diff options
| author | Karel Zak | 2016-09-06 10:19:52 +0200 |
|---|---|---|
| committer | Karel Zak | 2016-09-06 10:19:52 +0200 |
| commit | a55d646bd3986937cd3a8488b6abaf74b2b9e28a (patch) | |
| tree | 1876ccdc638c24b8411b9825b8b844084b2a264d | |
| parent | sfdisk: add --no-tell-kernel (diff) | |
| download | kernel-qcow2-util-linux-a55d646bd3986937cd3a8488b6abaf74b2b9e28a.tar.gz kernel-qcow2-util-linux-a55d646bd3986937cd3a8488b6abaf74b2b9e28a.tar.xz kernel-qcow2-util-linux-a55d646bd3986937cd3a8488b6abaf74b2b9e28a.zip | |
lib/randutils: add xsrand() and rand_get_number()
Signed-off-by: Karel Zak <kzak@redhat.com>
| -rw-r--r-- | include/randutils.h | 5 | ||||
| -rw-r--r-- | lib/randutils.c | 18 |
2 files changed, 20 insertions, 3 deletions
diff --git a/include/randutils.h b/include/randutils.h index 17e2a02fa..7094a4c74 100644 --- a/include/randutils.h +++ b/include/randutils.h @@ -6,6 +6,11 @@ #define rand() random() #endif +/* rand() based */ +extern void xsrand(void); +extern int rand_get_number(int low_n, int high_n); + +/* /dev/urandom based with fallback to rand() */ extern int random_get_fd(void); extern void random_get_bytes(void *buf, size_t nbytes); extern const char *random_tell_source(void); diff --git a/lib/randutils.c b/lib/randutils.c index 684ac0ac1..2e124bcb6 100644 --- a/lib/randutils.c +++ b/lib/randutils.c @@ -30,12 +30,24 @@ THREAD_LOCAL unsigned short ul_jrand_seed[3]; #endif +void xsrand(void) +{ + struct timeval tv; + + gettimeofday(&tv, 0); + srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec); +} + +int rand_get_number(int low_n, int high_n) +{ + return rand() % (high_n - low_n + 1) + low_n; +} + int random_get_fd(void) { int i, fd; - struct timeval tv; + struct timeval tv; - gettimeofday(&tv, 0); fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC); if (fd == -1) fd = open("/dev/random", O_RDONLY | O_NONBLOCK | O_CLOEXEC); @@ -44,7 +56,7 @@ int random_get_fd(void) if (i >= 0) fcntl(fd, F_SETFD, i | FD_CLOEXEC); } - srand((getpid() << 16) ^ getuid() ^ tv.tv_sec ^ tv.tv_usec); + xsrand(); #ifdef DO_JRAND_MIX ul_jrand_seed[0] = getpid() ^ (tv.tv_sec & 0xFFFF); |