security/selinux/ss/symtab.c

   1 /*
   2  * Implementation of the symbol table type.
   3  *
   4  * Author : Stephen Smalley, <sds@tycho.nsa.gov>
   5  */
   6 #include <linux/kernel.h>
   7 #include <linux/string.h>
   8 #include <linux/errno.h>
   9 #include "symtab.h"
  10
  11 static unsigned int symhash(struct hashtab *h, const void *key)
  12 {
  13         const char *p, *keyp;
  14         unsigned int size;
  15         unsigned int val;
  16
  17         val = 0;
  18         keyp = key;
  19         size = strlen(keyp);
  20         for (p = keyp; (p - keyp) < size; p++)
  21                 val = (val << 4 | (val >> (8*sizeof(unsigned int)-4))) ^ (*p);
  22         return val & (h->size - 1);
  23 }
  24
  25 static int symcmp(struct hashtab *h, const void *key1, const void *key2)
  26 {
  27         const char *keyp1, *keyp2;
  28
  29         keyp1 = key1;
  30         keyp2 = key2;
  31         return strcmp(keyp1, keyp2);
  32 }
  33
  34
  35 int symtab_init(struct symtab *s, unsigned int size)
  36 {
  37         s->table = hashtab_create(symhash, symcmp, size);
  38         if (!s->table)
  39                 return -ENOMEM;
  40         s->nprim = 0;
  41         return 0;
  42 }
  43