drivers/firmware/efi/libstub/string.c

   1 /*
   2  * Taken from:
   3  *  linux/lib/string.c
   4  *
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/string.h>
  10
  11 #ifndef __HAVE_ARCH_STRSTR
  12 /**
  13  * strstr - Find the first substring in a %NUL terminated string
  14  * @s1: The string to be searched
  15  * @s2: The string to search for
  16  */
  17 char *strstr(const char *s1, const char *s2)
  18 {
  19         size_t l1, l2;
  20
  21         l2 = strlen(s2);
  22         if (!l2)
  23                 return (char *)s1;
  24         l1 = strlen(s1);
  25         while (l1 >= l2) {
  26                 l1--;
  27                 if (!memcmp(s1, s2, l2))
  28                         return (char *)s1;
  29                 s1++;
  30         }
  31         return NULL;
  32 }
  33 #endif
  34
  35 #ifndef __HAVE_ARCH_STRNCMP
  36 /**
  37  * strncmp - Compare two length-limited strings
  38  * @cs: One string
  39  * @ct: Another string
  40  * @count: The maximum number of bytes to compare
  41  */
  42 int strncmp(const char *cs, const char *ct, size_t count)
  43 {
  44         unsigned char c1, c2;
  45
  46         while (count) {
  47                 c1 = *cs++;
  48                 c2 = *ct++;
  49                 if (c1 != c2)
  50                         return c1 < c2 ? -1 : 1;
  51                 if (!c1)
  52                         break;
  53                 count--;
  54         }
  55         return 0;
  56 }
  57 #endif