lib/libsys/env_get_prm.c

   1 #include "sysutil.h"
   2 #include <string.h>
   3
   4 int env_argc = 0;
   5 char **env_argv = NULL;
   6
   7 static char *find_key(const char *params, const char *key);
   8
   9 /*===========================================================================*
  10  *                              env_setargs                                  *
  11  *===========================================================================*/
  12 void env_setargs(arg_c, arg_v)
  13 int arg_c;
  14 char *arg_v[];
  15 {
  16         env_argc= arg_c;
  17         env_argv= arg_v;
  18 }
  19
  20 /*===========================================================================*
  21  *                              env_get_param                                *
  22  *===========================================================================*/
  23 int env_get_param(key, value, max_len)
  24 char *key;                              /* which key to look up */
  25 char *value;                            /* where to store value */
  26 int max_len;                            /* maximum length of value */
  27 {
  28   message m;
  29   static char mon_params[MULTIBOOT_PARAM_BUF_SIZE]; /* copy parameters here */
  30   char *key_value;
  31   int i, s;
  32   size_t keylen;
  33
  34   if (key == NULL)
  35         return EINVAL;
  36
  37   keylen= strlen(key);
  38   for (i= 1; i<env_argc; i++)
  39   {
  40         if (strncmp(env_argv[i], key, keylen) != 0)
  41                 continue;
  42         if (strlen(env_argv[i]) <= keylen)
  43                 continue;
  44         if (env_argv[i][keylen] != '=')
  45                 continue;
  46         key_value= env_argv[i]+keylen+1;
  47         if (strlen(key_value)+1 > (size_t) max_len)
  48               return(E2BIG);
  49         strcpy(value, key_value);
  50         return OK;
  51   }
  52
  53   /* Get copy of boot monitor parameters. */
  54   m.m_type = SYS_GETINFO;
  55   m.I_REQUEST = GET_MONPARAMS;
  56   m.I_ENDPT = SELF;
  57   m.I_VAL_LEN = sizeof(mon_params);
  58   m.I_VAL_PTR = mon_params;
  59   if ((s=_kernel_call(SYS_GETINFO, &m)) != OK) {
  60         printf("SYS_GETINFO: %d (size %u)\n", s, sizeof(mon_params));
  61         return(s);
  62   }
  63
  64   /* We got a copy, now search requested key. */
  65   if ((key_value = find_key(mon_params, key)) == NULL)
  66         return(ESRCH);
  67
  68   /* Value found, see if it fits in the client's buffer. Callers assume that
  69    * their buffer is unchanged on error, so don't make a partial copy.
  70    */
  71   if ((strlen(key_value)+1) > (size_t) max_len) return(E2BIG);
  72
  73   /* Make the actual copy. */
  74   strcpy(value, key_value);
  75
  76   return(OK);
  77 }
  78
  79
  80 /*==========================================================================*
  81  *                              find_key                                            *
  82  *==========================================================================*/
  83 static char *find_key(params,name)
  84 const char *params;
  85 const char *name;
  86 {
  87   register const char *namep;
  88   register char *envp;
  89
  90   for (envp = (char *) params; *envp != 0;) {
  91         for (namep = name; *namep != 0 && *namep == *envp; namep++, envp++)
  92                 ;
  93         if (*namep == '\0' && *envp == '=')
  94                 return(envp + 1);
  95         while (*envp++ != 0)
  96                 ;
  97   }
  98   return(NULL);
  99 }
 100