darren Reed.
   3  * See the IPFILTER.LICENCE file for details on licencing.
   4  */
   5
   6 #include <ctype.h>
   7
   8 #include "ipf.h"
   9
  10 typedef struct  variable        {
  11         struct  variable        *v_next;
  12         char    *v_name;
  13         char    *v_value;
  14 } variable_t;
  15
  16 static  variable_t      *vtop = NULL;
  17
  18 static variable_t *find_var __P((char *));
  19 static char *expand_string __P((char *, int));
  20
  21
  22 static variable_t *find_var(name)
  23 char *name;
  24 {
  25         variable_t *v;
  26
  27         for (v = vtop; v != NULL; v = v->v_next)
  28                 if (!strcmp(name, v->v_name))
  29                         return v;
  30         return NULL;
  31 }
  32
  33
  34 char *get_variable(string, after, line)
  35 char *string, **after;
  36 int line;
  37 {
  38         char c, *s, *t, *value;
  39         variable_t *v;
  40
  41         s = string;
  42
  43         if (*s == '{') {
  44                 s++;
  45                 for (t = s; *t != '\0'; t++)
  46                         if (*t == '}')
  47                                 break;
  48                 if (*t == '\0') {
  49                         fprintf(stderr, "%d: { without }\n", line);
  50                         return NULL;
  51                 }
  52         } else if (ISALPHA(*s)) {
  53                 for (t = s + 1; *t != '\0'; t++)
  54                         if (!ISALPHA(*t) && !ISDIGIT(*t) && (*t != '_'))
  55                                 break;
  56         } else {
  57                 fprintf(stderr, "%d: variables cannot start with '%c'\n",
  58                         line, *s);
  59                 return NULL;
  60         }
  61
  62         if (after != NULL)
  63                 *after = t;
  64         c = *t;
  65         *t = '\0';
  66         v = find_var(s);
  67         *t = c;
  68         if (v == NULL) {
  69                 fprintf(stderr, "%d: unknown variable '%s'\n", line, s);
  70                 return NULL;
  71         }
  72
  73         s = strdup(v->v_value);
  74         value = expand_string(s, line);
  75         if (value != s)
  76                 free(s);
  77         return value;
  78 }
  79
  80
  81 static char *expand_string(oldstring, line)
  82 char *oldstring;
  83 int line;
  84 {
  85         char c, *s, *p1, *p2, *p3, *newstring, *value;
  86         int len;
  87
  88         p3 = NULL;
  89         newstring = oldstring;
  90
  91         for (s = oldstring; *s != '\0'; s++)
  92                 if (*s == '$') {
  93                         *s = '\0';
  94                         s++;
  95
  96                         switch (*s)
  97                         {
  98                         case '$' :
  99                                 bcopy(s, s - 1, strlen(s));
 100                                 break;
 101                         default :
 102                                 c = *s;
 103                                 if (c == '\0')
 104                                         return newstring;
 105
 106                                 value = get_variable(s, &p3, line);
 107                                 if (value == NULL)
 108                                         return NULL;
 109
 110                                 p2 = expand_string(value, line);
 111                                 if (p2 == NULL)
 112                                         return NULL;
 113
 114                                 len = strlen(newstring) + strlen(p2);
 115                                 if (p3 != NULL) {
 116                                         if (c == '{' && *p3 == '}')
 117                                                 p3++;
 118                                         len += strlen(p3);
 119                                 }
 120                                 p1 = malloc(len + 1);
 121                                 if (p1 == NULL)
 122                                         return NULL;
 123
 124                                 *(s - 1) = '\0';
 125                                 strcpy(p1, newstring);
 126                                 strcat(p1, p2);
 127                                 if (p3 != NULL)
 128                                         strcat(p1, p3);
 129
 130                                 s = p1 + len - strlen(p3) - 1;
 131                                 if (newstring != oldstring)
 132                                         free(newstring);
 133                                 newstring = p1;
 134                                 break;
 135                         }
 136                 }
 137         return newstring;
 138 }
 139
 140
 141 void set_variable(name, value)
 142 char *name;
 143 char *value;
 144 {
 145         variable_t *v;
 146         int len;
 147
 148         if (name == NULL || value == NULL || *name == '\0')
 149                 return;
 150
 151         v = find_var(name);
 152         if (v != NULL) {
 153                 free(v->v_value);
 154                 v->v_value = strdup(value);
 155                 return;
 156         }
 157
 158         len = strlen(value);
 159
 160         if ((*value == '"' && value[len - 1] == '"') ||
 161             (*value == '\'' && value[len - 1] == '\'')) {
 162                 value[len - 1] = '\0';
 163                 value++;
 164                 len -=2;
 165         }
 166
 167         v = (variable_t *)malloc(sizeof(*v));
 168         if (v == NULL)
 169                 return;
 170         v->v_name = strdup(name);
 171         v->v_value = strdup(value);
 172         v->v_next = vtop;
 173         vtop = v;
 174 }