From 738d70e430b0f4cb9ac71d2811b3f6a4c74abbf6 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Fri, 11 Jun 2010 14:10:36 +0200 Subject: include support for a simple pseudo number generator Signed-off-by: Sascha Hauer --- include/net.h | 1 + include/stdlib.h | 16 ++++++++++++++++ lib/Makefile | 1 + lib/random.c | 26 ++++++++++++++++++++++++++ 4 files changed, 44 insertions(+) create mode 100644 include/stdlib.h create mode 100644 lib/random.c diff --git a/include/net.h b/include/net.h index 8db83d8309..709e76c895 100644 --- a/include/net.h +++ b/include/net.h @@ -16,6 +16,7 @@ #include #include #include +#include #include /* for nton* / ntoh* stuff */ diff --git a/include/stdlib.h b/include/stdlib.h new file mode 100644 index 0000000000..dc720132e8 --- /dev/null +++ b/include/stdlib.h @@ -0,0 +1,16 @@ +#ifndef __STDLIB_H +#define __STDLIB_H + +#define RAND_MAX 32767 + +/* return a pseudo-random integer in the range [0, RAND_MAX] */ +unsigned int rand(void); + +/* set the seed for rand () */ +void srand(unsigned int seed); + +/* fill a buffer with pseudo-random data */ +void get_random_bytes(char *buf, int len); + + +#endif /* __STDLIB_H */ diff --git a/lib/Makefile b/lib/Makefile index b072fb6bea..4a33aaa3c0 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o obj-y += glob.o obj-y += notifier.o obj-y += copy_file.o +obj-y += random.o obj-y += lzo/ obj-$(CONFIG_LZO_DECOMPRESS) += decompress_unlzo.o obj-$(CONFIG_PROCESS_ESCAPE_SEQUENCE) += process_escape_sequence.o diff --git a/lib/random.c b/lib/random.c new file mode 100644 index 0000000000..352d6bf3f7 --- /dev/null +++ b/lib/random.c @@ -0,0 +1,26 @@ +#include +#include + +static unsigned int random_seed; + +#if RAND_MAX > 32767 +#error this rand implementation is for RAND_MAX < 32678 only. +#endif + +unsigned int rand(void) +{ + random_seed = random_seed * 1103515245 + 12345; + return (random_seed / 65536) % (RAND_MAX + 1); +} + +void srand(unsigned int seed) +{ + random_seed = seed; +} + +void get_random_bytes(char *buf, int len) +{ + while (len--) + *buf++ = rand() % 256; +} + -- cgit v1.2.3